Upper extremity nerve transfers for acute flaccid myelitis: a systematic literature review.

BACKGROUND: Acute flaccid myelitis (AFM) is a rare disease that commonly affects young children. AFM's pathophysiology involves loss of lower motor neurons following a viral infection and induces acute asymmetric flaccid paralysis most commonly in the upper extremities. Nerve transfers have emerged as a treatment option for these patients with permanent motor deficits. OBJECTIVE: To summarize the literature and report safety and efficacy outcomes following nerve transfers for recovery of shoulder abduction and external rotation, and elbow flexion and extension in pediatric patients with AFM. Recovery of at least antigravity function was defined as a successful outcome. This systematic review was performed according to the PRISMA guidelines. The PubMed, Embase and Cochrane databases were utilized. RESULTS: Five studies comprising 44 patients (median age 2.95 years; 71% male), and 93 upper extremity nerve transfers were included. Thirty-eight patients received 65 nerve transfer procedures aiming for recovery of shoulder abduction and/or external rotation with a transfer to the axillary and/or suprascapular nerve. The recovery of shoulder abduction and external rotation was achieved in 40.7% (n = 11/27) and 60% (n = 6/10) of patients, respectively. Time from injury to surgery showed an inverse relationship with the odds for successful recovery (OR: 0.81; 95% CI: 0.64-1.02; p = 0.07); however, statistical significance was not reached. Successful recovery of elbow flexion with a transfer to the musculocutaneous was reported at a rate of 92.3% (n = 12/13). Successful re-innervation of the radial nerve with recovery of elbow extension was found in 75% (n = 6/8) of patients. No complications were reported. CONCLUSIONS: Upper extremity nerve transfers appear to be promising and safe for AFM patients. Shoulder abduction is the most challenging upper extremity function to recover. Further studies are warranted to identify whether nerve transfers are associated with superior outcomes when performed earlier.

Endovascular management of pediatric high-flow vertebro-vertebral fistula with reversed basilar artery flow. A case report and review of the literature.

Vertebral artery arteriovenous fistula (VAVF) is mostly known as a post-traumatic and/or iatrogenic arteriovenous complication. However, spontaneous high-flow VAVF associated with flow reversal in the basilar artery has not been reported in children. We describe a unique asymptomatic presentation of a spontaneous high-flow VAVF associated with flow reversal in the basilar artery in a pediatric patient. The literature for classification, pathophysiology, treatment strategies, and post-procedural complications is also reviewed.

Serum cortisol response to transsphenoidal surgery for Cushing disease.

OBJECT: Transsphenoidal surgery remains the optimal treatment for Cushing disease, but the definitions of surgical cure and failure remain debatable. In this study the authors evaluated serum cortisol levels in patients before and after they underwent transsphenoidal surgery to elucidate the patterns of cortisol decrease and the optimal time and criteria for determining surgically induced remission. METHODS: Twenty-seven patients were evaluated throughout an 8-month period. Serum cortisol levels were obtained before surgery and at 6-hour intervals postoperatively. No exogenous steroid medications were administered until after cortisol sampling was discontinued, following diagnosis of remission. Twenty-one (78%) of 27 cases were labeled initial surgically induced remissions. Twenty-two (81%) of 27 cases were deemed surgically induced remissions at follow-up examination. Following surgery, initial remissions and failures demonstrated divergent patterns of cortisol levels. No patient whose condition was deemed an initial surgically induced remission has experienced definitive relapse of disease since discharge. One patient whose condition was initially deemed a surgical failure, eventually was found to exhibit surgically induced remission without further intervention. CONCLUSIONS: Given such findings, exogenous steroid medications do not appear to be required for patients until after the determination of remission. During the 1st postoperative day, there is a time period during which serum cortisol values significantly differ between the categories of surgically induced remissions and surgical failures. Surgically induced remissions were identified when postoperative values of cortisol were lower than preoperative midnight levels and when absolute values of cortisol were less than 10 microg/dl. In a small proportion of patients remission on a delayed basis may also be demonstrated. These data allow for a simple and rapid determination of postoperative remission in patients undergoing transsphenoidal surgery for Cushing disease.

