Recombinant human bone morphogenetic protein-2 on an absorbable collagen sponge with an osteoconductive bulking agent in posterolateral arthrodesis with instrumentation. A prospective randomized trial

BACKGROUND

Recombinant human bone morphogenetic protein-2 (rhBMP-2) on an absorbable collagen sponge has been shown to be a safe and effective replacement for iliac crest bone graft when used with a threaded fusion device in anterior lumbar interbody arthrodesis. Use of rhBMP-2 on an absorbable collagen sponge in posterolateral lumbar arthrodesis requires the addition of a bulking agent to provide resistance against compression and to serve as an osteoconductive scaffold for new bone formation.

METHODS

We performed a prospective, randomized, multicenter pilot study to investigate the use of rhBMP-2 on an absorbable collagen sponge combined with a ceramic-granule bulking agent as a replacement for autogenous iliac crest bone graft in single-level posterolateral lumbar arthrodesis with instrumentation. The investigational group (twenty-five patients) was treated with a 1.5 mg/mL solution of rhBMP-2 on two strips of absorbable collagen sponge (total dose of rhBMP-2, 12 mg) combined with 10 cm(3) of ceramic granules. The control group (twenty-one patients) received iliac crest bone graft. Clinical outcomes were assessed with use of well-established instruments. Radiographs were reviewed to assess consolidation of fusion.

RESULTS

Eighty-eight percent (twenty-two) of the twenty-five patients in the investigational group and 86% (eighteen) of the twenty-one patients in the control group were considered to have completed the twenty-four-month follow-up. At all follow-up intervals, there were significant improvements in the clinical outcome measures, including the Oswestry Disability Index (ODI) scores, Short Form-36 scores, and back and leg pain scores, in both groups. At twenty-four months, the improvement in the mean ODI score, as compared with the preoperative score, was 28.2 points in the investigational group and 23.0 points in the control group. By twenty-four months, 95% (eighteen) of nineteen patients in the investigational group compared with 70% (fourteen) of twenty in the control group had a radiographically documented fusion. The overall success rate was 81% (seventeen of twenty-one) in the investigational group and 55% (eleven of twenty) in the control group (p = 0.345).

CONCLUSIONS

Compared with an iliac crest bone graft, the combination of an absorbable collagen sponge soaked with rhBMP-2 and ceramic granules resulted in trends toward improvements in clinical outcomes and toward a higher rate of radiographic fusion. This combination of an osteoinductive agent with an osteoconductive matrix may be an effective replacement for autograft in single-level posterolateral lumbar arthrodeses with instrumentation.

Ophthalmologic complications associated with prone positioning in spine surgery

Visual impairment and blindness associated with general anesthesia and prone positioning in spine surgery have been increasing in incidence over the past several decades. Corneal abrasion, the most common ophthalmologic injury, is usually self-limiting. However, prolonged surgical procedures (>7 hours) associated with acute blood loss anemia, hypotension, and hypoxia may lead to posterior ischemic optic neuropathies. Direct pressure to the periorbital region of the eye can cause increased intraocular pressure and blindness as the result of central retinal artery occlusion. Hypoxia and cerebral embolism are associated with occipital cortical infarct or cortical blindness. The prognosis for visual recovery from ischemic neuropathy and retinal artery occlusion is poor. Cortical blindness usually improves to varying degrees. Effective treatment of perioperative amaurosis is lacking and usually ineffective, making prevention the cornerstone of management. To best prevent permanent ophthalmologic complications associated with prone positioning during spine surgery, orthopaedic surgeons should be aware of pathophysiology and related risks associated with spine surgery in the prone position, and initiate preventive measures and predictable treatment options.

