Fundamentals of Mechanobiology and Potential Applications in Spinal Fusion.

BACKGROUND: Mechanobiology can help optimize spinal fusion by providing insights into the mechanical environment required for bone healing and fusion. This includes understanding the optimal loading conditions, the mechanical properties of implanted materials, and the effects of mechanical stimuli on the cells involved in bone formation. The present article reviews the evidence for surface technologies and implant modification of spinal cages in enhancing spinal fusion. METHODS: Databases used included Embase, MEDLINE, Springer, and Cochrane Library. Relevant articles were identified using specific keywords and search fields. Only systematic reviews, meta-analyses, review articles, and original research articles in English were included. Two researchers independently performed the search and selection process. A flowchart of the search strategy and study selection method is provided in the article. RESULTS: The studies indicate that surface modification can significantly enhance osseointegration and interbody fusion by promoting cellular adhesion, proliferation, differentiation, and mineralization. Various surface modification techniques such as coating, etching, nanotopography, and functionalization achieve this. Similarly, implant material modification can improve implant stability, biocompatibility, and bioactivity, leading to better fusion outcomes. Mechanobiology plays a vital role in this process by influencing the cellular response to mechanical cues and promoting bone formation. CONCLUSIONS: The studies reviewed indicate that surface technologies and implant material modification are promising approaches for improving the success of spinal cage fusion. Mechanobiology is critical in this process by influencing the cellular response to mechanical signals and promoting bone growth.

A systematic review of anterior lumbar interbody fusion (ALIF) versus posterior lumbar interbody fusion (PLIF), transforaminal lumbar interbody fusion (TLIF), posterolateral lumbar fusion (PLF).

PURPOSE: The rate of elective lumbar fusion has continued to increase over the past two decades. However, there remains to be a consensus on the optimal fusion technique. This study aims to compare stand-alone anterior lumbar interbody fusion (ALIF) with posterior fusion techniques in patients with spondylolisthesis and degenerative disc disease through a systematic review and meta-analysis of the available literature. METHODS: A systematic review was performed by searching the Cochrane Register of Trials, MEDLINE, and EMBASE from inception to 2022. In the two-stage screening process, three reviewers independently reviewed titles and abstracts. The full-text reports of the remaining studies were then inspected for eligibility. Conflicts were resolved through consensus discussion. Two reviewers then extracted study data, assessed it for quality, and analysed it. RESULTS: After the initial search and removal of duplicate records, 16,435 studies were screened. Twenty-one eligible studies (3686 patients) were ultimately included, which compared stand-alone ALIF with posterior approaches such as posterior lumbar interbody fusion (PLIF), transforaminal lumbar interbody fusion (TLIF), and posterolateral lumbar fusion (PLF). A meta-analysis showed surgical time and blood loss was significantly lower in ALIF than in TLIF/PLIF, but not in those who underwent PLF (p = 0.08). The length of hospital stay was significantly shorter in ALIF than in TLIF, but not in PLIF or PLF. Fusion rates were similar between the ALIF and posterior approaches. The Visual Analogue Scale (VAS) scores for back and leg pain were not significantly different between the ALIF and PLIF/TLIF groups. However, VAS back pain favoured ALIF over PLF at one year (n = 21, MD - 1.00, CI - 1.47, - 0.53), and at two years (2 studies, n = 67, MD - 1.39, CI - 1.67, - 1.11). The VAS leg pain scores (n = 46, MD 0.50, CI 0.12 to 0.88) at two years significantly favoured PLF. The Oswestry Disability Index (ODI) scores at one year were not significantly different between ALIF and the posterior approaches. At two years, ODI scores were also similar between the ALIF and the TLIF/PLIF. However, the ODI scores at two years (2 studies, n = 67, MD - 7.59, CI - 13.33, - 1.85) significantly favoured ALIF over PLF (I2 = 70%). The Japanese Orthopaedic Association Score (JOAS) for low back pain at one year (n = 21, MD - 0.50, CI - 0.78) and two years (two studies, n = 67, MD - 0.36, CI - 0.65, - 0.07) significantly favoured ALIF over PLF. No significant differences were found in leg pain at the 2-year follow-up. Adverse events displayed no significant differences between the ALIF and posterior approaches. CONCLUSIONS: Stand-alone-ALIF demonstrated a shorter operative time and less blood loss than the PLIF/TLIF approach. Hospitalisation time is reduced with ALIF compared with TLIF. Patient-reported outcome measures were equivocal with PLIF or TLIF. VAS and JOAS, back pain, and ODI scores mainly favoured ALIF over PLF. Adverse events were equivocal between the ALIF and posterior fusion approaches.

