Sex-Specific Size Analysis of Carpal Bones: Implications for Orthopedic Biomedical Device Design and Therapy Planning.

Consideration of the individual carpal bone characteristics of the wrist plays a key role in well-functioning biomedical devices and successful surgical procedures. Although geometric differences and individual bone sizes have been analyzed in the literature, detailed morphologic descriptions and correlations covering the entire wrist reported in a clinical context are lacking. This study aimed to perform a comprehensive and automatic analysis of the wrist morphology using the freely available "Open Source Carpal Database" (OSCD). We quantified the size of each of the individual carpal bones and their combination. These sizes were extracted in n = 117 datasets of the wrist of the OSCD in anatomical directions and analyzed using descriptive statics and correlation analysis to investigate the morphological characteristics under sex-specific aspects and to provide regression plots and equations to predict individual carpal bone sizes from the proximal and distal row dimensions. The correlations in the proximal row were higher compared to the distal row. We established comprehensive size correlations and size rations and found that there exist statistical differences between sex, particularly of the scaphoid. The regression plots and equations we provided will assist surgeons in a more accurate preoperative morphological evaluation for therapy planning and may be used for future anatomically inspired orthopedic biomedical device designs.

L4/5 accessibility for extreme lateral interbody fusion (XLIF): a radiological study.

INTRODUCTION: Potential advantages of the Extreme Lateral Interbody Fusion (XLIF) approach are smaller incisions, preserving anterior and posterior longitudinal ligaments, lower blood loss, shorter operative time, avoiding vascular and visceral complications, and shorter length of stay. We hypothesize that not every patient can be safely treated at the L4/5 level using the XLIF approach. The objective of this study was to radiographically (CT-scan) evaluate the accessibility of the L4/5 level using a lateral approach, considering defined safe working zones and taking into account the anatomy of the superior iliac crest. METHODS: Hundred CT examinations of 34 female and 66 male patients were retrospectively evaluated. Disc height, lower vertebral endplate (sagittal and transversal), and psoas muscle diameter were quantified. Accessibility to intervertebral space L4/5 was investigated by simulating instrumentation in the transverse and sagittal planes using defined safe zones. RESULTS: The endplate L5 in the frontal plane considering defined safe zones in the sagittal and transverse plane (Zone IV) could be reached in 85 patients from the right and in 83 from the left side. Through psoas split, the safe zone could be reached through psoas zone II in 82 patients from the right and 91 patients from the left side. Access through psoas zone III could be performed in 28 patients from the right and 32 patients from the left side. Safe access and sufficient instrumentation of L4/5 through an extreme lateral approach could be performed in 76 patients of patients from the right and 70 patients from the left side. CONCLUSION: XLIF is not possible and safe in every patient at the L4/5 level. The angle of access for instrumentation, access of the intervertebral disc space, and accessibility of the safe zone should be taken into account. Preoperative imaging planning is important to identify patients who are not suitable for this procedure.

Development of the German social attitude barriers and facilitators to participation-scales: an analysis according to the Rasch model.

BACKGROUND: Social attitudes experienced by people with disabilities can strongly impact upon their health and quality of life. The extent to which social attitude measurement transcends specific cultures is unknown. Thus, the aim of the study was to develop German item banks to assess social attitude barriers and facilitators to participation and compare the construct definition with that developed in the United States. METHODS: The American version of the two item banks assessing social attitudes that act as barriers and facilitators in persons with disabilities was translated into German and culturally adapted. The sample consisted of 410 in- and outpatients treated for spinal diseases at a German University Hospital. The psychometric properties of the resulting 53 items-item pool were evaluated using Rasch analysis. A special focus was placed on the investigation of unidimensionality, local independence, differential item functioning (DIF) and targeting. To evaluate convergent and divergent validity correlations with perceived social support, depression and pain interference were calculated. RESULTS: Unlike the American version, both the barriers and facilitators item banks had to be divided into two subscales assessing attitudes that individuals with disabilities experience as being directed towards them (individual perception) or attitudes that respondents experience as being directed towards people with disabilities as a social group (societal perception). Four unidimensional scales were constructed. Fit to the Rasch model required item deletion and forming testlets to account for extensive local dependence. There was no evidence of DIF with regard to gender or age. Targeting of the subscales was moderate to good. CONCLUSIONS: Results support a distinction between social attitudes at the individual and societal level, allowing a more specific assessment than is possible when this distinction is ignored.