Herpes zoster--varicella complicating anterior thoracic surgery: 2 case reports

This article reviews the reactivation of the latent varicella-zoster virus infection within the sensory dorsal root ganglia resulting in shingles. Although the association between surgery and reactivation of the varicella-zoster virus is known, we feel it is important to keep the diagnosis of shingles in mind especially in a patient with sudden onset of increased pain after surgery. Our purpose is to report 2 rare clinical presentations of shingles after spinal surgery in which the patient's initial diagnosis was not clear until the classical rash was observed. Two case reports are presented in which 1 patient developed shingles 5 days after surgery with distribution of the maculopapular rash in a surgical incision, whereas the second patient did not present until 4 weeks after surgery with a disseminated picture. Early recognition of this postoperative problem is imperative for prompt and appropriate management, as misdiagnosis can lead to short-term and long-term pain control issues, postherpetic neuralgia, neuropathic pain, or other related sequelae.

Epidural hematoma secondary to a rupture of a synovial cyst

BACKGROUND CONTENT

With modern advances in imaging studies, synovial cysts are becoming more evident as a common component of erosive lumbar degenerative disc disease causing spinal stenosis and radiculopathy. Whereas hemorrhage can occur inside the cyst and is reported, rupture causing epidural hematoma is a rare complication and finding of this disorder.

PURPOSE

To report a rare clinical presentation of a synovial cyst and spinal stenosis, where rupture of the cyst leads to an early cauda equina syndrome.

STUDY DESIGN

Case report with a review of literature.

METHODS

Clinical history, physical findings, and magnetic resonance imaging studies of a patient with an intraspinal synovial cyst at L4-5 1 week before a sudden worsening of symptoms are reported.

RESULTS

A case report is presented of a male with a known synovial cyst at L4-5, presenting initially with neurogenic claudication. This patient developed sudden worsening of symptoms with bilateral lower extremity pain, weakness, and radiculopathy with difficult voiding. The patient had developed an epidural hematoma, secondary to rupture of a synovial cyst, documented at surgical decompression.

CONCLUSIONS

Although synovial cyst associated with erosive facet and erosive degenerative disc disease are common, rupture of the cyst is not. A case report of a ruptured synovial cyst leading to an early cauda equina syndrome is presented. This case illustrates the spectrum of clinical features and presentations possible with spinal stenosis complicated by lumbar synovial cyst formation.

Acute spinal cord compression caused by vertebral hemangioma

BACKGROUND CONTEXT

The reported incidence of vertebral hemangioma within the spinal column is common. Most often these benign vascular tumors are incidental radiographic findings and do not cause neurological sequelae. Rarely, vertebral hemangiomas will cause compressive neurological symptoms, such as radiculopathy, myelopathy and paralysis. In these cases the clinical presentation is usually the subacute or delayed onset of progressive neurological symptoms. This report demonstrates a symptomatic vertebral hemangioma presenting with rapid onset neurologic sequelae.

PURPOSE

To discuss diagnostic and management issues presented by symptomatic vertebral hemangioma.

STUDY DESIGN

Case report and review of literature.

PATIENT SAMPLE

Sixty-one-year-old white woman with low back pain and rapidly progressive myelopathic symptoms.

METHODS

A case of vertebral hemangioma with neurological sequelae is presented followed by a discussion of the literature concerning diagnostic and therapeutic options in the management of this pathologic entity.

RESULTS

The results of our review reveal that the incidence of vertebral hemangioma causing compressive neurological symptoms is rare despite the overall prevalence of vertebral hemangioma. Vertebral hemangioma may present with rapid onset myelopathic symptoms and may mimic those symptoms caused by a malignancy. Radiographic imaging modalities are extremely useful and display characteristic findings in the diagnostic evaluation of these tumors. Angiographic embolization of feeding vessels has been effective in minimizing operative blood loss, and surgical decompression and stabilization is frequently indicated. Postsurgical radiotherapy has also been demonstrated to serve as a limited adjunct to surgery by reducing tumor recurrence in the event of less than complete tumor resection.

