Functional outcome after transfer of brachialis on anterior interosseous and supinator on posterior interosseous nerves: A preliminary report

Abstract

Objective Traumatic spinal cord injury (SCI) resulting in tetraplegia is a leading cause of morbidity among young adults worldwide and its management remains challenging. Restoring hand function in these patients must be considered a top priority with great impact on their quality of life (QOL); although nerve and tendon transfer have been extensively described, type of procedure to be chosen is not standardized and few studies have determined the functional outcome of those procedure and their impact on QOL is still poorly assessed. We report a preliminary retrospective study regarding feasibility and functional outcomes of nerve transfer procedures including bilateral brachialis nerve on anterior interosseous nerve (AIN) and supinator branch on posterior interosseous nerve (PIN) for hand reanimation following SCI focusing on the impact of these procedures on QOL. Methods We performed a retrospective study involving patient sustained SCI and underwent nerve transfer of brachialis branch from musculocutaneous nerve on AIN and supinator branch from the trunk of the radial nerve on the PIN. We included 11 patients (14 limbs) with traumatic SCI resulting in C4 level tetraplegia in five patients, C5 in four and C6 and C7 in one case each, with a median age of 31.5 years underwent surgery at a median of 10 months after injury; including both transfers in 10 cases and AIN reanimation only in one. Functional assessment including medical research council (MCR) grade, graded redefined assessment of strength sensation and prehension (GRASSP) and spinal cord independence measure (SCIM) were performed at least 12 months follow up. Results Thirteen PIN innervated muscles achieved an MRC score ≥3/5 whereas AIN supplied muscles in 5 out of 15. GRASSP qualitative measure improved from a baseline value of 1 to 2, while quantitative measure passed from 1 to 3 after 12 months; the difference was statistically significant (p = .005 and p = .008, respectively). SCIM self‐care sub‐score also statistically significant improved from 3 to 4 at 12 months (p = .016). No complication or donor morbidity occurred. Conclusions Functional performance has been significantly improved by nerve transfer procedures 1 year after surgery. Nerve transfers may represent a valuable option for the restoration of the hand function in patients with tetraplegia with minor or no morbidity.

Supinator to Posterior Interosseous Nerve Transfer for Recovery of Hand Opening in the Tetraplegic Patient: A Case Series

“…There are few reports on outcomes of nerve transfers for SCI. [5][6][7][8][9] Existing reports convey that the SUP-PIN transfer has been found to be generally more reliable than nerve transfers for elbow extension and finger flexion and that only antigravity strength is required for functionality. Bertelli's series found that 12/13 transfers achieved antigravity strength.…”

“…8 Another found that 50% achieved (an average of) M3 in the EDC and 43% M3 for thumb extension. 9 We report the MRC for every digit as we felt taking the strongest digit value does not fully represent the extent of hand opening and failing digits could adversely affect function and require additional procedures (eg, side-to-side tenodesis). Typically, though, we found the distribution of EDC strength to be relatively uniform.…”

“…2a Nerve transfers have shown promising results for hand function recovery in patients with tetraplegia. 3a,4a Previous studies have evaluated hand function restoration following supinator to posterior interosseous nerve (SUP-PIN) transfer, 3a-5a demonstrating varying rates of patients achieving a Medical Research Council (MRC) Grade of 3 or higher for finger extension. In this study, the authors aim to add their center's SUP-PIN transfer hand function restoration outcomes to the limited reports currently in the literature.…”

“…Previous SUP-PIN publications have reported MRCs as either an average of all digits or just the strongest of the digits. [5][6][7][8][9] We feel that this could misrepresent some hands that fail functionally, yet have one or more digits with a good outcome. In this case series, we report the strength of each digit as well as the associated angles of finger and thumb extension achieved.…”

Review of outcomes measures used to evaluate upper extremity surgical treatment of cervical spinal cord injury with recommendations for the future

“…The Graded Redefined Assessment of Strength, Sensibility and Prehension (GRASSP) Test is a valid and reliable test that was designed to measure functional outcomes in complete and incomplete cervical SCI [45] . The GRASSP has been shown to be predictive of overall UE and self-care function [49] and was used in 1/26 studies [50] . GRT was originally developed to assess outcomes after neuroprosthesis implantation in people with SCI [46] .…”