A new technique for subtotal (cranial wedge) ostectomy in the treatment of impinging/overriding spinous processes: Description of technique and outcome of 25 cases

REASONS FOR PERFORMING STUDY: Surgical management for overriding spinous processes of the thoracolumbar vertebrae (SPs) is often favoured when conservative therapies have failed, pathology is severe, or in competition horses constrained by drug withdrawal periods. OBJECTIVES: To evaluate whether subtotal (cranial wedge) ostectomy represents an effective treatment for overriding SPs, with short surgery time and low complication rates, maintains the contour of the spine and produces a functionally and cosmetically better outcome than previously reported surgical techniques for management of overriding/impinging SPs. STUDY DESIGN: Retrospective study. METHODS: A new technique is described and records were retrieved for 25 cases that had undergone the procedure at Newmarket Equine Hospital between 2009 and 2011. Case records were evaluated for anamnesis, clinical findings and details of surgical and post operative management. Outcome of surgery was assessed by telephone questionnaire with owners, relating to both functional and cosmetic results. RESULTS: Of cases treated using the described technique, 78.9% had resolution of clinical signs and returned to full work and a further 18.2% were improved. Outcome was unrelated to number of SPs resected or mean radiographic grade of impingement. Cosmetic outcome was described as excellent in 81.8% and good in the remainder. Surgery time ranged from 20 to 70 (median 30) min and there were no intra‐ or post operative complications. CONCLUSIONS: In contrast to previously described amputation techniques, subtotal (cranial wedge) ostectomy removes only impinging portions of SPs. General anaesthesia and lateral recumbency facilitate access and enable a short surgery time. The procedure maintains the contour of the back and has fewer complications, but produces functional outcomes similar to more invasive procedures.