Hip dysplasia and JPS surgery in puppies
Hip dysplasia is a common orthopaedic condition that primarily affects dogs and occasionally affects cats. It is especially common in larger breeds such as Great Danes, Saint Bernards, Labradors, Golden Retrievers and German Shepherds, to name a few. It is a genetic disorder with multiple genes involved in its inheritance, and certain environmental conditions can influence the expression of the disease.
In all cases, the hips are normal at birth, but proceed to develop abnormally. This process results in “laxity” or “looseness” of the hips. With the increase in laxity across the hip joint, comes an increase in stress and concussive force across the hip joint when the dog is moving. This creates recurrent stretching of the hip joint capsule. The increase in hip laxity allows the hips to subluxate (partially dislocate). This exerts a recurrent traumatic force across the hip joint. It is this abnormal force across a small area that leads to the inflammation and eventually boney changes of the hip joint – also known as osteoarthritis. When the cartilage in the joint becomes damaged, hip pain and osteoarthritis develop.
Some environmental factors that contribute to hip dysplasia include: rapid growth, excess body weight, excessive activity or exercise, too much calcium and phosphorus in the diet and age of desexing.
Hip laxity – the ability of the hip to subluxate (partially dislocate) over time will lead to osteoarthritis of the hip joint. Early detect of hip laxity in puppies is important as they may be a candidate for a procedure called JPS (Juvenile Pubic Symphysiodesis).
The JPS procedure involves us triggering early closure of the growth plate of the pubic bone of the pelvis, which allows the pelvis to grow differently and improves how well the socket of the hip covers the ball of the hip. If we can improve the depth of the socket that the ball of the hips sit in, the hips will subluxate less/or not at all. This will lead to less trauma on the hips and therefore less arthritis in the future.
Around 90% of dogs will benefit from this preventative measure as they will not display any sign of arthritis or require any advanced surgery for their hip joint. This procedure is not super invasive and has low morbidity with similar recovery time and discomfort to a desexing procedure.
Optimal age for the JPS procedure is between 12-16 weeks old, with 20 weeks old being the higher end of the age cut off. To determine if the patient is a candidate for JPS surgery, hip x-rays are taken under general anaesthetic and submitted for PennHIP testing, which is the gold standard in the evaluation of the hips for laxity and congruency and is used globally. PennHIP testing is accurate in puppies as young as 16 weeks old, which is why x-rays are usually recommended at 16 weeks old in asymptomatic puppies. However, if the puppy is showing discomfort in their hips or lameness, we may recommend doing the x-rays from 12 weeks old so that we can time their JPS procedure a little earlier to achieve optimal outcomes.
Doug’s JPS Procedure and Outcome
Doug is a German Shepherd cross Malamute who is an at risk breed for hip dysplasia. He is Dr Jaimie’s fur baby and she opted to do the screening hip x-rays for hip laxity at 15.5 weeks old. This involved Doug having a general anaesthetic and special x-ray views of his hips taken under general anaesthetic by Dr Jenny. His distraction index (DI) was between 0.4 – 0.7 (normal hip with no laxity has a DI of ≤0.3), which made him a candidate for JPS surgery.
Doug was booked in the following week for JPS surgery – at 16.5 weeks old. This involved him coming in for a general anaesthetic, having his pelvic region shaved and a small incision made over his pelvic region. An electrocautery pen was used to trigger early closure of a portion of the pubic growth plate. He then had internal stitches to close his skin.
Dr Jaimie knew this procedure was relatively lowly invasive, however she was still a bit concerned her little boy would be sore and sorry for himself. Doug received the same level of pain relief our desexing patients receive and felt great. So great in fact that he was back to being a mischievous puppy by that evening and was very difficult to keep quiet in his post operative period. Doug received some additional medication called trazodone to help keep him relaxed and quiet so he would be properly rested in his recovery period. It is recommended that patients are kept rested for 7 days after the procedure, and in our experience, Doug was not the only puppy who required trazodone to help with this!
Doug is now a 2 year old very handsome man with normal hips! He was desexed last week at GAH, and while under his anaesthetic, Dr Jenny repeated his hip x-ray to assess the level of hip laxity he has after the JPS procedure he had nearly 2 years ago. His results are fantastic, showing he has no hip laxity/hip joints are now within normal limits. This is a great relief to his parents knowing that the procedure was successful and will mean he will not experience hip dysplasia/arthritis as he ages.
Below are Doug’s values at 15.5 weeks old prior to the JPS procedure, and now at 2 years old.