CONCLUSIONS

Because of the rapid presentation of myelopathic symptoms in this case, preoperative angiographic embolization was not performed, and the patient underwent emergent decompressive surgery. In this case emergent operative decompression and stabilization was effective in reversing the patient's myelopathic symptoms, while maintaining long-term stability of the spinal column. Postoperative radiation was not administered because of the extent of tumor resection. Surgical intervention has produced long-term cure of this patient's myelopathy and T10 vertebral hemangioma.

Acute cauda equina syndrome after total knee arthroplasty as a result of epidural anesthesia and spinal stenosis

An unusual complication of epidural anesthesia performed for routine total knee arthroplasty is presented. Epidural catheter placement or removal resulted in an acute cauda equina syndrome in a patient with asymptomatic high-grade lumbar spinal stenosis at L3-4. The case is presented along with a literature review.

Delayed postoperative epidural hematoma formation after heparinization in lumbar spinal surgery

Treatment of thromboembolic disease in the postoperative lumbar spine patient is controversial. This case report describes an epidural hematoma with neurologic sequelae in an elderly patient who received intravenous heparin therapy over 2 weeks after lumbar decompression. Implications for treatment of thromboembolic disease in the postoperative lumbar spine is reviewed.

Subarachnoid drainage of an established or chronic pseudomeningocele

Incidental dural tears are a common complication of lumbar spine surgery, but if unrecognized cerebrospinal fluid (CSF) leakage can lead to the formation of a fistula or pseudomeningocele. Traditionally, fistulae and pseudomeningoceles have been treated with open revision surgery, but acute fistulae with direct CSF leakage through the incision site have reportedly been treated by extracorporal drainage. This report presents a case in which an established or chronic pseudomeningocele was successfully managed without open surgical repair.

Strength and fatigue resistance of thoracolumbar spine implants: an experimental study of selected clinical devices

Results of strength and endurance tests of several screw/rod thoracolumbar spinal implants are presented. The devices tested were: AcroMed ISOLA, CD systems, Depuy systems, and Synergy systems. The AcroMed ISOLA devices had the greatest stiffness and strength. The Synergy and AcroMed systems had the greatest fatigue resistance. The predominant failure mode was screw bending, although several instances of rod fracture and screw fracture were observed. A number of design improvements are identified, including reducing the number of components, thereby reducing the number of failure mechanisms; avoiding notches and knurled surfaces to provide greater resistance to crack initiation; and strengthening attachments between components, particularly between pedicle screws and horizontal rods.

Lumbosacral instrumented fusion: analysis of 124 consecutive cases

One hundred twenty-four cases of lumbosacral fusion receiving transpedicular screw fixation were divided into two groups and reviewed retrospectively. The conditions treated include spondylolisthesis, scoliosis, tumor, trauma, and degenerative disc disease. There were 83 males and 41 females in this consecutive series averaging a 45.2-month follow-up. The primary or first-time arthrodesis rate was 91.9%. A learning curve effect as it relates to operative time but not pedicular screw placement was shown. Instrumentation-related and general medical and surgical complications were low. Infection rates were also low; superficial 2.4%, deep 1.6%. Nonunion or delayed union was salvaged in 10 cases, improving the overall fusion rate to 97.6%. The results of this study support the use of lumbosacral transpedicular screw fixation in select spinal conditions.

Effects of cross-linkage on fatigue life and failure modes of stainless steel posterior spinal constructs

