Axial Fracture Research Articles

Ventral fixation in atlantoaxial instability with axial fracture in a dog

This study reports the diagnosis and the surgical management of atlanto-axial instability with an oblique axial fracture in a dog. The fracture was diagnosed by radiography and Computed Tomography (CT). In the CT views, the appearance of the distortion of the atlantoaxial articular surface was interpreted as instability. The stabilization was achieved with the cancellous screws. Following the surgery, the neurological status improved and the dog no longer had marked neurological deficits.

Acute combination fracture of atlas and axis: “triple” anterior screw fixation in a 92-year-old man: Technical note

Background The combination of odontoid and bilateral transarticular C1-C2 anterior screw fixation is a recent addition in treating C1-type II odontoid fractures. When feasible, it ensures early maximal stability, even if it slightly reduces the mobility of C1-C2 complex. We report a case of combination atlas-type II odontoid fracture that occurred in a 92-year-old man. The instability was treated with odontoid screw fixation and anterior bilateral C1-C2 transarticular screw fixation in a single stage. The aim of the article is to describe the feasibility of “triple” anterior screw fixation in the presence of C1-type II odontoid fracture. Methods The diagnosis, treatment, and outcome of a 92-year-old patient with mild tetraparesis caused by C1-type II odontoid fracture were assessed. Results Cervical x-rays, computed tomographic scan, and magnetic resonance imaging demonstrated a fracture of posterior arch of C1, associated with type II odontoid fracture and with presumable damage of C1 transverse ligament. Magnetic resonance imaging also showed a high cervical centromedullary area slightly hyperintense in T1-weighted images. Treatment consisted of odontoid and bilateral C1-C2 transarticular screw fixation with single anterior approach. The admission neurologic conditions improved and the patient was early mobilized. Conclusions The authors suggest that in presence of C1-type II odontoid fracture, the triple anterior screw fixation has to be taken into account as salvage procedure, especially if other methods of stabilization failed or cannot be safely performed. This technique seems to be safety feasible also in old patients, as our report and the experience of others confirm.

Management of Acute Traumatic Atlas Fractures

A prospective review of a clinical series was performed. The treatment features of atlas fractures with and without associated axis injuries were investigated. Twenty-nine patients were investigated. No displaced fractures were treated with a cervical orthosis. Patients with displaced fractures were managed with a halo vest immobilization; 96.4% patients had a solid fusion at their last follow-up evaluations. Isolated not displaced or combined with not displaced axis fractures atlas fractures can be treated effectively with a rigid cervical collar alone. Isolated displaced fractures or not displaced but with concurrent displaced axis fractures require immobilization by the halo vest.

Quantification of neotectonic stress orientations and magnitudes from field observations in Finnmark, northern Norway

Fieldwork was conducted in Finnmark, northern Norway, with the purpose of detecting and measuring stress-relief features, induced by quarrying and road works, and to derive from them valuable information on the shallow-crustal stress orientations and magnitudes. Two kinds of stress-relief features were considered in this study. The first consists of drillhole offsets that were found along blasted road-cuts and which were triggered by the sudden rock unloading following the actual blasting. Vertical axial fractures found in the concave remains of boreholes represent the second kind of stress-relief feature. The axial fractures are tension fractures produced by gas overpressure inside the drillhole when the blast occurs. As such, their strike reflects the orientation of the ambient maximum horizontal stress axis. The borehole offsets show mostly reverse-slip displacements to the E–SE and the axial fractures trend NW–SE on average, in agreement with NW–SE compression induced by North Atlantic ridge-push forces. Mechanical considerations of the slip planes offsetting some of the drillholes lead to the conclusion that the magnitude of the maximum horizontal stress at the surface is in the range ∼0.1–∼1 MPa. This range of magnitudes is 1–2 orders less than the horizontal stress magnitudes measured at the surface in other post-glacial environments (e.g. Canada). It is suggested that this difference is related to the marked decline in stress that followed the tremendous post-glacial burst of earthquake activity that affected Fennoscandia but apparently not the Canadian Shield.

