Two and three-dimensional computed tomography for the classification and management of distal humeral fractures. Evaluation of reliability and diagnostic accuracy

BACKGROUND: Complex fractures of the distal part of the humerus can be difficult to characterize on plain radiographs and two-dimensional computed tomography scans. We tested the hypothesis that three-dimensional reconstructions of computed tomography scans improve the reliability and accuracy of fracture characterization, classification, and treatment decisions. METHODS: Five independent observers evaluated thirty consecutive intra-articular fractures of the distal part of the humerus for the presence of five fracture characteristics: a fracture line in the coronal plane; articular comminution; metaphyseal comminution; the presence of separate, entirely articular fragments; and impaction of the articular surface. Fractures were also classified according to the AO/ASIF Comprehensive Classification of Fractures and the classification system of Mehne and Matta. Two rounds of evaluation were performed and then compared. Initially, a combination of plain radiographs and two-dimensional computed tomography scans (2D) were evaluated, and then, two weeks later, a combination of radiographs, two-dimensional computed tomography scans, and three-dimensional reconstructions of computed tomography scans (3D) were assessed. RESULTS: Three-dimensional computed tomography improved both the intraobserver and the interobserver reliability of the AO classification system and the Mehne and Matta classification system. Three-dimensional computed tomography reconstructions also improved the intraobserver agreement for all fracture characteristics, from moderate (average kappa [kappa2D] = 0.554) to substantial agreement (kappa3D = 0.793). The addition of three-dimensional images had limited influence on the interobserver reliability and diagnostic characteristics (sensitivity, specificity, and accuracy) for the recognition of specific fracture characteristics. Three-dimensional computed tomography images improved intraobserver agreement (kappa2D = 0.62 compared with kappa3D = 0.75) but not interobserver agreement (kappa2D = 0.24 compared with kappa3D = 0.28) for treatment decisions. CONCLUSIONS: Three-dimensional reconstructions improve the reliability, but not the accuracy, of fracture classification and characterization. The influence of three-dimensional computed tomography was much more notable for intraobserver comparisons than for interobserver comparisons, suggesting that different observers see different things in the scans-most likely a reflection of the training, knowledge, and experience of the observer with regard to these relatively uncommon and complex injuries.     

Two-year fusion and clinical outcomes in 224 patients treated with a single-level instrumented posterolateral fusion with iliac crest bone graft

Background contextReported fusion rates for spine fusions using iliac crest bone graft (ICBG) vary between 40% and 100% because of different fusion techniques, patient comorbidity, diagnosis and assessment criteria.PurposeWe report two-year results of single-level instrumented posterolateral fusions evaluated with radiographs, fine-cut computed tomography (CT) scans with reconstructions and outcome measures.Study design/ settingRetrospective analysis of data from a prospective multicenter randomized clinical controlled trial.Patient samplePatients with various degenerative diagnoses enrolled in the control arm of a Food and Drug Administration (FDA)-regulated, multicenter trial of single-level decompression and posterolateral fusion for degenerative lumbar disease.Outcome measuresShort Form-36 (SF-36), Oswestry Disability Index (ODI), Numeric Rating Scales (0–20) for back, leg, and graft site pain, CT scans, anteroposterior and lateral flexion/extension radiographs.MethodsPatients enrolled in an FDA-regulated, multicenter trial at 29 sites with degenerative lumbar disease treated with single-level instrumented posterolateral fusion with ICBG were included in the analysis. Demographic and surgical data were collected. Clinical outcomes were followed using standard metrics. Fusion was assessed by independent radiologists at 6, 12, and 24 months postoperatively. Two fusion criteria were compared: anteroposterior and flexion/extension radiographs to assess motion and bridging bone, with CT scans as needed to confirm bridging bone; and CT scan assessment for bridging bone only.ResultsOne hundred ninety-four of 224 subjects (86.6%) completed the study. The mean operative time was 2.9 hours with a blood loss of 448.6 mL. The average graft volume was 36.3 mL. There were 21 (9.4%) wound infections, 18 (8.0%) incidental durotomies, 3 (1.3%) implant displacements, 2 (0.9%) malpositioned implants, and 17 (7.6%) graft-related complications. Twenty-seven patients (13.9%) required reoperation, the majority for nonunions. Fusion rates based on radiographs with selective CTs at 6, 12, and 24 months were 65.3%, 82.5%, and 89.3%, respectively. Fusion rates based on bridging bone on CT scans were 56.1%, 71.5%, 83.9%, respectively. Two-year improvement for all outcome measures was significant (p<.001)—ODI 25.3, SF-36 Physical Component Score (PCS) 12.2, back pain 7.9, and leg pain 7.1. Two years postoperatively, 60% of patients complained of graft site pain (mean pain score=8.5).ConclusionIn a large series of patients who had primary single-level instrumented posterolateral fusion with ICBG, evidence of bridging bone on fine-cut CT scans improved with time to 83.9% at 24 months. Significant improvement from baseline was noted in all clinical outcome measures at all time intervals with 75% achieving minimum clinically important difference (MCID) for ODI and 66% achieving MCID for SF-36 PCS.     

