Prospective, Randomized Comparison of Cervical Total Disk Replacement Versus Anterior Cervical Fusion: Results at 48 Months Follow-up.

STUDY DESIGN: This was a prospective, randomized, controlled multicenter trial. OBJECTIVE: The purpose of this study was to compare clinical outcomes at 4-year follow-up of patients receiving cervical total disk replacement (TDR) with those receiving anterior cervical discectomy and fusion (ACDF). SUMMARY OF BACKGROUND DATA: ACDF has been the traditional treatment for symptomatic disk degeneration. Several studies found single-level TDR to be as safe and effective as ACDF at ≥2 years follow-up. METHODS: Patients from 23 centers were randomized in a 2:1 ratio with 164 receiving the investigational device (Mobi-C Cervical Disc Prosthesis) and 81 receiving ACDF using an anterior plate and allograft. Patients were evaluated preoperatively and 6 weeks, 3, 6, 12, 18, 24, 36, and 48 months postoperatively. Outcome assessments included a composite success score, Neck Disability Index, visual analog scales assessing neck and arm pain, patient satisfaction, major complications, subsequent surgery, segmental range of motion, and adjacent-segment degeneration. RESULTS: The composite success rate was similar in the 2 groups at 48-month follow-up. Mean Neck Disability Index, visual analog scale, and SF-12 scores were significantly improved in early follow-up in both groups with improvements maintained throughout 48 months. On some measures, TDR had significantly greater improvement during early follow-up. At no follow-up were TDR scores significantly worse than ACDF scores. Subsequent surgery rate was significantly higher for ACDF compared with TDR (9.9% vs. 3.0%, P<0.05). Range of motion was maintained with TDR having a mean baseline value of 8 degrees compared with 10 degrees at 48 months. The incidence of adjacent-segment degeneration was significantly higher with ACDF at inferior and superior segments compared with TDR (inferior: 50% vs. 30%, P<0.025; superior: 53% vs. 34%, P<0.025). CONCLUSIONS: Significant improvements were observed in pain and function. TDR patients maintained motion and had significantly lower rates of reoperation and adjacent-segment degeneration compared with ACDF. This study supports the safety and efficacy of TDR in appropriately selected patients.

Effect of sacroiliac fusion on gait, standing balance, and pelvic mobility for unilateral sacroiliac joint dysfunction.

Background: Sacroiliac joint fusion (SIF) has been shown to effectively alleviate pain and improve functional deficits associated with sacroiliac joint dysfunction (SIJD). Previous studies have demonstrated significant improvements in gait function, however, none have reported both over-ground walking and quiescent standing, and additionally, none have included analysis of pelvic kinematics which may contain important information regarding pain avoidant compensatory behaviors. The purpose of this study was to identify objective functional differences between symptomatic and asymptomatic sides of unilateral sacroiliac joint dysfunction (SIJD) patients and to demonstrate the effectiveness of unilateral sacroiliac fusion (SIF) to improve gait and balance function compared to matched controls. Methods: Thirteen unilateral SIJD patients were evaluated before and 6 months after SIF and were compared to matched asymptomatic controls. Pain and disability were assessed using visual analog scales and the Oswestry disability index respectively. Over ground walking and standing balance were assessed using 3D joint kinematics and kinetic ground reaction force analyses. Results: Preoperatively, SIJD patients reported high levels of pain and disability and exhibited significant deficits in gait including elevated step width, reduced hip flexion/extension, and elevated pelvic motion as well as elevated center of pressure sway characteristics during standing. After unilateral SIF, patients reported significant reductions in pain and demonstrated significant improvements in gait including normalization of step width between sides and improved hip motion however elevated pelvic obliquity and rotation motion remained. Improvements in standing balance included reduced coronal sway characteristics and normalization of loading symmetry between sides. Conclusion: Unilateral SIF resulted in significant improvements in both gait and balance function among SIJD patients to levels comparable to matched controls, however elevated pelvic motion remained. These findings help inform surgeons on the effectiveness of SIF for unilateral SIJD and provide important information regarding interpretation of functional outcomes.

