Lateral compression fracture of the pelvis represents a heterogeneous group of complex 3D patterns of displacement.

Although clinical and radiological criteria exist to direct the non-operative and operative treatment of other types of pelvic injuries, none exist for lateral compression (LC) fractures. The purpose of this study is to describe the patterns of injury in LC fractures through quantitative 3D radiographic analysis. It is hypothesised that LC fractures represent a spectrum of injuries with a combination of translational and rotational displacements. CT data from 60 patients with unilateral lateral compression fractures were obtained. Quantification of translations and rotations of the fractures was performed using 3D visualisation software. Fractures initially diagnosed as LC actually represent a spectrum of displacement patterns, ranging from a minimally displaced hemipelvis to complex combinations of displacements. Fractures were grouped based on pattern of rotation and translation into 5 distinct groups. 3D analysis of displacement patterns demonstrated a complexity in LC fractures which may explain the variations seen in outcomes associated with this injury.

Fractures of the talus: experience of two level 1 trauma centers.

Fifty-eight patients with 60 talar fractures were retrospectively reviewed. There were 39 men and 19 women. The age average was 32 (range, 14-74). Eighty six percent of the patients had multiple injuries. The most common mechanism of injury was a motor vehicle accident. Twenty-seven (45%) of the fractures were neck, 22 (36.7%) process, and 11 (18.3%) body. Forty-eight fractures had operative treatment and 12 had non-operative management. The average follow-up period was 30 months (range, 24-65). Thirty-two fractures (53.3%) developed subtalar arthritis. Two patients had subsequent subtalar fusion. Fifteen fractures (25%) developed ankle arthritis. None of these patients required ankle fusion. Fractures of the body of the talus were associated with the highest incidence of degenerative joint disease of both the subtalar and ankle joints. Ten fractures (16.6%) developed avascular necrosis (AVN), only one of which had subsequent slight collapse. Avascular necrosis occurred mostly after Hawkins Type 3 and 2 fractures of the talar neck. Three rating scores were used in this series to assess the outcome: the American Orthopedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Score, Maryland Foot Score, and Hawkins Evaluation Criteria. The outcome was different with every rating system. However, the outcome with AOFAS Ankle-Hindfoot Score and Hawkins Evaluation Criteria were almost equivalent. Assessment with the three rating scores showed that the process fractures had the best results followed by the neck and then the body fractures.

Economic evaluations in the hip arthroplasty literature: lessons to be learned.

Readers are increasingly encountering articles dealing with health economic evaluations that compare various surgical strategies, leaving orthopaedists with the challenge of determining which program is cost-efficient and truly pertains to their setting. This study carries out a systematic review of the literature to appraise the quality, quantity, and type of economic evaluation as it pertains to the hip arthroplasty literature. To identify all relevant articles, we conducted a comprehensive computerized bibliographic search of Medline from 1966 to 1996. This search produced 1,611 abstracts that were screened. Studies that were incorporated met the following inclusion criteria: i) formal economic analysis, ii) an intervention specific to hip arthroplasty, and iii) the perspective of the study was evident (ie, patient, provider, society). These studies were appraised with regards to methodologic soundness based on 8 established economic principles. Only 68 articles from the 138 retrieved met the study criteria. Only 2 of the 68 articles met all 8 criteria of a comprehensive economic evaluation. The hip arthroplasty literature is deficient in methodologically sound economic evaluations. Several guidelines are introduced to aid orthopaedists in appraising the various economic studies, and recommendations are made to improve the quality of these studies in the orthopaedic literature. We suggest that the generation of such information should rank high on the priority list of the orthopaedic profession, granting agencies, and governments.

Effect of pin location on stability of pelvic external fixation.

Pelvic external fixators allow two locations of pin purchase: anterosuperior (into the iliac crest) and anteroinferior (into the supraacetabular dense bone, between the anterior superior and anterior inferior iliac spine). The purpose of this study was to compare the stability of these two methods of fixation on Tile Type B1 (open book) and C (unstable) pelvic injuries. Five unembalmed cadaveric pelves (mean age, 68 years; four males and one female) were loaded vertically in a servohydraulic testing machine in a standing posture. The AO tubular system and Orthofix were used. On each pelvis, a Type B1 injury was simulated. Each external fixator was applied in each location in random order. Cyclic loads were applied through the sacral body to a maximum of approximately 200 N while force and displacement of the pelvic ring were recorded digitally. Sacroiliac joint motion was quantified tridimensionally with displacement transducers, mounted on the sacrum and contacting a target fixed to the posterior superior iliac spine. A Type C injury was created and augmented with two iliosacral lag screws, and the tests were repeated. For the Type B1 injuries with anteroinferior pin purchase, the mean stiffness was 201.2 N/mm for the AO frame and 203.2 N/mm for the Orthofix. For the anterosuperior frames the mean stiffness was 143.9 N/mm for the AO frame and 163.3 N/mm for the Orthofix. For Type B1 and Type C injuries, the anteroinferior location of pin purchase resulted in significantly reduced sacroiliac joint separation. There were no significant differences between the frame types. Dissection of the preinserted anatomic specimen revealed no evidence of injury to the lateral femoral cutaneous nerve after blunt dissection and drilling with protective drill sleeves. It is concluded that the anteroinferior location of external fixation pins is a safe technique with the potential for increased stability of fixation.

