Abstract
Objectives:
Patellofemoral instability (PFI) commonly requires surgical intervention in adolescent and young adult athletes. However, the clinical impact of graft selection, which may vary amongst surgeons, has not been well studied. The purpose of this study was therefore to compare clinical outcomes, including recurrent instability reoperations and complications, of medial patellofemoral ligament reconstruction (MPFLR), based on graft type.
Methods:
Electronic medical records of patients who underwent primary MPFLR surgery for PFI over a 10-year period between 2010 and 2019 at a single center were retrospectively reviewed. Collected data included demographic, clinical, and radiologic parameters of instability and post-operative clinical outcomes. Exclusion criteria included concomitant extensor realignment procedures (tibial tubercle osteotomy, patellar tendon transfer procedures) and factors that would alter routine surgical indications or technical approaches, such as fixed or syndromic PFI, osteochondral shear fractures undergoing fixation or >1 cm in diameter, and prior ipsilateral knee surgery.
Results:
One-hundred and one patients (average age 15.2 years, 63% female), underwent primary isolated MPFLR with an average follow up time of 2.87 years. There were no significant differences in demographic and radiographic parameters between autograft and allograft, other than more semitendinosus grafts, increased number of pre-op dislocation events, and higher sulcus angle in autograft (Table 1). The autograft group had a higher rate of recurrent instability (41% vs 14%, p = 0.01) but no significant difference in return to sport, complications, and reoperations (Table 2). Reoperations for recurrent instability were performed in 9% of all patients (Table 3). Subgroup analysis of allograft tendon type demonstrated more dislocations and recurrent instability in gracilis than semitendinosus, though these differences were not statistically significant, and there was no difference in recurrent instability surgery or complications (Table 4).
Conclusions:
In adolescent and young adult athletes undergoing isolated primary MPFLR for PFI, allograft may be associated with decreased rates of recurrent instability compared to autograft. While trends towards higher recurrent instability were detected with gracilis allograft, compared to semitendinosus allograft, the precise role of allograft tendon type would benefit from future studies with larger sample size to better elucidate its impact on clinical outcomes.
