Cervical spine fusion have gained interest in the literature since these procedures are now ever more frequently being performed in an outpatient setting with few complications and acceptable results. The purpose of this study was to assess the rate of blood transfusion after cervical fusion surgery, and its effect, if any on complication rates. The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was used to identify patients that underwent cervical fusion surgery from 2010 to 2013. Univariate and multivariate regression analysis was used to determine post-operative complications associated with transfusion and cervical fusion. We identified 11,588 patients who had cervical spine fusion between 2010 and 2013. The overall rate of transfusion was found to be 1.47%. All transfused patients were found to have increased risk of: venous thromboembolism (TBE) (OR 3.19, CI: 1.16–8.77), myocardial infarction (MI) (OR 9.12, CI: 2.53–32.8), increased length of stay (LOS) (OR 28.03, CI: 14.28–55.01) and mortality (OR 4.14, CI: 1.44–11.93). Single level fusion had increased risk of: TBE (OR 3.37, CI: 1.01–11.33), MI (OR 10.5, CI: 1.88–59.89), and LOS (OR 14.79, CI: 8.2–26.67). Multilevel fusion had increased risk of: TBE (OR 5.64, CI: 1.15–27.6), surgical site infection (OR 16.29, CI: 3.34–79.49), MI (OR 10.84, CI: 2.01–58.55), LOS (OR 26.56, CI: 11.8–59.78) and mortality (OR 10.24, CI: 2.45–42.71). ACDF surgery had an increased risk of: TBE (OR 4.87, CI: 1.04–22.82), surgical site infection (OR 9.73, CI: 2.14–44.1), MI (OR 9.88, CI: 1.87–52.2), LOS (OR 28.34, CI: 13.79–58.21) and mortality (OR 6.3, CI: 1.76–22.48). Posterior fusion surgery had increased risk of: MI (OR 10.45, CI: 1.42–77.12) and LOS (OR 4.42, CI: 2.68–7.29). Our results demonstrate that although cervical fusions can be done as outpatient procedures special precautions and investigations should be done for patients who receive transfusion after cervical fusion surgery. These patients are demonstrated to have higher rate of MI, DVT, wound infection and mortality when compared to those who do not receive transfusion

In multilevel posterior cervical instrumented fusions, extending the fusion across the cervico-thoracic junction at T1 or T2 (CTJ) has been associated with decreased rate of re-operation and pseudarthrosis but with longer surgical time and increased blood loss. The impact on patient reported outcomes (PROs) remains unclear. The primary objective was to determine whether extending the fusion through the CTJ influenced PROs at 3 and 12 months after surgery. Secondary objectives were to compare the number of patients reaching the minimally clinically important difference (MCID) for the PROs and mJOA, operative time duration, intra-operative blood loss (IOBL), length of stay (LOS), discharge disposition, adverse events (AEs), re-operation within 12 months of the surgery, and patient satisfaction. This is a retrospective analysis of prospectively collected data from a multicenter observational cohort study of patients with degenerative cervical myelopathy. Patients who underwent a posterior instrumented fusion of 4 levels of greater (between C2-T2) between January 2015 and October 2020 with 12 months follow-up were included. PROS (NDI, EQ5D, SF-12 PCS and MCS, NRS arm and neck pain) and mJOA were compared using ANCOVA, adjusted for baseline differences. Patient demographics, comorbidities and surgical details were abstracted. Percentafe of patient reaching MCID for these outcomes was compared using chi-square test. Operative duration, IOBL, AEs, re-operation, discharge disposittion, LOS and satisfaction were compared using chi-square test for categorical variables and independent samples t-tests for continuous variables. A total of 206 patients were included in this study (105 patients not crossing the CTJ and 101 crossing the CTJ). Patients who underwent a construct extending through the CTJ were more likely to be female and had worse baseline EQ5D and NDI scores (p> 0.05). When adjusted for baseline difference, there was no statistically significant difference between the two groups for the PROs and mJOA at 3 and 12 months. Surgical duration was longer (p 0.05). Satisfaction with the surgery was high in both groups but significantly different at 12 months (80% versus 72%, p= 0.042 for the group not crossing the CTJ and the group crossing the CTJ, respectively). The percentage of patients reaching MCID for the NDI score was 55% in the non-crossing group versus 69% in the group extending through the CTJ (p= 0.06). Up to 12 months after the surgery, there was no statistically significant differences in PROs between posterior construct extended to or not extended to the upper thoracic spine. The adverse event profile did not differ significantly, but longer surgical time and blood loss were associated with construct extending across the CTJ