Reliability and accuracy of fine-cut computed tomography scans to determine the status of anterior interbody fusions with metallic cages

BACKGROUND CONTEXT: Computed tomography (CT) scan has been shown to be more accurate than radiographs in evaluating anterior interbody fusion but may still over-read the extent of fusion. PURPOSE: To assess the reliability and accuracy of fine-cut CT scans with reconstructions in evaluating anterior lumbar interbody fusion (ALIF) with metallic cages using surgical exploration as the reference standard. STUDY DESIGN: Accuracy of a diagnostic test referenced to the gold standard. PATIENT SAMPLE: A total of 49 patients and 69 surgical levels. OUTCOME MEASURES: Evaluation of fine-cut CT scans for evidence of fusion with subsequent surgical exploration as the reference standard. METHODS: Forty-nine patients who underwent ALIF with metallic cages over 69 levels, who had a fine-cut CT scan before revision were included. Five spine surgeons unaware of the findings on surgical exploration evaluated pre-revision CT scans, classified these as fused or not; and determined the presence of a "sentinel sign" and a "posterior sentinel sign." Kappa coefficients for interobserver reliability, sensitivity, and specificity to detect fusion were determined. RESULTS: There were 26 males and 23 females with a mean age of 43 years. There were 27 smokers. Average time from index to revision surgery was 22 months. Interobserver kappa for classification as fused or not was 0.25 with 70% to 97% sensitivity and 28% to 85% specificity. The interobserver kappa for the sentinel sign was 0.34 with 13% to 33% sensitivity and 77% to 92% specificity. The interobserver kappa for the posterior sentinel sign was 0.23 with 33% to 87% sensitivity and 56% to 90% specificity. CONCLUSIONS: Raters generally overstated fusion with low specificities across raters and low consensus specificity. Overall accuracy of the posterior sentinel sign (74%) was higher than the sentinel sign (61%). The low kappa value indicates fair reliability. In patients with metallic interbody devices, surgeons should be cautious about interpreting the findings on fine-cut CT scans whether using a general assessment of the fusion, the sentinel sign, or the posterior sentinel sign.     

Interobserver and intraobserver reliability of two classification systems for intra-articular calcaneal fractures

BACKGROUND: For a fracture classification to be useful it must provide prognostic significance, interobserver reliability, and intraobserver reproducibility. Most studies have found reliability and reproducibility to be poor for fracture classification schemes. The purpose of this study was to evaluate the interobserver and intraobserver reliability of the Sanders and Crosby-Fitzgibbons classification systems, two commonly used methods for classifying intra-articular calcaneal fractures. METHODS: Twenty-five CT scans of intra-articular calcaneal fractures occurring at one trauma center were reviewed. The CT images were presented to eight observers (two orthopaedic surgery chief residents, two foot and ankle fellows, two fellowship-trained orthopaedic trauma surgeons, and two fellowship-trained foot and ankle surgeons) on two separate occasions 8 weeks apart. On each viewing, observers were asked to classify the fractures according to both the Sanders and Crosby-Fitzgibbons systems. Interobserver reliability and intraobserver reproducibility were assessed with computer-generated kappa statistics (SAS software; SAS Institute Inc., Cary, North Carolina). RESULTS: Total unanimity (eight of eight observers assigned the same fracture classification) was achieved only 24% (six of 25) of the time with the Sanders system and 36% (nine of 25) of the time with the Crosby-Fitzgibbons scheme. Interobserver reliability for the Sanders classification method reached a moderate (kappa = 0.48, 0.50) level of agreement, when the subclasses were included. The agreement level increased but remained in the moderate (kappa = 0.55, 0.55) range when the subclasses were excluded. Interobserver agreement reached a substantial (kappa = 0.63, 0.63) level with the Crosby-Fitzgibbons system. Intraobserver reproducibility was better for both schemes. The Sanders system with subclasses included reached moderate (kappa = 0.57) agreement, while ignoring the subclasses brought agreement into the substantial (kappa = 0.77) range. The overall intraobserver agreement was substantial (kappa = 0.74) for the Crosby-Fitzgibbons system. CONCLUSIONS: Although intraobserver kappa values reached substantial levels and the Crosby-Fitzgibbons system generally showed greater agreement, we were unable to demonstrate excellent interobserver or intraobserver reliability with either classification scheme. While a system with perfect agreement would be impossible, our results indicate that these classifications lack the reproducibility to be considered ideal.     

