Essentials of Orthopedic Surgery, third edition / 14-Answers to Questions

Slipped Capital Femoral Epiphysis

JOHN N. DELAHAY

History

V.C. is a slightly overweight 11-year-old Caucasian girl who presented with the chief complaint of leg pain and limp for a period of 3 months. The pain began somewhat insidiously and without antecedent trauma. The pain was dull and aching in character and without significant radiation. The pain was relieved by rest and accentuated by standing and walking. She had actually attempted to play soccer during this period but had to stop because of the pain.

Her past medical history was entirely negative. However, of note, her brother had previously been diagnosed with slipped capital epiphysis and had been operated upon sequentially for bilateral disease.

Physical Examination

Pertinent findings were confined to the musculoskeletal system. Observation of gait demonstrated an antalgic limp on the right side. She was, however, able to walk without an assistive device and in fact was able to stand only on the affected side with the opposite leg off the ground.

In the resting position (hip extended), the leg tended to lie in the externally rotated position. When evaluating range of motion (ROM), the hip was noted to flex up in the externally rotated position. Attempts to internally rotate the hip in flexion or extension demonstrated the inability to do so as well as guarding because of pain. The flexion–extension range was normal. Leg lengths were equal, and the neurovascular status of the limb intact.

Laboratory and Radiographic Evaluation

Complete blood count (CBC), sedimentation rate, C-reactive protein (CRP), thyroid hormone assays, and renal function studies (BUN, creatinine, UA) were all within normal limits.

556

Slipped Capital Femoral Epiphysis

557

Initial radiographs are shown in Figures 1 and 2. Figure 1 is an anteroposterior (AP) view of the pelvis and both hips. Figure 2 is a “frog leg” lateral of both hips. As is often the case, the radiographic findings are most pronounced on the frog leg lateral view.

1.Kline’s line is a line drawn along the superior neck of the femur. Normally, it should intersect a small portion of the capital femoral epiphysis. It can be seen in Figure 2 that if one were to draw this line it would not intersect the epiphysis but rather go above it.

2.Physeal widening can also be seen in Figure 2 and to a lesser degree in Figure 1.

3.Cystic changes are seen in the metaphysis in both figures but again are more apparent in the frog leg lateral view.

Careful review of those radiographs also shows similar changes on the opposite (left) unaffected and presumptively “normal” side.

Diagnosis is bilateral slipped capital epiphysis.

Treatment

Although these slips were considered stable, the patient was placed on crutches to restrict weight-bearing while arrangements were made for surgical treatment. She was taken to the operating room in a timely fashion

FIGURE 1. An anteroposterior (AP) view of the pelvis and both hips.

558 J.N. Delahay

FIGURE 2. A “frog leg” lateral view of both hips.

Slipped Capital Femoral Epiphysis

559

(2 days after presentation) and underwent bilateral percutaneous pinning in situ using 7.3-mm cannulated screws. One screw was used on each side. No attempt was made to reduce the slips. Postoperatively, she was discharged home on crutches. Her weight-bearing status was slowly advanced, and the crutches were discontinued when the adductor spasm had resolved. No plans exist to remove hardware. Follow-up X-rays are planed at 6- month intervals until growth completion.

Discussion

Slipped capital femoral epiphysis (SCFE) is a relatively common cause of hip pain and limp in the preadolescent population. Typically, however, it affects Afro-Americans more commonly than Caucasians and males more commonly than females. Typically the patient is somewhat overweight and has had the pain and limp for several months at the time of presentation. The incidence of bilaterality is somewhat debated, but most texts report it to be about 25%. There is rarely a family history (as is the case here), and that of course raises the question of genetic association (which has never been demonstrated).

Because the patient was a female and Caucasian with a strong family history, the other issue to be considered is an endocrine etiology, and this was the rationale for obtaining thyroid and renal function studies. One other area to be considered would be growth hormone abnormalities.

Her presenting complaints were rather typical. The pain was more localized to the thigh; this phenomenon is usually explained as referral along the course of the obturator nerve. The pain was mechanical and relieved by rest. The limp was antalgic with a shortened stance time on the affected limb.

