Metacarpophalangeal Joint Of Index Finger Research Articles

E064 A rare hereditary haemochromatosis type three (3) related arthritis

Abstract Background/Aims Arthritis is a common manifestation in hereditary haemochromatosis (HHC). Haemochromatosis arthropathy frequently involves small joint of hands especially the metacarpo-phalangeal joints (MCPJs) and hence is one of the differentials when assessing for rheumatoid arthritis, psoriatic arthritis along with osteoarthritis but requires a high index of suspicion. We report a case of Haemochromatosis arthropathy where the arthropathy was due to type 3 hereditary haemochromatosis (HHC) which is a much rarer form and requires specialist genetic testing. Methods A 38-year-old lady was referred with abnormal iron profile and ten-month history of small joint arthralgia mainly affecting the index and middle finger in right hand with occasional swelling. She had a normal body mass index with minimal alcohol intake. Clinical examination showed low grade synovitis in index finger metacarpo-phalangeal joint (MCPJ). Blood investigations for Rheumatoid arthritis and connective tissue diseases were negative with normal CRP & ESR, Ferritin was slightly raised at 236 and transferrin saturation was 100% on two successive occasions, LFTs were normal. Xray of hands showed slight narrowing of 2nd MCPJ and US hands showed thickened synovium but no erosions or Doppler activity in 2nd MCPJ. Results Based on these, possible hereditary haemochromatosis (HHC) arthropathy was considered. By that time, she had been seen by the hepatology service where no evidence of iron deposition in other organs was found. Surprisingly her genetic testing for hereditary haemochromatosis (HHC) (Cys282Y/H63D in HFE gene) was negative resulting in most common HFE-related HHC excluded. Iron studies were repeated which were still raised, hence after discussion with hepatologist and biochemist the plan was made to investigate for rarer form of hereditary haemochromatosis (HHC), genetic tests showed that she had TFR2 variant mutation which would be consistent with type 3 hereditary haemochromatosis (HHC), which is inherited in autosomal recessive pattern. Venesections were started with ferritin levels improving to less than 50 with plans to monitor arthralgia to see if there is any improvement over time. Conclusion Metacarpo-phalangeal joints (MCPJs) involvement is common in various arthropathies. This case highlights the importance of considering other, much rarer forms of hereditary haemochromatosis (HHC) as treatment will help in preventing iron deposition in other organs like liver, heart, pancreas etc. These conditions are very rare and there is need to create awareness of genetic testing as hereditary haemochromatosis (HHC) arthropathy does present not uncommonly to rheumatology services and requires dedicated non-HFE molecular panel. Disclosure H. Umair: None. M. Kazmi: None.

Reliability, validity and clinical usability of a robotic assessment of finger proprioception in persons with multiple sclerosis.

Multiple sclerosis often leads to proprioceptive impairments of the hand. However, it is challenging to objectively assess such deficits using clinical methods, thereby also impeding accurate tracking of disease progression and hence the application of personalized rehabilitation approaches. We aimed to evaluate test-retest reliability, validity, and clinical usability of a novel robotic assessment of hand proprioceptive impairments in persons with multiple sclerosis (pwMS). The assessment was implemented in an existing one-degree of freedom end-effector robot (ETH MIKE) acting on the index finger metacarpophalangeal joint. It was performed by 45 pwMS and 59 neurologically intact controls. Additionally, clinical assessments of somatosensation, somatosensory evoked potentials and usability scores were collected in a subset of pwMS. The test-retest reliability of robotic task metrics in pwMS was good (ICC=0.69-0.87). The task could identify individuals with impaired proprioception, as indicated by the significant difference between pwMS and controls, as well as a high impairment classification agreement with a clinical measure of proprioception (85.00-86.67%). Proprioceptive impairments were not correlated with other modalities of somatosensation. The usability of the assessment system was satisfactory (System Usability Scale ≥73.10). The proposed assessment is a promising alternative to commonly used clinical methods and will likely contribute to a better understanding of proprioceptive impairments in pwMS.

Reliable and Valid Robotic Assessments of Hand Active and Passive Position Sense in Children With Unilateral Cerebral Palsy.

