Observational, Multicenter Study of the Efficacy and Safety of Cervical Disk Arthroplasty With Mobi-C in the Treatment of Cervical Degenerative Disk Disease. Results at 10 years Follow-Up.

BACKGROUND: Cervical disk arthroplasty replacement (CDA) was developed to avoid specific disadvantages of cervical fusion. The purpose of this paper is to provide 10-year follow-up results of an ongoing prospective study after CDA. METHODS: Three hundred eighty-four patients treated using the Mobi-C (ZimVie, Troyes, France) were included in a prospective multicenter study. Routine clinical and radiologic examinations were reported preoperatively and postoperatively with up to 10-year follow-up. Complications and revision surgeries were also documented. RESULTS: At 10 years showed significant improvement in all clinical outcomes [Neck Disability Index, visual analog scale (VAS) for arm and neck pain, physical component summary of SF36, and mental component summary of SF36). Motion at the index level increased significantly over baseline (mean range of motion=7.6 vs. 8 degrees at five years and 6.0 degrees preoperatively; P <0.001) and 71.3% of the implanted segments remained mobile (range of motion>3 degrees). Adjacent disks were also mobile at 10 years with the same mobility as preoperatively. At 10 years, 20.9% of the implanted segments demonstrated no heterotopic ossification. Thirty-four patients (8.9%) experienced 41 adverse events, with or without reoperation during the first five years. We found only two additional surgeries after five years. We observed an increased percentage of working patients and a decrease in medication consumption. Regarding the overall outcome, 94% of patients were satisfied. CONCLUSIONS: Our 10-year results showed significant improvement in all clinical outcomes, with low rates of revision or failure. This experience in patients with long-term follow-up after CDA endorses durable, favorable outcomes in properly selected patients.

Rehabilitation and lumbar surgery: the French recommendations for clinical practice.

BACKGROUND: Indications and techniques of rehabilitation differ widely across types of lumbar surgery, including timing (before or after surgery) and prescriptions (surgeons but also medical or paramedical professionals). OBJECTIVES: This project aimed to build consensual recommendations for practice in this context. METHODS: The SOFMER methodology was used to establish recommendations for physical medicine and rehabilitation: a steering committee defined the types of lumbar surgery involved and developed the main questions to be addressed; a scientific committee performed a literature review for grading evidence and proposed the first version of recommendations, which were discussed during a dedicated session at the national Physical and Rehabilitation Medicine congress; then an e-Delphi method with cross-professional experts was used to finalise recommendations and reach a multidisciplinary consensus. RESULTS: The main questions developed were the value of rehabilitation before and after surgery, timing and type of rehabilitation, benefit of supervision and instrumental rehabilitation, value of patient education, and complementary interventions concerning rehabilitation for discectomy, fusion, and disc prosthesis (excluding decompression for spinal stenosis). The literature review identified 60 articles, but for several of the questions, no article in the literature addressed the issue. The multidisciplinary scientific committee analysed the literature and addressed the questions to propose the first version of a set of 23 recommendations. The congress session failed to answer all questions or to reach consensus for all items. After a three-step e-Delphi, 20 recommendations were retained, for which consensus among experts was reached. The recommendations are applicable only to patients without a neurological lesion. CONCLUSIONS: These recommendations provide important and consensual knowledge to assist clinicians in decision-making for rehabilitation in lumbar surgery. Despite many of the recommendations relying exclusively on expert opinion rather than published evidence, this approach is an important advance to improve concordance among healthcare professionals.

rhBMP-2 (Recombinant Human Bone Morphogenetic Protein-2) in real world spine surgery. A phase IV, National, multicentre, retrospective study collecting data from patient medical files in French spinal centres.

