3/26/2014

1

Overuse InjuriesHow to Solve the Challenging Puzzle

Anthony Luke MD, MPH

Primary Care Medicine: Update 2014 

Disclosures

• Founder, RunSafe™

• Founder & CEO, SportZPeak Inc.

• Sanofi, Investigator initiated grant 

Acute injuries Approach to Overuse Injuries

1. Mechanism of Injury / Pain

2. Location

3. Type of tissue

4. Identify risk factors

5. Education/Modifications to reduce overuse activity

3/26/2014

2

Overuse Injuries

• Occur due to repetitive submaximal loading of the musculoskeletal system when rest is not adequate to allow for structural adaptation to take place.

DiFiori et al.  Overuse Injuries and Burnout in Youth Sports:  A Position Statement from the American Medical Society for Sports Medicine, accepted for publication, 2014.  

Key Features

• Repetitive loading (rather than traumatic)

• Overwhelm the ability of the tissue to remodel, resulting in a weakened, damaged structure

• Imbalance between training loads and recovery is a key factor

• Mechanism  Preventable?

1. MechanismWhy did I get an injury?

• Too much

• Too hard

• Too fast

…for your body !!

It’s all about Physics…

Newton’s Law #1

• An object in motion, stays in motion

…Unless an external force stops it

• Wind & Road resistance

• Hills

• Metabolic (Fatigue, Dehydration)

STRESS !!!

3/26/2014

3

Adaptation to stress

Newton’s Law #2

• Force = mass x acceleration

• Force results in stress

Shock Absorption

Newton’s Law #3

• Every force has an equal and opposite force

• “Striking” mass

• “Shock” absorption

2. Location

• Point with One Finger

Windlass Mechanism

Midstance Toe - off

3/26/2014

4

Achilles Tendinopathy

Mechanism

• Repetitive eccentric load on tendon

• Pushing off, running, sprinting, jumping

Presentation• Tender over

achilles +/- swelling• Pain with resisted

toe off• Pain with passive

ankle dorsiflexion

Risk FactorsKhan KM, et al. Phys Sportsmed 2000.

• Tight Achilles and plantar fascia

• Hyperpronation

• Cavus foot

• Advancing age - decreased blood flow

• Overweight

• Poor footwear

• Weak hip abductors and medial quadriceps

Plantar Fascitis• Tender on insertion on medial aspect of

heel

• Associated with:– Age

– Pes planus and pes cavus

– Obesity (OR =5.6 (95% C.I., 1.9-16.6)

– Poor shoes, working on feet (OR = 3.6 (95% C.I., 1.3-10.1)

– ≤0 degrees of dorsiflexion had OR = 23.3 (95% C.I. , 4.3 to 124.4)

Riddle et al. JBJS-A, 2003

– Limb leg discrepancy (longer leg associated with plantar fasciitis)

Mahmood et al, J Am Podiatr Med Assoc, 2010

Tendinosis

• Hyaline degeneration

• Mucoid degeneration

• Fibrillation of collagen

• Absence of inflammatory cells

3/26/2014

5

Mechanics

• Usually tendons surrounding joints with high degree of motion

• Usually tendons that cross two joints

• Eccentric overload• Mechanical

impingement• Temperature

breakdown• Angiogenesis?

Conservative Treatment

REDUCE STRESS• Modified activities, ice

• Calf / Achilles stretching

• Hold each stretch for 30 seconds

Soleus stretch

Gastrocnemius stretch

Treatment

• Heel lifts

• Modify footwear

• Custom orthotics

• Night splints

• PT is a major key

Rarely

• Surgical debridement

Physical Therapy for AchillesAlfredson H, Pietilä T, Jonsson P, et al. Am J Sports Med,

1998; 26:3: 360-366.

