Arthroscopic Management of Elbow Dysplasia
Elbow dysplasia is a developmental condition (i.e. occurs during growth) of the elbow joint. The dysplastic elbow joint does not “fit together” as well as a normal joint; abnormal loading occurs resulting in excessive forces in certain areas of the joint which cause damage and affect normal development. As elbow dysplasia is a developmental condition with a genetic basis both elbows are often affected.
Elbow dysplasia may have several clinical manifestations; these include stress fracturing (microfracturing) of th e medial coronoid process, which may result in fragments of bone breaking away (FCP), the development of a cartilage flap affecting the medial aspect of the humeral condyle (OCD) and ununited anconeal process (UAP). Osteoarthritis develops early in dogs affected by elbow dysplasia. Progression of osteoarthritis is inevitable, however early treatment may reduce the speed of progression of osteoarthritis.
Elbow dysplasia is a complex condition and a number of factors can affect the manifestation of the disease, however genetics play a significant role; for example coronoid disease (FCP) is most commonly recognised in the Labrador and ununited anconeal process is most commonly seen in the German shepherd.
The purposes of surgery are as follows:
to arthroscopically assess the elbow joint, and in particular the medial coronoid process and opposing surface of the medial humeral condyle, in addition to the anconeal process. Critical assessment for evidence of other elbow conditions e.g. IOHC will also be performed.
to arthroscopically (“keyhole” surgery) treat manifestations of elbow dysplasia e.g. debridement/removal of medial coronoid process fragments, removal of cartilage flap in osteochondral dissecans (OCD).
in cases of coronoid disease, surgical removal of a significant portion of the still attached medial coronoid process (subtotal coronoidectomy) may be performed to relieve pain caused by repeated microfracturing (stress fracturing) of the process. This is typically done with either a very small osteotome to"chisel" away the bone, or a high-speed bur.
to reduce the excessive forces acting on the medial coronoid process or anconeal process. Partial coronoidectomy will by definition reduce the forces acting on the coronoid region. Cutting the ulna (ostectomy/osteotomy) may also be performed in selected cases.
Surgery is used to treat manifestations of elbow dysplasia; however the underlying problem of incongruency or “poor-fit” of the elbow joint persists. i.e. the elbow will never be normal and some degree of progression of osteoarthritis is inevitable. Studies have shown that approximately 70 per cent of dogs treated arthroscopically for elbow dysplasia before 12 months of age will show improvement in degree of lameness. Dogs much older than this can still be treated successfully, however the success rate is likely to be somewhat lower in older dogs. It is an unfortunate reality that some dogs treated surgically for elbow dysplasia will not improve despite appropriate surgery and good post-operative care.
Arthroscopy is known as "keyhole surgery" because it is performed through very small incisions. Discomfort after surgery, however, is also affected by what is done inside the joint. In cases where only small bone fragments are removed and minimal joint manipulation is required discomfort may be barely noticeable and resolve in a matter of days. For cases where coronoidectomy (i.e. "chiselling" away bone) is performed and significant joint manipulation is required soreness may persist for several months.
As with any surgery complications may arise and are detailed below, although serious complications are rare.
Even though very uncommon, anaesthetic death can occur. With the use of modern anaesthetic protocols and careful monitoring the risk of problems with anaesthesia is minimised, but never eliminated.
Excessive early activity will damage newly forming cartilage which may delay progress or even affect outcome in the longer term.
Some dogs may temporarily deteriorate after surgery and may take several months to recover their pre-surgical state. Causes of deterioration may include ligament strain produced by joint distraction/manipulation during surgery (to aid arthroscope and instrument access) and microfractures produced in the peri-coronoid region during coronoidectomy. Management of these dogs may include strictly limited activity in addition to pain relieving medications. Additional physiotherapy including ultrasound, laser and shockwave therapy are likely to be beneficial
Infection is a rare complication follow arthroscopic surgery as strict sterile technique is used during the surgery and antibiotics are administered during and after the procedure. Should infection occur, early detection and treatment generally results in rapid resolution. More serious problems may occur if infection progresses untreated or if your dog suffers infection with a multiple resistance bacteria e.g. MRSA. If you suspect an infection contact your VET immediately.
It is important to have a controlled, gradual increase in activity, similar to human patients undergoing rehabilitation following surgery. If activity in dogs is increased too quickly after surgery straining of joint structures may occur. Management is as above.
Occasionally, dogs that have coronoid fragments removed may have further bone fragments break away over time. This has become much less common as management techniques have evolved e.g. more aggressive debridement of the coronoid including subtotal coronoidectomy.
The antebrachium (forearm) is mildly weakened after cutting the ulna (when performed) until the bone has healed; this places the radius at a mildly increased risk of fracture if excessive forces are applied i.e. jumping, running, turning sharply, although the incidence of radial fracture in these circumstances is extremely rare.
Arthritis is always present at the time of surgery. It is not possible to reverse the arthritic changes in the joint, although the progression of osteoarthritis may be slowed in some cases.
AFTERCARE OF YOUR DOG FOLLOWING ARTHROSCOPY:
Your pet should be kept confined (e.g. to a large cage or alternatively a single room with non-slip flooring) to restrict activity. Short leash walks in the garden (a few minutes four to six times daily) are recommended to allow toileting. Confinement should be maintained at all times for at least the first three to four weeks following surgery, with the exception of scheduled rehabilitation as detailed below.
Ice packs for 10 to 15 minutes several times daily are recommended in the first few days following surgery to reduce swelling and improve comfort.
Two weeks following surgery lead walking may commence for up to 10 minutes at a time, two to three times daily; confinement should be maintained at other times. Lead walking may gradually increase by approximately five minutes each week.
Hydrotherapy is beneficial and may commence following suture removal.