Total hip replacement after acetabular fracture.

The controversies surrounding total hip arthroplasty after acetabular fracture are presented in this article. Hip arthroplasty for acute treatment of acetabular fractures is rarely indicated. In general, total hip arthroplasty should be reserved for the late salvage of hips in which symptomatic, post-traumatic arthritis has developed after acetabular fracture. Preoperative, intraoperative, and postoperative management are discussed. Modern surgical techniques may improve the long-term survival of total hip arthroplasty after acetabular fracture, particularly the acetabular component

Long-term outcomes in open pelvic fractures.

BACKGROUND: Open pelvic fractures represent one of the most devastating injuries in orthopedic trauma. The purpose of this study was to document the injury characteristics, complications, mortality, and long-term, health-related quality of life outcomes in patients with open pelvic fractures. METHODS: The trauma registry at an adult trauma center was used to identify all multiple system blunt trauma patients with a pelvic fracture from January of 1987 to August of 1995 (n = 1,179). Demographic data, mechanism of injury, and fracture type were determined from hospital records. Short-term outcome measures included infectious complications, mortality, and length of stay in hospital. Long-term outcomes of survivors were obtained by telephone interview using the SF-36 Health Survey and the Functional Independence Measure. RESULTS: Open pelvic fractures were uncommon, occurring in 44 patients (4%). Patients with open fractures were about 9 years younger, on average, than patients with closed fractures (30 vs. 39, p < 0.001). Similarly, patients with open fractures were more likely to be male (75 vs. 57%, p < 0.02), more likely to have been involved in a motorcycle crash (27 vs. 6%, p < 0.001), and more likely to have an unstable pelvic ring disruption (45 vs. 25%, p < 0.001). Open pelvic fracture patients required more blood than closed pelvic fracture patients, both in the first day (16 vs. 4 units, p < 0.001) and during the total hospital admission (29 vs. 9 units, p < 0.001). Five patients with perineal wounds did not receive a diverting colostomy; in turn, these individuals had a total of six pelvic infectious complications (one abscess, two with osteomyelitis, and three perineal wound infections). Overall, 11 patients died, six patients were lost to follow-up, and 27 were long-term survivors (mean duration of 4 years). Chronic disability was common after a pelvic fracture, with problems related to physical role performance and physical functioning, and was particularly severe after an open pelvic fracture (p < 0.05 for both as measured by the SF-36). CONCLUSIONS: Patients with open pelvic fractures often survive, need to be treated with massive blood transfusions, and often require a colostomy. They are frequently left with chronic pain and residual disabilities in physical functioning and physical roles, and many remain unemployed years after injury.

The strength of iliosacral lag screws and transiliac bars in the fixation of vertically unstable pelvic injuries with sacral fractures.

This study compares the relative strengths of iliosacral lag screws and transiliac bars in the fixation of vertically unstable pelvic injuries with sacral fractures. A vertical sacral fracture was artificially induced by vertical loading in eight pelvises from cadavers, which were then fixed with two 6.5 mm iliosacral lag screws or two 6.4 mm transiliac bars. The pelvises were then loaded again to failure. The mean strength of iliosacral lag screw fixation was 819 newtons and for transiliac bars it was 1066 newtons, but the study was too small for the difference to be judged as statistically significant. Various advantages and disadvantages of each method of fixation are discussed.

Acute Pelvic Fractures: I. Causation and Classification.

Acute pelvic fractures are potentially lethal, even with modern techniques of poly-trauma care. The appropriate treatment of such fractures is dependent on a thorough understanding of the anatomic features of the pelvic region and the biomechanical basis of the various types of lesions. Although the anterior structures, the symphysis pubis and the pubic rami, contribute approximately 40% to the stiffness of the pelvis, clinical and biomechanical studies have shown that the posterior sacroiliac complex is more important to pelvic-ring stability. Therefore, the classification of pelvic fractures is based on the stability of the posterior lesion. In type A fractures, the pelvic ring is stable. The partially stable type B lesions, such as "open-book" and "bucket-handle" fractures, are caused by external- and internal-rotation forces, respectively. In type C injuries, there is complete disruption of the posterior sacroiliac complex. These unstable fractures are almost always caused by high-energy severe trauma associated with motor vehicle accidents, falls from a height, or crushing injuries. Type A and type B fractures make up 70% to 80% of all pelvic injuries. Because of the complexity of injuries that most often result in acute pelvic fractures, they should be considered in the context of polytrauma management, rather than in isolation. Any classification system must therefore be seen only as a general guide to treatment. The management of each patient requires careful, individualized decision making.

