Influence of an artificial cervical joint compared with fusion on adjacent-level motion in the treatment of degenerative cervical disc disease

2002 ◽  
Vol 96 (1) ◽  
pp. 17-21 ◽  
Author(s):  
Crispin Wigfield ◽  
Steven Gill ◽  
Richard Nelson ◽  
Ilana Langdon ◽  
Newton Metcalf ◽  
...  

Object. The authors report the preservation of motion at surgically treated and adjacent spinal segments after placing an artificial cervical joint (ACJ) and they describe the influence of interbody fusion on changes in angulation occurring in the sagittal plane at adjacent levels in the treatment of cervical spondylosis. Methods. The authors conducted a prospective nonrandomized study of patients in whom an ACJ was placed or autologous bone graft interbody fusion was performed. Angular measurements at levels adjacent to that surgically treated were calculated using plain flexion—extension radiographs obtained at 6-month intervals. Analyses of qualitative data, such as increase or decrease in adjacent-level motion, and the degree of disc degeneration were performed. Quantitative data were also analyzed. In the fusion group a significant increase in adjacent-level movement was demonstrated at the 12-month follow-up visit compared with the group of patients in whom ACJs were placed (p < 0.001). The increase in movement occurred predominantly at intervertebral discs that were preoperatively regarded as normal (p < 0.02). An overall reduction in adjacent-level movement was observed in patients who underwent joint replacement, although this was compensated for by the movement provided by the ACJ itself. Conclusions. Fusion results in increased motion at adjacent levels. The increase in adjacent-level motion derives from those discs that appear radiologically normal prior to surgery. It remains unknown whether ACJs have a protective influence on adjacent intervertebral discs.

2005 ◽  
Vol 3 (1) ◽  
pp. 24-28 ◽  
Author(s):  
Jyi-Feng Chen ◽  
Chieh-Tsai Wu ◽  
Sai-Cheung Lee ◽  
Shih-Tseng Lee

Object. Polymethylmethacrylate (PMMA) bone cement has been used as a spacer in the treatment of patients with cervical disc disease with good long-term outcomes, but solid bone fusion has not been demonstrated in all cases. To achieve cervical interbody fusion, the authors designed a modified PMMA cervical cage that they filled with spongy bone for the treatment of single-level cervical disc herniation. Methods. Sixty-three patients underwent anterior cervical microdiscectomy and implantation of a PMMA cervical cage filled with autograft cancellous bone and were followed for a minimum of 2 years. The fusion rates were 90.5 and 100% at the 6- and 12-month follow-up examinations, respectively. The mean intervertebral disc height gain was 3.4 ± 1.9 mm when preoperative and 24-month postoperative values were compared. Neck pain, measured using the Huskissan visual analog scale (0 mm, no pain; 100 mm, worst possible pain), decreased from 71 ± 13 mm at preoperative baseline to 28 ± 17 at 6, 23 ± 19 at 12, and 31 ± 19 mm at 24 months. Based on the same scale, radicular pain decreased from 83 ± 15 mm at preoperative baseline to 24 ± 11 at 6, 27 ± 13 at 12, and 22 ± 11 mm at 24 months. The self-rated clinical outcome was excellent in 45 (71.4%) and good in 18 (28.6%) of the 63 patients. Conclusions. The autograft cancellous bone—filled PMMA cage is safe and effective for cervical interbody fusion in the treatment of single-level cervical disc herniation and monoradiculopathy.


