SPORTS MEDICINE

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Ovid: Pediatrics

Editors: Tornetta, Paul; Einhorn, Thomas A.; Cramer, Kathryn E.; Scherl, Susan A.

Title: Pediatrics, 1st Edition

> Table of Contents > Section III: – Specialty Clinics > 24 – SPORTS MEDICINE

SPORTS MEDICINE

24.1 KNEE PAIN

LAWRENCE WELLS

Knee pain as the presenting symptom or complaint can
come from a variety of sources. The approach to diagnosis, and to
ultimately recommending a course of treatment, lies in four steps:

Have an appreciation of normal knee anatomy.
Obtain a thorough history, including onset and duration of symptoms, mechanism of injury, and precipitating causes of pain.
Perform a complete physical examination
if necessary, taking into account surrounding areas (spine, hip, ankle)
that may be sources of referred knee pain.
Order supplemental studies, such as
radiographs, magnetic resonance imaging (MRI), bone scans, and special
procedures (arthrocentesis, arthrometer testing, and examination under
anesthesia) if they can aid in identifying the cause of knee pain.

The knee is a hinged joint with three major bony articulations surrounded by a complex array of ligaments and tendons (Figs. 24.1-1, 24.1-2 and 24.1-3 and Table 24.1-1).
The menisci are found between the medial and lateral femoral tibial
articulations. They provide increased surface area to dispense
weightbearing forces between the femur and tibia, as well as provide
supplemental stability for the knee (Fig. 24.1-4).

There are several bursae, which are fluid-filled sacs
that allow adjacent soft tissue envelopes to glide across one another
about the knee. The most commonly involved in injury are the
prepatellar bursa (Fig. 24.1-5), pes anserine
bursa, and infrapatellar tendon fat pad. When inflamed, they present as
tender, soft, boggy structures overlying the area of injury.

The knee also is surrounded by a complex array of
neurovascular structures—the popliteal artery and vein and the tibial,
common peroneal, and saphenous nerves.

Appreciating the anatomy of the knee helps one to
conduct specific examinations of each area previously listed and
identify areas of injury. Localizing the pain to a particular area is
the key to making the correct diagnosis. If the pain cannot be
localized on physical examination, one should consider a referred pain
from another area, such as the hip, spine, or ankle (Fig. 24.1-6).

Figure 24.1-1 Surface anatomy of the knee. A; Suprapatellar and infrapatellar depressions. B; Adductor tubercle. C; Patella. D; Joint line. E; Tibial tubercle.

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Figure 24.1-2 Normal knee anatomy.

Figure 24.1-3 Ligaments of the knee. A; Posterior cruciate ligament. B; Anterior cruciate ligament. C; Patellofemoral articulation.

TABLE 24.1-1 KNEE LIGAMENT AND TENDON ANATOMY

Structure	Origin	Insertion
Anterior cruciate	Posterior lateral intercondylar notch	Medial tibial spine
Posterior cruciate	Anterior medial femoral notch	Proximal posterior tibia
Lateral collateral ligament	Lateral femoral condyle	Fibular head
Medial collateral ligament	Medial femoral epicondyle	Medial tibial shaft
Quadriceps tendon	Rectus femoris and 3 vastus muscles	Superior patella
Patella tendon	Inferior patella	Tibial tubercle
Pes anserine tendons	Gracilis, semitendinosis, and semimembranosus muscles	Medial tibial shaft superficial to medial collateral ligament
Lateral hamstring	Long and short biceps femoris muscle	Fibular head and proximal tibia
Iliotibial band	Tensor fascia lata	Gerdy tubercle

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Figure 24.1-4 Axial view of knee menisci.

PATHOGENESIS

The most common causes of knee pain are from traumatic
injuries—acute versus repetitive microtrauma accumulated over time.
However, one needs to take a comprehensive approach in identifying the
cause of pain. The anagram VINDICATER is a useful tool as one begins to
formulate a differential diagnosis for knee pain (Box 24.1-1).

DIAGNOSIS

Patient History

The history can frequently provide many helpful clues to
identify the cause of knee pain. Obtaining a complete history can be
difficult in a young child. Therefore, in addition to the child, it is
important to interview the caretakers who are familiar with the child
and circumstances related to the child’s symptoms (Tables 24.1-2 and 24.1-3).

Figure 24.1-5 Prepatellar bursa.

Figure 24.1-6 Sources of referred pain.

Physical Examination

Begin with inspection of the knee alignment (Fig. 24.1-7), observation of the gait pattern, palpating pulses, and a neurologic exam (Table 24.1-4).
Follow with evaluation of joint motion, tests for ligament stability, and direct palpation to identify specific areas of injury.
- □ Localized tenderness is an important finding to identify the source of pain (Fig. 24.1-8).
- □ Meniscal injuries often present with
  joint line tenderness extending from the midportion of the knee in the
  coronal plane posteriorly behind the femoral condyle.
- □ Tender crepitance along the joint line
  with flexion-rotation (McMurray test) or compressionrotation maneuvers
  (Appley test) suggest a meniscal tear.
- □ Severely displaced menisci often found in buckethandle type tears can also limit full knee motion, especially extension.
The patellofemoral joint is assessed with the patient lying supine and sitting with the knee bent at 90 degrees (Fig. 24.1-9).
- □ Attempts at translating the patella
  medially and laterally can elicit a sense of apprehension or resistance
  from the patient in the case of patellar subluxation or dislocation (Fig. 24.1-10).
- □ Painful crepitance and tenderness along medial or lateral parapatellar retinaculum are also signs of patellofemoral injury.
- □ Malalignment is determined by measuring
  the Q angle, which is formed by the intersection of a line drawn along
  the long axis of the thigh and a line drawn from the midpoint of the
  patella to the tibial tubercle.
  - □ The normal value of the Q angle is 10 degrees in men and 15 degrees in women.
  - □ Increased Q angles are thought to represent lateral tracking or misalignment of the patellofemoral joint.
- □ Direct tenderness of the infrapatellar tendon can represent patellar tendonitis, commonly seen in repetitive jumping sports.
- □ Sinding-Larsen-Johansson syndrome and
  Osgood-Schlatter disease are represented by tenderness over the
  inferior pole of the patella and tibial tubercle, respectively.
- □ Tenderness over the lateral femoral
  epicondyle is often present with iliotibial band tendonitis, and
  tenderness over the pes anserine area can represent an inflamed bursa
  adjacent to medial hamstring insertions (Figs. 24.1-8B and 24.1-11, 24.1-12, 24.1-13, and 24.1-14; Table 24.1-5).
The knee ligament exam is conducted with both the patient sitting and supine.
- □ Lying supine often helps the patient to
  relax, thus avoiding inadvertent hamstring contraction that can
  compromise the examination results (Table 24.1-6).

