Approaches to Tendon & Ligament Disease 2023 PDF

APPROACHES TO TENDON & LIGAMENT DISEASE JODIE DAGLISH BVSC MS DACVSMR MRCVS EQUINE SPORTS MEDICINE AND REHABILITATION CLINICIAN 1 TENDONS AND LIGAMENTS Learning objectives: 1. Construct a differential diagnosis list based on clinical presentat...

APPROACHES TO TENDON & LIGAMENT DISEASE JODIE DAGLISH BVSC MS DACVSMR MRCVS EQUINE SPORTS MEDICINE AND REHABILITATION CLINICIAN 1 TENDONS AND LIGAMENTS Learning objectives: 1. Construct a differential diagnosis list based on clinical presentations associated with tendon and ligament lesions 2. Select appropriate diagnostics to confirm the lesion 3. Select appropriate medical, surgical and complementary treatment(s) of the specific lesion 4. Determine appropriate prognosis for the specific lesion 2 HOW DO WE APPROACH A TENDON OR LIGAMENT INJURY? § How do we determine location and severity? § Function of the structure § How does this change with injury? § Constituent parts § How does injury affect them? § How do they heal? § How can we restore or improve function? 3 INJURY DIAGNOSIS ¡ History ¡ Clinical exam ¡ Palpation – be systematic, be thorough ¡ Dynamic exam ¡ Straight line walk & trot ¡ Circles at walk, trot and canter ¡ Discipline specific exam if relevant ¡ Flexion tests / System perturbation ¡ Ancillary tests ¡ Diagnostic analgesia – regional nerve vs intra-synovial blocks ¡ Diagnostic imaging Sagittal PET-CT image of the right antebrachium demonstrating increased radionuclide uptake (SUVmax = ¡ What is the ‘Gold Standard’? 2.43; high contrast LUT) in the flexor carpi ulnaris muscle. Frank et al., 2019 4 INJURY DIAGNOSIS ¡ Palpation Findings: ¡ Dynamic Exam Findings: ¡ Heat ¡ Variable severity of lameness ¡ Sensitivity to digital pressure ¡ Mild with desmopathy ¡ Swelling or thickening – may be focal or diffuse ¡ Moderate with tendonitis, enthesopathy ¡ Moderate to severe with partial to complete ¡ Specific loss of definition of the margins of the ligament or tendon rupture structure ¡ Evident when affected region under tension ¡ Reduced ROM ¡ Positive to flexion of the affected joint ¡ +/- Synovial distension 5 DIAGNOSTIC IMAGING OF SOFT TISSUES – WHICH WOULD YOU PREFER IF IT WAS YOUR CASE? 6  ***Don’t forget about the axial skeleton INJURY DIAGNOSIS ¡ Common soft tissue injury diagnoses of the limbs: Canine Front Limb Equine Front Limb Biceps tendon Superficial digital flexor tendon Supraspinatus tendon Deep digital flexor tendon Collateral ligament of the elbow ALDDFT/Inferior Check Ligament (in ponies) Digital flexor tendons Proximal suspensory ligament Flexor carpi ulnaris Suspensory ligament branches Canine Hind Limb Equine Hind Limb Cranial cruciate ligament Proximal suspensory ligament Gastrocnemius +/- Common calcaneal tendon Medial cranial meniscotibial ligament Digital flexor tendons Suspensory ligament branches 7 INJURY DIAGNOSIS ¡ Why do these injuries occur at predilection sites? ¡ Degeneration ¡ Progressively weaken due to ECM synthesis imbalances ¡ Mechanical overuse (micro-injuries) ¡ Trauma ¡ Sudden overloading which overwhelms resistive strength e.g. at entheses ¡ External injury à usually at a random site – e.g. associated with a wound 8 INJURY DIAGNOSIS ¡ Tendon Lesion Types § Core lesions § Margin tears or flaps § Fibrillation § Avulsions / Rupture Pastern - Dorsal Margin Lesion DDFT Foot - Dorsal Margin Lesion DDFT Pastern - Core Lesion DDFT § Adhesions / Contracture § Ligament Lesion Types § Strains § Enthesopathy § Desmopathy – sprain § Avulsions – partial or complete rupture § (Rarely core lesions) Proximal Metatarsus – Suspensory Ligament Distal Metacarpus – Medial Suspensory Desmopathy, Enthesopathy and Avulsion Ligament Branch Desmopathy 9  NORMAL STRUCTURE AND FUNCTION Tenocytes (Elongated fibroblasts) Tendon Water (66%) Collagen Type 1 (Mostly) (80% dry