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The Bone & Joint Journal
Vol. 102-B, Issue 5 | Pages 627 - 631
1 May 2020
Mahon J Ahern DP Evans SR McDonnell J Butler JS

Aims. The timing of surgical fixation in spinal fractures is a contentious topic. Existing literature suggests that early stabilization leads to reduced morbidity, improved neurological outcomes, and shorter hospital stay. However, the quality of evidence is low and equivocal with regard to the safety of early fixation in the severely injured patient. This paper compares complication profiles between spinal fractures treated with early fixation and those treated with late fixation. Methods. All patients transferred to a national tertiary spinal referral centre for primary surgical fixation of unstable spinal injuries without preoperative neurological deficit between 1 July 2016 and 20 October 2017 were eligible for inclusion. Data were collected retrospectively. Patients were divided into early and late cohorts based on timing from initial trauma to first spinal operation. Early fixation was defined as within 72 hours, and late fixation beyond 72 hours. Results. In total, 86 patients underwent spinal surgery in this period. Age ranged from 16 to 88 years. Mean Injury Severity Score (ISS) was higher in the early stabilization cohort (p = 0.020). Age was the sole significant independent variable in predicting morbidity on multiple regression analysis (p < 0.003). There was no significant difference in complication rates based on timing of surgical stabilization (p = 0.398) or ISS (p = 0.482). Conclusion. Our results suggest that these patients are suitable for early appropriate care with spinal precautions and delayed definitive surgical stabilization. Earlier surgery conferred no morbidity benefit and had no impact on length of stay. Cite this article: Bone Joint J 2020;102-B(5):627–631


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_6 | Pages 24 - 24
1 Feb 2016
Bertram W Harding I
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Background:. Outcome after traumatic spinal fracture is difficult to predict. Some patients have ongoing pain while others make a good recovery and there is therefore considerable debate as to which fractures should be treated operatively. Delayed operations for ongoing pain post fracture are more expensive with a longer recovery. The sagittal balance of the spine may predict patient outcomes post fracture. Aim:. Identify subjects with stable spine fractures not requiring acute fixation and compare their sagittal parameters measured on initial standing x-ray with whether or not they have ongoing pain. Methods:. A retrospective review was undertaken of patients presenting with a spine fracture to North Bristol Trust over a five year period. Sagittal parameters on initial standing x-rays were measured. The presence or absence of pain at last follow up was recorded. Results:. 399 fractures were identified. 100 were taken to theatre for acute fixation. Only 120 of those remaining had x-rays available which allowed full sagittal parameters to be measured. Clinical outcomes were available on 97 of these subjects. The measurement of pelvic incidence was not found to be significantly different in the two groups (p=0.218). The differences in pelvic tilt between those with and without pain was significant (p=0.004). Conclusion:. A lower pelvic tilt correlates with pain post fracture. Whether this is predictive of pain or not is unclear. Further investigation is indicated to examine the clinical outcomes and economic impact on subjects presenting with a fracture of the spine as well as the economic impact to the health service


The Bone & Joint Journal
Vol. 97-B, Issue 2 | Pages 235 - 239
1 Feb 2015
Prime M Al-Obaidi B Safarfashandi Z Lok Y Mobasheri R Akmal M

This study examined spinal fractures in patients admitted to a Major Trauma Centre via two independent pathways, a major trauma (MT) pathway and a standard unscheduled non-major trauma (NMT) pathway. A total of 134 patients were admitted with a spinal fracture over a period of two years; 50% of patients were MT and the remainder NMT. MT patients were predominantly male, had a mean age of 48.8 years (13 to 95), commonly underwent surgery (62.7%), characteristically had fractures in the cervico-thoracic and thoracic regions and 50% had fractures of more than one vertebrae, which were radiologically unstable in 70%. By contrast, NMT patients showed an equal gender distribution, were older (mean 58.1 years; 12 to 94), required fewer operations (56.7%), characteristically had fractures in the lumbar region and had fewer multiple and unstable fractures. This level of complexity was reflected in the length of stay in hospital; MT patients receiving surgery were in hospital for a mean of three to four days longer than NMT patients. These results show that MT patients differ from their NMT counterparts and have an increasing complexity of spinal injury. Cite this article: Bone Joint J 2015;97-B:235–9


