Opportunistic hand radiographs to screen for low forearm bone mineral density: a prospective and retrospective cohort study.

Background: Low bone mineral density affects 53% of women over age 65 in the US, yet many are unaware and remain untreated. Underdiagnosis of forearm osteoporosis and related fragility fractures represent missed warning signs of more deadly, future fractures. This study aimed to determine if hand radiographs could serve as early, simple screening tools for predicting low forearm bone mineral density (BMD).

Helping Surgeons' Hands: A Biomechanical Evaluation of Ergonomic Instruments.

Purpose: "Ergonomic" is a common descriptor for a desk or computer workspace but is a term rarely used to describe a surgical instrument. Instead, surgeons spend many hours in inconvenient positions, often using instruments that are not ergonomic. Improving the ergonomics of surgical instruments may decrease the required force for simple tasks and allow for more efficient surgery.

Using a finite element model of the thumb to study Trapeziometacarpal joint contact during lateral pinch.

Background: Finite element (FE) analysis is widely used in different fields of orthopaedic surgery, however, its application to the trapeziometacarpal joint has been limited due to the small size, complex biconcave-convex joint geometry, and complex musculature. The goal of this study was to improve upon existing models by creating a muscle-driven FE thumb model and use the model to simulate the biomechanical effect of hand therapy exercises and ligament reconstructive surgeries.

Methods: Bone and cartilage geometry were based on a CT dataset of a subject performing a static lateral pinch task.

The biomechanics of osteoarthritis in the hand: Implications and prospects for hand therapy.

Background: The unique anatomy of the human hand makes it possible to carefully manipulate tools, powerfully grasp objects, and even throw items with precision. These apparent contradictory functions of the hand, high mobility for manual dexterity vs high stability during forceful grasping, imply that daily activities impose a high strain on a relatively instable joint. This makes the hand susceptible to joint disorders such as osteoarthritis.

The Role of the Flexor Carpi Radialis Groove in Trapeziometacarpal Osteoarthritis.

Background: Thumb carpometacarpal (CMC) osteoarthritis (OA) is a common condition. The contribution of surrounding ligaments and tendons to the stability of the CMC joint is likely altered in OA. The flexor carpi radialis (FCR) tendon runs in the trapezial FCR groove and is often noted to be frayed during CMC arthroplasty.

Characterization of Trapezial Pommel in Relation to Radiographic and Wear Patterns in Carpometacarpal Osteoarthritis.

Background: Trapezial pommel, or ulnar osteophyte positioned at the vertex of the saddle-shaped facet, is a consistent structural appearance in osteoarthritis (OA) of the first carpometacarpal. This study investigates its relation to radiographic measures (modified Eaton staging and thumb OA [ThOA] index) and wear patterns (trapezial surface morphology and cartilaginous eburnation).

Methods: In all, 137 whole trapezia were explanted from 116 patients and evaluated for Eaton staging, morphology (saddle, cirque, or dish), and eburnation (degree of cartilaginous effacement) of the articular surface of the trapezium.

Ultrasound of Thumb Muscles and Grasp Strength in Early Thumb Carpometacarpal Osteoarthritis.

Purpose: The pathophysiology of thumb carpometacarpal (CMC) osteoarthritis (OA) involves complex interactions between the ligaments and muscles supporting the joint. Factors such as muscle volume and strength may be more relevant in early disease. We used ultrasound as a noninvasive method to explore differences in the intrinsic hand muscles of patients with early CMC OA, as determined using physical exam and radiographs, and healthy controls.

Radiographic Progression of Thumb CMC Osteoarthritis: A Systematic Review.

Purpose: Thumb carpometacarpal (CMC) osteoarthritis (OA) is a prevalent disease that causes pain and disability. Determining the progression of CMC OA is problematic given the lack of consensus for classifications and scoring systems. We performed a systematic review to (1) determine which imaging modalities or scoring systems are used to evaluate CMC OA progression, and (2) describe the progression of CMC OA through available metrics.

