Michael D. Sussman

The Risser sign: a critical analysis.

Orthopedic surgeons commonly use the Risser sign to estimate skeletal maturity; however, the data presented in the orthopedic literature supporting the accuracy of the Risser sign in estimating skeletal maturity do not stand up to critical statistical analysis. The Risser sign is less accurate than chronologic age as a predictor of skeletal age and should not be used as a substitute for a hand and wrist radiograph in most cases. The Risser sign is also no better a predictor of scoliosis progression than is chronologic age.

Recurrence after femoral derotational osteotomy in cerebral palsy.

The authors studied the long-term results of femoral derotational osteotomy (FDO) for medial femoral torsion in ambulatory children with cerebral palsy. Thirty children with 45 femurs that underwent distal FDO were followed for a mean of 6.5 years. Although correction was achieved after surgery, recurrence occurred during follow-up in 15 femurs. Preoperative mean external hip rotation of 10.7 ± 7.2 degrees increased to 41.3 ± 16.6 degrees 1 year after surgery and decreased to 28.2 ± 14.7 degrees 5 years after surgery. On kinematic data, maximum hip rotation in stance of 30 degrees before surgery decreased to 8.7 degrees 1 year after surgery and increased to 16.1 degrees 5 years after surgery. Minimum hip rotation of 10.4 degrees before surgery was corrected to -4.3 degrees 1 year after surgery and was 0.8 degrees 5 years after surgery. Passive hip external rotation and kinematic hip rotation showed progressive deterioration of the initial correction. Patients having surgery prior to age 10 were more likely to show deterioration.

Electromyographic investigation of extensor activity in cerebral-palsied children in different seating positions.

This study was designed to determine whether tonic myoelectric activity of low‐back extensors of spastic cerebral‐palsied children changed in response to changes in seating position, and if so, which position was coincident with the least extensor activity. Using two pairs of surface electrodes, the electrical activity of the lumbar erector spinae muscles was monitored in seven combinations of backrest inclinations (75o, 90o, 105o and 120o) and seat surface elevations (0o and 15o degrees). Off‐line analysis of action potential counts per second of recorded electromyographic signals showed that electrical activity was least when the seat surface elevation was 0o and the backrest inclination 7o. The results showed that differences existed in the activity of the low‐back extensors in the seating positions that were assessed.

Spinal deformity after selective dorsal rhizotomy in ambulatory patients with cerebral palsy.

Thirty-four patients with ambulatory spastic diplegia (ages 10–19.8 years) who were part of a prospective study of selective dorsal rhizotomy (SDR) had standardized radiographs before and after SDR. Follow-up ranged from 5 to 11.6 years after surgery. Two different surgical approaches were used: laminectomy (14 patients) and laminoplasty (20 patients). Radiographs were measured for coronal and sagittal balance. Thirty patients had a spinal deformity at long-term follow-up compared with 10 patients before surgery. Seventeen patients (50%) developed lumbar hyperlordosis greater than 60°. Six patients (18%) developed grade 1 spondylolisthesis, Scoliosis occurred de novo in eight patients (24%) and progressed by greater than 5° in two patients with preoperative scoliosis. No significant differences were found between laminoplasty and laminectomy patients. None of the patients have undergone any surgical intervention for spinal deformity. There was a higher incidence of spinal deformity after SDR than in normals and an historical control population, which warrants clinical and radiographic long-term follow-up.

Outcome of patients after Achilles tendon lengthening for treatment of idiopathic toe walking.

