Early efficacy of three dimensional printed anatomical biomimetic cervical artificial disc replacement in the treatment of cervical degenerative diseases / 中华外科杂志

Objective: To investigate the efficacy and safety of a new cervical artificial disc prosthesis in the treatment of cervical degenerative diseases. Methods: The clinical data of 18 patients with single-level cervical degenerative diseases who underwent three dimensional printed anatomical bionic cervical disc replacement at Department of Spinal Surgery,Honghui Hospital,Xi'an Jiaotong University from May 2019 to July 2020 were analyzed retrospectively. There were 7 males and 11 females,aged (45±8) years old(range:28 to 58 years).The surgical segment was located at C3－4 level in 2 cases, C4－5 level in 5 cases, C5－6 level in 9 cases, and C6－7 level in 2 cases.The clinical and radiographic outcomes were recorded and compared at preoperative,postoperative times of one month and twelve months.The clinical assessments contained Japanese orthopedic association (JOA) score,neck disability index (NDI) and visual analogue scale (VAS).Imaging assessments included range of motion (ROM) of cervical spine, prosthesis subsidence and prosthesis anteroposterior migration.Repeated measurement variance analysis was used for comparison between groups,and paired t test was used for pairwise comparison. Results: All patients underwent the operation successfully and were followed up for more than 12 months.Compared with preoperative score,the JOA score,NDI and VAS were significantly improved after surgery (all P<0.01).There was no significant difference in postoperative ROM compared with 1-and 12-month preoperative ROM (t=1.570,P=0.135;t=1.744,P=0.099). The prosthesis subsidence was (0.29±0.13) mm (range: 0.18 to 0.50 mm) at 12-month postoperatively.The migration of prosthesis at 12-months postoperatively were (0.71±0.20) mm (range: 0.44 to 1.08 mm).There was no prosthesis subsidence or migration>2 mm at 12-month postoperatively. Conclusion: Three dimensional printed anatomical biomimetic cervical artificial disc replacement has a good early clinical effect in the treatment of cervical degenerative diseases, good mobility can be obtained while maintaining stability.

The development of artificial cervical disc replacement from the perspective of orthopedic bionic therapy / 中华外科杂志

The modern surgical treatment of cervical degenerative disc disease can be traced back to the advent of anterior cervical decompression and fusion.With the emergence of fusion-related complications,different scholars have promoted the gradual transformation of cervical degenerative disc diseases from "fusion fixation" to "non-fusion reconstruction" through in-depth fusion with materials science,engineering mechanics and other disciplines.The innovation of this treatment concept is consistent with the original intention of "structural remodeling,functional reconstruction,maximum repair and reconstruction of the morphology and function of skeletal muscle system" in orthopedic bionic treatment,which is essentially in line with the "bionic alternative therapy" in orthopedic bionic therapy.This paper focuses on the surgical treatment of cervical degenerative disc diseases,reviews the development history of artificial cervical disc replacement,analyzes the evolution from orthopedic biomimetic therapy,and explores a new direction for the design of artificial cervical disc prostheses and the treatment of cervical degenerative disc diseases in the future.

Comparison of clinical effects of different anterior surgical methods for the treatment of single segment cervical disc herniation / 中国骨伤

OBJECTIVE@#To compare the clinical effects of different anterior surgical methods in treating single segment cervical disc herniation.@*METHODS@#The clinical data of 46 patients with single-segment cervical disc herniation underwent surgical treatment from September 2013 to September 2018 were retrospectively analyzed. The patients were divided into three groups according to different surgical methods. Among them, 23 patients in the anterior percutanousendomic cervical dissection (APECD) group, there were 8 males and 15 females, aged (47±3) years old, prominent segments were C@*RESULTS@#All 46 patients were followed up for 12 to 24 (17.57±3.15)months. The follow-up time of APECD, CDR, ACDF groups were (17.30±3.25), (17.80±3.16), (17.85±2.88) months, and operation time were (95.48 ±13.85), (58.50±7.09), (76.00±15.72) min, respectively, there were no significant differences in follow-up time and operation time between two groups(@*CONCLUSION@#The three anterior surgical approaches can achieve satisfactory clinical results for the treatment of single-segment cervical disc herniation. However, the improvement rate of the CDR group and the activity of the retained responsibility segment are better than those of the other two groups. APECD surgery may have recurrence.

