Humerus Lengthening With the PRECICE Internal Lengthening Nail.

BACKGROUND Deformity and growth arrest of the humerus in children may result as sequelae of proximal humerus fractures and unicameral bone cysts, or as complications of their treatment. As approximately 80% of the growth of the humerus arises from the proximal physis, the resultant upper limb-length discrepancy can be substantial. Benefits to lengthening the shortened arm have been previously demonstrated with the use of external fixation devices. To our knowledge, no reports have been published on the use of intramedullary implants for this purpose. METHODS A 15-year-old girl with humeral shortening secondary to proximal humeral growth disturbance following treatment for a unicameral bone cyst was treated with humeral osteoplasty and gradual lengthening with an off-label use of a fully implantable motorized intramedullary lengthening nail. A varus proximal humeral deformity and lateral starting point allowed for avoidance of the rotator cuff insertion. RESULTS Humeral lengthening (5 cm) was achieved at 9 weeks, with bony union at 7 months, and hardware removal at 9½ months. Shoulder and elbow motion was maintained during and after treatment. CONCLUSIONS This is the first case report of humeral lengthening using a fully implantable motorized intramedullary lengthening nail. Although some technical limitations remain when compared with other methods, the procedure was well tolerated throughout the course of treatment. LEVEL OF EVIDENCE Level IV-case report.