2005 ◽  
Vol 3 (6) ◽  
pp. 417-423 ◽  
Author(s):  
James T. Robertson ◽  
Stephen M. Papadopoulos ◽  
Vincent C. Traynelis

Object. The authors compared the incidence of radiologically documented changes and symptomatic adjacent-level cervical disc disease after single-level discectomy and subsequent cervical fusion or arthroplasty in two independent prospective clinical studies. Methods. The patients were treated with the Affinity Anterior Cervical Cage System or the Bryan Artificial Cervical Disc. In each study the patients were required to undergo serial cervical radiography preoperatively and 24 months postoperatively, as well as serial clinical evaluations including documentation of adverse events, neurological status, and results of the 36-item Short Form Health Survey. All serial radiographs were reviewed prior to evaluating the clinical symptoms for development of increasing or new adjacent degenerative disc disease (DDD). Subsequently, the clinical data were analyzed. For various reasons of exclusion, the cases analyzed in the Bryan disc—treated cohort consisted of 74 patients and in the Affinity system—treated cohort there were 158 patients. New anterior osteophyte formation or enlargement, increased narrowing of an interspace, new DDD, and calcification of the anterior longitudinal ligament were the radiological findings indicative of adjacent-level disease. Fusion was associated with a significant increase in x-ray film—based changes of adjacent-disc disease (p = 0.009, odds ratio [OR] 2.44). In the cage fusion series, the incidence of symptomatic adjacent-level DDD was statistically greater than that in the group treated with the artificial disc (p = 0.018), and the patients required a statistically greater number of medical treatments related to episodic symptoms of neck, shoulder, and arm pain attributed to new disc disease (p = 0.001, OR 35.8). Conclusions. In comparing these prospective studies the authors demonstrated that maintaining motion rather than fusion will prevent symptomatic adjacent-disc disease and will decrease adjacent-level radiological indicators of disease at a 24-month postoperative interval.


2005 ◽  
Vol 3 (5) ◽  
pp. 335-341 ◽  
Author(s):  
Lali H. S. Sekhon ◽  
William Sears ◽  
Neil Duggal

Object. The potential role of cervical arthroplasty in patients who have undergone previous cervical surgery is unknown. The authors performed a prospective study involving nonrandomized clinical and radiological assessment in patients who had undergone either previous posterior cervical foraminotomy or anterior interbody fusion and who suffered new or persistent arm/neck symptoms related to neural compression. Methods. During a 30-month period, 15 patients who had previously undergone cervical spinal surgery underwent cervical arthroplasty that involved placement of the Bryan disc for neck or arm symptoms related to cervical disc disease. A total of 24 devices were implanted. Six of the 15 patients had undergone a previous posterior foraminotomy, and in nine cases an anterior interbody fusion had been perfomed at some stage prior to surgery. Clinical and radiological evaluations were performed preoperatively and after surgery to assess outcomes. A total of 24 arthroplasties were performed encompassing between one and three levels. There were no major perioperative complications or immediate device-related failures. Two patients were lost to follow up. The follow-up period ranged from 12 to 43 months (mean 24.2 ± 10.5 months). Good results were obtained in all cases as reflected by an increase in the visual analog scale score of 6.4 in terms of neck/arm pain (p < 0.05). There was no difference in Oswestry Disability Index scores for neck pain (p > 0.05) and no patient required surgery at the same level. In one patient hypermobility developed with internal subluxation of the device, which suggested a compromise adjacent to a two-level fusion at 21 months. The segment was hypermobile preoperatively. The patient has experienced recurrent neck pain but otherwise remains clinically well and has not required revision surgery to date. Conclusions. Insertion of the Bryan artificial cervical disc in patients who have previously undergone cervical fusion or posterior foraminotomy, in general, appears to be safe. It provided encouraging early clinical results, although patients with preoperative hypermobility should be treated with caution. Issues such as accelerated device-related wear and the use of arthroplasty after aggressive facetectomy resection will need further study; however, in carefully selected patients who have undergone previous surgery cervical arthroplasty may provide an additional tool in the management of cervical disc disease.


1973 ◽  
Vol 39 (2) ◽  
pp. 203-208 ◽  
Author(s):  
Dwight Parkinson ◽  
Christopher Shields

✓ Thirty-three intervertebral disc patients who otherwise would have been subjected to surgery were treated by injection with chymopapain. The pharmacology, toxicology, physiology, immunology, and chemical action of this enzyme, which specifically reacts with chondromucoproteins, are discussed. Results indicate that this method, although still experimental and unapproved by the U. S. Food and Drug Administration, may become a useful addition to the surgeon's armamentarium in the treatment of intervertebral disc disease.


