Eva Einola Koponen, DVMTRIPLE PELVIC OSTEOTOMY AS TREATMENT OF CANINE HIP DYSPLASIA - RESULTSHipdisplasia is a condition of the hip joint characterised by instability of the joint. The mechanism for the development of laxity is largely genetically mediated but is influenced by environmental factors. It is gererally considered that puppies are born with normal conformation of the joint but laxity or instability developes early in the life. Initially there will be a synovitis of the joint included by abnormal stress placed on the supporting structures. These changes encourage the stabilisation of the joint. Experience with triple pelvic osteotomy in seventeen instable hip joint in evelen young dogs is presented. A few years follow up showed that artrosis may even be completely arrested by stabilizing the hip joint and increasing the load-bearing surface. TPO, TRIPLE PELVIC OSTEOTOMYThis is a technique which has been developed to increase the coverage of the acetabulum over the femoral head. This idea is first described by Salter in 1961 as innominate osteotomy for the treatment of congenital hip dislocation in the child. Hohn and James introduced this technique into veterinary medicine in 1969. The ideal candidate for this surgery still has some coverage of the femoral head by the acetabulum and no signs of degenerative joint disease of the hip. In this procedure an osteotomy of pelvis is performed at the ilium, pubis and ischium so that the acetabulum can be rotated laterally. On the clinical examination of the dogs pain is evident of joint amnipulation, especially on extension and/or abduction, and most will have a positive Ortolani sign. In selecting the patients for this procedure standard ventrodorsal, lateral and frog view radiographs are taken. Acetabular rim projection radiographic view has advantages when assessing dogs as candidates for a triple pelvic ostetomy (Slocum and Devine 1986). TPO surgery is contraindicated when there are radiographic or palpable signs of advanced degenerative joint disease, breakdown of the dorsal acetabulum rim or shallow acetabulum. Surgical techniqueThe procedure is performed in three stages. The pubic ramus is exposed through a ventral approach. One cm of the pubic ramus is removed. The second incision is med over the ischium and the table of ischium is cut after preplacement of the 20-gauge wire drilled on both sides of the osteotomy. A lateral approach is made to the shaft of the ilium. An iliac osteotomy is performed just caudal to the sacrum. Following this osteotomy the acetabular segment is fixated with a prebended plate to the caudal segment. In all surgeries an AO Synthes TPO 3.5 mm 5 or 6 hole -plate was used as fixator of the ileal osteotomy. RESULTSThirteen young dogs had the TPO surgery done on 19
hips.
Nine dogs were males and 2 females.
Two of the dogs, nr 7 and 10, had not a good result after surgery. In dog nr 7 there was a communication problem with the owner about the restriction of excercise after surgery. The dog was not kept on leash more than 3 weeks and the osteotomy in the ileum broke and the hip subluxated again. The dog was euthanized. Dog nr. 10 has also bad subluxation of the hocks and the TPO surgery did not improve the situation. All the other dogs improved clinically very soon after surgery. At the 2 week postoperative check the dogs were usually bearing weight on the foot. At 4 weeks very mild lameness was seen and the healing was complete at 12-16 weeks after surgery. The dogs had restricted excercise for 6 weeks on short leash, some of the dogs (4,6,9) were in normal activity at 10 weeks after surgery. The follow up time was between 5 and 24 months so these results are preliminary. Complications from this surgery involve case selection errors, technical errors and lack of animal and client compliance. Literature
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