Arbeitsgemeinschaft Für Osteosynthesefragen Classification Research Articles

The Effect of Fracture Type on Restoration of Radiographic Parameters and Early Loss of Reduction in Surgical Treated Distal Radius Fractures

Purpose: Early loss of reduction remains a challenging complication in distal radius fracture management. There are limited data on factors that correlate with early loss of reduction. The Arbeitsgemeinschaft für Osteosynthesefragen (AO) classification has become a popular way of evaluating complex fracture patterns. This study aims to determine the impact of fracture pattern, as determined by the AO classification, on restoration of intraoperative parameters, early loss of reduction, and time to fracture union in operatively treated distal radius fractures. Methods: Following IRB approval, adult patients with surgically treated acute distal radius fractures at a single level I institution were identified. Retrospective chart and radiographic review were used to obtain AO classification, postoperative radiographic parameters, early loss of reduction, time to fracture union, as well as any complications. Results: 422 patients with operatively treated distal radius fractures were included in this study. Across fracture patterns, there were no significant differences in restoration of radial height or inclination. Higher severity fracture classifications had decreased restoration of volar tilt. Overall, simple fractures (A2, C1) and partial articular fractures (B1, B2, B3) had higher rates of satisfactory alignment restoration compared to comminuted fractures (A3, C2, C3). Although there were differences in restoration of radiographic parameters, fracture type did not correlate with loss of reduction within 30 days. C type fractures correlated with increased weeks to radiographic healing. Conclusions: This study establishes that distal radius fracture pattern, as determined by the AO classification, has a significant impact on intraoperative restoration of parameters but does not correlate with early loss of reduction. Furthermore, more difficult fracture patterns may have a longer time to fracture union, but fracture type does not appear to have an effect on postoperative complications.

A comparative study on efficacies of posterior microscopic mini-open and open technique for thoracolumbar burst fractures with severe traumatic spinal stenosis

PurposeThis study compares the efficacies of minimally invasive decompression by posterior microscopic mini-open technique combined with percutaneous pedicle fixation (hereafter MOT) to traditional open surgery in patients with severe traumatic spinal canal stenosis resulting from Arbeitsgemeinschaft für Osteosynthesefragen (AO) type A3 or A4 thoracolumbar burst fractures and provides references for clinical treatment.MethodsIn total, 133 patients with severe traumatic spinal canal stenosis caused by AO type A3 or A4 thoracolumbar burst fractures who underwent MOT (group A) or traditional open surgery (group B) were retrospectively enrolled. The demographic and radiological data of the two groups were analyzed and compared.ResultsA total of 64 patients were finally recruited in this study. There were no significant differences in gender, age, follow-up time, injury mechanism, injury level, AO classification, American Spinal Injury Association (ASIA) score, visual analogue scale (VAS) score, and duration of hospital stay between the two groups (P > 0.05). After the procedures, the prevertebral height ratio (PHR), the Cobb angle, and the mid-sagittal canal diameter compression ratio (MSDCR) were significantly improved (P < 0.05) in both groups. However, group A demonstrated less intraoperative bleeding and a greater VAS score improvement postoperatively and at the last follow-up but involved a longer operation time (P < 0.05). The PHR and the Cobb angle in the two groups showed no significant difference postoperatively and at the last follow-up (P > 0.05). In contrast, a significant improvement in MSDCR was observed at the last follow-up when compared with the postoperative value (P < 0.05). However, the Cobb angle in group A was better maintained than in group B at the last follow-up (P < 0.05), while the MSDCR in group B demonstrated a greater improvement at the last follow-up than in group A (P < 0.05).ConclusionsBoth the MOT and traditional open surgery are effective treatment options for AO type A3 and A4 thoracolumbar burst fractures with severe traumatic spinal stenosis. The advantages of MOT include the minimally invasive procedure, extremely fine spinal canal decompression, less intraoperative bleeding, and significant pain relief. We suggest that MOT should be preferentially performed for AO type A3 or A4 thoracolumbar burst fractures with severe traumatic spinal stenosis.

Clinical applications of internal fixation via the volar approach with pronator quadratus preservation for distal radius fractures.