Single-Level Total Disc Replacement: Index-Level and Adjacent-Level Revision Surgery Incidence, Characteristics, and Outcomes.

BACKGROUND: The literature reports that index level (IL) revision spine surgery (RSS) and adjacent level (AL) RSS are diminished in lumbar TDR compared with fusion procedures. There is a paucity of PROMs reported after RSS. OBJECTIVE: To present the incidence of RSS at the IL and AL following single-level lumbar total disc replacement (TDR) and to document patient-related outcome measures (PROMs) associated with RSS. METHODS: PROMs and timelines were analyzed for 32 RSS patients from a prospective cohort study of 401 patients treated with TDR for single-level degenerative disc disease. The data collected prospectively are analyzed from baseline (prior to index surgery) to latest follow-up following RSS. PROMs, including visual analog scales for back and leg, Oswestry Disability Index, and Roland-Morris Disability Questionnaire, were collected preoperatively; postoperatively at 3, 6, and 12 months; and annually thereafter until RSS. The time to RSS was recorded, and PROMs for RSS (IL, AL, or both) were documented, analyzed, and compared. RESULTS: The median time to RSS in the IL cohort was 35 months (interquartile range [IQR] = 9-51 months). The median time to RSS cohort was 70 months (IQR = 41.3-105.3 months). Timepoints facilitate PROM discussion for RSS. Patients in both groups achieved thresholds for the minimum clinically important difference for pain and disability scores. The small sample size in each group contributed to the variability demonstrated by the 95% CIs, thereby cautioning definitive conclusions. CONCLUSIONS: This study reveals that statistically significant and modest clinical improvements in PROMs can be achieved in RSS for lumbar TDR at IL and AL. The surgical approach and technique are reflective of the pathology and suggest that anterior RSS for AL degeneration and posterior RSS for IL pathology yield similar results. CLINICAL RELEVANCE: Statistical and clinical improvements can be achieved in IL-RSS and AL-RSS following single level TDR. It is essential for clinicians to understand and verify the underlying IL and/or AL pathology to select an appropriate management strategy and to facilitate balanced informed discussions with patients.

Single-Level Total Disc Replacement: Mid- to Long-Term Outcomes.

BACKGROUND: Total disc replacement (TDR) has been shown to be effective for the treatment of lumbar degenerative disc disease (DDD) in carefully selected patients. Previous studies have demonstrated high rates of patient satisfaction and improvement in patient-reported outcome measures (PROMs) compared with preoperative status but most have short-term follow-up or small cohort sizes only. OBJECTIVE: The aim of this study is to report mid- to long-term PROMs from the treatment of symptomatic single-level lumbar DDD with TDR. METHODS: Data collected prospectively concerning single-level TDR performed via an anterior approach were included for analysis. A preoperative assessment was obtained followed by postoperative follow-up assessments at 3, 6, and 12 months, and yearly follow-up thereafter. PROMs included patient satisfaction, visual analog score back and leg, Oswestry Disability Index, and Roland-Morris Disability Questionnaire. RESULTS: A total of 211 patients (118 men, 93 women) operated on between June 1997 and July 2015 were included in this study. Minimum follow-up was 4 years. The average age was 42.2 (range 24-87) years and median follow-up 96 interquartile range 72-132, range 48-120) months. The operative levels were L5-S1 (160, 75.8%) and L4-L5 (61, 24.2%). Both statistically and clinically significant improvements observed postoperatively were maintained at 10 years. In addition, 92% of patients reported either good (n = 29) or excellent satisfaction (n = 155) with treatment at final review. CONCLUSIONS: This study shows that single-level lumbar TDR used appropriately in selected patient results in clinically significant improvements in pain and function, well above the minimum clinically important difference, and good to excellent satisfaction in most patients. Further study to define long-term outcomes and survivorship is required. CLINICAL RELEVANCE: Statistically significant and clinically relevant improvements can be achieved by single-level lumbar TDR, in the treatment of single-level discogenic axial low back pain, with or without radiculopathy. These outcomes are sustained in the mid- to long-term followup periods.

