Intrarater and Interrater Reliability of Radiographic Characteristics in Skeletally Immature Patients With Anterior Cruciate Ligament Tears: A PLUTO Study Group Reliability Study.

BACKGROUND: Radiographic measurements of limb alignment in skeletally immature patients with anterior cruciate ligament (ACL) tears are frequently used for surgical decision-making, preoperative planning, and postoperative monitoring of skeletal growth. However, the interrater and intrarater reliability of these radiographic characteristics in this patient population is not well documented. HYPOTHESIS: Excellent reliability across 4 raters will be demonstrated for all digital measures of length, coronal plane joint orientation angles, mechanical axis, and tibial slope in skeletally immature patients with ACL tears. STUDY DESIGN: Cohort study (diagnosis). METHODS: Three fellowship-trained orthopaedic surgeons and 1 medical student performed 2 rounds of radiographic measurements on digital imaging (lateral knee radiographs and long-leg radiographs) of skeletally immature patients with ACL tears. Intrarater and interrater reliability for continuous radiographic measurements was assessed with intraclass correlation coefficients (ICCs) across 4 raters with 95% CIs for affected and unaffected side measurements. Interrater reliability analysis used an ICC (2, 4) structure and intrarater reliability analysis used an ICC (2, 1) structure. A weighted kappa coefficient was calculated for ordinal variables along with 95% CIs for both interrater and intrarater reliability. Agreement statistic interpretations are based on scales described by Fleiss, and Cicchetti and Sparrow: <0.40, poor; 0.40 to 0.59, fair; 0.60 to 0.74, good; and >0.74, excellent. RESULTS: Radiographs from a convenience sample of 43 patients were included. Intrarater reliability was excellent for nearly all measurements and raters. Interrater reliability was also excellent for nearly all reads for all measurements. CONCLUSION: Radiographic reliability of long-leg radiographs and lateral knee x-rays in skeletally immature children with ACL tears is excellent across nearly all measures and raters and can be obtained and interpreted as reliable and reproducible means to measure limb length and alignment. LEVEL OF EVIDENCE: Level III.

Descriptive Epidemiology of a Surgical Patellofemoral Instability Population of 492 Patients.

Background: Patellofemoral instability (PFI) occurs most commonly in pediatric and adolescent patients, with evolving indications for surgery and changes in surgical techniques over the past decade. Purpose: To characterize the demographic, clinical, and radiologic characteristics of a large cohort of patients undergoing PFI surgery and investigate longitudinal trends in techniques utilized over a 10-year period at a tertiary-care academic center. Study Design: Case series; Level of evidence, 4. Methods: Electronic medical records of patients younger than 25 years of age who underwent primary surgery for lateral PFI from 2008 to 2017 at a single center by 1 of 5 different sports medicine surgeons were retrospectively reviewed. Demographic, clinical, and radiographic parameters of instability were analyzed. Routine surgical techniques included medial retinacular plication/reefing/repair (MRP), medial patellofemoral ligament reconstruction (MPFLR), tibial tubercle osteotomy (TTO), or a combination thereof, with or without lateral retinacular release (LR) or lateral retinacular lengthening (LRL). Exclusion criteria, selected for potentially altering routine surgical indications or techniques, included fixed/syndromic PFI, a formally diagnosed collagen disorder, cases in which a chondral/osteochondral shear fragment underwent fixation or was >1 cm in diameter, and body mass index >30 kg/m2. Results: Of the 492 study patients (556 knees; 71% female; median age, 15.2 years; 38% open physes), 88% were athletes, with the most common sports participated in being soccer, basketball, dance, football, gymnastics, and baseball/softball. While 91% of the cohort had recurrent dislocations, the 9% with primary dislocations were more likely to have small osteochondral fractures/loose bodies (P < .001). Female patients were younger (P = .002), with greater patellar tilt (P = .005) than male patients. Utilization of MPFLR and TTO increased significantly over the study period, while use of MRP+LR decreased. Conclusion: Most patients younger than 25 years of age who underwent PFI surgery were skeletally immature, female, and athletes and had recurrent dislocations. The <10% who had primary dislocations and underwent surgery were likely to have osteochondral fractures. Surgical techniques have changed significantly over time, with increasing use of TTO and MPFLR, while the use of MRP+LR/LRL has significantly decreased.