Introduction Locking plates are the most used devices for achieving anterior cervical spinal fusion and offer considerable advantages such as faster and easier implantation and fewer implant-related failures than older plate systems. Recently polyaxial locking screws were introduced to make the implantation of these plates even easier by facilitating the implantation of the screw in all directions. However polyaxial screws may have the disadvantage of losing the angular stability with subsequent failure of the plate. The aim of this study was the radiological follow up of the patients with polyaxial screw and to compare them with the conventional looking plates. Methods Patients underwent anterior cervical discectomy and fusion in which either ventral cervical locking plates or a polyaxial locking screw were used for indications including cervical spondylotic radiculopathy, disc herniation, trauma, and myelopathy. Patients underwent anterior cervical discectomy and interbody fusion and / or corpectomy. Preoperative and postoperative radiographic data included sagittal angle, translation, and settling of the graft. Results One hundred and forty patients were investigated (mean age of 49 years) with an average follow up period of 21.5 months (range from 4 to 50 months). All underwent anterior cervical plate fusion as a component of the surgical treatment for symptomatic degenerative cervical spinal disease (55%) or for vertebral destruction caused by trauma (45%).100 (71%) of patients were treated with a conventional locking plate and 29 % with a plate with polyaxial screw fixation. Besides plate fixation, 4 of the 140 patients had a combined ventrodorsal fusion. In 46 cases (25%), one or more vertebral bodies were removed and replaced with either iliac bone graft (two levels, 21% of all cases) or fibula strutgraft (4%). In the group with conventional locking plates no patient had to be revised, 3 showed a subluxation (up to 1/3 of the vertebral body diameter) and 2 screw back out posteriorly without clinical relevance. In the group with the plate with polyaxial screw fixation two patient had to be revised (posterior stabilisation) because of subluxation due to loss of angular stability of the screws and one patient developed subluxation of 1/3 of the vertebral body also due to loss of angular stability. Discussion The complication rate and the revision rate for anterior cervical discectomy and fusion with plates with and without polyaxial screw fixation were similarly low. Polyaxial screw may have the theoretical disadvantage of loosening with loss of the angular stability and subsequent failure necessitating revision

Aim: To determine the incidence of adjacent level osteophytes in patients who have had anterior cervical fusion using an anterior cervical plate as compared to those who are fused without an anterior cervical plate. Design: We retrospectively reviewed the lateral radiograms of sixty two patients who have had an anterior cervical fusion with a minimum follow up of twelve months. Materials and methods: We looked for the development of adjacent level osteophytes in these patients at their final follow up, which was generally at the time radiological fusion. There were 27 patients in the first group who had an anterior cervical plate used to fix the vertebrae in addition to the Cervios cage, while the 35 patients in the second group in whom only a Rabea cage was used for the fusion. The mean follow-up was 20.6 months (range 12–48). Results: 64.3% of the patients who had an anterior cervical plate developed adjacent level osteophytes while none of the patients who have had the fusion without the cage developed the osteophytes. Conclusion: We found the patients who had an anterior cervical interbody fusion using a plate had a significant risk of developing adjacent level osteophytes while this is not seen in patients who do not have the plate for the fixation

Objective: To determine if a porous, coralline-derived hydroxyapatite block (ProOsteon 500. TM. , Interpore, Irvine, CA) is a suitable substitute for tricortical iliac crest autograft in cervical interbody fusion. Design: A prospective randomised trial with two-year follow-up comparing clinical and radiographic outcomes in patients receiving either iliac crest or hydroxyapatite grafts in cervical interbody fusion. Subjects: Twenty-nine patients undergoing cervical fusion and anterior plating were randomised to receive either iliac crest (Group I) or hydroxyapatite (Group II) interbody grafts. Fourteen patients (19 grafts) in Group I and twelve patients (18 grafts) in Group II were available for final analysis. Both groups were similar with respect to age, sex, diagnosis and levels fused. Outcome Measures: The SF-36 and Oswestry Disability Index were used to measure clinical outcome. Post-op and final follow-up radiographs were analysed for graft fragmentation, loss of height, loss of angular alignment and hardware failure to assess structural integrity of the graft. Computed or plain tomography was used to evaluate fusion. Results: Groups I and II demonstrated improvement in preoperative scores for bodily pain (p=. 016 and. 016 respectively) and physical functioning (p=. 050 and. 016 respectively) at final follow-up. There was no significant difference in SF-36 and Oswestry scores between the two groups. Successful radiographic fusion was similar in both groups (79% in Group I and 76% in Group II). Graft fragmentation occurred in 89% of the hydroxyapatite grafts and 11% of the autografts (p=. 001). Greater than 2mm of graft height and 3° of segmental lordosis were lost in 55% of hydroxyapatite grafts vs. 11% of autografts (p=. 009). One patient in Group II and none in Group I required revision surgery for graft failure. The high rate of early radiographic failure in the hydroxyapatite grafts prompted suspension of further enrolment in the clinical trial. Conclusions: ProOsteon 500 coralline hydroxyapatite blocks do not possess adequate structural integrity to resist axial loading and maintain disc height or segmental lordosis during cervical interbody fusion