Impaired hand proprioception can lead to difficulties in performing fine motor tasks, thereby affecting activities of daily living. The majority of children with unilateral cerebral palsy (uCP) experience proprioceptive deficits, but accurately quantifying these deficits is challenging due to the lack of sensitive measurement methods. Robot-assisted assessments provide a promising alternative, however, there is a need for solutions that specifically target children and their needs. We propose two novel robotics-based assessments to sensitively evaluate active and passive position sense of the index finger metacarpophalangeal joint in children. We then investigate test-retest reliability and discriminant validity of these assessments in uCP and typically developing children (TDC), and further use the robotic platform to gain first insights into fundamentals of hand proprioception. Both robotic assessments were performed in two sessions with 1-h break in between. In the passive position sense assessment, participant's finger is passively moved by the robot to a randomly selected position, and she/he needs to indicate the perceived finger position on a tablet screen located directly above the hand, so that the vision of the hand is blocked. Active position sense is assessed by asking participants to accurately move their finger to a target position shown on the tablet screen, without visual feedback of the finger position. Ten children with uCP and 10 age-matched TDC were recruited in this study. Test-retest reliability in both populations was good (intraclass correlation coefficients (ICC) >0.79). Proprioceptive error was larger for children with uCP than TDC (passive: 11.49° ± 5.57° vs. 7.46° ± 4.43°, p = 0.046; active: 10.17° ± 5.62° vs. 5.34° ± 2.03°, p < 0.001), indicating discriminant validity. The active position sense was more accurate than passive, and the scores were not correlated, underlining the need for targeted assessments to comprehensively evaluate proprioception. There was a significant effect of age on passive position sense in TDC but not uCP, possibly linked to disturbed development of proprioceptive acuity in uCP. Overall, the proposed robot-assisted assessments are reliable, valid and a promising alternative to commonly used clinical methods, which could help gain a better understanding of proprioceptive impairments in uCP, facilitating the design of novel therapies.

P 61 Robotic assessments of upper limb sensorimotor impairments in neurological disorders

Background: Upper limb sensorimotor impairments are common in neurological disorders. In order to personalize and evaluate interventions aiming to improve upper limb function, it is essential to accurately assess the presence and extent of these impairments. Clinical assessments rely on experience-based observations, subjective evaluation, and ordinal scales, thus challenging a sensitive capture of intervention-induced changes in clinical trials. Novel robotic technologies promise sensitive and objective endpoints describing upper limb kinematic and kinetics during behavioural tasks. Over the last decades, we successfully developed, validated, and clinically applied such technologies in neurological disorders. The aim is to report on the feasibility, clinimetric properties, and clinical applicability of two complementary robotic assessments quantifying upper limb sensorimotor impairments. Methods: First, we relied on a haptic end-effector to record upper limb movement patterns and hand grip forces during a goal-directed pick-and-place task (Kanzler et al. 2020). Second, we custom-designed a robotic device and behavioural tasks providing precise stimuli to the index finger metacarpophalangeal joint, thereby allowing to study finger proprioception as well as motor and sensorimotor impairments (Zbytniewska et al. 2021). The recorded sensor data is analyzed with signal processing pipelines to generate objective digital health metrics describing movement quality (e.g., efficiency), grip force control (e.g., smoothness), and the response to well-controlled displacements (e.g., position matching error). Results: Feasibility of the assessments was established in persons with stroke, multiple sclerosis, or ataxia and matched able-bodied controls, revealing that the approaches are rapidly and easily applicable in a wide range of patients. For each platform, a core set of statistically optimal metrics was selected based on their test-retest reliability, measurement error, and discriminative power. Concurrent validity indicated low-moderate correlations with clinical scales, highlighting that the metrics provide novel, complementary information. By applying the metrics, we were able to reveal the presence of sensorimotor impairments and subtle longitudinal changes in persons that did not show abnormalities in clinical assessments. Conclusions: Robotic assessments are valuable tools to accurately and sensitively assess upper limb sensory, motor, and sensorimotor impairments in neurological disorders, thus opening novel avenues for evaluating clinical trials. References Kanzler CM, et al. A data-driven framework for selecting and validating digital health metrics: use-case in neurological sensorimotor impairments. npj Digit. Med. 2020;3(1):80. Zbytniewska M, et al. Reliable and valid robot-assisted assessments of hand proprioceptive, motor and sensorimotor impairments after stroke. J. Neuroeng. Rehabil. 2021;18(1):115.

