The Effect of Implant Density on Adolescent Idiopathic Scoliosis Fusion: Results of the Minimize Implants Maximize Outcomes Randomized Clinical Trial

BACKGROUND

Severe adolescent idiopathic scoliosis (AIS) can be treated with instrumented fusion, but the number of anchors needed for optimal correction is controversial.

METHODS

We conducted a multicenter, randomized study that included patients undergoing spinal fusion for single thoracic curves between 45° and 65°, the most common form of operatively treated AIS. Of the 211 patients randomized, 108 were assigned to a high-density screw pattern and 103, to a low-density screw pattern. Surgeons were instructed to use ≥1.8 implants per spinal level fused for patients in the high-implant-density group or ≤1.4 implants per spinal level fused for patients in the low-implant-density group. The primary outcome measure was the percent correction of the coronal curve at the 2-year follow-up. The power analysis for this trial required 174 patients to show equivalence, defined as a 95% confidence interval (CI) within a ±10% correction margin with a probability of 90%.

RESULTS

In the intention-to-treat analysis, the mean percent correction of the coronal curve was equivalent between the high-density and low-density groups at the 2-year follow-up (67.6% versus 65.7%; difference, -1.9% [95% CI: -6.1%, 2.2%]). In the per-protocol cohorts, the mean percent correction of the coronal curve was also equivalent between the 2 groups at the 2-year follow-up (65.0% versus 66.1%; difference, 1.1% [95% CI: -3.0%, 5.2%]). A total of 6 patients in the low-density group and 5 patients in the high-density group required reoperation (p = 1.0).

CONCLUSIONS

In the setting of spinal fusion for primary thoracic AIS curves between 45° and 65°, the percent coronal curve correction obtained with use of a low-implant-density construct and that obtained with use of a high-implant-density construct were equivalent.

LEVEL OF EVIDENCE

Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence.

Predicting Satisfaction of Parents of Pediatric Patients: Perceived Quality of Providers' Communication Mitigates Negative Effects of Shorter than Desired Consultations

This research investigated the predictors of satisfaction for parents of pediatric patients after a clinical consultation. Specifically, we assessed whether perceptions of their provider's communication quality influenced the degree to which their (dis)satisfaction with consultation length associated with their provider rating and intent to recommend the provider's office. Using patient satisfaction survey data collected after initial clinical visits to a pediatric hospital (N = 12,004), we found that communication quality was a stronger predictor for those who were dissatisfied with their consultation length, whereas communication quality made a relatively smaller difference for those who were satisfied with their consultation length. Put another way, parents' dissatisfaction with their child's consultation length mattered little when they perceived their provider to be high in communication quality, but it reduced their ratings and intentions to recommend when they perceived their provider to be low in communication quality. These results suggest that providers' communication behaviors have the capacity to buffer patients' negative evaluations otherwise incurred from shorter than desired consultations.

Narrative Review of the objective analysis of long-term outcome of the Ponseti technique: experience from Dallas

In 2001, Texas Scottish Rite Hospital for Children (TSRH) prospectively began a clubfoot database that included all of our patients with clubfeet who were willing to enroll. Nonoperative treatment, primarily the Ponseti method, was utilized. This article summarizes the experience from Dallas treating idiopathic clubfeet using the Ponseti technique, and is based on previously published studies utilizing information from the database. Patient clinical outcomes were defined as “good” (plantigrade foot achieved either with or without a percutaneous heel-cord tenotomy), “fair” (a plantigrade foot that required a limited procedure, such as tibialis anterior tendon transfer or posterior release), or “poor” (a plantigrade foot that required posteromedial release). Nearly 95% of idiopathic clubfeet obtained initial correction using the Ponseti technique, but relapses occurred and by age two years 24% needed some surgical intervention, usually limited procedures. Use of Dimeglio’s rating system before treatment strongly correlated with the probability of a “good” outcome at two years. Objective measurements of brace wear compliance (iButton) in those who reached age two years with “good” outcomes demonstrated an unexpected pattern of diminishing use of the foot abduction orthoses over the first two years of brace wear. By the 18-month period of brace wear, 1/3 patients wore the orthoses less than 6 hours per day, and nearly half of the patients wore the orthoses less than 8 hours per day. Between ages 2–5 years, nearly 21% of the corrected clubfeet at age two years needed limited procedures to maintain/regain plantigrade positioning. Lateral weight-bearing radiographs between 18–24 months were not helpful in predicting future relapse in these patients, and are no longer routinely obtained. Following these patients for normal development is important, as nearly 9% of infants initially presenting as idiopathic clubfeet were eventually found to have another disorder including neurological, syndromic, chromosomal, or spinal abnormalities. We continue to emphasize the need to devote great attention to detail when using the Ponseti method in an effort to optimize the clinical outcomes.

Genetic association and characterization of FSTL5 in isolated clubfoot

Talipes equinovarus (clubfoot, TEV) is a congenital rotational foot deformity occurring in 1 per 1000 births with increased prevalence in males compared with females. The genetic etiology of isolated clubfoot (iTEV) remains unclear. Using a genome-wide association study, we identified a locus within FSTL5, encoding follistatin-like 5, significantly associated with iTEV. FSTL5 is an uncharacterized gene whose potential role in embryonic and postnatal development was previously unstudied. Utilizing multiple model systems, we found that Fstl5 was expressed during later stages of embryonic hindlimb development, and, in mice, expression was restricted to the condensing cartilage anlage destined to form the limb skeleton. In the postnatal growth plate, Fstl5 was specifically expressed in prehypertrophic chondrocytes. As Fstl5 knockout rats displayed no gross malformations, we engineered a conditional transgenic mouse line (Fstl5LSL) to overexpress Fstl5 in skeletal osteochondroprogenitors. We observed that hindlimbs were slightly shorter and that bone mineral density was reduced in adult male, but not female, Prrx1-cre;Fstl5LSL mice compared with control. No overt clubfoot-like deformity was observed in Prrx1-cre;Fstl5LSL mice, suggesting FSTL5 may function in other cell types to contribute to iTEV pathogenesis. Interrogating published mouse embryonic single-cell expression data showed that Fstl5 was expressed in cell lineage subclusters whose transcriptomes were associated with neural system development. Moreover, our results suggest that lineage-specific expression of the Fstl genes correlates with their divergent roles as modulators of transforming growth factor beta and bone morphogenetic protein signaling. Results from this study associate FSTL5 with iTEV and suggest a potential sexually dimorphic role for Fstl5 in vivo.

The Lumbar Gap Measurement in Lenke 1-4C Curves

STUDY DESIGN

Retrospective review.

OBJECTIVES

To assess whether the lumbar gap (LG) measurement, which is the distance between the center sacral vertical line and the concave edge of the apical vertebra of the lumbar curve, would be a useful tool to predict the need for lumbar curve fusion in the Lenke 1-4C curves.

SUMMARY OF BACKGROUND DATA

The current treatment guidelines of selective thoracic fusion in the Lenke 1-4C curves are not routinely accepted.

METHODS

One hundred three adolescent idiopathic scoliosis (AIS) patients had undergone either selective thoracic fusion (STF) or both thoracic and lumbar curves fusion (TLF) for Lenke 1-4C curves. The correlations between the fusion decision making and preoperative LG, coronal balance, thoracic and lumbar Cobb, apical vertebra translation, and rotation were analyzed. The radiographic outcomes and SRS-30 of a minimum 2-year follow-up were reviewed in each group.

RESULTS

A total of 51 patients (49.5%) underwent an STF, and 52 patients (50.5%) underwent a TLF. The mean LG was 22.0 ± 8.8 mm in the TLF, which was 2.3 times greater than the STF (9.6 ± 3.9 mm) (p < .0001). Only 5% of the lumbar curves were fused when the LG was 10 mm or less. Ninety percent of the lumbar curves were fused when the LG was 16 mm or greater, and 100% lumbar curves were fused with an LG of 21 mm or greater. The preoperative coronal imbalance to the left in the TLF was significantly greater than the STF. A mean 47% thoracic correction corresponded to a mean 39% spontaneous correction of the lumbar curve obtained in the SFT, which was significantly different from the TLF (56% and 65%). There were no differences in the SRS-30 scores at 2 years postoperatively between the STF and the TLF.

