Patient-Reported Outcomes After Revision Surgery for Failed Medial Patellofemoral Ligament Reconstruction: A Matched-Pair Analysis Including Correction of Predisposing Factors.

ABSTRACT

BACKGROUND: Complications and the need for revision surgery after medial patellofemoral ligament reconstruction (MPFLR) are evident in the current literature. However, there is a shortage of clinical data evaluating the results of revision surgery in individual patients after failed MPFLR. PURPOSE: To investigate the results of tailored revision surgery for failed MPFLR, including the correction of predisposing factors. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Between August 2015 and March 2019, 25 patients (malefemale, n = 916; mean ± SD age, 25.9 ± 6.5 years) underwent revision surgery for failed MPFLR (study group). The Banff Patella Instability Instrument 2.0 (BPII 2.0) and a numerical analog scale (0-10) for patellofemoral pain and subjective knee joint function were used to assess patient-reported quality of life before and after revision surgery. The control group of 50 patients (malefemale, n = 1832; age, 22.8 ± 4.3 years) who underwent identical patellar-stabilizing procedures was matched 12 by the surgical procedure, predisposing factors, sex, age, and follow-up time. RESULTS: Evaluation was performed postoperatively at a mean 27.8 ± 14.0 months (range, 12-54 months) in the study group and 26.1 ± 11.2 months (range, 12-56 months) in the control group (P = .55). The BPII 2.0 score increased from 28.6 ± 17.9 points to 68.7 ± 22.3 points (P < .0001) in the study group and from 43.8 ± 22.5 points to 75.5 ± 21.4 points (P < .0001) in the control group from preoperatively to postoperatively, respectively. Before revision surgery, the BPII 2.0 scores in the study group were significantly inferior to those in the control group (P = .0026). At the final follow-up, the BPII 2.0 score in the study group was not significantly lower (P = .174), and a similar number of patients in the study group and the control group achieved the minimally clinically important difference (P = .49). Patellofemoral pain and subjective knee joint function improved significantly in both groups (P < .0001, P < .0001), without any significant difference between them at the final follow-up (P = .85, P = .86). CONCLUSION: Revision surgery for MPFLR failure, including the correction of major anatomic risk factors, yielded a significant improvement in patient-reported quality-of-life outcome measures. Patients with failed MPFLR, however, were significantly more restricted before revision surgery than patients without previous interventions when evaluated with the BPII 2.0.