Background: Smaller versions of threaded lumbar cages were developed for cervical spine to obviate the need for allograft, iliac autograft use and to provide initial stability before fusion. Clinical trials of threaded cervical fusion cages have shown higher fusion rates and lower rates of graft-donor site complications. Study design/Aims: Prospective. Radiological and clinical outcomes of an age, sex and diagnosis matched patient population who underwent cervical fusion with (A) BAK/C cages filled with autograft reamings (Center-pulse Spine-tech Inc., Minneapolis, MN) (N=50) were compared with (B) Anterior cervical decompression and fusion (ACDF, N=50). Methods: Patients with symptomatic cervical discogenic radiculopathy were treated with either anterior cervical discectomy with uninstrumented bone-only fusion (ACDF) or BAK/C fusion cage(s). Independent radiographic assessment of fusion was made and patient-based outcome was assessed by a Short Form (SF)-36 Health Status Questionnaire. All patients had minimum follow up of at least 2 years. Results: Similar outcomes were noted for duration of surgery, hospital stay, improvements in neck pain and radicular pain in the affected limb, improvements in the SF-36 Physical Component subscale and Mental Component subscale, and the patients’ perception of overall surgical outcome. Symptom improvements were maintained at 2 years. Iliac crest harvesting was carried out as a standard procedure in all cases of ACDF whereas only 2 cases in BAK/C group required the same. Average operative time of 115 minutes and 145 minutes, blood loss of 110ml and 175ml and hospital stay of 1.5 and 3.5 days were noted for BAK/C and ACDF groups respectively. Successful fusion was achieved in 49 cases in BAK/C and 46 patients in ACDF group. None of the patients in the BAK/C group had reappearance of symptoms while 3 patients in ACDF group had developed symptomatic adjacent level disc disease. The complication rate for the ACDF group was 9% compared with an overall complication rate of 3% with BAK/C. Complications that necessitated a second operative procedure included. Graft dislodgement (N=3) and. Cage subsidence, both requiring re-operation in the form of ACDF with plate supplementation. Conclusions: These results demonstrate that outcomes after a cervical fusion procedure with a threaded cage are the same as those of a conventional uninstrumented bone-only anterior discectomy and fusion with a low risk of complications, less operative time and rare need for autogenous bone graft harvest

Introduction: Many different techniques exist for cervical interbody fusion after discectomy for soft and hard disc prolapses. The six years clinical and radiological results and the complications with a hydroxy-apatite ceramic (hac)-titanium implant are presented. Methods: Between 1/1995 and 12/2000 a titanium implant coated with hydroxy-apatite ceramic (hac) has been used for ventral cervical interbody fusion after discectomy in 596 patients with soft and hard disc prolapses who were operated in 670 levels. There were 333 male and 263 female patients. The mean age was 48.2 years. Clinical and radiological follow-up studies were performed direct after operation and 6 weeks, 6 months and 1 year later with an average follow-up of 14 months. The functional outcome was assessed according to Odom’s score, and the neurological outcome according to Kadoya’s score. Results: 93.2 % of the patients had a good to excellent result according to Odom’s score at follow-up whereas the neurological findings showed improvement in 71.2 % and no change in 27.9 %. After 6 months a good bony fusion could be seen around 91.2 % of the implants, and after 12 months around 95.7 %. 1,7 % of the operated patients developed a recurrent laryngeal nerve injury. Three implants broke into the adjacent vertebral endplate. Six patients had a second operation because of a dislocated cage. An adjacent segment pathology occured in 25 patients (4.2 %), of whom 15 patients had a second operation. Conclusions: With the use of this hydroxy-apatite ceramic (hac)-titanium implant we get an immediate postoperative stability of the cervical spine without the need of any orthosis. Harvesting of bone grafts is unnecessary which reduces operation time and eliminates donor site complications. The clinical and radiological are good and comparable to other fusion techniques in the cervical spine and the complication rate is low. If the number of adjacent segment pathology can be reduced with total disc arthroplasty has to be clarified in further comparable studies