The story of the Texas Pain Society: formation and function of a regional pain society.

The idea of forming a Texas Pain Society came to the Founders in 1987 due to disparity and deficiencies in the practice of pain management in the United States and, in particular, the State of Texas. The Founders considered very carefully the implication of forming such a society. They diligently mapped out the mission and goals of the Texas Pain Society in those early formative years. This report is the history of Texas Pain Society as the activities unfolded from 1989 to 2011. The reader may question why there is a need to tell such a story. We believe strongly that, with disparities of standards of practice in pain medicine and poor recognition of advances in pain management, this scenario is quite common in many states and countries. The practitioners of pain management in these regions certainly must have considered getting together and forming a consensus on the standards of practice in their communities. This historical report of the Texas Pain Society provides the relevant information necessary and the efforts to be made for a society's mission to achieve its goals and have an ongoing impact in its own region. We hope that we have shed some light on a process for the formation of a regional pain society such as ours.

Sacroiliac Joint Pain and Its Treatment.

The sacroiliac joint (SIJ) as a source of symptoms has been controversial; however, as knowledge about the joint increased, its role as a pain generator in patients complaining of symptoms that are often attributed to spinal pathology has become better appreciated. The literature reports that the SIJ is the pain origin in as many as 30% of patients presenting with low back pain. Clinically, the SIJ can be challenging to evaluate; however, assessing pain location, patient posture/movement, and provocative manual testing are useful in making the presumptive diagnosis of SIJ disruption. The most definitive evaluation is image-guided injection of anesthetic solutions into the joint which is diagnostic if there is at least 75% symptom relief acutely. Treatment begins with nonoperative intervention including physical therapy and/or chiropractic care. If these fail, the next option is generally radiofrequency denervation (rhizotomy) of the joint. If this does not provide adequate relief, surgical intervention, in the form of minimally invasive SIJ fusion may be considered. The literature increasingly supports favorable results of SIJ fusion in appropriately selected patients. The purpose of this review is to provide an overview of the current literature on the SIJ, with focus on its surgical treatment.

Multi-center, prospective, randomized, controlled investigational device exemption clinical trial comparing Mobi-C Cervical Artificial Disc to anterior discectomy and fusion in the treatment of symptomatic degenerative disc disease in the cervical spine.

BACKGROUND: Anterior cervical discectomy and fusion (ACDF) is the gold standard for treating symptomatic cervical disc degeneration. Cervical total disc replacements (TDRs) have emerged as an alternative for some patients. The purpose of this study was to evaluate the safety and effectiveness of a new TDR device compared with ACDF for treating single-level cervical disc degeneration. METHODS: This was a prospective, randomized, controlled, multicenter Food and Drug Administration (FDA) regulated Investigational Device Exemption (IDE) study. A total of 245 patients were treated (164 TDR: 81 ACDF). The primary outcome measure was overall success based on improvement in Neck Disability Index (NDI), no subsequent surgical interventions, and no adverse events (AEs) classified as major complications. Secondary outcome measures included SF-12, visual analog scale (VAS) assessing neck and arm pain, patient satisfaction, radiographic range of motion, and adjacent level degeneration. Patients were evaluated preoperatively and postoperatively at 6 weeks, 3, 6, 12, 18, and 24 months. The hypothesis was that the TDR success rate was non-inferior to ACDF at 24 months. RESULTS: Overall success rates were 73.6% for TDR and 65.3% for ACDF, confirming non-inferiority (p < 0.0025). TDR demonstrated earlier improvements with significant differences in NDI scores at 6 weeks and 3 months, and VAS neck pain and SF-12 PCS scores at 6 weeks (p<0.05). Operative level range of motion in the TDR group was maintained throughout follow-up. Radiographic evidence of inferior adjacent segment degeneration was significantly greater with ACDF at 12 and 24 months (p < 0.05). AE rates were similar. CONCLUSIONS: Mobi-C TDR is a safe and effective treatment for single-level disc degeneration, producing outcomes similar to ACDF with less adjacent segment degeneration. LEVEL OF EVIDENCE: Level I. CLINICAL RELEVANCE: This study adds to the literature supporting cervical TDR as a viable option to ACDF in appropriately selected patients with disc degeneration.