Orthopaedic Proceedings
Vol. 86-B, Issue SUPP_III | Pages 266 - 266
1 Mar 2004
Haentjens P Autier P Collins J Boonen S
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Aims: The aim of our study was to compare relative risk of hip fracture after wrist or spine fracture, in both men and women. Methods: We performed a systematic literature review of cohort studies reported since 1982 that included low-trauma wrist or spine fracture as a risk factor for subsequent hip fracture among (white) women and men aged 50 years or older. A fixed effects meta-analysis was used to calculate a common relative risk (RR) with 95% confidence interval (95% CI). Results: Ten cohort studies (six from the U.S.A. and four from Europe) contributed to this meta-analysis. Among postmenopausal women, RRs for future hip fracture after wrist and spine fracture were 1.53 (95% CI 1.34–1.74, p< 0.001) and 2.22 (95% CI 1.95–2.52, p< 0.001), respectively. The RR was significantly higher after spine fracture than after wrist fracture (p< 0.001). Among ageing men, these RRs for future hip fracture were 3.26 (95% CI 2.08–5.11, p< 0.001) and 3.54 (95% CI 2.01–6.23, p< 0.001), respectively. In contrast to the observation in women, this difference was not statistically significant (p=0.82). The RR was significantly higher in men than in women after wrist fracture (p=0.002), but not after spine fracture (p=0.12). Conclusions: Recent studies have shown consistent and strong prospective associations of hip fracture with previous wrist or spine fracture among postmenopausal women. The findings of our meta-analysis confirm these results and extend them to ageing men. In addition, our results indicate that wrist and spine fractures are equally important risk factors for future hip fracture in ageing men


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXIX | Pages 96 - 96
1 Sep 2012
Kumar A Lee C
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We hypothesised whether MIS techniques confer any benefit when treating thoracolumbar burst fractures. This was a prospective, non-randomised study over the past seven years comparing conservative (bracing:n=27), conventional surgery (open techniques:n=23) and MIS techniques (n=21) for stabilisation and correction of all thoracolumbar spinal fractures with kyphosis of >20. 0. , using Camlok S-RAD 90 system (Stryker Spine). All patients previously had normal spines, sustained only a single level burst fracture (T12, L1 or L2) as their only injury. Age range 18–65 years. All patients in both operatively treated groups were corrected to under 10. 0. of kyphosis, posteriorly only. All pedicle screws/rods were removed between 6 months and 1 year post surgery to remobilise the stabilised segments once the spinal fracture had healed, using the original incisions and muscle splitting/sparing techniques. Patients were assessed via Oswestry Disability Index (ODI) and work/leisure activity status 1 year post fracture. The conservatively treated group fared worst overall, with highest length of stay, poorest return to work/activity, and with a proportion (5/27) requiring later intervention to deal with post-traumatic deformity. 19/27 returned to original occupation, at average 9 months. ODI 32%. Conventional open techniques fared better, with length of stay 5 days, most (19/23) returning to original work/activity, and none requiring later intervention. Average return to work was at 4 months. ODI 14%. MIS group fared best, with shorter length of stay (48 hours), all returning to original work/activity at average 2 months, and none requiring later intervention. ODI negligible. There was no loss of correction in either operatively treated groups. The Camlok S-RAD 90 system is a powerful tool for correction of thoracolumbar burst fractures, and maintains an excellent correction. MIS techniques provide the best outcomes in treating this group of spinal fractures, and offer patients the best chance of restoration to pre-fracture levels of activity


The Journal of Bone & Joint Surgery British Volume
Vol. 71-B, Issue 2 | Pages 256 - 258
1 Mar 1989
Lowe J Kaplan L Liebergall M Floman Y

We report two cases of Serratia marcescens infection at the sites of spinal fractures and emphasise the fact that neurological deterioration soon after spinal fracture may be due to acute vertebral osteomyelitis


The Journal of Bone & Joint Surgery British Volume
Vol. 68-B, Issue 1 | Pages 83 - 90
1 Jan 1986
Fidler M