CONCLUSION

The lumbar curve should not be fused when the LG was 10 mm or less, and very likely should be fused when the LG exceeds 20 mm in the Lenke 1-4C AIS patients.

LEVEL OF EVIDENCE

Level III.

Repeat Surgical Interventions Following "Definitive" Instrumentation and Fusion for Idiopathic Scoliosis: 25-Year Update

STUDY DESIGN

Single-institution, retrospective review of prospectively collected data on pediatric patients with adolescent idiopathic scoliosis (AIS) undergoing spinal fusion with a minimum two-year follow-up.

OBJECTIVE

To determine the rate of reoperation in AIS patients undergoing spine fusion from 2008 to 2012.

SUMMARY OF BACKGROUND DATA

Recent trends in the surgical treatment of AIS have included increased use of all-pedicle screw constructs, smaller implants, more posterior-only approaches, and improved correction techniques.

METHODS

A retrospective review of 467 patients undergoing spinal fusion from 2008 to 2012 was performed. Demographic, clinical, radiographic, and surgical data were collected prospectively on all patients for the index procedure and any reoperations. Data were compared to previously published cohorts of patients from the authors' institution who underwent spinal fusion for AIS between 1988 and 2007.

RESULTS

The rate of reoperation in this five-year cohort of patients was 9.9%. The most common indications for reoperation were infection (4.5%: 2.4% delayed infections and 2.1% acute infections), symptomatic implants (2.1%), and misplaced pedicle screws (1.7%). When compared to the 2003-2007 cohort, the rate of reoperation for acute infection and malpositioned pedicle screws increased significantly (p = .01 and p = .04), whereas the rate of reoperation for curve progression decreased (p = .01). Reoperations for acute infections and malpositioned pedicle screws also increased significantly (p = .047 and p = .042) compared with the 1988-2002 cohort, whereas the rate of reoperation for pseudarthrosis decreased (p = .002).

CONCLUSION

Reoperation rates for AIS have not improved with more sophisticated implants and techniques, predominantly because of increased acute infections and malpositioned pedicle screws despite decreasing pseudarthrosis rates and curve progression.

LEVEL OF EVIDENCE

Level II.

Enhancing the photoluminescence of surface anchored metal-organic frameworks: mixed linkers and efficient acceptors

We present two approaches to enhance the photoluminescence quantum yield (PLQY) of surface-anchored metal-organic frameworks (SURMOFs). In the first approach we fabricate SURMOFs from a mix of an emissive linker with an optically-inert linker of equivalent length, diluting the emissive linker while maintaining the SURMOF structure. This approach enhances the internal PLQY. However, the increase in internal PLQY is achieved at the expense of a drastic reduction in optical absorption, thus the external PLQY remains low. To overcome this limitation, a second approach is explored wherein energy-accepting guest chromophores are infiltrated into the framework of the active linker. At the correct acceptor concentration, an internal PLQY of 52% - three times higher than the previous approach - is achieved. Additionally, the absorption remains strong leading to an external PLQY of 8%, an order of magnitude better than the previous approach. Using this strategy, we demonstrate that SURMOFs can achieve PLQYs similar to their precursor chromophores in solution. This is of relevance to SURMOFs as emitter layers in general, and we examine the optimized emitter layer as part of a photon upconversion (UC) SURMOF heterostructure. Surprisingly, the same PLQY is not observed after triplet-triplet annihilation in the UC heterostructure as after its normal photoexcitation (although the UC layers exhibit low thresholds consistent with those reported in our previous work). We discuss the potential bottlenecks in energy transport that could lead to this unexpected reduction in PLQY after excitation via triplet-triplet annihilation, and how future design of SURMOF UC multilayers could overcome these limitations.

Infiltrated photonic crystals for light-trapping in CuInSe2 nanocrystal-based solar cells

Solution processable nanocrystal solar cells combine the advantages of low-cost printing and wide range of accessible absorber materials, however high trap densities limit performance and layer thickness. In this work we develop a versatile route to realize the infiltration of a photonic crystal, with copper indium diselenide nanocrystal ink. The photonic crystal allows to couple incident light into pseudo-guided modes and thereby enhanced light absorption. For the presented design, we are able to identify individual guided modes, explain the underlying physics, and obtain a perfect match between the measured and simulated absorption peaks. For our relatively low refractive index layers, a 7% maximum integrated absorption enhancement is demonstrated.

Nonoperatively Corrected Clubfoot at Age 2 Years: Radiographs Are Not Helpful in Predicting Future Relapse

BACKGROUND

Nonoperative treatment of idiopathic clubfoot is standard. The purpose of this study was to determine if measurements made on standing lateral radiographs of successfully treated clubfeet made at 18 to 24 months of age were predictive of late recurrence.

METHODS

Inclusion criteria were idiopathic clubfoot with an age at presentation of ≤3 months, nonoperative treatment resulting in a clinically plantigrade foot at 2 years of age, standing lateral radiograph of the involved foot made at 18 to 24 months of age, and a minimum age of 4 years at the time of follow-up. The radiographs were assessed for the talocalcaneal angle and the tibiocalcaneal angle, with measurements made by 2 trained practitioners. The average values of the 2 raters were used. The interobserver reliability was calculated using intraclass correlation coefficients (ICCs). A total of 211 patients with 312 clubfeet were evaluated. The average age at the time of follow-up was 8.0 years (range, 4.0 to 13.3 years). Results at the time of follow-up were rated as good (maintained plantigrade foot), fair (required limited surgery to maintain, or return to, a plantigrade position), or poor (required posteromedial release).

RESULTS

Over time, 75% of the feet had a good result, 19% had a fair result, and 6% had a poor result. With regard to radiographic assessment, the ICCs were 0.97 (talocalcaneal angle) and 0.98 (tibiocalcaneal angle), demonstrating excellent agreement between the raters. The mean talocalcaneal angle differed significantly between the feet with a good clinical outcome and those with a fair outcome (28° versus 24°; p < 0.02), but did not differ significantly between those with a good versus poor outcome (28° versus 26°), or a fair versus poor outcome (24° versus 26°). There were no significant differences in the mean tibiocalcaneal angle among the groups (86°, 90°, and 84°, respectively) (p = 0.17).

CONCLUSIONS

Most clubfeet that were clinically plantigrade at 2 years of age remained so, while one-fourth subsequently required some surgery for late recurrence, primarily limited procedures. The tibiocalcaneal angle and talocalcaneal angle from standing lateral radiographs made at 18 to 24 months of age were not helpful in predicting future relapse.

LEVEL OF EVIDENCE

Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

What would be the annual cost savings if fewer screws were used in adolescent idiopathic scoliosis treatment in the US?

OBJECT

There is substantial heterogeneity in the number of screws used per level fused in adolescent idiopathic scoliosis (AIS) surgery. Assuming equivalent clinical outcomes, the potential cost savings of using fewer pedicle screws were estimated using a medical decision model with sensitivity analysis.

METHODS

Descriptive analyses explored the annual costs for 5710 AIS inpatient stays using discharge data from the 2009 Kids’ Inpatient Database (Healthcare Cost and Utilization Project, Agency for Healthcare Research and Quality), which is a national all-payer inpatient database. Patients between 10 and 17 years of age were identified using the ICD-9-CM code for idiopathic scoliosis (737.30). All inpatient stays were assumed to represent 10-level fusions with pedicle screws for AIS. High screw density was defined at 1.8 screws per level fused, and the standard screw density was defined as 1.48 screws per level fused. The surgical return for screw malposition was set at $23,762. A sensitivity analysis was performed by varying the cost per screw ($600–$1000) and the rate of surgical revisions for screw malposition (0.117%–0.483% of screws; 0.8%–4.3% of patients). The reported outcomes include estimated prevented malpositioned screws (set at 5.1%), averted revision surgeries, and annual cost savings in 2009 US dollars, assuming similar clinical outcomes (rates of complications, revision) using a standard- versus high-density pattern.