Objective: To compare fusion time, Neck Disability scores, Pain scores, interbody height ratio and angulation, in cervical interbody fusion performed using tricortical graft or Ostapek cage, and a comparison between smokers and non smokers in fusion times. Design: A prospective randomised study. Subjects: Forty-two patients aged between 30 and 71years. Eighteen tricortical graft fusions, and 24 Ostapek cage fusions. Outcome measures: Grading of fusion from plain radiographs, Neck Disability Scores, Pain scores, interbody height ratio, and interbody angulation. Results: Mean time to good quality fusion was 4.66 months in the cage group and 5.97 months in the tri-cortical graft group with p< 0.5 and 5.00 months in the smoking population and 5.6 months in the non-smoking population with p< 0.5. At six months: mean percent NDI was 66.75 in the cage group and 50.67 in the tri-cortical graft group 0.1< p< 0.5;mean percent pain scores were 70.33 in the cage group and 34.50 in the tricortical graft group 0.02< p< 0.05; mean percent interbody height ratio was 98.68 in the cage group and 95.22 in the tricortical graft group 0.1< p< 0.5; mean change in interbody angle was 1.36° kyphosis in the cage group and 3.8° of kyphosis in the tricortical graft group 0.05< p< 0.1. Conclusions: Tricortical graft fusion gives equal results to cage fusion and is much cheaper

Study Design: Retrospective review of patients treated with mineralized collagen matrix hydrated with bone marrow in Anterior Cervical Decompression and Fusion (ACDF).

Background: Autologous iliac crest bone is regarded as the gold standard graft material for ACDF. Postoperative donor site pain and morbidity made us seek for an alternative while still providing a high rate of fusion as attained with autologous bone.

Methods: All patients who underwent ACDF between August 2005 and May 2007 by the senior author for cervical myelopathy or radiculopathy secondary to degenerative changes or trauma were included. Patients with an additional posterior fusion were excluded. A total of 80 patients were observed for 16 months (range, 6–27 months). In all patient we used a mineralized collagen matrix hydrated with bone marrow aspirate from the left iliac crest as our cage graft material. All patients had PEEK interbody cages and anterior cervical plating. Clinical and radiographic follow-up data were obtained. X-rays were reviewed by both the senior author and an independent radiologist. Clinical outcomes were measured as described by Robinson and with the Nurick scale.

Results: 31 single-level fusions, 35 two-level, 13 three-level and 1 four-level fusion were performed. No revision surgery was needed. One patient had a subsequent laminectomy for residual cord compression. All patients achieved a solid fusion. No symptomatic pseudoarthrosis was noted. No donor site morbidities were noted.

With a successful clinical result defined as an excellent or good outcome accompanied by significant pain relief, 73 patients had a successful clinical result.

Conclusion: The use of a mineralized collagen matrix in combination with bone marrow aspirate in ACDF eliminates iliac crest donor site morbidities while still providing high rates of fusion.

Anterior decompression and adequate spine fixation in patients with cervical radiculopathy and myelopathy are essential for functional restoration of cervical spine. In this study, we performed evaluation and comparative radiological assessment of several types of spinal implants in terms of bone block formation, sagittal alignment and effectiveness as a structural support.

Materials and Methods: From 1993 to 2003, 165 patients with radiculopathy and myelopathy due to degenerative disease of cervical spine were operated on. The age of patients was 32–74 years (mean age 57, 8). The interbody fusion was performed by several methods.

Group1. Autograft – 91 patients

Group 2. TiNi alloy cages – 74 patients.

Group 3. Varilift expandable cages without plate fixation – 22 patients

Group 4. Verilift cages with plate fixation – 8 patients

Group 5. Bone substitute spacer and plate fixation – 3 patients.

Results: In groups 1 and 2, the bone and bone-metal block was formed during the first 3–4 months after surgery in all patients. There were no cases of bone resorbtion around the TiNi cages or loosening of the device. In patients with one-level (15 patients) interbody fusion by Varilift cages (group 3); formation of the bone block during the same time period was observed in 14 out of 15 patients. In cases with two-level fusion (7 patients), the bone block at the second level was not formed for longer than 6 months. There were 7 cases of subsiding and segmental kyphosis. In group 4, we did not detect any cases of loosening, subsiding or segmental kyphosis. In group 5, no bone block formation was observed after 6 months despite plate fixation.

Conclusions: A high fusion rate was achieved after a single or multi-level discectomy and interbody fusion by autograft and TiNi cages, which did not subside due to their design and superelasticity and can therefore be used without plate fixation. Varilift cages were also very effective, but if used without plate fixation may be associated with subsiding effect. The use of the bone substitute spacer is questionable in cervical spine surgery. Cervical plate fixation is effective as a prophylactic measure against segmental kyphosis in all types of interbody fusion.

