Thomas A. DeCoster

Fracture and dislocation classification compendium - 2007: Orthopaedic Trauma Association classification, database and outcomes committee.

The purpose of this new classification compendium is to republish the Orthopaedic Trauma Associations (OTA) classification. The OTA classification was originally published in a compendium of the Journal of Orthopaedic Trauma in 1996. It adopted The Comprehensive Classification of the Long Bones developed by Müller and colleagues and classified the remaining bones. In this compendium, the introductory chapter reviews new scientific information about classifying fractures that has been published in the last 11 years. The classification is presented in a revised format that is easier to follow. The OTA and AO classification will now have a unified alpha-numeric code eliminating the differences that have existed between the 2 codes. The code was significantly revised for the clavicle and scapula, foot and hand, and patella. Dislocations have been expanded on an anatomic basis and for most joints will be coded separately. This publication should stimulate new developments and interest in a unified language to code and classify fractures. Further improvements in classification will result in better patient care and clinical research.

Optimizing bone screw pullout force.

Stability of internal fixation by plate and screw depends on the interface of bone and screw threads. Bone-screw thread design was tested in a synthetic bone model to determine maximum bone-screw pullout force. The model was confirmed to provide reproducible results in a clinically relevant range. Consistent material properties were reflected in the relatively small standard deviations in pullout force, which were less than 10% of mean values. As expected, major diameter was an important determinant of pullout force in a roughly linear manner. Pitch was important with a finer thread giving greater purchase. Minor diameter and the ratio of major to minor diameter had a small but significant effect on pullout force. This study was significant for establishing a good bone-screw testing model and suggesting important thread parameters in selecting or manufacturing a bone screw to optimize its holding power.

Management of Posttraumatic Segmental Bone Defects

Abstract Because of difficulty in managing posttraumatic segmental bone defects and the resultant poor outcomes, amputation historically was the preferred treatment. Massive cancellous bone autograft has been the principal alternative to amputation. Primary shortening or use of the adjacent fibula as a graft also has been used to attempt limb salvage. Of more recent methods of management, bone transport with distraction osteogenesis has been suggested as the leading option for defects of 2 to 10 cm, but problems include delayed union at the docking site and prolonged treatment time. Free vascularized bone transfer has been suggested as the leading option for defects of 5 to 12 cm, but hypertrophy of the graft is unreliable and late fracture, common. Bone graft substitutes continue to be developed, but they have not yet reached clinical efficacy for posttraumatic segmental bone defects. Although each of the new techniques has shown some limited success, complications remain common.

Rapid prototyping: the future of trauma surgery?

Surgeons frequently must perform delicate surgery without the benefit of a firsthand look at what they will be operating on. Fracture orientation can be difficult to conceptualize, especially in the acetabulum or spine. Anatomic reduction and stable fixation remain a challenge and have required long incisions with wide exposure, sometimes with increased postoperative morbidity1-9. The inadvertent penetration of screws into the hip joint, during the treatment of both complex acetabular fractures and posterior wall pelvic fractures, has been well documented10,11. Successful surgical correction of deformities of the hip joint before the onset of osteoarthritis requires accurate characterization of the anatomic deviations from normal as the first step in the planning of a corrective osteotomy. Pedicle screws inserted with a standard surgical technique have sometimes penetrated the wall or even missed the pedicle12-20. Diagnostic techniques such as radiography, computed tomography, and magnetic resonance imaging provide only two-dimensional images of fractures and may not depict subtle fractures. Advances in radiology combined with advances in computer technology have made the three-dimensional representation of anatomic structures in living subjects easily obtainable. With use of modern rapid prototyping techniques, computers can now accurately reproduce three-dimensional models of actual osseous anatomy, which can be invaluable for understanding the characteristics of the fracture, for preoperative contouring of plates, and for selection of screw trajectories. The surgical precision that is possible with use of computer image guidance for placement of screws or pins about the hip joint for the treatment of complex acetabular fractures and for insertion of pedicle screws is impressive1,2,21-27. However, this technology is not yet commonly used by surgeons because of its apparent complexity. Easy fabrication of accurate three-dimensional models of the osseous anatomy, easy …

Mechanics of retrograde nail versus plate fixation for supracondylar femur fractures

Summary: Two common types of internal fixations for the supracondylar femur fractures—the retrograde intramedullary nail and the 95° sideplate and screw—were mechanically tested in synthetic composite femur bones to determine the quantitative differences in their inherent rigidity. The medial and lateral femoral condyles were separated by a sagittal osteotomy, and a standardized medial segmental shaft defect was created at the distal shaft. The osteotomized specimens were stabilized using one of the two implants and were tested in different modes of loading. The bending stiffness of both constructs were not significantly different in varus compression, medial bending (pure varus), and bending in flexion. The plate and screw implant was three times stiffer in lateral bending (pure valgus) and 1.2 times stiffer in valgus compression than the retrograde supracondylar nail (p<0.01). The torsional stiffness of the plate and screw implant was significantly higher, 1.6 times that of the nail. Clinically, the most important and common cause of implant failure is varus loadings due to loss of medial cortical contact. Although the retrograde nail was less rigid in other physiologically less critical modes of loading, it had a rigidity comparable to that of the plate in varus loading. Therefore, a supracondylar nail may be considered a mechanically possible alternative to plate fixation.