Midterm osteolysis-induced aseptic failure of the M6-C™ cervical total disc replacement secondary to polyethylene wear debris.

BACKGROUND: According to published meta-analyses, cervical total disc replacement (CTDR) seems to be superior to anterior cervical decompression and fusion (ACDF) in most clinical parameters. Despite short-term clinical success of CTDR, there are concerns regarding long-term durability of these prostheses. METHODS: This prospective study involved 382 patients who received standalone CTDR or a hybrid procedure (ACDF/CTDR). A retrospective comparison between different CTDR devices was conducted regarding patient-reported outcome measures (PROMs), failure scenarios, and revision surgeries. The M6-C™ Artificial Cervical Disc (Orthofix, Lewisville, Texas) cohort was compared to the other CTDR devices clinically. Etiological reasons for revision, and the surgical technique of the revision was investigated. RESULTS: Fifty-three patients received M6-C CTDR. Eighteen patients (34%) were revised at an average of 67 months postoperatively for wear-induced osteolysis. There were three additional cases of pending revision. The PROMs of the two groups were similar, indicating that the failure mode (wear-induced osteolysis) is often asymptomatic. The demographics of the two groups were also similar, with more women undergoing revision surgery than men. There were three one-level CTDR, four two-level hybrids, seven three-level hybrids, and three four-level hybrids revised anteriorly. Sixteen patients underwent removal of the prosthesis and were treated according to the extent of osteolysis. There were four vertebrectomies, six revisions to ACDF, and six revisions to another CTDR. One patient underwent supplemental fixation using a posterior approach. The other CTDR cohort had an incidence of 3.3% at the equivalent time, and none of these were due to osteolysis or wear-related events. CONCLUSIONS: There is a concerning midterm failure rate related to ultra-high-molecular-weight-polyethylene wear-induced osteolysis in the M6-C. Patients implanted with the M6-C prosthesis should be contacted, informed, and clinically and radiologically assessed.

Comparison of Mid- to Long-term Follow-up of Patient-reported Outcomes Measures After Single-level Lumbar Total Disc Arthroplasty, Multi-level Lumbar Total Disc Arthroplasty, and the Lumbar Hybrid Procedure for the Treatment of Degenerative Disc Disease.

STUDY DESIGN: Prospective cohort study. OBJECTIVE: The aim of this article is to compare the mid- to long-term patient-reported outcome measures (PROMs) between single-level total disc arthroplasty (TDA), multi-level TDA, and hybrid constructs (combination of TDA and anterior lumbar interbody fusion [ALIF] across multiple levels) for symptomatic degenerative disc disease (DDD). SUMMARY OF BACKGROUND DATA: The treatment of single-level DDD is well documented using TDA. However, there is still a paucity of published evidence regarding long-term outcomes on multi-level TDA and hybrid constructs for the treatment of multi-level DDD, as well as lack of long-term comparisons regarding treatment of single-level DDD and multi-level DDD. METHODS: A total of 950 patients underwent surgery for single-level or multi-level DDD between July 1998 and February 2012 with single-level TDA (n = 211), multi-level TDA (n = 122), or hybrid construct (n = 617). Visual Analog Score for the back (VAS-B) and leg (VAS-L) were recorded, along with the Oswestry Disability Index (ODI) and Roland Morris Disability Questionnaire (RMDQ). RESULTS: All PROMs in all groups showed statistically and clinically significant improvements (P < 0.005) in pain and function that is well above the corresponding minimum clinically important difference (MCID) and exceeds literature thresholds for substantial clinical benefit (SCB). Unadjusted analyses show that there were no statistically significant differences in the change scores between the surgery groups for VAS back and leg pain, and RMDQ up to 8 years' follow-up. Adjusted analyses showed the ODI improvement score for the single group was 2.2 points better (95% confidence interval [CI]: 0.6-3.9, P = 0.009) than in the hybrid group. The RMDQ change score was better in the hybrid group than in the multi-level group by 1.1 points (95% CI: 0.4-1.9, P = 0.003) at 6 months and a further 0.4 point at 2 years (95% CI: 0.1-0.8, P = 0.011). CONCLUSION: In the setting of meticulous preoperative evaluation in establishing a precision diagnosis, clinically and statistically equivalent results can be achieved when treating symptomatic DDD through single-level TDA, multi-level TDA, and hybrid constructs. These results are sustained at mid- to long-term follow-up.Level of Evidence: 3.

