Clinical Biomechanics最新文献

{"title":"A novel acoustic emission screwdriver reduces surgeons´ cancellous screw stripping rate - A biomechanical study","authors":"Bryan Joseph Wright ,&nbsp;Stephen Grigg ,&nbsp;John McCrory ,&nbsp;Rhys Pullin ,&nbsp;Jan Egil Brattgjerd","doi":"10.1016/j.clinbiomech.2025.106467","DOIUrl":"10.1016/j.clinbiomech.2025.106467","url":null,"abstract":"<div><h3>Background</h3><div>Orthopedic surgeons refine their torque sensitive skills from tightening cancellous screws. Still, experienced surgeons exhibit surprisingly high screw stripping rates in osteopenic cancellous bone. Whether Acoustic-Emission technology, detecting energy waves from microstructural damage during screw purchase, can reduce these rates is unclear. Our aim was to evaluate if surgeons, irrespective of their experience, reduced cancellous screw stripping rate by combining their skills with feedback from an innovative Acoustic-Emission screwdriver.</div></div><div><h3>Methods</h3><div>Thirteen orthopedic surgeons with 0–23 years´ experience inserted 468 large fragment cancellous screws through plates into synthetic osteoporotic bone. The 1st stage, surgeons tightened 9 screws each without Acoustic-Emission feedback. The 2nd stage, each tightened 18 screws using the Acoustic-Emission feedback modified screwdriver. The last stage, surgeons tightened 9 screws each, again without Acoustic-Emission feedback. A strain gauge on the screwdriver was used to verify screw stripping.</div></div><div><h3>Findings</h3><div>Surgeons stripped 36 out of 115 screws (31 %) in stage 1, 37 out of 227 screws (16 %) in stage 2, and 26 out of 114 screws (23 %) in stage 3. A significant reduced screw stripping rate was found in stage 2 compared to in stage 1 (<em>p</em> &lt; 0.001). Neither the individual surgeon nor experience of the surgeon contributed to screw stripping probability in a mixed effect logistical regression model.</div></div><div><h3>Interpretations</h3><div>Acoustic-Emission technology is superior to the torque sensitive skills of surgeons, demonstrating its potential to assist surgeons in real time, regardless of their experience, in reducing screw stripping rates in cancellous bone.</div></div>","PeriodicalId":50992,"journal":{"name":"Clinical Biomechanics","volume":"123 ","pages":"Article 106467"},"PeriodicalIF":1.4,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143464501","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}

{"title":"Similarity of shoulder kinematics between people with subacromial pain syndrome and asymptomatic individuals: A study using inertial measurement units","authors":"Adrien Beaud ,&nbsp;Quentin Lejeune ,&nbsp;Hélène Pillet ,&nbsp;Antoine Mazarguil ,&nbsp;Josette Bertheau ,&nbsp;Marie-Martine Lefèvre-Colau ,&nbsp;Alexandra Rören","doi":"10.1016/j.clinbiomech.2025.106462","DOIUrl":"10.1016/j.clinbiomech.2025.106462","url":null,"abstract":"<div><h3>Background</h3><div>Subacromial pain syndrome is the most common cause of shoulder pain and is associated with altered humeral and scapular kinematics. Symptoms can be improved by rehabilitation. Accurate tools to analyze shoulder kinematic curves are lacking.</div></div><div><h3>Methods</h3><div>A single-center prospective pilot study using inertial measurement units located on both arms and scapulae to assess bilateral arm elevation in the sagittal, scapular and frontal planes. Reparameterization and signal registration algorithms compared similarity of global shoulder and scapular kinematic curves from participants with subacromial pain syndrome before and after a short rehabilitation program, with a control template combining the curves of asymptomatic participants. A similarity score used curve comparisons; the more closely the curve shapes matched, the closer the score was to zero. We used a paired Wilcoxon test to compare the scores.</div></div><div><h3>Findings</h3><div>We included 9 right-handed symptomatic participants (10 shoulders): 2 males (22 %), mean (SD) age 53.8 (13.7) years, symptom duration 29 (23) months, pain (Numeric Rating Scale) 61.1 (22.4)/100, activity limitation (Quick-Dash): 48.3 (26.6)/100 points, and 10 asymptomatic age-matched right-handed participants (20 shoulders): 4 males (40 %), 54.2 (5.4) years old. Post-rehabilitation similarity scores decreased non-significantly for shoulder elevation (scapular and frontal planes), scapular lateral rotation (sagittal and scapular planes) and anterior-posterior tilt (scapular plane) and significantly for shoulder sagittal elevation (<em>P</em> = 0.004). Participant heterogeneity was high.