Interobserver and intraobserver agreement of radiograph interpretation with and without pedicle screw implants: the need for a detailed classification system in posterolateral spinal fusion

STUDY DESIGN: A prospective randomized clinical study in which four observers evaluated radiographs of posterolateral fusion masses. OBJECTIVES: To evaluate the accuracy of radiograph interpretation of the posterolateral spinal fusion mass when using a detailed classification system and to analyze the influence of metallic internal fixation devices on radiologic inaccuracy. SUMMARY OF BACKGROUND DATA: In general, the literature describing the classification criteria used for radiograph interpretation of spinal posterolateral fusion has serious deficiencies. There is a need for a detailed classification system. METHODS: Seventy patients were randomly allocated to receive no instrumentation (n = 36) or Cotrel-Dubousset instrumentation (n = 34) in posterolateral lumbar fusion. All four observers participated in a prestudy discussion and evaluated the radiographs (anteroposterior, lateral) taken at the 1-year follow-up evaluation. The observers scored the radiographs twice (30 days apart). Each level on each side was judged separately. A continuous intertransverse bony bridge involving at minimum one of the two sides indicated a fusion at that level. "Fusion" indicated this quality of fusion at all intended levels. If the fusion was doubtful on both sides of the interspace, the individual case could not be classified as "fused." RESULTS: The mean interobserver agreement was 86% (Kappa 0.53), and the mean intraobserver agreement was 93% (Kappa 0.78). No difference in interobserver and intraobserver agreement was found between patients with and without supplementary pedicle screw fixation. All mean Kappa values were classified as fair or good. The four observers identified a mean fusion rate of 81%. CONCLUSION: It is extremely difficult to interpret radiographic lumbar posterolateral fusion success. Such an assessment needs to be performed by use of a detailed radiographic classification system. The classification system presented here revealed good interobserver and intraobserver agreement, both with and without instrumentation. The classification showed acceptable reliability and may be one way to improve interstudy and intrastudy correlation of radiologic outcomes after posterolateral spinal fusion. Instrumentation did not influence reproducibility but may result in slightly underestimated fusion rates.     

Interobserver agreement in fusion status assessment after instrumental desis of the lower lumbar spine using 64-slice multidetector computed tomography: impact of observer experience

Purpose

Persistent lower back pain after instrumental posterolateral desis may arise from incomplete fusion. We investigate the impact of experience on interobserver agreement in fusion estimation.

Methods

Four independent observers, two residents and two musculoskeletal radiologists, reviewed dedicated lumbar 64-MDCT scans and scored vertebral levels 1–5 after Glassman’s grades, 1: solid bilateral fusion, 2: solid unilateral fusion, 3: partial bilateral fusion, 4: partial unilateral fusion, 5: non-fusion. We investigated two simplifying dichotomizations, solid bilateral fusion (Glassman 1) versus all others and uni- or bilateral fusion (Glassman 1–2) versus partial or non-fusion.

Results

Thirty-six patients with 61 operated lumbar levels were included. Interobserver agreement rates for four observers using Glassman’s system were fair (kappa 0.32), either dichotomization showed moderate agreement (kappa 0.53 and 0.59). Observer pairs had comparable prevalence adjusted interobserver agreement rates (residents: PABAK 0.67 and 0.54; consultants: PABAK 0.57 and 0.71).

Conclusions

Difference in observer experience seems of minor impact.     

Classification of intertrochanteric fractures with computed tomography: a study of intraobserver and interobserver variability and prognostic value

The purpose of this prospective study was to determine the level of interobserver and intraobserver agreement among orthopedic surgeons and radiologists when computed tomography (CT) scans are used with plain radiographs to evaluate intertrochanteric fractures. In addition, the prognostic value of current classifications systems concerning quality of life was evaluated. Sixty-one patients who presented with intertrochanteric fractures received open reduction and internal fixation with compression hip screw. Three orthopedic surgeons and 2 radiologists independently classified the fractures according to 2 systems: Evans-Jensen and AO (Arbeitsgemeinschaft für Osteo-synthesefragen). Fractures were initially graded with plain radiographs and then again in conjunction with CT. Results were analyzed using the (kappa) kappa coefficient. The 36-item Short-Form Health Survey was administered at baseline, 3 months, and 1 year, and results were correlated with fracture grade. Mean kappa coefficients when comparing radiography alone with radiography and CT scan were 0.63 for the AO system and 0.59 for the Evans-Jensen system. Both represent "fair" agreements. Mean overall interobserver kappa coefficients were 0.67 for radiologists and 0.57 for orthopedic surgeons. Radiologists also had higher intraobserver kappa coefficients. No significant relationships were found between follow-up Short Form Health Survey results and intraoperative grading of fractures. When these classification schemes are compared, interobserver agreement does not appear to change dramatically when information from CT scans is added. This may suggest that (1) more data have been provided by CT with greater possibilities for misinterpretation and (2) these classification schemes may not be comprehensive in describing fracture pattern and displacement. Finally, both systems failed to provide any prognostic value.     

