Specialists in pediatric hospital medicine are commonly involved in the care of patients with a broad variety of orthopedic conditions, including a newborn with congenital anomalies, the postoperative care of patients undergoing elective orthopedic surgery, evaluation of a patient with bone or joint pain (or both), and care of patients with musculoskeletal trauma. A vast spectrum of issues therefore confronts the hospitalist in the evaluation and care of patients with orthopedic conditions. This chapter addresses some of the more common scenarios and diagnoses that are encountered by the pediatric hospitalist and emphasizes the early diagnosis of complications in patients hospitalized with orthopedic conditions.

Many congenital orthopedic conditions are associated with anomalies of other organ systems, as they develop at the same time in embryologic development. All patients with congenital orthopedic conditions therefore require a thorough evaluation to diagnose associated anomalies, since some of these may potentially be life threatening.

DEVELOPMENTAL DYSPLASIA OF THE HIP

Developmental dysplasia of the hip (DDH) may occur as an isolated finding (so-called typical DDH) or in association with a variety of syndromes (e.g. arthrogryposis or Larsen syndrome) or neuromuscular diseases (e.g. spina bifida or spinal muscular atrophy). These associated syndromes and diseases typically require further evaluation and treatment from other specialties, whereas typical DDH can be treated by an orthopedist without further medical evaluation. Nonoperative treatment with a Pavlik harness or splint is usually successful for typical DDH when the diagnosis is established shortly after birth, but surgery is frequently required for cases of DDH that present late or are refractory to nonoperative treatment, and those associated with syndromes or neuromuscular diseases.¹ Historical features suggestive of a risk of DDH include family history, breech birth, first born, and female. Screening in the newborn nursery is completed by physical examination, including the Barlow and Ortolani maneuvers. Patients with an abnormal examination are commonly referred for orthopedic evaluation, and those with equivocal findings or significant risk factors are often referred for an ultrasound examination.

LIMB DEFICIENCIES AND DEFORMITIES

Ultrasound screening during the prenatal period has led to detection of limb deformities in utero. Examples include congenital limb deficiencies (proximal femoral focal deficiency [PFFD], longitudinal deficiency of the tibia or fibula), tibial bowing, arthrogryposis, congenital dislocation of the knee, and amniotic band syndrome. All of these conditions should be evaluated by an orthopedic surgeon. A spectrum of femoral dysplasia may be encountered, from the congenital short femur to the more severe proximal femoral focal deficiency in which the proximal femur may be absent. Longitudinal deficiency of the tibia involves partial or complete absence of the tibia in association with a variety of abnormalities of the limb such as femoral hypoplasia, absent knee ligaments, fibular bowing, tarsal coalition, and absence of the medial rays of the foot. Treatment recommendations are based on whether or not the quadriceps are functional, stability of the knee and ankle, the severity of foot deformity, and the anticipated leg length discrepancy at maturity. In many cases, an early amputation provides the best chance of adequate long-term function.

Longitudinal deficiency of the fibula involves partial or complete absence of the fibula, and a variety of coexisting abnormalities are often encountered including femoral deficiency, patellar dysplasia, absent knee ligaments, genu valgum, tarsal coalition, and absence of the lateral rays of the foot. Treatment considerations are similar to those of tibial deficiencies, although a treatment strategy involving limb salvage is more commonly in fibular deficiencies. Patients often require multiple surgical interventions through adolescence, including limb lengthening, in order to avoid amputation and prosthetic fitting. Bowing of the tibia is classified by the direction of the apex of the deformity. Three deformities are classically seen: anterolateral, anteromedial, and posteromedial. Anterolateral bowing of the femur is associated with congenital pseudarthrosis of the tibia, and 55% of these involving patients with neurofibromatosis type 1 (NF-1).² Anterolateral bowing thus represents a “pre-pseudarthrosis,” and should be referred to an orthopedic surgeon immediately. Anteromedial bowing of the tibia is associated with fibular hemimelia. Posteromedial bowing of the tibia is associated with a calcaneovalgus foot deformity. It is important to note the location of the apex of the deformity (either in the tibia or the ankle) when making the diagnosis. While the bowing corrects spontaneously or at least improves considerably in all patients, most patients will require surgical treatment (epiphysiodesis) to treat leg length discrepancy, which averages approximately 3 to 4 centimeters.² These patients should be followed by an orthopedic surgeon.

