Hypothenar Hammer Syndrome: A Systematic Review and Meta-Analysis of Patency Rates and Patient-Reported Outcome Measures

Abstract

Hypothenar hammer syndrome (HHS) is a rare condition typically seen in patients with repetitive trauma to the hand. Multiple treatment options are available, and these range from conservative options to surgery, depending on severity of symptoms. There is an abundance of case reports reporting on HHS, with limited large studies reporting patency findings and patient-reported outcome measures (PROM). The main objective of this study was to review long-term patency rates and PROMs in HHS patients undergoing surgical intervention with a focus on vein graft repair, arterial graft repair, and direct repair without a graft. A total of 1399 publications were screened, and 14 were included (patency rates papers n = 13; PROM papers n = 5). The pooled patency rates were 65% for vein grafts (with a yearly rate decline of 4.4%; P = .243), 100% for the arterial grafts (4 studies; n = 23; mean follow-up 40.8 months), and 67% for the direct repair group. Longitudinal patency rates were higher with arterial grafts than with vein grafts (β = 0.36, P = .001). Pooled Disabilities of the Arm, Shoulder, and Hand (DASH) scores were comparable between vein grafts and direct repair (10.9 vs. 11.5; P = .958). In summary, there is a downward yearly trend in patency rates of vein grafts. Compared to vein grafts, arterial grafts have higher long-term patency rates. Vein grafts and direct repair, however, yield promising postoperative function and pain as assessed via DASH and Visual Analog Scale (VAS) scores.