Anterior cervical discectomy: is fusion necessary? A prospective randomized comparison of rectangular titanium cage fusion and iliac crest autograft fusion in patients undergoing anterior cervical discectomy. Comparison of anterior cervical fusions using autogenous bone graft obtained from the cervical vertebrae to the modified Smith-Robinson technique. Anterior cervical discectomy with and without fusion. A prospective study. A comparison of changes over time in cervical foraminal height after tricortical iliac graft or polyetheretherketone cage placement following anterior discectomy. A prospective randomized study comparing a cervical carbon fiber cage to the Smith-Robinson technique with allograft and plating: up to 24 months follow-up. Anterior cervical discectomy (ACD) versus anterior cervical fusion (ACF), clinical and radiological outcome study. PMMA versus titanium cage after anterior cervical discectomy - a prospective randomized trial. A randomized prospective study of an anterior cervical interbody fusion device with a minimum of 2 years of follow-up results. Outcome scores in degenerative cervical disc surgery. Fusion and failure following anterior cervical plating with dynamic or rigid plates: 6-months results of a multi-centric, prospective, randomized, controlled study. Radiographic analysis of fusion progression following one-level cervical fusion with or without plate fixation. A prospective randomized comparison of coralline hydroxyapatite with autograft in cervical interbody fusion. Comparative evaluation of microdiscectomy only, autograft fusion, polymethylmethacrylate interposition, and threaded titanium cage fusion for treatment of single-level cervical disc disease: a prospective randomized study in 125 patients. Clinical and radiological evaluation of Trabecular Metal and the Smith-Robinson technique in anterior cervical fusion for degenerative disease: a prospective, randomized, controlled study with 2-year follow-up. Biocompatible osteoconductive polymer versus iliac graft. A prospective comparative study for the evaluation of fusion pattern after anterior cervical discectomy. Full-endoscopic anterior decompression versus conventional anterior decompression and fusion in cervical disc herniations. Anterior cervical microdiscectomy with or without fusion. Anterior cervical fusion with interbody cage containing beta-tricalcium phosphate augmented with plate fixation: a prospective randomized study with 2-year follow-up. Choice of plate may affect outcomes for single versus multilevel ACDF: results of a prospective randomized single-blind trial. Anterior cervical discectomy with and without interbody bone graft. Effect of autologous platelet gel on early and late graft fusion in anterior cervical spine surgery. Anterior cervical fusion with tantalum implant: a prospective randomized controlled study. Anterior cervical discectomy with or without fusion with ray titanium cage: a prospective randomized clinical study. Autograft versus interbody fusion cage without plate fixation in the cervical spine: a randomized clinical study using radiostereometry. Discectomy versus discectomy with fusion versus discectomy with fusion and instrumentation: a prospective randomized study. A prospective randomized comparison between the cloward procedure and a carbon fiber cage in the cervical spine: a clinical and radiologic study. A prospective, randomized, controlled cervical fusion study using recombinant human bone morphogenetic protein-2 with the CORNERSTONE-SR allograft ring and the ATLANTIS anterior cervical plate. Rigid fusion after cloward operation for cervical disc disease using autograft, allograft, or xenograft: a randomized study with radiostereometric and clinical follow-up assessment. Anterior cervical discectomy with or without fusion with acrylate. A randomized trial. [Anterior cervical interbody fusion with treathed cylindrical bone versus bak-cace: a comparative study]. A prospective randomized study of anterior single-level cervical disc operations with long-term follow-up: surgical fusion is unnecessary.
A prospective, randomized trial was performed to compare the efficacy of anterior cervical discectomy (ACD) with ACD and fusion (ACDF) for the treatment of cervical spondylosis in patients with neurological compromise.
                Forty-four patients underwent ACD and 40 underwent ACDF. Operative time and length of hospital stay were shorter and there was less need for analgesia in the ACD group. It was found that whereas the incidence of fusion was greater in the ACDF group compared to the ACD group (97 compared with 70%, respectively; p<0.01), patient satisfaction and a return to preoperative activity level was similar between groups.
                Analysis of the results suggests that the addition of a fusion procedure may be unnecessary. The authors compare clinical outcome and fusion rates after iliac crest autograft (ICAG)- and rectangular titanium cage (RTC)-augmented fusion in patients undergoing anterior cervical discectomy (ACD).
                One hundred consecutive patients with 127 levels of cervical disc disease refractory to conservative treatment were randomized into one of the two treatment groups (ICAG/RTC fusion). The visual analog scale was used by the patient to rate overall pain and head, neck, arm, and donor site pain separately. Myelopathy was documented according to Japanese Orthopaedic Association and Nurick grading systems. Outcome was analyzed using Odom criteria, the 36-Item Short Form (SF-36), and Patient Satisfaction Index scales. Fusion rates were assessed on standard and flexion-extension radiographs. Follow-up data of at least 12 months' duration were available for 95 patients. More residual overall pain after 12 months was documented in patients who underwent ICAG fusion (3.3 +/- 2.5 [ICAG] and 2.2 +/- 2.4 [RTC]; p < 0.05). Although arm and head pain were minimal in both groups, neck pain proved to be the predominant symptom (2.7 +/- 2.5 [ICAG] and 1.9 +/- 2.1 [RTC]), which resolved in only 67 and 48% of RTC- and ICAG-treated patients, respectively (p < 0.05). Myelopathy improved comparably in both groups. Regardless of increased pain in ICAG-treated patients, PSI and SF-36 scores were not significantly different between groups (only four [8%] of 47 ICAG-treated patients and five [10%] of 48 RTC-treated patients were unsatisfied). Good to excellent functional recovery according to Odom criteria was observed in 75 and 79% of ICAG- and RTC-treated patients, respectively. Fusion rates were 81 and 74%, respectively (p = 0.51).
