Clinical Biomechanics最新文献

Mid-vastus approach induces milder short-term effects on postural control compared to parapatellar approach in total knee arthroplasty. 在全膝关节置换术中，与髌旁入路相比，中轴入路对姿势控制的短期影响较小。

IF 1.4 3区医学 Q4 ENGINEERING, BIOMEDICAL

Clinical Biomechanics

Pub Date : 2024-09-22 DOI: 10.1016/j.clinbiomech.2024.106354

Background

Mid-Vastus and Medial Parapatellar techniques are used for total knee arthroplasty. Their short-term effects within the first month after surgery are yet unexplored. The purpose of this study was to compare Mid-Vastus and Medial Parapatellar effects on knee strength and balance control, at 5 days, 2 weeks and one month after surgery. It was hypothesized that Mid-Vastus would induce milder effects on the dependent variables due to its less invasive nature.

Methods

Twenty females, randomly assigned to either the Mid-Vastus or the Medial Parapatellar group performed knee flexion-extension force and 30 s of bipedal stance before, 5 days, 2 weeks and one month after surgery. Maximum force, weight distribution and travel distance of the Center of Pressure were calculated.

Findings

Both groups showed decreased force output at all post-measurements compared to before surgery. Medial Parapatellar group showcased significantly higher travel distance at the 2 weeks measurement (Z = −2.268, p = .023, |r| = 0.507) compared to before surgery. This result was also imprinted on the travel distance of the non-surgical knee limb in the post (t = 3.259, p = .004, d = 1.456), 2 weeks (Z = −2.570, p = .009, |r| = 0.574) and one month measurement (t = 2.653, p = .016, d = 1.185).

Interpretation

While force is affected for both approaches, Mid-Vastus approach does not affect postural control. Therefore, Mid-Vastus is a less invasive technique compared to Medial Parapatellar. This work highlights the differences between Mid-Vastus and Medial Parapatellar approaches at least until the first month of rehabilitation.

背景在全膝关节置换术中使用了中腹股沟技术和内侧髌旁技术。但它们在术后一个月内的短期效果尚未得到研究。本研究的目的是比较术后 5 天、2 周和 1 个月时中瓣和内侧副髌对膝关节力量和平衡控制的影响。方法20名女性被随机分配到髌骨内侧旁组或髌骨外侧旁组，分别在术前、术后5天、2周和1个月进行膝关节屈伸力训练和30秒双足站立训练。与手术前相比，两组在所有术后测量中的力量输出都有所下降。与手术前相比，髌骨内侧组在两周后的测量中显示出明显更高的移动距离（Z = -2.268，p = .023，|r| = 0.507）。在术后（t = 3.259，p = .004，d = 1.456）、两周（Z = -2.570，p = .009，|r| = 0.574）和一个月（t = 2.653，p = .016，d = 1.185）的测量中，这一结果也体现在非手术膝肢的移动距离上。因此，与内侧髌旁相比，中腹腔是一种创伤较小的技术。这项研究强调了至少在康复后的第一个月内，中-瓣法和内侧髌旁法之间的差异。

{"title":"Mid-vastus approach induces milder short-term effects on postural control compared to parapatellar approach in total knee arthroplasty.","authors":"","doi":"10.1016/j.clinbiomech.2024.106354","DOIUrl":"10.1016/j.clinbiomech.2024.106354","url":null,"abstract":"<div><h3>Background</h3><div>Mid-Vastus and Medial Parapatellar techniques are used for total knee arthroplasty. Their short-term effects within the first month after surgery are yet unexplored. The purpose of this study was to compare Mid-Vastus and Medial Parapatellar effects on knee strength and balance control, at 5 days, 2 weeks and one month after surgery. It was hypothesized that Mid-Vastus would induce milder effects on the dependent variables due to its less invasive nature.</div></div><div><h3>Methods</h3><div>Twenty females, randomly assigned to either the Mid-Vastus or the Medial Parapatellar group performed knee flexion-extension force and 30 s of bipedal stance before, 5 days, 2 weeks and one month after surgery. Maximum force, weight distribution and travel distance of the Center of Pressure were calculated.</div></div><div><h3>Findings</h3><div>Both groups showed decreased force output at all post-measurements compared to before surgery. Medial Parapatellar group showcased significantly higher travel distance at the 2 weeks measurement (Z = −2.268, <em>p</em> = .023, <em>|r|</em> <em>= 0</em>.507) compared to before surgery. This result was also imprinted on the travel distance of the non-surgical knee limb in the post (<em>t</em> = 3.259, <em>p</em> = .004, <em>d</em> <em>=</em> 1.456), 2 weeks (Z = −2.570, <em>p</em> = .009, <em>|r|</em> <em>= 0</em>.574) and one month measurement (<em>t</em> = 2.653, <em>p</em> = .016, <em>d</em> <em>=</em> 1.185).</div></div><div><h3>Interpretation</h3><div>While force is affected for both approaches, Mid-Vastus approach does not affect postural control. Therefore, Mid-Vastus is a less invasive technique compared to Medial Parapatellar. This work highlights the differences between Mid-Vastus and Medial Parapatellar approaches at least until the first month of rehabilitation.</div></div>","PeriodicalId":50992,"journal":{"name":"Clinical Biomechanics","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142318621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Between-limb difference in peak knee flexion angle can identify persons post-stroke with Stiff-Knee gait 膝关节屈曲角度峰值的肢间差异可识别中风后的僵膝步态患者

IF 1.4 3区医学 Q4 ENGINEERING, BIOMEDICAL

Clinical Biomechanics

Pub Date : 2024-09-21 DOI: 10.1016/j.clinbiomech.2024.106351

Background

Stiff-Knee gait affects 25–75 % of individuals with post-stroke gait impairment and is typically defined as reduced swing phase knee flexion. Different studies use various measures to identify Stiff-Knee gait, such as peak swing knee flexion angle, timing of peak knee flexion, knee range of motion, and ankle push-off acceleration, leading to inconsistent results.