weight) Extracellular Matrix Proteoglycans (33%) (1-5%) Elastin ¡ Tenocytes (fibroblasts) arranged linearly in parallel between (2%) collagen bundles à fibres Inorganic ¡ Improved arrangement with skeletal maturation (0.2%) ¡ Declines with age 10 Electron microscope section of the collagen fibrils within an equine SDFT. The main component is collagen type 1. Reproduced from Hinchcliff et al., 2014 11 NORMAL STRUCTURE & FUNCTION Tendons transmit forces between muscle and bone: ¡ Mainly tensile (Highest tensile strength à 17x body weight) ¡ Compressive regions (point of hock, sites of sesamoid bones) Functions: ¡ Concentrates muscle forces and allows directional changes of the skeleton ¡ Energy storage (Elastic modulus) ¡ Proprioception (Golgi tendon organ) ¡ Strength depends on collagen type 1 fibers: ¡ Number ¡ Size ¡ Orientation Slide courtesy of Dr. K. Sikes 12 NORMAL TENDON STRUCTURE AND FUNCTION Elastic Region Plastic 1. Toe Region Non-linear stretch as crimp is eliminated 2. Linear Deformation Area of curve where stiffness is determined 3. Yield region Irreversible lengthening of the tendon 4. Failure Rupture (Approx. 4-10% strain) Strain = (∆length/original length) x 100 At 4-10% strain a 30cm length SDFT will be stretched to 31.2-33cm From: Goodship et al., 1994 13 NORMAL TENDON STRUCTURE AND FUNCTION ¡ Protective Mechanisms: ¡ Tendon sheaths – protects a longer surface ¡ Bursa – protects one point ¡ Designed to protect the tendons from shear damage ¡ Frictionless tendon gliding ¡ Dictates tendon orientation ¡ Synovial fluid – nutrients & assists movement ¡ BUT Tendon sheaths may also limit healing capability ¡ Paratenon is absent – minimal provision of fibroblasts ¡ Synovial fluid interrupts healing matrix 14 From: McIlwraith et al., 2015  NORMAL LIGAMENT STRUCTURE AND FUNCTION ¡ Ligaments transmit forces from bone to bone: ¡ Mainly tensile ¡ Structural integrity of joints ¡ Compared to tendon a ligament has: ¡ Increased % type III collagen (9-12%), therefore lower volume collagen type I (70%) ¡ Higher number of cells ¡ Increased PG at sites of high compression ¡ Location: ¡ Incorporated into joint capsule (e.g. collaterals, suspensory ligament branches) ¡ Intra-synovial (e.g. Cr & Ca CXL, straight distal sesamoidean ligament) 15 Post natal development of tendon & ligament in sheep. From: Meller, et al, 2009 RESPONSE OF TENDONS & LIGAMENTS TO INJURY Tendons Ligaments US Enlargement Enlargement US Intra-tendinous oedema Minimal oedema evident Hypoechoic foci due to loss of fibres – Loss of definition of ligament / muscle / US develop fibrin clot fat bundle fibre US Peritenon thickening Peri-ligamentous thickening Loss of myotendinous or osseous-tendon Palpation Enthesopathy incl. resorption, avulsion junctions Palpation Increased stiffness = reduced elasticity Increased stiffness = reduced elasticity Function Reduced ROM Reduced ROM or Increased ROM Function May not be a functional repair Repair tissue functional Function Rate of healing depends on lesion Slow healing up to 1 year Function Moderate prognosis - re-injury rate high Moderate prognosis 16  PATHOPHYSIOLOGY – IT’S A SLIDING SCALE Physiological Physiological Pathological Pathological Failure Modelling Remodelling Remodelling Remodelling Normal Healthy Physiological Mild Degenerative More Severe Sudden Overloading Tendon/Ligament Remodelling with Change with Ageing, Degenerative Change with Excessive Exercise Exercise or Training Repetitive Strain with Continue Strain or Trauma (Micro-injury) 17 AGEING AND INJURY OF TENDONS ¡ Ageing Tendons ¡ Darker brown and reddish centre seen at post mortem = degenerative change ¡ Focal sites of chondroid (cartilaginous) metaplasia à high pressure sites ¡ Osseous metaplasia is pathologic ¡ Pathological Remodelling and Progression to Injury (Tendons & Ligaments) ¡ Predisposed sites of injury = high strain sites ¡ Structure is stretched beyond its elastic loading capacity à microdamage ¡ If excessive à failure ¡ Microdamage causes: ¡ Fibril breakdown / Collagen disruption ¡ Loss of structural cross links between collagen fibres ¡ Chrondroid metaplasia ¡ Ischaemia due to rupture of capillaries 18 HEALING OF TENDONS & LIGAMENTS ¡ Consequences of tissue damage à 3 phase of healing ¡ Inflammation (24 hrs – 14 days) à Pro-inflammatory mediators increase ¡ Oedema ¡ Increased temperature ¡ Pain ¡ Redness (if visible) ¡ Loss of function (Instability) ¡ Repair (2-28 days, peaking at 21days) ¡ Proliferation of Tenocytes ¡ Production of new ECM 24 ¡ Remodelling (60+ days) hours ¡ Consolidation of repaired tissue and maturation ¡ Aim to minimise scar tissue formation – myofibroblastic scar Type III collagen 19  HEALING OF TENDONS & LIGAMENTS ¡ Pathological events can have varied consequences ¡ Dependent on location of lesion (Ligaments slower than tendons to heal) ¡ Intra-synovial (e.g. sheathed tendons or intra-capsular ligaments) ¡ Delayed healing à Frequently needs surgical debridement or repair ¡ Extra-synovial (e.g. SDFT) à Follows the 3 phases of healing more typically ¡ Blood supply to the tendon or ligament is poor – reduces healing capacity ¡ Dependent on duration of lesion ¡ Acute lesions – increased inflammatory response (5 signs) ¡ Chronic lesions – lower inflammatory response, morphological changes observed ¡ Dependent on severity of lesion ¡ Tendon necrosis with large lesions and persistent inflammatory response ¡ Sequestrum of avulsion fragments ¡ Adhesion formation with misalignment of fibrils and fibrin clot formation 20 TREATMENT OF TENDONS & LIGAMENTS ¡ Goals of treatment: ¡ Resolve pain and inflammation ¡ Restore function ¡ Optimize function ¡ Many treatment options available and few used in isolation ¡ Best outcomes are found with: ¡ Controlled and gradually increasing exercise ¡ Eccentric loading of the affected structure – human Achilles ¡ Gold standard = Heel raises and backwards downhill walking 21 TREATMENT OF TENDONS & LIGAMENTS But first, let us take … away the pain ¡ Comfortable (normal) movement will not occur until pain and associated inflammation is controlled ¡ May require more invasive treatment to be performed first and then should be multifactorial: ¡ Surgical debridement or repair of lesion ¡ Treat lesion and/or synovial cavity - IRAP, PRP, APS, MSCs, PSGAG, HA ¡ NSAIDs – systemic (carprofen, meloxicam, phenylbutazone) and topical (diclofenac ointment, DMSO) ¡ Cryotherapy – ice water slurry or ice in compression sleeve ¡ Compression ¡ Rest with short duration exercise sessions ¡ Underwater treadmill very effective ¡ Rehab Modalities (Laser, TU, ECSWT) 22 TREATMENT OF TENDONS & LIGAMENTS Surgical Treatments ¡ Aim to minimize adhesion formation, improve gliding function & remove contamination ¡ Arthroscopic or endoscopic debridement of lesions (common in equine) ¡ Fetlock joint – suspensory ligament branches ¡ Stifle – cruciate ligaments, medial cranial meniscotibial ligament) ¡ Digital flexor tendon sheath – DDFT and manica flexoria tears ¡ Navicular bursa – DDFT tears ¡ Open approach surgical repair (More typical in canine patients, very rare in the horse) ¡ Tenorrhaphy – Tendon suture (with tendon lacerations or ruptures) ¡ Tenotomy – Tendon release (e.g. Biceps ulnar release procedure) ¡ Tenodesis – Re-attachment of the tendon to another site (e.g. Biceps) 23 BURP Procedure. From: Fitzpatrick and Yeadon 2009 TREATMENT OF TENDONS & LIGAMENTS ¡ Tenorrhaphy = Tendon suture, tenosuture or tendinosuture ¡ According to BSAVA manual of MSK disorders the suture material should be: ¡ Easy to pass through tissue ¡ Non-irritant ¡ Good knot security ¡ Adequate strength ¡ Goal is not to fail but also not to pull through… ¡ Options include: ¡ Monofilament nylon ¡ Polypropylene ¡ Polydioxanone (absorbable) if good blood supply & low loading ¡ Tensile strength at 1 year = 80% (50% at 6 weeks) 24 TREATMENT OF TENDONS & LIGAMENTS ¡ Ligament Surgical Repair (Mostly canine, rarely equine) ¡ Aim to restore joint stability ¡ Suture repair as for tendons ¡ Anchor through bone tunnel or suture anchor if tissue destroyed ¡ Screw and washer for avulsions ¡ Prosthetics or implants for restructuring joints (e.g.TPLO) ¡ Immobilsation à Arthrodesis as a salvage procedure 25 TREATMENT OF TENDONS & LIGAMENTS ¡ Restore function = Requires TIME ¡ Increasing use of biologic therapies to encourage ‘normal’ structural re-development ¡ Given by intra-lesional, intra-synovial, intravenous and intra-arterial routes ¡ Mesenchymal stem cells – do better with a scaffold to work around ¡ Adipose derived stem cells ¡ Dental pulp derived stem cells ¡ Platelet rich plasma – common in ligamentous injury ¡ Autologous protein solution – increasing popularity in the US ¡ Goal is to encourage increased number of active fibroblasts to be present in healing tissue ¡ One of the most significant promoters of collagen synthesis however is EXERCISE ¡ Avoid high intensity exercise, encourage gradual and controlled exercise ¡ Monitor response with serial imaging studies when possible 26 TREATMENT OF TENDONS & LIGAMENTS ¡ Optimize function ¡ Humans – significant contribution to prognosis from rehabilitation ¡ Veterinary rehabilitation - Literature in its infancy ¡ Clinically superior results when programs implemented Example of active lateral bending to the hind fetlock ¡ What does rehabilitation comprise? ¡ Rehab is never wrong – all conditions will benefit in some way from correctly planned rehabilitation ¡ Controlled exercise program à improves collagen synthesis and organisation, encourages normal gait patterns, returns fitness level ¡ Walking ¡ Underwater treadmill ¡ Pole work / Cavaletti ¡ Daily stretches à restores normal joint ROM, re-establishes neuromotor control, improves collagen organisation, reduces adhesions ¡ Passive and active, manual therapy ¡ Modalities à promotes further healing & may reduce inflammation created by exercise ¡ Laser, ECSWT, therapeutc US, cryotherapy, Ktape, acupuncture, massage 27 PREVENTION OF TENDON & LIGAMENT INJURY ¡ It starts from birth à low level exercise (e.g. pasture turnout, voluntary playful activity) positive effect on development ¡ Tendons and Ligaments should be exposed to the stresses they will need to withstand gradually ¡ Progressive increases in demands – gradually challenge the system ¡ Sensible approach to fitness ¡ Warm up tissues – e.g. before starting to stretch ¡ Cool down tissues ¡ Regular stretching - don’t expect it to be easy to begin with! ¡ Hydration – helps to keep tissue elastic ¡ Rest days ¡ Appropriate nutrition ¡ Adequate support (where previous injury present) 28 SUMMARY ¡ How do you approach you presenting patient? ¡ Systematic and thorough approach to clinical exam ¡ Dynamic exam can be very rewarding ¡ All areas can be evaluated with diagnostic imaging ¡ Select which will give you the most useful information ¡ Tendons and ligaments are unforgiving and require time and appropriate exercise to restore function ¡ Can be assisted by surgical repair or debridement of affected structure ¡ Encourage normal structural healing with biologic therapy and appropriate exercise regime ¡ Have fun with thinking up rehab plans à what stretch elicits the movement I want? ¡ Use diagnostic imaging to monitor your progress ¡ Prognosis will depend on severity of the lesion at the outset, time from injury, resolution of pain and restoration of normal (or as close to normal) function as possible ¡ It will also be significantly improved by client education and commitment to correct rehabilitation 29 REFERENCES ¡ Good reference reads: ¡ A lot of the tendon and ligament physiology is in each of these books and common presenting diseases show up frequently. ¡ Canine Rehabilitation and Physical Therapy – Millis and Levine 2nd Edition ¡ Equine Sports Medicine and Surgery – Hinchcliff, Kaneps and Geor 2nd Edition ¡ Equine Surgery - Auer and Stick 5th Edition ¡ Animal Physiotherapy – McGowan, Stubbs and Goff ¡ Atlas of Equine Ultrasonography – Kidd, Lu and Frazer ¡ The Racehorse, A Veterinary Manual - Ramzan 30 Any Questions? 