The latest in orthopedics

The 2009 meeting of the Veterinary Orthopedic Society was held in Steamboat Springs, Colorado and featured a wide range of orthopedic presentations.

Fragmentation of the medial coronoid process of the ulna is a common cause of forelimb lameness in large breed dogs. Recently it has been suggested that this problem may be mistaken for shoulder pain in some patients (1). This can occur because the biceps and brachialis muscles that originate in the shoulder region, have an insertion on the medial coronoid process. Contraction of this muscle group, as in some shoulder diagnostic manipulations, may actually press a fragmented medial coronoid against the radial head evoking a pain response (1,2). Dr. Noel Fitzpatrick has presented and published work on several approaches to this condition including humeral osteotomies designed to “off-load” the medial elbow compartment and subtotal coronoidectomy to remove abnormal bony tissue (3). His presentation at VOS 2009 described surgical release of the biceps tendon in 49 elbows near its insertion on the ulna, parallel to the caudal border of the medial collateral ligament (2). This preliminary study involved 39 dogs, 25 of which also received subtotal coronoidectomy, while 14 received only the biceps ulnar release procedure (BURP). Evaluation at a mean follow-up time of 83 weeks revealed statistically significant improvement based on clinician and owner subjective evaluation. Force plate data comparing BURP limbs with normal limbs in the same dog revealed no statistically significant difference. No adverse effects were associated with the procedure. The investigators acknowledge that the results are very preliminary and that case selection criteria have yet to be clearly defined; however, initial results are encouraging and the procedure warrants further investigation (2).

A link between cranial cruciate ligament rupture and damage to the medial meniscus has long been recognized. Reported percentages vary, but at least 50% of stifles with a cranial cruciate ligament rupture also have some form of medial meniscal damage (4). Colleagues in British Columbia presented a link between the duration and extent of cruciate ligament pathology and the presence and severity of medial meniscal pathology (5). A retrospective analysis of records on 917 stifles in 503 dogs that underwent tibial plateau leveling osteotomy (TPLO) examined the degree of cruciate ligament damage, the duration of clinical symptoms, and the corresponding rate and severity of medial meniscal damage. The status of the stifle was classified as laxity, partial rupture, or complete rupture. Medial meniscal changes were classified as fibrillation (grade 1), partial tear (grade 2), complete tear (grade 3), or multiple tears or caudal pole avulsion (grade 4). Grade 3 or 4 meniscal damage was not seen in stifles with laxity or partial tears for up to 8 wk. Meniscal pathology of this severity was seen as early as 2 wk with complete cruciate ruptures. Meniscal damage correlated directly with the severity and duration of cruciate pathology. Medial meniscal damage was detected in 19% of stifles at 0 to 12 wk, 45% at 13 to 24 wk, 73% at 25 to 36 wk, and 89% after 36 wk. The authors concluded that medial meniscal damage was directly associated with stifle instability (5).

A prospective study of 110 dogs with cranial cruciate ligament disease was presented, 51% of the dogs had histologic evidence of lymphoplasmacytic synovitis (LPS) on examination of synovial biopsies taken at the time of surgery (6,7). There were no significant differences between the LPS group and those without LPS in terms of age, body weight, duration or severity of lameness or radiographic signs of degenerative joint disease, extent of cruciate ligament rupture (partial or complete), or meniscal pathology. The only significant difference noted was that the tibial plateau angle was lower in the LPS group. The presence of inflammatory mediators and cells within the joint fluid and synovium of dogs with cranial cruciate disease has been documented in the past. However, the significance of these findings has been the subject of debate. Whether the inflammatory milieu is a proximate “cause” or “effect” in cruciate disease remains unclear. These findings fall far short of identifying an autoimmune component to cruciate disease, but what they clearly show is that not every cruciate ligament rupture is created equal!

Lumbosacral degenerative stenosis is a painful and debilitating disease common in larger breed dogs. Conservative medical therapy is effective in some cases, while others have traditionally been treated with decompressive surgery. The use of epidural corticosteroids was presented as a treatment alternative (8). Specifically, 38 dogs with lumbosacral stenosis were treated with fluoroscopic-guided epidural injections of methylprednsiolone acetate on day 1, days 12 to 16, and days 40 to 60. The median number of treatments was 5 per dog. Owner questionnaires were sent out at a median of 46 months. Thirty owners reported improvement in clinical signs while 20 considered the signs to be completely resolved. The authors feel this success rate is comparable to conservative and surgical therapies and warrants further investigation (8).