Structural allograft impaction enables fast rehabilitation in opening-wedge high tibial osteotomy: a consecutive case series with one year follow-up.

ABSTRACT

PURPOSE: Painful and slow recovery are the presumed disadvantages after opening-wedge high tibial osteotomy (HTO) and play a role in favouring arthroplasty as treatment for moderate isolated medial knee arthritis. The primary study objective was to investigate the effect of press-fit structural impacted bone allograft with locking plate fixation on early ambulation, postoperative pain levels, and resumption of daily-life activities in opening-wedge HTO. METHODS: A prospective consecutive opening-wedge HTO case series was conducted, including 103 patients with final follow-up at 1 year. Weight-bearing was allowed from the day after surgery "as tolerated" by the patient. Clinical assessment included the Numeric Rating Scale (NRS), Knee injury and Osteoarthritis Outcome Score (KOOS), and Lysholm score. Additionally, the Knee Society Score (KSS) was assessed during consultation at 1, 3, and 12 months postoperatively with special attention for clinical anchor questions. Required sample size was calculated and a linear mixed-effect model was used for repeated measures over time of the clinical scores. RESULTS: The NRS decreased by 1.5 at 1 month (p < 0.01) and 2.1 at 3 months (p < 0.01), while KOOS pain significantly improved with 19.2 (p < 0.01) by this time compared to baseline. Under reduced pain levels, 98% were able to walk > 500 m without support, while all patients were able to climb up and down the stairs 3 months postoperatively. CONCLUSION: The study strongly supports the initial hypothesis that applying structural triangular bone allograft in HTO leads to low postoperative pain levels, early ambulation, and excellent short-term clinical outcomes. Study results have the potential to alter the general perception about HTO being a painful procedure with painstakingly slow recovery and consequently encourage the consideration of HTO as a highly valuable joint-preserving option, while treating unicompartmental knee arthritis. LEVEL OF EVIDENCE IV (case series).