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

We conducted a prospective follow-up MRI study of originally asymptomatic healthy subjects to clarify the development of Modic changes in the cervical spine over a ten-year period and to identify related factors. Previously, 497 asymptomatic healthy volunteers with no history of cervical trauma or surgery underwent MRI. Of these, 223 underwent a second MRI at a mean follow-up of 11.6 years (10 to 12.7). These 223 subjects comprised 133 men and 100 women with a mean age at second MRI of 50.5 years (23 to 83). Modic changes were classified as not present and types 1 to 3. Changes in Modic types over time and relationships between Modic changes and progression of degeneration of the disc or clinical symptoms were evaluated. A total of 31 subjects (13.9%) showed Modic changes at follow-up: type 1 in nine, type 2 in 18, type 3 in two, and types 1 and 2 in two. Modic changes at follow-up were significantly associated with numbness or pain in the arm, but not with neck pain or shoulder stiffness. Age (≥ 40 years), gender (male), and pre-existing disc degeneration were significantly associated with newly developed Modic changes. In the cervical spine over a ten-year period, type 2 Modic changes developed most frequently. Newly developed Modic changes were significantly associated with age, gender, and pre-existing disc degeneration

The optimal method for the management of neglected traumatic bifacetal dislocation of the subaxial cervical spine has not been established. We treated four patients in whom the mean delay between injury and presentation was four months (1 to 5). There were two dislocations at the C5-6 level and one each at C4-5 and C3-4. The mean age of the patients was 48.2 years (27 to 60). Each patient presented with neck pain and restricted movement of the cervical spine. Three of the four had a myelopathy. We carried out a two-stage procedure under the same anaesthetic. First, a posterior soft-tissue release and partial facetectomy were undertaken. This allowed partial reduction of the dislocation which was then supplemented by interspinous wiring and corticocancellous graft. Next, through an anterior approach, discectomy, tricortical bone grafting and anterior cervical plating were carried out. All the patients achieved a nearly anatomical reduction and sagittal alignment. The mean follow-up was 2.6 years (1 to 4). The myelopathy settled completely in the three patients who had a pre-operative neurological deficit. There was no graft dislodgement or graft-related problems. Bony fusion occurred in all patients and a satisfactory reduction was maintained. The posteroanterior procedure for neglected traumatic bifacetal dislocation of the subaxial cervical spine is a good method of achieving sagittal alignment with less risk of iatrogenic neurological injury, a reduced operating time, decreased blood loss, and a shorter hospital stay compared with other procedures

The effect of rheumatoid arthritis on the anatomy of the cervical spine has not been clearly documented. We studied 129 female patients, 90 with rheumatoid arthritis and 39 with other pathologies (the control group). There were 21 patients in the control group with a diagnosis of cervical spondylotic myelopathy, and 18 with ossification of the posterior longitudinal ligament. All had plain lateral radiographs taken of the cervical spine as well as a reconstructed CT scan. The axial diameter of the width of the pedicle, the thickness of the lateral mass, the height of the isthmus and internal height were measured. The transverse diameter of the transverse foramen (d1) and that of the spinal canal (d2) were measured, and the ratio d1/d2 calculated. The width of the pedicles and the thickness of the lateral masses were significantly less in patients with rheumatoid arthritis than in those with other pathologies. The area of the transverse foramina in patients with rheumatoid arthritis was significantly greater than that in the other patients. The ratio of d1 to d2 was not significantly different. A high-riding vertebral artery was noted in 33.9% of the patients with rheumatoid arthritis and in 7.7% of those with other pathologies. This difference was statistically significant. In the rheumatoid group there was a significant correlation between isthmus height and vertical subluxation and between internal height and vertical subluxation

1. Experimental radiological and mechanical studies on a cadaveric cervical spine are reported. 2. A series of fifty-nine dislocations and fracture-dislocations of the cervical spine is reviewed. 3. The methods of reduction and indications for operation are discussed