Clinical observation on the treatment of cervical degenerative diseases with Hybrid surgery / 中国骨伤

OBJECTIVE@#To investigate the clinical effect of anterior cervical Hybrid surgery in the treatment of cervical degenerative diseases (CDD) and observe the incidence of heterotopic ossification of disc replacement segment at 1 year after surgery.@*METHODS@#From January 2015 to April 2018, 35 patients who received anterior cervical hybrid surgery met the inclusion and exclusion criteria and the complete clinical follow up data were analyzed retrospectively. Complete imaging follow-up data were obtained from 24 patients. There were 15 males and 20 females, aged from 39 to 70(55.57±7.73) years old. The amount of bleeding was for 20 to 100 (40.29±18.39) ml, and the hospitalstay was for 4 to 28(11.03±4.63) days, and the follow-up time was(12.97±1.36) months. Clinical outcomes were assessed by the Tanaka Yasushi cervical spondylitis symptom scale 20 score (YT20), and Japanese Orthopaedic Association (JOA) score. The occurrence of heterotopic ossification after Hybrid surgery was evaluated by X-ray according to McAfee standard one year after operation. Patients with or without heterotopic ossificationwere divided into two groups and their clinical effects were compared.@*RESULTS@#At the final follow up, the mean YT20 score and JOA score were significantly higher than those before operation (P <0.05), and the average improvement rate of JOA was (70.66 ±0.44)%. One year after operation, the heterotopic ossification occurred in 10 of 24 segments, with incidence of 41.70%(10/24), including 29.20% in gradeⅠand 12.50% in gradeⅡ. The results of clinical efficacy comparison between patients with and without heterotopic ossification were as follows:there was no significant difference in JOA score before and after operation (@*CONCLUSION@#The short-term clinical effect of Hybrid surgery is satisfactory for cervical degenerative diseases, and the cause of heterotopic ossification still needs tobe further explored.

Results of Total Cervical Disc Replacement with a Minimum Follow-up of 10 Years / Resultados da artroplastia total de disco cervical com acompanhamento mínimo de 10 anos

Abstract Objective In the present study, we present the results with at least 10 years of follow-up of the cervical disc prosthesis implanted in a single level. Methods Retrospective study of patients undergoing single-level total cervical disc replacement (TCDR). Clinical results included the neck disability index (NDI) and the visual analogue scale (VAS) in the preoperative period, one year postoperatively, and a minimum of 10 years of follow-up. The radiographic parameters included cervical mobility, segmental lordosis, C2-C7 angle, heterotopic ossification (HO), facet and joint degeneration (FJD) and adjacent segment disease (ASD). Results We identified 22 patients, 16 women and 6 men with mean age of 39.7 years old (26-51 years old), of which fifteen completed a minimum follow-up of 10 years. There was a statistically significant improvement of NDI and VAS (p < 0.001) between the preoperative and the postoperative periods (1 year or > 10 years). At the end of 10 years, HO was observed in 59% of the cases. The mobility of the implant was preserved in 80% of the patients. Radiological evidence of ASD was recorded in 6 patients (40%). There was no correlation between the clinical parameters evaluated and the presence of ASD or the different classes of HO. Conclusion Clinical improvement in all evaluated parameters, which persists over time. Most implants maintained mobility, as has already been demonstrated in other studies with shorter follow-ups. In a significant percentage of cases, ASD was observed, questioning the concept of motion preserving technology. However, we did not have any surgical intervention for this reason, since there was no correlation with worse clinical results.

Resumo Objetivo No presente estudo, apresentamos os resultados com um acompanhamento mínimo de 10 anos da artroplastia total do disco cervical (ATDC) em um nível. Métodos Estudo retrospectivo de pacientes submetidos a ATDC em um nível. Os resultados clínicos incluíram o índice de incapacidade relacionada ao pescoço (IIRP) e a escala visual analógica (EVA) no período pré-operatório, um ano pós-operatório e um mínimo de 10 anos de acompanhamento. Os parâmetros radiográficos incluíram a mobilidade cervical, lordose segmentar, ângulo C2-C7, ossificação heterotópica (OH), degeneração facetária e articular (DFA) e doença do segmento adjacente (DSA). Resultados Identificados 22 pacientes, 16 mulheres e 6 homens com média de idade de 39,7 anos (26-51 anos), dos quais 15 tiveram um acompanhamento mínimo de 10 anos. Foi verificada melhoria estatisticamente significativa do IIRP e EVA (p < 0,001) entre pré-operatório e pós-operatório. (1 ano ou > 10 anos). Ao final de 10 anos, OH foi observada em 59% dos casos. A mobilidade do implante foi preservada em 80% dos pacientes. Houve evidência radiológica de DSA em 6 pacientes (40%). Não houve correlação entre os parâmetros clínicos avaliados e a presença de DSA ou as diferentes classes de OH. Conclusão Melhoria clínica em todos os parâmetros avaliados, que persiste ao longo do tempo. A maioria dos implantes manteve a mobilidade, como já demonstrado em estudos anteriores com acompanhamentos mais curtos. Numa percentagem significativa, a DSA estava presente, questionando o conceito da tecnologia de preservação de movimento. No entanto, sem nenhuma intervenção cirúrgica por esse motivo, uma vez que não houve correlação com piores resultados clínicos.

