Ana Presedo

Complications of Intrathecal Baclofen Pump Therapy in Pediatric Patients

Background The aim of this study was to investigate and evaluate complications of intrathecal baclofen (ITB) pump implantation and maintenance in children with cerebral palsy. Methods We reviewed our entire consecutive series of pediatric patients treated with ITB between 1997 and 2006 at our hospital. There were 174 patients with a diagnosis of cerebral palsy, 8 with mixed dystonia, 2 with athetosis, and 3 with pure dystonia. During follow-up, 8 deaths occurred with no evidence of pump or catheter malfunction in any way contributing to the cause of death. Acute infection within 60 days of the surgery and late infection rates were calculated on the basis of number of incidents and incidents/follow-up patient years, respectively. Independently, a blinded caregiver phone questionnaire was completed in 92 cases. Results There were 316 surgical procedures; 161 were initial ITB pump implants at our institution. The average age at initial implant was 12 years, with an average follow-up of 3 years, 2 months. There were 80 planned replacement procedures (46 battery expirations and 3 planned pump replacements during posterior spinal fusion, 26 catheter replacements for posterior spinal fusion, and 5 reinsertions). There were 78 procedures in 57 patients related to complications, and the acute infection rate was 4.0%. The probability of developing a late infection was 1.0% per year of follow-up. On the basis of the follow-up questionnaire, 81% of parents/caregivers were satisfied with the treatment, and 87% would recommend ITB therapy. Conclusions ITB therapy is a safe and effective treatment for severe spasticity in the pediatric population, but does have a 31% rate of complications requiring surgical management over a 3-year treatment period. Parents and caregivers have a high rate of satisfaction and most would recommend the treatment to others.

Bioactive glass as a bone substitute for spinal fusion in adolescent idiopathic scoliosis: a comparative study with iliac crest autograft.

Background: Iliac crest autograft is currently the gold standard material for spinal fusion. However, its use is limited by additional operative time, increased blood loss, and morbidity. Recently, a synthetic osteoconductive bone graft material composed of bioactive glass has been described, with high effectiveness in animal models. Its ability to achieve spinal fusion in human has never been reported. The aim of this study was to compare bioactive glass and iliac crest autograft as bone substitutes in the treatment thoracic adolescent idiopathic scoliosis (AIS). Methods: Eighty-eight consecutive patients underwent posterior spinal fusion for progressive thoracic AIS. There were 2 study groups based on the type of bone graft used: iliac crest autograft (n = 40) or bioglass (n = 48). A minimum 2-year follow-up was required. Medical data and radiographs were retrospectively analyzed and compared using unpaired t test and Mann-Whitney U test. Results: Mean follow-up was 40 months in the autograft group and 38 months in the bioglass group. In the autograft group, there were 2 infections (5%) and 3 mechanical failures (7.5%). One infection (2%) and 1 early mechanical failure (2%) occurred in the bioglass group. Loss of correction of the main thoracic curve between immediate postoperative and latest follow-up averaged 15.5% for autograft group and 11% for the bioglass group (P = 0.025).The mean (±SD) gain of frontal balance between immediate postoperative latest follow-up was 0.8 (±9.3) mm in the autograft group and 8.1 (±12) mm for the bioglass group (P = 0.005). Conclusions: Results of this retrospective study suggest that bioglass is as effective as iliac crest graft to achieve fusion and maintain correction in AIS. Less complications were seen in the bioactive glass group, but the difference did not reach statistical significance. Bioactive glass can be proposed in the treatment of AIS, avoiding the morbidity of iliac crest harvesting. However, clinical and radiological outcomes need to be confirmed at long-term follow-up. Level of Evidence: Level III

Fractures in patients with cerebral palsy.

