Orthopedic disorders may be developmental and may lead to longstanding problems involving growth and normal physical activity. As with acute entities, the earlier these problems are recognized, the better they can be treated. Detection may be as early as birth in some cases, but other, more subtle problems may only become clear at major milestones like the onset of ambulation or during periods of rapid growth.

Although many of these entities may require a specialist’s evaluation, this chapter describes the role of the primary care provider in diagnosing and helping to instruct and support the family during the long and frustrating clinical course of managing chronic orthopedic problems.

Developmental dysplasia of the hip is more frequent in girls, especially first-born (Weinstein, 1996). It is also associated with conditions that limit the room for the fetus, especially breech position and multiple births. There is a close association between DDH and other molding disorders, such as wryneck and foot deformities. However, there is a clear familial tendency to dysplastic hips, although the exact genetic basis is unknown.

Early in development, even dysplastic hips tend to be free of symptoms. Because muscle development may be normal, children will not have delayed ambulation except in very extreme cases or in cases associated with neurologic disorders. Later, the child may complain of increased tiredness or stiffness. By the late teens to early adulthood, the hips may be painful, particularly with running and other strenuous activity. This probably indicates the early development of arthritis. Table 59-1 presents data regarding the examination of range of motion, gait, and specific tests for normal hips and early versus late DDH.

At birth, the hips may be innately loose, but the laxity should resolve by 2 to 4 weeks. In the nursery, laxity is felt by pushing the hips outward (Barlow test) or bringing them back to the socket (Ortolani test). Figure 59-1 illustrates these maneuvers. These tests typically elicit an emphatic “clunk.” More subtle noises, such as “clicks” or “pops” may represent insignificant ligamentous snapping. Other early signs include leg length discrepancy, as illustrated in Figure 59-2 by the Galleazzi test, asymmetry of thigh folds, as seen in Figure 59-3, or widening of the pelvis. For late physical findings see Table 59-1.

Because the proximal hip is entirely cartilage for the first 4 to 5 months, early radiographs may not reliably show the condition of the joint. Ultrasound is the most useful imaging modality in younger infants from birth to age 4 or 5 months (Harding et al., 1997). A good ultrasound image demonstrates not only the formation of the ball and socket, but also instability of the joint. To prevent false-positive studies due to the generalized joint laxity that is common in all newborns, ultrasound should be done no earlier than 2 weeks of age, except in extreme cases.

At older ages, the radiographs may show partial or complete migration of the hip from its socket. This is illustrated in Figure 59-4. The socket itself may be very shallow and oversized. Later radiographs may also demonstrate pressure areas, which may represent early arthritis.

If detected early, mild to moderate cases of DDH can be treated in abduction braces, such as the Pavlik harness seen in Figure 59-5. This device directs the hip in a stable position and thus maximizes the child’s own developmental potential (Harding et al., 1997). This treatment is most effective under 3 months of age. Multiple diapers (triple or double) may have some benefit early on, particularly while waiting for a consultative appointment, but they do not provide enough stability to maintain a corrective position, so they are not definitive treatment. Beyond 6 months of age, more rigid immobilization, such as casting, and possibly surgical procedures, such as open hip reduction and realignment of
the bones of the hip and pelvis, more frequently become necessary.

The knee is not just a simple hinge joint; it is complicated by rotation and translation of the components. The forces across the knee may total up to eight times the body weight in running and on stairs (Simonsen et al., 1995), so even minimal pain or dysfunction can lead to disability. The distribution of force is reliant on muscle balance, bone alignment, and the condition of the soft-tissue stabilizers (ligaments and menisci).

Gait should be assessed, with attention to alignment of the feet, rotation of the legs and thighs, and angulation of the knee itself. The knee should angle slightly inward (7–10 degrees) in stance. The knee is then observed and palpated
for swelling (or effusion). Normally there is dimpling at the joint lines, so loss of these contours points to fluid in the joint space. The joint lines and bones are palpated for tenderness or bony spurs. The patella is pushed downward to rule out grind pain suggestive of cartilage injury, as described in the following section.

Stability of the knee is tested with simple provocative maneuvers. With the knee at a 30-degree angle, the examiner must first stabilize the femur with one hand while pulling on the tibia with the other hand. The knee is then pushed inward and outward from the side to rule out varus or valgus laxity (collateral ligament injury). With the knee flexed to 90 degrees, the Drawer test is performed by pulling the tibia. The knee is then pushed back to test anterior-posterior laxity. The Lachman test for anterior cruciate instability is performed by pulling forward on the tibia with the knee at 30 degrees flexion. The examiner then needs to push inward and outward on the side of the kneecap in extension and flexion to assess patellar stability.

