Displaced Olecranon Fractures Clinical Trial
Official title:
A Prospective Randomised Trial of Plate Fixation Versus Tension Band Wire for Olecranon Fractures
Proximal forearm fractures comprise approximately 5% of all fractures, with olecranon fractures accounting for almost 20% of thes fractures. There is limited conclusive evidence regarding the optimal treatment and outcome of these fractures with only one prospective randomized trial (1992) in the literature comparing tension band wire and plate fixation for displaced olecranon fracture. Our trial includes all patients under the age of 75yrs presenting to the Edinburgh Orthopaedic Trauma Unit with an isolated olecranon fracture requiring operative intervention. Patients who consent to enrol in the trial will be randomised to operative fixation using one of two recognised fixation techniques - tension band wire fixation or plate fixation. Patients will be evaluated over a one year period following their surgery.
Background
Proximal forearm fractures comprise approximately 5% of all fractures, whilst olecranon
fractures account for almost 20% of fractures occurring around the elbow1. There is limited
conclusive evidence regarding the epidemiology, optimal treatment and outcome of isolated
olecranon fractures.
Patients with undisplaced olecranon fractures can be treated non-operatively2,3. The aims of
treatment in displaced olecranon fractures are the restoration of function and stability to
the elbow joint4. The technique employed should allow preservation and reconstruction of the
articular surface with minimal associated complications. Tension-band wiring (TBW) is the
most recognised and commonly used fixation method, although plate fixation and
intramedullary screw fixation are noted alternatives2,4-10. Potential problems with the TBW
technique are wound breakdown, infection, prominent metalwork, malunion and
non-union2,4,7,11-13. Furthermore, plate fixation is considered to be superior in
distal/comminuted/oblique fractures and fracture-dislocations, with superior fracture
reduction and fixation results, as well as a lower rate of re-operation2,5,13,14. There is
only one prospective randomized trial in the literature comparing TBW and plate fixation for
displaced olecranon fracture13. The major conclusions from this study were:
- The functional outcome at six months was not significantly different in the two groups
- Post-operative loss of fracture reduction (53% vs 5%) and prominent symptomatic
metalwork was more frequently observed after TBW
This study was performed in 1992 with less sophisticated plates when compared with the
location specific plates currently available.
Research Aim
To determine if any difference exists in outcome (primary measure - DASH score) after one
year between open reduction and internal fixation with tension band wiring AND plate and
screw fixation for olecranon fractures.
Methodology
This trial involves identifying patients under the age of 75yrs (<75yrs) presenting to the
Edinburgh Orthopaedic Trauma Unit with an isolated olecranon fracture requiring operative
intervention. Patients who consent to enrol in the trial will be randomised to one of two
recognised operative fixation techniques - tension band wire fixation or plate fixation. The
trial will commence once ethical approval is granted by the Lothian Research Ethics
Committee.
All statistical analysis was/will be performed by Dr Rob Elton. Prior to the study a power
analysis determined the number of patients required in each trial. The primary outcome
measure will be the DASH score, a continuous variable that follows a normal
(Gaussian-shaped) distribution. This study is designed to determine a clinically relevant
mean difference of 10 points between the two cohorts at one year after enrolment. A power
analysis indicated that a total sample size of 50 (25 in each group) subjects will provide
80% statistical power to detect significant differences (0.05) in DASH scores, assuming an
effect size of 0.8 (mean difference of 10 points, standard deviation of 12 points) using an
unpaired t-test. To account for a possible loss to follow-up of up to 25%, we anticipate
enrolling 35 subjects in each cohort for a total sample size of 70 subjects. A p value of <
0.05 was considered statistically significant.
All adult patients presenting to the Edinburgh Orthopaedic Trauma Unit with a fracture of
the olecranon that satisfy the inclusion criteria will be invited to participate in our
study. All adult patients with an olecranon fracture best treated operatively are eligible
for enrolment in this study regardless of sex, race or ethnicity. Vulnerable populations
will not be recruited.
A qualified member of the on-call team will introduce the study to the patient and initiate
informed consent. If the patient agrees, a research fellow (Trauma and Orthopaedic StR3
level), not involved with the patient's care will review the study protocol in detail and
address any questions the patient may have. If the patient is willing to participate, the
research fellow will complete the informed consent. Patients will be given a copy of the
consent form, and be informed that their participation is voluntary and that they can
withdraw at any time during the study without detriment to their normal care in any way.
Patients may take as long as they like to consider participation, provided that they still
meet all the eligibility criteria documented above. Patients that are willing to participate
in this study will get the same care of their fracture as patients that decide not to
participate in the study.
On enrolment, a data collection form will be started with demographic and injury-related
information collected. Prior to surgery, patients will be randomised (performed by Dr Rob
Elton using closed opaque envelopes) into one of the two groups (tension band wire fixation
or plate fixation). Following surgery, the post-operative assessment and course will be as
per normal protocol for patients who are not in this study. Patients will be immobilised
depending on fracture fixation during surgery and the decision will be made by the treating
surgeon. Physiotherapy will be arranged when required
Follow-up All follow-up assessment will take place during follow-up visits initially with
the treating consultant surgeon's team and a dedicated research physiotherapist. Radiographs
and other diagnostic studies will be obtained at the discretion of the treating surgeon and
will not differ from routine clinical care.
Follow-up assessment will be collected over a one year period (2 weeks, 6 weeks, 3 months, 6
months and one year). Routine follow-up in our institution for patients who have sustained
an olecranon fracture that is managed operatively involves outpatient clinic reviews with
radiographs at 2 weeks, 6 weeks, three months and six months. Therefore, one additional
visit at 1 year is required for this study with no additional radiographs. Radiographs will
only be performed at one year on clinical indication.
At each visit physical examination, treatment, complications and re-operation (e.g. hardware
removal), for each patient will be recorded. A research physiotherapist, blinded to the
treatment method by sticking plaster over the entry position, will undertake functional
testing and assessment.
Outcome and statistical methods By statistically analysing the outcome scores in the two
groups, I aim to better determine the optimal management of this fracture in this age group.
Using univariate analysis and multivariate regression analysis I will determine significant
(p<0.05) predictors of outcome in relation to functional outcome score (DASH at one year).
;
Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Single Blind (Outcomes Assessor), Primary Purpose: Treatment