Reliable and valid robot-assisted assessments of hand proprioceptive, motor and sensorimotor impairments after stroke

BackgroundNeurological injuries such as stroke often differentially impair hand motor and somatosensory function, as well as the interplay between the two, which leads to limitations in performing activities of daily living. However, it is challenging to identify which specific aspects of sensorimotor function are impaired based on conventional clinical assessments that are often insensitive and subjective. In this work we propose and validate a set of robot-assisted assessments aiming at disentangling hand proprioceptive from motor impairments, and capturing their interrelation (sensorimotor impairments).MethodsA battery of five complementary assessment tasks was implemented on a one degree-of-freedom end-effector robotic platform acting on the index finger metacarpophalangeal joint. Specifically, proprioceptive impairments were assessed using a position matching paradigm. Fast target reaching, range of motion and maximum fingertip force tasks characterized motor function deficits. Finally, sensorimotor impairments were assessed using a dexterous trajectory following task. Clinical feasibility (duration), reliability (intra-class correlation coefficient ICC, smallest real difference SRD) and validity (Kruskal-Wallis test, Spearman correlations rho with Fugl-Meyer Upper Limb Motor Assessment, kinesthetic Up-Down Test, Box & Block Test) of robotic tasks were evaluated with 36 sub-acute stroke subjects and 31 age-matched neurologically intact controls.ResultsEighty-three percent of stroke survivors with varied impairment severity (mild to severe) could complete all robotic tasks (duration: <15 min per tested hand). Further, the study demonstrated good to excellent reliability of the robotic tasks in the stroke population (ICC>0.7, SRD<30%), as well as discriminant validity, as indicated by significant differences (p-value<0.001) between stroke and control subjects. Concurrent validity was shown through moderate to strong correlations (rho=0.4-0.8) between robotic outcome measures and clinical scales. Finally, robotic tasks targeting different deficits (motor, sensory) were not strongly correlated with each other (rho le0.32, p-value>0.1), thereby presenting complementary information about a patient’s impairment profile.ConclusionsThe proposed robot-assisted assessments provide a clinically feasible, reliable, and valid approach to distinctly characterize impairments in hand proprioceptive and motor function, along with the interaction between the two. This opens new avenues to help unravel the contributions of unique aspects of sensorimotor function in post-stroke recovery, as well as to contribute to future developments towards personalized, assessment-driven therapies.

Design and Preliminary Performance Assessment of a Wearable Tremor Suppression Glove.

Approximately 25% of individualsliving with parkinsonian tremor do not respond to traditional treatments. Wearable tremor suppression devices (WTSD) provide an alternative approach, however, tremor in the fingers has not been given as much attention as tremor in the elbow and the wrist. Therefore, the objective of this study is to design a wearable tremor suppression glove that can suppress tremor simultaneously, but independently, in multiple hand joints without restricting the user's voluntary motion. A WTSD was designed for managing tremor in the index finger metacarpophalangeal (MCP) joint, thumb MCP joint, and the wrist. The prototype was tested and assessed on a participant living with parkinsonian tremor. The experimental evaluation showed an overall suppression of 73.1%, 80.7%, and 85.5% in resting tremor, 70.2%, 79.5%, and 81% in postural tremor, and 60.0%, 58.7%, and 65.0% in kinetic tremor in the index finger MCP joint, the thumb MCP joint, and the wrist, respectively. This first assessment of a WTSD for people living with Parkinson's disease provides confirmation of the feasibility of the approach. The next step requires a comprehensive validation on a broader population in order to evaluate the performance of the WTSD. This study demonstrates the feasibility of using a WTSD to manage hand and finger tremor. The device enriches the field of upper-limb tremor management, as the first WTSD for multiple joints of the hand.