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TABLE 24.1-2 HISTORY OF KNEE INJURY

Question	Areas to Consider
Is the pain localized to a specific area? Ask patient to point to exact area.	Joint line, patella tendon, pes anserine bursa
Is there a sense of giving way or locking?	Meniscal tear, loose body, chronic muscle weakness
What is nature of pain? Activity-related, sharp, dull, burning, acute, or chronic?	Overuse syndrome, fracture, reflex sympathetic dystrophy
Is one awakened at night from pain? Is pain relieved by salicylates or nonsteroidal antiinflammatory medications?	Infection or tumor
Was a “pop” felt or heard preceding symptoms? Was patient able to continue activity?	Ligament injury
Did knee swell immediately?	Meniscal, ligament injury or fracture
Is the pain accentuated with going up or down stairs?	Patellofemoral joint irritation

TABLE 24.1-3 OUTCOMES ANALYSIS OF KNEE INJURY MECHANISM

Mechanism	Potential Outcomes
Twisting planted foot	Meniscal or ligament injury
Fall directly onto knee	Contusion extensor mechanism or PCL injury
Valgus or varus stress	MCL, MM or LCL, LM injury, respectively
Sense of “pop,” immediate swelling, inability to continue activity participation	ACL or fracture
Sense of “giving way” or locking	Meniscal tear or patellofemoral injury
Constant or nighttime pain, relief with nonsteroidal antiinflammatory medications	Infection or tumor
Pain with use of stairs or prolonged sitting/squatting	Patellofemoral injury
ACL, anterior cruciate ligament; LCL, lateral collateral ligament; LM, lateral meniscus; MCL, medial collateral ligament; MM, medial meniscus; PCL, posterior cruciate ligament.

TABLE 24.1-4 PHYSICAL EXAMINATION FOR KNEE PAIN

Inspection	Varus/Valgus Alignment	Thigh and Calf Circumference	Foot Position	Swelling, Absence of Normal Parapatellar Concavities
Gait	Limp	Short leg	Kneeling	Jump—double/single leg
Joint motion	Extension: normal 0 degrees	Flexion: normal 145 degrees	Popliteal angle: normal <20 degrees
Neurovascular examination	Popliteal, dorsalis pedis, posterior tibial artery	Tibial, common peroneal, and saphenous nerves	Skin color, warmth

Figure 24.1-7 Knee alignment.

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Figure 24.1-8 Potential causes of knee pain and their respective anatomic locations.

Figure 24.1-9 Supine evaluation of patellofemoral joint.

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Figure 24.1-10 Lateral translation and palpation of lateral patellar facet.

Figure 24.1-11 Testing collateral ligaments of the knee.

Figure 24.1-12 Lachman test for anterior cruciate ligament deficiency.

Figure 24.1-13 (A) Posterior sag sign, indicating posterior cruciate injury. (B) Absence of posterior sag, indicating normal posterior cruciate ligament.

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Figure 24.1-14 Meniscal injuries.

TABLE 24.1-5 DIAGNOSIS OF KNEE PAIN^a

Localized Tenderness	Diagnostic Considerations
Joint line	Meniscal injury
Patellofemoral	Patellar subluxation/prepatellar bursitis
Inferior patella	Sinding-Larsen-Johansson syndrome
Infrapatella tendon	Patellar tendonitis/anterior fat pad
Tibial tubercle	Osgood-Schlatter disease
Gerdy tubercle/lateral femoral epicondyle	Iliotibial band syndrome, lateral collateral ligament injury
Pes anserine	Pes anserine bursitis
^a See also Figure 24.1-8.

TABLE 24.1-6 LIGAMENT EXAMINATION

Ligament	Test	Treatment	Outcome
MCL	Valgus stress at 30 degrees of flexion (Fig. 24.1-11)	Brace/early ROM	4-6 wk recovery
LCL	Varus stress at 30 degrees of flexion (Fig. 24.1-11)	Brace/early ROM	Same as MCL
ACL	Lachman, anterior drawer, pivot shift (Fig. 24.1-12)	Acute: ROM, hamstring strengthening, avoid sudden deceleration sports; ACL reconstruction after full ROM restored	Excellent with ACL reconstruction and post-op rehabilitation; return to sports 6-12 mo
PCL	Posterior drawer, posterior sagittal (Fig. 24.1-13), quad active test	Rehabilitate quads	Generally good for grade 1 and 2 injuries
PCL/PLC	Same as PCL plus reverse pivot shift and increased external rotation at 30 and 90 degrees of flexion	Surgical reconstruction within 2 wk of injury	Expect mild residual but improved laxity
ACL, anterior cruciate ligament; LCL, lateral collateral ligament; MCL, medial collateral ligament; PCL, posterior cruciate ligament; PLC, posterior lateral corner; ROM, range of motion.

Radiographic Features

Routine x-rays of the knee should be part of every “painful knee” evaluation.
- □ A standard knee x-ray exam should
  include a weight-bearing posteroanterior (10 to 15 degrees flexed),
  lateral, Merchant or sunrise patella view, and an intercondylar notch
  view of the knee.
- □ When the patient is unable to stand, an anteroposterior view of the knee should be obtained.
- □ After a satisfactory film is obtained, systematic careful evaluation of the x-ray is performed.
- □ Although seemingly evident, it is wise to confirm the name on the films with the name of the patient being examined.
- □ Appropriate indicators of the side (right vs. left) being examined should also be noted (Table 24.1-7).
When knee x-rays are normal, evaluate the spine, hip, and ankle regions to rule out sources of referred pain.
Additional imaging studies such as MRI
and bone scans can be useful in determining and localizing the extent
of injury and in making treatment decisions, but they should not be
used as primary screening studies.