Methods

This study used univariate cluster analysis to examine the independence, consistency, validity, and accuracy of different definitions in 50 post-stroke individuals (24 with and 26 without Stiff-Knee gait), as determined by a physiatrist. Spearman's rank correlation was used for correlation analysis, and five clustering techniques along with clinician evaluations were used for validity analysis.

Findings

Correlation analysis showed that peak knee flexion timing and knee hyperextension are poorly correlated with reduced swing-phase knee flexion angle (ρ = −0.09 and ρ = −0.26 respectively). Validity analysis indicated that the between-limb difference in peak swing knee flexion angle and peak swing knee flexion angle at self-selected gait speeds were the most valid differentiators. At the fastest comfortable gait speed, the between-limb difference of peak knee flexion angle had the highest sensitivity, lowest specificity, and highest F1 scores.

Interpretation

We determined thresholds of less than 44.3° for peak swing knee flexion angle and greater than 17.0° for the between-limb difference of peak knee flexion angle identify Stiff-Knee gait during self-selected walking. We recommend using the difference in peak swing knee flexion angle between limbs to diagnose post-stroke Stiff-Knee gait due to its robustness to changes in gait speed.

背景僵膝步态影响着 25%-75% 的卒中后步态障碍患者，通常被定义为摆动阶段膝关节屈曲减少。本研究采用单变量聚类分析法，对物理治疗师确定的 50 名中风后患者（24 名有中风后膝关节步态障碍，26 名无中风后膝关节步态障碍）的不同定义的独立性、一致性、有效性和准确性进行了研究。相关性分析采用了斯皮尔曼等级相关性，有效性分析采用了五种聚类技术和临床医生的评价。相关性分析表明，膝关节屈曲峰值时间和膝关节过伸与摆动阶段膝关节屈曲角度减小的相关性较差（ρ = -0.09，ρ = -0.26）。有效性分析表明，自选步速下摆动阶段膝关节屈曲角峰值和摆动阶段膝关节屈曲角峰值的肢间差异是最有效的区分指标。在最快的舒适步速下，膝关节屈曲角峰值的肢间差具有最高的灵敏度、最低的特异性和最高的 F1 分数。释义我们确定在自选步行过程中，摆动膝关节屈曲角峰值的阈值小于 44.3°，膝关节屈曲角峰值的肢间差大于 17.0°，可识别僵膝步态。我们建议使用肢体间摆动膝关节屈曲角峰值的差异来诊断卒中后的僵膝步态，因为它对步速的变化具有稳健性。

{"title":"Between-limb difference in peak knee flexion angle can identify persons post-stroke with Stiff-Knee gait","authors":"","doi":"10.1016/j.clinbiomech.2024.106351","DOIUrl":"10.1016/j.clinbiomech.2024.106351","url":null,"abstract":"<div><h3>Background</h3><div>Stiff-Knee gait affects 25–75 % of individuals with post-stroke gait impairment and is typically defined as reduced swing phase knee flexion. Different studies use various measures to identify Stiff-Knee gait, such as peak swing knee flexion angle, timing of peak knee flexion, knee range of motion, and ankle push-off acceleration, leading to inconsistent results.</div></div><div><h3>Methods</h3><div>This study used univariate cluster analysis to examine the independence, consistency, validity, and accuracy of different definitions in 50 post-stroke individuals (24 with and 26 without Stiff-Knee gait), as determined by a physiatrist. Spearman's rank correlation was used for correlation analysis, and five clustering techniques along with clinician evaluations were used for validity analysis.</div></div><div><h3>Findings</h3><div>Correlation analysis showed that peak knee flexion timing and knee hyperextension are poorly correlated with reduced swing-phase knee flexion angle (ρ = −0.09 and ρ = −0.26 respectively). Validity analysis indicated that the between-limb difference in peak swing knee flexion angle and peak swing knee flexion angle at self-selected gait speeds were the most valid differentiators. At the fastest comfortable gait speed, the between-limb difference of peak knee flexion angle had the highest sensitivity, lowest specificity, and highest F1 scores.</div></div><div><h3>Interpretation</h3><div>We determined thresholds of less than 44.3° for peak swing knee flexion angle and greater than 17.0° for the between-limb difference of peak knee flexion angle identify Stiff-Knee gait during self-selected walking. We recommend using the difference in peak swing knee flexion angle between limbs to diagnose post-stroke Stiff-Knee gait due to its robustness to changes in gait speed.</div></div>","PeriodicalId":50992,"journal":{"name":"Clinical Biomechanics","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0268003324001839/pdfft?md5=8b8d6d5104fe90a420720631b7611e8b&pid=1-s2.0-S0268003324001839-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142316112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Fall assessment in healthy older adults: Approach using rambling-trembling decomposition method 健康老年人的跌倒评估：使用漫步-颤抖分解法的方法

IF 1.4 3区医学 Q4 ENGINEERING, BIOMEDICAL

Clinical Biomechanics

Pub Date : 2024-09-21 DOI: 10.1016/j.clinbiomech.2024.106355

Background

This study explored useful indices of potential fall risk in healthy older adults based on comprehensive clinical and simple quantitative posturographic measurements.

Methods

A total of 64 community-dwelling older adults aged ≥65 years were classified into fallers and non-fallers based on previous fall history. After excluding two participants due to missing data, 16 and 46 participants were included in the faller and non-faller groups, respectively. We conducted major clinical measurements, including timed up and go test, 10-m walk test, functional reach test, one-leg stand test, isometric muscle strength tests, open-close stepping test, and sit-to-stand test. For quantitative posturographic measurements, participants performed standing tasks with their eyes open and closed. In the standing tasks, the time series of the center of pressure in the anteroposterior and mediolateral directions were measured and decomposed into rambling and trembling components to evaluate postural control in detail, separately. The mean velocity and root mean square of the center of pressure, rambling, and trembling were calculated and compared between fallers and non-fallers.