Hypotensive Patients with Blunt Abdominal Trauma: Performance of Screening US

To determine retrospectively the accuracy of screening ultrasonography (US) in patients with hypotension (systolic blood pressure <or= 90 mm Hg) after blunt abdominal trauma. The investigational review board approved the study and waived informed consent. The study group consisted of 128 hypotensive patients with blunt abdominal trauma who underwent screening US over a 9-year period. Abdomens were scanned for free fluid and for parenchymal heterogeneity in visceral organs; scans that depicted these were considered positive. Prospective reports were used to calculate diagnostic performance. Patients were retrospectively given a fluid score according to the number of fluid pockets visualized (0, 1, or > or =2) (consensus by three readers) and were assigned to a low- or high-risk group according to the presence of hematuria and/or axial fracture on radiographs. Screening US results were compared with findings with the best available reference standard (computed tomography [CT]), repeat US, other diagnostic test, laparotomy, autopsy, clinical course). Data were compared by using chi(2) or Fisher exact test, depending on expected frequencies, with Bonferroni correction for multiple comparisons. Continuous variables were compared by using unpaired Student t test or Mann-Whitney U test, depending on data distribution. The study included 77 male and 51 female patients (mean age, 42 years). Sensitivity was 85% (44 of 52) for detection of any injuries, 97% (30 of 31) for surgical injuries (ie, injuries requiring surgery), and 100% (10 of 10) for fatal injuries. Specificity was 96% (73 of 76), 82% (80 of 97), and 69% (81 of 118), and accuracy was 91% (117 of 128), 86% (110 of 128), and 71% (91 of 128), for respective injury categories. One nonfatal surgical injury was missed in a high-risk patient. For each injury category, frequency of injury in patients with a fluid score of 2 or more was nine times that in patients with a score of 0 (P < .001 for all comparisons). Frequency of false-negative US findings in high-risk patients was eight times that in low-risk patients (P < .01). In patients who are hypotensive after blunt abdominal trauma and not hemodynamically stable enough to undergo diagnostic CT, negative US findings virtually exclude surgical injury, while positive US findings indicate surgical injury in 64% of cases.

Comparison of Computer‐Assisted Surgery with Conventional Technique for the Treatment of Axial Distal Phalanx Fractures in Horses: An In Vitro Study

To compare the precision obtained with computer-assisted screw insertion for treatment of mid-sagittal articular fractures of the distal phalanx (P3) with results achieved with a conventional technique. In vitro experimental study. Thirty-two cadaveric equine limbs. Four groups of 8 limbs were studied. Either 1 or 2 screws were inserted perpendicular to an imaginary axial fracture of P3 using computer-assisted surgery (CAS) or conventional technique. Screw insertion time, predetermined screw length, inserted screw length, fit of the screw, and errors in placement were recorded. CAS technique took 15-20 minutes longer but resulted in greater precision of screw length and placement compared with the conventional technique. Improved precision in screw insertion with CAS makes insertion of 2 screws possible for repair of mid-sagittal P3 fractures. CAS although expensive improves precision in screw insertion into P3 and consequently should yield improved clinical outcome.

05/00324 The combustion of oil sand beds containing an axial fracture: Mehta, S. and Karim, G. A. International Journal of Global Energy Issues, 2003, 20, (3), 277–289

05/00324 The combustion of oil sand beds containing an axial fracture: Mehta, S. and Karim, G. A. International Journal of Global Energy Issues, 2003, 20, (3), 277–289

In situ rock stress determinations in deep boreholes at the Underground Research Laboratory

Deep in situ rock stress determinations are typically conducted using hydraulic fracturing in an existing borehole or by applying specialized overcoring techniques that require the installation of a strain-monitoring instrument in a central pilot borehole that is subsequently overcored. The unusually high horizontal to vertical stress ratio at depth in Canada's Underground Research Laboratory (URL) results in problems in the application of either of these methods. At 420-m depth, the rock in the URL is massive granite with virtually no fractures. The maximum principal stress is approximately 60 MPa and is sub-horizontal. The minimum principal stress is only 11 MPa, resulting in a horizontal to vertical stress ratio of almost 6 to 1. In these conditions, hydraulic fracturing is unable to produce axial fractures in sub-vertical boreholes or is unable to fracture the rock at all. Overcoring methods requiring a pilot hole are not feasible because of persistent core discing. To resolve these problems, AECL has applied a remote data logger/signal conditioner to the design of a Deep Doorstopper Gauge System (DDGS) for use to 1000-m depth. The DDGS is much less susceptible to core discing than most other overcoring methods because it does not require a pilot hole. This paper describes the operating principle of the DDGS and the results of field testing at the URL, as well as issues related to its use and the interpretation of results.