Cost-Effectiveness Analysis of Cervical Anterior Fusion and Cervical Artificial Disc Replacement in the Korean Medical System

OBJECTIVE: This study is a retrospective cost-benefit analysis of cervical anterior interbody fusion and cervical artificial disc replacement, which are the main surgical methods to treat degenerative cervical disc disease.METHODS: We analyzed 156 patients who underwent anterior cervical disc fusion and cervical artificial disc replacement from January 1, 2008 to December 31, 2009, diagnosed with degenerative cervical disc disorder. In this study, the costs and benefits were analyzed by using quality adjusted life year (QALY) as the outcome index for patients undergoing surgery, and a Markov model was used for the analysis. Only direct medical costs were included in the analysis; indirect medical costs were excluded. Data were analyzed with TreeAge Pro 2015™ (TreeAge Software, Inc, Williamstown, MA, USA).RESULTS: Patients who underwent cervical anterior fusion had a total cost of KRW 2501807/USD 2357 over 5 years and obtained a utility of 3.72 QALY. Patients who underwent cervical artificial disc replacement received 4.18 QALY for a total of KRW 3685949/USD 3473 over 5 years. The cumulative cost-effectiveness ratio of cervical spine replacement surgery was KRW 2549511/QALY (USD 2402/QALY), which was lower than the general Korean payment standard.CONCLUSION: Both cervical anterior fusion and cervical artificial disc replacement are cost-effective treatments for patients with degenerative cervical disc disease. Cervical artificial disc replacement may be an effective alternative to obtain more benefits.

Cost-Effectiveness Analysis of Cervical Anterior Fusion and Cervical Artificial Disc Replacement in the Korean Medical System

OBJECTIVE: This study is a retrospective cost-benefit analysis of cervical anterior interbody fusion and cervical artificial disc replacement, which are the main surgical methods to treat degenerative cervical disc disease. METHODS: We analyzed 156 patients who underwent anterior cervical disc fusion and cervical artificial disc replacement from January 1, 2008 to December 31, 2009, diagnosed with degenerative cervical disc disorder. In this study, the costs and benefits were analyzed by using quality adjusted life year (QALY) as the outcome index for patients undergoing surgery, and a Markov model was used for the analysis. Only direct medical costs were included in the analysis; indirect medical costs were excluded. Data were analyzed with TreeAge Pro 2015™ (TreeAge Software, Inc, Williamstown, MA, USA). RESULTS: Patients who underwent cervical anterior fusion had a total cost of KRW 2501807/USD 2357 over 5 years and obtained a utility of 3.72 QALY. Patients who underwent cervical artificial disc replacement received 4.18 QALY for a total of KRW 3685949/USD 3473 over 5 years. The cumulative cost-effectiveness ratio of cervical spine replacement surgery was KRW 2549511/QALY (USD 2402/QALY), which was lower than the general Korean payment standard. CONCLUSION: Both cervical anterior fusion and cervical artificial disc replacement are cost-effective treatments for patients with degenerative cervical disc disease. Cervical artificial disc replacement may be an effective alternative to obtain more benefits.

Progression of Ossification of the Posterior Longitudinal Ligament after Cervical Total Disc Replacement / 대한신경손상학회지

OBJECTIVE: Total disc replacement (TDR) is frequently performed anterior approaching method for the patients diagnosed with cervical disc herniation. This study aimed to assess the degree of ossification of the posterior longitudinal ligament (OPLL) progression after cervical TDR. METHODS: Twenty-two male soldiers who underwent cervical TDR surgery from 2009 to 2016 and were followed-up for more than 12 months were enrolled. The enrolled patients were classified as; 1) patients with pre-existing OPLL and without; and 2) patient showing progression of OPLL or not. RESULTS: Twenty-two men were included in the analysis. The mean follow-up period from the surgery was 41.4 months (range, 12–114 months). The mean age of all patients was 40.7 years (range, 31–52 years). TDR-only was used in 7 cases, and the hybrid surgery (TDR+ACDF) was used in 15 cases. The incidence of progression or newly development of OPLL was significantly higher in pre-existing OPLL group (p=0.01). In 11 cases showing the progression of the OPLL, the mean size of OPLL progression was 4.16 mm (range, 0.34–18.87 mm) in the longitudinal height and 1.57 mm (range, 0.54–3.91 mm) in thickness. CONCLUSION: The progression of OPLL after cervical TDR was more frequent in patients with pre-existing OPLL than in patients without OPLL. Even though TDR is a major alternative to the treatment of cervical lesions to preserve vertebral segmental motion, careful attention should be paid to whether TDR should be used in patients with OPLL and this should be fully explained to the patient.