Findings

A significant fall-related difference was found only in the mean velocity of the rambling in the anteroposterior direction; fallers displayed greater values than non-fallers, especially while standing with their eyes closed.

Interpretation

The clinical measures failed to distinguish differences in fall risk, whereas the rambling component in the anteroposterior direction could detect substantial differences. The mean velocity of the rambling component could be useful as a sensitive screening biomarker for potential fall risks in healthy older adults.

背景本研究根据综合临床和简单定量的体位测量方法，探讨了健康老年人潜在跌倒风险的有用指标。方法根据既往跌倒史，将 64 名年龄≥65 岁的社区老年人分为跌倒者和非跌倒者。在排除了两名数据缺失的参与者后，分别有 16 名和 46 名参与者被纳入跌倒者和非跌倒者组。我们进行了主要的临床测量，包括定时起立行走测试、10 米步行测试、功能性伸展测试、单腿站立测试、等长肌力测试、开合步法测试和坐立测试。在进行定量后视测量时，参与者分别在睁眼和闭眼状态下完成站立任务。在站立任务中，测量前后方向和内外侧方向压力中心的时间序列，并将其分解为漫步和颤抖成分，以分别详细评估姿势控制。结果发现，只有在前胸方向的漫游平均速度中发现了与跌倒相关的显著差异；跌倒者比非跌倒者显示出更大的数值，尤其是在闭眼站立时。漫游分量的平均速度可作为一种敏感的生物标志物，用于筛查健康老年人的潜在跌倒风险。

{"title":"Fall assessment in healthy older adults: Approach using rambling-trembling decomposition method","authors":"","doi":"10.1016/j.clinbiomech.2024.106355","DOIUrl":"10.1016/j.clinbiomech.2024.106355","url":null,"abstract":"<div><h3>Background</h3><div>This study explored useful indices of potential fall risk in healthy older adults based on comprehensive clinical and simple quantitative posturographic measurements.</div></div><div><h3>Methods</h3><div>A total of 64 community-dwelling older adults aged ≥65 years were classified into fallers and non-fallers based on previous fall history. After excluding two participants due to missing data, 16 and 46 participants were included in the faller and non-faller groups, respectively. We conducted major clinical measurements, including timed up and go test, 10-m walk test, functional reach test, one-leg stand test, isometric muscle strength tests, open-close stepping test, and sit-to-stand test. For quantitative posturographic measurements, participants performed standing tasks with their eyes open and closed. In the standing tasks, the time series of the center of pressure in the anteroposterior and mediolateral directions were measured and decomposed into rambling and trembling components to evaluate postural control in detail, separately. The mean velocity and root mean square of the center of pressure, rambling, and trembling were calculated and compared between fallers and non-fallers.</div></div><div><h3>Findings</h3><div>A significant fall-related difference was found only in the mean velocity of the rambling in the anteroposterior direction; fallers displayed greater values than non-fallers, especially while standing with their eyes closed.</div></div><div><h3>Interpretation</h3><div>The clinical measures failed to distinguish differences in fall risk, whereas the rambling component in the anteroposterior direction could detect substantial differences. The mean velocity of the rambling component could be useful as a sensitive screening biomarker for potential fall risks in healthy older adults.</div></div>","PeriodicalId":50992,"journal":{"name":"Clinical Biomechanics","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142318622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Biomechanical analysis of the effect of postero-latero-central tibial plateau fractures in the knee joint: Can posterior soft tissues prevent instability? A finite element study. 膝关节胫骨平台后中央骨折影响的生物力学分析：后软组织能否防止失稳？有限元研究。

IF 1.4 3区医学 Q4 ENGINEERING, BIOMEDICAL

Clinical Biomechanics

Pub Date : 2024-09-21 DOI: 10.1016/j.clinbiomech.2024.106353

Background

Almost 86 % of all tibial plateau fractures involves the failure of the postero-latero-central region of the tibial plateau. Surgical treatment of this region is technically demanding and in case of limited depression, it's occasionally chosen to leave them untreated. The aim of the study is to numerically check to what extent this choice can be accepted avoiding inferior outcomes (i.e. joint instability), and to analyze posterior soft tissues role in presence of this fractures.

Methods

Starting from a previous validated finite element model with baseline structures, several configurations were developed by inserting posterior soft tissues and postero-latero-central fracture, with different articular depressions. Squat motion was numerically simulated and tibio-femoral kinematics were compared among configurations.

Findings

An increasing step-off led to a progressive joint instability, especially in the first 35°-40° of flexion. Posterior soft tissues showed to be beneficial in initial stabilization and early flexion. Tibial Axial Rotation didn't show any restorative effect of posterior soft tissues on knee kinematics. Tibial Antero-Posterior Translation is the most significant biomechanical parameter, showing posterior soft tissues restoring native antero-posterior translation, completely for 1-mm step-off fracture, only partially for 2-mm step-off fracture, and not sufficiently for 3-mm step-off fracture, at least in the first 30° of flexion.

Interpretation

The results suggest that postero-latero-central fractures with step-off ≥2 mm should be treated to restore articular kinematic, whereas fractures with step-off <2 mm need a broad evaluation to assess the effective need of surgery. These information can be valuable for surgeons, to aid their decision to surgically operate or not.