Amniotic band syndrome (early amniotic rupture sequence, Streeter dysplasia) involves disruption of the lining of the amniotic sac which may result in limb deformities such as syndactyly of the hands and feet, constriction bands around the limbs, or even longitudinal growth disturbance or transverse amputations may occur. Surgical release of these bands may be indicated, especially when limb viability is threatened.

CLUBFOOT

Foot deformities include clubfoot (talipes equinovarus), congenital vertical talus, metatarsus adductus, and calcaneovalgus. The most common of these is clubfoot, with an incidence of approximately 1 in 1000 live births. The clinical appearance of a clubfoot is often confused with metatarsus adductus, whereas a calcaneovalgus foot may be confused with a vertical talus. Clubfoot and metatarsus adductus both appear as a foot with a “C” or bean shape in the midfoot and forefoot, with the lateral border of the foot curved instead of straight. The convexity of this curvature is on the outside. A clubfoot, however, is also characterized by supination of the foot and hindfoot equinus (caused by a contracture of the Achilles tendon and ankle capsule) (Figure 161-1).³ This hindfoot equinus is a major finding differentiating clubfoot from metatarsus adductus. In addition, atrophy of the calf will be noted on the affected side in a child with clubfoot. Metatarsus adductus and clubfoot both have a weak association with DDH. All patients with this condition should therefore have a thorough hip examination performed and documented. Hip ultrasound may be obtained if further hip imaging is needed. Clubfoot may also be associated with neurologic conditions or other genetic conditions, so a thorough physical examination, including a neurologic assessment, should be performed. Radiographs are not typically needed in the diagnosis and initial treatment of clubfoot. In all cases, orthopedic referral should be made. Treatment should ideally begin as early as possible. The most common treatment approach is the Ponseti method, which involves serial casting. Most patients will require a percutaneous release of the Achilles tendon to treat residual equinus, and long term night splinting is required. This minimally invasive approach has shown better long-term outcomes in comparison with clubfoot treated by extensive surgical release.² Treatment of metatarsus adductus is generally determined by the flexibility of the foot. Supple metatarsus adductus can usually be treated with stretching exercises. Rigid metatarsus adductus has a less favorable natural history and may require casting for treatment.⁴

OTHER CONGENITAL AND POSITIONAL FOOT DEFORMITIES

Congenital vertical talus is an uncommon foot deformity that consists of dorsal dislocation of the midfoot on the hindfoot as well as equinus positioning of the hindfoot.⁴ Similar to clubfoot, a hallmark of congenital vertical talus is a rigid plantar flexion deformity of the hindfoot. In addition, the midfoot in congenital vertical talus has a rocker-bottom configuration with a convexity on the plantar aspect of the foot. It is bilateral 50% of the time, and about half the time it is associated with other musculoskeletal conditions such as arthrogryposis; neural tube defects; sacral agenesis; neuromuscular disorders; spinal muscular atrophy; trisomy 13, 15, 17, and 18; and Turner syndrome.⁵ For this reason, an infant with a congenital vertical talus should undergo a genetics evaluation as well as an orthopedic consultation. Treatment consists of stretching and casts, followed by surgical correction, with surgery generally occurring between 6 and 12 months of age.⁵ Lateral radiographs of the foot both in the plantigrade position and in forced plantar flexion can differentiate a congenital vertical talus from a congenital oblique talus, which has a more benign course.

Calcaneovalgus deformity of the foot is a positional foot deformity that may be confused with congenital vertical talus. The foot is everted, and the top of the foot may lie alongside the lateral aspect of the distal lower extremity. In contrast to congenital vertical talus, the ankle in a calcaneovalgus foot dorsiflexes freely. Calcaneovalgus occurs secondary to intrauterine positioning and is not associated with any other systemic, genetic, or neurologic conditions. Calcaneovalgus is a flexible condition that usually responds well to stretching.⁶

CONGENITAL ANOMALIES OF THE UPPER EXTREMITY

A wide variety of congenital anomalies occur in the upper extremities. Although a detailed discussion of congenital limb differences is beyond the scope of this chapter, it should be noted that most congenital upper extremity anomalies are isolated in nature. There are some notable exceptions to this generalization, however, and these exceptions need to be recognized because some upper extremity anomalies may signal the presence of coexisting life-threatening conditions in other organ systems.

