MPFL reconstruction reduces recurrent patellar instability fivefold in adolescents
Compared with repair or no treatment, medial patellofemoral ligament reconstruction yielded the best outcomes in adolescent patients with an acute first-time patellar dislocation and an associated intra-articular loose body.
At Rady Children’s Hospital in San Diego, Pradyuma Gurusamy, MD, and colleagues performed a prospective analysis of 30 adolescent patients with acute first-time patellar dislocations and associated loose bodies who underwent MPFL reconstruction between 2015 and 2017. Researchers retrospectively analyzed data from a matched cohort of 46 adolescent patients – also with acute first-time patellar dislocation and associated loose bodies – who underwent either MPFL repair or no treatment.
According to the study, minimum follow-up was 2 years. Outcome measures included recurrent subluxation, recurrent dislocation, need for further stabilization, Kujala score, single assessment numeric evaluation score, patient satisfaction and return to sport.
Despite no differences in patient-reported outcome measures between the cohorts, Gurusamy and colleagues found MPFL reconstruction was associated with fewer instances of recurrent instability (10%), fewer secondary procedures (6.7%) and faster return to sport (66.7%) compared with a combined rate for MPFL repair or no treatment (58.7%, 47.8% and 39.1%, respectively).
“The standard of care for the majority of patients with a first-time dislocation is nonoperative treatment,” the researchers wrote in the study. “The rate of recurrent dislocation in these patients may be up to 61% if the MPFL is repaired or not addressed surgically,” they added.
MPFL reconstruction in this adolescent population results in a “[fivefold] reduction in recurrent instability, reduces the need for subsequent surgery and improves patients’ ability to return to sports compared with repairing or not treating the MPFL,” Gurusamy and colleagues concluded.
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In the study by Gurusamy and colleagues, they looked at rate of recurrent patellar instability, the need for further stabilization procedures and the ability to return to sport in young patients with a first-time patellar dislocation who required surgery for a loose body. They compared those who underwent MPFL repair or no treatment with those who underwent an MPFL reconstruction during the index procedure. Their idea for the research study stemmed from a previous article by the similar authors in 2019 showing that in children or adolescents who undergo loose body removal or fixation without MPFL reconstruction, the rate of recurrent patellar instability was 61%.
The results of this study showed that patients who were stabilized acutely with MPFL reconstruction had a significantly lower risk of recurrent instability and required fewer subsequent surgeries. Those patients were also more likely to return to sports at a minimum of 2-year follow-up. The focus of the study and the difference between other published studies is on the intra-articulate loose body after the dislocation. In this study, regardless of how the MPFL was managed, most patients had their loose body removed, but 24% underwent fixation. The rates of fixation of the loose bodies were not different between the MPFL repair/no-treatment group and the MPFL reconstruction group.
It is well known that young patients with first-time patellar dislocations do well with conservative management, as long as there is no associated chondral or loose body injury. Especially in children, loose bodies after patellar dislocations can encompass a large portion of the patellar chondral surface and have a good chance of healing with an acute repair of the cartilage fragment.
I believe this is a good study showing that if you are considering operating on a young patient with a first-time patellar dislocation and a loose body, that performing an MPFL reconstruction is better than just a loose body removal, an MPFL repair or doing nothing. Although some of the risks of doing an MPFL reconstruction include stiffness with poor graft positioning and/or growth plate injury in children with open physes, the overall risks of doing an MPFL reconstruction surgery do not outweigh the benefits of a patellar stabilization surgery with a properly placed MPFL reconstruction.
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I want to further emphasize what Dr. Bicos is saying. MPFL surgery must be anatomic to be better than nonoperative. Some of the worst problems I see are poorly done MPFL reconstructions. Anatomic graft placement is imperative. If there is any doubt about knowing the anatomy, just remove the loose body.
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