RANDOMIZED COMPARATIVE STUDY OF DEFINITIVE EXTERNAL FIXATION VERSUS ORIF IN PILON FRACTURES: AN EARLY CLINICAL OUTCOME REPORT

Repairing Pilon fractures remains challenging. ORIF allows direct anatomical reduction, but at the expense of soft tissues dissection which are associated with recovery. On the other hand, External Fixation allows indirect reduction and causes less soft tissue damage. However, a few studies conclude that External Fixation is associated with high rates of malunion.The objectives were to evaluate and compare: primary outcome measure: ankle hindfoot function (AOFAS at 9 months) and secondary outcome measures: quality of reduction, bone union, arthritic changes, other potential complications and ultimately the optimum management for pilon fractures.A prospective randomized comparative clinical study. 40 Patients were included in the study with comminuted closed Pilon fracture. Patients were randomized by closed envelope technique into two groups: Group (1) Included 20 patients managed by external fixation with limited internal fixation. Group (2) Included 20 patients managed by open reduction and internal fixation. Skeletally immature, type 43A AO/OTA, Open fractures, compartment syndrome, Pathological fractures were excluded.There was no significant difference between External fixation and ORIF as methods of fixation for Pilon fracture in the functional activity of the patient after 9 months as evidenced by AOFAS score (P=0.547) and the development of complications (P=0.227). However, there was statistically significant difference (P<0.001) regarding the time to weight bearing between both groups, and statistically significant difference (P=0.042) regarding time to union.The best surgical modality to treat Pilon fractures is still debatable. While external fixation is used by many to avoid major complications, it has been associated with high rates of malunion, and osteoarthritis.

AB0712 Digital Ischemic Complications in Systemic sclerosis associated Raynaud’s: Prevalence, Risk factors and Treatment patterns from a Single Center Cohort

Background

A significant number of Systemic sclerosis (SSc) patients with Raynaud’s phenomenon (RP) experience digital ischemic complications (DICs-digital ulcers, digital pitting/scars, gangrene and/or amputation).

Objectives

We reviewed the prevalence & risk factors for DICs in SSc-RP and compared treatment patterns among patients with & without DICs.

Methods

SSc patients meeting ACR/EULAR 2013 classification criteria that underwent an upper extremity arterial study between 2001-2018 were included. Clinical characteristics, treatment for RP, use of antiplatelet (aspirin 81 mg), statin therapy & occurrence of DICs, digital occlusive arterial disease (DOAD) on laser doppler flowmetry (LDF) and macrovascular disease (MVD) on duplex US were abstracted. Risk factors for DICs and their associations with therapy were evaluated.

Results

We identified 273 SSc patients (mean age 57±13 y, 81% F, 93% Caucasian, mean disease duration 4.8 ± 7.1 y). Cohort characteristics are described in Table 1. 79% (217/273) patients experienced DICs (digital ulcers 203, digital pitting/scar 138, digital gangrene 76). Patients with DICs had a higher prevalence of DOAD (89% vs 54%, p <0.001), MVD (32% vs 9%, p <0.001), ILD (41% vs. 27%, p=0.04), calcinosis (95/192 (49%) vs. 7/44 (16%), p<0.001), and pericardial effusion (25% vs. 12%, p=0.047), compared to those without DICs. No difference was noted between the 2 groups in regard to skin severity, smoking, BMI, hypertension, hyperlipidemia, diabetes, coronary artery disease, telangiectasias, pulmonary hypertension, renal crisis, GI dysmotility or myositis.

Treatment patterns are described in Figure 1. Calcium channel blocker (CCB) and phosphodiesterase 5 inhibitor (PDE5I) use was higher among SSc patients with DICs than in those without DICs (CCBs: 53% vs. 34%, p=0.01; PDE5: 29% vs. 2%, p=0.01) likely due to confounding by indication. The use of aspirin or statins was not associated with DICs, even after adjusting for CV risk factors (ASA: OR 0.83, 95% CI 0.45-1.54; statin OR 0.67, 95% CI 0.28-1.62).

