Karl E. Rathjen

Definition and Classification of Negative Motor Signs in Childhood

In this report we describe the outcome of a consensus meeting that occurred at the National Institutes of Health in Bethesda, Maryland, March 12 through 14, 2005. The meeting brought together 39 specialists from multiple clinical and research disciplines including developmental pediatrics, neurology, neurosurgery, orthopedic surgery, physical therapy, occupational therapy, physical medicine and rehabilitation, neurophysiology, muscle physiology, motor control, and biomechanics. The purpose of the meeting was to establish terminology and definitions for 4 aspects of motor disorders that occur in children: weakness, reduced selective motor control, ataxia, and deficits of praxis. The purpose of the definitions is to assist communication between clinicians, select homogeneous groups of children for clinical research trials, facilitate the development of rating scales to assess improvement or deterioration with time, and eventually to better match individual children with specific therapies. “Weakness” is defined as the inability to generate normal voluntary force in a muscle or normal voluntary torque about a joint. “Reduced selective motor control” is defined as the impaired ability to isolate the activation of muscles in a selected pattern in response to demands of a voluntary posture or movement. “Ataxia” is defined as an inability to generate a normal or expected voluntary movement trajectory that cannot be attributed to weakness or involuntary muscle activity about the affected joints. “Apraxia” is defined as an impairment in the ability to accomplish previously learned and performed complex motor actions that is not explained by ataxia, reduced selective motor control, weakness, or involuntary motor activity. “Developmental dyspraxia” is defined as a failure to have ever acquired the ability to perform age-appropriate complex motor actions that is not explained by the presence of inadequate demonstration or practice, ataxia, reduced selective motor control, weakness, or involuntary motor activity.

A Comparison of Two Nonoperative Methods of Idiopathic Clubfoot Correction: The Ponseti Method and the French Functional (Physiotherapy) Method

BACKGROUND In the treatment of idiopathic clubfeet, the Ponseti method and the French functional method have been successful in reducing the need for surgery. The purpose of this prospective study was to compare the results of these two methods at one institution. METHODS Patients under three months of age with previously untreated idiopathic clubfeet were enrolled. All feet were rated for severity prior to treatment. After both techniques had been described to them, the parents selected the treatment method. Outcomes at a minimum of two years were classified as good (a plantigrade foot with, or without, a heel-cord tenotomy), fair (a plantigrade foot that had or needed to have limited posterior release or tibialis anterior transfer), or poor (a need for a complete posteromedial surgical release). Two hundred and sixty-seven feet in 176 patients treated with the Ponseti method and 119 feet in eighty patients treated with the French functional method met the inclusion criteria. RESULTS The patients were followed for an average of 4.3 years. Both groups had similar severity scores before treatment. The initial correction rates were 94.4% for the Ponseti method and 95% for the French functional method. Relapses occurred in 37% of the feet that had initially been successfully treated with the Ponseti method. One-third of the relapsed feet were salvaged with further nonoperative treatment, but the remainder required operative intervention. Relapses occurred in 29% of the feet that had been successfully treated with the French functional method, and all required operative intervention. At the time of the latest follow-up, the outcomes for the feet treated with the Ponseti method were good for 72%, fair for 12%, and poor for 16%. The outcomes for the feet treated with the French functional method were good for 67%, fair for 17%, and poor for 16%. CONCLUSIONS Nonoperative correction of an idiopathic clubfoot deformity can be maintained over time in most patients. Although there was a trend showing improved results with use of the Ponseti method, the difference was not significant. In our experience, parents select the Ponseti method twice as often as they select the French functional method.

Calcaneal-cuboid-cuneiform osteotomy for the correction of valgus foot deformities in children

We performed combination calcaneal-cuboid-cuneiform osteotomies in 18 patients (26 feet) with severe valgus foot deformity. The operation consists of a sliding calcaneal osteotomy, an opening-wedge cuboid osteotomy, and a pronation, plantar flexion closing-wedge osteotomy of the medial cuneiform in addition to appropriate soft-tissue releases. The preoperative goals of restoring the axis of the foot parallel to the axis of progression and relieving pain, as well as shoe, brace, and skin problems, were met in 23 of the 24 feet available for review at an average of 18 months after surgery. This procedure has the advantage of localized correction of deformity without the problems associated with arthrodesis.

Serial casting as a delay tactic in the treatment of moderate-to-severe early-onset scoliosis.

