Nancy E. Epstein

Anterior approaches to cervical spondylosis and ossification of the posterior longitudinal ligament: review of operative technique and assessment of 65 multilevel circumferential procedures.

BACKGROUNDnMultilevel anterior cervical corpectomy with fusion (ACF) offers direct resection of spondylostenosis and ossification of the posterior longitudinal ligament (OPLL) with immediate stabilization. Ideal candidates for multilevel ACF include younger patients (<65 years of age), or older individuals (>65 years of age) with loss or reversal of the cervical lordosis (kyphosis).nnnMETHODSnSixty-five patients, averaging 56 years of age and including 40 males and 25 females, with multilevel MR- and CT-documented spondylostenosis and OPLL were studied. Preoperatively, patients exhibited moderate to severe myelopathy (average Nurick grade 3.8), and were managed with 2- to 4-level ACF with posterior wiring and fusion (PWF) procedures with halo application. The first 22 patients had no plate instrumentation, the next 22 had constrained (Orion) plates applied followed sequentially by the application of 13 semi-constrained (Atlantis) plates, and finally, 8 dynamic (ABC Aesculap) plates.nnnRESULTSnPatients improved an average of three postoperative Nurick grades. None exhibited new cord injuries, whereas three had transient C5 root paresis. Graft/plate or vertebral fracture with extrusion were observed in 3/22 nonplated patients, 2/22 constrained-plated patients, 3/13 semi-constrained-plated patients, and 0/8 dynamic-plated patients. Fusion was documented on dynamic radiographs and 2D-CT or 3D-CT studies obtained 3 and 6 months postoperatively, or later where indicated.nnnCONCLUSIONSnMultilevel ACF/PWF offers direct resection of spondylostenosis and OPLL with immediate maximal stabilization. Thus far, no graft/plate or vertebral body fracture or extrusions have been seen with dynamic plates, whereas the absence of plating and constrained and semi-constrained plating systems have failed.

Reoperation rates for acute graft extrusion and pseudarthrosis after one-level anterior corpectomy and fusion with and without plate instrumentation: etiology and corrective management.

BACKGROUNDnReoperation rates after one-level anterior cervical corpectomy with fusion (ACF) performed without and with plates need further evaluation.nnnMETHODSnReoperation rates for graft extrusion and symptomatic pseudarthrosis were analyzed following 48 nonplated (1989-1996) and 35 plated (1997-2000) one-level ACF. Preoperatively, patients typically exhibited mild/moderate myelopathy attributed to spondylostenosis and ossification of the posterior longitudinal ligament (OPLL). Thirty-five ACF were performed with plates: 3 Orion, 12 Atlantis, and 20 ABC Aesculap plates. Fusion was documented on both dynamic X-rays and 2- or 3-dimensional CT studies 3 and 6 months postoperatively, or until fusion occurred. Follow-up averaged 82 months for the nonplated patients, and 21 months for the plated patients.nnnRESULTSnOut of 48 nonplated patients, 3 developed immediate graft extrusions within 24 hours of surgery requiring graft replacement. Another 2 exhibited symptomatic pseudarthrosis 6 months postoperatively, and required secondary posterior wiring with fusion (PWF). In comparison, 1 of the 35 patients with plated one-level ACF developed plate displacement 6 weeks postoperatively, while 3 exhibited symptomatic pseudarthrosis 6 months after surgery, and required secondary posterior wiring and fusion (PWF).nnnCONCLUSIONSnComparison of one-level ACF performed with and without plates showed that plating did not appear to reduce pseudarthrosis or graft extrusion rates.

Beta tricalcium phosphate: observation of use in 100 posterolateral lumbar instrumented fusions.