Influence of pitching grip on shoulder and elbow injuries in junior baseball players, focusing on hand length and the metacarpophalangeal joint angle

[Purpose] We investigated the relationship of pitching grip with hand length and index finger metacarpophalangeal joint angle. [Participants and Methods] A total of 650 junior baseball players divided into two groups according to whether they experienced shoulder or elbow pain were divided into two groups based on their pitching grip, i.e., those who held the ball with the ulnar side of the thumb and those who held it with the finger pad of the thumb. The metacarpophalangeal joint angle was measured while the participants held a ball. [Results] The average hand length was 16.3 ± 1.4 cm for those holding the ball with the ulnar side of the thumb and 15.8 ± 1.2 cm for those holding it with the finger pad of the thumb. Hand length and metacarpophalangeal angle were significantly greater in the group using the ulnar side of the thumb. The two groups showed no significant differences in the distribution of grip type or history of shoulder/elbow pain. The index finger metacarpophalangeal angle and shoulder/elbow pain were significantly lower in the pain group. [Conclusion] With respect to the pitching grip for junior baseball players, we recommend a slightly flexed rather than extended position with the metacarpophalangeal angle.

The Index Finger Metacarpal Tubercle

PurposeThe region of the index finger metacarpophalangeal joint is a common source of hand pain with variable, well-known etiologies. We have identified the tubercle at the dorsoradial neck of the index finger metacarpal as a distinct and specific site of pain in a subset of patients who presented with a chief report of index finger pain. Although experienced hand surgeons may recognize this clinical entity, we found no previous description within the literature.MethodsAfter institutional review board approval, we performed a retrospective review of all patients presenting to a single surgeon practice with severe pain at the dorsoradial tubercle of the index finger metacarpal unattributable to known etiologies. Patients underwent initial management of steroid injection followed by surgical excision if conservative measures failed.ResultsSteroid injection was administered as initial management in 9 of 10 afflicted hands. Five of these hands experienced complete resolution of pain at 4 weeks after injection whereas 4 developed recurrence at an average of 3 months after injection. Among patients with recurrence, one patient opted for a second injection that led to pain resolution 4 weeks later, whereas the remaining 3 hands had surgical excision. All patients who underwent surgical excision reported minimal discomfort and marked improvement in pain after surgery.ConclusionsWe identified the tubercle at the dorsoradial neck of the index finger metacarpal as a distinct and specific site of pain in a subset of patients. We postulate that the pathophysiology of pain at the prominent index finger metacarpal tubercle may be related to a subacute radial collateral ligament injury. Steroid injection to the tubercle is a reasonable initial treatment option and satisfactory results may also be obtained with surgical excision.Type of study/level of evidenceTherapeutic IV.

Index Finger Metacarpophalangeal Joint Arthrodesis With a Dorsal Locking Plate.

Index finger metacarpophalangeal (MCP) joint arthrodesis is a potential reconstructive option for recalcitrant MCP arthritis. Due to lateral forces applied by the thumb, our institutional experience supports index finger MCP arthrodesis as a successful option in younger, higher demand patients and in the setting of significant joint instability. We present our technique of performing index finger MCP arthrodesis using a dorsal locking plate. The proposed benefits of this technique include the ability to position the MCP joint in the desired degree of flexion, generation of parallel fusion surfaces with even compression across the arthrodesis site, and stable fixation.