                Fusion rates and clinical outcome at 12 months after ACD were comparable between patients who underwent ICAG and RTC fusion. The use of rectangular cages, however, avoids donor site morbidity and reduces overall pain and, thus, seems to be an advantageous treatment alternative. Anterior cervical discectomy and interbody grafting provide excellent results in treating cervical radiculopathy. This prospective study compares the results of the technique obtaining autogenous bone from the cervical vertebrae for grafting to the modified Smith-Robinson technique using autogenous iliac crest graft. Seven levels in six patients were fused using the vertebral body autograft technique and 43 levels in 40 patients using the standard technique. All patients had radiculopathy and neck pain. Statistically significant differences in fusion rate (4/7 vertebral body autograft; 40/43 modified Smith-Robinson) (p = 0.029), disc height maintenance (p = 0.001), and neck pain improvement (p = 0.05) occurred between the techniques. We do not recommend vertebral body autograft over the modified Smith-Robinson technique for anterior cervical fusion following discectomy. A prospective randomized study to compare discectomy without (DE) and with fusion (DEF) included 63 patients operated on with DE returned to work during the first 9 weeks postoperatively than patients operated on with DEF (p less than 0.005 to 0.05). The prognosis is significantly better for men than for women after DEF (p less than 0.005), while no difference can be shown after DE. The authors prospectively evaluated cervical foraminal height changes after anterior cervical discectomy and fusion. To their knowledge, this prospective study is the first in which foraminal height changes over time are compared following the placement of a tricortical graft or a polyetheretherketone (PEEK) cage.
                The patients were randomly divided in two groups. In one group, 30 patients underwent anterior cervical microdiscectomy and free bone graft (FBG) insertion at 46 levels via the Smith-Robinson technique. The FBG was harvested from the right iliac crest. Another 35 patients underwent the same operation, but fusion was provided by the insertion of PEEK intervertebral cages at 41 levels. Fusion status and the C2-7 Cobb angle, interspace height, and foraminal height changes were observed on anterior, lateral, and oblique radiographs obtained at the 18-month follow-up examination. There were no differences between the groups with regard to clinical recovery, fusion status, and Cobb angle. A significant interspace height reduction was observed in the FBG group during the 1st postoperative month. In the FBG group, the mean heights (+/- standard deviation) of the foramina were 8.2 +/- 2.7 mm preoperatively, 10.8 +/- 2.6 mm on postoperative Day 2, and 8.1 +/- 1.5 mm after 18 months of follow up. In the PEEK cage group, the mean heights were 8.4 +/- 2.8 mm preoperatively, 10.3 +/- 1.1 mm on postoperative Day 2, and 9.6 +/- 1.2 mm after 18 months of follow up. The increase in foraminal height was significantly preserved at the 6th, 12th, and 18th months in the cage group.
                In both groups the foraminal height increased sufficiently and the nerve root was decompressed postoperatively. The PEEK cages may provide sufficient preservation of foraminal height even 1.5 years after the operation. Intervertebral carbon fiber cages may reduce graft collapse and promote bony fusion. Their safety and efficacy in the cervical spine have been investigated; however, no study has compared the outcomes of anterior cervical decompression and placement of a carbon fiber cage with placement of allograft and plate.
                Forty consecutive patients who met inclusion criteria were enrolled and randomized to anterior cervical discectomy with carbon fiber cage alone (n=20) or with allograft with plating (n=20). Clinical and radiographic evaluations were performed at baseline and at 6 weeks, 3, 6, 12 and 24 months. Neck and arm pain as well as neck disability index (NDI) were assessed at every visit. The Short Form (SF)-36 was completed prior to operation and at 12-month intervals. Cervical radiographs were evaluated pre-op and at every follow-up for evidence of fusion and instability.
                No significant difference was found between the two randomized groups with respect to pre-operative age (mean 50 years), sex, employment status, duration of pain or cervical levels affected. The mean follow-up period was 14 months (range, 6-26 months). The clinical pain and disability improvements were similar for both treatments. Post-operative donor site pain was only present in the cage group, but not of significant long-term disability. At up to 24 months, NDI scores were significantly improved in both groups when compared with baseline. At 12 and 24 months, all SF-36 questionnaire responses were also improved in both the treatment groups. However, there was no statistically significant difference in outcomes between the two groups at any time. The fusion rate was 100% in both groups by 12 and 24 months, without evidence of instability. There were no differences in complications between both groups.
                The outcomes after cervical decompression and placement of a carbon fiber cage appear to be similar to cervical decompression with allograft and plating by the Smith-Robinson technique. This study was conducted on 90 patients with symptomatic cervical disc disease with one or two-level disc pathology. Clinical and radiological outcome was compared to determine which technique was advantageous for patients with disc disease. Problems related to donor site as well as those related to fusion bed and grafts have stimulated investigators to avoid fusion. Patients were allocated at random for either the ACF (n=50) or the ACD (n=40) procedures. The standard Smith-Robinson technique was performed on all patients in this study. Patients were followed-up clinically and radiologically according to the study protocol. The clinical long-term outcome was comparable in both groups, though those who had ACF were more satisfied. There was significant incidence of kyphosis in the ACD group (P=0.02). Osseous union was slow and less satisfactory with ACD (64%) than with ACF (94%). Pain at the donor site was not a significant problem in the long-term. Hospital stay and operative time was shortened in ACD patients though not significantly. Spondylotic patients were less satisfied with ACD though not significantly. Conclusions. The issue of whether to fuse or not to fuse has not come to an end yet. The technique is still in need of more refinement of disc excision and graft harvesting and shaping, as well as more adequately controlled studies. Until that, ACD has to be limited to those patients with a soft single disc without spondylosis. Nonautologous interbody fusion materials are utilised in increasing numbers after anterior cervical disc surgery to overcome the problem of donor site morbidity of autologous bone grafts. This study investigates the performance of two nonautologous materials, the bone cement Polymethylmethacrylate (PMMA) and titanium cages. This prospective randomised trial, with assessment of the results by an independent observer, evaluates whether a Polymethylmethacrylate (PMMA) spacer or a titanium cage provides a better fusion rate around the implant and a better clinical outcome.
                Between 2000 and 2002, 115 patients with monoradicular cervical nerve root compression syndrome caused by soft cervical disc herniation were eligible for this study. Myelopathy, excessive osteophyte formation, and adjacent level degeneration were exclusion criteria. A block-restricted randomisation was applied. The 2-year clinical outcome served as the primary endpoint of the study. Clinical outcome was assessed according to the Odom scale by an independent observer at the follow-up examination. Preoperative, postoperative, and follow-up radiographs were taken.