</div></div><div><h3>Interpretation</h3><div>The similarity methodology, used for the first time in the context of subacromial pain syndrome, offers a new quantitative tool to assess kinematic changes, measure movement-related impairments and monitor patient progress.</div></div>","PeriodicalId":50992,"journal":{"name":"Clinical Biomechanics","volume":"123 ","pages":"Article 106462"},"PeriodicalIF":1.4,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143455067","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}

{"title":"Dynamic subtalar joint space measurement analysis following tibiotalar arthrodesis and total ankle replacement","authors":"Rich J. Lisonbee ,&nbsp;Andrew C. Peterson ,&nbsp;Megan K. Mills ,&nbsp;Andrew E. Anderson ,&nbsp;Amy L. Lenz","doi":"10.1016/j.clinbiomech.2025.106464","DOIUrl":"10.1016/j.clinbiomech.2025.106464","url":null,"abstract":"<div><h3>Background</h3><div>Tibiotalar arthrodesis and total ankle replacement are current standards for treating end-stage ankle osteoarthritis. Our clinical understanding of biomechanical causes and risk factors for subtalar secondary osteoarthritis development following surgical treatment is limited. The objective of this retrospective study was to investigate subchondral bone morphometric differences of individuals treated with a tibiotalar arthrodesis or ankle arthroplasty that may influence subtalar joint measurements during overground walking; results were compared between surgical groups, their unaffected limb, and asymptomatic controls.</div></div><div><h3>Methods</h3><div>Previously collected kinematics were used to measure and compare subtalar joint space and congruence throughout the dynamic activity utilizing a correspondence-based joint measurement analysis. A morphometric analysis evaluated subchondral bone differences of the calcaneus subtalar joint between groups.</div></div><div><h3>Findings</h3><div>The affected subtalar joint of arthrodesis participants showed increased joint space distance in the medial facet during early stance that was related to kinematic differences compared to controls and their contralateral untreated limbs. Our morphometric analyses demonstrated subchondral bone asymmetries in both surgical groups compared to their contralateral untreated limbs.</div></div><div><h3>Interpretation</h3><div>Previously reported kinematic differences between treated and untreated limbs in arthrodesis participants may translate to the variations in joint space and morphology observed in this study. Our earlier findings within the arthroplasty group indicated no significant kinematic differences between treated and untreated limbs, and the current study showed minimal significant differences in joint space distances. Collectively, this suggests that arthroplasty joint space and subchondral bone shapes are not as strongly influenced by functional asymmetries as those in the arthrodesis group.</div></div>","PeriodicalId":50992,"journal":{"name":"Clinical Biomechanics","volume":"123 ","pages":"Article 106464"},"PeriodicalIF":1.4,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143471326","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}

{"title":"Assessing dynamic stability in children with idiopathic toe walking during overground walking","authors":"Michelle Gwerder ,&nbsp;Michèle Widmer ,&nbsp;Olivia Schären ,&nbsp;Navrag B Singh ,&nbsp;Morgan Sangeux ,&nbsp;Elke Viehweger","doi":"10.1016/j.clinbiomech.2025.106468","DOIUrl":"10.1016/j.clinbiomech.2025.106468","url":null,"abstract":"<div><h3>Background</h3><div>Children with idiopathic toe walking present with reduced ankle mobility, impaired balance, and difficulties in motor control. There is a need to diagnose idiopathic toe walking in a holistic manner and improve the monitoring of interventions. The aim is to assess dynamic stability with measures of margin of stability and whole-body angular momentum and evaluate their clinical relevance.</div></div><div><h3>Methods</h3><div>A retrospective cross-sectional study with 35 idiopathic toe walkers (23 male, mean age (SD) 10.0 (2.9) years) and 20 typically developing controls (10 male, 11.4 (2.8) years). All participants had a clinical gait analysis at the local hospital. Dynamic stability was assessed with margin of stability, whole-body angular momentum, GaitSD, and spatiotemporal gait parameters. Student <em>t</em>-tests with adjustments for multiple comparisons were performed.