Summary

The incidence of localized periosteal thickening (LPT, also termed beaking) of the lateral cortex that often precedes an atypical femoral fracture (AFF) was not high in patients with rheumatoid arthritis (RA) but incomplete AFFs developed in two patients. Higher-dose prednisolone was a significant risk factor for LPT in patients with RA.

Introduction

Atypical femoral fractures (AFFs) are stress fractures; bisphosphonate (BP) use is a major risk factor for the development of such fractures. Localized periosteal thickening (LPT, also termed beaking) of the lateral cortex often precedes a complete or incomplete AFF. We evaluated the incidence of latent LPT in patients with rheumatoid arthritis (RA), to evaluate LPT progression, and to define LPT risk factors.

Methods

A total of 254 patients with RA were included; all underwent annual X-ray evaluation, dual-energy X-ray absorptiometry, and analyses of serum and bone metabolic markers for 2–3 years. LPT of the lateral cortex was sought in femoral X-rays.

Results

The incidence of LPT was 2.4% (6/254). Among patients on both BP and prednisolone (PSL) at enrollment, the incidence was 2.3% (3/131). Two femurs of two patients with LPT developed incomplete AFFs; LPT was extensive and associated with endosteal thickening. One patient had been on BP and PSL and microscopic polyangiitis was comorbidity. The other was on a selective estrogen receptor modulator and PSL. A daily PSL dose >5 mg (OR 11.4; 95%CI 2.15–60.2; p = 0.004) and higher-dose methotrexate (OR 1.22; 95%CI 1.01–1.49; p = 0.043) were significant risk factors for LPT.

Conclusions

The incidence of latent LPT was not high (2.4%) but incomplete AFFs developed in two RA patients. Higher-dose PSL because of a comorbid disease requiring glucocorticoid treatment other than RA or refractory RA were risk factors for LPT; X-ray screening for latent LPT would usefully prevent complete AFFs.

中文翻译：

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类风湿关节炎患者非典型股骨骨折前的股骨局部骨膜增厚（喙）累积发生率。

概要

类风湿关节炎（RA）患者的外侧皮层局限性骨膜增厚（LPT，也称为喙）的发生率通常在非典型股骨骨折（AFF）之前，但是在两名患者中发展为不完全。大剂量泼尼松龙是RA患者LPT的重要危险因素。

介绍

非典型股骨骨折是应力性骨折。使用双膦酸盐（BP）是造成此类骨折的主要危险因素。外侧皮质的局部骨膜增厚（LPT，也称为喙）通常先于完全或不完全的AFF。我们评估了类风湿关节炎（RA）患者潜在LPT的发生率，以评估LPT进展并确定LPT危险因素。

方法

总共254例RA患者被纳入研究。所有患者均接受了每年的X射线评估，双能X射线吸收测定以及2-3年的血清和骨代谢指标分析。在股骨X线片中寻找外侧皮质的LPT。

结果

LPT的发生率为2.4％（6/254）。在入组时同时使用BP和泼尼松龙（PSL）的患者中，发生率为2.3％（3/131）。2名LPT患者的2个股骨发展为不完全AFF。LPT广泛且与骨内膜增厚有关。一名患者曾接受过BP和PSL治疗，镜下多发性血管炎为合并症。另一个是选择性雌激素受体调节剂和PSL。每日PSL剂量> 5 mg（OR 11.4； 95％CI 2.15–60.2；p  = 0.004）和大剂量甲氨蝶呤（OR 1.22； 95％CI 1.01-1.49；p  = 0.043）是LPT的重要危险因素。

结论

潜在的LPT发生率不高（2.4％），但在两名RA患者中发生了不完全的AFF。由于合并症，需要除RA或难治性RA以外的其他糖皮质激素治疗的高剂量PSL是LPT的危险因素。潜在的LPT的X射线筛查将有效地阻止完整的AFF。