The indications, surgical technique, and the results of fixation using plates with metal wedges were assessed in proximal tibia medial opening wedge osteotomy.
Forty knees in 38 consecutive patients (5 men, 33 women; mean age 51 years; range 36 to 65 years) with medial compartment osteoarthritis of the knee were treated with proximal tibia medial opening wedge osteotomy using plates with wedges. Following arthroscopic debridement, medial proximal tibial osteotomy was performed laterally and proximally on an oblique line and 3-4 cm distal to the medial joint space. Disruption of the lateral cortex was avoided. Fixation of the osteotomy was performed using plates with wedges. The plates which were designed by the author were either rectangular in shape with two or four holes or had an inverse "L" shape with four holes, bearing metal wedges at varying heights from 5 to 15 mm. The plates were fixed with screws. Tricortical (n=8) or bicortical (n=25) iliac bone autografts and allografts (n=7) were used. Clinical and functional evaluations were made using the HSS scoring system. The mean follow-up was 17 months (range 9 to 36 months).
The mean preoperative and postoperative tibiofemoral angles were 4.3 degrees varus (0 degrees -10 degrees ) and 5.8 degrees valgus (3 degrees -11 degrees ), respectively. The mean HSS score increased from 59 (range 52 to 75) preoperatively to 90 (range 79 to 96) on final evaluations. During surgery, lateral tibial plateau fissures and lateral cortex fractures occurred in three (7.5%) and 11 (27.5%) knees, respectively. Delayed healing and delayed union and breakdown of a distal screw were encountered in one patient (2.5%).
Fixation of proximal tibia medial opening wedge osteotomy using plates with wedges provides adequate stabilization to maintain the desired correction and to allow early functional rehabilitation in the treatment of medial osteoarthritis of the knee.