</div></div><div><h3>Findings</h3><div>Margin of stability in anterior direction was significantly shorter (ES = 1.29) and whole-body angular momentum in the coronal plane was significantly larger (ES = 0.90) in idiopathic toe walkers compared to typically developing children. No other results were below the set threshold for significance.</div></div><div><h3>Interpretation</h3><div>Children with idiopathic toe walking continue to use an immature, falling forward movement strategy to maintain forward momentum. It is probable that those children adopted toe walking behavior to support increased energy absorption during the initial fall. Furthermore, the addition of dynamic stability measures not only provides insight into their ability to balance, these measures also allow an understanding of the plausible strategies adopted during walking and could potentially improve diagnosis and quantification of therapeutic outcomes.</div></div>","PeriodicalId":50992,"journal":{"name":"Clinical Biomechanics","volume":"123 ","pages":"Article 106468"},"PeriodicalIF":1.4,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143445250","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}

{"title":"Lower extremity energy absorption in individuals with lower extremity musculoskeletal injury history during functional tasks: A scoping review","authors":"Tsung-Yeh Chou ,&nbsp;Colin M.S. Mulligan ,&nbsp;Yu-Lun Huang","doi":"10.1016/j.clinbiomech.2025.106463","DOIUrl":"10.1016/j.clinbiomech.2025.106463","url":null,"abstract":"<div><h3>Background</h3><div>Recent evidence has utilized energetic absorption as an alternative method to evaluate biomechanical profiles associated with lower extremity injury risk. The aim of scoping review is to summarize the literatures that utilized energetic analysis in individuals with lower extremity injury history during functional tasks.</div></div><div><h3>Methods</h3><div>A literature search, conducted in August 2023, involved four databases—PubMed, SPORTDiscus, Scopus, and Web of Science. A manual search was performed to identify additional articles.</div></div><div><h3>Findings</h3><div>Among the 17 included studies, we identified 11 and 6 articles investigated lower extremity energetic absorption in individuals with anterior cruciate ligament reconstruction and chronic ankle instability history during jump-related tasks, receptively. Individuals with anterior cruciate ligament reconstruction displayed a reduction of energetic absorption in the involved knee, coupled with increased energetic absorption in the involved hip, as compared to the uninvolved limb or the reference group. The findings in those with chronic ankle instability were varied. Most studies suggested that individuals with chronic ankle instability displayed a compensatory movement pattern to off-load their ankle joint, while concurrently increasing energy absorbed at the knee joint compared to the reference group. Conversely, one study suggested that individuals with chronic ankle instability might rely more on their ankle joint for energy absorption.</div></div><div><h3>Interpretation</h3><div>Our findings indicated that both individuals with anterior cruciate ligament reconstruction and chronic ankle instability displayed a distinctive compensatory strategy during landing. This strategy is characterized by increasing energy dissipation on the proximal joints, compensating for a reduction on the distal joint to dissipate less energy.</div></div>","PeriodicalId":50992,"journal":{"name":"Clinical Biomechanics","volume":"123 ","pages":"Article 106463"},"PeriodicalIF":1.4,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143430258","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}

