Tibial condylar valgus osteotomy (TCVO) for osteoarthritis of the knee: 5-year clinical and radiological results

Abstract

Purpose: Tibial condylar valgus osteotomy (TCVO) is a type of opening-wedge high tibial osteotomy for advanced medial knee osteoarthritis (OA) with subluxated lateral joint. We report the concept, the current surgical technique with a locking plate, and the short-term clinical and radiological results of this procedure.

Methods: 11 knees with medial OA and a widened lateral joint were treated by TCVO (KL stage III: 6, IV: 5). In this procedure, by the L-shaped osteotomy from the medial side of the proximal tibia to the intercondylar eminence and the valgus correction, lateralization of the mechanical axis and reduction of the subluxated lateral joint are obtained with early postoperative weight-bearing. Before, 6 months, 1, and 5 years after the operation, a visual analog scale (VAS), the Western Ontario and McMaster Universities Arthritis Index (WOMAC), alignment of the lower extremity, and congruency and stability of the femorotibial joint were investigated.

Results: The VAS improved from an average of 73 mm to 13 mm, and the total WOMAC score from 52 to 14 before to 5 years after the operation, respectively. The mechanical axis changed from 1 to 60%, and the FTA changed from 186° to 171°. The joint line convergence angle (JLCA) changed from 6° to 1°, and the angle difference of JLCA between varus and valgus stress improved from 8° to 4° after the procedure.

Conclusion: Improvements in pain and activities of daily living were observed by TCVO along with valgus correction of the lower extremity and stabilization of the femorotibial joint.

Keywords: High tibial osteotomy; Osteoarthritis of the knee; Tibial condylar valgus osteotomy.

Fig. 1

With an L-shaped osteotomy from the medial side of the proximal tibia to the intercondylar eminence and making the valgus correction (a), lateralization of the load line and definite reduction of the subluxated lateral joint are obtained (b, c)

Fig. 2

Advanced cases of varus knee OA have a dilated and subluxated lateral joint (a). Even when the mechanical axis has been moved to the lateral side by HTO, the lateral joint occasionally does not make contact (b), which means that the purpose of HTO, the reallocation of stress distribution, is not achieved

Fig. 3

Mechanical axis (percentage of MA: %MA), femorotibial angle (FTA), lateral distal femoral angle (LDFA), and medial proximal tibial angle (MPTA) were measured to evaluate leg alignment

Fig. 4

Joint line convergence angle (JLCA) and joint space width (JS) were measured to evaluate joint congruity. JLCAs with 100-N varus and valgus stress and their difference (ΔJLCA) were measured to evaluate joint stability

Fig. 5

Individual changes of VAS before, 6 months after, 1 year after, and 5 years after TCVO. In most cases, VAS has improved 6 months after the procedure

Fig. 6

Joint space width before and 1 year after TCVO. The joint space is narrowed in the medial joint and widened in the lateral joints before the procedure. Not only the joint space narrowing of the medial joint but joint congruence of the lateral joints has improved after the procedure