Acute Pelvic Fractures: II. Principles of Management.

The past two decades have seen many advances in pelvic-trauma surgery. Provisional fixation of unstable pelvic-ring disruptions and open-book fractures with a pelvic clamp or an external frame with a supracondylar pin has proved markedly beneficial in the resuscitative phase of management. In the completely unstable pelvis, external clamps and frames can act only as provisional fixation and should be combined with skeletal traction. The traction pin is usually used only until a definitive form of stabilization can be applied to keep the pelvic ring in a reduced position. If the patient is too ill to allow operative intervention, the traction pin can remain in place with the external frame as definitive treatment. Symphyseal disruptions and medial ramus fractures should be plated at the time of laparotomy. Lateral ramus fractures can usually be controlled with external frames. A role has been suggested for percutaneous retrograde fixation of the superior pubic ramus; however, the benefits to be gained may not be enough to outweigh the serious risks of penetrating the hip, and this technique should therefore be used only by surgeons trained in its performance. The techniques for posterior fixation are becoming more standardized, but all still carry significant risks, especially to neurologic structures.

Micromotion of cementless hemispherical acetabular components. Does press-fit need adjunctive screw fixation?

Adult human cadaver pelves were tested to determine micromotion at the prosthesis-bone interface in cementless hemispherical acetabular components during simulated single-limb stance. The micromotion of non-press-fit components with screw fixation in response to cyclic loads to a maximum of 1500N was compressive (interface closing) at the superior iliac rim and distractive (interface opening) at the inferior ischial rim; that of press-fit components was compressive all around the acetabular rim regardless of screw fixation. Adding screws to the component decreased the micromotion at the site of the screw, but sometimes increased it at the opposite side. Two dome screws with the press-fit component decreased the micromotion at the superior iliac rim but at the inferior ischial rim there was either no change or increased movement. A press-fit cup shows less micromotion than a non-press-fit cup with screw fixation. The addition of screws to a press-fit cup does not necessarily increase the initial stability.

Lateral extension of the ilioinguinal incision in the operative treatment of acetabulum fractures.

The choice of which decision to use for open reduction and internal fixation of complex acetabulum fractures depends on several variables. We report on 26 patients in whom a lateral extension of the ilioinguinal incision was used to achieve fracture reduction and stabilization. The lateral extension allowed visualization of the lateral ilium, in some cases passage of cerclage wires around the anterior and posterior columns, and in some cases placement of lateral to medial lag screws above the dome of the acetabulum. Reduction with a step of 1 mm or less and a gap of 3 mm or less with joint congruence was achieved in 21 patients (81 per cent). No patients had clinically significant heterotopic ossification. One patient had a transient postoperative femoral neuropathy, one a superficial infection, and one a deep infection. We recommend this lateral extension as an option during surgery of complex acetabular fractures through the ilioinguinal incision.

Effects of method of internal fixation of symphyseal disruptions on stability of the pelvic ring.

This study tested different methods of internal fixation of a symphyseal disruption, in comparison with the mechanics of the intact pelvis. Unembalmed cadaveric pelves were tested in simulated bilateral stance in a servohydraulic materials-testing machine. Motion of the superior and inferior pubic symphysis, and at two levels of the posterior sacroiliac complex, was measured using high resolution displacement transducers. The fixations tested were (1) double plating (4.5 mm reconstruction plates), (2) wire loops around two 6.5 mm, fully threaded cancellous screws, and (3) an absorbable suture material (polydioxanone). Each pelvis was first tested intact, recording displacements in response to a cyclic axial load up to a maximum of 500 N applied through the proximal sacrum. The pubic symphysis was then sectioned and the sacrum fractured to produce an unstable pelvis (Tile C-type). Recordings were then repeated, following fixation of the sacral fracture with lag screws and sequential fixation of the symphysis with each of the test methods. The results from eight pelves revealed that internally fixed symphyseal motion was generally greater than intact, regardless of fixation method. The superior symphysis was usually compressed, while there was distraction inferiorly. Wiring resulted in significantly less symphyseal motion than the other methods (P < 0.02), provided four loops were used, reducing the separation inferiorly. There was no significant difference in sacral fracture motion between the three methods. The results indicate that in osteoporotic bone, as used in this study, symphyseal wiring is best able to oppose the tensile loads in the inferior symphysis that are associated with bilateral stance loading. These biomechanical findings must be interpreted within the broader context of surgical management of these complex injuries.

Ligamentous contributions to pelvic stability.