背景几乎 86% 的胫骨平台骨折都发生在胫骨平台的后中央区。该区域的手术治疗技术要求较高，在凹陷有限的情况下，有时会选择不进行治疗。本研究的目的是通过数值检查在多大程度上可以接受这种选择，避免出现不良后果（即关节不稳定），并分析后软组织在出现这种骨折时的作用。方法从以前经过验证的具有基线结构的有限元模型开始，通过插入后软组织和不同关节凹陷的后后中央骨折，开发了几种配置。对下蹲运动进行了数值模拟，并比较了不同结构的胫骨-股骨运动学特性。研究结果随着下蹲幅度的增大，关节不稳定性逐渐增加，尤其是在屈曲的前35°-40°。后部软组织对初始稳定和早期屈曲有好处。胫骨轴向旋转没有显示出后软组织对膝关节运动学有任何恢复作用。胫骨前-后平移是最重要的生物力学参数，结果表明后部软组织可完全恢复原生前-后平移，对于1毫米的台阶式骨折，后部软组织可完全恢复原生前-后平移，对于2毫米的台阶式骨折，后部软组织只能部分恢复原生前-后平移，而对于3毫米的台阶式骨折，后部软组织则不能完全恢复原生前-后平移，至少在屈膝的前30°时是如此。释义结果表明，阶差≥2 mm的后中央骨折应进行治疗以恢复关节运动学，而阶差<2 mm的骨折则需要进行广泛评估，以评估手术的有效需求。这些信息对外科医生很有价值，有助于他们决定是否进行手术。

{"title":"Biomechanical analysis of the effect of postero-latero-central tibial plateau fractures in the knee joint: Can posterior soft tissues prevent instability? A finite element study.","authors":"","doi":"10.1016/j.clinbiomech.2024.106353","DOIUrl":"10.1016/j.clinbiomech.2024.106353","url":null,"abstract":"<div><h3>Background</h3><div>Almost 86 % of all tibial plateau fractures involves the failure of the postero-latero-central region of the tibial plateau. Surgical treatment of this region is technically demanding and in case of limited depression, it's occasionally chosen to leave them untreated. The aim of the study is to numerically check to what extent this choice can be accepted avoiding inferior outcomes (i.e. joint instability), and to analyze posterior soft tissues role in presence of this fractures.</div></div><div><h3>Methods</h3><div>Starting from a previous validated finite element model with baseline structures, several configurations were developed by inserting posterior soft tissues and postero-latero-central fracture, with different articular depressions. Squat motion was numerically simulated and tibio-femoral kinematics were compared among configurations.</div></div><div><h3>Findings</h3><div>An increasing step-off led to a progressive joint instability, especially in the first 35°-40° of flexion. Posterior soft tissues showed to be beneficial in initial stabilization and early flexion. Tibial Axial Rotation didn't show any restorative effect of posterior soft tissues on knee kinematics. Tibial Antero-Posterior Translation is the most significant biomechanical parameter, showing posterior soft tissues restoring native antero-posterior translation, completely for 1-mm step-off fracture, only partially for 2-mm step-off fracture, and not sufficiently for 3-mm step-off fracture, at least in the first 30° of flexion.</div></div><div><h3>Interpretation</h3><div>The results suggest that postero-latero-central fractures with step-off ≥2 mm should be treated to restore articular kinematic, whereas fractures with step-off <2 mm need a broad evaluation to assess the effective need of surgery. These information can be valuable for surgeons, to aid their decision to surgically operate or not.</div></div>","PeriodicalId":50992,"journal":{"name":"Clinical Biomechanics","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142323936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Biomechanical modelling of indirect decompression in oblique lumbar intervertebral fusions – A finite element study 斜行腰椎间融合间接减压的生物力学模型--有限元研究

IF 1.4 3区医学 Q4 ENGINEERING, BIOMEDICAL

Clinical Biomechanics

Pub Date : 2024-09-20 DOI: 10.1016/j.clinbiomech.2024.106352

Background

Oblique lumbar intervertebral fusion aims to decompress spinal nerves via an interbody fusion cage, but the optimal surgical strategy, including implant selection for specific patient characteristics, remains unclear. A biomechanical model was developed to assess how pathophysiological characteristics and instrumentation impact spinal realignment, indirect decompression, and cage subsidence risk.

Methods

A finite element model of the L4-L5 segment was derived from a validated asymptomatic T1-S1 spine model. Five cases of grade I spondylolisthesis with normal or osteoporotic bone densities and initial disc heights of 4.3 to 8.3 mm were simulated. Oblique lumbar intervertebral fusion with cage heights of 10, 12, and 14 mm (12° lordosis) was examined. Postoperative changes in disc height, foraminal and spinal canal dimensions, segmental lordosis, and vertebral slip were assessed. Vertebral stresses and displacements under 10 Nm flexion and 400 N gravitational load were compared between stand-alone constructs and bilateral pedicle screw fixation using rods of 4.75, 5.5, and 6 mm diameters.

Findings

Oblique lumbar intervertebral fusion significantly improved postoperative disc height, foraminal and spinal canal dimensions, with the greatest enhancements observed with 14 mm cages. Bilateral pedicle screw fixation markedly reduced cortical endplate stresses and displacements compared to stand-alone constructs, with added benefits from larger rod diameters. Low bone density increased displacements by 63 %.

Interpretation

Thicker cages achieve better decompression but increase subsidence risk. Bilateral pedicle screw fixation with 6 mm rods minimizes endplate stresses and displacements, especially in osteoporotic cases. Future research will validate these findings and explore the model's potential for surgical planning.