The term longitudinal deficiency of the radius encompasses a wide spectrum of deformity; problems range from a hypoplastic radius or thumb to complete absence of the radius, thumb, and radial side of the hand and wrist (Figure 161-2). Longitudinal deficiency of the radius is frequently associated with other syndromes. Longitudinal deficiency of the radius (radial clubhand) is one such anomaly that may be accompanied by serious problems in other organ systems.⁷ It is vital to recognize these associations in order to diagnose any underlying syndromes (Table 161-1). These include blood dyscrasias (Fanconi anemia), thrombocytopenia-absent radius (TAR) syndrome, congenital heart anomalies (Holt-Oram syndrome), craniofacial defects, and vertebral anomalies such as the VACTERL association (vertebral defects, imperforate anus, cardiac anomalies, tracheoesophageal fistula, radial and renal dysplasia, and limb defects).⁷ Other nonsyndromic anomalies may also be associated with longitudinal deficiency of the radius, including DDH, scoliosis, and clubfoot. Patients with congenital upper extremity differences and/or symbrachydactyly should also have their chest evaluated for chest dysplasia or hypoplasia because the combination of upper extremity anomalies and developmental disruption of the pectoralis major muscle in the chest wall exists in Poland syndrome. Orthopedic treatment of patients with upper extremity anomalies is individualized for each patient, typically after evaluation by an orthopedic surgeon and an occupational therapist.

Preaxial (radial-sided) and postaxial (ulnar-sided) deformities are often seen in the newborn nursery. Preaxial polydactyly have been classified by Wassel,⁸ ranging from partial to complete thumb duplications. Preaxial hypoplasia has been described by Blauth,⁹ encompassing a spectrum from a slightly small thumb to an incompetent or absent thumb. The level of the deformity and the status of the carpometacarpal joint and thenar musculature determine treatment. While these deformities require the attention of a pediatric hand specialist, postaxial polydactyly is sometimes treated by the pediatric hospitalist. Suture ligation in the nursery of a rudimentary digit has often been employed, but more substantial postaxial duplications would be ablated by a pediatric hand specialist for a more cosmetic (and sometimes more functional) hand.

BRACHIAL PLEXUS BIRTH PALSY

In newborns with lack of spontaneous movement of the upper extremity, the differential includes perinatal trauma or infection. Brachial plexus birth palsy (BPBP) is due to stretching of the brachial plexus during birth. Macrosomia, prolonged labor, dystocia, and a previous child with BPBP are risk factors. BPBP is classified as upper trunk (C5-C6) illustrated clinically with the “waiter’s tip position” of Erb-Duchenne palsy, lower trunk (C8-T1) in Klumpke palsy, or global (C5-T1). Severity can range from mild neuropraxia to cervical spine nerve root avulsions. Gain of biceps function by 3 to 6 months correlates with a favorable outcome,¹⁰ while presence of a Horner sign (ptosis, meiosis, and anhidrosis) is associated with a poor outcome. A small percentage of children will ultimately require surgical intervention, but nerve exploration has been recommended prior to 6 months of age, therefore referral to a pediatric upper extremity specialist should be instituted early. Maintenance of range of motion to the upper extremity is the early goal. Fractures of the humerus or, more often, the clavicle can occur in difficult labor. These usually heal uneventfully. Clavicle fractures should not be confused with congenital pseudarthrosis of the clavicle, which usually occurs on the right side and results from failure of the clavicle ossification centers to fuse. The diagnosis is made by absence of callus formation indicative of a healing fracture. Finally, septic arthritis of the shoulder can also present with pseudoparalysis. Usually, the infant has more systemic symptoms or abnormal vitals or lab values to raise suspicion. Imaging such as ultrasound or magnetic resonance imaging (MRI) can be used as an adjunct for diagnosis.