Knee Injuries in the Skeletally

Immature Adolescent Athlete: Current Questions and Challenges

Corey Dean MD Internal Medicine-Pediatrics, CAQ Sports Medicine

Mascots….

Mascots….

Objectives

1. Discuss the most common cause of adolescent knee pain,

ways to treat this without referral and when to allow the

athlete to return to play.

2. Discuss the various apophysitis/tendonitis injuries

associated with the skeletally immature knee.

3. Discuss the anterior cruciate ligament (ACL) epidemic

in young women, treatment controversies, and ways to

prevent them.

4. Discuss the one knee injury you do not want to miss and

why referral early is so crucial.

Anatomy of the knee-3

compartments The Knee is broken

down into 3

compartments:

1. Patellofemoral

(including bursa)

2. Ligamentous

3. Meniscal

Case 1

An 17-year-old cross country runner c/o anterior knee pain for 6 weeks.

Provoked by walking up and down stairs and sitting in class.

No history of locking, catching, swelling, or instability.

On physical exam, Mild tenderness over the medial aspect of the patella. Quadriceps tone was poor over vastus medialis. + Patellar inhibition testing (subluxation tenderness).

Patellofemoral knee physical

exam

Patellofemoral Knee

Dysfunction(PFKD)

Pathophysiology of PFKD-most common knee injury in adolescents

Weakness of the quadiceps, specifically VMO dysplasia

Tight iliotibial bands

Tight hamstring muscles

Weakness or tightness of the hip muscles (adductors, abductors, external rotators)

Tight calf muscles

Q angle

Woman more

predisposed to PFKD

secondary to widened

Q angle

Knock knees or genu

valgum

PFKD

Diagnostic Testing:

1. No testing is needed-

clinical diagnosis

2. X-rays-usually

normal. Rare cases of

severe PFKD leading

to arthritic changes.

PFKD-Treatment

- Running was reduced (preferably on grass or on a treadmill).

- Keep the athlete in the game-Swimming as cross training.

- Ice massage was recommended three to four times daily over patellofemoral complex.

- Open and closed-chain exercises with an emphasis on the vastus medialis obliques strengthening.

- A lower-extremity flexibility program was also started, focusing on the hamstrings/quadriceps.

- Use of NSAIDs as needed.

PFKD-Return to play

-90/90 rule (90% range of

motion and 90% strength in

comparison to the unaffected

side)

-10% rule - Graded progression

in return to athletic competition

in using “pain as your guide” to

increase mileage of running (by

10% per week). If pain recurs,

then plateau running.

Foot Exam and Running shoes

Importance of the feet-

proper running shoes

were recommended

and evaluation of foot

alignment was

assessed (+/-orthotics).

Orthotics

Case 2

14 year old basketball player has

c/o anterior knee pain for 3

months. He has grown 4 inches

in the past 5 months. No

locking or giving way.

-Provoked by jumping, kneeling

and palliated by rest.

-On examination, tenderness

localized to the tibial tubercle.

All other tests are normal.

Differential Diagnosis for

Anterior Knee Pain (a)Osgood-Schlatter disease

(b)Inferior patellar pole traction apophysitis (Sinding-Larsen disease)

(c)Patellofemoral pain syndrome

Osteochondritis dissecans

*Patellar or quadriceps tendonitis

Fat pad hypertrophy/impingement (Hoffa's disease)

Patellar stress fracture

Prepatellar or infrapatellar bursitis

Referred pain

Adapted with permission from Patel DR, Nelson TL.

Sports injuries in adolescents. Med Clin North Am 2000;84:983-1007.