Conclusion

Our study confirms a high prevalence of DICs in SSc, with digital ulcers occurring in nearly 75% patients. A higher risk of DICs is associated with DOAD, MVD, ILD, calcinosis and pericardial effusion. While there is a significantly higher utilization of vasodilators among patients with DICs, the utilization of antiplatelet therapy and statins was not different among these groups. Whether this suggests a lack of evidence supporting their use in clinical practice, or inefficacy in preventing DICs remains unclear and warrants further study.

Table 1.Overall (N=273)DICs (N=217)No DICs (N=56)p-valueDemographicsAge at procedure(y); mean (SD)57.5 (13.3)56.9 (13.6)59.4 (11.8)0.25Sex (Female)220 (81%)173 (80%)47 (84%)0.48Race (White)253 (93%)199 (92%)54 (96%)0.73BMI (kg/m2) at study; mean (SD)26.6 (6.1)26.3 (6.1)27.4 (6.1)0.14Smoking statusNever154 (56%)120 (55%)34 (61%)0.76Former102 (37%)83 (38%)19 (34%)Current17 (6%)14 (6%)3 (5%)Disease characteristicsSSc subtype:Limited211 (77%)166 (76%)45 (80%)0.18Diffuse59 (22%)49 (23%)10 (18%)Time from SSc diagnosis to duplex US (months) mean (SD)57.9 (85.7)63.5 (91.5)36.1 (52.9)0.04Digital occlusive arterial disease223 (82%)193 (89%)30 (54%)<0.001Macrovascular disease74 (27%)69 (32%)5 (9%)<0.001Ulnar Occlusive disease68 (25%)63 (29%)5 (9%)0.002Telangiectasias239 (88%)192 (89%)47 (84%)0.27Calcinosis102 (43%)95 (49%)7 (16%)<0.001Interstitial lung disease105 (38%)90 (41%)15 (27%)0.04Pulmonary hypertension50 (18%)43 (20%)7 (12%)0.21Pericardial effusion61 (22%)54 (25%)7 (12%)0.047Gastrointestinal dysmotility194 (71%)159 (73%)35 (62%)0.11Renal crisis17 (6%)12 (6%)5 (9%)0.35SSc specific antibodies:175 (68%)138 (67%)38 (69%)0.77Centromere116 (63%)95 (63%)21 (64%)0.97Scl-7048 (19%)36 (18%)12 (22%)0.57RNA-Polymerase19 (20%)14 (19%)5 (22%)0.79Figure 1.

Disclosure of Interests

None declared

POS0325 RADIOMIC BIOMARKER OF PULMONARY VASCULAR RELATED STRUCTURES PREDICTS MORTALITY IN SYSTEMIC SCLEROSIS

Background:

Quantitative computed tomography (QCT) extracts features from high-resolution CT scans and quantifies lung parenchymal and vascular abnormalities which may not be discernable by qualitative review. The threshold values of individual parenchymal abnormalities and vascular features measured by QCT methods which associate with mortality in systemic sclerosis (SSc) are currently unknown.

Objectives:

To determine whether QCT measures, specifically pulmonary parenchymal abnormalities and pulmonary vascular related structures (PVRS), can predict mortality in SSc and to determine the optimal quantitative thresholds for those parameters.

Methods:

A total of 133 subjects (76% women) meeting 2013 ACR/EULAR classification criteria for SSc with a baseline CT within 3 years of diagnosis were retrospectively identified for inclusion. CALIPER (Computer-Aided Lung Informatics for Pathology Evaluation and Rating) was used to quantitatively measure volume of ground glass opacities (GGO), reticular densities, and honeycombing (HC). Total interstitial lung disease (ILD) was the summation of these features. PVRS was also quantified using CALIPER. Values for each feature were expressed as a percentage of total lung volume. Cox models evaluated the hazard ratio (HR) for mortality for each parameter adjusting for age at SSc diagnosis, sex, diffuse SSc subtype, and history of smoking. The optimal thresholds for mortality prediction for each parameter were determined using consensus between 4 methods: Contal and O’Quigley Method, Cox Model Hazard Ratio, Cox Model Wald P-value, and False Discovery Rate. The c-statistic was used to assess each models’ ability to predict mortality.

