Biomedical subjects

Federico P Girardi

Publications and source records attributed to Federico P Girardi.

At least 19 recordsLinked to original sources

PubMed2006

Discordantly high spinal bone mineral density values in patients with adult lumbar scoliosis.

STUDY DESIGN: Retrospective study. OBJECTIVE: The purposes of this study were: 1) to investigate the validity of bone mineral density measurements with DEXA in patients with adult lumbar scoliosis and 2) to investigate the association between osteoporosis and adult lumbar scoliosis. SUMMARY OF BACKGROUND DATA: Osteoporosis and lumbar degenerative scoliosis are phenomena encountered with increased frequency in aging, often concurrently. It has been suggested that scoliosis predisposes to osteoporosis, but degenerative scoliosis could falsely elevate spinal bone mineral density measurements. METHODS: The feasibility of measuring Cobb's angle in DEXA scans was established in 48 surgical candidates with standing anteroposterior lumbar radiographs and supine DEXA scans. Charts and radiographs of 454 consecutive adult patients evaluated at an osteoporosis center were reviewed thereafter. The association between age, lumbar curve, and various bone density measurements was investigated. Bone density measurements between nonscoliotic and scoliotic patients with and without a history of adolescent scoliosis were compared. RESULTS: Cobb's angle on DEXA scan was measured with an error of 4 degrees and correlated highly with the plain lumbar radiographs. The prevalence of scoliosis was 9.47% in this cohort of patients. Advancing age was associated with an increase in osteoporosis in both scoliotic and nonscoliotic patients. Scoliotic patients demonstrated increased spinal bone mineral density (BMD) measurements compared with nonscoliotic patients, resulting in discrepancies between hip and spine BMD values. This discrepancy correlated with aging and curve magnitude (up to 30% for curves of 43 degrees ). Scoliotic patients demonstrated significantly lower hip BMD values than nonscoliotic. Curve magnitude did not correlate with severity of osteoporosis. CONCLUSIONS: Cobb's angle measurements on DEXA scans are reliable and comparable to conventional radiographs. Spinal BMD values are less valuable for monitoring osteoporosis than hip values in scoliotic patients; an increasing discrepancy with age was noted. Scoliotic patients exhibited discordantly high spinal BMD values, despite significant hip osteoporosis. The discrepancy correlated with aging and curve magnitude. Scoliosis was common among the osteoporotic population (9.47%). Lumbar scoliosis is a useful clinical marker for osteoporosis, irrespective of scoliosis history and magnitude. Viable alternatives for osteoporosis evaluation of adult patients with lumbar scoliosis are hip DEXA values, in conjunction with other BMD measurements.

Absorptiometry, Photon↗

PubMed2006

Outcome of revision discectomies following recurrent lumbar disc herniation.

STUDY DESIGN: Retrospective study. OBJECTIVES: To assess the difference in the outcome score between a primary surgery to treat lumbar disc herniation and a revision surgery for recurrent herniation at the same location with the use of a validated lumbar spine outcome instrument. SUMMARY OF BACKGROUND DATA: Paucity of studies comparing the results of revision discectomy for true recurrent disc herniation at the same location to that reported for primary discectomy. METHODS: A total of 27 patients who had undergone revision discectomies for recurrent lumbar disc herniations were surveyed to assess their clinical outcomes. Patients were compared with a control group of 30 matched patients who had undergone only a primary discectomy. The spine module of the MODEMS outcome instrument was used to evaluate the patients' satisfaction, their pain and functional ability following discectomy, as well as their quality of life. All patients were also asked whether they were improved or worsened with surgery. Those undergoing revision surgery were asked whether the improvement following the second surgery was more or less than the improvement following the first surgery. RESULTS: Improvement following the repeat discectomy was not statistically different from the improvement that occurred in patients who underwent just the primary operation. Differences in residual numbness/tingling in the leg and/or the foot as well as in frequency of back and/or buttock pain were identified. CONCLUSION: Based on patient derived outcome data using a validated instrument, revision discectomy is as efficacious as primary discectomy in selected patients.

Adult↗

PubMed2006

Measurement error of lumbar total disc replacement range of motion.

