Canine Carpal Laxity Syndrome

Trisha J OuraMarch 26, 2012

“Carpal Laxity Syndrome”Encompasses hyperextension and

hyperflexion of the carpusAKA: Carpal Hyperextension, Carpal

Hyperflexion, Carpal Flexural Deformity, Carpal Instability, Carpal Flexion Syndrome

Inspired by:Accession: 131102Patient ID: 1546654 mo WeimeranerAcute onset carpal

flexure w/o pain on palpation

RIGHT

LEFT

EtiologyLarge animal cases well documented

Congenital (in utero positioning, genetic, etc)Acquired (diet, exercise)

Few case series in the literature for small animalsCause unknown:

Rapid growth = excessive wt gain before adequate bone development

Asynchronous development between skeletons and muscuolotendinous apparatus Faster bone growth = relative musculotendinous shortening

Diet? 1 case series w/ over-supplemented or imbalanced diet, others with no dietary abnormalities

SignalmentYoung (6-12 wk old)Large breeds: GSD, Doberman*, SharPei*, Great

Dane, etcMale > Female?Unilateral, bilateral, flexion, extension, flexion &

extensionClinical signs:

Acute onset limb deformity without pain, swelling, CP deficits, etc

Pain on manipulation—should think of other concurrent disease (e.g. HOD)

Presentation

AnatomyGinglymus joint (hinge w/

movement in 1 plane)Majority of motion

antebrachiocarpal joint (70%)Least at carpometacarpal

joint (~5%)Predominant disruptive

force = hyperextensionPrevented by plamar

radiocarpal & ulnocarpal ligaments, flexor retinaculum, palmar carpal fibrocartilage

**

Therapy ControversialExercise….

Or not….Splint

Or not….Good prognosis: self-limiting, almost all resolve

within 4 weeks, most within first 2 weeksThose that don’t improve may require splints,

rarely require surgical resection of contracted tendons or arthrodesis

DDXTraumatic hyperextension

Jump/fall with acute disruption of palmar supportOften w/ associated injuries (e.g. proximal MC

fractures)Degenerative carpal

hyperextensionMiddle-aged, older Collie-

type breeds w/o hx of trauma

Usually non-painful but may have periarticular soft tissue thickening and reduced range of motion

DDXFlexor carpi ulnaris

injuryDocumented in racing

Greyhounds, Weimeraners

Grading of accessory carpal bone fractures (type I-V)

May present with carpal flexion

Radiographic abnormalities** Soft tissue swelling +/- carpal bone avulsion fragments

FYI: Caudal distal luxation

of radial carpal boneRare! Reported in dog

and catOccurs with

hyperextension, pronation, THEN suppination

Rupture of short radial collateral, dorsal radiocarpal, and intercarpal ligaments

ReferencesAltunatmaz K, S Ozsoy. Carpal flexural deformity

in puppies. Veterinaria Medicina 2006:2:71-74.Cetinkaya, MA, et al. Carpal laxity syndrome in 43

puppies. Vet Comp Orthop Traumatol 2007;20:126-130.

Harasen, G. Canine carpal conundrums. Can Vet J 2010;51:909-10.

Vaughan LC. Flexural deformity of the carpus in puppies. J Small Anim Pract 1992;33:381-384.

Whitelock R. Conditions of the carpus in the dog. In Practice 2001:2-13.