O2101: Isolated Medial Patellofemoral Ligament Reconstruction With and Without Bony Patellar Fixation In Young Patients - A Multicenter Comparison of Three Operative Techniques

Background: Various techniques have been described for medial patellofemoral ligament reconstruction (MPFLR) in the setting of patellofemoral instability (PFI). Most rely on bony patellar-sided fixation, carrying the small but not insignificant risk of iatrogenic patellar fracture as well as implant cost. Alternative soft tissue patellar-sided fixation options have been described, but comparisons with traditional techniques are limited. The purpose of this study was to compare postoperative complication and risk of recurrent instability among three MPFLR techniques in a multicenter population young PFI patients.

Methods: A retrospective comparative study was conducted from 2010-2021 at two large tertiary care pediatric hospitals identifying child and adolescent (≤19) who underwent isolated MPFLR. Patients were grouped based on patellar fixation: (1) allograft bony patellar fixation (BPF) with suture anchors or interference screws, (2) autograft quadriceps tendon turndown (QTT), and (3) allograft modified basketweave (MBW). The latter two techniques utilize suture-based fixation of the graft to the anterior patellar periosteum. Patient demographics, preoperative imaging measures, postoperative complications, and need for subsequent stabilization surgery were recorded. Treatment groups were compared with univariate testing.

Results: We identified 217 patients undergoing isolated MPFLR (83 BPF, 98 QTT, 36 MBW) who had a mean age of 15.3+/-2.36 years (8.0 - 18.9 years) and were predominantly female (60%). All baseline characteristics and preoperative imaging measures were similar between treatment groups (Table 1) except for sex distribution (p=0.017). At a mean follow-up of 1.62+/-1.63 years, there was a 6% overall rate of early postoperative complication (BPF 8%, QTT 6%, and MBW 8%), and a 13% rate of persistent subluxation or dislocation (BPF 16%, QTT 10%, and MBW 14%) of which 3.7% (BPF 3.6%, QTT 3.1% and MBW 5.6%) required revision surgical stabilization. There were no significant differences in the rate of complications or subsequent surgical treatment among treatment groups (p>0.05).

Conclusion: This large, multicenter cohort of adolescents and young adults undergoing isolated MPFLR identified no significant difference in the rate of complications or persistent instability following surgical reconstruction among the three compared operative techniques. Our findings indicate that soft-tissue patellar fixation techniques demonstrate comparable risk profile and early outcomes to bony fixation options. Given the risks and costs of bony constructs in the setting of the evolving patellar ossification in skeletally immature patients, pediatric surgeons may safely consider these alternative options for patellar-sided MPFLR fixation.