Posterolateral lumbar spine fusion with INFUSE bone graft.

BACKGROUND CONTEXT: INFUSE has been proven effective in conjunction with threaded cages and bone dowels for single-level anterior lumbar interbody fusion (ALIF). The published experience with posterolateral fusion, although encouraging, utilizes a significantly higher dose and concentration of recombinant human bone morphogenic protein-2 (rhBMP-2) and a different carrier than the commercially available INFUSE. PURPOSE: To present an assessment of fusion rate for posterolateral spine fusion with INFUSE Bone Graft. STUDY DESIGN/SETTING: Retrospective review of patients treated using INFUSE in posterolateral spine fusion in a single institution. PATIENT SAMPLE: 91 patients with minimum 2-year follow-up who underwent posterolateral spine fusion using INFUSE as an iliac crest bone graft (ICBG) substitute. OUTCOME MEASURES: Fusion rate based on fine-cut computed tomographic (CT) scans with sagittal and coronal reconstructions. METHODS: Fusion was performed using one large INFUSE kit (12 mg rhBMP-2, 1.5 mg/mL), which was prepared according to the manufacturer's instructions. The INFUSE sponge was wrapped around the local bone or graft extender and placed over the decorticated surfaces in the lateral gutters. Postoperative CT scans with reconstructions were reviewed by two independent orthopedic spine surgeons. CT scans of a comparison group of 35 patients who underwent primary single-level posterolateral fusion with ICBG were also reviewed. RESULTS: The overall group had a mean 4.38 CT fusion grade and a 6.6% nonunion rate. Primary one-level fusion cases (n=48) had a mean 4.42 fusion grade a 4.2% nonunion rate. Primary multilevel fusions (n=27) had a mean 4.65 CT grade and no nonunions detected. Assessment of the 35 primary one-level ICBG control cases demonstrated a mean CT grade of 4.35 and a nonunion rate of 11.4%. In the 16 cases of revision for prior nonunion, mean CT grade was 3.81 and 4 subjects had nonunions. Additional subgroup analysis showed that smokers (n=14) had a mean 4.32 CT grade with no nonunions. Men had a mean 4.04 CT grade and an 11.1% nonunion rate compared with a mean 4.61 CT grade and 3.6% nonunion rate in women. This difference was statistically significant (p=.036). No significant differences in fusion rate were observed based upon the specific graft extender used (p=.200). CONCLUSIONS: Posterolateral spine fusion involves a more difficult healing environment with a limited surface for healing, a gap between transverse processes and the milieu of distractive forces. Historically, only ICBG has been able to overcome these challenges and reliably generate a successful posterolateral lumbar spine fusion. In contrast to prior studies, clinically available INFUSE delivers only 12 mg rhBMP-2 at a concentration of 1.5 mg/mL. Despite the lower dose and concentration of rhBMP-2, this study suggests that fusion success with INFUSE is equivalent to ICBG for posterolateral spine fusion. As with ICBG, development of solid fusion or nonunion is a multifactorial process. The use of INFUSE is not a substitute for proper surgical technique or optimization of patient-related risk factors. Additional studies are needed to determine the incremental benefit of a greater rhBMP-2 dose or use of alternative carriers for posterolateral fusion. Finally, correlation between radiographic findings and clinical outcomes, and a cost-benefit analysis are needed. Despite these issues, this study presents compelling evidence that commercially available INFUSE is an effective ICBG substitute for one- and two-level posterolateral instrumented spine fusion.     

Assessment of two thoracolumbar fracture classification systems as used by multiple surgeons