Comparison of Optimization Strategies for Musculoskeletal Modeling of the Wrist for Therapy Planning in Case of Total Wrist Arthroplasty.

The human wrist joint is an elegant mechanism. The wrist allows the positioning and orienting of the hand to the forearm. The computational modeling of the human hand, especially of the wrist joint, can reveal important information about biomechanical mechanisms and provide the basis for its dysfunction and pathologies. For instance, this could be used for therapy planning in total wrist arthroplasty (TWA). In this study, different optimization methods and sensitivity analyses of anatomical parameters for musculoskeletal modeling were presented. Optimization includes finding the best available value of an objective function, including a variety of different types of objective functions. In the simplest case, optimization consists of maximizing or minimizing a function by systematically choosing input values from within an allowed set and computing the value of the function. Optimization techniques are used in many facets, such as the model building of joints or joint systems such as the wrist. The purpose of this study is to show the variability and influence of the included information for modeling, investigating the biomechanical function and load situation of the joint in representative scenarios. These possibilities to take them into account by an optimization and seem essential for the application of computational modeling to joint pathologies.

Musculoskeletal Modeling of the Wrist via a Multi Body Simulation.

In this study, three different musculoskeletal modeling approaches were compared to each other. The objective was to show the possibilities in the case of a simple mechanical model of the wrist, using a simple multi-body-simulation (MBS) model, and using a more complex and patient-specific adaptable wrist joint MBS model. Musculoskeletal modeling could be a useful alternative, which can be practiced as a non-invasive approach to investigate body motion and internal loads in a wide range of conditions. The goal of this study was the introduction of computer-based modelling of the physiological wrist with (MBS-) models focused on the muscle and joint forces acting on the wrist.

Total Wrist Arthroplasty-A Systematic Review of the Outcome, and an Introduction of FreeMove-An Approach to Improve TWA.

The Swanson silicone prosthesis was one of the first devices to realize total wrist arthroplasty (TWA). It has been used regularly since the early 1960s. This systematic review of the literature evaluated the status quos of TWA. The present study was conducted according to the PRISMA guidelines. A literature search was made in Medline, PubMed, Google Scholar, and the Cochrane Library databases. The focus of the present study was on implant survivorship and related functional outcomes. Data from 2286 TWA (53 studies) were collected. Fifteen studies were included for the analysis of implant survivorship. Fifteen studies were included for the analysis of pain. Twenty-eight studies were included for the analysis of the Disabilities of the Arm, Shoulder, and Hand (DASH) score. Grip strength was tracked in 16 studies. The range of motion (RoM) was evaluated in 46 studies. For supination and pronation, 18 articles were available. Despite some methodological heterogeneities, TWA may be effective and safe in pain reduction and improving function and motion. There is still a range for a future improvement of the procedure.

Anatomy, Biomechanics, and Loads of the Wrist Joint.

The wrist is by far the most differentiated section of the musculoskeletal system. The spectrum of wrist injuries ranges from minor injuries to complex traumas with simultaneous loss of functions, resulting in enormous economic costs. A proper understanding of the anatomy and biomechanics is essential for effective treatment, whether conservative or surgical; this applies to the wrist no less than to other parts of the human body. Here; information on the wrist anatomy; kinematics; and biomechanical behavior is presented, commencing with a brief explanation of the structure of its hard and soft tissues. Eight carpal bones in combination with two forearm bones (radius and ulna) construct the wrist joint. The motion of the wrist joint is initiated by the muscles of the forearm, and strong and short ligaments ensure the stability of the wrist. All of these components are essential to bringing functions to the wrist joint because these structures allow wrist mobility and sustainability. In addition, the kinematics of the wrist joint is presented and different biomechanical model approaches. The therapeutic (surgical) restoration of the balance between the load-bearing capacity and the actual stress on a joint is the prerequisite for a lifelong and trouble-free function of a joint. Regarding the complex clinical problems, however, a valid biomechanical wrist joint model would be necessary as assistance, to improve the success of systematized therapies based on computer-aided model-based planning and intervention.