Epidemiology of Apophysitis

Knee Injuries in Adolescents Osgood Schlatter

disease(OSD)

-Prevalence athletic

adolescents 21% vs. 4.5%

of age matched non-

athletes

-Age of onset:

Girls 8-13 Boys 10-15

-Boys > Girls, equalizing

-Bilateral in 20%

Sinding-Larsen-Johansson disease(SLD)

-Prevalence athletic adolescents unkown, but 10-20% coexist with OSD

-Age of onset-similar to OSD

-Boys > Girls

Diagnostic testing of Apophysitis

of the knee Clinical diagnosis-If

the history and

physical exam indicate

OSD or SLD

radiographs are not

needed.

Treatment-Apophysitis and

Patellar Tendonitis OSD Patellar tendonitis SLD

1. Cross training 1. Cross training 1. Cross training

2. Ice massage 2. Ice massage 2. Ice massage

3. Hamstring & 3. Hamstring & 3. Hamstring &

Quad stretching Quad stretching Quad stretching

4. Tibial tubercle 4. Cho-pat strap 4. Patellar knee

Padded neoprene 5. NSAIDs prn neoprene sleeve

Sleeve 6. Orthotics 5. NSAIDs prn

5. NSAIDs prn 6. Orthotics

6. Assess feet-

orthotics

Cho-pat strap

Complications of Apophysitis

Painful kneeling-60% of all OSD patients

have chronic pain on hitting tibial tuberosity

Painless “bump” over tibial tuberosity-most,

benign

Painful ossicle @ distal or proximal patellar

tendon insertion or avulsion of tibial

tubercle - surgical removal (rare)

Case 3 14 year old female basketball

player c/o knee pain after sudden fall to floor. No contact or trauma occurs to the knee. She heard a “pop.” She is still growing and is currently going through “puberty” w/o menses yet. Her knee is acutely swollen.

On examination:

Inspection: + effusion

Special tests: + Anterior drawer and + Lachmans. Remainder of testing difficult due to swelling.

Physical Exam of Anterior

Cruciate Ligament

Epidemiology of ACL injuries-

epidemic in woman athletes

80,000 – 250,000 ACL injuries per year in

young athlete (15-25 years of age)

More common in woman than in men

Non-contact mechanism much more

common in woman and in jumping and

quick starting and stopping sports

(basketball, soccer, etc.)

Why is an ACL tear an epidemic

in woman in sports? Risk factors in woman

1. Anatomy-smaller femoral notch

width (bony impingement or

houses smaller ACL?) and

ACL size is smaller in

woman

2. Hormonal effects-estrogen and

progesterone receptors on

ACL. Higher levels

decreases collagen synthesis

of ACL fibroblasts

Why is an ACL tear an epidemic

in woman in sports? 3. Environmental-improper

shoes (cross trainers) and

improper jumping

technique

4. Biomechanical-

Ligamentous laxity of

ACL and limb alignment

with greater Q angle

(miserable malalignment

syndrome)

Physes of immature knee

Distal femoral and proximal tibial physes account for 65% of lower extremity growth

MRI evaluation of physes

-0% closed at 11 years

-5% at 12 yrs

-34% at 13 yrs

-53% at 14 yrs

-94% at 15 yrs

-100% at 16 yrs

*girls earlier than boys

Evaluation of skeletal maturity

An accurate assessment of skeletal maturity aids in

discussing risks and benefits of operative and non-

operative treatment options.

-Tanner staging

-Radiographs of the hand and knee

-Timing of adolescent growth spurt

-Onset of menses

-Comparison of parental height

Treatment

Midsubstance Tears

-Non-operative treatment-traditionally accepted as standard

1. Activity modification: no cutting or stop/start activities

2. Physical therapy

3. Bracing

4. Monitor until skeletal maturity-once reaches skeletal maturity, then operative ACL reconstruction

Return to play-to brace or not to

brace……

Derotational braces by most authorities in

Sports Medicine are thought as simply

“psychological aids to recovery.”

-Problems: Difficult to properly fit

No Evidence based studies to

support

Treatment

Problem: Adolescent population by nature is

active and commonly suffers other injuries due to

an unstable knee

-Multiple studies have shown increased rates of

meniscal tears, chondral injuries, and early

degenerative arthritis *Graf et al, Arthroscopy, 1992 and Pressman et al, J Ped Ortho, 1997.