Morphologic analysis of BMP-9 gene therapy-induced osteogenesis.

The present study was performed to determine the histological, ultrastructural, and radiographic changes that occur over time at intramuscular BMP-9 gene therapy treatment sites. Several members of the bone morphogenetic protein (BMP) family have the potential to induce osteochondrogenesis when the protein is delivered to rodents, canines, rabbits, and nonhuman primates. Previous studies have also demonstrated that BMP gene therapy utilizing adenoviral vectors can also stimulate orthotopic and heterotopic bone formation in rodents and rabbits. Athymic nude and Sprague-Dawley rats were injected with Ad-BMP-9 or Ad-beta-Gal (3.75 x 10(9) particles) in their thigh musculature and light microscopic, electron microscopic, and computerized tomography analysis was performed 3, 6, 9, 12, 15, 18, 21, and 100 days later. To assess early mesenchymal cell proliferation, a bromodeoxyuridine (BrdU) immunohistochemical analysis was also performed 48, 60, and 72 hr postinjection in athymic nude rats. All animals demonstrated extensive endochondral bone formation at the Ad-BMP-9 treatment sites within 3 weeks. The Sprague-Dawley rats also exhibited a massive, acute inflammatory infiltrate during the first week. Proliferating mesenchymal stem cells were clearly evident as early as 2 days after treatment, which differentiated into small or hypertrophied chondrocytes during the next week. During the third week, the cartilaginous matrix mineralized and formed woven bone, which converted to lamellar bone by 3 months. No evidence of bone formation was demonstrated at the Ad-beta-Gal injection sites in the athymic nude or Sprague-Dawley rats. In addition, no cellular proliferation was seen at the Ad-beta-Gal treatment sites in the athymic nude animals as assessed by light microscopy and BrdU immunohistochemistry. The extensive bone formation induced by Ad-BMP-9 suggests that BMP gene therapy may have potential utility in the treatment of degenerative, rheumatic, or traumatic bone pathology.

Fluoroscopic frameless stereotaxy for transsphenoidal surgery.

OBJECTIVE: To assess the value of frameless fluoroscopy-guided stereotactic transsphenoidal surgery using the FluoroNav Virtual Fluoroscopy System (Medtronic Sofamor Danek, Inc., Memphis, TN). METHODS: Twenty consecutive patients undergoing transsphenoidal surgery for sellar lesions were assigned to transsphenoidal surgery with or without computer-assisted fluoroscopic image guidance using the FluoroNav system. Prospective data regarding patient age, sex, lesion characteristics, operative time, and treatment cost were obtained. RESULTS: Although patients in the FluoroNav group were, on average, 17 years younger than the patients in the control group, more patients with recurrent adenomas were treated in the image guidance group. No other significant differences between the groups were found. FluoroNav provided accurate, continuous information regarding the anatomic midline trajectory to the sella turcica as well as anatomic structures (e.g., sella, sphenoid sinus) in the lateral view. No patient required reversion to intraoperative videofluoroscopy. No statistically significant differences were found with regard to preincision setup time, operative time, or cost. FluoroNav allowed procedures to be performed with significantly fewer x-rays being taken. CONCLUSION: Fluoroscopic computer-assisted frameless stereotaxy furnishes accurate real-time information with regard to midline structures and operative trajectory. Although it is useful in first-time transseptal transsphenoidal surgery, its primary benefit is realized in recurrent surgery.

Surgical treatment of Chiari I malformation: indications and approaches.

