Small Finger Research Articles

Design and fabrication of the Cubital Tunnel Control Orthosis (CTCO)

Cubital tunnel syndrome (CuTS) involves ischemia or damage to the ulnar nerve through compression, friction, or stretching and is the second most common neuropathy of the upper extremity.1-4 Symptoms commonly reported include paresthesia of the small finger and ulnar half of ring finger, difficulty maintaining grasp on objects and difficulty sleeping.5,6 Multiple causes have been identified within the literature to cause CuTS including but not limited to systemic diseases, occupational activities, external sources of compression, fractures and dislocations of the medial epicondyle and elbow deformities after trauma.

Biomechanical Modeling of Connecting Intermetacarpal K-Wires in the Treatment of Metacarpal Shaft Fractures.

Clinical series have been published using the configuration of 2 intercarpal Kirschner wires (K-wires) adjacent to the fracture being connected, but biomechanical analysis is lacking. The objective of this pilot biomechanical study was to model and compare the effects of externally connecting 2 intermetacarpal K-wires for the stabilization of transverse metacarpal shaft fractures. Our research hypothesis was that the connected constructs would be stiffer than the unconnected K-wires. A 3-dimensional computer-based model of small finger transverse metacarpal fracture stabilization was designed with 3 transverse 1.1 mm K-wires being anchored to the adjacent metacarpal. Three arrangements were tested: all 3 K-wires in parallel, the middle K-wire angled toward the proximal wire, and the middle angled K-wire being rigidly fixed to the proximal K-wire. The proximal wire was proximal to the fracture. A finite element analysis was performed by applying a cantilever force of 100 N at the head of the metacarpal. The metacarpal was considered to be uniform in composition with parameters typical for human bone. Kirschner wire parameters for stainless steel were used. Force (N) versus displacement was measured. The configuration with the middle angled K-wire being rigidly fixed to the proximal K-wire showed greater stiffness (12 N/mm) than nonattached constructs. The connected construct was 2.3 times more stiff than the unattached parallel construct and 2.5 times more stiff than angling the middle K-wire without attachment. In a computer model simulation, our results show that attaching 2 K-wires adjacent to the fracture provides more than twice the stiffness of unconnected K-wires.

Morphological Analysis of Metacarpal Shafts With Respect to Retrograde Intramedullary Headless Screw Fixation.

Background: The use of retrograde intramedullary headless compression screw fixation for metacarpal neck and shaft fractures has been described in the literature. The purpose of this study was to perform a computed tomography (CT)-based morphological analysis of metacarpal size to help surgeons anticipate expected hardware needs. Methods: In all, 108 consecutive hand CT scans were evaluated for the medullary diameter in the volar-dorsal and radial-ulnar planes at the narrowest point of the canal, as well as for the distance from the articular surface to this point. Results were then analyzed by finger and by sex. Results: The ring finger had the smallest average medullary canal diameter for both men and women (2.7 and 2.6 mm, respectively); the small finger had the largest average diameter (3.9 mm) for men and the middle finger (3.6 mm) for women. Radial-ulnar was the rate-limiting dimension in the index, middle, and ring fingers, whereas volar-dorsal was the smallest dimension in the small finger, regardless of sex. Medullary diameter tended to be larger in patients aged more than 50 years. More than 50% of fingers have diameters >3.0 mm, and at least 40% of index, middle, and small fingers have diameters >3.5 mm, which are common diameters of commercially available headless compression screws. Conclusions: When preparing to perform open reduction internal fixation of a metacarpal using retrograde intramedullary headless compression screws, the surgeon needs to be prepared with screws of larger diameters to optimize fixation. Screws of larger diameters are needed to achieve endosteal purchase, regardless of sex.

Extensor tendon ruptures in rheumatoid wrists

Background and aimsRheumatoid arthritis is a chronic inflammatory disease. The associated involvement of hands and tendons is over 90% and impairs overall function. In the course of the disease, the joints are often operated on. During this operation, ruptures of the extensor tendons are found by chance without the patients noticing them. The aim of this retrospective study is the prevalence of extensor tendon rupture. Which tendon is destroyed most frequently? How can the functional outcome be measured after reconstruction?Materials and methodsFrom 1572 operations on rheumatoid wrists, 61 extensor tendon ruptures were identified in 41 patients. The average time between the first rheumatic symptoms of the hand and surgery was 6.4 years. The average duration of RA was 7.8 years. 26 patients with 27 tendon reconstructions were included in the follow-up with an average postoperative duration of 4.6 years (3 to 14.2 years).ResultsExtensor tendons ruptures typically occurred at mechanically stressed sites. The most frequent rupture was found in the extensor pollicis longus tendon (21 tendons), followed by the small finger extensor tendon (14 tendons). A transfer was performed on 7 tendons. Fifty-five tendon lesions were sutured at other intact tendons. Free grafts were not used. The results in Clayton and QuickDASH scores were significantly different. Functional improvement was consistent with the results of tendon reconstructions in healthy control groups.ConclusionIn rheumatoid patients, a rupture of an extensor tendon must be expected at 4%. Patients tolerate and compensate this damage for a long time. The function of the hand including the tendon function is the most important factor in assessing the success of the operation. The subjective patient acceptance depends on the progress of the underlying disease, postoperative care (ergotherapy, physiotherapy, orthosis) and the patients' demands.