1. The pathology and pathogenesis of dislocations and fracture-dislocations of the cervical spine has been reviewed. 2. A method of treatment using skeletal traction and manipulation under relaxant general anaesthesia is described. Results of treatment are given for all patients admitted to the Centre with flexion-rotation dislocations of the cervical spine complicated by neurological lesions, between November 1961 and December 1968. 3. After reviewing the literature and considering the results obtained in seventy-six cases, we advocate a policy of conservative management with gentle manipulation of the cervical spine in selected cases, reduction being maintained thereafter by skeletal traction. We reserve operation for the few cases that demonstrate late instability or for those rarer cases in which manipulation fails and the patient has either an incomplete neurological lesion or a double skeletal injury. 4. The low incidence of late instability after adequate conservative treatment is stressed, and the danger of overdistraction of the cervical spine by heavy traction in patients with severe ligamentous damage is emphasised

Aims

Developmental cervical spinal stenosis (DcSS) is a well-known predisposing factor for degenerative cervical myelopathy (DCM) but there is a lack of consensus on its definition. This study aims to define DcSS based on MRI, and its multilevel characteristics, to assess the prevalence of DcSS in the general population, and to evaluate the presence of DcSS in the prediction of developing DCM.

Aims

The optimal procedure for the treatment of ossification of the posterior longitudinal ligament (OPLL) remains controversial. The aim of this study was to compare the outcome of anterior cervical ossified posterior longitudinal ligament en bloc resection (ACOE) with posterior laminectomy and fusion with bone graft and internal fixation (PTLF) for the surgical management of patients with this condition.

We present a study of 30 fusion operations in 26 rheumatoid arthritics with cervical spine instability. Atlanto-axial instability was present in 15, of whom 12 were fused; three had cord involvement and all made a partial or complete recovery following fusion. Cranial settling necessitated cranio-cervical fusion in four patients; all fused, and one with myelopathy was relieved. Subaxial instability required fusion in seven cases; two postoperative deaths followed the only two anterior interbody fusions. Posterior fusion was successful in the other five, with remission of neurological compromise in the three with myelopathy and one with radiculopathy. We conclude that neurological compromise in an unstable but mobile rheumatoid cervical spine can usually be brought to remission by immobilisation alone, so decompressive procedures are unnecessary in the first instance

Aims

The aim of this study was to investigate whether the type of cervical disc herniation influences the severity of symptoms at the time of presentation, and the outcome after surgical treatment.

The loss of cervical lordosis in radiographs of patients presenting with neck pain is sometimes ascribed to muscle spasm. We performed a cross-sectional study of the prevalence of 'straight' cervical spines in three populations: 83 patients presenting to an accident department with acute neck pain, 83 referred to a radiology department with chronic neck problems, and 80 radiographs from a normal population survey carried out in 1958. Curvature was assessed on lateral radiographs both subjectively and by measurement. The prevalence of 'straight' cervical spines was 19% in the acute cases and 26% in the chronic cases. The 95% confidence interval for the difference was -6.4% to +19.3%. In the normal population 42% showed a straight spine, but a further third of these films had been taken in a position of cervical kyphosis; this probably reflects a difference in positioning technique. Women were more likely than men to have a straight cervical spine, with an odds ratio of 2.81 (95% CI 1.23 to 6.44). Our results fail to support the hypothesis that loss of cervical lordosis reflects muscle spasm caused by pain in the neck

Unstable degenerative spondylolisthesis of the cervical spine is very rare. Slip usually occurs at the C3 on C4 or C4 on C5 levels, immediately above a stiff lower cervical spine. There are two clinical patterns: that with neurological involvement causing cervicobrachial pain or myelopathy and that with neck pain alone. The diagnosis can be made by flexion/extension radiography. All of our eight patients had localised fusion, three anterior and five posterior, and all had satisfactory results one to seven years after operation

This paper describes seven patients who developed late vertebral deformity after flexion injuries of the cervical spine. In four the clinical and radiological features were subtle and because the patients walked into an emergency department the severity of the injury was not initially appreciated. Certain specific clinical and radiological features of flexion injury are described and emphasis is placed on the importance of correct management. A radiological tetrad is described which should alert the surgeon to the possibility of damage to the posterior interspinous complex of the cervical spine and so lead to further radiological investigations. Despite the frequency of flexion injuries the alarming complications described in this paper are rare

