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H N Herkowitz

Publications and source records attributed to H N Herkowitz.

At least 19 recordsLinked to original sources
PubMed1997

Spinal instrumentation in the management of degenerative disorders of the lumbar spine.

The use of spinal instrumentation as an adjunct to fusion for the treatment of degenerative disorders of the lumbar spine is controversial. Instrumented lumbar fusions, in specific instances, may improve patient outcomes. For patients undergoing single level primary lumbar arthrodesis, the available data do not conclusively support the efficacy of spinal instrumentation. However, in the setting of previous failed lumbar surgery, iatrogenic or degenerative lumbar spondylolisthesis, spinal instrumentation may be useful as an adjunct to fusion. Possible advantages associated with the use of instrumentation include: correction of deformity in frontal and sagittal planes; decreased pseudarthrosis rates; prevention of progression of spondylolisthesis, and provision of spinal stability in the absence of intact posterior elements. Complications associated with the use of instrumentation include: increased cost; increased operative times; increased infection rate; increased reoperation rate; and a steep learning curve. Therefore, when instrumentation is to be used, the benefits must outweigh the risks. These risks can be minimized by the judicious use of instrumentation by experienced surgeons, for specific indications as supported by the literature.

Discitis↗
PubMed1996

Is pathology examination of disc specimens necessary after routine anterior cervical discectomy and fusion?

STUDY DESIGN: A retrospective chart review was performed from 1990-1994. OBJECTIVES: To evaluate the outcome of pathologic examination of cervical disc specimens submitted after anterior cervical discectomy. SUMMARY OF BACKGROUND DATA: This study is the first to review the outcome of pathologic examination of disc specimens after anterior cervical discectomy and fusion. METHODS: Charts were reviewed based on the procedure code of anterior cervical fusion and the main diagnoses of cervical disc and spondylosis. The following data were recorded for each patient: symptoms, examination, diagnostic studies, operative procedure, operative findings, and pathology report. Statistical analysis was performed. RESULTS: Five hundred six disc levels in 394 patients were reviewed. All patients had symptoms and examination results consistent with cervical radiculopathy. All patients had cervical radiographs and some combination of myelography, computed tomography, or magnetic resonance imaging. Findings at the time of surgery included the presence of either a herniated disc or degenerative spondylitic changes. The pathologic examination results of all specimens reported fibrocartilaginous tissue consistent with disc material with the presence of degenerative changes. No infectious, benign, or malignant process was identified at the time of surgery or on gross and histologic examination of any of the disc specimens. Using confidence intervals (95%) for exact proportions and given 500 negatives, the chance the next occurrence would be positive would be 0.0060 or 0.60% or six of 1000. CONCLUSIONS: This study shows that if the symptoms, physical examination, radiographic diagnostic studies, and surgical findings are consistent with those of cervical disc herniation of spondylosis, the chance of an unexpected, clinically important pathologic finding within the disc specimen is extremely small. The time and expense involved in routine pathologic examination of cervical disc specimens can be avoided.

Cervical Vertebrae↗
PubMed1996

Efficacy of closed wound suction drainage after single-level lumbar laminectomy.

The use of closed suction drainage after spinal surgery remains controversial. The purpose of this study was to determine the indications for closed suction drainage after single-level lumbar surgery. Two hundred patients who were scheduled to undergo single-level lumbar surgery without fusion were prospectively randomized into two groups. One group had a closed wound suction drain placed deep to the lumbodorsal fascia before routine closure, whereas the second group had no drain placed. Hemostasis was achieved in all patients before the surgeon had knowledge of the randomization outcome. All drains were removed on the 2nd postoperative day, and the amount of drainage was recorded. After surgery, the patients were evaluated for signs and symptoms of continued wound drainage, hematoma/seroma formation, and/or infection as well as evidence of an acquired neurologic deficit. One hundred three patients had a drain placed before closure and two patients developed postoperative wound infection, both of which were successfully treated with orally administered antibiotics. Of the 97 patients who had no drain placed after the surgical procedure, one patient developed a postoperative wound infection that was treated with surgical incision and drainage, as well as intravenously administered antibiotics. Statistical analysis revealed that the presence or absence of a drain did not affect the postoperative infection rate. No new neurologic deficits occurred in any postoperative patient. The use of drains in single-level lumbar laminectomy without fusion did not affect patient outcome. There was no significant difference in the rate of infection or wound healing and no patient developed a postoperative neurologic deficit.

