Histological changes in the proximal suspensory ligament after neurectomy of the deep branch of the lateral palmar nerve of horses with induced proximal suspensory desmitis.

The research paper examines the changes in horse’s suspensory ligaments resulting from neurectomy, a nerve removal surgery, on horses with inflicted proximal suspensory desmitis, a common lameness condition. The study highlights the effects of the surgery in terms of clinical response and the subsequent histological changes.

Objective and Methodology

The study aimed to determine the impacts and potential risks of neurectomy of the deep branch of the lateral palmar nerve (DBLPaN), a procedure previously shown to restore soundness in horses with persistent lameness due to proximal suspensory desmitis (PSD). This investigation sought to uncover whether this procedure leads to changes in the suspensory ligament (SL) that might make the horse prone to future injury.

• The researchers carried out this study on eight horses. They inflicted unilateral PSD by injecting collagenase into the proximal section of the SL.
• Following the induction of PSD, they performed a neurectomy of the DBLPaN.
• This research involved quantitative lameness evaluation, and gross and histological examination of the affected SL section. In the histological examination, they particularly looked for changes in the tissue structure and composition.

Results and Findings

The surgery resulted in the resolution of lameness in all subjects, proving it to be effective in treating PSD-induced lameness. However, there were also significant histological changes observed.

• The muscle fibers of the denervated ligaments display signs of atrophy, show infiltration with fat and connective tissue, indicating that the surgery influenced the tissue’s composition and structure.
• These infiltrations in the ligaments result in reduced strength and elasticity, which might increase the risk of re-injury to the ligaments in the future.

Conclusion

The research yields crucial insights into the implications of performing a neurectomy on horses suffering from PSD. Though the surgery was effective in eliminating lameness, it led to significant detrimental changes in the structure and properties of the suspensory ligaments. The findings suggest that there might be a trade-off between the immediate benefits of the surgery and the potential long-term risks associated with reduced ligament strength and elasticity. Thus, further research is needed to weigh these considerations and to determine the best surgical practice for horses afflicted with PSD.