This study tested the effects of cross-linkage on the fatigue performance of posterior spinal constructs (i.e., AcroMed stainless steel Isola systems). The failure modes encountered during fatigue were also examined. The results of this study confirmed earlier findings that the use of cross-linkage does not significantly affect the stability of posterior constructs during axial loading. Their influence in torsion loading is much more pronounced. During the fatigue tests, posterior stainless steel spinal implants instrumented without cross-linkage reached 1 million cycles at 500- and 750-N loads. When the load was increased to 1,000 N, the number of cycles to failure dropped by two-thirds. These findings demonstrate that the endurance limit was between 750 N and 1,000 N for spinal constructs without cross-linkage, with the limit being closer to 750 N. Devices equipped with one or two cross-linkages reached 1 million cycles at 500 N. The number of cycles to failure dropped dramatically as the load was increased to 750 and 1,000 N. It appears that the endurance limits for spinal devices using cross-linkage should be 500 and 750 N, with the limit closer to the 500-N load. All rod fractures occurred near the junction between the longitudinal and transverse rods. Stress concentration was greatly in the vicinity of that contact point. These results should provide a basis for future improvement in endurance limits of spinal implants equipped with cross-linkage. Higher endurance limits will reduce the toxic effects encountered during fracture modes. The implants will also be better able to withstand the high physiologic loads experienced by obese individuals.

Lumbar disk herniation: an analysis of 175 surgically treated cases

This is a retrospective review of 175 consecutive open lumbar diskectomies with a minimum 1-year follow-up (average follow-up, 54 months). Results of the diskectomies were: 91.0% good-to-excellent result, 3.4% fair, and 1.1% poor. Complications were few, and the overall recurrence rate was 4.6%. By multiple linear regression analysis, no one factor could predict the relief of leg pain.

Biomechanical assessment of titanium and stainless steel posterior spinal constructs: effects of absolute/relative loading and frequency on fatigue life and determination of failure modes

The goal of this study was to examine the effects of absolute/relative loads and frequency on the fatigue life of titanium and stainless steel posterior spinal constructs, and to determine the failure fracture modes. The stainless steel constructs had higher stiffness and yield strength than the titanium constructs, but the ultimate static strength was almost equal for both types of constructs. Titanium constructs, however, exhibited higher variability than the stainless steel constructs. In fatigue tests, the stainless steel constructs were significantly affected by the external load and were frequency independent. It appears from fatigue curves that 500 N can be approximated as the endurance limit for the stainless steel constructs. Titanium constructs were load-frequency dependent, and their endurance limit was somewhere between the 500 and 750 N load levels. There were no differences in performance between the stainless steel and titanium constructs at 16 Hz. At 4 Hz, titanium constructs performed as well or better than stainless steel constructs. Also, the titanium constructs resulted in better performance than the stainless steel constructs in the elastic region, and with smaller differences in the plastic region. Most of the failure modes for stainless steel constructs were in screw bending at 16 Hz with a smaller percentage of rod fractures at high loads, with a higher percentage of rod fractures observed for the stainless steel constructs at 4 Hz. Most of the failure modes for titanium constructs occurred in screw bending or fracture.

Posterior instrumentation for thoracolumbar trauma

The majority of thoracolumbar spine fractures and fracture dislocations may be considered acute sagittal plane deformities. Unstable thoracolumbar spine injuries require stabilization to (1) allow mobilization of the patient to prevent pulmonary and venous complications; (2) to relieve pain; (3) to realign the spine and spinal canal, and (4) to decompress directly or indirectly the neural elements. Posterior spinal instrumentation is a safe, available, familiar, and effective method to achieve these goals. Posterior spinal instrumentation techniques used rod hook systems or screw rod and screw plate systems. Most of these unstable injuries can be managed using these well established techniques without the need for additional combined or staged anterior spinal surgery.

Frankel A paraplegia: a comparison of two spinal instrumentation systems

Seventeen patients with unstable thoracolumbar fracture dislocations and Frankel A (complete) paraplegia had posterior spinal fusion and instrumentation--nine with Cotrel-Dubousset instrumentation and eight with Luque rod instrumentation (LRI). Both systems maintained fracture reduction, and fusion occurred in all cases within a mean of 42 months (range, 30 to 66 months). Operative time and associated blood loss was less in the LRI group. One patient with LRI had fracture of the sublaminar wires that did not lead to loss of reduction or nonunion. Both instrumentation systems provided long-term posterior spinal stabilization in these patients.

