Introduction: The evolution of treatment options for painful spinal disorders in diverse settings has produced a variety of approaches to patient care among clinicians from multiple professional backgrounds. The American Society of Pain and Neuroscience (ASPN) Best Practice group identified a need for a multidisciplinary guideline regarding appropriate and effective informed consent processes for spine procedures. Objective: The ASPN Informed Consent Guideline was developed to provide clinicians with a comprehensive evaluation of patient consent practices during the treatment of spine pathology. Methods: After a needs assessment, ASPN determined that best practice regarding proper informed consent for spinal procedures was needed and a process of selecting faculty was developed based on expertise, diversity, and knowledge of the subject matter. A comprehensive literature search was conducted and when appropriate, evidence grading was performed. Recommendations were based on evidence when available, and when limited, based on consensus opinion. Results: Following a comprehensive review and analysis of the available evidence, the ASPN Informed Consent Guideline group rated the literature to assist with specification of best practice regarding patient consent during the management of spine disorders. Conclusion: Careful attention to informed consent is critical in achieving an optimal outcome and properly educating patients. This process involves a discussion of risks, advantages, and alternatives to treatment. As the field of interventional pain and spine continues to grow, it is imperative that clinicians effectively educate patients and obtain comprehensive informed consent for invasive procedures. This consent should be tailored to the patient's specific needs to ensure an essential recognition of patient autonomy and reasonable expectations of treatment.

Objective Lumbar fusion performed through lateral approaches is becoming more common. The interbody devices are generally supported by supplemental posterior fixation implanted through a posterior approach, potentially requiring a second incision and intraoperative repositioning of the patient. A minimally invasive lateral interspinous fixation device may eliminate the need for intraoperative repositioning and avoid disruption of the supraspinous ligament. The objective of this in vitro biomechanical study was to investigate segmental multidirectional stability and maintenance of foraminal distraction of a lateral interspinous fixation device compared to commonly used pedicle screw and facet screw posterior fixation constructs when combined with lumbar interbody cages. Methods Six human cadaver lumbar spine specimens were subjected to nondestructive quasistatic loading in the following states: (1) intact; (2) interspinous fixation device alone and (3) with lateral interbody cage; (4) lateral lumbar interbody cage with bilateral pedicle screws; (5) lateral lumbar interbody cage with unilateral pedicle screws; and ( 6) lateral lumbar interbody cage with facet screws. Multidirectional pure bending in 1.5 Nm increments to 7.5 Nm, and 7.5 Nm flexion-extension bending with a 700 N compressive follower load were performed separately with optoelectronic segmental motion measurement. Relative angular motions of L2-L3, L3-L4, and L4-L5 functional spinal units were evaluated, and the mean instantaneous axis of rotation in the sagittal plane was calculated for the index level. Foraminal height was assessed during combined flexion-extension and compression loading for each test construct. Results All implant configurations significantly restricted flexion-extension motion compared with intact (p < 0.05). No significant differences were found in flexion-extension when comparing the different posterior implants combined with lateral lumbar interbody cages. All posterior fixation devices provided comparable neuroforaminal distraction and maintained distraction during flexion and extension. Conclusions When combined with lateral lumbar interbody cages, the minimally invasive lateral interspinous fixation device effectively stabilized the spine and maintained neuroforaminal distraction comparable to pedicle screw constructs or facet screws. These results suggest the lateral interspinous fixation device may provide a favorable alternative to other posterior systems that require patient repositioning during surgery and involve a greater disruption of native tissues.

Background Previous reports of lumbar total disc replacement (TDR) have described significant complications. The US Food and Drug Administration (FDA) investigational device exemption (IDE) study of the Charité artificial disc represents the first level I data comparison of TDR to fusion. Methods In the prospective, randomized, multicenter IDE study, patients were randomized in a 2:1 ratio, with 205 patients in the Charité group and 99 patients in the control group (anterior lumbar interbody fusion [ALIF] with BAK cages). Inclusion criteria included confirmed single-level degenerative disc disease at L4-5 or L5-S1 and failure of nonoperative treatment for at least 6 months. Complications were reported throughout the study. Results The rate of approach-related complications was 9.8% in the investigational group and 10.1% in the control group. The rate of major neurological complications was similar between the 2 groups (investigational = 4.4%, control = 4.0%). There was a higher rate of superficial wound infection in the investigational group but no deep wound infections in either group. Pseudarthrosis occurred in 9.1% of control group patients. The rate of subsidence in the investigational group was 3.4%. The reoperation rate was 5.4% in the investigational group and 9.1% in the control group. Conclusions The incidence of perioperative and postoperative complications for lumbar TDR was similar to that of ALIF. Vigilance is necessary with respect to patient indications, training, and correct surgical technique to maintain TDR complications at the levels experienced in the IDE study.

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.

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.

BACKGROUND CONTEXT: Previous presenters and authors have described follow-up of various lengths for patients having had lumbar arthroplasty for the treatment of degenerative disc disease. Follow-up in these patients has been reported from 6 months to 17 years. Though long-term follow-up of large single-center patient cohorts is important, only long-term follow-up of patients enrolled in prospective, randomized, controlled studies represents Level I data. The IDE study of the Charité Artificial Disc was the first prospective, randomized, controlled trial studying lumbar arthroplasty at one level from L4 to S1 compared to fusion. Because of this, longer-term data from this clinical should always be available ahead of long-term data from other IDE studies.

BACKGROUND CONTEXT: There is no standardized method to determine the results of spine surgery. One method of assessing results is termed "minimal clinically important difference (MCID)". This parameter has been developed in several studies including that by Hagg et al. (Spine, 2003). This value has not been evaluated in total disc replacement (TDR) studies.

BACKGROUND CONTEXT: There have been several studies reporting the results or total disc replacement (TDR). More recently, trials comparing this technology to fusion have been reported. There is little information available directly comparing TDR devices.