2004 ◽  
Vol 1 (2) ◽  
pp. 155-159 ◽  
Author(s):  
Praveen V. Mummaneni ◽  
Regis W. Haid

✓ In the past 50 years tremendous advances have been made in the treatment of cervical disc disease with cervical fusion. Fusion rates have surpassed 95% after application of anterior cervical implants. Adjacent-segment degeneration, however, has plagued the long-term clinical success of cervical fusion. Cervical arthroplasty has been introduced to maintain cervical motion and potentially avoid or minimize adjacent-segment degeneration. If cervical arthroplasty is successful, the long-term results of surgery for cervical disc disease may improve; however, there are associated drawbacks that must be overcome. Implant wear, fatigue, and failure have been reported in cases of large-joint arthroplasty, and research is underway to limit these problems in cervical arthroplasty. In this article the authors trace the evolution of cervical fusion and the new technique of cervical arthroplasty. The nomenclature of cervical arthroplasty will also be introduced.


2000 ◽  
Vol 92 (1) ◽  
pp. 87-92 ◽  
Author(s):  
Annette Kettler ◽  
Hans-Joachim Wilke ◽  
Rupert Dietl ◽  
Matthias Krammer ◽  
Christianto Lumenta ◽  
...  

Object. The function of interbody fusion cages is to stabilize spinal segments primarily by distracting them as well as by allowing bone ingrowth and fusion. An important condition for efficient formation of bone tissue is achieving adequate spinal stability. However, the initial stability may be reduced due to repeated movements of the spine during everyday activity. Therefore, in addition to immediate stability, stability after cyclic loading is of remarkable relevance; however, this has not yet been investigated. The object of this study was to investigate the immediate stabilizing effect of three different posterior lumbar interbody fusion cages and to clarify the effect of cyclic loading on the stabilization. Methods. Before and directly after implantation of a Zientek, Stryker, or Ray posterior lumbar interbody fusion cage, 24 lumbar spine segment specimens were each evaluated in a spine tester. Pure lateral bending, flexion—extension, and axial rotation moments (± 7.5 Nm) were applied continuously. The motion in each specimen was measured simultaneously. The specimens were then loaded cyclically (40,000 cycles, 5 Hz) with an axial compression force ranging from 200 to 1000 N. Finally, they were tested once again in the spine tester. Conclusions. In general, a decrease of movement in all loading directions was noted after insertion of the Zientek and Ray cages and an increase of movement after implantation of a Stryker cage. In all three cage groups greater stability was demonstrated in lateral bending and flexion than in extension and axial rotation. Reduced stability during cyclic loading was observed in all three cage groups; however, loss of stability was most pronounced when the Ray cage was used.


2004 ◽  
Vol 100 (4) ◽  
pp. 337-342 ◽  
Author(s):  
Yoshihisa Kotani ◽  
Kuniyoshi Abumi ◽  
Yasuo Shikinami ◽  
Masahiko Takahata ◽  
Ken Kadoya ◽  
...  

Object. This 2-year experimental study was conducted to investigate the efficacy of a bioactive three-dimensional (3D) fabric disc for lumbar intervertebral disc replacement. The authors used a bioresorbable spinal fixation rod consisting of a forged composite of particulate unsintered hydroxyapatite/poly-l-lactide acid (HA/PLLA) for stability augmentation. The biomechanical and histological alterations as well as possible device-related loosening were examined at 2 years postoperatively. Methods. Two lumbar intervertebral discs (L2–3 and L4–5) were replaced with the 3D fabric discs, which were augmented by two titanium screws and a spanning bioresorbable rod (HA/PLLA). The segmental biomechanics and interface bone ingrowth were investigated at 6, 15, and 24 months postoperatively, and results were compared with the other two surgical groups (3D fabric disc alone; 3D fabric disc with additional anterior instrumentation stabilization). The 3D fabric disc and HA/PLLA—spinal segments demonstrated segmental mobility at 15 and 24 months; however, the range of motion (ROM) in flexion—extension decreased to 49 and 40%, respectively, despite statistically equivalent preserved torsional ROM. Histologically there was excellent osseous fusion at the 3D fabric disc surface—vertebral body interface. At 2 years posttreatment, no adverse tissue reaction nor aseptic loosening of the device was observed. Conclusions. Intervertebral disc replacement with the 3D fabric disc was viable and when used in conjunction with the bioresorbable HA/PLLA spinal augmentation. Further refinements of device design to create a stand-alone type are necessary to obviate the need for additional spinal stabilization.


