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- Fahlgren, Anna, 1972-
(författare)
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Early knee osteoarthrosis after meniscectomy : studies in rabbits
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Post-traumatic osteoarthrosis develops after intraarticular injuries. It is a disease, which affects both articular cartilage and subchondral bone, and progresses over 10-20 years. Irreversible damage has often occurred by the time clinical diagnosis is possible. More knowledge about the early phase of the disease might yield measures to detect and delay or even prevent progression. This thesis evaluates changes in articular cartilage and subchondral bone at an early stage of post-traumatic osteoarthrosis.Simultaneous changes in articular cartilage and subchondral bone were evaluated 3 to 40 weeks post-operatively in a rabbit meniscectomy model for post-traumatic osteoarthrosis. Rabbits were meniscectomized in the right knee and sham-operated in the left knee. Osteoarthrotic cartilage changes were evaluated by histology. Changes in the subchondral bone were evaluated by histology, scintimetry and dual-energy X-ray absorptiometry (DEXA). Joint space narrowing, and its utility as diagnostic tool at early stages of osteoarthrosis, was assessed with weight-bearing radiographs. The prognostic value of transforming growth factor-ßI (TGF-ß1) and proteoglycan fragment concentrations in the joint fluid at an early stage was also assessed.We found slight cartilage changes and an increased metabolic activity in the subchondral bone as early as 3 weeks after meniscectomy. However, sham-operated knees displayed similar changes, although to a lesser degree. Cartilage fibrillation progressed at areas of high load within the meniscectomized knee joint. The subchondral bone showed a general response such as high scintimetric activity 3 weeks after surgery, and a decreased bone mineral density at later time points. Local adaptation in areas of high load within the subchondral bone was also seen. There was an increased osteoid content at the border between the cancellous bone and the marrow cavity already 3 weeks after meniscectomy, and at 13 weeks the subchondral bone plate was thickened. This thickening of the bone plate persisted up to 40 weeks. Joint space narrowing occurred after removal of the meniscus, but weight-bearing radiographs were not sensitive enough to measure early cartilage changes. Increased concentration of TGF-ß1 in the joint fluid at 3 weeks after surgery was associated with a higher degree of histological osteoarthrotic changes at a later time point.Simultaneous changes in both cartilage and bone were apparent already 3 weeks after surgery, indicating that both tissues are involved from a very early stage. The localisation of cartilage changes illustrates that mechanical consequences of meniscectomy play a crucial role in progression of the disease. Surgical trauma resulted in increased release of TGF-ß1 at 3 weeks after surgery. This was found to be indicative for the severity of later osteoarthrosis. Thus, factors solely associated with the surgical trauma may also be important for the progression of osteoarthrosis.
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| 2. |
- Maletius, Wolfgang
(författare)
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Long term prognosis of intraarticular knee injuries
- 1999
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Intraarticular knee injuries, still are a challenge for proper treatment in Sports Medicine today .The increasing life expectancy as well as the patient expectation to maintain a sufficiant physical activity up to high ages gives the topic an increasing publicity. Still, the long tenn prognosis of the most conunon intraarticular knee injuries including cartilage injuries remaines unclear. The general purpose of this work was to investigate the long- term prognosis after common intraarticular knee injuries in respect to lrnee function, sports performance, knee stability and development of radiographical osteoarthrosis.In this series, 221 patients were examined. The initial diagnosis in all cases was placed by manual examination under anesthesy and arthroscopy. The patients were reexamined at different long-term follow-up intervalls by an interview, including a subjective lmee score and an activity score, a thorough manual examination, and a radiographical examination including weight-bearing radiographs. In a part of the patients, a quality of life score was used.Patients with isolated chondral damage in one knee had a good long-term functional' prognosis but developed mild to moderate signs of radiographical osteoarthrosis in the majority of the cases.Complete ACL tears resulted in a permanent increase of sagittal knee translation no matter which initial treatment Injuries to knee joint cartilage or menisci or partial injuries to the ACL did not result in an increase of sagittal translation.Radiographical signs for osteoarthrosis were encountered in 55 to 87% after different knee injuries, and seemed to advance slowly during the years.Combined intraarticular knee injuries seemed to have a higher risk for development of radiographical osteoarthrosis than isolated injuries within the same time period.Older age at initial diagnosis and treatment of an intraarticular knee injury is associated with a higher risk to develop radiographlcal osteoarthrosis.After 12 to 20 years, patients with minor intraarticular knee injuries seem to have only a marginally better longterm prognosis for knee function and activity participation than patients with combined, major intraarticular knee injuries. However, the higher dissatisfaction with the results, the higher rate of symptoms and subsequent repeat surgery as well as the higher development of oeteoarthrosis during the years in the latter cases may point to that the risk for future lmee deterioration is greater after a combined than after a minor or/and isolated knee injury.Subjective satisfaction and quality of life was high after a partial rupture of the ACL with minor concomitant injuries, and stayed unchanged over the years. In contrast, a complete rupture of the ACL did adversely influence quality of life, and subjective satisfaction with knee performance declined with time.
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