Characterization and treatment of symptomatic bipartite patella in pediatric, adolescent, and young adult patients: a large case series.

INTRODUCTION

Bipartite patella (BPP) results from ossification center fusion failure during development. Treatment of symptomatic BPP varies and may include nonoperative management or surgical interventions. However, characteristics distinguishing symptomatic from asymptomatic and operative from nonoperative BPP remain unclear. This study presents a large case series of pediatric, adolescent, and young adult patients with symptomatic BPP and assesses the association between radiographic characteristics and symptomatology.

METHODS

We retrospectively reviewed patients ≤21 years diagnosed with BPP or multipartite patella at a single tertiary care hospital from January 2016 to September 2024. Among 73 knees (70 patients), 23 (32 %) were symptomatic. Saupe classification and fragment-to-patellar ratios were obtained from imaging. Radiographic measurements were compared using t tests or Mann-Whitney U tests.

RESULTS

No differences in age, sex, laterality, or fragment size were found between asymptomatic and symptomatic BPP. Of 23 symptomatic knees, 15 (65 %) were treated nonoperatively and 8 (35 %) operatively. Operative patients were older than nonoperative patients (15.3 ± 2.1 vs. 11.3 ± 3.0 years, P = 0.002). All symptomatic patients played at least one sport and, on average, presented with PROMIS mobility, pain interference, physical activity, and HSS Pedi-FABS scores of 38.8 ± 5.8, 52.9 ± 7.8, 47.9 ± 14.2, and 27.0 ± 4.0. There was no significant correlation between preoperative PROMs and fragment size, and no differences in symptom duration or fragment size between nonoperative and operative patients. All 8 operative extremities ultimately underwent fragment excision.

CONCLUSIONS

Most symptomatic BPP were managed nonoperatively. Radiographic features did not distinguish symptomatic from asymptomatic or operative from nonoperative cases. Larger studies are needed to refine treatment algorithms and reduce reoperations.