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Special procedures for diagnosing knee pain are given in Table 24.1-8.

TABLE 24.1-7 RADIOGRAPH EVALUATION GUIDELINES

Areas to Study	Significant Findings
Soft tissue contours	Effusion, soft tissue mass
Cortical margin	Erosions, lytic changes
Marrow contents	Lucency, blastic changes, calcification
Air-fluid levels	Open knee joint, penetrating trauma
Cortical discontinuity	Fracture

TABLE 24.1-8 SPECIAL PROCEDURES

Procedure	Benefits
Arthrocentesis	Decreased symptoms, diagnostic information; acute hemarthrosis suggests meniscal or ACL injury
Stress radiographs^a	Rule out underlying physeal injury
Arthrometer testing	Noninvasive tool for ACL/PCL laxity assessment
Examination under anesthesia	Preoperative injury confirmation, improved clinical examination
^aCaution: avoid iatrogenic popliteal artery injury with overzealous stress.
ACL, anterior cruciate ligament; PCL, posterior cruciate ligament.

TABLE 24.1-9 VASCULAR CAUSES OF KNEE PAIN

Cause	History	Physical Examination	Treatment	Outcome
Sickle cell disease	Pain crisis, +HbSS electrophoresis	Joint effusion, pyoarthrosis	Arthrotomy, antibiotics	Arthritis, disability
Hemophilia	Male gender, factor VIII deficiency	Painful swollen joint	Factor replacement, RICE, joint motion, arthroscopic synovectomy	Good with attention to prevention, maintaining adequate factor level
HbSS, homozygosity for hemoglobin S; RICE, rest, ice, compression, elevation.

TABLE 24.1-10 INFECTIOUS CAUSES OF KNEE PAIN

Cause	History	Physical Examination	Laboratory Findings	Diagnostic Tests	Treatment	Outcome
Septic arthritis	Sexually active adolescent	Swollen, tender, limited motion	↑Synovial WBC, ↑ESR, CRP, +blood culture, bone scan	Aspiration, culture	Arthroscopic lavage, RICE, joint motion after acute symptoms resolved	Excellent if treated within a few days of onset; delayed treatment results in arthritis
Osteomyelitis	Low-grade fever, dull pain	Metaphyseal tenderness, limited motion	↑WBC, ESR	X-ray shows osteolytic changes; biopsy, culture routine, +AFB	Surgical débridement, antibiotics	Physeal injury; limb length inequality if extensive
AFB, acid-fast bacillus; CRP, C-reactive protein; ESR, erythrocyte sedimentation rate; RICE, rest, ice, compression, elevation; WBC, white blood cell count.

Differential Diagnosis

Vascular causes of knee pain are listed in Table 24.1-9.
Infectious causes of knee pain are listed Table 24.1-10.
As a whole, primary bone tumors around the knee are rare.
- The most common and the most dangerous neoplastic lesions are listed in Table 24.1-11. Recognizing
  
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  them is vital to delivering appropriate treatment without delay.
- Degenerative conditions are typically not found in the pediatric age group.
- Primary inflammatory conditions of the knee are rare.
  - □ Generally, juvenile rheumatoid arthritis presents in the 2- to 6-year-old age group as a swollen knee and a limp.
  - □ Workup to rule out trauma, infection, and tumor are normal.
  - □ Treatment is primarily medical, and patients should be referred to a rheumatologist.
  - □ Outcomes are generally good with appropriate medical management.
  - □ Other considerations for inflammatory causes of knee pain include Lyme disease and lupus erythematosus.
  - □ Extensor mechanism disorders typically fall under the scope of overuse syndromes (Box 24.1-2), which are considered more fully in section 24.2.
- Congenital causes—conditions with
  generalized ligamentous laxity, such as Ehlers-Danlos syndrome, Down
  syndrome, and nail-patella syndrome—typically make children more prone
  to injury, particularly of the patellofemoral joint.
  
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  - □ Treatment protocols usually do not differ from those of children without congenital conditions.
- Traumatic causes of knee pain are listed in Table 24.1-12.
- In cases in which the physical
  examination is unremarkable, one needs to consider referred sources of
  knee pain, which are given in Box 24.1-3.

TABLE 24.1-11 NEOPLASTIC CAUSES OF KNEE PAIN

Cause	History	Physical Examination	Laboratory Findings	Radiographic Findings	Treatment	Outcome
Baker cyst	Painless mass popliteal fossa	Firm rubbery nodule, transilluminates light	None needed	Normal	Observation	Many resolve spontaneously
Meniscal cyst	Painful nodule at joint line	Lateral mass, aspiration yields yellow gelatinous fluid	Normal	Usually associated with meniscal tear on MRI	Aspiration and arthroscopic partial meniscectomy	Good; unlikely recurrence with treatment of meniscal tear
Osteogenic sarcoma	2nd decade, insidious pain day and night	Tender soft tissue mass	↑Alkaline phosphatase, ↑LDH	Lytic/blastic changes; may present as pathologic fracture	Chemotherapy, limb salvage, rotationplasty, or amputation	70% 5-yr survival without metastatic disease
Chondroblastoma	Ill-defined pain	Swelling; may have localized tenderness	Normal	Epiphyseal location	Excision and curettage	<25% recurrence
Osteochondroma	Painful snapping sensation, adolescent	Palpable nodule in metaphyseal area	Normal	Metaphyseal nodularity; may be multiple	Excise if enlarged or increased tenderness	Generally benign
Osteoid osteoma	2nd decade; boys/girls 2:1; dull achy pain increased at night; relief possible but not certain with NSAIDs	Occasionally area of point tenderness is found; thigh/calf atrophy	Normal	Radiolucent nidus surrounded by reactive bone; increased uptake on bone scan	NSAIDs provide temporary relief; excision for persistent symptoms; preoperative CT helpful for defining lesion	Excellent with complete excision
Myositis ossificans	Recurrent contusions, contact sports	Swelling commonly of the distal thigh; limited ROM	Normal	Organized zonal pattern of peripheral ossification	RICE, ROM; avoid contracture formation	Excellent, full recovery expected
CT, computed tomography; LDH, lactate dehydrogenase; MRI, magnetic resonance imaging; NSAIDs, nonsteroidal anti-inflammatory drugs; RICE, rest, ice, compression, elevation; ROM, range of motion.

