Ng Wei Xiang, Acharyya Sanchalika, Huang Shirong, Kwek Ernest Beng Kee, Tan Bryan Yijia
Department of Orthopaedic Surgery, Tan Tock Seng Hospital, Singapore, Singapore.
Clinical Research & Innovation Office, Tan Tock Seng Hospital, Singapore, Singapore.
J Shoulder Elbow Surg. 2025 Mar;34(3):e133-e140. doi: 10.1016/j.jse.2024.05.018. Epub 2024 Jul 10.
Fragility fracture of the proximal humerus is a common occurrence. Current literature suggests that poor local bone density is a significant predictor of surgical fixation failure. The deltoid tuberosity index (DTI) is a simple radiographic tool that strongly correlates with local humeral bone mineral density (BMD), aiding surgical planning to consider adjuncts or arthroplasty. However, there is a lack of data in the reliability of assessment of DTI, as well as its correlation to systemic osteoporosis. Our study investigates the reliability of DTI as a predictor of systemic osteoporosis.
A retrospective cohort of patients with proximal humeral fracture (PHF) treated at a trauma center in Singapore from August 2017 to July 2018 were recruited. Four raters at different levels of varying clinical seniority measured DTI using shoulder radiographs. The dual-energy x-ray absorptiometry (DEXA) BMD scan of the hip and lumbar spine was used to diagnose osteoporosis. Area under the receiver operating characteristic curve analysis was calculated to study the diagnostic utility of DTI for predicting the risk of osteoporosis.
Our study sample had 87 patients comprising 18 men and 69 women, mainly of Chinese ethnicity (84%), and with a mean age of 69.7 years (standard deviation 9.52, range 39-92). For assessment of DTI, there was good intrarater reliability among 4 raters (correlation coefficient range 0.805-0.843) and excellent interrater reliability between all raters (intraclass correlation coefficient 0.898, 95% confidence interval [CI] 0.784-0.950, P < .001). Based on the BMD, 55.2% (n = 48) had osteoporosis, with a T score <2.5. The highest correlation of DTI to BMD was with femoral neck density at 0.580. The DTI cutoff of 1.6 had the highest combined sensitivity and false positive rate, with areas under the curve of 0.682 (95% CI 0.564-0.799) for the overall population and 0.706 (95% CI 0.569-0.842) for patients aged <75 years.
The DTI is a simple and reliable tool and has a strong applicability in clinical practice to enhance preoperative planning in the surgical fixation of PHF. DTI with a cutoff of 1.6 may help prompt clinicians to initiate workup and thus manage underlying osteoporosis.
肱骨近端脆性骨折很常见。当前文献表明，局部骨密度差是手术固定失败的重要预测指标。三角肌粗隆指数（DTI）是一种简单的影像学工具，与肱骨局部骨矿物质密度（BMD）密切相关，有助于手术规划时考虑辅助治疗或关节置换术。然而，缺乏关于DTI评估可靠性及其与全身性骨质疏松症相关性的数据。我们的研究调查了DTI作为全身性骨质疏松症预测指标的可靠性。
招募了2017年8月至2018年7月在新加坡一家创伤中心接受治疗的肱骨近端骨折（PHF）患者的回顾性队列。4名不同临床资历水平的评估者使用肩部X线片测量DTI。采用髋部和腰椎的双能X线吸收法（DEXA）骨密度扫描来诊断骨质疏松症。计算受试者操作特征曲线下面积分析，以研究DTI预测骨质疏松症风险的诊断效用。
我们的研究样本有87例患者，包括18名男性和69名女性，主要为华裔（84%），平均年龄69.7岁（标准差9.52，范围39 - 92岁）。对于DTI评估，4名评估者之间的评分者内信度良好（相关系数范围0.805 - 0.843），所有评估者之间的评分者间信度极佳（组内相关系数0.898，95%置信区间[CI] 0.784 - 0.950，P <.001）。根据骨密度，55.2%（n = 48）患有骨质疏松症，T值<2.5。DTI与骨密度的最高相关性是与股骨颈密度，为0.580。DTI临界值为1.6时，综合敏感性和假阳性率最高，总体人群曲线下面积为0.682（95% CI 0.564 - 0.799），75岁以下患者为0.706（95% CI 0.569 - 0.842）。
DTI是一种简单可靠的工具，在临床实践中具有很强的适用性，可加强PHF手术固定的术前规划。临界值为1.6的DTI可能有助于促使临床医生开展检查，从而管理潜在的骨质疏松症。
