The consequences of lateral release in total knee replacement: a review of over 1000 knees with follow up between 5 and 11 years

Abstract

Background: The relationship between lateral release in total knee arthroplasty and subsequent patello-femoral problems is contentious. Variable rates of instability, patella fracture and other complications have been demonstrated after lateral release. Significant measures have been taken by some surgeons to avoid a lateral release. We wished to determine whether lateral release was detrimental or beneficial in terms of mid- to long- term patellofemoral problems. Methods: We examined 1071 total knee arthroplasties with a follow-up of 5 to 11 years to determine the longer-term consequences of lateral release. Lateral release was performed as clinically indicated after a ‘no thumbs’ assessment in 51% of cases. The knees requiring a lateral release had lower pre-operative Hospital for Special Surgery (HSS) scores and demonstrated a greater improvement in post-operative HSS scores. Results: The difference in HSS scores, between the groups, was significantly less post-operatively than prior to surgery. Overall, we had a high incidence of lateral release (51%), but low fracture rate (1.2%), and very low instability rate (0.6%). Only three surgeries were required for patello-femoral problems. Conclusion: This study suggests that any negative consequences of lateral release are minimal and we recommend lateral release continue to be performed as clinically indicated.

Introduction

The relationship between lateral release in total knee replacement and patello-femoral problems is contentious [7], [9], [13], [14], [24], [27], [30], [31], [36], [37], [38]. Both an increase [31] and a decrease [30], [7] in patella fracture rate have been demonstrated after lateral release. Changes in the blood supply of the patella, after a lateral release, may be related to fracture incidence [20], [24], [34], [32], [36]. Patella fractures have been associated with mal-alignment [8], [13], [22], [25], [26], [29], surgical technique [5], [6], [7], [11], [18], [24], [27], [33], thermal necrosis [2], [8], [11], [14] and prosthetic design [2], [5], [8], [16], [33], [35], [39].

Measures have been taken to avoid a lateral release, including external rotation particularly of the femoral component [12] and the subvastus approach [13]. Others have performed a lateral release with attempted preservation of the superior lateral geniculate artery [3], [9], [12], [13], [18], [25], [27], [35] [37], [38].

We studied a series of over 1000 total knee replacements with two surgeons working together with a single prosthetic design and uniform surgical technique. We wished to determine whether lateral release was detrimental or beneficial in terms of mid- to long- term patellofemoral problems.