Chiari I malformation is a well-described entity characterized by hindbrain herniation through the foramen magnum. Although the exact origin of congenital Chiari I malformation is unknown, it appears to be caused by a mismatch between the volume of the posterior fossa neural elements and the posterior fossa cranial content. Several theories have been proposed to describe the resultant pathophysiology of this mismatch. It is clear, however, that abnormal cerebrospinal fluid flow and velocity play a role in the symptoms and signs associated with this disorder. The authors will review the pathophysiology, clinical presentation, and treatment options for patients with Chiari I malformation.

A light and electron microscopic study of ectopic tendon and ligament formation induced by bone morphogenetic protein-13 adenoviral gene therapy.

OBJECT: Bone morphogenetic proteins (BMPs) are involved in the growth and development of many tissues, but it is their role in skeletal development and their unique ability to induce ectopic and orthotopic osteogenesis that have attracted the greatest interest. Expression of the BMP-13 gene is predominantly localized to hypertrophic chondrocytes in regions of endochondral bone formation during development, as well as in mature articular cartilage in the adult. In addition, the application of BMP-13 on a collagen carrier induces neotendon/neoligament formation when delivered subcutaneously or intramuscularly in rodents. The aim of the present study was to determine the histological and ultrastructural changes that occur after the intramuscular injection of a first-generation BMP-13 adenoviral vector. METHODS: Athymic nude rats were injected with 3.75 x 10(10) plaque-forming units of adenovirus (Ad)-BMP-13 or Ad-beta-galactosidase in the thigh musculature, and the region was examined using light and electron microscopy at various time points between 2 days and 100 days postinjection. As early as 2 days after injection of Ad-BMP-13, progenitor cells were observed infiltrating between the transduced muscle fibers. These cells subsequently proliferated, differentiated, and secreted large amounts of collagenous extracellular matrix. By 100 days postinjection, the treated tissue displayed the histological and ultrastructural appearance of neotendon/neoligament, which was clearly demarcated from the surrounding muscle. Small foci of bone and fibrocartilage were also seen within the treated tissue. A short-term bromodeoxyuridine study also demonstrated rapid mesenchymal cell proliferation at the Ad-BMP-13 injection site as early as 48 hours postinjection. At all time points, the control AD-beta-gal injection sites were found to contain only normal muscle, without evidence of inflammation or mesenchymal cell proliferation. CONCLUSIONS: The results of this study indicate that in the future the use of the BMP-13 gene may have therapeutic utility for the healing of tendon and ligament tears and avulsion injuries.

Bone morphogenetic proteins and bone morphogenetic protein gene therapy in neurological surgery: a review.

OBJECTIVE: To review the uses of bone morphogenetic proteins (BMPs) and BMP gene therapy for the treatment of neurosurgical disorders. METHODS: Literature review. RESULTS: BMPs are members of the transforming growth factor beta superfamily, and they play an important role in the growth and development of numerous tissues, including bone, brain, and spinal cord. Although the majority of previous studies have focused on the regulatory functions of BMPs in the normal growth and differentiation of the skeletal system, BMPs also seem to be exquisitely involved in the regulation of cellular proliferation, survival, differentiation, apoptosis, and lineage commitment in the central nervous system. When specific BMPs are delivered on biological matrices, they have the capacity to induce bone, cartilage, ligament, and tendon at both heterotopic and orthotopic sites, suggesting that they may play a major role in the future treatment of spinal and craniofacial pathology. For example, recent studies have clearly demonstrated the usefulness of BMPs and BMP gene therapy for the induction of spinal arthrodesis in several animal models. In addition, several BMPs have been shown to have a neuroprotective effect in animal models of head injury, cerebral ischemia, and Parkinson's disease and may therefore have direct clinical applications for the treatment of central nervous system disorders. CONCLUSION: As the physiological activity of BMPs in the development and pathology of the central nervous system and spine are more fully elucidated, BMP therapeutics and gene therapy will probably have numerous applications in neurological surgery.

Use of bone morphogenetic protein-9 gene therapy to induce spinal arthrodesis in the rodent.