TREATMENT

In general, most sources of knee pain in children are
from minor contusions, muscle strains, or tendonitis related to minor
trauma or overactivity. Most are resolved with conservative measures,
which include rest, application of ice to reduce swelling, compressive wraps, temporary bracing or splinting, and elevation
to prevent edema. This is known as the RICE program, which also
includes activity modification or restriction until symptoms have
resolved. Occasionally, a course of physical therapy is needed to aid
in restoring joint range of motion and muscle strength.

TABLE 24.1-12 TRAUMATIC CAUSES OF KNEE PAIN

Cause	History/Mechanism	Physical Examination	Treatment	Outcome
Contusion	Fall, blunt trauma	Localized tenderness	RICE	Self-limited recovery
Patellar subluxation, dislocation, or malalignment	Blunt trauma Twisting injury	Parapatellar tenderness Apprehension ↑Q angle	RICE, ROM, quadriceps strengthening	Typically resolves with nonoperative treatment Proximal or distal realignment procedures for recurrent cases
Meniscal injuries (Fig. 24.1-14)	Twisting injury “Locked knee”	Effusion Joint line tenderness	RICE, ROM Arthroscopy for persistent mechanical symptoms	Prognosis good with preservation of as much meniscus as possible
Ligament injuries	Planted foot ± contact with sudden deceleration or valgus/varus stress	Point tenderness, instability on exam	RICE, restore ROM Ligament reconstruction for persistent instability or multiple ligament injuries	Prognosis generally good for isolated single ligament injuries; combined injuries have longer rehab. and more guarded chance of full recovery
Osteochondritis desiccans	Diffuse pain, limp in adolescents	Effusion, occasional point tenderness	RICE, activity modification, arthroscopy for persistent or mechanical symptoms	Prognosis agedependent; spontaneous healing can occur in those <13 yr old
Bipartite patella	Adolescent, parapatellar pain Usually discovered after blunt injury	Tenderness corresponds to superior lateral defect in patella ossification (75%)	RICE, activity modification Surgical excision and reattachment of extensor mechanism for recalcitrant cases	Most respond to conservative treatment with resolution of symptoms
Knee dislocation	Older adolescent High-impact injury, obvious deformity	Obvious deformity, generalized tenderness, may have associated neurovascular injury	Correct deformity emergently, careful neurovascular exam and repair for sustained vascular injury. Ligament reconstruction 7-10 days after injury	Good for discovered and repaired vascular injuries. Residual instability (PCL) expected but minimal symptoms if repaired
Reflex sympathetic dystrophy	Disproportionate burning pain relative to injury	Marked tenderness to light touch, skin discoloration, atrophy, stiffness	Sympathetic block, TENS, physical therapy	Variable; advanced cases have poorer prognosis for recovery
LDH, lactate dehydrogenase; PCL, posterior cruciate ligament; RICE, rest, ice, compression, elevation; ROM, range of motion; TENS, transcutaneous electrical nerve stimulation.

Referral should be made when the patient is not
responding to conservative measures, or if there is suspicion of
infection, vascular injury, obvious deformity, or fracture.

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Acknowledgment

I thank Kathrin Halpern for her assistance in the preparation of this manuscript.

SUGGESTED READING

Bruns DM, Maffuci N. Lower limb injuries in children in sports. Clin Sports Med 2000;19:4:637-662.

DeVellis
JP, Andrish JT. Knee ligament injuries in the skeletally immature
athlete. In: Orthopaedic knowledge update: sports medicine 2. Rosemont,
IL: American Academy of Orthopaedic Surgeons, 1999:355-364.

Gebhardt
MC, Hornicek FJ. Osteosarcoma. In: Orthopaedic knowledge update:
musculoskeletal tumors. Rosemont, IL: American Academy of Orthopaedic
Surgeons, 2002:175-186.

Gebhardt MC, Ready JE, Mankin HJ. Tumors about the knee in children. Clin Orthop 1990;255:86-110.

Iobst CA, Stanitski CL. Acute knee injuries. Clin Sports Med 2000; 19:621-635.

Smith
A, Scoles PV. The knee. In: Pediatric orthopaedics in clinical
practice, 2nd ed. Chicago: Yearbook Medical Publishers, 1988: 122-139.

Stanitski CL. Anterior knee pain syndromes in the adolescent. Instruct Course Lect 1994:211-220.

Stanitski
CL. Knee disorders. In: Orthopaedic knowledge update: pediatrics.
Rosemont, IL: American Academy of Orthopaedic Surgeons, 2002:191-201.

Stanitski CL, DeLee JC, Drez D. Pediatric and adolescent sports medicine. Vol 3. Philadelphia: WB Saunders, 1994.

Swenson TM, Harner CD. Knee ligament and meniscal injuries. Orthop Clin North Am 1995;26:529-545.

24.2 OVERUSE INJURIES

MICHAEL BUSCH ▪ DAVID L. MARSHALL ▪ KEITH H. MAY

An increasing number of young athletes are participating
in organized sports programs. Sports programs and recreational,
seasonal participation in a variety of sports are being replaced by
year-round competition in a single sport or activity. This trend toward
early specialization in a single activity has increased the number of
sports-related injuries in young athletes. In addition, there has been
a change in the pattern of injuries observed with the microtraumatic or
overuse injury predominating over the acute, or macrotraumatic injury.