The X-rays were diagnostic, showing the most typical findings: positive Kline’s line on the right and arguably the left, and physeal widening and metaphyseal cysts on both sides. Additional imaging studies are not needed in this patient. Occasionally, when the diagnosis is in question, a magnetic resonance imaging (MRI) scan or a Tc-99 bone scan may provide confirmation of the diagnosis, although some authors question the efficacy of either. There are many who believe that if a child presents with the classic history and physical findings, they should be considered as having “preslips” and treated as such.

This girl’s treatment was the norm: restrict weight-bearing and pin the

SCFE in situ in a timely manner. No attempt to reduce the slip should be made when the slip is stable as doing so increases the risk of vascular necrosis. A child with a stable slip can still bear weight on the limb and walk. The child with an unstable slip cannot bear weight on the extremity. Pinning in situ is the standard treatment for this condition; the goal of the

560 J.N. Delahay

treatment is primarily to stop any further slipping and initiate or facilitate plate closure.

In this case, both hips were pinned because there was radiographic evidence of bilateral disease. This author and others routinely pin both sides whether or not there is evidence of bilaterality, the rationale being the relatively high incidence of bilaterality (this patient’s brother had to have his pinned sequentially) and resultant leg length discrepancy that results from unilateral pinning. In the case of an 11-year-old girl, who would have about

3 years of growth left, one could expect a 1.8-cm discrepancy (6 mm × 3). This girl’s postoperative course was benign. The two major complications of SCFE are avascular necrosis (AVN) and chondrolysis. AVN is usually considered a complication of the treatment of the disease, resulting from aggressive manipulation to reduce the slip or osteotomies of the femoral neck. Chondrolysis is considered by most to be a complication of the disease itself. This loss of the articular cartilage is much more likely to be seen in African-Americans and can actually be seen at the time of

presentation before treatment has been initiated.

Overall, the prognosis for SCFE is good. With early diagnosis and appropriate surgical treatment, most children can be restored to normal function rather quickly.

Cubital Tunnel Syndrome

MUSTAFA A. HAQUE

History

This patient is a healthy, 34-year-old woman who started to develop pain, numbness, and tingling in her dominant right hand 3 months ago. She points to the medial elbow as the source of her symptoms but notes radiation all the way to the tips of her ring and small finger. She is a laboratory medical researcher and has worsening of her symptoms while pipetting under a sterile hood. She is starting to have weakness with opening jars or grasping objects. She has no history of injury or trauma. Her remaining medical and surgical history are negative; in particular, she has no history of diabetes, hypothyroidism, or renal failure. She is not on any medications and has no allergies.

Physical Examination

The patient is a healthy, athletic-appearing female in no distress. Her upper extremities and left hand have no deformity and full active range of motion.

She is tender to palpation over the ulnar nerve just posterior to the medial epicondyle, and tapping over the nerve at that site creates tingling that radiates all the way to the small fingertip. Full elbow flexion for more than 30 seconds reproduces her symptoms. Elbow flexion greater than 90 degrees causes subluxation of the ulnar nerve on to the medial epicondyle. The patient is nontender over the medial and lateral epicondyle or over the wrist. Carpal tunnel compression and Phalen’s test are negative, as is Tinel’s testing at the wrist. Sensation to light touch is normal over the thumb through radial border of the ring finger and subjectively decreased over the ulnar border of the ring finger and all of the small finger. She has slight finger abduction weakness.

Radiographs and Laboratory Values

This patient’s X-rays were completely normal. Her laboratory studies were also unremarkable; in particular, serum glucose and thyroid function tests were within normal limits.

561

562 M.A. Haque

Diagnosis and Treatment

This patient has compression of the ulnar nerve at the elbow, more commonly known as cubital tunnel syndrome. She was treated with nonsteroidal antiinflammatory drugs (NSAIDs), a custom-molded night splint to avoid elbow flexion greater than 30 degrees, ergonomic workstation adjustments, and therapy. Her symptoms unfortunately worsened over the next 3 months despite these interventions, and she developed significant finger abduction weakness. She was then surgically treated with an anterior subcutaneous transposition of the ulnar nerve. Within a few weeks her symptoms resolved, and by 3 months after surgery, she had regained completely normal hand and elbow function.