STUDY DESIGN: A retrospective review of lumbar total disc replacement (TDR) radiographs. OBJECTIVE: To determine the error and variability in measuring TDR radiographic range of motion (ROM). SUMMARY OF BACKGROUND DATA: Motion preservation is the driving force behind lumbar TDR technology. In the recent literature, sagittal radiographic TDR ROM as low as 2 degrees has been reported. In these studies, ROM was determined by using the Cobb method to measure TDR sagittal alignment angles in flexion-extension lateral radiographs. However, previous studies in the spinal deformity literature have shown that the Cobb method is very susceptible to measurement error. METHODS: There were 5 observers, including 2 attending orthopedic spine surgeons, 1 spine fellow, 1 fifth-year resident, and 1 fourth-year resident, who measured the ROM of 50 ProDisc II (Synthes Spine Solutions, New York, NY) TDRs on standard flexion-extension lumbar spine radiograph sets. Repeated measurements were made on 2 occasions using the Cobb method. Measurement variability was calculated using 3 statistical methods. RESULTS: The 3 statistical methods resulted in extremely similar values for TDR ROM observer variability. Overall, the intraobserver variability of TDR ROM measurement was +/-4.6 degrees, and interobserver variability was +/-5.2 degrees . CONCLUSIONS: To be 95% certain that an implanted TDR prosthesis has any sagittal motion, a ROM of at least 4.6 degrees must be observed, which is the upper limit of intraobserver measurement variability for a TDR with a true ROM of 0 degrees. To be 95% certain that a change in TDR ROM has occurred between 2 measurements by the same observer, a change in ROM of at least 9.6 degrees must be observed (the entire range of +/-4.6 degrees intraobserver variability). ROM measurement variability should be considered when evaluating the success or failure of motion preservation in lumbar TDR.

Adult↗

PubMed2006

Three-level anterior cervical discectomy and fusion with plate fixation: radiographic and clinical results.

STUDY DESIGN: Retrospective review of patients with cervical spondylosis treated with 3-level anterior cervical discectomy and fusion with plate fixation. OBJECTIVE: To assess the radiographic and clinical outcome of 3-level instrumented anterior cervical discectomy. SUMMARY OF BACKGROUND DATA: Three-level cervical discectomy without plate fixation has shown high rates of pseudarthrosis and poor outcomes. The addition of internal fixation may improve these parameters. METHODS: A total of 46 patients were observed for an average of 17.6 months (range, 6-51 months). All had 3-level anterior cervical discectomy and fusion with tricortical iliac crest autograft (4 cases), fibular ring allograft (38 cases), or titanium cage (4 cases). Allografts and cages were filled with iliac crest autograft. All patients had semirigid plating. Clinical and radiographic follow-up data were obtained. Clinical outcomes were measured as described by Robinson and with the Nurick scale. RESULTS: Forty-four patients achieved solid fusion. Two patients had additional surgery for junctional disease, and in 1 of them pseudarthrosis repair was also performed. One asymptomatic pseudarthrosis was noted. With a successful result defined as an excellent or good outcome accompanied by significant pain relief, 38 patients had a successful result (83%). Radiographic adjacent level disease was diagnosed in 11 patients after surgery and was symptomatic in 5. CONCLUSION: Three-level anterior cervical discectomy with plate fixation has a high rate of fusion, a low complication rate, and acceptable outcome in the treatment of multilevel cervical spondylosis.

Adult↗

PubMed2006

Pott disease in the thoracolumbar spine with marked kyphosis and progressive paraplegia necessitating posterior vertebral column resection and anterior reconstruction with a cage.

STUDY DESIGN: Case report. OBJECTIVES: To report on a patient with Pott disease, progressive neurologic deficit, and severe kyphotic deformity, who had medical treatment fail and required posterior/anterior decompression with instrumented fusion. Treatment options will be discussed. SUMMARY OF BACKGROUND DATA: Tuberculous spondylitis is an increasingly common disease worldwide, with an estimated prevalence of 800,000 cases. METHODS: Surgical treatment consisting of extensive posterior decompression/instrumented fusion and 3-level posterior vertebral column resection, followed by anterior debridement/fusion with cage reconstruction. RESULTS: Neurologic improvement at 6-month follow-up (Frankel B to Frankel D), with evidence of radiographic fusion. CONCLUSIONS: A 70-year-old patient with progressive Pott paraplegia and severe kyphotic deformity, for whom medical treatment failed is presented. A posterior vertebral column resection, multiple level posterior decompression, and instrumented fusion, followed by an anterior interbody fusion with cage was used to decompress the spinal cord, restore sagittal alignment, and debride the infection. At 6-month follow-up, the patient obtained excellent pain relief, correction of deformity, elimination of the tuberculous foci, and significant recovery of neurologic function.

