| 1. |
- Akermark, C, et al.
(author)
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A prospective randomized controlled trial of plantar versus dorsal incisions for operative treatment of primary Morton's neuroma
- 2013
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In: Foot & ankle international. - : SAGE Publications. - 1071-1007 .- 1944-7876. ; 34:9, s. 1198-1204
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Journal article (peer-reviewed)abstract
- There are a great number of studies on the outcome of surgery for Morton’s neuroma. However, there is a lack of controlled trials to determine the outcome in general and for the 2 most used surgical approaches. This prospective and randomized trial studied the outcome and adverse events of resected primary Morton’s neuromas, comparing plantar and dorsal incisions. Methods: Seventy-six patients were randomized to treatment with either a plantar or a dorsal incision by 2 senior surgeons. Questionnaires were evaluated and physical examinations performed at baseline and at 3 and 12 months postoperatively by the treating surgeon and at a mean of 34 months (range, 28-42 months) by an independent surgeon. The follow-up rate was 93%. Results: Histological examination of specimens verified resection of nerves in all cases except 1, which was in the dorsal group (artery). The main outcome variable, pain at daily activities, was significantly reduced by 96% (plantar) and 97% (dorsal) and restrictions in daily activities were reduced by 77% (plantar) and 67% (dorsal) at the final follow-up. Scar tenderness was noted by 3% (plantar) and 0% (dorsal) at the final evaluation. Clinically good results with surgery were noted in 87% (plantar) and 83% (dorsal) of cases. There were 5 complications in the plantar group and 6 in the dorsal group, with a difference in type of complications. Conclusions: This study demonstrated 87% (plantar) and 83% (dorsal) clinically good outcomes and no significant differences between the procedures in regard to pain, restrictions in daily activities, and scar tenderness. However, there was a difference between the groups in the type of complications. Level of Evidence: Level I, prospective randomized trial.
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| 2. |
- Arndt, A, et al.
(author)
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Ankle and subtalar kinematics measured with intracortical pins during the stance phase of walking
- 2004
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In: Foot & ankle international. - : SAGE Publications. - 1071-1007 .- 1944-7876. ; 25:5, s. 357-364
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Journal article (peer-reviewed)abstract
- The absence of external landmarks on the talus has rendered the description of ankle and subtalar joint kinematics difficult. Abnormal motion at these joints has, however, been implied in the etiology of an array of lower extremity overuse injuries. Methods: Intracortical pins were inserted under local anesthesia in the tibia, talus, and calcaneus with external marker clusters traced by a video motion analysis system. Kinematic data were collected during walking trials on a flat surface for three subjects. Gait pattern was monitored by comparison of ground reaction force curves during stance phase with and without the pins inserted. Results: Results were presented in terms of helical axis orientation for both joints and the component rotations about these axes. Large intersubject differences were seen in both ankle and subtalar joint helical axis orientation. Maximum rotations over the complete stance phase for the ankle and subtalar joints respectively were: eversion/inversion, 6.3° and 8.3°; dorsiflexion/plantarflexion, 18.7° and 3.7°; and abduction/adduction, 5.0° and 6.1°. Conclusions: The majority of ankle eversion/inversion occurred at the subtalar joint; however, the ankle component cannot be ignored. Abduction/adduction range of motion at the subtalar joint was surprisingly high, indicating that this component motion during walking is not purely attributable to the ankle joint. Future research should include greater subject numbers in order to present more universally applicable results. Clinical Relevance: The in vivo kinematics of the talus during weightbearing activity are poorly understood. The description of this motion may assist in the structuring of clinical rehabilitation and in the design and insertion of ankle joint prostheses.
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| 3. |
- Arndt, A, et al.
(author)
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Asymmetrical loading of the human triceps surae: I. Mediolateral force differences in the Achilles tendon
- 1999
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In: Foot & ankle international. - : SAGE Publications. - 1071-1007 .- 1944-7876. ; 20:7, s. 444-449
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Journal article (peer-reviewed)abstract
- An in vitro experiment was designed to identify whether tensile force on different triceps surae components would result in nonhomogenous force distribution across the human Achilles tendon. Medial tendon forces were significantly higher than lateral (23.2 ± 6.6%; P ≤ 0.05) when only the gastrocnemius medialis was subjected to force. Lateral forces were significantly higher when both gastrocnemii (30.6 ± 16.5%) or all three muscles (20.7 ± 10.9%) were loaded. Experimental identification of force concentrations in the human Achilles tendon contributes to the understanding of the origin of its injury.
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| 4. |
- Arndt, A, et al.
(author)
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Asymmetrical loading of the human triceps surae: II. Differences in calcaneal moments
- 1999
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In: Foot & ankle international. - : SAGE Publications. - 1071-1007 .- 1944-7876. ; 20:7, s. 450-455
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Journal article (peer-reviewed)abstract
- An in vitro experimental study is presented investigating differences in moments calculated at the calcaneus, resulting from tensile forces input in various configurations of triceps surae muscles. Results indicated significantly higher values for plantarflexion moments when forces were input in both gastrocnemii than in the soleus ( P ≤ 0.05). Tensile force applied solely to the gastrocnemius lateralis produced a mean eversion moment at the calcaneus, whereas all other configurations demonstrated the expected inversion moment. An abduction moment was reported throughout. The presented data provides valuable input for optimizing future biomechanical models.
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| 5. |
- Cöster, Maria C, et al.
(author)
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Age- and Gender-Specific Normative Values for the Self-Reported Foot and Ankle Score (SEFAS)
- 2018
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In: Foot & Ankle International. - : SAGE Publications. - 1944-7876 .- 1071-1007. ; 39:11, s. 1328-1334
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Journal article (peer-reviewed)abstract
- BACKGROUND: The Self-Reported Foot and Ankle Score (SEFAS) is a foot- and ankle-specific patient-reported outcome measurement (PROM) score that has been validated with good results for a variety of foot and ankle disorders. SEFAS is sensitive detecting improvement or deterioration after surgery. However, normative values, required to put a specific patient's summary score into perspective, are lacking.METHODS: In this report, we included 396 population-based men and 383 women (43% of the invited individuals), age 20-89 years, who had completed the SEFAS questionnaire and questions regarding anthropometrics and health. We used Mann-Whitney U test to test gender differences and Spearman correlation coefficients to determine any association between SEFAS score and age. We present gender-specific median SEFAS scores with range and 5th to 95th percentiles and mean with standard deviation.RESULTS: The SEFAS normative values were median 48 in men (range 11-48), 5th to 95th percentiles 31 to 48 and mean 45 ± 6, and in women, median 47 (range 6-48), 5th to 95th percentiles 23 to 48 and mean 43 ± 8 (gender comparison P < .001). SEFAS normative values correlated inversely with age (r = -0.12, P < .001).CONCLUSION: In the general population, older age was associated with lower SEFAS value, and men had higher values than women. The population-based normative SEFAS values provided in this study can facilitate quantification of disability related to foot and ankle with and without surgery in the foot and ankle.LEVEL OF EVIDENCE: Level II, prospective comparative study.
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| 6. |
- Cöster, Maria, et al.
