We aimed to analyse complication rates following medial opening-wedge high tibial osteotomy (OWHTO) for knee OA.

A regional retrospective cohort study of all patients who underwent HTO for isolated medial compartment knee OA from 2003–2013.

115 OWHTO were performed. Mean age = 47 (95%CI 46–48). Mean BMI = 29.1 (95%CI 28.1–30.1).

Implants used: 72% (n=83) Tomofix, 21% (n=24) Puddu plate, 7% (n=8) Orthofix Grafts used: 30% (n=35) autologous, 35% (n=40) artificial and 35% (n=40) no graft. 25% (n=29) of patients suffered 36 complications. Complications included minor wound infection 9.6%, major wound infection 3.5%, metalwork irritation necessitating plate removal 7%, non-union requiring revision 4.3%, vascular injury 1.7%, compartment syndrome 0.9%, and other minor complications 4%.

Apparent higher rates of non-union occurred with the Puddu plate (8.3%) relative to Tomofix (3.6%) but was not statistically significant. No other significant differences existed in complication rates relative to implant type, bone graft used, patient age or BMI.

Serious complications following HTO appear rare. The Tomofix has an apparent lower rate of non-union compared to older implants but greater numbers are required to determine significance. There is no significant difference in union rate relative to whether autologous graft, artificial graft or no graft is used.

The primary aim was to assess survival of the opening wedge high tibial osteotomy (HTO) for medial compartment osteoarthritis. The secondary aim was to identify independent predictors of early (before 12 years) conversion to total knee arthroplasty (TKA). During the 18-year period (1994–2011) 111 opening wedge HTO were performed at the study centre. Mean patient age was 45 years (range 18–68) and the majority were male (84%). Mean follow-up was 12 (range 6–21) years. Failure was defined as conversion to TKA. Kaplan-Meier, Cox regression and receiver operating curve (ROC) analyses were performed. Forty (36%) HTO failed at a mean follow-up of 6.3 (range 1–15) years. The five-year survival rate was 84% (95% confidence interval (CI) 82.6–85.4), 10-year rate 65% (95% CI 63.5–66.5) and 15-year rate 55% (95% CI 53.3–56.7). Cox regression analysis identified older age (p<0.001) and female gender (hazard ratio (HR) 2.37, 95% CI 1.06–5.33, p=0.04) as independent predictors of failure. ROC analysis identified a threshold age of 47 years above which the risk of failure increased significantly (area under curve 0.72, 95% CI 0.62–0.81, p<0.001). Cox regression analysis, adjusting for covariates, identified a significantly greater (HR 2.49, 95% CI 1.26–4.91, p=0.01) risk of failure in patients aged 47 years old or more. The risk of early conversion to TKA after an opening wedge HTO is significantly increased in female patients and those older than 47 years old. These risk factors should be considered pre-operatively and discussed with patients when planning surgical intervention for isolated medial compartment osteoarthritis

Introduction. Trends in hallux valgus surgery continue to evolve. Basal metatarsal osteotomy theoretically provides the greatest correction, but is under-represented in the literature. This paper reports our early experience with a plate-fixed, opening- wedge basal osteotomy, combined with a new form of distal soft tissue correction (in preference to Akin phalangeal osteotomy). Materials and Methods. Thirty-three patients are reported here. The basal metatarsal osteotomy is fixed with the ‘Low Profile’ Arthrex titanium plate. No bone graft or filler is required, providing the osteotomy is within about 12mm of the base. Distal soft tissue correction comprised a full lateral release, and then proximal advancement of a complete capsular ‘sleeve’ on the medial side. The plate serves as a rigid anchoring point for the tensioning stitches. Using this technique, almost any degree of hallux valgus can be corrected, and there is even potential for over-correction. Functional outcome was assessed using the Manchester-Oxford foot and ankle score (MOXF). Radiographically the intermetatarsal angle was evaluated pre-operatively and at least 6 months postoperatively. Patients’ satisfaction and complication rates were recorded. Results. Clinical 87% (29 of 33) reported high satisfaction with the functional and cosmetic outcome. The opening basal wedge osteotomy slightly lengthens the first ray and as result none of our patients developed transfer metatarsalgia. Results. Radiology Hallux valgus angle (HVA) and inter-metatarsal angle (IMA) were measured on pre- and post-operative weight bearing radiographs. The radiological correction seen was very striking The mean correction of the IMA was 14 degrees; mean HVA correction was … degrees. Complications. One osteotomy was too distal, leading to a non-union, which required revision and bone grafting. Swelling and stiffness were seen in some patients, but these problems resolved steadily, with physiotherapy if needed. Discussion. This operation is a combined proximal/distal, bone/soft tissue procedure. It can obtain correction of almost any degree of hallux valgus. The slight first- ray lengthening is an advantage, as it neutralizes potential second ray problems. However, this is a very early result and long-term outcomes are as yet unknown