Adult↗
PubMed1995

The effect of interposition membrane on the outcome of lumbar laminectomy and discectomy.

STUDY DESIGN: This study evaluated clinical and magnetic resonance imaging differences of patients treated surgically for lumbar disc herniation. Clinical follow-up and magnetic resonance imaging evaluation of epidural fibrosis were used to assess patient outcome. OBJECTIVES: The purpose of this study was to evaluate the difference in clinical outcome with either free-fat graft, Gelfoam, or no interposition membrane placed in the laminectomy defect after nerve root decompression. SUMMARY OF BACKGROUND DATA: Epidural fibrosis has been considered a cause of recurrent symptoms after lumbar laminectomy, and numerous materials have been evaluated for prophylaxis of the "laminectomy membrane." These have been mainly histologic and animal studies with no data correlating clinical symptoms and postoperative epidural scar formation. METHODS: One hundred fifty-six patients who were treated surgically for lumbar disc herniation were randomly assigned to one of three groups and followed prospectively for at least 1 year. Thirty-three of these patients were received magnetic resonance imaging evaluations after 6 months by an independent radiologist who graded the amount of epidural scar formation. The patients were assessed at 1 year and given a rating of excellent, good, fair, or poor, and the scar was graded as none, minimal, or moderate. RESULTS: Although 97% of all patients improved, 83% were rated excellent or good. There were no statistical differences between the three groups clinically and radiographically. Patients with workers compensation had a statistically significant lower success rate (P < 0.001). CONCLUSIONS: Clinical outcome after lumbar disc surgery does not correlate with the use or type of interposition membrane used to prevent epidural fibrosis.

Adolescent↗
PubMed1995

Spine update. Degenerative lumbar spondylolisthesis.

Degenerative lumbar spondylolisthesis associated with spinal stenosis is a common condition of the aging spine. This article presents a detailed description of the pathophysiology, clinical presentation, and nonoperative and operative intervention of this condition.

Female↗
PubMed1995

The effect of prophylactic antibiotics on iatrogenic intervertebral disc infections. a rabbit model.

STUDY DESIGN: A rabbit model was used to test the efficacy of two commonly used prophylactic antibiotics, cefazolin and vancomycin, in preventing iatrogenically introduced Staphylococcus aureus intervertebral disc infections. OBJECTIVE: This study was performed to assess the efficacy of two prophylactic antibiotics in preventing iatrogenically introduced Staphylococcus aureus intervertebral disc infections. SUMMARY OF BACKGROUND DATA: Previous studies have had conflicting results regarding the penetration of antibiotics into the nucleus pulposus and their ability to eradicate infection. METHODS: In this study, 40 adult New Zealand White rabbits underwent inoculation of 10(1) or 10(3) Staphylococcus aureus/ml into 3-6 lumbar intervertebral discs under direct visualization. Either no antibiotics (control groups) or various preoperative and postoperative dosing schedules of cefazolin or vancomycin were given intravenously. Five days after surgery, the discs were harvested and cultured. RESULTS: All 40 discs inoculated in the control groups became infected. None of the 35 discs inoculated in the cefazolin groups became infected. Infection developed in 23 of 107 discs inoculated in the vancomycin groups. Most notable of these were 17 of 17 positive cultures in animals given vancomycin 8 hours preoperatively only. CONCLUSIONS: Based on these results, it was concluded that intravenous cefazolin or vancomycin given within 1 hour before surgery can effectively prevent postoperative discitis. No advantage was found with additional postoperative antibiotics.

Animals↗
PubMed1995

A modified posterolateral approach to the thoracic spine.

We describe a modified technique for posterolateral approach to the thoracic spine and report the use of this procedure in 21 patients. The technique is safe and effective for selected indications. The evolution of the posterolateral or costotransversectomy approach to the thoracic spine has in large part focused on enlarging the exposure to the vertebral bodies and epidural space by resecting an increasing number of ribs and removing a wider portion of those ribs resected. In this modified approach to the thoracic spine, the costovertebral articulation is preserved, and no rib resection is necessary to gain adequate exposure to the thoracic vertebral body and epidural space. We did a retrospective review of 21 patients undergoing 22 modified posterolateral approaches to the thoracic spine. Sixteen patients had biopsies of thoracic vertebral lesions through this approach; 3 underwent decompression of the thoracic spinal cord; 2 approaches were done for the removal of a herniated thoracic disc; and in one, the pedicle was removed. This modified posterolateral approach allowed adequate exposure for selected indications. One complication, a wound infection, developed after biopsy for suspected osteomyelitis. This modified posterolateral approach is well suited to provide access for biopsy of thoracic spinal lesions; for decompression of a paraspinal abscess; and for decompression of the thoracic spinal cord by anterolateral compressive lesions such as herniated thoracic disc or epidural tumor when resection of the vertebral body is not necessary; or the approach may be used for patients who are debilitated or at poor risk to undergo thoracotomy.

