Simon P. Kelley

EOS Low-Dose Radiography: A Reliable and Accurate Upright Assessment of Lower-Limb Lengths

BACKGROUND Children with lower-limb-length discrepancy require repeated radiographic assessment for monitoring and as a guide for management. The need for accurate assessment of length and alignment is balanced by the need to minimize radiation exposure. We compared the accuracy, reliability, and radiation dose of EOS, a novel low-dose upright biplanar radiographic imaging system, at two different settings, with that of conventional radiographs (teleoroentgenograms) and computed tomography (CT) scanograms, for the assessment of limb length. METHODS A phantom limb in a standardized position was assessed ten times with each of four different imaging modalities (conventional radiographs, CT scanograms, EOS-Slow, EOS-Fast). A radiation dosimeter was placed on the phantom limb, on a portion closest to the radiation source for each modality, in order to measure skin-entrance radiation dose. Standardized measurements of bone lengths were made on each image by consultant orthopaedic surgeons and residents and then were assessed for accuracy and reliability. RESULTS The mean absolute difference from the true length of the femur was significantly lower (most accurate) for the EOS-Slow (2.6 mm; 0.5%) and EOS-Fast (3.6 mm; 0.8%) protocols as compared with CT scanograms (6.3 mm; 1.3%) (p < 0.0001), and conventional radiographs (42.2 mm; 8.8%) (p < 0.0001). There was no significant difference in accuracy between the EOS-Slow and EOS-Fast protocols (p = 0.48). The mean radiation dose was significantly lower for the EOS-Fast protocol (0.68 mrad; 95% confidence interval [CI], 0.60 to 0.75 mrad) compared with the EOS-Slow protocol (13.52 mrad; 95% CI, 13.45 to 13.60 mrad) (p < 0.0001), CT scanograms (3.74 mrad; 95% CI, 3.67 to 3.82 mrad) (p < 0.0001), and conventional radiographs (29.01 mrad; 95% CI, 28.94 to 29.09 mrad) (p < 0.0001). Intraclass correlation coefficients showed excellent (>0.90) agreement for conventional radiographs, the EOS-Slow protocol, and the EOS-Fast protocol. CONCLUSIONS Upright EOS protocols that utilize a faster speed and lower current are more accurate than CT scanograms and conventional radiographs for the assessment of length and also are associated with a significantly lower radiation exposure. In addition, the ability of this technology to obtain images while subjects are standing upright makes this the ideal modality with which to assess limb alignment in the weight-bearing position. This method has the potential to become the new standard for repeated assessment of lower-limb lengths and alignment in growing children. CLINICAL RELEVANCE This study assesses the reliability and accuracy of a diagnostic test used for clinical decision-making.

The levels of evidence in pediatric orthopaedic journals: where are we now?

Background: In recent years, it has become common to publish a level of evidence grading for orthopaedic journal publications. Our primary research question is: is there an improvement in levels of evidence of articles published in pediatric orthopaedic journals over time? In addition, what is the current status of levels of evidence in pediatric orthopaedic journals? Methods: All articles in Journal of Pediatric Orthopaedics-A (JPO-A) and Journal of Pediatric Orthopaedics-B (JPO-B) for 2001, 2002, 2007, and 2008 and those in Journal of Childrens Orthopaedics (JCO) for 2007 and 2008, were collected by an independent reviewer. Of the 1039 articles identified, animal, cadaveric and basic science studies, expert opinion and review articles were excluded. Seven hundred fifty remaining articles were blinded and randomized with respect to journal, title, publication date, author, and institution. According to the currently accepted grading system, study type and level of evidence was assigned to each article. Interobserver and intraobserver reliability were investigated. Statistical analysis was carried out using SPSS software. Results: There were no statistically significant differences in study type or levels of evidence in articles published before and after 2003. Of articles published during 2007/2008, 3.0% were graded as level I, 5.0% as level II, 24.1% as level III, and 58.0% as level IV. Analysis of the separate journals for all 4 years revealed that JPO-A published 2.6% (13 of 503) level I studies, whereas JPO-B published 4.3% (7 of 163) and JCO published 1.2% (1 of 84). The intraobserver reliability was high for study type (, 0.842) and substantial for level of evidence (, 0.613).The interobserver reliability for study type and level of evidence was high ( 0.921 and 0.860, respectively). Conclusions: Since the introduction of levels of evidence to orthopaedic journals in 2003, there has been minimal change in the quality of evidence in pediatric orthopaedic publications. We note a modest increase in level III articles and a corresponding decrease in level IV articles. Articles can be reliably graded by nonepidemiologically trained individuals. Level of Evidence: Not applicable.