• RCT – eccentric exercises (3 x 15 reps, 2 times/day, 7 days a week x 12 wks)

• Results: Significant difference in pain levels VAS 81.2 mm (+/- 18) to 4.8 mm (+/- 6.5) in 12 weeks

• 81% eccentric satisfied vs 38% concentric satisfied

3/26/2014

6

Eccentric Drop program Terminology

• Tendinopathy –“tendon injury that originates from intrinsic and extrinsic etiological factors”

• Usually not tendinitis

Classification of Tendon Disorders(Modified from Khan et al. 1999, Clancy 1990)

Pathologic Dx Macroscopic Histopathologic

Tendinosis Intratendinous degeneration

Disorganized collagen, mucoid degen

Tendinitis Degeneration with inflammatory repair response

Fibroblasts, hemorrhage, granulation tissue

Paratenonitis Inflammation of paratenon only

Mucoid degen. if areolar tissue, fibrinous exudate

Paratenonitis with tendinosis

As above As above

Mechanics

• Usually tendons surrounding joints with high degree of motion

• Usually tendons that cross two joints

• Eccentric overload• Mechanical

impingement

3/26/2014

7

Where does the injury occur?

Insertional• Occurs at

insertions near the joint

• Joint sideTears• At the musculo-

tendinous junction• Areas of friction

3 Basic P/E findings for tendinopathy

1. Tenderness on direct palpation 2. Reproduction of pain with resisted

contraction (eccentric loading)3. Reproduction of pain with passive

stretch

Tendon Healing

• requires around 100 days to synthesize collagen

Mild – 2 to 4 weeksModerate – 4 to 6 weeksSevere – 6 to 12 weeks or longer

Physical therapy for tendons

Stretching• Improves pain and ROM

Strengthening – eccentric loading• Mechanical loading accelerates tenocyte

metabolism

Modalities• Ultrasound and laser increase collagen

synthesis in fibroblasts in animals

3/26/2014

8

Anti-Inflammatory?

• Little evidence to support use of NSAIDs in management

• Good Analgesic

• Steroid injection?• Needle tenotomy?

How do you exam for lateral epicondylosis ?

3. Type of Tissue

• Muscle‐tendon unit

• Articular cartilage (physis)

• Bone

• Soft tissues (bursa, and/or neurovascular structures) 

What is Osteoarthritis?

• OA is a disease characterized by cartilage degeneration

• Cartilage loss and OA symptoms are preceded by damage to the collagen-proteoglycan (PG) matrix

Superficial Zone

Transition Zone

Radial Zone

Tidemark

Calcified cartilage

Subchondral bone plate

Vascular plexus

3/26/2014

9

Cartilage Damage

Outerbridge Classification, 1961

Arthroscopy

Arthroscopy Osteoarthritis

3/26/2014

10

Novel MRI Techniques

• 3T MRI provides a higher signal-to-noise ratio and better spatial and spectral resolution

• T1ρ spin-lattice relaxation reflect proteoglycan content

• T2 reflect collagen matrix orientation

(a) a healthy volunteer, male, 30; T1ρ = 40.0511.43 ms

(b) a patient with early OA (post-traumatic OA), female, 27. T1ρ = 50.5619.26 ms

Li et al. Magn Reson Med, 2005.

MR Relaxation Times (in ms)

Luke et al., Am J Sports Med, 2010

T2 T1ρ

Findings

• T1ρ values stay elevated over 3 months, which suggests that this sequence demonstrates more than water shifts

• 2/10 runners and 2/10 controls had abnormal patellar cartilage lesions

• Changes in T1ρ and T2 were greatest in medial compartment and the patellofemoral joints, especially at the trochlea

Luke et al., Am J Sports Med, 2010

Children and Sports injuries

• Almost 1/3 of injuries from all causes due to sports– Bijur PE et al. Arch

Pediatr Adolesc Med. 1995; 149: 1009-1016.

• participation of kids in organized sports

3/26/2014

11

Why do kids get injured ?

