Review Question - QID 217893

This soldier sustained a scaphoid fracture over one year ago and has gone onto scaphoid nonunion. Open reduction internal fixation with bone grafting is considered an appropriate first-line treatment.

It is important to diagnose and treat scaphoid nonunions in order to prevent the characteristic progressive degenerative changes of the wrist labeled scaphoid nonunion advanced collapse (SNAC). The goals of treatment for scaphoid nonunion include union, correction of deformity, alleviating symptoms, and limiting the risk for degenerative changes. While some patients may be treated with casting and immobilization alone, they require prolonged (4-6 months) of cast immobilization and have a high risk of treatment failure compared to surgical management. This active soldier should be treated with operative fixation and bone grafting.

Buijze et al. performed a review on the diagnosis and treatment of scaphoid nonunion. They describe the two common procedures of non-vascularized bone grafting: (1) The Matti-Russe inlay technique (volar approach with fracture site excavation and inlay backfilling with bone graft) (2) The Fisk-Fernandez interposition technique (utilization of anterior wedge bone graft for humpback deformity correction). They conclude that there are many variations to scaphoid nonunion surgery with continued debate regarding the best surgical treatment modality.

Kawamura and Chung also performed a review on the diagnosis and management of scaphoid nonunion. They argue that surgical treatments are more effective than bone stimulation or casting, and the indication for nonoperative management is restricted to patients who cannot have surgery for any reason. They conclude that surgical treatment should be directed at correcting any deformity through open reduction internal fixation with either vascularized or non-vascularized bone grafting.

Figure A shows two-view imaging of the patient’s right wrist displaying a scaphoid waist fracture with apparent intraosseous cystic formation. The lateral imaging shows an extended lunate with an increased scapholunate angle, indicating a chronic injury with the development of dorsal intercalated segment instability (DISI). Figure B displays coronal CT imaging displaying bone loss about the scaphoid waist and would be suggestive of the need for bone grafting during operative fixation.

Incorrect Answers:
Answers 1, 4, 5: Immobilization and casting are appropriate in the setting of acute, nondisplaced scaphoid fractures. In regard to the different types of cast options, cast immobilization of the wrist alone is sufficient for stabilizing scaphoid fractures. Incorporating the thumb (thumb spica) and elbow (above elbow) in the cast is cumbersome to patients and has not been found to improve union rates or functional outcome scores. In a young, active soldier surgical management is the first line of treatment.
Answer 3 and 4: Scaphoid excision and intercarpal fusion, proximal row carpectomy or wrist fusion would be appropriate salvage procedures for patients with scaphoid nonunion that progressed to advanced SNAC wrist. This patient did not display advanced SNAC wrist on presenting imaging.