Total knee arthroplasty after prior high tibial osteotomy results in comparable survival and clinical outcomes but significantly higher complication rates compared to primary total knee arthroplasty: a systematic review and meta-analysis of 550,000 patients

BackgroundHigh Tibial Osteotomy (HTO) is an effective surgical option in managing medial compartment knee osteoarthritis in the relatively younger population group but most will eventually require conversion to Total Knee Arthroplasty (TKA). TKA post-HTO is considered more complex than a primary TKA, given the numerous factors that increase the difficulty of the surgery-skin and soft tissue scarring, patella baja, limited knee motion, anatomical deformity or bony distortion of the proximal tibial metaphysis after HTO. MethodsA random-effects meta-analysis of comparative studies between TKA post-HTO and primary TKA was performed. We searched MEDLINE, EMBASE, Cochrane Library and SCOPUS from inception to August 1, 2024. Survivorship outcomes in terms of revision rates were analyzed. Where possible, further subgrouping to assess the impact of different techniques was performed. Secondarily, associated complications, surgical duration and clinical outcomes (Hospital for Special Surgery (HSS) Scores and Knee Society Scores (KSS) (Knee & Function)) were pooled. ResultsAt short-term follow-up, pooled revision rate for TKA post-HTO was 2.9% (95%CI 1.7-5.1) while that for primary TKA was 1.9% (95%CI 1.2-2.9). At mid-term follow-up, the pooled revision rate was 4.8% (95%CI 2.8-8.2) compared to 3.0% (95%CI 1.9-4.8) in primary TKA. At long-term follow-up, the pooled revision rate for TKA post-HTO was 7.2% (95%CI 1.3-30.9), while that of primary TKA was 4.1% (95%CI 1.6-10.2). No significant differences were noted between both groups at each follow-up. Pooled complication rate for TKA post-HTO was 15.8% (95%CI 12.3-20.0%), while that for primary TKA group was 6.1% (95%CI3.5-10.4). TKA post-HTO had significantly greater complication rates than in primary TKA (WMD: 2.6, 95%CI 2.2-3.1, p < 0.01). Pooled mean postoperative HSS scores were 83.5 (95% CI 80.1-86.8) in the TKA post-HTO group, compared to 86.1 (95% CI 82.3-90.0) in the primary TKA group. Pooled mean postoperative KSS (Knee) scores were 85.9 (95% CI 83.6-88.2) in the TKA post-HTO group, and 88.1 (95% CI 84.4-91.7) in the primary TKA group. Pooled mean postoperative KSS (Function) scores were 77.1 (95% CI 72.1-82.1) in the TKA post-HTO group and 78.4 (95% CI 74.5-82.5) in the primary TKA group. No significant differences were noted between both groups. ConclusionTKA post-HTO has comparable survival but significantly higher complication rates than primary TKA.