WMG, The University of Warwick, Coventry CV4 7AL, UK.
Department of Trauma & Orthopaedics, University Hospitals Coventry and Warwickshire NHS Trust, Coventry, CV2 2DX, UK.
Comput Methods Programs Biomed. 2022 Jul;222:106937. doi: 10.1016/j.cmpb.2022.106937. Epub 2022 Jun 8.
Pre-operative surgical planning using computer simulation is increasingly standard practice before Total Hip Arthroplasty (THA), in order to determine the optimal implant positions, and thereby minimise post-operative complications such as dislocation, wear and leg length discrepancy. One of the limitations of current methods, however, is the lack of information on the subject-specific reference range of motion (ROM) that could be used as targets for surgical planning. Only a limited number of hip motions are considered, which are neither subject-specific, nor representative of all the hip motions associated with all the activities of daily livings (ADLs). In this paper, therefore, a method was developed to calculate subject-specific representative bony range of motion (B-ROM) that would cover all the possible joint motions and presented in terms of pure joint motions.
Only 3D bone geometries of femur and pelvis, constructed from personalised CT scan, were used as inputs for healthy hip joint whereas implant geometries and their positions on native bone geometries were required for planned treatment side or replaced side. Hip joint motion simulation was carried out using six different Tait-Bryan intrinsic rotation sequences of three pure joint motions - flexion-extension, abduction-adduction and internal-external rotation, and B-ROM was then identified for any of these six different sequences which caused earliest feasible impingement. The B-ROM could be used as a list of ROM data points or visualised as multiple 2D surface plots or a 3D envelop. Using the developed method, the B-ROM of a contralateral healthy hip joint of a patient can be used to define the subject-specific target ROM values to inform the surgical planning of the arthritic hip side so that the patient's natural ROM could be restored as closely as possible by the planned implant placements. This was demonstrated with a clinical verification study using 'non-dislocating' and 'dislocating' THA patients.
The results supported the study hypothesis that the percentage of intersected volume of the healthy and replaced side B-ROM was higher for the 'Non-Dislocator' patient (95%) compared to 'Dislocator' (78%). Also, the results showed that the only one sequence (first flexion-extension, then abduction-adduction and finally internal-external rotation) was not adequate to identify all the possible limiting B-ROM, and therefore, all the six rotation sequences should be considered.
The method encompasses every potential ADL, and as a result, more comprehensive surgical planning is possible, as the implant positions can be optimised in order to maximise impingement-free ROM, and consequently minimise clinical complications.
术前使用计算机模拟进行外科规划在全髋关节置换术 (THA) 之前越来越普遍，目的是确定最佳的植入物位置，从而最大限度地减少术后并发症，如脱位、磨损和肢体长度差异。然而，目前方法的一个局限性是缺乏可用于手术规划的特定于主体的运动范围 (ROM) 的信息。目前仅考虑了有限数量的髋关节运动，这些运动既不是特定于主体的，也不是代表与所有日常活动 (ADL) 相关的所有髋关节运动。因此，本文开发了一种计算特定于主体的代表性骨骼运动范围 (B-ROM) 的方法，该方法可以涵盖所有可能的关节运动，并以纯关节运动的形式呈现。
仅使用来自个性化 CT 扫描构建的股骨和骨盆的 3D 骨骼几何形状作为健康髋关节的输入，而对于计划治疗侧或替换侧，则需要植入物几何形状及其在原生骨骼几何形状上的位置。使用六个不同的 Tait-Bryan 固有旋转序列模拟髋关节运动，这些序列由三个纯关节运动组成——屈伸、外展内收和内旋外旋，然后确定任何一个序列都可以引起最早的可行撞击。B-ROM 可以用作 ROM 数据点列表，也可以可视化作为多个 2D 表面图或 3D 包络。使用所开发的方法，可以使用患者对侧健康髋关节的 B-ROM 来定义特定于主体的目标 ROM 值，以告知关节炎髋关节侧的手术规划，以便尽可能通过计划的植入物放置来恢复患者的自然 ROM。这通过对“非脱位”和“脱位”THA 患者进行临床验证研究得到了证明。
研究结果支持这样的假设，即健康侧和替换侧 B-ROM 的相交体积百分比对于“非脱位”患者 (95%) 高于“脱位”患者 (78%)。此外，结果表明，只有一个序列（首先是屈伸，然后是外展内收，最后是内旋外旋）不足以确定所有可能的限制 B-ROM，因此，应该考虑所有六个旋转序列。
该方法涵盖了所有潜在的 ADL，因此可以进行更全面的手术规划，因为可以优化植入物位置，以最大限度地增加无撞击 ROM，从而最大限度地减少临床并发症。