• Kids do what adults do

• Kids get tired faster• Limited strength• Flexibility issues• Excess stress /

overuse leads to failure

Case 1

• Who? 14 year old male football player, also runs track

• When? 8 weeks • What? Right>left knee pain with running,

stairs, bending and especially kneeling• How? Worsening anterior knee pain since

preseason running • Where? Tibial tubercle of the right>left

Case 1

LOOK• Prominent bump over

tibial tubercle R>LFEEL• Tender tibial tubercleMOVE• ROM 10° to 130°SPECIAL TESTS• Popliteal angle 40°• Ely’s test positive

Apophysitis

• Osgood Shlatter’s Disease

• Sever’s Disease (heel)

• Can also occur in the spine, iliac crest, the metatarsals

3/26/2014

12

Osgood-Schlatter’s Disease

• Most improve in 1-2 years with activity modification

• Rarely operate prior to skeletal maturity

• Goal is to eliminate pain, not for cosmesis

Sinding-Larsen-Johansson

• Common in 10-12 year old boys

• jumping activities/ repetitive stress

• Ant knee pain distal pole of patella

• Xrays: fragmentation of distal pole of patella or small calcifications prox patellar tendon

• Differentiate from Sleeve avulsion!!!

Treatment for Apophysitis

• Rest, modify activity• How long? 6 to 8 weeks• Immobilize if significant pain• Include low impact activity and conditioning• Focus on strength and flexibility while healingExamples:• Hip and quads strengthening program, core

stability• Overhead and Throwing athlete rehab

– Long ball toss, Medicine balls, Rotator cuff, Periscapular exercises

Return to play

Can the athlete return:

• Safely?

• Effectively?

• Relatively painfree?

Avoid the secondary or CHRONIC injury

3/26/2014

13

Case 5

• Who? 16 year old pre-professional female ballet dancer

• When? 3 months • What? Severe pain with weight

bearing• How? Was dancing 6 hours a day,

worse since jumped and landed • Where? Over right anterior mid tibia

Case 5

Height 5’5” Weight 105 lbsLOOK• Thin build, antalgic gaitFEEL• Point tender over R mid tibia, localized soft

tissue swelling MOVE• Ankle dorsiflexion 0°SPECIAL TESTS• Can’t do a Hop test

4. Identify Risk Factors What are the risk factors?

Training

ImpactBone Health

Gait Mechanics

BONE LOADING

Brukner P, Bennell K, Matheson G. Stress fractures, Blackwell Science, 1999.

3/26/2014

14

Medial Tibial Stress SyndromeIntrinsic

•Women > Men (1.5-3.5 x higher)

•Excessive foot pronation

•Pes cavus

•Leg length discrepancies

•Higher BMI

•Decreased bone density, disordered eating

•Muscular imbalances– Tight triceps surae

– Weak hip and core muscles

Extrinsic

•Increased activity, intensity, or duration

•Poor footwear

•Overtraining

•Increased mileage (>20 miles/week)

Galbraith et al, Curr Rev Musculoskelet Med, 2009

Stress Fractures

• Stress fracture group showed greater peak hip adduction and greater peak rearfoot eversion angles vs. control group

Milner et al, JOSPT, 2010

Shoes or No shoes ?

• Heel strike causes a force impact Saw-toothed force profile with High rate of loading 400-500 bw/sec

• Forefoot striking reduces the peak impact force

Lieberman et al, Nature, 2010

How stress fractures occur?

• Failure of bone to adapt to stress

• Microinjury/microcracks in the bone

3/26/2014

15

Bone remodeling

• Causes relative weakness

• Osteoclastic activity faster than osteoblasts

• Excess stress

Bone Response to Stress

Complete FractureComplete Fracture

Stress FractureStress Fracture

Stress injuryStress injury

Stress reactionStress reaction

Accelerated remodelingAccelerated remodeling

Normal remodelingBrukner P, Bennell K, Matheson G. Stress fractures, Blackwell Science, 1999.

Compression vs Tension

• Delayed union rate estimated at 5%Orava, Hulkko. Acta Orthop Scand, 1984.