Objectives. Loss of motion following spine segment fusion results in increased strain in the adjacent motion segments. However, to date, studies on the biomechanics of the cervical spine have not assessed the role of coupled motions in the lumbar spine. Accordingly, we investigated the biomechanics of the cervical spine following cervical fusion and lumbar fusion during simulated whiplash using a whole-human finite element (FE) model to simulate coupled motions of the spine. Methods. A previously validated FE model of the human body in the driver-occupant position was used to investigate cervical hyperextension injury. The cervical spine was subjected to simulated whiplash exposure in accordance with Euro NCAP (the European New Car Assessment Programme) testing using the whole human FE model. The coupled motions between the cervical spine and lumbar spine were assessed by evaluating the biomechanical effects of simulated cervical fusion and lumbar fusion. Results. Peak anterior longitudinal ligament (ALL) strain ranged from 0.106 to 0.382 in a normal spine, and from 0.116 to 0.399 in a fused cervical spine. Strain increased from cranial to caudal levels. The mean strain increase in the motion segment immediately adjacent to the site of fusion from C2-C3 through C5-C6 was 26.1% and 50.8% following single- and two-level cervical fusion, respectively (p = 0.03, unpaired two-way t-test). Peak cervical strains following various lumbar-fusion procedures were 1.0% less than those seen in a healthy spine (p = 0.61, two-way ANOVA). Conclusion. Cervical arthrodesis increases peak ALL strain in the adjacent motion segments. C3-4 experiences greater changes in strain than C6-7. Lumbar fusion did not have a significant effect on cervical spine strain. Cite this article: H. Huang, R. W. Nightingale, A. B. C. Dang. Biomechanics of coupled motion in the cervical spine during simulated whiplash in patients with pre-existing cervical or lumbar spinal fusion: A Finite Element Study. Bone Joint Res 2018;7:28–35. DOI: 10.1302/2046-3758.71.BJR-2017-0100.R1

The aim of most new implants for cervical disc replacement is to maintain or restore function. The Dynamic Cervical Implant (DCI(tm), Paradigm Spine) aims at combining the advantages of the gold standard fusion technique with the motion preservation philosophy. DCI has a limited motion: it works like a shock absorbing spring and may help to slow down adjacent segment degeneration. Between 2007 and 2009 we selected 79 patients aged 32 to 73 years for treatment with DCI at either one or two levels (10 patients). Indications were radiculopathies (n=45), axial pain (n=4) or spondylotic spinal stenosis (n=30) with out chronic myelopathy. Patients are followed up at 3, 6, and 12 months after surgery. Disc surgery was performed at C3/C4 (n=2), C4/5 (n=6), at C5/6 (n=43), C6/7 (n=37) and at C7/T1 (n=1). In flexion/extension radiographs motion rapidly increased after surgery. However, 5 of 19 treated levels were fused (seen at 6 or 12 months). After implant footprint was changed and larger sizes were provided only 2 of 67 segments fused. Still 96% of the patients rated their clinical result as excellent or good. There were no implant related complications or revision surgery. Disc replacement with DCI is a new strategy that is positioned in between anterior cervical fusion and disc prosthesis. Clinical results are as good as in anterior cervical fusion. Adjacent segment protection must be judged in future follow-ups. We were able to show that the change of implant footprint has significantly reduced fusion rate

To provide short- term follow-up data on the surgical success and patient outcome following early anterior cervical fusion in this particular type of injury. A prospective study of 10 consecutive patients. Stage I compressive extension injury of the cervical spine, as described by Allen and Ferguson, is not always a stable injury. The combined unilateral failure of the posterior structures under compression together with failure of the anterior structure under tension will lead to a rotationally unstable segment. Various treatment options are available including halo vest immobilization, posterior stabilization with plating and anterior fusion and plating. 10 consecutive patients diagnosed with stage I compressive extension injury (fracture subluxation of the cervical spine). All subjects presented with a neurological deficit and vertebral subluxation. All patients were investigated with CT scan of the involved segment; in addition 2 patients had MRI scans. The surgical protocol consisted of early reduction followed by anterior cervical fusion using a tricortical iliac graft, and stabilization, using locking plate fixation. Follow-up was by radiographs and clinical examination. Intraoperative assessment revealed disc injury in all patients. Anatomical realignment was achieved together with a solid fusion in all of the patients. All patients showed improvement in the neurological deficit. One patient remains with some residual weakness in his triceps and another patient required removal of a prominent screw. Early anterior fusion and plating for this type of injury is a safe procedure

