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External Immobilization of Odontoid Fractures: A Systematic Review to Compare the Halo and Hard Collar
Accepted Manuscript External immobilisation of odontoid fractures: a systematic review to compare the halo and hard collar Mueez Waqar, MB ChB, MRes, Dmitri Van-Popta, FRCS, Damiano G. Barone, MD, MRCS, Zaid Sarsam, FRCS PII:
S1878-8750(16)31023-3
DOI:
10.1016/j.wneu.2016.10.035
Reference:
WNEU 4703
To appear in:
World Neurosurgery
Received Date: 28 June 2016 Revised Date:
3 October 2016
Accepted Date: 5 October 2016
Please cite this article as: Waqar M, Van-Popta D, Barone DG, Sarsam Z, External immobilisation of odontoid fractures: a systematic review to compare the halo and hard collar, World Neurosurgery (2016), doi: 10.1016/j.wneu.2016.10.035. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
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External immobilisation of odontoid fractures: a systematic review to compare the halo and hard collar
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Article Type: Systematic review Authors and affiliations Mueez Waqar1, MB ChB, MRes Dmitri Van-Popta1, FRCS Damiano G Barone2, MD, MRCS Zaid Sarsam2, FRCS
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1. 2. 3. 4.
Correspondance Please send all correspondence to:
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Department of 1Spinal Surgery, Salford Royal NHS Foundation Trust, Stott Lane, Salford M6 8HD Department of 2Neurosurgery, The Walton Centre NHS Foundation Trust, Liverpool, Merseyside L9 7LJ
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Dr Mueez Waqar Salford Royal NHS Foundation Trust Stott Lane Manchester M6 8HD UK +44 161 789 7373
Funding This study was not funded in any way.
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Conflicts of interest The authors declare that they have no conflicts of interest that may have influenced this work.
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Highlights
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Current data relating to the external immobilisation of odontoid fractures, is sparse and of poor quality. There is no difference in failure rates between the halo and collar for the commonest type of odontoid fractures. Malunion in odontoid fractures usually represents a stable clinical outcome and surgical intervention is rarely required. Although mortality rates are similar, the complication rate is higher with the halo.
Abstract
Introduction. The aim of this systematic review was to compare the halo and hard collar in the management of adult odontoid fractures.
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Methods. Systematic and independent searches on MEDLINE (PubMed) and the Cochrane database. Inclusion criteria: (1) clinical outcomes, (2) in adults (≥18), (3) with odontoid fractures, (4) immobilised using a halo or hard collar, (5) in multiple (>5) patients. Treatment failure rates were calculated as the proportion requiring operative intervention. Results. 714 cases were included, managed in a halo (60%) or collar (40%). The mean age was 66 (range 18-96). Type 2 odontoid fractures were the commonest (83%). There was no significant difference in failure rates between the halo and collar in patients with type 2 odontoid fractures (p = 0.111). This was also true in elderly (>65) patients (p = 0.802). The collar had a higher failure rate in type 3 odontoid fractures, though numbers were small (p = 0.035). Fibrous malunion occurred in 56 patients and only 7% failed. There was only one case of neurological deterioration. Although mortality rates were similar between the collar and halo (p = 0.173), the halo was associated with a significantly higher complication rate (p < 0.001).
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Conclusions. For the commonest clinical scenario, the halo and collar have similar failure rates, such that the higher morbidity associated with the halo may not be justified, especially in elderly patients. Malunion usually represents a stable clinical outcome and surgery is rarely required. Prospective randomised studies are awaited to more definitively compare the devices.
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Odontoid fractures; cervical spine; spinal fractures; halo; collar; external immobilisation.
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Introduction
Odontoid fractures constitute between 10-20% of cervical fractures and occur most commonly in elderly patients.1-3 They are the most common spinal fracture type in the over 70 age group.4 Extrapolation from national figures yields an overall incidence of around 2-3 per 100,000 of the western population, and this number is increasing.1, 5 Although this increase could be attributed solely to an ageing population, the number of C2 fractures, of which odontoid fractures are the most common subgroup, are increasing at a rate more than threefold the elderly population growth rate.5
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As with most spinal fractures, odontoid fractures occur more commonly in males, with an imbalanced gender ratio of about 3:1.1 The most common causes of these fractures are road traffic accidents and low velocity falls, in younger and older patients, respectively.6 The mechanism of injury is usually forced hyperextension or hyperflexion, which exerts significant stress at the base of the odontoid, the most common site of injury.
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The Anderson-D’Alonzo classification for odontoid fractures divides them into three types. Briefly, type I fractures occur obliquely through the odontoid process itself and are generally stable injuries. Type 2 fractures are the commonest odontoid fractures, occurring at the junction between the base of the odontoid process and the body of C2. These fractures are inherently unstable. Type 3 fractures occur more caudally than type 2 fractures and involve the body of C2. Their stability is variable.7
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Management of odontoid fractures involves advanced trauma and life support principles, with early surgical fixation or external immobilisation for unstable fractures. Several studies have evaluated the need for surgical fixation, and an upcoming multicentre randomised controlled trial will help to more definitively answer this question.8, 9 An important consideration in patients managed conservatively, is the choice of immobilisation technique. Few studies have evaluated this variable, though it is of direct clinical relevance. It appears to be even more important currently, as more patients are being managed conservatively.10 Two popular devices to immobilise the cervical spine are the halo and the hard cervical collar. Studies have shown that these devices restrict cervical spine movement to a similar degree in healthy subjects.11, 12 In cadaveric studies, the halo has been shown to be superior in restricting spinal movement.13 However, the clinical efficacy of these devices in the context of adult odontoid fractures remains unknown. The aim of this review is to compare these treatment modalities in the light of existing literature.
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Search strategy Our search strategy was registered on Prospero (Registration number CRD42015019262). The MEDLINE database (PubMed interface) was queried using combinations of the following keywords: odontoid, dens, axis, C2, fracture*, conservative, halo, collar, orthosis, immobilisation. MeSH terms used included: “odontoid process”. Articles were limited to the English language. The search was performed until 06/2015. Two authors (MW and DVP) working independently from one another examined titles and abstracts from the electronic list. Study inclusion criteria were as follows: (1) clinical outcomes, (2) in adult patients (≥18), (3) with odontoid fractures, (4) immobilised using a halo or hard collar as the primary intervention, (5) to be included, studies had to present outcomes with both devices in multiple patients (n > 5). Data extraction and analysis Data was extracted into an electronic spreadsheet. From each study, data concerning patient demographics, treatment and follow-up, was extracted. Data concerning complications, quality of life measures, neurological outcomes and mortality was also collected. Subgroup analysis was carried out based on fracture type. The risk of bias was assessed at study and outcome levels, by considering the proportions of patients in each subgroup. Studies were not excluded based on unequal group sizes but this factor was considered in interpretation of results.
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Outcomes The primary outcome was rate of treatment failure, defined as the need for operative intervention after a course of conservative treatment. Secondary outcomes included rates of malunion, complications, mortality, neurological outcomes and quality of life outcomes. Descriptive statistics were used in data analysis. Fisher’s Exact test was used to compare proportions in two-by-two contingency tables. Statistics was performed using SPSS version 20 (SPSS Inc., Chicago, Illinois, USA).
