Mobilization of a Congenital Proximal Radioulnar Synostosis with a Vascularized Fascio-fat Graft in 104 Forearms of 87 Patients: Level 4 Evidence

Abstract

There is no financial information to disclose. Congenital proximal radioulnar synostosis is a rare congenital anomaly characterized by a fixed forearm rotation. It has the high tendency toward re-ankylosis after separation without interposition between separated radius and ulna. Can the congenital radioulnar synostosis be mobilized? If so, what is the safe and simple procedure for mobilization? We performed mobilization procedures for 104 forearms in 87 patients. Through a posterior incision, the synostosis was exposed and separated with a high-speed burr. After separation, osteotomy of the radius was performed to reduce the dislocated radius head. After that, a vascularized fascio-fat was interposed between separated radius and ulna. Four different procedures were used to interpose the vascularized fat. A free vascularized fascio-fat graft (FVFG) was used in 26 forearms, a pedicle forearm fascio-fat graft with one incision (PVFG-1) in 25, a pedicle forearm fascio-fat graft with both anterior and posterior incisions (PVFG-2) in 26, and a pedicle upperarm fascio-fat graft in two incisions (PVFG-3) in 27. The mean age at the surgery was 8.1 years (range, 5.1 to 13 years), 7.4 years (range, 4.3 to 10.9 years), 7.8 years (range, 4 to 14 years) and 6.0 years (range 4.5 to 6.0) respectively. Preoperative forearm ankylosis was 34.8 degrees of pronation in FVFG, 39.3 degrees in PVFG-1, 40.2 degrees in PVFG-2, and 37.4 degrees in PVFG-3. They were followed-up more than 2 years after surgery. All patients reported improvements in performing some activities, such as catching a ball, accepting objects such as coins, holding a bowl of soup, and performing gymnastics. Four re-ankyloses were observed among 104 mobilizations. The mean range of active forearm rotation (mean ± SD) after mobilization was 81.6 ± 15.8 degrees in FVFG, 75.4 ± 23 degrees in PVFG-1 excluding 3 re-ankyloses, 71.1 ± 27.4 degrees in PVFG-2, and 70.2 ± 25.4 degrees in PVFG-3 excluding 1 re-ankylosis. The average surgery time was 9.8 ± 0.79 hours in FVFG, 4.3 ± 2.0 hours in PVFG-1, 3.9 ± 1.3 hours in PVFG-2, and 4.2 ± 1.7 hours in PVFG-3. •This mobilization procedure prevented re-ankylosis after separation of the synostosis and provided some forearm rotation that improved a child's daily activities.•Mobilization with a pedicle fascio-fat graft shortened the surgery time than those with free vascularized fascia-fat graft.•Two-incision technique could securely fasten PVFG to the space between separated radius and ulna and may prevent re-ankylosis.