Primary Hinged External Fixator for Complex Fracture Dislocations of the Elbow (Systematic Review/Meta-Analysis)
Authors: Abouseif Salah , Alkersh Mohamed , Mohamed Ahmed Medhat 
Published: August 2023

Background
High-energy and fracture dislocations with compromise of the medial and lateral ligamentous complex, the joint capsule, and potentially the tertiary stabilizers (i.e., the flexor pronator, extensor supinator masses, and brachialis) often demonstrate residual instability after osseous and ligamentous stabilization. The optimal management of a complex elbow injury should results in restoring joint stability and its full range of motion. However, this is often difficult to achieve by surgical means and a marked restriction of movement remains a frequent con- sequence of severe elbow injury.

Aim of the Study
The aim of this study is to discuss the results of using a lateral hinged external fixator as an adjunct stabilizer in the treatment of a variety of acute destabilizing elbow injuries as a primary method of fixation not only in chronic or complicated cases.

Patients and Methods
Types of studies: Randomized controlled trials, including cluster RCTs, controlled (non-randomized) clinical trials or cluster trials, prospective and retrospective comparative cohort studies, and case-control or nested case-control studies. Types of participants: Only studies on human subjects with acute complex elbow fracture dislocation treated by hinged elbow external fixator. Types of interventions: Surgical treatment of acute complex elbow fracture dislocation with hinged external fixation of elbow. Types of outcome measures: Operative details, intra and postoperative complications and final clinical outcome. Literature searches will be conducted using the following databases:” PubMed, Ovid, Web of Science, ScienceDirect, Scopus, Cochrane Library, Google Scholar, Medline” using the following Keywords: acute complex elbow fracture dislocation, hinged external fixator, unstable elbow, terrible triad and long term for published studies from 2010-2021.

Results
Regarding studies done on the use of a lateral hinged external fixator on the elbow for complex fracture dislocation which are numerous in the last 11 years, we have reviewed the most applicable studies in our review. Regarding the mean flexion-extension arc and pronation-supination arc, the results were 121.5 º and 81 º respectively. Regarding the complications, wound infection was found in 10 patients out of 69 cases (14.4%) including pin tract infection and ORIF wound infection. Secondary humeral and ulnar shaft fractures were found in 3 patients out of 69 cases (4.3%) as a recognized complication of the shanz screws application in both humerus and ulna. Another complication founded was elbow joint incongruity in 5 patients among 69 cases (7.2%) which leads to series consequences like arthritis, progressive pain and instability. Instability as a postoperative complication was found in 1 patient out of 69 cases (1.4%) which shows the huge effect of adding a hinged external fixator to the ORIF construct. In fact, this was the only reason to add a hinged external fixator in the past where it was used in cases of recurrent and chronic instability. Non union was found in 2 patients out of 69 patients (2.8%) while heterotrophic calcification was found in 8 patients out of 69 cases (11.5%). Iordens et al in 2015 was the only paper to calculate the quick-dash score where among 27 patients the score were 30 at 6 weeks and 7 at 1 year. Regarding the mayo elbow performance score (MEPS), among the 69 patients 21 patients (30.4%) were not affiliated while the score was poor in 1 patient (1.4%), fair in 7 patients (10.1%), good in 18 patients (26%) and excellent in 22 patients (31.8%) which shows that above 50% of cases where good to excellent showing the effect of early protected range of motion gained by the addition of a hinged external fixator.

Conclusion
The best management for complex elbow fracture dislocations is still controversy but the additional use of a hinged external fixator to the ORIF repair shows better outcomes as described.