OBJECT: Bone morphogenetic proteins (BMPs) have been shown to have significant osteoinductive activity in numerous in vitro and in vivo assay systems, and BMP-2 and BMP-7 are currently being evaluated in human clinical studies. In the spinal region, BMPs have been shown to promote spinal arthrodesis at a higher rate than autologous bone alone. The delivery of BMPs via direct or ex vivo gene therapy techniques is also currently being evaluated and has shown promise in several mammalian models. The present study was designed to evaluate the efficacy of the use of direct, percutaneous BMP-9 adenoviral gene therapy to promote spinal fusion in the rodent. METHODS: Each animal was injected with 7.5x10(8) pfu of a BMP-9 adenoviral vector in the lumbar paraspinal musculature and allowed to survive 16 weeks. Computerized tomography studies and histological analysis demonstrated massive bone induction at the injection sites, clearly leading to solid spinal arthrodesis, without evidence of pseudarthroses, nerve root compression, or systemic side effects. CONCLUSIONS: The results of this study strongly support the advancement of BMP gene therapy techniques toward clinical use.

The use of bone morphogenetic protein gene therapy in craniofacial bone repair.

Bone morphogenetic proteins (BMPs) are capable of inducing endochondral bone formation when applied on biologic carriers in numerous mammalian in vivo assay systems. Bone morphogenetic protein gene therapy is also currently being developed to promote osteogenesis for clinical indications such as spinal fusions, craniofacial bone loss, and osteoporosis. In this study, critical-sized mandibular defects were treated with a control adenoviral vector (Ad-beta-gal), a BMP-2 adenoviral vector (Ad-BMP-2), or a BMP-9 adenoviral vector (Ad-BMP-9). Gross tissue examination, radiographic analysis, and histologic analysis demonstrated significant bony healing in the BMP treated groups compared to controls. Osteogenesis was limited to the bony defect, without extension into the surrounding soft tissues. The study suggests that with further development, BMP gene therapy may be potentially useful for repair of bony defects in the craniofacial region.

Mechanisms of premature closure of cranial sutures.

Craniosynostosis is defined as premature closure of the sutures of the skull, resulting in cranial deformity. Since Virchow's original paper describing the relationship between premature suture closure and skull morphology, we have learned much about the underlying mechanisms and consequences of premature suture closure. In this paper we will describe the biology of suture closure, the rules governing the resulting phenotypes seen clinically, and a prospective study of skull growth during the 1st year of life.

Secondary gain influences the outcome of lumbar but not cervical disc surgery.

BACKGROUND: The expectation of monetary compensation has been associated with poor outcomes in lumbar discectomy, fueling a reluctance among surgeons to treat worker's compensation cases. This issue, however, has not been investigated in patients undergoing cervical disc surgery. This study analyzes the relationship between economic forms of secondary gain and surgical outcome in a group of patients with common pay scales, retirement plans, and disability programs. METHODS: All procedures were performed at the Portsmouth Naval Medical Center between 1993 and 1995; active duty military servicepersons who were treated for cervical radiculopathy were prospectively included. Clinical, demographic, and financial factors were analyzed to determine which were predictive for outcome. Financial data were used to create a compensation incentive (CI) which is proportional to the rank, years of service, potential disability, retirement eligibility, and base pay and reflects the monetary incentive of disability. The results of cervical surgery were compared to a previously reported companion population of patients treated for lumbar disc disease. A good outcome is defined as a return to active duty, whereas a referral for disability is considered a poor surgical result. RESULTS: One hundred percent follow-up was obtained for 269 patients who were treated with 307 cervical operations. Only 16% (43/269) of cervical patients received disability, whereas 24.7% (86/348) of lumbar patients obtained a poor result (p = 0.0082). Although economic forms of secondary gain were not associated with outcome in cervical disease, both the position (p = 0.002) and duration of an individual's military career were significant factors (p = 0.02). Of the medical variables tested, multilevel surgery (p = 0.03) and revision operations at the same level (p = 0.03) were associated with referral for medical discharge. CONCLUSIONS: Secondary gain in the form of economic compensation influences outcome in lumbar but not cervical disc surgery; this observation may in part account for the success of cervical surgery relative to lumbar discectomy. Social factors that are independent of the anticipation of economic compensation seem to influence the outcome of cervical disc surgery.

