Isolated Medial Patellofemoral Ligament Reconstruction Can Be an Effective Procedure in Patellofemoral Instability with Risk Factors

Abstract

Patellofemoral instability is a severe problem in young and active patients. This pathology is influenced by ligamentous, bony, and neuromuscular parameters. The reconstruction of the medial patellofemoral ligament (MPFL) evolved to a primary procedure, but combined procedures were more frequently performed in the past years. However, additional operative procedures are associated with increased morbidity and no absolute indication can be identified in the literature. This study is intended to clarify whether addressing only ligamentous influence factors (MPFL) in chronic patellofemoral instability is sufficient to produce good clinical outcomes, or whether other risk factors influence the results negatively and should also be treated at some point. In 52 patients with chronic patellofemoral instability patellar height according to Caton-Deschamps, trochlear dysplasia according to Dejour, the leg axis, the femoral antetorsion, tibial tubercle (TT)–trochlear groove, and TT–posterior cruciate ligament distance were evaluated. All patients were treated with isolated MPFL reconstruction. After a minimum follow-up period of 24 months (24–36 months), the clinical outcome results were calculated using the scoring system according to Lysholm and Tegner. Correlation between clinical outcome scores and anatomic risk factors were calculated. The analysis was performed using a standard statistical software package (JMP version 12, SAS Institute, Cary, NC). The average postoperative Lysholm score increased significantly from 57.23 ± 19.9 to 85.9 ± 17.2 points (p < 0.0001) after isolated MPFL reconstruction. Moreover, the Tegner and Lysholm scores significantly improved both in patients without and with different risk factors postoperative. There were no significant differences in the outcome sores between the groups. Even the degree of trochlear dysplasia (types I–III) did not influence the results. Finally, there was no significant correlation found between all collected risk factors and the postoperative outcome scores. Isolated MPFL reconstruction can be an effective procedure in patients with patellofemoral instability and mild to moderate risk factors.

Identifying Patients With Patella Alta and/or Severe Trochlear Dysplasia Through the Presence of Patellar Apprehension in Higher Degrees of Flexion

“…12 Commonly cited clinical thresholds for bony procedures include a TT-TG distance of greater than 16 mm or a CD index of greater than 1.2; however, the original surgical "a la carte menu" that established these criteria predates the surgical option of MPFL reconstruction. 8 There are few outcome studies of MPFL reconstruction evaluating the influence of TT-TG distance and patella alta on isolated MPFL reconstruction; however, several recent retrospective cohort studies 4,10,15,18,24 have demonstrated little influence of TT-TG distance and moderate patella alta on the outcomes of MPFL reconstruction. These studies suggest that isolated MPFL reconstruction can be successful in cases with a higher CD index and TT-TG distance than previously thought.…”

“…8 Patients with patella alta as defined by a Caton-Deschamps (CD) index of greater than 1.2 may be candidates for tibial tubercle distalization, 8 those with severe trochlear dysplasia may be candidates for trochleoplasty, 2 and those with an elevated TT-TG distance may benefit from tibial tubercle medialization. 8 These indications remain controversial, and several recent studies 4,10,15,18,24 have demonstrated good outcomes of isolated MPFL reconstruction in patients with some anatomic risk factors.…”

Medial Patellofemoral Ligament Reconstruction With or Without Derotational Distal Femoral Osteotomy in Treating Recurrent Patellar Dislocation With Increased Femoral Anteversion: A Retrospective Comparative Study

“…Recently, another study supported the view that the isolated MPFL-R could be effective in treating RPD with bony risk factors, including increased FAA. 1…”

Preoperative Complete Patellofemoral Dislocation in Extension Predicts an Inferior Clinical Outcome After Medial Patellofemoral Ligament Reconstruction in Patients With Recurrent Patellar Dislocation

“…Over the past decade, medial patellofemoral ligament (MPFL) reconstruction (MPFL-R) has been considered the most effective treatment for recurrent patellar dislocation (RPD), with a low redislocation rate. 1,2,10,13,19 However, because of the structural complexities of this disorder, unfavorable clinical outcomes after MPFL-R have also been reported recently. 23 It has been reported that isolated MPFL-R does not considerably improve patellar tracking or restore patellofemoral kinematics.…”