Cotrel-Dubousset instrumentation and thoracolumbar spine trauma: a review of 55 cases

A series of 55 patients treated with posterior Cotrel-Dubousset instrumentation and osteosynthesis for unstable thoracolumbar spine fractures were reviewed. Follow-up averaged 48.3 months. The fractures were all unstable, with 27 classified as fracture-dislocations (FD) and 28 classified as flexion compression injuries or unstable burst fractures (FC/B). The study population was composed of 29 men and 26 women with an average age of 31 (range 20-45) years. Mechanisms of injuries included 35 motor vehicle accidents, 19 falls, and one blunt trauma. No case worsened as a result of surgery, and 31% of the cases improved an average of 0.5 Frankel grade (range 0-2). Sixty percent of patients were braced with a custom molded thoracolumbosacral orthosis (TLSO) fitted after surgical stabilization. Minor complications occurred in 45% of the cases (urinary tract infection most common). There was a singular deep wound infection and another iliac crest donor site infection. There were no instrument failures or pseudarthroses. Radiographic analysis showed the following improvements in fracture angle, vertebral body compression, and fracture displacement. The pattern of radiographic improvement in the FD and FC/B subgroups showed significant improvement in each parameter when comparing preoperative to immediate postoperative values. Of importance, the radiographic findings comparing 1 month to the final follow-up showed little to no deterioration. Cotrel-Dubousset instrumentation proved to be a highly effective device for immediate restabilization of unstable thoracolumbar injuries.

Recurrent same-level, ipsilateral lumbar disc herniation

An operative technique for the surgical management of the recurrent lumbar disc herniation is illustrated and presented. Five cases of ipsilateral, same-level, recurrent disc herniations are reviewed and discussed in light of the available literature. All patients presented with severe recurrent sciatica at variable times from the incident surgery. The treatment and possible factors favoring recurrence are discussed.

Critical analysis of strut grafts in anterior spinal fusions

Fifty patients undergoing anterior spinal decompression with partial or complete corpectomy and fusion with strut grafting were reviewed. The etiology of the spinal lesions included pathologic fracture (9 patients), trauma (22 patients), congenital/developmental lesions (6 patients), failed fusion (6 patients), and degenerative lesions (7 patients). Vertebral body reconstruction of the cervical, thoracic, or lumbar spine used iliac crest (20 cases), rib (12 cases), and fibular autografts (9 cases). Additionally, in 10 cases fibular allografts were used. There were four deaths, all secondary to systemic disease. Of the remaining 46 patients, 2 required revisions and all subsequently progressed to a solid anterior arthrodesis with an average follow-up of 30.4 months (range 12-62 months). Posterior spinal fusion was staged in 38 patients. Twenty of 29 patients with neurologic lesions improved after corpectomy. Eleven cases treated for a progressive, painful kyphosis averaged correction of 11.4 degrees (26%), which was maintained on long-term follow-up. Complications were primarily pulmonary and/or genitourinary. Others included a pseudarthrosis, an early fractured strut, and a late allograft infection. On the basis of this review, it appears that spinal arthrodesis with anterior decompression and strut grafting is an effective method of treating anterior compressive syndromes of the spine and painful progressive kyphoses.

Latissimus dorsi rupture: an unusual complication of anterior spine surgery

Anterior spinal surgery is a common part of the treatment for spinal trauma and deformity. Two cases of an unusual postoperative complication of the surgical exposure for anterior spinal fusion with rib strut grafts are herein reviewed. In each case, the patient presented 3-6 months postoperatively with a large, painful mass along the posterior axillary line near the surgical incision. The mass was diagnosed as a rupture of the latissimus dorsi. The cause of this disruption is unclear, but it appears to be a complication of the surgical approach; therefore, surgeons performing transthoracic and thoracoabdominal approaches should be aware of it.

Central retinal artery occlusion: a complication of the knee-chest position

A rare complication of the knee-chest position used for lumbar disk surgery is reported. Central retinal artery occlusion resulted in permanent loss of vision secondary to direct ocular pressure. Prevention is the only rational treatment for this unfortunate condition.