Results:

Mean ±SD for age at SSc diagnosis was 61 ± 13 years and length of follow-up was 4.7 ± 3.0 years. There were 32 deaths (24%). A Cox model including age (HR 1.05, 95% CI: 1.01-1.09), female sex (HR 0.49, 95% CI: 0.22-1.08), diffuse SSc subtype (HR 1.50, 95% CI: 0.69-3.30), and history of smoking (HR 2.09, 95% CI: 0.97-4.53) (Model 1) significantly predicted mortality (C-statistic 0.72, 95% CI: 0.63-0.81). Adjusting for Model 1, reticular densities% (HR 1.19, 95% CI: 1.05-1.35), total ILD% (HR 1.02, 95% CI: 1.00-1.03), and PVRS% (HR 1.19, 95% CI: 1.05-1.35) were associated with mortality on univariable analyses; GGO% (HR 1.01, 95% CI: 0.98-1.04) was not significantly associated with mortality. The optimal thresholds for mortality prediction were then determined and were as follows: GGO=20%, reticular densities=8%, total ILD=20%, and PVRS=5%. While the risk of mortality was significantly increased in subjects with GGO ≥20% (HR 2.70, 95% CI: 1.21-6.05), reticular densities ≥8% (HR 4.64, 95% CI: 1.68-12.81), and total ILD ≥20% (2.59, 95% CI: 1.12-5.99), these baseline thresholds did not improve upon mortality prediction when added individually to Model 1 (C-statistic 0.73 for each). PVRS ≥5%, which had an over six-fold increase in mortality (HR 6.42, 95% CI: 2.60-15.88), did improve mortality prediction when added to Model 1 (C-statistic 0.78, 95% CI: 0.70-0.86).

Conclusion:

PVRS strongly associates with early mortality in patients with SSc and represents a novel radiomic biomarker that provides prognostic information on mortality beyond pulmonary parenchymal abnormalities. CALIPER derived PVRS quantifies CT data through a function that defines connected tubular branching structures. This extracts pulmonary arteries and veins from the adjacent parenchyma but could potentially also include regions of adjoining of fibrosis.1 Larger studies examining the association between PVRS and progression of cardiopulmonary disease are warranted.

References:

[1]Jacob J, Bartholmai BJ, Rajagopalan S, et al. Predicting Outcomes in Idiopathic Pulmonary Fibrosis Using Automated Computed Tomographic Analysis. Am J Respir Crit Care Med 2018;198:767-76.

Acknowledgements:

This project was supported by the Mayo Clinic Margaret Harvey Schering Clinician Career Development Award.

Disclosure of Interests:

Alicia Hinze: None declared, Yasser Radwan: None declared, Mamoun Elnagar: None declared, Reto Kurmann: None declared, Shreyasee Amin: None declared, Robert Vassallo Grant/research support from: Pfizer, Bristol Myers Squibb, Sun Pharma, Cynthia S. Crowson: None declared, Brian Bartholmai Consultant of: AstraZenica, Boehringer Ingelheim, Promedior LLC (all <$5,000 annually)

OP0177 PRESENCE AND SEVERITY OF DIGITAL OCCLUSIVE ARTERIAL DISEASE PREDICTS DIGITAL ISCHEMIC COMPLICATIONS IN SYSTEMIC SCLEROSIS

Background:

Vasculopathy is a key feature of systemic sclerosis (SSc), manifesting clinically as Raynaud’s phenomenon (RP) with or without digital ischemia. Laser doppler flowmetry (LDF) with thermal challenge is a safe, noninvasive and reproducible technique to detect digital occlusive arterial disease (DOAD) with a high sensitivity and specificity of >90% (1).

Objectives:

To study the prevalence and clinical correlates of DOAD assessed by LDF in patients with SSc referred for evaluation of RP at a tertiary referral center.

Methods:

Medical records of all patients with SSc meeting ACR/EULAR 2013 classification criteria that underwent LDF between Jan 2001-Dec 2018 at our institution were retrospectively reviewed to abstract the presence or absence of DOAD. The presence of DOAD on LDF was confirmed if pre- and post-warming skin blood flow was ≤206 arbitrary units. Severity of DOAD was assessed based on number of digits involved. Risk factors associated with presence of DOAD in SSc, and correlation between presence and severity of DOAD with digital ischemic complications were studied.