BACKGROUND: The reproducibility and repeatability of modern systems for classification of thoracolumbar injuries have not been sufficiently studied. We assessed the interobserver and intraobserver reproducibility of the AO (Arbeitsgemeinschaft für Osteosynthesefragen) classification and compared it with that of the Denis classification. Our purpose was to determine whether the newer, AO system had better reproducibility than the older, Denis classification. METHODS: Anteroposterior and lateral radiographs and computerized tomography scans (axial images and sagittal reconstructions) of thirty-one acute traumatic fractures of the thoracolumbar spine were presented to nineteen observers, all trained spine surgeons, who classified the fractures according to both the AO and the Denis classification systems. Three months later, the images of the thirty-one fractures were scrambled into a different order, and the observers repeated the classification. The Cohen kappa (kappa) test was used to determine interobserver and intraobserver agreement, which was measured with regard to the three basic classifications in the AO system (types A, B, and C) as well as the nine subtypes of that system. We also measured the agreement with regard to the four basic types in the Denis classification (compression, burst, seat-belt, and fracture-dislocation) and with regard to the sixteen subtypes of that system. RESULTS: The AO classification was fairly reproducible, with an average kappa of 0.475 (range, 0.389 to 0.598) for the agreement regarding the assignment of the three types and an average kappa of 0.537 for the agreement regarding the nine subtypes. The average kappa for the agreement regarding the assignment of the four Denis fracture types was 0.606 (range, 0.395 to 0.702), and it was 0.173 for agreement regarding the sixteen subtypes. The intraobserver agreement (repeatability) was 82% and 79% for the AO and Denis types, respectively, and 67% and 56%, for the AO and Denis subtypes, respectively. CONCLUSIONS: Both the Denis and the AO system for the classification of spine fractures had only moderate reliability and repeatability. The tendency for well-trained spine surgeons to classify the same fracture differently on repeat testing is a matter of some concern.     

CT-Based Classification Systems for Intra-Articular Calcaneal Fractures: The Inter- and Intraobserver Variations as well as Integrality

The aim of this study was to measure the inter- and intraobserver variations as well as integrality of the Zwipp, Crosby-Fitzgibbons, Sanders, and Eastwood-Atkins classification systems based on more accurate CT scans. Five hundred and forty-nine patients with intra-articular calcaneal fractures from January 2018 to December 2019 taken from a database in our level-I trauma center (3 affiliated hospitals) were included. For each case, normative CT (1 mm slices) scans were available. Four different observers reviewed all CT scans 2 times according to these 4 most prevalent fracture classification systems (FCSs) within a 2-month interval. For these 4 FCSs, the kappa [κ] coefficient was used to evaluate interobserver reliability and intraobserver reproducibility, and the percentage that can be classified was used to indicate integrality. The κ values were measured for Zwipp (κ = 0.38 interobserver, κ = 0.61 intraobserver), Crosby-Fitzgibbons (κ = 0.48 interobserver, κ = 0.79 intraobserver), Sanders (κ = 0.40 interobserver, κ = 0.57 intraobserver), and Eastwood-Atkins (κ = 0.44 interobserver, κ = 0.72 intraobserver). Furthermore, the integralities were calculated for Zwipp (100%), Crosby-Fitzgibbons (100%), Sanders (92%) as well as Eastwood-Atkins (89.6%). Compared with previous literatures, CT scanning with higher accuracy can significantly improve intraobserver reproducibility of Zwipp and Eastwood-Atkins FCSs, but it has no positive effect on variability of Sanders FCS and interobserver reliability of Crosby-Fitzgibbons FCS. In terms of integrality, Zwipp and Crosby-Fitzgibbons FCSs appear to be superior to the other 2 FCSs.     

Rapid prototyping in the assessment, classification and preoperative planning of acetabular fractures

AIM: To evaluate the use of rapid prototyping in the assessment, classification and preoperative planning of acetabular fractures. INTRODUCTION: The complex three-dimensional anatomy of the pelvis and acetabulum make assessment, classification and treatment of fractures of these structures notoriously difficult. Conventional imaging only provides two-dimensional images of these fractures. While interpretation of traditional imaging techniques becomes better with experience, novel techniques may assist in the understanding of these complex injuries. METHODS: Twenty patients with acetabular fractures were studied. Life size three-dimensional models were manufactured from standardised CT scans, using the rapid prototyping process, selective laser sintering. Each model was presented to the operating surgeon prior to surgery. The surgeons found that the models greatly assisted in their understanding of the personality of the fracture. Three consultant orthopaedic surgeons and three senior trainees were asked to classify each fracture using conventional radiographs (AP pelvis, Judet views and CT scans) and then using the model. The kappa statistic was used to evaluate inter- and intraobserver agreement. RESULTS: Interobserver agreement was not absolute using either conventional radiographs or the models. For the consultants the kappa statistic using conventional radiographs was 0.61 while the kappa value using the model was 0.76 (p<0.05). For the trainees the kappa value was 0.42, using conventional radiographs and 0.71 using the model (p<0.01). CONCLUSION: Full sized models of acetabular fractures greatly assisted surgeons understand the personality of complex fractures prior to surgery and have been shown in this study to significantly reduced the degree of interobserver variability in fracture classification. This effect is particularly evident for less experienced surgeons. This technique is available and relatively inexpensive. The use of these models should prove invaluable as a tool to aid clinical practice.     

Computed tomographic scanning of cervical spine fractures: does it influence treatment?

