Supporting physical activity for health: What activities would people with transtibial amputation like to perform?

Background: Participation in physical activity (PA) for health by people with transtibial amputation (PTTA) may moderate comorbidities experienced by this population. It is more likely that interventions which aim to increase participation by PTTA in PA for health will increase participation if the type of PA used is tailored to the preferences of the PTTA.

Objective: This study aimed to identify the types of PA performed by PTTA, the types of PA PTTA who performed no physical activities would like to adopt, and if these outcomes were influenced by the cause of amputation.

Undifferentiated Round Cell Sarcoma With CRTC1::SS18 Fusion: Expanding Clinicopathologic Features of a Rare Translocation Sarcoma With Prominent Desmoplastic Stroma.

Undifferentiated round cell sarcomas (URCS) represent a diverse group of tumors, including conventional Ewing sarcoma, round cell sarcoma with EWSR1/FUS-non-ETS fusions, CIC-rearranged sarcoma, and sarcoma with BCOR alterations. Since 2018, 3 cases of URCS with a novel CRTC1::SS18 gene fusion have been reported in the literature. Herein, we report 3 additional cases of CRTC1::SS18 sarcoma, thereby doubling the number of described cases and expanding the clinicopathologic features of this rare translocation sarcoma.

Are inter-limb differences in change of direction velocity and angle associated with inter-limb differences in kinematics and kinetics following anterior cruciate ligament reconstruction?

Background: Quantifying inter-limb differences in kinematics and kinetics during change of direction is proposed as a means of monitoring rehabilitation following anterior cruciate ligament reconstruction (ACLR). Velocity and centre of mass (CoM) deflection angle are fundamental task descriptors that influence kinematics and kinetics during change of direction. Inter-limb differences in approach velocity and CoM deflection angle have been identified following ACLR and may contribute to the presence of inter-limb differences in kinematics and kinetics during change of direction.

Training program intervention to encourage physical activity for health in people with transtibial amputation: A feasibility study.

Background: People with transtibial amputation (PTTA) would benefit from increased physical activity levels (PAL) but generic programs developed to support increased PAL do not address the barriers which PTTA experience.

Objective: To evaluate the effect of a 12-week training program, developed for PTTA, on their PAL.

Methods: Ten PTTA participated in a 12-week training program, which involved one instructor-led supervised group session per week.

Metastatic sarcomatoid carcinoma to bone.

Background And Objectives: Distinguishing sarcomatoid carcinoma from primary sarcoma is clinically important. We sought to characterize metastatic sarcomatoid bone disease and its management.

Methods: We analyzed the characteristics of all cases of sarcomatoid carcinoma to bone at a single institution from 2001 to 2021, excluding patients with nonosseous metastases.

Symptomatic Neuroma Development following En Bloc Resection of Skeletal and Soft-Tissue Tumors: A Retrospective Analysis of 331 Cases.

Background: Although symptomatic neuroma formation has been described in other patient populations, these data have not been studied in patients undergoing resection of musculoskeletal tumors. This study aimed to characterize the incidence and risk factors of symptomatic neuroma formation following en bloc resection in this population.

Methods: The authors retrospectively reviewed adults undergoing en bloc resections for musculoskeletal tumors at a high-volume sarcoma center from 2014 to 2019.

The Role of Denosumab in the Treatment of Primary Tumors of Bone.

Many hand surgeons treat benign bone tumors without referral to orthopedic oncologists. However, there have been considerable advances in medical therapy for some of these tumors, with which hand surgeons may not be as familiar. This review focuses on the mechanism and uses of denosumab in the treatment of benign tumors of bone.

Altered mechanics and increased loading on intact limbs of individuals with a unilateral transtibial amputation in comparison with non-amputees during a start-stop task.

Individuals with a unilateral transtibial amputation (ITTA) often experience greater loading on the intact limb during running and stepping tasks compared to individuals without amputation. This study aimed to investigate the mechanics of load absorption in the intact limb of ITTA and determine if increased ground reaction forces (GRF) persist during a start-stop task which (i) controlled touch-down velocity and (ii) removed the requirement for on-going locomotion. Data were collected using a twelve-camera motion capture system with two Kistler force platforms.

Indications and outcomes of palliative major amputation in patients with metastatic cancer.

Background: Patients with stage IV cancer often experience diminished quality of life and pain. Although palliative amputation (PA) can reduce pain, it is infrequently performed because of the morbidity associated with amputation and the limited life expectancy in this population. Here, we describe the indications for PA in patients with stage IV carcinoma or sarcoma and discuss their clinical courses and outcomes.

The associations between asymmetries in quadriceps strength and gait in individuals with unilateral transtibial amputation.

Background: Individuals with unilateral transtibial amputations (ITTAs) are asymmetrical in quadriceps strength. It is unknown if this is associated with gait performance characteristics such as walking speed and limb symmetry.

Research Question: Are quadriceps strength asymmetries related to walking speed and/ or gait asymmetries in ITTAs?

Methods: Knee-extensor isometric maximum voluntary torque (MVT) and rate of torque development (RTD) were measured in eight ITTAs.

Six methods for classifying lower-limb dominance are not associated with asymmetries during a change of direction task.

Quantifying asymmetries between dominant and non-dominant limbs is a common research objective aimed at identifying systematic differences between limbs and establishing normative ranges of asymmetry. Multiple methods for classifying limb dominance exist, and it is unclear how different methods relate to directional asymmetries during change of direction (CoD). This study aimed to determine whether different methods of classifying limb dominance, including a novel CoD task-specific method, identified significant inter-limb asymmetries during a 90° CoD task.

