Compressive damage to the deep branch of the lateral plantar nerve associated with lameness caused by proximal suspensory desmitis.

The study explores the impact of compressive damage to the deep branch of the lateral plantar nerve (DBLPN) in horses diagnosed with proximal suspensory desmitis (PSD) lameness. The report analyzes the pathological changes in the affected nerve and the outcomes post nerve segment excision. The study findings reveal that chronic nerve compression, which could potentially aggravate PSD, was found in most nerves examined. Post nerve removal, more than half of the horses returned to soundness.

Objective and Methodology of the Study

• The study aimed at exploring the pathological changes in the deep branch of the lateral plantar nerve (DBLPN) in horses diagnosed as lame due to proximal suspensory desmitis (PSD). The research also observed the effectiveness of treating this condition by removing a segment of the horses’ DBLPN.
• The study employed a retrospective case series method involving adult horse subjects (n=16).
• Of the horses studied, those determined to be lame on one or both pelvic limbs due to PSD were treated by removing a segment of the DBLPN. A total of 30 nerves were examined histologically.
• Post-surgery, the animal owners were contacted to provide information about the horses’ condition six months or more after the surgery.

Results of the Study

• The study results showed histological changes hinting at chronic nerve compression in both nerves of 11 bi-lame horses and in the lame limb of 5 uni-lame horses.
• The nerve of the unaffected limb in 2 out of 3 uni-lame horses, which underwent bilateral nerve resection, also showed histological changes consistent with nerve compression.
• Of the 16 horses under review, 10 (62.5%) returned to soundness following excision of the DBLPN.

Conclusions of the Study

• It was concluded that pathological changes in the DBLPN associated with compression could potentially complicate PSD in the pelvic limbs of horses.
• The surgery performing excision of the affected nerve might effectively resolve the lameness in horses.
• It seems that horses diagnosed as lame from PSD in the pelvic limb could remain lame post desmitis resolution due to DBLPN compression. Therefore, removing a portion of the affected nerve could potentially restore the lameness.