Postoperative wound infections complicating adult spine surgery

A review of 19 consecutive patients treated for deep wound infections after spinal surgery was performed. Patients were analyzed for preoperative risk factors, original diagnosis requiring surgery, onset of infection, presentation, treatment, and outcome. These patients (10 men, nine women), with a mean age of 44 years (range 18-74) were treated for 13 deep and six subcutaneous infections: 16 spine infections and nine graft site infections (six with both). All 19 presented with draining wounds on an average of 17 days after surgery (range 4-86). Staphylococcus aureus was cultured in 14. Patients were treated with i.v. antibiotics for an average of 3 weeks (range 0-14) followed by oral antibiotics for an average of 6 weeks (range 2-12). Surgical treatment included an average of 1.8 debridements (range 0-5), primary closure in two, delayed primary closure in seven, and healing by secondary intent in 10. All but three patients were noted to be malnourished at the onset of their infection, with a total lymphocyte count of less than 2,000. Three patients required removal of their hardware. Eighteen of 19 healed or their infections were stabilized, 17 of 18 arthrodeses fused, and no patient had neurological deterioration secondary to the infection. The treatment outlined produced satisfactory results in all but one patient. We conclude that postoperative spine infections are frequently associated with poor nutrition. Although definitive diagnosis is determined by the culture, clinical exam is helpful in establishing a presumptive diagnosis and, thus, earlier institution of surgical and antibiotic treatment.

Radiographic evaluation of the degenerative cervical spine

Despite some claims to the contrary, the use of plain film radiography can be an inexpensive initial means of evaluating the degenerative cervical spine if viewed in the context of the patient's clinical history and physical examination and may serve as a guide for further imaging techniques. This article presents a systematic approach for evaluating cervical spine radiographs for the spectrum of degenerative changes, followed by a brief discussion of differential diagnoses.

Spinal cord compression in Scheuermann's kyphosis: case report

Compression of the spinal cord secondary to disc disorders in Scheuermann's kyphosis is rare. This review reports an unusual case emphasizing mechanisms of compression of the spinal cord from this disc disorder. Contrasts and comparisons with previously published cases are included.

Stable and unstable fractures of the femoral shaft

A retrospective review of 99 cases of stable and unstable femoral shaft fractures treated with Grosse-Kempf intramedullary fixation is presented. Despite minor complications and technical problems, the procedures resulted in union with acceptable alignment in 98% of cases. Details of the complications and technical problems are reviewed. There was no incidence of deep infection despite 16 open fractures. The two cases of nonunion were salvaged with revision internal fixation and bone grafting. Grosse-Kempf interlocking intramedullary fixation is a technically demanding procedure, but offers excellent results in the management of stable and unstable, open and closed fractures of the femoral shaft.

Technique for occipito-cervical fusion in osteopenic patients

A technique for occipito-cervical fusion in patients with upper cervical spine abnormalities and osteopenia is described and illustrated. This technique combines the use of autogenous bone graft and a polymethylmethacrylate (PMMA)-wire construct.

Somatosensory cortical evoked potentials: a review of 100 cases of intraoperative spinal surgery monitoring

A review of our experience with evoked potential monitoring of over 100 spinal procedures is summarized here. Typical results of somatosensory cortical evoked potential (SCEP) testing found that latency of responses increased slightly and amplitude decreased substantially from preanesthesia to predistraction with no further changes. SCEP results are effected by many factors, but when they are understood and recognized, evoked potential monitoring can play a significant role in recognizing potential problems and preventing postoperative neurological problems in patients undergoing spinal surgery.

A rare intradural tumor simulating spondylolisthetic radiculopathy

Intradural tumors can produce nerve root symptoms similar to those caused by extradural compressive processes. In a 48-year-old man, the preoperative evaluation was spondylolisthetic radiculopathy; however, a lumbar myelogram prior to surgery revealed an unsuspected intradural tumor. The patient's symptoms resolved after removal of the tumor without treatment of the spondylolisthesis. When planning surgical treatment for any extradural process, intradural abnormalities must be ruled out by appropriate preoperative studies. Myelography and magnetic resonance imaging are now standard methods of evaluating the dural contents.