Seventeen patients with pathological fractures of the thoracolumbar spine which had not responded to conservative treatment are reported. All had compression of the spinal cord and/or severe pain. All (except one treated by lateral rhachotomy) were treated by anterior decompression followed by stabilisation; when the lesion was below T2 the spine was stabilised anteriorly, and when it was higher posterior instrumentation was used. Sixteen of the 17 patients benefited from the procedure.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_III | Pages 518 - 519
1 Aug 2008
Finkelstien J Khoury A Whyne C
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The importance of mechanism of injury was initially introduced by Holdsworth who made the supposition that all fractures are created when the spine is subject to one of 5 types of violence. It has been our experience that similar injury mechanisms can lead to variable fracture patterns. Alternatively, different injury mechanisms can lead to the same fracture pattern.

Purpose: To evaluate the variation in fracture patterns when a single and uniform force vector is applied to the spine with variable degrees of spinal flexion. Finite element modeling was used for this analysis.

Methods: Three different finite element models were created to represent each accident situation. The straight spine was modeled as a simple column with alternating vertebrae and disc segment. The moderately flexed and significantly flexed spines were modeled as curved cylinders sectioned into vertebrae and discs, then bent around a solid cylinder representing the abdomen. A 1000 N compressive load was applied vertically to the top of the spine. The model was restrained along all bottom surfaces, and the interface between the spine and abdomen sections was defined as frictionless. The model is fixed at the lower end and the area of greatest interest is the transition zone from the most rigid to the less rigid portion. Although no specific area of the spine is intended for purposes of the model, this composition is much like the thoracolumbar junction – the location of the majority of spinal injuries.

Results: The straight spine showed pure compression throughout the length of the spine, while the moderately curved spine showed the posterior elements of the region of interest in tension and the anterior elements in compression. The significantly curved spine was found to be in tension in both posterior and anterior elements.

Conclusion: In a situation where the patient is sitting upright with a straight spine, a compressive load will cause a burst fracture. When the patient is partially bent over, such as with a shoulder seat belt, a flexion distraction injury will occur with the posterior aspect of the spine failing in tension and the anterior in compression. When the patient is fully bent over, such as with a laponly seat belt, a purely distractive fracture can occur.


The Bone & Joint Journal
Vol. 98-B, Issue 1 | Pages 109 - 116
1 Jan 2016
Chou P Ma H Liu C Wang S Lee OK Chang M Yu W

Methods

In this study of patients who underwent internal fixation without fusion for a burst thoracolumbar or lumbar fracture, we compared the serial changes in the injured disc height (DH), and the fractured vertebral body height (VBH) and kyphotic angle between patients in whom the implants were removed and those in whom they were not. Radiological parameters such as injured DH, fractured VBH and kyphotic angle were measured. Functional outcomes were evaluated using the Greenough low back outcome scale and a VAS scale for pain.

Results

Between June 1996 and May 2012, 69 patients were analysed retrospectively; 47 were included in the implant removal group and 22 in the implant retention group. After a mean follow-up of 66 months (48 to 107), eight patients (36.3%) in the implant retention group had screw breakage. There was no screw breakage in the implant removal group. All radiological and functional outcomes were similar between these two groups. Although solid union of the fractured vertebrae was achieved, the kyphotic angle and the anterior third of the injured DH changed significantly with time (p < 0.05).


Bone & Joint 360
Vol. 11, Issue 6 | Pages 34 - 36
1 Dec 2022

The December 2022 Spine Roundup. 360. looks at: Deep venous thrombosis prophylaxis protocol on a Level 1 trauma centre patient database; Non-specific spondylodiscitis: a new perspective for surgical treatment; Disc degeneration could be recovered after chemonucleolysis; Three-level anterior cervical discectomy and fusion versus corpectomy- anterior cervical discectomy and fusion “hybrid” procedures: how does the alignment look?; Rivaroxaban or enoxaparin for venous thromboembolism prophylaxis; Surgical site infection: when do we have to remove the implants?; Determination of a neurologic safe zone for bicortical S1 pedicle placement; Do you need to operate on unstable spine fractures in the elderly: outcomes and mortality; Degeneration to deformity: when does the patient need both?