Evaluation of Current Symptoms in Postoperative Achilles Tendons: A Multimodal Ultrasound Study.

(1) Background: It is unknown which imaging parameters are associated with clinical persistent symptoms in postoperative Achilles tendons. This study used B-Mode, Power Doppler (PD-US), Ultrasound Tissue Characterization (UTC) and Shear Wave Elastography (SWE) to investigate which imaging parameters are associated with persistent symptoms in postoperative Achilles tendon tissue. (2) Methods: Retrospective, cross-sectional, multimodal imaging study. Based on the VISA-A score, postoperative tendons were assigned to two groups: 1. asymptomatic (VISA-A ≥ 90, n = 18); 2. symptomatic (VISA-A < 90, n = 10). The following imaging parameters were analyzed: UTC (echo type I, II, III, IV), B-Mode (diameter, cross sectional area, calcification, fiber irregularity), PD-US (Öhberg score) and SWE (SWE 3 mm, SWE area) using a t-test and a Mann-Whitney U test. (3) Results: SWE and PD-US showed significantly reduced elasticity and increased neovascularization in symptomatic tendons (SWE 3 mm p = 0.031, SWE area p = 0.046, Öhberg score p < 0.001). The only significant correlation between imaging parameters and the VISA-A score was assessed for SWE 3 mm (r = 0.378; p = 0.047) and the Öhberg score (r = -0.737; p < 0.001). Conclusions: Symptomatic postoperative Achilles tendons showed increased neovascularization and lower SWE values than asymptomatic ones. Future studies should examine the diagnostic accuracy of PD-US and SWE in detecting current symptoms in postoperative Achilles tendons.

Multimodal Ultrasound Versus MRI for the Diagnosis and Monitoring of Achilles Tendinopathy: A Prospective Longitudinal Study.

BACKGROUND: The diagnosis and monitoring of Achilles tendinopathy with imaging are challenging. There is a lack of studies comparing the diagnostic accuracy of magnetic resonance imaging (MRI), brightness mode ultrasound (B-mode), and power Doppler ultrasound with recent technologies such as ultrasound tissue characterization (UTC) and shear wave elastography (SWE). PURPOSE: To assess whether SWE and UTC, which offer quantitative values, show a superior diagnostic accuracy and capacity to detect structural improvement in Achilles tendinopathy compared with MRI, B-mode, or power Doppler. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2. METHODS: Patients with insertional (n = 28) and midportion (n = 38) Achilles tendinopathy were evaluated at baseline and 6-month follow-up using MRI, B-mode, power Doppler, SWE, and UTC. Asymptomatic controls (n = 37) were evaluated at T 0. Diagnostic accuracy was analyzed based on a quantitative receiver operating characteristic (ROC) analysis with quantitative cutoff values (anteroposterior diameter, Öhberg score, UTC echo type, Young modulus) and by semiquantitative Likert scale-based assessment of experienced physicians. RESULTS: For diagnosing insertional Achilles tendinopathy, semiquantitative MRI and power Doppler were most favorable (diagnostic accuracy, 95%), while the cross-sectional area of MRI revealed 89% accuracy in the ROC analyses (area under the curve [AUC], 0.911; P < .001). For diagnosing midportion Achilles tendinopathy, semiquantitative MRI and B-mode were most favorable (diagnostic accuracy, 87%), while UTC echo types 3 and 4 revealed 86% and 87% accuracy, respectively, in the ROC analyses (AUC, 0.911 and 0.941, respectively; P < .001). However, for quantitative and semiquantitative evaluation of diagnostic accuracy in both insertional and midportion Achilles tendinopathy, there was no significant difference in favor of one imaging modality over the others. Compared with baseline, only SWE showed a significant change at the 6-month follow-up (P = .003-.035), but there were only fair to poor monitoring accuracies of 71% (insertion) and 60% (midportion). However, compared with the other modalities, the monitoring accuracy of SWE was significantly higher (P = .002-.039). CONCLUSION: There was no statistically significant difference in favor of one imaging modality over the others, but MRI revealed the highest overall diagnostic accuracy for the diagnosis of both insertional and midportion Achilles tendinopathy.

