COLORADO SPRINGS, Colo. — Patients who underwent isolated medial patellofemoral ligament reconstruction maintained outcomes at 5 years with low recurrent instability rates and high return to sport rates, according to results presented here.
“Completion of the study enrollment with long-term follow-up will allow for a more robust assessment of long-term outcomes and incidence of recurrent instability events after isolated MPFL reconstruction,” Elizabeth Dennis, MD, said in her presentation at the American Orthopaedic Society for Sports Medicine Annual Meeting.
Dennis and colleagues retrospectively collected baseline demographics, recurrent instability events, return to sport rates, knee-specific patient-reported outcome measures and radiographic measurements of 138 patients who underwent isolated MPFL reconstruction for treatment of recurrent patellar instability from March 2014 to December 2019.
“One hundred and nineteen patients reached the greater than 2-year time point, of which we had 75% completed follow-up. And 50 patients reached the greater than 5-year timepoint, of which 80% completed follow-up,” Dennis said.
Dennis noted a statistically significant improvement in all patient-reported outcome measures, except for the pediatric functional activity brief scale, which had no change over time. Patients had an average tibial tuberosity-trochlear groove distance (TT-TG) of 15.1, a Caton-Deschamps index of 1.1, a trochlear depth index of 2.5, a patellar tendon-lateral trochlear ridge of 5.7 and a trochlear tuberosity-lateral trochlear ridge of 8.4, according to Dennis.
“There were six patients who experienced recurrent instability during these 5 years-plus follow-up time,” Dennis said. “The mean time to recurrent instability event was 2.97 years. The redislocation rate was 2% and the resubluxation rate was 4%.”
Although all but one patient had a TT-TG greater than 15, Dennis noted the one patient with low TT-TG had significant patellar alta with a Caton-Deschamps of 1.45.
Of the 100 patients who participated in sports prior to surgery, 89% were able to return to sport and 84% were able to return to sport at the same or higher level, according to Dennis.
“All patients returned to sport within 2 years, with a mean time of 9.1 months,” Dennis said. “Notably, five patients did not participate in sports prior to surgery, but after surgery were able to participate in sports.”