Mason Type I Fractures of the Radial Head

Mason type I fractures are the most common fractures of the radial head. The fractures have a benign character and often result in good, pain-free function. Nevertheless, up to 20% of patients with a Mason type I fracture report loss of extension and residual pain. Currently, there is a lack of consensus concerning diagnosis and treatment of these fractures. The goal of this study was to systematically review incidence, diagnosis, classification, treatment, and outcome of Mason type I radial head fractures in adults and establish an evidence-based treatment guideline. A search of the MEDLINE, EMBASE, and Cochrane databases was conducted for English titles without restrictions on publication date. The authors included titles that addressed Mason type I radial head fractures and covered incidence, diagnostics, treatment, or functional or patient-related outcome. Included were randomized controlled trials; case-control studies; comparative cohort studies; case series with more than 10 patients; and expert opinions. Reference lists were cross-checked for additional titles. The search yielded 1734 studies, of which 95 met the inclusion criteria. Seven studies showed that the elbow extension test has a high sensitivity (88.0-97.6) to rule out Mason type I radial head fractures. If radiography is required, antero-posterior and lateral radiographs suffice. For pain relief, hematoma aspiration seems safe and effective. Mason type I fractures are best treated with 48 hours of rest with a sling, followed with active mobilization. Cast immobilization should be avoided. Mobilization should be encouraged and if needed supported by physical therapy.