Changes in muscle activities and kinematics due to simulated leg length inequalities.

Muscle imbalances are a leading cause of musculoskeletal problems. One example are leg length inequalities (LLIs). This study aimed to analyze the effect of different (simulated) LLIs on back and leg muscles in combination with kinematic compensation mechanics. Therefore, 20 healthy volunteers were analyzed during walking with artificial LLIs (0-4 cm). The effect of different amounts of LLIs and significant differences to the reference condition without LLI were calculated of maximal joint angles, mean muscle activity, and its symmetry index. While walking, LLIs led to higher muscle activity and asymmetry of back muscles, by increased lumbar lateral flexion and pelvic obliquity. The rectus femoris showed higher values, independent of the amount of LLI, whereas the activity of the gastrocnemius on the shorter leg increased. The hip and knee flexion of the long leg increased significantly with increasing LLIs, like the knee extension and the ankle plantarflexion of the shorter leg. The described compensation mechanisms are explained by a dynamic lengthening of the short and shortening of the longer leg, which is associated with increased and asymmetrical muscle activity. Presenting this overview is important for a better understanding of the effects of LLIs to improve diagnostic and therapy in the future.

Opioids for chronic low back pain management: a Bayesian network meta-analysis.

Introduction: Chronic low back pain (LBP) is common, and some patients require opiates therapy. This Bayesian network meta-analysis (NMA) analyzed available randomized clinical trials (RCTs) on the use of opioids for LBP.Methods: All RCTs comparing two or more opioids for chronic LBP and reporting results under the Numeric Rating Scale were included. The following drugs were analyzed: fentanyl, morphine, tapentadol, oxycodone, buprenorphine, oxymorphone, tramadol. The NMA was performed through the STATA routine for Bayesian hierarchical random-effects model analysis, with standardized mean difference (SMD) effect measure. Data regarding the rate of adverse events and different drug formulations were also reported.Results: Data from 2933 patients were obtained, with a mean age of 53.30 ± 6.95 years. The mean duration of symptoms prior to beginning the trial was 95.16 ± 47.29 months. The mean follow-up was 3.29 ± 1.72 months. Among the analyzed compounds, oxymorphone, tapentadol and fentanyl showed the highest efficacy in terms of pain reduction.Conclusion: According to published level I evidence, oxymorphone, tapentadol and fentanyl were the most effective drugs in the treatment of chronic LBP. However, different formulation and pharmacokinetic characteristics need to be taken into consideration when choosing the ideal compound for a given patient.

Evaluation of an occipito-cervico fusion with a new implant design: a biomechanical study.