(author)
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Comparison of the Self-Reported Foot and Ankle Score (SEFAS) and the American Orthopedic Foot and Ankle Society Score (AOFAS)
- 2014
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In: Foot & ankle international. - Thousand Oaks, CA : SAGE Publications (UK and US): 12 month Embargo. - 1071-1007 .- 1944-7876. ; 35:10, s. 1031-1036
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Journal article (peer-reviewed)abstract
- Background: The Self-reported Foot and Ankle Score (SEFAS) is a patient-reported outcome measure, while the American Orthopedic Foot and Ankle Society Score (AOFAS) is a clinician-based score, both used for evaluation of foot and ankle disorders. The purpose of this study was to compare the psychometric properties of these 2 scoring systems. Methods: A total of 95 patients with great toe disorders and 111 patients with ankle or hindfoot disorders completed the 2 scores before and after surgery. We evaluated time to complete the scores in seconds, correlations between scores with Spearmans correlation coefficient (r(s)), floor and ceiling effects by proportion of individuals who reached the minimum or maximum values, test-retest reliability and interobserver reliability by intraclass correlation coefficient (ICC), internal consistency by Cronbachs coefficient alpha (CA), and responsiveness by effect size (ES). Data are provided as correlation coefficients, means, and standard deviations. Results: SEFAS was completed 3 times faster than AOFAS. The scores correlated with an r(s) of .49 for great toe disorders and .67 for ankle/hindfoot disorders (both P less than .001). None of the scores had any floor or ceiling effect. SEFAS test-retest ICC values measured 1 week apart were .89 for great toe and .92 for ankle/hindfoot disorders, while the corresponding ICC values for AOFAS were .57 and .75. AOFAS interobserver reliability ICC values were .70 for great toe and .81 for ankle/hindfoot disorders. SEFAS CA values were .85 for great toe and .86 for ankle/hindfoot disorders, while the corresponding CA values for AOFAS were .15 and .42. SEFAS ES values were 1.15 for great toe and 1.39 for ankle/hindfoot disorders, while the corresponding ES values for AOFAS were 1.05 and 1.73. Conclusion: As SEFAS showed similar or better outcome in our tests and was completed 3 times faster than AOFAS, we recommend SEFAS for evaluation of patients with foot and ankle disorders.
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| 7. |
- Dahmen, J., et al.
(author)
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Osteochondral Lesions of the Tibial Plafond and Ankle Instability With Ankle Cartilage Lesions: Proceedings of the International Consensus Meeting on Cartilage Repair of the Ankle
- 2022
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In: Foot & Ankle International. - : SAGE Publications. - 1071-1007 .- 1944-7876. ; 43:3, s. 448-452
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Journal article (peer-reviewed)abstract
- Background: An international consensus group of experts was convened to collaboratively advance toward consensus opinions based on the best available evidence on key topics within cartilage repair of the ankle. The purpose of this article is to present the consensus statements on osteochondral lesions of the tibial plafond (OLTP) and on ankle instability with ankle cartilage lesions developed at the 2019 International Consensus Meeting on Cartilage Repair of the Ankle. Methods: Forty-three experts in cartilage repair of the ankle were convened and participated in a process based on the Delphi method of achieving consensus. Questions and statements were drafted within 4 working groups focusing on specific topics within cartilage repair of the ankle, after which a comprehensive literature review was performed and the available evidence for each statement was graded. Discussion and debate occurred in cases where statements were not agreed on in unanimous fashion within the working groups. A final vote was then held. Results: A total of 11 statements on OLTP reached consensus. Four achieved unanimous support and 7 reached strong consensus (greater than 75% agreement). A total of 8 statements on ankle instability with ankle cartilage lesions reached consensus during the 2019 International Consensus Meeting on Cartilage Repair of the Ankle. One achieved unanimous support, and seven reached strong consensus (greater than 75% agreement). Conclusions: These consensus statements may assist clinicians in the management of these difficult clinical pathologies.
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| 8. |
- Ekenman, I, et al.
(author)
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A study of intrinsic factors in patients with stress fractures of the tibia
- 1996
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In: Foot & ankle international. - : SAGE Publications. - 1071-1007 .- 1944-7876. ; 17:8, s. 477-482
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Journal article (peer-reviewed)abstract
- We aimed to study intrinsic factors in 29 consecutive patients with well-documented unilateral stress fractures of the tibia. Anthropometry, range of motion, isokinetic plantar flexor muscle performance, and gait pattern were analyzed. The uninjured leg served as the control. A reference group of 30 uninjured subjects was compared regarding gait pattern. Anterior stress fractures of the tibia (N = 10) were localized in the push-off/ landing leg in 9/10 athletes, but were similarly distributed between legs in posteromedial injuries (N = 19). Ten (30%) of the stress fracture subjects had bilateral high foot arches, similar to those found in the reference group. There were no other systematic differences in anthropometry, range of motion, gait pattern, or isokinetic plantar flexor muscle peak torque and endurance between injured and uninjured legs. No other differences were found between anterior and posteromedial stress fractures. We conclude that anterior stress fractures of the tibia occur mainly in the push-off/landing leg in athletes. Within the limitations of our protocol, no registered intrinsic factor was found to be directly associated with the occurrence of a stress fracture of the tibia.
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| 9. |
- Ekenman, I, et al.
(author)
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Local bone deformation at two predominant sites for stress fractures of the tibia: an in vivo study
- 1998
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In: Foot & ankle international. - : SAGE Publications. - 1071-1007 .- 1944-7876. ; 19:7, s. 479-484
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Journal article (peer-reviewed)abstract
- Local bone deformation was registered at two predominant injury sites for tibial stress fractures in a healthy female volunteer. Two instrumented strain gauge staples were inserted under local anesthesia to the anterior middiaphysis (AM) and to the posteromedial part of the distal tibia (PD). Calibration and reliability of the instrumented staple system have previously been demonstrated in vitro. Concomitant ground reaction forces were registered with a Kistler force plate. Studying peak values, it was shown that during a voluntary 30-cm forward jump, PD deformation was greater during forefoot landing (2700–4200 microstrain) than during a heel strike landing (1200–1900 microstrain) and also compared with the concomitant AM deformation under both above testing conditions (1300–1900 microstrain). The stance phase during walking resulted in PD deformation of 950 microstrain, whereas the concomitant AM deformation was 334 microstrain. The greatest AM deformation (mean, 2128 microstrain) was registered during ground contact after a voluntary vertical drop from a height of 45 cm, concomitant with a PD deformation of 436 microstrain. These data are the first to show different local deformations at various sites of the tibia in vivo. The PD deformation was larger than previously noted from other parts of the tibia, whereas the middiaphysis data are consistent with other reports. The results may support the clinical assumption of different etiologies for stress fractures at these predominant sites.
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| 10. |
- Eneroth, Magnus, et al.
(author)
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Clinical characteristics and outcome in 223 diabetic patients with deep foot infections
- 1997
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In: Foot and Ankle International. - : SAGE Publications. - 1071-1007 .- 1944-7876. ; 18:11, s. 716-722
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Journal article (peer-reviewed)abstract
- Clinical characteristics and outcome in 223 consecutive diabetic patients with deep foot infections are reported. Patients were treated by a multidisciplinary diabetic foot-care team at the University Hospital, Lund, Sweden, and were prospectively followed until healing or death. About 50% of patients lacked clinical signs of infection, such as a body temperature > 37.8°C, a sedimentation rate > 70 mm/hour, and white blood cell count (WBC) > 10 x 109/liter. Eighty-six percent had surgery before healing or death. Thirty-nine percent healed without amputation; 34% healed after a minor and 8% after a major amputation. Sixteen percent were unhealed at death, and 3% were unhealed at the end of the observation period. Of those unhealed at death or follow-up, 4 patients had had a major and 11 a minor amputation. After correction for age and sex, duration of diabetes < 14 years, palpable popliteal pulse, a toe pressure > 45 mmHg, and an ankle pressure > 80 mm Hg, absence of exposed bone and a white blood cell count < 12 x 109/liter were all related to healing without amputation in a logistic regression analysis. We conclude that although only 1 in 10 had a major amputation, nearly all diabetic patients with a deep foot infection needed surgery and more than one third had a minor amputation before healing or death in spite of a well- functioning diabetic foot-care team responsible for all included patients.
