Stiffness after total knee arthroplasty: does component alignment differ in knees requiring manipulation? A retrospective cohort study of 281 patients.

This study aims to evaluate component alignment in a large cohort of total knee arthroplasties (TKAs) and ascertain whether alignment in TKAs undergoing postoperative manipulation under anesthetic is significantly different from those achieving good function. A retrospective review of 281 consecutive primary TKAs was performed. All TKAs underwent computed tomographic scanning (Perth computed tomography knee protocol). Of 281 TKAs, 21 (7.4%) underwent manipulation, performed at a mean of 8.1 weeks (range, 3-14 weeks) after surgery. No statistically significant difference was seen between groups for any of 12 parameters of alignment. Postoperative stiffness with the need for manipulation under anesthetic is multifactorial in origin. This study found insufficient evidence to support the theory that component alignment contributes significantly to the etiology of this difficult problem.

Good alignment after total knee arthroplasty leads to faster rehabilitation and better function.

The aim of this study was to identify what aspects of implant alignment and rotation affect functional outcome after total knee arthroplasty (TKA). One hundred and fifty-nine total knee arthroplasties were performed at the authors' institution between May 2003 and July 2004. All patients underwent an objective and independent clinical and radiological assessment before and after surgery. A computed tomography scan was performed at 6 months. The alignment parameters that were measured included sagittal femoral, coronal femoral, rotational femoral, sagittal tibial, coronal tibial, and femorotibial mismatch. The cumulative error score, which represents the sum of the individual errors, was calculated. Functional outcome was measured using the Knee Society Score. Good coronal femoral alignment was associated with better function at 1 year (P = .013). Trends were identified for better function with good sagittal and rotational femoral alignment and good sagittal and coronal tibial alignment. Patients with a low cumulative error score had a better functional outcome (P = .015). These patients rehabilitated more quickly and their length of stay in hospital was 2 days shorter.