Component alignment and clinical outcome following total knee arthroplasty: a randomised controlled trial comparing an intramedullary alignment system with patient-specific instrumentation.

AIMS: We conducted a randomised controlled trial to assess the accuracy of positioning and alignment of the components in total knee arthroplasty (TKA), comparing those undertaken using standard intramedullary cutting jigs and those with patient-specific instruments (PSI). PATIENTS AND METHODS: There were 64 TKAs in the standard group and 69 in the PSI group. The post-operative hip-knee-ankle (HKA) angle and positioning was investigated using CT scans. Deviation of > 3° from the planned position was regarded as an outlier. The operating time, Oxford Knee Scores (OKS) and Short Form-12 (SF-12) scores were recorded. RESULTS: There were 14 HKA-angle outliers (22%) in the standard group and nine (13%) in the PSI group (p = 0.251). The mean HKA-angle was 0.5° varus in the standard group and 0.2° varus in the PSI group (p = 0.492). The accuracy of alignment in the coronal and axial planes and the proportion of outliers was not different in the two groups. The femoral component was more flexed (p = 0.035) and there were significantly more tibial slope outliers (29% versus 13%) in the PSI group (p = 0.032). Operating time and the median three-month OKS were similar (p = 0.218 and p = 0.472, respectively). Physical and mental SF-12 scores were not significantly different at three months (p = 0.418 and p = 0.267, respectively) or at one year post-operatively (p = 0.114 and p = 0.569). The median one-year Oxford knee score was two points higher in the PSI group (p = 0.049). CONCLUSION: Compared with standard intramedullary jigs, the use of PSI did not significantly reduce the number of outliers or the mean operating time, nor did it clinically improve the accuracy of alignment or the median Oxford Knee Scores. Our data do not support the routine use of PSI when undertaking TKA. Cite this article: Bone Joint J 2016;98-B:1043-9.

Operative and non-operative treatment options for dislocation of the hip following total hip arthroplasty.

BACKGROUND: Dislocation following hip replacement is associated with significant morbidity and functional cost. The cause is usually multifactorial. A variety of treatment options are available which can broadly be classified into operative and non-operative. OBJECTIVES: To determine the best methods of treatment of recurrent dislocation following total hip replacement. SEARCH STRATEGY: The following databases were searched until August 2006: MEDLINE, EMBASE, CINAHL, the Cochrane Central Register of Controlled Trials (CENTRAL), Health Technology Assessment database (HTA), Database of Abstracts of Reviews of Effectiveness (DARE), International Standard Randomised Controlled Trial Number Register (ISRCTN), and MetaRegister of Controlled Trials (mRCT). SELECTION CRITERIA: Randomised and quasi-randomised trials comparing operative and non-operative treatments for recurrent dislocation following total hip replacement. DATA COLLECTION AND ANALYSIS: Two independent reviewers applied the inclusion criteria to identified studies. MAIN RESULTS: Searches identified 269 studies. None fulfilled the inclusion criteria. AUTHORS' CONCLUSIONS: The authors invite researchers to perform RCTs comparing different treatment options for recurrent dislocation of the hip. The heterogeneity of the population and variety of underlying causes would favour a multi-centre study to achieve an adequate sample size.