Biomechanical factors and physical examination findings in osteoarthritis of the knee: associations with tissue abnormalities assessed by conventional radiography and high-resolution 3.0 Tesla magnetic resonance imaging.

INTRODUCTION: We aimed to explore the associations between knee osteoarthritis (OA)-related tissue abnormalities assessed by conventional radiography (CR) and by high-resolution 3.0 Tesla magnetic resonance imaging (MRI), as well as biomechanical factors and findings from physical examination in patients with knee OA. METHODS: This was an explorative cross-sectional study of 105 patients with knee OA. Index knees were imaged using CR and MRI. Multiple features from CR and MRI (cartilage, osteophytes, bone marrow lesions, effusion and synovitis) were related to biomechanical factors (quadriceps and hamstrings muscle strength, proprioceptive accuracy and varus-valgus laxity) and physical examination findings (bony tenderness, crepitus, bony enlargement and palpable warmth), using multivariable regression analyses. RESULTS: Quadriceps weakness was associated with cartilage integrity, effusion, synovitis (all detected by MRI) and CR-detected joint space narrowing. Knee joint laxity was associated with MRI-detected cartilage integrity, CR-detected joint space narrowing and osteophyte formation. Multiple tissue abnormalities including cartilage integrity, osteophytes and effusion, but only those detected by MRI, were found to be associated with physical examination findings such as crepitus. CONCLUSION: We observed clinically relevant findings, including a significant association between quadriceps weakness and both effusion and synovitis, detected by MRI. Inflammation was detected in over one-third of the participants, emphasizing the inflammatory component of OA and a possible important role for anti-inflammatory therapies in knee OA. In general, OA-related tissue abnormalities of the knee, even those detected by MRI, were found to be discordant with biomechanical and physical examination features.

Medial malleolar osteotomy for the correction of varus deformity during total ankle arthroplasty: results in 15 ankles.

BACKGROUND: Preoperative deformity in the frontal plane in the arthritic ankle is a risk factor for failure after total ankle arthroplasty. Medial malleolar lengthening osteotomy was developed to correct varus malalignment. MATERIALS AND METHODS: From 1998 to 2005 total ankle arthroplasty combined with medial malleolar lengthening osteotomy was done in 15 ankles (13 patients) with a mean preoperative varus deformity of 14.9 (SD, 7.8) degrees. Diagnosis was arthritis with instability in 11 ankles (9 patients) and inflammatory joint disease in 4 ankles. Two mobile-bearing designs were used. Osteosynthesis of the osteotomy was done in 2 ankles; for the remaining 13 osteotomies, no fixation was used. RESULTS: Followup was 5 (range 2 to 8) years. Neutral alignment was obtained in all ankles. In 3 patients residual hindfoot varus remained, for which a second-stage hindfoot correction was done. Two rheumatoid ankles developed a symptom-free nonunion of the medial malleolus, all other malleolar osteotomies united. One tibial component, implanted with too much anterior slope, developed early aseptic loosening and was revised. Debridement for talar-malleolar arthritis was done in two ankles. Of the 14 ankles in followup, 12 were rated as excellent or good, one as fair. One ankle with subsidence of the talar component was rated as unsatisfactory. AOFAS score increased from 30.8 preoperative to 81.0 at followup (p < 0.01). CONCLUSION: Medial malleolar lengthening osteotomy is an easy technique for the realignment of the varus ankle at the time of total ankle arthroplasty, and served as an alternative to medial ligament release or lateral ligament reconstruction.