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Results Studies included The initial search revealed 846 unique references and 81 abstracts were reviewed. 15 articles meeting inclusion criteria were identified, of which 12 presented data on rates of treatment failure after use of a Halo or collar in patients with odontoid fractures (Table 1).6, 14-27 All studies were retrospective, non-randomised case-series.
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Patient characteristics 714 published cases were managed non-operatively in a halo (n = 430, 60%) or collar (n = 284, 40%). The mean age was 66 (range 18-96). The majority (n = 593, 83%) of patients had sustained type 2 odontoid fractures and were treated in a halo (n = 339, 57%) or collar (n = 254, 43%). A smaller number had sustained type 3 odontoid fractures (n = 120, 17%), treated in a halo (n = 90, 75%) or collar (n = 30, 25%). Type 3 odontoid fractures were more likely to be managed with a halo than type 2 fractures (Fisher’s Exact, p = 0.007). There was only one reported case of an unstable type 1 odontoid fracture managed in a halo, with successful outcome.14
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Treatment failure Data relating to the primary outcome was available in 501 cases (including one type 1 odontoid fracture), treated with a collar (n = 149) or halo (n = 352). Data from these cases is presented in Table 1 and Fig. 1. In patients with type 2 odontoid fractures, there was no significant difference in failure rates between the collar and halo (31/119, 26% vs. 45/261, 17%; Fisher’s Exact, p = 0.111). In patients with type 3 odontoid fractures, the collar had a significantly higher failure rate, though numbers were small (5/30, 17% vs. 3/90, 3%; Fisher’s Exact, p = 0.035).
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Data relating to the primary outcome in only elderly patients (>65) was available in 148 patients. There was no difference in failure rate between the collar and halo in elderly patients (8/82, 10% vs. 9/66, 14%; Fisher's Exact, p = 0.610). In type 2 odontoid fractures in elderly patients, there was also no difference in failure rate between the collar and halo (8/52, 15% vs. 9/74, 12%; Fisher's Exact, p = 0.802). Data relating to the primary outcome in only young patients (<70) was presented in only one study yielding a small sample of 36 patients, but again there was no significant difference in failure rate between the collar and halo (2/10, 20% vs. 3/26, 12%; Fisher's Exact, p = 0.620).6 Failure rates were also compared between type 2 and type 3 odontoid fractures. Overall, type 2 odontoid fractures had a higher failure rate than type 3 fractures (76/380, 20% vs. 8/120, 7%; Fisher's Exact, p = 0.003). In patients managed with a collar, type 2 fractures had a higher failure rate than type 3 fractures, though differences were not statistically significant (31/119, 26% vs. 5/30, 17%; Fisher’s Exact, p = 0.482). In patients managed with a halo, type 2 fractures had a significantly higher failure rate than type 3 fractures (45/261, 17% vs. 3/90, 3%; Fisher’s Exact, p = 0.002).
Complications and mortality Fibrous malunion was noted in 56 cases overall and only 4 cases required surgical fixation, representing a failure rate of 7%. There was no significant difference in failure rates of malunited fractures managed in a collar or halo (3/25, 12% vs. 1/29, 3%; Fisher’s Exact, p = 0.345).
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Neurological outcomes were almost universally favourable. There was only 1 reported case of neurological deterioration, in an elderly lady with dementia who attempted self-removal of a collar, resulting in quadriplegia and death.18 Data relating to complications was available in 461 cases (Table 2). In the collar group, 15% (26/172) of patients experienced complications and most of these (18/26, 69%) were unspecified in studies. In the halo group, 34% (98/289) of patients experienced complications. The proportion of medical complications (44/98, 45%) was relatively high in the halo group. Overall, the complication rate was higher with a halo than collar (98/289, 34% vs. 26/172, 15%; Fisher’s Exact, p < 0.001).
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Mortality data was available in 477 cases. Mortality rates were similar between the collar and halo (50/221, 23% vs. 42/256, 16%; Fisher’s Exact, p = 0.173). Mortality data in elderly patients (>65) was available in 301 cases. Mortality rates were similar between the collar and halo in elderly patients (46/176, 26% vs. 31/125, 25%; Fisher's Exact, p = 0.897). Three studies had used allcause mortality as the primary method to compare between the collar and halo 20, 22, 25. Data from these studies also showed that the collar and halo had similar mortality rates (42/135, 31% vs. 27/78, 35%; Fisher’s Exact, p = 0.775).
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Functional outcomes Functional outcomes were reported in two studies.21, 23 In one study, patients managed in a collar had significantly lower rates of shoulder and neck pain, physical symptoms such as paraesthesias and weakness, as well as psychological distress. Oddly, patients managed in a halo had less restriction to engage in normal activities, than patients managed in a collar. Neck pain scores were lower in patients managed in a collar, though differences were not statistically significant.23 Another study reported functional outcomes but did not use statistical tests to evaluate the significance of differences.21
Discussion
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The halo and hard collar are commonly used in the external immobilisation of odontoid fractures. In this study, we reviewed existing literature and found that for the most clinical scenario - type 2 odontoid fractures, failure rates were similar between the devices. This was true regardless of patient age, though the number of young patients was small. Although the halo had a superior outcome in type 3 odontoid fractures, numbers were again small. Fibrous malunion signified a stable clinical outcome in the majority of patients and surgery was rarely required in this setting. Neurological complications were almost never reported. Although mortality rates were similar between the devices, the halo was associated with significantly higher complication rate, which may preclude its use in elderly patients.
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Treatment failure The rate of surgical intervention was used as a more clinically relevant indicator of device failure than absolute rates of non-union and/or mal-union. This is because several patients with odontoid fractures display clinical stability on follow-up, with imperfect union on imaging. Such patients are excluded from the present definition of treatment failure. Some believe that this group is at a higher risk of delayed neurological complications, though this is probably in the context of further trauma.17, 28 The pertinent finding of our review is that for the commonest odontoid fracture type (type 2 fractures), failure rates were statistically similar between the halo and collar. Although this was not found with type 3 fractures, unequal numbers precluded meaningful interpretation of these results. Indeed, there were only 30 type 3 odontoid fractures treated in a collar, of which 5 failed, but 4 of these failures were reported by a single study.15 These 4 failed cases consisted of 1 case of nonunion and 3 cases of mal-union; it is unusual that the authors intervened in 3 cases of mal-union, out of the 4 mal-union cases they reported. This study represents an early reported experience with odontoid fractures, such that surgical intervention may not have been clinically required in all of these cases of mal-union, though this is purely speculative. Exclusion of this study’s results would have produced homologous failure rates with the two devices.23, 26, 27
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ACCEPTED MANUSCRIPT Our findings contrast to another recently published review. Delcourt et al. recently reviewed the literature to evaluate outcomes of upper cervical fractures in general in elderly patients. They concluded that the halo had the highest rates of non-union, morbidity and mortality and should therefore no longer be used in this age group.29 Actually, we have found that in elderly patients, the halo and collar have similar outcomes and mortality, but complication rate of the halo is significantly higher. Therefore, it is hard to justify use of the halo in these patients. In younger patients, although we found similarly that the halo and collar had similar outcomes, the sample size was too small to allow for a meaningful conclusion to be formed in this age group.