Fracture risk in monoclonal gammopathy of undetermined significance.

To assess fractures in monoclonal gammopathy of undetermined significance (MGUS), the precursor of multiple myeloma, we followed 488 Olmsted County, MN, residents with MGUS in a retrospective cohort study. There was a 2.7-fold increase in the risk of axial fractures but no increase in limb fractures. The pathophysiologic basis for the increased axial fractures should be determined. Multiple myeloma is often preceded by monoclonal gammopathy of undetermined significance (MGUS). Fractures are common in myeloma as a result of lytic bone lesions, generalized bone loss, and elevated bone turnover from excessive cytokine production. Whether fractures are also increased in MGUS is unknown. In a population-based retrospective cohort study, 488 Olmsted County, MN, residents with MGUS first diagnosed in 1960-1994 (52% men; mean age, 71.4 +/- 12.8 years) were followed for 3901 person-years; follow-up was censored at progression to myeloma. The relative risk of fractures was assessed by standardized incidence ratios (SIRs), and risk factors were evaluated in proportional hazards models. Altogether, 200 patients experienced 385 fractures. Compared with expected rates in the community, statistically significant increases were seen for fractures at most axial sites, for example, vertebrae (SIR, 6.3; 95% CI, 5.2-7.5). There was a slight increase in hip (SIR, 1.6; 95% CI, 1.2-2.2) but not distal forearm fractures (SIR, 0.8; 95% CI, 0.4-1.5). The relative risk (SIR) of any axial fracture was 2.7 (95% CI, 2.3-3.1) compared with only 1.1 (95% CI, 0.9-1.4) for all limb fractures combined. In a multivariate analysis, the independent predictors of any subsequent fracture were age (hazard ratio [HR] per 10-year increase, 1.4; 95% CI, 1.2-1.6) and corticosteroid use (HR, 1.8; 95% CI, 1.2-2.6); greater weight at diagnosis (HR per 10 kg, 0.8; 95% CI, 0.8-0.9), and IgG monoclonal protein (HR, 0.7; 95% CI, 0.5-0.97) were protective. Baseline monoclonal protein level, a determinant of myeloma progression, did not predict fracture risk. Thus, the risk of axial, but not peripheral, fractures is increased among MGUS patients even before progression to myeloma. The pathophysiologic basis for this should be determined because elevated bone turnover, for example, might be treatable.

Neck injuries among the elderly in Sweden

Neck injuries are some of the most important injuries as they have the potential to influence the spinal cord. A previous national survey of neck injuries in Sweden revealed that injury incidence was increasing for the population over 65 years of age, although it was decreasing for the population as a whole. The aim of this study was therefore to further clarify the magnitude, severity, and external causes of neck injuries in the elderly people in Sweden. A national incidence study, with focus on the age group above 65 years, was undertaken with data from the injury surveillance program at the Swedish National Board of Health and Welfare. The investigation includes cervical vertebral fractures reported between 1987 and 1999, and cervical soft tissue injuries from 1997 to 1999. Data in the hospital discharge register were reported in ICD9 from 1987 to 1996, while data from 1997 to 1999 were reported in ICD10. During the study period 4168 cervical injuries occurred of which 341 were fatal. People above 65 years of age made up 17% of the population and sustained 30% of all cervical injuries and 43% of all fatal cervical injuries. Half of the cervical injuries were axis (C2) fractures. Lower vertebral fractures occurred in 16% of the cases and atlas (C1) fractures in 11%. The cervical soft tissue injuries amount to 19% of all injuries. Fall accidents account for the majority (71%) of the accidents. There is an increasing trend for fall accidents resulting in neck injuries. The male population has a higher incidence for neck fractures than females, disregarding the external cause of injury. The upper cervical injuries are the most common, have the longest hospital treatments, and seem to be caused mainly by low energy falls. Further research is needed to understand the mechanisms of these injuries and in this aspect engineering could contribute with valuable knowledge, through accident simulations with numerical models. The increasing incidence of fall injuries calls for further preventive actions. The public sector should implement preventive strategies to reduce the number of extrinsic accidents, while the health care sector should focus on preventing intrinsic accidents with individual actions for each patient.