背景斜腰椎椎间融合术旨在通过椎体间融合器笼为脊神经减压，但最佳手术策略，包括针对特定患者特征选择植入物，仍不明确。我们建立了一个生物力学模型，以评估病理生理特征和器械如何影响脊柱对位、间接减压和椎间融合器笼下沉风险。模拟了五例骨密度正常或骨质疏松、初始椎间盘高度为 4.3 至 8.3 毫米的 I 级脊柱滑脱病例。对椎弓根高度为 10、12 和 14 毫米（后凸 12°）的斜腰椎椎间融合术进行了研究。评估了术后椎间盘高度、椎孔和椎管尺寸、节段前凸和椎体滑移的变化。研究结果腰椎间融合术明显改善了术后椎间盘高度、椎管和椎间孔的尺寸，14 毫米的椎体保持架改善最大。与独立结构相比，双侧椎弓根螺钉固定明显降低了皮质终板应力和位移，而更大直径的螺钉杆也带来了更多益处。低骨密度会使位移增加 63%。使用6毫米杆进行双侧椎弓根螺钉固定可最大限度地减少终板应力和位移，尤其是在骨质疏松的病例中。未来的研究将验证这些发现，并探索该模型在手术规划方面的潜力。

{"title":"Biomechanical modelling of indirect decompression in oblique lumbar intervertebral fusions – A finite element study","authors":"","doi":"10.1016/j.clinbiomech.2024.106352","DOIUrl":"10.1016/j.clinbiomech.2024.106352","url":null,"abstract":"<div><h3>Background</h3><div>Oblique lumbar intervertebral fusion aims to decompress spinal nerves via an interbody fusion cage, but the optimal surgical strategy, including implant selection for specific patient characteristics, remains unclear. A biomechanical model was developed to assess how pathophysiological characteristics and instrumentation impact spinal realignment, indirect decompression, and cage subsidence risk.</div></div><div><h3>Methods</h3><div>A finite element model of the L4-L5 segment was derived from a validated asymptomatic T1-S1 spine model. Five cases of grade I spondylolisthesis with normal or osteoporotic bone densities and initial disc heights of 4.3 to 8.3 mm were simulated. Oblique lumbar intervertebral fusion with cage heights of 10, 12, and 14 mm (12° lordosis) was examined. Postoperative changes in disc height, foraminal and spinal canal dimensions, segmental lordosis, and vertebral slip were assessed. Vertebral stresses and displacements under 10 Nm flexion and 400 N gravitational load were compared between stand-alone constructs and bilateral pedicle screw fixation using rods of 4.75, 5.5, and 6 mm diameters.</div></div><div><h3>Findings</h3><div>Oblique lumbar intervertebral fusion significantly improved postoperative disc height, foraminal and spinal canal dimensions, with the greatest enhancements observed with 14 mm cages. Bilateral pedicle screw fixation markedly reduced cortical endplate stresses and displacements compared to stand-alone constructs, with added benefits from larger rod diameters. Low bone density increased displacements by 63 %.</div></div><div><h3>Interpretation</h3><div>Thicker cages achieve better decompression but increase subsidence risk. Bilateral pedicle screw fixation with 6 mm rods minimizes endplate stresses and displacements, especially in osteoporotic cases. Future research will validate these findings and explore the model's potential for surgical planning.</div></div>","PeriodicalId":50992,"journal":{"name":"Clinical Biomechanics","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0268003324001840/pdfft?md5=4af0124a21469945931be9cc0d98da41&pid=1-s2.0-S0268003324001840-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142316117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Determinants of pivot kinematics in posterior stabilized total knee arthroplasty 后稳定全膝关节置换术中枢轴运动学的决定因素

IF 1.4 3区医学 Q4 ENGINEERING, BIOMEDICAL

Clinical Biomechanics

Pub Date : 2024-09-18 DOI: 10.1016/j.clinbiomech.2024.106350

Background

Restoring medial knee pivot kinematics post-total knee arthroplasty is widely recognized to enhance patient satisfaction. Our study investigates the kinematics of patients who received posterior stabilized implants via robotic-arm assisted surgery, specifically analyzing effects of implant alignment and soft tissue balance on pivot location.

Methods

Twelve high-functioning patients with unilateral posterior stabilizing knee implants underwent CT-guided robotic-arm assisted surgery. We then evaluated their knee kinematics using stereo radiography during gait, stair descent, lunge, seated knee extension and leg press. Femoral low-point condylar kinematics were used to calculate the transverse center of rotation, or pivot, using principal component analysis. Linear mixed effects regression was used to identify surgical parameters that influence pivot location across a flexion range.

Findings

Across all five activities a central pivot pattern emerged as the primary pivot location (40 %) followed by medial (25 %), no pivot (22 %) and lateral (14 %). Tibial medial resection depth and Tibial implant flexion-extension placement were significantly associated with shifting the pivot location laterally prior to cam-post engagement. Femoral implant external-internal implant placement, and medial compartment laxity in extension were significantly associated with shifting the pivot location laterally during the cam-post engagement, while femoral distal-lateral resection depth was associated with a medial shift.

Interpretation

Central and medial pivot locations are predominant in patients with posterior stabilized total knee arthroplasty, facilitated by robotic-arm assisted surgery. Despite significant associations between surgical parameters such as tibial medial resection depth and lateral compartment laxity with medial pivot, these variables explained a small portion of the variability in pivot location. This suggests that while surgical precision influences pivot kinematics, individual patient factors may play a more critical role, suggesting a need for further research into patient-specific biomechanics to optimize post-surgical outcomes.

