according to research published online July 4 ahead of print in the Lancet. Combining nerve transfer with tendon transfer may maximize the functional benefit of surgery.
The loss of upper extremity function after cervical spinal cord injury can reduce independence and social and vocational engagement. People with tetraplegia rank improvement in hand function as their most important goal. Tendon transfers have been the traditional method of restoring function, but interest in nerve transfers has been increasing with the publication of successful results. Nerve transfers can reanimate several muscles at once and require a smaller incision and shorter immobilization, compared with tendon transfers.
Injury had occurred less than 18 months previously
Natasha van Zyl, MBBS, a plastic and reconstructive surgeon at Austin Health in Melbourne, and colleagues conducted a prospective case series to examine the clinical and functional outcomes of nerve transfer surgery for the reanimation of upper limb function in patients with tetraplegia. The investigators also sought to compare these outcomes with published outcomes for tendon transfer surgery.
Between April 14, 2014, and Nov. 22, 2018, Dr. van Zyl and colleagues recruited consecutive patients of any age with early cervical spinal cord injury of motor level C5 and below. Injury was required to have occurred fewer than 18 months before enrollment. Eligible participants had been referred to a single center for upper extremity reanimation and were considered candidates for nerve transfer.
Every participant underwent single or multiple nerve transfers in one or both upper limbs, and some participants also underwent tendon transfers. The goal of surgery was the restoration of elbow extension, grasp, pinch, and hand opening. An independent assessor evaluated participants at baseline and at 12 months and 24 months after surgery. The primary outcome measures were the action research arm test (ARAT), the grasp release test (GRT), and the spinal cord independence measure (SCIM).
Grasp function improved significantly
Dr. van Zyl and colleagues recruited 16 participants with traumatic spinal cord injury who underwent 59 nerve transfers. Ten participants also underwent tendon transfers. The population’s mean age at time of injury was 27.3 years. Three patients were female. Motor vehicle accidents were the most common cause of injury (31%). Follow-up data at 24 months were unavailable for three patients.
Participants’ median ARAT total score significantly improved from 16.5 at baseline to 34.0 at 24 months. Median GRT total score significantly improved from 35.0 at baseline to 125.2 at 24 months. The population’s mean total SCIM score and mobility in the room and toilet SCIM score improved by more than the minimal detectable change and the minimal clinically important difference. The mean self-care SCIM score improved by more than the minimal detectable change between baseline and 24 months.
The researchers observed six adverse events related to the surgery, but none had sustained functional consequences. No patients had an increase in musculoskeletal or neuropathic pain. Four of the 50 nerve transfers with 24-month follow-up failed.