|
| Patellar Luxation |  |
|
|
| True dislocation of the patella is uncommon in horses. When it does occur, it is usually a serious injury and the lateral luxation is readily apparent. In some breeds, a congenital form of lateral luxation is seen similar to that in small dogs ( Patellar Luxation). The most frequent problem involving the patella is upward fixation or locking of the medial patellar ligament over the proximal part of the medial femoral trochlear ridge. Some pony breeds may have a hereditary predisposition, but patellar luxation is also seen in immature animals with poorly developed thigh muscles. It may be uni- or bilateral. The classical signs are of an intermittent locking of the limb in extension followed by a sudden jerk or hyperflexion as the patellar ligament becomes freed from the medial trochlear ridge. The signs are most frequently seen after standing still for any period (eg, overnight in the stable, or after travelling in a trailer). However, the clinical signs are often much less dramatic, which makes diagnosis difficult. There may simply be a lack of hindlimb impulsion associated with a rather jerky patellar action. |
| In many cases, a general improvement in fitness and muscle tone of the hindquarters effects a cure. In the more severe and persistent cases, desmotomy of the medial patellar ligament is indicated. However, desmotomy, which has been commonly used in the past, is currently in disfavor. A fragmentation of the distal extremity of the patella is believed to follow the surgery, particularly if postoperative exercise is initiated early. When surgery is done, rest should be sufficient (eg, 4-6 wk) to permit complete healing before training is resumed. |
 |
| See Also |
| Introduction |
| The Lameness Examination |
| Overview |
| Imaging Techniques |
| Overview |
| Anatomic Imaging Techniques |
| Physiologic Imaging Techniques |
| Arthroscopy |
| Regional Analgesia |
| Disorders of the Foot |
| Bone Cyst in Pedal Bone |
| Bruised Sole and Corns |
| Canker |
| Contracted Heels |
| Fracture of Navicular Bone |
| Fracture of Pedal Bone |
| Keratoma |
| Laminitis |
| Navicular Disease |
| Pedal Osteitis |
| Puncture Wounds of the Foot |
| Pyramidal Disease |
| Quittor |
| Sandcrack |
| Scratches |
| Seedy Toe |
| Sheared Heels |
| Sidebone |
| Thrush |
| Disorders of the Fetlock and Pastern |
| Fracture of Phalanges and Proximal Sesamoids |
| Osselets |
| Ringbone |
| Sesamoiditis |
| Villonodular Synovitis |
| Windgalls |
| Disorders of the Carpus and Metacarpus |
| Overview |
| Bucked Shins |
| Degenerative Subchondral Lesions of the Carpal Bones |
| Desmitis or Sprain of the Inferior Check Ligament |
| Fracture of the Carpal Bones |
| Intra-articular Osteochondral Chip Fragments of the Carpus |
| Carpal Slab Fractures |
| Accessory Carpal Bone Fractures |
| Fractures of the Small Metacarpal and Metatarsal (Splint) Bones |
| Fracture of the Third Metacarpal (Cannon) Bone |
| Hygroma |
| Osteoarthritis (Degenerative Joint Disease) |
| Osteochondrosis |
| Osteochondroma of the Distal Radius (Supracarpal Exostosis) |
| Rupture of the Common Digital Extensor Tendon |
| Splints |
| Subchondral Cysts and Septic Arthritis |
| Suspensory Desmitis |
| Synovial Hernia and Ganglion and Synovial Fistulae |
| Tearing of the Medial Palmar Intercarpal Ligament |
| Tenosynovitis of the Tendon Sheaths Associated with the Carpus |
| Traumatic Synovitis and Capsulitis |
| Disorders of the Shoulder and Elbow |
| Arthritis of the Shoulder Joint |
| Bicipital Bursitis |
| Fractures of the Elbow |
| Fractures of the Shoulder |
| Sweeney |
| Disorders of the Tarsus |
| Overview |
| Bog Spavin |
| Bone Spavin |
| Curb |
| Displacement of Superficial Flexor Tendon from the Point of the Hock |
| Fracture of the TArsus |
| Hindlimb Tendon Ruptures |
| Rupture of the Peroneus Tertius Muscle |
| Stringhalt |
| Thoroughpin |
| Disorders of the Stifle |
| Fracture of the Stifle |
| Gonitis |
| Subchondral Bone Cyst |
| Disorders of the Hip |
| Coxitis |
| Dislocation of the Hip |
| Pelvic Fracture |
| Trochanteric Bursitis |
| Disorders of the Back |
| Fractures |
| Muscle and Ligament Strain |
| Ossifying Spondylosis |
| Overriding of the Dorsal Spinous Processes |
| Sacroiliac Injury |
| Developmental Orthopedic Disease |
| Overview |
| Osteochondrosis |
| Physitis |
| Flexion Deformities |
|