Surgical interventions for treating fractures of the olecranon in adults.

BACKGROUND: Fractures of the olecranon (the bony tip of the elbow) account for approximately 1% of all upper extremity fractures. Surgical intervention is often required to restore elbow function. Two key methods of surgery are tension band wire fixation and plate fixation.

OBJECTIVES: To assess the effects (benefits and harms) of different surgical interventions in the treatment of olecranon fractures in adults.

SEARCH METHODS: We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (22 September 2014), the Cochrane Central Register of Controlled Trials (CENTRAL, 2014, Issue 8), MEDLINE (1946 to September week 2 2014), EMBASE (1980 to 19 September 2014), trial registers, conference proceedings and reference lists of articles.

SELECTION CRITERIA: Randomised controlled trials (RCT) and quasi-RCTs that compared different surgical interventions for the treatment of olecranon fractures in adults.

DATA COLLECTION AND ANALYSIS: Two review authors independently performed study selection, risk of bias assessment and data extraction. The primary outcomes of this review were function, pain and adverse events.

MAIN RESULTS: We included six small trials involving 244 adults with olecranon fractures. Of these, four were RCTs and two were quasi-RCTs; both of were at high risk of selection bias. All six trials were at high risk of performance bias, reflecting lack of blinding, and four trials were at high risk of detection bias. The quality of the evidence for most outcomes was generally very low because of limitations in study design and implementation, and either imprecision of the results or inadequate outcome measures. Thus, we are very uncertain about the estimates of effect.One trial (41 participants) comparing plate fixation with standard tension band wiring provided very low quality evidence at 16 to 86 weeks' follow-up of a better clinical outcome after plate fixation (good outcome (little pain or loss of elbow motion): 19/22 versus 9/19, risk ratio (RR) 1.82 favouring plate fixation, 95% confidence interval (CI) 1.10 to 3.01). There was very low quality evidence of less symptomatic prominent metalwork after plate fixation (1/22 versus 8/19; RR 0.11, 95% CI 0.01 to 0.79). The results for other adverse effects (infection and delayed or non-union) were inconclusive. Evidence is pending from a newly (September 2014) completed trial (67 participants) making the same comparison.Four trials compared four different modified techniques of tension band wiring (i.e. additional intramedullary screw fixation, biodegradable pins, Netz pins and cable pin system) versus standard tension band wiring. There was very low quality evidence of little difference at six to 14 months in function assessed by a non-validated scoring tool from the addition of an intramedullary screw. However, there were fewer cases of metalwork prominence in the intramedullary screw group (1/15 versus 8/15; RR 2.00, 95% CI 1.15 to 3.49; one trial; 30 participants). There was very low quality evidence from one trial (25 participants) of little difference in subjectively or objectively assessed good outcome at a mean of 20 months between tension band wiring with biodegradable implants versus metal implants. There were no adverse events, either non-union or sinus or fluid accumulation, reported. All 10 participants in the metalwork group had an extra operation to remove their metalwork at one year. One trial, which did not report on function or pain, provided very low quality evidence of lower rates of metalwork for any reason or for symptoms after Netz pin tension band wiring compared with standard tension band wiring (11/21 with Netz pin versus 17/25 with standard tension band wiring; RR 0.77, 95% CI 0.47 to 1.26; 46 participants); this evidence also supports the possibility of higher rates of metalwork removal for Netz pins. Two intra-operative complications occurred in the Netz pin group. The fourth trial, which compared the cable pin system with standard procedure, found low quality evidence that cable pin improved functional outcome at a mean of 21 months (Mayo Elbow Performance Score (MEPS), range 0 to 100: best outcome: mean difference (MD) 7.89 favouring cable pin, 95% CI 3.14 to 12.64; one trial; 62 participants). It also found low quality evidence of fewer postoperative complications in the cable pin group (1/30 with cable pin system versus 7/32 standard tension band wiring; RR 0.15, 95% CI 0.02 to 1.17), although the evidence did not rule out the converse.One trial provided very low quality evidence of similar patient-reported function using the Disabilities of the Arm, Shoulder and Hand questionnaire (0 to 100: worst function) at two or more years after fixation using a novel olecranon memory connector (OMC) compared with locking plate fixation (MD -0.70 favouring OMC, 95% CI -4.20 to 2.80; 40 participants). The only adverse event was a superficial infection in the locking plate group.

AUTHORS' CONCLUSIONS: There is insufficient evidence to draw robust conclusions on the relative effects of the surgical interventions evaluated by the included trials. Further evidence, including patient-reported data, on the relative effects of plate versus tension band wiring is already pending from one recently completed RCT. Further RCTs, using good quality methods and reporting validated patient-reported measures of function, pain and activities of daily living at set follow-ups, are needed, including checking positive findings such as those relating to the use of an intramedullary screw and the cable pin system. Such trials should also include the systematic assessment of complications, further treatment including routine removal of metalwork and use of resources.