Fractures in children with cerebral palsy (CP) constitute a common clinical problem. The purpose of this retrospective study is to analyze the demographics, identify risk factors, and delineate guidelines for treatment in 156 children with CP who were treated for fractures. To identify changes in demographics, children treated before 1992 (56 patients) were compared with those treated from 1992 to 2000. The latter group of children was compared with an age- and gender-matched group of CP children without fractures. Ambulatory status, the presence of contractures, nutritional status, seizure medication, the type of treatment received, final outcomes, and complications were recorded and statistically analyzed. The mean age at the time of the first fracture was 10 years. Sixty-six percent of patients had spastic quadriplegia, of whom 83% were nonambulatory. Eighty-two percent of fractures occurred in the lower limbs. Forty-eight percent were delayed in diagnosis with no cause determined. Children treated after 1992 had higher incidence of multiple fractures, lower incidence contractures, and a younger age at first fracture. This group showed a statistically significant difference for anticonvulsant therapy (P = 0.001), CP pattern (P = 0.005), ambulatory status (P = 0.001), and osteopenia (P = 0.001) when compared with the group of CP patients without fractures. Eighty percent of fractures were treated with a soft bulky dressing. Complications occurred in 17% of patients. The greatest risk factor for fracture is the nonambulatory CP child on anticonvulsant therapy. These risk factors seem to have increased, resulting in a higher prevalence of low energy fractures. Future research must focus on the underlying mechanisms and prevention of this condition.

How to determine the upper level of instrumentation in Lenke types 1 and 2 adolescent idiopathic scoliosis: a prospective study of 132 patients.

The selection of fusion levels continues to be controversial in adolescent idiopathic scoliosis (AIS). The classifications of King and Lenke remain the most widely used, but recent studies have demonstrated their shortcomings, including poor interobserver reproducibility. We propose a method of preoperative planning that is independent of anatomical classifications, based on the anticipated effect of curve reduction. The objectives of this preoperative strategy are (1) to achieve satisfactory T1 tilt and shoulder balance and (2) to restore balance in the coronal and sagittal planes. The purpose of the present study was to evaluate the results of our strategy of deciding the proximal level of arthrodesis in Lenke types 1 and 2 AIS. Methods: We included 132 adolescents operated on for thoracic AIS by posterior instrumentation. The choice of the proximal fusion level was based on preoperative analysis of the rigidity of the proximal curvature, T1 tilt, and shoulder balance. The preoperative, postoperative, and last follow-up radiographs were digitized then analyzed using computer software. Radiological parameters were compared using paired t tests. Results: Average age at the time of surgery was 15.2 years (SD, 1.7 years). Mean follow-up was 30.2 months. The clavicle angle and T1 tilt were significantly improved in both Lenke types 1 and 2 curves. No correlation was found between T1 tilt and shoulder balance. At last follow-up, 89% of the patients satisfied all criteria for balance. Conclusions: The results of the present preoperative strategy, to which we adhered in 97% of cases, are encouraging and show that the systematic instrumentation of the entire proximal curvature is not justified in Lenke type 2 curves. However, long-term consequences of the residual T1 tilt need to be studied further. Level of evidence: therapeutic level IV.

The risk of progression of scoliosis in cerebral palsy patients after intrathecal baclofen therapy.

Study Design. Retrospective radiographic and medical chart review with matched control group. Objective. To identify the effect of intrathecal baclofen on the incidence of scoliosis, rate of curve progression, and pelvic obliquity compared with a matched cohort. Summary of Background Data. Although intrathecal baclofen therapy (ITB) has been shown to be effective in decreasing spasticity, case reports have described some children receiving ITB in whom progressive scoliosis was noted; other authors have described no effect on the spinal column. A controlled study has not been performed. Methods. All patients with spastic CP treated with ITB between 1997 and 2003 at a single institution were reviewed. A total of 107 patients undergoing ITB for a minimum of 2 years were identified, of which 26 patients subsequently developed or had progression of scoliosis. Twenty-five age, gender, and gross motor function classification system (GMFCS) score-matched quadriplegic CP patients with scoliosis who did not receive ITB constituted the control group used to compare the rate of curve progression and pelvic obliquity. Results. The average curve progression for the baclofen group after pump implantation was 16.3° per year; and for the control group was 16.1° per year. Both groups’ curves progressed over time during growth (P = 0.001), but baclofen did not have an independent effect on curve progression (P = 0.181). Average pelvic obliquity for the 2 groups increased over time (P = 0.001), but there was no difference between the groups (P = 0.536). Twelve of 57 patients (21%) developed scoliosis after pump implantation during a mean of 3.6 years of follow-up. Thirty of 92 matched control patients (32%) not treated with ITB within the same time interval had scoliosis by maturity. Conclusion. This study demonstrates that ITB has no significant effect on curve progression, pelvic obliquity, or the incidence of scoliosis when compared with an age, gender, and GMFCS score-matched control group of patients with spastic CP without ITB.