Ischioplasty for Femoroischial Impingement

Hip pain with mechanical snapping is a common symptom with a wide-ranging differential diagnosis, including both extra and intra-articular etiologies. Femoroischial impingement should also be considered since many cases of recalcitrant hip pain may be misdiagnosed cases of this form of impingement. To the best of our knowledge, femoroischial impingement was first described by Johnson in 19771. He hypothesized that superior and medial migration of the lesser trochanter as a result of degenerative changes, posttraumatic changes, or surgery causes a decrease in the distance from the lesser trochanter to the ischium, thus leading to painful impingement. His report included three cases that were limited to older patients: there were two cases with a malpositioned total hip prosthesis and one case with degenerative changes prior to arthroplasty. Subsequent reports have involved only adult patients2-5. Quadratus femoris muscle tears have also been described as an unusual cause of hip pain6-8, and they have been reported in cases of femoroischial impingement3,5. They affect women much more frequently than men3,5, and they may or may not include a history of trauma or surgery9. The pain may radiate to the legs, which may be related to the proximity of the sciatic nerve4,10. Anti-inflammatory medications have been used with variable results as a first-line treatment3-5. Lesser trochanteric resection has been advocated in recalcitrant cases1,2,5. To our knowledge, we present the first documented case of primary femoroischial impingement as a cause of snapping hip syndrome in a fourteen-year-old girl. This diagnosis should be considered in the investigation of snapping hip syndrome as a readily identifiable and treatable cause of hip pain. We offer …

Levels of evidence at the Pediatric Orthopaedic Society of North America annual meetings.

Background Since 2003, levels of evidence have been used in the orthopaedic literature to inform the reader of the study quality and its relative significance. Our primary research question was to identify if, since their introduction, there has been an improvement in the levels of evidence of the scientific papers presented at Pediatric Orthopaedic Society of North America (POSNA) meetings. Methods The abstract of every paper presented orally at the POSNA annual meeting were identified for the years 2001, 2002 (pre-2003) and 2007, 2008 (post-2003). In all, 364 abstracts were identified by an independent reviewer who then excluded cadaver, animal, and basic science studies. The 307 included abstracts were then independently blinded and randomized. Two nonepidemiologically trained pediatric orthopaedic fellows independently assigned a study type and level of evidence to each abstract based on the primary research question. The first reviewer reanalyzed 50 randomly selected abstracts. Disagreement was resolved by consensus opinion with an epidemiologically trained pediatric orthopaedic surgeon. The interobserver and intraobserver reliability was calculated for the assignment of study type and levels of evidence. Changes in the study types and levels of evidence were analyzed to compare papers presented pre-2003 and post-2003. Results For study type and levels of evidence the interobserver reliability between the authors showed substantial agreement (&kgr; 0.755 and 0.647, respectively). The intraobserver reliability also showed substantial agreement (&kgr; 0.806 and 0.789, respectively). Comparing pre-2003 and post-2003 studies there were no significant differences between the types of study presented. An increase in the number of level III studies was identified. A decrease in level I and level IV studies was identified. Conclusions There has been no significant improvement in the scientific quality of studies presented at POSNA Annual Meetings as measured by levels of evidence since their introduction. We have shown substantial agreement between nonepidemiologically trained orthopaedic surgeons when categorizing abstracts using this system. Study types and levels of evidence can be difficult to assign from the current abstract format due to their brevity and structure. Level of Evidence Not applicable.

Management of hip instability in trisomy 21.

