2019 ISAKOS Biennial Congress ePoster #1215
A Retrospective Comparison of Union Rates After Open Wedge High Tibial Osteotomies with and without Synthetic Bone Grafts at Two Years
Kyung-Wook Nha, Prof., Goyang, Gyeonggi KOREA, REPUBLIC OF
Seung-Min Oh, MD, Seoul KOREA, REPUBLIC OF
Dong-Hun Suh, MD, PhD, Prof., Ansan, Gyeonggi KOREA, REPUBLIC OF
Jae Gyoon Kim, MD, PhD, Prof., Ansan, Gyeonggi KOREA, REPUBLIC OF
Yoon-Won Ha, MD, Seoul KOREA, REPUBLIC OF
Inje University, Ilsan Paik Hospital, Goyang, Gyounggi, KOREA, REPUBLIC OF
FDA Status Not Applicable
Summary
The no bone graft group showed significantly more incorporation than the synthetic bone graft group within 2 years.
Abstract
Objective
Synthetic bone grafts also have several disadvantages including soft tissue irritation and infection, lack of primary stability, poor remodeling, and incorporation into bone. Some recent studies reported good results after OWHTO without bone graft and also reported similar results to other bone graft methods. And there is no published study which directly comparing synthetic bone graft and without bone graft in OWHTO.
The purposes of this study were to evaluate the clinical and radiological results of no bone graft after OWHTO and to compare the bone union rate between the synthetic bone graft (SBG) group and no bone graft (NBG) group. The hypothesis was that a good clinical and radiological results would be obtained after OWHTO using a locking plate without bone graft, and the bony union rate after OWHTO without bone graft would be faster than that of OWHTO with synthetic bone graft.
Methods
From 2012 to 2015, OWHTOs were performed with synthetic bone graft or without bone graft using long locking plates by one senior surgeon. Inclusion criteria were 1) OWHTO for disease of the medial compartment with varus deformity, and 2) minimum 2-year follow-up and x-rays taken serially to 2-years. Exclusion criteria were 1) follow-up period < 2years (n=8) or 2) absence of at least one x-ray taken at each follow-up point (n=14). Groups comprised those filled with a synthetic bone (n=33, SBG group) or without a bone graft (n=38, NBG group). A total 71 knees from 63 patients were retrospectively reviewed using radiographs taken preoperatively and at 6 weeks, 3 months, 6 months, 1 year, and 2 years postoperatively. Triangular surface along the borders and corner of the osteotomy site was drawn on digitized standing ateroposterior (AP) radiographs, and this triangular surface was divided into five zones with the same surface area on pre- and postoperative radiographs (Figure 1). Each area corresponded to 20% of the osteotomy. The osteotomy was considered stable if the site was 40% to 60% filled (zone 3). We compared bone union rate between the two groups by measuring the union zone from zone 1 to zone 5 in serial radiographs of each follow-up points using Fisher’s exact test.
Results
Both groups showed good clinical and radiological results without correction loss at 2 years. The entire NBG group and 93.9% of the SBG group showed union over zone 3 at 2 years. However, the NBG group showed significantly more incorporation than the SBG group at 6 months (P= .006), 1 year (P= .0003), and 2 years (P= .0003).
Conclusions
Union without correction loss was obtained in all cases after OWHTO without bone graft using a locking plate. The no bone graft group showed significantly more incorporation than the synthetic bone graft group within 2 years.