                The study was completed by 107 patients (53 with PMMA and 54 with titanium cage). No significant difference between the two groups could be established with respect to the clinical outcome. In each group, 26 patients scored excellent. Good results were found in 19 PMMA patients and 16 titanium cage patients; satisfactory results were found in 8 PMMA patients and 9 titanium cage patients; bad results were found in 3 titanium cage patients. In 47 titanium cage cases (87%), fusion occurred radiologically as bony bridging around the implant. The fusion rate was significantly lower (p=0.011) in the PMMA group, with 35 cases (66%) united at follow-up.
                The radiological result of the titanium cage is superior to that of PMMA with respect to the fusion rate. Although the titanium cage achieves a better fusion rate, there is no difference between titanium cages and PMMA with respect to the clinical outcome. Despite variations in technique, inherent problems persist with current approaches to anterior cervical fusion. This study was performed to determine whether anterior cervical fusion performed using an investigational device was safe and effective in the treatment of degenerative cervical disc disorders and whether this device offered advantages over current techniques.
                Fifty-four patients with radiculopathy with or without mild myelopathy due to one- or two-level cervical degenerative disc disease were randomized as part of a Food and Drug Administration device study. Following microsurgical discectomy, the control group was treated with iliac crest graft fusion; the experimental study group underwent insertion of an interspace cage and placement of a local autograft. All patients received postoperative follow-up care for at least 2 years. Good or excellent results were found in approximately 97% of the experimental group and 88% of the control group. A solid fusion was achieved in all patients who underwent one-level cage placement, and a solid fusion at one or both levels was achieved in over 90% of both groups. Chronic donor site pain was reported by 31% of the control group.
                In this study, the use of an interbody fusion cage avoided donor site morbidity and placement of autograft achieved a high rate of good or excellent results. Interbody fusion cages appear safe and effective, and their use helps to avoid some of the inherent problems in performing current anterior cervical fusion techniques. Forty-six consecutive patients with neck pain and arm radiculopathy were treated with anterior cervical discectomy and fusion. All patients had neurological symptoms corresponding to a herniated disc and/or spondylosis at one or two cervical levels, verified by magnetic resonance imaging. The patients were stabilized with an anterior graft and randomized to either fixation with a CSLP plate or no internal fixation. Preoperatively and 2 years postoperatively the patients filled in a questionnaire that included a modified Million Index, a modified Oswestry Index and the Zung Depression Scale. They were also asked to register their pain in the arm and in the neck on a vertical visual analogue scale (VAS). At the 2-year follow-up, an unbiased observer graded the patients' clinical outcome using Odom's criteria. A test-retest procedure was carried out to examine the questionnaire reproducibility. In the group that was operated at one level, there was no significant improvement in any of the scores. Nevertheless, 81% of the patients were satisfied with the outcome of the surgery. All scores improved in the group operated at two levels. The pain in the neck and arm, as measured on a VAS, decreased in both groups. The improvement in arm pain was significantly more pronounced in patients operated with a plate at two levels compared to those who were operated without a plate. At the 2-year follow-up, patients with an excellent or good result according to Odom's criteria had a lower Million Index (P < 0.0005), Oswestry Index (P < 0.0005), and Zung (P = 0.024) score, than the group classified as fair or poor. There was a significant correlation (P < 0.0001 for all scores) between the test and retest results. We conclude that the modified Million Index and Oswestry Index are clinically useful tools in the evaluation of outcome after degenerative cervical disc surgery. The clinical benefits of plate fixation were minimal. The outcome after surgery, measured with the Oswestry Index, Million Index and VAS for arm and neck pain, seems to correlate well with the classification of outcome by Odom. Anterior cervical plate fixation is an approved surgical technique for cervical spine stabilization in the presence of anterior cervical instability. Rigid plate design with screws rigidly locked to the plate is widely used and is thought to provide a better fixation for the treated spinal segment than a dynamic design in which the screws may slide when the graft is settling. Recent biomechanical studies showed that dynamic anterior plates provide a better graft loading possibly leading to accelerated spinal fusion with a lower incidence of implant complications. This, however, was investigated in vitro and does not necessarily mean to be the case in vivo, as well. Thus, the two major aspects of this study were to compare the speed of bone fusion and the rate of implant complications using either rigid- or dynamic plates. The study design is prospective, randomized, controlled, and multi-centric, having been approved by respective ethic committees of all participating sites. One hundred and thirty-two patients were included in this study and randomly assigned to one of the two groups, both undergoing routine level-1- or level-2 anterior cervical discectomy with autograft fusion receiving either a dynamic plate with screws being locked in ap - position (ABC, Aesculap, Germany), or a rigid plate (CSLP, Synthes, Switzerland). Segmental mobility and implant complications were compared after 3- and 6 months, respectively. All measurements were performed by an independent radiologist. Mobility results after 6 months were available for 77 patients (43 ABC/34 CSLP). Mean segmental mobility for the ABC group was 1.7 mm at the time of discharge, 1.4 mm after 3 months, and 0.8 mm after 6 months. For the CSLP- group the measurements were 1.0, 1.8, and 1.7 mm, respectively. The differences of mean segmental mobility were statistically significant between both groups after 6 months (P = 0.02). Four patients of the CSLP-group demonstrated surgical hardware complications, whereas no implant complications were observed within the ABC-group (P = 0.0375). Dynamic plate designs provided a faster fusion of the cervical spine compared with rigid plate designs after prior spinal surgery. Moreover, the rate of implant complications was lower within the group of patients receiving a dynamic plate. These interim results refer to a follow-up period of 6 months after prior spinal surgery. Further investigations will be performed 2 years postoperatively. Anterior cervical discectomy and fusion (ACDF) using bone graft or a cage with plate fixation is an accepted technique for the treatment of symptomatic degenerative disc disease. It is, however, debatable whether a plate is really necessary to increase the progress of fusion. Thus, the aim of this randomized and controlled prospective study was to evaluate whether ACDF with a cage and anterior plate fixation results in a greater progress of fusion compared with ACDF using a stand-alone cage.