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Factors influencing outcome Factors reported to predict outcome include age, degree of fracture displacement and fracture type. Studies have generally recommended collar immobilisation in elderly (>65) patients.6, 19, 26, 27 This is due to the high morbidity associated with halo immobilisation, though mortality rates are similar between collar and halo, as we found. Fracture type was also found to influence outcome, with a higher failure rate in patients with type 2 fractures.14, 17, 27 Type 3 fractures extend into the body of the odontoid, such that vascular and mechanical factors that can limit union in type 2 fractures, are less likely to affect fracture healing.
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Malunion Patients with fibrous union or “malunion” rarely underwent surgery. This complication tends to occur in elderly patients and in fact, patients may ultimately go on to complete fracture healing. Hanssen et al. reported 2 cases of type 2 odontoid fractures with malunion, both of whom went on to complete trabecular union at up to 15 months follow-up.16 Several authors have affirmed the stability of malunited odontoid fractures and not recommended further treatment.6, 14, 15, 17, 18, 21 However, notably, the lack of bony union can be associated with significant neck pain.6
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Complications Common complications with the halo include pin-site infection, aspiration, pneumonia and respiratory failure. Complications with hard collars are generally rare and include skin abrasions, though patients can also experience similar respiratory compromise to those treated in a halo.24 Long-term neurological complications are rare.6, 15, 19 There were significantly more complications with the halo.6, 20, 22, 23, 26 In one study, respiratory complications occurred in 31% of the halo group, versus 4% of patients managed in a hard collar.22
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Quality of life outcomes are generally lacking in the literature. One study used the Cervical Spine Outcome Questionnaire (CSOQ) and found that raw scores for neck pain, shoulder and arm pain, physical symptoms (e.g. numbness, weakness, clumsiness) and psychological distress, were better in patients treated with a collar. However, and perhaps unexpectedly, the patient-reported rate of functional disability, assessing limitation of activities, was higher in patients managed with a hard collar.23 These results should be interpreted with caution due to the limited number of patients treated with a collar, as well as the lack of multivariate statistics to account for variables such as age, for each reported outcome. Limitations Our findings are based on retrospective case series, which employ an open-label, non-randomised design, without matched controls. There were significant differences in study inclusion and exclusion criteria, such that summation of results is unreliable. Studies were also heterogeneous in data presented, with few presenting data on key variables that affect fracture healing (e.g. fracture displacement/angulation). For example, it is possible that patients treated with halos had a larger degree of fracture displacement/angulation which may have biased results. Some studies did not include data on rates of re-intervention, such that rates of non-union had to be substituted as appropriate. There were also differences in study follow-up periods and this may be particularly relevant in the case of malunion. Our analysis was based on univariate statistics as there was insufficient data concerning confounding variables to derive a multivariate model.
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Conclusion
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In this review we used existing literature, comprised of retrospective case series, to compare the halo and hard collar for immobilisation of odontoid fractures. For the commonest clinical scenario that of type 2 odontoid fractures, we found that failure rates were similar between the two devices. This was also true in elderly patients, and although mortality rates were similar, the higher complication rate of the halo makes its use hard to justify in this age group. Other conclusions are difficult to draw using the existing evidence base and multicentre randomised controlled trials are required to evaluate the comparative efficacy of these devices in the external immobilisation of odontoid fractures.
Acknowledgements The authors have no acknowledgements.
References
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1. Fredo HL, Rizvi SA, Lied B, Ronning P, Helseth E. The epidemiology of traumatic cervical spine fractures: a prospective population study from Norway. Scandinavian journal of trauma, resuscitation and emergency medicine 2012;20:85. 2. Tee JW, Chan CH, Fitzgerald MC, Liew SM, Rosenfeld JV. Epidemiological trends of spine trauma: an Australian level 1 trauma centre study. Global spine journal 2013;3(2):75-84. 3. Wang H, Xiang Q, Li C, Zhou Y. Epidemiology of traumatic cervical spinal fractures and risk factors for traumatic cervical spinal cord injury in China. Journal of spinal disorders & techniques 2013;26(8):E306-13. 4. Ryan MD, Henderson JJ. The epidemiology of fractures and fracture-dislocations of the cervical spine. Injury 1992;23(1):38-40. 5. Zusman NL, Ching AC, Hart RA, Yoo JU. Incidence of second cervical vertebral fractures far surpassed the rate predicted by the changing age distribution and growth among elderly persons in the United States (2005-2008). Spine 2013;38(9):752-6. 6. Muller EJ, Wick M, Russe O, Muhr G. Management of odontoid fractures in the elderly. European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society 1999;8(5):360-5. 7. Anderson LD, D'Alonzo RT. Fractures of the odontoid process of the axis. The Journal of bone and joint surgery American volume 1974;56(8):1663-74. 8. Shears E, Armitstead CP. Surgical versus conservative management for odontoid fractures. Cochrane Database Syst Rev 2008(4):CD005078. 9. Huybregts JG, Jacobs WC, Peul WC, Vleggeert-Lankamp CL. Rationale and design of the INNOVATE Trial: an international cooperative study on surgical versus conservative treatment for odontoid fractures in the elderly. BMC musculoskeletal disorders 2014;15:7. 10. Pearson AM, Martin BI, Lindsey M, Mirza SK. C2 Vertebral Fractures in the Medicare Population: Incidence, Outcomes, and Costs. The Journal of bone and joint surgery American volume 2016;98(6):449-56. 11. Schneider AM, Hipp JA, Nguyen L, Reitman CA. Reduction in head and intervertebral motion provided by 7 contemporary cervical orthoses in 45 individuals. Spine 2007;32(1):E1-6. 12. Koller H, Zenner J, Hitzl W, Ferraris L, Resch H, Tauber M, et al. In vivo analysis of atlantoaxial motion in individuals immobilized with the halo thoracic vest or Philadelphia collar. Spine 2009;34(7):670-9. 13. Richter D, Latta LL, Milne EL, Varkarakis GM, Biedermann L, Ekkernkamp A, et al. The stabilizing effects of different orthoses in the intact and unstable upper cervical spine: a cadaver study. J Trauma 2001;50(5):848-54. 14. Wang GJ, Mabie KN, Whitehill R, Stamp WG. The nonsurgical management of odontoid fractures in adults. Spine 1984;9(3):229-30. 15. Clark CR, White AA, 3rd. Fractures of the dens. A multicenter study. The Journal of bone and joint surgery American volume 1985;67(9):1340-8.