Disc replacement in lumbar spine / Artroplastia de disco na coluna lombar / Artroplastia de disco en la columna lumbar

ABSTRACT With the increase in the elderly population worldwide, the prevalence of degenerative diseases tends to grow, especially degenerative disc disease (DDD) in the lumbar spine. It is important to seek excellence treatments to ensure a better quality of life for patients. In this sense, the total disc replacement and the use of prostheses in the lumbar spine have been pointed out as alternative and promising treatments when compared to the standard treatment. The aim of this study is to show the results of total replacement of the intervertebral disc, through a review of the literature. The electronic search was performed in the PubMed databases, with the keywords "Total Disk Replacement", "Low Back Pain", and "Arthroplasty" in articles published as of 2012. We selected 16 articles. Level of Evidence: II. Type of study: Systematic reviewb of Level II studies or Level I studies with inconsistent results.

RESUMO Com o aumento da prevalência de idosos no mundo, a incidência de doenças degenerativas tende a crescer, especialmente a Doença degenerativa de disco (DDD) na coluna lombar. É importante buscar por tratamentos de excelência, para garantir melhor qualidade de vida aos pacientes. Nesse sentido, a substituição total do disco e o uso de próteses na coluna lombar tem sido apontados como tratamentos alternativos e promissores, quando comparado ao tratamento padrão. O objetivo deste artigo é mostrar os resultados da substituição total do disco intervertebral, por meio de uma revisão da literatura. Foi realizada a busca eletrônica nas bases de dados PubMed, a partir das palavras-chave: Substituição Total do Disco; Dor lombar; Artroplastia, publicados a partir de 2012. Foram selecionados um total de 16 artigos.Nível de Evidência: II. Tipo de estudo: Revisão sistemáticab de Estudos de nível II ou nível I com resultados discrepantes.

RESUMEN Con el aumento de la población de ancianos en todo el mundo, la prevalencia de enfermedades degenerativas tiende a crecer, especialmente la enfermedad degenerativa del disco (EDD) en la columna lumbar. Es importante buscar tratamientos de excelencia para garantizar una mejor calidad de vida a los pacientes. En este sentido, la sustitución del disco y el uso de prótesis en la columna lumbar han sido señalados como tratamientos alternativos y prometedores, en comparación con el tratamiento estándar. El objetivo de este estudio es mostrar los resultados de la sustitución total del disco intervertebral, por medio de una revisión de la literatura. Se realizó la búsqueda electrónica en las bases de datos PubMed, con los descriptores "Reemplazo total de disco", "Dolor lumbar", "Artroplastia", en artículos publicados a partir de 2012. Se seleccionaron 16 estudios. Nivel de Evidencia: II. Tipo de estudio: Revisión sistemáticab de Estudios de nivel II o nivel I con resultados discrepantes.

Rare Intractable Cervicalgia Related to Exaggerated Disc Height Distraction : Report of Two Cases and Literature Review

We present two cases of unexpected postoperative intractable cervicalgia due to over-sized implant insertion during simple anterior cervical decompression and fusion (ACDF) or artificial disc replacement (ADR). These patients experienced severe cervicalgia mostly related to their neck motion even after standard cervical operations. In both cases, the restored disc heights after the operations were prominently greater than the preoperative disc heights. The patients had not responded to any of the conservative treatments, and unloading of these excessively distracted segments through ultimate revision surgery led to dramatic pain relief. This report emphasizes the increase in distractional forces that takes place after a standard ACDF or ADR, as well as the importance of a proper sized implant. It also includes the reviews of other biomechanical or clinical reports dealing with this issue, thereby cautioning the surgeons not to disregard these factors, which might have an adverse effect in patients with cervicalgia even after radiographically successful cervical procedures.

Rare Intractable Cervicalgia Related to Exaggerated Disc Height Distraction : Report of Two Cases and Literature Review

We present two cases of unexpected postoperative intractable cervicalgia due to over-sized implant insertion during simple anterior cervical decompression and fusion (ACDF) or artificial disc replacement (ADR). These patients experienced severe cervicalgia mostly related to their neck motion even after standard cervical operations. In both cases, the restored disc heights after the operations were prominently greater than the preoperative disc heights. The patients had not responded to any of the conservative treatments, and unloading of these excessively distracted segments through ultimate revision surgery led to dramatic pain relief. This report emphasizes the increase in distractional forces that takes place after a standard ACDF or ADR, as well as the importance of a proper sized implant. It also includes the reviews of other biomechanical or clinical reports dealing with this issue, thereby cautioning the surgeons not to disregard these factors, which might have an adverse effect in patients with cervicalgia even after radiographically successful cervical procedures.

