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Biomedical subjects

R W Lindsey

Publications and source records attributed to R W Lindsey.

At least 19 recordsLinked to original sources
PubMed1992

Femoral artery thrombosis after open reduction of an acetabular fracture.

The increasingly popular ilioinguinal anterior approach for select fractures of the acetabulum provides excellent exposure with minimal soft tissue dissection. Vascular complications reported with this procedure, although infrequent, are usually quite pronounced in their presentation. The authors encountered a more subtle case of femoral artery thrombosis secondary to vessel retraction while using this approach. The susceptibility of major vessels to thrombus formation is noteworthy. The precautions, and the close postoperative monitoring necessary to detect such vascular lesions, are emphasized.

Acetabulum↗
PubMed1991

Early experience with the gamma interlocking nail for peritrochanteric fractures of the proximal femur.

Surgical fixation, early weight-bearing, and bony union remain a challenge in the treatment of peritrochanteric femur fractures, especially if the fractures are comminuted or unstable. Preliminary experience with the Gamma locking nail, a short intramedullary nail connected to a sliding compression screw augmented with distal locking screws, is presented. In a consecutive series of 29 patients, all fractures were adequately reduced and immediate weight-bearing was begun regardless of fracture configuration (13/27 fractures classified as unstable). Twenty-seven patients were reviewed at 6 months. At follow-up, all patients continued to be ambulatory and all fractures healed. Major complications included screw migration in the femoral head (two patients), difficulty in securely placing the distal screws (eight patients), and a femoral shaft fracture through the distal locking screws following a fall. The technical problems inherent in the device and its instrumentation are discussed. In this early experience, the Gamma nail appears to allow for early patient ambulation regardless of the fracture configuration with excellent clinical results.

Adolescent↗
PubMed1991

The fixateur interne in the reduction and stabilization of thoracolumbar spine fractures in patients with neurologic deficit.

A prospective analysis of 80 consecutive patients who underwent stabilization with the fixateur interne for thoracolumbar spine fractures with complete or incomplete paraplegia was undertaken to determine the results after bone healing. Follow-up examination at an average of 35 months (minimum, 24 months) included all 76 patients still alive. One patient died from a pulmonary embolism, and there were three other unrelated deaths. The mean wedge angle of the fractured vertebra was corrected from 17.4 degrees to 7.9 degrees and remained almost unchanged after 1 year (8.4 degrees) and 2 years, or 1 year after implant removal (8.2 degrees). Also, the wedge index showed nearly no bony loss of correction within the reduced fracture vertebra (0.61 before operation, 0.83 after operation; 0.81 at 1-year follow-up, 0.81 at 2-year follow-up, respectively). In the kyphosis angle measured by the Cobb method, however, there was a loss of 5 degrees after implant removal within the next year because of the disc space collapsed above the fractured vertebra. In this series, 70% of the cases had no formal fusion. All 29 cases of translational displacement of 4-36 mm were anatomically reduced. No neurologic or vascular complication occurred. Posterolateral fusion or transpedicular interbody fusion in the disrupted disc space is recommended.

Adult↗
PubMed1989

The clinician's ability to evaluate the strength of healing fractures from plain radiographs.

The present study was designed to analyze the usefulness of plain radiographs in evaluating bone healing. Rabbit tibiae were osteotomized, externally fixed, and allowed to heal for 3-8 weeks. Bones were harvested, x-rayed, and tested to failure in a dynamic torsion tester. AP and lateral radiographs of 10 rabbit tibia pairs and 10 individual rabbit tibiae were selected randomly for use in a questionnaire, given to 93 physicians who routinely assess fracture healing to evaluate clinicians' ability to assess bone strength. The results indicated that clinicians can differentiate the relative strength of bones by comparing two sets of radiographs. However, the strength determination from a single set of radiographs of a fracture is unreliable, the tendency being to evaluate the fracture to be weaker than it actually is.

Animals↗
PubMed1989

Esophageal perforation following anterior cervical spine surgery.

