Selective dorsal rhizotomy in ambulant children with cerebral palsy.

BACKGROUND: Selective dorsal rhizotomy (SDR) is a surgical procedure for treating spasticity in ambulant children with cerebral palsy (CP). However, controversies remain regarding indications, techniques and outcomes. CURRENT EVIDENCE SUMMARY: Because SDR is an irreversible procedure, careful patient selection, a multi-disciplinary approach in assessment and management and division of the appropriate proportion of dorsal rootlets are felt to be paramount for maximizing safety. Reliable evidence exists that SDR consistently reduces spasticity, in a predictable manner and to a substantial degree. However, functional improvements are small in the short-term with long-term benefits difficult to assess. FUTURE OUTLOOK: There is a need for high-quality studies utilizing long-term functional outcomes and well-matched control groups. Collaborative, multicentre efforts are required to further define the role of SDR as part of the management paradigm in maximizing physical function in spastic CP.

The effect of distal femoral extension osteotomy on muscle lengths after surgery.

PURPOSE: The distal femoral extension osteotomy (DFEO) is often used in the treatment of crouch gait to help compensate for knee flexion contractures. The effects of DFEO on skeletal and muscle lengths are incompletely understood, but are important to consider in planning concomitant surgeries such as patellar tendon advancement (PTA). Therefore, the purpose of this study was to quantify the changes in femur, quadriceps, and hamstring lengths with DFEO, and to determine the sensitivity to surgical factors such as wedge location and magnitude. METHODS: A musculoskeletal model with six degrees of freedom tibiofemoral and patellofemoral joints was used for analysis. A wedge was removed from the distal femur and the remaining bone segments were plated together to simulate the DFEO. After simulating the knee's post-operative equilibrium, the surgically-induced changes in muscle and bone lengths were analysed. RESULTS: Relative to the pre-operative state, DFEO stretches the hamstrings while shortening the femur and quadriceps. A more posterior wedge apex location (i.e. creation of a cuneiform wedge) diminished the stretch of the hamstrings, but induced greater shortening of the femur and quadriceps. More proximal wedge locations necessitated greater translation of the distal fragment to maintain the knee joint axis. CONCLUSION: Reduced quadriceps length after DFEO shown in this study is consistent with the need for simultaneous PTA. The induced hamstring stretch also may represent a potential mechanism for post-operative nerve palsies. Overall, the numerical results provide a firmer basis for planning the specifics of DFEO such that desired muscle lengths and joint alignment are achieved.

An update on the treatment of gait problems in cerebral palsy.

This article summarizes our experience with cerebral palsy over the past 20 years. The primary and secondary deformities that occur with cerebral palsy are described. Following this, there is a brief overview of the nature and role of gait analysis in the treatment of gait problems in cerebral palsy. The concept of lever-arm dysfunction is introduced. Our current treatment algorithm is then presented along with a brief discussion of our current treatment program, which is illustrated by a case example. Finally, a brief study of a group of patients with spastic diplegia or quadriplegia is presented to illustrate our current method of evaluating treatment outcomes and the need for team management in the treatment of this complex condition.

A tool for quantifying hip flexor function during gait.

An index to measure the change in hip flexor function after hip surgery was developed in the Motion Analysis Laboratory at Gillette Children's Specialty Healthcare (GCSH). The hip flexor index (HFI) utilizes principal component analysis applied to five kinematic and kinetic variables collected during normal acquisition of gait data. A single index number is derived that describes accurately the overall hip function. Initial clinical validation was carried out using a data set of 23 normal controls and six patients with a diagnosis of cerebral palsy. The patients were all independent ambulators who had undergone orthopedic hip surgery. The controls were used to establish patterns of interdependency between selected gait parameters and form a basis for the index number. The HFI based surgical outcome was compared to the subjective rating of six clinicians. The clinicians were versed in gait analysis and were blinded to the HFI based outcome. The HFI measure of post-operative change in hip function was found to correspond well with the subjective clinical evaluation. A valid tool such as the HFI can be used to objectify clinical impressions of change in hip function, and can thereby assist researchers with statistical and outcome analysis of interdependent and redundant gait variables.