Are Controversial Issues in Cervical Total Disc Replacement Resolved or Unresolved?: A Review of Literature and Recent Updates

Since the launch of cervical total disc replacement (CTDR) in the early 2000s, many clinical studies have reported better outcomes of CTDR compared to those of anterior cervical discectomy and fusion. However, CTDR is still a new and innovative procedure with limited indications for clinical application in spinal surgery, particularly, for young patients presenting with soft disc herniation with radiculopathy and/or myelopathy. In addition, some controversial issues related to the assessment of clinical outcomes of CTDR remain unresolved. These issues, including surgical outcomes, adjacent segment degeneration (ASD), heterotopic ossification (HO), wear debris and tissue reaction, and multilevel total disc replacement (TDR) and hybrid surgeries are a common concern of spine surgeons and need to be resolved. Among them, the effect of CTDR on patient outcomes and ASD is theoretically and clinically important; however, this issue remains disputable. Additionally, HO, wear debris, multilevel TDR, and hybrid surgery tend to favor CTDR in terms of their effects on outcomes, but the potential of these factors for jeopardizing patients' safety postoperatively and/or to exert harmful effects on surgical outcomes in longer-term follow-up cannot be ignored. Consequently, it is too early to determine the therapeutic efficacy and cost-effectiveness of CTDR and will require considerable time and studies to provide appropriate answers regarding the same. For these reasons, CTDR requires longer-term follow-up data.

Results of total lumbar intervertebral disk replacement with m6-l: a multicenter study / Resultados da substituição total de disco intervertebral lombar com m6-l: um estudo multicêntrico / Resultados de la sustitución total de disco intervertebral lumbar con m6-l: un estudio multicéntrico

ABSTRACT Objective: In this paper we report the clinical and radiological results of lumbar intervertebral disk (IVD) replacement with M6-L for the treatment of patients with IVD degeneration. Methods: One hundred and fifty-six patients with IVD degeneration were operated with the one level implantation of an M6-L prosthesis at three neurosurgical departments, in Irkutsk, Krasnoyarsk and Vladivostok. We assessed pain intensity (VAS), the Oswestry disability index (ODI) and outcomes by the Macnab scale up to 36 months after surgery. Instrumental data were used to assess range of motion in the operated segment and heterotopic ossification by the McAfee-Suchomel classification. Results: The average VAS before surgery was 6.9 ± 1.6 cm. After surgery, this value reduced significantly, to an average of 1.3 ± 1.2 cm (p<0.001). The average ODI before surgery was 40.2 ± 6.9%, and after IVD arthroplasty, this indictor improved to 12.3 ± 6.1% (p <0.001). Range of motion in the operated segment at baseline averaged 36.8 ± 2.6o, and within 36 months after the operation, this had increased to 41.2 ± 2.9o. During the entire follow-up period, signs of severe (13.4%, n = 21) or moderate (10.2%, n = 16) heterotopic ossification were observed. Conclusions: The use of M6-L prosthesis can significantly reduce the level of pain, improve quality of life and maintain the physiological range of motion in the operated spinal segment in patients with degenerative lesions IVD at a low level of adverse outcomes. [249 Words].

RESUMO Objetivo: Neste artigo, relatamos os resultados clínicos e radiológicos da substituição de disco intervertebral lombar (IVD) com M6-L para tratamento de pacientes com degeneração de IVD. Métodos: Cento e cinquenta e seis pacientes com degeneração de IVD foram operados com a implantação de prótese M6-L em um nível, em três departamentos neurocirúrgicos de Irkutsk, Krasnoyarsk e Vladivostok. Avaliamos a intensidade da dor (EVA), o Índice de Incapacidade de Oswestry (ODI) e os resultados pela escala de Macnab até 36 meses após a cirurgia. Os dados de instrumentação foram utilizados para avaliar a amplitude de movimento no segmento operado e a ossificação heterotópica pela classificação McAfee-Suchomel. Resultados: O valor médio da EVA para dor antes da cirurgia foi de 6,9 ± 1,6 cm. Após a cirurgia, esse valor teve redução significativa, em média de 1,3 ± 1,2 cm (p < 0,001). O ODI médio antes da cirurgia foi de 40,2 ± 6,9%, e depois da artroplastia do IVD esse índice melhorou para 12,3 ± 6,1% (p < 0,001). A amplitude de movimento do segmento operado no início do estudo foi em média 36,8 ± 2,6o e 36 meses após a cirurgia, aumentou para 41,2 ± 2,9o. Durante todo o acompanhamento, foram observados sinais de ossificação heterotópica grave (13,4%, n = 21) ou moderada (10,2%, n = 16). Conclusões: O uso da prótese M6-L pode reduzir significativamente o nível de dor, melhorar a qualidade de vida e manter a amplitude de movimento fisiológico no segmento espinal operado em pacientes com lesões degenerativas do IVD com baixo nível de desfechos adversos.