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16. Hanssen AD, Cabanela ME. Fractures of the dens in adult patients. J Trauma 1987;27(8):928-34. 17. Polin RS, Szabo T, Bogaev CA, Replogle RE, Jane JA. Nonoperative management of Types II and III odontoid fractures: the Philadelphia collar versus the halo vest. Neurosurgery 1996;38(3):450-6; discussion 6-7. 18. Seybold EA, Bayley JC. Functional outcome of surgically and conservatively managed dens fractures. Spine 1998;23(17):1837-45; discussion 45-6. 19. Kuntz Ct, Mirza SK, Jarell AD, Chapman JR, Shaffrey CI, Newell DW. Type II odontoid fractures in the elderly: early failure of nonsurgical treatment. Neurosurgical focus 2000;8(6):e7. 20. Tashjian RZ, Majercik S, Biffl WL, Palumbo MA, Cioffi WG. Halo-vest immobilization increases early morbidity and mortality in elderly odontoid fractures. J Trauma 2006;60(1):199-203. 21. Koech F, Ackland HM, Varma DK, Williamson OD, Malham GM. Nonoperative management of type II odontoid fractures in the elderly. Spine 2008;33(26):2881-6. 22. Smith HE, Kerr SM, Maltenfort M, Chaudhry S, Norton R, Albert TJ, et al. Early complications of surgical versus conservative treatment of isolated type II odontoid fractures in octogenarians: a retrospective cohort study. Journal of spinal disorders & techniques 2008;21(8):535-9. 23. Butler JS, Dolan RT, Burbridge M, Hurson CJ, O'Byrne JM, McCormack D, et al. The longterm functional outcome of type II odontoid fractures managed non-operatively. European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society 2010;19(10):1635-42. 24. Lewis E, Liew S, Dowrick A. Risk factors for non-union in the non-operative management of type II dens fractures. ANZ journal of surgery 2011;81(9):604-7. 25. Schoenfeld AJ, Bono CM, Reichmann WM, Warholic N, Wood KB, Losina E, et al. Type II odontoid fractures of the cervical spine: do treatment type and medical comorbidities affect mortality in elderly patients? Spine 2011;36(11):879-85. 26. France JC, Powell EN, 2nd, Emery SE, Jones DL. Early morbidity and mortality associated with elderly odontoid fractures. Orthopedics 2012;35(6):e889-94. 27. Patel A, Zakaria R, Al-Mahfoudh R, Clark S, Barrett C, Sarsam Z, et al. Conservative management of type II and III odontoid fractures in the elderly at a regional spine centre: A prospective and retrospective cohort study. Br J Neurosurg 2014:1-5. 28. Kepler CK, Vaccaro AR, Dibra F, Anderson DG, Rihn JA, Hilibrand AS, et al. Neurologic injury because of trauma after type II odontoid nonunion. The spine journal : official journal of the North American Spine Society 2014;14(6):903-8. 29. Delcourt T, Begue T, Saintyves G, Mebtouche N, Cottin P. Management of upper cervical spine fractures in elderly patients: current trends and outcomes. Injury 2015;46 Suppl 1:S24-7.
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Table and figure captions
Table 1. Reported rates of treatment failure in patients with odontoid fractures treated with a halo or a hard cervical collar. Please note that this table only includes those studies presenting data relating to treatment failure. Treatment failure was defined as intention to treat with surgical fixation after failure of external immobilisation. The rate of non-union was used if data concerning re-intervention was not presented. *Grouped other cervical orthoses with collars, but these were accounted for where possible. Avg = average; NR = not reported.
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Table 2. Complications in patients with odontoid fractures treated with a collar (n = 172) or halo (n = 289). In the collar group, complications were mostly unspecified in the literature. In the halo group, medical complications were very common and almost as common as device related complications grouped together. *The other or unspecified category includes 18 unspecified cases in the collar group. In the halo group, the category includes 3 cases of neck stiffness, 1 case of pinsite related facial palsy and 3 unspecified complications.
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Figure 1. Treatment failure rates. Treatment failure was defined as the need for operative intervention after a course of conservative treatment. In patients with type 2 odontoid fractures, there was no significant difference in failure rates between the collar and halo (p = 0.111). This was also true in elderly (>65) patients (p = 0.802). In patients with type 3 odontoid fractures, the collar had a higher failure rate (p = 0.035), though differences in group sizes did not allow for a meaningful comparison. Fibrous malunion also represented a relatively stable clinical outcome as only a minority of patients (4/56) required operative fixation. OF = odontoid fractures; NS = not significant; * = significant (p<0.05).
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Table 1. Reported rates of treatment failure in patients with odontoid fractures treated with a halo or a hard cervical collar. Please note that this table only includes those studies presenting data relating to treatment failure. Treatment failure was defined as intention to treat with surgical fixation after failure of external immobilisation. The rate of non-union was used if data concerning reintervention was not presented. *Grouped other cervical orthoses with collars, but these were accounted for where possible. Avg = average; NR = not reported.
Treatment failure
Avg age (range)
Avg followup, months (range)
Collar type
Type 2 fractures
Type 3 fractures
Collar
Halo
Collar
Halo
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Level of evidence
Study
Wang 198414
IV
40 (17-80)
NR (>3)
Clark 198515
IV
Type 2: 42.7 (14-84) Type 3: 43.9 (11-86)
NR
Hanssen 198716
IV
50.4 (14-87)
29 (5-77)
Polin 199617
IV
50.7 (NR)
Seybold 199818
IV
Muller 19996
IV
4/7*
1/5
0/2*
0/10
NR
2/3*
8/38
4/10*
2/16
Philadelphia
1/2
2/10
NR
0/14
8 (2.5-56)
Philadelphia
4/16
3/19
0/5
0/13
51.8 (16-93)
29 (2-120)
Philadelphia
0/5
7/23
NR
1/21
80.9 (71-96)
NR
Philadelphia
5/14
0/3
0/1
NR
47.6 (15-69)
NR
Philadelphia
1/5
3/18
1/5
0/8
81 (66-92)
13 (2-32)
Miami J
0/2
4/8
NR
NR
IV
Koech 200821
IV
80 (67-91)
24 (9-24)
Philadelphia/ Aspen
1/10
0/32
NR
NR
Butler 201023
IV
41.92 (NR)
66 (NR)
Miami J
0/6
0/44
NR
NR
Lewis 201124
IV
NR (≥18)
NR (>6)
NR
11/17
12/30
NR
NR
France 201226
IV
81.7 (>65)
8.5 (0-33)
NR
0/9
2/15
NR
NR
IV
78 (60-92)
6 (NR)
Aspen
2/23
3/16
0/7
0/8
31/119
45/261
5/30
3/90
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Patel 201427
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Kuntz 200019
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Philadelphia
Total
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Table 2. Complications in patients with odontoid fractures treated with a collar (n = 172) or halo (n = 289). In the collar group, complications were mostly unspecified in the literature. In the halo group, medical complications were very common and almost as common as device related complications grouped together. *The other or unspecified category includes 18 unspecified cases in the collar group. In the halo group, the category includes 3 cases of neck stiffness, 1 case of pin-site related facial palsy and 3 unspecified complications Collar, n (% of all complications in group)
Halo, n (% of all complications in group)
Site infection or pressure related ulceration from collar or pins
3 (12%)
20 (20%)
Mechanical device failure (e.g. pin loosening)
0 (0%)
Medical complications (e.g. pneumonia)
5 (19%)
Other or unspecified*
18 (69%)
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Total
27 (28%)
44 (45%)
7 (7%) 98
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ACCEPTED MANUSCRIPT Conflicts of interest
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The authors declare that they have no conflicts of interest that may have influenced this work.