Bone & Joint 360
Vol. 4, Issue 2 | Pages 23 - 25
1 Apr 2015

The April 2015 Spine Roundup360 looks at: Hyperostotic spine in injury; App based back pain control; Interspinous process devices should be avoided in claudication; Robot assisted pedicle screws: fad or advance?; Vancomycin antibiotic power in spinal surgery; What to do with that burst fracture?; Increasing complexity of spinal fractures in major trauma pathways; Vitamin D and spinal fractures


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_9 | Pages 88 - 88
17 Apr 2023
Aljuaid M Alzahrani S Alzahrani A Filimban S Alghamdi N Alswat M
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Cervical spine facet tropism (CFT) defined as the facets’ joints angles difference between right and left sides of more than 7 degrees. This study aims to investigate the relationship between cervical sagittal alignment parameters and cervical spine facets’ tropism. A retrospective cross-sectional study carried out in a tertiary center where cervical spine magnetic resonance imaging (MRI) radiographs of patients in orthopedics/spine clincs were included. They had no history of spine fractures. Images’ reports were reviewed to exclude those with tumors in the c-spine. A total of 96 patients was included with 63% of them were females. The mean of age was 45.53± 12.82. C2-C7 cobb's angle (CA) and C2-C7 sagittal vertical axis (SVA) means were −2.85±10.68 and 1.51± 0.79, respectively. Facet tropism was found in 98% of the sample in at least one level on either axial or sagittal plane. Axial C 2–3 CFT and sagittal C4-5 were correlated with CA (r=0.246, P 0.043, r= −278, P 0.022), respectively. In addition, C2-C7 sagittal vertical axis (SVA) was moderately correlated with axial c2-3 FT (r= −0.330, P 0.006) Also, several significant correlations were detected in our model Cervical vertebral slopes and CFT at the related level. Nonetheless, high BMI was associated with multi-level and multiplane CFT with higher odd's ratios at the lower levels. This study shows that CFT at higher levels is correlated with increasing CA and decreasing SVA and at lower levels with decreasing CA. Obesity is a risk factor for CFT


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_7 | Pages 41 - 41
4 Apr 2023
Benca E Zderic I van Knegsel K Caspar J Hirtler L Fuchssteiner C Strassl A Gueorguiev B Widhalm H Windhager R Varga P
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Odontoid fracture of the second cervical vertebra (C2) is the most common spinal fracture type in elderly patients. However, very little is known about the biomechanical fracture mechanisms, but could play a role in fracture prevention and treatment. This study aimed to investigate the biomechanical competence and fracture characteristics of the odontoid process. A total of 42 human C2 specimens (14 female and 28 male, 71.5 ± 6.5 years) were scanned via quantitative computed tomography, divided in 6 groups (n = 7) and subjected to combined quasi-static loading at a rate of 0.1 mm/s until fracturing at inclinations of −15°, 0° and 15° in sagittal plane, and −50° and 0° in transverse plane. Bone mineral density (BMD), specimen height, fusion state of the ossification centers, stiffness, yield load, ultimate load, and fracture type according to Anderson and d'Alonzo were assessed. While the lowest values for stiffness, yield, and ultimate load were observed at load inclination of 15° in sagittal plane, no statistically significant differences could be observed among the six groups (p = 0.235, p = 0.646, and p = 0.505, respectively). Evaluating specimens with only clearly distinguishable fusion of the ossification centers (n = 26) reveled even less differences among the groups for all mechanical parameters. BMD was positively correlated with yield load (R² = 0.350, p < 0.001), and ultimate load (R² = 0.955, p < 0.001), but not with stiffness (p = 0.070). Type III was the most common fracture type (23.5%). These biomechanical outcomes indicate that load direction plays a subordinate role in traumatic fractures of the odontoid process in contrast to BMD which is a strong determinant of stiffness and strength. Thus, odontoid fractures appear to result from an interaction between load magnitude and bone quality


