Summary

In this first clinical series, displacement of the proximal radius relative to the capitellum on initial radiographs predicted the need for collateral ligament repair in transolecranon fracture dislocations. 0-5mm displacement did not require ligament repair, 5-10mm sometimes required ligament repair and those with more than 10mm displacement all required ligament repair at the time of fixation.

Abstract

Background

Biomechanical studies have shown inferior translation of the proximal radius relative to the capitellum in the sagittal plane can predict integrity of the collateral ligaments in a transolecranon fracture model, no studies have examined this in clinical practice.

Methods

Nineteen consecutive transolecranon fracture dislocations were retrospectively reviewed. Data collection included: patient demographics, fracture classifications, surgical management and failure with instability. Distance between the centre of the radial head and the centre of the capitellum was measured on initial radiographs by 2 independent raters on several occasions. Statistical analysis was used to compare the mean inferior displacement between patients who required collateral ligament repair and those who did not.

Results

Sixteen cases with a mean age of 57 years (32-85) were analysed with an inter-rater Pearson coefficient of 0.89. 3 cases were excluded due to inadequate imaging. Mean inferior displacement where collateral ligament repair was needed was 16.3mm (SD +- 4.5) compared with 7.1mm (SD +- 7.5) where collateral ligament repair was found not to be needed intra-operatively; p=0.024. 75% of cases with ligament repair were classified as Wrightington D+, Ring III or Jupiter IIB types. Older patients more likely required ligament repair (63 vs 50 years; p=0.108). In 3 cases, ligament repair was not performed initially but deemed necessary later. Of these, the mean inferior displacement was 14.48mm (SD +- 2.50) and 2 of these required revision fixation.

Conclusion

This clinical study can offer some guidance of the impact of radiographic sagittal inferior displacement on management of transolecranon fracture dislocations. Where inferior displacement on initial radiographs exceeded 10mm lateral collateral ligament repair was required in all cases, except for one. If less than 5mm, ligament repair was not required in any of the cases. Older patients, associated radial head fractures and posterior apex injuries showed trend towards ligament repair.