Biomedical subjects
Publications and source records attributed to Martin J Herman.
This article presents a practical approach to management of displaced radius and ulna fractures in children and adolescents while addressing areas of controversy. Nonsurgical and surgical management are discussed. A technique for intramedullary fixation of the radius and ulna is presented in detail.
Spondylolysis and spondylolisthesis are often diagnosed in children presenting with low back pain. Spondylolysis refers to a defect of the vertebral pars interarticularis. Spondylolisthesis is the forward translation of one vertebral segment over the one beneath it. Isthmic spondylolysis, isthmic spondylolisthesis, and stress reactions involving the pars interarticularis are the most common forms seen in children. Typical presentation is characterized by a history of activity-related low back pain and the presence of painful spinal mobility and hamstring tightness without radiculopathy. Plain radiography, computed tomography, and single-photon emission computed tomography are useful for establishing the diagnosis. Symptomatic stress reactions of the pars interarticularis or adjacent vertebral structures are best treated with immobilization of the spine and activity restriction. Spondylolysis often responds to brief periods of activity restriction, immobilization, and physiotherapy. Low-grade spondylolisthesis (< or =50% translation) is treated similarly. The less common dysplastic spondylolisthesis with intact posterior elements requires greater caution. Symptomatic high-grade spondylolisthesis (>50% translation) responds much less reliably to nonsurgical treatment. The growing child may need to be followed clinically and radiographically through skeletal maturity. When pain persists despite nonsurgical interventions, when progressive vertebral displacement increases, or in the presence of progressive neurologic deficits, surgical intervention is appropriate.
Surgical management is indicated for children and adolescents with spondylolysis and low-grade spondylolisthesis (< or =50% slip) who fail to respond to nonsurgical measures. In situ posterolateral L5 to S1 fusion is the best option for those with a low-grade slip secondary to L5 pars defects or dysplastic spondylolisthesis at the lumbosacral junction. Pars repair is reserved for patients with symptomatic spondylolysis and low-grade, mobile spondylolisthesis with pars defects cephalad to L5 and for those with multiple-level defects. Screw repair of the pars defect, wiring transverse process to spinous process, and pedicle screw-laminar hook fixation are surgical options. The ideal surgical management of high-grade spondylolisthesis (>50% slip) is controversial. Spinal fusion has been indicated for children and adolescents with high-grade spondylolisthesis regardless of symptoms. In situ L4 to S1 fusion with cast immobilization is safe and effective for alleviating back pain and neurologic symptoms. Instrumented reduction and fusion techniques permit improved correction of sagittal spinal imbalance and more rapid rehabilitation but are associated with a higher risk of iatrogenic nerve root injuries than in situ techniques. Wide decompression of nerve roots combined with instrumented partial reduction may diminish the risk of neurologic complications. Pseudarthrosis and neurologic injury presenting as L5 radiculopathy and sacral root dysfunction are the most common complications associated with surgical management of high-grade spondylolisthesis.
Injuries of the cervical spine in the pediatric and adolescent athlete are less common than other musculoskeletal injuries. Although many of these injuries are relatively minor, serious and potentially unstable or progressive spinal injury must be excluded. Important anatomic differences between the child younger than 10 years and older children and adolescents influence the types of injuries sustained and make assessment of the child's cervical spine sometimes difficult for practitioners accustomed to treating adolescent and adult athletes. Stable soft-tissue injuries of the cervical spine are the most common injuries that occur in all athletes. These injuries are responsive to symptomatic treatment and aggressive rehabilitation. Stingers are injuries of the brachial plexus and upper cervical roots that result from stretching or compressive forces associated with collision sports. Rapid return of sensory and motor dysfunction of a single upper extremity characterizes this entity; long-term disability is rare. Cervical cord neurapraxia (CCN) with transient quadriplegia is most commonly seen in football players. Most athletes fully recover. Cervical canal stenosis as defined by a Pavlov/Torg ratio of less than or equal to 0.8 is predictive of recurrent CCN. Young athletes sustain CCN secondary to hypermobility of the immature cervical spine. Return to play after these injuries is controversial. The athlete with Down syndrome and potential cervical hypermobility requires a careful cervical and neurologic evaluation prior to clearance for participation in sports.