S1878-8750(16)31023-3
DOI:
10.1016/j.wneu.2016.10.035
Reference:
WNEU 4703
To appear in:
World Neurosurgery
Received Date: 28 June 2016 Revised Date:
3 October 2016
Accepted Date: 5 October 2016
Please cite this article as: Waqar M, Van-Popta D, Barone DG, Sarsam Z, External immobilisation of odontoid fractures: a systematic review to compare the halo and hard collar, World Neurosurgery (2016), doi: 10.1016/j.wneu.2016.10.035. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
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External immobilisation of odontoid fractures: a systematic review to compare the halo and hard collar
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Article Type: Systematic review Authors and affiliations Mueez Waqar1, MB ChB, MRes Dmitri Van-Popta1, FRCS Damiano G Barone2, MD, MRCS Zaid Sarsam2, FRCS
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1. 2. 3. 4.
Correspondance Please send all correspondence to:
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Department of 1Spinal Surgery, Salford Royal NHS Foundation Trust, Stott Lane, Salford M6 8HD Department of 2Neurosurgery, The Walton Centre NHS Foundation Trust, Liverpool, Merseyside L9 7LJ
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Dr Mueez Waqar Salford Royal NHS Foundation Trust Stott Lane Manchester M6 8HD UK +44 161 789 7373
Funding This study was not funded in any way.
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Conflicts of interest The authors declare that they have no conflicts of interest that may have influenced this work.
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Highlights
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Current data relating to the external immobilisation of odontoid fractures, is sparse and of poor quality. There is no difference in failure rates between the halo and collar for the commonest type of odontoid fractures. Malunion in odontoid fractures usually represents a stable clinical outcome and surgical intervention is rarely required. Although mortality rates are similar, the complication rate is higher with the halo.
Abstract
Introduction. The aim of this systematic review was to compare the halo and hard collar in the management of adult odontoid fractures.
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Methods. Systematic and independent searches on MEDLINE (PubMed) and the Cochrane database. Inclusion criteria: (1) clinical outcomes, (2) in adults (≥18), (3) with odontoid fractures, (4) immobilised using a halo or hard collar, (5) in multiple (>5) patients. Treatment failure rates were calculated as the proportion requiring operative intervention. Results. 714 cases were included, managed in a halo (60%) or collar (40%). The mean age was 66 (range 18-96). Type 2 odontoid fractures were the commonest (83%). There was no significant difference in failure rates between the halo and collar in patients with type 2 odontoid fractures (p = 0.111). This was also true in elderly (>65) patients (p = 0.802). The collar had a higher failure rate in type 3 odontoid fractures, though numbers were small (p = 0.035). Fibrous malunion occurred in 56 patients and only 7% failed. There was only one case of neurological deterioration. Although mortality rates were similar between the collar and halo (p = 0.173), the halo was associated with a significantly higher complication rate (p < 0.001).
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Conclusions. For the commonest clinical scenario, the halo and collar have similar failure rates, such that the higher morbidity associated with the halo may not be justified, especially in elderly patients. Malunion usually represents a stable clinical outcome and surgery is rarely required. Prospective randomised studies are awaited to more definitively compare the devices.
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Odontoid fractures; cervical spine; spinal fractures; halo; collar; external immobilisation.
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Introduction
Odontoid fractures constitute between 10-20% of cervical fractures and occur most commonly in elderly patients.1-3 They are the most common spinal fracture type in the over 70 age group.4 Extrapolation from national figures yields an overall incidence of around 2-3 per 100,000 of the western population, and this number is increasing.1, 5 Although this increase could be attributed solely to an ageing population, the number of C2 fractures, of which odontoid fractures are the most common subgroup, are increasing at a rate more than threefold the elderly population growth rate.5
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As with most spinal fractures, odontoid fractures occur more commonly in males, with an imbalanced gender ratio of about 3:1.1 The most common causes of these fractures are road traffic accidents and low velocity falls, in younger and older patients, respectively.6 The mechanism of injury is usually forced hyperextension or hyperflexion, which exerts significant stress at the base of the odontoid, the most common site of injury.
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The Anderson-D’Alonzo classification for odontoid fractures divides them into three types. Briefly, type I fractures occur obliquely through the odontoid process itself and are generally stable injuries. Type 2 fractures are the commonest odontoid fractures, occurring at the junction between the base of the odontoid process and the body of C2. These fractures are inherently unstable. Type 3 fractures occur more caudally than type 2 fractures and involve the body of C2. Their stability is variable.7
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Management of odontoid fractures involves advanced trauma and life support principles, with early surgical fixation or external immobilisation for unstable fractures. Several studies have evaluated the need for surgical fixation, and an upcoming multicentre randomised controlled trial will help to more definitively answer this question.8, 9 An important consideration in patients managed conservatively, is the choice of immobilisation technique. Few studies have evaluated this variable, though it is of direct clinical relevance. It appears to be even more important currently, as more patients are being managed conservatively.10 Two popular devices to immobilise the cervical spine are the halo and the hard cervical collar. Studies have shown that these devices restrict cervical spine movement to a similar degree in healthy subjects.11, 12 In cadaveric studies, the halo has been shown to be superior in restricting spinal movement.13 However, the clinical efficacy of these devices in the context of adult odontoid fractures remains unknown. The aim of this review is to compare these treatment modalities in the light of existing literature.
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Search strategy Our search strategy was registered on Prospero (Registration number CRD42015019262). The MEDLINE database (PubMed interface) was queried using combinations of the following keywords: odontoid, dens, axis, C2, fracture*, conservative, halo, collar, orthosis, immobilisation. MeSH terms used included: “odontoid process”. Articles were limited to the English language. The search was performed until 06/2015. Two authors (MW and DVP) working independently from one another examined titles and abstracts from the electronic list. Study inclusion criteria were as follows: (1) clinical outcomes, (2) in adult patients (≥18), (3) with odontoid fractures, (4) immobilised using a halo or hard collar as the primary intervention, (5) to be included, studies had to present outcomes with both devices in multiple patients (n > 5). Data extraction and analysis Data was extracted into an electronic spreadsheet. From each study, data concerning patient demographics, treatment and follow-up, was extracted. Data concerning complications, quality of life measures, neurological outcomes and mortality was also collected. Subgroup analysis was carried out based on fracture type. The risk of bias was assessed at study and outcome levels, by considering the proportions of patients in each subgroup. Studies were not excluded based on unequal group sizes but this factor was considered in interpretation of results.
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Outcomes The primary outcome was rate of treatment failure, defined as the need for operative intervention after a course of conservative treatment. Secondary outcomes included rates of malunion, complications, mortality, neurological outcomes and quality of life outcomes. Descriptive statistics were used in data analysis. Fisher’s Exact test was used to compare proportions in two-by-two contingency tables. Statistics was performed using SPSS version 20 (SPSS Inc., Chicago, Illinois, USA).
