Proximal Suspensory Proximal Suspensory

Ligament DesmitisLigament Desmitis

Luke Bass, DVM, MSLuke Bass, DVM, MS

SignalmentSignalment

�� 9 yr old QH gelding9 yr old QH gelding

�� Function: Barrel racing Function: Barrel racing

(nationwide)(nationwide)

HistoryHistory

�� Forelimb fetlock joint injections, chiropractic adjustments, andForelimb fetlock joint injections, chiropractic adjustments, and acupuncture acupuncture

�� 5/055/05-- LH lameness (2+/5) blocked to TMT jointLH lameness (2+/5) blocked to TMT joint

�� RadsRads-- No Significant findings No Significant findings

�� Stall rest and NSAID Stall rest and NSAID

�� 6/05 6/05 –– Chronic LH lamenessChronic LH lameness

�� Nuclear Scintigraphy Nuclear Scintigraphy

�� DIT & TMT injectedDIT & TMT injected

�� 4/064/06-- RH lamenessRH lameness

�� Chiropractor adjustment & acupunctureChiropractor adjustment & acupuncture

HistoryHistory

�� 5/06 5/06 -- LH lameness (2/5), + flexions, LH fetlock joint block LH lameness (2/5), + flexions, LH fetlock joint block (70%)(70%)�� LH fetlock injectedLH fetlock injected

�� 7/067/06-- Lameness unchanged, LH fetlock U/SLameness unchanged, LH fetlock U/S�� SSL & OSL fiber disruptionSSL & OSL fiber disruption

�� 8/068/06-- ESWT ESWT -- LH fetlockLH fetlock

�� 8/068/06-- LH lameness LH lameness -- 70% improvement with fetlock block70% improvement with fetlock block�� Diagnostic arthroscopy Diagnostic arthroscopy

HistoryHistory

�� 1010--12/06 12/06 -- Chiropractor adjustment, acupunctureChiropractor adjustment, acupuncture

�� 2/072/07-- Bilateral lameness; moderate OA changesBilateral lameness; moderate OA changes

�� Both hocks were medicatedBoth hocks were medicated

�� 2/072/07-- Chronic LH lameness, + flexionsChronic LH lameness, + flexions

�� Proximal suspensory blockProximal suspensory block

�� U/S U/S -- enthesiophyte @ origin, suggested MRIenthesiophyte @ origin, suggested MRI

UltrasoundUltrasound

•Mild desmitis- Origin of the LH SL

•Mild enthesopathy- Origin of the LH SL

MRI and Surgical treatmentMRI and Surgical treatment

�� LHLH-- Acute desmitisAcute desmitis-- thickening, focal bony resorption at that thickening, focal bony resorption at that

origin on MT3, and fluid in origin MT3 & MT4 origin on MT3, and fluid in origin MT3 & MT4

�� RHRH-- Chronic desmitisChronic desmitis-- Thickened, severe scarring (scout images)Thickened, severe scarring (scout images)

�� DecisionDecision-- Bilateral plantar fasciotomy and neurectomyBilateral plantar fasciotomy and neurectomy

MRIMRI

Moderate enlargement – Origin of SL Scarring to SL - Previous injury

MRIMRI

Tenosynovitis – RH tendon sheath

Chronic PSLD in RH

Mild degenerative LH SL

Acute PSLD in LH

Forelimb Proximal SL DesmitisForelimb Proximal SL Desmitis

�� 44--12 cm DACB12 cm DACB

�� Acute casesAcute cases-- Pain and swelling in regionPain and swelling in region

�� Chronic casesChronic cases-- No palpable abnormalitiesNo palpable abnormalities

�� Positive distal limb flexionPositive distal limb flexion-- 50% of cases50% of cases

�� Lameness accentuated on circle, extended trotLameness accentuated on circle, extended trot

�� Foot imbalance Foot imbalance –– predisposing factorpredisposing factor

Perineural AnesthesiaPerineural Anesthesia

�� Lateral palmar nerve Lateral palmar nerve

-- Medial and lateralMedial and lateral

palmar metacarpal nervespalmar metacarpal nerves

�� Ensures that carpal joints Ensures that carpal joints

are not inadvertantly injectedare not inadvertantly injected

�� Palmar outpouching of CMC Palmar outpouching of CMC

joint > TMT jointjoint > TMT joint

Hindlimb Proximal SL DesmitisHindlimb Proximal SL Desmitis

�� 22--10 cm distal to TMT joint10 cm distal to TMT joint

�� Pain on palpation of proximal SL (acute)Pain on palpation of proximal SL (acute)

�� Persistent lameness post restPersistent lameness post rest

�� Hock flexionHock flexion-- Accentuates lameness (85%)Accentuates lameness (85%)

�� Infiltration of anesthetic Infiltration of anesthetic –– Origin of SLOrigin of SL