Discussion

Cubital tunnel syndrome results from compression of the ulnar nerve around the elbow. Patients classically present with medial elbow pain and paresthesias in an ulnar nerve sensory distribution (the ulnar half of the ring finger and all the small finger). As the condition progresses, patients can develop weakness to finger abduction. Tinel’s sign, or tapping on the nerve dorsal to the medial epicondyle, causes paresthesias radiating to the small finger. A positive elbow flexion test reproduces the patient’s symptoms after 60 seconds of maximal elbow flexion. Another classic late finding is the Froment’s sign, in which attempts at key pinch result in flexion of the thumb interphalangeal (IP) joint as the extensor pollicis longus (EPL) and flexor pollicis longus (FPL) compensate for adductor weakness.

The differential diagnosis includes medial epicondylitis, cervical radiculopathy, thoracic outlet syndrome, carpal tunnel syndrome, and ulnar tunnel syndrome, and several of these conditions can occur concurrently. History and physical examination are the keys to making the correct diagnosis, but EMG and nerve conduction studies are helpful. The electrical criteria for confirming cubital tunnel syndrome includes a drop in conduction velocity of 11 m/s or greater across the elbow compared to below the elbow. Lesser velocity decreases, however, do not rule out the disease.

Treatment is usually conservative with nighttime extension splinting, NSAIDs, and rest. Occasionally, hand therapy with nerve and tendon gliding exercises can be helpful. If a patient’s symptoms do not resolve after 3 months of this management, one can consider surgical intervention. The options include in situ decompression, medial epicondylectomy, and anterior transposition of the ulnar nerve. The anterior transpositions include subcutaneous, intramuscular, and submuscular techniques. It is important to completely release the arcade of Struthers (see Fig. 1), the medial intermuscular septum (see Fig. 2), the fascia over the groove dorsal

Cubital Tunnel Syndrome

563

FIGURE 1. Medial exposure to the ulnar nerve prior to transposition. The nerve can be seen subluxating over the medial epicondyle at the bottom of the picture. The forceps point to the arcade of Struthers, the most proximal site of compression in cubital tunnel syndrome.

FIGURE 2. The arcade of Struthers has been released. The intermuscular septum has been dissected away from the nerve and is held in the forcep.

564 M.A. Haque

FIGURE 3. The decompression and anterior transposition of the ulnar nerve have been completed.

to the medial epicondyle, the ligament of Osborne (the fascial band between the ulnar and humeral heads of the flexor carpi ulnaris), and the exit of the nerve from the flexor carpi ulnaris. The nerve should be completely free at the end of the release and transposition (see Fig. 3).

Flexor Tendon Avulsion

MUSTAFA A. HAQUE

History

This patient is a healthy, 27-year-old man who was playing flag football 2 days ago. While trying to grab an opponent’s flag, his nondominant left hand became caught in the other player’s belt. He felt a “pop” in his ring finger, and he noted moderate pain in this digit. He soon developed mild swelling of the digit and has been unable to flex it ever since. He has no other injury or history of trauma. His remaining medical and surgical history are negative. He is a first-year medical student with aspirations of becoming an orthopedic surgeon.

Physical Examination

The patient is a healthy-appearing male in no distress. His left hand has an extension deformity of the ring finger with inability to actively flex the distal interphalangeal joint (DIP) joint and loss of the normal hand flexion cascade (see Fig. 1). He has full passive range of motion, but he is painful with full extension of the wrist and finger. He is tender over the flexor tendon sheath at the level of the proximal phalanx shaft with a small area of fullness there. He is also tender at the base of the distal phalanx, and he has mild ecchymosis in this area.

Radiographs and Laboratory Values

This patient’s X-rays and laboratory studies were completely normal.

Diagnosis and Treatment

This patient has an avulsion of the flexor digitorum profundus (FDP) tendon. He was treated with surgical repair the next day by approaching the retracted tendon through a volar zigzag (Bruner) incision, passing it

565