RESULTS

The total annual costs for 5710 AIS hospital stays was $278 million ($48,900 per patient). Substituting a high for a standard screw density yields 3.2 fewer screws implanted per patient, with 932 malpositioned screws prevented and 21 to 88 revision surgeries for implant malposition averted, and a potential annual cost savings of $11 million to $20 million (4%–7% reduction in the total cost of AIS hospitalizations).

CONCLUSIONS

Reducing the number of screws used in scoliosis surgery could potentially decrease national AIS hospitalization costs by up to 7%, which may improve the safety and efficiency of care. However, such a screw construct must first be proven safe and effective.

Are More Screws Better? A Systematic Review of Anchor Density and Curve Correction in Adolescent Idiopathic Scoliosis

STUDY DESIGN

Systematic review of clinical studies.

OBJECTIVES

To critically evaluate existing literature to determine whether increased anchor or implant density (screws, wires, and hooks per level fused) results in improved curve correction for adolescent idiopathic scoliosis (AIS) surgery.

SUMMARY OF BACKGROUND DATA

Wide variability exists in the number of screws used for AIS surgery. High numbers of pedicle screws are increasingly used, but there is limited evidence to support this as best practice.

METHODS

Online English-language databases were searched to identify articles addressing anchor density. Articles were reviewed for anchor type/number, radiographic measures, and patient-reported outcomes.

RESULTS

Of 196 references identified, 10 studies totaling 929 patients met the inclusion criteria. Reported mean anchor density varied from 1.06 to 2.0 implants per level fused. Mean percent coronal curve correction varied from 64% to 70%. Two studies (463 patients) analyzed hook, hybrid (combined hooks and screws), and screw constructs as a single cohort. Both found increased correction with high-density constructs (p = .01, p < .001), perhaps as a result of the hooks and hybrid constructs. Eight retrospective studies and 1 prospective randomized, controlled trial had predominantly screw constructs (466 patients). Increased anchor density was not associated with improved curve correction. The studies evaluating screw density are significantly underpowered to detect a difference in curve correction.

CONCLUSIONS

Wide heterogeneity in anchor density exists in the surgical treatment of AIS. Reports evaluating the effects of increased anchor density are mostly retrospective and significantly underpowered to detect a difference in curve correction and patient outcomes. At this time, there is insufficient evidence to show that anchor density affects clinical outcomes in AIS.

Outcomes Following Posterior Fusion for Adolescent Idiopathic Scoliosis With and Without Autogenous Iliac Crest Bone Graft Harvesting

STUDY DESIGN

Retrospective.

SUMMARY OF BACKGROUND DATA

There is continued controversy regarding the morbidity associated with harvesting iliac crest bone graft (ICBG). More important, its effect on clinical outcomes is poorly understood.

OBJECTIVES

The purpose of this study was to determine whether harvesting ICBG affects clinical outcomes after posterior instrumented fusion in patients with adolescent idiopathic scoliosis (AIS).

METHODS

We identified patients enrolled in a prospective, multicenter database of patients with AIS who had posterior instrumented fusion with complete preoperative and 2-year postoperative Scoliosis Research Society (SRS)-22R data. Patients who had a previous fusion, thoracoplasty, or anterior surgery were excluded. We classified patients into 2 groups: those who underwent ICBG harvest (ICBG group) and those who did not (non-ICBG group).

RESULTS

We included 342 patients in the ICBG group versus 563 in the non-ICBG group. There were no significant differences in preoperative age (14.9 vs. 14.8; p = .178), major Cobb angle (51.3 vs. 51.8; p = .782), minor Cobb angle (34.8 vs. 35.1; p = .846), or Pain (4.11 vs. 4.11; p = .912), Appearance (3.29 vs. 3.33; p = .384), Activity (4.15 vs. 4.14; p = .847); Mental (3.95 vs. 4.00; p = .313), or Total (3.86 vs. 3.87; p = .603) SRS-22R scores. The average operative time was slightly longer in the ICBG group (293.55 vs. 276.21 minutes; p = .002). Estimated blood loss was greater in the ICBG group (939.47 vs. 723.63 mL; p = .000; 12.2% vs. 9.2% estimated blood volume; p = .000). The average number of levels fused was similar between groups (10.6 vs. 10.3; p = .137). There were no significant differences in any of the postoperative SRS-22R domains: Pain (4.30 vs. 4.34; p = .373), Appearance (4.23 vs. 4.19; p = .310), Activity (4.31 vs. 4.33; p = .509), Mental (4.20 vs. 4.23; p = .532), Satisfaction (4.42 vs. 4.43; p = .870), or Total Score (4.27 vs. 4.29; p = .674). By 2-year follow-up, there was 1 nonunion reported in the ICBG group and none in the non-ICBG group.

CONCLUSIONS

After posterior instrumented fusion surgery for AIS, ICBG harvesting was associated with longer operative times and increased blood loss, but did not influence 2-year outcomes, which included pain and appearance scores.

Studies of TBX4 and chromosome 17q23.1q23.2: an uncommon cause of nonsyndromic clubfoot

Clubfoot is a common birth defect characterized by inward posturing and rigid downward displacement of one or both feet. The etiology of syndromic forms of clubfoot is varied and the causes of isolated clubfoot are not well understood. A microduplication of 2.2 Mb on chromosome 17q23.1q23.2 which includes T-box 4 (TBX4), a hindlimb-specific gene, and 16 other genes was recently identified in 3 of 66 families reported as nonsyndromic clubfoot, but additional non-foot malformations place them in the syndromic clubfoot category. Our study assesses whether variation in or around TBX4 contributes to nonsyndromic clubfoot. To determine whether this microduplication was a common cause of nonsyndromic clubfoot, 605 probands (from 148 multiplex and 457 simplex families) with nonsyndromic clubfoot were evaluated by copy number and oligonucleotide array CGH testing modalities. Only one multiplex family (0.68%) that had 16 with clubfoot and 9 with other foot anomalies, had a 350 kb microduplication, which included the complete duplication of TBX4 and NACA2 and partial duplication of BRIP1. The microduplication was transmitted in an autosomal dominant pattern and all with the microduplication had a range of phenotypes from short wide feet and toes to bilateral clubfoot. Minimal evidence was found for an association between TBX4 and clubfoot and no pathogenic sequence variants were identified in the two known TBX4 hindlimb enhancer elements. Altogether, these results demonstrate that variation in and around the TBX4 gene and the 17q23.1q23.2 microduplication are not a frequent cause of this common orthopedic birth defect and narrows the 17q23.1q23.2 nonsyndromic clubfoot-associated region.

The effect of intermittent operation on a wind-powered membrane system for brackish water desalination

Renewable energy powered membrane systems that are directly-connected must take account of both the inherent fluctuations and the intermittency of the energy resource. In order to determine the effect of intermittent operation, a membrane system was tested with variables of (i) amplitude from 60 to 300 W and (ii) length of time with no power from 0.5 to 3 min. This was performed over one hour periods with six on/off cycles to simulate the system operating under intermittent operation for short periods of time when directly-connected to a small wind turbine. The setup used a Filmtec BW30-4040 brackish water reverse osmosis membrane with feed waters of 2,750 mg/L and 5,500 mg/L NaCl. The results showed that the membrane system produced potable water under the majority of intermittency experiments performed. There was a relatively large increase in the average salt concentration of the permeate, especially when the system was off for shorter periods of time (0.5-1 min). Longer periods of no power (1-3 min) did not have as significant an effect on the average water quality. This is important when the need for energy buffering or short term storage is considered for these systems as it shows the potential for improving the overall flux and water quality using temporary energy storage.

