Slipped Capital Femoral Epiphysis

By admin On Oct 31, 2023

Ovid: 5-Minute Sports Medicine Consult, The

Tara Merrit

W. Franklin Sease Jr.

Basics

Description

A disorder of unknown cause in which the proximal femoral epiphysis (head of the femur) begins to “fall off” the femoral neck.
The slippage occurs at the epiphyseal plate, which begins to weaken as it matures.
There are 4 presentation patterns for SCFE:
- Preslip
- Acute
- Acute-on-chronic
- chronic
SCFEs are classified based on the intensity and duration of symptoms present as well as the radiographic findings.

Epidemiology

The disorder affects 0.2–10/100,000 children.
Predominant age: The mean age at which it occurs is 12 yrs in girls and 13.5 yrs in boys. Age decreases with increasing obesity.
The disorder is bilateral in 18–63% of affected children.
The disorder frequently occurs in 2 distinct body types: (1) slender, tall, rapidly growing boys and (2) large, obese boys ± undeveloped sexual characteristics. The 2nd body type is more prevalent than the 1st.
Pacific Islanders have the highest incidence, followed by African Americans, Hispanics, Native Americans, Americans, and children of Indonesian/Malay descent.

Risk Factors

Occurs during the rapid growth spurt
Endocrine disorders that weaken the physis are associated with slipped epiphyses and are particularly prevalent in preadolescent children.
Radiation therapy and renal failure are also associated with slipped capital femoral epiphysis (SCFE).
Obesity

Etiology

Biomechanical and biochemical factors play a role in SCFE.

Biomechanical factors include obesity, femoral retroversion, and increased physeal obliquity.
Biochemical factors include increased growth hormone during puberty, which increases the height of the zone of hypertrophy, and increased testosterone, which decreases physeal strength.

Commonly Associated Conditions

GH deficiency
Hyperthyroidism
Hypothyroidism
Multiple endocrine neoplasia
Panhypopit
Renal failure
Radiation therapy

Diagnosis

Determined by history, physical examination, and anteroposterior (AP) and frog lateral view radiographs.
It is important to always examine both sides owing to possibility of bilateral disease.

Physical Exam

The most common presenting complaint is hip pain and a limp (antalgic gait). Trendelenburg test is positive when the patient stands on the affected leg and a downward pelvic tilt occurs due to hip weakness on the affected side.
The pain typically is located in the groin area and very commonly presents as referred medial knee pain ± thigh pain.
Pain is usually gradual in onset, and symptoms occur even when minimal displacement is present. Pain also may occur acutely with a dramatic onset of injury and sudden severe hip or knee pain and inability to bear weight.
The physical exam reveals tenderness over the hip joint capsule, and an external rotation deformity of the lower extremity may be present.
There is restricted hip motion, especially internal rotation, abduction, and forward flexion.
The hip tends to rotate externally and abduct as it is flexed (Whitman sign).
In chronic cases, the affected leg may be 1–3 cm shorter than the normal leg, and the thigh muscles may be atrophied.

Diagnostic Tests & Interpretation

Imaging

CT is occasionally useful for grading chronic slips.
MRI is useful for detecting preslips that may be symptomatic but have normal radiographs.
AP and frog-leg lateral views confirm the diagnosis. The affected side always should be compared with the unaffected leg. Up to 10% of SCFE patients have normal radiographs initially.
The capital epiphysis is seen to displace posteriorly and downward, whereas the femoral neck displaces upward and anteriorly. In some patients, displacement is not obvious, but the physeal plate is widened (preslipping stage).
Classification is based on the severity of the slip. Type 1 slips involve <33% of the width of the femoral epiphysis. Type 2 involves a 33–50% slip, and a type 3 involves >50% of the width of the femoral epiphysis.

Differential Diagnosis

Femoral cutaneous nerve entrapment (more common in muscular girls)
Proximal femur fracture
Avascular necrosis
Juvenile rheumatoid arthritis
Chondrolysis
Psoas abscess
Legg-Calve-Perthes disease (in younger age range)
Septic joint
Toxic synovitis
Intra-abdominal tumor

P.541

Treatment

Long-term treatment
Acute treatment: Orthopedic referral should be made immediately on diagnosis.

Surgery/Other Procedures

Surgical stabilization is the mainstay of treatment for all types of slippages.

In-Patient Considerations

Initial Stabilization

Acute treatment involves cessation of weight bearing and surgical stabilization.
A displaced epiphysis may require reduction before fixation.
In the preslip phase, with widening of the physeal plate evident on radiographs, in situ operative fixation is recommended.
Weight bearing is begun at 6 wks postoperatively.

Ongoing Care

Follow-Up Recommendations

Orthopedic referral should be made immediately on diagnosis.

Prognosis

Prognosis is usually good, except in patients with acute traumatic separation.
Slight shortening of the leg of <1.25 cm may result, along with a mild external rotation deformity.
The internal fixation devices are removed after the physeal plate closes in 1–2 yrs.

Additional Reading

Aronsson DD, Loder RT, Breur GJ, et al. Slipped capital femoral epiphysis: current concepts. J Am Acad Orthop Surg. 2006;14:666–679.

Mercier L. Practical orthopedics. St. Louis: Mosby-Year Book, 1995.

Paletta GA, Andrish JT. Injuries about the hip and pelvis in the young athlete. Clin Sports Med. 1995;14:591–628.

Snider RK, Greene WB, Johnson TR, et al. Essentials of musculoskeletal care. Rosemont, IL: American Academy of Orthopedic Surgeons, 1998.

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

Codes

ICD9

732.2 Nontraumatic slipped upper femoral epiphysis

Clinical Pearls

In acute traumatic separations, avascular necrosis of the femoral head is a common complication, and this usually results in severe arthritis of the hip.
Another complication is acute cartilage necrosis or lysis of the articular cartilage of the hip joint. A painful fibrous ankylosis of the hip joint is frequently the end result.
All adolescent patients with thigh or hip pain should get x-rays. SCFE can present unilaterally or bilaterally with only knee or thigh pain; not all cases have hip pain. Abnormal range of motion may be noted on physical examination. The recommended radiographs are AP and frog-leg lateral pelvis views, not individual hip radiographs.
Acute SCFE: Sudden onset severe pain usually of <3 wks' duration that prevents weight bearing. Usually associated with trauma. Joint effusion and no metaphyseal remodeling. Examination reveals external rotational deformity, shortening of the affected limb, decreased range of motion at the hip and severe pain with attempted manipulation.
Treatment: Immediately make patient non–weight bearing; refer urgently to pediatric orthopedic surgery
Acute on chronic SCFE: History of at least 3 wks of hip pain and/or limp with a sudden increase in pain and inability to bear full weight. Patients usually have a joint effusion and metaphyseal widening.
Treatment: Treat like an acute SCFE. Make patient non–weight bearing, and refer to pediatric orthopedic surgery.
Chronic SCFE: Most common presentation; vague intermittent symptoms of hip, thigh, or knee pain, worsened by activity and relieved by rest. Exam reveals antalgic gait and even a Trendelenburg or waddling depending on whether unilateral or bilateral. Often the affected foot is turned outward. Often pain with internal rotation, abduction, and flexion of the hip with reduced movement in these planes. Metaphyseal modeling is present but no effusion.
Treatment: Make patient non–weight bearing, and refer to pediatric orthopedic surgery.