Purpose: To study the pattern of neurological lesions and the frequency they occur in patients with cervical injuries. The relationship of these lesions with certain types of injuries and the cause of omjury. Patients and methods: Between 1970–2001, 665 patients suffering a cervical injury were studied in our Department. There were 192 male and 73 female patients aged 42,3 years on average. Two hundred sixty-five of these cases (38,5%) were presented with neurological symptoms.The mean time of hospitalization was 43,45 days. The patients were classified according to the type and the level of injury. ASIA‘s functional classification was used (35,1% were ASIA A, 13,96% ASIA B, 10,57% ASIA C and 40,37% ASIA D). 194 were followed up for a mean period of 7 years. Conservative treatment was applied to 183 (69%) patients while 82 patients (31%) were treated operatively with anterior cervical fusion, posterior cervical fusion, or combined anterior and posterior fusion. Postoperatively, most of the patients with incomplete neurological lesion, were improved. Conclusions: An analysis of our cases showed the following: a) There is a relationship between the type of neurological signs and the type of osseous or ligamentous injuries. b) There is relationship between type of osseous or ligamentous injury and severity of neurological lesion.. c) Burst fractures are the most severe fractures, followed by bilateral dislocations and tear-drop fractures. d) There is a relationship between mechanism of injury and severity of neurological lesion

Injuries of the cervical spine can be classified into six categories according to a mechanistic system describing the biomechanical deficiencies incurred in a cervical spine injury. However high velocity flexion compression loads cause multiple contiguous and noncontiguous fractures due to multiple force vectors. A universal classification system cannot be applied. Instability exists if there is greater than 3.5 mm of translation or greater than 11 degrees of angulation as compared to other segments. The degree of ligamentous injury on MRI correlates with instability in patients with lateral mass facet fractures, with rupture of multiple ligaments including the anterior longitudinal, posterior longitudinal, interspinous, or facet capsule. Patients with less than 13 mm of narrowing of the sagittal canal are predisposed to neurologic injury. Vertical compression injuries cause canal occlusion and vertebral column shortening. The timing of surgery in cases of spinal cord injury is controversial. There is no difference in outcome between early (< 72 hours) and late (> 5 days) surgery. However, there remains at least a theoretical benefit to early surgery. Compression-flexion injuries result in loss of the anterior column by compression followed by the posterior column in distraction. The injury is considered unstable if there is a vertical cleavage fracture of the vertebral body or displacement. Treatment includes a cervical orthosis or halo for minor injuries, depending on the degree of kyphosis. Major injuries with displacement should be treated surgically by anterior corpectomy and plate or an anterior/posterior fusion, depending on the degree of posterior instability. The most common level of vertical-compression injuries is at the C6 or C7 level. Minimally displaced injuries can be treated with a collar or halo. Fragmentation and peripheral displacement of the bony fragments needs a halo followed by surgery and this may include an anterior corpectomy and plating. Distraction-flexion injuries may result in facet sub-luxation with less than 25% displacement, or dislocation of one (UFD) or both (BFD) facet joints. When there is 3 mm of translation (25%), the canal is occluded 20–25%. With 6mm of translation (50%), there is 40–50% canal occlusion. MRI can help analyse the soft tissue and ligamentous injuries. In UFD, all posterior ligamentous structures including joint capsule, and half the disc annulus are disrupted. Disruption of ALL and PLL is not necessary to create a UFD. In addition to the posterior structures, the ALL, the PLL and disc are disrupted in BFD. Rupture of the intervertebral disc may include posterior herniation or circumferential disruption. All distraction flexion injuries should be reduced closed. The necessity of a preoperative MRI is undetermined. Preoperative MRI is recommended if there is an unreliable exam due to the patient being uncooperative, if there is neurological worsening with, or failure of closed reduction. If the patient is neurologically intact and closed reduction successful, a posterior cervical fusion is advocated if there is no evidence of an extruded disc on the post reduction MRI. If the closed reduction failed, or MRI indicated, and there is no evidence of a herniated disc, an open posterior reduction followed by fusion is performed. Anterior discectomy with reduction, a graft and a plate is performed for a herniated disc. Compression-extension injuries fail by compression of the posterior elements followed by distraction of the anterior elements. There are unilateral or bilateral fractures of the laminae/neural arch with degrees of displacement. Undisplaced neural arch fractures can be treated with a cervical orthosis or halo. Displaced neural arch fractures are treated with a posterior cervical fusion. There are two stages in the distraction-extension injury group. The anterior longitudinal ligament is disrupted with possibly a transverse fracture of the body. With more major injuries, there is a significant displacement injuring the posterior column. Stage 1 injuries can be treated with a halo and Stage 2 with an anterior decompression and fusion with a plating device. There are two stages to lateral flexion injuries. Minor injuries include asymmetric centrum fracture and a unilateral arch fracture. In addition, there is displacement of the body with contralateral ligamentous failure in major injuries. The treatment for Stage 1 is usually a collar while treatment for Stage 2 is usually a posterior cervical fusion. Posterior stabilization procedures may be performed with wires and cables with or without rods. Posterior clamps usually are not recommended; while plates and screws are preferred. The plates and screws are biomechanically superior to wiring and avoid canal penetration. They are ideal when there is loss of the posterior elements. Pedicle fixation should be considered when operating on the C2 or C7 level. One in five patients may have complete disruption of vertebral artery blood flow. This occurs most commonly with flexion-distraction or flexion-compression injuries. Vertebral artery evaluation is recommended in patients with flexion injuries and symptoms consistent with vertebral artery insufficiency. It is important to understand the mechanism of injury; to understand which elements are compromised. We have to get the appropriate imaging studies, we have to be cognizant of the fact that the vertebral artery may be injured, or there may be an associated herniated disc. We have to understand the degree of instability, which dictates the appropriate treatment and we have to understand the risk benefit of the specific internal fixation systems that we use