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Results Studies included The initial search revealed 846 unique references and 81 abstracts were reviewed. 15 articles meeting inclusion criteria were identified, of which 12 presented data on rates of treatment failure after use of a Halo or collar in patients with odontoid fractures (Table 1).6, 14-27 All studies were retrospective, non-randomised case-series.
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Patient characteristics 714 published cases were managed non-operatively in a halo (n = 430, 60%) or collar (n = 284, 40%). The mean age was 66 (range 18-96). The majority (n = 593, 83%) of patients had sustained type 2 odontoid fractures and were treated in a halo (n = 339, 57%) or collar (n = 254, 43%). A smaller number had sustained type 3 odontoid fractures (n = 120, 17%), treated in a halo (n = 90, 75%) or collar (n = 30, 25%). Type 3 odontoid fractures were more likely to be managed with a halo than type 2 fractures (Fisher’s Exact, p = 0.007). There was only one reported case of an unstable type 1 odontoid fracture managed in a halo, with successful outcome.14
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Treatment failure Data relating to the primary outcome was available in 501 cases (including one type 1 odontoid fracture), treated with a collar (n = 149) or halo (n = 352). Data from these cases is presented in Table 1 and Fig. 1. In patients with type 2 odontoid fractures, there was no significant difference in failure rates between the collar and halo (31/119, 26% vs. 45/261, 17%; Fisher’s Exact, p = 0.111). In patients with type 3 odontoid fractures, the collar had a significantly higher failure rate, though numbers were small (5/30, 17% vs. 3/90, 3%; Fisher’s Exact, p = 0.035).
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Data relating to the primary outcome in only elderly patients (>65) was available in 148 patients. There was no difference in failure rate between the collar and halo in elderly patients (8/82, 10% vs. 9/66, 14%; Fisher's Exact, p = 0.610). In type 2 odontoid fractures in elderly patients, there was also no difference in failure rate between the collar and halo (8/52, 15% vs. 9/74, 12%; Fisher's Exact, p = 0.802). Data relating to the primary outcome in only young patients (<70) was presented in only one study yielding a small sample of 36 patients, but again there was no significant difference in failure rate between the collar and halo (2/10, 20% vs. 3/26, 12%; Fisher's Exact, p = 0.620).6 Failure rates were also compared between type 2 and type 3 odontoid fractures. Overall, type 2 odontoid fractures had a higher failure rate than type 3 fractures (76/380, 20% vs. 8/120, 7%; Fisher's Exact, p = 0.003). In patients managed with a collar, type 2 fractures had a higher failure rate than type 3 fractures, though differences were not statistically significant (31/119, 26% vs. 5/30, 17%; Fisher’s Exact, p = 0.482). In patients managed with a halo, type 2 fractures had a significantly higher failure rate than type 3 fractures (45/261, 17% vs. 3/90, 3%; Fisher’s Exact, p = 0.002).
Complications and mortality Fibrous malunion was noted in 56 cases overall and only 4 cases required surgical fixation, representing a failure rate of 7%. There was no significant difference in failure rates of malunited fractures managed in a collar or halo (3/25, 12% vs. 1/29, 3%; Fisher’s Exact, p = 0.345).
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Neurological outcomes were almost universally favourable. There was only 1 reported case of neurological deterioration, in an elderly lady with dementia who attempted self-removal of a collar, resulting in quadriplegia and death.18 Data relating to complications was available in 461 cases (Table 2). In the collar group, 15% (26/172) of patients experienced complications and most of these (18/26, 69%) were unspecified in studies. In the halo group, 34% (98/289) of patients experienced complications. The proportion of medical complications (44/98, 45%) was relatively high in the halo group. Overall, the complication rate was higher with a halo than collar (98/289, 34% vs. 26/172, 15%; Fisher’s Exact, p < 0.001).
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Mortality data was available in 477 cases. Mortality rates were similar between the collar and halo (50/221, 23% vs. 42/256, 16%; Fisher’s Exact, p = 0.173). Mortality data in elderly patients (>65) was available in 301 cases. Mortality rates were similar between the collar and halo in elderly patients (46/176, 26% vs. 31/125, 25%; Fisher's Exact, p = 0.897). Three studies had used allcause mortality as the primary method to compare between the collar and halo 20, 22, 25. Data from these studies also showed that the collar and halo had similar mortality rates (42/135, 31% vs. 27/78, 35%; Fisher’s Exact, p = 0.775).
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Functional outcomes Functional outcomes were reported in two studies.21, 23 In one study, patients managed in a collar had significantly lower rates of shoulder and neck pain, physical symptoms such as paraesthesias and weakness, as well as psychological distress. Oddly, patients managed in a halo had less restriction to engage in normal activities, than patients managed in a collar. Neck pain scores were lower in patients managed in a collar, though differences were not statistically significant.23 Another study reported functional outcomes but did not use statistical tests to evaluate the significance of differences.21
Discussion
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The halo and hard collar are commonly used in the external immobilisation of odontoid fractures. In this study, we reviewed existing literature and found that for the most clinical scenario - type 2 odontoid fractures, failure rates were similar between the devices. This was true regardless of patient age, though the number of young patients was small. Although the halo had a superior outcome in type 3 odontoid fractures, numbers were again small. Fibrous malunion signified a stable clinical outcome in the majority of patients and surgery was rarely required in this setting. Neurological complications were almost never reported. Although mortality rates were similar between the devices, the halo was associated with significantly higher complication rate, which may preclude its use in elderly patients.
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Treatment failure The rate of surgical intervention was used as a more clinically relevant indicator of device failure than absolute rates of non-union and/or mal-union. This is because several patients with odontoid fractures display clinical stability on follow-up, with imperfect union on imaging. Such patients are excluded from the present definition of treatment failure. Some believe that this group is at a higher risk of delayed neurological complications, though this is probably in the context of further trauma.17, 28 The pertinent finding of our review is that for the commonest odontoid fracture type (type 2 fractures), failure rates were statistically similar between the halo and collar. Although this was not found with type 3 fractures, unequal numbers precluded meaningful interpretation of these results. Indeed, there were only 30 type 3 odontoid fractures treated in a collar, of which 5 failed, but 4 of these failures were reported by a single study.15 These 4 failed cases consisted of 1 case of nonunion and 3 cases of mal-union; it is unusual that the authors intervened in 3 cases of mal-union, out of the 4 mal-union cases they reported. This study represents an early reported experience with odontoid fractures, such that surgical intervention may not have been clinically required in all of these cases of mal-union, though this is purely speculative. Exclusion of this study’s results would have produced homologous failure rates with the two devices.23, 26, 27
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ACCEPTED MANUSCRIPT Our findings contrast to another recently published review. Delcourt et al. recently reviewed the literature to evaluate outcomes of upper cervical fractures in general in elderly patients. They concluded that the halo had the highest rates of non-union, morbidity and mortality and should therefore no longer be used in this age group.29 Actually, we have found that in elderly patients, the halo and collar have similar outcomes and mortality, but complication rate of the halo is significantly higher. Therefore, it is hard to justify use of the halo in these patients. In younger patients, although we found similarly that the halo and collar had similar outcomes, the sample size was too small to allow for a meaningful conclusion to be formed in this age group.