A New Surface Landmark for Thumb Digital Nerve Bifurcation: A Cadaveric Study

The radial and ulnar thumb digital nerves are critical for tactile sensation and dexterity in the hand. This cadaveric study sought to validate a surface landmark for the bifurcation of the thumb radial digital nerve (RDN) and ulnar digital nerve (UDN). We used 24 fresh-frozen cadaveric specimens for dissections. With the thumb placed in the plane of the palm and fully radially abducted, the index finger metacarpophalangeal joint was flexed to 90°. Then, while keeping the distal interphalangeal joint straight, the proximal interphalangeal joint was flexed until the fingertip contacted the thenar eminence to identify the point of bifurcation. We made a U-shaped incision and identified the bifurcation of the thumb RDN and UDN. The point of bifurcation was measured from the ulnar- and proximal-most aspects of the incision. The bifurcation of the thumb RDN and UDN was consistently identified within the U in 22 of 24 specimens (92%). In 16 specimens, the index RDN was also identified either trifurcating with the thumb RDN and UDN or branching from a common digital nerve of index RDN and thumb UDN. Most bifurcation points were found directly along the ulnar and proximal edge of the incision. Two specimens contained a bifurcation point 2 mm ulnar to the ulnar limb of the U. The bifurcation U is a consistent landmark for the thumb RDN and UDN point of bifurcation. The variable branching patterns in this region confirms the importance of thorough clinical examination with penetrating injuries to the thenar eminence. This surface anatomic landmark for the thumb RDN and UDN bifurcation may aid in preventing iatrogenic injuries during elective procedures and identifying at-risk structures during penetrating injuries to the palm.

Transfer of the triceps brachii to the finger and thumb extensors: Anatomical study and report on one case

Our aims were to study the anatomical feasibility of triceps brachii long head (TBLH) transfer to the extensor digitorum communis (EDC) and extensor pollicis longus (EPL) tendons through a medial route, and to report on its first clinical application. Dissections were conducted on 10 fresh-frozen cadaver specimens. Using a posteromedial approach, the TBLH was separated from the remaining triceps and extended distally with a fascia lata strip. This strip was then tunneled through a medial route and secured distally to the EDC and EPL tendons. The transfer tenodesis effect during elbow extension was assessed with metacarpophalangeal (MCP) joint motion of the thumb and index finger, and the distance between the thumb and index finger tips (TI distance). This transfer was performed in an eight-year-old boy with incomplete recovery of a right brachial plexus birth palsy; preoperatively, shoulder and elbow functions were recovered as well as active gripping distally, but he had no active wrist or finger extension. With the trapeziometacarpal and radiocarpal joints stabilized, 90° elbow extension provided a mean extension of the thumb and index finger MCP joints of 34 ± 5° and 90 ± 11°, respectively, with a mean TI distance of 116 ± 16 mm. Twelve months after surgery, the boy had full active MCP joint extension, independent from elbow extension. Transferring the TBLH to the EDC and EPL tendons is anatomically feasible. Larger clinical studies will be needed to assess more adequately its functional outcomes.

Pollicization of Biphalangeal Index Finger for Type IV Thumb Hypoplasia: A Case Report Describing Preoperative Planning, Intraoperative Decision-Making, and Technical Modifications

Index finger (IF) pollicization is the standard treatment for severe congenital thumb hypoplasia. The procedure requires a supple and anatomically normal IF. No guidelines exist for IF pollicization in patients who have concomitantly underdeveloped IF, specifically when the digit has only 2 phalanges and 1 interphalangeal joint. We present a case of a 20-month-old boy with congenital type IV thumb hypoplasia who also had biphalangeal IF. We proposed an IF pollicization operation that required significant modifications to the traditional procedure. Preoperative planning and intraoperative execution are described. The modifications to the traditional procedure included: (1) removal of proximal third of IF metacarpal; (2) creation of a de novo thumb carpometacarpal (CMC) joint by fibrous union whereby the IF CMC joint cartilaginous components are maintained and the remaining distal IF metacarpal is translocated down and secured to this cartilage (in contrast to the traditional use of IF metacarpophalangeal joint as a de novo thumb CMC joint); (3) preservation of IF joints at their "natural" position and function; (4) maintenance of intrinsic muscles at their original distal insertion sites; and (5) important adjustments to skin incision. Pollicization of biphalangeal IF can be executed in a safe and efficient manner. Early recovery has shown promising signs. Long-term results, including the de novo thumb CMC joint function, remain to be evaluated.