PATHOPHYSIOLOGY

Overuse injuries are defined as those that occur when
repetitive submaximal stresses are applied to otherwise normal tissues.
If there is adequate time for the tissue to repair itself, the tissue
adapts to the demand and is able to undergo further loading without
injury. Without adequate recovery, the normal reparative processes are
overwhelmed; tissue failure (due to microtrauma) develops and
stimulates the body’s inflammatory response, leading to clinical injury.

Overuse injuries can occur in a variety of tissues such as bone, tendons, or growth cartilage (Box 24.2-1).
Growth cartilage is found in three locations in the child: the physes,
the epiphyseal surfaces, and the apophyses, all of which are
susceptible to overuse injuries.

DIAGNOSIS

Patient History

As in any aspect of physical diagnosis, the history is
important in diagnosing and treating overuse injuries. One must
remember that the period of abusive training may have occurred weeks to
months before the onset of clinical pain. Predisposing factors leading
up to the onset of pain must be sought.

Predisposing factors for overuse injuries can be grouped into two broad categories: intrinsic factors and extrinsic factors (Box 24.2-2).
Intrinsic factors such as limb alignment and resulting biomechanics are
innate to the athlete. Extrinsic factors are determined by the athlete,
and these include training regiments, shoes, and running surfaces.

OVERUSE SYNDROMES OF BONE

Stress injuries of bone can occur in any part of the
bone. Much like repetitive bending of a paperclip, repetitive loading
of virtually any element of the musculoskeletal system can lead to
structural fatigue. Ideally, this leads to remodeling and strengthening
that allows more activity as time

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goes on. If fatigue occurs faster than remodeling, the tissue fails resulting in clinical injury.

BOX 24.2-2 PREDISPOSING FACTORS FOR OVERUSE INJURIES

Intrinsic Factors

Anatomic malalignment

Pes planus
Hyperpronation
Tibial torsion
Femoral anteversion
Patellofemoral malalignment (Q angle)
Leg length discrepancy

Growth-related factors

During growth, lengthening of bone occurs more rapidly than surrounding muscle leaving the muscle-tendon unit tight
Susceptibility of growth cartilage

Underlying disease states

Scoliosis
Arthritis
Nutritional deficiency
Excessive ligament laxity
Previous injury

Extrinsic Factors

Training errors

Sudden increase in intensity, frequency, or duration of an activity
Addition of new program or sport
Attendance at a specialty camp

Incorrect technique

Pitching style

Improper equipment

Wornout footwear (should be replaced every 250-400 miles)
Grip size, string tension

Environmental factors

Change in surface (wood, pavement, grass)
Hill or bleacher training

METAPHYSEAL/DIAPHYSEAL STRESS INJURIES

The simplest example of stress injury in bone is the
stress fracture. Among youths, these most commonly occur with distance
running. The athlete may experience gradual onset of symptoms and
eventually be unable to run because of pain. Acute failure can occur
through the weakened bone resulting in a complete fracture.

Pathogenesis

Virtually any bone can be affected
Most common metaphyseal and diaphyseal
stress fractures in young athletes include the fibula, metatarsals,
tibia, femur, and ulna.
Stress fractures of the metatarsals
(typically the second or third) and the distal fibula rarely have
complications other than pain and disability.
Fractures of the tibia, humerus, and forearm rarely displace but do represent potential risk for morbidity.

Epidemiology

Most occur in later adolescence, ages 16 to 19.
Boys and girl are equally affected.

Diagnosis

Initially, only about 10% of radiographs are abnormal.
Bone scan and magnetic resonance imaging (MRI) are much more sensitive.
Bones scans result in radiation exposure,
but are useful if the exact area of involvement is in question.
Findings must be correlated to the clinical symptoms. As many as 50% of
adolescents with stress fractures will show multiple areas of stress
response on bone scans that do not correlate to areas of symptoms.
MRI detects subtle marrow edema and early cortical failure.

Treatment

Rest treats most diaphyseal and metaphyseal stress fractures.
Crutches are often necessary. Occasionally, immobilization is needed.
Healing time can range from 4 to 12 weeks.
Alternative training, gradual resumption of sports, and monitoring for recurrent symptoms are necessary.
Some stress fractures require surgery.
- □ Stress fractures of the hip are rare
  but have the highest potential for morbidity. Femoral neck fractures
  can displace, disrupt the blood supply to the femoral head, and lead to
  avascular necrosis.
- □ Stress fractures of the fifth metatarsal tend to be recurrent and are often best managed with an intramedullary screw.

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SPONDYLOLYSIS

Pathogenesis

Fracture through the pars interarticularis of the lumbar vertebrae.
Commonly seen in athletes who are under
the age of 20 and involved in a sport that requires repetitive
extension of the lumbar spine, such as gymnastics, cheerleading,
diving, football (linemen), and dance.
The most common location is L5-S1, followed by L4-L5.

Diagnosis

Pain with palpation is worse with single or dual leg hyperextension.
Flexion usually is painless.
Hamstrings frequently are tight.
Anteroposterior, lateral, and oblique x-rays of the lumbar spine may be negative.
Look for the fracture through the neck of the “Scotty dog” on the obliques.
If clinical suspicion is high, and x-rays
negative, consider computed tomography (CT), single-photon emission
computed tomography (SPECT), or MRI.

Treatment

Modify activities to avoid extension for 4 to 8 weeks.
Consider rigid lumbar support bracing for 4 to 8 weeks.
Physical therapy for truncal stabilization, and functional progression back to sport.
Can resume activities without the brace 8 to 12 weeks from diagnosis.

APOPHYSEAL CONDITIONS

OSGOOD-SCHLATTER DISEASE

Pathogenesis

A disorder of the proximal tibial
apophysis that commonly affects young athletes, but may bother other
active youngsters who are not involved in formal, organized sports.
The tubercle of the proximal tibia is the insertion site of the patellar tendon.
Because of the strength or the quadriceps, large tensile forces are transmitted through the patellar tendon insertion.
The normal transition from the ossified
and unossified tubercle into the tendon undergoes fatigue failure and a
healing response ensues.