2005 ◽  
Vol 3 (6) ◽  
pp. 465-470 ◽  
Author(s):  
Christopher P. Ames ◽  
Frank L. Acosta ◽  
Robert H. Chamberlain ◽  
Adolfo Espinoza Larios ◽  
Neil R. Crawford

Object. The authors present a biomechanical analysis of a newly designed bioabsorbable anterior cervical plate (ACP) for the treatment of one-level cervical degenerative disc disease. They studied anterior cervical discectomy and fusion (ACDF) in a human cadaveric model, comparing the stability of the cervical spine after placement of the bioabsorbable fusion plate, a bioabsorbable mesh, and a more traditional metallic ACP. Methods. Seven human cadaveric specimens underwent a C6–7 fibular graft—assisted ACDF placement. A one-level resorbable ACP was then placed and secured with bioabsorbable screws. Flexibility testing was performed on both intact and instrumented specimens using a servohydraulic system to create flexion—extension, lateral bending, and axial rotation motions. After data analysis, three parameters were calculated: angular range of motion, lax zone, and stiff zone. The results were compared with those obtained in a previous study of a resorbable fusion mesh and with those acquired using metallic fusion ACPs. For all parameters studied, the resorbable plate consistently conferred greater stability than the resorbable mesh. Moreover, it offered comparable stability with that of metallic fusion ACPs. Conclusions. Bioabsorbable plates provide better stability than resorbable mesh. Although the results of this study do not necessarily indicate that a resorbable plate confers equivalent stability to a metal plate, the resorbable ACP certainly yielded better results than the resorbable mesh. Bioabsorbable fusion ACPs should therefore be considered as alternatives to metal plates when a graft containment device is required.


2002 ◽  
Vol 97 (1) ◽  
pp. 40-48 ◽  
Author(s):  
Frank Kandziora ◽  
Hermann Bail ◽  
Gerhard Schmidmaier ◽  
Georg Schollmeier ◽  
Matti Scholz ◽  
...  

Object. Growth factors such as bone morphogenetic protein—2 (BMP-2) have been proven to promote spine fusion and to overcome the disadvantages of an autologous bone graft. The optimum method to deliver such growth factors remains a matter of discussion. The purpose of this study was to determine the safety and efficacy of a new poly(d,l-lactide) (PDLLA) carrier system for BMP-2 and to compare this carrier system with a collagen sponge carrier in a sheep cervical spine interbody fusion model. Methods. Thirty-two sheep underwent C3–4 discectomy and fusion: Group 1, titanium cage (eight animals); Group 2, titanium cage coated with a PDLLA carrier (eight animals); Group 3, titanium cage coated with a PDLLA carrier including BMP-2 (150 µg) (eight animals); and Group 4, titanium cage combined with a collagen sponge carrier including BMP-2 (150 µg) (eight animals). Blood samples, body weight, and temperature were assessed. Radiographs were obtained pre- and postoperatively and after 1, 2, 4, 8, and 12 weeks. At the same time points, disc space height, intervertebral angle, and lordosis angle were measured. After the sheep were killed 12 weeks postoperatively, flexion—extension radiography was performed to evaluate fusion sites. Quantitative computerized tomography scans were obtained to assess bone mineral density (BMD), bone mineral content (BMC), and bone callus volume (BCV). Biomechanical testing was performed in flexion, extension, axial rotation, and lateral bending. Stiffness, range of motion, neutral, and elastic zone were determined. Histomorphological and -morphometrical analyses were performed, and polychrome sequential labeling was used to determine the timeframe of new bone formation. There were no differences among the groups concerning blood counts, body weight, and temperature. Compared with the noncoated cages, all PDLLA-coated cages showed significantly higher values for BMD of the callus, as well as slightly higher values for BMC, BCV, and the bone volume/total volume ratio. In comparison with the cage-alone group, the BMP-2 groups showed significantly higher values for BMD and biomechanical stiffness. Histomorphological, -morphometrical, and polychrome sequential labeling analyses demonstrated greater progression of callus formation in the BMP-2 groups than in any other group. Compared with BMP-2 delivered using a collagen sponge carrier, BMP-2 application with a PDLLA carrier resulted in a higher BCV and a greater progression of interbody callus formation in the histomorphometrical analysis. Conclusions. The use of cervical spine interbody fusion cages coated with PDLLA as a delivery system for growth factors was effective. In this 12-week follow-up study, the PDLLA coating showed no adverse effects. The slight but not significant positive effect of the PDLLA carrier on interbody fusion might be a result of the degradation process of the biodegradable carrier. Compared with collagen sponge delivery of BMP-2, the PDLLA-coated interbody cages significantly increased the results of interbody bone matrix formation. In this new combination (implant + PDLLA + growth factor) the cage represents a “real fusion” cage, because it not only serves as a mechanical device for spinal fixation but also as a local drug delivery system.