The authors surveyed the Cervical Spine Research Society to compile a series of esophageal perforations following anterior cervical spine surgery. Twenty-two cases were assembled. Six occurred at the time of surgery, 6 in the postoperative period, and 10 weeks to months later. Eight surgeries were because of fracture. Hardware was implicated in 25% of cases occurring after surgery. Diagnosis was confirmed most often by direct vision at reexploration or esophography. Treatment usually consisted of drainage, repair, and parenteral antibiotics; 2 cases were successfully treated by enteral feeding and antibiotics alone. There was one fatality, and all patients required prolonged hospitalization. Cervical fracture and the use of hardware may be associated with this complication. Clinical suspicion and esophography are important diagnostic tools. Drainage and parenteral antibiotics are recommended treatment.

Adult↗
PubMed1988

Strength reduction and the effects of treatment of long bones with diaphyseal defects involving 50% of the cortex.

Currently, three criteria are accepted as indications for prophylactic internal fixation of metastatic disease in long bone, including lesions (a) destroying 50% or more of the cortex; (b) 2.5 cm or greater in diameter; or (c) with pain unrelieved by radiation therapy. Using an oblong defect configuration in which one half of the cross-sectional area was destroyed, canine femora were torsion-tested at high speed to determine (a) the actual strength reduction incurred by a lesion destroying 50% of the cortical circumference, and (b) the effects and benefits of internal fixation using polymethylmethacrylate and/or a six-hole compression plate on such a defect. The femurs with a 50% circumferential cortical defect demonstrated only 12.7 +/- 3.8% of intact strength. Defects treated with a combination of plating (all screws bicortical) and polymethylmethacrylate (torque to failure 4.39 +/- 0.90 times greater than the defect alone or TE/TD = 4.39 +/- 0.90) were statistically stronger than defects treated with polymethylmethacrylate alone (TE/TD = 2.48 +/- 0.66; p less than 0.025) or by plating alone (TE/TD = 2.61 +/- 0.91; p less than 0.025), but torque-to-failure was only increased to approximately 56% of an intact bone. Plated intact bones (TE/TD = 5.33 +/- 0.41) were significantly weaker than intact bones (TE/TD = 8.50 +/- 2.52; p less than 0.001). Our results substantiate the need for using polymethylmethacrylate and internal fixation in combination when prophylactically fixing pathologic lesions of this proportion.

Animals↗
PubMed1988

Permanent post-traumatic patellar dislocation.

Permanent post-traumatic dislocation of the patella is an extremely rare condition, and is often confused with congenital dislocation. The anatomic abnormalities differ in the two conditions: in the former there is an adaptive flattening of the patella, in the latter there is a propensity for flexion contractures and incongruity of the patella and trochlea. Treatment options include observation, patellar realignment, and patellectomy. In the patient reported, surgical correction appeared to result in patellar alignment.

Accidental Falls↗
PubMed1988

Duration of symptoms and disc configuration in chemonucleolysis.

Previous studies have compared the effectiveness of chemonucleolysis with surgery, but currently, no objective criteria have been correlated with the clinical outcome. The authors reviewed 28 cases where the patients had undergone chymopapain injection to determine the significance of disc herniation size, disc space height reduction, and the duration of symptoms on clinical outcome. All patients had a complete history, physical examination, and discogram, and most had pre- and post-injection computerized tomography (CT) or myelogram. Nine of the 28 patients were considered clinical failures. Seven underwent laminectomy and discectomy and were improved markedly. Two patients were advised to have surgery but refused and were considered clinical failures. The causes of failure were unknown in three patients, free fragment in two patients, and diabetic neuropathy in one. Only two patients who did well showed complete resolution of the disc deformity on repeat CT scan. The remainder still had evidence of an avascular deformity that persisted although reduced in size. The failures showed no changes in disc size. The height of the disc space was too variable to be correlated with clinical outcome. Patients who failed had a longer duration of symptoms than the ones who did well (15.1 months for failures vs. 5 months). Therefore, some reduction of disc deformity size, but not necessarily complete reduction, is necessary for a good result, and the enzyme is not as effective in patients with long-standing symptoms.

Adult↗
PubMed1988

Refracture of bones of the forearm after the removal of compression plates.