Adult↗
PubMed1994

Anular incision technique on the strength and multidirectional flexibility of the healing intervertebral disc.

STUDY DESIGN: This study used a sheep model to biomechanically analyze the healing strength of the anulus fibrosus after two types of anular incisions. OBJECTIVE: This study evaluated whether the type of anular incision made at the time of lumbar discectomy plays a role in the subsequent healing strength of the anulus and the biomechanical flexibility of the corresponding motion segment. METHODS: Two types of anular incision, a full thickness removal of a box or window of anulus and a full thickness straight transverse slit through the anulus, were made in the intervertebral discs of 18 adult sheep. After healing times of 2, 4, and 6 weeks, the intervertebral discs were tested versus control levels for strength of anular healing and biomechanical flexibility of the corresponding motion segment. RESULTS: The box incised discs showed a significantly greater loss in strength during the early healing phase (2 to 4 weeks) and a longer response before recovering anular strength when compared with the slit-incised discs. The type of incision also affected the multidirectional flexibility of the motion segments in a differentiated manner. Larger amounts of motion were seen with the box incision when compared with the slit incision at all time periods and in all pure moments. CONCLUSION: The technique of anular incision plays a definite role in the timing and strength of subsequent anular healing. The box incision through the anulus led to significantly weaker healing than did the slit incision in the early healing phase (2-4 weeks). Also, larger amounts of motion were seen in the vertebral motion segments of those discs undergoing box incision when compared with slit or control levels.

Animals↗
PubMed1993

A biomechanical comparison of cervical laminaplasty and cervical laminectomy with progressive facetectomy.

The effects of multilevel cervical laminaplasty and laminectomy with increasing amounts of facetectomy on stability of the cervical spine were tested with physiologic loading in nine cadaveric specimens. Cervical spines, levels C2-C7, were tested with physiologic loading in a constraint-free test system, the motion of each body being tracked in a three-dimensional coordinate system. Cervical laminectomy with 25% or more facetectomy resulted in a highly significant increase in cervical motion compared to the intact specimens for the dominant motions of flexion/extension (P < 0.003), axial torsion (P < 0.001), and lateral bending (P < 0.001). Cervical laminaplasty was not significantly different from the intact control, except for a marginal increase in axial torsion. Coupled motion did not change with laminaplasty or laminectomy with progressive facetectomy. As little as 25% facetectomy adversely affects stability after multilevel cervical laminectomy. Cervical laminaplasty avoids this problem, while still affording multilevel decompression. Therefore in patients undergoing cervical laminectomy accompanied by more than 25% bilateral facetectomy, concurrent arthrodesis should be performed.

Absorptiometry, Photon↗
PubMed1993

Spinal pedicle fixation. Confirmation of an image-based technique for screw placement.

Although many advances in the technique of pedicle screw insertion have been made, there still exist unacceptable rates of perforations through the pedicle cortex. Successful placement of a pedicle screw requires accurate identification of the entry point, correct transverse and sagittal plane angulation, safe preparation of a pilot hole, and appropriate depth of insertion. The authors propose that a technique of pedicle screw insertion using posteroanterior image intensification angled in the axis of the pedicle to define the entry point and guide insertion would improve the accuracy of this procedure. This study tests the accuracy of pedicle screw placement using this technique. Ninety pedicle screws were placed in human cadaveric lumbar spines. All specimens were then dissected and split longitudinally to assess accuracy of pedicle insertion by both visual and palpatory means. Five of 90 (5.5%) pedicle screws were found to have perforated the pedicle. Three of these were at L1, two of which were due to the transverse pedicle diameter being smaller than the screw diameter. Therefore, a 3.4% incidence of pedicle perforation due to malpositioning and a 2.1% incidence of pedicle perforation secondary to pedicle/screw size discrepancy was determined. This technique may lead to significant improvements over recently reported rates of pedicle screw perforations; however, this in vitro condition eliminated many potentially complicating factors that might be encountered in the clinical setting.

Bone Screws↗
PubMed1993

Upper lumbar disc herniations.

