The effect of propofol anaesthesia on oocyte fertilization and early embryo quality.

Propofol, frequently used for i.v. induction of anaesthesia in assisted reproduction procedures, has been suspected of damaging oocytes. Concentrations of propofol have recently been shown to increase in follicular fluid during oocyte retrieval. Our study was designed to assess whether exposure to increasing concentrations of propofol has a measurable effect on in-vitro fertilization, cleavage and embryo development. A cohort of 130 women underwent i.v. anaesthesia using propofol and fentanyl. Time of anaesthesia from i. v. injection of propofol was measured, as were the doses of the two drugs. In 32 women expected to have more than 15 oocytes retrieved, first, middle and last oocytes were cultured separately. The mean time from i.v. injection to first follicle aspiration was 200 s. The mean time for the aspiration of each additional oocyte was 17.6 s. In 10 out of 11 cases where follicular fluid concentrations of propofol were measured, there was an increase from the first to the last follicle, but no difference was found in the ratio of mature to immature oocytes. Nor were any differences found in fertilization, cleavage and embryo cell number. In so far as in-vitro development reflects embryo quality, we conclude that the time elapsed between retrieval of the first and last oocyte does not affect oocyte quality.

Instrumented posterior arthrodesis of the lumbar spine in patients with diabetes mellitus.

The existence of diabetes mellitus has been postulated to have a deleterious effect on the outcome following lumbar spine surgery. We retrospectively examined the records and radiographs of 32 diabetic patients (mean age, 60 years) who underwent posterior lumbar fusions using transpedicular instrumentation and iliac crest autograft. Ten patients were insulin-dependent and 22 required oral hypoglycemic agents for at least 1 year prior to surgery. The minimum follow-up time was 2 years after surgery (mean, 2.5 years). Surgical indications included herniated lumbar disk, lumbar spinal stenosis, thoracolumbar trauma, and lumbar pseudarthrosis. Clinical results were evaluated by chart review and/or interview by using Odom's criteria. At follow-up, 75% of patients were graded as excellent or good, and 25% as fair or poor. Twenty-five of 32 patients (78%) had improvement of back pain. Twenty of 27 (74%) patients had improvement of leg pain. Eight of 15 (53%) patients had improvement in motor strength, and 6 of 11 (54%) had improvement in light-touch sensation. Insulin dependence and the presence of polyneuropathy were associated with a poorer outcome. The average time to radiographic fusion was 5 months. Twenty-nine of 32 patients (91%) developed solid fusion by strict radiographic criteria. The three patients with a pseudarthrosis had persistent back pain and a poor result. Ten of 32 (31%) of the patients experienced perioperative complications, including prolonged wound drainage (n = 5), deep wound infection (n = 1), superficial wound infection (n = 1), atrial fibrillation (n = 1), ruptured cerebral aneurysm (n = 1), and ulnar nerve neuropathy (n = 1). We conclude that posterolateral lumbar spinal fusion with internal fixation in diabetic patients yields clinical results comparable to those of nondiabetic patients, with similar risks of perioperative complications.

Bupivacaine for postoperative pain relief at the iliac crest bone graft harvest site.

An inevitable side effect of iliac crest bone graft harvesting is postoperative pain at the donor site. Bupivacaine hydrochloride is a long-acting local anesthetic that is clinically effective for approximately 8 hours. The present study was undertaken to assess postoperative pain relief with locally injected bupivacaine at the iliac crest bone graft harvest site. Pain relief with locally injected bupivacaine or saline at the iliac bone harvest site using an indwelling catheter was studied in 13 patients in a prospective, double-blind, crossover study. Twelve patients had cervical diskectomy and arthrodesis with autograft and one patient had a triple arthrodesis of the foot. There were no statistically significant differences between patients given bupivacaine and patients given saline with respect to pain relief ratings and hip-pain ratings at rest and motion during the first 24-hour postoperative period and the second 24-hour postoperative period (Mann-Whitney test). The single diabetic patient who had a triple arthrodesis developed a wound infection at the catheter placement site. The number of patients was too small to draw conclusions about the differences in pain-medication requirements between patients undergoing single versus multiple diskectomies and fusions. In view of the lack of improvement in pain relief and the risk of infection, local administration of bupivacaine at the iliac bone harvest site is not recommended in its present form for postoperative analgesia.