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| 11. |
- Grondal, L, et al.
(author)
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Arthrodesis compared to Mayo resection of the first metatarsophalangeal joint in total rheumatoid forefoot reconstruction
- 2005
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In: Foot & ankle international. - : SAGE Publications. - 1071-1007 .- 1944-7876. ; 26:2, s. 135-139
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Journal article (peer-reviewed)abstract
- Background: Painful forefoot deformity from rheumatoid arthritis can be treated with resection of the lesser metatarsal heads combined with either resection or arthrodesis of the first metatarsophalangeal (MTP) joint. Methods: In a prospective, randomized study we compared arthrodesis of first MTP joint with Mayo resection as part of total forefoot reconstruction in patients with painful forefoot deformity from rheumatoid arthritis. The lesser metatarsal heads were resected and extensor tenotomy was done in all patients. Thirty-one patients were randomized to either the arthrodesis or resection group. Results: After a mean followup of 36 (26 to 52) months, the median subjective satisfaction score was 96 points out of 100 in the resection group and 92 points in the arthrodesis group. Significant improvements in pain, handicap, and activity according to Foot Function Index (FFI) were found in both groups ( p < 0.001 except for handicap in resection group and activity in fusion group were p = 0.02). There were no statistically significant differences between the groups in these measures, nor in the patients' willingness to have the procedure again. There were no recurrences of prominences or tenderness under the forefoot in either group and no recurrence of severe hallux valgus in the resection group. The arthrodeses healed in 93%. There was no higher risk for clinically relevant IP joint symptoms after arthrodesis. The operating time was significantly longer in the arthrodesis group but this was not linked to a higher wound infection rate. Conclusion: These results indicate that Mayo resection may still be a good choice for the first MTP joint in total forefoot reconstruction in patients with rheumatoid arthritis.
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| 12. |
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| 13. |
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| 14. |
- Kamrad, Ilka, et al.
(author)
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Outcome After Salvage Arthrodesis for Failed Total Ankle Replacement.
- 2016
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In: Foot & Ankle International. - : SAGE Publications. - 1944-7876 .- 1071-1007. ; 37:3, s. 255-261
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Journal article (peer-reviewed)abstract
- In cases with total ankle replacement (TAR) failure, a decision between revision TAR and salvage arthrodesis (SA) must be made. In a previous study, we analyzed revision TAR and found low functional outcome and satisfaction. The aims of the current study were to analyze SA concerning failure rate and patient-related outcome measures (PROMs).
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| 15. |
- Milgrom, C, et al.
(author)
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Metatarsal strains are sufficient to cause fatigue fracture during cyclic overloading
- 2002
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In: Foot & ankle international. - : SAGE Publications. - 1071-1007 .- 1944-7876. ; 23:3, s. 230-235
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Journal article (peer-reviewed)abstract
- Human in vivo tibial strains during vigorous walking have not been found to exceed 1200 microstrains. These values are below those found in ex vivo studies (>3000 microstrains) to cause cortical bone fatigue failure, suggesting that an intermediate bone remodeling response may be associated with tibial stress fractures. Metatarsal stress fractures, however, often develop before there is time for such a response to occur. Simultaneous in vivo axial strains were measured at the mid diaphysis of the second metatarsal and the tibia in two subjects. Peak axial metatarsal compression strains and strain rates were significantly higher than those of the tibia during treadmill walking and jogging both barefoot and with running shoes and during simple calisthenics. During barefoot treadmill walking metatarsal compression strains were greater than 2500 microstrains. During one- and two-leg vertical jumps and broad jumping, both metatarsal compression and tension strains were >3000 microstrains. Compression and tension strains in the metatarsus unlike those of the tibia may be sufficiently high even during moderate exertional activities to cause fatigue failure of bone secondary to the number of loading cycles without an intermediate bone remodeling response.
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| 16. |
- Movin, T, et al.
(author)
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Intratendinous alterations as imaged by ultrasound and contrast medium-enhanced magnetic resonance in chronic achillodynia
- 1998
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In: Foot & ankle international. - : SAGE Publications. - 1071-1007 .- 1944-7876. ; 19:5, s. 311-317
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Journal article (peer-reviewed)abstract
- Objectives: We performed a comparative study of ultrasonography and gadolinium imaging contrast-enhanced T1-weighted magnetic resonance to evaluate tendon pathology in chronic Achilles tendon disorder. Another main issue was to evaluate the structural basis as defined by histopathology from hypoechoic compared with normoechic areas within the same tendon. Materials and Methods: Twenty patients (16 male, 4 females, median age 40 years) with chronic achillodynia participated in the study. Clinical examination revealed swelling and tenderness localized to the midportion of the Achilles tendon. Contrast medium-enhanced magnetic resonance imaging (CME-MRI) was performed in all patients. Ultrasonography-guided core biopsies were taken from regions with a clear widening of the tendon and a pathologic low-echo signal as well as from normoechoic areas. The specimens were analyzed with a standardized protocol giving a total tendon score (0–24), and a stereologic method for quantification of glycosaminoglycan (GAG)-rich areas. Results: The volume of the intratendinous abnormality was larger in 13 of 20 when imaged by CME-MR ( P < 0.05), whereas the shape and enlargement of the tendon per se were similarly imaged by ultrasound (US) and CME-MR. Tendon pathology as imaged by US was graded as severe from hypoechoic regions and moderate from normoechoic regions. The corresponding quantification of GAGs was 0.36 compared with 0.17, respectively ( P < 0.001). Conclusion: CME-MR imaging revealed greater sensitivity in demonstrating intratendinous pathology than the ultrasound; this was documented by the larger size of the corresponding lesion and the fact that the pathology was occurring in areas that were considered normal by ultrasonography. US hypoechoic areas showed a markedly abnormal tendon structure including an increased amount of GAG-rich areas. However, moderate pathology was also found in the neighboring normoechogenous areas within the same tendon, indicating a more generalized disorder than depicted by echogenic properties.
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| 17. |
- Movin, T, et al.
(author)
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Pathology of the Achilles tendon in association with ciprofloxacin treatment
- 1997
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In: Foot & ankle international. - : SAGE Publications. - 1071-1007 .- 1944-7876. ; 18:5, s. 297-299
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Journal article (peer-reviewed)abstract
- Achilles tendon pain or rupture after fluoroquionolone treatment has been described as an uncommon adverse effect. We report two patients with ciprofloxacin-associated Achilles tendon disease, one with histopathological examination. Microscopic evaluation showed irregular collagen fiber arrangement, hypercellularity, and increased interfibrillar glycosaminoglycans. These pathological features are also seen in tendon overuse injuries in athletes.
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| 18. |
- Peng, WC, et al.
