The short-term efficacy and safety of artificial total disc replacement for selected patients with lumbar degenerative disc disease compared with anterior lumbar interbody fusion: A systematic review and meta-analysis

The Decline of Lumbar Artificial Disc Replacement

Lower back pain associated with degenerative disc disease is a common occurrence, with many surgical treatments targeting the degenerated disc to relieve symptoms. Current surgical options for degenerative disc disease primarily consist of a discectomy followed by either spinal fusion or artificial disc replacement, with the former being increasingly more common in the lumbar region despite the risk of adjacent segment disease. Though artificial disc replacement aims to provide an increase in range of motion and decreases risk of adjacent segment disease, surgeons are increasingly opting for spinal fusion in the lumbar region. This review investigates underlying factors that may be contributing to this trend by assessing lumbar artificial disc replacement selection criteria, clinical outcomes, surgical technique, complications, revision burden, and overall cost. While these factors had some role in the physician's decision, ultimately the narrow selection criteria and lack of cost reimbursement by insurance has primarily led to the decline in lumbar artificial disc replacement.

Lumbar Disc Replacement Versus Interbody Fusion: Meta-analysis of Complications and Clinical Outcomes

Background

Lumbar spinal fusion is a commonly performed operation with relatively high complication and revision surgery rates. Lumbar disc replacement is less commonly performed but may have some benefits over spinal fusion. This meta-analysis aims to compare the outcomes of lumbar disc replacement (LDR) versus interbody fusion (IBF), assessing their comparative safety and effectiveness in treating lumbar DDD.

Methods

PubMed, Cochrane, and Google Scholar (pages 1-2) were searched up until February 2024. The studied outcomes included operative room (OR) time, estimated blood loss (EBL), length of hospital stay (LOS), complications, reoperations, Oswestry Disability Index (ODI), back pain, and leg pain.

Results

Ten studies were included in this meta-analysis, of which six were randomized controlled trials, three were retrospective studies, and one was a prospective study. A total of 1720 patients were included, with 1034 undergoing LDR and 686 undergoing IBF. No statistically significant differences were observed in OR time, EBL, or LOS between the LDR and IBF groups. The analysis also showed no significant differences in the rates of complications, reoperations, and leg pain between the two groups. However, the LDR group demonstrated a statistically significant reduction in mean back pain (p=0.04) compared to the IBF group.

Conclusion

Both LDR and IBF procedures offer similar results in managing CLBP, considering OR time, EBL, LOS, complication rates, reoperations, and leg pain, with slight superiority of back pain improvement in LDR. This study supports the use of both procedures in managing degenerative spinal disease.

Comparison of value per operative time between anterior lumbar interbody fusion and lumbar disc arthroplasty: A propensity score-matched analysis

Context

Despite the growing evidence demonstrating its effectiveness, lumbar disc arthroplasty (LDA) rates have not increased significantly in recent years. A likely contributing factor is uncertainties related to reimbursement and insurers' denial of coverage due to fear of late complications, reoperations, and unknown secondary costs. However, no prior study has compared the physician reimbursement rates of lumbar fusion and LDA.

Aim

The aim of this study was to compare the relative value units (RVUs) per min as well as 30-day readmission, reoperation, and morbidity rates between anterior lumbar interbody fusion (ALIF) and LDA.

Settings and Design

This was a retrospective cohort study.

Subjects and Methods

The current study utilizes data obtained from the National Surgical Quality Improvement Program database. Patients who underwent ALIF or LDA between 2011 and 2019 were included in the study.

Statistical Analysis Used

Propensity score matching analysis was performed according to demographic characteristics and comorbidities. Matched groups were compared through Fisher's exact test and independent t-test for categorical and continuous variables, respectively.

Results

Five hundred and two patients who underwent ALIF were matched with 591 patients who underwent LDA. Mean RVUs per min was significantly higher for ALIF compared to LDA. ALIF was associated with a significantly higher 30-day morbidity rate compared to LDA, while readmission and reoperation rates were statistically similar. ALIF was also associated with higher frequencies of deep venous thrombosis (DVT) and blood transfusions.

Conclusions

ALIF is associated with significantly higher RVUs per min compared to LDA. ALIF is also associated with higher rates of 30-day morbidity, DVT, and blood transfusions, while readmission and reoperation rates were statistically similar.

Radiological Changes in Adjacent and Index Levels after Cervical Disc Arthroplasty

PURPOSE

The purpose of this retrospective study was to evaluate radiological and clinical outcomes in patients undergoing cervical disc arthroplasty (CDA) for cervical degenerative disc disease. The results may assist in surgical decision-making and enable more effective and safer implementation of cervical arthroplasty.