Seven men with a mean age of 63.9 years (59 to 67) developed dysphagia because of oesophageal compression with ossification of the anterior longitudinal ligament (OALL) and radiculomyelopathy due to associated stenosis of the cervical spine. The diagnosis of OALL was made by plain lateral radiography and classified into three types; segmental, continuous and mixed. Five patients had associated OALL in the thoracic and lumbar spine without ossification of the ligamentum flavum. All underwent removal of the OALL and six had simultaneous decompression by removal of ossification of the posterior longitudinal ligament or a bony spur. All had improvement of their dysphagia. Because symptomatic OALL may be associated with spinal stenosis, precise neurological examination is critical. A simultaneous microsurgical operation for patients with OALL and spinal stenosis gives good results without serious complications

Entire human cadaveric cervical spines with the basiocciput were subjected to load in a compression apparatus to simulate the clinical situation of forward dislocation. The movements were recorded by lateral cineradiography. Vertical load was measured by a potentiometric transmitter synchronised with each frame of the cineradiograph. The lower part of the spine was flexed and fixed, and the upper extended and free to move forward. Vertical compression then produced bilateral dislocation of the facets without fracture. If lateral tilt or axial rotation occurred as well, a unilateral dislocation was produced. The maximum vertical load was only 145 kilograms, and coincided with the rupture of the posterior ligament and capsule and the stripping of the anterior longitudinal ligament, but this occurred before dislocation. The low vertical load indicates a peculiar vulnerabiity of the cervical spine in this position and correlates well with the minor trauma often seen in association with forward dislocation

We investigated the incidence of anomalies in the vertebral arteries and Circle of Willis with three-dimensional CT angiography in 55 consecutive patients who had undergone an instrumented posterior fusion of the cervical spine. We recorded any peri-operative and post-operative complications. The frequency of congenital anomalies was 30.9%, abnormal vertebral artery blood flow was 58.2% and vertebral artery dominance 40%. . The posterior communicating artery was occluded on one side in 41.8% of patients and bilaterally in 38.2%. Variations in the vertebral arteries and Circle of Willis were not significantly related to the presence or absence of posterior communicating arteries. Importantly, 18.2% of patients showed characteristic variations in the Circle of Willis with unilateral vertebral artery stenosis or a dominant vertebral artery, indicating that injury may cause lethal complications. One patient had post-operative cerebellar symptoms due to intra-operative injury of the vertebral artery, and one underwent a different surgical procedure because of insufficient collateral circulation. . Pre-operative assessment of the vertebral arteries and Circle of Willis is essential if a posterior spinal fusion with instrumentation is to be carried out safely. Cite this article: Bone Joint J 2014;96-B:535–40

We report 16 cases in which the upper cervical spine was approached through the mouth for operative decompression and stabilisation, with or without removal of diseased tissues. The indications are discussed and the technique is described. Results are compared with those of other reported series. We believe that this operation has a place in the treatment of certain conditions affecting the upper part of the cervical spine and the foramen magnum, with or without involvement of the medulla and spinal cord

Bilateral interlocking of the articular facets of the cervical spinal column results from excessive flexion. Unilateral interlocking (hemiluxation) results from simultaneous excessive flexion and rotation. Patients with hemiluxation of the cervical spine often have only mild complaints and the clinical signs may be slight. The diagnosis is made radiologically, but it is often overlooked. Various forms of treatment may give good results. In recent hemiluxation, reduction is advisable to promote recovery of radicular symptoms. The effect of reduction on spinal cord symptoms is uncertain. Manual reduction under general anaesthesia is usually successful, with the possible exception of some cases of interlocking at C.6-C.7, or C.7-T.1. Skull traction with weights of 5 to 10 kilograms even when prolonged is hardly ever successful; with weights of 10 kilograms or more there is a chance of success. Surgical reduction is not always necessary. A hemiluxation of more than two weeks' standing may still be reduced but non-operative methods offer little chance of success. In this series there has been no aggravation of the neurological deficit after reduction. Although hemiluxation shows a tendency to spontaneous stabilisation it is wise in our opinion to apply some form of fixation. The selection of the method of fixation depends on the neurological picture and on the estimated degree of instability. The latter depends on the presence or absence of additional damage to the interlocked and adjacent vertebrae. Manual reduction by means of traction in the longitudinal axis of the cervical spine under general anaesthesia with muscle relaxation, followed by immobilisation in a plaster jacket (Minerva type) for three months is successful in many cases. If surgical stabilisation is considered necessary an attempt at manual reduction should be made before operation so that when the patient is placed on the table the cervical spinal canal has regained its normal shape. In general, sufficient stability will have been achieved after approximately three months, so that for hemiluxations of more than three months duration surgical treatment will only rarely be necessary. Figure 11 shows the methods of treatment that we advise

