2017 ISAKOS Biennial Congress ePoster #205

 

Mosaic Osteochondral Autograft Transplantation Versus Bone Marrow Stimulation Technique as a Concomitant Procedure with Opening-Wedge HTO for Spontaneous Osteonecrosis of the Knee

Ken Kumagai, MD, Yokohama JAPAN
Yasushi Akamatsu, MD, PhD, Yokohama JAPAN
Hideo Kobayashi, Yokohama JAPAN
Yoshihiro Kusayama, MD, Yokohama JAPAN
Masaki Tsuji, MD, Yokohama JAPAN
Tomoyuki Saito, MD, PhD, Yokohama, Kanagawa JAPAN

Yokohama City University, Yokohama, Kanagawa, JAPAN

FDA Status Not Applicable

Summary

Mosaic osteochondral autograft transplantation is superior to bone marrow stimulation technique as a concomitant procedure with opening-wedge valgus high tibial osteotomy for spontaneous osteonecrosis of the knee in postoperative cartilage repair.

Abstract

Background

Spontaneous osteonecrosis of the knee (SONK) can be treated with joint-preserving surgery, since subchondral lesion with histopathological abnormalities was restricted to the superficial layer. The treatment strategy for SONK is repair of articular surface and realignment of varus deformity. However, postoperative status of articular cartilage has not been characterized and the effect of concomitant procedures to promote cartilage regeneration, such as bone marrow stimulation (BMS) or osteochondral autograft transplantation (OAT/mosaicplasty), need to be elucidated.

Methods

Fifty-seven patients with SONK (mean age 68 years) were treated with opening-wedge valgus high tibial osteotomy (HTO) and concomitant procedure of BMS (27 patients) or OAT (30 patients). Clinical evaluation was carried out using the Knee Society Score (KSS). Postoperative status of articular cartilage was assessed by arthroscopy according to the ICRS grade at the time of plate removal. The effects of concomitant procedures with opening-wedge valgus HTO on clinical outcomes and cartilage status were compared between BMS by drilling and OAT mosaicplasty.

Results

The KSS objective score was improved at postoperative 2 years compared with pre-operative value in both groups, but no significant difference was found between two groups. According to the ICRS overall repair grade, cartilage status was rated as normal or nearly normal (ICRS overall score = 8) in 41% of BMS group and 90% of OAT group. The results suggested that cartilage repair in OAT was significantly better than in BMS (p<0.05). Furthermore, BMS group revealed that repair with normal or nearly normal was observed in all less than 4 cm2 of lesion size, whereas OAT group exhibited that repair with normal or nearly normal was independent of lesion size.

Conclusion

This study was intended to evaluate the effect of mosaicplasty as a concomitant procedure with opening-wedge HTO on the cartilage repair and the clinical outcomes. The results of the present series support the initial hypothesis that OAT mosaicplasty is superior to BMS drilling as a concomitant procedure with opening-wedge valgus HTO for SONK in postoperative cartilage repair, but clinical outcomes are not significantly different between these two procedures. The major advance in the present study is the provision of evidence that lesion size does not affect cartilage repair after mosaicplasty in combination with opening-wedge valgus HTO.