{"title":"Novel radiographic stem version predictor from anterior-posterior radiographs","authors":"Oscar Denton ,&nbsp;Chris Madden-McKee ,&nbsp;Nicholas Dunne ,&nbsp;John O'Connor ,&nbsp;Janet Hill ,&nbsp;David Beverland ,&nbsp;Alex Lennon","doi":"10.1016/j.clinbiomech.2025.106465","DOIUrl":"10.1016/j.clinbiomech.2025.106465","url":null,"abstract":"<div><h3>Background</h3><div>Implant orientation has been linked to postoperative outcomes and is frequently assessed on radiographs. However, the projection of the three-dimensional joint and implant structure to a two-dimensional radiograph complicates its assessment. The main objective of this study was to demonstrate a novel method for evaluating radiographic stem version, in a manner robust to multiaxial rotations, particularly AP tilt and flexion.</div></div><div><h3>Methods</h3><div>Radiographic features where synthesised using a computational stem geometry and radiographic simulation, building in clinical error sources. Features trained a Gaussian process regression predictor of radiographic stem version. The impact of AP tilt on the accuracy of the Weber technique was then evaluated and the feasibility of AP tilt assessment from the same radiograph investigated.</div></div><div><h3>Findings</h3><div>Radiographic stem version prediction accuracy was evaluated on <em>in vitro</em> radiographs with R² rising from 0.85 (<em>P</em> &lt; 0.01) using the Weber technique to 0.98 (<em>P</em> &lt; 0.01) using the trained model. Similar results were observed in a larger <em>in silico</em> dataset with <em>R</em>² rising from 0.89 (<em>P</em> &lt; 0.01) to 0.98 (<em>P</em> &lt; 0.01). Tilt was shown to reduce the accuracy of the Weber technique. Projectional symmetry was then demonstrated about the femoral implant with AP tilt, elucidating ambiguity when assessing tilt on an AP radiograph.</div></div><div><h3>Interpretation</h3><div>The novel feature-based method is a reliable measure of radiographic stem version that is robust to variation on multiaxial orientation, allowing assessment of changing rotation in series of postoperative radiographs. However, a controlled radiograph is required to ensure this mirrors implanted stem version.</div></div>","PeriodicalId":50992,"journal":{"name":"Clinical Biomechanics","volume":"123 ","pages":"Article 106465"},"PeriodicalIF":1.4,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143454883","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}

{"title":"Biomechanical evaluation of posterolateral corner reconstruction with suture augmentation in a posterolateral corner and posterior cruciate ligament deficient knee model","authors":"Ajith Malige ,&nbsp;Andrew Carbone ,&nbsp;Dave T. Huang ,&nbsp;Shrey Kanjiya ,&nbsp;Omar Rahman ,&nbsp;Michael Banffy ,&nbsp;Melodie F. Metzger","doi":"10.1016/j.clinbiomech.2025.106461","DOIUrl":"10.1016/j.clinbiomech.2025.106461","url":null,"abstract":"<div><h3>Background</h3><div>Posterolateral corner injuries are relatively uncommon but difficult to successfully treat. This study evaluates the biomechanical stability of a novel reconstruction technique utilizing suture augmentation and compare it to the traditional LaPrade technique.</div></div><div><h3>Methods</h3><div>Eight matched pairs of all-male cadaveric knees were divided into two groups: (1) Posterolateral corner reconstruction and (2) reconstruction with suture augmentation. Each knee was tested in 3 states sequentially in isolation: (1) intact, (2) deficient posterolateral corner+Posterior cruciate ligament, and (3) after posterolateral corner reconstruction or reconstruction with suture augmentation. Each knee was repeatedly tested by applying a 134 N posterior load, 10 Nm varus moment, and 5 Nm of external rotary moment at 0, 30, 60, and 90 degrees of flexion while rotation and displacement of the tibia relative to the femur were recorded.</div></div><div><h3>Findings</h3><div>Both reconstruction techniques restored posterior tibial displacement to levels that were less than the deficient state (<em>p</em> &lt; 0.01) but greater than intact knees (<em>p</em> &lt; 0.001). Suture augmentation recorded less posterior displacement compared to reconstruction alone (30^o = −1.2 mm, 60^o = −1.0 mm, 90^o = −0.6, <em>p</em> &lt; 0.01). Both techniques restored varus stability to intact levels at all flexion angles except at 90^o. Suture augmentation allowed external rotation closer to intact values compared to reconstruction alone at all angles (0^o = −3.7^o, 30^o = −4.8^o, 60^o = −6.0^o, 90^o = −5.3 ^o).”</div></div><div><h3>Interpretation</h3><div>At time zero, reconstruction with suture augmentation decreases knee external rotation compared to reconstruction alone. Both reconstruction techniques restored restraint to varus rotation back to intact levels at most flexion angles, while neither restored posterior translation back to intact levels.</div></div>","PeriodicalId":50992,"journal":{"name":"Clinical Biomechanics","volume":"123 ","pages":"Article 106461"},"PeriodicalIF":1.4,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143455066","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}