When to return to sports

• N=53• Length of recovery

and MRI Grade 1-4 Pearson r= 0.627, p= 0.001)

• Grade 3 takes 12 weeks, Grade 4 takes 16 weeks

• Bone remodeling takes around 180 d

Arendt et al., AJSM, 2003

3/26/2014

16

Diagnostic Imaging

Grade X-ray Bone Scan MRI

1 Normal Small, ill-defined cortical area, mildincrease

Positive STIR image

2 Normal Better defined cortical area, moderate increase

+ STIR+ T2 weighted

3 Periosteal reaction

Wide to fusiform cortical-medullary area of highactivity

+ T1, T2, STIRNo cortical break

4 Injury of periosteal rx

Transcortical area of increased activity

+ injury line on T1 or T2 scans

Arendt, Griffiths, Clin Sports Med, 1997.

Treatment of Stress Fractures

• Avoid stress to the bone

• Allow the remodeling process to occur

• Immobilize or remove stress completely if traction

• If non-union or elite high demand athlete, consider surgical fixation

ORIF?

• Excision and Bone graft

• I.M. Nailing considered case by case

• Suggested after failure of conservative treatment > 1yearChang, Harris, AJSM, 1996

Who and Where?

• Common locations for stress fractures

• Who does it happen to?

3/26/2014

17

Who and Where? Base of the 5th Metatarsal

• At risk due to strong ligamentous support and poor vasculature

• Non-union rate with conservative treatment 7 to 28%

• Refracture rate after ORIF still 10-40%

Femoral Neck

• MRI 100% sensitive (gold standard)Shin et al. AJSM, 1996

If displaced,• Risk of AVN 42%

(n=5/12)Visuri et al. J Trauma, 1990

• 30% required major surgery for complications (n=7/23)Johansson et al. AJSM, 1990

Femoral Neck ORIF?

Indications• Grade 4 changes

on Bone Scan or MRI

• Tension side• Displaced

3/26/2014

18

Women in Sports (Title IX) Female Athlete Triad

• Disordered eating, loss of periods (amenorrhea), and thin bones (osteoporosis)

• Often presents with stress fractures• Caloric imbalance• Can be very dangerous

Female Athlete Triad

Warning signs• Irregular periods or delayed menarche• Recurrent stress fractures• Vegetarian at young age• Avoids eating with others• Skips meals• Trains excessively• Using dieting methods inappropriately

Amenorrhea

• B-Hcg• LH/FSH• sTSH• PRL

3/26/2014

19

Osteoporosis

• DEXA bone density• Increased risk of stress fractures if

low BMD• Effects on BMD may be irreversible

Nutritional and metabolic factors

• Calcium – If poor diet or

low bone density– 1200-1500 mg/d

• Vitamin D– Deficiency

common?– 800 IU/day

Make ours doubles

Medications

• Oral contraceptive pills

• SSRI antidepressants

TEAM approach

• Psychologist / psychiatrist

• Nutritionist• Family• Coach• Sports Physician• Family Physician• OB/GYN

3/26/2014

20

Conservative treatments

• Activity modifications (painfree)1. NWB, swimming or biking 2. Nonimpact upright activities3. Sport-specific drills; limited sports4. Full activities no restrictions

• Pneumatic brace• Adjunct modalities• Manage expectations

Manage

• Patient states irregular periods• Counsel, consider oral contraceptive

pills• Calcium 1200-1500 mg, Vit D 400-

800 IU• If recurrent history of stress

fractures, consider bone density• Consider referral to “TEAM”

• Can modify activity to avoid pain

Approach to Overuse Injuries

1. Mechanism of Injury / Pain

2. Location

3. Type of tissue

4. Identify risk factors

5. Education/Modifications to reduce overuse activity

Key Features

• Repetitive loading (rather than traumatic)

• Overwhelm the ability of the tissue to remodel, resulting in a weakened, damaged structure

• Imbalance between training loads and recovery is a key factor

• Mechanism  Preventable?

3/26/2014

21

9th UCSF Primary Care Sports Medicine Conference: ABC’s of Musculoskeletal Care

December 5‐6,  2014San Francisco, California