2015 ISAKOS Biennial Congress ePoster #1921

Medial Patellofemoral Ligament Reconstruction Femoral Tunnel Accuracy: Relationship to Disease-Specific Quality of Life

Laurie A. Hiemstra, MD, PhD, FRCSC, Banff, AB CANADA
S. Mark A. Heard, MD, FRCS, Canmore, AB CANADA
Mark Lafave, PhD, Calgary, Alberta CANADA
Mineral Springs Hospital, Banff, Alberta, CANADA

FDA Status Not Applicable

Summary: Accurate femoral tunnel placement during MPFL reconstruction may not correlate to patient-reported quality of life following surgery.

Abstract:

Background

Medial patellofemoral ligament reconstruction (MPFL-R) is a procedure aimed to re-establish the checkrein to lateral patellar translation in patients with symptomatic patellofemoral instability. Correct femoral tunnel position is thought to be crucial to successful MPFL-R but the accuracy of this statement in terms of patient outcomes has not been tested. The Banff Patella Instability Instrument (BPII) is a valid and reliable disease-specific quality of life score that has been shown to be valid, reliable and responsive to change.

Purpose

The purpose of this study was to assess the accuracy of femoral tunnel placement in an MPFL-R cohort from a high-volume sport-medicine surgery practice, and to compare tunnel accuracy to a validated disease-specific patient report quality of life outcome measure (BPII).

STUDY DESIGN: Prospective Cohort

Methods

139 subjects who had undergone an MPFL-R were assessed. Lateral radiographs were measured to determine the accuracy of the femoral tunnel. Femoral tunnel accuracy was measured in relation to Schottle’s point. Rating categories and criteria for tunnel position were standardized and defined apriori as: Ideal (0-6mm), Good (>6-12mm) or Poor (>12mm). The Banff Patella Instability Instrument (BPII) was collected at a minimum of one-year post operative.

Results

One hundred and thirty nine femoral tunnels were assessed. The mean duration of follow-up was 19.8 months (range 12-38 months). Measurement from the centre of the femoral tunnel to Schottle’s point resulted in 129/139 (92.8%) tunnels being categorized as ‘good’ or ‘excellent’. The mean distance was 6.15 mm (range 0.8-25.9) from the centre of the MPFL tunnel to the centre of Schottle’s point. The mean overall BPII score was 62.8/100 (range 13.1-98.9). The mean BPII scores by tunnel accuracy category were poor = 55.9/100 (range 33.5-98.9, n = 10), good = 66.7/100 (range 13.1-98.9, n = 46), and excellent 64.2/100 (range 17.4-97.6, n = 83). Pearson r correlation demonstrated no statistically significant relationship between accuracy of tunnel position and BPII score (r= -0.02).

Conclusions

In this prospective cohort, accurate femoral tunnels were placed greater than 92% of the time during MPFL-R. There was no evidence of a correlation between the accuracy of the femoral tunnel in relation to Schottle’s point, and post-operative disease-specific quality of life score.

CLINICAL RELEVANCE
Accurate femoral tunnel placement during MPFL reconstruction may not correlate to patient-reported quality of life following surgery. Future research should investigate the factors and characteristics that influence post-operative quality of life following MPFL_R.