Understanding the natural history of lateral femoral stress fractures helps to guide their management. Improvement in their radiographic characteristics is rare. Progression was generally sequential, most developing an incomplete fracture line before fracture displacement. Stopping bisphosphonates decreased the fracture rate, a feasible management option for lesions without incomplete fracture lines. INTRODUCTION Retrospective study evaluating the natural history of lateral femoral stress fractures (FSF) by serial radiography over a variable period of time in a cohort of patients treated for some time with bisphosphonates for osteoporosis, whilst also identifying the fracture response in cases where bisphosphonates were discontinued. METHODS The radiographs of 76 consecutive patients (92 femurs) with 161 FSF were reviewed to document their change over time. Femurs were classified into the following: A-normal, B-focal cortical thickening, C-dreaded black line and D-displaced fracture. Bisphosphonate history was recorded. RESULTS 66.5% FSF showed group stability between the first and last radiographs: group B (79.1%), group C (45.7%). 28.6% progressed, mostly following an ordered sequence starting from group A, progressing to B, then C, before culminating in D. Progression rate was as follows: A-100% (11/11), B-18.3% (21/115), C-40% (14/35). Regression in FSF was uncommon-5.6% (8/161). 34.8% (32/92) sustained displaced fractures. Kaplan-Meier analysis showed statistically significant difference between the groups; median survival (95% CI): A-4189 (-), B-3383.0 (-), C-1807 (0.0-3788.6) and progression to displaced fracture when bisphosphonate had been stopped for at least 6 months. The group without recent bisphosphonates had a lower group progression rate (17.1%, 12/70). Nevertheless, 10.9% (5/46) progressed to displaced fracture. This group also had the highest proportion of stable (77.1%, 54/70) and regressive lesions (5.7%, 4/70). CONCLUSIONS In FSF, there is natural progression from normal bone, to focal cortical thickening, to dreaded black line and eventually to displaced fracture. Most lesions persist, remaining static or progressing, especially if a dreaded black line is present and bisphosphonates are continued. Regression is uncommon and more frequent when bisphosphonates are discontinued. Despite stopping bisphosphonates, there remains a 10.9% risk of progression to displaced fracture.

中文翻译：

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长期和可变的双膦酸盐治疗疗程后患者不完全非典型股骨骨折的自然病程 - 长期放射学随访。

了解股骨外侧应力性骨折的自然病程有助于指导其治疗。其放射学特征的改善很少见。进展通常是连续的，大多数在骨折移位之前形成不完整的骨折线。停用双膦酸盐可降低骨折率，对于没有不完整骨折线的病变来说，这是一种可行的治疗选择。引言 回顾性研究通过连续 X 线摄影在一组接受双膦酸盐治疗骨质疏松症患者一段时间内评估股骨外侧应力性骨折 (FSF) 的自然病程，同时确定停用双膦酸盐时的骨折反应. 方法 回顾 76 名连续患者（92 股股骨）的 161 个 FSF 的 X 光片，以记录他们随时间的变化。股骨分为以下几类：A-正常、B-局灶性皮质增厚、C-可怕的黑线和 D-移位骨折。记录双膦酸盐的历史。结果 66.5% FSF 在第一次和最后一次 X 光片之间显示组稳定性：B 组（79.1%），C 组（45.7%）。28.6% 进展，主要遵循从 A 组开始的有序序列，进展到 B，然后是 C，最后是 D。进展率如下：A-100% (11/11)，B-18.3% (21/115 ), C-40% (14/35)。FSF 的回归不常见 - 5.6% (8/161)。34.8% (32/92) 持续移位骨折。Kaplan-Meier 分析显示组间差异有统计学意义；中位生存期 (95% CI)：A-4189 (-)、B-3383.0 (-)、C-1807 (0. 0-3788.6) 并在停用双膦酸盐至少 6 个月后进展为移位性骨折。近期未使用双膦酸盐的组的组进展率较低（17.1%，12/70）。然而，10.9% (5/46) 进展为移位骨折。该组的稳定（77.1%，54/70）和退行性病变（5.7%，4/70）比例也最高。结论 在 FSF 中，从正常骨到局灶性皮质增厚、到可怕的黑线并最终到移位骨折有自然进展。大多数病变持续存在，保持静止或进展，特别是如果出现可怕的黑线并且继续使用双膦酸盐。当双膦酸盐停药时，退行并不常见且更为频繁。尽管停止使用双膦酸盐，但仍有 10.9% 的风险进展为移位骨折。6) 当双膦酸盐停药至少 6 个月时进展为移位性骨折。近期未使用双膦酸盐的组的组进展率较低（17.1%，12/70）。然而，10.9% (5/46) 进展为移位骨折。该组的稳定（77.1%，54/70）和退行性病变（5.7%，4/70）比例也最高。结论 在 FSF 中，从正常骨到局灶性皮质增厚、到可怕的黑线并最终到移位骨折有自然进展。大多数病变持续存在，保持静止或进展，特别是如果出现可怕的黑线并且继续使用双膦酸盐。当双膦酸盐停药时，退行并不常见且更为频繁。尽管停止使用双膦酸盐，但仍有 10.9% 的风险进展为移位骨折。6) 当双膦酸盐停药至少 6 个月时进展为移位性骨折。近期未使用双膦酸盐的组的组进展率较低（17.1%，12/70）。然而，10.9% (5/46) 进展为移位骨折。该组的稳定（77.1%，54/70）和退行性病变（5.7%，4/70）比例也最高。结论 在 FSF 中，从正常骨到局灶性皮质增厚、到可怕的黑线并最终到移位骨折有自然进展。大多数病变持续存在，保持静止或进展，特别是如果出现可怕的黑线并且继续使用双膦酸盐。当双膦酸盐停药时，退行并不常见且更为频繁。尽管停止使用双膦酸盐，但仍有 10.9% 的风险进展为移位骨折。