BACKGROUNDnBeta tricalcium phosphate (B-TCP) is increasingly used to supplement lamina autograft to perform posterolateral lumbar-instrumented arthrodesis.nnnPURPOSEnTo determine the radiographic arthrodesis and pseudarthrosis rates after multisegment lumbar laminectomies and one- or two-segment posterolateral instrumented fusion using lamina autograft and an artificial bone graft expander B-TCP (Vitoss; Orthovita, Malvern, PA, USA).nnnSTUDY DESIGN/SETTINGnTo document radiographic arthrodesis/pseudarthrosis rates using lamina autograft and B-TCP.nnnPATIENT SAMPLEnOne hundred patients with lumbar spinal stenosis underwent multisegment laminectomies (average 3.6 segments) and one- (78 patients) or two- (22 patients) segment posterolateral instrumented arthrodesis.nnnOUTCOME MEASURESnTwo-year postoperative outcomes were assessed using Short-Form 36 questionnaires.nnnMETHODSnThe arthrodesis mass consisted of lamina autograft and B-TCP. Two independent neuroradiologists, using both dynamic X-rays and 2D-CT studies performed 3, 4.5, 6, and up to 12 months postoperatively, documented radiographic arthrodesis progression.nnnRESULTSnOne-segment arthrodesis was performed in 79 patients; 74 (93.7%) were radiographically fused early (6.5 postoperative months), 2 (2.5%) fused late (6.5-12 months), and 3 (3.8%) exhibited pseudarthrosis. Two-segment arthrodesis was performed in 21 patients; 14 (66.7%) radiographically fused early, 5 (23.8%) fused late, and 2 (9.5%) exhibited pseudarthrosis. Although chi-square analyses revealed a significant increase in the number of late radiographic fusions occurring for patients undergoing two-level arthrodesis, no significant difference in radiographic pseudarthrosis rates was noted between the two patient populations. In both groups, Short-Form 36 questionnaires revealed nearly comparable maximal improvement on seven of eight Health Scales by the second postoperative year.nnnCONCLUSIONSnAt 6.5 months after multisegment lumbar laminectomies with posterolateral instrumented lumbar arthrodesis using lamina autograft/B-TCP, more one-segment (93.7%) versus two-segment (66.7%) radiographic arthrodesis occurred. By 1 year after operation, there was no significant difference in fusion rates between one- and two-segment radiographic arthrodeses.

Diagnosis and surgical management of cervical ossification of the posterior longitudinal ligament

BACKGROUND CONTEXTnThe diagnosis and treatment of multilevel cervical ossification of the posterior longitudinal ligament (OPLL) is continuing to evolve as its effects become more readily recognized and surgical alternatives expand.nnnPURPOSEnTo review the clinical, neurodiagnostic and surgical management of OPLL.nnnSTUDY DESIGN/SETTINGnPatients with early OPLL, often in their mid-forties, present with radiculopathy or mild/moderate myelopathy. Radiographically, hypertrophy of the posterior longitudinal ligament with punctate ossification appears opposite multiple disc spaces. Patients with classic OPLL frequently become symptomatic in their mid-fifties with radiographic characteristics showing ossification of the ligament behind the vertebrae alone (segmental), behind the vertebrae including the intervertebral disc spaces (continuous), and combinations of the segmental and continuous variants and OPLL opposite disc spaces alone. Both magnetic resonance imaging (MRI) and computed tomography (CT) examinations are critical. MRI better delineates the extent of soft tissue abnormalities in three dimensions, including the cervicothoracic junction, whereas CT more readily identifies the foci of frank ossification. Surgical alternatives include anterior, posterior or combined approaches. Anterior surgical options include plated multilevel anterior discectomy and fusion, anterior cervical corpectomy with fusion (ACF), or plated multilevel ACF with differing posterior fusion techniques. Posterior surgical options vary from laminectomy with or without simultaneous fusion and laminoplasty. Although outcomes with different approaches vary, many direct anterior resection techniques achieve more favorable results because of appropriate and adequate resection of the ligament.nnnCONCLUSIONSnThe clinical and neuroradiographic documentation of OPLL and its appropriate surgical management anteriorly, posteriorly or circumferentially remain a therapeutic challenge.