The digital human forearm and hand.

How changes in anatomy affect joint biomechanics can be studied using musculoskeletal modelling, making it a valuable tool to explore joint function in healthy and pathological joints. However, gathering the anatomical, geometrical and physiological data necessary to create a model can be challenging. Very few integrated datasets exist and even less raw data is openly available to create new models.

Trapeziometacarpal stabilization through dorsoradial ligament reconstruction: An early post-surgery in vivo biomechanical analyses.

Ligament reconstruction can provide pain relief in patients with a painful, unstable, pre-arthritic trapeziometacarpal (TMC) joint. Imbrication of the dorsoradial ligament (DRL) has been proposed as a minimal invasive stabilization technique. It requires less invasive surgery than an Eaton-Littler technique and shows promising long-term clinical outcome.

Insights into the musculature of the bonobo hand.

The human hand is well known for its unique dexterity which is largely facilitated by a highly mobile, long and powerful thumb that enables both tool manufacturing and use, a key component of human evolution. The bonobo (Pan paniscus), the closest extant relative to modern humans together with the chimpanzee (Pan troglodytes), also possesses good manipulative capabilities but with a lower level of dexterity compared with modern humans. Despite the close phylogenetic relationship between bonobos and humans, detailed quantitative data of the bonobo forelimb musculature remains largely lacking.

Impact of Osteoarthritis and Total Joint Arthroplasty on the Kinematics of the Trapeziometacarpal Joint: A Pilot Study.

Purpose: To quantify the effect of osteoarthritis (OA) and total trapeziometacarpal (TMC) joint replacement on thumb kinematics during the primary physiological motions of the thumb.

Methods: We included 4 female patients with stage III TMC OA. A computed tomography-based markerless method was used to quantify the 3-dimensional thumb kinematics in patients before and after TMC joint replacement surgery with the Arpe implant.

In vivo biomechanical behavior of the trapeziometacarpal joint in healthy and osteoarthritic subjects.

Background: The contact biomechanics of the trapeziometacarpal joint have been investigated in several studies. However, these led to conflicting results and were mostly performed in vitro. The purpose of this study was to provide further insight on the contact biomechanics of the trapeziometacarpal joint by in vivo assessment of healthy and osteoarthritic subjects.

In vivo kinematics of the thumb during flexion and adduction motion: Evidence for a screw-home mechanism.

The thumb plays a crucial role in basic hand function. However, the kinematics of its entire articular chain have not yet been quantified. Such investigation is essential to improve our understanding of thumb function and to develop better strategies to treat thumb joint pathologies.

Subject-specific thumb muscle activity during functional tasks of daily life.

Background: The trapeziometacarpal joint is subjected to high compressive forces during powerful pinch and grasp tasks due to muscle loading. In addition, muscle contraction is important for stability of the joint. The aim of the present study is to explore if different muscle activation patterns can be found between three functional tasks.

In vivo contact biomechanics in the trapeziometacarpal joint using finite deformation biphasic theory and mathematical modelling.

The assessment of the contact biomechanics in the trapeziometacarpal (TMC) joint during functional tasks represents a relevant way to obtain a better understanding of the onset of osteoarthritis (OA). CT scans of the hand region of 20 female volunteers were taken in relaxed neutral, lateral key pinch and power grasp configuration. 3D models of the first metacarpal (MC1) and the trapezium were created.

Physical strain of handcycling: an evaluation using training guidelines for a healthy lifestyle as defined by the American College of Sports Medicine.

Objective: Developments in assistive technology such as handcycling provide attractive possibilities to pursue a healthy lifestyle for patients with spinal cord injury. The objective of the study is to evaluate physical stress and strain of handcycling against training guidelines as defined by the American College of Sports Medicine (ACSM).

Design: Seven able-bodied males conducted an incremental peak exercise handcycling test on a treadmill.