Aged↗

PubMed2006

Postoperative infections in interbody fusion for degenerative spinal disease.

UNLABELLED: Scant literature exists on the treatment of infection after interbody fusion. Some authors advocate removal of the interbody grafts. Salvage of the grafts was possible in 92.3% (12 of 13) of the infections in a series of 326 consecutive patients with degenerative spinal diseases treated by three surgeons. Posterior interbody fusion and posterolateral instrumented fusion was performed in 267 patients and anterior interbody fusion was done in 59 patients. Eight infections in the first group (3%) and six in the second group (10.1%) were identified. Mean followup was 18 months (range, 12-38 months). All infections were early, presenting at a mean of 18 days (range, 11-28 months). All but one infection were in the posterior wound and deep. A high number of risk factors were present in these patients. Initial treatment included wound debridement and broad spectrum antibiotics, until culture results indicated the final antibiotic regimen. Infection recurred as osteomyelitis in one patient with multiple previous surgeries and anterior/posterior fusion. This was treated with removal of the posterior instrumentation and the interbody graft and extensive anterior/posterior reconstruction. Clinical outcomes were good in 10 patients, fair in two and poor in one using the Stauffer-Coventry scale. One pseudarthrosis was identified in a patient with anterior interbody fusion at final followup. Salvage of the interbody graft and retaining the instrumentation was safe in most cases in the presented series and did not adversely affect outcome. LEVEL OF EVIDENCE: Therapeutic study, level IV (case series). Please see the Guidelines for Authors for a complete description of levels of evidence.

Adult↗

PubMed2006

Chronic infections of the spine: surgical indications and treatments.

UNLABELLED: Chronic vertebral osteomyelitis is a disease of substantial morbidity. Although uncommon to most spinal surgeons, the incidence of pyogenic and granulomatous spondylitis worldwide is on the rise. Although antibiotic therapy remains the initial treatment for most patients, surgical debridement with or without stabilization may be required for effective eradication of the disease. Indications for surgery in pyogenic and granulomatous osteomyelitis include the need to obtain a bacteriologic diagnosis when other methods have failed, the presence of a clinically significant abscess, an infection refractory to prolonged nonoperative treatment, cord compression with considerable neurologic deficit, and substantial deformity or spinal instability. Currently, controversy remains regarding the timing of surgery, the approach used, and the use of instrumentation. We reviewed the contemporary literature available through the Medline database, focusing on larger case series and, when existing, prospective randomized trials. The rationale for surgical treatment of the most common pathogens (eg, Mycobacterium tuberculae and Staphylococcus aureus) is reviewed. Commonly, anterior debridement with or without posterior instrumentation is used for cases of advanced disease, but more limited approaches may have a role in less severe cases or patients unable to tolerate extensive surgery. LEVEL OF EVIDENCE: Therapeutic study, level III (systematic review of level III studies). Please see the Guidelines for Authors for a complete description of levels of evidence.

Chronic Disease↗

PubMed2006

Lumbar total disc replacement. Surgical technique.

BACKGROUND: Symptomatic lumbar degenerative disc disease is a challenging entity to treat. The results of arthrodesis may be compromised in the short term by pseudarthrosis and in the long term by pain at the iliac-crest donor site and by junctional degeneration. Total disc replacement has the potential to provide long-lasting relief to these patients. The purpose of this study was to present the clinical and radiographic results assessed seven to eleven years following a Prodisc total lumbar disc replacement. METHODS: Sixty-four patients had single or multiple-level implantation of a total lumbar disc replacement between 1990 and 1993. The mean duration of follow-up was 8.7 years. Clinical results were evaluated by assessing preoperative and postoperative lumbar pain, radiculopathy, disability, and modified Stauffer-Coventry scores. Preoperative and post-operative radiographs were evaluated by assessing preoperative and postoperative lumbar pain, radiculopathy, disability, and modified Stauffer-Coventry scores. Preoperative and post-operative radiographs were evaluated as well. Subgroup analysis was performed to determine if gender, an age of less than forty-five years, previous surgery, or multilevel surgery had an effect on outcome. RESULTS: At an average of 8.7 years post-operatively, there were significant improvements in the backpain, radiculopathy, disability, and modified Stauffer-Coventry scores. Thirty-three of the fifty-five patients with sufficient follow-up had an excellent result, eight had a good result, and fourteen had a poor result. Neither gender nor multilevel surgery affected outcome. An age of less than forty-five years and prior lumbar surgery had small but significant negative effects on outcome. Radiographs did not demonstrate loosening, migration, or mechanical failure in any patient. Five patients had approach-related complications. CONCLUSIONS: The Prodisc lumbar total disc replacement appears to be effective and safe for the treatment of symptomatic degenerative disc disease. Gender and multilevel surgery did not affect the outcomes, whereas prior lumbar surgery or an age of less than forty-five years was associated with slightly worse outcomes. Longer follow-up of this cohort of patients and randomized trials comparing disc replacement with arthrodesis are needed.

