Movable surface models of hand joints using visible korean / Modelos de superficies móviles de articulaciones de manos utilizando visible Korean

SUMMARY: The human hand can make precise movements utilizing several joints of various articular types. To understand hand movements more accurately, it is essential to view the actual movements of bones and muscles considering the X, Y, and Z axes in the joints. This study aimed to investigate the joint movements in a hand using movable surface models, including these axes. These movable surface models of the hand will improve medical students' understanding of hand movements around the joints. To achieve this aim, 70 surface models were adopted from a Visible Korean model. Using Maya software, 20 virtual joints with X, Y, and Z axes included nine distal and proximal interphalangeal joints, five metacarpophalangeal joints, five carpometacarpal joints, and one wrist joint were created. Bone surface models were elaborately polished to maintain their original shape during movement. Muscle surface models were also processed to display the deformation of the muscle shape during movement. The surface models of the hand joints were moved by virtual control of the joints. We saved 87 movable surface models of the hand, including bones, muscles, and joint axes in stereolithography format, and compiled a Portable Document Format (PDF) file. Using the PDF file, the joint movements in a hand could be observed considering the X, Y, and Z axes alongside the stereoscopic shapes of the bones and muscles. These movable surface models of the hand will improve medical students' understanding of hand movements around the joints.

RESUMEN: La mano humana puede realizar movimientos precisos utilizando varias articulaciones de diferentes tipos articulares. Para comprender los movimientos de las manos con mayor precisión, es esencial ver los movimientos reales de los huesos y los músculos considerando los ejes X, Y y Z de las articulaciones. Este estudio tuvo como objetivo investigar los movimientos articulares en una mano utilizando modelos de superficies móviles, incluidos estos ejes. Estos modelos de superficie móvil de la mano mejorarán la comprensión de los estudiantes de medicina de los movimientos de la mano alrededor de las articulaciones. Para lograr este objetivo, se adoptaron 70 modelos de superficie de un modelo coreano visible. Con el software Maya, se crearon 20 articulaciones virtuales con ejes X, Y y Z que incluyeron nueve articulaciones interfalángicas distales y proximales, cinco articulaciones metacarpofalángicas, cinco articulaciones carpometacarpianas y una articulación de muñeca. Los modelos de superficie ósea se pulieron minuciosamente para mantener su forma original durante el movimiento. También se procesaron modelos de superficie muscular para mostrar la deformación de la forma del músculo durante el movimiento. Los modelos de superficie de las articulaciones de las manos se movieron mediante el control virtual de las articulaciones. Guardamos 87 modelos de superficies móviles de la mano, incluidos huesos, músculos y ejes articulares en formato de estereolitografía, y compilamos un archivo en formato de documento portátil (PDF). Usando el archivo PDF, los movimientos de las articulaciones en una mano se pueden observar considerando los ejes X, Y y Z junto con las formas estereoscópicas de los huesos y músculos. Estos modelos de superficie móvil de la mano mejorarán la comprensión de los estudiantes de medicina sobre los movimientos de la mano alrededor de las articulaciones.

Role of Active Range of Motion in Hand and Wrist Joint Photography: A Preliminary Analysis.

INTRODUCTION: Hand photography is effective and advantageous for assessing functional deficits and improvements related to surgery. In this study, it is aimed to investigate whether the correct active range of motion (ROM) is masked by the passive ROM in a wrist joint. METHOD: Eleven patients who were treated for unilateral wrist fractures were included in the study. Photography was performed in all patients by the same surgeon according to the conventional hand surgery photography approach and the active ROM photography approach. Differences between the noninjured side and injured side were assessed. RESULTS: No differences were found between the active ROM and passive ROM during the extension and flexion movements in the noninjured side group. However, in the injured side group, the results from the photographs obtained with the conventional method were significantly better than the results from the photographs obtained when the wrist was actively moved. CONCLUSION: These findings suggest that photographs of wrists during passive motion may affect the results of a treatment or study by showing false positivity. We propose obtaining images of active ROM instead of passive ROM in hand photography.

Accuracy and Validity of Goniometer and Visual Assessments of Angular Joint Positions of the Hand and Wrist.

PURPOSE: To compare goniometric and visual assessments of angular hand joint and wrist joint positions measured by board-certified hand surgeons and certified hand therapists. We hypothesized that visual estimation would be similar to the goniometric measurement accuracy of digital and wrist joint positions. METHODS: The wrist, index finger metacarpophalangeal (MCP) joint, and index finger proximal interphalangeal (PIP) joint were evaluated in different positions by 40 observers: 20 board-certified hand surgeons and 20 certified hand therapists. Each observer estimated the position of the wrist, index MCP joint, and index PIP joint of the same volunteer, who was positioned in low-profile orthoses to reproduce predetermined positions. Following visual estimation, the participants measured the same joint positions using a goniometer. The control measurement was digitally determined by a radiologist who obtained radiographs of the hand and wrist positions in each orthosis. Observers were blinded to the results of control measurements. RESULTS: When considering all joints at all positions, neither visual assessments nor goniometer assessments were consistently within ± 5° of the measurements obtained on control radiographs. When considering individual joints, goniometer measurements were significantly closer to control radiograph measurements than the visual assessments for all 3 PIP joint positions. There was no difference for the measurements at the wrist or for 2 of the 3 MCP joint positions. Significant differences between surgeon and therapist joint angle measurements were not observed when comparing visual and goniometer assessments to radiograph controls. CONCLUSIONS: Compared with radiograph measurements, neither visual nor goniometer assessment displayed high levels of accuracy. On average, visual assessment of the angular positions of the index MCP and wrist joint were as accurate as the goniometer assessment, whereas goniometer assessment of the angular position of the PIP joint was more accurate than visual assessment. There was a relatively high degree of between-observer variability in measurements, and therefore, no one person's measurements could be consistently relied upon to be accurate. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic II.

