PURPOSE: Although recovery occurs in the majority of cases of brachial plexus birth palsy (BPBP), long-term shoulder disability is relatively common. The aim of this study was to establish an animal model to study BPBP-associated shoulder deformities. METHODS: A right-side C5, C6 root neurotomy was performed under the surgical microscope in 5-day-old Sprague-Dawley rats (N = 9). The contralateral side served as a control. The development of shoulder deformity and range of motion loss were followed longitudinally. Animals were killed 4 months after surgery. Both shoulders were harvested, decalcified, and transected in the axial plane for glenoid version measurement and shoulder histology. RESULTS: All animals developed shoulder internal rotation contracture within 4 weeks after the C5, C6 neurotomy. The average shoulder external rotation loss was 52 degrees +/- 7, 59 degrees +/- 10, and 82 degrees +/- 11 in comparison with the control side 1, 2, and 4 months after neurotomy, respectively. Glenoid version changed from 2 degrees +/- 2 of retroversion (left side) to 8 degrees +/- 3 of anteversion. Five shoulders were subluxated clinically with a pseudoglenoid formation observed radiographically. Histologic study demonstrated marked glenoid and humeral head deformities. CONCLUSIONS: This neonatal rat model clearly demonstrated typical shoulder deformities similar to that resulting from Erb's palsy. This model can be useful in studying BPBP-associated shoulder deformities.
PURPOSE: Although recovery occurs in the majority of cases of brachial plexus birth palsy (BPBP), long-term shoulder disability is relatively common. The aim of this study was to establish an animal model to study BPBP-associated shoulder deformities. METHODS: A right-side C5, C6 root neurotomy was performed under the surgical microscope in 5-day-old Sprague-Dawley rats (N = 9). The contralateral side served as a control. The development of shoulder deformity and range of motion loss were followed longitudinally. Animals were killed 4 months after surgery. Both shoulders were harvested, decalcified, and transected in the axial plane for glenoid version measurement and shoulder histology. RESULTS: All animals developed shoulder internal rotation contracture within 4 weeks after the C5, C6 neurotomy. The average shoulder external rotation loss was 52 degrees +/- 7, 59 degrees +/- 10, and 82 degrees +/- 11 in comparison with the control side 1, 2, and 4 months after neurotomy, respectively. Glenoid version changed from 2 degrees +/- 2 of retroversion (left side) to 8 degrees +/- 3 of anteversion. Five shoulders were subluxated clinically with a pseudoglenoid formation observed radiographically. Histologic study demonstrated marked glenoid and humeral head deformities. CONCLUSIONS: This neonatal rat model clearly demonstrated typical shoulder deformities similar to that resulting from Erb's palsy. This model can be useful in studying BPBP-associated shoulder deformities.
Authors: Nikhil N Dixit; Daniel C McFarland; Matthew B Fisher; Jacqueline H Cole; Katherine R Saul Journal: J Biomech Date: 2020-01-24 Impact factor: 2.712
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Authors: Nikhil N Dixit; Carolyn M McCormick; Eric Warren; Jacqueline H Cole; Katherine R Saul Journal: J Hand Surg Am Date: 2020-09-10 Impact factor: 2.230
Authors: Francisco Soldado; David Benito-Castillo; Cesar G Fontecha; Ignasi Barber; Mario Marotta; Sleiman Haddad; Mariano E Menendez; Vasco V Mascarenhas; Scott H Kozin Journal: J Brachial Plex Peripher Nerve Inj Date: 2012-12-06