KS30: MEGA OATS FOR LARGE OSTEOCHONDRAL DEFECTS OF THE FEMORAL CONDYLE: A 5 YEAR FOLLOW UP

Abstract

Large osteochondral defects of the femoral condyle still pose a difficult problem to treat. A variety of options is available but most of result in replacement with inferior fibrous or hyaline-like cartilage in the load-bearing zone of the knee joint. We present the five year results of Mega-OATS. This technique utilizes the posterior femoral condyle for coverage of osteochondral defects and is called Mega-OATS.

From July 1999, 33 patients of mean age 34.3 years (15–59) were treated with MEGA-OATS. Fifteen patients additionally underwent high tibial osteotomy and two bone grafting using bone harvested from the proximal tibia. The average defect size was 6.2±1.8 cm2. The mean follow up was 66.4±13.2 months. The technique calls for excision of the posterior femoral condyle which is placed in a specially designed work station.

The Lysholm score increased post-operatively from 49.0±19.4 to 88.5±14.9 12 months post surgery to 85.5±16.0 five years post surgery. Three months post-operatively, patients attained a full range of motion and became fully weight-bearing. There was no difference in patients undergoing combined surgery with high tibial osteotomy and patients undergoing Mega OATS as a single procedure after five years. No post-operative meniscal lesions of the posterior horn have been observed.

Mega-OATS achieves a congruent reconstruction of the articular surface in the load bearing zone of the femoral condyle. We consider it a good alternative and salvage procedure in the treatment of large osteochondral defects of the femoral condyle.