The purpose of this study is to investigate the success rate of volar plate treatment of distal radius fractures with preservation of the pronator anterior muscle; the incidence of complications, such as infection, vascular nerve injury, and tendon injury; fracture healing rate; and changes in muscle anatomy. The Henry approach was adopted to treat distal radius fractures with pronator quadratus (PQ) preservation on a trial basis. Between June 2015 and January 2017, 46 cases of distal radius fractures were considered according to the Arbeitsgemeinschaft für Osteosynthesefragen (AO) classification. The PQ was preserved, the distal margin was exposed, and a fracture reset was completed by pulling the muscles toward the near side. The K-wires were temporarily fixed, and the plate was placed by a plate channel. The mean operation duration was 52 min and the average blood loss was approximately 30 mL. There were no implant failures, adhesions requiring tenolysis, and tendon rupture. No patient developed carpal tunnel syndrome. All fractures healed without infection, radial artery injury, nerve damage, tendon rupture, and nonunion. A guider was applied to implant a screw under the muscle. In total, 46 patients with PQ preservation between ages 29 to 52 were performed distal radius fracture surgery. AO classification revealed that there were four cases of type A, seven cases of type B3, 10 cases of type C1, 13 cases of type C2, and 12 cases of type C3. For most fractures, such as Types A, B3, C1, C2, and C3, the fracture sites were located around the muscle distal margin. Thus, slight pulling of the muscles to the near side can reveal the fracture, and surgery with PQ preservation can be implemented. The postoperative muscle structures found during hardware removal procedures were similar to the muscle structures before the first operation. The radiographic outcome of fracture fixation was satisfactory. Surgery with PQ preservation is suitable for most distal radius fractures other than Types B1 and B2. For a small part of fractures involving the shaft of the radius, the PQ needed to be partially cut off to complete the operation. The postoperative muscle structures were close to normal.

Evaluation of Radiological Parameters in Elderly Patients Treated Conservatively for Distal Radius Fracture

Aim: Distal radius fractures are one of the most common fractures in the elderly population. In this study, we aimed to evaluate the changes in radiological parameters in patients treated conservatively for distal radius fractures according to fracture types and age groups.Methods: Patients who received conservative treatment for distal radius fractures between 10 January 2015 and January 2019 were retrospectively screened. Fractures of the patients were divided according to the Arbeitsgemeinschaft für Osteosynthesefragen (AO) classification, and the patients were divided into two groups as under 75 years old and over 75 years old. Ulnar variance, radial inclination, and volar tilt values of the patients after fracture reduction and at the end of the treatment were examined and compared with each other.Results: Wrist radiographs of 232 patients were evaluated in the study. According to the AO classification, 151 patients had type A (A2:144, A3:7), 46 patients had type B (B1:6, B2:33, B3:7), and 35 patients had type C (C1:21, C2:10, C3:4) fractures. While there were 134 patients in the group under 75 years old, there were 98 patients in the patient group over 75 years old. Radiological parameters (except volar tilt in AO type C fractures) were found to be impaired according to the initial evaluation after treatment, regardless of the fracture type and age.Conclusion: It should be kept in mind that patients treated conservatively for distal radius fractures may impair the reduction quality of the patients, the accepted radiological parameters may deteriorate. In elderly patients, the deterioration in these parameters was independent of gender, the presence of ulnar fractures, and fracture classification.

Evaluation of the Inter and Intra-Observer Reliability of the AO Classification of Intertrochanteric Fractures and the Device Choice (DHS, PFNA, and DCS) of Fixations.

ArbeitsgemeinschaftfürOsteosynthesefragen (AO) classification is the most frequently used tool to classify intertrochanteric fractures. However, there is limited evidence regarding its reliability. Therefore, this study was designed to evaluate inter-observer and intra-observer reliability of the AO-2018 intertrochanteric fracture classification. A retrospective study was conducted in Imam Khomeini Hospital Complex, on radiography of patients who came with intertrochanteric fractures from March 21, 2018, to March 19, 2019. Four orthopedic trauma surgeons assessed 96 anteroposterior pelvic radiographs of intertrochanteric fractures and classified using an AO intertrochanteric fracture classification of 2018. The reading and review of radiography were performed in 2 separate occasions in a 1-month interval. The inter-observer and intra-observer reliability was assessed using kappa statistics. The level of both mean inter-observer (K =0.322; 95%CI: 0.321-0.323) and intra-observer agreement (K =0.317; 95%CI: 0.314-0.320) in AO intertrochanteric fracture classification subgrouping were not satisfactory. The inter-observer (K =0.61; 95%CI: 0.608-0.611) and intra-observers' (K=0.560; 95%CI: 0.544-0.566) reliability in AO main groupings showed moderate agreement. The AO classification does not show adequate and acceptable inter-observer and intra-observer reliability and reproducibility. Therefore, it will be hard to base on the AO classification for treatment protocols.