RESUMEN Objetivo: En este trabajo, relatamos los resultados clínicos y radiológicos de la sustitución de disco intervertebral lumbar (IVD) con M6-L para tratamiento de pacientes con degeneración de IVD. Métodos: Ciento cincuenta y seis pacientes con degeneración de IVD fueron operados con la implantación de prótesis M6-L en un nivel, en tres departamentos de neurocirugía de Irkutsk, Krasnoyarsk y Vladivostok. Se evaluó la intensidad del dolor (EVA), el Índice de Discapacidad de Oswestry (ODI) y los resultados por escala de Macnab hasta 36 meses después de la cirugía. Los datos de instrumentación se utilizaron para evaluar el rango de movimiento en el segmento operado y la osificación heterotópica mediante la clasificación de McAfee-Suchomel. Resultados: El valor promedio de la EVA para el dolor antes de la cirugía fue de 6,9 ± 1,6 cm. Después de la cirugía, ese valor tuvo una reducción significativa, en promedio de 1,3 ± 1,2 cm (p < 0,001). El ODI promedio antes de la cirugía fue de 40,2 ± 6,9% y después de la artroplastia del IVD ese índice mejoró para 12,3 ± 6,1% (p < 0,001). El rango de movimiento del segmento operado al inicio del estudio fue en promedio 36,8 ± 2,6o y 36 meses después de la cirugía, aumentó a 41,2 ± 2,9o. Durante toda el seguimiento se observaron signos de osificación heterotópica grave (13,4%, n = 21) o moderada (10,2%, n = 16). Conclusiones: El uso de la prótesis M6-L puede reducir significativamente el nivel de dolor, mejorar la calidad de vida y mantener el rango de movimiento fisiológico en el segmento espinal operado en pacientes con lesiones degenerativas de IVD con bajo nivel de resultados adversos.

Comparative Analysis between Total Disc Replacement and Posterior Foraminotomy for Posterolateral Soft Disc Herniation with Unilateral Radiculopathy : Clinical and Biomechanical Results of a Minimum 5 Years Follow-up

OBJECTIVE: To compare the clinical outcomes and biomechanical effects of total disc replacement (TDR) and posterior cervical foraminotomy (PCF) and to propose relative inclusion criteria. METHODS: Thirty-five patients who underwent surgery between 2006 and 2008 were included. All patients had single-level disease and only radiculopathy. The overall sagittal balance and angle and height of a functional segmental unit (FSU; upper and lower vertebral body of the operative lesion) were assessed by preoperative and follow-up radiographs. C2–7 range of motion (ROM), FSU, and the adjacent segment were also checked. RESULTS: The clinical outcome of TDR (group A) was tended to be superior to that of PCF (group B) without statistical significance. In the group A, preoperative and postoperative upper adjacent segment level motion values were 8.6±2.3 and 8.4±2.0, and lower level motion values were 8.4±2.2 and 8.3±1.9. Preoperative and postoperative FSU heights were 37.0±2.1 and 37.1±1.8. In the group B, upper level adjacent segment motion values were 8.1±2.6 and 8.2±2.8, and lower level motion values were 6.5±3.3 and 6.3±3.1. FSU heights were 37.1±2.0 and 36.2±1.8. The postoperative FSU motion and height changes were significant (p<0.05). The patient’s satisfaction rates for surgery were 88.2% in group A and 88.8% in group B. CONCLUSION: TDR and PCF have favorable outcomes in patients with unilateral soft disc herniation. However, patients have different biomechanical backgrounds, so the patient’s biomechanical characteristics and economic status should be understood and treated using the optimal procedure.

A Comparison of Anterior Cervical Discectomy and Fusion versus Fusion Combined with Artificial Disc Replacement for Treating 3-Level Cervical Spondylotic Disease

OBJECTIVE: The purpose of this study is to evaluate the efficacy and safety of 3-level hybrid surgery (HS), which combines fusion and cervical disc replacement (CDR), compared to 3-level fusionin patient with cervical spondylosis involving 3 levels. METHODS: Patients in the anterior cervical discectomy and fusion (ACDF) group (n=30) underwent 3-level fusion and the HS group (n=19) underwent combined surgery with fusion and CDR. Clinical outcomes were evaluated using the visual analogue scale for the arm, the neck disability index (NDI), Odom criteria and postoperative complications. The cervical range of motion (ROM), fusion rate and adjacent segments degeneration were assessed with radiographs. RESULTS: Significant improvements in arm pain relief and functional outcome were observed in ACDF and HS group. The NDI in the HS group showed better improvement 6 months after surgery than that of the ACDF group. The ACDF group had a lower fusion rate, higher incidence of device related complications and radiological changes in adjacent segments compared with the HS group. The better recovery of cervical ROM was observed in HS group. However, that of the ACDF group was significantly decreased and did not recover. CONCLUSION: The HS group was better than the ACDF group in terms of NDI, cervical ROM, fusion rate, incidence of postoperative complications and adjacent segment degeneration.

