Comparative Outcomes of Treatment Strategies for Traumatic Distal Humerus Physeal Separation in Children: A Systematic Review.

Background: Distal humerus physeal separation (DHPS) presents a rare injury type in young children often associated with misdiagnosis and delayed treatment. The aim of this study was to summarize all the available current evidence regarding the management and outcome of DHPS and determine the incidence of complications and particularly the cubitus varus deformity and avascular necrosis of the trochlea. Methods: A systematic review was conducted under the PRISMA guidelines. Medline/Pubmed, Scopus, Web of Science, and Cochrane were searched for studies dealing with children suffering from traumatic DHPS. Results: Twelve studies with a total of 257 children with DHPS were included for analysis. The mean age was 16.8 months (range: 0.1-46 months) with a mean follow-up of 37 months (range: 0.5-516 months). Non-accidental trauma was reported in 17.2% and misdiagnosis at initial assessment in 7.8%. Closed reduction and percutaneous pinning (CRPP) was the treatment of choice in 54.4%, open reduction and percutaneous pinning (ORPP) in 26.5%, closed reduction and cast immobilization (CR+cast) in 10.9%, and cast immobilization without reduction in 8.2%. The average range of extension-flexion arc was 2.1° to 127.8° (range: -10-140°). The mean Bauman's angle was 72.4° (range: 66-79°), the mean shaft-condylar angle was 43.8° (range: 25-59°), the mean humeral length was 21.9 cm (range: 15.5-25.8 cm), and the mean carrying angle was 5.1° (range: 16° varus-19° valgus). According to Flynn's criteria, 85.2% of cases were classified as excellent or good. The ORPP technique was associated with excellent results, while the CR+cast treatment combination was correlated with the poorest outcome (p = 0.001). Cubitus varus occurred in 18.9% (34 cases) and was highly correlated with CR+cast or cast immobilization alone without fracture reduction (p = 0.014). Avascular necrosis of the trochlea was found in 3.9% (7 cases) and was mainly apparent after cast immobilization without reduction (p < 0.001). Conclusions: Post-traumatic cubitus varus deformity may be encountered in approximately one-fifth of young children with DHPS. Surgical intervention with either CRPP or ORPP is the most effective treatment approach, leading to superior functional outcome and a lower complication rate.