MATERIALS AND METHODS

A total of 125 patients who were treated with CDA between 2006 and 2019 were assessed. Radiological measurements and clinical outcomes included the visual analogue scale (VAS), the Neck Disability Index (NDI), and the Japanese Orthopaedic Association (JOA) myelopathy score assessment preoperatively and at ≥2 years of follow-up.

RESULTS

The mean follow-up period was 38 months (range, 25-114 months). Radiographic data demonstrated mobility at both the index and adjacent levels, with no signs of hypermobility at an adjacent level. There was a non-significant loss of cervical global motion and range of motion (ROM) of the functional spinal unit at the operated level, as well as the upper and lower adjacent disc levels, compared to preoperative status. The cervical global and segmental angle significantly increased. Postoperative neck VAS, NDI, and JOA scores showed meaningful improvements after one- and two-level CDA. We experienced a 29.60% incidence of heterotrophic ossification and a 3.20% reoperation rate due to cervical instability, implant subsidence, or osteolysis.

CONCLUSION

CDA is an effective surgical technique for optimizing clinical outcomes and radiological results. In particular, the preservation of cervical ROM with an artificial prosthesis at adjacent and index levels and improvement in cervical global alignment could reduce revision rates due to adjacent segment degeneration.

Upper and lower adjacent segment range of motion after fixation of different lumbar spine segments in the goat: an in vitro experiment

Objectives

The purpose of this study was to examine the biomechanical effects of fixation on range of motion (ROM) in the upper and lower adjacent segments of different lumbar spine segments in a goat spine model.

Methods

Fifteen goat spine specimens (vertebrae T12–S1) were randomly divided into three groups: A (single-segment fixation), B (double-segment fixation), and C (triple-segment fixation). Motion in different directions was tested using a spinal motion simulation test system with five external loading forces. Transverse, forward–backward, and vertical displacement of the upper and lower adjacent segments were measured.

Results

As the external load increased, the upper and lower adjacent segment ROM increased. A significantly greater ROM in group C compared with group A was found when the applied external force was greater than 75 N. The upper adjacent segment showed a significantly greater ROM than the lower adjacent segment ROM within each group.

Conclusions

Adjacent segment ROM increased with an increasing number of fixed lumbar segments. The upper adjacent segment ROM was greater than that of the lower adjacent segments. Adjacent segment stability after lumbar internal fixation worsened with an increasing number of fixed segments.

Biomechanics of spinal implants-a review

Spinal instrumentations have been classified as rigid fixation, total disc replacement and dynamic stabilization system for treatment of various spinal disorders. The efficacy and biomechanical suitability of any spinal implant can be measured through in vitro, in vivo experiments and numerical techniques. With the advancement in technology finite element models are making an important contribution to understand the complex structure of spinal components along with allied functionality, designing and application of spinal instrumentations at preliminary design stage. This paper aimed to review the past and recent studies to describe the biomechanical aspects of various spinal implants. The literatures were grouped and reviewed in accordance to instrumentation category and their functionality in the spinal column at respective locations.

Intervertebral Disc Diseases PART 2: A Review of the Current Diagnostic and Treatment Strategies for Intervertebral Disc Disease

With an aging population, there is a proportional increase in the prevalence of intervertebral disc diseases. Intervertebral disc diseases are the leading cause of lower back pain and disability. With a high prevalence of asymptomatic intervertebral disc diseases, there is a need for accurate diagnosis, which is key to management. A thorough understanding of the pathophysiology and clinical manifestation aids in understanding the natural history of these conditions. Recent developments in radiological and biomarker investigations have potential to provide noninvasive alternatives to the gold standard, invasive discogram. There is a large volume of literature on the management of intervertebral disc diseases, which we categorized into five headings: (a) Relief of pain by conservative management, (b) restorative treatment by molecular therapy, (c) reconstructive treatment by percutaneous intervertebral disc techniques, (d) relieving compression and replacement surgery, and (e) rigid fusion surgery. This review article aims to provide an overview on various current diagnostic and treatment options and discuss the interplay between each arms of these scientific and treatment advancements, hence providing an outlook of their potential future developments and collaborations in the management of intervertebral disc diseases.

Artificial disc replacement in spine surgery

Total disc replacement (TDR) is an innovative procedure that has gained traction in spine surgery. A large amount of data in the literature report on the short-term outcomes of TDR surgery favorably. However, surgeons remain reluctant to opt for TDR surgery due to uncertainty of long-term outcomes. Recently, long term data regarding TDR surgery has become available, with some studies showing superior outcomes to fusion surgery. The goal of this review is to synthesize and clinically contextualize the recent literature on TDR surgery. This article also provides brief discussion of the biggest challenges currently facing disc arthroplasties and the ways in which they are being tackled.