Retrospective study on effectiveness of activ L total disc replacement: clinical and radiographical results of 1- to 3-year follow-up

Long-Term Clinical Outcomes With the Activ-L Lumbar Arthroplasty System

BACKGROUND

Low back pain (LBP) due to degenerative disc disease (DDD) is the most common occupational disorder worldwide. Lumbar total disc replacement (LTDR) has provided an alternative to rigid fusion to relieve pain with less motion restriction. We present clinical results with long-term follow-up from a single-center, single-surgeon series of patients treated with the Activ-L artificial disc.

METHODS

Thirty-three patients with symptomatic single-level DDD who failed nonsurgical therapy for a minimum of 6 months underwent single-level arthroplasty with the Activ-L system between 2007 and 2012. Demographic, preoperative, and postoperative data were collected prospectively. Clinical factors reviewed included occupational status, sensory deficits, functional status determined by Oswestry Disability Index (ODI), back pain, leg pain, pain medication consumption, and radiographic imaging.

RESULTS

Average age at surgery was 38.0 ± 7.8 years, and the majority of patients were male (60.6%). Average follow-up was 2.7 ± 1.7 years. Average ODI at preoperative baseline was 54.6 ± 13.5, with scores significantly improved at 6 weeks (28.6 ± 17.4, P < .0001), 3 months (24.1 ± 16.8, P < .0001), 6 months (22.3 ± 16.3, P < .0001), 1 year (18.8 ± 15.3, P < .0001), and final follow-up (15.6 ± 16.4, P < .0001). Most patients (87.8%) reported pain medication usage within 14 days of baseline evaluation, with consumption decreasing significantly at 1-year (34.5%, P < .0001) and long-term follow-up (21.2%, P < .0001). One patient experienced mild unilateral graft subsidence at 1 year, which remained stable on radiographs at 5 years. None of the prostheses required revision surgery.

CONCLUSIONS

The Activ-L disc replacement system is safe and effective for treating single-level lumbar DDD. Patients reported significant improvement in functional outcomes and decreases in pain medication consumption. Further investigation of the Activ-L system in larger populations is warranted.

CLINICAL RELEVANCE

LBP is a common cause of disability worldwide, and better treatment options are needed to improve outcomes, including pain and mobility. Spine surgeons may choose the Activ-L disc replacement as a safe and effective treatment for LBP caused by single-level lumbar DDD.

Long-term clinical results following Charite III lumbar total disc replacement

BACKGROUND CONTEXT

Lumbar total disc replacement (TDR) operation represents an alternative to lumbar fusion for the treatment of symptomatic lumbar intervertebral disc degeneration and has gained increasing attention in recent years.

PURPOSE

This study aimed to assess clinical outcomes in a cohort of patients with TDR and the long-term survival rate of the prostheses.

STUDY DESIGN

This is a retrospective, single-center clinical study.

PATIENT SAMPLE

The sample comprised 30 patients, giving a total of 35 prostheses after an average follow-up (FU) of 15.2 years following TDR, which was performed for the treatment of lumbar degenerative disc disease.

OUTCOME MEASURES

Clinical evaluation included visual analog scale (VAS) and the Oswestry Disability Index (ODI). Radiological parameters of intervertebral disc height (IDH), range of motion (ROM), lumbar lordosis, lumbar scoliosis, and prosthesis position were evaluated in surgical and adjacent levels. Complications and re-operation rates were also assessed.

METHODS

Clinical evaluation and radiological parameters were evaluated preoperatively and at final FU. All data were collected by members of our department, including research assistants and nurses who were not involved in the decision making of this study.

RESULTS

Thirty of the 35 patients participated in the final FU. The cumulative survival rate of the prosthesis at a mean FU of 15.4 years was 100%. The clinical success rate was 93.3%. The VAS and ODI scores at final FU were significantly lower than preoperatively (p<.001). The average ROM of the operated and superior adjacent segment decreased significantly at the final FU, whereas the inferior adjacent segment was not affected. The IDH of all surgical and adjacent levels were well maintained at the final FU. Ten patients had a lumbar scoliosis >3° and the mean angle was 8.5°, of which 7 had left convex curvature. Three prostheses were offset more than 5 mm from the midline on the coronal plane. Four prostheses showed subsidence. Twenty-six operative segments and five adjacent segments showed heterotopic ossification. Two patients of the total 35-patient cohort underwent a secondary operation.

CONCLUSIONS

Satisfactory clinical results and good prosthesis survival can be achieved in the long term. Lumbar TDR surgeries also have the potential to reduce the incidence of adjacent segment disease.

Patient-reported Outcomes and Revision Rates at a Mean Follow-up of 10 Years After Lumbar Total Disc Replacement

STUDY DESIGN

Prospective observational cohort study.

OBJECTIVE

The aim of this study was to determine the long-term clinical results and prosthesis survival in patients treated with lumbar total disc replacement (TDR).

SUMMARY OF BACKGROUND DATA

Fusion has become the current standard surgical treatment for lumbar degenerative disease. TDR is an alternative treatment that seeks to avoid fusion-related adverse events, specifically adjacent segment disease.

METHODS

Sixty-eight consecutive patients treated with TDR from 2003 to 2008 were invited to follow-up and complete a Visual Analog Scale (VAS) for back and leg pain, the Dallas Pain Questionnaire (DPQ), and the Short Form-36. These surveys were also administered to the subjects before their index TDRs. Data on reoperation were collected from the patients' medical records.

