Prediction of Nonunion After Nonoperative Treatment of a Proximal Humeral Fracture

BACKGROUND

The prevalence of nonunion after a proximal humeral fracture (PHF) and the risk factors for its occurrence are poorly defined. We aimed to estimate the rate of nonunion in nonoperatively treated patients and to produce a clinical model for its prediction.

METHODS

Two thousand two hundred and thirty adult patients (median age, 72 years [range, 18 to 103 years]; 75.5% were female) with a PHF underwent assessment of fracture union using standard clinical evaluation and conventional radiographs. We assessed the prevalence of nonunion and measured the effect of 19 parameters on healing. Best statistical practices were used to construct a multivariate logistic regression model. The PHF assessment of risk of nonunion model (PHARON) was externally validated in a subsequent prospectively collected population of 735 patients, treated by the same protocol in our institution.

RESULTS

Overall, 231 (10.4%) of 2,230 patients developed nonunion. Only 3 (0.8%) of 395 patients with a head-shaft angle (HSA) of >140° developed nonunion; in this cohort, none of the measured candidate variables were independently predictive of nonunion on multivariate logistic regression analysis. In the larger cohort of 1,835 patients with an HSA of ≤140°, 228 (12.4%) developed nonunion. Decreasing HSA, increasing head-shaft translation (HST), and smoking were independently predictive of nonunion on multivariate analysis. The prevalence of nonunion was very low (1%) in the majority with both an HSA of >90° and HST of <50%, whereas the risk was much higher (83.7%) in the 8.3% with an HSA of ≤90° and HST of ≥50%. In both groups, the prevalence of nonunion was much higher in smokers.

CONCLUSIONS

The prevalence of nonunion after PHF is higher than previously reported. Most patients have favorable risk-factor estimates and a very low risk of this complication, but a smaller subgroup is at much higher risk. The risk can be accurately estimated with PHARON, using standard clinical assessment tools.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Complications after non-surgical management of proximal humeral fractures: a systematic review of terms and definitions

Background

A majority of proximal humeral fractures can be managed without surgery. Recent randomized clinical trials and meta-analyses even question the benefit of surgical treatment for displaced 3-, and 4-part fractures. However, evidence-based treatment recommendations, balancing benefits and harms, presuppose a common reporting of complications and adverse events, which at the moment is largely missing. Therefore we systematically reviewed the use of terms and definitions of complications after nonsurgical management of proximal humeral fractures.

Methods

We searched PubMed, EMBASE, Cochrane Library, Scopus and WorldCat (2010–2017) and included articles and book chapters containing complication terms or definitions. Two reviewers independently extracted and grouped terms and definitions according to a predefined scheme. Terms and definitions concerning non-surgical management were tabulated, grouped and analyzed qualitatively.

Results

The initial search identified 1376 references from which 470 articles were selected for full-text retrieval. Data-extraction included first articles published in 2017, was then performed iteratively in batches of 20 articles, and terminated after retrieval of 91 articles when no additional definitions or terms was found. In addition, 12 book chapters were reviewed from an initial list of 100. No general definition of a complication was found. A total of 69 terms for complications after non-surgical management were identified from 19 articles. Sixty-seven terms regarded local events. The most commonly reported event terms regarded osteonecrosis, malunion, secondary displacement and rotator cuff problems. Seven individual terms were accompanied by some kind of definition. Most terms and definitions were based on radiographical assessments.

Conclusions

We found no consensus in the use of terms and definitions of complications after nonsurgical management of proximal humeral fractures. Multiple terms, some synonymous, some partly synonymous, some distinct, were used. Few complication terms were explicitly defined. Development and validation of an internationally consensus-based core event set for complications after proximal humeral fractures managed non-surgically is needed.

Electronic supplementary material

The online version of this article (10.1186/s12891-019-2459-6) contains supplementary material, which is available to authorized users.