Hybrid Constructs for Tridimensional Correction of the Thoracic Spine in Adolescent Idiopathic Scoliosis: A Comparative Analysis of Universal Clamps Versus Hooks

Study Design. Retrospective study of prospectively collected data. Objective. Compare Universal Clamps (UCs) and hooks for the thoracic correction of adolescent idiopathic scoliosis (AIS). Summary of Background Data. In scoliosis surgery, sagittal correction is as important as frontal correction due to the risk of junctional kyphosis. Compared to all-screw constructs, hybrid constructs with lumbar pedicle screws and thoracic hooks or sublaminar wires have been shown to achieve similar coronal correction while providing superior postoperative thoracic kyphosis. The authors used a novel sublaminar thoracic implant, the UC with improvements over sublaminar wires. Hybrid constructs using thoracic UCs were compared to those with thoracic hooks. Methods. This series involved 150 patients treated for AIS with hybrid constructs. A total of 75 consecutive patients operated from 2001 to 2003, who had thoracic hooks with in situ contouring, distraction, and compression (Group 1), were compared to 75 consecutive patients operated from 2004 to 2006, who had thoracic UCs with posteromedial translation (Group 2). All had intraoperative somatosensory/motor-evoked potential monitoring and at least 2-years follow-up. Results. Except for follow-up (longer in Group 1), the 2 groups were similar before surgery. The UCs achieved better thoracic coronal correction (P < 0.001), Cincinnati index (P < 0.001), kyphosis (P = 0.02), and apical rotation (P < 0.001). In normokyphotic or hypokyphotic patients, the UC corrected thoracic kyphosis by 11.2° (55%) versus 0.4° (2%) achieved by hooks (P < 0.0001). These differences were stable at last follow-up. There were no intraoperative complications or changes in somatosensory/motor-evoked potentials. UC reduced operative time by 20% (60 minutes; P < 0.001) and blood loss by 23% (250 mL; P < 0.001). Conclusion. Although both of these hybrid constructs efficaciously corrected the coronal and axial deformities in AIS, the results of the UC technique were superior to those achieved with hooks in all 3 planes, especially the sagittal plane. Moreover, the UC technique is straightforward and safe, reducing both operative duration and blood loss.

The gait variability index: a new way to quantify fluctuation magnitude of spatiotemporal parameters during gait.

This article describes a conglomerate measure of gait variability based on nine spatiotemporal parameters: the Gait Variability Index (GVI). Concurrent validity, inter-session reliability and minimum detectable change (MDC) were evaluated in 31 patients with Friedreichs Ataxia (FRDA), through comparisons with classically used evaluation tools such as the International Cooperative Ataxia Rating Scale (ICARS). GVI scores for the healthy population were 100.3±8.6 and were significantly reduced in FRDA patients (70.4±7.9). The GVI was correlated with the global ICARS score and was sensitive enough to differentiate between groups of FRDA patients categorized by the Posture and Gait Disturbances sub-score. The GVI was found to have a high inter-session reliability with an intraclass correlation coefficient of 0.91. A MDC of 8.6 points was found necessary to ensure that a change in GVI reflects a true change rather than measurement error. The GVI provides a quantitative measure of variability which behaves well statistically in both HP and patients with FRDA. It can be easily implemented using the supplemental data provided with this article. Complementary work is necessary to strengthen the GVI validation.

Intrasacral rod fixation for pediatric long spinal fusion: results of a prospective study with a minimum 5-year follow-up.