There are three major causes of nontraumatic knee pain in children (Table 59-2):

▪ Osteochondritis Dissecans

Osteochondritis dissecans is thought to represent chronic fatigue injury or disruption of the blood supply to the bone (Schenck & Goodnight, 1996). The resultant collapse of the bone directly beneath the joint surface can lead to chronic pain or mechanical symptoms, such as snapping or giving way of the knee. Seldom will the pain be severe or acute, although it may crest.

The age range of presentation is from 10 to 16 years, with boys having a higher prevalence for uncertain reasons. As is frequently the case, younger children do best clinically. Older children may have long-term chronic pain and are more likely to need surgery. Young adults may progress to arthrosis or arthritis and may need cartilage transplantation or bony reconstruction. OCD may be bilateral in up to 40% of cases (Schenck & Goodnight, 1996).

The knee may show signs of generalized inflammation, including slight effusion and pain on extremes of motion, especially flexion, but will demonstrate no instability. There is tenderness at the joint line, especially over the distal end of the femur.

Radiographs of the knees will show a characteristic defect on the lower end of the femur, usually the lateral side of the medial femoral condyle. A rim of reactive or sclerotic bone, which indicates that the lesion is healing, may surround the area of collapsed bone. There is usually no collapse of the joint itself, except in older teens with large lesions. Figure 59-6 illustrates this finding.

Management is normally provided by a pediatric ortho-paedist. Bracing or a short period of casting may reduce painful symptoms and help promote healing. Short-term activity modification is also frequently necessary. Surgical intervention, including arthroscopic drilling or bone or cartilage transplants, is seldom required before early adulthood.

The PFSS appears to arise from an imbalance in the muscles of the front of the thigh, with much stronger pull laterally than medially. This is often accentuated by residual inward rotation of the hip and a relatively externally rotated lower leg. The knee angles more inward (or valgus), leading to increased lateral pull and increased stress on the kneecap itself.

Although the natural history of PFSS is most often resolution of the symptoms, pain may be extreme enough to significantly limit a young teenager’s lifestyle. Fortunately, even minimal intervention may improve the symptoms.

Clinically, PFSS covers a spectrum, ranging from vague discomfort or tiredness in the knees to recurrent dislocation of the kneecap. Children with PFSS are frequently loose-jointed and very flexible.

In flexion, the kneecap will be tilted laterally or even pulled to the outside by muscle forces. There may be tenderness along the borders of the kneecap with apprehension of dislocation on lateral stress. Patellar grind is frequently positive and indicates cartilage injury (or chondromalacia). Feet are generally flat and externally rotated. Hips will most frequently demonstrate increased internal rotation.

The diagnosis of CMP, which is a pathologic diagnosis, is based on clinical, radiologic, or surgical demonstration of cartilage damage.

Radiographs of the knees are not routinely ordered in the initial workup, except to differentiate OCD or Osgood-Schlatter disease. Radiographic studies may show tilt or even lateral subluxation of the kneecap in its groove. Findings can be confirmed on cross-sectional imaging studies, such as computed tomographic (CT) or MRI scans. Radiographic studies are useful for differentiating subluxation from lateral tilt and for ruling out cartilage damage. Study findings govern the treatment approach (Fulkerson, 1994).

Treatment may often be initiated by the primary care provider. Acute-phase management should be aimed initially at reconstituting muscle balance through rest; appropriate applications of moist ice or heat (depending on response to the specific modality) for 20 to 30 minutes at a time, with a full 60 minutes elapsing before reapplying the modality; and exercise of supporting musculature. The kneecap can be centralized with bracing or taping. Referral to an athletic trainer or a physical therapist may assist the youngster in attaining a satisfactory muscle-strengthening response.

Medial shoe supports (arch supports) that will help balance the rotation of the leg segments and decompress the kneecap can be designed by either a podiatrist or an orthopaedist. If all these efforts fail, surgical rebalancing or reconstruction of the kneecap mechanism may be necessary.

The feet should be carefully examined in the newborn nursery and in subsequent well child visits. Note should be made of the position and size of the toes. The presence or absence of a longitudinal arch may be noted, although the arch generally does not form fully until age 6 years.

By walking age, the foot position during gait should be assessed. Presence of the arch in both standing and sitting positions should be noted. The alignment of the legs and thighs is very critical to the function of the knee and is best judged in ambulation. Finally, it is essential that the provider assess flexibility of the foot while making careful note of any tender or painful areas.

Examination of the flatfoot is made to determine if there is a flexible arch that reappears when the foot is unloaded, as seen in Figure 59-7. The provider should note whether there is any bony tenderness suggestive of some other process. The foot should be observed in stance and with the child sitting. In true flexible flatfoot, the arch will be present when the foot is lifted off the ground. These children may show other signs of hyperlaxity, including increased hip rotation, hyperextension of the elbows, and sometimes looseness of the shoulders.

Radiographs do not add to the diagnostic or treatment plan and are not routinely needed.