Patient Characteristics and Postoperative Outcomes of Surgically Treated Inferior Pole Patellar Sleeve Fractures.

Background: Despite representing over half of all pediatric patella fractures, inferior pole patellar sleeve fractures (PSFs) are a relatively uncommon pediatric injury. As a result, existing literature on PSFs is limited to case reports and small case series. The purpose of this study was to evaluate the radiographic and clinical characteristics of operatively treated PSFs as well as outcomes following surgical management.

Methods: A retrospective review of all inferior pole PSFs requiring surgery from 2007 to 2023 was performed at a single urban tertiary care children's hospital. Cases were identified using diagnostic and billing codes. Patient demographics, injury characteristics, surgical techniques, and postoperative rehabilitation practices were recorded. Regional skeletal maturity, fracture characteristics, and postreduction patellar height were recorded. Postoperative complications were recorded and categorized using the modified Clavien-Dindo Classification System (CDS).

Results: Thirty-eight inferior pole PSFs were identified meeting study criteria. The majority of patients were male (86.8%), and the mean age at injury was 11.0 years (range: 7.2 to 15.0). Mean BMI was 21.1. Radiographically, the majority of patients were Epiphyseal Fusion Stage 0 (nonunion), with a median postreduction Caton-Deschamps index (CDI) of 1.2 (IQR: 1.1 to 1.3). These fractures were predominantly treated with suture-based fixation (84%). Postoperative immobilization varied within the cohort, and the initiation of knee ROM was permitted at a median of 3.5 (IQR: 2.0 to 4.6) weeks. All patients regained full range of motion and straight leg raise without extensor lag, and return-to-sport was achieved by a median of 17.6 weeks (IQR: 12.8 to 30.3). Complications occurred in 10 (26.3%) patients, with 3 (7.9%) requiring a return to the OR (CDS Grade III).

Conclusions: Inferior pole PSFs appear to occur most commonly among prepubertal males of normal BMI and normal patellar height. Despite variable rehabilitation protocols, operative management resulted in restoration of extensor mechanism function. Eight percent of patients experienced complications requiring unplanned surgery. This large series improves our understanding of the epidemiology, injury characteristics, and postoperative outcomes of an operatively treated cohort of a rare injury pattern.

Level of evidence: Level IV.