Biomechanical but Not Strength or Performance Measures Differentiate Male Athletes Who Experience ACL Reinjury on Return to Level 1 Sports.

Background: Performance measures such as strength, jump height/length, and change of direction (CoD) time during anterior cruciate ligament (ACL) rehabilitation have been used to determine readiness to return to play and identify those who may be at risk of rerupture. However, athletes may reach these criteria despite ongoing biomechanical deficits when performing these tests. Combining return-to-play criteria with an assessment of movement through 3-dimensional (3D) biomechanics in male field sports athletes to identify risk factors for ACL rerupture has not been explored previously.

Can Biomechanical Testing After Anterior Cruciate Ligament Reconstruction Identify Athletes at Risk for Subsequent ACL Injury to the Contralateral Uninjured Limb?

Background: Athletes are twice as likely to rupture the anterior cruciate ligament (ACL) on their healthy contralateral knee than the reconstructed graft after ACL reconstruction (ACLR). Although physical testing is commonly used after ACLR to assess injury risk to the operated knee, strength, jump, and change-of-direction performance and biomechanical measures have not been examined in those who go on to experience a contralateral ACL injury, to identify factors that may be associated with injury risk.

Purpose: To prospectively examine differences in biomechanical and clinical performance measures in male athletes 9 months after ACLR between those who ruptured their previously uninjured contralateral ACL and those who did not at 2-year follow-up and to examine the ability of these differences to predict contralateral ACL injury.

Lead limb loading during a single-step descent in persons with and without a transtibial amputation in the trailing limb.

Background: Decreased mechanical work done by the trailing limb when descending a single-step could affect load development and increase injury risk on the leading limb. This study assessed the effect of trailing limb mechanics on the development of lead limb load during a step descent by examining individuals with unilateral transtibial amputations who are known to exhibit reduced work in the prosthetic limb.

Methods: Eight amputees and 10 able-bodied controls walked 5 m along the length of a raised platform, descended a single-step of 14 cm height, and continued walking.

Whole-Body Change-of-Direction Task Execution Asymmetries After Anterior Cruciate Ligament Reconstruction.

Cutting maneuvers can be executed at a range of angles and speeds, and these whole-body task descriptors are closely associated with lower-limb mechanical loading. Asymmetries in angle and speed when changing direction off the operated and nonoperated limbs after anterior cruciate ligament reconstruction may therefore influence the interpretation of interlimb differences in joint-level biomechanical parameters. The authors hypothesized that athletes would reduce center-of-mass heading angle deflection and body rotation during the change-of-direction stance phase when cutting from the operated limb, and would compensate for this by orienting their center-of-mass trajectory more toward the new intended direction of travel prior to touchdown.

The effect of simulated marker misplacement on the interpretation of inter-limb differences during a change of direction task.

The objective assessment of biomechanical asymmetries during movement tasks is used to monitor rehabilitation following anterior cruciate ligament reconstruction (ACLR). Marker placement is an important source of methodological variability within human motion analysis. It is currently unclear how marker placement error effects the interpretation of biomechanical asymmetries throughout post ACLR rehabilitation.

Tumors of the Hand and the Wrist.

Most tumors of the hand and the wrist are benign; however, malignant conditions can mimic benign tumors and must be worked up accordingly. Advanced imaging should be followed by biopsy before definitive treatment of tumors of unknown diagnosis. The most common soft-tissue masses in the hand and the wrist are ganglion cysts, whereas the most common bone tumors are enchondromas.

The sensitivity of joint kinematics and kinetics to marker placement during a change of direction task.

The conventional gait model (CGM) refers to several closely related biomechanical models used in the objective analysis of human motion. Their use has become popular in the analysis of change of direction tasks to inform best practice in the prevention and rehabilitation of anterior cruciate ligament injury. As externally-placed markers define segment axes origins and orientations, kinematic and kinetic outputs from the CGM are sensitive to marker placement.

Foot strike alters ground reaction force and knee load when stepping down during ongoing walking.

Background: When stepping down from a raised surface, either a toe or heel contact strategy is performed. Increased vertical momentum is likely to be experienced during a step descent, yet the extent to which these descent strategies influence the development of load at the ground and knee has not been examined.

Research Question: Does descent strategy influence ground and knee joint loading? Does the contribution from leading and trailing limb joint mechanics differ between descent strategies?

Methods: Twenty-two healthy male participants (age: 34.

Mechanisms to Attenuate Load in the Intact Limb of Transtibial Amputees When Performing a Unilateral Drop Landing.

Individuals with unilateral transtibial amputations experience greater work demand and loading on the intact limb compared with the prosthetic limb, placing this limb at a greater risk of knee joint degenerative conditions. It is possible that increased loading on the intact side may occur due to strength deficits and joint absorption mechanics. This study investigated the intact limb mechanics utilized to attenuate load, independent of prosthetic limb contributions and requirements for forward progression, which could provide an indication of deficiencies in the intact limb.

The effects of long-term muscle disuse on neuromuscular function in unilateral transtibial amputees.

New Findings: What is the central question of this study? The effects of long-term muscle disuse on neuromuscular function are unclear because disuse studies are typically short term. In this study, we used a new model (unilateral transtibial amputees) to investigate the effects of long-term disuse on quadriceps neuromuscular function. What is the main finding and its importance? Kinetic analysis (knee-extension moments during gait) indicated habitual disuse of the amputated limb quadriceps, accompanied by lower quadriceps muscle strength (60-76%) and neural activation (32-44%), slower contractile properties and altered muscle architecture in the amputated limb, which could not be predicted from short-term disuse studies.