Putative proprioceptive function of the pelvic ligaments: biomechanical and histological studies.

The sacrospinous (SS) and sacrotuberous (ST) ligaments of the pelvic ring are known as mechanical stabilisers of the pelvic girdle, primarily against rotational forces in the sagittal and horizontal planes. Earlier studies, however, raised the possibility that ST/SS ligaments possess significant proprioceptive function, while the mechanical role of these ligaments in maintaining the structural integrity of the pelvis is of less importance. The aim of this study is to determine whether the function of these ligaments is strictly to provide mechanical stability or if they have any additional functional properties, i.

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.

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).

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.

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.

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.

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).

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

The unstable pelvic fracture. Operative treatment.

While the pendulum has swung to the operative side, open reduction and internal fixation will surely not prove to be the panacea for all unstable pelvic fractures. The lasting effects, however, of attempts at aggressive fixation of the pelvic fracture will be the principles of management that are being established. This begins with the recognition of pelvic instability.

Immediate internal fixation of open fractures of the diaphysis of the forearm.

Between 1975 and 1983, fifty-seven patients were treated at Sunnybrook and Harborview Medical Centers with immediate internal plate fixation of an open diaphyseal fracture of the forearm. Fifty patients were available for follow-up, which ranged from one to nine years and averaged three years. The injuries were classified on the basis of the extent of soft-tissue injury as defined by Gustilo and Anderson, and consisted of twenty Type-I injuries, nineteen Type-II injuries, and eleven Type-III injuries.

Centrode patterns in the lumbar spine. Baseline studies in normal subjects.

Segmental spinal instability is a known cause of back pain, but no method of accurately quantifying instability exists. The movement of complex joints with rotational and translational components (such as the lumbar motion segment) is tracked by a pathway of instantaneous centers of rotation, or a centrode. Instability, ie, excessive and/or erratic movement, is reflected by increased centrode length in cadaver studies.