Abstract: Fifteen children who were diagnosed with idiopathic toe walking that cannot be corrected by nonoperative treatment were assessed by clinical examination and computer-based gait analysis preoperatively and approximately 1 year after Achilles tendon lengthening. Passive dorsiflexion improved from a mean plantarflexion contracture of 8 degrees to dorsiflexion of 12 degrees after surgery. Ankle kinematics normalized, with mean ankle dorsiflexion in stance improving from −8 to 12 degrees and maximum swing phase dorsiflexion improving from −20 to 2 degrees. Peak ankle power generation increased from 2.05 to 2.37 W/kg but did not reach values of population norms. No patient demonstrated clinically relevant triceps surae weakness or a calcaneal gait pattern. Seven patients had a stance phase knee hyperextension preoperatively, and 6 of these corrected after surgery. Achilles tendon lengthening improves ankle kinematics without compromising triceps surae strength; however, plantarflexion power does not reach normal levels at 1 year after surgery.

Posterior Instrumentation and Fusion of the Thoracolumbar Spine for Treatment of Neuromuscular Scoliosis

We reviewed the clinical and technical outcomes of 25 patients with neuromuscular scoliosis, who were treated by Luque instrumentation and posterior spinal fusion from the upper thoracic spine to L5 between 1981 and 1988. A mean curve correction of 46% was obtained operatively with a mean 8 degrees loss of correction during the follow-up period that ranged from 1.9 to 9.4 years (mean, 5.5). Pelvic obliquity was improved 50% from a mean of 16.1 degrees to a mean of 8.1 degrees in 24 patients for whom data were available. At final follow-up, the mean pelvic obliquity increased to 11.4 degrees with only two patients increasing > 8 degrees. The cause for major postoperative increase in pelvic obliquity was continued anterior spinal growth with torsion of the fusion mass and was not related to changes limited to the L5-S1 motion segment. Posterior fusion and instrumentation from the upper thoracic spine to L5 without anterior fusion provides adequate correction and control of spinal deformity for many patients with cerebral palsy. Those patients with significant growth remaining, or with severe deformities, may benefit by preliminary anterior release and fusion or inclusion of the pelvis and sacrum.

Treatment of spastic diplegia in patients with cerebral palsy.

Appropriate treatment, which includes orthopaedic surgery, physical and occupational therapy, recreational therapy, orthotics, and utilization of assistive devices, will improve the functional outcomes of children with cerebral palsy. Medical modalities such as intramuscular injections of botulinum toxin, and constant intrathecal administration of Baclofen via an implanted pump may also be of benefit. There is a defined set of orthopaedic surgical procedures that can enhance function, and the challenge for the surgeon is to identify which combination of procedures is appropriate for each individual patient and at what point during development to implement them. Some surgeons prefer to wait until patients are older (8–10 years) and perform all of their surgical interventions in one sitting. We, however, favor a different approach wherein surgical procedures are done as indicated during childhood development to enhance function and allow further improvement of motor skills. We refer to this approach as ‘Staged Multilevel Interventions in the Lower Extremity’ or ‘SMILE’. This paper will discuss the rationale for this approach and our recommendations regarding the indications and timing of surgical interventions, as well as techniques and outcomes as reported in the literature.

Orthopaedic Manifestations of Congenital Myotonic Dystrophy During Childhood and Adolescence