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Factors influencing outcome Factors reported to predict outcome include age, degree of fracture displacement and fracture type. Studies have generally recommended collar immobilisation in elderly (>65) patients.6, 19, 26, 27 This is due to the high morbidity associated with halo immobilisation, though mortality rates are similar between collar and halo, as we found. Fracture type was also found to influence outcome, with a higher failure rate in patients with type 2 fractures.14, 17, 27 Type 3 fractures extend into the body of the odontoid, such that vascular and mechanical factors that can limit union in type 2 fractures, are less likely to affect fracture healing.
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Malunion Patients with fibrous union or “malunion” rarely underwent surgery. This complication tends to occur in elderly patients and in fact, patients may ultimately go on to complete fracture healing. Hanssen et al. reported 2 cases of type 2 odontoid fractures with malunion, both of whom went on to complete trabecular union at up to 15 months follow-up.16 Several authors have affirmed the stability of malunited odontoid fractures and not recommended further treatment.6, 14, 15, 17, 18, 21 However, notably, the lack of bony union can be associated with significant neck pain.6
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Complications Common complications with the halo include pin-site infection, aspiration, pneumonia and respiratory failure. Complications with hard collars are generally rare and include skin abrasions, though patients can also experience similar respiratory compromise to those treated in a halo.24 Long-term neurological complications are rare.6, 15, 19 There were significantly more complications with the halo.6, 20, 22, 23, 26 In one study, respiratory complications occurred in 31% of the halo group, versus 4% of patients managed in a hard collar.22
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Quality of life outcomes are generally lacking in the literature. One study used the Cervical Spine Outcome Questionnaire (CSOQ) and found that raw scores for neck pain, shoulder and arm pain, physical symptoms (e.g. numbness, weakness, clumsiness) and psychological distress, were better in patients treated with a collar. However, and perhaps unexpectedly, the patient-reported rate of functional disability, assessing limitation of activities, was higher in patients managed with a hard collar.23 These results should be interpreted with caution due to the limited number of patients treated with a collar, as well as the lack of multivariate statistics to account for variables such as age, for each reported outcome. Limitations Our findings are based on retrospective case series, which employ an open-label, non-randomised design, without matched controls. There were significant differences in study inclusion and exclusion criteria, such that summation of results is unreliable. Studies were also heterogeneous in data presented, with few presenting data on key variables that affect fracture healing (e.g. fracture displacement/angulation). For example, it is possible that patients treated with halos had a larger degree of fracture displacement/angulation which may have biased results. Some studies did not include data on rates of re-intervention, such that rates of non-union had to be substituted as appropriate. There were also differences in study follow-up periods and this may be particularly relevant in the case of malunion. Our analysis was based on univariate statistics as there was insufficient data concerning confounding variables to derive a multivariate model.
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Conclusion
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In this review we used existing literature, comprised of retrospective case series, to compare the halo and hard collar for immobilisation of odontoid fractures. For the commonest clinical scenario that of type 2 odontoid fractures, we found that failure rates were similar between the two devices. This was also true in elderly patients, and although mortality rates were similar, the higher complication rate of the halo makes its use hard to justify in this age group. Other conclusions are difficult to draw using the existing evidence base and multicentre randomised controlled trials are required to evaluate the comparative efficacy of these devices in the external immobilisation of odontoid fractures.
Acknowledgements The authors have no acknowledgements.
References
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1. Fredo HL, Rizvi SA, Lied B, Ronning P, Helseth E. The epidemiology of traumatic cervical spine fractures: a prospective population study from Norway. Scandinavian journal of trauma, resuscitation and emergency medicine 2012;20:85. 2. Tee JW, Chan CH, Fitzgerald MC, Liew SM, Rosenfeld JV. Epidemiological trends of spine trauma: an Australian level 1 trauma centre study. Global spine journal 2013;3(2):75-84. 3. Wang H, Xiang Q, Li C, Zhou Y. Epidemiology of traumatic cervical spinal fractures and risk factors for traumatic cervical spinal cord injury in China. Journal of spinal disorders & techniques 2013;26(8):E306-13. 4. Ryan MD, Henderson JJ. The epidemiology of fractures and fracture-dislocations of the cervical spine. Injury 1992;23(1):38-40. 5. Zusman NL, Ching AC, Hart RA, Yoo JU. Incidence of second cervical vertebral fractures far surpassed the rate predicted by the changing age distribution and growth among elderly persons in the United States (2005-2008). Spine 2013;38(9):752-6. 6. Muller EJ, Wick M, Russe O, Muhr G. Management of odontoid fractures in the elderly. European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society 1999;8(5):360-5. 7. Anderson LD, D'Alonzo RT. Fractures of the odontoid process of the axis. The Journal of bone and joint surgery American volume 1974;56(8):1663-74. 8. Shears E, Armitstead CP. Surgical versus conservative management for odontoid fractures. Cochrane Database Syst Rev 2008(4):CD005078. 9. Huybregts JG, Jacobs WC, Peul WC, Vleggeert-Lankamp CL. Rationale and design of the INNOVATE Trial: an international cooperative study on surgical versus conservative treatment for odontoid fractures in the elderly. BMC musculoskeletal disorders 2014;15:7. 10. Pearson AM, Martin BI, Lindsey M, Mirza SK. C2 Vertebral Fractures in the Medicare Population: Incidence, Outcomes, and Costs. The Journal of bone and joint surgery American volume 2016;98(6):449-56. 11. Schneider AM, Hipp JA, Nguyen L, Reitman CA. Reduction in head and intervertebral motion provided by 7 contemporary cervical orthoses in 45 individuals. Spine 2007;32(1):E1-6. 12. Koller H, Zenner J, Hitzl W, Ferraris L, Resch H, Tauber M, et al. In vivo analysis of atlantoaxial motion in individuals immobilized with the halo thoracic vest or Philadelphia collar. Spine 2009;34(7):670-9. 13. Richter D, Latta LL, Milne EL, Varkarakis GM, Biedermann L, Ekkernkamp A, et al. The stabilizing effects of different orthoses in the intact and unstable upper cervical spine: a cadaver study. J Trauma 2001;50(5):848-54. 14. Wang GJ, Mabie KN, Whitehill R, Stamp WG. The nonsurgical management of odontoid fractures in adults. Spine 1984;9(3):229-30. 15. Clark CR, White AA, 3rd. Fractures of the dens. A multicenter study. The Journal of bone and joint surgery American volume 1985;67(9):1340-8.