In vivo endochondral bone formation using a bone morphogenetic protein 2 adenoviral vector.

Bone morphogenetic proteins (BMPs) are polypeptides that induce ectopic bone formation in standard rat in vivo assay systems. Previous studies have demonstrated the clinical utility of these proteins in spinal fusion, fracture healing, and prosthetic joint stabilization. Gene therapy is also a theoretically attractive technique to express BMPs clinically, since long-term, regulatable gene expression and systemic delivery with tissue-specific expression may be possible in future. This study was performed to determine whether an adenoviral vector containing the BMP-2 gene can be used to express BMP-2 in vitro and promote endochondral bone formation in vivo. In vitro, U87 MG cells transduced per cell with 20 MOI of an adenoviral construct containing the BMP-2 gene under the control of the universal CMV promoter (Ad-BMP-2) showed positive antibody staining for the BMP-2 protein at posttransfection day 2. The synthesis and secretion of active BMP-2 into the conditioned medium of Ad-BMP-2-transduced 293 cells were confirmed by Western blot analysis and the induction of alkaline phosphatase activity in a W-20 stromal cell assay. In vivo, Sprague-Dawley rats and athymic nude rats were injected with Ad-BMP-2 in the thigh musculature and were sacrificed on day 3, 6, 9, 12, 16, 21, 60, and 110 for histological analysis. The Sprague-Dawley rats showed evidence of acute inflammation, without ectopic bone formation, at the injection sites. In the athymic nude rats, BMP-2 gene therapy induced mesenchymal stem cell chemotaxis and proliferation, with subsequent differentiation to chondrocytes. The chondrocytes secreted a cartilaginous matrix, which then mineralized and was replaced by mature bone. This study demonstrates that a BMP-2 adenoviral vector can be utilized to produce BMP-2 by striated muscle cells in athymic nude rats, leading to endochondral bone formation. However, in immunocompetent animals the endochondral response is attenuated, secondary to the massive immune response elicited by the first-generation adenoviral construct.

Frameless stereotaxy for transsphenoidal surgery.

OBJECTIVE: To evaluate the utility of performing transsphenoidal surgery with computer-assisted image guidance. METHODS: Thirty-seven patients underwent transsphenoidal surgery in which a frameless stereotactic system was used to confirm the trajectory to the sella and to locate the anatomic midline. This technique was compared with our standard method of using an image intensifier to confirm the approach (n = 43). The numbers of complications associated with the approach, the times required to set up and perform each operation, and the average costs for each group were compared. RESULTS: There were no complications attributable to inaccurate localization from the neuronavigational system. Additional setup time was necessary to calibrate and register the system; this represented a mean of 17 minutes in transsphenoidal procedures performed for the first time (n = 30), whereas reoperations required an average of 22 minutes (n = 7) (P < 0.05). The operative times, defined as time from incision to closure, were not statistically different (P = 0.38). To reduce assistant variation, a subset of this group in which the same assistant was used (n = 18) was analyzed. The additional setup time was reduced to a mean of 12 minutes (P < 0.05). The total case times were actually reduced in this group (127 versus 133 min), but this was not statistically significant (P = 0.75). Fluoroscopy was not required when frameless stereotaxy was used. The cost savings were partially offset by the cost of the preoperative computed tomographic study necessary for fiducial registration and the additional cost of setup time in the operating room. When all factors were analyzed, an additional cost to the patient of $318.00 was noted. The image guidance in axial, coronal, and sagittal planes provided by frameless stereotaxy was subjectively beneficial; it increased our confidence with the approach to the sella and intraoperative localization and was particularly helpful in reoperations where standard anatomic landmarks were distorted. CONCLUSION: Frameless stereotaxy is a technology that provides continuous, three-dimensional information for localization and surgical trajectory to the surgeon and can be applied to transsphenoidal surgery with minimal additional cost and time requirements.