BACKGROUND: A novel implant for occipitocervical fusion consisting of a median plate with an additional hook inserting in the foramen magnum was tested. Aim of this study was to test the stability of a new implant for occipitocervical fusion against the already available and employed median plate implant without hook. MATERIAL AND METHOD: 36 rigid polyurethane foams occipital artificial bones were used. The two occipital implants, namely the occipital plate with hook (Group 1) and the one without hook (Group 2), were applied to the artificial occiput trough three occipital screws and ensured into the experimental setup trough a crossbar. The test parameters were set using the testing machine software as follows: (1) test speed: 10 mm/ min, with 25 mm/ min maximum; (2) preload: 5 N; (3) force switch-off threshold: 90% force drop from F_max. Failure force and path were recorded. Failure force is defined as the maximum reaction force under which failure occurs (F_max), while failure path is the travel path during which failure occurs (dL). RESULTS: Group 1 (plate with hook) showed a mean failure force of 459.3 ± 35.9 N and a mean failure path of 5.8 ± 0.3 mm Group 2 (plate without hook) showed a mean failure force of 323.9 ± 20.2 N and a mean failure path of 7.2 ± 0.4 mm. The Shapiro-Wilk test score was not significant (P >  0.1), assuming that data were normally distributed. Group 1 had a statistically significant greater F_max (+ 135.37; P >  0.0001) and less dL (- 1.52; P > 0.0001) compared to group 2. CONCLUSIONS: Medial plates with foramen magnum hooks showed to be more stable that plates without a hook. These new implants may represent a new tool in OCJ fixation, but further studies are required to investigate their behavior in an anatomical setting.

The influence of smartphone use on spinal posture - A laboratory study.

BACKGROUND: Smartphones have become increasingly more popular and complicated tasks can be performed with these devices. However, the increasing use is associated with shoulder and neck pain, as well as with psychological addiction. RESEARCH QUESTION: Do different smartphone tasks lead to changes in spinal posture and pelvic position? Is there a relationship between smartphone addiction and changes in posture? METHODS: A cross-sectional study including 50 participants was performed. Test subjects completed the Smartphone Addiction Scale and the SF-36 health questionnaire. Subjects spinal posture and pelvic position during different smartphone tasks were measured through a surface topography system. The different tasks were: standing in an upright position, simulating a phone call, texting with one or two hands during standing or while walking on a treadmill. Paired T-tests and ANOVA tests were performed to evaluate differences. The Kendall rank test was used to investigate the association between clinical scores and changes in spinal posture. RESULTS: All smartphone tasks lead to a significant increase in thoracic kyphosis and trunk inclination during standing and while walking. A significant increased lumbar lordosis was also found. Texting with one or two hands correlated with increased surface rotation. No associations between smartphone addiction and changes of the spinal posture were reported. SIGNIFICANCE: This represents the first surface topography study that investigated the influence of different smartphone tasks on the spinal posture and pelvic position during standing and while walking. With the results of this study we demonstrated that smartphone use leads to significant changes of sagittal and frontal spine parameters. Further research should focus on the evaluation of possible detrimental effects of long-term smartphone use on the spinal posture and on the development of preventive measures.

Line- and Point-Focused Extracorporeal Shock Wave Therapy for Achilles Tendinopathy: A Placebo-Controlled RCT Study.

BACKGROUND: Extracorporeal shock wave therapy (ESWT) is a widely considered treatment option for Achilles tendinopathy. Line-focused ESWT is a novel technique treating a larger tendon area than point-focused ESWT. Monitoring capacities of clinical symptoms with ultrasound under ESWT treatment are unknown. HYPOTHESIS: Point- and line-focused ESWT have a superior outcome than placebo ESWT. ESWT leads to morphological tendon changes detectable with ultrasound. STUDY DESIGN: Single-blinded placebo-controlled randomized contolled trial. LEVEL OF EVIDENCE: Level 1. METHODS: The study was conducted in 3 cohorts, namely ESWT point (n = 21), ESWT line (n = 24), and ESWT placebo (n = 21). Victorian Institute of Sports Assessment-Achilles (VISA-A) score was measured before the intervention (T0), after 6 weeks (T1), and after 24 weeks (T2). All cohorts performed daily physiotherapy for 24 weeks and received 4 sessions of point-focused, line-focused, or placebo ESWT in the first 6 weeks. Ultrasound was performed with B-mode, power Doppler, shear wave elastography (SWE) at T0 and T2 and with ultrasound tissue characterization (UTC) at T0, T1, and T2. Data were analyzed with a mixed analysis of variance and t test. RESULTS: There was a significant VISA-A improvement over time for all groups (P < 0.001). ESWT point had the strongest VISA-A score improvement +23 (ESWT line: +18; ESWT placebo: +15), but there was no significant interaction between time and any of the groups: F(4, 116) = 1.393; P = 0.24. UTC, power Doppler, and B-mode could not show significant alterations over time. SWE revealed a significant increase of elastic properties for ESWT point in the insertion (t = -3.113, P = 0.03) and midportion (t = -2.627, P = 0.02) over time. CONCLUSION: There is a significant VISA-A score improvement for all study groups without a statistically significant benefit for ESWT point or ESWT line compared with ESWT placebo. Tendon adaptation could only be detected with SWE for ESWT point. CLINICAL RELEVANCE: The present study could not detect any statistically relevant effect of ESWT compared to placebo. SWE is able to demonstrate tendon adaptation.