2002 ◽  
Vol 96 (3) ◽  
pp. 321-332 ◽  
Author(s):  
Frank Kandziora ◽  
Georg Schollmeier ◽  
Matti Scholz ◽  
Jan Schaefer ◽  
Alexandra Scholz ◽  
...  

Object. The purpose of this study was to compare the characteristics of interbody fusion achieved using an autologous tricortical iliac crest bone graft with those of a cylinder- and a box-design cage in a sheep cervical spine model. This study was designed to determine whether there are differences between three interbody fusion procedures in: 1) ability to preserve postoperative distraction; 2) biomechanical stability; and 3) histological characteristics of intervertebral bone matrix formation. Methods. Twenty-four sheep underwent C3–4 discectomy and fusion in which the following were used: Group 1, autologous tricortical iliac crest bone graft (eight sheep); Group 2, titanium cylinder-design cage filled with autologous iliac crest bone graft (eight sheep); and Group 3, titanium box-design cage filled with autologous iliac crest graft (eight sheep). Radiography was performed pre- and postoperatively and after 1, 2, 4, 8, and 12 weeks. At the same time points, disc space height, intervertebral angle, and lordosis angle were measured. After 12 weeks, the sheep were killed, and fusion sites were evaluated by obtaining functional radiographs in flexion and extension. Quantitative computerized tomography scans were acquired to assess bone mineral density, bone mineral content, and bone callus volume. Biomechanical testing was performed in flexion, extension, axial rotation, and lateral bending. Stiffness, range of motion, neutral zone, and elastic zone were determined. Histomorphological and histomorphometric analyses were performed, and polychrome sequential labeling was used to determine the time frame of new bone formation. Over a 12-week period significantly higher values for disc space height and intervertebral angle were shown in cage-treated sheep than in those that received bone graft. Functional radiographic assessment revealed significantly lower residual flexion—extension movement in sheep with the cylinder cage-fixed spines than in those that received bone graft group. The cylinder—design cages showed significantly higher values for bone mineral content, bone callus content, and stiffness in axial rotation and lateral bending than the other cages or grafts. Histomorphometric evaluation and polychrome sequential labeling showed a more progressed bone matrix formation in the cylindrical cage group than in both other groups. Conclusions. Compared with the tricortical bone graft, both cages showed significantly better distractive properties. The cylindrical cage demonstrated a significantly higher biomechanical stiffness and an accelerated interbody fusion compared with the box-design cage and the tricortical bone graft. The differences in bone matrix formation within both cages were the result of the significantly lower stress shielding on the bone graft by the cylinder-design cage.


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