Pediatric pedicle screws: comparative effectiveness and safety: a systematic literature review from the Scoliosis Research Society and the Pediatric Orthopaedic Society of North America task force

BACKGROUND

Pedicle screws are widely used in spinal surgery. There is extensive published literature concerning the use of pedicle screw instrumentation for spinal surgery in adults. Now there is a trend to use pedicle screws in pediatric patients, including the very young. A systematic review of the current English-language literature on the use of pedicle screw instrumentation in the pediatric age group was performed to specifically determine (1) the pedicle screw placement accuracy in patients with spine deformity and (2) the effect size of all-pedicle screw constructs compared with other methods of spinal instrumentation in terms of the percentage of scoliosis correction.

METHODS

English-language studies of pedicle screw use in pediatric patients (defined as those younger than eighteen years of age) were included. Descriptive statistics synthesized the accuracy of pedicle screw placement. Accuracy rates were compared between pediatric and adult patients. The effect of pedicle screw instrumentation on scoliosis correction was calculated with use of Cobb angle measurements.

RESULTS

On the basis of the literature search, 1181 articles were screened, 320 abstracts were examined, and ninety full-text articles representing 5761 patients were reviewed in detail. Seventeen studies met the inclusion criteria for the analysis of pedicle screw placement accuracy. A total of 13,536 pedicle screws were placed in 1353 pediatric patients. The overall placement accuracy rate in pediatric patients was 94.9%, which was higher than the rate of 91.5% reported for adults. The weighted, geometric, and 5% trimmed mean accuracy rates of pedicle screw placement were 91.9%, 88.5%, and 89.1%, respectively (standard deviation = 10%; interquartile range = 10%). Sixteen comparative studies met the inclusion criteria for the analysis of the effect of pedicle screw instrumentation on scoliosis correction. Pedicle screw constructs had a significantly larger percentage of Cobb angle correction compared with hooks (Cohen's d = 1.14) and hybrid constructs (Cohen's d = 0.49).

CONCLUSIONS

The accuracy of pedicle screw placement in the pediatric spine exceeds the accuracy rate reported in adults. Pedicle screw instrumentation constructs are significantly more effective for scoliosis correction, as determined on the basis of Cobb angle measurements, than are hook constructs and hybrid constructs.

Kyphectomy improves sitting and skin problems in patients with myelomeningocele

BACKGROUND

Progressive kyphosis occurs in up to 20% of patients with myelomeningocele. Severely affected patients can develop recurrent skin breakdown, osteomyelitis, sitting imbalance, and poor cosmetic appearance.

QUESTIONS/PURPOSES

We (1) assessed the ability of kyphectomy to restore an intact skin envelope and allow comfortable seating in a wheelchair; (2) reviewed the complications of kyphectomy and spinal fusion in myelomeningocele; and (3) determined whether patients requiring unexpected reoperation had worse correction or more ulceration compared with those patients treated with a single surgery.

METHODS

We retrospectively reviewed the records of 23 children with thoracic-level myelomeningocele who were treated with kyphectomy and spinal fusion since 1980. Indications for surgery included recurrent skin breakdown (15 patients) and poor sitting balance or unacceptable cosmetic deformity (three patients). We evaluated operative technique, type of sacropelvic fixation, surgical complications, radiographic correction, and skin condition at followup. The minimum followup was 2 years (median, 4.1 years; range, 2.1-10 years); 18 of the 23 children had greater than 2 years followup and are reported here.

RESULTS

Kyphectomy achieved a sitting balance and resolved in skin ulceration in 17 of 18 patients. Seven patients had complications requiring reoperation. Three patients had multiple reoperations for early deep infection and one patient each had reoperation for late infection, pseudarthrosis, implant-related sacral pressure sore, and planned extension of proximal fusion after growth. Patients requiring multiple operations had similar correction and relief of ulceration to those treated with a single procedure.

CONCLUSIONS

Complications after kyphectomy are frequent and many children with myelomeningocele and severe hyperkyphosis require multiple procedures and lengthy hospital stays. Nonetheless, improved seating balance and resolution of skin problems was achieved in 17 of 18 patients.

A comparison of two nonoperative methods of idiopathic clubfoot correction: the Ponseti method and the French functional (physiotherapy) method. Surgical technique

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.

Clubfoot treatment: Ponseti and French functional methods are equally effective

Over the past 15 years, the reemergence of nonoperative treatment of clubfeet throughout the world has been profound. Two methods have been utilized-the Ponseti method and, to a lesser extent, the French functional method. Our review presents one institution's experience using both methods. Satisfactory initial correction was achieved in 95% of idiopathic clubfeet, regardless of method. However, maintenance of the correction was challenging as relapses occurred in 37% of feet treated by the Ponseti method and 29% of feet treated by the French functional method. At an average 4.3 year followup, using either method, posteromedial releases were avoided in 84% of our patients. Using gait analysis to evaluate the function of children treated with these techniques, there was no difference in cadence parameters between the two groups. More of the children treated with the French method walked with knee hyperextension, a mild equinus gait, and mild footdrop. In contrast, more of the patients in the Ponseti group demonstrated mildly increased stance-phase dorsiflexion and a calcaneus gait.

LEVEL OF EVIDENCE

Level V, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Measurement method for photoluminescent quantum yields of fluorescent organic dyes in polymethyl methacrylate for luminescent solar concentrators

A method for measuring the photoluminescent quantum yields (PLQY) of luminescent organic dyes is presented. The self-absorption probability calculated at different dye concentrations is used to determine the absolute quantum yield from the observed values. The results for a range of commercially available dyes show high quantum yields, even at high concentrations, and an absence of quenching. The PLQY of several dye mixtures are also presented. The results indicate an absence of any reduction of PLQY in a dye mixture as compared with the individual PLQY of the dyes.

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.

Gait analysis of children treated for clubfoot with physical therapy or the Ponseti cast technique

BACKGROUND

Currently, clubfoot is initially treated with nonoperative methods including the Ponseti cast technique and the French functional physical therapy program. Our goal was to evaluate the function of children treated with these techniques.

METHODS

We reviewed the cases of 182 patients with idiopathic clubfoot (273 feet) who were initially treated nonoperatively. Seventy-seven patients (119 feet) were excluded because they had either received a combination of nonoperative treatments or had undergone surgery prior to testing. Gait analysis was performed when the children were approximately two years of age. Temporal and kinematic data were classified as abnormal if they were more than one standard deviation from normal.

RESULTS

Gait analysis was performed on 105 patients (fifty-six treated with casts and forty-nine treated with physical therapy) with 154 involved feet (seventy-nine treated with casts and seventy-five treated with physical therapy). These patients were an average of two years and three months of age, and their initial Diméglio scores ranged between 10 and 17. No significant differences in cadence parameters were found between the two groups. The rate of normal kinematic ankle motion in the sagittal plane was higher in the group treated with physical therapy (65% of the feet) than it was in the group treated with the Ponseti cast technique (47%) (p = 0.0317). More children treated with physical therapy walked with knee hyperextension (37% of the feet) (p < 0.0001), an equinus gait (15%) (p = 0.0051), and footdrop (19%) (p = 0.0072); only one patient treated with casts walked with an equinus gait, and only three demonstrated footdrop. In contrast, more of the patients in the cast-treatment group demonstrated excessive stance-phase dorsiflexion (48% of the feet) (p < 0.0001) and a calcaneus gait (10%). More feet in the physical therapy group had an increased internal foot progression angle (44% compared with 24% in the cast-treatment group; p = 0.0144) and increased shank-based foot rotation (73% compared with 57% in the cast-treatment group; p = 0.05).

CONCLUSIONS

While the rate of normal kinematic ankle motion in the sagittal plane was 65% in the group treated with physical therapy, the gait abnormalities that were seen in that group were characterized by mild equinus and/or footdrop. The rate of normal kinematic ankle motion in the sagittal plane was 47% in the cast-treatment group, but the most common gait abnormality in this group was mildly increased dorsiflexion in the stance phase. The rates of calcaneus gait and equinus gait were <or=15% in each nonoperative group. The differences between the physical therapy and cast-treatment groups may, in part, be the result of the percutaneous Achilles tendon lengthening that is performed as part of the Ponseti cast technique but not as part of the physical therapy program.