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_II | Pages 48 - 48
1 Feb 2012
Madhu T Raman R Giannoudis P
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To analyse and compare long-term functional outcome of combined spino-pelvic injuries to an isolated pelvis and spinal fractures, the outcome of matched 30 patients with combined pelvic and spinal fractures was compared with 32 patients with isolated pelvic fractures and 30 patients with isolated spinal fractures. Functional outcome was measured using the self-report questionnaire EuroQol EQ-5D, a generic outcome tool. The functional outcome was compared with the average UK population scores. The mean age, median ISS and demographic profile were similar in all 3 groups. Neurological injuries were seen in 10 patients in the combined injury group, 5 patients in the pelvic injury group and 3 patients in the spinal fracture group. 1 patient had sexual dysfunction in the combined injury group. The EuroQol EQ-5D descriptive scores for the combined group were 0.67±0.11 (0.71±0.12 for spine fracture, 0.61±0.18 for pelvic fracture) and Valuation scores for the combined injury were 69.6±11.4 (65.1±19.4 for spine fracture, 61.5±21.9 for pelvic fracture), which are p=0.004 and p=0.003 for the combined injury compared to the average UK population. Duration of hospital stay was a mean of 13 days in spine injury group compared to 49 days in the combined injury group. 70% of patients with spinal injuries returned to the same level of employment in a mean duration of 5.3 months with only 10% retired due to injury; compared to 56.6% returned to work in the combined injury group after a mean duration of 12.8 months with 23.3% retired due to injury. Long-term functional outcome is significantly better with isolated spinal injuries compared to pelvic injury or combined injury. There is no significant long-term difference between the combined spino-pelvic group and the isolated pelvic injury group. We feel that the spinal injuries in a patient with coexisting pelvic fracture do not contribute towards the overall functional outcome in those patients


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_10 | Pages 44 - 44
1 Oct 2019
Watt T Abbott C Oxborrow N Siddique I Verma R Angus M
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Purpose. A Virtual Spinal Clinic (VSC) was set-up at a regional spinal referral centre to see if patient care could be improved through early advice to provide timely management, early onward referral, improve patient satisfaction and minimise chronicity. The clinic was based on the successful virtual model used throughout the country within orthopaedic fracture clinics. VSC is a Consultant led multi-disciplinary (MDT) clinic run by Advanced Practitioners (AP). Methods. A 3-month trial of the VSC was completed bi-weekly. Patients diagnosed with conservatively managed spinal fractures were referred from the on-call service. A management plan was devised by a Consultant Spinal Surgeon and communicated to patients by the AP via a telephone-call consultation where clinical advice and management could be discussed. Results. 23 clinics completed. 271 patient contacts. 216 reviewed virtually. Completed outcomes of VSC. 34.65% Discharged. 51.18% Routine appointment. 14.17% Urgent appointment. Conclusion. VSC successfully completed safe and timely assessments, management plans, telephone consultations and onward referrals for Greater Manchester patients with acute spinal fractures. Patients had earlier access to health professionals to provide advice, reassurance, complete onward referrals and safety-netting. Patient satisfaction improved, with patient reporting the telephone consultation was reassuring and allowed early return to previous function. VSC reduced patients waiting time for a follow-up appointment and reduced patients travel time across Greater Manchester. In the future, it is hoped that the 6-week follow-up telephone call service will be utilised more as VSC develops. No conflicts of interest. No funding obtained


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_I | Pages 64 - 64
1 Mar 2008
Sahajpal V Fisher C Dvorak M
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A prospective cohort outcome evaluation of unstable thoracic spine fractures treated with posterior pedicle screw fixation. The purpose of this study was to determine the accuracy of placement and safety of pedicle screws in open reduction of unstable thoracic spine fractures. The surgeries were performed by one of five fellowship trained spinal surgeons. CT scans were formed on twenty-three patients totaling two hundred screws using 3mm cuts. Three independent reviewers assessed and categorized the screw position as within the pedicle or as a violation of the pedicle wall. 98% of the screws were accurate and we recommend the use of pedicle screws in thoracic fractures . A prospective cohort outcome evaluation of unstable thoracic spine fractures treated with posterior pedicle screw fixation. This study is to determine the accuracy of placement, safety of pedicle screws in open reduction of unstable thoracic spine fracture. Surgery was performed by one of five fellowship trained spine surgeons. CT scans were performed on twenty-three patients using 3mm cuts in both sagittal and transverse planes. Pedicle screw position was assessed by three independent reviewers. Screw position was categorized as within the wall of the pedicle or in violation of the wall. Further sub-classification of pedicle wall violation reviewed the direction and distance of perforation. Independent perioperative and postoperative surveillance for complications was done. Twenty-three unstable thoracic spine fractures treated with two hundred posterior pedicle screws were analyzed. The pedicle screws spanned from T1-T12 with the majority of screws in the mid-thoracic region. Of the two hundred thoracic pedicle screws placed, 70% were fully contained within the pedicle wall. The remaining screws were deemed “out” with cortical perforation (30%). Of these, 20% were lateral perforations, 5% were medial perforations and 5% were anterolateral perforations. No superior, inferior, or anteromedial perforations were found. There was no regional area variation in incidence of perforations. 10% of all perforations were directly related to pedicle diameter to screw diameter mismatch. There were no adverse neurological, vascular, or visceral injuries detected intraoperatively or postoperatively. Surgical management of unstable thoracic spine fractures with posterior pedicle screw fixation is safe. 98% of screws had satisfactory accuracy. Although very minor misplacement of pedicle screws occurred, there were no complications and we recommend the use of pedicle screws in thoracic fractures