Is the Additional Effort for an Intraoperative CT Scan Justified for Distal Radius Fracture Fixations? A Comparative Clinical Feasibility Study.

Introduction: It is currently unclear whether the additional effort to perform an intraoperative computed tomography (CT) scan is justified for articular distal radius fractures (DRFs). The purpose of this study was to assess radiological, functional, and clinical outcomes after surgical treatment of distal radius fractures when using conventional fluoroscopy vs. intraoperative CT scans. Methods: Inclusion criteria: Surgical treatment of DRF between 1 January 2011 and 31 December 2011, age 18 and above. Group distribution: intraoperative conventional fluoroscopy (Group Conv) or intraoperative CT scans (Group CT). Exclusion criteria: Use of different image intensifier devices or incomplete data. DRF classification according to the Arbeitsgemeinschaft für Osteosynthesefragen (AO) classification. Outcome variables included requirement of revision surgeries, duration of surgery, absorbed radiation dose, and requirement of additional CT scans during hospitalization. Results: A total of 187 patients were included (Group Conv n = 96 (51.3%), Group CT n = 91 (48.7%)). AO Classification: Type A fractures n = 40 (50%) in Group Conv vs. n = 16 (17.6%) in Group CT, p < 0.001; Type B: 10 (10.4%) vs. 11 (12.1%), not significant (n.s.); Type C: 38 (39.6%) vs. 64 (70.3%), p < 0.001. In Group Conv, four (4.2%) patients required revision surgeries within 6 months, but in Group CT no revision surgery was required. The CT scan led to an intraoperative screw exchange/reposition in 23 (25.3%) cases. The duration of the initial surgery (81.7 ± 46.4 min vs. 90.1 ± 43.6 min, n.s.) was comparable. The radiation dose was significantly higher in Group CT (6.9 ± 1.3 vs. 2.8 ± 7.8 mGy, p < 0.001). In Group Conv, 11 (11.5%) patients required additional CT scans during hospitalization. Conclusion: The usage of intraoperative CT was associated with improved reduction and more adequate positioning of screws postoperatively with comparable durations of surgery. Despite increased efforts by utilizing the intraoperative CT scan, the decrease in reoperations may justify its use.

Effect of intramedullary nail compression amount on the union process of tibial shaft fracture and the evaluation of this effect with a different parameter.

This study aims to investigate the effects of different amounts of compression used in intramedullary nailing on the stress values of the fracture surface and time of the union process in tibia diaphysis fractures treated with intramedullary nails. Seventy patients (50 males, 20 females; mean age 34.0±10.7 years; range, 20 to 56 years) who had suffered from tibial shaft fractures between January 2007 and December 2015 were included in the study. Patients who had A2, A3, and B2 type fractures according to AO (Arbeitsgemeinschaft für Osteosynthesefragen) classification and those with closed fractures were included. The patients were divided into three groups. No compression was applied to Group A, dynamic compressive fixation intramedullary nailing was applied to Groups B and C. Amount of applied compression was 1 mm for Group B and 1.5 mm for Group C. Postoperative and follow-up radiographs of patients were evaluated according to Rust criteria, and functional results were evaluated according to Johner-Wrush criteria. Additionally, finite element analyses were performed separately for 1 mm and 1.5 mm compressions that were applied in Group B and C, respectively. The data were analyzed using a statistical software package. Clinical and radiological union was achieved in all patients. The average time of radiological union was 15.05±2.06 weeks in Group A, 12.48±1.42 weeks in Group B, and 11.64±1.63 weeks in Group C. The time of union for the group in which no compression was applied (Group A) was significantly longer than the other groups in which compression was applied (Group B and C) (p<0.001). Functional outcomes were 17 patients (85%) with excellent and three patients (15%) with good-moderate results in Group A, 23 (92%) excellent and two (8%) good-moderate in Group B, and 23 (92%) excellent and two patients (8%) with good-moderate results in Group C. In total, seven patients had knee pain. No infection was seen in any patient. Interlocking compression intramedullary nailing is a very effective treatment method for tibial shaft fractures. As the compression applied by the nail increases, the time of union shortens significantly.

