Ulnar lengthening for forearm deformities in hereditary multiple exostoses: a systematic review and meta-analysis (2015–2025)

BACKGROUND: Hereditary multiple exostoses (HME) is an autosomal dominant skeletal disorder frequently associated with progressive forearm deformities, including ulnar shortening, radial bowing, and radial head dislocation. Ulnar lengthening using distraction osteogenesis has become the principal surgical strategy; however, outcomes, techniques, and complication profiles vary across studies. This systematic review and meta-analysis synthesize contemporary evidence on radiographic correction, functional outcomes, and complications following ulnar lengthening for HME-related forearm deformities. METHODS: statistic. RESULTS: = 58%). Radial head reduction was achieved in 76% of affected forearms. Functional outcomes improved significantly, with DASH scores decreasing by a pooled mean of 12.7 points (p < 0.001). The overall complication rate was 18.1%, with most complications being minor and manageable. CONCLUSIONS: Ulnar lengthening via distraction osteogenesis provides effective radiographic correction and meaningful functional improvement in patients with HME-related forearm deformities, with acceptable complication rates. Monolateral external fixation is the most commonly employed technique and yields reliable outcomes. Despite encouraging results, the evidence base is limited to observational studies with heterogeneous reporting, underscoring the need for prospective studies with standardized outcome measures and longer follow-up.