Digital Gangrene as a Sign of Catastrophic Coronavirus Disease 2019-related Microangiopathy

Sir: Emerging evidence suggests that coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), induces a hypercoagulable state with micro- and macroangiopathy.1–3 As plastic surgeons are called on to evaluate the visible manifestations of this hypercoagulability, we must understand the pathophysiology behind these cutaneous lesions. Here, we report 2 critically ill patients with COVID-19-related retiform purpura progressing to digital gangrene in an attempt to elucidate the etiology of thrombotic microangiopathy secondary to SARS-CoV-2 infection. A 40-year-old, previously healthy man presented with respiratory distress, cough, and fever due to COVID-19. He immediately developed hypoxemic respiratory failure, requiring intubation, prone positioning, veno-venous extracorporeal membrane oxygenation, and vasopressors. On hospital day (HD) 3, he developed retiform purpura of the right foot with loss of dorsalis pedis pulse, which persisted despite argatroban infusion. On HD 13, digital gangrene ensued, despite resurgence of his dorsalis pedis pulse. Of note, the retiform nature of the purpura and sporadic digital ischemia (Fig. 1A) were distinct from the typically homogenous pattern seen in pressor-induced necrosis. On HD 21, the patient died due to septic shock.Fig. 1.: Acral gangrene in late-stage COVID-19 patients. A, Gangrene of the right foot involving the hallux and fourth toe with retiform purpura on the dorsal midfoot. B, Gangrene of the right hand involving the thumb, index, and small fingers, with prominent retiform purpura on the ring finger (arrow).A 68-year-old man with a similar clinical course required intubation and vasopressors on HD 5. Twenty-four hours later, he developed retiform purpura of the right hand with triphasic Doppler signals of his palmar arch and proximal digital arteries. Despite consistent therapeutic anticoagulation, digital gangrene ensued (Fig. 1B). On HD 26, further care was withdrawn in the setting of persistent encephalopathy, and the patient expired. Both patients’ serologies revealed elevated D-dimer (10.3 and 6.2), antithrombin III deficiency, and positive anticardiolipin IgG/IgM antibodies. Hematoxylin and eosin preparations of their skin biopsies showed extensive vascular microthrombi and eccrine gland necrosis. Our patients developed nonsequential digital gangrene with a retiform morphology in the setting of severe SARS-CoV-2 infection. Although acral gangrene in the setting of COVID-related hypercoagulability has been described,4,5 sparse data exist on the pathophysiology of this phenomenon. Retiform purpura reflects the cutaneous manifestation of an occlusive microthrombotic process, as evidenced by the pervasive small vessel thrombi on biopsy (Fig. 2). Progression despite preserved major peripheral pulses also suggests a microvascular etiology to the digital necrosis. Acral distribution and delayed progression of ischemia after the acute respiratory insult imply that the thrombotic microangiopathy is secondary to cold-sensitive antibody/immunoglobulin activation in response to the virus, rather than a direct viral effect.Fig. 2.: Immunofluorescence image of skin biopsy from purpuric region in COVID-19 patients. Hematoxylin and eosin stain demonstrates microthrombi.Recent data suggest the presence of a complement-mediated microvascular injury in multiple organ systems,3 and we are pursuing direct immunofluorescence of the skin biopsies with this in mind. Currently, there is no accepted treatment protocol for COVID-19, and digital gangrene appears to portend end-stage disease. Although we advocate expectant management with no surgical intervention, we believe defining the etiology behind these dermatologic changes can contribute to the understanding and treatment of COVID-19. As demonstrated by our cases, progression of cutaneous ischemia despite early and aggressive anticoagulation underscores the need for a targeted immunotherapy that would effectively manage the catastrophic microangiopathic response induced by SARS-CoV-2.