Renewable energy powered membrane technology. 2. The effect of energy fluctuations on performance of a photovoltaic hybrid membrane system

This paper reports on the performance fluctuations during the operation of a batteryless hybrid ultrafiltration--nanofiltration/reverse osmosis (UF-NF/RO) membrane desalination system powered by photovoltaics treating brackish groundwater in outback Australia. The renewable energy powered membrane (RE-membrane) system is designed to supply clean drinking water to a remote community of about 50 inhabitants. The performance of the RE-membrane system over four different solar days is summarized using four different NF membranes (BW30, NF90, ESPA4, TFC-S), and examined in more detail for the BW30 membrane. On an Australian spring day, the system produced 1.1 m3 of permeate with an average conductivity of 0.28 mS x cm(-1), recovering 28% of the brackish (8.29 mS x cm(-1) conductivity) feedwater with an average specific energy consumption of 2.3 kWh x m(-3). The RE-membrane system tolerated large fluctuations in solar irradiance (500--1200 W x m(-2)), resulting in only small increases in the permeate conductivity. When equipped with the NF90 (cloudy day) and ESPA4 (rainy day) membranes, the system was still able to produce 1.36 m(-3) and 0.85 m(-3) of good quality permeate, respectively. The TFC-S membrane was not able to produce adequate water quality from the bore water tested. It is concluded that batteryless operation is a simple and robust way to operate such systems under conditions ranging from clear skies to medium cloud cover.

Infantile tibia vara: correction of recurrent varus deformity following epiphyseolysis

Infantile tibia vara (infantile Blount's disease) is a condition in which progressive varus of the knee develops due to diminished physeal growth of the medial aspect of the proximal tibia. A 6-year-old boy with severe bilateral infantile tibia vara (Langenskiold stage V) underwent operative correction of his deformities. Surgery consisted of epiphyseolyses of the medial proximal tibiae and valgus-producing corrective tibial osteotomies. Nearly 5 years after symmetric growth, he again developed progressive varus involving his left knee. Usually, a repeat proximal tibial osteotomy is required along with consideration for completion of epiphyseodesis. In this case report, a simpler approach using staples was taken to successfully regain correction in a patient with recurrent deformity who was treated previously by a combination of epiphyseolysis and proximal tibial osteotomy. Stapling of the lateral aspect of the physis allowed the limited remaining growth potential within the abnormal medial physeal region to correct the angular deformity. A small overcorrection into valgus corrected after subsequent removal of the staple. At 14 years, with clinical and radiologic alignment normal, bilateral proximal tibial epiphysiodeses were performed. The patient returned to playing football at a high school level and had no functional limitations. To our knowledge, this is the first report of growth modulation (physeal stapling) resulting in successful correction of recurring genu varum in a knee that had previously undergone epiphyseolysis of the medial proximal tibial physis in advanced infantile tibia vara.

The Spinal Appearance Questionnaire: results of reliability, validity, and responsiveness testing in patients with idiopathic scoliosis

STUDY DESIGN

Prospective, sequential enrollment.

OBJECTIVE

We report the development and testing of the Spinal Appearance Questionnaire (SAQ) for reliability, validity, and responsiveness in patients with idiopathic scoliosis.

SUMMARY OF BACKGROUND DATA

The SAQ was designed to measure patients' and their parents' perception of their spinal deformity's appearance using standardized drawings and questions. This study was designed to test the instrument's psychometric properties.

METHODS

The SAQ was administered as a test-retest to idiopathic scoliosis patients and parents for reliability and initial validity assessment (Group I). It was then administered to patients before surgery and 1 year after surgery (Group II) for responsiveness and further validity testing. Finally, both the SAQ and SRS instruments were administered to adolescent idiopathic patients before surgery and 1 year after surgery (Group III) for comparison of the 2 instruments.

RESULTS

Group I: The individual scale items had good to excellent reliability (Spearman's rho, 0.57-0.99) and high internal scale consistency (Cronbach's alpha >0.7). The mean scale scores differentiated between curves greater than 30 degrees and lesser curves (P < 0.01). Surgery improved scores compared with those with "surgery recommended." Group II: The domains correlated with clinical and radiographic aspects of the deformity before surgery. All of the domains showed significant difference after surgery (P < 0.0001) and large effect size for all domains except for the patient chest domain. Group III: Both the SAQ and the SRS instruments had significant improvement in all of their domains except for the SRS Activity scale. The relative efficiency of the SAQ domains to the SRS appearance domain (the most responsive SRS domain) was greater for 5 SAQ domains.

CONCLUSION

The SAQ is reliable, responsive to curve improvement, and shows strong evidence of validity. It provides more detail than the SRS in the appearance domain, and provides explanation of spinal deformity's concerns and improvements.

Lenke 1C, King type II curves: surgical recommendations

The objectives of this article are twofold. The first is to discuss the surgical experience in patients who have Lenke 1C (King type II) curves, including the experience with newer instrumentation. These patients present a significant challenge to the deformity surgeon because they have structural thoracic deformities and significant, but nonstructural, lumbar curves. Over the years, selective instrumentation and fusion of the thoracic curve have been the primary approach to preserve motion of the lumbar segments, and thus, improve the long-term outlook. This strategy has been undertaken with the expectation that the uninstrumented lumbar curve will allow for a well-balanced spinal column postoperatively. The second objective of this article is to present basic strategies that may be helpful when planning for surgery in these patients.

Risk factors for the development of delayed infections following posterior spinal fusion and instrumentation in adolescent idiopathic scoliosis patients

STUDY DESIGN

Retrospective comparison study of patients who had a delayed infection following a posterior spinal fusion and instrumentation (PSFI) for adolescent idiopathic scoliosis (AIS).

OBJECTIVE

To define risk factors for the development of delayed infections following PSFI for AIS by comparing those patients who developed this complication to a randomly selected group of patients who did not.

SUMMARY OF BACKGROUND DATA

Despite studies reporting the incidence and treatment of delayed infection following PSFI for AIS, there are no studies analyzing risk factors for its occurrence.

METHODS

All patients who required treatment for delayed infections following PSFI for AIS were identified (infection group, n = 36). A random selection of patients who did not develop a delayed infection (no infection, n = 90) was made in a ratio of 3:1 (no infection/infection). The 2 groups were compared using statistical methods.

RESULTS

Parameters associated with the infection group included: presence of a significant medical history, surgeon, less surgical time, a more distal fusion level (16% infection rate with a thoracic LIV vs. 33% infection rate with a lumbar LIV), not using postoperative drains, and increased drainage when drains were used. Other factors associated with infection were use of a blood transfusion and when increasing units of transfusion were used. Multivariate logistic regression analysis identified 3 factors that remained statistically significant: 1) significant medical history, 2) receiving a blood transfusion, and 3) not using a postoperative drain. Factors that were not associated with delayed infection included body mass index, the number of anchor points used, use of allograft bone, and the total number of levels instrumented and antibiotic regimen.

CONCLUSION

The occurrence of a delayed infection is most likely multifactorial and is related to a positive past medical history and the use of blood transfusions. Postoperative use of a drain may be important to avoid delayed infection.

Developing outcome measures for pediatric deformity surgery

STUDY DESIGN

: Review article regarding the development of outcome measures for pediatric spinal deformity.

OBJECTIVE

: To discuss the role of patient-based outcomes and process measures in pediatric spinal deformity patients.

SUMMARY OF BACKGROUND DATA

: A number of health-related quality of life (HRQOL) questionnaires assess, from patients' perspectives, the effectiveness of spinal deformity correction. The SRS instrument is the most prominent HRQOL tool used in North American adolescent scoliosis studies today. However, these patient-based outcomes and perceptions do not necessarily correlate with process measurements, particularly in the area of increase spinal deformity correction being achieved with newer, more powerful, pedicle screw instrumentation. Furthermore, spinal deformity presenting during infancy or early childhood poses a particular challenge for developing useful evidence-based outcomes tools.