The Feasibility of Anterior Spinal Access: The Vascular Corridor at the L5-S1 Level for Anterior Lumbar Interbody Fusion.

STUDY DESIGN: Cross-sectional study. OBJECTIVE: To analyze the feasibility of anterior spinal access to the vascular corridor at the L5-S1 junction, by evaluating three crucial anatomical landmarks. This provides a framework for risk-stratification for the clinician during preoperative evaluation. SUMMARY OF BACKGROUND DATA: The anterior lumbar interbody fusion (ALIF) offers many advantages for fusion at the L5-S1 junction. However, the variant iliac vasculature may preclude safe anterior access. METHODS: Five hundred magnetic resonance imaging (MRI) images of the L5-S1 level were identified, with 379 meeting inclusion criteria. We graded the anterior access into three grades, namely, easy, advanced, or difficult by looking at three important anatomical landmarks-the vascular corridor (narrow if ≤25 mm, medium if 25-35 mm [inclusive], and wide if >35 mm), the left common iliac vein (LCIV) location (grades A-D based on the relative position of the LCIV to the L5-S1 disc space), and the presence or absence of a fat plane. RESULTS: Our results showed that 43.27% of the patients had wide corridor for the anterior access, 19.26% of patients had no fat plane, and 7.65% had a LCIV that extended past the midline of the disc (Grade C, D: >50%). By combining these three factors, 37.20% would have easy anterior access, while a minority (1.85%) would have a difficult anterior access. CONCLUSION: The ALIF at L5-S1 offers significant benefits to the patient. The surgeon should be aware of the dangers in an anterior access by looking at three crucial factors to determine whether the access is easy, advanced, or difficult. Patients with a difficult access should be attempted by experts, vascular access surgeons, or consider an alternative approach to L5-S1.Level of Evidence: 3.

Clinical Outcomes of Cervical Hybrid Reconstructions: A Prospective Study.

BACKGROUND: The study design was a prospective clinical cohort study. The aim of this study was to assess the patient-reported outcome measures (PROMs), patient satisfaction, as well as complication and reoperation rate of cervical hybrid procedures for symptomatic cervical multilevel degenerative disc disease (MLDDD). Cervical total disc replacement (CTDR) has been shown to be safe and effective for the treatment of degenerative pathologies. However, there is minimal PROMs data on the outcomes of combined CTDR and anterior cervical decompression and fusion procedures, commonly referred to as cervical hybrid surgery. METHODS: Prospectively collected PROMs were analyzed from patients receiving cervical hybrid surgery for symptomatic cervical MLDDD. Between 2004 and 2016, data were collected preoperatively and postoperatively at 3, 6, and 12 months, then yearly thereafter. Patient reported outcome measures included patient satisfaction, visual analog score for neck and arm, and Neck Disability Index. Complication and reoperation rates were also assessed. RESULTS: A total of 151 patients (80 males, 71 females) who had a minimum of 12 months follow up were included. The mean age was 53 years (range = 24-81), and median follow up was 2 years (range = 1-10). The median number of levels treated was 3, with 29.8%, 49.0%, and 21.2% of patients having 2, 3, and 4 levels treated, respectively. The most common indication for surgery was multilevel cervical spondylotic radiculopathy (52.8%), followed by combined cervical spondylotic radiculomyelopathy (16.7%), axial neck pain (16%), and cervical spondylotic myelopathy (13.9%). Improvement in pain and disability scores were both clinically and statistically significant (P < .001), and these improvements were sustained throughout the course of follow up. There was a 16% incidence of minor adverse events, and 3 (1.9%) reoperations. CONCLUSIONS: Cervical hybrid surgery for cervical MLDDD demonstrates favorable and sustained clinical outcomes at short-term to midterm follow up. LEVEL OF EVIDENCE: 4. CLINICAL RELEVANCE: Statistically and substantial clinical benefits can be achieved by cervical hybrid surgery, in the treatment of cervical pathologies including radiculopathy and myelopathy. The key principles is to follow strict indications, and to match technology with the pathology.