Background: Serial casting can cure mild infantile idiopathic scoliosis. Its use in delaying surgery in older children and those with larger curves or syndromes is poorly defined. Methods: A review of a single center’s experience with casting was performed. Patients were included if they had a syndromic, neuromuscular, or congenital scoliosis or were older than 2.5 years with an idiopathic scoliosis measuring >50 degrees. Results: A retrospective review was performed on 29 patients meeting all inclusion criteria. Of these, 12 were idiopathic and 17 were nonidiopathic curves. Average age at first cast was 4.4±2.1 years, and 3.0±1.8 cast changes were performed over 1.4±1.1 years. Patients were transitioned to a brace and followed up for 5.5 years (range, 2.2 to 11.4 y). The main thoracic Cobb angle before casting was 68.8±12.3 degrees, which corrected to 39.1±16.4 degrees in a cast. Cobb angle after cast removal was 60.9±18.4 degrees, which increased to 76.3±24.0 degrees at final follow-up. T1-T12 height increased to 1.1±2.6 cm during the treatment period (P=0.05). There were 5 minor complications. Fifteen patients (51.7%) required surgical treatment for their scoliosis at most recent follow-up and an additional 7 patients (24.1%) were delayed until a definitive anterior/posterior spinal fusion could be performed. Surgery was delayed 39±25 months from the first cast. Growing rods were required in 8 patients (27.6%). The patients who ultimately underwent surgical intervention (SG) were more likely to have a larger postcasting residual main thoracic Cobb angle than those who did not require surgery [NS; 69.5±14.6 degrees (SG) vs. 51.6±17.9 degrees (NS), P=0.007] and had a greater progression of their curves after cast removal [20.9±13.5 degrees (SG) vs. 9.4±11.0 degrees (NS), P=0.02]. Conclusions: Serial casting is a viable alternative to surgical growth sparing techniques in moderate-to-severe early-onset scoliosis and may help delay eventual surgical intervention. Although a cure cannot be expected, an average of 39 months of delay was achieved in this patient cohort and 72.4% have avoided growing spine surgery. Level of Evidence: Level IV, case series.

Clinical and radiographic results after implant removal in idiopathic scoliosis.

Study Design. Prospective radiographic and clinical analysis of patients with idiopathic scoliosis who had complete implant removal following posterior spinal fusion (PSF) at least 2 years previously. Objective. To evaluate the clinical and radiographic effect of implant removal after PSF for idiopathic scoliosis. Summary of Background Data. Occasionally, implants must be removed following instrumented PSF. Indications for removal include infection and late operative site pain. Previously, it has been thought that there was little morbidity associated with implant removal in the presence of a solid fusion. However, recent studies have reported loss of coronal correction after implant removal in patients who had a PSF for adolescent idiopathic scoliosis. Few long-term studies have assessed the clinical or radiographic results of complete implant removal after PSF. Methods. We identified 56 patients who had undergone PSF for idiopathic scoliosis and subsequently had complete removal of all instrumentation. None of these patients had a pseudarthrosis at the time of implant removal. After IRB approval, 43 of 56 (77%) patients returned for new standing posteroanterior and lateral spine radiographs and completion of an SRS-22 questionnaire. Results. For the 43 patients who had new radiographs and completed an SRS-22, the time from the original PSF to complete implant removal averaged 2.9 years (range, 7 months to 7.25 years). Twenty-two patients had implants removed because of infection, and 21 patients had implants removed secondary to pain. The average time from implant removal to completion of the most recent radiographs and SRS-22 questionnaire was 9.5 years (range, 3.2–17.9 years). Patients were considered to have had progression of deformity after implant removal if their Cobb angle measurements increased by more than 10°. Two patients had 11° to 20° of coronal plane progression of their main thoracic curve. No patient had more than 10° of coronal plane progression of a lumbar curve. Sagittal curve progression was identified more frequently. Nineteen patients had between an 11° and 20° increase in thoracic kyphosis, and 5 patients had >20° of thoracic kyphosis progression. Patients with >20° of thoracic kyphosis progression after implant removal had greater thoracic kyphosis before surgery and larger main thoracic and lumbar coronal curves at the time of implant removal. Progressive kyphosis did not correlate with: reason for implant removal, length of follow-up, or time from fusion to implant removal. Although total SRS-22 scores correlated inversely with increased thoracic kyphosis, this trend did not reach statistical significance. Conclusion. Implant removal after PSF for idiopathic scoliosis may be complicated by progression of deformity. Patients requiring implant removal should be appropriately counseled and monitored.

Guided growth for the correction of pediatric lower limb angular deformity.

&NA; Guided growth is useful in correcting pediatric angular deformities. Although growth manipulation has been applied to various deformities, it is most commonly used to correct coronal plane deformity about the knee. Temporary hemiepiphysiodesis is performed using staples, percutaneous transphyseal screws, or a tension band plate. Permanent hemiepiphysiodesis can be done using either an open Phemister or a percutaneous approach. These techniques function by tethering one side of a growing physis, thereby allowing differential growth. Applied correctly, this can also result in angular deformity correction. Undercorrection and overcorrection are common problems with guided growth. However, careful preoperative planning and appropriate follow‐up can minimize complications and allow for excellent deformity correction with minimal morbidity.

