Ortho: Lecture 15 Part 2

Angle of osteotomy: caudoproximal to craniodistal + craniolateral to caudomedial*; bandage 3-5 days

Elevation of interosseous ligament off ulna aids in distal migration of ulna; may -> significant hemorrhage

Lameness of one forelimb typical; stiff gait/stilted if bilateral lameness (may walk w/ shortened steps)

3cm incision over lateral distal 1/3 of ulna ending at distal ulnar physis

Incise + elevate periosteum - isolate ulna w/ Hohnmann retractor; remove 5mm section of ulna (osteotome, saw, rongeur)

CT: more accuracy in evaluating incongruence then rads; Arthroscopy most accurate for diagnosing

This is an arthroscopic view of elbow showing MCD w/ full thickness (grade IV) cartilage damage (cartilage loss)

Full thickness fissuring

By decreasing transarticular loads - sliding humeral osteotomy, radial osteotomy, segmental ulnar osteotomy*

Forelimb lameness worsens after exercise; acute/chronic; stiff in morning or after rest

Etiology unknown; mechanical overload or incongruity of elbow joint; severity of cartilage loss; mod. outerbridge scale

Segmental osteotomy in proximal 1/3 of ulna - removing approx. 1/2cm of bone; periosteum/fascia - simple continuous

Severity of radiographic changes does not correlate w/ severity of cartilage damage

Bilateral* lameness of forelimbs typical; stiff gait/stilted if bilateral (walk w/ shortened steps)

Microfracture + abrasion arthroplasty - create channels for revascularization of arthritic lesion from bone marrow

Chrondromalacia

Release of ulnar insertion: decrease transarticular forces b/w distal medial humeral condyle + medial coronoid process

Osteophytes assoc. w/ coronoid process + tip of anconeus may be visible; severe diffuse osteophytosis may be observed

Dissect b/w tendon of lateral digital extensor muscle + tendon of ulnaris lateralis muscle - expose diaphysis of ulna

Incongruence of joint; investigated w/ plain film radiography or CT; MCP will appear proximal to radial head*

Palpation of dog standing - may have symmetrical or asymmetrical muscle atrophy (chronic pain + decreased muscle use)

Routine medial-lateral rads inaccurate for diagnosis of mild incongruity; Flexed lateral views evaluate more accurately

Mechanical forces that led to cartilage erosion also prevent healing of cartilage lesion

Palpation of dog standing: may have symmetrical or asymmetrical muscle atrophy (chronic pain + decreased muscle use)

Asynchronous growth b/w radius + ulna; ^ forces across medial compartment of elbow -> fragmentation + cartilage damage

Joint effusion + periarticular soft tissue swelling; most easily felt when standing; +/- decreased ROM

Medial portion of coronoid process; medial distal aspect of humeral condyle; some: medial most portion of radial head

Release of biceps insertion on ulna: biceps exerts sig. proximal forces on radius + ulna

Moderate to severe cartilage erosion - limited to medial aspect of canine elbow joint

May aid in recruiting stem cells to area to aid in healing; techniques likely of limited benefit

Allows less invasive exam of greater portion of joint; severity + extent of cartilage damage more easily seen

Most definitive tool for diagnosing; enable direct visualization + assessment of cartilage surface; superior to open sx

Decreased ability to flex elbow indicative of more severe OA: manipulation of joint often painful

Partial thickness fibrillation + fissuring

Pain on hyperextension of elbow (may be earliest sign of FCP); decreased ability to flex elbow (indicates ^ severe OA)

Replacing bearing surface (total elbow replacement)

Forelimb lameness worsens after exercise, acute/chronic, stiff in morning/after rest, coincidental history of trauma

Shoulder not flexed + extended during elbow manipulation* prevents mistaking shoulder pain for elbow pain

Joint effusion + periarticular soft tissue swelling; most easily felt while dog standing; +/- decreased range of motion

Large-breed dogs usually affected - diagnosed in any size dog; age of onset unknown; 6 months or several years of age

Elevation of coronoid above level of radial head; suggested cause of fragmentation of MCP + medial compartment disease

Release of biceps may aid in healing of microcracks in coronoid + decrease risk of MCD

Severe cases (greater than 4mm); incongruence recognized on lateral or craniocaudal view

Eburnated cartilage

Decrease pain + joint inflammation by decreasing stimulation of nerve endings in subchondral bone; removal of coronoid*

Full thickness cartilage loss

Many patients also have FCP; fragment removal alone benefit questionable; pain assoc. w/ cartilage damage repairs

Rad signs of DJD; variable; severe cartilage damage may be present w/ minimal radiographic changes

Large dogs; disease process starts when animal is immature; 5-7months; dogs may present at any age for OA via dysplasia

Periosteum/fascia simple continuous; bandage 3-5d; various locations; interosseous ligament limitations

Restore normal congruence b/w proximal articular surfaces of radius + ulna; shortening ulna or lengthening radius

Crepitation during elbow flexion + extension if advanced OA present; manipulation of joint often painful