Incidence, clinical outcomes, and transmission dynamics of hospitalized 2019 coronavirus disease among 9,596,321 individuals residing in California and Washington, United States: a prospective cohort study

BackgroundThe United States is now the country reporting the highest number of 2019 coronavirus disease (COVID-19) cases and deaths. However, little is known about the epidemiology and burden of severe COVID-19 to inform planning within healthcare systems and modeling of intervention impact. MethodsWe assessed incidence, duration of hospitalization, and clinical outcomes of acute COVID-19 inpatient admissions in a prospectively-followed cohort of 9,596,321 individuals enrolled in comprehensive, integrated healthcare delivery plans from Kaiser Permanente in California and Washington state. We also estimated the effective reproductive number (RE) describing transmission in the study populations. ResultsData covered 1277 hospitalized patients with laboratory- or clinically-confirmed COVID-19 diagnosis by April 9, 2020. Cumulative incidence of first COVID-19 acute inpatient admission was 10.6-12.4 per 100,000 cohort members across the study regions. Mean censoring-adjusted duration of hospitalization was 10.7 days (2.5-97.5%iles: 0.8-30.1) among survivors and 13.7 days (2.5-97.5%iles: 1.7-34.6) among non-survivors. Among all hospitalized confirmed cases, censoring-adjusted probabilities of ICU admission and mortality were 41.9% (95% confidence interval: 34.1-51.4%) and 17.8% (14.3-22.2%), respectively, and higher among men than women. We estimated RE was 1.43 (1.17-1.73), 2.09 (1.63-2.69), and 1.47 (0.07-2.59) in Northern California, Southern California, and Washington, respectively, for infections acquired March 1, 2020. RE declined to 0.98 (0.76-1.27), 0.89 (0.74-1.06), and 0.92 (0.05-1.55) respectively, for infections acquired March 20, 2020. ConclusionsWe identify high probability of ICU admission, long durations of stay, and considerable mortality risk among hospitalized COVID-19 cases in the western United States. Reductions in RE have occurred in conjunction with implementation of non-pharmaceutical interventions.

Patient-Reported Outcome Measures After Multilevel Lumbar Total Disc Arthroplasty for the Treatment of Multilevel Degenerative Disc Disease.

STUDY DESIGN: Case series OBJECTIVE.: The aim of this study was to assess the patient-reported outcome measures (PROMs) and patient satisfaction of multilevel lumbar total disc arthroplasty (TDA) for symptomatic multilevel degenerative disc disease (MLDDD). SUMMARY OF BACKGROUND DATA: TDA has been shown to be safe and effective for the treatment of symptomatic single level degenerative disc disease. There is minimal PROMs data on the mid- to long-term outcomes of multilevel TDA constructs. METHODS: Prospectively collected PROMs were analyzed from patients receiving multilevel TDA for symptomatic MLDDD. Data were collected preoperatively and postoperatively at 3, 6, and 12 months, then yearly. PROMs included patient satisfaction, Visual Analog Score back and leg, Oswestry Disability Index, and Roland-Morris Disability Questionnaire. RESULTS: One hundred twenty-two patients (77 men, 45 women) who had preoperative and at least 24-month follow-up data were included. The average age was 42 ±â€Š8.2 years (range 21-61) and mean follow-up 7.8 years (range 2-10). The majority received two-level TDA, except two patients (1.6%) who received three-level TDA. The two- to three-level TDA's were at the levels L3-4, L4-5, and L5-S1, whereas most two levels (n = 110, 90.2%) were at L4-5 and L5-S1; the remainder (n = 10, 8.2%) being at L3-4 and L4-5. Implants used were Charité (DePuy Spine, Raynham, MA) in 119 patients (240 levels) and InMotion (DePuy Spine) in 3 patients (6 levels). Improvement in pain and disability scores were both clinically and statistically significant (P < 0.001), and this improvement was sustained in those patients over the course of their follow-up. Ninety-two percent of patients reported good or excellent satisfaction with treatment at final review. CONCLUSION: Multilevel TDA constructs for MLDDD demonstrate favorable and sustained clinical outcomes at mid- to long-term follow-up. LEVEL OF EVIDENCE: 4.

Total Disc Replacement Surgery in a Professional Australian Rugby League Player: A Case Report.

Chronic persistent lower back pain due to degenerative disc disease (DDD) of the lumbar spine is a common condition in the athletic population, which does not always improve with nonoperative treatment. We present a case report of a professional Australian rugby league player with DDD of the lumbar spine presenting with persistent lower back pain, which was not responding to conventional nonsurgical treatment. He then underwent a surgical total disc replacement of the lumbar spine and was subsequently able to return to playing professional rugby league at his previous level of competition. This is the only known documented case of a professional athlete in any form of contact sport successfully returning to his previous level of function and competition after undergoing a total disc replacement of the lumbar spine.