1. Seventy-five injuries of the cervical spine are reported. Fifty-three were dislocations and fracture-dislocations involving the third to the seventh segments. 2. The importance of careful examination in all neck injuries is stressed. 3. The injuries are divided into stable and unstable types and the causation of the instability is discussed. 4. Plaster immobilisation for more than six months failed in some patients to prevent recurrence of dislocation. 5. Operative treatment was advised in all cases of dislocation, the spine being wired and grafted with iliac bone. This prevents recurrence and shortens the period of convalescence

Six patients, aged between 3 and 51 years, with tuberculosis of the upper cervical spine were studied. Prominent features of the disease included pain and stiffness, paralysis, swelling of the retropharyngeal soft tissue, osteolytic erosions, and atlanto-axial subluxation. Cure was obtained with antibiotics, transoral decompression and C1-2 fusion

Wrong-level surgery is a unique pitfall in spinal surgery and is part of the wider field of wrong-site surgery. Wrong-site surgery affects both patients and surgeons and has received much media attention. We performed this systematic review to determine the incidence and prevalence of wrong-level procedures in spinal surgery and to identify effective prevention strategies. We retrieved 12 studies reporting the incidence or prevalence of wrong-site surgery and that provided information about prevention strategies. Of these, ten studies were performed on patients undergoing lumbar spine surgery and two on patients undergoing lumbar, thoracic or cervical spine procedures. A higher frequency of wrong-level surgery in lumbar procedures than in cervical procedures was found. Only one study assessed preventative strategies for wrong-site surgery, demonstrating that current site-verification protocols did not prevent about one-third of the cases. The current literature does not provide a definitive estimate of the occurrence of wrong-site spinal surgery, and there is no published evidence to support the effectiveness of site-verification protocols. Further prevention strategies need to be developed to reduce the risk of wrong-site surgery

Three unusual injuries of the cervical spine in wearers of safety belts are reported. In each case, the presence of diagonal bruising and abrasions in the line of the sash strap indicated its involvement in the mechanism of the injury

1. Nineteen patients with classical rheumatoid arthritis complicated by severe subluxation of the cervical spine are reported. 2. Thirteen patients had atlanto-axial subluxation. This was the only level ofinvolvement in ten. 3. The next most frequent level to be involved was C.4-5. This occurred in five patients. 4. Eleven patients required surgery for symptoms or signs of spinal cord compression or vertebral artery insufficiency. 5. Operations included six posterior fusions, three anterior fusions and two laminectomies. 6. The differential diagnosis, the radiological findings, the indications for surgery and the results of treatment are discussed

Fifteen patients with ankylosing spondylitis who had developed a severe flexion deformity of the cervical spine which restricted their field of vision to their feet, were treated by an extension osteotomy at the C7/T1 level. The operation was performed under general anaesthesia with the patient in the prone position and wearing a halo-jacket. Three had internal fixation using a Luque rectangle and wiring. Their mean age was 48 years. Before operation the mean cervical kyphosis was 23°; this was corrected to a mean of 31° of lordosis, a mean correction of 54°. All the patients were able to see straight ahead. One patient with normal neurology soon after operation became quadraparetic after one week; two others had unilateral palsy of the C8 root, which improved. There was subluxation at the site of osteotomy in four patients, and two of them developed a pseudarthrosis which required an anterior fusion