Cervical total disc replacement with the Mobi-C cervical artificial disc compared with anterior discectomy and fusion for treatment of 2-level symptomatic degenerative disc disease: a prospective, randomized, controlled multicenter clinical trial: clinical article.

OBJECT: Cervical total disc replacement (TDR) is intended to treat neurological symptoms and neck pain associated with degeneration of intervertebral discs in the cervical spine. Anterior cervical discectomy and fusion (ACDF) has been the standard treatment for these indications since the procedure was first developed in the 1950s. While TDR has been shown to be a safe and effective alternative to ACDF for treatment of patients with degenerative disc disease (DDD) at a single level of the cervical spine, few studies have focused on the safety and efficacy of TDR for treatment of 2 levels of the cervical spine. The primary objective of this study was to rigorously compare the Mobi-C cervical artificial disc to ACDF for treatment of cervical DDD at 2 contiguous levels of the cervical spine. METHODS: This study was a prospective, randomized, US FDA investigational device exemption pivotal trial of the Mobi-C cervical artificial disc conducted at 24 centers in the US. The primary clinical outcome was a composite measure of study success at 24 months. The comparative control treatment was ACDF using allograft bone and an anterior plate. A total of 330 patients were enrolled, randomized, and received study surgery. All patients were diagnosed with intractable symptomatic cervical DDD at 2 contiguous levels of the cervical spine between C-3 and C-7. Patients were randomized in a 2:1 ratio (TDR patients to ACDF patients). RESULTS: A total of 225 patients received the Mobi-C TDR device and 105 patients received ACDF. At 24 months only 3.0% of patients were lost to follow-up. On average, patients in both groups showed significant improvements in Neck Disability Index (NDI) score, visual analog scale (VAS) neck pain score, and VAS arm pain score from preoperative baseline to each time point. However, the TDR patients experienced significantly greater improvement than ACDF patients in NDI score at all time points and significantly greater improvement in VAS neck pain score at 6 weeks, and at 3, 6, and 12 months postoperatively. On average, patients in the TDR group also maintained preoperative segmental range of motion at both treated segments immediately postoperatively and throughout the study period of 24 months. The reoperation rate was significantly higher in the ACDF group at 11.4% compared with 3.1% for the TDR group. Furthermore, at 24 months TDR demonstrated statistical superiority over ACDF based on overall study success rates. CONCLUSIONS: The results of this study represent the first available Level I clinical evidence in support of cervical arthroplasty at 2 contiguous levels of the cervical spine using the Mobi-C cervical artificial disc. These results continue to support the use of cervical arthroplasty in general, but specifically demonstrate the advantages of 2-level arthroplasty over 2-level ACDF. Clinical trial registration no.: NCT00389597 (ClinicalTrials.gov).

Algorithmic approach to the management of the patient with lumbar spinal stenosis.

A 71-year-old generally healthy woman presents for her first visit in 3 years. She ambulates slowly from the waiting room, with a more stooped posture than previously. She reports a 2-year history of slowly worsening buttock and leg pain when she walks any distance. She has noticed that her symptoms are much less when she leans on a shopping cart in the grocery store. Her buttock/leg pain resolves within a few minutes when she sits down. The patient exhibits signs and symptoms suggestive of lumbar spinal stenosis.

Relationship between the length of time off work preoperatively and clinical outcome at 24-month follow-up in patients undergoing total disc replacement or fusion.

