Treatment of Scaphoid Nonunion by Surgery and Extracorporeal Shockwave Therapy

Abstract

Objective/Hypothesis: Nonunion of the scaphoid is even today a challenge for the treating hand surgeon. Main cause of a scaphoid nonunion is the missed fracture, an inadequate immobilization or a fracture in the proximal third. As a consequence, scaphoid nonunion led to an osteosclerosis at the fracture surfaces and tilting of the fracture (“humpback deformity”). These changes consequently result in the end in a carpal collapse, the so-called scaphoid nonunion advanced collapse (SNAC) wrist. Several methods for treating scaphoid nonunion are available, like sole bone graft in the technique according to Matti-Russe, with or without additional stabilization by a headless bone screw or plate. In the last decades, Extracorporeal Shockwave Therapy (ESWT) has become an established procedure for nonunion treatment. However, the mechanism of shockwave therapy is poorly understood, but it is considered verified, that it leads to angiogenesis and vasculogenesis in the treated tissue, which causes a persisting increase of blood supply. Main aim of this study was to investigate union rate and clinical outcome of a combined treatment of scaphoid nonunion by surgery and ESWT. Material and Methods: Twenty-three patients with scaphoid nonunion treated by nonvascularized bone graft from the iliac crest, followed by ESWT within 2 weeks postsurgery, were investigated. A scaphoid plate was used in 11 patients, a double cannulated compression screw (CCS) in 9 patients, and 1 CCS in 3 patients. Age, gender, range of motion (ROM), date of surgery, the last follow-up examination, and surgical technique were included in the statistical analysis. Disabilities of the Arm, Shoulder and Hand (DASH) scores, Patient Rated Wrist Evaluation (PRWE), the Green O’Brien Score, and the Michigan Hand Questionnaire score were determined for all patients. A computed tomography (CT) was performed to analyze union and signs of osteoarthritis. An existing dorsal intercalated segment instability (DISI) deformity, a SNAC wrist, or a humpback deformity were registered. Results: The mean duration of follow-up was 20 ± 10 months. In the last CT, 87% of scaphoid nonunions healed. All scaphoid nonunions treated by plate showed union at follow-up. The mean DASH score was 12 ± 13 points, PRWE 12 ± 12 points, and Michigan Hand Questionnaire score 86%. The mean Green O’Brien was 87, which indicates a good clinical outcome. The mean ROM in the sagittal plane was 88 ± 18% while forearm rotation was 98 ± 5% compared with the healthy side. Two patients had a humpback deformity and 5 a mild DISI deformity. No patient had a SNAC wrist. Conclusion: The results of this case series suggest that a combination of surgery and extracorporeal shockwave is suitable for treating scaphoid nonunion with a good functional outcome. An additional finding was that all nonunions treated by a scaphoid plate healed at follow-up.