This study reviews the presentation, diagnosis, and outcomes of upper lumbar disc herniations (L1-2, L2-3, L3-4). One hundred forty-one patients operated upon at three centers between 1980 and 1990 were analyzed (102 men, 39 women; 3 L1-2, 21 L2-3, 117 L3-4; average age 51.6 years; 10.4% of all lumbar discectomies performed). Preoperative signs and symptoms were highly variable. Sensory, motor, and reflex testing was variable and potentially misleading in suggesting a level of herniation. In analyzing radiographic studies (noncontrast CT, myelography, MRI) individually and using other radiographic studies and operative findings as a standard for comparison, a high false-negative rate was found for all studies when considered individually, especially at the higher L2-3 level. Intraoperative radiographs were employed with increasing frequency as the level of herniation ascended. Six operative complications (4.3%) were identified, all of which were treated and were resolving at the time of discharge. Follow-up obtained at an average of 2.2 years in 87% of patients by chart review showed no reoperations or late complications. Noncompensation patients had a significantly higher percentage of good/excellent results (86%) than those with compensation or legal claims pending (45% good/excellent results). Based upon these data, we recommend myelogram with postmyelogram CT and/or MRI in the workup of these patients and intraoperative radiographs in all cases when decompressing an upper lumbar disc herniation. Patients with compensation/legal claims should be approached cautiously, because their subjective results are significantly worse than those of noncompensation patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Pseudarthrosis of the spine.

Pseudarthrosis remains the leading cause of failed spinal fusions. The common causes of this complication are inadequate surgical technique, excessive stresses across the fusion site, insufficient internal or external stabilization, and unrecognized metabolic abnormalities. Many radiologic techniques have been used to diagnose pseudarthrosis in the spine. Nonetheless, the diagnosis of a nonunion as well as the ability to correlate the nonunion with the patient's clinical symptoms remains a challenge. In treating a symptomatic pseudarthrosis, the surgeon should first attempt to identify those factors that contributed to the development of a nonunion. The approach can then either be exploration of the fusion mass with regrafting of the pseudarthrosis or extending a fusion to locations within the abnormal segment of spinal motion.

Diagnostic Imaging↗
PubMed1992

Surgical management of myelopathy.

We have presented a comparative analysis of the ability of four surgical procedures to address adequately the problems sustained by a patient with symptomatic cervical myelopathy. AIA is a safe procedure whose effectiveness may be limited when the extent of disease is more than three intervertebral disk levels. ACA permits more direct and extensive access to the spinal cord and is the procedure of choice for cervical spondylotic myelopathy associated with spinal deformity. However, rigid external immobilization is necessary, and operative morbidity may be greater. Cervical laminectomy may be effective for decompressing the spinal cord when no associated spinal deformity or instability is present, provided that extensive resection of facet joints is avoided. Cervical laminaplasty is ideally suited for the patient with three or more levels contributing to a cervical myeloradiculopathy. Mild instability may be addressed by performing arthrodesis on the hinge side.

Adult↗
PubMed1991

Modified anterior approach to the cervicothoracic junction.

The surgical management of tumors at the cervicothoracic junction is hindered by various anatomic structures. Standard approaches to the cervical or thoracic spine provide inadequate exposure. An approach to the cervicothoracic junction that provides exposure from C3 to T4 is described. The approach allows extensive bony resection, spinal cord decompression, correction of deformity, spinal reconstruction, and stabilization. Four patients with tumors metastatic to the cervicothoracic junction underwent this surgical approach. All had significant kyphosis and neck pain unresponsive to nonsurgical treatment. After surgery, neurologic function improved in three patients and remained normal in one. All patients had relief of neck pain and reduction of kyphosis.

Adult↗
PubMed1991

Osteolytic monostotic Paget's disease of the fifth lumbar vertebra. A case report.

Osteolytic monostotic Paget's disease or osteitis deformans of the fifth lumbar vertebra occurred in a 55-year-old woman. An isolated lytic process involving the entire vertebral body and posterior elements and an open biopsy showed extensive remodeling with cement lines, myelofibrosis, and osteoclastic resorption typical of Paget's disease.

Female↗
PubMed1991

Current status of percutaneous discectomy and chemonucleolysis.

This article provides an updated review of chemonucleolysis and percutaneous discectomy. Dr. Herkowitz recommends discontinuing the use of chymopapain. Percutaneous discectomy may play a small role in the invasive management of a lumbar disc herniation.

Humans↗