OBJECTIVE: To determine whether the superior sensitivity of computed tomography (CT) results in changes in treatment plans for cervical spine fractures that have been diagnosed on plain films alone. DESIGN: Retrospective review of radiographic studies for cervical spine trauma. SETTING/PARTICIPANTS: An orthopaedic spine surgeon (SS), an orthopaedic traumatologist (OT), an orthopaedic spine fellow (SF), and an orthopaedic chief resident (CR) were independently presented thirty-nine cases of cervical spine trauma imaged with adequate plain radiographs and with CT. MAIN OUTCOME MEASURES: Agreement was measured by calculation of kappa coefficients. RESULTS: The detection rate of total fractures on plain radiographs alone ranged from 47 percent to 71 percent, and the diagnosis changed an average 53 percent of cases. Change in treatment plans ranged from 10 percent (SS) to 46 percent (CR) of cases. Of these changes, undertreatment occurred as follows: SS =3 percent, OT =8 percent, SF =36 percent, and CR = 46 percent. The mean kappa coefficient for intraobserver agreement of treatment plans was 0.69. The experienced observers demonstrated "excellent" agreement with an average kappa coefficient of 0.85, whereas the mean coefficient for inexperienced observers was 0.54 or "moderate" agreement. Complete diagnostic agreement occurred between the experienced observers after review of both the plain films and CT scans. The interobserver agreement of treatment plans for the experienced observers increased from 0.79 to 0.88. CONCLUSIONS: CT scanning afforded additional information for all observers. Experienced observers can reliably determine treatment plans for cervical spine trauma diagnosed on plain films alone, whereas inexperienced observers are less reliable. For the experienced observers, interobserver agreement on treatment plans increased after the addition of CT.     

Impact of MRI on treatment plan and fracture classification of tibial plateau fractures

OBJECTIVE: To evaluate the interobserver agreement for both treatment plan and fracture classification of tibial plateau fractures using plain radiographs, computed tomography (CT) scan, and magnetic resonance imaging (MRI). DESIGN: Prospective study to assess the impact of an advanced radiographic study on the agreement of treatment plan and fracture classification of tibial plateau fractures among three orthopaedic surgeons. SETTING/PARTICIPANTS: Patients presenting with tibial plateau fractures to a level I trauma center were evaluated with plain knee radiographs (anteroposterior, lateral, two oblique views), CT scan, and MRI. Three experienced attending orthopaedic trauma surgeons were randomly presented three sets of studies for each injury: radiographs alone, radiographs with CT, and radiographs with MRI (including soft tissue injuries documented by an experienced MRI radiologist). The surgeons were asked to render fracture classification and treatment plan based upon the blind reading of each individual radiographic set. MAIN OUTCOME MEASURES: Agreement among the three surgeons was measured using kappa coefficients. RESULTS: For fracture classification, radiographs alone yielded a mean kappa coefficient of 0.68, which increased to 0.73 for radiographs with CT scan and 0.85 for radiographs with MRI. Fracture classification (Schatzker) was changed an average of 6% with the addition of the CT scan and 21% based on radiographs with MRI. For the fracture management plan, the mean interobserver kappa coefficient for radiographs alone was 0.72, which increased to 0.77 for radiographs with CT scan and 0.86 for radiographs with MRI. MRI changed treatment plan in 23% of the cases. CONCLUSION: Magnetic resonance imaging increases the interobserver agreement on fracture classification and operative management of tibial plateau fractures.     

An independent inter- and intraobserver agreement assessment of the AOSpine sacral fracture classification system

BACKGROUND CONTEXTThe AOSpine sacral classification scheme was recently described. It demonstrated substantial interobserver and excellent intraobserver agreement in the study describing it; however, an independent assessment has not been performed.PURPOSETo perform an independent inter- and intraobserver agreement evaluation of the AOSpine sacral fracture classification system.STUDY DESIGNAgreement study.METHODSComplete computerized tomography (CT) scans, including axial images, with coronal and sagittal reconstructions of 80 patients with sacral fractures were selected and classified using the morphologic grading of the AOSpine sacral classification system by six evaluators (from three different countries). Neurological modifiers and case-specific modifiers were not assessed. After a four-week interval, the 80 cases were presented to the same raters in a random sequence for repeat assessment. We used the Kappa coefficient (κ) to establish the inter- and intraobserver agreement.RESULTSThe interobserver agreement was substantial when considering the fracture severity types (A, B, or C), with κ=0.68 (0.63–0.72), but moderate when considering the subtypes: κ=0.52 (0.49–0.54). The intraobserver agreement was substantial considering the fracture types, with κ=0.69 (0.63–0.75), and considering subtypes, κ=0.61 (0.56–0.67).CONCLUSIONThe sacral classification system allows adequate interobserver agreement at the type level, but only moderate at the subtypes level. Future prospective studies should evaluate whether this classification system allows surgeons to decide the best treatment and to establish prognosis in patients with sacral fractures.     