An analysis of noninstrumented posterolateral lumbar fusions performed in predominantly geriatric patients using lamina autograft and beta tricalcium phosphate

BACKGROUND CONTEXTnThe artificial bone-volume expander, beta tricalcium phosphate (B-TCP, Vitoss, OrthoVita, Malvern, PA), is increasingly used to supplement autograft in posterolateral lumbar fusions.nnnPURPOSEnTo determine fusion rates/outcomes using B-TCP/autograft.nnnSTUDY DESIGN/SETTINGnFusion rates and outcomes were assessed for 60 predominantly geriatric patients undergoing multilevel lumbar laminectomies and 1- to 2-level noninstrumented fusions using B-TCP/autograft.nnnPATIENT SAMPLEnPatients on average were 70 years old.nnnOUTCOME MEASURESnOdoms criteria and Short-Form 36 (SF-36) outcomes were studied 2 years postoperatively.nnnMETHODSnSixty patients underwent an average of 5.4-level laminectomies with 1- to 2-level noninstrumented fusions. Based on dynamic X-ray/magnetic resonance/computed tomography (CT) studies, laminectomies addressed multilevel stenosis (60 patients), ossification of the yellow ligament (46 patients), disc herniations (20 patients), or synovial cysts (8 patients), and fusions addressed degenerative spondylolisthesis (48 patients), spondylolisthesis/lysis (2 patients), or degenerative scoliosis (10 patients). The fusion mass on each side contained half of all harvested autograft combined with one to 1.5 strips of B-TCP (saturated in 10cc of bone marrow aspirate/strip). Fusion rates were documented by two independent neuroradiologists using both dynamic X-rays, and thin-cut CT (2-dimensional/3-dimensional CT) studies obtained up to 2 years postoperatively. Odoms criteria and SF-36 outcomes were assessed over the same interval.nnnRESULTSnPseudarthrosis was documented in nine (15%) patients. Two years postoperatively, Odoms criteria revealed 28 excellent, 23 good, 5 fair, and 4 poor results, whereas SF-36 data revealed improvement on 6 of 8 Health Scales in all patients.nnnCONCLUSIONSnA 15% pseudarthrosis rate followed multilevel laminectomy and 1- to 2-level noninstrumented posterolateral fusion using lamina autograft/B-TCP.

Dural repair with four spinal sealants: focused review of the manufacturers’ inserts and the current literature

BACKGROUND CONTEXTnDeliberate or traumatic dural fistulas are typically augmented by a sealant or fibrin glue to enhance the strength of dural closure.nnnPURPOSEnLittle is known about the risks and complications associated with two specific sealants and two specific fibrin glues used for dural closure.nnnSTUDY DESIGN/SETTINGnReview of the manufacturers inserts and a focused review of the literature concerning the pros and cons for two sealants (DuraSeal [Confluent Surgical Inc., Waltham, MA, USA] and BioGlue [Cryolife, Kennesaw, GA, USA]) and two fibrin glues (EVICEL [Johnson and Johnson Wound Management, Ethicon Inc., Somerville, NJ, USA] and Tisseel [fibrin sealant; Baxter International Inc., Westlake Village, CA, USA]) were assessed.nnnPATIENT SAMPLEnA focused review of the literature using four different sealants or fibrin glues was performed.nnnOUTCOME MEASURESnDocumentation of persistent/recurrent postoperative cerebrospinal fluid fistulas was an end point for failure for the four different sealants and fibrin glues.nnnMETHODSnManufacturers inserts and a focused review of the literature concerning the relative safety and efficacy of two sealants (DuraSeal and BioGlue) and two fibrin glues (EVICEL and Tisseel) used to augment dural closure were assessed.nnnRESULTSnAlthough DuraSeal is approved by the Federal Drug Administration (FDA) for intracranial and spinal application, two instances of paralysis are described in the literature. BioGlue is classified by the manufacturer as neurotoxic. EVICEL, one of the fibrin glues, appeared in just two animal studies, whereas Tisseel, the other fibrin glue, has been used in many large clinical series without adverse events.nnnCONCLUSIONnDespite the lack of FDA approval, Tisseel (fibrin glue) has seen wide adoption in off-label use. DuraSeal, which is FDA approved, was associated with two instances of paralysis. Alternatively, BioGlue was described as neurotoxic even by the manufacturer.