Age-, gender- and Arbeitsgemeinschaft f\xfcr Osteosynthesefragen type-specific clinical characters of adult tibial plateau fractures in eighty three hospitals in China

ObjectiveThe purpose of this study was to verify the age-, gender- and Arbeitsgemeinschaft für Osteosynthesefragen (AO) type-specific clinical characters of adult tibial plateau fractures in 83 hospitals in China and to investigate whether altitude has potential relationships with adult tibial plateau fractures.MethodsA retrospective investigation was performed on consecutive patients with tibial plateau fractures treated in 83 hospitals in China between January 2010 and December 2011, data including age, gender and imaging were collected retrospectively through the PACS system and case reports checking system, imaging were classified into six types under fully qualified estimation based on AO classification. To further investigate imparities among different altitudes in China, all data were classified into four groups according to the centre altitudes of each city, G1 = plains group (<500 m), G2 = hills group (500-1000 m), G3 = mountain areas group (1000-2000 m), and G4 = plateau group (>2000 m). Comparison of gender distribution, age distribution and AO type were done.ResultsA total of 6,227 adult tibial plateau fractures were included. Men in the age range of 40–44 years were the most affected patients, and the overall high-risk injury type was 44-B. In four groups, the same peak age showed, namely, 40-44 years in males and 55–59 years in females. Age distribution showed no statistically significant difference in four groups (P > 0.05), while sex distribution and AO type indicated statistically significant differences (P < 0.05). Note an inversion of sex ratio among people over 60 years.ConclusionOur study showed that men in the 40–44 year age range are the most affected patients, and different sex distribution as well as injury type of adult tibial plateau fractures differed with various altitudes in China.

The Correlation of Fracture Patterns of Distal Radius Fractures and Triangular Fibrocartilage Complex Injures

Purpose: The aim of the study was to determine the correlation of patterns of distal radius fractures with the triangular fibrocartilage complex (TFCC) injures. Methods: Sixty adult patients (mean age, 43 years) with distal radius fractures were included. The patients were analyzed according to the fracture character at the time of injury and classified with an Arbeitsgemeinschaft für Osteosynthesefragen (AO) classification system. Wrist arthroscopy was performed for all cases to identify and classify TFCC injuries according to Palmer’s classification system. Results: TFCC lesion of varying severity was present in 39 fractures. Statistical analysis yielded a correlation with any patterns of the distal radius fractures with the associated TFCC injuries. The comminution or dorsal angulation of the distal radius, ulnar styloid fracture, and AO classification system have no correlation with associated TFCC injuries. Conclusions: The patterns of a distal radius fracture do not predict a TFCC injury. TFCC injury should be considered with all distal radial fractures.

Reliability of the radiographic variables in the International Spinal Cord Injury Spinal Column Injury Basic Data Set compared with the AO classification.

Intra- and interrater reliability study for radiological variables of the International Spinal Cord Injury (SCI) Spinal Column Injury Basic Data Set. To test reliability of the radiological variables in the International SCI Spinal Column Injury Basic Data Set and compare it with the Arbeitsgemeinschaft für Osteosynthesefragen (AO) classification. The database of Eastern Denmark Regional SCI Referral Center, Copenhagen, Denmark. Ratings of the International SCI Spinal Column Injury Basic Data Set radiological variables and AO classification were obtained by two international observers for all the surgically treated spine trauma patients between 1st October 2010 and 31st December 2012 at the Spine Unit, Rigshospitalet, Denmark. Statistical analyses for intra- and interrater crude agreement and Cohen's unweighted kappa (κ) coefficients were performed. For 283 spine injuries, the intra- and interrater reliability for the individual radiological variables of the International SCI Spinal Column Injury Basic Data Set was at least substantial (κ=0.67-0.97 for interrater, κ=0.79-0.89 for the intrarater agreement). For the AO classification, intrarater reliability was moderate-to-substantial (κ=0.57-0.75), whereas interrater reliability was substantial (κ=0.67-0.69). The crude intra- and interrater agreement for a combined radiographic SCI Spinal Column Injury Basic Data Set variable showed no significant difference compared with the AO classification (P=0.067-0.895). The reliability of International SCI Spinal Column Injury Basic Data Set radiological variables is comparable to the AO classification system. We encourage its use for spinal column injury description, thus facilitating data collection and comparison between centres and countries.

