Elbow dysplasia - a review -

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1 Elbow dysplasia - a review - Andrea Meyer-Lindenberg Clinic of Small Animal Surgery and Reproduction Ludwig-Maximilians-University Munich Elbow dysplasia Group of congenital diseases of the elbow joint fragmented medial coronoid process (FPC) osteochondritis medial humeral condyle (OCD) ununited anconeal process (UAP) incongruency of joint surface step formation Others Medial compartment disease (MCD) ossification of tendon, muscle, joint capsule Incomplete ossification of humeral condyle (IOHC) Treatment elbow dysplasia depends on: - type of disease - type of incongruity - short-ulna-syndrome - short-radius-syndrome - degree of incongruity - age of the patient => individual case! UAP +/- Short-ulna-syndrome up to 8 months of age no or mild arthrosis before arthrotomy - arthroscopy - coexisting FCP/OCD - assessment of: joint cartilage movability of UAP UAP (loose +/- short ulnar syndrom) treatment (1): - stabilising with implants: -lag screw, Kirschner wire - two lag screws => via lateral approach to the joint UAP (loose +/-shortulnarsyndrom) treatment (2): - proximal oblique ulna ostectomy => restore joint congruity => relieve pressure on UAP - width depends on age 1

2 UAP (loose +/-shortulnarsyndrom) Treatment results of 22 cases: - anconeal proc. fused with ulna - step was leveled in most cases Long-term results: good - 17 joints satisfactory - 4 joints unsatisfactory - 1 joints no or minor progression of arthrosis UAP (tight +/- short ulnar syndrom) proximal oblique ulna ostectomy - as single measure => 2-3cm below the radial head => 45 angle => from caudal/proximal to cranial/distal => prevents complete dislocation of prox. ulna UAP (tight +/- short ulnar syndrom) Treatment results of 15 cases: - anconeal proc. fused with ulna - step disappeared in all but two cases Long-term results: good - 12 joints satisfactory - 3 joints unsatisfactory - 0 joints no progression of arthrosis in most cases UAP (+/- short ulnar syndrom) older dogs advanced arthrosis coexisting FCP => remove UAP via mini medial approach => if FCP is present => remove by arthroscopy first => no ostectomy of the ulna Short-ulna-syndrome withoutuap very rare? - arthroscopy => possible coexisting FCP, OCD - proximal ulna ostectomy => reduce the step => decrease pressure on anconeal process FCP (+/- short-radius-syndrome) many cases with FCP + step treatment strategy: - depends on degree - step/incongruity no step steplessthan2 mm medial compartment disease - removing FCP - together with cranial part of the mcp - arthroscopically with a thin chisel => subtotal coronoidectomy 2

3 step less than 2 mm => coronoidectomy step less than 2 mm => subtotal coronoidectomy step more than 2 mm ( Bernese mountain dogs) => resection of FCP => proximal osteotomy => resection of a slice of bone => allows radial head - move proximal - articulation with lateral humeral condyle Treatment results of 17 cases: (step more than 2 mm) - step disappeared in most cases Long-term results: good - 9 joints satisfactory - 6 joints unsatisfactory - 2 joints progression of arthrosis in most cases of different degree Short-radius-syndrome (+/- FCP) step up to 1 cm - e.g. traumatically physial disc disturbance => lengthening osteotomy of the radius => plate fixation => arthroscopical resection of FCP, if present FCP + Trochlear notch dysplasia / MCD no obvious step formation visible on x-ray - but dysplasia present - diagnosed by arthroscopy => abrasions on medial CP and humeral trochlea FCP+MCD => subtotal coronoidectomy => no step between lateral CP and radius 3

4 FCP/UAP + Trochlear notch dysplasia / MCD - removing FCP arthroscopically - removing UAP via medial mini-approach => fixation not practical due to existent incongruity Trochlear notch dysplasia/mcd without FCP obvious abrasions (medial compartment) treatment(arthroscopically): 1. osteotomy/ removal of the affected part of mcp with a thin chisel 2. remove a little more of the abraided areas with a shaver => prevent further abrasions => enable the formation of replacement cartilage Trochlear notch dysplasia/mcd without FCP Treatment results of 29 cases: good satis- unsatis- sum factory factory bicipital ulnar release procedure - reduction of pressure - medial compartment resection 8 (47%) 8 (47%) 1 (6%) 17 ostectomy 5 (42%) 6 (50%) 1 (8%) 12 sum 13 (45%) 14 (48%) 2 (7%) 29 progression of arthrosis in all cases - unsuccessful first treatment - more severe cases, permanent lameness sliding humeral osteotomy (SHO) - realigment of the limb - shifting of load - unsuccessful first treatment - more severe cases - permanent (severe) lameness elbow protheses - partial (medial compartment) - total (TATE) Wendelburg, Kyon, Symp proximal angulating Ulna leveling (PAUL) - perhaps the best treatment measure? 4

5 Many Thanks! 5