                37 candidates for ACDF were treated either with a stand-alone cage (study group) or with a cage+plate fixation (control group). 19 patients were randomized to be stabilized with a stand-alone cage and 18 patients were treated with a cage and additional anterior plate fixation. The progress of cervical fusion over time was compared by radiostereometric analysis (RSA). Follow-up examinations pre- and postoperatively were done using the Visual Analogue Scale (VAS) for neck and arm pain. Radiographic assessment of fusion using an RSA-control was done after one, six and twelve weeks, as well as after six months, and one and two years postoperatively. Mann-Whitney test for unpaired values was used to determine the statistical differences in residual intervertebral motion.
                Three-dimensional analysis of segmental motion (left-right, cranio-caudal, and posterior-anterior) did not reveal any statistical differences between both groups at any examination time postoperatively ( P>0.05). The VAS score did not differ between the groups ( P>0.05).
                Anterior plate fixation did not demonstrate an improvement in the progress of fusion in one-level ACDF. A prospective randomized trial with independent clinical and radiographic outcome review of patients receiving either hydroxyapatite or tricortical iliac crest graft for cervical interbody fusion was conducted.
                To determine whether coralline-derived hydroxyapatite is a suitable bone graft substitute in cervical interbody fusion.
                Tricortical iliac crest bone is the "gold standard" graft material for cervical interbody fusion. Various bone substitutes have been used for this procedure to avoid potential donor site morbidity. ProOsteon 200 is a coralline-derived hydroxyapatite product, the use of which remains unclear for cervical interbody fusion.
                In this study, 29 patients undergoing anterior cervical fusion and plating were randomized to receive either ProOsteon 200 or iliac crest grafts. The SF-36 and Oswestry Disability Index were used to measure clinical outcome. Postoperative radiographs were analyzed for graft fragmentation, loss of height, angular alignment, and hardware failure to assess structural integrity of the graft material. Plain radiographs and computed tomography scans were used to evaluate fusion.
                Both the ProOsteon 200 and iliac crest groups demonstrated significant improvement in clinical outcome scores. There was no significant difference in clinical outcome or fusion rates between the two groups. Graft fragmentation occurred in 89% of the hydroxyapatite grafts and 11% of the autografts (P = 0.001). Significant graft settling occurred in 50% of the hydroxyapatite grafts, as compared with 11% of the autografts (P = 0. 009). One patient in the ProOsteon 200 group required revision surgery for graft failure.
                ProOsteon 200 does not possess adequate structural integrity to resist axial loading and maintain disc height or segmental lordosis during cervical interbody fusion. The need for interbody fusion or stabilization after anterior cervical microdiscectomy is still debated. The objectives of this prospective randomized study were 1) to examine whether combined interbody fusion and stabilization is more beneficial than microdiscectomy only (MDO) and 2) if fusion is found to be more beneficial than MDO, to determine which is the best method of fusion by comparing the results achieved using autologous bone graft (ABG), polymethylmethacrylate (PMMA) interposition, and threaded titanium cage (TTC).
                A total of 125 patients with a single-level cervical disc disease were included in this prospective study. All patients were randomized and assigned to one of the four following groups: Group 1 (33 patients), MDO; Group 2 (30 patients), microdiscectomy followed by ABG; Group 3 (26 patients), microdiscectomy followed by injection of PMMA; and Group 4 (36 patients), microdiscectomy followed by placement of a TTC. Clinical outcome according to Odom criteria was summarized as 1) excellent and good or 2) satisfactory and poor. One-year follow-up examination was performed in 123 patients. Patients in the TTC group experienced a significantly better outcome 6 months after surgery (92% excellent and good results) compared with those in the MDO and ABG groups (72.7 and 66.6% excellent and good results, respectively). Twelve months after surgery there was still a significant difference in outcomes between the TTC group (94.4% excellent and good results) and the MDO group (75.5% excellent and good results). Outcome in patients treated with PMMA was comparable with that in those treated with TCC after 6 (91.6%) and 12 months (87.5%), but no segmental fusion was achieved. Differences compared with MDO and ABG were, however, not significant, which may be related to the smaller number of patients in the PMMA group.
                Interbody cage-assisted fusion yields a significantly better short- and intermediate-term outcome than MDO in terms of return to work, radicular pain, Odom criteria, and earlier fusion. In addition, the advantages of interbody cages over ABG fusion included better results in terms of return to work, Odom criteria, and earlier fusion after 6 months. These results suggest that interbody cage-assisted fusion is a promising therapeutic option in patients with single-level disc disease. Polymethylmethacrylate seems to be a good alternative to interbody cage fusion but is hindered by the absence of immediate fusion. A prospective, randomized, controlled study was carried out to compare the radiological and clinical outcomes after anterior cervical decompression and fusion (ACDF) with Trabecular Metal (TM) to the traditional Smith-Robinson (SR) procedure with autograft. The clinical results of cervical fusion with autograft from the iliac crest are typically satisfactory, but implications from the donor site are frequently reported. Alternative materials for cervical body interfusion have shown lower fusion rates. Trabecular Metal is a porous tantalum biomaterial with structure and mechanical properties similar to that of trabecular bone and with proven osteoconductivity. As much as 80 consecutive patients planned for ACDF were randomized for fusion with either TM or tricortical autograft from the iliac crest (SR) after discectomy and decompression. Digitized plain radiographic images of 78 (98%) patients were obtained preoperatively and at 2-year follow-up and were subsequently evaluated by two senior radiologists. Fusion/non-fusion was classified by visual evaluation of the A-P and lateral views in forced flexion/extension of the cervical spine and by measuring the mobility between the fused vertebrae. MRI of 20 TM cases at 2 years was successfully used to assess the decompression of the neural structures, but was not helpful in determining fusion/non-fusion. Pain intensity in the neck, arms and pelvis/hip were rated by patients on a visual analog scale (VAS) and neck function was rated using the Neck Disability Index (NDI) the day before surgery and 4, 12 and 24 months postoperatively. Follow-ups at 12 and 24 months were performed by an unbiased observer, when patients also assessed their global outcome. Fusion rate in the SR group was 92%, and in the TM group 69% (P < 0.05). The accuracy of the measurements was calculated to be 2.4 degrees . Operating time was shorter for fusion with TM compared with autograft; mean times were 100 min (SD 18) and 123 min (SD 23), respectively (P = 0.001). The patients' global assessments of their neck and arm symptoms 2 years postoperatively for the TM group were rated as 79% much better or better after fusion with TM and 75% using autograft. Pain scores and NDI scores were significantly improved in both groups when compared with baseline at all follow-ups, except for neck pain at 1 year for the TM group. There was no statistically significant difference in clinical outcomes between fusion techniques or between patients who appeared radiologically fused or non-fused. There was no difference in pelvic/hip pain between patients operated on with or without autograft. In our study, Trabecular Metal showed a lower fusion rate than the Smith-Robinson technique with autograft after single-level anterior cervical fusion without plating. There was no difference in clinical outcomes between the groups. The operative time was shorter with Trabecular Metal implants. One hundred fifteen patients having symptomatic cervical disc disease were recruited prospectively for this study. They were allocated randomly for either autologous iliac bone graft or biocompatible osteoconductive polymer implants. Both groups were compared clinically and radiologically.
