Vishwas R. Talwalkar

Posterior spinal fusion in paralytic scoliosis and myelomeningocele.

The Shriners Hospital, Lexington, KY, experience with posterior spinal fusion for scoliosis in 50 patients with myelomeningocele was reviewed. Six patients were fused with Harrington rods and 47 of 50 patients were treated with some form of segmental fixation. The complication rate was 48% (24/50) resulting in 1.48 procedures per patient. The deep infection rate was 8% (4/50) and the pseudarthrosis rate was 16% (8/50). The use of modern segmental instrumentation systems has improved the pseudarthrosis rates for posterior spinal fusion in scoliosis associated with myelomeningocele but not to the point of displacing the current approach of an anterior and posterior spinal fusion.

A Comparison of Three Methods of Pain Control for Posterior Spinal Fusions in Adolescent Idiopathic Scoliosis

Study Design. Retrospective cohort study. Objective. To compare the efficacy of patient-controlled analgesia (PCA) with morphine alone, a single preoperative intrathecal morphine injection and PCA (IT/PCA), and epidural catheter infusion without PCA (EPI) for postoperative pain control after posterior spinal fusion (PSF) and segmental spinal instrumentation (SSI) in adolescent idiopathic scoliosis (AIS). Summary of Background Data. Postoperative pain control after PSF and SSI in AIS can be managed in different ways. EPI provides for a longer period of pain relief but is reliant on the correct placement and maintenance of the catheter in the epidural space. A single preoperative intrathecal morphine injection also provides for long acting analgesia. No direct comparison of these 3 methods of postoperative pain control has been reported. Methods. An IRB-approved retrospective chart review was performed at 2 institutions from 1997 to 2005. The medical record was reviewed to determine pain scores after surgery at multiple time periods. The 3 groups were compared using Student t test and &khgr;2 and significance was defined as P < 0.05. Results. There was no statistical difference in the gender, age, magnitude of curve, or number of levels fused in the IT/PCA (N = 42), PCA (N = 41), or EPI (N = 55) groups. Postoperative pain scores were lowest in the IT/PCA group in the first 8 hours (P < 0.05) but the pain scores in the EPI group were then lower through 24 hours (P < 0.05). Total morphine use (mg/kg) was lower in the IT/PCA group compared with the PCA group at 12 hours and 24 hours (P = 0.0001). Return to solid food ingestion was quickest in the EPI group (2.0 days) followed by the IT/PCA (2.6 days) and PCA alone (3.2 days) (P < 0.002). Respiratory depression and transient neurologic change occurred most frequently in the EPI group (EPI 11/55 pts vs. 1/42 IT/PCA vs. 0/41 PCA P < 0.001). Pruritis was greatest in the epidural group (11/55 P < 0.05). There were no intraoperative somatosensory-evoked potential changes or permanent neurologic injury recorded in any group. Conclusion. An EPI controls postoperative pain for the longest period of time and allows for a quicker return to consumption of solid foods. However, a single preoperative intrathecal morphine injection controls the pain equally for the first 24 hours with less pruritis and with less adverse events thus requiring less nursing and physician intervention after PSF and SSI in AIS. All methods were safe with no neurologic injury recorded.

Development of an injectable two‐phase drug delivery system for sequential release of antiresorptive and osteogenic drugs

Unlike controlled release systems that deliver a single drug, dual or multidrug delivery systems with distinct release profiles are more likely to promote timely and effective tissue regeneration as they provide both temporally and concentration-dependent release of different molecules to mimic natural biological events. In this study, an injectable and biodegradable delivery system was developed to sequentially release an antiresorptive drug (clodronate) followed by an osteogenic agent (simvastatin) to treat bone disease. The injectable delivery system comprised simvastatin-loaded gelatin microspheres suspended in a viscous solution of carboxymethylcellulose (CMC) containing clodronate. Several factors (CMC concentration, glutaraldehyde concentration, simvastatin loading, and gelatin microsphere processing conditions) were investigated for their effects on drug release. Clodronate release was not affected by CMC concentration, with complete delivery within 12 hr, and simvastatin release could be modulated by cross-linking of the gelatin microspheres, loading, and washing conditions. Burst release of simvastatin was reduced from 70% to 6% in conjunction with sustained release for up to 3 weeks. The combined system showed early release of the antiresorptive clodronate sequentially followed by sustained delivery of the osteogenic simvastatin. This robust and flexible two-phase delivery system may prove useful for applications in which multiple drug delivery is desired.