We do know that the use of stand-alone cage with no plate is prone to subsidence and segmental kyphosis. Cage and plate construct are prone to adjacent level ossification. Zero P (Synthes, UK) cage combines the functionality of spacer and anterior plate. Radiological evaluation of subsidence of cervical spine after anterior cervical interbody fusion using Zero P cage system. Method: Retrospective review of radiographic records of patients undergoing surgery between June 2008- Oct 2009. We evaluated lateral cervical standing radiographs before, after, 6 weeks, 3, 6 months of surgery. We measured subsidence (using Total Intervertebral Height (TIH). All measurements were done using Web 1000 (Impax Agfa). Two level was treated as single segment. Subsidence > 3mm was considered significant. 20 patients (11 male: 9 female) with median age of 51 yrs (40-65) underwent one (n=10) or two level (n= 10) cervical fusion. Immediately post-op there was increase in TIH in one and two level group by 1.74mm (1.61 and 4.25mm (1.48 respectively, which at 6 months reduced to 1.05mm (0.24 (p< 0.003) and 1.32mm (1.29 (p< 0.085) at 6 months respectively. Subsidence was seen in all cases and was rapid in first 3 months and then tailed off. It was significant (> 3mm) only in 2/20 (2%) patients at 6 months. Early results indicate that spine alignment is maintained radiologically with no associated complications as screw loosening, cage extrusion etc

Study Design/Objective: Prospective two-leg cohort study on anterior cervical fusion versus cervical arthroplasty with emphasis on clinical outcome measures. Patients and Methods: Between August 2003 and May 2005 21 consecutive patients underwent anterior cervical fusion with or without anterior decompression with 26 levels fused. Between December 2004 and August 2006 24 patients had cervical arthroplasty with 30 levels replaced. The mean age at operation of the fusion group was 52 years and 5 months (46–69) and for the arthroplasty group 51 years and 2 months (42–62). To establish fusion the Cervios® cage (Synthes) with or without anterior plating was used. In the arthroplasty group the Prodisc C® disc prothesis (Synthes) was used. Contraindication for arthroplasty were osteoporosis, osteopathies, spinal canal stenosis, hypertrophic spondylarthrosis, spondylolisthesis, tumors and privious infection. Both groups were comparable with respect to age and gender, diagnosis, level distribution and preoperative clinical outcome measures (VAS for nack pain and arm pain, neck disability index and SF-36–sub-scores pain, function, vitality). Results: Postoperatively all of the clinical outcome measures significantly improved in both groups. After three months postoperatively no significant further improvement was evident. VAS neck pain: Fusion group/arthroplasty group: Preoperatively 6.2/5.9 n.s., 6 weeks 3.5/3.1 n.s., 12 weeks 2.1/1.9 n.s, 1 year 2/2.1 n.s. VAS arm pain: Fusion group/arthroplasty group: Preoperatively 5.5/5.3 n.s., 6 weeks 2.6/2.4 n.s., 12 weeks 1.7/1.8 n.s, 1 year 2/1.9 n.s. Neck disability index: Fusion group/arthroplasty group: Preoperatively 43/40 n.s., 6 weeks 28/23 p< 0.05., 12 weeks 18/14 p< 0.05, 1 year 20/15 p< 0.05. SF-36 subscore pain: Fusion group/arthroplasty group: Preoperatively 36/37 n.s., 6 weeks 42/44 n.s., 12 weeks 52/58 p< 0.05, 1 year 52/60 p< 0.05. SF-36 subscore function: Fusion group/arthroplasty group: Preoperatively 52/54 n.s., 6 weeks 57/59 n.s., 12 weeks 60/62 n.s, 1 year 64/67 n.s. SF-36 subscore vitality: Fusion group/arthroplasty group: Preoperatively 42/44 n.s., 6 weeks 45/46 n.s., 12 weeks 50/52 n.s, 1 year 54/56 n.s. In the fusion group we had 1 recurrent radiculopathy and 1 non union without the need of further intervention. In the arthroplasty group we faced 1 recurrent laryngeus recurrens nerve palsy and 3 spontaneus fusions within 1 year postoperatively, which might not be classified as complication. Conclusion: Short term outcome after both procedures is excellent in terms of pain relief and function. 10% spontaneus fusion after disc replacement within the first year was evident. In our series we found better results after 3 months to 1 year postoperatively with respect to the neck disability index and SF-36 subscore pain within the arthroplasty group