Reliability and validity of the Gillette Functional Assessment Questionnaire as an outcome measure in children with walking disabilities.

A 10-level, parent-report walking scale encompassing a range of walking abilities from nonambulatory to ambulatory in all community settings and terrains was developed at Gillette Children's Specialty Healthcare (GCSH) as part of the Gillette Functional Assessment Questionnaire (FAQ). The reliability and validity of the walking-scale portion of the FAQ were tested on a group of individuals seen in the Motion Analysis Laboratory at GCSH between May 1996 and January 1997. A complete data set on 41 individuals with neuromuscular conditions represented the community ambulation levels (6-10) of the walking scale. Good test-retest reliability among parents and good interrater reliability between parents and community caregivers was demonstrated. Content and concurrent validity were also high, as assessed by correlation to standardized functional outcome measures, energy expenditure, and gait-analysis information. A reliable and valid scale specific to the task of walking such as the FAQ can assist clinicians in documenting functional change in children with chronic neuromuscular conditions.

Developmental dysplasia of the hip.

The essential points regarding screening for and detection of developmental dysplasia of the hip are emphasized. Background information is provided to understand why this entity presents in a variable fashion. This article is not intended to comprehensively cover treatment methodology for the orthopedic surgeon. Instead, the information provided is meant to aid the primary care practitioner in identification of the problem and in supporting the family during the treatment process when an abnormality is detected.

Perioperative blood loss: the effect of valproate.

The purpose of this investigation was to determine the effect of the use of valproate (VPA) on bleeding and requirement for replacement blood products in patients undergoing major surgical procedures. One hundred thirty-nine patients had posterior spinal fusion performed by 1 of 3 surgeons at our institution from 1987 to 1993. The clinical status of the patient, pre- and postoperative laboratory values, type and extent of instrumentation, surgeon performing the procedure, and medications (including VPA) were variables considered. The outcome measures were intra- and postoperative blood loss and number of blood products used. Intraoperative blood loss was correlated with the method of instrumentation, platelet count, and the surgeon performing the procedure. Postoperative blood loss was correlated with the diagnosis of cerebral palsy. By hierachical stepwise regression analysis, the only outcome measure correlated with VPA was the number of blood products used.

Walking, running, and sprinting: a three-dimensional analysis of kinematics and kinetics.

Just as in running, the two-joint muscles acting at the hip and at the knee work to transfer energy efficiently between body segments. This can be seen in Figure 12. The powers at the hip and knee are overlaid to show that when power is generated at the hip, it is absorbed at the knee and vice versa. For example, a concentric contraction of the hamstrings proximally at the hip is coupled with an eccentric contraction at the knee just prior to initial contact in terminal swing. The rectus femoris functions in a similar way but in an opposite direction in initial swing. For the three conditions discussed, the relative contribution of work occurring at each joint is different. Figure 13 shows that the muscles about the ankle are the most important source of work in walking and that the knee musculature does not significantly contribute to the work done for walking. In walking, the knee is felt to be important for the smoothing of gait. The quadriceps are a much more important source of energy at the knee in both running and sprinting, as can be seen in Figure 13. Finally, the hip musculature becomes the dominant source of work in sprinting in our group of untrained subjects with significant contributions from both the hip flexors and extensors. One would expect that the relative importance of each of the muscle groups about each of these joints in terms of sources of energy might change with training. The intent of this work was to evaluate the three conditions of walking, running, and sprinting. I hope that it will stimulate further interest and research in this area in order to come to a greater understanding of human locomotion. As more knowledge and experience are gained, the motion analysis lab will be able to offer insight into training strategies, injury prevention, and the treatment of pathologic running and sprinting conditions.