Kinematic alignment has increased in popularity over the last few years in an attempt to improve clinical outcomes following total knee arthroplasty (TKA). In our unit kinematic alignment has been used with patient-specific cutting guides as part of on-going clinical trials. We performed a retrospective analysis on all the TKA which had been planned to be implanted outside of the mechanical axis (0° ± 3°) based on pre-operative MRI scans and looked at their radiographic and clinical outcomes. We identified 21 knees which had been implanted as ‘planned outliers’. All had clinical and radiographic follow up to a mean 11.6 months post op. All had a standard long leg alignment radiograph performed at 6 weeks post op to confirm alignment. All patients had a good improvement in their Oxford Knee Scores with mean improvement from 23 pre-op to 42 at 1 year. Of our patients none had a poor clinical outcome due to the alignment of their TKA, 1 patient had a poor outcome because of a quadriceps rupture which occurred 4 months post-op. There were no post-operative radiographic abnormalities. In our unit kinematic alignment outside of the mechanical axis is not associated with an increased rate of short term complications.
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.
