1. Feline Knees & Teeth Syndrome
Feline Knees & Teeth syndrome is a newly recognized syndrome of concurrent dental and orthopedic developmental pathologies; specifically, retained deciduous teeth, impacted permanent teeth, and non-traumatic patellar fractures. It is not known if this is an acquired or a genetic problem, but most speculation is leaning towards a genetic cause.

2. Feline Knees & Teeth Syndrome
Zora was the first known case reported by our practice in 2004.
Earlier that year she was treated for multiple retained deciduous teeth and impacted adult teeth via surgical extractions. This is very uncommon.
Zora:

3. Zora:
3 months later she returned for predominantly left sided rear leg lameness and palpable distal quadriceps swelling.

4. Zora:
VD Pelvic Girdle

5. Zora:
2 weeks later she returned again, worse.

6. Spaz
Spaz was treated for retained deciduous teeth in Left mandible:

7. Spaz
Retained deciduous teeth and deeply impacted permanent teeth.

8. Spaz
Aggressive surgical extraction required. Left mandible post extraction.

9. Spaz
Tooth Roots and sectioned crowns:

10. Spaz
Closure.

11. Spaz
Right side pre-surgery:

12. Spaz
Retained deciduous teeth and deeply impacted permanent teeth.

13. Spaz
Aggressive surgical extraction required. Right mandible, post extraction.

14. Spaz
Tooth Roots and sectioned crowns:

15. Spaz
Our records showed that “This patient had a hind leg lameness at about 2 years of age that the owner never pursued.”
2 years after the above dental care we saw Spaz again and opted to radiograph his stifles “just to see.”

16. Feline Knees & Teeth Syndrome
Coincidence?
The occurrence of these two very unusual pathologies occurring in the same patient seemed very odd.
Occurring in two patients, more than a coincidence.
Michele Gaspar, DVM, DABVP reported on a 3rd case in 2006.
Since then, we have accounted for 17 similar cases and over a dozen possibly related cases (with the absence of dental pathology).

17. Age at time recognition of lameness and/or patellar lesions:
VIN CASES, 17 REPORTED:
Average: 23 months (when recognized)
Range 10 months to 7 years.
EUROPE (Langley-Hobbes) CASES, 43 REPORTED:
Average 29 months (when recognized)
Range 4 months to 5.5 years
10 With Patella and Tibia fractures
33 With Patella fractures
5 with reported retained deciduous teeth (Under-reported?)

18. Feline Knees & Teeth Syndrome
 Salas N, Popovitch C. Surgical versus conservative management of patella fractures in cats: a retrospective study. Can Vet J 2011;52:
(Note: no dental pathology reported)
Langley-Hobbs SJ. Survey of 52 fractures of the patella in 34 cats. Vet Rec 2009;164:80-86.
(Note: 5 of 34 cats had dental pathology)
Langley-Hobbs SJ, Ball S, McKee WM. Transverse stress fractures of the proximal tibia in 10 cats with non-union patellar fractures. Vet Rec 2009;164:
(Note: no dental disease reported)

19. Feline Knees & Teeth Syndrome
Some speculate that this may be related to osteogenesis imperfecta, which may occur along with dentinogenesis imperfecta in man.
There is no similar syndrome that occurs in man.
We are collecting blood samples for DNA analysis with Dr. Casal at The University of Pennsylvania in hopes to uncover a common defect.
Langley-Hobbs SJ. Survey of 52 fractures of the patella in 34 cats. Vet Rec 2009;164:80-86.
Little, S. (2012). The cat : clinical medicine and management. St. Louis, Elsevier Saunders.

20. Feline Knees & Teeth Syndrome
These cases are likely missed.
Cats are very difficult to appreciate dental pathology when they are awake. Subsequently, veterinarians do a poor job a recognizing dental disease in cats unless the practice culture is dedicated toward dental care. When referred for surgery, the orthopedic surgeons are even more not oriented toward assessing dental pathology.
Even when we see the pathology, we may not recognized the pathology for what it is: retained deciduous canine teeth. A classic description was “the teeth were wonky.”
Many of these cats when left to their own recover to varying degrees from their patellar fractures, so even these patients may go unnoticed.

21. Patellar Pathology Zora:
Because of the loss of quadriceps function, the reciprocal ability to extend the hock is similarly affected and these cats often walk with a plantigrade stance:
Zora:

22. Patellar Pathology
Over time, the proximal patella segment may continue to migrate further up the leg.
The insertion of the rectus femoris and the vastus intermedius are centered on the proximal portion of the patella.
The insertion of the vastus lateralis and the vastus medialis are distributed along the sides, continuous with the patellar tendon.

23. Other Bony lesions:

24. THE KNEES & TEETH SYNDROME
Summary
Young cats, 1 to 2 years.
Presence of (unrecognized) multiple retained deciduous cheek, +/- canine teeth, and impacted permanent cheek teeth
Spontaneous onset of lameness and swelling of the distal quadriceps
Followed by pathologic fracture(s) of the patella(s), +/- patellar sclerosis
The proximal patellar segment often migrates over time as the vastus intermedius and the rectus femoris contract
These cat may have an altered, plantigrade stance
Possible concurrence of other pathologic bony changes or non- traumatic fractures: pelvic, tibial, femoral, spinal, humoral
Surgery to reduce the fracture(s) often results in less “return to function” than conservative care.
THE KNEES & TEETH SYNDROME