Bifocal Patellar Tendon Avulsion Fractures in Children and Adolescents: Diagnosis and Treatment Considerations for a Unique Injury Pattern

Abstract

Purpose To highlight important diagnostic and treatment considerations in patients who present with bifocal patellar tendon avulsion fractures from the tibial tubercle and inferior patellar pole. Methods Radiographic presentation, surgical technique, and complications of 5 children who sustained bifocal patellar tendon avulsion fractures with ≥6 months postoperative follow-up were retrospectively reviewed. Hospital for Special Surgery (HSS) Brief Functional Activity Scale (HSS Pedi-FABS), Patient-Reported Outcomes Measurement Information System (PROMIS) pain interference, PROMIS mobility, and Pediatric International Knee Documentation Committee Scale (Pedi-IKDC) were assessed at most recent follow-up. Results Five children (4 boys, 1 girl) presented with bifocal patellar tendon avulsion fractures with a median follow-up of 12.8 months (range 7.7 to 26.4). In 1 case, advanced imaging was not pursued, and the bifocal nature of injury was subsequently discovered intraoperatively. In all other cases, magnetic resonance imaging (MRI) correctly characterized the bifocal injuries and revealed the full extent of fractures and soft tissue injury. Surgical management involved suture anchor repair with heavy nonabsorbable sutures. Postoperative functional and patient-reported outcomes were within the range of population healthy/normative values (for those that were available for comparison, e.g., Pedi-IKDC), and clinically relevant improvement was noted when comparing preoperative and postoperative patient-reported outcome measures of both pain and mobility. Conclusions Advanced imaging (e.g., MRI) is required to understand the full extent of injury and should be obtained in the setting of traumatic patella alta to evaluate for the presence of a bifocal lesion and plan surgical intervention accordingly. These patients demonstrate satisfactory functional and patient-reported outcomes after operative repair. Level of Evidence IV, therapeutic case series.