Treatment

-Alternative treatment: Transphyseal, soft tissue

allograft (patellar tendon) reconstruction.

Concern: Growth abnormalities

One study of 16 pts Tanner stage 3 or 4 showed all

athletes returned to competitive athletics w/o

growth abnormalities *Shelbourne et al, AJSM, 2004.

ACL injury prevention programs

Prevention Programs: combine proper jumping, landing and cutting techniques for athletes while providing strength training, flexibility, plyometrics and sports specific exercises.

-Baystate, Massachusetts-Jump Program

-University of Michigan-Leap program

-California Prevention Injury and Enhance Performance Program (PEP)-17 minutes

www.aclprevention.org

Case 4

JL is a 15 yo boy w/ acute onset of R knee pain and swelling x 1 day

-Tackled in football, knee “twisted” and he heard a “pop”

-Denies knee “giving out under him”

-On exam had effusion and right thigh atrophy over VMO. Tenderness over medial femoral condyle. Decreased ROM as could flex only 45 degrees. Remainder of exam (including ligament testing) was normal.

-PMH- Knee injury 1 year ago.

Osteochondritis Dissecans of the

Knee(OCD)-Epidemiology Most common in 13-21 yr olds in sports

Most common site is medial femoral condyle

Likely secondary to avascular necrosis of subchondral bone from multifactorial causes (trauma, repetitive impact to tibial spine, abnormal ossification of epiphyseal cartilage)

Clinical Findings of OCD

Physical exam often inconclusive.

Most consistent finding is thigh atrophy secondary

to lack of use and de-conditioning.

With floating bodies, can develop locking,

catching, pain and effusion

Meniscal tests are frequently positive due to the

asymmetry of the joint and the compensation by

the athlete for the pain.

OCD-Diagnostic testing

X-rays of the knee-

Testing of choice for

screening for boney

injury secondary to

trauma.

*Radiographic testing

via AP, lateral, and

tunnel view of knee

Pittsburgh and Ottawa Knee rules

Pittsburgh decision rules 1. Blunt trauma or a fall as mechanism of injury plus either of the following:

A. Age younger than 12 years or older than 50 years and/or

B. Inability to walk four weight-bearing steps in the ER

Ottawa Knee rules

1. Age 55 or over

2. Isolated tenderness of the patella

3. Tenderness at the head of the fibula

4. Inability to flex to 90 degrees

5. Inability to weight bear both immediately and in the ER (4 steps)

Staging of OCD Lesions

MRI- test of choice to

stage severity of OCD.

Early Referral is key

to orthopedic surgeon

to help prevent further

meniscal damage and

premature arthritis.

Treatment of OCD

Stage Age Sign/symptoms Treatment

1 10-13 pain w/o mech activity mod until pain gone,

acute symptoms F/U in 3-6 mo, re-eval if pain

2 12-15 chronic pain, Activity rest., crutch use, cast,

chronic effusion arthroscopy with revasc drilling

3 13-21 chronic pain, catch, Arthroscopy for removal osteo

osteo body lock, giving way body, no wt bear 6-12 wks, rehab

in situ

4 13-21 chronic pain, catch, Arthroscopy for removal of loose

loose body lock, giving way body, no wt bear for 3 mo, rehab

Take Home Points

1. PFKD-most common knee injury in adolescents.

2. If the history and physical exam indicate OSD, SLD, or Patellar tendonitis radiographs are not needed.

3. An accurate assessment of skeletal maturity aids in discussing risks and benefits of operative and non-operative treatment options in ACL injuries.

4. ACL Prevention Programs combine proper jumping, landing and cutting techniques for athletes while providing strength training, flexibility, plyometrics and sports specific exercises.

5. Utilize the Pittsburgh or Ottawa knee rules to determine when to obtain radiographs of knee injuries.