Chest wall soft tissue thickness is associated with humeral shaft nonunion: a radiographic study
Authors:
Alex, Choudhary, Kizzie Peters, Henry Colaco, Iain MacLeod
Hospital:
Hampshire Hospitals NHS Foundation Trust
Introduction:
Anecdotally, pendulous breasts have often been associated with inferior outcomes from non-operative management of diaphyseal humerus fractures. However, this assertion is without basis in the literature.
Aims:
To produce radiographic measurements of chest wall soft tissue thickness and determine association with nonunion and angulation in diaphyseal humerus fractures.
Methods:
217 patients who underwent conservative management for a diaphyseal humeral fracture were identified retrospectively from 2008-2017. Radiographic chest wall soft tissue thickness (STT) measurements were taken at three standardised points (upper, middle and lower) using a simple reproducible method. Ratios were also derived, dividing these figures by the mid-humerus diameter. Bivariate and multivariate analysis was used to assess association with nonunion.
Results:
There were 58 (26.7%) cases of nonunion. On multivariate analysis, the middle (OR 1.39, 95% p<0.001) and lower (OR 1.23, p=0.009) STT measurements were independently associated with nonunion. Additionally, the middle (OR 1.85, p<0.001), lower (OR 1.47, p=0.005) and maximum (OR 1.40, p<0.001) STT ratios were independently associated with nonunion. A receiver operating characteristic curve was used to determine threshold values for middle STT of 6.2cm (sensitivity 62.1%, specificity 61.6%) and middle STT ratio of 3.0 (sensitivity 69.0%, specificity 62.3%). A middle STT of ≥6.2cm (OR 2.68, p=0.004) and a middle STT ratio of ≥3.0 (OR 3.73, p<0.001) were each independently predictive of nonunion.
Conclusions:
Chest wall soft tissue thickness is independently associated with humeral shaft nonunion. A middle STT ratio of ≥3 was predictive of nonunion. Threshold values can assist in decision making for these fractures.