A biomechanical and evolutionary perspective on the function of the lumbrical muscle.

The lumbrical muscles of the hand originate from the flexor digitorum profundus tendons and insert onto the lateral band of the extensor tendons. Owing to these movable attachments, the function of this muscle is difficult to visualize. To better determine the function of this muscle, we considered its relative anatomy, biomechanical characteristics, and evolution. With the smallest physiological cross-sectional area in the upper extremity, the lumbrical muscles have weak motor function, which is only 1/10 of the interosseous muscle. Because they are spindle rich, the lumbrical muscles play an important role in the sensory feedback of the distal interphalangeal, proximal interphalangeal, and metacarpophalangeal joints of the fingers. The first 2 lumbrical muscles have lower variation in anatomy and higher density of muscle spindles compared to the ulnar 2 lumbricals. In addition, the index and middle finger lumbrical muscles are innervated by the median nerve, which also innervates the thenar muscles of the thumb. Therefore, it is possible that the first 2 lumbricals are functionally more important than the 2 ulnar lumbricals, specifically for precision pinch movements.

Range of motion measurements in hand surgery: should they be used for assessing outcomes?

PURPOSE: The purpose of the study was to assess how context influences range of motion measurements in hand surgery. METHODS: One hundred seventy-five consecutive patients presenting to a hand surgery clinic were evaluated over 7 sessions. Passive and active motion were measured with a goniometer and by visual estimation. The affected joint was measured by 3 different examiners-one hand surgeon and 2 research assistants (RAs). Measurements by the RAs were performed under the pretense of imaginary project titles and purposes. RESULTS: Range of motion measurements were easily influenced. As the invented project's purpose became more specific and dependent on physician intervention, the bias became more pronounced. Measurements performed under construed project titles that promoted surgical intervention garnered outcomes that supported surgery (P < 0.01). Conversely, when the manufactured study's intent was to find support in conservative treatment, this outcome could also be generated (P < 0.01). DISCUSSION: Range of motion measurements can easily be influenced by the context of the study, even in seemingly blinded examiners. Reliable range of motion measurements can only be made when the examiner has no knowledge of the study's intent.

Associations between MRI-defined synovitis, bone marrow lesions and structural features and measures of pain and physical function in hand osteoarthritis.

OBJECTIVES: To explore associations between MRI features and measures of pain and physical function in hand osteoarthritis (OA). METHODS: Eighty-five patients (77 women) with mean (SD) age of 68.8 (5.6) years underwent contrast-enhanced MRI of the interphalangeal joints (dominant hand) and clinical joint assessment. One investigator read the MRIs for presence/severity of osteophytes, joint space narrowing, erosions, bone attrition, cysts, malalignment, synovitis, flexor tenosynovitis, bone marrow lesions (BMLs) and ligament discontinuity according to the proposed Oslo hand OA MRI score. Pain and physical function were assessed by joint palpation (tenderness yes/no), self-reported questionnaires (Australian/Canadian (AUSCAN) hand index, Functional Index of hand osteoarthritis (FIHOA), Arthritis Impact Measurement Scale-2 (AIMS-2) hand/finger) and grip strength. Logistic regression with generalised estimating equations was used to explore associations between the presence of MRI features and joint tenderness, and linear regression for associations between the burden of MRI abnormalities and patient-reported outcomes and grip strength (adjusted for age and sex). MRI features with p<0.25 were introduced into a multivariate model. The final model included features with p≤0.10 (backward selection). RESULTS: MRI-defined moderate/severe synovitis (OR=2.4; p<0.001), BMLs (OR=1.5; p=0.06), erosions (OR=1.4; p=0.05), attrition (OR=2.5; p<0.001) and osteophytes (OR=1.4; p=0.10) were associated with joint tenderness independently of each other (final model adjusted for age and sex). The sum score of MRI-defined attrition was associated with FIHOA (B=0.58; p=0.005), while the sum score of osteophytes was associated with grip strength (B=-0.39; p<0.001). No significant associations were found with AUSCAN pain/physical function or AIMS-2 hand/finger subscales. CONCLUSION: MRI-defined synovitis, BMLs, erosions and attrition were associated with joint tenderness. Synovitis and BMLs may be targets for therapeutic interventions in hand OA.

Functional reconstruction of the hand: the stiff joint.