METHODS

: The rationale for patient-based outcome development in pediatric spinal deformity is discussed, along with its important association with process measures.

RESULTS

: Newer HRQOL tools are under development that may better recognize and differentiate changes in adolescent patients' appearances before and after surgery. For early-onset spinal deformity patients, newer process measures for periodic outcome assessment, such as volume measurement of lung parenchyma and spine/chest cage measurement, are being developed.

CONCLUSION

: Ultimately, both patient and process measures are necessary to fully evaluate the results of pediatric spinal deformity surgery.

Screening the newborn for developmental dysplasia of the hip: now what do we do?

The Pediatric Orthopaedic Society of North America recommends that all health care providers who are involved in the care of infants continue to follow the clinical practice guideline for early detection of developmental hip dysplasia (DDH) outlined by the American Academy of Pediatrics. Although evaluation of children with risk factors for DDH is important, most DDH occurs in infants who have no risk factors. For all infants, a competent newborn physical examination using the Ortolani maneuver is the most useful procedure to detect hip instability. Early treatment of an unstable hip with a Pavlik harness or similarly effective orthosis is effective, safe, and strongly advised. Despite having had normal newborn and infant hip examinations, there remains the possibility of a late-onset hip dislocation needing treatment in approximately 1 in 5000 infants.

Magnetic resonance imaging of the congenital clubfoot treated with the French functional (physical therapy) method

The purpose of this study was to assess magnetic resonance imaging (MRI) changes that occur in clubfeet after nonoperative treatment with the French functional method, specifically pertaining to the chondro-osseous anatomy and the joint relationships. The magnetic resonance images were obtained in 6 infants before treatment and 3 months later. The MRI protocol described previously for clubfeet which were treated by the Ponseti method (J Pediatr Orthop. 2001;21:719) was closely adhered to, except that no sedation was allowed by our institutional review board. The severity of the clubfoot deformities before treatment made assessment of the tibiotalar, talonavicular, and talocalcaneal joint relationships difficult in some feet. Despite this, improvements were noted after treatment in tibiotalar plantarflexion, the talonavicular relationship, the calcaneocuboid relationship, and the varus position of the calcaneus. The wedge shape of both the navicular and distal end of the calcaneus that occasionally was noted on the MRI before treatment improved after therapy. Although improved clinically, persistent equinus of the calcaneus on MRI was significant in 2 feet and was associated with slight dorsal displacement of the cuboid on the calcaneus (MRI evidence of rocker bottom). As noted with use of the Ponseti nonoperative treatment method, the chondro-osseous abnormalities seen on MRI studies in congenital clubfoot improve after treatment with the French functional (physical therapy) method, with the exception of equinus.

Renewable energy powered membrane technology. 1. Development and characterization of a photovoltaic hybrid membrane system

In isolated communities where potable water sources as well as energy grids are limited or nonexistent, treating brackish groundwater aquifers with small-scale desalination systems can be a viable alternative to existing water infrastructures. Given the unavailability of power in many such situations, renewable energy is an obvious solution to power such systems. However, renewable energy is an intermittent power supply and with regards to the performance of intermittently operated desalination systems, only very limited experience exists, both with regards to efficiency as well as water quality. In this paper, this lack of knowledge is addressed by evaluating a system operated with varying parameters (pressure and flow) with constant power as a step toward defining a safe operating window, and they provide a basis for interpreting future data obtained with a renewable energy source. Field trials were performed on a brackish (5300 mg/L TDS; 8290 microS/cm) bore in Central Australia with a photovoltaic-powered membrane filtration (PV-membrane) system. Four nanofiltration and reverse osmosis membranes (BW30, ESPA4, NF90, TFC-S) and a number of operation parameter combinations (transmembrane pressure, feed flow, TFC-S) and operating parameters transmembrane pressure and feed flow were investigated to find the best operating conditions for maximum drinking water production and minimum specific energy consumption (SEC). The ESPA4 membrane performed best for this brackish source, producing 250 L/h of excellent drinking water (257 mg/L TDS; 400 microS/ cm) at an SEC of 1.2 kWh/m3. The issue of brine disposal or reuse is also discussed and the article compares the salinity of the produced brine with livestock water. Since the feedwater is disinfected physically using ultrafiltration (UF), the brine is free from bacteria and most viruses and hence can be seen more as a reusable product stream than a waste stream with a disposal problem.

Repeat surgical interventions following "definitive" instrumentation and fusion for idiopathic scoliosis

STUDY DESIGN

A retrospective chart review was performed on all idiopathic scoliosis patients treated with instrumented spinal fusion over a 15-year period.

OBJECTIVES

To provide an experience from a single institution over a prolonged time period. The goal was to determine the frequency of repeat surgical interventions following the "definitive" spinal fusion surgery and identify the factors responsible for these reoperations.

SUMMARY OF BACKGROUND DATA

Instrumented spinal fusion remains the standard of care in the surgical management of idiopathic scoliosis. This surgery is considered a "definitive" procedure where, barring a complication, no additional surgical procedures are planned. Although many studies have reported the frequency of specific complications following spinal fusion, little information currently exists regarding the cumulative average of these repeat surgical interventions that occur following these "definitive" procedures.

METHODS

Surgical logs were reviewed on all patients who had an instrumented spinal fusion for idiopathic scoliosis from January 1988 through December 2002. All subsequent surgical interventions on these patients were then identified from the logs through December 2004. Pertinent information was gleaned from surgical logs and patient charts to provide details for these reoperations.

RESULTS

A total of 1,046 patients underwent an instrumented spinal fusion for idiopathic scoliosis: 809 had a posterior-only fusion, 228 had an anterior-only fusion, and 9 had a combined anterior/posterior spinal fusion. A total of 172 repeat surgical interventions were performed in 135 patients (12.9%). Of these 135 patients, 29 patients (21.5%) had two or more separate procedures performed. The most common reasons for reoperation were infection, symptomatic implant, and pseudarthrosis. Patients who had posterior fusions had a significantly higher rate of reoperation than patients who had anterior fusions (14.0% vs. 9.3%). Reoperations due to infections and symptomatic implants occurred with significantly higher frequency in the posterior spine fusion group compared with those with anterior spinal fusion. No differences in rates of reoperation for pseudarthrosis were noted between posterior and anterior fusion groups.

CONCLUSIONS

Repeat surgical interventions are relatively common following these supposedly definitive surgical procedures. The most common reasons for return to surgery are infection, symptomatic implant, and pseudarthrosis.

Comparison of the lowest instrumented, stable, and lower end vertebrae in "single overhang" thoracic adolescent idiopathic scoliosis: anterior versus posterior spinal fusion

STUDY DESIGN

A retrospective multicenter study.

OBJECTIVE

To investigate the relationship between the lowest instrumented, stable, and lower end vertebrae in patients with "single overhang" thoracic (main thoracic) curves treated with anterior or posterior spinal fusion.

SUMMARY OF BACKGROUND DATA

Previous studies have shown "saving" fusion levels with anterior spinal fusion, as opposed to posterior spinal fusion; however, to our knowledge, none of these studies evaluated the relative position to the lower end vertebra to compare study groups accurately. For clarification, "single overhang" includes Lenke 1A and 1B curves. For these thoracic curves, the lumbar curve does not cross the midline.

MATERIALS AND METHODS

A retrospective multicenter study of adolescent idiopathic scoliosis was performed to identify specifically patients with "single overhang" thoracic (Lenke 1A and 1B) curves with more than a 2-year follow-up. To analyze relative fusion levels, the differences were computed as follows: (1) the difference between the vertebra position for the stable vertebra of the main thoracic (MT) curve and the lowest instrumented vertebra, as noted on postoperative radiographs, or [equation: see text] (2) the difference between the vertebra position for the lower end vertebra of the main thoracic (MT) curve and the lowest instrumented vertebra, as noted on postoperative radiographs, or [equation: see text].