Adult↗

PubMed2005

Accuracy of computerized frameless stereotactic image-guided pedicle screw placement into previously fused lumbar spines.

STUDY DESIGN: A retrospective chart and radiographic review of 122 pedicle screws placed with computerized stereotactic image-guidance into posterolateral fusion masses. OBJECTIVES: To determine the accuracy rate of computerized stereotactic image-guided pedicle screw placement in previously fused lumbar spines. SUMMARY OF BACKGROUND DATA: Placement of pedicle screws into a previously fused lumbar spine is challenging. The normal anatomic landmarks used to determine the starting point and trajectory of the screws have either been removed or are obscured by the fusion mass. Computerized frameless stereotaxis provides precise intraoperative real time multiplanar image-guidance and may be valuable in this clinical situation. METHODS: Computerized frameless stereotactic image-guidance was used to place pedicle screws into 78 consecutive patients with prior lumbar spine fusions. Postoperative computed tomography was available on 35 patients (231 screws). One hundred and twenty-two screws were placed into fusion masses. Pedicle cortical perforations were characterized by the direction (medial, inferior, lateral, or superior) and magnitude (in 2-mm increments) of perforation. RESULTS: Five (4.1%) of the 122 pedicle screws placed into previously fused levels were found to have unintentional cortical violations. There were 1 superior (<2 mm), 1 medial (<2 mm), and 3 lateral perforations (<2, 4, and 6 mm). None of these perforations led to clinically apparent radicular pain or weakness. No pedicle screws required revision for malpositioning. CONCLUSIONS: The accuracy rate of stereotactic image-guided pedicle screw placement into previously fused lumbar spine levels is 96%. Computerized stereotactic image-guidance may have particular application in situations in which posterior element anatomy is altered, such as in the presence of a prior fusion mass.

Adult↗

PubMed2005

Correlation between range of motion and outcome after lumbar total disc replacement: 8.6-year follow-up.

STUDY DESIGN: Retrospective radiographic and chart review. OBJECTIVE: To examine the relationship between lumbar total disc replacement (TDR) range of motion (ROM) and clinical outcome at 8.6-year follow-up. SUMMARY OF BACKGROUND DATA: There are no studies on the relationship between TDR motion and clinical outcomes. METHODS: We reviewed 38 patients who underwent 1 or 2-level TDR implantation with 51 TDR. Flexion-extension ROM was measured on lateral radiographs. Clinical outcomes were measured at 8.6 years by modified Stauffer-Coventry scores, Oswestry Disability Questionnaires (ODQ), and subjective ratings of back pain, leg pain, and disability. Spearman rank correlation coefficient was used to determine if ROM was correlated with clinical outcome. Patients were divided into 2 groups by motion (< or = 5 degrees and > 5 degrees ). Statistical differences in outcome were sought. RESULTS: Spearman rank correlation coefficient revealed weak-to-moderate but statistically significant associations between ROM and outcome for postoperative back pain (r = -0.35, P = 0.034), ODQ (r = -0.33, P = 0.046), and modified Stauffer-Coventry scores (r = 0.42, P = 0.0095). Patients with motion of > 5 degrees had superior outcomes in ODQ (mean difference 12.6 points, P = 0.026) and Stauffer-Coventry scores (mean difference 2.2 points, P = 0.015). CONCLUSIONS: The radiographic ROM at 8.6-year follow-up was positively correlated with several outcomes measures. Patients with motion > 5 degrees had clinically modest but statistically better outcomes in ODQ and modifiedStauffer-Coventry scores. Longer follow-ups will be necessary to measure fully the impact of TDR ROM on outcome.

