Research in context
Evidence before this study
We reviewed the published literature for the primary outcome of nerve transfers for restoration of upper extremity function in tetraplegic patients. This search added to a review published by the first author in 2015. Using the key terms “tetraplegia”, “quadriplegia”, “nerve transfer”, and “spinal cord injury”, we searched MEDLINE, PubMed, Embase, and CINAHL databases from Feb 12, 2015, to Nov 31, 2018. We also manually checked the references of retrieved articles to identify additional studies. Nerve transfer surgery has been shown to be feasible, safe, and effective in numerous single case reports and small, retrospective case series. The case reports mainly focused on the description of new surgical procedures. The reporting quality of the case series was not high, lacking clarity in some areas such as the specific inclusion and exclusion criteria and the consecutive inclusion of patients. Although many reports included videotapes as supplementary material, only the Medical Research Council strength grading was used to measure outcomes, with no standardised functional outcome measures used. Rigorous prospective studies using standardised outcome measures in this population are scarce. A case series presenting outcomes for combinations of multiple nerve and tendon transfer surgeries has not previously been reported.
Added value of this study
This study reports on the largest prospective, consecutive case series of nerve transfers done at a single centre in the tetraplegic population to date, and examines the clinical and functional outcomes of nerve transfer surgery in detail. The use of qualitative outcome measures adds a subjective patient perspective. The unique combination of tendon and nerve transfers permits intraindividual comparison of tendon and nerve transfers for grasp and pinch and expands reconstructive options, while allowing patients to benefit functionally from the innate strengths of each technique.
Implications of all the available evidence
Nerve transfer surgery is a safe and reliable addition to the surgical options for upper extremity reconstruction in tetraplegia and leads to functional improvements similar to those of tendon transfer surgery. The assessment measures used and outcomes presented provide a baseline for comparison and are essential for international, collaborative research into this small population group with unique needs. Whether function and strength in muscles reanimated by nerve transfer continues to improve beyond 24 months remains to be shown. Consideration should be given to the inclusion of nerve transfer donors in the International Classification for Surgery of the Hand in Tetraplegia.