Results:

304 patients with SSc (mean age 57.1 ± 3.3 y, 81% females, 93% Caucasians) underwent LDF during the study period. Median time between SSc diagnosis and performing LDF was 12.9 months. Majority of patients with SSc had limited cutaneous SSc (lcSSc) (79.6%) and 64.1% had a positive SSc specific antibody.

On LDF with thermal challenge, presence of DOAD was noted in 243 (79.9%) patients, of whom 78.6% had lcSSc, 42.4% had a centromere antibody (Ab), 17.3% had a Scl-70 Ab, 53.5% had interstitial lung disease, 36.6% had pulmonary arterial hypertension, and 73.3% had gastrointestinal dysmotility (GID). Of 159 patients with DOAD who also had a nailfold capillaroscopy, 70.4% had abnormalities. Large vessel occlusive disease was significantly higher in patients with DOAD in comparison to those without DOAD (29.2% vs 16.4%; p: 0.04). After adjusting for age and sex, GID (OR: 2.73 [95%CI 1.52-4.92]) and telangiectasia (OR: 2.83 [95%CI 1.23-6.40]) were significantly associated with DOAD.

Digital ischemic complications among patients with SSc with DOAD were significantly higher than among those without DOAD (79.8% vs 41.0% had digital ulcers, 53.9% vs 26.2% had pitting/scars, 31.3% vs 8.2% had gangrene/amputation; p <0.001). (Figure 1) Increasing severity of DOAD was associated with a statistically significantly higher incidence of digital ischemic complications as presented in Table 1.

Figure 1.

Correlation between the presence of digital occlusive arterial disease (DOAD) and digital ischemic complications in systemic sclerosis

Table 1.

Logistic regression models for association of digital ischemic complications and severity of digital occlusive arterial disease

Digital InvolvementComplicationOdds Ratio (OR)Reflects “digits vs. 0”ORCI 95%Digital UlcerUnit Increase1.281.19-1.391-22.110.927-4.923-75.572.84-11.28-1010.94.98-25.4Digital Tip Pitting/ScarsUnit Increase1.171.10-1.261-21.920.803-4.613-72.621.35-5.288-105.452.72-11.4Digital Gangrene/AmputationUnit Increase1.261.16-1.371-21.360.317-5.483-74.101.62-12.68-109.053.60-27.7Any Digital InvolvementUnit Increase1.351.24-1.491-22.981.27-7.303-76.163.08-12.78-1018.57.46-53.2

Conclusion:

This is the largest single center study to describe the prevalence and predictors of DOAD on LDF in a well-defined cohort of patients with SSc.

The high prevalence of DOAD on LDF noted in SSc-RP make it a valuable tool not only for evaluation of vasculopathy in SSc but also to distinguish it from Primary RP. The presence and severity of DOAD strongly correlates with digital ischemic complications and can be used as a guide to counsel patients and determine the aggressiveness of therapeutic interventions. Our study underscores the significance of LDF as a reliable non-invasive modality to detect DOAD and a prognostic tool to identify patients at highest risk of digital ischemic complications.

References:

[1]Mahe G et al. J Vasc Surg. 2014 Apr;59(4):1051-1057.e1

Disclosure of Interests:

None declared

POS0838 EPIDEMIOLOGY AND TRENDS IN SURVIVAL OF SYSTEMIC SCLEROSIS IN OLMSTED COUNTY: A POPULATION-BASED STUDY (1980-2018)

Background:

Systemic sclerosis (SSc) is a complex immune-mediated disease with heterogeneous manifestations, which is characterized by vasculopathy and fibrosis of the skin and visceral organs. Mortality associated with SSc exceeds that of other rheumatic diseases, though population-based studies assessing recent trends in survival are lacking.

Objectives:

We aimed to determine the incidence and prevalence of physician-diagnosed SSc in a population-based cohort over a 39-year time period, and assess for trends in survival over time.

Methods:

Medical records of patients with a diagnosis or suspicion of SSc in a geographically well-defined area from Jan 1, 1980 to Dec 31, 2018 were reviewed to identify incident cases of SSc. Cases were defined by physician diagnosis of SSc, and fulfillment of the 2013 ACR/EULAR classification criteria was ascertained. Prevalent cases of SSc on Jan 1, 2015 were also identified. Incidence and prevalence rates were age- and sex-adjusted to the 2010 U.S. white population. Survival rates were compared with expected rates in the general population.