Percutaneous spinal fusion using bone morphogenetic protein-2 gene therapy.

OBJECT: Gene therapy has many potential applications in neurosurgery. One application involves bone morphogenetic protein-2 (BMP-2), a low-molecular-weight glycoprotein that induces bone formation in vivo. Numerous studies have demonstrated that the BMP-2 protein can enhance spinal fusion. This study was undertaken to determine whether direct injection of an adenoviral construct containing the BMP-2 gene can be used for spinal fusion. METHODS: Twelve athymic nude rats were used in this study. Recombinant, replication-defective type 5 adenovirus with the cytomegalovirus (CMV) promoter and BMP-2 gene (Ad-BMP-2) was used. A second adenovirus constructed with the CMV promoter and beta-galactosidase (beta-gal) gene (Ad-beta-gal) was used as a control. In three groups (four rats each) 7.5 microl of virus (5x10(8) particles/microl) was injected percutaneously and paraspinally at the lumbosacral junction: Group 1 received Ad-BMP-2 bilaterally; Group 2 received Ad-BMP-2 on the right, Ad-beta-gal on the left; and Group 3 received Ad-beta-gal bilaterally. Computerized tomography (CT) scans of the lumbosacral spine were obtained at 3, 5, 8, and 12 weeks. At 12 weeks, the animals were killed and underwent histological inspection. Ectopic bone formation was observed both on three-dimensionally reconstructed CT scans and histological examination in all rats at sites treated with Ad-BMP-2. Histological analysis demonstrated bone at different stages of maturity adjacent to the spinous processes, laminae, and transverse processes. CONCLUSIONS: Results of this study clearly demonstrated that it is possible to produce in vivo endochondral bone formation by using direct adenoviral construct injection into the paraspinal musculature, which suggests that gene therapy may be useful for spinal fusion in the future.

Estrogen receptors in prolactinomas: a clinico-pathological study.

BACKGROUND: Antiestrogens are effective in the treatment of estrogen receptor (ER) positive breast carcinoma. The use of antiestrogen therapy in pituitary adenomas, however, has not been explored. This study attempted to identify a population who may benefit from antiestrogen therapy. MATERIALS & METHODS: Prolactinomas from 29 patients (10 men, 19 women) were analyzed for ER and Ki-67 labeling index using immunohistochemistry. Nine of the 19 women were either amenorrheic or had not received exogenous estrogen for at least one year. Ten women were menstruating either spontaneously or as a result of estrogen administration. Factors including age, serum prolactin level, tumor size, evidence of tumor invasiveness and recurrence of tumor were evaluated to determine if they were predictive of ER expression. RESULTS: Tumors from 6/10 (60%) men were positive for ER. Among women who were having menses, 9/10 (90%) tumors were positive, whereas 6/9 (67%) tumors from amenorrheic women were positive. Statistical analysis revealed that none of the variables: gender, age, menstrual status, Ki-67 proliferative rate, exposure to dopamine agonists, preoperative prolactin level, tumor size, or invasiveness was predictive for the presence of the receptor. The incidence of ER, however, was significantly reduced in recurrent tumors (p = 0.03). CONCLUSIONS: ER expression is less likely in recurrent tumors. The efficacy of ER antagonists cannot be inferred by gender or estrogen exposure.

A new technique for the surgical management of unstable thoracolumbar burst fractures: a modification of the anterior approach and an outcome comparison to traditional methods.