Management of Distal Humerus Fractures With Jess Fixator

INTRODUCTION: Fractures of distal humerus are rare comprising approximately 2% of all fractures and a third of all humerus fractures. Even with the development of newer fixation techniques, the treatment of distal humerus fractures remains a great challenge to any orthopaedic surgeon. Thus this present study was conducted to evaluate the results of Joshi's External Stabilization System (JESS) in the management of distal humerus fracture with or without intercondylar extension.&#x0D; MATERIALS AND METHODS: This retrospective study was conducted by collecting records of thirty two adult patients who sustained distal humerus fracture and were managed with JESS fixation under anaesthesia over a period of two years in Universal College of Medical Sciences Teaching Hospital (UCMSTH) after obtaining permission from Institutional ethical committee.&#x0D; RESULTS: According to AO (Arbeitsgemeinschaft für Osteosynthesefragen) classification, 2 patients had C1 fracture and 30 patients had C2 fractures. The mean duration of JESS application was 16 weeks. The mean follow up was 8 months. The functional outcome was evaluated by using Cassebaum's functional rating system. Among C1 fractures, 50% showed fair and 50% showed good result whereas among C2 fractures, 40% showed good, 46.66% showed fair and 13.33% showed poor results. &#x0D; CONCLUSIONS: JESS fixation technique represents a viable option in the management of open as well as close intercondylar fractures of the distal humerus.

Trends in epidemiology and patho-anatomical pattern of proximal humeral fractures.

Proximal humeral fractures are common and frequently associated with osteoporosis. Little is known about the association between the patho-anatomical fracture pattern of proximal humeral fractures and patient characteristics. The purpose of this six year longitudinal registry analysis of proximal humeral fractures was to study overall numbers, certain predefined pathoanatomical patterns and distribution compared with specific patient characteristics. Data of patients treated between 2006 and 2011 in a country hospital that provides care >95 % of the city's hospitalised patients with fractures was retrospectively reviewed. Data were analysed according to patient characteristics of age, gender, comorbidity, accompanying injuries and radiological analysis of pathoanatomical fracture patterns based on Neer and Arbeitsgemeinschaft für Osteosynthesefragen (AO) classification. Eight hundred and fifteen proximal humeral fractures (67% women/33% men; mean age 66 years, range 19-99) were analysed. During the study period, an overall increase of 42.5% was found: according to AO classification, 46% were type A, 22% type B and 32% type C. Based on the Neer classification, 86% were displaced, and 49% were complex with more than three parts. Of complex fractures, 57% were female patients >60 years. The number of complex fractures was five times higher in women >60 years than in men of the same age group. An overall increase of inpatients with displaced proximal tibial fractures was documented. Interestingly, complex displaced proximal humeral fractures, especially in older women with comorbidities, accounted for the majority of cases. These results suggest that health-care planning and hospital-based therapeutic strategies should focus on this patient group.

Do computed tomography and its 3D reconstruction increase the reproducibility of classifications of fractures of the proximal extremity of the humerus?

Objectiveto determine whether 3D reconstruction images from computed tomography (CT) increase the inter and intraobserver agreement of the Neer and Arbeitsgemeinschaft für Osteosynthesefragen (AO) classification systems. Methodsradiographic images and tomographic images with 3D reconstruction were obtained in three shoulder positions and were analyzed on two occasions by four independent observers. Resultsthe radiographic evaluation demonstrated that using CT improved the inter and intraobserver agreement of the Neer classification. This was not seen with the AO classification, in which CT was only shown to increase the interobserver agreement. Conclusionuse of 3D CT allows better evaluation of fractures with regard to their component parts and their displacements, but nevertheless the intraobserver agreement presented is less than ideal.

A tomografia computadorizada e sua reconstrução 3D aumentam a reprodutibilidade das classificações das fraturas da extremidade proximal do úmero?