Avascular necrosis of the femoral head: inter- and intraobserver variations of Ficat and ARCO classifications

Diagnosis of avascular necrosis (AVN) of the femoral head depends on the combination of clinical symptoms and evaluation of radiographs and/or magnetic resonance imaging (MRI). To evaluate the evolution of AVN, the Ficat and the Association Research Circulation Osseous (ARCO) classification are commonly used to assess both imaging modalities. For comparison reasons, these classifications need to be reliable and reproducible to provide sufficient therapy options for the patient. Therefore, the aim of our study was to evaluate the interobserver reliability and the intraobserver reproducibility of these classifications. Patients with suspected AVN were examined using either radiographs or radiographs and MRI. The radiographs and/or MR images were reviewed initially and at 3 months by two general orthopaedic surgeons, two orthopaedic residents, and two general radiologists using the Ficat classification for radiographs and MR images as well as the ARCO classification for MR images only. In all, 38 patients (54 hips) were enrolled. There were 10 patients who presented with radiographs and 28 patients with radiographs and MR scans. Paired comparisons revealed a mean interobserver kappa reliability coefficient of 0.39 for the first and of 0.32 for the second review using the Ficat classification for radiographs, whereas for the MR images a mean of 0.39 in the first and of 0.34 in the second reading resulted. The MRI evaluation using the ARCO classification resulted in a mean interobserver reliability coefficient of 0.37 in the first and of 0.31 in the second reading. The mean kappa value for intraobserver reproducibility using the Ficat classification was 0.52 for radiographs and 0.50 for MR images, whereas a reproducibility of 0.43 resulted for the ARCO classification. This study showed poor interobserver reliability and fair intraobserver variability, diminishing any meaningful comparison of studies using the Ficat as well as the ARCO classification. Thus, the Ficat and ARCO staging systems are still not sufficient to reliably assess the status of AVN alone.     

Computed tomography scanning of intra-articular distal radius fractures: does it influence treatment?

The purpose of this study is to determine whether the addition of computed tomography (CT) results in changes in the evaluation and treatment of intra-articular distal radius fractures. Fifteen intra-articular distal radius fractures were evaluated independently by 4 hand surgeons. Plain x-rays were reviewed initially followed by the corresponding CT scans for comparison of articular step-off and gapping, comminution, and treatment. Kappa coefficients (kappa) of intraobserver and interobserver reliability for treatment plans were generated. Computed tomography scans improved the sensitivity of measurement of articular surface gapping, improved the accuracy of detection of comminution and distal radioulnar joint involvement, and altered proposed treatment plans within observers (intraobserver agreement: kappa =.54, moderate) and improved agreement of proposed treatment plans between observers (kappa =.34 to kappa =.44, fair to moderate). Computed tomography scanning influenced observers to change treatment plans and resulted in increased interobserver reliability in the proposed management of these injuries.     

Circumferential and posterolateral fusion for lumbar disc disease

Clinical outcome of low back fusion is unpredictable. There are various reports discussing the merits and clinical outcome of these two procedures. The patients were selected from a population of patients who had chronic low back pain unresponsive to conservative treatment. Thirty-six instrumented posterolateral fusions and 35 instrumented circumferential fusions with posterior lumbar interbody fusions were done simultaneously. Preoperative radiographic assessment included plain radiographs, magnetic resonance imaging scans, and provocative discography in all the patients. Posterolateral fusion or anterior lumbar interbody fusion was done for internal disc disruption. The Oswestry disability index, subjective scoring, and assessment of fusion were done at a minimum followup of 2 years. On subjective scoring assessment there was a satisfactory outcome of 63.9% (23 patients) in the posterolateral fusion group and 82.8% (29 patients) in the posterior lumbar interbody fusion group. On assessment by the Oswestry index no difference was found in outcome between the two groups. The posterolateral fusion group had a 63.9% satisfactory outcome and the posterior lumbar interbody fusion group had an 80% satisfactory outcome using the Oswestry disability index for postoperative assessment. There was 61.1% improvement in working ability in the posterolateral fusion group and 77.1% improvement in the posterior lumbar interbody fusion group which was not statistically significant. The authors consider instrumented circumferential fusion with posterior lumbar interbody fusion better than instrumented posterolateral fusion for managing chronic disabling low back pain.     

