The lexicon for periprosthetic bone loss versus osteolysis after cervical disc arthroplasty: a systematic review

Background Periprosthetic bone loss is a common observation following arthroplasty. Recognizing and understanding the nature of bone loss is vital as it determines the subsequent performance of the device and the overall outcome. Despite its significance, the term “bone loss” is often misused to describe inflammatory osteolysis, a complication with vastly different clinical outcomes and treatment plans. Therefore, the goal of this review was to report major findings related to vertebral radiographic bone changes around cervical disc replacements, mitigate discrepancies in clinical reports by introducing uniform terminology to the field, and establish a precedence that can be used to identify the important nuances between these distinct complications. Methods A systematic review of the literature was conducted following PRISMA guidelines, using the keywords “cervical,” “disc replacement,” “osteolysis,” “bone loss,” “radiograph,” and “complications.” A total of 23 articles met the inclusion criteria with the majority being retrospective or case reports. Results Fourteen studies reported periprosthetic osteolysis in a total of 46 patients with onset ranging from 15–96 months after the index procedure. Reported causes included: metal hypersensitivity, infection, mechanical failure, and wear debris. Osteolysis was generally progressive and led to reoperation. Nine articles reported non-inflammatory bone loss in 527 patients (52.5%), typically within 3–6 months following implantation. The reported causes included: micromotion, stress shielding, and interrupted blood supply. With one exception, bone loss was reported to be non-progressive and had no effect on clinical outcome measures. Conclusions Non-progressive, early onset bone loss is a common finding after CDA and typically does not affect the reported short-term pain scores or lead to early revision. By contrast, osteolysis was less common, presenting more than a year post-operative and often accompanied by additional complications, leading to revision surgery. A greater understanding of the clinical significance is limited by the lack of long-term studies, inconsistent terminology, and infrequent use of histology and explant analyses. Uniform reporting and adoption of consistent terminology can mitigate some of these limitations. Executing these actionable items is critical to assess device performance and the risk of revision. Level of Evidence IV Diagnostic: individual cross-sectional studies with consistently applied reference standard and blinding.

Bibliometric and visualized analysis of the top 100 most-cited articles on anterior cervical surgery

Anterior cervical surgery (ACS) owes its development to various pioneering individuals whose revolutionary works form key advances and guide current medical decisions. This bibliometric study aimed to identify, analyse and visualize the main features of the most-cited papers in ACS. The citation count for the top 100 most-cited articles ranged from 148 to 1,197, and citations per year ranged from 3.1 to 89.8. The articles were published from 1958 to 2016, with the 2000s being the most active decade. There was an inverse correlation between the average citations per year since publication and article age. The oldest as well as most-cited two articles were both published in 1958 by Smith and Robinson, and Cloward, respectively. In their studies, the authors individually described the technique of anterior cervical discectomy with fusion (ACDF). The most popular keywords were: ‘fusion’ (22), ‘spine’ (20), ‘cervical spine’ (16), ‘complications’ (15), ‘arthrodesis’ (13), ‘interbody fusion’ (13), ‘bone morphogenetic protein’ (13), and ‘radiculopathy’ (12). ACDF was the most frequent surgical procedure (80%), while cervical disc arthroplasty is of gradual greater impact. The surgical techniques of ACDF have remained unaltered for over 60 years. More attempts are needed to promote its development. Cite this article: EFORT Open Rev 2021;6:1203-1213. DOI: 10.1302/2058-5241.6.210074

P.229 Epidemiology and Outcomes of Neck Pain Following Surgery for Degenerative Cervical Radiculopathy

Background: Many studies have demonstrated improved arm pain (AP) following surgery for degenerative cervical radiculopathy (DCR); however, axial neck pain (NP) is generally not felt to improve. The purpose of this study was to determine whether surgery for DCR improves NP. Methods: A ambispective cohort study of the Canadian Spine Outcomes Research Network (CSORN) registry for patients who received 1-level, 2-level, 3-level ADCF (anterior cervical discectomy and fusion) or cervical disc arthroplasty (CDA) for DCR. Outcomes: 12-month post-operative Visual Analogue Scale for NP (VAS-NP), Neck Disability Index (NDI), VAS for AP (VAS-AP), Short-Form Physical Health Composite Scale (SF36-PCS), and Mental Health Composite Scale (SF36-MCS). Results: We identified 603 patients with DCR. CDA patients were the youngest (ANOVA; p<0.001). Patients reported similar pre-operative AP, NP, disability, and health-related quality of life, regardless of procedure (ANOVA; all P>0.05). All procedures offered a statistically significant reduction in VAS-NP, VAS-AP, and NDI (ANOVA; all P<0.001). Mean change from baseline in NP, AP, and disability, were similar across procedures. At 12 months, mean reduction in VAS-AP, VAS-NP, and NDI exceeded minimal clinically important differences for nearly all procedures. Conclusions: Patients undergoing surgery for DCR can expect a clinically significant, approximate 50% reduction in NP, AP, and neck-related disability.

Hybrid surgery: a comparison of early postoperative outcomes between anterior cervical discectomy and fusion and cervical disc arthroplasty

OBJECTIVE Hybrid surgery (HS) is the combination of anterior cervical discectomy and fusion (ACDF) and cervical disc arthroplasty (CDA) at different levels in the same operation. The aim of this study was to investigate perioperative variables, 30-day postoperative outcomes, and complications of HS in comparison with those of CDA and ACDF. METHODS The authors queried the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) registry for patients who underwent multilevel primary HS, CDA, and ACDF for degenerative disc disease from 2015 to 2019. The authors compared these three operations in terms of 30-day postoperative outcomes, specifically readmission and reoperation rates, discharge destination, and complications. RESULTS This analysis included 439 patients who underwent HS, 976 patients who underwent CDA, and 27,460 patients who underwent ACDF. Patients in the HS and CDA groups were younger, had fewer comorbidities, and myelopathy was less often the indication for surgery compared with patients who underwent ACDF. For the HS group, the unplanned readmission rate was 0.7%, index surgery–related reoperation rate was 0.3%, and nonroutine discharge rate was 2.1%. Major and minor complications were also rare, with rates of 0.2% for each. The mean length of stay in the HS group was 1.5 days. The association of HS with better outcomes in univariate analysis was not evident after adjustment for confounding factors. CONCLUSIONS The authors found that HS was noninferior to ACDF and CDA in terms of early postoperative outcomes among patients treated for degenerative disc disease.