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Biomedical subjects

P F O'Leary

Publications and source records attributed to P F O'Leary.

13 recordsLinked to original sources

Early fracture of the sacrum or pelvis: an unusual complication after multilevel instrumented lumbosacral fusion.

STUDY DESIGN: A retrospective review of a series of cases with a complication of instrumented lumbosacral fusion. OBJECTIVES: To present a previously undescribed complication, early sacral or pelvic stress fracture, after instrumented lumbosacral fusion and to identify the risk factors associated with this complication. BACKGROUND: There are a number of well-described complications of instrumented lumbosacral fusion, including delayed stress fracture of the pelvis. Early sacral or pelvic stress fracture after instrumented lumbosacral fusion has not been previously reported, to the authors' knowledge. METHODS: The authors present three cases of early stress fracture occurring at 2-4 weeks after surgery in patients who underwent instrumented multilevel lumbosacral fusions for degenerative lumbosacral disease. RESULTS: Two patients had sacral fracture, which to the authors' knowledge, has not been previously reported. Risk factors included lumbosacral instrumentation and fusion, osteoporosis in elderly women, and iliac crest bone graft procurement. All patients were treated conservatively, with restricted ambulation and gradual return to activity. CONCLUSION: This complication can cause significant morbidity and a delay in the patient's return to function. A better understanding of the related biomechanical forces and preoperative risk factors may identify patients at risk and may aid in surgical planning and in expectations of postoperative recovery.

Aged↗

Decompressive surgery for typical lumbar spinal stenosis.

Between 1991 and 1992, 103 consecutive patients (average age, 65 years) underwent decompressive surgery for treatment of typical lumbar spinal stenosis. Clinical results at 1-year followup revealed that four patients had revision surgery. At 2- to 5-years followup, there were no additional revision surgeries. Two patients underwent revision surgery for a deep infection, and two underwent revision surgery for a superficial infection. Outcome results showed that 77 patients completed the questionnaire, 15 were lost to followup and 11 died. Postoperative results showed that 64 of 77 patients had no or mild pain, 72 of 77 patients stated that they were satisfied or somewhat satisfied with their overall results of surgery, and 73 of 77 were satisfied with pain relief. Younger patients had greater improvement in function and a greater reduction in severity scores. However, satisfaction was similar in both groups. Survivorship results (failure was revision surgery) showed at the end of 4 years, a patient had a 95% chance of not having revision surgery. Statistically, there was no association between outcome and cofactors such as scoliosis, spondylolisthesis, number of levels decompressed, discectomy, or smoking. Satisfaction rates for older patients were similar to patients younger than 65 years although physical function scores and severity scores were less.

Aged↗

Decompression, fusion, and instrumentation surgery for complex lumbar spinal stenosis.

Between 1990 and 1993, 54 consecutive patients were treated with decompression, fusion and instrumentation surgery for complex lumbar spinal stenosis. The mean age of the patients was 60 years. The average followup was 39 months. Clinically, there was one deep wound infection, and three mechanical failures. There were two staged operations. There were three revision surgeries performed for mechanical reasons. Of the 47 patients who completed the questionnaire, 96% of patients were very satisfied or somewhat satisfied with the operation, 98% were satisfied with relief of pain, 94% were satisfied with their ability to walk, 89% were satisfied with their strength, and 94% were satisfied with balance. Survivorship analysis (failure endpoint was revision surgery) revealed that at the end of 4 years, the patient had a 92% chance of not undergoing revision surgery for any reason (mechanical and infectious), and a 94% chance of not undergoing revision surgery for mechanical reasons. Lumbar decompression, fusion, and instrumentation surgery seems to be efficacious in patients with complex lumbar spinal stenosis (associated previous lumbar spine operations with evidence of radiographic instability, radiographic evidence of junctional stenosis after surgery, radiographic evidence of instability, degenerative spondylolisthesis greater than Grade I with instability, if present, and degenerative scoliosis with a curve greater than 20 degrees).

Decompression, Surgical↗

Distraction laminoplasty for decompression of lumbar spinal stenosis.

Distraction laminoplasty is a technical modification of routine laminectomy that allows decompression of the lumbar spinal canal with maximal bone preservation. The technique involves the application of a distraction force, in conjunction with an undercutting laminoplasty technique. It is safe, easily applied, and allows excellent canal visualization and decompression with minimal bone resection. The purpose of the current study is to describe the technical aspects of the technique.

Decompression, Surgical↗

Intravertebral body reconstruction with an injectable in situ-setting carbonated apatite: biomechanical evaluation of a minimally invasive technique.

The ability to mechanically reinforce an osteoporotic vertebral body could impede spinal compression fracture and the associated pain and complications. Previous studies have shown that reinforcement of fractured vertebrae with conventional acrylic cement can relieve symptoms and avoid further collapse. In this study, we explored the use of a carbonated apatite cement combined with a minimally invasive injection technique to improve the compressive mechanical properties of cadaveric vertebral bodies. After establishing the biomechanical characteristics of cement formulations intended to have appropriate viscosities, we evaluated the infiltration of the cements into thoracic vertebral bodies using a combined suction-injection technique. The energy-absorption capabilities of the reinforced vertebral bodies were then measured during axial compressive tests and compared with those of nonreinforced vertebrae. The ultimate compressive strength of the cement formulations averaged from 11.6 to 17.7 MPa, depending on curing conditions. The suction-injection technique allowed from one-half to two-thirds of each vertebral body to be infiltrated with cement. Energy absorption was significantly higher (p < 0.05) between 25 and 70% collapse of the vertebral body in the specimens that received the apatite injection as compared with the controls. These results suggest that osteoporotic vertebral-body augmentation with the injection of apatite cement could prevent further collapse after initial failure has occurred. The osteoconductive nature of the cement and its ability to be remodeled by bone, together with its compressive strength, which is higher than that of cancellous bone, could provide better clinical results than those of current treatments with acrylic cement.