Clinical and Radiographic Results of Artificial Disc Replacement Combined with Anterior Cervical Discectomy and Fusion Versus Two-Level Anterior Cervical Discectomy and Fusion in Two-Level Cervical Disc Disease

STUDY DESIGN: Retrospective case-control study. OBJECTIVES: To compare the clinical and radiographic outcomes of a hybrid construct (HC) of cervical artificial disc replacement (CADR) combined with anterior cervical discectomy and fusion (ACDF) (group I) with 2-level ACDF (group II) in patients with 2-level cervical disc disease. SUMMARY OF LITERATURE REVIEW: ACDF is reported to potentially promote degenerative changes in the adjacent segment. CADR has been expected to reduce the risk of adjacent segment degeneration. However, its clinical course has yet to be sufficiently clarified. MATERIALS AND METHODS: Twenty-six patients underwent 2-level cervical disc surgery. Single-level CADR combined with ACDF was performed in 14 patients. Twelve patients underwent 2-level ACDF. Clinical profiles were assessed using the neck disability index (NDI) and visual analogue scale scores of arm and neck pain. Dynamic lateral cervical radiographs were obtained preoperatively and at 1, 6, 12, and 18 months postoperatively. The range of motion (ROM) of the overall cervical spine (C2-7) and the adjacent segments was measured. RESULTS: Group I showed superior NDI 18 months postoperatively (p 0.05). CONCLUSIONS: The HC group showed comparable clinical and radiographic outcomes to those of the 2-level ACDF group. HC can be used selectively in the treatment of patients with 2-level cervical disc disease.

Radiological Parameters of Undegenerated Cervical Vertebral Segments in a Korean Population

BACKGROUND: Several scoring systems for cervical disc and facet joint degeneration, using radiography or computed tomography, have been developed and tested for reliability. However, definitions of disc height and facet joint space narrowing vary. To our knowledge, no study has reported quantitative data for normal radiologic values of the cervical spine in the Korean population. The purpose of this study is to determine normal cervical disc height, disc height ratio, and facet joint space values, and investigate the correlation between demographic data and these values. METHODS: We performed a retrospective study of patients who underwent artificial disc replacement of the cervical spine. Disc heights and facet joint spaces were measured using cervical neutral lateral radiographs and computed tomography. The means, standard deviations, and 95% confidence intervals of the values were determined. RESULTS: We measured 148 intervertebral discs and 352 posterior facet joints. The mean disc height measured by plain radiography and computed tomography was 5.57 ± 0.81 mm and 4.94 ± 0.94 mm, respectively. The mean facet joint space values measured by plain radiography and computed tomography were 1.94 ± 0.45 mm and 1.43 ± 0.39 mm, respectively. The disc heights and facet joint space values measured by plain radiography were greater than those measured by computed tomography. The lower limit of the 95% confidence interval of the disc height ratio calculated by plain radiography and computed tomography was greater than 0.94 at all levels except for C5–6. Patient height and disc height showed a tendency of positive correlation. CONCLUSIONS: In a Korean population, the normal cervical disc height was about 5.0 mm and the normal facet joint space was 1.4 mm. Disc height ratio can reliably identify normal cervical disc height in patients with mild degeneration. Patient height was positively correlated with disc height and facet joint space. Thus, when selecting a cervical implant, surgeons should consider patient height as well as estimated normal disc height.

Radiographic Analysis of the Lumbosacral Juncture: Is There a Critical Sacral Angle for Total Disc Replacement?

STUDY DESIGN: Retrospective review of a patient cohort through a prospective study. PURPOSE: To determine whether there are correlations between radiographic measurements, including sacral slope (SS) and pelvic incidence (PI), and self-reported clinical outcomes among single-level L5/S1 ProDisc-L patients. OVERVIEW OF LITERATURE: The lumbosacral juncture presents unique biomechanical challenges with respect to artificial disc replacement (ADR) because of its orientation and consequential shear loading. Reports of inferior outcomes at L5/S1 compared to those of the outcomes at the levels above, including increased facet joint pain, suggest a relationship with the sacral inclination at L5/S1. METHODS: Plain standing lateral radiographs of 71 patients (age, 26–65 years) who underwent ADR at L5/S1 for degenerative disc disease were reviewed. SS and PI were measured based on pretreatment and initial follow-up standing films. Patient's average adjusted self assessments included the Oswestry disability index and visual analog scale for pain 2 years after ADR. Correlation coefficients were computed to evaluate relationships between radiographic parameters and clinical outcomes. Analysis of covariance was used to evaluate multivariate relationships among factors, including radiographic parameters, body mass index (BMI), and clinical outcomes. RESULTS: SS and PI values were obtained from 71 patients. The average SS was 33.3° and average PI was 39.9°. At the 24-month follow-up, no significant correlations (p≥0.05) were observed between radiographic parameters and clinical outcomes. BMI, age, and sex did not explain any variability in the relationships between clinical outcomes and SS and PI. CONCLUSIONS: We reviewed a large range of SS angles and found no associations between SS, PI, or BMI and clinical outcomes after ADR at L5/S1. These preliminary results demonstrate that ADR provided maintainence of pain relief and functional improvement for a wide range of SS angles, suggesting that steeper angles are not a contraindication for ADR.