BACKGROUND CONTEXT: A recent study involving interbody fusion patients found that preoperative work status was significantly related to clinical outcome. In another study comparing the best and worst outcomes of total disc replacement, among a battery of variables analyzed, the only one that differentiated the best and worst outcome groups was the length of time off work before total disc replacement. PURPOSE: The purpose of this study was to determine if there was a relationship between the length of time off work and treatment outcome at 24-month follow-up. If such a relationship existed, a secondary study objective would be to determine if a duration of work could be identified beyond which would be associated with compromised clinical outcome. STUDY DESIGN AND SETTING: Data were collected prospectively from randomized clinical trials comparing total disc replacement with lumbar fusion conducted at a single site. PATIENT SAMPLE: A database of 232 patients enrolled in one of two Food and Drug Administration-regulated trials comparing total disc replacement with fusion for the treatment of symptomatic disc degeneration was the basis of the study group. Only patients who had reached 24-month follow-up were included. The 28 patients who were not employed by choice preoperatively were not included in the analysis. OUTCOME MEASURES: Primary outcome measures used were visual analog scales (VAS) assessing pain and Oswestry disability index. METHODS: The length of time off work before surgery was recorded in weeks. The mean percentage improvement between preoperative and 24-month follow-up scores were analyzed. RESULTS: There was a significant relationship between duration off work preoperatively and clinical outcome (p<.05). The length of time off work preoperatively was more strongly related to outcome than was surgery type, insurance type, job demand, or preoperative VAS and Oswestry scores. Further analysis of the data identified a window of approximately 0 to 13 weeks off work preoperatively that was related to significantly greater improvements on visual analog scales (VAS) and Oswestry scores after surgery compared with patients who were off work for more than 13 weeks preoperatively. Although the subgroup off work for more than 13 weeks improved significantly from their preoperative status, the improvement was not as great as in the subgroup off work for a shorter duration. CONCLUSIONS: The results of this study found that patients off work for a longer duration before surgery improved significantly postoperatively, but had less favorable clinical outcomes than patients off work for a lesser duration. This study suggests a window of approximately 13 weeks off work before surgery after which clinical improvement is reduced. Implications of this finding may be that once a patient becomes unable to work for an extended period, more rigorous psychological screening may be in order as well as perhaps engaging in more rigorous rehabilitation after surgery. Further investigation is needed to determine if the 13 weeks identified in this study is applicable to other populations.

Comparison of results of total disc replacement in postdiscectomy patients versus patients with no previous lumbar surgery.

STUDY DESIGN: Data for this study were collected as part of a prospective Food and Drug Administration regulated IDE trial for the ProDisc total disc replacement. OBJECTIVE: The purpose of the study was to compare the results of total disc replacement (TDR) in patients with previous discectomy to patients who had no such previous surgery. SUMMARY OF BACKGROUND DATA: Discectomy is a well accepted surgical procedure for appropriately selected patients. However, removal of a portion of the disc may lead to further disc degeneration and collapse of the disc space. In the past, treatment options for such patients included a variety of fusion procedures, particularly ones incorporating an interbody graft to restore disc space height. Currently, TDR is being used to treat symptomatic disc degeneration. The results of this procedure have not been specifically investigated in patients with previous discectomy. METHODS: Data were drawn from 1 center participating in the IDE trial for ProDisc. Only patients reaching the 24-month follow-up period were included. Patients were divided into 2 subgroups: those who had previously undergone lumbar discectomy (N = 20) and those who had not (N = 67). Data for this study were collected prospectively before surgery, and at 6 weeks, 3, 6, 12, 18, and 24 months after surgery. The primary outcome measures used were visual analog scales (VAS) assessing pain, Oswestry questionnaire, postoperative patient satisfaction measured on a 0 to 10 VAS, and asking patients if they would have the same procedure again. The outcome measures were compared between the 2 subgroups. RESULTS: The results of this study found no differences between the 2 groups based on any of the 4 outcome measures used at any of the follow-up periods (all P > 0.10). Both groups improved significantly from the preoperative baseline on the VAS assessing pain and the Oswestry questionnaire. The mean satisfaction scores were greater than 7.5 at all follow-up periods and more than 80% of patients in both groups indicated that they would have the same surgery again. DISCUSSION: The results of this study indicate that the outcome of TDR is not compromised among patients witha history of previous discectomy. This finding supports TDR as a viable treatment for patients with symptomatic disc degeneration arising from a previously operated lumbar disc.

