Abstract
Introduction and Aims: Patellar subluxation is most troublesome and accounts for a number of complications in total knee arthroplasty. The purpose of this study is to report the incidence of need for lateral release before and after tourniquet deflation, and the effect of the tourniquet on proper patellar tracking.
Method: A total of 171 knees in 133 patients were prospectively evaluated for the need for a lateral retinacular release before and after tourniquet deflation. All knees were implanted using the same knee system. An initial group of 99 knees were evaluated with tourniquet inflation while the knee was in flexion. Tourniquet inflation with the knee in flexion versus extension was subsequently assessed in a subset group of 72 knees. The need for lateral release was determined using the rule of ‘no-thumbs’ and rule of ‘full contact’.
Results: A total of 77 knees appeared to need a lateral release before tourniquet deflation. After tourniquet deflation 27 knees required lateral release representing a 65 percent reduction in lateral release. There was no statistically significant difference (p equals 0.5506: Pearson’s chi square) when comparing the flexion/extension groups.
Conclusion: Often, the surgeon evaluates patellar tracking with the tourniquet inflated, not taking into account the effect of tourniquet pressure on the quadriceps muscle. Our findings support the hypothesis that the resulting pressure from the tourniquet impacts patellar tracking. We conclude that if patellar tracking is questionable with the tourniquet inflated, tracking should be re-assessed with the tourniquet deflated before considering a lateral release.
These abstracts were prepared by Editorial Secretary, George Sikorski. Correspondence should be addressed to Australian Orthopaedic Association, Ground Floor, The William Bland Centre, 229 Macquarie Street, Sydney, NSW 2000, Australia.
At least one of the authors is receiving or has received material benefits or support from a commercial source.