RESULTS

A total of 298 "single overhang" thoracic curves (148 Lenke 1A, 150 Lenke 1B) were identified, of which 293 had either an anterior spinal fusion or posterior spinal fusion; 5 patients underwent a combined anterior-posterior spinal fusion. Anterior spinal fusion was performed in 70 patients (23.9%) and posterior spinal fusion in 223 (76.1%). While comparing the lowest instrumented vertebra to the stable vertebra with anterior spinal fusion, the lowest instrumented vertebra was identified either at the level of the stable vertebra or above in 97% of 1A/B curves (P < 0.001). Using posterior spinal fusion techniques, the lowest instrumented vertebra was identified either at the stable vertebra or above in 65% of the 1A/B curves (P < 0.05).

CONCLUSIONS

These data confirm that anterior spinal fusion techniques result in a mean shorter fusion of 1.5 vertebral segments/patient when compared to posterior spinal fusion techniques with respect to the position of the lowest instrumented and stable vertebrae for "single overhang" thoracic (Lenke 1A/B) curves. However, because this is a retrospective multicenter study over 10 years, it represents various posterior spinal fusion techniques that do not include all pedicle screw constructs.

Standardization of criteria for adolescent idiopathic scoliosis brace studies: SRS Committee on Bracing and Nonoperative Management

STUDY DESIGN

Literature review.

OBJECTIVE

To establish consistent parameters for future adolescent idiopathic scoliosis bracing studies so that valid and reliable comparisons can be made.

SUMMARY OF BACKGROUND DATA

Current bracing literature lacks consistency for both inclusion criteria and the definitions of brace effectiveness.

METHODS

A total of 32 brace treatment studies and the current bracing in adolescent idiopathic scoliosis proposal were analyzed to: (1) determine inclusion criteria that will best identify those patients most at risk for progression, (2) determine the most appropriate definitions for bracing effectiveness, and (3) identify additional variables that would provide valuable information.

RESULTS

Early brace studies lacked clarity in their inclusion criteria. In more recent studies, inclusion criteria have narrowed considerably to include primarily those patients most at risk for curve progression who may benefit from the use of a brace. Brace effectiveness was usually defined by various degrees of curve progression at maturity. Less frequently, it was defined by the resultant curve magnitude at maturity, whether or not surgical intervention was needed, or if there was change to another brace.

CONCLUSIONS

Optimal inclusion criteria for future adolescent idiopathic scoliosis brace studies consist of: age is 10 years or older when brace is prescribed, Risser 0-2, primary curve angles 25 degrees -40 degrees , no prior treatment, and, if female, either premenarchal or less than 1 year postmenarchal. Assessment of brace effectiveness should include: (1) the percentage of patients who have < or =5 degrees curve progression and the percentage of patients who have > or =6 degrees progression at maturity, (2) the percentage of patients with curves exceeding 45 degrees at maturity and the percentage who have had surgery recommended/undertaken, and (3) 2-year follow-up beyond maturity to determine the percentage of patients who subsequently undergo surgery. All patients, regardless of subjective reports on compliance, should be included in the results (intent to treat). Every study should provide results stratified by curve type and size grouping.

Assessment of trunk balance in thoracic scoliosis

STUDY DESIGN

A retrospective radiographic review was undertaken in patients with idiopathic thoracic scoliosis.

OBJECTIVES

To determine if a mathematical relationship exists between the 2 methods used to assess trunk balance (lateral trunk shift [LTS] and thoracic apical vertebral translation [AVT]), and to determine if one of these measurements can satisfactorily predict the value of the other.

SUMMARY OF BACKGROUND DATA

No previous reports exist, to our knowledge, comparing these 2 methods used to asess trunk balance.

METHODS

Coronal balance (CB), LTS, thoracic AVT, and curve magnitude were measured from standing preoperative posteroanterior radiographs of 91 patients with Lenke 1A/1B curves. The data were analyzed to determine if predictive relationships existed between LTS and thoracic AVT alone or between LTS and the sum of CB and thoracic AVT.

RESULTS

A statistically significant relationship was shown between LTS and the sum of thoracic AVT and CB. In general, the LTS can be estimated by taking two thirds of the sum of thoracic AVT and CB (in centimeters) and subtracting 0.8. This relationship weakened as CB improved. The relationship between LTS and AVT was not statistically significant when CB was excluded.

CONCLUSIONS

In patients with thoracic idiopathic scoliosis, if the CB and thoracic AVT values are known, then the LTS can be reliably estimated. The use of correct terminology for describing trunk balance and CB is important if valid comparisons of spinal deformity literature are desired.

Nonoperative clubfoot treatment using the French physical therapy method

Ninety-eight patients (142 clubfeet) treated nonoperatively by the French physical therapy method were reviewed to determine the effectiveness of this technique. All were 3 months old or less when treatment began and were rated for initial clubfoot severity using the Dimeglio scale (moderate, severe, very severe). Follow-up averaged 35 months (range 20-62 months). Forty-two percent of the feet needed no surgery to achieve a plantigrade position, 9% needed heelcord tenotomies, 29% needed posterior releases, and 20% needed comprehensive posteromedial releases. The Dimeglio scale was prognostic for outcomes, with moderate feet having the best results and very severe feet having the worst results. The French physical therapy method significantly reduced the need for operative intervention at the authors' institution.

Nonsurgical management of idiopathic clubfoot

Because nonsurgical management was thought not to yield adequate correction and a durable result, most children with idiopathic clubfoot have undergone surgery with extensive posteromedial and lateral release. However, surgical management caused residual deformity, stiffness, and pain in some children; thus, the favorable long-term results with the Ponseti and French methods of nonsurgical management have garnered interest. The Ponseti method consists of manipulation and casting of idiopathic clubfeet; the French method consists of physiotherapy, taping, and continuous passive motion. Careful evaluation of the techniques and results of these two approaches may increase their use and decrease or minimize the use of surgical management and thus the associated morbidity resulting from extensile releases.

Analysis of patient and parent assessment of deformity in idiopathic scoliosis using the Walter Reed Visual Assessment Scale

OBJECTIVES

This study evaluates the Walter Reed Visual Assessment Scale (WRVAS) compared with clinical parameters and written descriptions of the deformity from idiopathic scoliosis patients and their parents.

SUMMARY OF BACKGROUND DATA

The WRVAS demonstrates seven visible aspects of spinal deformity in an analogue scale. Higher scores reflect worsening deformity.

MATERIALS AND METHODS

The WRVAS was administered to 182 idiopathic scoliosis patients at four centers in conjunction with open-ended questions about patients' and their parents' perceptions of their spinal deformity. The open-ended responses were categorized as either "deformity noted" or "no deformity noted."

RESULTS

WRVAS scores strongly correlate with curve magnitude (P = 0.01) and clearly differentiates curves of 30 degrees or more from lesser curves. Among treatment groups, patients with surgery recommended had significantly higher scores than that of other patients. The instrument differentiated those noting no deformity from those noting a deformity. The correlation between patients' and parents' scores was high (Spearman's rho = 0.8). When a deformity was noted, parents gave higher scores than did their children for rib prominence, shoulder level, scapular rotation, and the total score, but not for the other dimensions.

CONCLUSIONS

Increasing scores of the WRVAS are strongly correlated with curve magnitude lending construct validity to this type of assessment tool. Patients with "surgery recommended" report more visible deformity on the scale than observed, braced, and postoperative patients, supporting the hypothesis that surgery improves the perceived appearance. Parents perceive more deformity of the ribs and shoulders more than did the patients, but other aspects of the deformity are identified equally. WRVAS scores correlate significantly with curve magnitude and treatment. Parents and patients have similar scores, but with parents perceiving more deformity of the ribs and shoulders than patients.

Comparison of reliability between the Lenke and King classification systems for adolescent idiopathic scoliosis using radiographs that were not premeasured

STUDY DESIGN

Multisurgeon comparison of two radiographic scoliosis curve classification systems was performed.

OBJECTIVE

To determine the reliability of the King and Lenke classifications systems for adolescent idiopathic scoliosis using radiographs that had not been premeasured.

