Muscle Injuries
Neil Jain, Steve Kemp
ESSKA Comprehensive Review Course May 2014, Amsterdam, Netherlands
Overview • • • • • •
Basic Anatomy Basic Physiology Mechanism of muscle injury Pathophysiology of muscle repair Classification Treatment – Traditional – New Techniques
• Injury Prevention
Anatomy • Muscle – Proximal Bone-Tendon Origin – Proximal MusculoTendinous Junction – Muscle Belly – Distal Musculo-Tendinous Junction – Distal Bone-Tendon Insertion
Injury • Bony Avulsions / Tendon Ruptures
– Rotator Cuff (Shaffer 2014) – Triceps (Bain 2010) – Biceps (Kokkalis 2009) – Pectoralis Major (de Castro Pochini 2014) – Hamstrings (Konan 2010) – Quads / Patella Tendon (Langer 2010) – Achilles Tendon (Maffuli 2011) • Consensus in ELITE athlete for surgical fixation
Physiology Sliding filament theory of muscle contraction
Mechanism of Injury • Contusion – Sudden significant force; Direct blow – Contact sports (e.g. Rugby, American Football)
• Strain – Excessive tensile force & overstrain of myofibres – Sprinting / Jumping – Classically superficial muscles crossing 2 joints
• Laceration – Rarest cause; Mechanism self-explanatory
• Overall 10 to 55% of all sports injuries sport)
(dependent upon
Muscle Healing • Heals by repair rather than regeneration (unlike bone regeneration) • 3 Phases – Destruction – Repair – Remodelling
Huard et al JBJS Am 2002
• Destruction / Degeneration – Rupture and necrosis of myofibres – Formation of haematoma between ruptured muscle stumps – Inflammatory cell reaction
• Repair / Regeneration – Phagocytosis of necrosed tissue – 3 processes occur simultaneously: • Regeneration of myofibres • Production of a connective tissue scar • Capillary ingrowth into injured area
• Remodelling / Fibrosis – Period characterized by the following occurring: • Maturation of regenerated muscle fibres • Contraction & reorganization of scar tissue • Recovery of the functional capacity of the muscle
Classification • Traditionally poor – O’Donoghue 1962 Clinical – Ryan 1969 Clinical – Takebayashi 1995 Ultrasound – Peetrons 2002 Ultrasound – Stoller 2007 MRI
• All graded out of 3 or 4 • All fairly arbitrary
Classification • Led to a consensus meeting • BJSM 2012
Classification • Grade 1 to 4 each with A & B sub groups • Additional contusion group • Descriptors: – Definition – Symptoms – Clinical Signs – Location – Ultrasound / MRI findings
Classification • Positive prognostic validity for return to play • Structural injuries associated with longer absence than functional muscle disorders • Sub-classification of structural injuries correlates with return to play
BJSM 2013
Treatment • Established treatment • Classically no evidence base but seemed to work • Once understanding of injury and repair, treatment made sense • But ‘controversies’ continue • ‘PRICE’ initially
Treatment • • • • •
Protection Rest Ice Compression Elevation
• Designed to reduce inflammation, decrease haematoma and subsequent scar
Treatment • Immobilisation? – Early mobilisation induces increased, rapid and organised growth of capillaries to injured area – More rapid return of strength with mobilising BUT – If immediate, a larger scar will form – Increased risk of recurrence
Treatment • Immobilisation – If immediate • • • •
Less scar Decrease re-rupture risk Provides new granulation tissue Helps to improve tensile strength & withstand forces experienced with contraction
Treatment – 3 to 5 days • If early stage has passed and symptoms improving then progression • Gradual introduction of exercise to muscle – Isometric training • Muscle length constant, tension changes
– Isotonic training • Muscle length changes, tension stays constant
– Isokinetic training • Dynamic with minimal load
Treatment • PRICE needs updating, should we call the POLICE? Bleakley BJSM 2011
• Protection • Optimal Loading • Introduced to help decrease scar
• Ice • Compression • Elevation
Treatment • Mechanotherapy Khan BJSM 2009
• Mechanotransduction – Cells sense and respond to mechanical load
• Using principle as therapy – Load stimulates tissue repair and remodelling
• Emphasises optimising load
Treatment • Heat – May help in association with stretching – Warm up: • Reduced muscle tightness / viscosity • Absorb more energy and withstand more load • Combined with stretching improves elasticity
– Stretching • Elongates maturing scar in plastic phase
Treatment • Persistent symptoms beyond 5 days – May require aspiration of haematoma – In very rare cases surgical excision • • • •
Removal of all haematoma and necrotic tissue Debridement of stumps Loose closure of fascia only More likely in laceration
– Surgery also an option for excision of adhesions • Longer term – c. 6 months
Treatment • As our understanding of injury has improved so has attempts to improve healing – Medication – Therapeutic Ultrasound – Hyperbaric Oxygen – Kinesiotape – Growth Factors / PRP
Medication - NSAIDs • Role uncertain • Few controlled studies exist to demonstrate effect • Some have suggested a transient improvement in recovery from exercise-induced muscle injury • Short term may help • Long-term use of NSAIDs is potentially detrimental to the regenerating skeletal muscle – Suggestion that it is harmful in the eccentric contraction induced strain injury model
Therapeutic ultrasound • No objective evidence exists • No RCT • Studies support the use of low-intensity pulsed ultrasound (LIPUS) – Induces organised tissue structure at the site of injury – Stimulates expression of COX-2 and formation of new muscle fibres
• Other studies show no effect
Hyberbaric Oxygen • Knowledge base suggests it should work • Anecdotes / cases • Some suggestion it significantly improves the rate of repair of injured muscle • Cochrane Review stated insufficient evidence
Kinesiotape
Kinesiotape • Colourful • Looks good! • A systematic review November 2012 – Concluded insufficient evidence to support the use of kinesiotape following musculoskeletal injury – Due to there being few high-quality studies that have investigated its use – Unable to discount a perceived benefit to the athlete – No ill effects were perceived; may be placebo effect?
Maybe one bad outcome?!!!
Growth Factors / PRP • Ideally : – Enhance muscle regeneration – Prevent fibrosis
• Cellular level – bFGF, IGF-1, NGF may improve regeneration – TGFβ1 antagonist may prevent fibrosis
• Hence appeal of PRP
PRP • Case series and anecdotes suggest it may work – Possibly when used properly?
• Review article has suggested that no PRP proven to work • IOC consensus group – Proceed with caution in the use of PRP – Further clinical trials are required
• One study is progressing and may be of suitable design quality in order to provide and answer
Treatment • In essence, nothing better than the original! • So we keep going with it, or maybe we should look at something else?
Injury Prevention
• “an ounce of prevention is worth a pound of cure” – Benjamin Franklin
Injury Prevention • FIFA 11+ – Football – Basketball
• Neuromuscular Control – Volleyball
• Core stability – American Football
• Adductors – Ice Hockey
Summary • Classification by Munich • Muscle injury has an accepted treatment • Little evidence exists supporting alternative treatment • Most convincing evidence is regarding injury prevention • Focus for teams should be on injury prevention rather than cure
THANK YOU / GRAZIE MILLE
TIME FOR LUNCH?
(AND MAYBE A DIFFERENT RESULT THIS TIME?!)