                Complications, long-term clinical and radiologic outcome, and hospital stay were compared to determine if biocompatible osteoconductive polymer was an improvement on iliac bone graft in terms of reduced donor site pain and shortened hospital stay.
                Donor site morbidity is a significant problem in anterior cervical fusion. Hospital stay is another factor in the recent era of cost consciousness. Biocompatible osteoconductive polymer has been used in many centers as a biodegradable implant to circumvent these problems.
                Smith-Robinson technique was used in 74 patients, and Cloward technique was used in 41 patients. Sixty-five patients had biocompatible osteoconductive polymer implants, and 50 patients had iliac bone graft. Patients were followed-up routinely in the outpatient clinic where pain visual analogue scale and Odom's criteria were used for outcome evaluation. Plain radiography, computed tomography scan, and magnetic resonance imaging were used for radiologic evaluation.
                The mean hospital stay was 4.8 days for those with iliac bone graft and 4.7 days for those with biocompatible osteoconductive polymer. Clinical outcome was identical in both groups. The incidence of partial graft protrusion and postoperative intersegmental kyphosis was statistically higher with iliac bone graft (P = 0.018 and P = 0.02, respectively). "Sclerosis" started to form around biocompatible osteoconductive polymer like a "halo" at 2 months. It increased with time, and sometimes was associated with new osteophyte formation; however, there was no biocompatible osteoconductive polymer incorporation or biodegradation
                Biocompatible osteoconductive polymer acts as a good "spacer" that reduces graft collapse and intersegmental kyphosis. However, it did not show any radiologic evidence of biodegradation or incorporation during the follow-up period of 24 months. Anterior cervical decompression and fusion (ACDF) is the standard for cervical discectomies. With the full-endoscopic anterior cervical discectomy (FACD) a minimally invasive procedure is available. The objective of this prospective, randomised, controlled study was to compare the results of FACD with those of ACDF in mediolateral soft disc herniations. A total of 103 patients with ACDF or FACD were followed up for two years. In addition to general parameters specific measuring instruments were used. Postoperatively 85.9% of the patients no longer had arm pain, and 10.1% had occasional pain. There were no significant clinical differences between the decompression with or without fusion. The full-endoscopic technique afforded advantages in operation technique, rehabilitation and soft tissue injury. The recorded results show that FACD is a sufficient and safe alternative to conventional procedures when the indication criteria are fulfilled. At the same time, it offers the advantages of a minimally invasive intervention. Anterior cervical microdiscectomy (ACD) is commonly applied in the surgical treatment of cervical disc herniation. However, following discectomy procedure to perform a fusion process is still controversial. Therefore, a controlled, multicentric, prospective, randomized study was designed.
                Totally 20 patients were operated. Eleven patients were operated with applying simple anterior microdiscectomy technique. Nine patients were operated via ACD and fusion with a semirigid plate technique. Preoperative and postoperative [immediate; postoperative first day and postoperative 1 y (mean 13.95 mo)] computed tomography studies and plain x-rays were obtained. The cervical disc and bilateral neural foramen heights of the operated level and adjacent segments were calculated. Pain assessment was performed using visual analog pain scale. Mann-Whitney statistical analysis method was applied to compare the outcomes for both groups.
                Satisfactory result was achieved in both groups. The pain scores for major complaint (arm pain) were decreased significantly in all patients after surgery regardless of the type of technique applied. The improvement in neck pain scores was significant only in patients who were treated with fusion procedure. There were no significant changes in disc height and neural foramen height measurements for both groups in adjacent levels in immediate and 1-year postoperative periods. The patients who were operated with simple ACD technique showed no significant decrease at postoperative first day in disc height and neural foramen height. However, the 1-year postoperative radiologic studies showed a significant decrease in disc height and neural foramen dimensions compared with preoperative values. The patients who were treated with fusion process showed a significant increase in disc height and nonsignificant increase in neural foramen heights at immediate postoperative study. However, with time, all dimensions showed significant decrease compared with preoperative values.
