The With Or Without Olecranon K-wires Trial (WOW-OK)

The With Or Without Olecranon K-wire (WOW OK) Trial of Tension Band Wire Fixation Versus Cerclage Fixation Without K-wires in Displaced Stable Olecranon Fractures

Fractures of the elbow tip (olecranon) that leave the elbow joint stable but where the fracture ends are separated (Mayo type 2a and 2b) can be treated with pins and a metal wire (tension band wiring, TBW) or metal wiring alone (cerclage fixation, CF ). Previous studies have reported high re-operation and complication rates following TBW. The current study's hypothesis, based on two retrospective studies, is that CF of these fractures yield lower re-operation rates compared with TBW. The investigators also hypothesize that the overall complication rate will be lower following CF. The aim is to investigate this hypothesis in a randomized controlled trial. Patients that are 18 years or older with Mayo type 2a and 2b olecranon fractures at Skåne University hospital will be invited to the study. Participation is voluntary. Patients who accept participation will be randomly assigned to surgery by either TBW or cerclage fixation. Two hundred participants will be followed by physiotherapists for 36 months post-surgery assessing re-operations, complications, patient reported outcome, and elbow function.

The complete study protocol including a detailed description of the trial will be published in a journal before the start of the trial. Olecranon fractures account for approximately 20% of all proximal fractures of the forearm. Stable, undisplaced fractures (Mayo type 1a and 1b) are routinely treated non-operatively, while displaced and unstable fractures (Mayo type 3a and 3b) are typically operated with plate fixation. Stable, displaced fractures (Mayo type 2a and 2b) are often treated with tension band wiring (TBW) or plate fixation. TBW is associated with soft tissue irritation and high re-operation rates with hardware removal, ranging from 25% to 84% in the literature. Plate fixation was associated with fewer re-operations compared with TBW in a randomized controlled trial, but complications following plate fixation were more severe. A Cochrane review from 2014 did not find any significant support favouring either of the two methods. Non-operative treatment of Mayo type 2a and 2b fractures can yield acceptable results in elderly patients, but is not routinely used in younger individuals with higher functional demands. Two previous retrospective studies from 2002 and 2021 reported that Mayo 2a and 2b fractures can be operated with cerclage fixation alone yielding half the re-operation rates when compared to TBW. As of April 2022 there are two studies (one active (NCT03280602) and one completed (NCT01391936)) comparing TBW vs plate fixation, three studies (two active (NCT04670900 and NCT04401462) and one terminated (NCT01397643)) comparing non-operative vs operative treatment in elderly and one active study (NCT04189185) comparing TBW vs suture fixation registered on this site. The hypothesis of the current study is that the re-operation rate and the complication rate will be lower following CF compared with TBW while yielding equal results in other outcome measures. The aim is to to investigate this in a prospective randomized clinical trial. Methodology: All patients presenting at Skåne University Hospital in Malmö and Lund, Sweden, with olecranon fractures of Mayo type 2a and 2b will be invited to participate in the study if they do not meet any exclusion criteria. Potential subjects will be asked to sign a consent form after receiving written and oral information about the trial. Subjects will be randomized 1:1 to surgery with TBW or cerclage. 200 subjects will be recruited based on sample size calculations derived from the re-operation frequency in a previous study (PMID: 34236459) Baseline descriptive data will be collected at inclusion or in the peri-operative period. Operation time, intra-operative effective radiation dose and radiation time will be recorded. Subjects will be invited to follow-up to a physiotherapist at 2 weeks, 6 weeks, 3 months, 12 months and 36 months after the operation assessing re-operations, complications, post-operative antibiotics, range of elbow motion, grip strength, the Quick Disabilities of the Arm, Shoulder and Hand score (Quick-DASH, references PMID: 8773720 and 6709254), overall patient satisfaction, pain, return to work and secondary dislocation. The Short Musculoskeletal Function Assessment (SMFA, references PMID: 27994082 and 14763711) score will be assessed 12 months post-operatively. The physiotherapist will be masked to the treatment method. At 6 months one radiograph will be collected for assessment of non-union. The primary outcome measure will be re-operations. Secondary outcome measures will be patient reported outcome measures and complications. Tertiary outcome measures are post-operative range of motion and grip strength, secondary dislocation rate, time to return to work after surgery, operation time, effective intra-operative radiation dose and radiation time. The hypothesis of the current study is that cerclage fixation will yield less re-operations, less overall complications and less severe complications while other outcome measures will be equal.

