Faculty Bibliography

BACKGROUND:Cervical spondylotic myelopathy (CSM) is a commonly encountered surgical disease that may be approached through a variety of operative techniques. Operative goals in the treatment of CSM include effective neural element decompression and maintaining spinal stability to avoid delayed deformity progression and neurologic compromise. Determining the most appropriate operative approach requires careful consideration of the patient's clinical presentation and radiographic imaging. PURPOSE/OBJECTIVE:To review the indications and techniques for multilevel laminectomy and fusion in the treatment of CSM. CONCLUSIONS:When indications permit, a multilevel laminectomy is an effective and safe method of neural element decompression. Recognizing the potential for spinal instability is essential to prevent neurologic compromise and intractable axial neck pain caused by deformity progression. A variety of techniques have been described to supplement the posterior tension band after laminectomy; however, lateral mass fixation has evolved into the preferred stabilization technique. Although clinical success is well documented, a successful outcome is dependent on a comprehensive, individualized evaluation of each patient presenting with CSM.

A wide variety of pathologic processes can involve the cervicomedullary junction leading to spinal cord compression and mechanical instability. Effective surgical management involves accurate patient selection, appropriate operative planning, and meticulous surgical technique. Many different options for decompression exist, each associated with a unique set of risks and benefits. Spinal stabilization has been enhanced greatly through the evolution of posterior occipitocervical instrumentation constructs. Careful attention to detail may decrease the incidence of potential complications and provide the surgeon with an effective management strategy to maximize clinical outcome.

Multilevel cervical spondylosis is a common disorder encountered by most actively practicing spine surgeons. Patients can present with a combination of complaints, including mechanical neck pain, radiculopathy, and myelopathy. A comprehensive evaluation is required for appropriate diagnosis and treatment. Accurate interpretation of imaging techniques, including plain x-rays, CT, and MRI, is necessary to formulate the optimal surgical strategy. Key points to address during construction of the operative plan include the direction of approach, the extent of the decompression, and the type of stabilization construct when necessary. This article outlines various techniques to facilitate operative planning, optimize the surgical objective, and minimize potential complications.

The effects of cold stress, immunization and genetic selection on the expression of mRNA for cytokine genes in poultry have not been completely elucidated. Therefore, in the present experiment, using real-time quantitative RT-PCR, we evaluated the effect of cold stress and immunization with complete Freund's adjuvant (CFA) on expression of mRNA for pro-inflammatory (interleukin-1beta [IL-1beta], IL-6, IL-12beta), Th(1) (IFN-gamma and IL-2), and Th(2) (IL-4 and IL-10) cytokine genes in peripheral blood leukocytes (PBL) of chicken lines divergently selected for either high or low antibody responses. Irrespective of the duration, cold stress enhanced expression of mRNA for IL-1beta, IL-6, IL-12beta and IL-4 cytokine genes in both selection lines. These results indicate that cold stress stimulates both the innate and parts of the adaptive cellular immune system. Immunization with CFA resulted in higher expression of mRNA for pro-inflammatory cytokines and lower expression of mRNA for both Th(1) and Th(2) cytokines.

Surgical intervention is indicated for pyogenic vertebral discitis and osteomyelitis in patients in whom medical therapy has failed, and in those with neurological compromise, mechanical instability, epidural abscess, or intractable pain. Surgical management has evolved to include single-stage operations for debridement and stabilization as well as more aggressive reconstruction strategies with respect to instrumentation. A review of the literature demonstrates excellent outcomes with single-stage operations and placement of hardware wherever it is required. Using this method, the authors have treated 16 patients without a single incidence of recurrent infection or hardware failure after almost 2 years of follow up.

STUDY DESIGN/METHODS:A case of surgical management of dissociated motor loss after decompression of the cervical spine is reported. OBJECTIVES/OBJECTIVE:To present a rationale for surgical treatment of postdecompressive cervical radiculopathy with an illustrative case example. SUMMARY OF BACKGROUND DATA/BACKGROUND:The unusual complication of radiculopathy after multilevel cervical decompressive procedures is characterized by pain or dissociated motor weakness of the C5 and C6 nerve roots. Conservative management paradigms, including analgesics and steroids, are the rule, but symptoms often persist for many months. There are currently no reports describing foraminotomy as a means of more rapidly alleviating the symptoms of radicular pain and deltoid and biceps brachii weakness seen in the postoperative setting. METHODS:We present a case of bilateral C5 and C6 radiculopathy following multilevel cervical decompression for cervical spondylotic myelopathy, which we treated with posterior foraminotomies. RESULTS:The patient reported complete resolution of his dermatomal pain and demonstrated rapid improvement in upper extremity strength as compared to traditional conservative treatments. The historical experience and pathogenesis regarding this postoperative complication are reviewed. The rationale of root-specific posterior decompression for this debilitating complication is discussed. CONCLUSIONS:Foraminal decompression of the affected nerve roots as demonstrated here has not been described for postdecompressive dissociated motor loss. Such an approach may offer earlier and more complete relief to patients suffering from this unfortunate complication.