Aortic injuries in thoracolumbar spine fracture-dislocations: report of three cases

Patients with thoracolumbar fractures and fracture-dislocations of the spine often have associated injuries. One rare and potentially life-threatening concomitant injury is aortic trauma. In cases of fracture-dislocation at the thoracolumbar junction, injuries to the thoracic aorta must be diagnosed early and treated appropriately in conjunction with posterior fixation of the unstable spine.

Nonglucocorticoid-induced lumbar epidural lipomatosis: a case report and review of literature

A case of nonglucocorticoid-induced lumbar epidural lipomatosis in a middle-aged black woman with neurogenic claudication is presented. The etiology, diagnosis, management, and outcome are discussed in detail.

Long-term results of lumbar spine surgery complicated by unintended incidental durotomy

Unintended incidental durotomy is not an infrequent complication of spinal surgery (incidence, 0.3-13% reported). Although prompt repair is advocated, little has been written regarding any consequences of primarily repaired durotomies on long-term patient outcome. A retrospective review of 450 patients undergoing lumbar spine surgery revealed 17 cases (4%) of incidental durotomy, recognized intraoperatively and repaired primarily. These patients were evaluated at long-term follow-up (mean, 25.1 months); and their results were compared with controls matched for age, diagnosis, procedure, and length of follow-up. No differences of statistical significance could be identified in comparing the outcomes of the two groups. Incidental durotomy, when recognized and repaired intraoperatively, does not increase perioperative morbidity or compromise final result.

Spinal epidural abscess. A case report and literature review

Spinal epidural abscess is a rare infectious disorder often subject to a delayed diagnosis. This delay can be disastrous, resulting in permanent neurologic dysfunction or death. Surgeons treating patients with spinal disorders must be aware of this condition to avoid confusing it with more frequent spinal problems, eg, herniated lumbar disk. This case report is presented to acquaint or refresh the occasional spinal surgeon with this condition.

Posttraumatic gluteal compartment syndrome. A case report

Posttraumatic sciatic nerve palsy associated with severe pain, swelling in the gluteal region, elevated tissue pressures, and diffuse edema of the gluteal musculature documented by computed tomography (CT) occurred in a 22-year-old man. Diffuse muscle swelling was observed intraoperatively, and sciatic nerve function returned within days following surgical decompression. This case represents an acute gluteal compartment syndrome, and this entity should be included in the differential diagnosis of posttraumatic sciatic nerve palsy.

Depth of intraspinal wire penetration during passage of sublaminar wires

A major concern with the use of sublaminar wires for segmental spinal instrumentation is the risk of neurologic compromise associated with repeated passage of wires through the epidural space. Because of the inability to visualize the wire tip during its sublaminar passage, the surgeon is unable to appreciate the depth of wire penetration (DOWP). The purpose of this investigation was to determine, through direct measurement, the depth of intraspinal penetration during the passage of sublaminar wires. Using their model, the authors have been able to define the optimal parameters for safe wire passage. Careful attention to maintaining contact between the wire tip and the under-surface of the lamina, using a wire of optimal configuration, will result in minimal DOWP and reduce the possibility of neurologic compromise.

Surgical management of sciatica involving anomalous lumbar nerve roots

Twenty patients with sciatica associated with anomalous lumbar nerve roots were reviewed with an average follow-up of 26.3 months. All patients had predominantly leg pain and their nerve root anomaly was known preoperatively. Overall success rate was 65% but was increased to 80% in patients with concurrent disk herniation. Improved results of surgical decompression were most consistently associated with concurrent disk herniation whereas other factors such as more extensive decompression were less strongly correlated. Surgery should only be offered with these results in mind.