Proper hand function relies on a combination of strength and mobility. The intricate architecture that allows for hand mobility includes the articular surfaces of joints, periarticular ligamentous structures, tendon mechanisms, and the soft-tissue envelope. These structures are subject to injury and scarring. The net effect of a variety of etiologic factors is stiffness of the hand with diminution of hand function. This article reviews the biology of healing, pertinent anatomy of the hand, and operative and nonoperative treatment of the stiff hand.

Repair of radiographic joint damage following treatment with etanercept in psoriatic arthritis is demonstrable by 3 radiographic methods.

OBJECTIVE: Psoriatic arthritis (PsA) is characterized by varied radiographic features. We describe a patient with PsA with severe radiographic damage that improved significantly following treatment with etanercept. The improvement was documented by several methods of radiographic assessment. METHODS: Etanercept was introduced in September 2005. Radiographs of the hands and feet were read using 3 methods: the modified Steinbrocker method, the van der Heijde (vdH) modification of the Sharp method, and the Ratingen scoring system. RESULTS: In July 2009, radiographs of the hands and feet showed improvement in erosion score and joint space narrowing, while bony proliferation remained the same [43 by modified Steinbrocker, 26 by the vdH Sharp score (12 for erosions and 14 for joint space narrowing), and 56 by the Ratingen (18 for erosion and 38 for proliferation]. CONCLUSION: The 3 radiographic methods were useful in demonstrating improvement in joint scores. The modified Steinbrocker method, which is the simplest, was able to reveal improvement in our patient.

[Tenodesis in hand surgery]. / Les ténodèses en chirurgie de la main.

Joining tendon's inextensibility with joint's mobility, a tenodesis fixes on the bones the two ends of a tendon on both sides of one or several joints. A "simple" tenodesis overrides only one joint, whereas a "dynamic" tenodesis crosses two or more joints. A "crossed" dynamic tenodesis crosses the line which joins rotation axes. A "direct" dynamic tenodesis is located on the same side of this line. The "tenodesis effect" is normally produced by the movements of the joint on the neighbouring tendons. Anatomical examples are given by the oblique retinacular ligaments (crossed dynamic tenodesis), and by the tenodesis effects linked to the flexion-extension of the wrist on the extrinsic tendons of the fingers (direct tenodesis effect), or to the flexion-extension of the PIP joints on the intrinsic tendons of the fingers (crossed tenodesis effect). Main tenodesis techniques are used for palliative surgery in paralysis of EDC, intrinsic muscles of the fingers, or extrinsic muscles of the thumb (EPL, FPL, APL and EPB).

Extensor tendon reconstruction for zones II and IV using local tendon flap: a cadaver study.

PURPOSE: To assess the feasibility of reconstructing extensor tendon segmental defects in zones II (over the middle phalanx) and IV (over the proximal phalanx) using local tendon flaps (LTFs), explore in these 2 zones the anatomical constraints that limit the use of the LTF as regards the maximum defect that could be reconstructed, and compare this flap with distant tendon grafts (DTG) reconstruction for similar size defects. METHODS: We dissected 33 fresh-frozen cadaver extensor tendons from the fingers of 9 fresh-frozen cadaver forearms. A 0.5-cm defect was created in each extensor tendon of 21 fingers: 12 in zone II and 9 in zone IV. In each of 12 additional fingers, we created a 1.0-cm defect in zone IV. In 25 fingers, LTFs measuring 0.5 and 1.0 cm in length were harvested from the extensor tendon proximal to each defect and were turned distally to reconstruct the respective 0.5- and 1.0-cm defects. In 8 fingers, palmaris longus tendon grafts measuring 0.5 and 1.0 cm in length were used to reconstruct the respective 0.5- and 1.0-cm defects. Limited kinematic analysis was performed on the repaired fingers by maximally flexing the metacarpophalangeal, proximal interphalangeal, and distal interphalangeal joints in sequential fashion. RESULTS: In zone II, repair was technically feasible using LTFs in all 9 of the 0.5-cm extensor tendon defects. Likewise, LTFs were feasible for zone IV to repair 6 of 8 and all 9 of the respective 0.5- and 1.0-cm extensor tendon defects. Two failed repairs occurred early in the study by suture gapping following LTF of 0.5 cm to repair extensor tendon defects in zone IV of a long and small finger during maximal flexion. We determined the anatomical constraints for the use of the LTFs. The maximum length of repairable defect using the LTF was 0.5 cm in zone II of the index, long, ring, and small fingers, and zone IV of the small finger. In zone IV of the index, long, and ring fingers, the largest defect that could be repaired was 1.0 cm. Similarly, DTGs were feasible in zone II to repair all 4 of the 0.5-cm defects and in zone IV to repair all 4 of the 0.5- and 1.0-cm extensor tendon defects. CONCLUSIONS: In a cadaver model, both the LTF and the DTG are anatomically feasible and technically easy to perform. However, the LTF avoids a distant donor site, provides morphologically similar donor tendon that is readily accessible, and avoids morbidity that may be associated with the use of DTG. In this study, however, the LTF was limited in its use to zones II and IV of the extensor tendon.