Success of High Tibial Osteotomy in the United States Military

Abstract

Historically, high tibial osteotomy (HTO) has been performed to treat isolated medial gonarthrosis with varus deformity. More recently, HTO has been utilized in conjunction with chondral, ligamentous, and/or meniscal procedures in young active patients with subtle varus malignment. However, occupational outcomes in a high-demand military cohort are largely unknown. A retrospective analysis of active duty servicemembers undergoing high tibial osteotomy for coronal plane malalignment and/or intra-articular pathology were isolated from the Military Health System Management Analysis and Reporting Tool between 2003 and 2011. Demographic variables such as age, sex, rank, and branch of service were extracted, and extensive medical record review was performed to identify surgical variables, including the rates of perioperative complications, radiographic findings, secondary surgery (including revision), activity limitations, and medical discharge as confirmed by the U.S. Army Physical Disability Agency database. For the current study, cumulative failure was defined as conversion to knee arthroplasty, or medical discharge with persistent knee dysfunction after index HTO. Univariate and multivariate analysis were performed to identify statistical associations with cumulative failure after HTO. A total of 80 patients with 93 HTOs were identified at an average follow-up of 43.7 months (range, 24-93 months). The mean age of all servicemembers was 35.5 years (range, 20-55), and the majority were males (91%) and of enlisted rank (76%). Approximately 92% of surgeries involved plate fixation, while the remainder utilized circular or monolateral external fixation. Concomitant or staged procedures were performed in 45 servicemembers (56%), including 29 ligamentous, 24 meniscal, and 21 chondral procedures. Complications necessitating unplanned reoperation occurred in 10 cases (11%), including infection (n=3), nonunion (n=2), fracture (n=2), hardware failure (n=1), dehiscence (n=1), and flexion contracture (n=1). Additionally, symptomatic hardware was noted after 18 surgeries (19%) and occasional knee pain was noted in 26 extremities (28%). When considering those individuals remaining on active duty, 21(26%) servicemembers were unable to return to full duty and required permanent activity limitations. Of the 80 servicemembers, 7 individuals received medical discharge for persistent knee pain or disability, and an additional 7 underwent conversion to total knee arthroplasty. The cumulative failure rate for all servicemembers was 18% at 2-8 year follow-up. In a young, active military population, HTO is moderately effective for the treatment of medial unicompartmental disease with associated intra-articular knee pathology. At early to mid-term follow-up, 82% of patients returned to military duty and were free from conversion knee arthroplasty. High tibial osteotomy is a useful in the treatment of medial unicompartmental disease and has demonstrated success in an active US military population at a minimum of 2-year follow-up.