Results:

85 incident cases of SSc (91% female, mean age 55.4 ± 16 y) and 49 prevalent cases on Jan 1, 2015 were identified. Patients had a mean 11.7 (SD 9.4) years of follow-up available. The overall age and sex adjusted annual incidence for 1980-2018 was 2.5 (95% CI: 2.0-3.1) per 100,000 population, with no change in incidence over time (p=0.32). The age-adjusted incidence was 4.4 (95% CI: 3.4-5.4) for females, and 0.56 (95% CI: 0.16-0.96) for males per 100,000 population. The age- and sex-adjusted prevalence on Jan 1, 2015 was 43.6 (95% CI: 31.3-55.8) per 100,000 population.

77 (91%) patients fulfilled the 2013 classification criteria; 38 (45%) fulfilled 1980 criteria. 70 (82%) had limited cutaneous involvement, 12 (14%) had diffuse cutaneous involvement, and 3 (4%) had sine scleroderma. At SSc diagnosis, 80 (94%) patients had Raynaud’s, 43 (51%) had sclerodactyly, 39 (46%) had telangiectasias, 14/48 (29%) had abnormal nailfold capillaries, 16/35 (46%) had digital ulcers or fingertip scarring, 8 (9%) had interstitial lung disease (ILD), and 7 (8%) had pulmonary arterial hypertension (PAH). 77/82 patients (91%) had a positive antinuclear antibody. 44 (52%) had a known SSc-related autoantibody: 32 (73%) with anti-centromere, 9 (20%) with anti-Scl-70, and 4 (9%) with anti-RNA-polymerase III.

Survival was 77% (95% CI: 69-87) at 5 years, 66% (95% CI: 56-78) at 10 years, and 42% (95% CI: 30-57) at 20 years, with no evidence of improved survival over time (p=0.46). Age (Hazard ratio [HR]: 1.49 per 10 year increase; 95% CI 1.19-1.88), smoking at time of diagnosis (HR: 2.37; 95% CI: 1.05-5.34), digital ischemia (HR: 2.54; 95% CI: 1.33-4.87), ILD (HR: 4.00; 95% CI: 2.11-7.59), and PAH (HR: 4.30; 95% CI: 2.24-8.25) had significant associations with mortality. Survival of patients with SSc was poorer than the general population (standardized mortality ratio: 2.48; 95% CI: 1.76-3.39).

Conclusion:

The average incidence of SSc in this population-based cohort spanning 39 years was 2.5 per 100,000 population, with no change in incidence over time. Age, smoking, digital ischemia, ILD and PAH were risk factors for poorer survival. Overall survival for patients with SSc is worse than that of the general population and shows no improvement over time, suggesting continued need for improved diagnostic and treatment measures.

Figure 1.

Survival of 85 Olmsted County residents with SSc compared with expected survival rates from Minnesota lifetables (observed: solid line, expected: dashed line).

Disclosure of Interests:

None declared

POS0836 CONDUCTION AND RHYTHM DISORDERS AMONG PATIENTS WITH SYSTEMIC SCLEROSIS: A US POPULATION BASED STUDY

Background:

Systemic sclerosis (SSc) can impact multiple areas of the heart through fibrotic and vascular processes; leading to variable cardiac involvement including electrocardiogram (ECG) abnormalities. Conduction and rhythm disorders are associated with worse prognosis in patients with SSc. (1, 2)

Objectives:

To study the incidence, risk factors and outcomes of conduction and rhythm disorders in a US population-based cohort of patients with SSc and non-SSc comparators from the same geographic area.

Methods:

A previously identified incident cohort of SSc patients (1980-2016) in a well-defined geographic area was compared to a randomly selected 2:1 cohort of age- and sex-matched non-SSc subjects from the same population base. Demographics, disease characteristics, cardiovascular risk factors and laboratory tests were abstracted by manual record review. ECGs and Holter ECGs were reviewed to determine the occurrence of any conduction or rhythm abnormalities. The need for cardiac interventions was also abstracted.