Objectiveto determine whether 3D reconstruction images from computed tomography (CT) increase the inter and intraobserver agreement of the Neer and Arbeitsgemeinschaft für Osteosynthesefragen (AO) classification systems. Methodsradiographic images and tomographic images with 3D reconstruction were obtained in three shoulder positions and were analyzed on two occasions by four independent observers. Resultsthe radiographic evaluation demonstrated that using CT improved the inter and intraobserver agreement of the Neer classification. This was not seen with the AO classification, in which CT was only shown to increase the interobserver agreement. Conclusionuse of 3D CT allows better evaluation of fractures with regard to their component parts and their displacements, but nevertheless the intraobserver agreement presented is less than ideal.

Clinical outcome and changes in gait pattern after pilon fractures.

Axial burst fractures of the distal tibia are challenging to treat and often lead to restricted function of the lower limb. The purpose of this study was to investigate the clinical outcome and changes in gait pattern in such patients. Thirty-five patients in a level 1 trauma centre were followed up clinically and by gait analysis. The American Orthopaedic Foot and Ankle Society (AOFAS), visual analogue scale (VAS) foot and ankle scale and Phillips scores were applied. Dynamic pedography (emed-M; Novel, Germany) with analyses of load, pressure and force-time integral were undertaken to investigate possible changes in gait pattern. Mean follow-up was 50 (19-100) months. Mean AOFAS, VAS foot and ankle and Phillips scores were 65, 63 and 55 points, respectively. There were clear correlations between fracture severity in the Arbeitsgemeinschaft für Osteosynthesefragen (AO) classification and functional outcome in AOFAS (-0.63; p < 0.01), VAS foot and ankle scale (-0.56; p < 0.01) and Phillips (-0.64; p < 0.01) scores. There was a high correlation of 0.74 (p < 0.01) between the severity of the injury in the AO-classification and onset of post-traumatic arthrosis. Dynamic pedography revealed lesser load bearing for the total foot, medial foot, heel, first metatarsal and medial forefoot for the affected limb, and increased load bearing was seen in the lateral midfoot region. Fractures of the tibial pilon lead to restricted function of the lower limb. Clinical outcome correlates with fracture severity in the AO classification, the onset of post-traumatic arthrosis and changes in gait patterns.

Factors associated with the decision for operative versus non-operative treatment of displaced proximal humerus fractures in the elderly

BackgroundIn the management of displaced proximal humerus fractures in the elderly, wide variation has been documented. However, no prior study has investigated the factors that currently lead surgeons to treat patients with surgical fixation, arthroplasty or non-operative management. The purpose of this study was to identify the factors associated with treatment selection in the management of displaced proximal humerus fractures in individuals over the age of 60 years. To this end, we conducted a retrospective review of all such injuries that presented to our two level-I trauma centres between 2006 and 2009. Patients and methodsFrom our prospectively collected trauma database, we identified 229 displaced proximal humerus fractures that met all inclusion and exclusion criteria. Data were collected on patient-, fracture- and surgeon-related characteristics that were plausibly related to the decision for treatment. The choice of management was recorded, and logistic regression was used to identify factors associated with the decision for treatment. ResultsIn the multivariate analysis, the predictors of operative intervention as opposed to non-operative treatment were younger patient age (p=0.038), associated orthopaedic injuries requiring surgery (p=0.012), higher Arbeitsgemeinschaft für Osteosynthesefragen (AO) classification (p=0.012), translation-type displacement (p=0.0012) and associated glenohumeral dislocation (p=0.0006). In addition, shoulder and upper extremity specialists were found to choose operative intervention significantly more frequently than orthopaedic trauma specialists (49.1% vs. 26.1%, adjusted relative risk (RR) 1.96, p=0.012). Factors associated with the decision for arthroplasty as opposed to fixation were higher Charlson score (p=0.045), higher Neer classification (p=0.012), and higher AO classification (p=0.0097). ConclusionsIn this study of displaced proximal humerus fractures in the elderly, the decision for surgery was influenced by the patient's age, the presence of associated orthopaedic injuries, the severity of the fracture and the presence of an associated glenohumeral dislocation. In addition, treatment by a shoulder or upper extremity specialist (as opposed to an orthopaedic trauma specialist) was associated with a higher likelihood of operative intervention. Further investigation into the resultant clinical outcomes is required to determine whether the use of these characteristics to select operative candidates is appropriate and beneficial for patients.

Assessment of Two Thoracolumbar Fracture Classification Systems as Used by Multiple Surgeons

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. 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. 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. 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.

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 (κ) 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.