                ACD technique offers satisfactory outcome regardless of whether fusion process is applied or not. Fusion with semirigid plate offers an advantage at operated level in immediate postoperative period in regard of disc height and neural foramen height. However, semirigid anterior plates by definition do not stop subsidence and the advantage that is offered by this technique is not persistent. On the other hand, to apply fusion process with semirigid plate system offers significantly less narrowing in disc height compared with simple ACD technique. A variety of bone graft substitutes, interbody cages, and anterior plates have been used in cervical interbody fusion, but no controlled study was conducted on the clinical performance of beta-tricalcium phosphate (beta-TCP) and the effect of supplemented anterior plate fixation. The objective of this prospective, randomized clinical study was to evaluate the effectiveness of implanting interbody fusion cage containing beta-TCP for the treatment of cervical radiculopathy and/or myelopathy, and the fusion rates and outcomes in patients with or without randomly assigned plate fixation. Sixty-two patients with cervical radiculopathy and/or myelopathy due to soft disc herniation or spondylosis were treated with one- or two-level discectomy and fusion with interbody cages containing beta-TCP. They were randomly assigned to receive supplemented anterior plate (n = 33) or not (n = 29). The patients were followed up for 2 years postoperatively. The radiological and clinical outcomes were assessed during a 2-year follow-up. The results showed that the fusion rate (75.0%) 3 months after surgery in patients treated without anterior cervical plating was significantly lower than that (97.9%) with plate fixation (P < 0.05), but successful bone fusion was achieved in all patients of both groups at 6-month follow-up assessment. Patients treated without anterior plate fixation had 11 of 52 (19.2%) cage subsidence at last follow-up. No difference (P > 0.05) was found regarding improvement in spinal curvature as well as neck and arm pain, and recovery rate of JOA score at all time intervals between the two groups. Based on the findings of this study, interbody fusion cage containing beta-TCP following one- or two-level discectomy proved to be an effective treatment for cervical spondylotic radiculopathy and/or myelopathy. Supplemented anterior plate fixation can promote interbody fusion and prevent cage subsidence but do not improve the 2-year outcome when compared with those treated without anterior plate fixation. Conflicting views exist according to the individual philosophy about various plate designs that can be used in anterior cervical discectomy and fusion (ACDF) to achieve clinical and radiological improvement within shortest time period. No prospective randomized study has ever been conducted to clarify the relationship between clinical outcomes, fusion rates, and the choice of plate (static vs. dynamic design).
                To compare the clinical and radiological outcomes of patients treated with one-level or multiple levels ACDF using cervical plates of dynamic (slotted-holes) versus static (fixed-holes) design.
                Single masked, prospective, randomized study.
                Over a 4-year period, 66 patients (M:F=37:29) had ACDF using either dynamic (n=33) or static (n=33) plates for intractable radiculopathy as the result of degenerative cervical spine disease. Overall, 28 patients had single-level fusion and 38 had two or three levels fused.
                Visual Analogue Pain scores (VASs), Neck Disability Index (NDI), and radiological criteria of established fusion.
                The qualifying subjects were randomized to receive ACDF using either fixed-holes (static) or the slotted-holes (dynamic) anterior cervical plates. Clinical and radiographic data were collected and analyzed. Paired-sample t test was used to correlate clinical and radiological outcomes and General Linear Model Analysis of Variance (GLM ANOVA) with repeated measures was used to detect outcome differences between the two groups for single and multiple fusions.
                At a mean follow-up of 16 months (range, 12-24), 49 patients (73.7%) had clinical success and 56 (85%) showed radiological fusion. Although clinical success was a predictor of fusion (p=.043), the reverse was not true (p=.61). In single-level fusion, no statistical difference of outcome was observed between the two groups but multilevel fusions with dynamic plate showed significantly lower VAS and NDI than those with static plates (p=.050).
                Although clinical improvement is a good predictor of successful ACDF, radiological evidence of fusion alone is not reliable as a parameter of success. The design of plate does not affect the outcomes in single-level fusions but statistics indicate that multiple-level fusions may have better clinical outcome when a dynamic plate design is used. Fifty-one patients with symptomatic cervical disc disease refractory to conservative management were allocated at random to one of two treatment groups. The standard anterior approach devised by Cloward was used for 25 patients, and radical discectomy and foraminotomy for the other 26. All patients were followed for 6 months or longer with interview, physical examination, and radiographic evaluation. There was no difference in the success rate between the two groups. The large majority (92%) of patients in both groups were pleased with results of their operation. Because of technical factors related to operative exposure of the spinal canal and nerve roots, we prefer the Cloward procedure for patients symptomatic from advanced spondylosis and reserve discectomy without bone graft insertion for those with minimal spondylosis or soft disc herniations. In a double-blind randomized study, platelet concentrate was used to treat 50 patients who underwent anterior cervical fusion with allograft bone and internal fixation, predominantly for degenerative disc disease or soft herniated cervical disc. The goal in this study was to compare the outcomes in patients treated with and without the platelet gel.
                Patients were assessed radiographically at 6, 12, and 52 weeks and at 2 years if needed. Clinically, patients were evaluated with the visual analog scale, Neck Disability Index, Short Form-36, and a modified Prolo Scale.
                Follow-up included 90% of the patients at 1 year and 84% at 2 years. The overall fusion rate was 84%.
                Whereas patients with degenerative discs treated with platelet gel demonstrated early fusion at the 12-week follow-up interval, no consistent early fusion was obtained with the use of the platelet gel preparation in patients with a soft disc herniation. A prospective randomized controlled study was carried out.
                To determine the effectiveness and safety of a tantalum implant in achieving anterior cervical fusion following 1-level discectomy as treatment of degenerative cervical disc disease with radiculopathy.
                The gold standard for the treatment of degenerative cervical disc disease could not be already identified. The morbidity of autologous graft and plating, and the doubt about the mechanical efficacy of plate fixation and the clinical benefits in 1-level fusion have promoted the use of other constructs.
                Sixty-one patients were randomized to anterior cervical discectomy and fusion with interbody implant of tantalum (n = 28) or by means of autologous iliac bone graft and plating (n = 33). Fusion rate and segmental height and alignment were blind assessed by radiographs by 2 independent reviewers. Clinical status was evaluated using pain visual analogue scale, the Neck Disability Index, and the Zung Depression Scale. Patient's subjective satisfaction was recorded. Complications and operative parameters were also taken into account.
                With an endpoint of 24 months, radiologic and clinical outcomes were similar for both treatments without significant difference. The safety of fusion with tantalum implant was obvious, based on the analysis of complications. Complication rate was considerably higher for the autologous graft plus plating procedure than for implant tantalum (P < 0.005).
                The efficacy to achieve fusion after 1-level anterior cervical discectomy, with a good radiologic and clinical outcome, using tantalum implant is equivalent to that of autologous graft and anterior plate, being safer as avoids donor-site graft harvesting and plating complications. A prospective randomized clinical study.
                To compare 2 surgical methods in the treatment of cervical radiculopathy caused by hard or soft disc herniation; namely, simple discectomy versus discectomy with an additional interbody fusion with a Ray titanium cage.