Torticollis is a clinical symptom and sign characterized by a lateral head tilt and chin rotation toward the side opposite to the tilt. Many conditions cause torticollis. The differential diagnosis is different for infants than for children and adolescents. Congenital muscular torticollis associated with a contracture of the sternocleidomastoid muscle is the most common etiology of torticollis in infants. The condition of most infants with congenital muscular torticollis improves with a regimen of manual cervical stretching. Congenital anomalies of the occipital condyles and upper cervical spine must be ruled out before performing a release of the sternocleidomastoid muscle in a child who fails to improve with physical therapy. Unusual nonmuscular causes of torticollis in the infant also must be considered and include ocular torticollis caused by eye muscle weakness, Sandifer's syndrome resulting from gastroesophageal reflux, neural axis abnormalities, and benign paroxysmal torticollis. Torticollis in the older child is most frequently a manifestation of atlantoaxial rotatory displacement resulting from trauma or oropharyngeal inflammation (Grisel's syndrome). Retropharyngeal abscesses and pyogenic cervical spondylitis are unusual infectious causes of torticollis. Intermittent torticollis associated with headaches, vomiting, or neurologic symptoms may be caused by tumors of the posterior fossa. Benign and malignant neoplasms of the upper cervical spine are rare causes of torticollis in children. Torticollis resulting from cervical dystonia is also rare in children but may be seen in older adolescents.
Spondylolysis and spondylolisthesis commonly are diagnosed in children and adolescents. The diagnostic workup and treatment plan vary widely among physicians. Although the orthopaedic literature is extensive on the topic, it is our opinion that a lack of clarity exists with regards to etiology, terminology, subtypes of spondylolysis and spondylolisthesis, and treatment. Important basic principles regarding spondylolysis and spondylolisthesis, with emphasis on clinical evaluation and nonsurgical treatment, serve as the basis for a new classification. We propose a new classification for pediatric spondylolysis and spondylolisthesis that is comprehensive, simple, and easily applied. This scheme is based on clinical presentation and spinal morphology and is more appropriate for the child and adolescent than the existing classification schemes of Wiltse-Newman and Marchetti-Bartolozzi. Algorithms for evaluation and treatment of spondylolysis and spondylolisthesis in children and adolescents, based on this new classification, are presented.
Tibial shaft fractures are among the most common pediatric injuries managed by orthopaedic surgeons. Treatment is individualized based on patient age, concomitant injuries, fracture pattern, associated soft-tissue and neurovascular injury, and surgeon experience. Closed reduction and casting is the mainstay of treatment for diaphyseal tibial fractures. Careful clinical and radiographic follow-up with remanipulation as necessary is effective for most patients. Surgical management options include external fixation, locked intramedullary nail fixation in the older adolescent with closed physis, Kirschner wire fixation, and flexible intramedullary nailing. Union of pediatric diaphyseal tibial fractures occurs in approximately 10 weeks; nonunion occurs in <2% of cases. Some clinicians consider sagittal deformity angulation >10 degrees to be malunion and indicate that 10 degrees of valgus and 5 degrees of varus may not reliably remodel. Compartment syndromes associated with tibial shaft fractures occur less frequently in children and adolescents than in adults. Diagnosis may be difficult in a young child or one with altered mental status. Although the toddler fracture of the tibia is one of the most common in children younger than age 2 years, child abuse must be considered in the young child with an inconsistent history or with suspicious concomitant injuries.
Spondylolysis and spondylolisthesis are common causes of low back pain in the competitive athlete. Repetitive loading of the lumbar spine results in stress reactions and spondylytic defects of the pars interarticularis. Spondylolysis and lesser degrees of spondylolisthesis frequently respond to activity restrictions, bracing (in specific situations), and physiotherapy. Spinal fusion is indicated for spondylolysis and spondylolisthesis that remain painful despite nonoperative measures and progressive, high-grade spondylolisthesis. Return-to-play guidelines are made for each athlete individually based on his or her specific diagnosis, response to treatment, and sporting activity.
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Evaluation of the child presenting with an irritable hip often requires aspiration of the hip. There are various methods for doing this procedure. We present a new technique for hip aspiration using high-resolution ultrasound imaging with color Doppler and a needle guide. This technique maximizes chances for a successful aspiration, minimizes risks to the child, avoids radiation exposure, and is easy to do and teach.
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This study investigates the hypothesis that the integrity of the cartilage hinge at the distal humeral epiphysis determines the stability of fractures of the lateral humeral condyle. Sixteen patients with lateral humeral condyle fractures were studied with radiographs and magnetic resonance imaging (MRI). The clinical course of each patient was compared using these imaging studies to determine whether initial fracture displacement and the integrity of the cartilage hinge correlated with fracture stability. Radiographically, 4 fractures were considered unstable (with initial fracture displacement >3 mm) and 12 were stable (initial displacement < or =3 mm). On MRI, 6 fractures were complete (with disruption of the lateral cartilage hinge) and 10 were incomplete. All unstable fractures had complete fractures on MRI. Ten of the 12 patients with radiographically stable injuries had incomplete fractures on MRI. None of these displaced during treatment. Two patients had radiographically stable fractures and complete fractures on MRI. One of these fractures displaced, confirming the hypothesis that the stability of lateral humeral condyle fractures is related to the integrity of the cartilage hinge.