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16. Hanssen AD, Cabanela ME. Fractures of the dens in adult patients. J Trauma 1987;27(8):928-34. 17. Polin RS, Szabo T, Bogaev CA, Replogle RE, Jane JA. Nonoperative management of Types II and III odontoid fractures: the Philadelphia collar versus the halo vest. Neurosurgery 1996;38(3):450-6; discussion 6-7. 18. Seybold EA, Bayley JC. Functional outcome of surgically and conservatively managed dens fractures. Spine 1998;23(17):1837-45; discussion 45-6. 19. Kuntz Ct, Mirza SK, Jarell AD, Chapman JR, Shaffrey CI, Newell DW. Type II odontoid fractures in the elderly: early failure of nonsurgical treatment. Neurosurgical focus 2000;8(6):e7. 20. Tashjian RZ, Majercik S, Biffl WL, Palumbo MA, Cioffi WG. Halo-vest immobilization increases early morbidity and mortality in elderly odontoid fractures. J Trauma 2006;60(1):199-203. 21. Koech F, Ackland HM, Varma DK, Williamson OD, Malham GM. Nonoperative management of type II odontoid fractures in the elderly. Spine 2008;33(26):2881-6. 22. Smith HE, Kerr SM, Maltenfort M, Chaudhry S, Norton R, Albert TJ, et al. Early complications of surgical versus conservative treatment of isolated type II odontoid fractures in octogenarians: a retrospective cohort study. Journal of spinal disorders & techniques 2008;21(8):535-9. 23. Butler JS, Dolan RT, Burbridge M, Hurson CJ, O'Byrne JM, McCormack D, et al. The longterm functional outcome of type II odontoid fractures managed non-operatively. European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society 2010;19(10):1635-42. 24. Lewis E, Liew S, Dowrick A. Risk factors for non-union in the non-operative management of type II dens fractures. ANZ journal of surgery 2011;81(9):604-7. 25. Schoenfeld AJ, Bono CM, Reichmann WM, Warholic N, Wood KB, Losina E, et al. Type II odontoid fractures of the cervical spine: do treatment type and medical comorbidities affect mortality in elderly patients? Spine 2011;36(11):879-85. 26. France JC, Powell EN, 2nd, Emery SE, Jones DL. Early morbidity and mortality associated with elderly odontoid fractures. Orthopedics 2012;35(6):e889-94. 27. Patel A, Zakaria R, Al-Mahfoudh R, Clark S, Barrett C, Sarsam Z, et al. Conservative management of type II and III odontoid fractures in the elderly at a regional spine centre: A prospective and retrospective cohort study. Br J Neurosurg 2014:1-5. 28. Kepler CK, Vaccaro AR, Dibra F, Anderson DG, Rihn JA, Hilibrand AS, et al. Neurologic injury because of trauma after type II odontoid nonunion. The spine journal : official journal of the North American Spine Society 2014;14(6):903-8. 29. Delcourt T, Begue T, Saintyves G, Mebtouche N, Cottin P. Management of upper cervical spine fractures in elderly patients: current trends and outcomes. Injury 2015;46 Suppl 1:S24-7.
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Table and figure captions
Table 1. Reported rates of treatment failure in patients with odontoid fractures treated with a halo or a hard cervical collar. Please note that this table only includes those studies presenting data relating to treatment failure. Treatment failure was defined as intention to treat with surgical fixation after failure of external immobilisation. The rate of non-union was used if data concerning re-intervention was not presented. *Grouped other cervical orthoses with collars, but these were accounted for where possible. Avg = average; NR = not reported.
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Table 2. Complications in patients with odontoid fractures treated with a collar (n = 172) or halo (n = 289). In the collar group, complications were mostly unspecified in the literature. In the halo group, medical complications were very common and almost as common as device related complications grouped together. *The other or unspecified category includes 18 unspecified cases in the collar group. In the halo group, the category includes 3 cases of neck stiffness, 1 case of pinsite related facial palsy and 3 unspecified complications.
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Figure 1. Treatment failure rates. Treatment failure was defined as the need for operative intervention after a course of conservative treatment. In patients with type 2 odontoid fractures, there was no significant difference in failure rates between the collar and halo (p = 0.111). This was also true in elderly (>65) patients (p = 0.802). In patients with type 3 odontoid fractures, the collar had a higher failure rate (p = 0.035), though differences in group sizes did not allow for a meaningful comparison. Fibrous malunion also represented a relatively stable clinical outcome as only a minority of patients (4/56) required operative fixation. OF = odontoid fractures; NS = not significant; * = significant (p<0.05).
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Table 1. Reported rates of treatment failure in patients with odontoid fractures treated with a halo or a hard cervical collar. Please note that this table only includes those studies presenting data relating to treatment failure. Treatment failure was defined as intention to treat with surgical fixation after failure of external immobilisation. The rate of non-union was used if data concerning reintervention was not presented. *Grouped other cervical orthoses with collars, but these were accounted for where possible. Avg = average; NR = not reported.
Treatment failure
Avg age (range)
Avg followup, months (range)
Collar type
Type 2 fractures
Type 3 fractures
Collar
Halo
Collar
Halo
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Level of evidence
Study
Wang 198414
IV
40 (17-80)
NR (>3)
Clark 198515
IV
Type 2: 42.7 (14-84) Type 3: 43.9 (11-86)
NR
Hanssen 198716
IV
50.4 (14-87)
29 (5-77)
Polin 199617
IV
50.7 (NR)
Seybold 199818
IV
Muller 19996
IV
4/7*
1/5
0/2*
0/10
NR
2/3*
8/38
4/10*
2/16
Philadelphia
1/2
2/10
NR
0/14
8 (2.5-56)
Philadelphia
4/16
3/19
0/5
0/13
51.8 (16-93)
29 (2-120)
Philadelphia
0/5
7/23
NR
1/21
80.9 (71-96)
NR
Philadelphia
5/14
0/3
0/1
NR
47.6 (15-69)
NR
Philadelphia
1/5
3/18
1/5
0/8
81 (66-92)
13 (2-32)
Miami J
0/2
4/8
NR
NR
IV
Koech 200821
IV
80 (67-91)
24 (9-24)
Philadelphia/ Aspen
1/10
0/32
NR
NR
Butler 201023
IV
41.92 (NR)
66 (NR)
Miami J
0/6
0/44
NR
NR
Lewis 201124
IV
NR (≥18)
NR (>6)
NR
11/17
12/30
NR
NR
France 201226
IV
81.7 (>65)
8.5 (0-33)
NR
0/9
2/15
NR
NR
IV
78 (60-92)
6 (NR)
Aspen
2/23
3/16
0/7
0/8
31/119
45/261
5/30
3/90
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Patel 201427
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Kuntz 200019
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Philadelphia
Total
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Table 2. Complications in patients with odontoid fractures treated with a collar (n = 172) or halo (n = 289). In the collar group, complications were mostly unspecified in the literature. In the halo group, medical complications were very common and almost as common as device related complications grouped together. *The other or unspecified category includes 18 unspecified cases in the collar group. In the halo group, the category includes 3 cases of neck stiffness, 1 case of pin-site related facial palsy and 3 unspecified complications Collar, n (% of all complications in group)
Halo, n (% of all complications in group)
Site infection or pressure related ulceration from collar or pins
3 (12%)
20 (20%)
Mechanical device failure (e.g. pin loosening)
0 (0%)
Medical complications (e.g. pneumonia)
5 (19%)
Other or unspecified*
18 (69%)
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Total
27 (28%)
44 (45%)
7 (7%) 98
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ACCEPTED MANUSCRIPT Conflicts of interest
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The authors declare that they have no conflicts of interest that may have influenced this work.