Brodke Dane J, Shear Brian M, Demyanovich Haley, Li Vivian, Bell Alice, Okhuereigbe David, SooHoo Nelson F, Slobogean Gerard P, O'Toole Robert V, O'Hara Nathan N
Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, Maryland.
Department of Orthopaedics and Rehabilitation, Oregon Health & Science University, Portland, Oregon.
J Bone Joint Surg Am. 2025 Jun 4;107(16):1825-1832. doi: 10.2106/JBJS.24.00842.
Surgeons often lack objective data on patient functional outcomes, particularly as compared with the patient's baseline. The present study aimed to determine whether gait parameters recorded on Apple iPhones provided longitudinal mobility data following lower-extremity fracture surgery that matched clinical expectations. We hypothesized that iPhones would detect the mobility changes of injury and early recovery, correlate with patient-reported outcome measures, and differentiate nonunion.
This cross-sectional study included 107 adult patients with lower-extremity fractures who owned iPhones and had at least 6 months of follow-up. Participants shared Apple Health data and completed Patient Reported Outcomes Measurement Information System (PROMIS) surveys. The primary outcome was the daily step count. Four other gait-related parameters were analyzed: walking asymmetry, double support, walking speed, and step length. Mixed-effects models compared mobility parameters at pre-injury, immediate post-injury, and 6-months post-injury time points. Correlations between mobility parameters and PROMIS surveys were assessed. A mixed-effect model evaluated the relationship between step count recovery and surgery for nonunion.
There was a 93% reduction in daily step count from the pre-injury period to the immediate post-injury period (95% confidence interval [CI], -94% to -93%). Other gait parameters also showed increased impairment from pre-injury to post-injury. At 6 months, step count improved sixfold relative to the immediate post-injury period but remained 52% below baseline (95% CI, -55% to -49%). PROMIS Physical Function correlated moderately with step count (r = 0.42; 95% CI, 0.25 to 0.57) and weakly with other gait parameters. Patients with a known nonunion had a 55% slower recovery of step count than those without a nonunion (95% CI: 44% to 66%).
Apple Health mobility parameters captured changes in mobility following lower-extremity fracture and throughout the subsequent recovery period. These metrics distinguished between patients with and without nonunions, demonstrating their potential usefulness as objective, real-world functional outcome measures. These "digital biomarkers" may aid clinical decision-making and research and could be utilized for the early identification of patients at risk for poor outcomes.
Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.
外科医生常常缺乏关于患者功能预后的客观数据，尤其是与患者基线水平相比。本研究旨在确定苹果手机记录的步态参数能否提供与临床预期相符的下肢骨折手术后的纵向活动数据。我们假设苹果手机能够检测损伤和早期恢复过程中的活动变化，与患者报告的结局指标相关，并区分骨不连情况。
这项横断面研究纳入了107名成年下肢骨折患者，这些患者拥有苹果手机且至少随访6个月。参与者分享了苹果健康数据并完成了患者报告结局测量信息系统（PROMIS）调查。主要结局指标是每日步数。还分析了其他四个与步态相关的参数：步行不对称性、双支撑、步行速度和步长。混合效应模型比较了伤前、伤后即刻和伤后6个月时间点的活动参数。评估了活动参数与PROMIS调查之间的相关性。一个混合效应模型评估了骨不连患者步数恢复与手术之间的关系。
从伤前期到伤后即刻，每日步数减少了93%（95%置信区间[CI]，-94%至-93%）。其他步态参数从伤前到伤后也显示出损伤增加。在6个月时，步数相对于伤后即刻增加了六倍，但仍比基线水平低52%（95%CI，-55%至-49%）。PROMIS身体功能与步数中度相关（r = 0.42；95%CI，0.25至0.57），与其他步态参数弱相关。已知骨不连患者的步数恢复比无骨不连患者慢55%（95%CI：44%至66%）。
苹果健康活动参数捕捉到了下肢骨折后及随后整个恢复期间的活动变化。这些指标区分了有骨不连和无骨不连的患者，证明了它们作为客观、真实世界功能结局测量指标的潜在用途。这些“数字生物标志物”可能有助于临床决策和研究，并可用于早期识别预后不良风险的患者。
预后水平III。有关证据水平的完整描述，请参阅作者指南。
