Long-Term Survivorship of Closed-Wedge High Tibial Osteotomy for Severe Knee Osteoarthritis: Outcomes After 10 to 37 Years.
Orthop J Sports Med 2021;
9:23259671211046964. [PMID:
34692884 PMCID:
PMC8532226 DOI:
10.1177/23259671211046964]
[Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 06/29/2021] [Indexed: 11/24/2022] Open
Abstract
Background:
High tibial osteotomy (HTO) was developed as a joint-preserving procedure to treat relatively young patients with isolated medial compartmental knee osteoarthritis (OA). Long-term survivorship after HTO is important to determine whether patients will need additional surgery.
Purpose:
To determine the long-term (>35-year) survivorship and prognostic factors for closed-wedge HTO (CWHTO) for severe medial OA.
Study Design:
Case series; Level of evidence, 4.
Methods:
We retrospectively evaluated patients who underwent CWHTO for severe medial knee OA between 1983 and 2009 at our institution, Nagoya University Graduate School of Medicine (Nagoya, Japan). Patient demographics, follow-up period, and pre- and postoperative femoral-tibial angle (FTA) were reviewed. The patients or the relatives of the patients were interviewed by telephone to record postoperative status, including conversion to total knee arthroplasty (TKA).
Results:
Of the 74 CWHTO procedures performed, we evaluated 56 procedures in 45 patients (mean age at time of surgery, 56.8 years). The mean follow-up period was 17.1 years. Nine knees (16.1%) underwent conversion to TKA. The mean time to TKA conversion was 15.6 years. Kaplan-Meier analysis revealed a 10-year survival rate of 90.1%, a 15-year rate of 83.8%, a 20-year rate of 75.9%, and a 35-year rate of 75.9%. Log-rank test showed that age ≥55 years (P = .044), body mass index (BMI) ≥25 kg/m2 (P = .0016), and preoperative FTA <185° (P = .0034) were risk factors associated with TKA conversion. Multivariate analyses adjusted for age and sex identified BMI ≥25 kg/m2 (hazard ratio [HR], 13.4; 95% CI, 1.7-106.9; P = .014) and preoperative FTA <185° (HR, 4.2; 95% CI, 1.1-16.6; P = .04) as risk factors associated with TKA conversion.
Conclusion:
The survival rate of CWHTO for severe medial knee OA was 90.1% at 10 years, 83.8% at 15 years, and 75.9% at 20 years and 35 years. Furthermore, a BMI ≥25 kg/m2 and FTA <185° were the independent risk factors associated with TKA conversion after CWHTO.
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