The purpose of this study was to examine the ligamentous contributions to pelvic stability. Thirteen fresh frozen cadaver pelves were loaded in an MTS materials testing machine, and the supporting ligaments were sequentially cut. After each ligament was cut, measurements of pelvic stability were made. Pelvic stability was maintained most effectively when the pelvic ring remained intact. The sacrotuberous and sacrospinous ligaments contributed little to overall pelvic stability. The posterior sacroiliac ligament and the pubic symphyseal ligaments contributed most to pelvic stability, but overall it was clear that a ligament's contributions to pelvic stability depended not only on the ligament's size, but also on the other ligament remaining intact and the mode in which the pelvis was loaded.

Biomechanical comparison of methods of fixation of isolated osteotomies of the posterior acetabular column.

Ten fresh frozen specimens of a hemipelvis, including the hip joint, capsule and proximal femur, from elderly cadavers were used to evaluate three methods of internal fixation of isolated posterior column osteotomies. Intact and reconstructed specimens were tested at 30 degrees and 60 degrees of hip flexion in a specially designed joint simulator. The three methods of fixation used were a single 3.5 mm reconstruction plate, two such plates, and a 4.5 mm lag screw with a single plate. Motion at the fracture site in three orthogonal directions, and the overall stiffness of the construct, were recorded simultaneously. No significant differences were noted in stiffness for the three procedures and all retained 80% of the intact stiffness. At 60 degrees of flexion, smaller interfragmentary compliances were allowed by fixation with a lag screw and a neutralisation plate (p < 0.05). At 30 degrees, the position of the load plane relative to the fracture plane allowed less interfragmentary motion, so that no significant differences were found between the 3 methods.

The effect of thread length and location on extraction strengths of iliosacral lag screws.

Although iliosacral lag screws are an established technique for fixation of sacroiliac joint dislocation and sacral fractures, there is a paucity of data on the relative strength of fixation of screws in the sacral ala and body. The purpose of this study was to quantify and compare the extraction strength of cancellous screws in the sacral ala and body. Twelve fresh frozen cadaveric human pelves (mean age 76) were used to test the extraction strength of three groups of 7.0 mm cannulated cancellous screws: long-threaded in the sacral body, short-threaded in the body and short-threaded in the ala. The mean extraction strengths were 925, 374 and 71 newtons (or 92, 37, and 7 kg) respectively. The differences between the three groups were highly significant (all P < 0.0025). These data strongly recommend that the goal in iliosacral lag screw fixation should be to insert a long-threaded screw into the sacral body, if safely feasible. Fixation in the ala is inferior and should be avoided in the elderly.

Cerclage wiring in internal fixation of acetabular fractures.

In the last 100 fractures of the acetabulum surgically treated in our institution, cerclage wires have been used as a reduction tool in 14 patients. In each case the fracture pattern affected both columns, and nine of them were approached through a single ilioinguinal exposure. To evaluate our initial experience with the method, these patients were reviewed using medical records, operative notes, and radiological assessment to determine its indications and effectiveness. In each patient, using a limited further dissection, at least one cerclage wire was passed through the greater sciatic notch, embracing the proximal extent of a posterior column fragment. It was then tightened above the anterior-inferior iliac spine, achieving reduction. In 11 cases reduction was obtained to within 1 mm, and joint congruence with < 3 mm of residual displacement was obtained in 13 hips. This reduction was maintained until union, except in one case, where it was lost postsurgery. Cerclage wires may be used to successfully effect an indirect reduction of the posterior column from an anterior approach in fractures affecting both columns, where the posterior column fracture line is proximal. The technique may contribute to fracture stabilization, but supplementary fixation was added in 12 of our patients.

Plate fixation of open fractures of the tibia.

The results of immediate plate fixation of 97 open fractures of the tibial shaft in 95 patients are reported. Significant joint stiffness occurred in 11.4% and angular malunion of greater than 5 degrees in any plane was seen in 3.1%. The infection rate was 10.3%. However, even in those cases which develop delayed union or other complications, plate fixation of open fractures can produce excellent recovery of limb function.

Anterior approach and stabilization of the disrupted sacroiliac joint.

Pelvic fractures with disruption of the important weight-bearing sacroiliac area can lead to impaired gait due to malunion or pelvic obliquity, back or buttock pain arising from the sacroiliac joint, and permanent neurologic damage. In eight patients with sacroiliac joint dislocation, an anterior retrofascial approach and stapling of the sacroiliac joint was performed. Six of these patients maintained an anatomic reduction of the sacroiliac joint and their results were rated as excellent. Two of the eight patients had a slight loss of reduction and because of intermittent mild pain were rated as having fair results. In another eight patients, plate fixation of the anterior sacroiliac joint was done. New stabilization methods utilizing dynamic compression plates, reconstruction plates, and a new four-hole plate have been developed to provide more secure fixation of these unstable injuries.