Anatomic considerations in headaches associated with cervical sagittal imbalance: A cadaveric biomechanical study.

Chronic Forward Head Posture is associated with headaches, neck pain, and disability, though few studies have investigated the effects it has on the suboccipital triangle. The objective of this study was to quantitatively assess whether the biomechanical changes in the suboccipital triangle help explain the clinical manifestations of Forward Head Posture. Specifically, this study aimed to identify whether the Greater Occipital Nerve or C2 nerve root may be compressed in Forward Head Posture. Three-dimensional, specimen-specific computer models were rendered from thirteen cadaveric cervical spine specimens. The spines transitioned from neutral to Forward head posture while motion data was collected. This data was synced with the computer models to make precise measurements. In Forward Head Posture, occiput-C1, C1-C2, and occiput-C2 segments extended by 10.7 ±â€¯4.6 deg, 4.6 ±â€¯4.3 deg, and 15.3 ±â€¯2.3 deg, respectively. The Rectus Capitis Posterior Major and Minor and Obliquus Capitis Superior muscles shortened by 20.0 ±â€¯4.6%, 15.0 ±â€¯7.6%, and 6.6 ±â€¯3.3%, respectively. The Obliquus Capitis muscle inferior length did not change. The suboccipital triangle area decreased by 18.7 ±â€¯6.4%, but the protective gaps surrounding the C2 nerve root and the Greater Occipital Nerve did not reveal clinically significant impingement. The C2 nerve root gap decreased by 1.0 ±â€¯1.3 mm and the Greater Occipital Nerve gap by 0.2 ±â€¯0.18 mm. These results demonstrate that the C2 nerve root and the Greater Occipital Nerve are protected by the bony landscape of the cervical spine. However, there is likely persistent contraction of the rectus muscles in Forward Head Posture, which suggests a secondary tension-type etiology of the associated headache.

Combined Aorto-Iliac and Anterior Lumbar Spine Reconstruction: A Case Series.

BACKGROUND: Treatment options for aortic-iliac pathology may include endovascular repair and open surgical repair. Treatment options for degenerative disc disease (DDD) are varied but commonly include anterior reconstruction. When both the aortic-iliac and spinal pathologies are significant and surgical intervention is indicated for each pathology, the opportunity exists for concurrent treatment of both the aortic-iliac pathology and DDD in the same operation. The purpose of this case series was to document the safety and feasibility of a surgical strategy whereby a combined elective reconstructive procedure was performed for aortic and anterior lumbar spinal pathologies. METHODS: The case histories of 5 patients who were treated for both spinal and vascular pathology are presented. Surgical outcome measures included operative time, blood loss, length of stay, and complications. Spine-specific outcome measures included Oswestry Disability Index, Roland Morris Disability Questionnaire, and visual analogue scores (back and leg). RESULTS: The spinal reconstructions performed included 1 L4-5 total disc replacement (TDR), 1 L4-5, L5-S1 anterior lumbar interbody fusion (ALIF), 1 L5-S1 ALIF, and 2 hybrid procedures (L4-5 TDR with L5-S1 ALIF). Vascular reconstructions included 4 aorto-bi-iliac bypass grafts and 1 aortic tube graft. The average operative time was 365 minutes (ranging between 330 and 510 minutes), the average blood loss was 1699 mL (range between 1160 and 2960 mL), and the average length of hospital stay was 14 days (range from 8 to 22 days). There were no in-hospital complications, and all patients experienced significant improvement in both back and leg pain. One patient developed kinking of the iliac limbs of the vascular graft 1 year postoperatively, which was managed with endovascular stenting of the graft. CONCLUSIONS: Aortic-iliac pathology and DDD are significant pathologies often treated in isolation. This study illustrates that, despite its complexity, highly trained individuals in a specialized setting can perform combined surgery to achieve a satisfactory outcome for the patient. LEVEL OF EVIDENCE: Level IV evidence.

Clinical and Radiological Mid-Term Outcomes of Lumbar Single-Level Total Disc Replacement.