Adult↗

PubMed2005

Advantages and disadvantages of nonfusion technology in spine surgery.

Nonfusion technology in spine surgery may improve outcomes by reducing surgical morbidity and the incidence of adjacent level degeneration; however, new technologies also introduce new short- and long-term complications. There is currently no evidence that nonfusion implants are superior to fusion in mid- to long-term follow-up. Understanding the potential risks and benefits of nonfusion technology is essential for spine surgeons and their patients. This article reviews the current evidence relating to the potential risks and benefits of nonfusion technology in spine surgery.

Arthroplasty, Replacement↗

PubMed2005

Lumbar total disc replacement part I: rationale, biomechanics, and implant types.

Lumbar total disc replacement is an evolving new technology designed to preserve motion and to perhaps supplant fusion as the current "gold standard" surgical treatment for lumbar degenerative disc disease. Given the intense interest in disc replacement as a paradigm shift from fusion, this article describes the anatomy, physiology, and biomechanics of degenerative disc disease. Various treatment options and their outcomes are reviewed. A brief history of disc replacement surgery is outlined, current indications and commonly accepted contraindications for disc replacement surgery are explained, and current implants likely to be available in the United States are described. An overview of the surgical procedure is provided, with technical tips and pitfalls included. Finally, a standard postoperative regime is described.

Arthroplasty, Replacement↗

PubMed2005

Lumbar synovial cysts of the spine: an evaluation of surgical outcome.

OBJECTIVE: Our aim was to study the outcomes and results of surgically treated patients with synovial cysts of the lumbar spine in our institution. METHODS: Retrospective data from 39 consecutive patients, treated during the period of December 1996 to August 2004, were analyzed. Twenty-eight men (70%) and 11 women (30%) of mean age 63.3 years were studied. All pre- and postoperative signs, symptoms, extension/flexion radiographs, magnetic resonance imaging (MRI), and computed tomography (CT) with or without myelography were reviewed. All underwent surgery for synovial cysts with excision and decompression. Additional fusion in 26 patients was performed; 22 of them had degenerative spinal spondylolisthesis. Nine (23%) patients had prior decompression procedures, with three (8%) having had prior spinal instrumentation. Surgical outcomes were evaluated according to a questionnaire scoring system (scale of 1-4; 4 = excellent, 3 = good, 2 = fair, 1 = poor). Various preoperative attributes such as gender, age, weight, and height were analyzed to see if they had any effect on the outcome of surgery. Modified musculoskeletal outcomes data evaluation and management system (MODEM), questionnaire was provided to all; 24 (62%) responded. The following categories were determined: excellent (<20), very good (21-40), good (41-60), fair (61-80), and poor (81-100). Postoperative complications were also recorded. RESULTS: All patients had pain in their lower extremities, with 62% experiencing pain bilaterally. Ninety-five percent had pain in their back and 36% in the buttocks (36%). Eighteen (46%) patients had CT myelography. A total of 42 cysts were found. Two patients had bilateral cysts at L4-L5 level. Histology revealed two hemorrhagic cysts. The average duration of surgery was 231 minutes (range 92-391 minutes), and a mean blood loss of 930 mL (range 200-2500 mL) was recorded. Two operative dural tears and one postoperative wound dehiscence were observed. One patient had a recurrent synovial cyst at the site of original surgery. Eight patients (four each in the fusion and nonfusion group) had junctional degeneration and symptoms. A regression analysis performed on age, height, weight, and gender showed that they were not determining factors of surgical outcome. Surgery of spinal cysts at L4-L5 segment produced good and those at L5-S1 and multilevel excellent results. Patients with spinal segment fusion had superior outcomes, with 80% having excellent or good outcomes versus approximately 70% without fusion. With the modified MODEM questionnaire, 22 of the 24 (92%) patients scored between excellent, very good, and good. Two patients scored in the fair range, and none of the 24 patients scored in the range of poor. CONCLUSIONS: Spinal cysts are commonly found at the L4-L5 level, the site of maximum instability. MRI is the tool of choice for diagnosis. The etiology is still unclear, but underlying spinal instability has a strong association for formation of spinal cysts and worsening symptoms. Synovial cysts resistant to conservative therapy should be treated surgically. Resection and decompression with fusion remain an appropriate option. The optimal approach for patients with juxtafacet cysts remains unclear. The best surgical treatment approach for each particular individual appears to remain speculative.