(author)
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Muscular Morphomechanical Characteristics After an Achilles Repair
- 2019
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In: Foot & ankle international. - : SAGE Publications. - 1944-7876 .- 1071-1007. ; 40:5, s. 568-577
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Journal article (peer-reviewed)abstract
- The purpose of the study was to compare the morphomechanical and functional characteristics during maximal isometric, concentric, and eccentric contractions in the legs of patients that underwent unilateral Achilles tendon repair with those in their noninjured control legs. Methods: Twenty participants (median age = 38.2 years; range, 21.1-57.3 years) who underwent Achilles repair between 3 and 12 months ago were recruited with the following measures: (1) mechanical stiffness of the aponeurosis and (2) electromyography and medial gastrocnemius fascicle angle and length, standing muscle and tendon length, and height of heel rise with isometric contraction. Results: Compared to the noninjured legs, the repaired legs showed less resting fascicle length, standing muscle length, isometric plantarflexion torque, and heel raise distance ( Ps ranged between .044 and <.001). During the concentric and eccentric phases of the raising and lowering test, the repaired legs demonstrated less fascicle length ( P ≤ .028) but greater tendinous tissue length ( Ps ranged between .084 and <.001) and fascicle angle ( Ps ranged between .247 and .008) and fewer change magnitudes of the fascicle length and tendinous tissue length ( P ≤ .003). The change magnitudes of the morphological characteristics showed correlations with the torque or distance. Conclusion: Selecting the appropriate surgical repair and rehabilitation for Achilles tendon ruptures is recommended for restoring the length and mechanical strength of the muscle-tendon unit of plantar-flexion muscles. Level of Evidence: Level III, comparative study.
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| 19. |
- Rein, S, et al.
(author)
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Comparative analysis of inter- and intraligamentous distribution of sensory nerve endings in ankle ligaments: a cadaver study
- 2013
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In: Foot & ankle international. - : SAGE Publications. - 1071-1007 .- 1944-7876. ; 34:7, s. 1017-1024
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Journal article (peer-reviewed)abstract
- The aim of this study was to analyze the inter-, intraligamentous, and side-related patterns of sensory nerve endings in ankle ligaments. Methods: A total of 140 ligaments from 10 cadaver feet were harvested. Lateral: calcaneofibular, anterior-, posterior talofibular; sinus tarsi: lateral- (IERL), intermediate-, medial-roots inferior extensor retinaculum, talocalcaneal oblique and canalis tarsi (CTL); medial: tibionavicular (TNL), tibiocalcaneal (TCL), superficial tibiotalar, anterior/posterior tibiotalar portions; syndesmosis: anterior tibiofibular. Following immunohistochemical staining, the innervation and vascularity was analyzed between ligaments of each anatomical complex, left/right feet, and within the 5 levels of each ligament. Results: Significantly more free nerve endings were seen in all ligaments as compared to Ruffini, Pacini, Golgi-like, and unclassifiable corpuscles ( P ≤ .005). The IERL had significantly more free nerve endings and blood vessels than the CTL ( P ≤ .001). No significant differences were seen in the side-related distribution, except for Ruffini endings in right TCL ( P = .016) and unclassifiable corpuscles in left TNL ( P = .008). The intraligamentous analysis in general revealed no significant differences in mechanoreceptor distribution. Conclusions: The IERL at the entrance of the sinus tarsi contained more free nerve endings and blood vessels, as compared to the deeper situated CTL. Despite different biomechanical functions in the medial and lateral ligaments, the interligamentous distribution of sensory nerve endings was equal. Clinical Relevance: The intrinsic innervation patterns of the ankle ligaments provides an understanding of their innate healing capacities following injury as well as the proprioception properties in postoperative rehabilitation.
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| 20. |
- Rein, S, et al.
(author)
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Histological analysis of the structural composition of ankle ligaments
- 2015
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In: Foot & ankle international. - : SAGE Publications. - 1944-7876 .- 1071-1007. ; 36:2, s. 211-224
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Journal article (peer-reviewed)abstract
- Various ankle ligaments have different structural composition. The aim of this study was to analyze the morphological structure of ankle ligaments to further understand their function in ankle stability. Methods: One hundred forty ligaments from 10 fresh-frozen cadaver ankle joints were dissected: the calcaneofibular, anterior, and posterior talofibular ligaments; the inferior extensor retinaculum, the talocalcaneal oblique ligament, the canalis tarsi ligament; the deltoid ligament; and the anterior tibiofibular ligament. Hematoxylin-eosin and Elastica van Gieson stains were used for determination of tissue morphology. Results: Three different morphological compositions were identified: dense, mixed, and interlaced compositions. Densely packed ligaments, characterized by parallel bundles of collagen, were primarily seen in the lateral region, the canalis tarsi, and the anterior tibiofibular ligaments. Ligaments with mixed tight and loose parallel bundles of collagenous connective tissue were mainly found in the inferior extensor retinaculum and talocalcaneal oblique ligament. Densely packed and fiber-rich interlacing collagen was primarily seen in the areas of ligament insertion into bone of the deltoid ligament. Conclusions: Ligaments of the lateral region, the canalis tarsi, and the anterior tibiofibular ligaments have tightly packed, parallel collagen bundles and thus can resist high tensile forces. The mixed tight and loose, parallel oriented collagenous connective tissue of the inferior extensor retinaculum and the talocalcaneal oblique ligament support the dynamic positioning of the foot on the ground. The interlacing collagen bundles seen at the insertion of the deltoid ligament suggest that these insertion areas are susceptible to tension in a multitude of directions. Clinical Relevance: The morphology and mechanical properties of ankle ligaments may provide an understanding of their response to the loads to which they are subjected.
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| 21. |
- Rolf, C, et al.
(author)
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Etiology, histopathology, and outcome of surgery in achillodynia
- 1997
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In: Foot & ankle international. - : SAGE Publications. - 1071-1007 .- 1944-7876. ; 18:9, s. 565-569
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Journal article (peer-reviewed)abstract
- Fifty-eight patients suffering from achillodynia for a median of 12 months (range, 4–240 months) were analyzed using history, clinical findings, ultrasound findings, histopathology, and surgical outcome. Surgical criteria were daily pain or inability to perform sports activity and failure of nonoperative treatment. There were 34 men and 24 women, 31% (18 of 58 patients) of whom had no direct association with sports or vigorous physical activity. Ultrasonography was performed in all cases and showed low echogenous areas (N = 48), increased tendon diameter (N = 40), and/or peritendinous fluid (N = 11). Histopathological evaluation of tendon biopsies, obtained from regions showing pathology at surgery (N = 35), revealed altered fiber structure and arrangement, focal variations in cellularity, extracellular glycosaminoglycans, neovascularization, and/or hyalinization. In no case was inflammatory cell infiltration observed. At a median clinical follow-up of 25 months after surgery, symptoms were decreased in 86% of patients, and 76% had reached a higher activity level compared with the level before surgery. Complications occurred in 13% of operations.In conclusion, achillodynia is not always associated with excessive physical activity. Macroscopic pathologic tendons showed marked histopathologic changes, correlating well with ultrasound findings. Surgical treatment was beneficial in most cases, despite a relatively high complication rate. The etiology and reason for the lack of healing response to rest and nonoperative treatment are unclear.
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| 22. |
- Sayed-Noor, Arkan S., et al.