Legg-Calve-Perthes disease. Part I: Classification of radiographs with use of the modified lateral pillar and Stulberg classifications

BACKGROUND: Accurate and reliable radiographic classifications of the relative severity and outcome of Legg-Calve-Perthes disease are essential in the study of that disease. As part of a prospective multicenter study, we sought to define more clearly the lateral pillar classification of severity and the Stulberg classification of outcome; we sought especially to define the borderlines between classification groups. METHODS: We performed interobserver and intraobserver trials of the lateral pillar and Stulberg classifications using sets of twenty radiographs chosen from a prospective study of 345 hips. To establish reliable definitions of the lateral pillar classification, we added a new, intermediate group termed the B/C border group, which includes femoral heads with a thin or poorly ossified lateral pillar and those with a loss of exactly 50% of the original height of the lateral pillar. The resulting classification consists of four groups: A, B, B/C border, and C. In our application of the classification system of Stulberg et al., we defined a class-II femoral head as round and fitting within 2 mm of a circle on both anteroposterior and frog-leg lateral radiographs. We defined a Stulberg class-III femoral head as out of round by more than 2 mm on either view and a Stulberg class-IV femoral head as one with at least 1 cm of flattening of the weight-bearing articular surface. To assess interobserver and intraobserver agreement, we performed two trials of each classification with six orthopaedic surgeons reviewing twenty radiographs or pairs of radiographs. RESULTS: In the first trial of the lateral pillar classification, there was 81% agreement per radiograph and the average weighted kappa was 0.71. In the second trial, there was 85% agreement per radiograph and the weighted kappa averaged 0.79. Intraobserver reliability testing showed a 77% match between Trials 1 and 2, an average weighted kappa of 0.81, and an average generalizability coefficient of 0.91. In Trial 1 of the Stulberg classification, there was 91% agreement per radiograph and an average weighted kappa of 0.82. In Trial 2, there was 92% agreement per radiograph and an average weighted kappa of 0.82. Intraobserver reliability testing showed an 89% match between Trials 1 and 2, an average weighted kappa value of 0.88, and an average generalizability coefficient of 0.92. CONCLUSIONS: The interobserver and intraobserver trials of these classifications produced kappa values and generalizability coefficients in the excellent range. The modified lateral pillar classification and the redefined Stulberg classification are sufficiently reliable and accurate for use in studies of Legg-Calve-Perthes disease.     

Classification of osteonecrosis of the femoral head. Reliability, reproducibility, and prognostic value

The purpose of the current investigation was to determine interobserver and intraobserver reliability of the classification system of Steinberg et al for osteonecrosis of the femoral head. Sixty-five anteroposterior and lateral radiographs of hips were selected randomly from a pool of patients with confirmed osteonecrosis of the femoral head. Six fellowship-trained observers viewed the radiographs (Reading 1). The observers used six main stages of the classification excluding A, B, and C subgroups. The same observers viewed the radiographs 4 months later in reverse order (Reading 2). Reading 1 was used to calculate interobserver kappa values. Reading 2 was used to calculate intraobserver kappa values. Stage-specific kappa values for interobserver variation between all viewers were as follows: Stage I, k = 0.64; Stage II, k = 0.51; Stage III, k = 0.21; Stage IV, k = 0.49; Stage V, k = 0.36; and Stage VI, k = 0.80. Stage-specific kappa values for intraobserver variation between all viewers were as follows: Stage I, k = 0.74; Stage II, k = 0.60; Stage III, k = 0.46; Stage IV, k = 0.59; Stage V, k = 0.27; and Stage VI, k = 0.78. An average of 10 of 21 (48%) of these errors involved Stage III. An average of 6.3 of 21 (30%) intraobserver errors involved Stage V. The presence of the crescent sign in Stage III and joint space narrowing in Stage V markedly diminished the overall reliability of any four- to six-stage classification system. Based on the authors' experience and analysis of the current classifications of osteonecrosis of the femoral head, an easy and reproducible Pittsburgh classification system is proposed.     

Interobserver and intraobserver variations in tibial pilon fracture classification systems

BackgroundTibial pilon injuries are a complex group of fractures, whose classification and radiological assessment has been under constant reform. Till date, there is no universally accepted classification system.ObjectiveTo determine the interobserver agreement and intraobserver reproducibility of Ruedi and Allgower, AO, and Topliss et al. classification systems for tibial pilon fractures, with CT scans.MethodForty-seven CT scans of tibial pilon fractures were evaluated independently by 5 orthopaedic surgeons. Fractures were classified according to Ruedi and Allgower, AO and Topliss et al. types. Assessment was done on two occasions, eight weeks apart.ResultsThe interobserver reliability and intraobserver reproducibility for Ruedi and Allgower, AO and Topliss et al. classifications showed only moderate agreement. The interobserver agreement was dependent on the familiarity and specificity of the classification system.ConclusionCurrently used classification systems for tibial pilon fracture have moderate interobserver and intraobserver agreements, even with the help of CT scans. Therefore Tibial pilon fracture classification still remains largely undetermined.