-- Possible diffusion to TMT jointPossible diffusion to TMT joint

�� Conformational abnormalities Conformational abnormalities -- (21%)(21%)

Perineural AnesthesiaPerineural Anesthesia

�� Subtarsal nerve blockSubtarsal nerve block

-- 12.5% 12.5% -- TMT jointTMT joint

-- 50% 50% -- Tarsal sheathTarsal sheath

�� Deep branch of lateral Deep branch of lateral plantar nerveplantar nerve

-- 0% 0% -- TMT jointTMT joint

-- 12.5% 12.5% -- Tarsal sheathTarsal sheath

Compartment SyndromeCompartment Syndrome

�� Enlargement of SL Enlargement of SL –– pressure to MT bones, pressure to MT bones, plantar plantar

MT nervesMT nerves

�� Persistent pain and lamenessPersistent pain and lameness

�� Early diagnosis and therapy to reduce size and Early diagnosis and therapy to reduce size and

minimize inflammationminimize inflammation

�� Current opinions refute this as 1Current opinions refute this as 1°° problemproblem

-- Ongoing neuritis due to inflammationOngoing neuritis due to inflammation

Compensatory DesmitisCompensatory Desmitis

�� Ipsilateral forelimb w/ 1Ipsilateral forelimb w/ 1°° foot lamenessfoot lameness

�� Contralateral fore/hind Contralateral fore/hind -- overload injuryoverload injury

�� Forelimb ipsilateral to Forelimb ipsilateral to 11°° hind lameness hind lameness -- pacerspacers

�� Contralateral forelimb (LH, RF) Contralateral forelimb (LH, RF) -- trotterstrotters

Differential DiagnosisDifferential Diagnosis

�� Middle carpal joint painMiddle carpal joint pain-- young TBsyoung TBs

�� DJD of middle carpal jointDJD of middle carpal joint

�� Palmar cortical fatigue fracturesPalmar cortical fatigue fractures-- MC3MC3

�� Avulsion fracturesAvulsion fractures-- origin of SLorigin of SL

�� TMT painTMT pain

�� Primary stress reactions of MT3Primary stress reactions of MT3

Radiographic FindingsRadiographic Findings

�� Sclerosis of MC3, lateral MT3 Sclerosis of MC3, lateral MT3 -- DP viewDP view

�� Enthesiophyte formation, subEnthesiophyte formation, sub--cortical cortical

sclerosis sclerosis –– Lateral viewLateral view

�� Hindlimb > ForelimbHindlimb > Forelimb

�� R/O avulsion fx MC3/MT3R/O avulsion fx MC3/MT3

�� Changes Changes –– rare in acute casesrare in acute cases

Ultrasonographic Findings Ultrasonographic Findings

�� Enlargement of the suspensory ligament Enlargement of the suspensory ligament

�� Poor definition of dorsal marginPoor definition of dorsal margin

�� Central core lesionCentral core lesion

�� Larger area of diffuse hypoechogenicityLarger area of diffuse hypoechogenicity

�� Focal demineralizationFocal demineralization

�� Examination of contralateral limbExamination of contralateral limb

Nuclear ScintigraphyNuclear Scintigraphy

�� Unnecessary for diagnosisUnnecessary for diagnosis

�� Bone turnover at insertion of SLBone turnover at insertion of SL

�� No uptakeNo uptake

�� Abnormal uptake w/ no U/S changesAbnormal uptake w/ no U/S changes

MRI FindingsMRI Findings

�� Enlargement/abnormal high signal intensity in Enlargement/abnormal high signal intensity in

ligamentligament

�� Bone injury Bone injury --Fluid in bone at insertion site Fluid in bone at insertion site

�� Comparison to contralateral limb Comparison to contralateral limb –– images side images side

to sideto side

MRI FindingsMRI Findings

�� Axial PD imagesAxial PD images

�� High signal in PSLHigh signal in PSL

�� Axial STIR imagesAxial STIR images

�� High signal in MT3High signal in MT3

PSLD TherapyPSLD Therapy

�� Severity of lesionsSeverity of lesions

�� Level of competitionLevel of competition

�� Urgency of upcoming competitionUrgency of upcoming competition

�� Financial contraintsFinancial contraints

�� Recurrence of problemRecurrence of problem

�� Prognosis for forelimb > hindlimbPrognosis for forelimb > hindlimb

PSLD TherapyPSLD Therapy

�� Stall rest and support bandages w/ slow return Stall rest and support bandages w/ slow return

to exercise (forelimb > hindlimb)to exercise (forelimb > hindlimb)

�� Corticosteroid & PSGAG therapyCorticosteroid & PSGAG therapy

�� Shockwave therapy Shockwave therapy -- 3 treatments3 treatments

PSLD TherapyPSLD Therapy

�� Bone marrow injection Bone marrow injection

�� AA--cell vs stem cell injectioncell vs stem cell injection

�� Internal blisterInternal blister

�� ShoeingShoeing-- Support fetlock w/o raising heelSupport fetlock w/o raising heel