Epidemiology

While activity plays a role, some
individuals appear to be predisposed to this condition; 20% to 30% of
youngsters will have siblings who have had the same problem.
Typically, the child is between 10 to 15 years of age at the onset.
Boys are more commonly affected than girls; however, female gymnasts seem to be particularly prone to this problem.
Approximately 15% of teenage boys and 10% of teenage girls are affected.
Incidence of bilaterality varies considerably.

Diagnosis

Typically significant pain and prominence on the presenting side and some degree of findings on the contralateral side.
Many patients have a prior history of heel pain compatible with Sever disease (calcaneal apophysitis).
Pain is usually well localized to the prominent tibial tubercle.
Pain is typically related to activities.
There should be no signs or symptoms of intraarticular problems of the knee joint itself.
The diagnosis can then be made clinically.
A lateral radiograph of the knee can be helpful to confirm the diagnosis by showing irregularity of the tibial tubercle.
The radiograph should also rule out any other osseous problems, such as tumor or infection.

Treatment

In most, it simply runs its course with time, with symptoms lasting 1 to 4 years.
In approximately 3% of patients a
persistent ossicle forms, which can remain symptomatic and ultimately
require surgical excision.
Associated tuberosity fractures are so rare that there appears to be no sound evidence that activity restriction is required.
Symptomatic measures include ice,
nonsteroidal antiinflammatory drugs (NSAIDs), compressive sleeve or
band, activity modifications as indicated by the symptoms, and
hamstring stretching.
Casts/rigid braces are rarely used, except for severe acute exacerbation.

SINDING-LARSEN-JOHANSSON SYNDROME

Pathogenesis

Pathophysiology is similar to Osgood-Schlatter disease but the pain is located over the inferior pole of the patella.
Typically patient is between 8 to 13 years of age at onset.
Bilaterality varies considerably.

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Diagnosis

The pain is well localized over the inferior pole of the patella.
The pain is related to activities.
The diagnosis is clinical.
Lateral radiograph may show irregular ossification over the distal patella.

Treatment

Same as Osgood-Schlatter disease.

SEVER’S DISEASE (CALCANEAL APOPHYSITIS)

Pathogenesis

Heel pain is a common complaint of the young adolescent.
It is due to the very powerful but tight gastrocsoleus complex as it inserts on the back of the calcaneus.

Epidemiology

Seen more often in boys age 9 to 13.
More common in gymnastics, running, and sports in which cleats are worn (football, soccer).
Bilateral in 50% of cases.

Diagnosis

Pain localized to posterior aspect of calcaneus.
Pain with medial and lateral pressure on the heel (squeeze test).
Disease is associated with hyperpronation, femoral anteversion, tibial torsion.
Those affected usually have tight plantarflexors and weak dorsiflexors.
The diagnosis is made clinically. A
lateral radiograph may show fragmentation and irregularity of the
calcaneal apophysis, but this can be seen in asymptomatic heels.

Treatment

The condition is self-limited so
treatment is conservative and aimed at symptomatic relief: ice, NSAIDs,
modification of activities, ¼-inch silicone or Sorbothane heel cups,
orthotics to correct any mechanical problem, physical therapy, and home
exercises to stretch the plantarflexors and strengthen the dorsiflexors.
Casting for 2 to 3 weeks may be needed in extreme cases.

ISELIN’S DISEASE

Pathogenesis

This is an uncommon traction apophysitis at the base of the fifth metatarsal at the insertion of the peroneus brevis.
It occurs in skeletally immature athletes.

Diagnosis

Pain is located on the lateral side of the foot and exacerbated by running, jumping, and cutting.
Pain with resisted eversion.
Radiographs may show a widened and prominent apophysis at the base of the fifth metatarsal.

Treatment

Ice
NSAIDS
Activity modification to avoid pain.
Physical therapy to stretch the ankle evertors and strengthen the invertors.

APOPHYSITIS OF THE MEDIAL EPICONDYLE

Pathogenesis

Throwing produces a valgus moment at the
elbow with compressive loads applied to the lateral side
(radiocapitellar joint) and traction loads across the medial side.
In the late teen years and above,
repetitive traction injuries involve the medial collateral ligament
itself, and can lead to rupture of the ligament.
In the immature skeleton, the apophysis
of the medial epicondyle can begin to fragment, which leads to a
reparative process leading to pain and prominence.

Diagnosis

Point tenderness over the medial epicondyle.
Little or no loss of extension.
Radiographs usually show some degree of irregularity or fragmentation of the apophysis.

Treatment

Pain usually resolves with time and rest.
Avulsion of the medial epicondyle can
occur with forceful throwing, so restriction of rigorous throwing, such
as pitching, is prudent.
- □ Batting is usually not troublesome, and many can play an infield position while this resolves.
- □ Return to pitching in less than 6 months often results in recurrence.

APOPHYSITIS OF THE PELVIS

Pathogenesis

During periods of rapid growth, there is
a strength-flexibility imbalance in the muscle tendon unit due to rapid
growth of the bone relative to the muscle tendon.
Several apophyses in the pelvis are susceptible to traction injuries (Table 24.2-1).
These are most commonly seen in runners, sprinters, football players, and soccer players.

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TABLE 24.2-1 APOPHYSES IN THE PELVIS

Apophysis	Muscle
Iliac crest	External obliques, gluteus medius, tensor fascia lata
Anterior superior iliac spine	Sartorius
Anterior inferior iliac spine	Rectus femoris
Ischial tuberosity	Hamstrings
Greater trochanter	Gluteus medius
Lesser trochanter	Iliopsoas

Treatment

Ice
NSAIDs
Modification of activities to maintain cardiovascular endurance
Stretching of the involved muscle-tendon unit once acute pain subsides
Gradual return to activities usually by
the direction of a physical therapist (usually after 2 to 4 weeks; 4 to
6 weeks if avulsion is present)

REPETITIVE PHYSEAL INJURIES

LITTLE LEAGUE SHOULDER

Pathogenesis

Repetitive stress to the shoulder can lead to widening and resorption around the proximal humeral physis.
This “physiolysis” has been termed “Little League shoulder” since it occurs primarily in Little League baseball players.
While typically affecting pitchers, other rigorous throwers, such as catchers, can develop this as well.