Congenital myotonic dystrophy (CMD) is a dominantly inherited disorder manifested in childhood by muscle weakness which can be profound at birth, but which progressively improves over the first few years. Congenital myotonic dystrophy represents the severe end of the spectrum of myotonic dystrophy, which in milder cases may not be diagnosed until adulthood. The goal of the study was to identify and quantitate the musculoskeletal deformities which may significantly affect the function of children with CMD. Methods: A retrospective chart and radiograph review was performed after Institutional Review Board approval for all cases of myotonic dystrophy from 1987 to 2004 followed at a childrens specialty orthopaedic hospital. Inclusion criteria were either a conclusive testing for CMD by gene testing, electromyography, and/or muscle biopsy in the child or parent and the presence of a typical clinical picture. Skeletal manifestations were classified by body segment (upper extremity, hand, spine, hip, lower extremity, foot) and by the type of deformity. Surgical procedures and outcomes were also documented. Results: Thirty children and adolescents met the inclusion criteria. The male/female ratio was 1 (15 boys and 15 girls). In 27 cases, the mother transmitted the disease, and in 2 cases, the father transmitted the disease; in one case, it was impossible to reconstitute the family history of the child who was adopted. The mean age at onset of gait was 29 months. Twenty-two (73%) out of 30 children underwent surgery for lower extremity-, foot-, or spinal-related deformities. The mean follow-up was 11.4 years (range, 3-20 years). No contractures or deformities were observed in the upper extremities. Spinal deformities affected 9 patients (30%), and 3 of these required surgery. These spinal deformities when present usually had an early onset and included thoracolumbar scoliosis as well as kyphoscoliosis. Problems at the level of the hips and knee were infrequent and included only 2 patients who had unilateral hip abduction contracture and 1 patient who had significant fixed knee flexion contracture. Congenital clubfoot occurred in 5 patients (17%) and generally responded well after posteromedial release and recurrence occurred in only one case. Developmental equinus and equinovarus exclusive of clubfoot affected 7 patients (23%), 70% of whom required surgery. Outcome after Achilles tendon lengthening was positive, and many of the children began walking soon after the Achilles lengthening, and recurrence did not occur. Conclusions: Child with CMD are at high risk for musculoskeletal deformities of the spine and lower extremities. In our experience, correction and improved function were likely after surgery. Level of Evidence: Retrospective study; level IV

Electromyographic and force patterns of cerebral palsy patients with windblown hip deformity

Summary: The electromyographic activity and the forces around the hip were measured in resting, neutral, and 25° abduction in 13 individuals with spastic quadriplegia and windblown deformity. A direct correlation was found between abduction force and myoelectric activity of the abductors. In the adducted hip, there was sustained activity of the adductors while the activity in the abductors was minimal in all positions. In the abducted hip, there was electrical activity in both abductors and adductors in all positions except 25° abduction when only the adductors were active. The results suggest that early detection of potentially progressive windblown hips in children with cerebral palsy may be achieved by careful assessment of hip range of motion, recognition of spasticity in abductors, and the presence of a “pseudo-Galleazzi sign.”

Iliopsoas tenotomy at the lesser trochanter versus at the pelvic brim in ambulatory children with cerebral palsy.

Background: Progressive hip flexion deformity is a common problem in ambulatory children with spastic cerebral palsy, causing static and dynamic deformity. The iliopsoas muscle is recognized as a major deforming force in the development of this problem. Many clinicians address this problem by lengthening the iliopsoas, either in an intramuscular location at the pelvic brim or by complete tenotomy at the lesser trochanter. The goal of this study was to compare the outcomes of patients with ambulatory cerebral palsy who had intramuscular lengthening at the pelvic brim to those who underwent complete release of the iliopsoas tendon at the level of the lesser trochanter. Methods: Twenty patients were included in the study, 11 of whom had iliopsoas release at the lesser trochanter (group 1) and 9 of whom had intramuscular lengthening at the pelvic brim (group 2). All patients had physical examinations, plus kinematic and kinetic analyses in our gait laboratory before and 1 year after surgery. Results: Hip flexion contracture was decreased significantly only in group 1, although there was a trend of decrease in group 2. There was a significant increase in maximum hip extension in terminal stance and a reciprocal decrease in maximum swing phase hip flexion ingroup 1, with a similar trend that did not reach significance in group2. Stride length increased significantly in both groups. There was no significant change in power generation of hip flexion during the swing phase in either group. Conclusions: We found improved static and dynamic parameters of hip extension after iliopsoas lengthening and did not detect any adverse kinematic or kinetic change in hip function after surgery. The improvement was more robust in the group who underwent release at the lesser trochanter. Because there are no adverse effects of iliopsoas release from the lesser trochanter and the improvement in hip extension is greater, this approach should be considered in ambulatory patients with spastic diplegia when a hip flexor weakening procedure is considered. Level of Evidence: Comparative cohort study, level III, case-control study.