(author)
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Interobserver reliability and intraobserver reproducibility of three radiological classification systems for intra-articular calcaneal fractures
- 2011
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In: Foot & ankle international. - Seattle, USA : American Orthopaedic Foot & Ankle Society. - 1071-1007 .- 1944-7876. ; 32:9, s. 861-866
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Journal article (peer-reviewed)abstract
- Background: The management of intra-articular calcaneal fractures is difficult. One aspect for successful management is the use of a reliable and reproducible fracture classification system (FCS). The purpose of this study was to evaluate the interobserver reliability and intraobserver reproducibility of Letournel, Sanders, and Zwipp classification systems on CT scan and the Bohler's angle measurement on plain X-ray. Furthermore, we studied if the addition of a CT scan to the plain X-ray influenced the evaluation of fracture extension to the calcaneocuboid joint.Methods: The CT scan and plain X-ray images of 51 intra-articular calcaneal fractures were evaluated two times by three observers (two radiologists and one orthopedic surgeon) within a 5-month interval. The interobserver reliability was measured using the Fleiss kappa while the intraobserver reproducibility was measured using the Cohen's kappa.Results: The mean kappa values for the interobserver reliability and intraobserver reproducibility of the Sanders classification were 0.25 and 0.39, respectively, of Zwipp classification were 0.24 and 0.16, respectively, while those of the Letournel classification were 0.50 and 0.42, respectively. For the Böhler's angle, the mean kappa values for the interobserver reliability and intraobserver reproducibility were 0.34 and 0.32, respectively. The addition of CT scan images to plain X-ray found a higher incidence of calcaneocuboid joint involvement.Conclusion: Clinicians should be aware of the limitation regarding the interobserver reliability and intraobserver reproducibility of the Letournel, Sanders and Zwipp classification systems for calcaneal fractures. Future studies should attempt to improve the present classification systems.
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| 23. |
- Stacoff, A, et al.
(author)
-
Movement coupling at the ankle during the stance phase of running
- 2000
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In: Foot & ankle international. - : SAGE Publications. - 1071-1007 .- 1944-7876. ; 21:3, s. 232-239
-
Journal article (peer-reviewed)abstract
- The purpose of this study was to quantify movement coupling at the ankle during the stance phase of running using bone-mounted markers. Intracortical bone pins with reflective marker triads were inserted under standard local anaesthesia into the calcaneus and the tibia of five healthy male subjects. The three-dimensional rotations were determined using a joint coordinate system approach. Movement coupling was observed in all test subjects and occurred in phases with considerable individual differences. Between the shoe and the calcaneus coupling increased after midstance which suggested that the test shoes provided more coupling for inversion than for eversion. Movement coupling between calcaneus and tibia was higher in the first phase (from heel strike to midstance) compared with the second phase (from midstance to take-off). This finding is in contrast to previous in-vitro studies but may be explained by the higher vertical loads of the present in-vivo study. Thus, movement coupling measured at the bone level changed throughout the stance phase of running and was found to be far more complex than a simple mitered joint or universal joint model.
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| 24. |
- van Dijk, P. A. D., et al.
(author)
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Post-treatment Follow-up, Imaging, and Outcome Scores: Proceedings of the International Consensus Meeting on Cartilage Repair of the Ankle
- 2018
-
In: Foot & Ankle International. - : SAGE Publications. - 1071-1007 .- 1944-7876. ; 39:S1
-
Journal article (peer-reviewed)abstract
- Background: The evidence supporting best practice guidelines in the field of cartilage repair of the ankle are based on both low quality and low levels of evidence. Therefore, an international consensus group of experts was convened to collaboratively advance toward consensus opinions based on the best available evidence on key topics within cartilage repair of the ankle. The purpose of this article is to report the consensus statements on Post-treatment Follow-up, Imaging and Outcome Scores developed at the 2017 International Consensus Meeting on Cartilage Repair of the Ankle. Methods: Seventy-five international experts in cartilage repair of the ankle representing 25 countries and 1 territory were convened and participated in a process based on the Delphi method of achieving consensus. Questions and statements were drafted within 11 working groups focusing on specific topics within cartilage repair of the ankle, after which a comprehensive literature review was performed and the available evidence for each statement was graded. Discussion and debate occurred in cases where statements were not agreed on in unanimous fashion within the working groups. A final vote was then held, and the strength of consensus was characterized as follows: consensus, 51% to 74%; strong consensus, 75% to 99%; unanimous, 100%. Results: A total of 12 statements on Post-treatment Follow-up, Imaging, and Outcome Scores reached consensus during the 2017 International Consensus Meeting on Cartilage Repair of the Ankle. All 12 statements reached strong consensus (greater than 75% agreement). Conclusions: This international consensus derived from leaders in the field will assist clinicians with post-treatment follow-up, imaging, and outcome scores after management of a cartilage injury of the ankle in the general population. Moreover, healing, rehabilitation, and final outcomes can be optimized for the individual patient.
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| 25. |
- Westblad, P, et al.
(author)
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Differences in ankle-joint complex motion during the stance phase of walking as measured by superficial and bone-anchored markers
- 2002
-
In: Foot & ankle international. - : SAGE Publications. - 1071-1007 .- 1944-7876. ; 23:9, s. 856-863
-
Journal article (peer-reviewed)abstract
- Bones of the ankle-joint complex are difficult to represent with superficial markers and an invasive approach is required to quantify skin movement artifact. Three-dimensional coordinates during gait were first calculated from sets of three superficial markers located on both the lower leg and heel. Intracortical pins equipped with external marker arrays were subsequently inserted in the tibia, talus and calcaneus for further trials. Tibiocalcaneal and talocalcaneal joint helical axis component rotations were calculated. Intersubject motion patterns were comparable. Root mean square (RMS) differences were chosen to describe discrepancies between temporal intracortical pin and superficial marker curves. Results for the tibiocalcaneal rotations inversion / eversion, plantarflexion / dorsiflexion and abduction / adduction were 2.5°, 1.7° and 2.8° respectively. Inversion / eversion about the talocalcaneal joint showed an RMS difference of 2.1°. A systematic over- or underestimation of superficial relative to bone-anchored markers could not be determined.
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| 26. |
- Zellers, J. A., et al.
(author)
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Achilles Tendon Resting Angle Relates to Tendon Length and Function
- 2018
-
In: Foot and Ankle International. - : SAGE Publications. - 1071-1007 .- 1944-7876. ; 39:3, s. 343-348
-
Journal article (peer-reviewed)abstract
- Background: Following Achilles tendon rupture, tendon elongation leads to long term deficits in calf function. A surrogate measure of Achilles tendon length, Achilles tendon resting angle (ATRA), has been described but has not been validated against length measured using ultrasound. Therefore, the purpose of this study was to validate the ATRA against ultrasound. Secondarily, this study aimed to identify the relationship of other factors (tendon mechanical properties, heel-rise test performance) to the ATRA. Methods: Individuals following unilateral Achilles tendon rupture were included. ATRA was measured in knee flexed and extended positions. Tendon elongation was measured using extended field of view ultrasound imaging. Continuous shear wave elastography quantified tendon mechanical properties. The relationship between variables was tested using Spearman’s ρ. Subgroup analysis was used to compare subjects with less then or greater than 1 year following rupture. A total of 42 participants (with a mean of 18.2 months following rupture [SD = 35.9]) were included. Results: Tendon elongation related with relative ATRA with knee flexed (ρ =.491, P =.001) and knee extended (ρ = 0.501, P =.001) positions. In individuals greater than 1 year following rupture, relative ATRA with the knee flexed related to shear modulus (ρ =.800, P =.01) and total work on the heel-rise test (ρ = –.782, P =.008) relative to the uninjured side. Conclusion: Relative ATRA in both knee flexed and knee extended positions has a moderate relationship to tendon elongation within the first year following rupture. After 1 year, the relative ATRA with knee flexed may be a better indicator of tendon elongation and also related to tendon mechanical properties and heel-rise test performance. Level of Evidence: Level III, case-control study. © 2017, © The Author(s) 2017.
