KISSING SPINE SURGERY AND REHABILITATION IN A SHOW JUMPER
Injuries and diseases of the back are a common cause of poor performance in sport horses (Jeffcott, 1980). Back pain tends to cause a decrease in range of movement i.e. an increase in stiffness of the back. Back pain may arise from any tissue within the back and can be quite difficult to diagnose as horses vary in their responses to back pain and in the way that they cope with it. Presenting signs could include everything from subtle changes in gait and performance right through to resistance to work including aggression on being saddled, bucking, inability to canter, refusal to jump etc.
The vertebral column of the horse is made up of up of 5 different regions (cervical, thoracic, lumbar, sacral, coccygeal) with different types of vertebrae in each region. Within the thoracolumbar spine, the vertebral bodies have dorsal spinous processes (DSPs) projecting from them for the attachment of soft tissue structures (tendon, ligament and muscle). Between adjacent vertebrae, a gap of 4 mm or more is considered normal (Zimmerman et al. 2012). If adjacent DSPs are touching they are considered to be ‘impinging’; if adjacent spinous processes are overlapping they would be considered to be ‘over-riding’. Both impinging and over-riding dorsal spinous processes (ORDSPs) otherwise known as kissing spines are a common cause of back pain in horses (Jeffcott 1980). In the worst affected cases adjacent DSP’s will show signs of change in bone density (sclerosis) and/or bone breakdown (radiolucencies on x-ray).
During the normal stride cycle, the back flexes (rounds) and extends (dips). The interspinous gaps narrow when the horse’s back is extended and increase when the back is flexed. The exact aetiology is unknown, but it has been suggested that horses with short backs, excessively extended backs (due to their conformation), horses subject to repetitive flexion-extension movements (e.g. jumping horses) or horses with an extended back posture due to concurrent hindlimb lameness or carrying excessive weight may be predisposed to the condition. Single or multiple DSPs may be involved. Diagnosis may be made on the basis of presenting signs, response to palpation, local analgesia, ultrasonography, radiography and nuclear scintigraphy (Zimmerman et al. 2012). Often multiple diagnostic techniques are used to confirm the diagnosis. Presence of ORDSPs on a radiograph may not correlate with the clinical signs, in other words horses with evidence of ORDSPs on x-ray may not exhibit signs of pain arising from that region; another horse may have only mild impingement but exhibit signs of significant pain.
Treatment can be conservative (i.e. rest, physical therapy and anti-inflammatory medication) or surgical. In some circumstances additional complementary therapy such as acupuncture may be used to decrease spasm of the muscles surrounding the painful vertebrae (see video). Surgical treatments are resection of DSPs under general anaesthetic, resection under standing sedation or interspinous ligment desmotomy which is carried out under standing sedation (Coomer et al. 2012). Comment [KN1]: Insert video of Fiona doing acupuncture. Outcomes may be improved in both instances by the use of physical therapy within the recovery period. Rehabilitation programmes are from 3 to 6 months (Walmsley et al. 2002). Physiotherapy is recommended post-surgery (Walmsley et al. 2002).
Show jumper (competing at 1.50 m level) suffering from poor performance (knocking down fences, often with hind limbs)
Diagnosis: ORDSPS with 3 intervertebral joints affected (T17-18, T18-L1 and L1-L2) (see x ray)
Treatment: Interspinous ligament desmotomy which was carried out by Chris Rea BVM&S, MRCVS at Three Counties Equine Hospital. The horse was then referred to Liz Launder, osteopath for treatment at the Equine Therapy Centre, Hartpury College.
Rehabilitation: 12 weeks
First 2 weeks: Box rest with in hand walking/grazing only. Sutures removed day 10. The horse begins a programme of electrotherapy (ultrasound and interferential treatment) as prescribed by Liz. (see pictures of the therapeutic ultrasound and interferential machines).
Work commences 2 weeks post surgery with controlled walking on ordinary treadmill (no incline).
3 weeks post surgery: Walking up to 45 mins per day (in 2 bouts consisting of 1 treadmill session and one ground schooling session in long lines with short periods of trot). Both osteopath and vet feel that the amount of propulsion from the hindlimbs could be improved by modifications to the shoeing and at the next appointment, Liz, Chris and Kelvin Lymer of Sandpitt Forge all see the horse together to discuss what can be achieved with shoeing. Kelvin uses a shoe with greater length and width to provide a larger bearing surface to the hindlimbs and ‘derotate’ the hindlimbs. Currently some of the drive is lost because the hindlimb (particularly the right hind) is overly outwardly rotated and isn’t able to push forward sufficiently, instead it tends to lands towards the midline which is increasing the amount of axial rotation along the spinal column (we want flexion of, and propulsion along the longitudinal axis, not around it). (see the photo showing the new shoe on the right hind with the old shoe laying on top of it. This shows how much more support the new shoe gives in comparison)
6 weeks post surgery: Introduce canter during ground schooling. The horse underwent osteopathic mobilisation under sedation to improve the range of movement of the caudal thoracic and lumbar spine. (see video).
10 weeks to 12 weeks: Cantering and jumping (under 1 m) with rider.