OBJECTIVE:The anterior lumbar interbody fusion (ALIF) procedure has become an accepted fusion technique for treating patients with degenerative disorders of the lumbar spine. Many consider laparoscopic ALIF to be the least invasive approach. A modification of the open laparotomy--the "mini-open" approach--is an attractive alternative. In this retrospective review, a comparison of these two ALIF approaches is presented. METHODS:We conducted a retrospective review of 98 patients who underwent ALIF procedures between 1996 and 2001 in which either a mini-open or a laparoscopic approach was used. Patient demographics, intraoperative parameters, length of hospitalization, and technique-related complications associated with the use of these two approaches were compared. The subset of patients who underwent L5-S1 ALIF procedures was analyzed separately. Statistical analysis was conducted with chi2 and Student's paired t tests. RESULTS:Between 1996 and 2001, a total of 98 patients underwent ALIF. A laparoscopic approach was used in 47 of these patients, and the mini-open technique was used in the other 51 patients. Operative preparation and procedure time were longer with the use of a laparoscopic approach, and significantly greater during L5-S1 ALIF procedures (P < 0.05). A marginal but significant increase in length of stay was observed after mini-open ALIF procedures (P < 0.05). The immediate postoperative complication rate was greater after mini-open ALIF procedures, 17.6 versus 4.3% (P < 0.05); however, the rate of retrograde ejaculation was higher in the laparoscopic group, 45 versus 6% (P < 0.05). CONCLUSION/CONCLUSIONS:Both the laparoscopic and mini-open techniques are effective approaches to use when performing ALIF procedures. On the basis of the data obtained in this retrospective review, the laparoscopic approach does not seem to have a definitive advantage over the mini-open exposure, particularly in an L5-S1 ALIF procedure. In our opinion, the mini-open approach possesses a number of theoretical advantages; however, the individual surgeon's preference ultimately is likely to be the dictating factor.

OBJECTIVE:Anterior plate fixation has gained widespread acceptance for the treatment of cervical spondylosis, theoretically enhancing the rate of arthrodesis. There are few studies comparing fusion rates after anterior cervical discectomy and fusion (ACDF) with and without a plate. The purpose of this study was to evaluate the efficacy of anterior cervical plating for fusion enhancement after one- and two-level ACDF with cortical allograft. METHODS:A retrospective review was performed with 251 patients who underwent one- or two-level ACDF with cortical allograft and plate stabilization between 1993 and 1999. An independent surgeon reviewer determined fusion status and complications. A successful fusion was defined by the absence of lucency around the graft, evidence of bridging bone between the endplate and the graft, and the absence of movement on dynamic imaging scans. Follow-up data, ranging from 9 months to 3.6 years, were available for 233 patients. A control group of 289 patients who underwent ACDF without plating was described in a previously published report by the senior author (RWH). Therefore, a total of 540 patients were evaluated for determination of the efficacy of anterior cervical plating with cortical allograft bone. Statistical significance was determined by chi(2) test. RESULTS:The fusion rates for one- and two-level ACDF with anterior fixation were 96 and 91%, respectively, compared with 90 and 72% for one- and two-level ACDF without anterior fixation. The observed increases in fusion rates for both one- and two-level procedures proved to be statistically significant (P < 0.05). There were no recorded infectious, neurological, or graft-related complications among the cohort treated with anterior cervical plating. Compared with the results for the cohort treated without anterior cervical plates, there was a statistically significant decrease in the graft-related complication rate with the application of plates (P < 0.001). Two patients who received plates were noted to have adjacent-segment degenerative changes that required surgical intervention. No hardware fractures were noted; however, one patient was noted to have a single displaced screw, without clinical consequences. CONCLUSION/CONCLUSIONS:The use of anterior cervical plating after one- and two-level ACDF with allograft cortical bone significantly enhanced arthrodesis. The improved fusion rate and negligible complication rate associated with anterior cervical plating are compelling factors justifying its use in the treatment of cervical spondylosis.