We have reviewed the cervical spine radiographs of 180 patients with athetoid cerebral palsy and compared them with those of 417 control subjects. Disc degeneration occurred earlier and progressed more rapidly in the patients, with advanced disc degeneration in 51%, eight times the frequency in normal subjects. At the C3/4 and C4/5 levels, there was listhetic instability in 17% and 27% of the patients, respectively, again six and eight times more frequently than in the control subjects. Angular instability was seen, particularly at the C3/4, C4/5 and C5/6 levels. We found a significantly higher incidence of narrowing of the cervical canal in the patients, notably at the C4 and C5 levels, where the average was 14.4 mm in the patients and 16.4 mm in normal subjects. The combination of disc degeneration and listhetic instability with a narrow canal predisposes these patients to relatively rapid progression to a devastating neurological deficit

We reviewed the magnetic resonance (MR) images of eight adults with acute hyperextension-dislocation of the cervical spine. The images were obtained to evaluate damage to the spinal cord. All eight patients had disruption of the anterior longitudinal ligament and of the annulus of the intervertebral disc, and separation of the posterior longitudinal ligament from the subjacent vertebra. Some, but not all, showed widening of the disc space, posterior bulging or herniation of the nucleus pulposus, and disruption of the ligamentum flavum. The MR demonstration of these ligament injuries, taken with the clinical and radiographic findings, establishes the mechanism of hyperextension-dislocation, confirms the diagnosis, and is relevant to management

Eight patients with neurofibromatosis presented with symptoms of cervical spine involvement over a period of 17 years, five of them within the second decade of life. The symptoms included neurological deficit in five, a neck mass in four, and deformity in three; only two complained of pain. Osteolysis of vertebral bodies with kyphosis of more than 90 degrees was the most common radiological feature. Posterior fusion failed in the one patient in whom it was performed. Good results were achieved by anterior fusion, alone, or combined with posterior fusion. Surgical complications included one death in a patient with a malignant neurofibroma, and one case of transient neurological deterioration

Eleven patients with metastases in the cervical spine had operations for severe pain due to a pathological fracture which, in eight of the cases, was unstable. Conservative treatment had either failed or was unsuitable. In the first five patients internal fixation with tension band wires and bone grafts was supported by a halo-brace. The method has evolved to the use of posterior instrumentation with laminar wires from two levels above the lesion to two levels below. Stability is increased by the use of bone cement with or without bone autografts applied to one side of the spine. This technique enables the patient to get up within a few days of operation--a great advantage when life expectancy is limited. The operations were successful in all except one case

The ratio of the sagittal diameter of the cervical canal to the corresponding diameter of the vertebral body has been described as a reliable means for assessing stenosis of the canal and detecting those at risk of cervical neuropraxia. The use of ratio techniques has the advantage of avoiding variation in magnification when direct measurements are made from plain radiographs. We examined the reliability of this method using plain lateral radiographs of unknown magnification and CT scans. We also assessed other possible ratios of anatomical measurements as a guide to the diameter of the canal. Our findings showed a poor correlation between the true diameter of the canal and the ratio of its sagittal diameter to that of the vertebral body. No other more reliable ratio was identified. The variability in anatomical morphology means that the use of ratios from anatomical measurements within the cervical spine is not reliable in determining the true diameter of the cervical canal

We treated 36 patients with unilateral facet dislocations or fracture-dislocations of the cervical spine at the Mayo Clinic between 1975 and 1986. Adequate records were available for 34: ten patients were treated by open reduction and posterior fusion, and 24 by nonoperative management. Of these, 19 had halo traction followed by halo-thoracic immobilisation, four had a simple cervicothoracic orthosis, and one received no active treatment. Anatomical reduction was achieved more frequently in the operative group (60% compared with 25%). Nonoperative treatment was more likely to result in cervical translation on flexion/extension lateral radiographs, and in significant symptoms. Only 36% of the patients treated by halo traction achieved anatomical alignment; in 25% halo traction failed to achieve or maintain any degree of reduction. During halo-thoracic immobilisation, half of the patients lost some degree of reduction and patient satisfaction with the appliance was low. Open reduction and internal fixation of unilateral facet injuries gave better results. 6

