Kissing Spines: Standing Resection of Impinging Spinous Processes

Introduction
Despite huge advances in diagnostic imaging techniques, the accurate investigation and diagnosis of “back pain” in the horse remains a problem. If we had magnetic resonance imaging (MRI) available for the horse’s back, there is no doubt it would ‘unlock’ many diagnoses not currently available, in the same way that MRI of the horse’s foot has identified and separated many problems that were historically grouped together as “navicular disease”.

It is very important to recognise the limitations of our current knowledge, and we must accept that in a proportion of cases our clinical diagnosis is at best slightly inaccurate, and at worst far from complete. Nothing is more important than a correct and secure diagnosis, in particular, if the effectiveness of a specific surgical treatment is to be fairly assessed.

Accepting these limitations, a well-recognized population of horses does exist, which suffer from back pain due to impinging dorsal spinous processes (iDSPs). The condition is a dynamic one, and often a progressive one. If problems persist despite conservative and medical treatments, surgery may be contemplated. Where genuine impingement occurs, with active/proliferative bridging callus formation between DSP’s, partial or total resection of the summits of the DSP’s in order to relieve the impingement is indicated. A variety of surgical techniques for this have been described. More recently desmotomy of the interspinous ligament has been recommended for the condition. This technique is not possible in cases where there is solid ‘bridging’ callus between DSP’s.  [...]