Diagnosis

Typically 12- to 15-year-old boys
Shoulder pain related to overhead throwing
Usually more painful in the deltoid region than the subacromial region
Differential diagnosis: rotator cuff tendonitis and impending pathologic fracture from a simple bone cyst to the upper humerus
Radiographic widening of the proximal humeral physis on the affected side confirms the diagnosis of Little League shoulder.
- □ Need comparison with other shoulder.

Treatment

Primarily involves rest
Complications are uncommon, so if the symptoms are minimal, batting and playing infield positions are usually not painful.
Resolution can take up to 6 months.
Pitching is gradually resumed.
Monitor for resumption of symptoms.

GYMNAST’S WRIST

Pathogenesis

Gymnastic training often begins as early
as age 4 or 5 and peaks in the early to mid-teens, during which the
time spent in training may reach as high as 30 to 40 hours per week.
Because many maneuvers in gymnastics
involve weight-bearing on the dorsiflexed wrist, often with a
rotational component, the wrist is a common site of overuse injury.
The term gymnast’s wrist is a catchall term often used to describe any of a wide variety of wrist injuries in gymnasts.
The most common chronic injury seen is at the level of the distal radial physis.

Epidemiology

80% to 90% of affected athletes are female.
Typically 12 to 14 years of age
Symptoms are bilateral in approximately one-third of patients.
Usually seen in gymnasts whose weekly training regimen exceeds 20 hours per week.
Vault and floor exercise are the events most likely to cause symptoms.

Diagnosis

Patients have pain with palpation over the distal radial physis.
There is pain at extremes of dorsiflexion.
This can be differentiated from dorsal impingement by the presence of pain on the volar and radial aspects of the physis.
Radiographs may be normal (stage 1), and the diagnosis is made clinically.
Radiographs may show widening of the
distal radial physis, irregularity or cystic changes on the metaphyseal
side of the growth plate, or breaking of the radial physis (stage 2).
With late presentations, the radiographs may show positive ulnar variance due to premature closure of the radial physis.

Treatment

Stage 1 (no radiographic changes)
- □ Modified rest, which involves avoidance
  of axial compressive loads for a period of 2 to 4 weeks. During this
  time the athlete may continue to condition, maintain flexibility, and
  continue to train on the beam, practice aerial stunts, as well as
  footwork on the floor exercise.
- □ After the pain resolves, a gradual return to activity is allowed with close supervision.
Stage 2 (radiographic changes with no ulnar variance)
- □ Avoidance of axial compressive loads for 6 to 12 weeks. Casting may be appropriate for the noncompliant athlete.
- □ To improve compliance, it is important
  to inform the gymnast that absolute rest will provide the best chance
  of returning to a competitive level.
Stage 3 (positive ulnar variance)
- □ Same as stage 2.
- □ Consider MRI arthrography for
  triangular fibrocartilage complex (TFCC) tears. This should be
  suspected in any gymnast with wrist pain on the ulnar side.
- □ Possible need for shortening osteotomy of the ulna.

Prevention

Educate athletes and coaches on the importance of wearing variance braces with workouts.
Recommend bi-annual routine wrist radiographs in all gymnasts training more than 16 hours per week.
Encourage strength and flexibility training of the wrists year-round.
Alternate compressive, axial-loading workouts (vault) with traction workouts (uneven bars).
Early stage diagnosis: encourage gymnasts at all ages to have wrist pain evaluated.

EPIPHYSEAL OVERUSE CONDITIONS

Perhaps the best example of a repetitive stress injury
of the epiphyses occurs at the capitellum—Panner disease and
osteochondritis of the capitellum. In these conditions, a segment of
epiphyseal bone becomes necrotic and can result in separation of the
bone segment and overlying articular cartilage. While technically
classified as an “osteochondrosis,” these have features of repetitive
stressinduced injuries, much like stress fractures.

PANNER’S DISEASE

Panner described a lesion of a young boy’s capitellum that he compared with Legg-Calvé-Perthes disease.
In patients under 10 years of age who develop irregularity of the capitellum, the course is usually quite benign.
An avascular segment of bone develops in the center of the capitellum, revascularizing in time.
Loose bodies do not typically form.
Sequelae are rare and treatment is simply rest.

OSTEOCHONDRITIS DISSECANS OF THE CAPITELLUM

Pathogenesis

While the term osteochondritis dissecans implies that there is an inflammatory process present, histologic studies have in fact failed to confirm this.
Appears to be a repetitive stress phenomenon
Most commonly occurs in baseball pitchers.
As the ball is accelerated during the pitching motion, a valgus moment is created at the elbow.
- □ There is tension on the medial side of the elbow and compressive forces across the radial capitellar articulation.
The capitellum has an end arterial blood
supply, which may explain its susceptibility to develop avascular
necrosis from chronic repetitive compression loads.

Diagnosis

Side arm pitches, many curve ball
techniques, and others can increase the compression loads across the
lateral side of the elbow by bringing the ball further away from the
midsagittal plane and accentuating the valgus moment.
Typically patients complain of an aching pain in the lateral side of the elbow.
Often they have flexion contractures.
Displaced fragments can result in a loose body sensation, a locked elbow, or significant synovitis and pain.
Plain radiographs typically show a sclerotic region or radiolucency. Tangential views may help.
Occasionally, CT scan or MRI are indicated.

Treatment

Osteochondritis of the capitellum can result in permanent arthrosis of the elbow joint.
Prevention through education is key.
- □ Junior baseball programs should have
  rules limiting how much youngsters can pitch, typically three innings
  per game, up to six innings per week.
Occasionally, intact lesions heal with prolonged rest, but surgery is often necessary to remove unstable or displaced fragments.
Compared with simple arthroscopic débridement, there is no proven benefit to grafting, or other procedures.

TENDINOSES

ROTATOR CUFF TENDONITIS

Pathogenesis

Unlike in adults, tendon degeneration and rupture are rarely seen in youths.