Tension Band Wiring, Cerclage, Surgery, Elbow injuries, Forearm injuries, Ulna fractures, Patient reported outcome measures

The assessor of all outcome measures except assessment of a postoperative radiograph will be masked. When the radiograph is viewed the operative method will be apparent, but this assessor is not the same as for the other outcome measures.

The intervention is by surgical open reduction and internal fixation of the fracture using two 1.0mm cerclage.

The intervention is by surgical open reduction and internal fixation of the fracture using a 1.0mm cerclage and two 1.6 mm k-wires as described in AO-guidelines.

Grips strength will be evaluated using a JAMAR dynamometer as detailed in the Swedish National Quality Register for Hand Surgery (HAKIR)

Grips strength will be evaluated using a JAMAR dynamometer as detailed in the Swedish National Quality Register for Hand Surgery (HAKIR)

Grips strength will be evaluated using a JAMAR dynamometer as detailed in the Swedish National Quality Register for Hand Surgery (HAKIR)

Grips strength will be evaluated using a JAMAR dynamometer as detailed in the Swedish National Quality Register for Hand Surgery (HAKIR)

Grips strength will be evaluated using a JAMAR dynamometer as detailed in the Swedish National Quality Register for Hand Surgery (HAKIR)

Active extension, flexion, pronation and supination will be evaluated using a goniometer following the Swedish National Quality Register for Hand Surgery (HAKIR) guidelines.

Active extension, flexion, pronation and supination will be evaluated using a goniometer following the Swedish National Quality Register for Hand Surgery (HAKIR) guidelines.

Active extension, flexion, pronation and supination will be evaluated using a goniometer following the Swedish National Quality Register for Hand Surgery (HAKIR) guidelines.

Active extension, flexion, pronation and supination will be evaluated using a goniometer following the Swedish National Quality Register for Hand Surgery (HAKIR) guidelines.

Active extension, flexion, pronation and supination will be evaluated using a goniometer following the Swedish National Quality Register for Hand Surgery (HAKIR) guidelines.

Secondary dislocation rate will be assessed with a one lateral view radiograph of the operated elbow.

Intra-operative fluoroscopy radiation DAP will be recorded at the time of surgery from the fluoroscopy machine used.

Intra-operative fluoroscopy time will be recorded at the time of surgery from the fluoroscopy machine used.

Inclusion Criteria: Sustained Olecranon type fracture of Mayo 2a or 2b Seeking healthcare in at the Skåne University Hospital in Lund and Malmö, Sweden. Exclusion Criteria: Subjects unable to participate in follow up (for example subjects with active substance abuse, dementia, inability to communicate or understand the questionnaires or subjects living in other administrative healthcare regions). Subjects unable to give informed written consent. Subject where non operative treatment is indicated due to frailty or severe ongoing disease. Fracture not operated within 14 days from the date the fracture was sustained. Subjects with severe open fractures of Gustilo-Anderson class III Subject with pathological fractures from metastatic disease. Subject with simultaneous or previous severe injury to the same arm are excluded for patient reported outcome measures but included for all other outcomes. Subjects with previously severe injuries to the same arm will be excludes for PROM analyses but included for reoperation and complication analyses. Subjects operated by an orthopedic trauma surgeons that did not attended our education on the study and the interventions, unless surgery is supervised by an orthopedic surgeon that has attended the education the subject will not be excluded.

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