Adult↗

PubMed2005

Lumbar total disc replacement. Seven to eleven-year follow-up.

BACKGROUND: Symptomatic lumbar degenerative disc disease is a challenging entity to treat. The results of arthrodesis may be compromised in the short term by pseudarthrosis and in the long term by pain at the iliac-crest donor site and by junctional degeneration. Total disc replacement has the potential to provide long-lasting relief to these patients. The purpose of this study was to present the clinical and radiographic results assessed seven to eleven years following a Prodisc total lumbar disc replacement. METHODS: Sixty-four patients had single or multiple-level implantation of a total lumbar disc replacement between 1990 and 1993. The mean duration of follow-up was 8.7 years. Clinical results were evaluated by assessing preoperative and postoperative lumbar pain, radiculopathy, disability, and modified Stauffer-Coventry scores. Preoperative and postoperative radiographs were evaluated as well. Subgroup analysis was performed to determine if gender, an age of less than forty-five years, previous surgery, or multilevel surgery had an effect on outcome. RESULTS: At an average of 8.7 years postoperatively, there were significant improvements in the back-pain, radiculopathy, disability, and modified Stauffer-Coventry scores. Thirty-three of the fifty-five patients with sufficient follow-up had an excellent result, eight had a good result, and fourteen had a poor result. Neither gender nor multilevel surgery affected outcome. An age of less than forty-five years and prior lumbar surgery had small but significant negative effects on outcome. Radiographs did not demonstrate loosening, migration, or mechanical failure in any patient. Five patients had approach-related complications. CONCLUSIONS: The Prodisc lumbar total disc replacement appears to be effective and safe for the treatment of symptomatic degenerative disc disease. Gender and multilevel surgery did not affect the outcomes, whereas prior lumbar surgery or an age of less than forty-five years was associated with slightly worse outcomes. Longer follow-up of this cohort of patients and randomized trials comparing disc replacement with arthrodesis are needed.

Adult↗

PubMed2005

Measurement of total disc replacement radiographic range of motion: a comparison of two techniques.

OBJECTIVE: Current methods used to measure total disc replacement (TDR) radiographic range of motion (ROM) have not been previously evaluated. Sagittal ROM is measured by determining the change in the Cobb angle of the prosthesis from the flexion to the extension radiographs. Either the metallic endplates or the keels of the TDR prosthesis can be used as radiographic landmarks in measuring ROM. We hypothesized that use of the prosthesis keels as radiographic landmarks, when compared with the use of prosthesis endplates, might lead to more precise measurements of TDR sagittal ROM. METHODS: Two observers (a fifth-year orthopedics resident and an attending orthopedic spine surgeon) measured the ROM of 51 Prodisc II TDRs on standard flexion and extension lumbar spine radiograph sets. Repeated measurements were made on two occasions using either the keels or the endplates as landmarks. Precision was defined as the mean of the absolute differences between measurements. RESULTS: For observer A, the mean absolute difference between two measurements was 1.4 degrees with the keel method compared with 3.0 degrees with the endplate method (P < 0.001). For observer B, the mean absolute difference between two measurements was 1.8 degrees with the keel method and 3.3 degrees with the endplate method (P < 0.001). When the interobserver differences were examined, the mean absolute difference was 1.8 degrees with the keel method and 3.3 degrees with the endplate method (P < 0.001). CONCLUSIONS: Our results show that the use of TDR prosthesis keels as radiographic landmarks, when compared with the use of prosthesis endplates, yields greater precision in ROM measurement. For TDR prostheses with a keel, we recommend using the keel to measure ROM.

Adult↗

PubMed2004

The prevalence of contraindications to total disc replacement in a cohort of lumbar surgical patients.