Lumbar spinal arthroplasty: analysis of one center's twenty best and twenty worst clinical outcomes.

STUDY DESIGN: This is a retrospective analysis of data that were collected prospectively from 2 concurrent FDA IDE lumbar arthroplasty clinical trials performed at a single center. OBJECTIVES: The purpose of this study was to determine if factors differentiating those patients with the best and worst clinical outcomes from total disc arthroplasty (TDR) could be identified. SUMMARY OF BACKGROUND DATA: Overall the results of TDR have been favorable, including recent results from 2 FDA IDE trials conducted in the United States. However, as with any surgical procedure, there were some patients with extremely good outcomes, and some with poor outcomes. If factors differentiating these groups could be identified, this may help refine patient selection criteria and improve future results. METHODS: The databases of Charite and ProDisc patients at a single site were reviewed to identify patients who reached the 24-month follow-up period. A total of 203 patients, 63 who were implanted with the Charite prosthesis, and 140 who were implanted with the ProDisc prosthesis, were identified. The percentage change in the preoperative to postoperative VAS and Oswestry scores were used to identify the 10 best and 10 worst outcomes for each of the device types. Logistic regression analysis was conducted to determine which of a battery of demographic and clinical assessments were related to the best/worst group classification. RESULTS: Results of the regression analysis found that the only factor significantly related to clinical outcome was the length of time off work before surgery. None of the demographic variables, preoperative VAS or Oswestry scores or radiographic assessment of device placement, were significantly related to clinical outcome. Patients who were off work for shorter durations, or not at all, were more likely to be in the best-outcome group compared with patients who were off work for an extended period of time before surgery. CONCLUSION: This study suggests that among patients undergoing TDR, the length of time off work before surgery was related to outcome. No additional factors related to the best/worst classification were identified in the current study.

Spinal cord stimulation has comparable efficacy in common pain etiologies.

Objectives. The probability of success with spinal cord stimulation (SCS) depends largely on appropriate patient selection. Here, we have assessed the predictive value of pain etiology as it relates to pain relief with SCS as part of a prospective multicenter clinical trial. Methods. Sixty-five subjects with chronic and intractable pain tested an epidural SCS system. Subjects reported pain ratings (visual analog scale) with stimulation off and stimulation on at scheduled follow-up visits for up to 18 months after activation of the system. Visual analog scale scores were averaged and stratified by dominant pain etiologies, comprising failed back surgery syndrome, complex regional pain syndrome, and a subgroup of subjects with miscellaneous other pain etiologies. Results. More than 70% of subjects in each subgroup had successful outcomes during the temporary trial period and similar percentages of subjects from each etiology subgroup subsequently went on to permanent implantation. After permanent implantation, all subgroups reported more than 50% pain relief, on average, at each follow-up time point. No predictive value of pain etiology was observed. Conclusions. Spinal cord stimulation is an effective therapy for neuropathic pain arising from a variety of causes. Failed back surgery syndrome, complex regional pain syndrome, and pain of other etiologies responded equally well to SCS.

Two- to 3-Year Follow-Up of ProDisc-L: Results From a Prospective Randomized Trial of Arthroplasty Versus Fusion.