The combustion of oil sand beds containing an axial fracture

The processes within simplified laboratory cylindrical beds of specially reconstituted oil sand during oil recovery are described. The beds contained a small diameter cylindrical axial passage of high permeability representing a fracture where hot vitiated air of known composition was fed steadily. The fuel sand cores tested contained either pure hydrocarbon or extracted oil off naturally occurring oil sands. It was shown that combustion appeared to have been sustained mainly by the oxidation of the light fuel fractions rather than by the coke deposits produced by the cracking reactions. Most of the burning took place, for the conditions examined, within the fracture rather than the main granular bed.

Axial ulnar carpometacarpal disruption

Carpal injuries resulting from antero-posterior compression forces demonstrate unusual axial fracture–dislocation patterns. This distinctive injury was first described by Oberst in 1901 1 and involves a traumatic longitudinal disruption of the carpus and its respective metacarpals. Flexor retinaculum disruption, permitting flattening of the carpal arch is common to all these injuries. Ogunru 2 and Norbeck et al. 3 however, reported cases of incomplete axial disruption, where the proximal carpal row and flexor retinaculum remain intact. No subsequent cases have been discovered in the literature. In this report, we describe a further case of an incomplete axial–ulnar carpometacarpal disruption with an oblique fracture of the body of the hamate and an intact proximal carpal row.

Effects of plate location and selection on the stability of midshaft clavicle osteotomies: A biomechanical study

Operative fixation of midshaft clavicle fractures is controversial with few biomechanical data to assist surgical decision making. The purpose of this 2-phase biomechanical investigation is to report on the effects of plate location and selection on the stability of midshaft clavicle fractures. Thirty matched pairs of human adult formalin-fixed clavicles were used. In the first phase, in which a 3.5-mm reconstruction plate and simulated midshaft transverse clavicle osteotomies were used, we observed the effect of superior plate placement compared with anterior placement on fracture rigidity, construct stiffness, and strength. In the second phase, in which simulated midshaft oblique clavicle osteotomies were repaired on the superior aspect, we compared the fracture rigidity, construct stiffness, and strength of the 3.5-mm reconstruction, 3.5-mm limited contact dynamic compression (LCDC), and 2.7-mm dynamic compression (DC) plates. Intact clavicles were prepared, potted, and tested for axial and torsional stiffness in an Instron test frame equipped with gimbaled fixtures. Clavicles were band-sawed to simulate an osteotomy, repaired, re-mounted on the test frame with shear and opening extensometers placed across the osteotomy site, and then tested to observe axial and torsional fracture rigidity and stiffness. Constructs were then loaded to failure in compression. First-order regressions were used to estimate fracture rigidity (in kilonewtons per millimeter)and retained construct stiffness (in kilonewtons per millimeter), whereas the maximum applied compressive load at collapse or gross deformation determined the failure load. Values for the comparisongroups were tested for significance at the 95% confidence level. In the first phase we found that constructs plated at the superior aspect of the clavicle exhibited significantly greater fracture rigidity and mean retained stiffness than the anterior location (P <.05). In the second phase we found that the torsional fracture rigidity of LCDC-plated constructs significantly exceeded that of the reconstruction and DC plates (P <.05), whereas the axial fracture rigidity of the LCDC-plated constructs significantly exceeded that of the reconstruction plate (P <.05). In retained stiffness the performance of the LCDC-plated constructs significantly exceeded that of the DC plate in torsion (P <.05), whereas in load to failure the LCDC plate withstood significantly more compressive load than the reconstruction plate (P <.05). We concluded that clavicles plated at the superior aspect exhibit significantly greater biomechanical stability than those plated at the anterior aspect. Furthermore, we concluded that the LCDC plate offers significantly greater biomechanical stability than the reconstruction and DC plates. (J Shoulder Elbow Surg 2002;11:457-62)

Orthopedic managements of skeletal trauma in multiple-injury patients: a retrospective review of 7 years of patients in a Japanese level 1 hospital