Inertial measurement units for the detection of the effects of simulated leg length inequalities.

BACKGROUND: Leg length inequalities (LLI) are a common condition that can be associated with detrimental effects like low back pain and osteoarthritis. Inertial measurement units (IMUs) offer the chance to analyze daily activities outside a laboratory. Analyzing the kinematic effects of (simulated) LLI on the musculoskeletal apparatus using IMUs will show their potentiality to improve the comprehension of LLI. METHODS: Twenty healthy participants with simulated LLI of 0-4 cm were analyzed while walking with an inertial sensor system (MyoMotion). Statistical evaluation of the peak anatomical angles of the spine and legs were performed using repeated measurement (RM) ANOVA or their non-parametric test versions (Friedman test). RESULTS: Lumbar lateral flexion and pelvic obliquity increased during the stance phase of the elongated leg and decreased during its swing phase. The longer limb was functionally shortened by higher hip and knee flexion, higher hip adduction, dorsiflexion, and lower ankle adduction. Finally, the shorter leg was lengthened by higher hip and knee extension, hip abduction, ankle plantarflexion, and decreased hip adduction. CONCLUSION: We found differing compensation strategies between the different joints, movement planes, gait phases, and amounts of inequality. Overall the shorter leg is lengthened and the longer leg is shortened during walking, to retain the upright posture of the trunk. IMUs were helpful and precise in the detection of anatomical joint angles and for the analysis of the effects of LLI.

Lateral retinacular release combined with MPFL reconstruction for patellofemoral instability: a systematic review.

INTRODUCTION: The role of the lateral retinaculum in patellofemoral instability is still debated. Lateral retinacular release (LRR), has been extensively performed in combination with different surgical procedures, including reconstruction of medio-patellofemoral ligament (MPFL). Despite controversial indications, the results from these studies seem promising. The present study conducts a systematic review about current biomechanical and clinical evidence concerning the role of LRR in combination with MPFL reconstruction. We performed a comprehensive literature research, comparing the outcomes of MPFL reconstruction with and without LRR. MATERIALS AND METHODS: This systematic review was conducted according to the PRISMA guidelines. The literature search was performed in August 2020. All articles describing the outcome of isolated MPFL reconstruction alone or in combination with a LRR in patients with recurrent patellofemoral instability were considered for inclusion. Only articles reporting data on patients with a minimum of 12-month follow-up were included. Only articles reporting quantitative data under the outcomes of interest were included. RESULTS: A total of 63 articles were eligible for this systematic review, including 2131 knees. The mean follow-up was 40.87 ± 24.1 months. All scores of interests improved in favour of the combined group: Kujala + 3.8% (P = 0.01), Lysholm + 4.2% (P = 0.004), Tegner + 0.8 points (P = 0.04), IKDC + 9.8% (P = 0.02). The ROM was comparable between the two groups (P = 0.4). Similarity was found in terms of positivity to the apprehension test (P = 0.05), rate of complications (P = 0.1), re-dislocations (P = 0.8), and revision surgeries (P = 0.1). CONCLUSION: There is no evidence that adding a lateral release impacts positively on the outcome of MPFL reconstruction. LEVEL OF EVIDENCE: IV, Systematic review.