Occipitocervical stabilization for myelopathy in patients with rheumatoid arthritis. Implications of not bone-grafting.

BACKGROUND: Approximately 0.9 percent of the white adult population of the United States and 1.1 percent of the adult population in Europe are affected by seropositive rheumatoid arthritis. As many as 10 percent of those patients may need an operation for atlantoaxial subluxation. Severe instability, especially when associated with vertical subluxation of the odontoid process, can result in progressive cervical myelopathy. Typically, occipitocervical fixation has been performed for these patients with use of autograft bone to achieve long-term stability through a solid fusion. Harvesting the bone graft increases the operative risk to the patient and may result in increased morbidity. In our experience, patients who have had no clear radiographic evidence of fusion following use of occipitocervical instrumentation seemed to have done as well as those who have had obvious fusion. One assumption is that the clinical improvement might be attributable simply to stabilization of the joint rather than to osseous fusion. A longitudinal study was performed on patients with rheumatoid arthritis who required an operation because of craniocervical or upper cervical instability. METHODS: The results of clinical, radiographic, functional, and self-evaluations were studied to determine the efficacy of treatment and to compare the outcomes of bone-grafting with those of procedures done without bone-grafting in a group of 150 patients who underwent posterior occipitocervical stabilization with use of a contoured metal implant (a Ransford loop) that was affixed by sublaminar wires. Internal fixation was performed in 120 patients without bone-grafting and in thirty patients with use of autogenous bone-grafting. Preoperatively, 23 percent (thirty-five) of the 150 patients had mild neurological involvement (class II, according to the system of Ranawat et al.), 45 percent (sixty-eight) had objective findings of weakness and long-tract signs but were able to walk (class III-A), and 29 percent (forty-three) were quadriparetic and unable to walk (class III-B). The age of the patients at the time of the operation ranged from twelve to eighty-three years (mean, sixty-two years). RESULTS: There were significant improvements in postoperative Ranawat classes at all time-periods (range, p < 0.00005 to p = 0.0066) and in patient ratings of neck pain (range, p < 0.00005 to p = 0.0044) compared with preoperative scores. With the numbers available, there were no significant differences between the patients managed with a graft and those managed without grafting with respect to survival after the operation, Ranawat class, head or neck-pain rating, presence of subaxial abnormalities, radiographic craniovertebral motion, or vertical subluxation. Overall mortality at one month was 10 percent (fifteen of 150), although this value varied directly with the degree of preoperative disability. A second cervical spine operation was required in 11 percent (sixteen) of the 150 patients. CONCLUSIONS: While patients who have rheumatoid disease with anterior atlantoaxial subluxation should be treated with posterior atlantoaxial arthrodesis with use of bone-grafting and internal fixation, we believe that those who present with vertical instability and multi-level involvement can be treated with posterior occipitocervical stabilization with use of a contoured occipitocervical loop and sublaminar wire fixation without bone-grafting. Furthermore, we believe that the use of preoperative traction, bone cement, or a postoperative halo vest is unnecessary. Avoiding the harvesting of autogenous bone for grafting reduced the morbidity of this operation without compromising the outcome in these already sick patients.

Midazolam/ketamine sedative combination compared with fentanyl/propofol/isoflurane anaesthesia for oocyte retrieval.

Assisted reproduction may be associated with repeated occasions of surgical intervention. Propofol, which is frequently used for induction of anaesthesia in such procedures, has been suspected of damaging oocytes. We compared in a randomized prospective design the use of general anaesthesia with fentanyl 0.017 mg/kg, propofol 2.5 mg/kg and isoflurane to that of sedation with midazolam 0.06 mg/kg and ketamine 0.75 mg/kg for transvaginal oocyte retrieval in 50 patients with no premedication. Overall, patient satisfaction was not different between the groups. Sedated patients were more arousable than anaesthetized patients during the procedure and experienced less postoperative abdominal pain at 30 min. Despite some movement in response to pain, oocyte retrieval was conveniently feasible in all sedated patients, of which none required a switch to general anaesthesia. A comparable number of oocytes was retrieved per cycle, 10.8 (+/-7.8) versus 9.6 (+/-10.9) with sedation and anaesthesia respectively. No patient recalled any pain sensation during the procedure. The rate of embryo transfers and pregnancies were not different between the two groups. We conclude that the sedative combination of midazolam and ketamine for oocyte retrieval may serve as an alternative for general anaesthesia.