Multiple-injury patients absorb a large amount of trauma energy in their trunk, resulting in multiple organ injuries and often long-bone and axial skeletal fractures. Severity of these injuries can be quantified using the Trauma Index (TI) and Injury Severity Score (ISS). These systems allow not only a comparison of mortality and morbidity among institutions, but also serve as criteria for triage, emergency, and subsequent management of patients. We reviewed 229 multiple-trauma patients with orthopedic injuries who were treated in our trauma center. Based on the aim of orthopedic intervention performed within 1 week of injury, patients were divided into four groups: group A, surgery for supporting patient's life (n=8); group B, surgery for salvaging limbs and limb function (n=81); group C, surgery for preventing the development of serious complications (n=92); and group D, minor surgery performed according to the general situation (n=48). Both the TI and ISS were compared among these four groups. Furthermore, both the TI and ISS were compared between patients who died within 24 h and those who survived for longer. The ISS was significantly different between groups B and C (P<0.05), while it was not different among the other groups. Both the TI and ISS were significantly different between the group in which the patients died within 24 h and the group in which the patients survived more than 24 h (P<0.0001). The most important points in treating the skeletal trauma in multiple-injury patients are to accurately evaluate injury severity and plan the optimal procedure taking into consideration the aim of treatment.

The Relationship Between Tectonic Stylolites and Fold Morphology in Limestones of the "Croatica Deposits" (Croatia)

Stylolites associated with axial plane fractures occur in Lower Pannonian clayey limestones (the "Croatica Deposits") from the "Hampovica 6" deep exploration well. A genetic link has been observed between the origin of fractures and the process of stylolitization. Strong tectonic deformations are present which have been formed under the influence of reverse bed faulting. Deformation is pronounced in the shape of folded marl layers along with the creation of thick cleavage (0.3-0.5 cm). Along the fractures of axial plane cleavage, microlithons are separated and moved apart for similar values (2-5 mm) forming a moderate synform. Stylolites are formed in the last phase of structure shaping when the effects of the local compressional stress have weakened under the influence of which the breaking off and folding of marl layers occurred. Their strike cut the bedding and older fracture systems.

Laboratory and field verification of a new approach to stress measurements using a dilatometer tool

Abstract A new method is proposed for in-situ stress measurements. The stresses are estimated from the borehole pressure required to open axial fractures emanating from the borehole, similar to hydrofracture stress measurements. However, the borehole is pressurized by inflation of a dilatometer, such as a packer and a sleeve, and the borehole pressure to reopen the fractures is detected from circumferential deformation of the borehole. The fractures are induced by hydraulic fracturing or sleeve fracturing in advance. To demonstrate this method, we developed a new dilatometer tool. The tool consists essentially of a packer around which deformation transducers sensitive to circumferential strain are affixed at 10°–30° intervals. The packer is inflated to touch the borehole wall, and then the packer pressure is increased step-wise and the resultant strains recorded. Initially, the circumferential strain developed around the borehole is radially symmetric. However, this becomes strongly asymmetric once the fractures begin to open. Thus, the records of strain at different locations around the borehole indicate both the reopening pressure and the orientation of fractures. In the case of a vertical borehole, the detected reopening pressure allows us to estimate the maximum horizontal stress on condition that the minimum horizontal stress is estimated using other approaches.

Utilization of Mud Weights in Excess of the Least Principal Stress to Stabilize Wellbores: Theory and Practical Examples

SummaryIn this paper, we address the theoretical possibility of drilling with mud weights in excess of the least principal stress for cases of particularly high pore pressure or severe wellbore instability. Because lost circulation caused by hydraulic fracturing is to be avoided, we consider three critical wellbore pressures, pfrac, plink, and pgrow. Tensile fractures initiate at the wellbore wall at pfrac, link up to form large axial fractures that are subparallel to the wellbore axis at plink, and propagate away from the wellbore at pgrow. It is obvious that lost circulation cannot occur if the wellbore pressure during drilling is below pfrac. However, even if pfrac is exceeded and tensile fractures are initiated at the wellbore wall, fracture propagation (and, hence, lost circulation) will be limited as long as the wellbore pressure is below plink. Finally, if the wellbore pressure is greater than plink, the fractures will not grow away from the wellbore (and significant lost circulation will not occur) if the wellbore pressure is below pgrow, which must exceed (if only slightly) the least principal stress. In general, our modeling shows that pfrac and plink can be maximized by drilling the wellbore in an optimally stable orientation, and pgrow can be maximized with noninvading drilling muds that prevent fluid pressure from reaching the fracture tip. We apply the model that uses in-situ stress data collected in real fields, such as the South Eugene Island field in the Gulf of Mexico and the Visund field in the northern North Sea.

Selective paralysis of the upper extremities after odontoid fracture: acute central cord syndrome or cruciate paralysis?