31 CASE EXAMPLES ¡ A Thoroughbred racehorse presents to you for lameness originating approximately 6-8 weeks ago, with soft tissue swelling focused over the medial aspect of the fetlock joint. The referring veterinarian thinks that the medial suspensory ligament branch is injured. ¡ Which other clinical findings would you expect? Select 3 of 4 answers A. Fetlock joint effusion B. Reduced ROM of the fetlock joint C. Loss of margins of the suspensory ligament branch D. Heat on palpation of the soft tissue swelling ¡ On your dynamic exam the horse is grade 2-3/10 lame RF and is moderately positive to flexion of the distal limb. ¡ What would you like to do next? A. Radiographs of the fetlock B. Ultrasound evaluation of the swollen region C. Ultrasound evaluation of the whole metacarpal region D. MRI of the fetlock region 32 CASE EXAMPLES ¡ XR = Avulsion fragments from the apical margin of the medial proximal sesamoid bone. ¡ US = Desmopathy, enthesopathy and avulsion fragments within the medial suspensory ligament branch ¡ Which ultrasound sign of desmopathy and enthesopathy on the list below is incorrect, and more likely to be a finding in tendon US? A. Periligamentous thickening B. Disruption of the normal fiber pattern C. Intra-ligament oedema D. Enlargement 33 CASE EXAMPLES ¡ Your horse had surgery to remove fragments from the fetlock and to debride the torn suspensory ligament branch. ¡ He now has reduced ROM, joint effusion and periligamentous thickening that need to be improved before he can go back to training. ¡ Which of the below options should be initiated for pain relief in the post operative (after sutures out) period? Select 3 of 4 answers A. Cryotherapy – submerge the limb in ice water slurry for 30 minutes twice daily B. Oral NSAIDs – 1g phenylbutazone once per day C. Topical NSAIDs – diclofenac ointment applied once daily D. Compression – stable bandage day and night 34 CASE EXAMPLES ¡ You are happy with the progress of the horse overall but ultrasound appearance is disappointing. Which of the following list is the most beneficial for improving collagen synthesis and getting this ligament looking better? A. Shockwave therapy B. Mesenchymal stem cells C. Controlled and gradually progressive exercise D. Laser therapy ¡ Prognosis: In the reported study, (Kadic et al., 2019) 15 of 18 horses were sound post-surgery with 13 returning to work at levels equal to or greater than those achieved preinjury. ¡ As always, prognosis is improved with close monitoring, controlled exercise regimen and can be improved further in more chronic cases with implementation of rehabilitation modalities. 35 CASE EXAMPLES ¡ There is a overweight Labrador on your schedule for clinics this morning. He has an acute onset non-weight bearing LH lameness following jumping off the sofa. ¡ What is the most common hind limb soft tissue injury in dogs, particularly large breeds? A. Gastrocnemius and common calcaneal tendon B. Cranial cruciate ligament C. Superficial digital flexor tendon D. Caudal cruciate ligament ¡ Which of the following diagnostic tests is needed for assessment of structures commonly injured in association with this? A. Radiographs B. Ultrasound C. Physical exam D. Magnetic resonance imaging 36 CASE EXAMPLES ¡ Options for treatment of Cranial Cruciate Ligament rupture include: ¡ Weight management ¡ NSAIDS ¡ Surgery: ¡