Posterior cervical wiring is commonly performed for patients with spinal instability, but has inherent risks. We report eight patients who had neurological deterioration after sublaminar or spinous process wiring of the cervical spine; four had complete injuries of the spinal cord, one had residual leg spasticity and three recovered after transient injuries. We found no relation between the degree of spinal canal encroachment and the severity of the spinal-cord injury, but in all cases neurological worsening appeared to have been caused by either sublaminar wiring or spinous process wiring which had been placed too far anteriorly. Sublaminar wiring has substantial risks and should be used only at atlantoaxial level, and then only after adequate reduction. Fluoroscopic guidance should be used when placing spinous process wires especially when the posterior spinal anatomy is abnormal

We report 13 patients with missed bilateral facet dislocation of the lower cervical spine who subsequently developed severe spinal-cord involvement. There were more women and the patients were older than in most groups with spinal injury. The commonest cause was a fall, and paralysis appeared from six to 48 hours after injury in most patients. Ten patients made some recovery after late reduction but three remained totally paralysed. We discuss the pathogenesis of the late cord lesion and the reasons for delay in diagnosis

The case is reported of an elderly man with asymptomatic cervical spondylosis who sustained a minor hyperextension injury of the cervical spine when the brakes of a car were applied suddenly to avoid a collision. Within six hours marked swelling of the neck and severe dyspnoea developed, and a lateral radiograph showed the pharyngeal shadow displaced far forwards and a crack fracture of an anterior osteophyte. Tracheostomy and evacuation of a massive prevertebral haematoma were performed, with immediate relief. The case draws attention to the possibility of this serious complication of a "whiplash" type of injury

The outcome of operations performed on 38 patients for rheumatoid disorders of the cervical spine were analysed 10 or more years later. The mean age of the patients at the time of operation was 56 years (35 to 77); 32 had seropositive disease. The mean duration of the disease was 17 years (four to 36). Twenty-seven patients had painful anterior atlanto-axial subluxation (AAS), nine had subaxial subluxation alone and two had severe cranial subluxation of the odontoid, one also with subaxial subluxation. One patient died from postoperative staphylococcal septicaemia and another 18 died during the follow-up period. Patients with coincident cardiac or other diseases, and those with cranial subluxation of the odontoid of more than 3 mm had an increased mortality. Neither the patients' age nor the magnitude of AAS correlated with mortality. Of the 37 patients with occipitocervical pain, 30 were relieved and all the six patients with tetraparesis were improved. Of the 24 Gallie fusions only 12 were solidly united; patients with long-term cortisone treatment were more likely to develop pseudarthrosis. There was no correlation between clinical outcome and radiological result. Four patients had further operations to treat subluxation which developed below the fused segments

We report and discuss a combined anterior, anterolateral and posterior approach to the lower cervical spine. This was used for the radical resection of a recurrent osteoblastoma which involved the lateral mass, pedicle, and lamina of the sixth cervical vertebra

We have reviewed 32 patients with rheumatoid disease of the cervical spine who underwent a total of 40 operations aimed at correcting instability and improving any associated neurovascular deficit. Apart from four patients with intractable pain, the main indication for surgery was progressive neurological impairment. Of the 32 primary operations, 19 (60%) were successful; the remainder failed to achieve their objective and there were two deaths in the immediate postoperative period. Of eight secondary operations performed for recurrence of symptoms or failure to relieve cervical myelopathy, only four were successful. Of nine operations for bony decompression to relieve cord compression from irreducible subluxation, only four were successful. The overall results show a success rate of 57% and a failure rate of 35% with early operative mortality in 8%. Indications for operation are discussed and earlier diagnosis is considered to be the key to improved results

This retrospective study assesses the complications affecting the cervical spine after halo-pelvic traction in 83 patients who were followed up for a minimum of five years. Forty-four patients (53 per cent) had significant cervical complications such as radiological degenerative changes, avascular necrosis of the dens, loss of movement, pain or spontaneous fusion. The most important predisposing factors were a long period in the halo-pelvic apparatus, tuberculous kyphosis, stiffness of the spinal deformity and an age of 15 years or more at the time of application