背景全膝关节置换术后恢复膝关节内侧枢轴运动学被广泛认为可以提高患者满意度。我们的研究调查了通过机械臂辅助手术接受后稳定植入物的患者的运动学情况，特别分析了植入物排列和软组织平衡对枢轴位置的影响。然后，我们在步态、下楼梯、弓步、坐位膝关节伸展和压腿过程中使用立体放射摄影对他们的膝关节运动学进行了评估。股骨低点髁运动学数据被用来通过主成分分析计算横向旋转中心或枢轴。在所有五种活动中，中心枢轴模式是主要的枢轴位置（40%），其次是内侧（25%）、无枢轴（22%）和外侧（14%）。胫骨内侧切除深度和胫骨假体屈伸位置与凸轮柱啮合前枢轴位置向外侧移动密切相关。股骨内外侧假体置入和伸展时内侧室松弛与凸轮柱接合时枢轴位置向外侧移动有显著相关性，而股骨远外侧切除深度与内侧移动相关。尽管手术参数（如胫骨内侧切除深度和侧室松弛度）与内侧枢轴之间存在明显关联，但这些变量只能解释枢轴位置变异的一小部分。这表明，虽然手术精度会影响枢轴运动学，但患者的个体因素可能起着更为关键的作用，因此有必要进一步研究患者的特异性生物力学，以优化术后效果。

{"title":"Determinants of pivot kinematics in posterior stabilized total knee arthroplasty","authors":"","doi":"10.1016/j.clinbiomech.2024.106350","DOIUrl":"10.1016/j.clinbiomech.2024.106350","url":null,"abstract":"<div><h3>Background</h3><div>Restoring medial knee pivot kinematics post-total knee arthroplasty is widely recognized to enhance patient satisfaction. Our study investigates the kinematics of patients who received posterior stabilized implants via robotic-arm assisted surgery, specifically analyzing effects of implant alignment and soft tissue balance on pivot location.</div></div><div><h3>Methods</h3><div>Twelve high-functioning patients with unilateral posterior stabilizing knee implants underwent CT-guided robotic-arm assisted surgery. We then evaluated their knee kinematics using stereo radiography during gait, stair descent, lunge, seated knee extension and leg press. Femoral low-point condylar kinematics were used to calculate the transverse center of rotation, or pivot, using principal component analysis. Linear mixed effects regression was used to identify surgical parameters that influence pivot location across a flexion range.</div></div><div><h3>Findings</h3><div>Across all five activities a central pivot pattern emerged as the primary pivot location (40 %) followed by medial (25 %), no pivot (22 %) and lateral (14 %). Tibial medial resection depth and Tibial implant flexion-extension placement were significantly associated with shifting the pivot location laterally prior to cam-post engagement. Femoral implant external-internal implant placement, and medial compartment laxity in extension were significantly associated with shifting the pivot location laterally during the cam-post engagement, while femoral distal-lateral resection depth was associated with a medial shift.</div></div><div><h3>Interpretation</h3><div>Central and medial pivot locations are predominant in patients with posterior stabilized total knee arthroplasty, facilitated by robotic-arm assisted surgery. Despite significant associations between surgical parameters such as tibial medial resection depth and lateral compartment laxity with medial pivot, these variables explained a small portion of the variability in pivot location. This suggests that while surgical precision influences pivot kinematics, individual patient factors may play a more critical role, suggesting a need for further research into patient-specific biomechanics to optimize post-surgical outcomes.</div></div>","PeriodicalId":50992,"journal":{"name":"Clinical Biomechanics","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142311452","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

An acoustic bellows-type round window transducer for middle-ear implants 用于中耳植入的波纹管型圆窗声学换能器

IF 1.4 3区医学 Q4 ENGINEERING, BIOMEDICAL

Clinical Biomechanics

Pub Date : 2024-09-18 DOI: 10.1016/j.clinbiomech.2024.106349

Background

This study describes the development of output devices for round window middle-ear. To overcome the problems of output devices that apply sound pressure directly to the round window, an acoustic bellows-type round window transducer was implemented by combining a small bellows, acoustic tube, and balanced armature driver.

Methods

The output characteristics of the proposed acoustic bellows-type round window transducer were confirmed through bench tests and distortion measurements. To compare the vibration transmission characteristics of the proposed transducer with those of sound pressure stimulation devices, an experiment was performed using four human temporal bones.

Findings

The average output magnitude of the acoustic bellows-type round window transducer was equivalent to sound pressure levels of 92, 96, and 108 dB for frequency ranges of <1, 1–2, and > 2 kHz, respectively. The results showed that the proposed transducer delivered vibration consistently without reducing the sound pressure level due to leakage, unlike the sound pressure stimulation device.

Interpretation

Therefore, the acoustic bellows-type round window transducer is a more stable and suitable output device for round window middle-ear implants than a sound pressure stimulation device. It is expected to overcome the limitations of sound pressure stimulation devices and to contribute to new technical solutions in the field of round window middle-ear implants development.

背景本研究介绍了圆窗中耳输出设备的开发情况。为了克服直接向圆窗施加声压的输出设备所存在的问题，研究人员将小波纹管、声学管和平衡电枢驱动器组合在一起，实现了声学波纹管式圆窗换能器。方法通过台架试验和失真测量确认了所提出的声学波纹管式圆窗换能器的输出特性。结果声学波纹管型圆窗换能器的平均输出幅度在频率范围为 1、1-2 和 2 kHz 时分别相当于 92、96 和 108 dB 的声压级。因此，与声压刺激装置相比，声学波纹管型圆窗换能器是一种更稳定、更适用于圆窗中耳植入的输出装置。它有望克服声压刺激装置的局限性，并为圆窗中耳植入物开发领域提供新的技术解决方案。