The unstable hip in Trisomy 21 presents with a spectrum of hip instability with different problems at different ages. What links this multiphase problem, in many patients, is the final common pathway of untreated instability, that of a stiff, dislocated, and often-painful hip, leading to significant functional disability. Historically, the results of treating hip instability in Trisomy 21 were variable with a notable frequency of poor results. With an improved understanding of the Trisomy 21 hip in terms of its pathoanatomy and a more contemporary surgical approach to hip reconstruction, much improved results can be expected and indeed have recently been shown. The mainstay of treatment for the habitual dislocation group presenting before 8 years of age is the femoral varus derotation osteotomy. The older group presenting with painful subluxation often show signs of secondary acetabular dysplasia and thus are best treated with redirectional acetabular osteotomy with or without the use of femoral varus derotation osteotomy. The presence of radiographic features of degenerative arthritis in the fixed dislocation group precludes the use of joint-preserving techniques for hip reconstruction, and these patients can achieve excellent results with total joint arthroplasty. The natural history, historical results, assessment, treatment, and management of complications of hip instability in Trisomy 21 are addressed in this paper.

Tibial hemimelia associated with GLI3 truncation

Tibial hemimelia is a rare, debilitating and often sporadic congenital deficiency. In syndromic cases, mutations of a Sonic hedgehog (SHH) enhancer have been identified. Here we describe an ~5 kb deletion within the SHH repressor GLI3 in two patients with bilateral tibial hemimelia. This deletion results in a truncated GLI3 protein that lacks a DNA-binding domain and cannot repress hedgehog signaling. These findings strengthen the concept that tibial hemimelia arises because of failure to restrict SHH activity to the posterior aspect of the limb bud.

A Reliable and Valid Objective Structured Assessment of Technical Skill for the Application of a Pavlik Harness Based on International Expert Consensus.

Background: The use of competency-based training is increasing in medical education as it offers individualized learning opportunities to master required skills. Inherent to this method of teaching is the need for standardized and objective assessments of skill mastery. In orthopaedic surgery, educational programs have focused on surgical skills with lesser emphasis on nonoperative techniques. Accordingly, formal evaluation tools specific to Pavlik Harness application do not exist, despite its widespread use and potential complications from inappropriate application. This study sought to develop a reliable and valid evaluation tool based on international expert consensus to standardize and evaluate Pavlik Harness application for developmental dysplasia of the hip. Methods: Consensus was sought from 10 content experts using Delphi methodology. Resulting items formed the Objective Structured Assessment of Technical Skill (OSATS). Thirty-five participants were selected into 3 a priori groups (expert, intermediate and novice) based on Pavlik Harness experience. On 2 occasions, 3 content experts assessed randomized and deidentified videotapes of each participant applying a Pavlik Harness to an infant model using the OSATS and global rating scales (GRS). The reliability and validity of the OSATS was determined with intraclass (ICC) and Pearson correlations and analysis of variance (ANOVA). Results: Consensus was obtained after 2 rounds of structured surveying and resulted in a 25-item OSATS. The reliability of the OSATS was excellent with an ICC of 0.96 for interrater and 0.98 for test-retest reliability. Construct validity was excellent with high correlations between OSATS and GRS (>0.90). In addition, the OSATS discriminated between expert, intermediate, and novice users. Conclusions: We have developed a competency-based evaluation tool for Pavlik Harness application based on consensus from international experts. The OSATS has been shown to be a reliable and valid method for assessing Pavlik Harness application that can discriminate between expert, intermediate, and novice users. Level of Evidence: Level II.

Skill Acquisition and Retention Following Simulation-Based Training in Pavlik Harness Application

Background: Simulation-based learning is increasingly prevalent in many surgical training programs, as medical education moves toward competency-based curricula. In orthopaedic surgery, developmental dysplasia of the hip is a commonly treated condition, where the standard of care for patients less than six months of age is an orthotic device such as the Pavlik harness. However, despite widespread use of the Pavlik harness and the potential complications that may arise from inappropriate application, we know of no previously described formal training curriculum for Pavlik harness application. Methods: We developed a video and model-based simulation learning module for Pavlik harness application. Two novice groups (residents and allied health professionals) were exposed to the module and, at pre-intervention, post-intervention, and retention testing, were evaluated on their ability to apply a Pavlik harness to the model. Evaluations were completed using a previously validated Objective Structured Assessment of Technical Skills (OSATS) and a global rating scale (GRS) specific to Pavlik harness application. A control group that did not undergo the module was also evaluated at two time points to determine if exposure to the Pavlik harness alone would affect skill acquisition. All groups were compared with a group of clinical experts, whose scores were used as a competency benchmark. Statistical analysis of skill acquisition and retention was conducted using t tests and analysis of variance (ANOVA). Results: Exposure to the learning module improved resident and allied health professionals’ competency in applying a Pavlik harness (p < 0.05) to the level of the expert clinicians, and this level of competency was retained one month after exposure to the module. Control subjects who were not exposed to the module did not improve, nor did they achieve competency. Conclusions: The simulation-based learning module was shown to be an effective tool for teaching the application of a Pavlik harness, and learners demonstrated retainable skills post-intervention. This learning module can form the cornerstone of formal teaching of Pavlik harness application for developmental dysplasia of the hip.