Posterior approaches in the management of cervical spondylosis and ossification of the posterior longitudinal ligament

BACKGROUNDnIf the cervical lordotic curvature has been well preserved, spondylostenosis or ossification of the posterior longitudinal ligament, with or without instability, may be approached posteriorly in selected older patients (over 65 years of age). Posterior surgical alternatives include the laminectomy with or without fusion, or laminoplasty. However, in younger patients or in geriatric patients with predominantly anterior disease with kyphosis, direct anterior surgical procedures yield better results.nnnMETHODSnLaminectomy with medial facetectomy and foraminotomy is classically performed in cases in which stability is preserved. However, posterior stabilization using either facet wiring or lateral mass fusion may be warranted. Although some consider the open door laminoplasty a reasonable alternative for dorsal decompression, limitations include restricted access to the hinged side, a potential for closing of the door, and it does not offer a real fusion.nnnRESULTSnPostoperative neurologic improvement may approximate an 85% incidence of good to excellent results. However, where a posterior decompression has been chosen, particularly in younger individuals with or without a lordotic curvature, or in older patients with kyphosis, they will fail to significantly improve, and will be susceptible to early neurologic deterioration.nnnCONCLUSIONSnPosterior approaches to cervical disease may be successful in geriatric individuals in whom the cervical lordotic curvature has been well preserved. However, it is inappropriate for either older or younger patients with predominantly anterior disease, for whom direct anterior decompression with or without posterior stabilization is indicated. In those patients with significant ventral ossification of the posterior longitudinal ligament (OPLL), direct anterior resection will result in improved neurologic outcomes, whereas posterior decompression will fail to achieve a similar degree of neurologic recovery. Furthermore, dorsal decompression of OPLL may promote a more rapid progression of OPLL growth and concomitant neurologic deterioration.

X-Stop: foot drop

BACKGROUND CONTEXTnThe X-Stop (Kyphon, Sunnyvale, CA), a device implanted between adjacent lumbar spinous processes at one or two levels particularly in the geriatric population, theoretically decompresses the spinal canal by reversing the lordosis.nnnPURPOSEnThe X-Stop relieves the symptoms of lumbar stenosis.nnnSTUDY DESIGN/SETTINGnA case report from the United States.nnnPATIENT SAMPLEnA case report focusing on how X-Stop placement resulted in a bilateral foot drop in an 84-year-old patient, which was relieved 9 months later with laminectomy.nnnOUTCOME MEASURESnThe patients outcome was based on the neurological examination.nnnMETHODSnAn 84-year-old male with lumbar neurogenic claudication/radiculopathy, exhibited magnetic resonance (MR)-documented L4-L5 lumbar stenosis and Grade I degenerative spondylolisthesis. At an outside institution, an L4-L5 X-Stop was placed; he immediately developed a bilateral foot drop. Three months later, the X-Stop extruded, and was removed; his foot drop remained unchanged. Nine months after the original surgery, based on new MR/computed tomography (CT) documented severe (L2-L3, L4-L5), moderate (L1-L2, L3-L4, L5-S1) stenosis, and the L4-L5 Grade I degenerative spondylolisthesis, the second surgeon performed an L1-S1 laminectomy with L4-L5 noninstrumented fusion.nnnRESULTSnPostoperatively, the patients bilateral foot drop largely resolved.nnnCONCLUSIONSnPlacing the X-Stop device at severely stenotic levels, particularly when accompanied by degenerative spondylolisthesis, may contribute to significant postoperative neurological sequelae in geriatric patients. For those with limited comorbidities, operative decompression may prove the safer alternative.