STUDY DESIGN: Prospective single-center case cohort study. OBJECTIVE: Evaluation of clinical and radiographic outcomes of a consecutive 122-patient cohort with discogenic back pain, at 2- to 10-year follow-up periods, treated by a single surgeon, with CHARITÉ Artificial Disc (DePuy Spine, Raynham, MA). SUMMARY OF BACKGROUND DATA: Minimum 2-year clinical and radiographic level 1 data for the first lumbar artificial disc, the CHARITÉ Artificial Disc (DePuy Spine), have recently been published, demonstrating sustained clinical benefit of the device for the treatment of degenerative disc disease. METHODS: Patients were assessed preoperatively using clinical outcome measures, including visual analog scale (VAS) score back and leg, Oswestry Disability Index (ODI), 36-Item Short Form Health Survey (SF-36), and Roland-Morris Questionnaires (RMDQ), and further assessed postoperatively, 3-, 6-, 12-months, and yearly thereafter. RESULTS: Average follow-up was 44.9 ±â€Š23.3 months (n = 122). The median age at surgery was 43.0 ±â€Š9.0 years. Preoperative diagnosis included degenerative disc disease in 118 (96.7%) and internal disc disruption in 4 (3.3%). Surgery was performed at L5-S1 in 96 (77.9%) patients and at L4-L5 in 27 (22.1%). Statistically significant clinical improvements from baseline were observed on VAS (back and leg), ODI, SF-36 PCS, SF-36 MCS, and RMDQ 3 months onward. Back VAS scores decreased from 78.2 ±â€Š21.3 preoperatively to 21.9 ±â€Š27.8 by final follow-up. ODI scores decreased from 51.1 ±â€Š17.3 to 16.2 ±â€Š17.9 at last follow-up. The RMDQ scores also decreased from 16.7 ±â€Š4.7 to 4.2 ±â€Š5.8. SF-36 PCS and MCS increased from 25.7 ±â€Š11.0 to 46.4 ±â€Š10.3 for PCS and from 35.5 ±â€Š17.4 to 51.6 ±â€Š10.8 for MCS. Patient satisfaction surveys indicated that 90.56% patients rated their satisfaction with the surgery as "excellent" or "good" at 2 years. Range of motion averaged 8.6 ±â€Š3.5 (median = 8.0°) at the last follow-up time point. CONCLUSION: Outcomes verify the clinical efficacy of total disc replacement for treatment of discogenic back pain with or without radiculopathy. The outcomes instruments demonstrated statistically significant improvements 3 months onward. LEVEL OF EVIDENCE: N/A.

Concurrent Use of Lumbar Total Disc Arthroplasty and Anterior Lumbar Interbody Fusion: The Lumbar Hybrid Procedure for the Treatment of Multilevel Symptomatic Degenerative Disc Disease: A Prospective Study.

STUDY DESIGN: A prospective study. OBJECTIVE: The aim of this study was to evaluate clinical and patient outcomes post combined total disc arthroplasty (TDA) and anterior lumbar interbody fusion (ALIF), known as hybrid surgery for the treatment of multilevel symptomatic degenerative disc disease (DDD). SUMMARY OF BACKGROUND DATA: Class I studies comparing the treatment of one-level lumbar DDD with TDA and ALIF have confirmed the effectiveness of those treatments through clinical and patient outcomes. Although the success of single-level disease is well documented, the evidence relating to the treatment of multilevel DDD with these modalities is emerging. With the evolution of the TDA technology, a combined approach to multilevel disease has developed in the form of the hybrid procedure. METHODS: A total of 617 patients underwent hybrid surgery for chronic back pain between July 1998 and February 2012. Visual Analog Pain Scale for the back and leg were recorded along with the Oswestry Disability Index and Roland Morris Disability Questionnaire. RESULTS: Both statistically and clinically significant (p < 0.005) reductions were seen in back and leg pain, which were sustained for at least 8 years postsurgery. In addition, significant improvements (P < 0.001) in self-rated disability and function were also maintained for at least 8 years. Patient satisfaction was rated as good or excellent in >90% of cases. CONCLUSION: The results of this research indicate that improvements in both back and leg pain and function can be achieved using the hybrid lumbar reconstructive technique. LEVEL OF EVIDENCE: 4.

Physiotherapeutic Rehabilitation Following Lumbar Total Disc Replacement: A Retrospective Study.

