Orthopedics
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Case Reports
Acetabular cup malalignment after total hip resurfacing arthroplasty: a case for elective revision?
This article describes the clinical course of a patient with a resurfacing implant in a poor cup position in combination with elevated serum metal ions prior to implant failure. Following resurfacing, the patient had substantial improvement from baseline in pain and functional status. Postoperative radiographs indicated the acetabular cup in an abducted and excessively anteverted position. ⋯ A recent study has shown a correlation between increased cup inclination and increased serum cobalt or chromium levels and this patient's levels were >40 times greater than that typically observed with this device. Early revision should be strongly considered if component malpositioning is noted, and abnormally elevated ion concentrations should signal the need for revision regardless of the patient's clinical status. The relationship of a malpositioned cup and uncharacteristically elevated metal ion levels is related to the metal-on-metal bearing coupling and likely applies to conventional metal-on-metal total hip prostheses as well.
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Sacral fractures are commonly associated with pelvic ring fractures due to high-energy mechanisms of injury. An understanding of the anatomic relation of the sacrum to the lumbar spine, pelvis, and surrounding neurovascular structures is critical in evaluating functional deficits that may be associated with sacral fractures. While displaced fractures can be easily diagnosed on high quality plain radiographs, nondisplaced or transverse fracture patterns may be difficult to diagnose without a computed tomography scan. ⋯ Stable nondisplaced fractures are usually treated nonoperatively, while significantly displaced fractures require reduction and internal fixation. Surgical fixation techniques include percutaneously placed iliosacral screws, posterior sacral "tension band" fixation, and for certain fracture patterns osteosynthesis that incorporates the lower lumbar spine (lumbopelvic or triangular fixation). This article reviews the approach to sacral fracture diagnosis and management.
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Case Reports
Brachial plexus palsy caused by secondary fracture displacement in a patient with closed clavicle fracture.
In adults, brachial plexus injury due to clavicle fractures is rare, and is most commonly caused by nonunion, malunited fragments, hypertrophic callus, or pseudoaneurysm of the subclavicular artery or vein. Brachial plexus palsy in acute fractures caused by direct fragment compression is exceptional. Conservative treatment of nondisplaced and displaced midclavicle fractures in adults usually produces satisfactory outcomes. ⋯ During surgery, the brachial plexus was found to be markedly stretched due to compression by the bony fragments and an organized blood clot. After meticulous neurolysis, the blood clot and intermediate bony fragments were removed and the distal fragments were reduced and fixed with a metal plate and interfragmentary screws. Secondary fracture displacement is possible after a nondisplaced clavicle fracture if the arm is not well protected, even if the original fracture appears stable and no neurological or circulatory symptoms are present.
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In closed intramedullary nailing of the femur in the lateral decubitus position without the use of a fracture table, access to the proximal femur is enhanced as compared to supine nailing, especially in large patients. The hip is typically flexed during the nailing, which allows the nail to be placed posterior to the gluteus medius, thus minimizing abductor damage. ⋯ Proper rotation of the leg can be assessed clinically or with the use of a femoral neck anteversion guide wire. Fluoroscopic visualization of the proximal femur is excellent, including the femoral head, thus facilitating reconstruction nailing.