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| 27. |
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| 28. |
- Alonso-Vazquez, A, et al.
(author)
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The effect of bone quality on the stability of ankle arthrodesis. A finite element study
- 2004
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In: Foot & Ankle International. - 1944-7876. ; 25:11, s. 840-850
-
Journal article (peer-reviewed)abstract
- Background: Despite uniform operating techniques, lack of fusion still occurs after ankle arthrodesis. Differences in the biological healing potential may be a factor but the mechanical performance of the arthrodesis construct because of varying bone quality also may be important. Internal compression techniques are preferred because of higher union rates, shorter fusion times, and fewer complications. A three-screw configuration has been shown to be more stable than a two-screw configuration, but it is not obvious when it should be used. Methods: Three-dimensional finite element models of intact and flat-cut ankle arthrodeses were built, using two and three screws in different configurations. Poor bone quality was simulated by decreasing Young's modulus of the bone. The constructs were loaded in torsion and dorsiflexion, and micromotions at the fusion site were measured. Results: Bone quality had a marked effect on the stability at the arthrodesis site. Inserting two screws at 30 degrees relative to the longitudinal axis of the tibia in an intact arthrodesis seemed the best option, especially as bone quality worsened. The addition of a third screw increased the stability at the arthrodesis site. Conclusions: Overall, intact joint surfaces and three-screw fixation, with the lateral and medial screws inserted produced the most stable arthrodesis constructs when bone quality was poor. Clinical Relevance. Ankle arthrodeses are technically demanding because of the shape and small size of the talus. Preoperative planning is an absolute necessity to determine placement and number of screws. This study shows that poor bone quality decreases the stability of the arthrodesis constructs, suggesting that an attempt should be made to create the most stable three-screw configuration. Finite element models can be used as an effective preoperative tool for planning screw number and placement.
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| 29. |
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| 30. |
- Carlsson, A S, et al.
(author)
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Arthrodesis of the ankle secondary to replacement
- 1998
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In: Foot & Ankle International. - 1944-7876. ; 19:4, s. 240-245
-
Journal article (peer-reviewed)abstract
- One hundred total ankle arthroplasties were performed in our department between 1974 and 1994, and of these, 21 have been reoperated on with arthrodesis due to septic or nonseptic failures after 6 months to 15 years (median 40 months). Immobilization using a Hoffman external fixator was the dominating method. The total ankles were of six different designs. Sixteen of the 21 patients suffered from rheumatoid arthritis. Four of the 21 ankles did not fuse whereas 17 did: 13 at the first attempt and 4 after repeat arthrodesis. At the time of the review, two patients had died. Of the remaining 15 patients whose ankles had fused, all but one were satisfied or somewhat satisfied with the result. Twelve of these 15 ankles rated excellent or good according to the Mazur and Kofoed scoring systems. We conclude that arthrodesis can be performed successfully after a failed ankle arthroplasty.
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| 31. |
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| 32. |
- Larsson, J, et al.
(author)
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Clinical characteristics in relation to final amputation level in diabetic patients with foot ulcers: a prospective study of healing below or above the ankle in 187 patients
- 1995
-
In: Foot & Ankle International. - 1944-7876. ; 16:2, s. 69-74
-
Journal article (peer-reviewed)abstract
- The aim of this study was to describe the clinical characteristics in relation to final amputation level in diabetic patients with foot ulcers. In a prospective series, 187 consecutively presenting patients were investigated. From admission until final outcome, the patients were treated by a multidisciplinary team both as in- and out-patients. All the patients had one or more signs of neuropathy and 171 had evidence of peripheral vascular disease. Healing with an amputation below the ankle occurred in 74 patients, 88 patients healed with an amputation above the ankle, and 25 patients died unhealed. Amputation above the ankle was associated with high age, living in an institution, a limited walking capacity, cerebrovascular disease, congestive heart failure, and a low hemoglobin level. Amputation below the ankle was associated with diabetes diagnosis before 30 years of age and diabetes duration. In conclusion, older age, history of cerebrovascular disease and low hemoglobin level are associated with above ankle amputation level in diabetic patients with foot ulcers. However, level selection cannot be based upon these factors only, since some patients at high age, with cerebrovascular disease or with a low hemoglobin value, healed with an amputation below the ankle. None of these factors per se should be taken as a cause to choose a primary amputation above the ankle, unless amputation is supported by the total clinical picture, including local characteristics, such as type and localization of ulcer, and signs of peripheral vascular disease. More attention should be paid to biological than to chronological age.
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| 33. |
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| 34. |
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| 35. |
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| 36. |
- Akil, Shahnaz, et al.
(author)
-
Appropriate coronary revascularization can be accomplished if myocardial perfusion is quantified by positron emission tomography prior to treatment decision
- 2021
-
In: Journal of Nuclear Cardiology. - : Springer Science and Business Media LLC. - 1071-3581 .- 1532-6551. ; 28:4, s. 1664-1672
-
Journal article (peer-reviewed)abstract
- Background: Many patients undergo percutaneous coronary intervention (PCI) without the use of non-invasive stress testing prior to treatment. The aim of this study was to determine the potential added value of guiding revascularization by quantitative assessment of myocardial perfusion prior to intervention. Methods and Results: Thirty-three patients (10 females) with suspected or established CAD who had been referred for a clinical coronary angiography (CA) with possibility for PCI were included. Adenosine stress and rest 13N-NH3 PET, cardiac magnetic resonance (CMR), and cardiopulmonary exercise test were performed 4 ± 3 weeks before and 5 ± 1 months after CA. The angiographer was blinded to the PET and CMR results. Myocardial flow reserve (MFR) < 2.0 by PET was considered abnormal. A PCI was performed in 19/33 patients. In 41% (11/27) of the revascularized vessel territories, a normal regional MFR was found prior to the PCI and no improvement in MFR was found at follow-up (P = 0.9). However, vessel territories with regional MFR < 2.0 at baseline improved significantly after PCI (P = 0.003). Of the 14 patients not undergoing PCI, four had MFR < 2.0 in one or more coronary territories. Conclusion: Assessment of quantitative myocardial perfusion prior to revascularization could lead to more appropriate use of CA when managing patients with stable CAD.
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| 37. |
- Akil, Shahnaz, et al.
