Correction of Humpback Deformities in Patients With Scaphoid Nonunion Using 1,2-Intercompartmental Supraretinacular Artery Pedicled Vascularized Bone Grafting With a Dorsoradial Approach

PURPOSE

Although 1,2-intercompartmental supraretinacular artery (1,2-ICSRA)-based vascularized bone grafting (VBG) has gained popularity in the treatment of scaphoid nonunion, correcting humpback deformities with this technique remains challenging. The purpose of this retrospective study was to determine the possibility of correcting humpback deformities using a 1,2-ICSRA VBG with a dorsoradial approach.

METHODS

We treated 25 patients with scaphoid nonunion using a 1,2-ICSRA VBG between January 2007 and December 2017. For those with a humpback deformity, we performed vascularized wedge grafting from the dorsoradial side, instead of inlay bone grafting from the dorsal or volar side of the scaphoid. After excluding patients with scaphoid nonunion without a humpback deformity and those followed up for less than 6 months, we reviewed the imaging results and union rate in the remaining 19 patients (18 men and 1 woman). The nonunion sites and patient distribution were as follows: proximal one-third, 2; waist, 16; and distal one-third, 1.

RESULTS

The union rate at the last follow-up performed a minimum of 6 months after the intervention was 94.7%. The correction was adequate in 17 patients and inadequate in 2 patients. The lateral intrascaphoid, radiolunate, and scapholunate angles were improved.

CONCLUSIONS

Humpback and dorsal intercalated segmental instability deformities can be corrected adequately using a 1,2-ICSRA VBG with a dorsoradial approach.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Treatment of the scaphoid humpback deformity - is correction of the dorsal intercalated segment instability deformity critical?

Treatment of scaphoid fractures has been focused mainly on achieving union, with less attention to restoring normal scaphoid shape and orientation. Malalignment of one carpal bone will disrupt the kinetics of the entire wrist. The dorsal intercalated segment instability deformity associated with scaphoid waist nonunion is a nondissociative form of carpal instability. It has to be reduced in the treatment of scaphoid waist nonunions to avoid kinetic problems that will lead to arthritic changes. Computerized tomography scanning has become indispensable to visualize the humpback deformity clearly. Different techniques may be used to restore the normal anatomy of scaphoid, from non-vascularized graft to arthroscopic bone grafting, and also the option of vascularized bone grafting.