{"title":"Safety and efficacy of vibrotactile feedback for adults with transtibial amputation: A randomized controlled cross-over trial","authors":"Harald Penasso ,&nbsp;Gerfried Peternell ,&nbsp;Rainer Schultheis ,&nbsp;Aaron Pitschl ,&nbsp;Ruth Leskovar ,&nbsp;Alexander Gardetto ,&nbsp;Jennifer Ernst ,&nbsp;Karin Schmid-Zalaudek ,&nbsp;Wolfgang Schaden","doi":"10.1016/j.clinbiomech.2025.106443","DOIUrl":"10.1016/j.clinbiomech.2025.106443","url":null,"abstract":"<div><h3>Background</h3><div>Pain, social integration, and walking safely with divided attention challenge people with lower-limb amputation. Tactile feedback systems aim to improve sensations and rehabilitation by facilitating prosthesis utility and embodiment. The non-invasive vibrotactile feedback device Suralis® (Saphenus Medical Technology, Vienna, Austria) aims to improve gait, postural control, and pain treatment. This randomized controlled cross-over trial investigated 60-day effects of vibrotactile ground-contact feedback on gait performance and quality of life in adults with unilateral transtibial amputation without targeted reinnervation.</div></div><div><h3>Methods</h3><div>We conducted gait assessments before and after the unblinded intervention period and compared within-period changes to the control period without intervention, separated by a one-week washout. The primary outcome substitute was affected-leg stance time, and secondary outcome measures included instrumented-walkway gait speed and four-square-step-test. The trial enrolled 18 participants during the COVID-19 pandemic and ended prematurely due to limitations in recruitment and integrity of the substituted primary outcome between-leg stance time difference.</div></div><div><h3>Findings</h3><div>Five participants ended the study prematurely, the dropouts were unrelated to adverse events where one experienced concentration difficulties. Analyzing 13 participants showed that participants walking slower than 1<em>.</em>41 ms⁻¹ [1<em>.</em>34 ms⁻¹, 1<em>.</em>49 ms⁻¹] [95 % highest-density interval] with affected-leg stance times above 0<em>.</em>64 s [0<em>.</em>58 s, 0<em>.</em>69 s] responded most positively. Four-square-step-test times had the largest within-period effect size (mean 0<em>.</em>89; [0<em>.</em>44, 1<em>.</em>34] for 0<em>.</em>5 s [0 s, 1 s] improvement), followed by period-one (−0<em>.</em>37; [−0<em>.</em>56, −0<em>.</em>18]), and treatment (0<em>.</em>28; [0<em>.</em>095, 0<em>.</em>46]). Affected-leg stance time did not change (0<em>.</em>21; [−0<em>.</em>26, 0<em>.</em>66]).</div></div><div><h3>Interpretation</h3><div>Despite the learning effects present, vibrotactile feedback had a small positive effect on functional balance and gait performance in slower-walking participants.</div></div><div><h3>Trial Registration</h3><div>The trial funded by the Austrian workers’ compensation board AUVA and supported by Saphenus Medical Technology was retrospectively registered on <span><span>clinicaltrials.gov</span><svg><path></path></svg></span> (no. <span><span>NCT05895253</span><svg><path></path></svg></span>; registration date: 19.05.2023) after a premature termination due to the limited availability of participants during the COVID 19 pandemic.</div></div>","PeriodicalId":50992,"journal":{"name":"Clinical Biomechanics","volume":"124 ","pages":"Article 106443"},"PeriodicalIF":1.4,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143552057","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}

