Pre-op fractured Feline Patella Fracture

Feline Patella Fracture/ Retained Deciduous Teeth Syndrome

Feline patella fracture and retained deciduous teeth syndrome is a condition which has only relatively recently been recognised in cats.  In this syndrome affected cats develop fractures of the patella (knee cap) without any obvious inciting cause such as trauma.  In addition affected cats frequently go on to develop fractures in other bones, again without any apparent cause.  The other bones most commonly involved are the tibia (shin bone), humerus (upper arm) and ishium (part of the pelvis).  In addition to bony problems, affected cats commonly also have retained deciduous (baby) teeth.  A finding that is normally rare in cats.

Repair of the patella fractures can frequently be challenging with many cases failing to achieve a radiographic union though many will do well clinically even if the repair fails.

A study group has been set up at the University of Bristol headed by Professor Sorrel Langley-Hobbs MA BVetMed DSAS(O) DECVS FHEA MRCVS to investigate the condition.  This study will look at many aspects of the disease including bone density, strength and collagen analysis.  One possible theory as to the cause of feline patella fracture syndrome is that this may be a manifestation of osteogenesis imperfecta – a disease which causes brittle bones.  There are however a number of disease processes which can result in bone fragility and therefore further study is needed to identify factors involved in these cases.  A few case reports of suspected feline osteogenesis imperfecta exist in the literature but none of these cases have been confirmed. We aim to investigate cases of feline patella fracture syndrome to identify if these are a form of OI or to see if alternative causes can be identified.

How can you help?

If you cat has been diagnosed with this condition*, or you are a vet and see a case of feline patella fracture retained deciduous teeth syndrome, then we would grateful if you could fill out the following survey. It should only take 5 minutes and will be very useful for our study.

*For owners, please fill out as much as you can and then ask your vet to complete any remaining sections.
Online questionnaire

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Does my cat need to have surgery?

This depends on the individual case.  If the fragments are not separated and there is minimal pain, then non-surgical management with strict rest  (cage confinement) may be possible.  In cases where the fragments have separated and or there is significant pain associated with the fracture then surgery should be considered.  If your cat has deciduous teeth which have not fallen out naturally then removal is recommended.  If complications occur as a result of retained teeth then these can be challenging to deal with.


What is the likely outcome?

There are a high proportion of cases that fail to achieve bone healing, even with surgery.  However a large proportion will achieve a clinical union.  This means that the pieces of bone have healed together with scar tissue but on x-rays the bone appears to still be fractured.  In these cases the prognosis can be fair though many cats will have ongoing intermittent lameness and there is a significant likelihood of arthritis developing at a later date.


If my cat has fractured one knee cap, will the other one also fracture?

This does depend on the individual case.  If your cat has fractured its’ knee cap without any trauma then there is a good chance that the other may fracture in the future – over half of the cats that we have information on have gone on to break their other kneecap.


How much will it cost to fix?  

This will depend on the individual veterinary practice.  This can vary widely depending upon the location of the practice and the level of experience of the surgeon.


How can my cat help with this project?

By allowing you vet to enrol your cat in the study, you can help us to identify the cause of this problem, potentially paving the way to better treatment options in the future.


What does enrolment in the project entail?  

We would like to obtain samples to enable us to conduct detailed research.  This will not result in any suffering or stress to your cat.  We simply require a blood sample (if blood is being taken for another reason e.g. a health check prior to anaesthesia) or a mouth swab (this can be taken while under anaesthetic if your cat is having surgery).  If your cat is undergoing surgery, we would also like to obtain a small piece of fibrous tissue taken from the surgical site.  This will not result in any increase in post-operative discomfort or affect the healing process. We are also hoping to collect bone samples from affected cats, this will only be relevant in the unfortunate circumstances where your cat dies or is euthanased for this or another unrelated reason.