The results of preoperative halo-gravity traction in children with severe spinal deformity.

Halo-gravity traction has been used preoperatively for patients with severe spinal deformity but there are limited data in the literature on the results and complications. We studied the outcomes of perioperative halo-gravity traction in children with severe spinal deformity. A retrospective study was carried out on patients who were treated at our center. Twenty-one patients were included in the study. Radiographic and pulmonary function parameters showed significant improvement during the course of traction and at the final follow-up. The overall complication rate was 19%, including two patients with pin loosening and two patients with superficial pin-site infections treated with oral antibiotics.

Novel three‐dimensional MRI technique for study of cartilaginous hip surfaces in Legg‐Calvé‐Perthes disease

Treatment of Legg‐Calvé‐Perthes disease (LCPD) may improve if new knowledge can be obtained regarding how articular cartilage changes shape during the course of this disorder. A new technique is presented showing how analyses of magnetic resonance images can be used to quantify the three‐dimensional changes in the femoral and acetabular articulating cartilage surfaces of children with LCPD. Ten male subjects (8 ± 1 years) with unilateral LCPD were enrolled in this IRB approved study. Sets of magnetic resonance images of both hips were obtained at three different times. Three‐dimensional virtual models of the cartilage were created from these images, and mathematical spheres were fit to the articulating surfaces. Five parameters (size, shape deformity (sphericity error), radial growth rate, joint fit, and joint incongruity) were used to quantify cartilage surface shape. Data were analyzed by using a linear mixed‐model. Joint incongruity, i.e., the distance between the centers of the femoral and acetabular spheres, was slightly more than 2.5 times larger (p = 0.001) in LCPD hips than the contralateral normal hips. Cartilage shape deformity was 65% larger in hips with LCPD than in normal hips. Growth rates of the femoral head and the opposing acetabular surface showed that distortion of the femoral surface occurred first and the opposing acetabular surface followed. Mean radial difference (acetabular surface radius minus femoral surface radius) in LCPD hips was less than half (p < 0.01) the value of normal hips. Interobserver variability was ∼10% of the value attributable to LCPD. This is the first known report presenting a technique that quantifies the three‐dimensional size, deformity, growth, fit. and incongruity of the femoral and acetabular articulating cartilaginous surfaces of LCPD and contralateral normal hips. The data obtained support the use of this technique and provide pilot data for a future clinical study of LCPD. Objective assessment of cartilage shape enabled by this technique may aid future diagnoses, enable monitoring of three‐dimensional femoral and acetabular remodeling, and permit quantitative assessment of treatment efficacy.

Correlation of spine deformity, lung function, and seat pressure in spina bifida.