RESULTS

Fifty-seven (84%) patients were available for follow-up at a mean 10.6 years post-operatively (range 8.1-12.6 years). There was a significant improvement from preop to latest follow-up in VAS (6.8 vs. 3.2, P < 0.000) and DPQ (63.2 vs. 45.6, P = 0.000) in the entire cohort. Nineteen patients (33%) had a revision fusion surgery after their index TDR. Patients who had revision surgery had statistically significant worse outcome scores at last follow-up than patients who had no revision. Thirty patients (52.6%) would choose the same treatment again if they were faced with the same problem.

CONCLUSION

This study demonstrated significant improvement in long-term clinical outcomes, similar to previously published studies, and two-thirds of the discus prostheses were still functioning at follow-up. However, there is still a lack of well-designed long-term studies, thus requiring further investigation.

LEVEL OF EVIDENCE

3.

Minimum Clinically Important Difference: Current Trends in the Spine Literature

STUDY DESIGN

Review of the 2011 to 2015 minimum clinically important difference (MCID)-related publications in Spine, Spine Journal, Journal of Neurosurgery-Spine, and European Spine Journal.

OBJECTIVE

To summarize the various determinations of MCID and to analyze its usage in the spine literature of the past 5 years in order to develop a basic reference to help practitioners interpret or utilize MCID.

SUMMARY OF BACKGROUND DATA

MCID represents the smallest change in a domain of interest that is considered beneficial to a patient or clinician. The many sources of variation in calculated MCID values and inconsistency in its utilization have resulted in confusion in the interpretation and use of MCID.

METHODS

All articles from 2011 to 2015 were reviewed. Only clinical science articles utilizing patient reported outcome scores (PROs) were included in the analysis. A keyword search was then performed to identify articles that used MCID. MCID utilization in the selected papers was characterized and recorded.

RESULTS

MCID was referenced in 264/1591 (16.6%) clinical science articles that utilized PROs: 22/264 (8.3%) independently calculated MCID values and 156/264 (59.1%) used previously published MCID values as a gauge of their own results. Despite similar calculation methods, there was a two- or three-fold range in the recommended MCID values for the same instrument. Half the studies recommended MCID values within the measurement error. Most studies (97.2%) using MCID to evaluate their own results relied on generic MCID. The few studies using specific MCID (MCID calculated for narrowly defined indications or treatments) did not consistently match the characteristics of their sample to the specificity of the MCID. About 48% of the studies compared group averages instead of individual scores to the MCID threshold.

CONCLUSION

Despite a clear interest in MCID as a measure of patient improvement, its current developments and uses have been inconsistent.

LEVEL OF EVIDENCE

N/A.

Lumbar total disc arthroplasty: outdated surgery or here to stay procedure? A systematic review of current literature

Background

The purpose of this study was to summarize the available evidence about total lumbar disc replacement (TDR), focusing our attention on four main topics: clinical and functional outcomes, comparison with fusion surgery results, rate of complications and influence on sagittal balance.

Materials and methods

We systematically searched Pubmed, Embase, Medline, Medscape, Google Scholar and Cochrane library databases in order to answer our four main research questions. Effective data were extracted after the assessment of methodological quality of the trials.

Results

Fifty-nine pertinent papers were included. Clinical and functional scores show statistically significant improvements, and they last at all time points compared to baseline. The majority of the articles show there is no significant difference between TDR groups and fusion groups. The literature shows similar rates of complications between the two surgical procedures.

Conclusions

TDR showed significant safety and efficacy, comparable to lumbar fusion. The major advantages of a lumbar TDR over fusion include maintenance of segmental motion and the restoration of the disc height, allowing patients to find their own spinal balance. Disc arthroplasty could be a reliable option in the treatment of degenerative disc disease in years to come.

Level of evidence

II.

Adjacent segment degeneration after lumbar spinal fusion compared with motion-preservation procedures: a meta-analysis

PURPOSE

This meta-analysis aimed to evaluate the efficacy of motion-preservation procedures to prevent the adjacent segment degeneration (ASDeg) or adjacent segment disease (ASDis) compared with fusion in lumbar spine.

METHODS

PubMed, Embase and the Cochrane Library were comprehensively searched and a meta-analysis was performed of all randomized controlled trials and well designed prospective or retrospective comparative cohort studies assessing the lumbar fusion and motion-preservation procedures. We compared the ASDeg and ASDis rate, reoperation rate, operation time, blood loss, length of hospital stay, visual analogue scale (VAS) and oswestry disability index (ODI) improvement of the two procedures.

RESULTS

A total of 15 studies consisting of 1474 patients were included in this study. The meta-analysis indicated that the prevalence of ASDeg, ASDis and reoperation rate on the adjacent level were lower in motion-preservation procedures group than in the fusion group (P = 0.001; P = 0.0004; P < 0.0001). Moreover, shorter length of hospital stay was found in motion-preservation procedures group (P < 0.0001). No difference was found in terms of operation time (P = 0.57), blood loss (P = 0.27), VAS (P = 0.76) and ODI improvement (P = 0.71) between the two groups.

CONCLUSIONS

The present evidences indicated that the motion-preservation procedures had an advantage on reducing the prevalence of ASDeg, ASDis and the reoperation rate due to the adjacent segment degeneration compared with the lumbar fusion. And the clinical outcomes of the two procedures are similar.

ISASS Policy Statement - Lumbar Artificial Disc

PURPOSE

The primary goal of this Policy Statement is to educate patients, physicians, medical providers, reviewers, adjustors, case managers, insurers, and all others involved or affected by insurance coverage decisions regarding lumbar disc replacement surgery.

PROCEDURES

This Policy Statement was developed by a panel of physicians selected by the Board of Directors of ISASS for their expertise and experience with lumbar TDR. The panel's recommendation was entirely based on the best evidence-based scientific research available regarding the safety and effectiveness of lumbar TDR.