STUDY DESIGN: This is a retrospective review of the epidemiology of contraindications to lumbar total disc replacement (TDR). OBJECTIVE: To define the prevalence of contraindications to lumbar total disc replacement in a cohort of patients undergoing lumbar surgery in the senior author's (F.P.C.) practice. SUMMARY OF BACKGROUND DATA: No published reports have documented the prevalence of contraindications to lumbar total disc replacement. METHODS: We performed a retrospective review of 100 consecutive patients who had lumbar surgery by one surgeon between September and December 2002. Procedures performed and contraindications to TDR were recorded. Contraindications to TDR included central or lateral recess stenosis, facet arthrosis, spondylolysis or spondylolisthesis, herniated nucleus pulposus with radiculopathy, scoliosis, osteoporosis, and postsurgical pseudarthrosis or deficiency of posterior elements. Patients were divided into fusion and nonfusion groups. The percentage of patients without contraindications to TDR was calculated. RESULTS: Of 100 patients, 56 had fusions and 44 had nonfusion surgery. In the fusion group, 56 of 56 patients had contraindications to TDR. In the nonfusion group, 11% (5 of 44) were candidates for TDR. Overall, 5% of patients in this series were candidates for TDR. The average number of contraindications to TDR was 2.48 (range, 0-5). CONCLUSIONS: Predictions that TDR will replace fusion are premature. A small percentage (5%) of the patients currently indicated for lumbar surgery at our institution have no contraindications to TDR. Future growth in TDR implantation will result from the indication of patients for surgery who would not be indicated today or from the elimination of current contraindications.

Adult↗

PubMed2004

Evaluation of a novel pedicle probe for the placement of thoracic and lumbosacral pedicle screws.

BACKGROUND: Pedicle screw instrumentation is common in the lumbar spine and is gaining acceptance in the thoracic spine. The pedicle is generally cannulated with a gearshift probe or curette. SafePath (Mekanika, Boca Raton, FL) is an alternative pedicle probe designed for pedicle cannulation. This is a blunt-tipped, nonaggressive drill that seeks the cancellous portion of the pedicle. OBJECTIVE: The objective of this study was to evaluate the accuracy of this device in comparison with techniques commonly used for pedicle cannulation. METHODS: Four osteoligamentous fresh-frozen thoracic to sacral cadaveric spines were studied. The pedicles of one side of each cadaver were cannulated with the SafePath device. The contralateral pedicles were cannulated with either a gearshift probe or a 3-0 cervical curette. The accuracy of pedicle probe placement was evaluated by radiography, computed tomography (CT) scan, and direct observation via dissection. RESULTS: By direct observation, 51 of 128 pedicles were violated (40%). There were not significant differences between the results obtained with the gearshift probe or curette; there were 2 of 22 lumbosacral violations (9%) and 14 of 45 thoracic violations (33%). With the SafePath device, there were 0 of 22 lumbosacral violations (0%) and 34 of 45 thoracic violations (76%). SafePath performed significantly better in the lumbar spine and significantly worse in the thoracic spine. The accuracy for determining pedicle violation was 88% for radiography and 85% for CT. CONCLUSIONS: The results of this in vitro study suggest that the SafePath device may represent an alternative to traditional pedicle cannulation techniques in the lumbosacral spine. However, the opposite is true in the thoracic spine, where SafePath performed significantly worse than traditional techniques.

Bone Screws↗

PubMed2003

Pathogenesis, presentation, and treatment of lumbar spinal stenosis associated with coronal or sagittal spinal deformities.

Sagittal- or coronal-plane deformity considerably complicates the diagnosis and treatment of lumbar spinal stenosis. Although decompressive laminectomy remains the standard operative treatment for uncomplicated lumbar spinal stenosis, the management of stenosis with concurrent deformity may require osteotomy, laminectomy, and spinal fusion with or without instrumentation. Broadly stated, the surgery-related goals in complex stenosis are neural decompression and a well-balanced sagittal and coronal fusion. Deformities that may present with concurrent stenosis are scoliosis, spondylolisthesis, and flatback deformity. The presentation and management of lumbar spinal stenosis associated with concurrent coronal or sagittal deformities depends on the type and extent of deformity as well as its impact on neural compression. Generally, clinical outcomes in complex stenosis are optimized by decompression combined with spinal fusion. The need for instrumentation is clear in cases of significant scoliosis or flatback deformity but is controversial in spondylolisthesis. With appropriate selection of technique for deformity correction, a surgeon may profoundly improve pain, quality of life, and functional capacity. The decision to undertake surgery entails weighing risk factors such as age, comorbidities, and preoperative functional status against potential benefits of improved neurological function, decreased pain, and reduced risk of disease progression. The purpose of this paper is to review the pathogenesis, presentation, and treatment of lumbar spinal stenosis complicated by scoliosis, spondylolisthesis, or flatback deformity. Specific attention is paid to surgery-related goals, decision making, techniques, and outcomes.

Analgesics↗