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

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.