A musculoskeletal model of the hand and wrist: model definition and evaluation

To improve our understanding on the neuromechanics of finger movements, a comprehensive musculoskeletal model is needed. The aim of this study was to build a musculoskeletal model of the hand and wrist, based on one consistent data set of the relevant anatomical parameters. We built and tested a model including the hand and wrist segments, as well as the muscles of the forearm and hand in OpenSim. In total, the model comprises 19 segments (with the carpal bones modeled as one segment) with 23 degrees of freedom and 43 muscles. All required anatomical input data, including bone masses and inertias, joint axis positions and orientations as well as muscle morphological parameters (i.e. PCSA, mass, optimal fiber length and tendon length) were obtained from one cadaver of which the data set was recently published. Model validity was investigated by first comparing computed muscle moment arms at the index finger metacarpophalangeal (MCP) joint and wrist joint to published reference values. Secondly, the muscle forces during pinching were computed using static optimization and compared to previously measured intraoperative reference values. Computed and measured moment arms of muscles at both index MCP and wrist showed high correlation coefficients (r = 0.88 averaged across all muscles) and modest root mean square deviation (RMSD = 23% averaged across all muscles). Computed extrinsic flexor forces of the index finger during index pinch task were within one standard deviation of previously measured in-vivo tendon forces. These results provide an indication of model validity for use in estimating muscle forces during static tasks.

Silicone Metacarpophalangeal Arthroplasty for Osteoarthritis: Long-Term Results.

To demonstrate that silicone metacarpophalangeal (MCP) arthroplasty provides excellent long-term outcomes with a low complication rate in osteoarthritis patients. A consecutive cohort of 35 patients with osteoarthritis of 1 or more MCP joints undergoing anatomically neutral silicone MCP arthroplasty was followed over a 15-year period. Functional outcomes including strength and range of motion (ROM), as well as complications, were recorded. All patients were available for long-term assessment including radiographs and outcomes questionnaire. Average follow-up for the cohort of 35 patients (40 implants) was 8.3 years (range, 2-17 years). Average age was 58 years (range, 42-80 years) with 22 men and 13 women. In 31 patients, a single MCP joint was involved (middle finger, 20; index finger, 10; little finger, 1). The dominant hand was involved in 23 patients. Seven (of 14) patients had a concomitant RCL reconstruction of the index finger MCP joint; no other digit had a collateral ligament reconstruction. Average final visual analog scale pain score was 0.3 of 10. Average final active ROM arc was from 4° (range, 0°-20°) to 73° (range, 50°-90°) of flexion. One patient had a revision MCP arthroplasty for a 97% clinical survivorship. Radiographs demonstrated fractured implants in 5 of 40 (12.5%) implants, but none exhibited instability, pain, or ROM deterioration. Average Michigan Hand Outcomes Questionnaire score was 82 (of 100) at final follow-up. Silicone arthroplasty is effective in the treatment of primary MCP osteoarthritis. Implant survivorship is 97% (clinical) and 88% (radiographic) in long-term follow-up. Therapeutic IV.

Biomechanics and Pinch Force of the Index Finger Under Simulated Proximal Interphalangeal Arthrodesis

To analyze the effect of simulated proximal interphalangeal (PIP) joint arthrodesis on distal interphalangeal (DIP) joint free flexion-extension (FE) and maximal voluntary pinch forces. Five healthy subjects were tested with the PIP joint unconstrained and constrained to selected angles to produce (1) free FE movements of the DIP joint at 2 selected angles of the metacarpophalangeal joint, and (2) maximal voluntary tip (thumb and index finger) and chuck (thumb, index, and middle fingers) pinch forces. Kinematic data from a motion analysis system, pinch force data from a mechanical pinch meter, and electromyography (EMG) data recorded from 2 flexor and extensor muscles of the index finger were collected during free FE movements of the DIP joint and pinch tests for distinct PIP joint constraint angles. The EMG root mean square (RMS) values of the flexor digitorum profundus (FDP) and extensor digitorum (ED) did not change during free FE of the DIP joint. The extension angle of the range of motion of the DIP joint changed during free FE. It increased as the PIP constraint angle increased. The EMG RMS value of FDP and ED showed maximum values when the PIP joint was unconstrained and constrained at 0° to 20° of flexion during tip and chuck pinch. Neither the index finger metacarpophalangeal and DIP joint positions nor pinch force measurements differed with imposed PIP joint arthrodesis. The PIP joint arthrodesis angle affects DIP joint extension. A minimal overall impact from simulated PIP arthrodesis in muscle activity and pinch force of the index finger was observed. The EMG RMS values of the FDP and ED revealed that a PIP arthrodesis at 0° to 20° of flexion leads to a more natural finger posture during tip and chuck pinch. This study provided a quantitative comparison of free FE motion of the DIP joint, as well as FDP and ED forces during pinch, under simulated index finger PIP arthrodesis angles.