                Although an interbody fusion after anterior decompressive surgery for hard or soft disc herniation is widely accepted, there is no scientific evidence that convincingly demonstrates that insertion of graft material for interbody fusion is necessary after discectomy and decompression of the nervous elements have been performed. To date, no randomized studies have compared simple discectomy with discectomy followed by an interbody fusion with a titanium cage.
                Eighty-six patients with symptoms of nerve root compression at 1 level were randomly allocated to either discectomy followed by fusion with a Ray titanium cage (40 patients) or to discectomy alone (46 patients). Clinical and radiologic follow-up was performed 3, 12, and 24 months after surgery.
                There was no statistically significant difference between the 2 groups concerning self-reported satisfaction or severity of pain in the neck and arm. Two years after the operation, 86.1% of the patients treated with cage stated a good outcome versus 76.7% in the discectomy group (P = 0.44). The rate of fusion was 83.3% in the cage group versus 81.0% in the discectomy group (P = 0.30). Furthermore, after 2 years, also the rates of new adjacent disc degeneration or spondylosis were the same in both groups.
                This study showed no statistically significant difference between simple discectomy and discectomy followed by interbody fusion with a titanium cage in the surgical treatment of cervical radiculopathy caused by disc herniation. A primary object with a fusion cage is avoidance of graft collapse with subsequent subsidence and malalignment of the cervical spine that is observed after bone grafting alone. No randomized studies exist that demonstrate the difference between these two methods in terms of graft subsidence and angulation of the fused segment. The size of the study population was calculated to be 24 patients to reach a significant difference at the 95% CI level. Patients with one-level cervical radiculopathy scheduled for surgery were randomized to anterior discectomy and fusion (ACDF) with autograft or to fusion cage, both without plate fixation. Tantalum markers were inserted in the two adjacent vertebrae at the end of surgery. Radiostereometry was performed immediately postoperatively and at regular intervals for 2 years. Questionnaires were used to evaluate the clinical outcome and an unbiased observer graded the outcome after 2 years. No significant differences were found between the two methods after 2 years in regard of narrowing of the disc space (mean 1.7 and 1.4 mm, respectively) or deformation of the fused segment into flexion (mean 7.7 degrees and 4.6 degrees , respectively). Patients in the cage group had a significantly better clinical outcome. The findings of subsidence and flexion deformation of the fused segment after 2 years seem to be of no clinical importance after one-level cervical disc surgery. However, in multi-level surgery using the same methods, an additive effect of the deformations of the fused segments may affect the clinical outcome. The need for interbody fusion after anterior cervical discectomy for radiculopathy remains controversial. The purpose of this study was to assess clinical and radiographic outcomes in patients with cervical radiculopathy after discectomy without fusion (ACD), discectomy with intervertebral fusion (ACDF), and discectomy with intervertebral fusion and instrumentation (ACDFI).
                Forty-two consecutive patients with cervical radiculopathy who failed medical management were randomized to one of three treatment groups: ACD, ACDF, or ACDFI. Indices including symptoms, work status, Short Form-36, McGill pain scores, and anteroposterior/lateral flexion/extension x-rays were obtained preoperatively and during the follow-up period.
                There were no inter-group differences observed during the 2-year follow-up period with respect to neck pain, interscapular pain, or arm pain (P > 0.05). Short Form-36 scores demonstrated a dramatic postoperative improvement followed by further gradual improvement in both physical and mental components as well as other subscale scores in all groups during the follow-up period (P < 0.05). Fusion occurred in 67% of the ACD patients compared with 93% of the ACDF patients and 100% of the ACDFI patients (P < 0.05). Segmental kyphosis was noted in 75% of the ACD patients postoperatively compared with 17% preoperatively. There was no change in sagittal balance in the ACDF or ACDFI groups (P > 0.05).
                Patient selection and surgical decompression remain the key to achieving desirable clinical outcomes after cervical discectomy for radiculopathy. Within a 2-year follow-up period, the technique of reconstruction plays no role in clinical results. However, ACD alone results in segmental kyphosis compared with ACDF and ACDFI. A prospective randomized study was conducted.
                To determine whether the use of a cervical carbon fiber intervertebral fusion cage improves the outcome of anterior cervical decompression and fusion, as compared with the Cloward procedure using autograft.
                Despite the theoretical advantages of using intervertebral cages, including reduced donor site morbidity and prevention of graft collapse, an improved clinical outcome has not yet been documented.
                For this study, 103 patients were randomized to anterior cervical decompression and fusion with a carbon fiber intervertebral fusion cage (n = 52) or the Cloward procedure (n = 51). An independent observer quantified pain and functional disability. Fusion rate, segmental kyphosis, and disc height were assessed by radiographs.
                During a mean follow-up period of 36 months (range, 24-72 months) for 89 patients (86%), the pain and disability were similar for both treatments. Postoperative donor site pain was significantly less in the carbon fiber intervertebral fusion cage group. The fusion rate was 86% in the Cloward procedure group and 62% in the carbon fiber intervertebral fusion cage group (P < 0.05). In the latter group, patients with pseudarthrosis reported more severe pain than fused patients (51 and 33 visual analog scores, respectively), but the difference was not significant. The segmental kyphosis was less and the disc height increased in the carbon fiber intervertebral fusion cage group, as compared with the Cloward procedure group. Disc height was not correlated with outcome. Segmental kyphosis showed a weak (r = -0.3) but significant (P < 0.05) correlation with improvement of the Cervical Spine Functional Score, but not with other outcome variables.
                Except for reduced donor site pain, the clinical outcome for the carbon fiber intervertebral fusion cage is the same as for the Cloward procedure. Use of the cage results in a more lordotic alignment and an increased disc height, but in a higher pseudarthrosis rate than use of the Cloward procedure. A prospective, randomized, pilot clinical trial compared recombinant human bone morphogenetic protein-2 (rhBMP-2) with iliac crest autograft bone for the treatment of human cervical disc disease.
                To examine the safety and effectiveness of using INFUSE Bone Graft (rhBMP-2 applied to an absorbable collagen sponge), as compared with an autogenous iliac crest bone graft placed inside the CORNERSTONE-SR fibular allograft, in anterior cervical discectomy and interbody fusion.