Aim: To determine the clinical improvement and the radiological time to fusion as well as correction of the lordosis angle in patients undergoing anterior cervical interbody fusion with the use of a silicate substituted calcium phosphate ceramic (Si-CaP) (Actifuse™ Synthetic Bone Graft, ApaTech, Ltd., Elstree, UK) as the bone graft substitute in the cage. Design: We conducted a prospective clinical and radiological study to evaluate the use of Si-CaP as bone graft substitute in anterior cervical fusion for degenerative cervical spondylosis. Materials and methods: Thirty patients were selected prospectively by preoperative and postoperative clinical and radiological assessments. All patients were operated on by a single surgeon (D.A.J.). Neck disability index and visual analogue score were used for the clinical assessment. Radiological assessment included improvement in the lordosis angle and time to fusion. Patients were evaluated at three months, six months and one year post-surgery. Results: At present 14 patients with a total of 19 levels have completed their one year follow-up. The patients had an average of 50.4 years (range 34–69), with ratio of male to female of 6:7. Lordosis angle improved significantly from a mean lordosis angle of 0.31 preoperatively to 4.75 degree postoperatively (p< 0.05). All the levels had fused at the 1 year follow up and there was no radiological evidence of sinkage of the cage. Conclusion: Substitution of silicate ions into calcium phosphate ceramics has been shown to impart a negative surface charge, leading to greater protein absorption, increased osteoblast proliferation, and higher production of extracellular matrix. Our results show that Si-CaP has excellent clinical performance as a synthetic bone graft in anterior cervical discectomy and fusion. Postoperatively, patients demonstrate a good fusion with an excellent correction and maintenance of the lordosis angle

Cervical total disc replacement has been in practice for years now as a viable alternative to cervical fusion in suitable cases, aspiring to preserve spinal motion and prevent adjacent segment disease. Reports are rife that neck pain emerges as an annoying feature in the early postoperative period. The facet joint appears to be the most likely source of pain. 50 patients were prospectively followed up through 5 years after having received disc replacement surgery, indicated for symptomatic soft disc herniation of the cervical spine presenting with radiculopathy. • All were skeletally mature and aged between 22 to 50. • All had failed a minimum of 6 months conservative therapy. • Up to 2 disc levels were addressed. C3 till C7 levels. • Single surgeon (first author). • NDI > 30% (15/50). • Deteriorating radicular neurology. We excluded those with degenerative trophic changes of the cervical spine, focal instability, trauma, osteoporosis, previous cervical spine surgery, previous infection, ossifying axial skeletal disease and inflammatory spondyloarthritides. The device used was an unconstrained implant with stabilizing teeth. Over the 5 years, we studied their postoperative comfort level via the Neck Disability Index (NDI) and Visual Analogue Score (VAS). Pre-operative and post-operative analysis of the sagittal axis and of involved facet joints were done. 22 patients suffered postoperative neck pain as reflected by the NDI and VAS scores. Of these, 10 reported of neck pain even 24 months after surgery. However, none were neurologically worse and all patients returned to their pre-morbid functions and were relieved of pain by 28 months. All 22 patients reported of rapid dissolution of neckache after peri-facetal injections of steroids were done under image guidance. We draw attention to the facet joint as the pain generator, triggered by inappropriate implant height, eccentric stresses via hybrid constructs, eccentric loading due to unconstrained devices and unaddressed Luschka joint degeneration. Such factors require careful selection of patients for surgery, necessitate proper pre-operative templating and call for appropriate technical solutions during surgery

Previous studies of cervical fusion have noted the appearance of new degeneration at levels adjacent to fused segments. The cause of this degeneration has not been accurately determined. The objective of this project is to determine the forces in normal and fused spines in vivo and compare the results to see if the forces in the fused spine are increased enough to cause degeneration in adjacent levels. A normal and a fused patient (one level fused in C5-C6) have been chosen to perform a full flexion and extension motion experiments. Kinematic functions were obtained from the images. Data was input into the mathematical model and the kinetic results have been decided. The result can help us understand in vivo kinematical and kinetic characteristics of cervical spine fusion and develop further studies in 3D models. The calculated forces will be compared to previously reported data to determine if the expected increased forces in the fused spinal are great enough to cause degeneration of adjacent levels. A better understanding will help in better treatment of cervical spine disorders