BackgroundSpinal deformity, a common problem in children with myelodysplasia, is associated with alterations in pulmonary function and sitting balance. Sitting imbalance causes areas of high pressure in patients already at high risk for developing pressure ulcers due to insensate skin.Questions/purposesWe asked: Does spinal deformity affect pulmonary function tests in children with myelodysplasia? Does the magnitude of spinal curvatures and pelvic obliquity affect seating pressures? Does spinal deformity and seated pressures correlate with a history of pressure ulcers?Patients and MethodsWe retrospectively reviewed 32 patients with myelodysplasia and scoliosis (mean age, 14 years). The mean thoracic scoliosis was 64° with a mean pelvic obliquity of 15°. The mean forced vital capacity was 59% of predicted. The mean of the average and peak seated pressures were 24 and 137 mm Hg, respectively. We examined spinal radiographs, pulmonary function tests, and seated pressure maps and evaluated correlations of spinal deformity measures, pulmonary function, and seated pressures.ResultsThe thoracic scoliosis inversely correlated with lung volume and weakly related with only the forced midexpiratory volume parameter (R2 = 31%). The curve magnitude was associated with % seated area with pressures of 38 to 70 mm Hg while lesser degrees of pelvic obliquity were associated with % seating area with pressures of less than 38 mm Hg (R2 = 25% and 24%, respectively). A history of pressure ulcers did not correlate with any spinal deformity or seated pressure measures.ConclusionsAll patients displayed a reduced forced vital capacity, but this reduction was not related to increasing scoliosis. The smaller scoliosis curves and lesser degrees of pelvic obliquity were associated with larger areas of low seated pressures.

Three-dimensional hindfoot motion in adolescents with surgically treated unilateral clubfoot.

Advances in imaging and computerized analyses have enabled three-dimensional bone motion in the treated clubfoot to be measured precisely. Three-dimensional translations and rotations of the talus, calcaneus, navicular, and cuboid of surgically treated clubfeet were less in magnitude and sometimes different in direction (or without motion in a specific plane) compared with the contralateral normal feet. Surgical techniques used for clubfoot treatment do not restore normal hindfoot bone motion when examined with high-resolution magnetic resonance imaging, computer reconstruction, and image analysis techniques. These data advance the knowledge of hindfoot bone motion and establish a new and quantitative objective.

Factors predictive of second recurrence in clubfeet treated by ponseti casting.

Background: Ponseti serial casting is the most commonly used method in North America to treat children with clubfeet. Despite initial correction, recurrence is common. tibialis anterior tendon transfer (TATT) is commonly used to treat recurrent clubfeet. Recurrence can occur after TATT, and patients at risk of recurrence may benefit from closer monitoring. We studied the rate of second recurrence (recurrence after TATT) and studied the predictive factors for this recurrence. Methods: Retrospective chart review of patients who have undergone TATT for recurrent clubfeet between 2002 and 2010 at our institution was performed. Recurrence was defined as recurrence of any elements of the clubfoot deformity that requires operative or nonoperative treatment. Effect of age at the time of TATT, initial severity of the deformity, and family history of clubfoot on rate of recurrence was studied. Results: Sixty patients with 85 clubfeet were included in the study. Sixteen feet in 12 patients (20%) developed recurrence after TATT. Eight feet were treated nonoperatively and the rest (8 feet) required surgical procedure. Young age at time of TATT and brace noncompliance significantly increased the rate of second recurrence. Effect of severity of initial deformity and family history did not reach statistical significance. Conclusions: Second recurrence can happen in around one fifth of patients with clubfeet after TATT. Patients with young age at TATT and patients with brace noncompliance are at an increased risk of recurrence and should be monitored closely. Level of Evidence: Level II—prognostic.

Recreational terminal devices for children with upper extremity amputations.

Children with upper extremity amputations are particularly challenged in sports and other recreational activities. Many find that a prosthesis is of no benefit in their routine daily activities. Although a number of recreational terminal devices are available for prosthetic modification, it is unclear how effective they are at improving a childs performance in sports or hobbies. Methods: We evaluated the usefulness of 15 recreational terminal devices for upper extremity prostheses in 11 children by chart review and patient survey. All patients had functional elbows, and all but one was a unilateral amputee. All patients were instructed in their use by a prosthetist, and 3 patients received occupational therapy. Results: Nine of 15 recreational terminal devices prescribed improved performance. However, they primarily were the adaptations for weight lifting and violin bows, where their use was obligatory for participation. The wholesale costs for the terminal devices ranged from

Syringomyelia and vertebral osteochondromas in patients with multiple hereditary exostosis.

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