Asymmetrically increased femoral version with high prevalence of moderate and severe femoral anteversion in unilateral Legg-Calvé-Perthes disease.

PURPOSE: To determine and stratify femoral version in Legg-Calvé-Perthes disease (LCPD), and to compare the femoral version between the LCPD hip and the contralateral unaffected hip. METHODS: We performed a retrospective review of 45 patients with unilateral LCPD who had available CT scan through the hips and knees between January 2000 and June 2017. There were 34 (76%) male cases with a mean age of 14 years (sd 4.69). Two independent readers measured femoral version on the affected and the unaffected contralateral femur. Femoral version was classified as follows: severely decreased version (< 10°); moderately decreased (10° to 14°); normal femoral version range (15° to 20°); moderately increased (21° to 25°); and severely increased version (> 25°). RESULTS: LCPD hips had predominantly increased femoral version (38% severely increased anteversion, 24% moderately increased anteversion), while 51% of the contralateral unaffected hips had normal femoral version (p < 0.001). LCPD hips had higher mean femoral version than the contralateral, unaffected side (mean difference = 13o; 95% confidence iterval 10o to 16o; p < 0.001). As the version of the affected hip increased, so did the discrepancy between sides. No effect of sex on the LCPD femoral version was detected (p = 0.34). CONCLUSION: This study included a selected group of patients with unilateral LCPD and available CT scans obtained for surgical planning. The femoral version was asymmetric, with a high proportion of excessive anteversion observed at later stages of disease in the affected hips. Future studies will be necessary to determine the pathogenesis of increased femoral version associated with LCPD. LEVEL OF EVIDENCE: Level IV, retrospective study.

Hip Reconstruction in Nonambulatory Children With Cerebral Palsy: Identifying Risk Factors Associated With Postoperative Complications and Prolonged Length of Stay.

BACKGROUND: The purpose of this study is to examine the relationship between preoperative comorbidities, surgical complications, and length of stay (LOS) after hip reconstruction in nonambulatory children with cerebral palsy (CP). METHODS: This single-center retrospective cohort study included 127 patients undergoing hip surgery between 2007 and 2016 who were diagnosed with CP (GMFCS IV/V). The cohort was 54% Gross Motor Function Classification System (GMFCS) V with an average age at surgery of 9 years (range, 3-19 y). Preoperative comorbidities included: presence of a gastrostomy tube, respiratory difficulty requiring positive-pressure ventilation or tracheostomy, history of seizures, and nonverbal status. Complications were dichotomized into major and minor complications according to severity. Multivariable general linear modeling was used to identify factors associated with complications and prolonged LOS. RESULTS: The median LOS in the hospital was 6 days (intequartile range, 5-9 d). The majority of procedures (72%) involved both the femur and acetabulum and 82% of surgeries were performed bilaterally. Patients who experienced a major complication were mostly GMFCS level V and were more likely to spend time in intensive care unit than postanesthetic care unit (P=0.001). Multivariable analysis for a major complication determined that the addition of each comorbid risk fact increased the odds of developing a major complication by 2.6 times (odds ratio, 2.64; 95% confidence interval, 1.56-4.47; P<0.001) regardless of GMFCS level. Multivariable analysis for prolonged LOS determined that major complications (P<0.001), bilaterality (P=0.01), age (P=0.02), female sex (P=0.01), and GMFCS V (P<0.001) were all factors that increased LOS. Migration percentage, acetabular index odds ratio, and pelvic obliquity were not associated with prolonged LOS or the presence of a major complication. CONCLUSIONS: From our analysis, the authors found that a patient's premorbid comorbidities were more predictive of the likelihood of sustaining a major complication than their GMFCS level. Identifying high-risk patients preoperatively may help reduce complications and LOS, which ultimately will improve the quality of care the authors deliver to nonambulatory children with CP undergoing hip reconstruction surgery. LEVEL OF EVIDENCE: Level III-retrospective cohort study.