Results:

78 incident SSc cases and 156 non-SSc comparators were identified [age 56 years± 15.7, 91% female]. Prevalence of any conduction disorders before SSc diagnosis compared to non-SSc comparators was 15% vs. 7% (p=0.06), and any rhythm disorder was 18% vs. 13% (p=0.33). During a median follow up of 10.5 years in patients with SSc and 13.0 years in non-SSc comparators, conduction disorders developed in 25 SSc patients with a cumulative incidence (ci) of 20.5% (95% CI: 12.4-34.1%) compared to 28 non-SSc patients with ci of 10.4% (95% CI: 6.2-17.4%) (HR: 2.57; 95% CI: 1.48-4.45), while rhythm disorders developed in 27 SSc patients with ci of 27.3% (95% CI: 17.9-41.6%) vs 43 non-SSc patients with ci of 18.0% (95% CI: 12.3-26.4%) (HR: 1.62; 95% CI: 1.00-2.64). (Figure 1).

Conduction disorders in patients with SSc during follow up included: 1st-degree atrioventricular block (AVB) (n=12), 2nd-degree AVB (n=1), 3rd-degree AVB (n=1), right bundle branch block (n=10), left bundle branch block (n=4), bifascicular block (n=6), and prolonged-QT (n=13). Rhythm disorders included: atrial fibrillation (n=10), atrial flutter (n=4), supraventricular tachycardia (n=4), ventricular tachycardia (n=1), and premature ventricular contractions (n=16).

Pulmonary hypertension (PHT) was the only significant risk factor identified for development of both conduction and rhythm disorders (HR=8.38, 95% CI: 1.32-53.40 and HR=8.07, 95% CI: 1.60-40.74, respectively). Current smoking significantly increased the risk for development of rhythm disorders (HR=2.91, 95% CI: 1.19-7.12). Conduction and rhythm disorders were associated with increased mortality among patients with SSc (HR=7.60, 95% CI: 3.49-16.55 and HR=4.87, 95% CI: 2.28-10.42, respectively, after adjusting for age, sex and calendar year of diagnosis).

Conclusion:

Patients with SSc have a significantly higher prevalence of conduction disorders at disease onset than non-SSc comparators. During the course of their disease, their risk of developing conduction disorders is 2.6-fold, and risk of rhythm disorders is 1.6-fold increased, compared to non-SSc subjects.

PHT was significantly associated with increased risk of developing conduction and rhythm disorders among patients with SSc, a finding that should warrant increased vigilance and screening for ECG abnormalities in this population.

References:

[1]Tyndall A.J. et al. Ann Rheum Dis, 2010. 69(10): p. 1809-15.

[2]Desai C.S. et al. Curr Opin Rheumatol, 2011. 23(6): p. 545-54.

Figure 1.

Cumulative incidence of any conduction or any rhythm disorder in SSc (solid line) vs non-SSc comparators (dashed line).

Disclosure of Interests:

None declared

Recovery of the jaw-opening reflex after lesions of the lingual nerve in the rat

In three groups of rats, lesions were produced in the right lingual nerves near the base of the tongue; the three types of injury inflicted (cryogenic, crush, and stretch) are reputed to spare the epineurium but produce different degrees of intraneural damage. In regular assessments of recovery, an electrical stimulus (sufficient to elicit the jaw-opening reflex) was applied to either side of the tongue in turn; the amplitude of the reflex was measured as the isometric force of jaw opening. The size of the reflex response to stimulation of the injured side was followed up to 4 months post-lesion, with the response elicited from the control side used as the reference level. The reflex was absent when the experimental side was stimulated immediately after creation of a lesion; the first sign of reflex recovery was found at about 15 days post-operative. Subsequently, in 84% of the animals, the reflex activity elicited from the experimental side increased until it exceeded that elicited from the reference side; this relative hyperreflexia started 1-4 months post-lesion and had a highly variable duration. There was no difference in the incidence, latency, or duration of the hyperreflexia following any of the three types of lesion. The hyperreflexia found in this study is not readily explained by existing hypotheses of the mechanisms underlying post-lesion hyperesthesia or central neuronal hyperexcitability.