I'm sorry that your question wasn't answered in a timely manner. I understand that you're concerned about angular deformaties in Swagger's front legs. Here's a good synopsis for you which I'd like you to peruse. It's written for the vet but you'll glean important information and I'd be pleased to explain anything you didn't fully understand. Most important, if you're seeing "bowing" of Swagger's front limbs and such a deformity hadn't been present earlier, Swagger should be referred to a veterinary specialist orthopedic surgeon (please see here: www.acvs.org) promptly. We need to avoid further damage to his front limbs as soon as possible.
An abnormal growth of the limb, more common in dogs than in cats, due to premature closure of a physis (growth plate). Most commonly occurs in the forelimb, with radial or ulnar physeal closure(s). Rarely affects the hindlimb, with premature closure of the tibial physis.
Premature closure of radial, ulnar, or tibial physis; radius curvus; carpus valgus
Species, Age, Sex
Primarily young dogs (<1 year old)
- Trauma to limb and physis
- Some chondrodystrophic breeds may be predisposed.
History, Chief Complaint
- Trauma to the limb 3-4 weeks before deformity
- Often, dog is presented when the limb begins to appear deformed
Physical Exam Findings
- Lameness of affected limb, with pain on palpation of carpus or elbow
- The limb may appear shortened or have an angular deviation.
Etiology and Pathophysiology
- Premature closure of the distal ulnar physis is the most common physeal injury, likely due to the conical shape of this physis in dogs.
- Because of the paired bone system, cessation of growth in the ulna causes cranial bowing, external rotation, and valgus deformity of the radius. Elbow and carpal incongruities can also occur.
- Asymmetric closure of the distal radial physis can cause an angular deformity similar to closure of the ulnar physis.
- Symmetric closure of the distal radial physis will often lead to radial shortening and elbow incongruity but no angular deformity.
The diagnosis of premature closure of a physis leading to an angular limb deformity is suspected in a young dog with a shortened or angularly deformed limb, and confirmed on radiographs when compared to the normal limb.
- Malunion of a fracture
- Ligamentous or tendinous damage at the elbow or antebrachiocarpal joint
- Retained cartilaginous cores of the ulna
- CBC and serum chemistry panel: no abnormal findings expected with this disorder
- Mediolateral and craniocaudal elbow-to-carpus radiographs of the affected and contralateral limb to assess location and degree of deformation
Advanced or Confirmatory Testing
- Computed tomography (CT) may be used for further defining the limb deformation and joint congruency.
- CT images can be utilized to produce three-dimensional life-sized stereolithographic models.
Surgical treatment aims to restore joint congruity, normalize limb length, and correct angular and rotational deformities. In immature dogs, additional aims are to restore unrestricted growth of affected bones and prevent joint incongruities from developing.
Acute General Treatment
- Ulnar ostectomy: used in an immature dog with premature closure of the ulnar physis, to restore growth potential.
- A fat graft placed in the ostectomy prevents premature bone union.
- Distraction osteogenesis (via circular external fixation): used for treating premature closure of the distal radius
- This allows for limb lengthening and correction of angular deformities.
- Corrective closing radial wedge osteotomy or dome osteotomy (stabilized with a “T” plate, circular or linear external fixation, in combination with an ulnar ostectomy): performed in mature dogs for acute correction of angular and rotational deformities and to restore joint congruity
- Dynamic proximal ulnar osteotomy: permits realignment of severe elbow incongruities
- In the postoperative period, a soft padded bandage or metasplint may be placed to protect the limb. The bandage or splint is often applied for 2-4 weeks.
- Physical rehabilitation to reduce risk of complications
Exercise restriction for at least 6 weeks until radiographs confirm bone healing
- External fixation may have premature loosening of the fixation pins or pin tract infection.
- Inappropriate amount of surgical correction may result in persistent valgus.
- Distal radial plating may result in decreased antebrachiocarpal joint range of motion.
- Distraction osteogenesis may lead to flexor tendon contracture.
- Suture removal and recheck 2 weeks after surgery
- Radiographs at 4 to 6 weeks to evaluate bone healing
Prognosis & Outcome
- Guarded after ulnar ostectomy alone. Often an additional surgical procedure is necessary at skeletal maturity to correct the angular deformity.
- Good after definitive corrective osteotomy if the amount of correction is adequate.
Pearls & Considerations
- Stereolithographic models produced from CT scan images may be utilized to preplan surgical correction.
- Corrective osteotomy is performed at the point of maximum deformity to provide optimal realignment of the articular surfaces and appropriate limb alignment.
- The deformity may be localized and quantified using the center of rotation of angulation (CORA) method.
- If there is minimal radial shortening but radial head subluxation, a proximal ulnar ostectomy will shorten the ulna and restore elbow congruity.
- During ulnar ostectomy, the periosteum must be removed completely to prevent premature healing of the ostectomy site.
- Pes varus is a rare condition associated with distal tibial physeal closure in dachshunds.