Aims: The role of unicompartmental knee arthroplasty (UKA) in the treatment of medial knee osteoarthritis (OA) is controversial. The purpose of the study was to analyse our mid-term results of our UKAs operated in 1991–94. Method: Patient þles, the special knee arthroplasty form and radiographs were used to retrospectively analyse the results of 155 UKAs in 142 patients operated for medial knee OA. Results: The mean age of the patients was 66,4 years (39–86), and 65,5% of the patients were women. Good pain relief was reached in all cases with an average ROM of 0–121 degrees at 3 months postoperatively. The operations were complicated by superþcial wound infection in three patients (2,1%), deep vein thrombosis in one patient (0,7%), and limited ROM in one patient (0,7%). The survival rate of UKA was 91,6% at 9,4 years. A total of 13 knees were revised with a total knee prosthesis. Polyethylene wear (n=9), disease progression (n=2), aseptic loosening (n=1) and fracture (n=1) were the indications for the revision. The postoperative period was uneventful in all patients, and mean ROM was 0–108 degrees at 3 months. Conclusion: In our experience, UKA is a procedure with rapid recovery, good knee motion and patient satisfaction for the carefully selected patients in the treatment of medial knee OA. Once failed, UKA is safely revised with a routine TKA

Aims: The aim of this prospective study was to measure changes of bone mineral density (BMD) in the proximal tibia after cemented total knee arthroplasty (TKA) in osteoarthrotic knee joints. Methods: Sixty-nine patients were scanned by dual-energy x-ray absorptiometry (DXA) within a week postoperatively, at 3, 6 and 12 months follow-up. Results:Medial metaphyseal measurement region on interest (ROI) showed a signiþcant decrease in BMD values in preoperatively varus knees joints (p < 0.0005). In preoperatively valgus knees there was a slight non-signiþcant increase in BMD (p=0.184). At the baseline the medial ROI BMD differed from each other signiþcantly in these alignment groups (p= 0.023, independent samples T-test). Alignment correction in the both groups showed bone remodeling towards similar actual BMD values. Finally medial and lateral BMD values were also more similar suggesting that the bone became equally strong on both compartments of metaphysis. We could not trace the effect of increasing AKS score values to the bone remodeling. Conclusions: We suggest that loading effect on bone may be a major profound bone remodeling factor. Its clinical value can not be ignored nor determined by other changes in knee joint status and function. These results conþrm the clinical importance of recreating the proper valgus alignment of the knee joint in TKA operation, which offers possibly better proof for the longevity of the tibial component.