Predictors of outcome in the quadriparetic nonambulatory myelopathic patient with rheumatoid arthritis: a prospective study of 55 surgically treated Ranawat class IIIb patients.

The functional results of surgery in patients with myelopathic nonambulatory rheumatoid arthritis (Ranawat Class IIIb) are often disappointing, with high rates of postoperative morbidity and mortality. The authors therefore undertook a detailed investigation of a cohort of 55 Ranawat Class IIIb patients (11 men and 44 women) with a mean age of 64.7 years who were recruited prospectively over a 10-year period (1983-1993), to determine what factors may accurately predict a good surgical outcome. Only 14 patients (25.5%) were judged to have had a favorable outcome as determined by an improvement to Ranawat Class I or II or an improvement of at least 0.5 points in the Stanford Health Assessment Questionnaire disability index. The early postoperative mortality rate was high (12.7%) in this group and almost one-quarter of the patients were dead within 6 months. These poor results mirror those already published in the existing literature. Univariate analysis revealed that age (p = 0.02), degree of vertical translocation (p = 0.05), and, more importantly, spinal cord area (p = 0.006) were significant predictors of outcome. Multiple logistic regression analysis showed that spinal cord area (p = 0.026) was, in fact, the major determinant of outcome and, indeed, of long-term survival (p = 0.001). The mean spinal cord area of those patients not achieving a good outcome was 44 mm2. The atlantodens interval (ADI) was not shown to be a significant outcome determinant, which may be explained by the correlation between an increasing vertical translocation and a decreasing ADI (r = 0.4, p = 0.01). Furthermore, as the degree of vertical translocation increased, the space available for the cord was observed to decrease (p = 0.003) commensurate with a reduction in spinal cord area (p = 0.02). Together, these findings strongly argue for earlier surgical intervention, before the development of vertical translocation, permanent neurological damage, and spinal cord atrophy can occur.

Surgery on the rheumatoid cervical spine for the non-ambulant myelopathic patient-too much, too late?

BACKGROUND: Opinions differ on the timing of surgery for rheumatoid arthritis patients with atlanto-axial subluxation. Some clinicians wait for development of neurological signs; others favour prophylactic fusion and decompression. We examined the results of surgery in relation to neurological state at the time of operation. METHODS: 134 patients underwent surgery for rheumatoid involvement of the cervical spine, after development of objective signs of myelopathy. Surgical outcomes were examined prospectively in two groups-patients who were still ambulant at the time of presentation (Ranawat class III A) and patients who had lost the ability to walk (Ranawat class III B)-by means of neurological and functional grading systems in conjunction with standard measures of postoperative morbidity and mortality. FINDINGS: 58% of the ambulant patients attained Ranawat neurological grades I or II compared with only 20% of the non-ambulant patients (p<0.0001). The non-ambulant group also fared worse in terms of postoperative complication rate, length of hospital stay, functional outcome, and ultimately survival. Radiologically, the non-ambulant patients were characterised by a smaller cross-sectional spinal cord area. INTERPRETATION: The strong likelihood of surgical complications, the poor survival, and the limited prospects for functional recovery in non-ambulant patients make a strong case for earlier surgical intervention. At a late stage of disease most patients will have irreversible cord damage.

Does the cervical canal to body ratio predict spinal stenosis?

The exact size of the bony cervical spinal canal and the vertebral body was measured in 368 cadaveric adult male vertebrae. A comparison of radiographic and direct measurements was also undertaken. The mean sagittal diameter of the spinal canal for C3-C7 was close to 14 mm (14.07 +/- 1.63 mm; N = 272). The mean ratio of the sagittal canal diameter to the vertebral body diameter (canal to body ratio) was 86.68 +/- 13.70 mm. Thirty-one percent of subaxial vertebrae would be diagnosed as having spinal stenosis if a canal to body ratio of less than 80% was considered abnormal. Measurements from plain radiographs overestimate the canal diameter. The average diameter for the lower cervical spinal canal is about 14 mm. The canal to body ratio is independent of radiographic magnification, but may produce misleading results.

