COMPARING THE MATHOULIN GRAFT AND ITS ALTERNATIVES FOR SCAPHOID NONUNION: A RETROSPECTIVE ANALYSIS

Scaphoid fractures are the most common carpal bone fracture. Non-union rates are relatively high despite appropriate treatment. The purpose of this study was to compare radiographic union rates, when treating unstable scaphoid non-unions (USNU), using a vascularized bone graft pedicled on the volar carpal branch of the radial artery (“Mathoulin Graft - MG”) against the 1,2 intercompartmental supraretinacular arterial graft (“Zaidemberg Graft - ZG”) and non-vascularized bone grafts (NVBG). Consecutive patients with USNU treated by a single surgeon at a single center were enrolled in this retrospective review. The primary outcome was radiographic union at six months post-operatively as determined on X-ray. Secondary outcomes included humpback deformity correction as measured on X-ray. Ninety patients were included: 41 MG, 27 ZG and 22 NVBG. Radiographic union rates were 97.6%, 92.6% and 72.7% for the MG, ZG and NVBG groups respectively. The MG had a significantly higher rate of union compared to the NVBG (p = 0.006). No difference existed when comparing the MG and ZG groups (p = 0.56) nor when comparing the ZG and NVBG groups (p = 0.12). Mean scapholunate angle (SLA) correction was 26, 10 and nine degrees for the MG, ZG and NVBG groups respectively. When adjusting for baseline values, the mean difference in SLA correction was 14 (p < 0.0001), 16 (p < 0.0001) and two (p = 0.52) degrees for the MG, ZG and NVBG respectively. In both scenarios, only the MG provided statistically significant greater SLA correction over alternative grafts. Mean scaphoid length change on the PA X-ray projection was three, −0.4 and one millimeters for the MG, ZG and NVBG groups respectively. The mean difference in length change between the MG and ZG groups (3 mm; p < 0.0001) was statistically significant and remained so when adjusting for baseline values (3 mm; p = 0.0003). This trend persisted when measuring scaphoid length on the lateral X-ray projection with mean changes in length of two, 0.4 and one millimeters for the MG, ZG and NVBG groups respectively. The difference in mean scaphoid length change was 2 mm when comparing the MG and ZG groups both in univariate analysis (p = 0.0013) and when adjusting for baseline values (p = 0.0135). The Mathoulin Graft has a high rate of radiographic union when treating USNU as well as significantly greater SLA correction and scaphoid length restoration when compared to other grafts.