What is Subtrochanteric Derotational Varus Osteotomy?
A dislocated hip in your dog could be an indication that the angle of the femur is not allowing the ball of the femur to “nest” into the socket of the hip. When these dislocations occur, either due to congenital problems with alignment or confirmation or due to trauma in the femur, surgery to correct the angle of the femur and allow the femur head to rest into the hip socket can be performed. An osteotomy is performed to lengthen or shorten a bone by cutting it and realigning it. The bone is then repaired with surgical plates affixed to reposition the bone and provide it with the correct alignment and structure. Derotational varus osteotomy is performed when an inward angulation is occurring in the femur, causing the ball of the femur to move out of joint, to correct the inward misalignment. The cut in the femur bone below the lesser trochanter, a projection on the upper femur of your dog, and up to 5 cm below this structure, is referred to as subtrochanteric. A surgical cut at this level of the femur, followed by repair or repair to an existing fracture at this level to correct the angle of the femur and allow it to move into the hip socket it a subtrochanteric derotation varus osteotomy. This surgical procedure is performed by a veterinarian with orthopedic training under general anesthetic.
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Subtrochanteric Derotational Varus Osteotomy Procedure in Dogs
Prior to an osteotomy procedure, radiographs will be taken to ensure your veterinarian has an adequate understanding of structural issues and to conduct a plan for subtrochanteric derotational varus repair. In addition, blood work will be conducted to ensure your dog is healthy prior to the procedure, which will minimize complications associated with anesthesia and surgery. Prior to surgery your dog should be fasted for 12 hours. At the veterinary hospital, on the day of surgery, your dog will be sedated and administered intravenous anesthetic to put him into a deep sleep prior to intubation with a breathing tube and the administration of gaseous general anesthesia. The area over your dog's thigh and hip, where incision(s) will be made to access the subtrochanteric region of your dog's femur, will be shaved and cleaned antiseptically prior to surgical procedure. An incision will be made to expose the area below the lower trochanter of the femur. A small piece of bone will then be cut from the subtrochanteric region of your dog's femur that will allow it be realigned and tilted so that the ball or head of the femur rests in the hip socket. A surgical metal plate is attached with surgical screws on either side of the break or cut in the bone to affix the femur in the correct position. Often for dogs, a surgical plate used for a similar procedure in human children is utilized to provide the correct sizing and allow for the correct femoral angle. Sometimes, the femoral head and hip socket also require surgical intervention by osteotomy in order to ensure the head and socket fit together correctly. If this is required, access to this structure will require further surgical incisions at the hip socket. Once repairs have been affected, incisions are closed and your dog is put into surgical and anesthesia recovery. A cast may not be required as the metal surgical plates used are strong and hold the bone in place.
Efficacy of Subtrochanteric Derotational Varus Osteotomy in Dogs
The effectiveness of the procedure depends on the degree of luxation present in the hip. Most procedures have successful outcomes, however complete soundness and correction of gait may not be achieved. The procedure is considered invasive, requiring substantial recovery time and complications such as delayed union or non-union of the joint are possible, as well as infection. As this is an elective procedure, owners will need to determine if this procedure is likely to achieve the desired outcome for their dog.
Subtrochanteric Derotational Varus Osteotomy Recovery in Dogs
Post surgery, pain killers, and anti-inflammatories will be prescribed by your veterinarian and should be administered as directed. If infection is present or suspected, antibiotics may also be prescribed. Activity should be restricted post-surgery and cage rest provided for several days. Keeping your dog indoors and allowing outdoor activity on a leash only for several weeks is recommended. Ensure that your dog’s footing in the house is stable by providing good traction with carpets and rugs, not slippery floors. Restrict access to stairs and furniture your dog might jump on until adequate healing occurs. Your dog will need an e-collar and supervision to ensure they do not interfere with their surgical incisions. Monitor incisions for signs of rupture or infection. Address issues with incision or signs of unwellness with your veterinarian. Sutures will need to be removed two weeks after surgery if non-dissolving stitches were used.
Cost of Subtrochanteric Derotational Varus Osteotomy in Dogs
The cost of subtrochanteric derotational varus osteotomy in your dog including consultation, radiographs, pre-surgery tests, anesthetic, procedure, hospitalization, and post-surgery care and medication can range from $1,000 to $4,000 or more. Cost varies depending on your location, expertise of an orthopedic veterinary surgeon, and intervention and reconstruction required to conduct subtrochanteric derotation varus osteotomy in your dog.
Dog Subtrochanteric Derotational Varus Osteotomy Considerations
This procedure is expensive and invasive and results can vary. It is an elective procedure, so owners will need to consider the likelihood of achieving a successful outcome for their pet. When performed in a healthy dog by an expert veterinarian, results can be good and resolve hip displacement conditions. Complications from anesthetic, hemorrhaging or infection are present as with all surgical procedures. Antiseptic procedures and an experienced veterinary anesthesiologist help mitigate these concerns.
Subtrochanteric Derotational Varus Osteotomy Prevention in Dogs
Dogs with congenital confirmation issues resulting in hip displacement should be removed from breeding programs. Reducing the likelihood your dog is subject to injury resulting in fractures to the femur that could result in varus rotation requiring surgical correction can be achieved by restricting outdoor activity that could result in accidents and falls by keeping your dog on leash when outside and ensuring your dog has good footing and traction indoors. If femoral fracture occurs, obtaining expert veterinary care to correct it initially may result in better outcomes, preventing misalignment of the femur resulting in displacements in the hip.