John A. Herring
INTRODUCTION
This chapter is designed to alert the pediatric practitioner to common conditions that are frequently missed in primary care practice. These conditions are those in which an early diagnosis can prevent long-term future problems. An awareness of the diagnostic features of these conditions gives primary care persons the ability to prevent the complications that occur as the disorders progress.
FIGURE 221-1. Slipped capital femoral epiphysis. Note the malposition of the femoral head on the metaphysis.
LOWER EXTREMITY “MISSES”
SLIPPED CAPITAL FEMORAL EPIPHYSIS
One should suspect this diagnosis when an obese teenager with an outturned foot limps into the office complaining of knee pain. Knee pain is most common, but some have hip or groin pain as well. Anteroposterior (AP) and frog-lateral radiographs of the pelvis show characteristic changes (Fig. 221-1). The patient should not weight-bear until after surgical stabilization to avoid sudden, drastic slipping of the femoral head.1 For further information, see Chapter 215.
DDH (DEVELOPMENTAL DISLOCATION OF THE HIP)
The diagnosis of DDH is sometimes missed in pediatric practice. The examiner must try to feel the hip move in and out of the joint with delicate pressure over the knee and greater trochanter. Sometimes it is easy to feel this, and at other times the finding is missed or not there at all. The exam is hard to teach because the babies with this finding are few. Consequently, the examiner must have a high index of suspicion based on the presence of known risk factors. Ultrasound examination and orthopedic referral are appropriate for babies with breech presentation, especially females, for those with a positive family history, for firstborn girls, and for any with abnormal exam findings.2 For further information, see Chapter 215.
FIGURE 221-2. Cozen fracture. A: There is a minimally displaced fracture of the proximal tibia on the left. B: The fracture has healed and the tibia has grown into a marked valgus alignment. This will usually self-correct but requires orthopedic attention.
ADOLESCENT SEPTIC KNEE
Septic arthritis of the knee in adolescence can be subacute with subtle physical findings and grave consequences. Patients may present with mild pain and swelling, low-grade fever, and often a history of a respiratory infection treated with antibiotics. The joint fluid may show only moderate leukocytosis and cultures may be negative, especially if antibiotics have been given. Joint lavage or drainage and appropriate antibiotic treatment, beginning with intravenous dosage and transitioning to orals after clinical response are the treatments of choice. Failure to treat may result in serious loss of joint function.3 For further information, see Chapter 234.
COZEN FRACTURE
The Cozen fracture is a proximal tibial fracture with slight displacement in a young child (Fig. 221-2A). As the fracture heals, the leg grows fairly rapidly into a valgus or knock-knee alignment (Fig. 221-2B). The parent returns alarmed 3 or 4 months after the cast is removed, wondering what happened. Fortunately, most of these spontaneously correct, and if the family is forewarned at the time of injury, there is much less distress for all concerned.6
TUMORS
Bone tumors are rare. They usually present with persistent pain and often produce night pain and enlargement of the extremity. Radiographic examination for unusually persistent complaints of knee pain or thigh pain enables an earlier diagnosis.8 Bilateral leg pain at night is typical of growing pains, whatever that entity is, and usually does not require radiographs or referral. For further information, see Chapters 219, 453, 454, and 463.
UPPER EXTREMITY “MISSES”
MISSED MONTEGGIA FRACTURE
The Monteggia fracture is a fracture or even a deformation of the ulna which results in dislocation of the radial head at the elbow. At times the ulnar fracture is not severely displaced, and it is easy to overlook the finding of a radial head that does not line up with the capitellum. The diagnosis is made by making certain that a line along the radius intersects the capitellum on all views of the elbow. Acutely this is easily treated, but late presentation may require major surgery and the outcome may be compromised.4
MISSED LATERAL CONDYLE
The lateral condyle fracture is easily missed at the elbow. It appears as a tiny crescent of bone slightly displaced from the distal humerus in the young child. The elbow will be swollen and tender laterally. This injury requires surgical stabilization to prevent later displacement and deformity.5
SPINE “MISSES”
SCREENING FOR SCOLIOSIS
This seemingly simple procedure is fraught with pitfalls. Patients with slight shoulder asymmetry, mild leg length discrepancy, and tiny curves need no treatment and are subjected to unnecessary anxiety by the referral process. Heavy patients may show mild asymmetry and hide fairly large curves that do require treatment. Because scoliosis progresses with growth, mild curves in post-menarchal girls and mature boys have little potential to progress, but mild curves in young children have significant progression potential.7 For further information, see Chapter 216.