Evidence-based Medicine in Pediatric Orthopaedics: Evidence-based Practice Committee Summary of Levels of Evidence, Clinical Practice Guidelines, Appropriate Use Criteria, and Best Practice Guidelines.

The concept of evidence-based medicine has evolved over the past 2 decades, and has become a cornerstone to clinical decision-making in virtually every aspect of medicine. With a commitment to providing its members with high-quality evidence-based guidelines, the American Academy of Orthopaedic Surgeons has instituted concerted efforts since 2006 to develop clinical practice guidelines (CPGs) and appropriate use criteria (AUCs) for certain orthopaedic conditions. Many of these CPGs and AUCs detail the management of pediatric orthopaedic conditions. By the same token, members of the Pediatric Orthopaedic Society of North America (POSNA) Evidence Based Practice Committee have been publishing succinct evaluations of randomized controlled trials in pediatric orthopaedic surgery to create an evidence-based repository for quick reference to available high-level evidence as well as resource to identify gaps in the current research and identify opportunities for future investigation. In instances where higher-level evidence needed to develop CPGs is not available to address a critically important clinical question, consensus recommendations from experts in the field have been obtained to develop best practice guidelines (BPGs). The purpose of this review is to provide readers with a deeper understanding of the key principles of evidence-based medicine and methodologies used for the development of CPGs, AUCs, and BPGs.

Relationships Between the Axial Derotation of the Lower Instrumented Vertebra and Uninstrumented Lumbar Curve Correction: Radiographic Outcome in Lenke 1 Adolescent Idiopathic Scoliosis With a Minimum 2-Year Follow-up.

BACKGROUND: Preoperative spinal parameters are used to guide the fusion levels in adolescent idiopathic scoliosis (AIS) spinal surgery. However, the impact of the factors modifiable by the surgeon in varying levels of preoperative patient-specific variables is not fully explored. The goal of this study was to identify the association between axial rotation correction of the lower instrumented vertebra (LIV) and spontaneous correction of the uninstrumented lumbar spine as a function of preoperative 3 dimensional (3D) curve characteristics in Lenke 1 AIS. METHODS: Twenty-three Lenke1 AIS with a minimum 2-year follow-up were included. All patients had biplanar spinal x-rays and 3D reconstructions at preoperative, first erect, and 2-year follow-up visits. Five patient factors were measured preoperatively: kyphosis and lumbar modifiers, and thoracic to lumbar curve rotation, translation, and frontal deformity angle ratios. One surgical factor, percentage of LIV rotation correction, was determined from the preoperative and first erect 3D models. A factorial design analysis was implemented to determine the impact of surgical and patient factors, both separately and in combination, on 2-year radiographic outcomes of spontaneous correction of the uninstrumented spine. RESULTS: Spontaneous lumbar Cobb and lumbar apical rotation correction were predicted significantly by patient and surgical factors, P<0.05. Lumbar modifier, percentage correction of LIV rotation, the interaction between LIV rotation correction and lumbar modifier, and the interaction between LIV rotation correction and thoracic to lumbar apical vertebrae translation ratio correlated significantly to 2-year outcomes of spontaneous lumbar Cobb correction, P<0.05. Lumbar modifier and the interaction between the Cobb ratio and the percentage of the LIV rotation correction correlated significantly to 2-year outcomes of lumbar apical rotation correction, P<0.05. CONCLUSION: The relationship between LIV rotation correction and spontaneous lumbar curve correction after selective thoracic fusion varied based on the patient's 3D preoperative curve characteristics. Patients with lumbar modifier C and apical vertebrae translation ratios >1.5 showed improved lumbar Cobb correction in 2-years when 50% or more LIV rotation correction was achieved surgically.

Performing a Definitive Fusion in Juvenile CP Patients is a Good Surgical Option.

