Residual instability of the radiocapitellar joint after treatment of acute pediatric Monteggia fractures: A single-center experience.

Abstract

Pediatric Monteggia fracture-dislocations are clinically challenging injuries due to the risk of radiocapitellar joint (RCJ) instability and subluxation despite treatment. This study aims to evaluate the mid- to long-term clinical and radiological outcomes of acute pediatric Monteggia fractures and to identify factors associated with residual RCJ instability. Thirty-nine patients who met the inclusion criteria and were treated for acute pediatric Monteggia fracture-dislocation between January 2015 and December 2023, with a minimum follow-up of 2 yr, were retrospectively evaluated. Patient demographic data, fracture characteristics, treatment methods, and clinical and radiological follow-up findings were reviewed. Radiological evaluation included measurement of initial ulnar angulation, RCJ reduction, radial head displacement index (RHDI), and elbow carrying angle (CA). Clinical outcomes were assessed using the Mayo Elbow Performance Score (MEPS). Radiological parameters associated with treatment success were analyzed, and cutoff values for initial ulnar angulation were determined using receiver operating characteristic (ROC) analysis. Successful outcomes were achieved in all patients who underwent surgical treatment, whereas the success rate of conservative treatment was 68.4% (P = 0.008). Initial ulnar angulation was significantly higher in the unsuccessful treatment group. At final follow-up, the median MEPS was 80 (good) in the unsuccessful group and 90 (excellent) in the successful group (P < 0.001). Most treatment failures were observed in Bado type III fractures. ROC analysis demonstrated that an initial anteroposterior ulnar angulation greater than 32.43° had high discriminatory power for predicting treatment failure. Treatment success in acute pediatric Monteggia fractures cannot be predicted solely based on the length stability of the ulnar fracture. Increased initial ulnar angulation, particularly in Bado type III fractures, is associated with failure of conservative treatment and residual RCJ instability. Treatment planning should consider fracture morphology, ulnar alignment, and the adequacy and stability of RCJ reduction.