BACKGROUND: This is a Phase IV, national, multicentre, retrospective study to observe the real-world use of rhBMP-2 in France. HYPOTHESIS: There was no statistical hypothesis, the statistical analyses were descriptive in nature. PATIENTS AND METHODS: Data was collected from patient medical files in 10 French spinal centres. Primary objectives were to understand which patients were treated with rhBMP-2, commercialised in Europe as InductOs™ and how rhBMP-2 was used during spinal fusion surgery in France between 2011 and 2012. RESULTS: Four hundred patients (634 levels) treated with rhBMP-2 were included in the analysis. The most frequent primary diagnostic indication for rhBMP-2 use was degenerative disc disease (DDD; 129/400; 32.3% of patients) followed by spondylolisthesis (119/400; 29.8%), deformity (59/400; 14.8%) and pseudoarthrosis (29/400; 7.3%). The most frequently treated level was L4-L5 (33.8% of levels in 53.5% of patients); followed by L5-S1 (29.8%, 47.3%), L3-L4 (16.7%, 26.5%), and L2-L3 (7.3%, 11.5%), all other levels (less than 5% of patients). No interbody fusion device was used in 42.7% of levels. Wetted matrix of rhBMP-2 was placed in the interbody space in 58.4% of levels (370/634). The most common procedure for rhBMP-2 treatment was posterior lumbar fusion (PLF) (221/634; 34.9% of levels), followed by anterior lumbar interbody fusion (ALIF) (188/634; 29.7%), posterior lumbar interbody fusion (PLIF) (111/634; 17.5%), lateral lumbar interbody fusion (LLIF) (106/634; 16.7%), transforaminal lumbar interbody fusion (TLIF) (4/634; 0.6%) and 'other' (4/634; 0.6%). Thirty-one adverse events of Interest (AEI) were recorded in 27 patients. One AEI was considered related to rhBMP-2. Unplanned secondary spine interventions at index level treated with rhBMP-2 were required in 4 patients. DISCUSSION: In years 2011 and 2012 when the surgeries captured in this retrospective study were done, rhBMP-2 was indicated for single level (L4-S1) anterior lumbar spine fusion as a substitute for autogenous bone graft in adults with DDD. The most common procedure for the treatment with rhBMP-2 was PLF (off-label use), followed by ALIF (on-label use). The safety findings confirm a predictable and manageable safety profile. LEVEL OF EVIDENCE: IV.

Clinical and radiological outcomes of a cervical cage with integrated fixation.

Cervical cages with integrated fixation have been increasingly used in anterior cervical discectomy and fusion (ACDF) to avoid complications associated with anterior cervical plates. The purpose of this paper is to provide 2-year follow-up results of a prospective study after implantation of a cervical cage with an integrated fixation system.This was a prospective multicenter outcome study of 90 patients who underwent ACDF with a cage with integrated fixation. Fusion was evaluated from computed tomography images (CT-images) by an independent laboratory at 2-year follow-up (FU). Clinical and radiological findings were recorded preoperatively and at FU visits and complications were reported.At 24 months, the fusion rate was 93.4%. All average clinical outcomes were significantly improved at 2 years FU compared to baseline: neck disability index (NDI) 18.9% vs 44.4%, visual analog scale (VAS) for arm pain 18.2 mm vs 61.9 mm, VAS for neck pain 23.9 mm vs 55.6 mm. Short form-36 (SF-36) scores were significantly improved. One case of dysphagia, which resolved within 12 months, and 1 reoperation for symptomatic pseudarthrosis were reported. Subsidence with no clinical consequence or reoperation was reported for 5/125 of the implanted cages (4%). There was also 1 case of per-operative vertebral body fracture that did not require additional surgery. Superior and inferior adjacent discs showed no significant change of motion at 2-year FU compared to baseline. Disc height index (DHI) and lordosis were enhanced and these improvements were maintained at 1 year.The ACDF using cages with an integrated fixation system demonstrated reliable clinical and radiological outcomes and a high interbody fusion rate. This rate is comparable to the rate reported in recent series using other implants with integrated fixation, but the present device had a lower complication rate.

Effects of lumbar artificial disc design on intervertebral mobility: in vivo comparison between mobile-core and fixed-core.

Although in theory, the differences in design between fixed-core and mobile-core prostheses should influence motion restoration, in vivo kinematic differences linked with prosthesis design remained unclear. The aim of this study was to investigate the rationale that the mobile-core design seems more likely to restore physiological motion since the translation of the core could help to mimic the kinematic effects of the natural nucleus. In vivo intervertebral motion characteristics of levels implanted with the mobile-core prosthesis were compared with untreated levels of the same population, levels treated by a fixed-core prosthesis, and normal levels (data from literature). Patients had a single-level implantation at L4L5 or L5S1 including 72 levels with a mobile-core prosthesis and 33 levels with a fixed-core prosthesis. Intervertebral mobility characteristics included the range of motion (ROM), the motion distribution between flexion and extension, the prosthesis core translation (CT), and the intervertebral translation (VT). A method adapted to the implanted segments was developed to measure the VT: metal landmarks were used instead of the bony landmarks. The reliability assessment of the VT measurement method showed no difference between three observers (p < 0.001), a high level of agreement (ICC = 0.908) and an interobserver precision of 0.2 mm. Based on this accurate method, this in vivo study demonstrated that the mobile-core prosthesis replicated physiological VT at L4L5 levels but not at L5S1 levels, and that the fixed-core prosthesis did not replicate physiological VT at any level by increasing VT. As the VT decreased when the CT increased (p < 0.001) it was proven that the core mobility minimized the VT. Furthermore, some physiologic mechanical behaviors seemed to be maintained: the VT was higher at implanted the L4L5 level than at the implanted L5S1 level, and the CT appeared lower at the L4L5 level than at the L5S1 level. ROM and motion distribution were not different between the mobile-core prosthesis and the fixed-core prosthesis implanted levels. This study validated in vivo the concept that a mobile-core helps to restore some physiological mechanical characteristics of the VT at the implanted L4L5 level, but also showed that the minimizing effect of core mobility on the VT was not sufficient at the L5S1 level.