Evaluation of Brace Treatment for Infant Hip Dislocation in a Prospective Cohort: Defining the Success Rate and Variables Associated with Failure.

BACKGROUND The use of a brace has been shown to be an effective treatment for hip dislocation in infants; however, previous studies of such treatment have been single-center or retrospective. The purpose of the current study was to evaluate the success rate for brace use in the treatment of infant hip dislocation in an international, multicenter, prospective cohort, and to identify the variables associated with brace failure. METHODS All dislocations were verified with use of ultrasound or radiography prior to the initiation of treatment, and patients were followed prospectively for a minimum of 18 months. Successful treatment was defined as the use of a brace that resulted in a clinically and radiographically reduced hip, without surgical intervention. The Mann-Whitney test, chi-square analysis, and Fisher exact test were used to identify risk factors for brace failure. A multivariate logistic regression model was used to determine the probability of brace failure according to the risk factors identified. RESULTS Brace treatment was successful in 162 (79%) of the 204 dislocated hips in this series. Six variables were found to be significant risk factors for failure: developing femoral nerve palsy during brace treatment (p = 0.001), treatment with a static brace (p < 0.001), an initially irreducible hip (p < 0.001), treatment initiated after the age of 7 weeks (p = 0.005), a right hip dislocation (p = 0.006), and a Graf-IV hip (p = 0.02). Hips with no risk factors had a 3% probability of failure, whereas hips with 4 or 5 risk factors had a 100% probability of failure. CONCLUSIONS These data provide valuable information for patient families and their providers regarding the important variables that influence successful brace treatment for dislocated hips in infants. LEVEL OF EVIDENCE Prognostic Level I. See Instructions for Authors for a complete description of levels of evidence.

Intraoperative assessment of closed reduction for developmental dislocation of the hip using 3-dimensional fluoroscopy.

Background: Postoperative imaging for operatively treated developmental dislocation of the hip typically uses computed tomography or a magnetic resonance imaging (MRI). Neither imaging modality offers the ability to intervene intraoperatively. The 3-dimensional (3D) C-arm provides an attractive alternative providing immediate intraoperative feedback on the quality of a hip reduction. Our primary research question was to determine whether 3D fluoroscopy could assess hip position after closed reduction and spica casting. Secondary questions included whether reduction was maintained postoperatively when compared with postoperative MRI, and to determine the radiation dose received by the infant. Methods: We retrospectively identified 16 patients from 2010 to 2013 who underwent closed reduction and spica casting for a developmentally dislocated hip who underwent both intraoperative 3D fluoroscopy and postoperative MRI imaging. Scans were retrieved and assessed by a blinded pediatric orthopaedic fellow. Assessment of hip reduction was graded based on the modified Shenton line of the pelvis in axial plane images. Effective radiation doses between imaging modalities were compared using an anthropomorphic phantom. Results: All hips were reduced on 3D fluoroscopic images. Comparing the intraoperative 3D scans with the postoperative MRI images all 16 hips were in the same position. At 12 weeks all hips were reduced and no signs of subluxation were identified on the plain anteroposterior radiograph. 3D fluoroscopy achieved the lowest effective dose of radiation per study measuring 0.3 mSv compared with 0.5 mSv for low-dose CT and 0.48 mSv for 60 seconds of live fluoroscopy. Conclusions: Accurate assessment of the quality of hip reduction is possible in the axial plane using 3D fluoroscopy with no significant loss of reduction in the early postoperative period. When comparing the effective radiation exposure to limited-cut computed tomography protocols, 3D fluoroscopy offers a low-dose alternative that may facilitate cost savings and early discharge. Level of Evidence: Diagnostic studies—investigating a diagnostic test; study of nonconsecutive patients with consistently applied gold standard; level III.