Dorsal Dislocation of the Metacarpophalangeal joint of the Left Index Finger in a Left-Handed Nigerian Teenager

Dorsal Dislocation of the Metacarpophalangeal joint of the Left Index Finger in a Left-Handed Nigerian Teenager

Development of a closed-loop system for tremor suppression in patients with Parkinson's disease.

More than 70% of patients suffering Parkinson's disease (PD) exhibit resting tremor in their extremities, hampering their ability to perform daily activities. Based on our earlier studies on corticospinal transmission of tremor signals [10,11], we hypothesize that cutaneous afferents evoked by surface stimulation can produce an inhibitory effect on propriospinal neurons (PN), which in turn will suppress tremor signals passing through the PN. This paper presents the development of a closed-loop system for tremor suppression by transcutaneous electrical nerve stimulation (TENS) of sensory fibers beneath the skin. The closed-loop system senses EMGs of forearm muscles, and detects rhythmic bursting in the EMG signal. When a tremor is detected by the system, a command signal triggers a stimulator to output a train of bi-phasic, current regulated pulses to a pair of surface electrodes. The stimulation electrode is placed on the dorsal hand skin near the metacarpophalangeal joint of index finger, which is innervated by the superficial radial nerve that projects an inhibitory afferent to PNs of forearm muscles. We tested the closed-loop system in 3 normal subjects to verify the algorithm and in 2 tremor dominated PD subjects for feasibility of tremor detecting and suppression. Preliminary results indicate that the closed-loop system can detect tremor in all subjects, and tremor in PD patients was suppressed significantly by electrical stimulation of cutaneous afferents.

Dislocation of metacarpophalangeal joint of bilateral index finger: A case report

Occurrence of bilateral dislocation of metacarpophalangeal joint of index finger are very uncommon. Most of the dislocation are complex in nature and require surgical open reduction. The need for surgical reduction is primarily due to entrapment of fibrocartilaginous volar plate between proximal phalanx and metacarpal head. The dislocation can be approached by either volar or dorsal approach. We advocates dorsal approach because of its definitive advantage over volar approach like reduced neurovascular injury and direct exposure of volar plate.

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

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. 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. 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. 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. Diagnostic II.

The Transverse Bone in Cleft Hand: A Case Cohort Analysis of Outcome After Surgical Reconstruction

To evaluate the implications of the transverse bone in cleft hand by assessing outcomes after reconstruction in comparison with a control group. This study is a retrospective review of 23 hands in 18 patients following surgical reconstruction of the cleft hand. Eleven hands had a transverse bone component, and 12 hands (control group) did not. Patients and their families were contacted to assess overall satisfaction following reconstruction. Clinical and radiographic records were reviewed to assess aesthetic and functional outcomes, the need for additional surgery, and radiographic divergence angles. There was no difference in aesthetic or functional subjective outcomes. There was no statistically significant difference in any objective outcome measure between the two groups. The use of the cleft for pinch was more dependent on the status of the index finger and the preoperative thumb-index webspace rather than the presence of a transverse bone. Eleven (4transverse and 7 control) hands required additional surgery to address abnormal function or posture of the index and ring fingers. Preoperative radiographic divergence angles were larger in the transverse bone group than in the control group, whereas postoperative divergence angles were nearly equivalent. Similar outcomes between the two groups demonstrate that the presence of a transverse bone in cleft hand was not associated with worse outcomes following cleft reconstruction. Preoperative narrowing of the thumb webspace and postoperative index finger metacarpophalangeal joint abnormality are associated with worse functional outcomes. Therapeutic Level III.