A patient presented with selective paralysis of the arms after having sustained a fall. X-ray of the cervical spine showed a type II odontoid fracture with posterior atlantoaxial dislocation. The diagnosis in the emergency room was cruciate paralysis, which is frequently associated with fractures of axis and/or atlas. However, magnetic resonance imaging (MRI) of the cervical spine revealed a lesion consistent with the acute central cord syndrome (CCS) at the C2–C6 level. The patient underwent posterior atlantoaxial arthrodesis to correct instability and was discharged, without much neurological improvement. Cruciate paralysis has been reported to be associated with fractures of axis and/or atlas, and acute CCS has rarely been associated with the fractures. However, this case illustrates that the lesion responsible for selective paralysis of the upper extremities is not as specific as it had been thought to be, and that it is difficult to accurately identify the level of the cervical cord injury by neurological diagnosis and X-rays alone. Supplementary diagnostic modalities, particularly MRI, are required to make a correct diagnosis and develop a therapeutic strategy.

Osteopenia risk factors in “tooth-losing” postmenopausal women: second report

The stability and mechanical functioning of teeth is related to the amount and architectural quality of periodontal tissue. In previous reports, we demonstrated that most postmenopausal (PM) women lose their teeth three times more quickly (Amaro et al., J Bone Miner Res, 1999). This loss was not found to be related to measurements of peripheral bone density (Amaro et al., Bone, in press). In this second report, a group of 426 PM women with and without atraumatic fractures were analyzed for their anthropomorphometric and age-related features using known risk factors for bone mass loss in order to describe probable predictors in the subgroup of “tooth-losing” women. The selection of patients and survey was carried out by physicians trained in the management of odontologic files and epidemiological characteristics of osteopathies using the ad hoc format. Details are provided in the aforementioned work. Daily consumption of calcium was found to be very low throughout most of the study and it was not correlated with the conservation of teeth (tooth losers 666.8 6 509.5 mg/day vs. tooth preservers 691.8 6 524.1 mg/day; p 5 n.s.). Menopause, cigarettes smoked per day, and physical activity did not differ statistically among the groups. The use of osteotropic medicines was more frequent among tooth preservers (26.7% vs. 15.2%; p 5 0.07). Except for those who received hormone replacement therapy (HRT; intent to treat), those patients treated with pamidronate, alendronate, or calcitonin did not differ from controls. Patients with HRT presented with a mean of 16 teeth vs. 12 in the remaining patients, but they were a mean of 10 years younger, with this being a significant difference. Women with appendicular fractures presented with 24.0 teeth and those with axial fractures 22.5 teeth, as compared to those with no fractures. We conclude that the risk of accelerated tooth loss cannot be predicted based on the existence of relevant risk factors of osteopenia, except in the presence of settled osteoporosis (fractures) and, consequently, it is advisable to perform maxillary exploration during menopause in women with no previous fractures.

A review of halo vest treatment of upper cervical spine injuries.

Thirty-five relevant studies involving in total 682 patients with 709 different types of injuries were evaluated in a review to determine the outcomes after immobilisation in a halo vest for various injuries to the upper cervical spine between 1962 and 1998. Studies were analysed according to the type of injury pattern and in terms of the treatment outcomes following primary treatment with a halo vest. The following types of injuries were evaluated: odontoid fractures (n = 420), hangman's fractures (n = 172), other axis fractures (n = 75), Jefferson fractures (n = 26), C1 arch fractures (n = 9), atlantooccipital (n = 2) and atlantoaxial dislocations (n = 5). The ligamentary atlantooccipital dislocations never healed. All isolated Cl ring fractures healed completely. The isolated C1 arch fractures healed in 83% of the cases. The ligamentary atlantoaxial dislocations had a 60% rate of healing. Healing was noted in all isolated odontoid type I fractures, 85% of the isolated odontoid type II fractures, and 67% of the odontoid type II fractures with combined injuries. The isolated odontoid type III fractures had a 97% healing rate. The non-classifiable odontoid fractures had a healing rate of 85%. The stable C2 arch fractures (hangman's fracture) healed consistently in 99%, and 90% success was found for other C2 fractures. A halo vest can be recommended for patients with isolated Jefferson fractures, hangman's fractures, odontoid type III and type II fractures, with a low dislocation rate. The results of treatment with a halo vest were unsatisfactory with regard to combined injuries with an odontoid type II fracture. An overall healing rate of 86%, however, allows one to conclude that this treatment continues to be a good alternative to operative stabilisation of bone injuries to the upper cervical spine.