Fig. 1 An extension-type supracondylar humerus fracture may result in traumatic motor and/or sensory nerve injury. In a minority of patients with severe traumatic nerve injuries, surgical intervention may be required.
Courtesy of Boston Children’s Hospital

AAOS Now

Published 1/1/2015
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Maureen Leahy

Timing of Motor Nerve Function Recovery in Children with Severe Supracondylar Humerus Fractures

Study finds most nerve injuries improve within 6 months

Data presented at the American Society for Surgery of the Hand annual meeting indicate that most motor nerve injuries associated with pediatric supracondylar humerus fractures improve within 3 to 6 months, although recovery may be delayed in patients with more than one injured nerve.

Supracondylar humerus fractures in children are primarily isolated injuries; however, patients with more severe extension-type fractures may experience concomitant nerve deficits, primarily of the median nerve. Yet, to date, no large-scale studies have analyzed the recovery of motor nerve injuries secondary to severe supracondylar extension fractures, according to Bryce T. Gillespie, MD, of The Hand & Upper Extremity Center of Georgia.

“The results of a recent meta-analysis of 3,500 patients demonstrated that traumatic motor and/or sensory nerve injuries occur in approximately 13 percent of pediatric extension-type supracondylar humerus fractures,” he said. “Although most of these traumatic nerve injuries are neurapraxic and spontaneously recover, neurologic function fails to recover with observation alone in a minority of patients with more severe injuries.

“We hypothesized that the time to motor nerve recovery would vary according to the specific nerve affected and the number of nerves involved, as well as whether acute nerve decompression was performed at the time of fracture care,” Dr. Gillespie said.

Retrospective evaluation
The researchers conducted a retrospective evaluation of 217 children (mean age = 6.4 years) with extension-type supracondylar humerus fractures and concomitant nerve injuries treated at Boston Children’s Hospital from 1996 to 2012 (Fig. 1). All fractures had been successfully treated with closed or open reduction and percutaneous pinning. Patients with iatrogenic nerve injuries, subjective paresthesias without motor deficit, or nerve injuries associated with flexion-type supracondylar or intra-articular distal humerus fractures were excluded.

Injuries to the following nerves were included:

  • median nerve, including isolated anterior interosseous nerve injuries (n = 139)
  • radial nerve (n = 52)
  • ulnar nerve (n = 3)
  • multiple nerves (n = 23)

“Twenty nine percent (n = 63) of the patients had concurrent vascular injuries, which ranged from weak pulse (n = 4), to ‘pink pulseless’ (n = 55), to an ischemic limb (n = 4),” Dr. Gillespie added.

At the surgeon’s discretion, 40 patients underwent immediate nerve decompression at the time of fracture fixation. Of these, 27 had concurrent vascular injuries.

Recovery times
Overall, 79 percent (n = 172) of the patients had full motor nerve recovery at the time of final follow-up, with median time to recovery of 2.3 months; 73 percent of the nerve injuries recovered within 6 months and 53 percent recovered within 3 months.

The median time to recovery was the shortest in patients with median nerve injuries (2.1 months). This was followed by ulnar nerve injuries (2.2 months), radial nerve injuries (3 months), and multiple nerve injuries (3.2 months).

“Multiple nerve injuries took 79 percent longer (P = 0.04) to recover than single nerve injuries. In addition, radial nerve injuries trended toward a 29 percent longer recovery time than median nerve injuries, although the difference was not statistically significant,” Dr. Gillespie said.

Multivariable analysis also revealed that when acute surgical decompression was performed, nerve injuries took 42 percent longer to recover, compared to those that had not been surgically decompressed (P = 0.006).

“Because the decision to perform immediate nerve decompression was at the surgeon’s discretion, these nerve injuries may have been considered more severe injuries. That may explain why these nerve injuries demonstrated a longer recovery time,” he explained.

“These findings can help inform surgeons and families about the recovery of motor nerve injuries associated with pediatric supracondylar humerus fractures and the potential need for nerve-related surgical intervention,” Dr. Gillespie concluded.

Dr. Gillespie’s coauthors of “Recovery of Motor Nerve Injuries Associated with Displaced, Extension-Type Pediatric Supracondylar Humerus Fractures” are Benjamin J. Shore, MD, MPH; Patricia E. Miller, MS; Donald S. Bae, MD; and Peter M. Waters, MD, of Boston Children’s Hospital. One or more of the authors reported potential conflicts of interest; disclosure information is available at www.aaos.org/disclosure

Maureen Leahy is assistant managing editor of AAOS Now. She can be reached at leahy@aaos.org

References:
Babal JC, Mehlman CT, Klein G: Nerve injuries associated with pediatric supracondylar humeral fractures: A meta-analysis. J Pediatr Orthop 2010;30(3):253-263.

Bottom Line

  • A majority of motor nerve injuries associated with pediatric extension-type supracondylar humerus fractures heal within 6 months, and most within 3 months.
  • Multiple nerve involvement is an independent risk factor for a prolonged recovery.
  • Acute nerve decompression performed at the time of fracture fixation increased time to recovery, while potentially decreasing the chance of poorer outcome and subsequent surgery.
  • This information provides general guidelines for surgeons and families regarding expected time to motor nerve recovery and potential criteria for initial and subsequent nerve-related surgical intervention.