Also known as periosteal "stripping", the periosteum over the growth plate on the concave side of the angular deformity is cut and lifted from the bone, accelerating growth on that side of the physis.
A bone screw is placed temporarily across the growth plate on the convex side of the angular deformity, slowing growth on that side. The screw is removed (standing: local anesthesia and sedation; no general anesthesia) when the limb is straight (2-4 weeks later, on average).
Transphyseal screw/wire bridge
For more extreme angular deformation, the growth plate on the convex side of the deformity is restricted with a screw and wire bridge. The construct is removed (standing: local anesthesia and sedation; no general anesthesia) when the limb is straight.
"Club foot" - Inferior check desmotomy
Upright, or "club foot", hoof conformation is caused by contraction of the deep digital flexor tendon. The inferior check ligament attaches the lower part of this tendon to the back of the cannon bone. Surgical transection of this tether releases contraction by allowing tension to diffuse into the deep digital flexor muscle belly. Therapeutic shoes with toe extensions are applied at the time of surgery to maximize correction. Ideally, surgery is performed when the horse is young (4-12 months old, depending on severity).
"Over at the knee" - Superior check desmotomy
Carpal contraction, or "over at the knee" conformation, is caused by contraction of the superficial digital flexor tendon. The superior check ligament attaches the upper portion of this tendon to the back of the radius. Surgical transection of this tether releases contraction by allowing tension to diffuse into the superficial digital flexor muscle belly. Therapeutic shoes are applied at the time of surgery to maximize correction. Ideally, surgery is performed when the horse is young (6-12 months old, depending on severity). This surgery can be done via an open approach or a tenoscopic approach through the carpal canal.
All joints, tendon sheaths and bursae
Minimally invasive removal of articular chip fractures improves athletic prognosis.
Osteochondrosis dissicans (OCD) lesions
Surgical removal of OCD lesions stops the cycle of chronic inflammation in the joint, cycle prevents cartilage destruction, and eliminates the chance of the osteochondral fragment breaking inside the joint. If removed before a young horse commences work or turn out, the classic effusive "bogged" joint appearance may be avoided. Early removal improves athletic prognosis.
The annular ligament passes around the flexor tendons as they pass down behind the fetlock through the digital flexor tendon sheath. In some cases of chronic tendon sheath effusion, this ligament restricts the gliding function of the flexor tendons, exacerbating lameness and effusion. Transection of this ligament can restore soundness and athletic function. This surgery should not be considered for simple "wind-puffs" in a sound horse.
Surgical management of septic synovitis
Endoscopic debridement is the gold standard for treatment of infected synovial structures (joints, tendon sheathes and bursae). Minimally invasive (endoscopic) lavage and debridement of the material (fibrin) that accumulates inside the synovial structure maximizes the chances of successful treatment. Addressing the infection less than 36 hours after contamination or on-set is of the utmost importance. Prognosis drops precipitously after that time period.
The arthroscope is inserted into the joint for an unsurpassed view of the articular surface during fracture reconstruction. Use of the scope eliminates the need for a large incision into the joint. Direct view guides accurate reconstruction for a perfectly congruent joint surface, minimizing the chances of future osteoarthritis.
Routine (e.g. condylar, carpal/tarsal slab and proximal phalanx fractures, etc.)
These fractures are simple in configuration and are repaired with bone screws alone.
Physeal (growth plate) fractures
Fractures involving active growth plates in young animals are describe according to the Salter-Harris classification system. Different principles must be taken into consideration when working with or around growth plates.
Foals sustain rib fracture during birth or shortly thereafter. All rib fractures should be evaluated but few need to be repaired. When the sharp bone ends puncture the lung or overlay the heart (threatening cardiac puncture) the rib fractures should be stabilized immediately.
Arthroscopically-guided articular fracture repair: See "arthroscopy"
Major fracture repair is a challenge in the horse. Mid-Atlantic Equine Medical Center stocks a full complement of fracture repair instrumentation and uses state-of-the-art locking compression bone plate/screw technology made by DePuy-Synthes.
Arthrodesis refers to surgical fusion of a joint. The two most common indications for arthrodesis are severe (end-stage) osteoarthritis and high-energy (comminuted) fractures that damage an articular surface beyond repair. Any remaining cartilage is removed and locking compression plates and bone screws are applied to stabilize the joint as it fuses. In some cases of advanced osteoarthritis, the procedure can be done with a minimally invasive approach. It is the motion of bone-on-bone contact that is so painful. Once the arthritic/damaged joint fuses motion is eliminated and the horse regains comfort. Fusion of low-motion joints (i.e. pastern and distal hock joints) does not eliminate the possibility of advanced athletic activity. Fusion of high-motion joints (i.e. fetlock, knee) offers comfort but alters the gait enough to preclude any real athletic activity.
Our surgical team also performs dental and sinus surgery, ophthalmic surgery and coil embolization of the carotid arteries for guttural pouch mycosis.