{"title":"An acoustic bellows-type round window transducer for middle-ear implants","authors":"","doi":"10.1016/j.clinbiomech.2024.106349","DOIUrl":"10.1016/j.clinbiomech.2024.106349","url":null,"abstract":"<div><h3>Background</h3><p>This study describes the development of output devices for round window middle-ear. To overcome the problems of output devices that apply sound pressure directly to the round window, an acoustic bellows-type round window transducer was implemented by combining a small bellows, acoustic tube, and balanced armature driver.</p></div><div><h3>Methods</h3><p>The output characteristics of the proposed acoustic bellows-type round window transducer were confirmed through bench tests and distortion measurements. To compare the vibration transmission characteristics of the proposed transducer with those of sound pressure stimulation devices, an experiment was performed using four human temporal bones.</p></div><div><h3>Findings</h3><p>The average output magnitude of the acoustic bellows-type round window transducer was equivalent to sound pressure levels of 92, 96, and 108 dB for frequency ranges of <1, 1–2, and > 2 kHz, respectively. The results showed that the proposed transducer delivered vibration consistently without reducing the sound pressure level due to leakage, unlike the sound pressure stimulation device.</p></div><div><h3>Interpretation</h3><p>Therefore, the acoustic bellows-type round window transducer is a more stable and suitable output device for round window middle-ear implants than a sound pressure stimulation device. It is expected to overcome the limitations of sound pressure stimulation devices and to contribute to new technical solutions in the field of round window middle-ear implants development.</p></div>","PeriodicalId":50992,"journal":{"name":"Clinical Biomechanics","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0268003324001815/pdfft?md5=814429f427855b445390e28b493e9f46&pid=1-s2.0-S0268003324001815-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142274445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

In response to “The type of gait disturbance in COVID-19 survivors depends on its etiology” 回应 "COVID-19幸存者的步态障碍类型取决于其病因"

IF 1.4 3区医学 Q4 ENGINEERING, BIOMEDICAL

Clinical Biomechanics

Pub Date : 2024-09-14 DOI: 10.1016/j.clinbiomech.2024.106348

引用次数: 0

Is the cadaveric model valid for examining orthopaedic manual therapy techniques? A cross-sectional comparative study in vivo and in vitro 尸体模型是否适用于检查矫形外科徒手治疗技术？体内和体外横断面比较研究

IF 1.4 3区医学 Q4 ENGINEERING, BIOMEDICAL

Clinical Biomechanics

Pub Date : 2024-09-13 DOI: 10.1016/j.clinbiomech.2024.106347

Background

Cadaveric models are sometimes used to test the effect of manual techniques. We have not found any studies comparing the effect of tibiotarsal joint distraction on cadaveric models versus live models for clinical use. The aim was to compare the effect on tibiotarsal joint distraction movement when applying three force magnitudes of tibiotarsal axial traction technique force between a cadaveric model and volunteers. In addition, to compare the magnitude of force applied between the cadaveric model and volunteers. Finally, to assess the reliability of applying the same magnitude of force in three magnitudes of tibiotarsal axial traction force.

Methods

A cross-sectional comparative study was conducted. Sixty ankle joints were in open-packed position and three magnitudes of tibiotarsal axial traction technique force were applied. Tibiotarsal joint distraction movement was measured with ultrasound.

Findings

No differences were found in applied force or tibiotarsal joint distraction between volunteers and cadavers in each magnitude of force (p > 0.05). The application of the technique showed moderate reliability for detecting low forces in both models. For medium and high force, it showed good reliability in the in vitro model and excellent reliability in the live model.

Interpretation

The amount of distraction produced in the tibiotarsal joint was similar in volunteers and cadavers. The cadaveric model is a valid model for testing and investigating orthopaedic manual therapy techniques. The force applied was similar in the two models. Medium and high force detection showed good reliability, while low force showed moderate.

背景尸体模型有时用于测试人工技术的效果。我们尚未发现任何研究可比较尸体模型与临床使用的活体模型对胫腓关节牵引的影响。我们的目的是比较尸体模型和志愿者在使用胫腓骨轴向牵引技术的三种力量时对胫腓骨关节牵引运动的影响。此外，比较尸体模型和志愿者施加的力量大小。最后，评估在三种胫腓骨轴向牵引力中施加相同大小的力的可靠性。将 60 个踝关节置于开放包裹位，并施加三种大小的胫跗关节轴向牵引力。研究结果志愿者和尸体在每个力量大小上的施力和胫腓关节牵引力均无差异（p >0.05）。在两种模型中，该技术的应用在检测低力时显示出中等可靠性。志愿者和尸体的胫腓关节牵张量相似。尸体模型是测试和研究骨科徒手治疗技术的有效模型。两种模型的作用力相似。中、高力检测显示出良好的可靠性，而低力检测显示出中等可靠性。

{"title":"Is the cadaveric model valid for examining orthopaedic manual therapy techniques? A cross-sectional comparative study in vivo and in vitro","authors":"","doi":"10.1016/j.clinbiomech.2024.106347","DOIUrl":"10.1016/j.clinbiomech.2024.106347","url":null,"abstract":"<div><h3>Background</h3><p>Cadaveric models are sometimes used to test the effect of manual techniques. We have not found any studies comparing the effect of tibiotarsal joint distraction on cadaveric models versus live models for clinical use. The aim was to compare the effect on tibiotarsal joint distraction movement when applying three force magnitudes of tibiotarsal axial traction technique force between a cadaveric model and volunteers. In addition, to compare the magnitude of force applied between the cadaveric model and volunteers. Finally, to assess the reliability of applying the same magnitude of force in three magnitudes of tibiotarsal axial traction force.</p></div><div><h3>Methods</h3><p>A cross-sectional comparative study was conducted. Sixty ankle joints were in open-packed position and three magnitudes of tibiotarsal axial traction technique force were applied. Tibiotarsal joint distraction movement was measured with ultrasound.</p></div><div><h3>Findings</h3><p>No differences were found in applied force or tibiotarsal joint distraction between volunteers and cadavers in each magnitude of force (<em>p</em> > 0.05). The application of the technique showed moderate reliability for detecting low forces in both models. For medium and high force, it showed good reliability in the in vitro model and excellent reliability in the live model.</p></div><div><h3>Interpretation</h3><p>The amount of distraction produced in the tibiotarsal joint was similar in volunteers and cadavers. The cadaveric model is a valid model for testing and investigating orthopaedic manual therapy techniques. The force applied was similar in the two models. Medium and high force detection showed good reliability, while low force showed moderate<strong>.</strong></p></div>","PeriodicalId":50992,"journal":{"name":"Clinical Biomechanics","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142232641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The biomechanical assessment of two stemless shoulder arthroplasty prostheses in uniformly poor-quality bone mineral density cadaveric specimens 两种无柄肩关节假体在骨矿物质密度均较差的尸体标本中的生物力学评估

