Impactful research changes clinical practice, according to pediatric orthopedic surgeon Mary Claire Manske, M.D. And that’s just what she has done with a paper on brachial plexus birth injury.
In the paper published in the Journal of Bone and Joint Surgery last year, Dr. Manske compared two surgical approaches used in infants for repairing the suprascapular nerve and restoring external shoulder rotation.
One approach she compared in the study is the nerve grafting technique, where a nerve graft is taken from the leg and used to reattach a torn and injured suprascapular nerve. The other is a nerve transfer technique, where the spinal accessory nerve is moved over and attached to the injured suprascapular nerve.
While grafting is used more frequently, her research demonstrates that the nerve transfer gets better results.
“What we found was that shoulder external rotation is difficult to recover with either of these techniques,” said Dr. Manske, a hand and microvascular surgeon at Shriners Hospitals for Children — Northern California. “But the nerve transfer technique gave kids a higher probability of recovering functional strength.”
“But the nerve transfer technique gave kids a higher probability of recovering functional strength.”
“This has definitely changed my clinical practice,” she added.
Shriners Hospitals for Children — Northern California is the busiest referral center for brachial plexus birth injuries in the state, according to Dr. Manske.
Dr. Manske’s paper reported on 145 patients, of whom 59 were grafted and 86 had transfers (J Bone Joint Surg Am 2020:102:298-308). Overall, it showed no difference between the groups in shoulder external rotation functioning at a median follow-up of 26 months. However, the transfer procedure produced a good or excellent result — defined as a range of motion better than half of normal or a full range of motion — in 24% of patients, compared with only 5% of the grafting procedure patients.
“Given the greater proportion of infants who achieve useful shoulder external rotation with transfer of the spinal accessory nerve to the suprascapular nerve, this transfer should be considered not only in infants with severe injury in whom grafting is not possible, but in all infants undergoing brachial plexus reconstruction,” Dr. Manske and her co-authors wrote in the publication.
Moreover, only 40% of the patients with a suprascapular nerve transfer had a secondary shoulder surgery during the follow-up, while 53% of those who had a nerve graft did.
To conduct her study, Dr. Manske used data from a project begun in 2003. That project, the “Treatment and Outcomes of Brachial Plexus Injury (TOBI) Study,” has been collecting information on patients from six North American hospitals, including Boston Children’s Hospital and the Northern California Shriners Hospital. Patients were followed for 18-36 months with the goal of answering a pressing question regarding the timing of surgery: Should surgery be performed within the first few months after birth for an optimal outcome? Or should surgery be delayed to see how much spontaneous recovery of function will occur before operating?
The study suggested that surgery can be delayed. However, Dr. Manske says debate continues, and the issue is not settled.
Surgeons choose to wait to perform surgery for brachial plexus injury because they can heal on their own. To assess brachial plexus injury, they generally use antigravity elbow flexion to measure the shoulder function. When there is improvement in the elbow function that is a good indication that the shoulder is improving as well. At present, it is estimated that 70% of affected infants recover from brachial plexus injury spontaneously during the first few months.
Dr. Manske said in an interview that grafting for the suprascapular nerve has been popular with surgeons for a couple of reasons. One is that they are doing grafting repairs on other nerves during the procedure, so they are comfortable with their ability to do the grafting. It made some sense to spare the area the trauma of looking for the spinal accessory nerve and retrieving it.
She thought that way. She’s changed her thinking now.
Nerve transfer “lets us do surgeries that are more impactful,” Dr. Manske said. “It’s going to have a better result. It’s a hard thing for parents to hand their six-month-old baby to you, while you are saying ‘I’m going to do a huge surgery.’ But, if we can do a surgery with evidence that it has better outcomes, then I think that is clearly the surgery we do.”