Aged↗

Hepatic dysfunction in a population of antibody-deficient patients: prevalence, aetiology and outcome of PCR screening for hepatitis C and G viruses.

BACKGROUND AND OBJECTIVES: A group of 40 antibody-deficient patients receiving regular infusions of intravenous immunoglobulin underwent close monitoring in an attempt to identify hepatic dysfunction. The continuing risk of hepatitis virus transmission, especially hepatitis C virus via immunoglobulin products prompted this policy. We report our findings. METHODS: Screening included measurement of transaminase levels at each infusion. The patients were also tested for evidence of infection with hepatitis viruses B, C and G. RESULTS: Abnormal liver function tests were identified in 6 cases. However, a blood-borne viral aetiology was not found in any of these cases. Additional investigation allowed an alternative aetiology to be identified in most cases. One patient found to be positive for hepatitis G virus (HGV)-RNA by reverse transcriptase-polymerase chain reaction has no evidence to date of clinical problems as a result. INTERPRETATION: The results are reassuring in that definite iatrogenic hepatitis virus transmission has not been found in this cohort, despite long-term treatment with a wide range of immunoglobulin products. The source of infection of the single patient infected with HGV remains as uncertain as the pathogenic potential of this virus. However, as long as the risk of immunoglobulin-associated viral transmission continues, a strict monitoring programme such as ours should continue to facilitate prompt detection of cases with abnormal liver function. Liver dysfunction in this group requires full investigation and we cannot exclude infection with hitherto unidentified blood-borne viruses.

Adolescent↗

Recurrent disk versus scar in the postoperative patient: the role of computed tomography (CT)/diskography and CT/myelography.

The purpose of this study was to compare computed tomography (CT)/myelography and CT/diskography images, in a given patient, as a method of distinguishing postoperative fibrosis from recurrent herniated disk material. The study population consisted of 20 patients who had undergone lumbar diskectomy and subsequently developed recurrent radicular pain. All patients underwent CT/myelography and CT/diskography, each procedure performed within 72 h of the other. Comparison of transaxial images from CT/myelography and CT/diskography at a given disk space level yielded the following results: in 12 patients the extradural mass seen via CT/myelography corresponded entirely to the contrast-filled disk fragment seen via CT/diskography (recurrent herniated disk); in three patients the extradural mass seen via CT/myelography was larger than the disk fragment seen via CT/diskography (recurrent herniated disk and fibrosis); and in five patients CT/diskography images appeared normal, but CT/myelography showed an extradural mass (fibrosis). Fifteen patients underwent surgical reexploration with the following results: in three of three patients, the suspicion of recurrent herniated disk and fibrosis by radiologic evaluation was confirmed by surgical reexploration; in nine of 12 patients, solely recurrent herniated disk shown by radiologic criteria was similarly confirmed. The remaining five patients presumed to have fibrosis by radiologic criteria were treated nonoperatively.

Adult↗

Percutaneous computed-tomography-guided biopsy of the thoracic and lumbar spine.

Axial computed tomographic scans were used to guide percutaneous needle biopsies in 76 patients with thoracic and lumbar spinal lesions. Prebiopsy evaluation included spine radiographs, radionuclide bone scans, computed tomographic scans, magnetic resonance imaging scans in some cases, and coagulation studies. Forty-five patients were diagnosed as having metastatic lesions, 11 infection, and 12 primary bone tumors. Of all patients, 34 had lytic vertebral lesions with significant collapse and questionable spinal stability. Six of those had a concomitant paravertebral mass. A clinical and pathologic correlation was completed for each of the cases studied. Histologic diagnosis confirming the clinical suspicion was obtained on the first biopsy attempt in 65 (86%) of the 76 cases.

Biopsy, Needle↗

Anterior cervical discectomy and fusion.

A retrospective review of 94 patients who had undergone anterior cervical discectomy and fusion was performed to analyze the result in patients who had a diagnosis of posterolateral spondylosis, disc herniation, or both. Although in 23 of 94 patients additional adjacent asymptomatic levels of spondylosis were noted, only the symptomatic levels were addressed in the 94 cases. Postoperatively two cases of dysphagia were noted, as well as a 4% pseudarthrosis rate. There was an 88% good or excellent result when no additional spondylosis was present, but only a 60% good or excellent result when just the symptomatic levels were addressed, leaving unoperated adjacent levels of spondylosis.

Adult↗

Thoracic disc disease. Clinical manifestations and surgical treatment.

Thoracic disc herniation in an uncommon spinal entity. The authors discuss three variations in the presentation of the disease and point out the importance of being able to recognize both the thoracic prolapsed disc and the symptomatic degenerated nonherniated disc. The seven cases that are reported demonstrate the unique presentations of this disease and the techniques for treatment. Utilization of the anterior transthoracic approach for the excision of the herniated disc is emphasized.

Female↗