Survival After Surgical Treatment of Axis Fractures in Elderly

NCT ID: NCT02839057

Last Updated: 2017-05-19

Basic Information

• Recruitment Status: COMPLETED
• Total Enrollment: 6231 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2015-10-31
• Study Completion Date: 2016-12-31

Brief Summary

Fractures of the second cervical vertebra (C2) are the most common spinal fracture among the elderly. Non-surgical treatment comprises of cervical collar treatment for 12 weeks, while surgical treatment for elderly could mean posterior fixation C1-C2 without collar treatment or anterior screw osteosynthesis C2 with 6 weeks of collar treatment. A meta-analysis of retrospective studies has recently found an improved survival with surgical treatment. This national registry study is designed to estimate the survival of non-surgical and surgical treatment in a population-based cohort.

Detailed Description

The Swedish National Patient Registry (NPR) is hosted by the Swedish Agency of Health and Welfare and contains all patient contacts within Sweden with a coverage of >90% for orthopaedic diagnoses. Registered are main diagnosis and co-morbidity using the ICD-9 code until 1996 and from 1997 onward ICD-10 codes. Treatment is coded since 1996 using the Swedish classification of surgical procedures. Furthermore, information on hospitalisation time is available from the registry.

In the Swedish Cause of Death Registry (CDR) all deaths in Sweden are registered with date of death and cause of death. While date of death coverage is complete, the cause of death has only 46% agreement with the final hospital diagnosis.

All patients with the main diagnosis of C2 fracture (ICD-10: S12.1) treated between January 1st 1996 to December 31st 2014 are extracted from the NPR and merged with the CDR for incident deaths. Prior to data transmission, the Swedish Agency of Health and Welfare anonymised the individual personal identification numbers using a key which remained with the Agency.

Invalid age data will be excluded either due to missing entries or mismatch with date of death. Multiple admissions (cases with same identification number but more than 12 months between admissions) and duplicate entries (cases with same identification number) will be removed from the dataset, after valuable co-morbidity data from the duplicate entries were stored in the original record. Duplicate entries originate from separate recordings from each hospital if the patient is referred to a specialised hospital. Furthermore, primarily non-surgically treated cases with a change of treatment modality are registered as surgical patients. The registered hospitalisation time for these patients is the combined non-surgical and surgical in-hospital treatment period.

From each record the Charlson Comorbidity Index (CCI) is calculated. Using Swedish surgical procedure codes for spinal fusion ("NAG") and spinal osteosynthesis ("NAJ") patients receiving surgical treatment were marked, and the cohort divided into two groups receiving non-surgical or surgical treatment.

The age distribution differences of patients with C2-fractures treated surgically and non-surgically was visualised with a density distribution plot. A logit logistic regression analysis identified covariates of surgical treatment assignment and was presented with 95% confidence intervals (C.I.) and statistical probability p. Goodness-of-fit of the model was presented with pseudo-r2 according to McFadden.

Using the Kaplan-Meier method for non-surgical and surgical treatment mean survival, as well as survival rate at 3 months, 1 year, and 2 years was determined, and visualised using a Kaplan-Meier plot with 99% C.I. With the Cox proportional hazards regression method multiple covariates contributing to survival are entered and hazard ratio (HR) presented with 95% C.I. and probability p. As relevant covariates for survival besides surgical treatment age, gender, spinal cord injury, and CCI were identified. Since the assumption was that the medical advancement improved patient survival in general during the last decades, even year of admission was included as covariate in the model. In order to identify a cut-off age where a treatment modality is not associated anymore with greater survival the adjusted HR of a certain age and above was plotted over age with 95% C.I.

Conditions

Spinal Fractures

Study Design

• Observational Model Type: COHORT
• Study Time Perspective: PROSPECTIVE

Study Groups

Surgical treatment

Patients ≥70 years with C2 fracture coded in patient registry (ICD-10: S12.1) treated with surgical fracture stabilisation

Surgical treatment

Intervention Type: PROCEDURE

Stabilisation of C2-fracture by posterior fusion C1-C2, posterior fusion C2-C3, anterior fusion C2-C3 (no postoperative collar) or anterior screw osteosynthesis C2 (postoperative collar for 6 weeks).

Non-surgical treatment

Patients ≥70 years with C2 fracture coded in patient registry (ICD-10: S12.1) treated non-surgically

Non-surgical treatment

Intervention Type: PROCEDURE

Cervical collar immobilisation for 12 weeks.

Interventions

Non-surgical treatment

Cervical collar immobilisation for 12 weeks.

Intervention Type: PROCEDURE

Surgical treatment

Stabilisation of C2-fracture by posterior fusion C1-C2, posterior fusion C2-C3, anterior fusion C2-C3 (no postoperative collar) or anterior screw osteosynthesis C2 (postoperative collar for 6 weeks).

Intervention Type: PROCEDURE

Other Intervention Names

Conservative treatment

Eligibility Criteria

Inclusion Criteria

• C2-fracture
• Age ≥70 years

Exclusion Criteria

• no C2-fracture
• Age <70 years

• Minimum Eligible Age: 70 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Uppsala University

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

References

Robinson Y, Robinson AL, Olerud C. Systematic review on surgical and nonsurgical treatment of type II odontoid fractures in the elderly. Biomed Res Int. 2014;2014:231948. doi: 10.1155/2014/231948. Epub 2014 Feb 10.

Reference Type: BACKGROUND

PMID: 24683543 (View on PubMed)

Other Identifiers

AxisFractureSweden

Identifier Type: -

Identifier Source: org_study_id