Volkmann contracture and compartment syndromes after femur fractures in children treated with 90/90 spica casts.

Abstract: Nine pediatric patients (mean age 3.5 yrs) with low energy femur fractures were treated with 90/90 spica casts and developed leg compartment syndromes, Volkmann contracture, and ankle skin loss. These cases are detailed and a proposed mechanism leading to this devastating complication is explained. The authors believe the technique of an initial below knee cast, and then using that cast for applying traction while immobilizing the child in the 90/90 spica is potentially dangerous. Alternative spica application methods are advocated.

Stainless steel flexible intramedullary fixation of unstable femoral shaft fractures in children.

To assess the role of stainless steel flexible intramedullary fixation in unstable pediatric femur fractures, we compared a group of 41 stable (transverse or oblique) fractures with a group of 40 unstable (spiral and/or comminuted) fractures treated with stainless steel (Ender) nails placed through a single lateral insertion. The fractures were followed up until clinical and radiographic union was evident with an average follow-up period of 13 months. All fractures were healed at an average of 1.4 months. No infections or refractures occurred. Although minor radiographic angular deformities and shortening were present in both groups, no patient had a clinically detectable angular deformity. Two patients with stable fracture patterns had 10 to 20 degrees of asymmetry in foot progression angles, and 1 patient with an unstable fracture pattern (Winquist grade IV comminution) had a 3-cm limb length difference at final follow-up. Stainless steel flexible intramedullary fixation is effective for unstable pediatric femur fractures if cortical abutment is present.

Mutations responsible for Larsen syndrome cluster in the FLNB protein

Background: A gene for Larsen syndrome was recently described, and mutations were reported in five cases. Objective: To test whether mutations in this gene, FLNB, could explain the disease in our independent collection of sporadic and dominant Larsen syndrome cases; and to test whether mutations occurred in a non-random pattern. Results: Missense mutations were found in each of five cases. Four of the five were new; one was reported in a sporadic case in the original Larsen syndrome study of five cases. All mutations from the two studies were compiled. Clustered mutations were observed within three filamin B protein domains: the calponin homology 2 domain, repeat 14, and repeat 15. This suggested that as few as five (of the total of 46) coding exons of FLNB could be screened to detect Larsen syndrome mutations. Four of these exons were screened in a sixth (sporadic) case and a previously reported G1691S substitution mutation detected. Conclusions: Mutations in FLNB may be responsible for all cases of Larsen syndrome. They appear to occur in specific functional domains of the filamin B protein. This should simplify diagnostic screening of the FLNB gene. Analyses in larger patient series are warranted to quantify this. The study confirmed the extreme variability in clinical presentation and the presence of unaffected carriers. A molecular screen would be valuable for diagnosis and genetic counselling.

Treatment of Adolescent Tibia Vara with Hemiepiphysiodesis: Risk Factors for Failure

BACKGROUND Lateral tibial hemiepiphysiodesis is an accepted surgical treatment for skeletally immature patients with adolescent tibia vara. However, the results of this procedure are unpredictable. This study was conducted to identify the risk factors associated with failure of hemiepiphysiodesis. METHODS We studied patients with adolescent tibia vara who were at least ten years of age, had open physes, had been treated with a lateral hemiepiphysiodesis, and had been followed for at least two years. The mechanical axis deviation, medial proximal tibial angle, and lateral distal femoral angle were measured on radiographs preoperatively, at six months postoperatively, and at the time of final follow-up. Failure was defined as a residual varus deformity requiring osteotomy or a mechanical axis deviation exceeding 40 mm (moderate or severe varus) at the time of final follow-up. RESULTS Forty-nine patients (forty-six male) with a total of sixty-four involved extremities met the inclusion criteria. The average age was 13.4 years, the average body mass index was 40.7 kg/m(2), and the average duration of follow-up was 3.3 years. The lateral hemiepiphysiodesis was unsuccessful in 66% of the patients. In a multivariate Cox proportional hazards regression analysis, the variables associated with a higher risk of failure included an age of fourteen years or more (hazard ratio = 3.9, p = 0.0009) and a body mass index of > or =45 kg/m(2) (hazard ratio = 2.8, p = 0.01). Greater deformity at baseline as indicated by a smaller medial proximal tibial angle was also found to be a significant factor in the multivariate analysis (p = 0.03). CONCLUSIONS Lateral hemiepiphysiodesis may be a valuable treatment option for non-morbidly obese patients with less severe adolescent tibia vara, but it is likely to fail in older adolescents with a high body mass index and greater deformity.