Aims

To compare time dependent functional improvement for patients with medial, respectively lateral knee osteoarthritis (OA) after treatment with opening wedge osteotomy relieving the pressure on the osteoarthritic part of the knee.

Introduction: The operational technique for opening wedge osteotomies has been simplified by the use of the Puddu-plate. This study presents results after use of Puddu-plates on distal femoral and proximal tibial osteotomies.

Methods: Fifteen distal femoral and 25 proximal tibial osteotomies have been performed with opening wedge technique due to knee osteoarthritis with malalignment in the period 2000–2004. The knee osteoarthritis was mainly due to a previous meniscal extirpation. Ten patients had an additional rupture of the anterior cruciate ligament. The mean age of the patients was 49 years (31–66 years), and 17 females and 23 males were operated. The patients with femoral osteotomies had a mean preoperative tibiofemoral valgus angle of 12° (8°–20°) whereas those with tibial osteotomies had a mean tibiofemora varus angel of 1° (7° varus – 3° valgus). The osteotomy was fixed with a Puddu-plate securing the planned angular correction, and the osteotomy cleft was filled by autogenous pelvic bone. The mean follow-up time was 18 months (3–42 months).

Results: The width of the osteotomy cleft was determined by the tooth of the implant. The mean width of the tooth was 8.6 mm (5–12.5 mm), and the mean angular correction measured on pre- and postoperative radiographs was 8.4° (5–15°). The osteotomy cleft healed after a mean of 13 weeks (7–26 weeks). One patient suffered venous thrombosis of the leg and one a postoperative wound infection. The knee injury and osteoarthritis outcome score (KOOS) increased significantly during the observation period. For pain the mean preoperative score was 53 and the score at follow-up was 82. The corresponding scores for symptoms were 56 and 75, for activity of daily life (ADL) 65 and 86, for sport and recreation 26 and 52 and for quality of life 33 and 64 (P< 0.001).

Conclusion: The results after opening wedge osteotomy using the Puddu-plate seem satisfactory. The operational technique is simpler compared to previous methods, and the degree of angular correction is accurate depending on the width of the tooth of the implant which in mm corresponds relatively well with the degrees of angular correction.