Increased postoperative cervical myelopathy and cord compression resulting from the use of Gelfoam.

BACKGROUND CONTEXTnThe immunogenicity of Gelfoam (Pharmacia and Upjohn, Kalamazoo, MI) or microfibrillar collagen, applied during laminectomy, may promote postoperative swelling and significant neural compression.nnnPURPOSEnTo document how Gelfoam contributes to marked cord/root compression on unenhanced/enhanced postoperative magnetic resonance (MR) scans.nnnSTUDY DESIGN/SETTINGnThis is a case report from the United States.nnnPATIENT SAMPLEnA case report.nnnOUTCOME MEASUREnThe patients neurological status was assessed using Nurick Grades.nnnMETHODSnA 73-year-old female with moderate myeloradiculopathy (Nurick Grade III) and MR/computed tomography (CT)-documented cord compression underwent a C6/C7 laminectomy (undercutting of C5-T1) with Gelfoam applied to the laminectomy site, followed by a C2-T2 fusion for instability (iliac autograft, Beta TriCalcium Phosphate).nnnRESULTSnThe patient improved for the first postoperative week (Nurick Grade 0-I), but deteriorated over the successive second and third postoperative weeks (Nurick Grade III). When the 3-week postoperative MR study documented marked dorsolateral cord compression at the laminectomy site, likely attributed to a postoperative seroma/hematoma, a second operation was performed. At surgery, no significant seroma/hematoma was found. Rather, markedly engorged Gelfoam densely adherent to and compressing the underlying dura was encountered; this was meticulously removed under the operating microscope using a small nerve hook. Postoperatively, the patient immediately improved. As the intraoperative culture revealed Acinetobacter baumannii, she required 6 weeks of intravenous Ertapenem (1-betamethyl-carbapenem). The MR scan performed on the third postoperative week revealed no residual cord compromise.nnnCONCLUSIONSnDelayed postoperative deterioration in a 73-year-old female was attributed to reactive swelling/engorgement of Gelfoam at the C6-C7 laminectomy site.

How often is minimally invasive minimally effective: what are the complication rates for minimally invasive surgery?

BACKGROUNDnMinimally invasive spine surgery is being popularized as a safe and effective alternative to open spine procedures. However, the negative results of this procedure are typically underreported in the literature because few spine surgeons submit and even fewer journals publish negative results.nnnMETHODSnUsing personal communications and second opinions with or without secondary surgery, the author reviewed negative results occurring within 1 year concerning 2 minimally invasive lumbar procedures: MED/METRx (Medtronic, Memphis, Tenn) and X-Stop (Kyphon Inc, St Francis Medical Technologies Inc, Alameda, Calif).nnnRESULTSnFor, MED/METRx, 4 patients underwent MED/METRx procedures at outside institutions. Two patients reoperated upon by the author showed no evidence of scarring at the site of the lateral and far lateral disk herniations. The third patient (seen for second opinion only) exhibited progressive L4-5 discitis/osteomyelitis on successive MRI studies and was referred back to her original surgeon. The fourth patient (personal communication) underwent 2 MED/METRx procedures within 2 days for recurrent/residual disk herniation excision. An evolving cauda equina syndrome 1 month later required open surgery to repair a CSF fistula. For X-Stop, through personal communication, 2 elderly patients with severe comorbidities underwent 1- to 2-level X-Stop lumbar procedures resulting in infection and hematoma, both of which required prolonged hospitalizations.nnnCONCLUSIONSnThe literature demonstrates few negative results/complications for minimally invasive spinal surgery. Encouraging more surgeons to submit and more journals to publish negative results for minimally invasive spinal approaches may better determine their safety/efficacy.