(author)
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Qualitative assessments of myocardial ischemia by cardiac MRI and coronary stenosis by invasive coronary angiography in relation to quantitative perfusion by positron emission tomography in patients with known or suspected stable coronary artery disease
- 2020
-
In: Journal of Nuclear Cardiology. - : Springer Science and Business Media LLC. - 1071-3581 .- 1532-6551. ; 27:6, s. 2351-2359
-
Journal article (peer-reviewed)abstract
- Background: To relate findings of qualitative evaluation of first-pass perfusion-CMR and anatomical evaluation on coronary angiography (CA) to the reference standard of quantitative perfusion, cardiac PET, in patients with suspected or known stable coronary artery disease (CAD). Methods and Results: Forty-one patients referred for CA due to suspected stable CAD, prospectively performed adenosine stress/rest first-pass perfusion-CMR as well as 13N-NH3 PET on the same day, 4 ± 3 weeks before CA. Angiographers were blinded to PET and CMR results. Regional myocardial flow reserve (MFR) < 2.0 on PET was considered pathological. Vessel territories with stress-induced ischemia by CMR or vessels with stenosis needing revascularization had a significantly lower MFR compared to those with no regional stress-induced ischemia or vessels not needing revascularization (P < 0.001). In 4 of 123 vessel territories with stress-induced ischemia by CMR, PET showed a normal MFR. In addition, 12 of 123 vessels that underwent intervention showed normal MFR assessed by PET. Conclusion: The limited performance of qualitative assessment of presence of stable CAD with CMR and CA, when related to quantitative 13N-NH3 cardiac PET, shows the need for fully quantitative assessment of myocardial perfusion and the use of invasive flow reserve measurements for CA, to confirm the need of elective revascularization.
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| 38. |
- Al-Mashat, Mariam, et al.
(author)
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Pulmonary perfusion and NYHA classification improve after cardiac resynchronization therapy
- 2022
-
In: Journal of Nuclear Cardiology. - : Springer Science and Business Media LLC. - 1071-3581 .- 1532-6551. ; 29:6, s. 2974-2983
-
Journal article (peer-reviewed)abstract
- Background: Evaluation of cardiac resynchronization therapy (CRT) often includes New York Heart Association (NYHA) classification, and echocardiography. However, these measures have limitations. Perfusion gradients from ventilation/perfusion single-photon emission computed tomography (V/P SPECT) are related to left-heart filling pressures and have been validated against invasive right-heart catheterization. The aim was to assess if changes in perfusion gradients are associated with improvements in heart failure (HF) symptoms after CRT, and if they correlate with currently used diagnostic methods in the follow-up of patients with HF after receiving CRT. Methods and results: Nineteen patients underwent V/P SPECT, echocardiography, NYHA classification, and the quality-of-life scoring system “Minnesota living with HF” (MLWHF), before and after CRT. CRT caused improvement in perfusion gradients from V/P SPECT which were associated with improvements in NYHA classification (P =.0456), whereas improvements in end-systolic volume (LVESV) from echocardiography were not. After receiving CRT, the proportion of patients who improved was lower using LVESV (n = 7/19, 37%) than perfusion gradients (n = 13/19, 68%). Neither change in perfusion gradients nor LVESV was associated with changes in MLWHF (P = 1.0, respectively). Conclusions: Measurement of perfusion gradients from V/P SPECT is a promising quantitative user-independent surrogate measure of left-sided filling pressure in the assessment of CRT response in patients with HF.
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| 39. |
- Hedeer, Fredrik, et al.
(author)
-
To what extent are perfusion defects seen by myocardial perfusion SPECT in patients with left bundle branch block related to myocardial infarction, ECG characteristics, and myocardial wall motion?
- 2021
-
In: Journal of Nuclear Cardiology. - : Springer Science and Business Media LLC. - 1071-3581 .- 1532-6551. ; 28:6, s. 2910-2922
-
Journal article (peer-reviewed)abstract
- Introduction: We investigated if uptake pattern on myocardial perfusion SPECT (MPS) in patients with left bundle branch block (LBBB) is related to myocardial fibrosis, myocardial wall motion, and electrocardiography (ECG) characteristics. Methods: Twenty-three patients (9 women) with LBBB, examined with MPS and cardiac magnetic resonance (CMR), were included. Tracer uptake on MPS was classified by visual interpretation as typical LBBB pattern (Defect+, n = 13) or not (Defect−, n = 10) and quantitatively. CMR images were evaluated for wall thickness and for myocardial wall motion both by visual assessment and by regional myocardial radial strain from feature tracking, and for presence and location of myocardial fibrosis. ECGs were analyzed regarding QRS duration and the presence of strict criteria for LBBB. Results: Wall thickness was slightly lower in the septum compared to the lateral wall in Defect+ patients (5.6 ± 1.1 vs 6.0 ± 1.3 mm, P = 0.03) but not in Defect− patients (5.6 ± 1.0 vs 5.6 ± 0.9 mm, P = 0.84). Defect+ patients showed a larger proportion of dyskinetic segments in the septum and hyperkinetic segments in the lateral wall compared to Defect− patients (P = 0.006 and P = 0.004, respectively). Decreased myocardial radial strain was associated with decreased tracer uptake by MPS (R = 0.37, P < 0.001). Areas of fibrosis did not match areas with uptake defect on MPS. No differences in ECG variables were seen. Conclusion: The heterogeneous regional tracer uptake in some patients with LBBB is related to underlying regional myocardial dyskinesia, wall thickening, and wall thickness rather than stress-induced ischemia, myocardial fibrosis, or specific ECG characteristics.
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| 40. |
- Oddstig, Jenny, et al.
(author)
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Differences in attenuation pattern in myocardial SPECT between CZT and conventional gamma cameras
- 2019
-
In: Journal of Nuclear Cardiology. - : Springer Science and Business Media LLC. - 1071-3581 .- 1532-6551. ; 26:6, s. 1984-1991
-
Journal article (peer-reviewed)abstract
- Background: In myocardial perfusion imaging (MPI), single-photon emission tomography (SPECT) soft-tissue attenuation by the abdomen, breasts, and lateral chest wall may create artifacts that mimic true perfusion defects. This may cause misdiagnosis of myocardial perfusion. The aim of the present study was to compare the localization, extent, and depth of attenuation artifacts in MPI SPECT for a multi-pinhole cadmium zinc telluride (CZT) camera vs a conventional gamma camera. Methods: Phantom and patient measurements were performed using a CZT camera (GE NM 530c) and a conventional gamma camera (GE Ventri). All images were attenuation corrected with externally acquired low-dose computed tomography. The localization, extent, and depth of the attenuation artifact were quantified by comparing attenuation-corrected and non-attenuation-corrected images. Results: Attenuation artifacts were shifted from the inferolateral wall to the lateral wall using the CZT camera compared to a conventional camera in both the patient and the phantom. The extent of the attenuation artifact was significantly larger for the CZT camera compared to the conventional camera (23 ± 5% vs 15 ± 5%, P < .001) for patients and the result was similar for the phantom (28% vs 19%). Furthermore, the depth of the attenuation artifact (percent of maximum counts) was less pronounced for the CZT camera than for the conventional camera, both for phantom measurements (73% vs 67%) and patients (72 ± 3% vs 68 ± 4%, P < .001). Conclusions: Attenuation artifacts are found in different locations to different extents and depths when using a CZT camera vs a conventional gamma camera for MPI SPECT. This should be taken into consideration when evaluating MPI SPECT studies to avoid misinterpretation of myocardial perfusion distribution.
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| 41. |
- Oddstig, Jenny, et al.