Radiological analysis of 37 segments in cervical spine implanted with a peek stand-alone device, with at least one year follow-up.

BACKGROUND: High incidence of subsidence in cervical stand-alone cages was reported in the literature. PURPOSE: The goal of this study was to assess the radiological outcomes of a PEEK anchored stand-alone cage (MC+®) with a minimum of 1 year follow-up. STUDY DESIGN: A retrospective radiological evaluation. PATIENT SAMPLE: The study was conducted in 4 hospitals and involved 28 patients (37 levels) treated by ACDF (Anterior Cervical Discectomy and Fusion) for spondylotic radiculopathy and/or myelopathy. OUTCOME MEASURES: We analyzed fusion, disc height, cage or anchor micro plate migration, discal and segmental lordosis and subsidence. METHODS: All the patients were controlled at least one year after surgery with an average of 31 months. Antero-posterior and lateral X-rays were performed pre-operatively, immediate post-operatively, and at final follow up. The different radiographic measurements were performed with the assistance of software (SpineView®). CT-scans were performed for each case at final follow-up to assess the fusion. RESULTS: No migration or breakage was reported for either the cage or the anchor micro plate. The fusion rate was 94.1% at the final follow-up. No subsidence was observed. The disc height increased between preop and final follow-up from 23.3% to 44.3%, from 22.1% to 35.1% and from 38.3% to 51.5% for anterior, posterior and midline disc height respectively. Mean Functional Spinal Unit Lordosis increased from 0.9° preop to 3.0° at final follow-up. No new kyphotic situation could be noticed. At the final follow-up, 96% of the patients stated they would undergo the procedure again. CONCLUSION: With a high rate of proven fusion, restoration of disc height and spinal alignment in most cases, and absence of subsidence or migration, our radiological results with MC+® at more than 1 year of follow-up show the implanted device to be safe and effective for use in treating degenerative conditions of the cervical spine.

Does core mobility of lumbar total disc arthroplasty influence sagittal and frontal intervertebral displacement? Radiologic comparison with fixed-core prosthesis.

BACKGROUND: An artificial disc prosthesis is thought to restore segmental motion in the lumbar spine. However, it is reported that disc prosthesis can increase the intervertebral translation (VT). The concept of the mobile-core prosthesis is to mimic the kinematic effects of the migration of the natural nucleus and therefore core mobility should minimize the VT. This study explored the hypothesis that core translation should influence VT and that a mobile core prosthesis may facilitate physiological motion. METHODS: Vertebral translation (measured with a new method presented here), core translation, range of motion (ROM), and distribution of flexion-extension were measured on flexion-extension, neutral standing, and lateral bending films in 89 patients (63 mobile-core [M]; 33 fixed-core [F]). RESULTS: At L4-5 levels the VT with M was lower than with F and similar to the VT of untreated levels. At L5-S1 levels the VT with M was lower than with F but was significantly different compared to untreated levels. At M levels a strong correlation was found between VT and core translation; the VT decreases as the core translation increases. At F levels the VT increases as the ROM increases. No significant difference was found between the ROM of untreated levels and levels implanted with either M or F. Regarding the mobility distribution with M and F we observed a deficit in extension at L5-S1 levels and a similar distribution at L4-5 levels compared to untreated levels. CONCLUSION: The intervertebral mobility was different between M and F. The M at L4-5 levels succeeded to replicate mobility similar to L4-5 untreated levels. The M at L5-S1 succeeded in ROM, but failed regarding VT and mobility distribution. Nevertheless M minimized VT at L5-S1 levels. The F increased VT at both L4-5 and L5-S1. CLINICAL RELEVANCE: This study validates the concept that the core translation of an artificial lumbar disc prosthesis minimizes the VT.