SUMMARY OF BACKGROUND DATA

Recent studies introducing the new Lenke classification system for idiopathic scoliosis have reported reliability improved over that of the King classification system. This newer classification system evaluates three different parameters (curve type, lumbar modifier, and sagittal thoracic modifier) and then combines them. The reliability of both classification systems had been determined using radiographs in which all of the curves had been premeasured (recorded on the radiographs) before review by examiners. However, in a normal clinical situation, spine surgeons need to determine the Cobb angles independently, thus introducing another variable.

METHODS

On two separate occasions, four orthopedic surgeons independently evaluated preoperative radiographs (standing posteroanterior, lateral, and two supine side-bending views) of 50 patients with adolescent idiopathic scoliosis. All measurements had been removed on every radiograph before each evaluation. The results were determined by calculating the average percentage of intraobserver and interobserver agreement. Reliability was quantified using kappa statistics.

RESULTS

The King classification demonstrated good intraobserver and fair interobserver reliability. Intraobserver percentage of agreement averaged 83.5% (kappa coefficient, 0.81). Interobserver percentage of agreement averaged 68.0% (kappa coefficient, 0.61). All three parameters of the overall Lenke curve classification demonstrated fair reliability. Intraobserver percentage of agreement averaged 65.0% (kappa coefficient, 0.60). Interobserver percentage of agreement averaged 55.5% (kappa coefficient, 0.50). When the Lenke curve type was examined separately, intraobserver percentage of agreement averaged 81.5% (kappa coefficient, 0.76) and interobserver percentage of agreement averaged 71.5% (kappa coefficient, 0.64). The results for this variable (curve type) were similar to those for the King classification. For the Lenke lumbar modifier, the percentage of agreement and reliability were excellent. For the sagittal thoracic modifier, the percentage of agreement was good, but the kappa values were low because of an extreme imbalance in the grouping of hypokyphotic, normal, and hyperkyphotic spines.

CONCLUSIONS

In this study, with each investigator performing the radiographic measurements, the King classification was found to be better than had been reported recently. The Lenke classification system for adolescent idiopathic scoliosis was found to be less reliable than previously reported when the radiographs were premeasured. This was particularly true when all three parameters of this new classification system were combined. This difference in reliability of the Lenke classification between studies can be attributed to the additional variable of determining the Cobb measurements on each of the unmarked radiographs. Although this new classification system has limitations with respect to interobserver and intraobserver reliability, for planning operative treatment, it offers a more comprehensive radiographic evaluation of patients with adolescent idiopathic scoliosis than previous systems.

A comparison of single-rod instrumentation with double-rod instrumentation in adolescent idiopathic scoliosis

STUDY DESIGN

A consecutive series of patients with idiopathic scoliosis treated with single-rod instrumentation was followed prospectively. Outcomes were compared with results obtained from a retrospective review of a consecutive series of patients treated with double-rod instrumentation.

OBJECTIVE

To compare single-rod instrumentation with segmental fixation with double-rod instrumentation for the treatment of adolescent idiopathic scoliosis.

SUMMARY OF BACKGROUND DATA

Mechanical testing of single-rod instrumentation with segmental fixation at every level showed it to be as resistant to torsion as a double-rod construct. A clinical trial was initiated to document the clinical outcome in single-rod patients.

METHODS

A total of 43 of 51 consecutive patients underwent spinal fusion with a single rod. Outcome was evaluated at a minimum of 2 years after surgery. The control group comprised 103 patients who had standard double-rod instrumentation at the same institution.

RESULTS

The single- and double-rod groups were similar with respect to age, sex, curve type, length of follow-up, curve magnitude, and best bend. For King III-V curves undergoing posterior spinal fusion, there was significantly less blood loss in the single-rod group (703 mL vs 1011 mL), less cell saver collection (189 mL vs 367 mL), and less operating time (220 minutes vs 260 minutes). Blood loss and operating time were not different for patients with King I and King II curves. There were eight patients (19%) requiring reoperation because of hardware-related problems in the single-rod group compared with four (4%) in the double-rod group. There were nine patients (21%) with broken rods in the single-rod group, six of whom were symptomatic and five of whom required reoperation. Two patients required multiple operations because of pseudarthrosis in the single-rod group. There were no broken rods in the double-rod group. The single-rod group had 2 early postoperative infections and no late infections compared with 10 late infections in the double-rod group. There was a statistically significant relationship between hardware problems and fusion below L1 in the single-rod group.

CONCLUSION

Because of rod failure, single-rod instrumentation should be considered only in curves that can be instrumented to L1 and higher.

Hemodilution as a method to reduce transfusion requirements in adolescent spine fusion surgery

STUDY DESIGN

A case-control study.

OBJECTIVES

1) To determine if hemodilution adequately meets the transfusion needs in children who undergo posterior spinal fusion for idiopathic scoliosis and 2) to compare the efficacy of the various methods used to reduce the risk of allogeneic blood transfusion at the authors' institution.

SUMMARY OF BACKGROUND DATA

Methods to reduce blood loss and avoid allogeneic blood transfusion caused by extensive spinal surgery in adolescents include 1) autologous blood predonation, 2) controlled hypotensive anesthesia, 3) intraoperative salvage of shed blood (cell saver), 4) acute normovolemic hemodilution, and 5) transfusion decisions by clinical judgment rather than by a preset value of hemoglobin. Although all methods have some efficacy, it is not clear which methods, separate or combined, are best in the adolescent scoliosis population.

METHODS

Hemodilution, hypotensive anesthesia, and cell saver were used in 43 children between June 1996 and July 1997. A comparison group (43 children) underwent similar surgery with hypotensive anesthesia and cell saver, but no hemodilution (between July 1995 and December 1996). These two groups were similar with respect to means of age, levels of instrumentation, magnitude of curvature, estimated blood volume, mean arterial pressure, duration of surgery, duration of anesthesia, estimated blood loss, volume returned from cell saver, volume in the hemovac drain, and length of hospitalization. The groups differed in preoperative hemoglobin and hematocrit and in volume of crystalloid used.

RESULTS

Transfusions were given to 34 of 43 patients (79%) in the nonhemodilution group. These patients received 61 units of packed cells (57 autologous, 2 donor directed, and 2 allogeneic). In comparison, 16 of 43 patients (37%) in the hemodilution group required transfusion. They received 16 units of packed cells (15 autologous and 1 allogeneic). There was no significant difference between the groups with respect to postoperative hemoglobin and hematocrit immediately after surgery (hemodilution, 10.2/29.2; nonhemodilution, 10.0/29.1), postoperative day 1 (hemodilution, 9.2/26.9; nonhemodilution, 9.2/27.3), and postoperative day 2 (hemodilution 9.0/26.4; nonhemodilution, 9.2/27.1). There were non complications related to the technique of hemodilution in the 43 patients of this group. Cell saver was used in all patients, but sufficient volume to return blood to the patient was available in only 23 hemodilution patients (mean volume, 230 mL) and 25 nonhemodilution patients (mean volume, 215 mL). In only two patients of each group (< 5%) did the volume returned prevent the absolute need for additional transfusions.

CONCLUSIONS

Hemodilution was safely used as a method to satisfy the perioperative transfusion requirements of adolescents undergoing extensive spinal surgery. By allowing patients to arrive at surgery with a higher preoperative hemoglobin and hematocrit, and by decreasing the quantity of predonated autologous blood-collected and therefore used, the hemodilution method may indirectly decrease the quantity of postoperative autologous transfusions in this population. Cell saver was not shown to be effective, and its selective use is recommended.

Back pain in childhood and adolescence

A variety of disorders can account for back pain in the child or adolescent (Outline 1). Some of these can result in significant morbidity if not properly diagnosed and treated. Fortunately, nearly all can be correctly diagnosed by taking a thorough medical history, performing a complete physical examination, and obtaining appropriate imaging and laboratory studies. Although back pain in children and adolescents may result from overuse or minor trauma and will respond to rest and anti-inflammatories, this review should enable the orthopaedist to systematically recognize those back disorders in need of more aggressive medical intervention.