Assessment of the AO/ASIF fracture classification for the distal tibia.

OBJECTIVES The purpose of this study was to assess the interobserver reliability and intraobserver reproducibility of the AO/ASIF and Rüedi and Allgöwer classifications for fractures of the distal tibia, and to determine the benefit of a computed tomography (CT) scan and experience on observer agreement for several fracture characteristics, including classification. METHODS The radiographs of forty-three fractures of the distal tibia, fourteen of which had CT scans, were assessed by groups of experienced and less-experienced observers. Each case was classified according to the AO/ASIF and Rüedi and Allgöwer systems. Several other fracture characteristics also were assessed. The kappa coefficient of agreement was calculated and used to compare the interobserver reliability and intraobserver reproducibility of the classification systems and to determine the benefit of experience and CT scans. The intraclass correlation coefficient was used to assess noncategoric data. RESULTS Interobserver and intraobserver agreements were good when classifying fractures into AO/ASIF types and significantly better than that for the Rüedi and Allgöwer system. However, agreement was poor when classifying the fractures into AO/ASIF groups. For most assessments, the experienced group tended to have higher levels of interobserver agreement, but not intraobserver agreement. Viewing the CT scans improved agreement on the percentage of articular surface involved, but it did not improve interobserver reliability or intraobserver reproducibility for either of the classification systems. CONCLUSION The AO/ASIF classification for fractures of the distal tibia has good observer agreement at the type level, but poor agreement at the group level. Experience tends to improve interobserver agreement, but not intraobserver agreement. Viewing CT scans does not improve agreement on classification, but it tends to improve agreement on articular surface involvement.

Plain radiographic interpretation in trimalleolar ankle fractures poorly assesses posterior fragment size

Summary: Twenty-five patients with trimalleolar ankle fractures were evaluated using both conventional radiography and computed tomography (CT) to determine the size of the posterior fragment along with other fracture characteristics. Plain radiograph measurements indicated very poor inter- and intraexaminer reliability. When compared to the CT scan measurement, 54% of the plain radiographic readings revealed <25% error. Plain radiographic interpretations erred in most cases by overrating the size of the fragment, but major underestimations also occurred. The larger size fragments showed more error than the smaller ones. This information confirms our clinical suspicion that the lateral radiograph is unreliable in assessing the posterior fragment size

Rank Order Analysis of Tibial Plafond Fractures: Does Injury or Reduction Predict Outcome?

We investigated the effects of severity of initial injury pattern and the quality of the articular reduction on outcome of displaced intra-articular distal tibial fractures, using a series of 25 patients who were treated with articulated external fixation and limited internal fixation, which provided a spectrum of reduction quality. Outcome was assessed by clinical ankle scores and radio-graphic arthrosis. The results demonstrate the rank order method to be a reliable means of stratifying severity of injury and quality of reduction. Neither injury nor reduction correlated with clinical ankle score. Reduction had a significant correlation with radiographic arthrosis. We conclude that the rank order method is useful in stratification of fracture patients, and that factors other than injury pattern and quality of articular reduction are important in determining outcome of patients with this severe articular injury.

External Fixation of Tibial Plafond Fractures: Is Routine Plating of the Fibula Necessary?

OBJECTIVES To determine the advantages and disadvantages of plating an associated fibula fracture in tibial plafond fractures treated with external fixation that spans the ankle. STUDY DESIGN Retrospective clinical review. METHODS The incidence of treatment complications and the outcomes achieved were compared between two groups of patients with tibial plafond fractures and associated fractures of the fibula. Both groups were treated by a uniform technique of monolateral external fixation. One group, consisting of twenty-two patients with twenty-two fractures, had plate fixation of the distal fibula and the other group, thirty-one patients with thirty-two fractures, had no fibular fixation. RESULTS The demographics of the two groups, including sex, fracture classification, and number of open fractures, were similar. The outcome of the two groups for radiographic arthrosis and clinical ankle score, measured at minimum two-year follow-up, showed no statistically significant difference. The total numbers of complications were not statistically different between the two groups (p = 0.15), but the types of complications varied. Group I had eight complications: five fibular wound infections, two fibular nonunions, and one angular nonunion. Group II had seven complications: six angular malunions and one tibial wound infection. CONCLUSION Open reduction and internal fixation of the fibula fracture in tibial plafond fractures treated with external fixation that spans the ankle is associated with a significant rate of complications, and good clinical results may be obtained without fixing the fibula.

Cast brace treatment of proximal tibia fractures. A ten-year follow-up study.

The long-term outcome of tibial plateau fractures treated by cast bracing was observed in 29 patients sustaining 30 tibial plateau fractures more than ten years after injury. Clinical and roentgenographic evaluation was performed and showed 61% good results overall. Range of motion averaged 117 degrees. Iowa knee score averaged 71 of 100 possible points. Thirty-two percent of the patients developed moderate or severe roentgenographic posttraumatic degenerative arthritis. Minimally displaced fractures were observed to do very well clinically without roentgenographic evidence of degenerative joint disease after a ten-year follow-up period. Seventy percent of displaced bicondylar fractures developed degenerative joint disease in clinical and roentgenographic evaluation. Cast bracing of minimally displaced fractures gave satisfactory results, whereas cast bracing of more complex fractures produced variable functional results.