Forty patients with tuberculosis of the lower cervical spine (second to seventh cervical vertebrae) have been reviewed. Pain and stiffness were important and dominant symptoms. Two types of disease were recognised. In children under 10 years old involvement was extensive and diffuse with the formation of large abscesses. In patients over 10 the disease was localised and produced less pus, but was associated with a much higher incidence of Pott's paraplegia. The overall incidence of cord compression was 42.5 per cent (17 out of 40); 13 of the 16 patients with the "adult" type of disease had this complication. The commonest method of treatment was with antituberculous drugs, anterior excision of diseased bone and grafting. This regime rapidly relieved pain, compressive respiratory symptoms due to abscesses and Pott's paraplegia. It also corrected kyphotic deformities from an average of 25.5 degrees to 5.4 degrees

Instability may present at a different level after successful stabilisation of an unstable segment in apparently isolated injuries of the cervical spine. It can give rise to progressive deformity or symptoms which require further treatment. We performed one or more operations for unstable cervical spinal injuries on 121 patients over a period of 90 months. Of these, five were identified as having instability due to an initially unrecognised fracture-subluxation at a different level. We present the details of these five patients and discuss the problems associated with their diagnosis and treatment

Ossification of the posterior longitudinal ligament in the cervical region is generally regarded as a rare disease, though a Japanese series of 185 cases has been reported. The main symptoms arise from a myelopathy, the degree of which varies from moderate to severe, due to stenosis of the spinal canal. In order to clarify the relationship between the severity of symptoms and the cross-sectional area of ossification, axial transverse tomography of the cervical spine has been carried out on twenty-six patients at intervals of 5 millimetres over the full extent of the ossification. In this way the cross-sectional areas of the ossified tissue and of the spinal canal were calculated. The former varied from a minimum of 0.8 to a maximum of 1.8 square centimetres. In cases of severe myelopathy the ossification was mainly at the fourth and fifth cervical levels and the stenosis ration exceeded 30 per cent

Aims

In this prospective observational study, we investigated the time-dependent changes and correlations of upper arm performance tests (ten-second test and Simple Test for Evaluating Hand Function (STEF), the Japanese Orthopaedic Association (JOA) score, and the JOA Cervical Myelopathy Evaluation Questionnaire (JOACMEQ) in 31 patients with cervical myelopathy who had undergone surgery.

C5 nerve root palsy is a rare and potentially debilitating complication of cervical spine surgery. Currently, however, there are no guidelines to help surgeons to prevent or treat this complication.

We carried out a systematic review of the literature to identify the causes of this complication and options for its prevention and treatment. Searches of PubMed, Embase and Medline yielded 60 articles for inclusion, most of which addressed C5 palsy as a complication of surgery. Although many possible causes were given, most authors supported posterior migration of the spinal cord with tethering of the nerve root as being the most likely.

Early detection and prevention of a C5 nerve root palsy using neurophysiological monitoring and variations in surgical technique show promise by allowing surgeons to minimise or prevent the incidence of C5 palsy. Conservative treatment is the current treatment of choice; most patients make a full recovery within two years.

Cite this article: Bone Joint J 2014;96-B:950–5.

The most common injury in rugby resulting in spinal cord injury (SCI) is cervical facet dislocation. We report on the outcome of a series of 57 patients with acute SCI and facet dislocation sustained when playing rugby and treated by reduction between 1988 and 2000 in Conradie Hospital, Cape Town. A total of 32 patients were completely paralysed at the time of reduction. Of these 32, eight were reduced within four hours of injury and five of them made a full recovery. Of the remaining 24 who were reduced after four hours of injury, none made a full recovery and only one made a partial recovery that was useful. Our results suggest that low-velocity trauma causing SCI, such as might occur in a rugby accident, presents an opportunity for secondary prevention of permanent SCI. In these cases the permanent damage appears to result from secondary injury, rather than primary mechanical spinal cord damage. In common with other central nervous system injuries where ischaemia determines the outcome, the time from injury to reduction, and hence reperfusion, is probably important.

In order to prevent permanent neurological damage after rugby injuries, cervical facet dislocations should probably be reduced within four hours of injury.