BACKGROUND AND PURPOSE: This study sought to answer the following questions: What are the outcomes of physiotherapy post lumbar total disc replacement (LTDR) compared with patient self-mediated rehabilitation? Is a difference in outcomes related to the number of physiotherapy sessions? METHODS: This is a retrospective observational study of 600 patients post TDR. Patient outcomes for self-mediated rehabilitation (Group 1), 1-3 sessions of clinic-based physiotherapy (Group 2) and ≥4 sessions of clinic-based physiotherapy (Group 3) were analysed. Outcomes measures included the Oswestry Disability Index (ODI), Roland Morris Disability Questionnaire (RMQ), Short Form-36 Physical (SF-36 PCS) and Mental Subscale Components (SF-36 MCS), Visual Analogue Scale (VAS) for back and leg pain intensity. Patient's pre-operative baseline measures and post-operative follow-up measures at 3, 6, 12 and 24 months post-operatively were analysed. RESULTS: Oswestry Disability Index and RMQ had significantly lower scores in Group 3 compared with Group 1 at 3, 6, 12 and 24 months follow-up. Significantly lower scores for Group 2 compared with Group 1 were observed for the ODI at 3 months follow-up and for the RMQ at 3 and 6 months follow-up. Significantly lower scores were observed in Group 3 compared with Group 1 for VAS back pain at 3 months and VAS leg pain at 6 months follow-up. Significantly higher scores in Group 3 compared with Group 1 were also observed in the SF-36 PCS at 6, 12 and 24 months. Significantly higher scores in Group 2 compared with Group 1 were observed at 6 months follow up. These trends were also observed when investigating the percentage of patients with a greater 50% improvement in the outcome measure. CONCLUSIONS: Physiotherapy post-LTDR produces statistically significant and possibly clinically important improvements in functional disability, pain and quality of life outcomes compared with self-mediated rehabilitation. Copyright © 2015 John Wiley & Sons, Ltd.

Fluoroscopic assessment of lumbar total disc replacement kinematics during walking.

STUDY DESIGN: Descriptive. OBJECTIVE: The purpose of this study was to determine the in vivo kinematics of functional spinal units, during gait, in individuals with a single-level lumbar total disc replacement (TDR). SUMMARY OF BACKGROUND DATA: TDR is a motion preservation technology that offers an alternative to spinal fusion for treatment of degenerative disc disease. The aim of TDRs is to replicate motion of the functional spinal units, which may protect adjacent intervertebral discs against accelerated degeneration. At present, there is limited understanding of the in vivo motion of TDRs, particularly during dynamic activities such as gait. Such information is important for understanding the wear characteristics of TDRs and furthering design rationale of future implants. METHODS: TDR motions were obtained from 24 participants who underwent implantation with single-level L4-L5 or L5-S1 CHARITÉ or In Motion TDRs. Video fluoroscopy was used to obtain measurements in the frontal and sagittal planes during fixed speed treadmill walking. RESULTS: The mean range of motion between the upper and lower lumbar TDR endplates during walking was 1.6° and 2.4° in the frontal and sagittal planes, respectively. These values were significantly different from zero and corresponded to 19% of the maximum static range of motion in each plane. CONCLUSION: Lumbar TDRs provide a degree of motion preservation at the operative level during moderate speed walking. The distribution of lumbar TDR motions during walking presented here will inform relevant standards for conducting standardized tests of lumbar TDRs, particularly wear assessments, and, hence, enable more realistic mechanical and computer-based wear simulations to be performed. LEVEL OF EVIDENCE: N/A.

Assessing illicit drug use among adults with schizophrenia.

Accurate drug use assessment is vital to understanding the prevalence, course, treatment needs, and outcomes among individuals with schizophrenia because they are thought to remain at long-term risk for negative drug use outcomes, even in the absence of drug use disorder. This study evaluated self-report and biological measures for assessing illicit drug use in the Clinical Antipsychotic Trials of Intervention Effectiveness study (N=1460). Performance was good across assessment methods, but differed as a function of drug type, measure, and race. With the Structured Clinical Interview for DSM-III-R as the criterion, self-report evidenced greater concordance, accuracy and agreement overall, and for marijuana, cocaine, and stimulants specifically, than did urinalysis and hair assays, whereas biological measures outperformed self-report for detection of opiates. Performance of the biological measures was better when self-report was the criterion, but poorer for black compared white participants. Overall, findings suggest that self-report is able to garner accurate information regarding illicit drug use among adults with schizophrenia. Further work is needed to understand the differential performance of assessment approaches by drug type, overall and as a function of race, in this population.