A biomechanical evaluation of internal lumbar laminoplasty: the preservation of spinal stability during laminectomy for degenerative spinal stenosis.

The long-term success of surgical management of spinal stenosis by decompressive lumbar laminectomy is predicated partly by the maintenance of intervertebral stability. Excessive bone removal, especially of the pars interarticularis, may predispose the spine to iatrogenic segmental instability and spondylolisthesis. Removal of too little bone may be inadequate to relieve stenotic or radicular symptoms. Wide decompression with concomitant arthrodesis has been advocated, but arthrodesis compounds the surgical complexity and increases the risks of surgical treatment. Internal lumbar laminoplasty obviates the problem of too little or too much bone removal in the surgical management of spinal stenosis. The spinal canal is enlarged internally by an undercutting facetectomy performed through a narrow central laminectomy. The pars interarticularis is left completely intact. Twenty five adult human cadaveric spinal units were subjected to biomechanical testing following hemilaminectomy, total laminectomy, internal laminoplasty, partial facetectomy, or disk transection and internal laminoplasty. Analysis was performed after video and computer acquisition of data from specimen testing on an Instron machine. Internal laminoplasty demonstrated more intrinsic stability than the other surgical procedures.

Nystagmus and joint position sensation: their importance in posterior occipitocervical fusion in rheumatoid arthritis.

It is widely believed that brain stem dysfunction and cranial nerve palsies in patients with rheumatoid arthritis (RA) are common and related to the vertical translocation of the odontoid process. In our database of 235 patients with seropositive RA and craniocervical junction involvement, we have found a very low incidence of such problems. Long tract signs were common, but loss of proprioception (joint position sensation) as the sole neurologic deficit was rare. Nystagmus was found to be associated with the tonsillar herniation of a Chiari 1 malformation and loss of joint position sensation with severe compression of the posterior aspect of the spinal cord at the craniocervical junction. The implications for posterior occipitocervical fusion, particularly by sublaminar wiring, are discussed.

Extracoelomic approach to the spine.

A modified transthoracic approach to the thoracic vertebral column is described. In this method, the parietal pleura is detached from the chest wall and retracted with the visceral pleura and its contents. A direct approach to the vertebral bodies is thus achieved without transgression of the intrapleural space. The technique can be extended to include exposure of the thoracolumbar spinal column, utilising a thoracoabdominal approach with extrapleural and extraperitoneal dissection. Management of the costophrenic detachment is thus simplified. This approach has significant advantages for orthopaedic, vascular and neurosurgical procedures.

Demineralized bone matrix. Enhancement of spinal fusion.

A study was conducted to determine the ability of demineralized bone matrix gel to act as an osteoconductive/osteoinductive material to enhance canine spinal fusion. Seven dogs underwent posterior spinal fusion. Four-level fusions were performed with one of four procedures at each level: decortication alone, with gel added, with autograft, or with both gel and autograft. Dogs were killed at 6 weeks and early histologic response was studied. At untreated control sites, little bone formation was evident. Gel-filled sites showed abundant osteoid, with 60% of demineralized particles fused to or surrounded by new bone. Sites filled with autograft had more new bone, but there was more osteoid at gel-treated sites. Autograft augmented with gel showed the most vigorous response, with extensive bridging between demineralized particles, host bone, autograft, and new bone. Significantly less autograft was needed to induce a similar amount of new bone formation when gel was added. Use of the gel as an autograft extender may improve the chance for successful spinal fusion.

Atlantoaxial arthrodesis using interlaminar clamps. An improved technique.

The atlantoaxial articulation is a multiaxial joint with a freedom of motion that presents unique problems in achieving surgical stability. Several methods of atlantoaxial arthrodesis have been established with varying degrees of immediate and sustained stability and safety. This study describes a new, improved method of posterior atlantoaxial arthrodesis, using (Halifax) interlaminar clamps with interposed bone graft, which provides distinct benefits over existing techniques. This method achieved atlantoaxial union within 12 weeks in 80% of the study's patients (20/25). The clamp fixation was revised in two patients, with subsequent fusion. Three other patients required revision surgery for nonunion due to loosening of the clamp. This was usually caused by incomplete tightening of the screws, with subsequent loosening or dislocation of the device. Possible clamp loosening is a potential problem with the currently available system, and may be a result of the clamp design. Techniques to minimize this risk and suggestions for improvement in the device are discussed. Nonunion is more likely to develop in patients with rheumatoid arthritis. If nonunion occurs, the pseudarthrosis is generally between the posterior bone graft and the ring of C1.