This study was conducted to determine the safety, efficacy, and complication rate associated with the anterior approach in the use of a new titanium mesh interbody fusion cage for the treatment of unstable thoracolumbar burst fractures. The experience with this technique is compared with the senior authors' (C.S., R.W., and M.S.) previously published results in the management of patients with unstable thoracolumbar burst fractures. Between 1996 and 1999, 21 patients with unstable thoracolumbar (T12-L3) burst fractures underwent an anterolateral decompressive procedure in which a titanium cage and Kaneda device were used. Eleven of the 21 patients had sustained a neurological deficit, and all patients improved at least one Frankel grade (average 1.2 grades). There was improvement in outcome in terms of blood loss, correction of kyphosis, and pain, as measured on the Denis Pain and Work Scale, in our current group of patients treated via an anterior approach when compared with the results in those who underwent a posterior approach. In our current study the anterior approach was demonstrated to be a safe and effective technique for the management of unstable thoracolumbar burst fractures. It offers superior results compared with the posterior approach. The addition of the new titanium mesh interbody cage to our previous anterior technique allows the patient's own bone to be harvested from the corpectomy site and used as a substrate for fusion, thereby obviating the need for iliac crest harvest. The use of the cage in association with the Kaneda device allows for improved correction of kyphosis and restoration of normal sagittal alignment in addition to improved functional outcomes.

The influence of secondary gain on surgical outcome: a comparison between cervical and lumbar discectomy.

Although the expectation of monetary compensation has been associated with failures in lumbar discectomy, the issue has not been investigated in patients undergoing cervical disc surgery. The authors analyzed the relationship between economic forms of secondary gain and surgical outcome in a group of patients with a common pay scale, retirement plan, and disability program. All procedures were performed at the Portsmouth Naval Medical Center between 1993 and 1995; active-duty military servicepersons treated for cervical radiculopathy were prospectively included. Clinical, demographic, and financial factors were analyzed to determine which were predictive of outcome. Financial data were used to create a compensation incentive, which is proportional to the patient's rank, years of service, potential disability, retirement eligibility, and base pay and reflects the monetary incentive of disability. The results of cervical surgery were compared to a previously reported companion population of patients treated for lumbar disc disease. A good outcome was defined as a return to active duty, whereas a referral for disability was considered a poor surgical result. A 100% follow-up rate was obtained for 269 patients who underwent 307 cervical operations. Only 16% (43 of 269) of patients who underwent cervical operation received disability, whereas 24.7% (86 of 348) of patients who underwent lumbar discectomy obtained a poor result (p = 0.0082). Although economic forms of secondary gain were not associated with a poor outcome in cervical disease, both the rank (p = 0.002) and duration (p = 0.03) of an individual's military career were significant factors (p = 0.02). Of the medical variables tested, multilevel surgery (p = 0.03) and revision operations at the same level (p = 0.03) were associated with referral for medical discharge. Secondary gain in the form of economic compensation influences outcome in lumbar but not cervical disc surgery patients; the increased rate of disability referral in patients who underwent lumbar discectomy may reflect an expectation of economic compensation. Social factors that are independent of the anticipation of economic compensation seem to influence the outcome in cervical disc surgery patients.

Intraoperative chymopapain in lumbar laminotomy for disc disease: a less invasive technique.

The use of chymopapain in the treatment of lumbar disc herniation has been widely studied since Smith first described its use in humans in 1963. The authors describe the use of chymopapain intraoperatively in open lumbar microdiscectomy in 63 patients. When combined with the results of a previous study performed at the same institution, the authors found that this technique significantly reduces the rate of recurrent disc herniation when compared with traditional laminotomy with discectomy. This procedure maximizes the benefits of each approach taken separately, allowing for decompression of the nerve root from a free fragment or sequestered disc and preventing recurrence through dissolution of the nucleus pulposus. Overall, outcome was good or excellent immediately postoperatively in 73% of the 63 patients and in 64% at last follow-up evaluation. Additionally, this procedure is safe with no complications noted in the immediate perioperative period or at follow-up evaluation.