Background. Chronic acquired radial head dislocations pose a complex problem in terms of surgical decision making, especially if surgery has already previously failed. There are several underlying causes that should be investigated, including previous trauma resulting in a missed Monteggia fracture. Aim. To review the clinical and radiological outcomes for children up to 18 years of age, with a radial head dislocation treated with circular frame surgery. Method. A retrospective study was designed to identify patients from our departmental database who had undergone circular frame surgery to reduce the radial head during the past 6 years. Results. 20 patients were identified with a mean age of 11 years (3 – 17). Fourteen patients had a diagnosis of missed Monteggia fracture, three patients had Hereditary Multiple Exostoses, one had Nail Patella syndrome, one had Osteogenesis Imperfecta and one had rickets. The average delay between trauma and frame surgery was three years (0 – 7). All patients achieved union of their ulnar or radial osteotomy. The average frame duration was 167 days (61 – 325) and complications included delayed union and residual radial head subluxation. Thirteen patients achieved at least 40 degrees of supination, and 10 patients achieved at least 40 degrees of pronation. Eighteen patients achieved an arc of movement from full extension to at least 110 degrees of flexion. Eleven patients reported their pain level at final follow-up, of which 9 had no pain at all. Conclusion and Discussion. Circular frame surgery was a reliable and consistent method of reducing chronic radial head dislocations and improving function. Radiological appearances of mild residual subluxation of the radial head were clinically well tolerated and generally required no further treatment

Introduction. Chronic radial head dislocation in children after trauma is a serious condition. Often the dislocation is overseen initially and is a part of the Monteggia fracture complex with anterior bowing of the ulna. Typical complaints are pain, decreased ROM and cubitus valgus. Radial head dysplasia often occurs. The treatment of this condition is debated. Only few series of patients treated with open reduction and ulnar osteotomy exists with long-term follow up. We present a group of rare patients with long-time follow-up treated by only two surgeons through a period of 16 years. Materials and Methods. All 16 patients had anterior radial head dislocation (Bado type 1). Mean age at the time of traumatic dislocation was 6 years ranging from 2 to 9. We found a mean delay of 17 (range 1–83) months before open reduction and ulnar open wedge osteotomy. In 8 cases reconstruction of the annular ligament was performed and in 6 patients temporary transarticular fixation of the radial head with a k-wire was performed. Follow-up time was 8 (range 3–17) years postoperatively. Patients were investigated with bilateral x-ray, arthrosis status, congruency of the radiocapitellar joint, Oxford Elbow Score, force measurements and range of motion. Results. There were no major complications to surgery such as infection, nerve palsies or pseudarthrosis. Radiological results showed 9/16 with reduction of the radial head and with no arthrosis, 4/16 with arthrosis or subluxation, and 2/16 with a dislocated radial head. We found a significant correlation between radiological outcome and delay to ulnar osteotomy (p = 0.03). At follow up the mean Function score was 92 (SD 9), Social/psychological score 83 (SD 14) and Pain score was 88 (SD 15). None of the patients with fully reduced radial head had progressed in increased valgus deformity. In contrast, one of two patients with postoperative secondary dislocation of the radial head had an increase in carrying angle on 25 degrees. Typical clinical findings were a small but significant extension deficit and median loss of supination on 10 grades ranging from 0–90 (p = 0.008). Five patients had subsequent surgery, of which one had an excision of the radial head 8 years after primary surgery. Ligament reconstruction or transfixation of the radial head did not influence the radiological or clinical outcome. Discussion and Conclusion. Case reports of similar patients treated conservatively demonstrate high morbidity and therefore open reduction and ulnar osteotomy is justified given the good clinical longterm outcome in the present study. However, this study underlines the importance of minimising the delay between trauma and open reduction. If surgery is performed before 40 months after trauma good to fair longterm radiological results can be obtained. After 40 months there is a high risk of recurrent luxation of the radial head