(author)
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The radiation dose to overweighted patients undergoing myocardial perfusion SPECT can be significantly reduced : validation of a linear weight-adjusted activity administration protocol
- 2017
-
In: Journal of Nuclear Cardiology. - : Springer Science and Business Media LLC. - 1071-3581 .- 1532-6551. ; 24:6, s. 1912-1921
-
Journal article (peer-reviewed)abstract
- Background: Large body size can cause a higher proportion of emitted photons being attenuated within the patient. Therefore, clinical myocardial perfusion SPECT (MPS) protocols often include unproportionally higher radioisotope activity to obese patients. The aim was to evaluate if a linear weight-adjusted low-dose protocol can be applied to obese patients and thereby decrease radiation exposure. Methods and result: Two hundred patients (>110 kg, BMI 18-41, [n = 69], ≤ 110 kg, BMI 31-58, [n = 131]) underwent 99mTc-tetrofosmin stress examination on a Cadmium Zinc Telluride or a conventional gamma camera using new generations of reconstruction algorithm (Resolution Recovery). Patients <110 kg were administered 2.5 MBq/kg, patients between 110 and 120 kg received 430 MBq and patients >120 kg received 570 MBq according to clinical routine. Patients >110 kg had 130% total number of counts in the images compared to patients <110 kg. Recalculating the counts to correspond to an administered activity of 2.5 MBq/kg resulted in similar number of counts across the groups. Image analyses in a subgroup with images corresponding to high activity and 2.5 MBq/kg showed no difference in image quality or ischemia quantification. Conclusion: Linear low-dose weight-adjusted protocol of 2.5 MBq/kg in MPS can be applied over a large weight span without loss of counts or image quality, resulting in a significant reduction in radiation exposure to obese patients.
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| 42. |
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| 43. |
- Kero, Tanja, et al.
(author)
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Quantification of (11)C-PIB kinetics in cardiac amyloidosis
- 2020
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In: Journal of Nuclear Cardiology. - : Springer Science and Business Media LLC. - 1071-3581 .- 1532-6551. ; 27:3, s. 774-784
-
Journal article (peer-reviewed)abstract
- BACKGROUND: The purpose of this work was to determine the optimal tracer kinetic model of (11)C-PIB and to validate the use of the simplified methods retention index (RI) and standardized uptake value (SUV) for quantification of cardiac (11)C-PIB uptake in amyloidosis. METHODS AND RESULTS: Single-tissue, reversible and irreversible two-tissue models were fitted to data from seven cardiac amyloidosis patients who underwent (11)C-PIB PET scans and arterial blood sampling for measurement of blood radioactivity and metabolites. The irreversible two-tissue model (2Tirr) best described cardiac (11)C-PIB uptake. RI and SUV showed high correlation with the rate of irreversible binding (Ki) from the 2Tirr model (r(2 )=0.95 and r(2 )=0.94). Retrospective data from 10 amyloidosis patients and 5 healthy controls were analyzed using RI, SUV, as well as compartment modelling with a population-average metabolite correction. All measures were higher in amyloidosis patients than in healthy controls (p=.001), but with an overlap between groups for Ki. CONCLUSION: An irreversible two-tissue model best describes the (11)C-PIB uptake in cardiac amyloidosis. RI and SUV correlate well with Ki from the 2Tirr model. RI and SUV discriminate better between amyloidosis patients and controls than Ki based on population-average metabolite correction.
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| 44. |
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| 45. |
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| 46. |
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| 47. |
- Arvidsson, Ida, et al.
(author)
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Deep learning prediction of quantitative coronary angiography values using myocardial perfusion images with a CZT camera
- 2023
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In: Journal of Nuclear Cardiology. - : Springer Science and Business Media LLC. - 1071-3581 .- 1532-6551. ; 30:1, s. 116-126
-
Journal article (peer-reviewed)abstract
- Purpose: Evaluate the prediction of quantitative coronary angiography (QCA) values from MPI, by means of deep learning. Methods: 546 patients (67% men) undergoing stress 99mTc-tetrofosmin MPI in a CZT camera in the upright and supine position were included (1092 MPIs). Patients were divided into two groups: ICA group included 271 patients who performed an ICA within 6 months of MPI and a control group with 275 patients with low pre-test probability for CAD and a normal MPI. QCA analyses were performed using radiologic software and verified by an expert reader. Left ventricular myocardium was segmented using clinical nuclear cardiology software and verified by an expert reader. A deep learning model was trained using a double cross-validation scheme such that all data could be used as test data as well. Results: Area under the receiver-operating characteristic curve for the prediction of QCA, with > 50% narrowing of the artery, by deep learning for the external test cohort: per patient 85% [95% confidence interval (CI) 84%-87%] and per vessel; LAD 74% (CI 72%-76%), RCA 85% (CI 83%-86%), LCx 81% (CI 78%-84%), and average 80% (CI 77%-83%). Conclusion: Deep learning can predict the presence of different QCA percentages of coronary artery stenosis from MPIs.
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| 48. |
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| 49. |
- Englund, Mikael C. O., 1971, et al.
(author)
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The establishment of 20 different human embryonic stem cell lines and subclones; a report on derivation, culture, characterisation and banking.
- 2010
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In: In vitro cellular & developmental biology. Animal. - : Springer Science and Business Media LLC. - 1543-706X .- 1071-2690. ; 46:3-4, s. 217-30
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Journal article (peer-reviewed)abstract
- This report summarises our efforts in deriving, characterising and banking of 20 different human embryonic stem cell lines. We have derived a large number of human embryonic stem cell lines between 2001 and 2005. One of these cell lines was established under totally xeno-free culture conditions. In addition, several subclones have been established, including a karyoptypical normal clone from a trisomic mother line. A master cell banking system has been utilised in concert with an extensive characterisation programme, ensuring a supply of high quality pluripotent stem cells for further research and development. In this report we also present the first data on a proprietary novel antibody, hES-Cellect, that exhibits high specificity for undifferentiated hES cells. In addition to the traditional manual dissection approach of propagating hES cells, we here also report on the successful approaches of feeder-free cultures as well as single cell cultures based on enzymatic digestion. All culture systems used as reported here have maintained the hES cells in a karyotypical normal and pluripotent state. These systems also have the advantage of being the principal springboards for further scale up of cultures for industrial or clinical applications that would require vastly more cells that can be produced by mechanical means.
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| 50. |
- Fransson, Helen, et al.
(author)
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An automatic method for quantification of myocardium at risk from myocardial perfusion SPECT in patients with acute coronary occlusion.
- 2010
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In: Journal of Nuclear Cardiology. - : Springer Science and Business Media LLC. - 1532-6551 .- 1071-3581. ; 17, s. 831-840
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Journal article (peer-reviewed)abstract
- BACKGROUND: In order to determine myocardial salvage, accurate quantification of myocardium at risk (MaR) is necessary. We present a validated novel automatic segmentation algorithm for quantification of MaR by myocardial perfusion SPECT (MPS) in patients with acute coronary occlusion. METHODS AND RESULTS: Twenty-nine patients with coronary occlusion were injected with a perfusion tracer before reperfusion, and underwent rest MPS within 4 hours. The MaR was quantified using the proposed algorithm (Segment software), the software Quantitative Perfusion SPECT (QPS) and by manual segmentation. The Segment MaR algorithm used a threshold of 55% of maximal counts and an a priori model based on normal coronary artery perfusion territories. The MaR was 30 +/- 10% left ventricular mass (%LVM) by manual segmentation, 31 +/- 12%LVM by Segment, and 36 +/- 14%LVM by QPS. There was a good agreement between automatic and manual segmentation for both of the algorithms with a lower bias for Segment (.8 +/- 4.0%LVM) than for QPS (5.8 +/- 5.8%LVM) when compared to manual segmentation. CONCLUSIONS: The Segment MaR algorithm can be used to correctly assess MaR from MPS images in patients with acute coronary occlusion without access to tracer-specific normal database. The MaR in relation to final infarct size enables determination of myocardial salvage.
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