Diseases of tendons and ligaments-Morton Flashcards
Tendon
Dense band fibrous tissue, intermediary in attachment of MUSCLE TO BONE
- wrapped in fluid filled sheaths near joints
- kept in place by annular ligaments
Ligament
Tough band or plate of dense, fibrous connective tissue OR fibrocartilage serving to unite or form JOINTS
- BONE TO BONE
- No sheaths
Tendon examples
- SDF
- DDF
- Common digital extensor
Ligament examples
- Check ligament SDF
- Check ligament DDF
- Suspensory ligament
Characteristics ligaments/tendons
- Mostly Type-1 collagen
- Limited stretch
- Force transmitters
- Mostly acellular/avascular (slow healing)
- Collagen bundles renew every 6 months (dynamic)
Injury
Abnormal biomechanical stress
- increased intensity
- increased frequency
- increased duration
Healing
Via fibroplasia
-don’t regain 100% structure/strength
Early passive motion (controlled exercise) promotes earlier parallel fiber arrangements
-better than inactivity (strict stall rest)
Spectrum of pathology
Asymptomatic
-repair exceeds rate of damage
Symptomatic
-mild-mod lameness
Breakdown
-disruption suspensory apparatus
Tendinitis SDFT/DDFT
SDFT > DDFT
Forelimbs > Hindlimbs
Mild tearing to complete disruption
Tendinitis pathogenesis
- Single episode of severe stress
- Failure of tendon after multiple episodes of submaximal strain and microdamage
- Improper application leg wraps (tendon bow)
SDF tendinitis pathogenesis
- Cross-sectional area of SDF smaller in midmetacarpal region
- Strain magnitudes 16% at gallop, can fail at 12-20% strain
- Mechanical failure likely result of multiple episodes strain and microdamage
Evidence for multiple episode strain and damage
- Fibril diameters smaller in center of SDF with training
- Weaker fibril bundles in center SDF with training
- Higher proportion type III collagen in center of tendon
Acute Tendinitis CS
- Mild-moderate lameness
- Usually resolves in a few days with rest - Diffuse swelling palmar/plantar metacarpus
- thick, heat, pain on palpation
Chronic Tendinitis CS
- Fibrosis and firm swelling
- Variable signs active inflammation
- acute on chronic - May be intermittently sound at walk/trot
Tendinitis DX
- PE
- Ultrasound (+re-exam)
- Rads to eval concurrent bony injury
- Thermography
- MRI
Tendinitis/Desmitis TX Goals
- EARLY DX
- Decrease inflammation
- cold (ice) 4-6 times per day 15-30 minutes for 48+ hours, until heat and acute inflammation have resolved
- Compressive, substantial support bandage between tx
- Poultice/Sweat once acute inflammation has resolved
- NSAIDs: topical/systemic - Minimize scar tissue
- Promote restoration normal structure
Tendinitis/Desmitis rehab
- Stall rest only 2-8 weeks
- Stall rest + handwalking 4-8 weeks
- recheck before increasing - Stall rest + tack walking 4-8 weeks
- Gradual increase in activity dictated by clinical and U/S eval every 4-8 weeks
- 6-12+ months total course of rehab
- Must be fit before turnout (fitness/fatigue)
Tendinitis/Desmitis medical TX
- Systemic PSGAGs, HA
- Adequan
- Legend
- Pentosan - Intralesional and regenerative therapies*
- Autologous mesenchymal stem cells from bone marrow or fat
- PRP
- IRAP/ACS - ESWT
- Laser (low/high E)
Tendinitis/Desmitis surgical TX
- Superior check desmotomy
- tx of choice for SDF tendinitis, not routine - Tenoscopy
- SDF, DDF, MF lesions within sheath - Palmar Annular desmotomy
- adjunct or solo - Ultrasound guided puncture and tendon splitting
Superior check desmotomy
- functional lengthening of SDF tendon, muscle belly absorbs more load
- Improves chance of return to racing
- More successful in STB than TBs
- INCREASES RISK SUSPENSORY INJURY
Tendinitis Tenoscopy
- Tenosynovitis
- Diagnostic
- Debride tears of DDF/SDF
- Resection MF
Palmar Annular Desmotomy
- Chronic tenosynovitis +/- tendinitis
- Tenoscopically better than blind
- decompresses tendon and sheath
Tendon Splitting
- Ultrasound guided
- Communication between core and surrounding tissue
- Decompresses hematoma, enhances revascularization and collagen prod
- Sites heal by fibroplasia
- Within 5 days of injury
* better therapies exist
* needle decompression less traumatic