Cervical Footprint Anthropometry in Indian Population: Implications on Design of Artificial Disc Replacement Devices

STUDY DESIGN: Cross-sectional study. PURPOSE: To accurately measure the dimensions of cervical endplates based on computed tomography (CT) scans in Indian population and assess accuracy of match with currently available cervical disc prostheses. OVERVIEW OF LITERATURE: The dimensions of currently available cervical disc replacement implants are based on early published geometrical measurements of vertebrae endplates for Caucasian population. To author's knowledge, similar study has not been published for patients from Indian subcontinent. METHODS: CT scans of cervical spine of patients from Indian subcontinent were collected and reviewed. Seventy patients (54 men and 16 women; aged 18-56 years with average of 37 years) who underwent CT scans of cervical spine were included in study. 3D CT scans of sub axial cervical spine (C3 to C7) were analyzed. The anterior-posterior (AP) and central mediolateral (CML) dimensions of superior and inferior endplates from C3 to C7 were measured using digital measuring system. RESULTS: A total of 560 endplates of 70 patients were included in the study. The AP diameter of cervical endplates ranged from 0.87 to 2.47 cm. The CML diameters ranged from 0.84 to 2.98 cm. For levels C3/C4 and C4/C5 for AP dimension Prestige-LP (90.5%) and Prodisc-C (89%) discs showed higher percentage of matching than Discover discs (58.5%). For CML diameter, Prestige-LP (69.5%), Prodisc-C (70%) and Discover (39.5%) discs showed almost similar matching with measured endplates. For levels C5/C6 and C6/C7 for AP dimension, Prestige-LP (67.25%), Prodisc-C (49.35%) and Discover (51.5%) discs showed similar matching. For CML diameter Prestige-LP (32%), Prodisc-C (27.5%) and Discover (42.2%) discs showed poor matching with measured endplates. CONCLUSIONS: This study indicates need for redesign of cervical disc prostheses to match Indian patients. The collected anthropometric dimensions from this study may be used to design and develop indigenous artificial total disc replacement prosthesis and even cervical cages in India. With the present study being a small pilot study, the authors recommend anthropometric CT measurements in larger number of Indian patients in order to validate footprint dimensions for designing better-matched prosthesis.

An imaging study on effect of total artificial disc replacement on lumbar sagittal alignment / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate effect of Activ L total lumbar disc replacement on lumbar sagittal alignment.</p><p><b>METHODS</b>The imaging data of patients with degenerative disc disease received Activ L total lumbar disc replacement at Department of Orthopedics, Beijing Chao-Yang Hospital, Capital Medical University from March 2009 to March 2013 were retrospectively analyzed. The average age was 45.6 years(range, 35-60 years)and the surgery levels were as follows: L3-4 2 cases, L4-5 15 cases, L5/S1 5 cases, L3-4+ L4-5 3 cases, L4-5+ L5/S1 7 cases. All patients were followed up for 15 to 63 months(average, 32 months). Radiographic parameters such as lumbar lordosis angle(LL), segment lordosis angle(SL) and sacral slope angle(SS) were recorded. All the radiographic parameters were compared using one-way ANOVA at different stage. Lumbar lordosis angle of the two-level was compared with the one of one-level by using independent sample t-test before and after the operation. A partial correction test was carried out to determine the corrections between the parameters preoperatively, one month after the operation and at final follow-up.</p><p><b>RESULTS</b>One month after the operation, the lumbar lordosis angle decreased by an average of 1.8°, but there was no statistically significant(P>0.05). Compared with one month postoperation, the lumbar lordosis angle increased by an average of 6.8°(P<0.05), which also increased a lot compared with preoperation(P<0.05). The value of segment lordosis angle was rising up from preoperation to the final follow-up(P<0.05), so was the value of sacral slope angle, but there was no statistically significant between different stage(P>0.05). The lumbar lordosis angle showed no significant difference between double-level ones and single-level ones at different stage(P<0.05). The lumbar lordosis angle showed positive correlation with the sacral slope(P<0.001), however, the lumbar lordosis angle showed no corrected with the segment angle all the time(P>0.05).</p><p><b>CONCLUSIONS</b>The total lumbar disc replacement with Activ L prosthesis had contributed to maintain and improve the lumbar alignment in the short and medium term. Double- or single-level total lumbar disc replacement had no significant effect on the value of lumbar lordosis angle. The lumbar lordosis angle showed positive correlation with the sacral slope all the time with no correlation between lumbar lordosis angle and sacral slope.</p>