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The rotator cuff is a convergence of the tendons of the subscapularis, supraspinatus, infraspinatus, and teres minor.
- □ These extend from the scapula out over the humeral head.
- □ Together, they stabilize the humeral
  head against the glenoid fossa and they prevent the humeral head from
  rubbing beneath the arch of the acromion.
- □ The supraspinatus muscle is the most important of these.

Etiology

Many factors contribute to rotator cuff tendonitis.
- □ In young athletes, inherent laxity of the glenohumeral capsule is likely a significant factor.
- □ Overhead throwing in baseball, swimming, serving motion in tennis, and gymnastics precipitate symptoms.
Pain produces inhibition of the rotator cuff muscles, which precipitates impingement of the humeral head beneath the acromion.
- □ With time, a well-established bursitis and tendonitis develop.

Diagnosis

Typical complaints: pain with overhead activities, and sensation of the arm becoming heavy, tired or “dead.”
Thoroughly examine the neck and shoulder looking for restriction of motion, muscle atrophy, and focal tenderness.
- □ There may be tenderness along the course of the biceps tendon, as well.
The supraspinatus strength should be tested.
- □ Glenohumeral laxity is common.
Plain radiographs are useful to rule out other bony abnormalities.
MRI can be diagnostic for rotator cuff tendonitis; however the diagnosis can usually be made clinically.
- □ Partial and full thickness rotator cuff tears are rarely seen before 18 years of age.

Treatment

The principles of treatment center on restoring strength and motion of the rotator cuff and scapular stabilizers.
NSAIDs.
Often overhead activities are curtailed
while physical therapy is initiated. Rehabilitation of the entire
scapular thoracic complex is key.
As pain diminishes and strength returns,
overhead sporting activities are initiated, with careful monitoring for
evidence of recurrent impingement.
In recalcitrant cases, a subacromial or intraarticular injection of steroids can hasten resolution of the inflammatory phase.
Occasionally, surgical stabilization is necessary, though subacromial decompression is rarely indicated for youths.

SHIN PAIN

Shin pain is a common complaint in young athletes. Much like the term headache,
the diagnosis of “shin splints” refers to a collection of maladies with
the common feature being activity-induced pain in the midportion of the
leg. Specific diagnoses include:

Periostitis
Chronic exertional compartment syndrome
Stress fracture
Muscle herniation
Superficial nerve entrapment

Shin pain in youths should be evaluated for a specific diagnosis. Other considerations in the differential diagnosis include:

Deep venous thrombosis
Tumor
Infection
Popliteal artery entrapment

PERIOSTITIS

Pathogenesis

This clinical entity is also termed medial tibial stress syndrome and soleus syndrome.
The soleus muscle and its investing fascia originate in this area and are also implicated in causing the syndrome.
Three-fourths of running athletes with shin pain have posteromedial tenderness, and half of them are bilateral.
Boys and girls are equally affected.
Predisposing factors include:
- □ Muscle weakness
- □ Running shoes with a lack of heel cushion, inadequate arch support
- □ Hard training surfaces.
- □ Training errors such as sudden increases in intensity or mileage
- □ Abnormal lower limb biomechanics

Diagnosis

Activity-related pain
No associated numbness
Recent increase in the intensity of sports participation, training, and competition schedule
Recent change in regimen or shoes, and surface training conditions
Pain and tenderness along the distal
third of the posteromedial tibia—extending longitudinally along several
centimeters, and not across to the anterior tibia
Varus hindfoot alignment, excessive forefoot pronation, genu valgum, excessive femoral anteversion, and external tibial torsion
No muscle herniation

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Negative Tinel test
Normal radiographs
If confirmation of the clinical diagnosis
is needed, bone scan shows a longitudinal pattern of radionuclide
concentration rather than a transverse pattern more typical of a stress
fracture.

Treatment

NSAIDs
Ice
Strengthening and stretching
Ultrasound
Foot orthoses
Graduated running program
Surgery rarely indicated

CHRONIC EXERTIONAL COMPARTMENT SYNDROME

Pathogenesis

With repetitive exercise, the interstitial pressure within the osseofascial compartments of the leg can become elevated.
When compartment pressures exceed capillary filling pressure, the muscle becomes ischemic and produces pain.
This usually has an onset associated with activity and is relieved by rest.
Unlike acute compartment syndromes
resulting from trauma or arterial insufficiency, the pressure and blood
flow to the muscles normalizes in chronic compartment syndromes and
rarely result in tissue necrosis or residual disability.
The anterior compartment is the most commonly involved, although any of the four compartments in the lower leg may be affected.

Diagnosis

Typical complaints: aching pain, tightness, or a squeezing sensation brought on by and interfering with athletics
Usually relieved promptly after exercise
Some experience transient foot-drop with paresthesias across the dorsum of the foot if the anterior compartment is involved.
Plantar paresthesias with chronic posterior compartment syndrome.
Fascial defects with muscle herniation may be present over the anterior and lateral compartments.
If clinically indicated or desired, dynamic measurement of compartment pressures during exercise can confirm the diagnosis.
- □ In chronic compartment syndrome, resting pressures typically are not elevated.
- □ With exercise, the pressures rise to 70 to 100 mm Hg, while normal compartments rise to less than 30 mm Hg
- □ MRI done immediately after exercise may have a role as well.

Treatment

Initial treatment includes activity modification, foot orthoses, physical therapy, and time.
Recalcitrant cases may require a fasciotomy.
- □ All involved compartments should be released.
- □ This can be done through limited skin
  incisions rather than through the extensive releases suggested for
  adequate management of the acute traumatic compartment syndrome.
- □ Care must be taken to protect the saphenous vein, saphenous nerve, and the superficial branch of the peroneal nerve.
All compartments should be assessed because symptoms may not be adequate to identify all involved compartments.
History of bilateral symptoms should be specifically sought.
- □ After unilateral surgical release,
  patients frequently increase their activity levels, only to develop
  pain on the side that had been asymptomatic.
Failures result from failing to
appreciate multiple compartment involvement; from inadequate
decompression, especially of the deep posterior compartments; and from
excessive scar tissue response.