{"title":"Precision of computer tomography based RSA on femoral implants in total knee arthroplasty: A porcine cadaver study","authors":"Frank-David Øhrn ,&nbsp;Lars H.W. Engseth ,&nbsp;Are H. Pripp ,&nbsp;Anselm Schulz ,&nbsp;Stephan M.H. Röhrl","doi":"10.1016/j.clinbiomech.2025.106456","DOIUrl":"10.1016/j.clinbiomech.2025.106456","url":null,"abstract":"<div><h3>Background</h3><div>Radiostereometric analysis is the gold standard for assessing migration of orthopaedic implants. The novel CT-based radiostereometric analysis yields high precision of evaluation of tibial implants. We analyzed the precision of CT-based radiostereometric analysis on femoral implants in knee arthroplasty at different dose levels, and compared it to previously published results on tibial implants and the available literature on precision of radiostereometric analysis.</div></div><div><h3>Methods</h3><div>We performed a total knee arthroplasty on a porcine cadaver knee. In the subsequent 7 CT scans, we analyzed the precision of the CT-based radiostereometric analysis method in 21 samples at two different effective doses (standard and low dose), and compared this to literature on radiostereometric analysis.</div></div><div><h3>Findings</h3><div>CT-based radiostereometric analysis of maximum total point motion of femoral and tibial components showed a precision difference of (mean, 95 % confidence interval) 0.18 mm (0.13 to 0.22), <em>P</em> &lt; 0.001. For femoral implants (mean, 95 % confidence interval, standard deviation) we found precisions of 0.25 mm (0.21–0.29, 0.1) and 0.29 (0.25–0.32, 0.08) mm for the standard and low dose protocols respectively. Variability ratios of tibia versus femur and standard versus low dose femur (95 % confidence interval) were 18.3 (7.4–45.1) and 0.7 (0.3–1.7) with respective <em>P</em>-values of &lt;0.001 and 0.40.</div></div><div><h3>Interpretation</h3><div>CT-based radiostereometric analysis on femoral implants in total knee arthroplasty is feasible and has a lower, yet still acceptable, precision compared to CT-based radiostereometric analysis on tibial implants in a porcine cadaver. However, confirmation in clinical studies is warranted.</div></div>","PeriodicalId":50992,"journal":{"name":"Clinical Biomechanics","volume":"123 ","pages":"Article 106456"},"PeriodicalIF":1.4,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143372168","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}

{"title":"Increasing the precision of intramedullary nailing in femoral derotation osteotomies by larger core locking bolts. A biomechanical study","authors":"Anders Grønseth ,&nbsp;Jan Egil Brattgjerd ,&nbsp;Joachim Horn","doi":"10.1016/j.clinbiomech.2025.106449","DOIUrl":"10.1016/j.clinbiomech.2025.106449","url":null,"abstract":"<div><h3>Background</h3><div>To correct increased femoral anteversion, surgeons perform femoral derotational osteotomies in symptomatic adolescents. Using an intramedullary nail as fixation in this setting, undersized locking screws reduce rotational precision by allowing nail toggling. However, the extent to which better-fitting locking bolts improve rotational precision in femoral derotational osteotomies remains unclear. Accordingly, we tested the hypothesis that adequately sized locking bolts enhance rotational stiffness and limit displacement, thereby decreasing nail toggling in femoral derotational osteotomies in vitro.</div></div><div><h3>Methods</h3><div>We evaluated rotational stiffness, angular displacement, and laxity at zero-loading in 12 synthetic femurs with a transverse gap osteotomy to the shaft. After inserting a pediatric intramedullary nail, femurs were fixed with either conventional 4.5 mm locking screws or locking bolts with a 0.3 mm larger core diameter. Non-destructive quasi-static rotational testing of 4 Nm external and internal torque was performed according to a predefined protocol.</div></div><div><h3>Findings</h3><div>We found significantly higher mean rotational stiffness with locking bolts than with locking screws, demonstrating a 150 % increase (0.4 Nm/degree vs. 1.0 Nm/degree, <em>P</em> &lt; 0.001). Mean angular displacement was significantly lower with locking bolts than with locking screws, exhibiting a 61 % decrease (21.9 vs. 8.6 degrees, <em>P</em> &lt; 0.001). Additionally, laxity with locking bolts was 69 % lower than with locking screws (3.2 degrees vs. 10.4 degrees, <em>P</em> = 0.0027).</div></div><div><h3>Interpretation</h3><div>Locking bolts with a larger core diameter enhances rotational stability and fixation precision, making them a valuable advancement in intramedullary nailing for femoral derotational osteotomies. These findings may also have implications for fracture treatment.</div></div>","PeriodicalId":50992,"journal":{"name":"Clinical Biomechanics","volume":"123 ","pages":"Article 106449"},"PeriodicalIF":1.4,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143349371","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}