Patella Luxation testing & scoring schemes in dogs
Patella luxation in dogs is a condition where the patella or "knee-cap" can move from its normal central position at the front of the knee or "stifle joint" to one side or the other. This condition is more common in the smaller breeds, however it may occur in large breeds and also cats.
In most dog breeds the most frequent direction of abnormal movement or "subluxation" is towards the midline of the dog- "medial patellar luxation". In some cases the subluxation can be away from the midline of the dog and is called "lateral patellar luxation".
What are Patella Luxation testing & scoring schemes?
Patella Luxation testing & scoring schemes in dogs are organised by many responsible breed associations or societies in breeds which have an increased frequency of patellar luxation.
The dog breeder or owners bring their dogs which they plan to breed from for an examination by a veterinary surgeon who is familiar with the Putnam Patellar Luxation Grading System. The examination is normally performed during an orthopaedic examination without sedation. Radiographs are not required but may be arranged in requested. In the UK & Ireland there is no official Kennel Club testing scheme for Patella Luxation as there are for Hip & elbow dysplasia and eye screening. However some breed Clubs hold a database of those dogs which have been checked for patella luxation using the Putnam (1968) testing and scoring method.
What do the different scores mean in the Putnam Patellar luxation Grading system for dogs?
The Putnam grading system grades dogs from Grade 0- no luxation present- normal, to increasing severity from Grade 1-4.
The following description is used by some breed societies as guidance although slight variations in the wording and description exists between breed societies. Most breed societies provide their own forms for the vet to complete. We have provided links to some breed societies operating these schemes and patellar subluxation assessment forms.
Grade 0: Normal
Grade 1: the patella can be manually luxated with the stifle in full extension, but when pressure is released without manipulation of the limb the patella regains its original position in the trochlea. Spontaneous luxation of the patella during normal joint motion rarely occurs. Typically stifle and hock in a straight line with no deviation of the hock.
Grade 2: the patella can be completely luxated, but manipulation of the hind limb (flexion of the stifle) causes the patella to regain its original position in the trochlear. On physical examination, the patella luxates easily, especially when the foot is rotated.
Grade 3: the patella is found (at least once) spontaneously luxated with the animal in a standing position or it is permanently luxated but can be repositioned manually or by manipulating the limb. Very shallow or flattened trochlear.
Grade 4: the patella is permanently luxated and cannot be repositioned. May scarcely be able to walk or may move in a crouched position with both limbs partially flexed, and/or they may carry the affected limb. Trochlea is shallow, absent or even convex.
Excessive force should not be used when manipulating the patella.
Where can I obtain the Patellar luxation testing forms for my vet to complete?
Contact your breed society to request to have a form sent to you for your specific breed as some forms may vary in the wording. Some forms are available for download below and links are provided to some breeds operating the system.
If you are a dog breeder and wish to have your breed listed or provide the up to date form please send this to us by email. Thank you.
What is the cost of patellar luxation scoring by a veterinary surgeon?
Costs for performing this test will vary depending on the clinic you attend. Not all veterinary clinics will perform the test or be aware of the Putnam system. The cost for this test in our clinic is £45 and the examination is performed by Ewing Walker, our orthopaedic surgeon who is experienced in the surgical corrective treatment of this condition.
The Griffon Bruxellois Club
Patella luxation testing forms. Page 1. Page 2
Pug Breeders Society
View Pug Breed Patella Luxation Testing Form-.pdf
German Spitz Breeder Club
German spitz breed patellar luxation testing form
Minature Pinscher Club
Affenpinscher breed patellar luxation testing form word document
Minature Pinscher Club
Minature Pinscher breed patellar luxation testing form pdf
Minature Pinscher breed patellar putnam form pdf
English Type (Toy) Terrier Club
Breeds listed under the KC assured Breeders Scheme advising Patella testing (slipping patella) under breed club scheme
include in addition to the above breeds: (sept 2013- KC assured Breeders Scheme -pdf)