Pediatric Flexor Pollicis Longus Injury: Practical Modifications of Assessment and Repair

Dear Sir, Pediatric flexor pollicis longus (FPL) injury is an uncommon entity with scarce literature pertinent to the results of repair. Although much has been inferred from the study of long flexor tendons of the other 4 digits, the FPL’s unique anatomy has been cited as justification for its independent study. The largest case series of 16 patients has reported outcome analysis using a modification of the otherwise complex Buck-Gramcko and Tubiana assessment scales.1-3 Such outcome assessment employing multiple joint angle measurement may not be practical in young children and place little emphasis on functional assessment. The Kapandji scale of thumb opposition assesses functional mobility of the thumb, but it can be difficult to employ in noncompliant pediatric patients.4 In a quest to propose a more practical pediatric assessment tool for FPL repair outcomes, we conducted a retrospective review of our practice. Seven children ranging in age from 9 months (Fig 1) to 14 years underwent primary repair of complete FPL lacerations (1 zone 1, 5 zone 2, and 1 zone 3) between 2000 and 2010 at our unit. A standard management protocol was observed in this cohort with the primary repair within 48 hours of injury, using a modified 4-strand Kessler core and Silfverskiöld epitendinous suture technique. Postoperative rehabilitation included 4 weeks of boxing glove/splint immobilization for those younger than 8 years and early active mobilization for older children. Patients received an average of 6 to 8 weeks of hand therapy and were followed up for a minimum of 3 months thereafter (mean = 9 months). Review of the hand therapy assessment charts showed challenges faced by both clinicians and hand therapists with documenting the complex joint measurements required by the existent assessment scales. We thus collaborated with specialist hand therapists to develop a functional assessment scale for more reliable and practical documentation of outcome measures in the pediatric population.