Localized pigmented villonodular synovitis of the knee. Arthroscopic treatment.

Localized pigmented villonodular synovitis is a lesion that may affect any joint but is frequently found in the knee. Because of its rarity, diagnostic omissions are common. Definitive treatment usually involves resection of the lesions as well as a synovectomy. Nine patients were treated arthroscopically, thereby avoiding arthrotomy. There was no evidence of recurrence at the follow-up evaluation (range, 25-108 months; mean, 48 months). The patients with mechanical knee symptoms had small nodular lesions anteriorly related to the menisci; those with degenerative symptoms had slightly more prolific nodules in other sites. No recurrence occurred in either group.

The rheumatoid cervical spine.

The cervical spine contains 31 joints and moves about 600 times per hour. This makes it a site with a predilection for synovitis, ligamentous inflammation and mechanical stress in all types of chronic arthritis. Accordingly, eight different atlantoaxial or subaxial sublaxations and numerous other pathologic conditions occur in this area. The vital structures contained in this area impart particular significance to this involvement. Because there are practically no similarities between the structure and function of the lumbar spine and cervical spine, no parallels can be drawn between these two anatomically separate sites. Therefore, the anatomy, physiology, pathology, clinical syndromes, and treatment of the rheumatoid cervical spine have to be understood and dealt with on their own. This review article contains an update of topics of utmost importance in patient care, in light of the most recent basic and clinical science studies. Particular attention has been paid to new imaging and neurophysiologic techniques and their relevance to clinical design and treatment decisions, and modes of treatment in light of new advances in surgical technique and in our understanding of the long-term effects of active expectance and surgical intervention.

Posttraumatic atlanto-axial subluxation and myelopathy. Efficacy of anterior decompression.

Compression of the neuraxis may occur after displaced fractures of the dens. Nonunion or malunion increases the risk of developing neurologic complications because of the resulting atlanto-axial instability. Posterior decompression has generally been the surgical solution to myelopathy at this level. Two patients with cervical myelopathy due to displaced ununited dens fractures were treated with posterior fossa decompression and high cervical laminectomy. Both patients deteriorated after the surgery. Most of their neurologic deficits finally resolved after microsurgical transoral decompression (by resection of the dens). In those patients in whom atlanto-axial instability causes primarily anterior compression of the neuraxis, especially by a bony lesion, decompression posteriorly may not achieve the desired effect, and, instead, may cause a deterioration in the patient's condition. Anterior atlanto-axial subluxation effectively lengthens the bony spinal canal, which results in stretching of the relatively inelastic spinal cord over the bony deformity. If indirect methods of reduction fail to relieve the condition, then anterior transoral decompression is recommended.

Myelopathy due to hypertrophic nonunion of the dens: case report.

Fractures which occur near the base of the dens have a low propensity to unite spontaneously. One of the major complications of nonunion is displacement of the fracture resulting in neuraxis compression and the development of myelopathy. Hypertrophic nonunion of the dens may cause spinal cord compression even if displacement does not occur. This situation has not to our knowledge previously been reported. A literature review and appraisal of the issues raised are discussed. Appropriate therapeutic options are outlined, including posterior surgery and the use of transoral decompression.

Intratendinous aponeurotic fibroma.

Juvenile aponeurotic fibroma is a distinctive fibroblastic tumor usually found in young children. The tumor has a predilection for the palms and soles, although it can occur elsewhere, either superficially in subcutaneous tissues or in deeper musculofascial and paraskeletal tissues. In this case the tumor occurred in an adult within the substance of the flexor pollicis longus tendon, a location not previously reported in the literature. Because of the unique location of the tumor, it was excised without sacrificing the tendon. Since recurrence of these lesions is common, continued observation was necessary. Magnetic resonance imaging in this patient 26 months after the operation showed restoration of the normal tendon contour.