Botulinum Toxin Injection for Internal Rotation Contractures in Brachial Plexus Birth Palsy. A Minimum 5-Year Prospective Observational Study.
BACKGROUND
Brachial plexus birth palsy is frequently associated with internal rotation contractures of the shoulder as a result of muscle imbalance. The purpose of this study is to assess the effect of botulinum toxin A (BTX-A) injection in the subscapular (SC) muscle on external rotation and the need for tendon transfer for external rotation of the shoulder.


METHODS
A prospective comparative study was performed including 15 consecutive patients treated with BTX-A and a historic control group of 67 patients with mean age 30 months (SD 10). The BTX-A injection (2 IU/kg body weight) was performed immediately following MRI under general anesthesia in the SC muscle. Passive external rotation, the need for tendon transfer surgery, glenohumeral deformity, and muscle degeneration were evaluated. The hazard ratio for no relapse of internal rotation contracture after BTX-A injection compared with no BTX-A injection was calculated.


RESULTS
In the BTX-A group, the passive external rotation in adduction increased from -1 degree (95% CI, -10 to 8) to 32 degrees (95% CI, 17-46) at 3 months and 6 patients were indicated for surgery compared with a decline from -2 degrees (95% CI, -7 to 3) to -11 degrees (95% CI, -17 to -6) in the control group with 66 indications for surgery. At 5 years of follow-up, 10 patients in the BTX-A group were indicated for surgery with a hazard ratio of 4.0 (95% CI, 1.9 to 8.4).


CONCLUSIONS
BTX-A injection in the SC muscle of brachial plexus birth palsy patients can reduce internal rotation contractures and subsequently the need for tendon transfer surgery. At 5 years of follow-up a relapse was seen in 67% of the patients treated with BTX-A. Because at MRI less SC degeneration was found in the good responders on BTX-A treatment, this group seems to be the best target group. Further research is needed on patient selection for BTX-A injection including glenohumeral deformity, SC degeneration, as well as doses of BTX-A to be used.


METHODS
Level II-prospective comparative study.
Departments of *Orthopaedics ‡Neurosurgery †Rehabilitation, Leiden University Medical Center, Leiden, The Netherlands.
Bouke J
BJ
Duijnisveld
Marie S
MS
van Wijlen-Hempel
Simone
S
Hogendoorn
Kees S
KS
de Boer
Martijn J A
MJ
Malessy
J Christiaan
JC
Keurentjes
Jochem
J
Nagels
Rob G H H
RG
Nelissen
D001720:Birth Injuries / Q000188:drug therapy*; D001905:Botulinum Toxins / Q000627:therapeutic use*; D020516:Brachial Plexus Neuropathies / Q000150:complications*; D002675:Child, Preschool; D003286:Contracture / Q000188:drug therapy* / Q000209:etiology; D005260:Female; D006801:Humans; D007223:Infant; D007273:Injections, Intramuscular; D008279:Magnetic Resonance Imaging / Q000009:adverse effects; D008297:Male; D009498:Neurotoxins / Q000627:therapeutic use*; D011446:Prospective Studies; D012008:Recurrence; D012399:Rotation; D012785:Shoulder Joint / Q000187:drug effects / Q000601:surgery; D013709:Tendon Transfer / Q000706:statistics & numerical data
D009498:Neurotoxins; D001905:Botulinum Toxins