Hindlimb PSLD TherapyHindlimb PSLD Therapy

�� Fasciotomy w/ Neurectomy (Compartment Syn)Fasciotomy w/ Neurectomy (Compartment Syn)

�� Desmoplasty (surgical splitting)Desmoplasty (surgical splitting)

�� Tibial neurectomyTibial neurectomy

�� Prognosis Prognosis –– Guarded to resume athletic functionGuarded to resume athletic function

�� Failure to recognize lameness in early stage of Failure to recognize lameness in early stage of

injuryinjury

Case UpdateCase Update

�� Chronic bilateral hindlimb lamenessChronic bilateral hindlimb lameness

�� History of hock injectionsHistory of hock injections

�� RadiographsRadiographs

�� UltrasoundUltrasound

�� Nuc ScanNuc Scan

�� MRIMRI

�� Surgical TherapySurgical Therapy

Fasciotomy with NeurectomyFasciotomy with Neurectomy

Releases compartment pressure of SLDeep br. of lateral plantar nerve

Postoperative CarePostoperative Care

�� Phenylbutazone Phenylbutazone -- (10 days)(10 days)

�� Stall rest Stall rest –– 2 weeks2 weeks

�� Introduce hand walking Introduce hand walking –– increase slowly over 8 increase slowly over 8

weeksweeks

�� ReRe--check lameness check lameness ±± U/S (8 weeks)U/S (8 weeks)

�� Total of 4Total of 4--6 months until return to full athletic 6 months until return to full athletic

functionfunction

ReRe--check Examcheck Exam

�� 7 wks 7 wks -- 3/5 LH, 1+/5 RH3/5 LH, 1+/5 RH

�� Chiropractor adjustment and acupunctureChiropractor adjustment and acupuncture

�� 15 wks 15 wks -- 1+/5 LH, 1/5 RH1+/5 LH, 1/5 RH

�� Recheck U/S, small paddockRecheck U/S, small paddock

�� 17 wks (7/10)17 wks (7/10)-- No lameness, reNo lameness, re--check U/S, check U/S,

increase exerciseincrease exercise-- over next 2 months over next 2 months

�� 9/079/07-- 6 month re6 month re--check scheduledcheck scheduled

ReferencesReferences

1.1. Auer & Stick, Equine Surgery, 3Auer & Stick, Equine Surgery, 3rdrd Ed. Saunders, p.1106Ed. Saunders, p.1106--7.7.

2.2. Dyson, S.J., et al. Suspensory Ligament Desmitis. Vet Clinics ofDyson, S.J., et al. Suspensory Ligament Desmitis. Vet Clinics of NA, 11: NA, 11: 177177--215, 1995.215, 1995.

3.3. Hewes, CA, White, NA. Outcome of desmoplasty and fasciotomy for Hewes, CA, White, NA. Outcome of desmoplasty and fasciotomy for desmitis involving the origin of the suspensory ligament in horsdesmitis involving the origin of the suspensory ligament in horses: 27 cases es: 27 cases (1995(1995--2004), JAVMA, 229: 4072004), JAVMA, 229: 407--412, 2006. 412, 2006.

4.4. Stashak, T.S, Adams Lameness in Horses, 5Stashak, T.S, Adams Lameness in Horses, 5thth Ed., p.622Ed., p.622--623.623.

5.5. Bathe, A.P. Current thoughts on the pathogenesis of hindlimb proBathe, A.P. Current thoughts on the pathogenesis of hindlimb proximal ximal suspensory desmitis. 13suspensory desmitis. 13thth ESVOT Congress: 169, 2006. ESVOT Congress: 169, 2006.

6.6. Dyson, S.J. Proximal suspensory desmitis in the forelimb and theDyson, S.J. Proximal suspensory desmitis in the forelimb and the hindlimb. hindlimb. AAEP Proceedings:137AAEP Proceedings:137--142, 2000. 142, 2000.

7.7. Schneider, R.K., Sampson, S.S., and Gavin, P.R. MRI evaluation oSchneider, R.K., Sampson, S.S., and Gavin, P.R. MRI evaluation of horses f horses with lameness problems. AAEP Proceedings: 21with lameness problems. AAEP Proceedings: 21--34 , 2005. 34 , 2005.

8.8. Gayle, J.M., Redding, W.R. Comparison of diagnostic anaesthetic Gayle, J.M., Redding, W.R. Comparison of diagnostic anaesthetic techniques of the proximal plantar metatarsus in the horse. EVE,techniques of the proximal plantar metatarsus in the horse. EVE, 5/07, p. 5/07, p. 222222--224.224.

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