1. Quadriceps Strains & Contusions

2. Normal Anatomy Quadriceps – 4 muscles – Rectus femoris – Vastus lateralis – Vastus medialis – Vastus intermedius Common insertion into superior aspect of patella via quadriceps tendon and tibial tuberosity via patella tendon Rectus femoris origin on AIIS – hip flexion & knee extension Vastus muscles origin on femur – knee extension only

3. Mechanism of Injury Strains Commonly occurs in sport e.g. rugby, tennis, football Sudden high force with eccentric contraction of hip flexion/knee extension e.g. deceleration Excessive passive stretching Activation of maximally stretched muscle e.g. kicking Muscle fatigue may play a role Rupture most often at musculotendinous junction Rectus femoris most commonly strained Contusions Direct blow to quadriceps causing significant muscle damage Rupture of muscle fibres directly in or adjacent to area of impact Haematoma formation within muscle Contracted muscle absorbs force better and commonly results in less severe injury

4. Classification Strains Grade% fibre disruption PainStrengthPhysical exam 1None/a few/Less than 5% MildNone or minimal loss No palpable muscle defect 2Moderate/5- 50% fibres with/without fascial injury ModerateModerate lossMay feel a small palpable muscle defect, partial muscle retraction 3Many/complete rupture/up to 100%/with fascial injury SevereUsually complete loss Often feel a palpable muscle defect, with or without muscle retraction Adapted from Mueller-Wohlfahrt et al (2012) and Kary (2010)

5. Classification Strains Due to the extent of inconsistency and insufficiency of the existing classification system, several other classification models have been proposed e.g. Mueller-Wohlfahrt et al (2012)

6. Classification Contusions Grade/painActive knee flexionGait Mild>90°Normal Moderate45-90°Antalgic Severe<45°Severely antalgic Taken from Kary (2010)

7. Associated Pathologies Myositis Ossificans Occurs as complication in approx 20% large haematomas associated with strains/contusions Prolonged pain, reduced flexibility, local tenderness and stiffness – lasts average 1.1 years Suspected when patient unresponsive to conservative management and demonstrates increasing pain and loss of ROM Proliferation of bone and cartilage tissue at site of injury Commonly found in muscle belly, but can also be present in tendons, joint capsules, ligaments and fascia

8. Subjective Strains Sudden traumatic onset Usually due to kicking, jumping, deceleration, change of direction Often immediate sharp pain in quadriceps associated with loss of function Sometimes pain does not develop until end of sporting activity Associated localised swelling, loss of motion, development of bruising Localised pain anywhere in quadriceps, however commonly in distal portion (at MTJ) or mid to proximal portion of rectus femoris Pain increased on activities requiring passive/eccentric hip extension/knee flexion or concentric hip flexion/knee extension Pain eased with ice/NSAIDs in acute stage History of previous strain/contusion

9. Subjective Contusions Sudden traumatic onset Direct blow to thigh e.g. opponents knee, foot Immediate localised pain at site of injury and possible loss of function Depending on severity, athlete may be able to continue play Associated localised swelling, loss of motion, development of bruising Pain increased on activities requiring passive/eccentric hip extension/knee flexion or concentric hip flexion/knee extension Pain eased with ice/NSAIDs in acute stage

10. Subjective Myositis ossificans Strain or contusion mechanism of injury Progressive increase in pain and loss of function/ROM Non responsive to conservative treatment or 10-14 days rest

11. Objective Strains Possible antalgic gait May be signs of inflammation and bruising Possible deformity to muscle e.g bulge or defect to muscle belly or retraction of muscle if severe Pain/tenderness on palpation to whole/part of muscle belly, with increased pain at site of injury. Pain/loss of strength on resisted knee extension/hip flexion Test knee extension with hip flexed (sitting) and extended (prone) - rectus femoris Pain and loss of ROM on passive testing of quadriceps

12. Objective Contusions Possible antalgic gait May be signs of inflammation and bruising Possible deformity to muscle Pain/tenderness on palpation to whole/part of muscle belly, with increased pain at site of injury Pain/loss of strength on resisted knee extension/hip flexion Test knee extension with hip flexed (sitting) and extended (prone) - rectus femoris Pain and loss of ROM on passive testing of quadriceps – loss of ROM will help classification and provide prognostic indicator

13. Objective Myositis ossificans (MO) Similar to strain/contusion PLUS Possible palpable mass at site of injury which develops over the weeks following injury Often severe pain/loss of strength on resisted knee extension/hip flexion Often severe pain and loss of ROM on passive testing of quadriceps Radiographic signs of ectopic bone usually develop approximately 3-5 weeks after injury MO tends to shrink as it matures over a 6 month period

14. Further Investigation X-ray May be helpful in differentiating between bony (femoral stress fracture, tumor, or myositis ossificans) and muscular etiologies of quadriceps pain in chronic cases MRI Provides detailed images of muscle injury and can be quite helpful in characterizing quadriceps injuries Can sometimes be difficult to distinguish between muscular contusion and strain on MRI (Kary, 2010)

15. Further Investigation Ultrasound imaging – Allows different planes of investigation to allow more effective visualisation of muscle & tendon due to variations in orientation & thickness – Allows positioning of the joint in different positions for optimal viewing of diff structures – can be used to identify localised bleeding/haematoma formation form a contusion and provide real-time imaging for needle aspiration can be used to image muscles dynamically – highly operator dependent, requires experienced, skilled clinician (Kary, 2010)

16. Management Goal of therapy is to protect site of injury promote healing reduce pain and oedema restore ROM restore strength prepare for return to sport

17. Conservative Management - Strains PRICE NSAIDs Soft tissue techniques – reduce pain and inflammation, restore full ROM, optimise healing – Early aggressive manual therapy may prolong recovery (Stainsby et al, 2012) Active mobilisations – within pain free range Strengthening – pain free – isometric, then isotonic – SLR, leg extension, leg press, squat, lunge, lateral lunge, deadlift Stretching techniques – Active, active-passive, passive, METs, dynamic – Emphasis on active and pain-free in acute/sub-acute stage Neuromuscular control and proprioception Specific drills to prepare for return to full function/sport

18. Conservative Management Contusions Management is essentially the same as for strains, except: – Place injured leg in position of 120° knee flexion for 24 hours to limit haematoma formation – use hinged knee brace or compression wrap (Kary, 2010) Myositis ossificans Management is similar to strains, focusing on stretching, ROM and strength. Patients may still be able to participate in sport, but may find they have restricted ROM and occasional flare-ups May require surgical excision – Not until ectopic bone formation has matured – 12-24 months ESWT may be beneficial in reducing symptoms and facilitating a return to full function (Torrance et al., 2011)

19. Surgical Management Surgical intervention is indicated for: Compartment syndrome (decompressive fasciotomy) Haematoma removal Complete quadriceps muscle rupture Chronic partial tears non-responsive to conservative treatment Bony avulsion of muscle insertion at the patellar tendon Ectopic bone formation in myositis ossificans