IF 1.4 3区医学 Q4 ENGINEERING, BIOMEDICAL

Clinical Biomechanics

Pub Date : 2024-09-13 DOI: 10.1016/j.clinbiomech.2024.106346

Background

Stemless shoulder arthroplasty offers several advantages, such as preserving bone stock and reducing periprosthetic fracture risk. However, implant motion can deter osteointegration and increase bone resorption, where micromotion less than 0.150 mm is crucial for bony ingrowth and vital to the success of the implant. The interaction between the implant and the metaphyseal bone and its effects on stability remains unclear. Therefore, this cadaveric study aims to assess the immediate stability of two stemless prostheses in low bone density specimens.

Methods

Twenty cadaveric shoulders were used to compare the stability of two stemless shoulder implants by Zimmer-Biomet (model A) and Exactech (model B), subjected to loads of 220 N, 520 N, and 820 N to assess strain and micromotion.

Findings

Micromotion at 220 N load was 0.061 ± 0.080 mm and 0.053 ± 0.050 mm, and at 520 N load, 0.279 ± 0.37 mm and 0.311 ± 0.35 mm for models A and B, respectively. The estimated mean force required to achieve a 150 μm micromotion was 356 ± 116 N and 315 ± 61 N for models A and B, respectively. Motion analysis revealed distinct movement patterns for each implant, with model B demonstrating better force distribution on the bone despite no significance.

Interpretation

Forces over 520 N (high postoperative rehabilitation force) could hinder bone integration with prostheses due to excessive micromotion. Conversely, forces around 220 N (preconditioning loading force) are considered safe for prosthesis stability even with low bone density. These insights may caution against using stemless implants when bone density is low, and help guide clinical decisions on the duration of rehabilitation and sling use after stemless arthroplasty.

背景无茎肩关节置换术具有多种优势，如保留骨量和降低假体周围骨折风险。然而，植入体的移动会阻碍骨整合并增加骨吸收，而小于 0.150 mm 的微动对骨的生长至关重要，也是植入体成功的关键。目前还不清楚种植体与骺端骨之间的相互作用及其对稳定性的影响。因此，这项尸体研究旨在评估两种无茎假体在低骨密度标本中的即时稳定性。方法用20个尸体肩部比较Zimmer-Biomet（A型）和Exactech（B型）两种无茎肩部假体的稳定性，分别承受220 N、520 N和820 N的负荷，以评估应变和微动。结果模型 A 和模型 B 在 220 N 负荷下的微动分别为 0.061 ± 0.080 mm 和 0.053 ± 0.050 mm，在 520 N 负荷下的微动分别为 0.279 ± 0.37 mm 和 0.311 ± 0.35 mm。模型 A 和 B 实现 150 μm 微动所需的估计平均力分别为 356 ± 116 N 和 315 ± 61 N。运动分析表明，每种假体都有不同的运动模式，模型 B 在骨上的力分布更好，尽管没有显著性。相反，即使骨密度较低，220 N左右的力量（预处理加载力）对假体的稳定性也是安全的。这些见解可提醒人们在骨密度较低时不要使用无茎假体，并有助于指导临床决定无茎假体植入术后康复和使用吊带的持续时间。

{"title":"The biomechanical assessment of two stemless shoulder arthroplasty prostheses in uniformly poor-quality bone mineral density cadaveric specimens","authors":"","doi":"10.1016/j.clinbiomech.2024.106346","DOIUrl":"10.1016/j.clinbiomech.2024.106346","url":null,"abstract":"<div><h3>Background</h3><p>Stemless shoulder arthroplasty offers several advantages, such as preserving bone stock and reducing periprosthetic fracture risk. However, implant motion can deter osteointegration and increase bone resorption, where micromotion less than 0.150 mm is crucial for bony ingrowth and vital to the success of the implant. The interaction between the implant and the metaphyseal bone and its effects on stability remains unclear. Therefore, this cadaveric study aims to assess the immediate stability of two stemless prostheses in low bone density specimens.</p></div><div><h3>Methods</h3><p>Twenty cadaveric shoulders were used to compare the stability of two stemless shoulder implants by Zimmer-Biomet (model A) and Exactech (model B), subjected to loads of 220 N, 520 N, and 820 N to assess strain and micromotion.</p></div><div><h3>Findings</h3><p>Micromotion at 220 N load was 0.061 ± 0.080 mm and 0.053 ± 0.050 mm, and at 520 N load, 0.279 ± 0.37 mm and 0.311 ± 0.35 mm for models A and B, respectively. The estimated mean force required to achieve a 150 μm micromotion was 356 ± 116 N and 315 ± 61 N for models A and B, respectively. Motion analysis revealed distinct movement patterns for each implant, with model B demonstrating better force distribution on the bone despite no significance.</p></div><div><h3>Interpretation</h3><p>Forces over 520 N (high postoperative rehabilitation force) could hinder bone integration with prostheses due to excessive micromotion. Conversely, forces around 220 N (preconditioning loading force) are considered safe for prosthesis stability even with low bone density. These insights may caution against using stemless implants when bone density is low, and help guide clinical decisions on the duration of rehabilitation and sling use after stemless arthroplasty.</p></div>","PeriodicalId":50992,"journal":{"name":"Clinical Biomechanics","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142274557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0