BACKGROUND: In juveniles with progressive curves, there is debate regarding the use of growth friendly implants versus definitive fusion. This study presents outcomes of juvenile cerebral palsy (CP) scoliosis patients who underwent definitive fusion before age 11. METHODS: A review of a prospective, multicenter registry identified patients 10 years and younger who had a definitive posterior fusion for their CP scoliosis. Preoperative and postoperative demographic and radiographic changes were evaluated with descriptive statistics. Repeated measures analysis of variance were utilized to compare outcome scores. RESULTS: Fourteen children with a mean age of 9.7 years (8.3 to 10.8 y) and a minimum of 2 years follow-up (range 2 to 3 y) were identified. The mean preoperative curve magnitude and pelvic obliquity was 84±25 degrees (range 63 to 144 degrees) and 25±14 degrees, respectively. All patients were skeletally immature with open triradiate cartilage. Three patients had unit rods with wires while the rest incorporated pedicle screws. Immediately postoperation, the average major curve was 25±17 degrees (P≤0.001, 71% correction rate). At most recent follow-up, the average major curve increased to 30±18 degrees (P≤0.001) for a 65% correction rate. Pelvic obliquity improved to 4±4 degrees (84% correction, P≤0.001) immediately postoperation and to 6±5 degrees (P=0.002) at latest follow-up for a 76% correction rate. None of the patients required revision surgery for progression. From pre to most recent follow-up, the CPchild Health outcome scores improved from 47 to 58 (P=0.019). One patient had a deep infection, and 1 patient had a broken rod that did not require any further treatment. CONCLUSIONS: Progressive scoliosis in juvenile CP patients requires the surgeon to balance the need for further growth with the risks of progression or repeated surgical procedures. Our study demonstrates that definitive fusion once the curves approach 90 degrees results in significant radiographic and quality of life improvements, but further follow-up is needed to determine whether those results remain after skeletal maturity. LEVEL OF EVIDENCE: Level IV-therapeutic.

SRS-7: A Valid, Responsive, Linear, and Unidimensional Functional Outcome Measure for Operatively Treated Patients With AIS.

STUDY DESIGN: Comparison of the Scoliosis Research Society-22 (SRS-22) questionnaire with a 7-item Rasch-derived questionnaire (SRS-7). OBJECTIVE: To compare the construct and discriminant validity, internal consistency, responsiveness, and dimensionality of SRS-7 against SRS-22 in operatively treated children with adolescent idiopathic scoliosis. SUMMARY OF BACKGROUND DATA: SRS-22 has not been shown to possess linearity or unidimensionality (internal validity). METHODS: A multicenter database was queried for children with adolescent idiopathic scoliosis who underwent spinal fusion and answered all preoperative and 1-year postoperative SRS-22 questions. SRS-7 scores for the 685 patients were calculated from SRS-22 item responses. Traditional psychometric properties were assessed for both instruments (significance, P < 0.01). RESULTS: SRS-7 and SRS-22 scores correlated preoperatively and postoperatively (r = 0.78, P < 0.001, and r = 0.78, P < 0.001, respectively). Both instruments showed good discriminant validity in segregating 4 groups of patients with adolescent idiopathic scoliosis by curve magnitudes (F = 8.36, P < 0.001, and F = 8.38, P < 0.001, respectively). Pre- and postoperative SRS-7 and SRS-22 had internal consistency Cronbach α values of 0.64 and 0.67, and 0.85 and 0.85, respectively. With SRS-7, mean postsurgical improvement was 18.7 points (46.6-65.3, P < 0.001), with effect size measures of Cohen d = 1.57, Hedge g = 1.57, and r = 0.62. With SRS-22, mean improvement was 11.6 points (84.5-96.1, P < 0.01), with effect size measures of Cohen d = 1.25, Hedge g = 1.25, and r = 0.53. Iterative principal factor analysis of pre- and postoperative SRS-7 and SRS-22 showed the presence of 1 dominant latent factor (unidimensionality) and 4 latent factors (multidimensionality), respectively. CONCLUSION: SRS-7 shows good concurrent and discriminative validity, reasonable internal consistency, and excellent responsiveness. It has the advantages over SRS-22 of being short, unidimensional, and an interval scale. LEVEL OF EVIDENCE: 4.