Introduction: One of the problems of high tibial valgus osteotomy is the loss of achieved correction, which, in turn, is associated with the deterioration of the patient’s symptoms.

Aim: The aim of the present retrospective study is the correlation of certain parameters of axial alignment of the knee joint with the possibility of varus recurrence, after high tibial osteotomy, with stable fixation.

Material – Method: For this purpose we studied 33 patients (37 knees), that had undergone high tibial osteotomy between 1989 and 1997. All the above patients had a follow up of at least 2 years, with a mean of 35 months. The axial parameters that were studied were the femoral condyle-femoral shaft angle, the tibial plateau-tibial shaft angle, the post operative valgus correction and the post operative medial joint space widening.

Results: Loss of femorotibial angle equal to or more than 3 degrees was regarded as recurrence. This was observed in 9 knees (24%). The possibility of recurrence was strongly associated (Logistic Regression Analysis), on the one hand, with a post operative valgus correction of less than 6 degrees, and, on the other hand, with a femoral condyle-femoral shaft angle of more than 84 degrees (varus orientation of the articular surface of femoral condyles).

Conclusion: It seems that both undercorrection of the femorotibial angle and varus orientation of the femoral condyles in the frontal plane do not allow the shift of the weight bearing axis of the lower extremity towards the lateral compartment and, thus, constitute risk factors for recurrence of the varus deformity.

Introduction: High tibial osteotomy is an established procedure for the mid-term treatment of unicompartmental osteoarthritis of the knee, especially in young patients. Nevertheless, its performance at the proximal end of the tibia, close to the site of insertion of the extensor mechanism of the knee, might produce anatomic alterations of the latter, which, in turn, could influence the final result.

Aim: The purpose of the present retrospective study is the radiologic evaluation of the anatomic changes of the extensor mechanism of the knee, caused by high tibial valgus osteotomy (closed-wedge step osteotomy, with internal fixation).

Material – Method: For this purpose we studied the X-rays of 44 kness (pre-op, p-op and 1 year p-op) that had undergone the above procedure. The assessed variables were the horizontal and vertical shift of tibial tubercle as well as the position of the patella (patellar vertical height, Linclau, Caton).

Results: We didn’t find any statistically significant difference of the postoperative position of the patella with respect to the preoperative one (p=0.88), whereas there was definite proximal and anterior shift of the tibial tubercle in a statistically significant degree (p< 0.01) with respect to the preoperative situation.

Conclusions: The certain type of high tibial osteotomy seems to impart an unloading effect on the patellofemoral joint (due to the anterior shift of the tibial tubercle). On the contrary, the vertical shift of the tibial tubercle seems to have no effect to the postoperative position of the patella.

Introduction: High tibial osteotomy is an established procedure for the mid-term treatment of unicompartmental osteoarthritis of the knee. Nevertheless, it produces anatomic alterations of the proximal part of tibia, which might affect the later performance of TKR. These anatomic changes are basically patella infera and medialization of the tibial medullary canal with respect to the tibial plateau (tibial condilar offset).

Material and Method: The purpose of the present retrospective study is the evaluation of the above mentioned anatomic changes, caused by high tibial valgus osteotomy (Mittelmeier’s technique). For this purpose we studied the X-rays of 44 kness (pre-op, p-op and 1 year p-op) that had under gone the above procedure.

Results: We didn’t find any statistically significant difference of the postoperative position of the patella with respect to the preoperative one, whereas there was definite medialization of the tibial anatomic axis with respect to the preoperative situation. The latter change was directly correlated with the degree of valgus correction. The mean change of the tibial anatomic axis (as estimated by the value of the tibial condylar offset ratio) was 15%.

Conclusions: Although Mittelmeier’s high tibial valgus osteotomy does not cause any significant alteration of the position of the patella, it does alter the relationship of the tibial medullary canal with respect to the tibial plateau in direct correlation with the degree of valgus correction. Thus, the performance of TKR after proximal tibial osteotomy necessitates a thorough preoperative plan and the selection of the appropriate implant.