Summary
Retrospective outcomes review of 31 patients (47 knees) diagnosed with Ehlers-Danlos hyper mobility syndrome who underwent MPFL reconstructtion
Abstract
Background
Ehlers-Danlos Syndrome (EDS) patients with patellar instability constitute a tough subset of patients to treat and pose significant challenges in Orthopaedic management. There is reluctance to manage EDS patients due to higher failure rate of surgery, out of proportion pain, numerous and vague symptoms and unsolvable problems. The outcomes of isolated Medial Patellofemoral Ligament Reconstruction (MPFL-R) for patellar instability in EDS patients are not known.
Purpose
To analyze midterm clinical outcomes of isolated MPFL-R in EDS patients.
Study Design: Retrospective chart review and prospective collection of patient-reported outcomes (PROs)
Methods
In a retrospective review, 47 knees in 31 patients with EDS that underwent isolated MPFL-R for recurrent patellar instability, with minimum 2 year follow-up, were identified. Clinical outcomes, including postoperative complications, were noted. Failure was defined as the need for revision surgery for recurrent instability. Postoperative PROs (Pedi-IKDC, Kujala, HSS Pedi-FABS, BPII 2.0, and KOOS) were collected in a prospective fashion.
Results
Mean age of the cohort was 14.9 years. 27/31 (87.1%) were females. 16/31 (51.6%) had bilateral knee involvement. All patients were diagnosed with EDS by Genetics Division. 26 patients had Beighton score of 9/9. At mean follow-up of 7.2 years, 9/47 (19.1%) knees had failed MPFL-R and required revision stabilization. Another 9/47 (19.1%) required other subsequent surgeries. 7/31 knees (22.6%) with autograft failed compared to 2/16 (12.5%) with allograft (p=0.69). For autograft, 6 failures occurred with gracilis (17 knees), one with quadriceps tendon (1 knee) and none with semitendinosus (13 knees). 4/16 (25%) patients with bilateral knee involvement had recurrent instability compared to 2/15 (13.3%) with unilateral involvement (p=0.69). Patients who required revision surgery were significantly younger (p<0.05) compared to those who didn’t require revision (12.8 vs 15.4 years). There was significantly (p=0.03) increased failure rate if patients were able to touch the palm to the floor with knees extended. At mean follow-up of 5.2 years, the postoperative PROs were inferior to those reported in non-EDS population. Mean scores of PROs: Pedi-IKDC 96.2 (+/-19.8), Kujala 75 (+/-20.1), HSS Pedi-FABS 5.9 (+/-6.7), BAFF PFI 58.8 (+/-25.1), KOOS pain 76.1 (+/-22.5), KOOS symptoms 71.2 (+/-19.4), KOOS ADL 82.3 (+/-21.0), KOOS Function 64.7 (+/-29.4); best possible score for each PRO measure is 100, except HSS Pedi FABS (best is 30). Despite repeated surgery or ongoing symptoms, all but 1 patient were satisfied with index surgery.
Conclusion
Isolated MPFL-R restored patellar stability in EDS patients with 19.1% failure rate at midterm follow-up. Failure was more likely in younger patients, bilateral involvement and in those who can touch the palm to the floor with knees extended. Allograft had less failure rate than autograft. Postoperative PROs were inferior compared to non-EDS population. Patients should be adequately counselled about potential risks and complications prior to surgery.