Of thirty-seven patients who had sixty-two diaphyseal plates removed from the forearm after fixation of a fracture, seven patients had a refracture, two of whom refractured both bones of the forearm. Six of the seven refractures were in patients who initially had had a fracture of both bones, and all were in patients in whom the original fracture had been caused by major trauma. The interval from the time of removal of the plate to refracture ranged from forty-two to 121 days. Only one of the seven patients who had a refracture had had adequate compression of the original fracture. The average interval from the time of the original trauma to internal fixation was two days in six patients who had a refracture and who originally had had primary plating, compared with 8.5 days in the patients who did not have a refracture. One of the seven patients who had a refracture had originally had delayed plating after closed treatment had failed. In retrospect, radiolucency at the site of the original fracture was seen in most patients when the plate was removed.

Adolescent↗
PubMed1988

Dynamic compression plate fixation: a biomechanical comparison of unicortical vs bicortical distal screw fixation.

The use of unicortical screws instead of bicortical screws in the extreme outer holes of dynamic compression plates (DCPs) has been recommended to minimize the stress riser effect at the end of the plates. The authors examined in vitro two groups of paired canine femurs after compression plates had been applied to the anterolateral diaphyseal surface bilaterally. Group I: intact paired femurs with bicortical peripheral screws in one DCP and unicortical peripheral screws in the other; Group II: osteotomized paired femurs again comparing unicortical and bicortical peripheral DCP screws. All specimens were torsion tested to failure and the torque, stiffness, energy, rotation, and failure fracture length were calculated. Unicortical screws did not enhance the torsional strength in either group, and significantly compromised stiffness, energy, and rotation in the osteotomized group. The only apparent benefit of unicortical peripheral screws in a DCP was a shorter, less comminuted fracture upon failure.

Animals↗
PubMed1987

Effects of bone graft and electrical stimulation on the strength of healing bony defects in dogs.

Autogenous cancellous bone graft alone or in combination with electrical stimulation is commonly employed yet there exists no conclusive data that the strength of the healing defect is actually modified. The authors examined three groups of paired canine femurs that were torsion tested to failure. Group I (in vitro): an intact femur was compared to a standard defect; Group II (in vivo): a defect alone was compared to a defect plus graft killed at eight weeks; Group III (in vivo): a defect plus graft was compared to a defect graft plus Osteostim (BGS Medical Corp., Milwaukee, Wisconsin) implantable stimulator killed at eight weeks. In Group I the defect decreased the average strength 45% (p = 0.005); in Group II the grafted defect decreased the strength 20% (p = 0.121); in Group III the defect graft plus electrical stimulation increased strength 4% (p = 0.669). At eight weeks, bone grafting, alone or with electrical stimulation did not statistically increase the torsional strength of the healing bony defect.

Animals↗
PubMed1987

Nonunion following two-level anterior cervical discectomy and fusion.

Nonunion is a potential complication of anterior cervical discectomy and fusion (ACDF). There are reports that cite the prevalence of nonunion for two-level ACDF with various fusion techniques, but they do not recommend treatment alternatives. Pseudarthrosis after a two-level ACDF occurred in a 69-year-old man. Posterior cervical wiring and autograft resulted in a successful fusion anteriorly and posteriorly. Posterior fusion augments stability, enhances the potential for eventual anterior fusion, avoids the risks of an additional anterior procedure, and is an excellent therapeutic alternative to a second anterior attempt at stabilization.

Aged↗
PubMed1986

The migration of a broken pin following fixation of the acromioclavicular joint. A case report and review of the literature.

The use of smooth and threaded pins for internal fixation is often complicated by component migration, especially when employed about the acromioclavicular joint. A case report of pin breakage with subsequent migration is presented. This phenomenon occurred despite efforts to stabilize the pin corroborating the potential hazards and unpredictability of these implants. A protocol for the management of these devices, before and after component failure, is presented.

Acromioclavicular Joint↗
PubMed1986

Computerized tomography with routine arthrography in early evaluation of congenital hip dysplasia.

The earliest accurate assessment of the pathologic anatomy in congenital hip dysplasia allows for the most effective treatment and ultimate joint development. Computerized tomography has been suggested to better delineate bony orientation, size, and congruity; however, the inability of the routine CT scan to clearly depict cartilaginous structures has further confirmed the adequacy of the arthrogram alone in most patients. We present a technique employing computerized tomography following routine arthrography to more thoroughly assess the cartilaginous and soft tissue structures in the younger patient. Although certainly not indicated in all patients, this technique provides an effective diagnostic adjunct in select patients with complicated hip dysplasia early in the hip development.

Arthrography↗