Background Lumbosacral fusion is often needed in cases of pediatric neuromuscular spinal deformities. Despite the numerous fixation techniques described, the procedure remains challenging. Jackson has described a method of intrasacral fixation providing immediate 3-dimensional stability and promising clinical results. The purpose of this study was to report our experience with long spinal fusion using Jackson intrasacral fixation in pediatric patients. Methods All patients with at least 5 years of follow-up were reviewed. No brace was used postoperatively. Clinical data and radiographs were collected and analyzed preoperatively, postoperatively, and at latest follow-up. Intraoperative and postoperative complications were reported. Paired t test was used for statistical analysis. Results Fifty-six patients were included. The average age at surgery was 15.3 years. Mean follow-up period was 10.3 years and no patient was lost to follow-up. All radiographic parameters (frontal balance, frontal Cobb angle of the primary curve, iliolumbar angle, pelvic obliquity, sagittal balance, lumbosacral lordosis, and sacral slope) were significantly improved postoperatively (P<0.001), without significant loss of correction at latest follow-up. Four early infections, 1 pressure sore, and 4 cases of radicular pain, which resolved without intervention, were reported postoperatively. At latest follow-up, no patient complained of lumbar pain, and neither ambulatory status nor activity level ability worsened in any case. Sixteen of the 20 patients who needed a sitting orthosis preoperatively achieved a functional sitting posture without bracing. Conclusions Jackson fixation is a safe and reliable technique providing immediate stability. In our series, no mechanical complication occurred and no loss of correction was observed, despite immediate unprotected mobilization. The method provides reliable good sacral fixation for pediatric neuromuscular spinal deformities, especially when the correction of severe pelvic obliquity is necessary. Level of Evidence This consecutive series provides level IV evidence.

Validity of Functional Ambulation Performance Score for the evaluation of spatiotemporal parameters of children's gait.

ABSTRACT Gait characteristics of a healthy adult population have been used to develop the Functional Ambulation Profile (FAP) score to evaluate gait in patients with neuromuscular or musculoskeletal involvement (A. J. Nelson, 1974). Further technological progress allowed a more precise recording of walk parameters and propitiated the development of the Functional Ambulation Performance Score (FAPS). The authors aimed to explore the evolution of the FAPS in healthy children to determine what the lower limit of age would be to ensure reliability of this score. Participants were 32 children with normal development. A GAITRite® walkway was used to log the spatiotemporal parameters. Compared with values obtained in adults, the average FAPS was significantly lower for children under 12 years old. The interparticipant variability was particularly high for the younger children and decreased with age. Similar trends were observed regarding the intraparticipant variability. In conclusion, the authors observed that the FAPS is not suitable to compare the gait of different children younger than 12 years old. At least, the adult standards used to calculate FAPS would need to be modified if the score has to be applied to a pediatric population.

Circumferential fusion with anterior strut grafting and short-segment multipoint posterior fixation for burst fractures in skeletally immature patients: a preliminary report.

Background: The Universal Clamp (UC) is a novel vertebral anchor consisting of a sublaminar polyester band connected to fusion rods by a titanium jaw locked with a screw. The authors prospectively studied patients treated for thoracic or lumbar burst fractures with short pedicle screw constructs reinforced with UCs to prevent screw pullout. Methods: Eleven patients below 18 years of age underwent 2-stage circumferential fusion for complete burst fractures (Magerl A 3.3). Two pedicle screws reinforced by 2 UCs were inserted in the vertebra proximal to the fracture and 2 pedicle screws reinforced by 2 UCs were inserted in the vertebra distal to the fracture. Within 7 days, cages filled with cancellous bone graft were added for anterior column support. T12 was fractured in 3 patients, L1 in 4, L3 in 2, and L4 in 2 patients. Preoperatively, 10 patients were neurologically intact (Frankel E) and 1 patient had an incomplete spinal cord injury (Frankel C). Results: Mean operative duration for the posterior and anterior procedures was 110±24 and 120±35 minutes, respectively. Average intraoperative blood loss was 355±60 mL. Mean hospital stay was 11±2 days and follow-up averaged 36.1±5 months. Mean kyphotic deformity was corrected from 25±9 to 5.3±4.5 degrees postoperatively (79%), without subsequent loss of correction (P=0.17). Regional kyphosis improved by 20±8 degrees postoperatively, without subsequent loss of correction (P=0.09). No intraoperative complication was observed. There was no neurological deterioration. The patient who had a Frankel C lesion recovered 1 Frankel level (Frankel D) at final follow-up. None of the patients exhibited significant correction loss during follow-up, and there was no pseudarthrosis. Conclusions: Thoracic and lumbar complete burst fractures in skeletally immature patients can be treated using anterior bone graft cages and posterior instrumented fusion augmented with UCs to prevent pedicle screw pullout. With these constructs, which are short to preserve mobile intervertebral segments, kyphosis was corrected, fusion achieved, and correction maintained in all subjects without neurological worsening. Level of Evidence: Level IV.