Outcomes of surgical stabilization in patients with combined ACL deficiency and patellofemoral instability - A case series.

BACKGROUND: The purpose of this study was to assess the disease-specific quality of life, and the objective clinical and functional outcomes of patients with symptomatic ACL deficiency and patellofemoral instability following surgical stabilization of both ligaments.

METHODS: Between February 2010 and August 2013, 22 subjects underwent a combined ACL reconstruction and patellofemoral stabilization. The anterior cruciate ligament quality of life questionnaire (ACL-QOL) was completed pre-operatively and two-years post-operatively. Clinical and functional assessments were performed two-years post-operatively. A paired t-test assessed the difference between the pre- and post-operative ACL-QOL scores. Effect size was calculated manually using the Eta squared formula. A Pearson r correlation coefficient assessed for a relationship between the post-operative ACL-QOL scores and functional tests.

RESULTS: Twenty patients completed the 24-month ACL-QOL, 17/20 completed clinical assessment, and 14/20 completed functional testing. The mean pre-operative ACL-QOL score was 21.20 (SD=7.25, range 5.8 to 31.7) and two-years post-operative it was 65.24 (SD=21.38, range 34.5 to 99.1). The paired t-test demonstrated a statistically significant improvement in ACL-QOL scores; t (19)=9.119, p<.001 (two-tailed). The Eta squared statistic (0.81) indicated a very large effect size. Statistically significant correlations (p<.05) were evident between post-operative ACL-QOL scores and all the operative limb single-leg hop tests.

CONCLUSIONS: Combined ACL reconstruction and patellofemoral stabilization surgery leads to good results. This patient cohort with chronic ACL-MPFL injuries demonstrated a statistically significant change in disease-specific quality of life following surgery. In addition, the patient-reported outcomes and objective functional testing results correlated.

LEVEL OF EVIDENCE: Case series - IV.