BACKGROUND: Although total disc replacement has been performed for years outside the United States, relatively little available data address clinical outcomes, particularly data from prospective studies. We report the 24- to 36-month follow-up of one center's experience with the ProDisc-L artificial disc as part of a prospective, randomized trial comparing total disc arthroplasty to combined anterior-posterior lumbar fusion. METHODS: The study involved clinical results for 157 patients from a single center enrolled in the US Food and Drug Administration-regulated trial comparing ProDisc-L to fusion. Only patients who had reached a minimum 24-month follow-up were included in the study. Patients were randomized to receive total disc replacement or circumferential fusion at 1 or 2 lumbar disc levels from L3 to S1, with specific inclusion and exclusion criteria. Data were collected preoperatively and at 6 weeks to 36 months postoperatively. The primary clinical outcome measures were Visual Analog Scale (VAS) scores to assess pain and Oswestry Disability Index (ODI) scores to measure function. RESULTS: The VAS and ODI scores in both treatment groups improved significantly as early as the 6-week followup visit and remained significantly improved throughout the 36-month follow-up period. Although a tendency was observed for the ProDisc-L scores to indicate more favorable outcome, the differences were not statistically significant. The proportion of patients who would have the same procedure again was greater in the total disc replacement group at all follow-up intervals, and significantly greater at the 6- month, 12-month, 24-month, and 36-month follow-up visits. CONCLUSIONS: The results of this study indicate that the total disc replacement with ProDisc-L produces improvements in pain and function that are at least as good as those provided by circumferential fusion. During the long-term follow-up of 24 and 36 months, outcomes did not become less favorable compared with the early outcomes. CLINICAL RELEVANCE: We found that results of total disc replacement were at least as good as those achieved with combined instrumented anterior-posterior fusion for the treatment of painful disc degeneration. Favorable results were maintained during 24- and 36-month follow-up.

A new spinal cord stimulation system effectively relieves chronic, intractable pain: a multicenter prospective clinical study.

Objectives. A prospective, open label, multicenter clinical trial confirmed the functionality of a new spinal cord stimulation (SCS) system for the treatment of chronic, intractable pain of the trunk and/or limbs. Materials and Methods. Sixty-five subjects tested a rechargeable 16-channel SCS system with individual current control of each contact on one or two percutaneous eight-contact epidural leads. After baseline measurements, subjects were tracked on pain ratings and complication rates for up to 18 months. Results. After a trial period, 75% of subjects underwent permanent implantation of the entire SCS system. More than one-half the implanted subjects experienced 50% or greater relief of pain after permanent implantation; some subjects reported relief of 90% or more of their pain. The most common complications after permanent implantation were lead migration, uncomfortable stimulation, and component failure; most resolved after reprogramming or device replacement. Conclusions. The new SCS system provided good pain relief to a majority of subjects, and the results confirm a favorable safety and efficacy profile for the SCS system.

Lumbar spine arthroplasty: early results using the ProDisc II: a prospective randomized trial of arthroplasty versus fusion.

This study represents the first 39 patients with at least 6-month follow-up enrolled in a prospective randomized Food and Drug Administration study evaluating the safety and efficacy of the ProDisc II versus the control, a 360 degrees lumbar spinal fusion. Data were collected preoperatively and at 6 weeks, 3 months, and 6 months postoperatively. Visual Analog Scale (VAS), Oswestry Low Back Pain Disability Questionnaire (ODQ), and patient satisfaction rates were evaluated at these intervals, as well as range of motion, return to work, and recreational and ambulatory status. There were 28 ProDisc patients and 11 who underwent fusion. Six patients had two-level surgery. Estimated blood loss (ProDisc = 69 mL versus fusion = 175 mL) and operative time (ProDisc = 75 minutes versus fusion = 219 minutes) were significantly different (P < 0.01). Hospital stays were shorter (ProDisc = 2.1 days versus fusion = 3.5 days [P < 0.01]) for ProDisc patients. There was a significantly greater reduction in the ODQ scores at 3 months in the ProDisc group compared with the fusion group (P < 0.05). No difference was noted in VAS. A trend was identified at 6 months in patient satisfaction rates favoring ProDisc versus fusion (P = 0.08), and motion was significantly improved in ProDisc patients compared with the fusion group (P = 0.02). Ambulatory status as well as recreational activity improved faster in the ProDisc group. The data suggest that total disc arthroplasty may be an attractive option as opposed to lumbar fusion for the surgical treatment of disabling mechanical low back pain secondary to lumbar disc disease.