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_II | Pages 222 - 223
1 May 2006
Molloy S Jayakumar P Kaila R Gow F Saifuddin A
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Background: There is conflicting evidence of correlation between clinical outcome and severity of thoracolumbar spine fractures in neurologically intact patients. 1. Kalyan et al2 presented the results of their prospective study of thoracolumbar spinal fractures and concluded that the clinical outcome was consistently better predicted by the severity of disc injury than that of the bony fracture. They suggested that if severe disc injury was present, treatment of the disc injury may result in a better short term clinical outcome. The aim of this study was to detail the incidence and type of disc injury in patients with thoracolumbar spinal fractures with intact neurology. Methods: Retrospective analysis of a prospectively collected spinal injury database at a regional spinal injuries unit. Only patients with a thoracolumbar spinal fracture and intact neurology were included. Retrospective analysis of magnetic resonance imaging (MRI) findings. One hundred and thirty nine neurologically intact patients (89M:50F, mean age 36 years, range 15 – 77yrs) with a thoracolumbar (T11 –L5) spinal fracture were admitted to our spinal unit over the last 11 years (1994 – 2004). Patient data was collected prospectively onto a spinal injuries database. All of these patients had an MRI scan on admission. All types of thoracolumbar fracture were included in this study and the presence or absence of an associated disc injury was recorded retrospectively from the MRI study. The type of disc injury was also recorded. Results: The incidence of severe disc injury adjacent to a thoracolumbar spinal fracture in our cohort of patients was 43% (60 patients). Disc prolapse or extradural herniation was seen in 16 patients (11%). Intraosseous disc herniation into an adjacent vertebral body was seen in 20 patients (14%). Internal disc disruption was seen in 24 patients (17%). Disc injury was found at more than one level in 21 patients (15%). Conclusion: The incidence of severe disc injury in our study of neurologically intact patients with a thoracolumbar fracture was considerable (43%). Kalyan et al. 2. suggested that treatment directed at addressing the disc injury in these patients may promote earlier pain relief and also earlier return to pre-morbid activities. If this is the case, then the decision making regarding operative versus non-operative management, in a patient with a thoracolumbar fracture and intact neurology, should be based on the severity of the disc injury as well as the bony injury