                Recombinant human bone morphogenetic protein-2 is an osteoinductive protein that induces a reliable fusion in the lumbar spine, but it has not been studied in patients with degenerative cervical disc disease.
                For this study, 33 patients with degenerative cervical disc disease were randomly assigned to investigational or control groups. The investigational group received a fibular allograft (CORNERSTONE-SR Allograft Ring) with an rhBMP-2-laden collagen carrier inside the graft along with an ATLANTIS anterior cervical plate. The control group received a fibular allograft with cancellous iliac crest autograft placed inside it, along with an ATLANTIS anterior cervical plate. The patients underwent plain radiographs at 6 weeks, then at 3, 6, 12, and 24 months, and CT scans at 3 and 6 months after surgery. They also completed general health profiles and self-evaluation scales. Adverse events were evaluated for severity, duration, association with the implant, and the need for a second surgical procedure.
                All the patients evaluated had solid fusions 6, 12, and 24 months after surgery. There were no device-related adverse events. At 24 months, the investigational group had mean improvement superior to that of the control group in neck disability and arm pain scores (P < 0.03 each).
                This pilot study demonstrates the feasibility of using rhBMP-2 safely and effectively in the cervical spine. In this study, 43 patients scheduled for a single-level cervical Cloward procedure for disc disease were randomized prospectively to fusion with autograft, allograft, or xenograft.
                To outline any differences in fusion over time in terms of final mobility and clinical outcome between the three bone grafts.
                Fusion is used to relieve pain from a spinal segment. The bovine xenograft gives a fibrous fusion in contrast to the solid bone fusion obtained with autograft from the iliac crest, but no definite differences in clinical outcome have been shown previously after surgery at a single level.
                By use of radiostereometric analysis, 33 patients were observed after 6, 12, and 24 to 50 (mean, 37) months. All 43 patients underwent clinical examination, which involved pain rating before and after surgery, with a final follow-up assessment by an unbiased observer.
                Mobility could be demonstrated in 9 patients after 1 year and in 6 patients at the final follow-up assessment, without pain, and with no difference between bone grafts. The patients who received autograft experienced a greater reduction of pain than the patients treated with xenograft.
                Most of the patients healed with a rigid fusion no matter which graft was used, but the healing process took longer than expected. The clinical results were not influenced by whether mobility could be demonstrated. There was a tendency toward better clinical results in the patients treated with autograft. A prospective randomized trial with assessment of treatment results by an independent observer and by patient questionnaire.
                This study evaluated whether implantation of polymethylmethacrylate after anterior cervical discectomy improved clinical results and whether polymethylmethacrylate provided a solid bony union with preservation of anatomical relations of the cervical spine.
                Discectomy without fusion disturbs anatomical relations of the cervical spine. Use of an autologous bone graft frequently causes donor-site complications. Therefore, synthetic materials such as polymethylmethacrylate have been used instead of bone to obtain spinal fusion. Whether these implants improve the clinical results of anterior discectomy is unknown. In addition, the radiological follow-up of discectomy with polymethylmethacrylate has hardly been investigated.
                Between April, 1986, and April, 1990, all patients with radiologically proven cervical disc pathology and a radicular syndrome were eligible for this study. The primary endpoint of the study was the clinical result after 2 years. Assessment of the result was rated both by an independent observer using Odom's criteria and by the patient using a written questionnaire. Before surgery and during follow-up, radiographs were obtained.
                Two patients died during follow up. A good result was obtained in 28 of 42 patients (70%) treated with polymethylmethacrylate and in 30 of 39 patients (77%) of patients treated with discectomy only. Pre-operative neck pain subsided earlier if polymethylmethacrylate was used, but the difference was temporary and clinically insignificant. The use of polymethylmethacrylate resulted in a significant lower bony union rate. Polymethylmethacrylate frequently migrated into adjacent vertebrae.
                No relevant clinical differences between treatments were found. The radiological results of anterior discectomy with polymethylmethacrylate were inferior to those of discectomy only. Based on these results, the use of polymethylmethacrylate to obtain fusion after anterior discectomy is not recommended. The authors conducted a prospective and randomized study in 44 consecutive patients requiring cervical interbody fusion following anterior cervical discectomy to compare the efficacy of heterologous threaded cylindrical bone (Unilab Surgibone) versus titanium implant (Bak-C; Spine-Tech, Minneapolis ). The patients were evaluated between two and five years postoperatively and the objectives of the study were to assess the potential differences in implant shifting, interespace collapse, angulation, maintenance of cervical alignment and lordosis, and clinical and radiographic fusion success rates between the two fusion substrates. Clinical results were satisfactory with both types of implant. However the threaded cylindrical titanium implant was found to be superior to the heterologous threaded cylindrical bone as an interbody substrate after single -and multiple- level anterior cervical decompression procedures with respect to maintenance of cervical interspace height, interspace angulation and radiographic fusion success rates. After 40 years of experience with anterior cervical operations, whether to fuse is still controversial. This study seeks to answer this question.
                In this prospective randomized study, we operated on 91 patients with single-level cervical root compression using three different methods: 1) discectomy without fusion, 2) fusion with autologous bone graft, and 3) fusion with autologous bone graft plus plating.
                After 4 years of follow-up, the radiological results indicated that complete bony union was achieved in almost all cases. A slight kyphosis developed in 62.5% of the patients who had undergone discectomy, 40% of the patients who had undergone fusion, and 44% of the patients who had undergone fusion plus plating (not significant). The clinical outcomes were good for 76% of the patients who had undergone discectomy, 82% who had undergone fusion, and 73% who had undergone fusion plus plating. The outcomes were poor in 0, 4, and 4%, respectively (not significant).
                According to this study, satisfactory results can be achieved by performing simple discectomy to treat single-level cervical root compressive disease.
When the working mechanism for pain relief and functional improvement is fusion of the motion segment, there is low quality evidence that iliac crest autograft appears to be the better technique. When ignoring fusion rates and looking at complication rates, a cage has a weak evidence base over iliac crest autograft, but not over discectomy alone. Future research should compare additional instrumentation such as screws, plates, and cages against discectomy with or without autograft.