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_4 | Pages 50 - 50
1 Apr 2019
Dharia M Wentz D Mimnaugh K
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INTRODUCTION. Tibiofemoral contact at the base of the articular surface spine in posterior-stabilized total knee arthroplasty (TKA) implants can lead to spine fracture [1]. Revision TKA implants also have an articular surface spine to provide sufficient constraint when soft tissues are compromised. While some revision TKA designs have metal reinforcement in the articular surface spine, others rely solely on a polyethylene spine. This study used finite element analysis (FEA) to study the effect of metal reinforcement on stresses in the spine when subjected to posteriorly directed loading. METHODS. Two clinically successful Zimmer Biomet revision TKA designs were selected; NexGen LCCK with metal reinforcement and all-poly Vanguard SSK. The largest sizes were selected. FEA models consisted of the polyethylene articular surface and a CoCr femoral component; LCCK also included a CoCr metal reinforcement in the spine. A 7° and 0° tibial slope, as well as 3° and 0.7° femoral hyperextension, were used for the LCCK and SSK, respectively. A posteriorly directed load was applied to the spine through the femoral component (Figure 1). The base of the articular surface was constrained. The articular surfaces for both designs are made from different polyethylene materials. However, for the purpose of this study, to isolate the effect of material differences on stresses, both were modeled using conventional GUR1050 nonlinear polyethylene material properties. Femoral component and metal reinforcement were modeled using linear elastic CoCr properties. Additionally, the LCCK was reanalyzed by replacing the metal reinforcement component with polyethylene material, in order to isolate the effect of metal reinforcement for an otherwise equivalent design. Frictional sliding contact was modeled between the spine and femoral/metal reinforcement components. Nonlinear static analyses were performed using Ansys version 17 software and peak von mises stresses in the spine were compared. RESULTS. Peak von mises stresses were predicted towards the base of the anterior aspect of the spine in both designs (Figure 2). In LCCK, the high stresses were also predicted on the medial and lateral edges of the anterior spine, matching the tibiofemoral contact (Figure 3). The LCCK with metal reinforcement design predicted 14% and 31% lower stress than LCCK and SSK all-poly designs. DISCUSSION. Clinical reports of spine fracture in TKA highlight the need for further understanding of the biomechanics of spine loading. Here, through comparison of two clinically successful devices, the effect of multiple design factors was quantified. Inclusion of metal reinforcement in the spine, as well as differences in the conforming geometry between the femoral component and the articular surface, resulted in a 31% decrease in polyethylene stress for the LCCK as compared to the all-poly SSK; of which only 16% was attributed to the metal reinforcement. Further improvements to articular surface design, as well as polyethylene material advances, have the potential to result in all-poly designs with strength characteristics equivalent to or exceeding those of designs with metal reinforcement


The Journal of Bone & Joint Surgery British Volume
Vol. 68-B, Issue 2 | Pages 178 - 181
1 Mar 1986
Gopalakrishnan K el Masri W

Twelve cases of sternal injury associated with spinal fractures have been reviewed. The sternum is regularly buckled or fractured in patients with high thoracic spinal fractures. Our review suggests that sternal injuries may also be associated with spinal fractures outside this region, and with types of fracture other than crushing of vertebral bodies. Injury to the sternum, when due to indirect violence, is almost always associated with a severe spinal column injury. A displaced fracture of the thoracic spine, with or without an associated sternal fracture, can produce significant widening of the mediastinal shadow on a chest radiograph. This is caused by a paravertebral haematoma, and can be difficult to differentiate from widening due to an aortic rupture


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_I | Pages 23 - 23
1 Mar 2009
Kelalis G Zahariou K Kollintzas L Kalampokis A Morakis A
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PURPOSE: To record our experience in surgical treatment of thoracic spine fractures with posterior stabilization, decompression and ligamentotaxis. MATERIALS AND METHODS: From January 2000 until July 2006, 67 patients (48 males and 19 females), aged 16 to 85 years old (average 41,2 y.o) were surgically treated in our department due to thoracic spine fractures. Preoperative X-Ray and CT scan were used in all cases while in most of the cases we performed MRI to further evaluate the damage. In all cases we performed decompression and posterior stabilization using four different hardware types and whenever possible ligamentotaxis. Continuous electrophysiological monitoring was alo ued in all operations. We recorded the pre- and postoperative neurological status, the vertebral height loss, the kyphotic angle and spinal canal occupation. Moreover we recorded the average hospitalization time, the transfusion needs as well as major and minor complications. At the follow-up we measured the loss of correction at 3, 6 and 12 months postoperatively. The follow up ranged from 4 to 48 months. RESULTS: Neurological damage was recorded in 43 % of the patients. The average preoperative kyphotic angle was 38.2° while the average spinal canal occupation was 29.8 %. The immediate postoperative correction was 16.7 °. During the follow-up we observed small, insignificant loss of correction. There were no major complications. CONCLUSION: In cases of thoracic spine fractures the surgical treatment with posterior stabilization and ligamentotaxis is offering significant stability and adequate long term results