WITHDRAWN: A subacute case of traumatic avulsion of the flexor digitorum pofundus tendon due to recurrent enchondroma of the distal phalanx

Abstract Avulsion of the flexor digitorum profundus (FDP) tendon associated to an enchondroma fracture in the distal phalanx is very rare. We report a subacute case of a type II FDP tendon avulsion of the small finger at its insertion, in combination with a fracture of the distal phalanx due to enchondroma. The bone lesion was curated and grafted using autogenous bone harvested from the ipsilateral radius. The FDP tendon was reattached to the distal phalanx using the pullout transosseous technique. Delayed protected active mobilization was used to treat the repaired tendon. According to the adjusted Strickland score, a good result was obtained and grip strength was similar between hands and PRWHE score was very low at 5 months from surgery. Early diagnosis leads to a fast surgery with good functional mobility and pain outcomes. If closely monitored by an experienced medical team, as this case demonstrates, an attempt to treat the benign tumor with a curettage, bone filling and reattachment of the tendon through the pullout technique in young motivated patients can be an alternative.

High‐Performance Flexible Pressure and Temperature Sensors with Complex Leather Structure

AbstractThe ability of the skin to be pressure‐sensitive has prompted scientists to develop materials and equipment to simulate this function. Recently, flexible and stretchable artificial electronic skin has received increasing attention with its unique ability to detect subtle pressure changes. Pressure sensing is one of the key functions of electronic skin devices. Here, a stretchy and highly sensitive pressure sensor is developed that used a polydimethylsiloxane (PDMS) film with leather composite layer as flexible part. These features enable the sensor to accurately detect a variety of human activities, such as small finger movements and bending, pulse and so on. The sensor is found to have a good sensing signal for temperature. This feature provides great promise for sensors to detect temperature.

Small Finger Abduction Test to Evaluate the Flexor Carpi Ulnaris Tendon.

We describe a simple and effective method to assess the integrity of the flexor carpi ulnaris muscle and tendon. This method is called the Small Finger Abduction Test. The study also evaluates the efficacy and practicality of the test.Level of Evidence: Level II.

Outcomes After Flexor Tendon Injuries in the Pediatric Population: A 10-Year Retrospective Review.

Background: Pediatric outcomes after flexor tendon repairs are variable, and evidence in the literature remains scarce. Methods: Repair of pediatric flexor tendon injuries was reviewed over a 10-year period (2005-2015). Data collection consisted of patient demographics, injury characteristics, anesthetic choice, repair technique, rehabilitation protocol, American Society for Surgery of the Hand Total Active Motion (TAM) scores, and complications. Results: There were 109 patients included in our study, with a total of 162 digits injured and 235 flexor tendon injuries. The mean age was 12 ± 4.6 years. The small finger (48 of 162; 30%) and the flexor digitorum profundus tendon (126 of 235) were the most commonly injured. The mechanism of injury was mainly from a knife (46 of 109; 42.2%) in zone II (82 of 159; 52%). Injuries were mostly repaired under general anesthetic (61 of 104; 56%). The Kessler technique was the predominant repair mechanism (111 of 225 repairs; 49%). Most patients (103 of 109; 95%) had excellent or good TAM scores with 5 postoperative ruptures reported. The most common complication was stiffness (17 of 121 complications; 14%), with most patients having no complications ( 74 of 109 patients; 68%). Patients were commonly immobilized (mean 8.4 ± 10.3 weeks) with a splint (93 of 109; 85%). There were 85 patients who followed a postoperative rehabilitation protocol for 12 ± 18 weeks. Patient demographics, time of repair, injury characteristics, anesthetic choice, and rehabilitation protocol were not significantly correlated with TAM scores or complication rates. Conclusions: Pediatric tendon injuries have good outcomes with no predictive factors identified. Surgical repairs performed under local anesthetic have similar outcomes without increased rates of complications, but remain underused in the pediatric population.

Экспериментальная оценка прочности склеивания древесины по длине на прямоугольные прессованные шипы

Commercialization of the new splicing method requires confirmation of its high quality. The main quality indicator of adhesive joint is its strength. The aim of the study is an experimental evaluation of the bending strength and tensile strength of end joints with rectangular pressed fingers (case study of pine wood blanks). The joints of two types: A and B, with a pitch of 4.2 and 8.2 mm and depth of mortises of 10 and 20 mm, respectively, were studied. The strength of the samples was determined taking into account the requirements of the Russian State Standards GOST 15613.4 and GOST 15613.5. In order to evaluate the quality of joints, we used the indicator “relative strength”; it is the ratio of the joint strength to the solid wood strength. Statistical processing was carried out both by data groups, and for each size and each test type separately. This allowed us to establish the average values of strength for each individual group of samples, as well as to obtain a statistically valid joint evaluation of some indicators. Joints of type A with small fingers showed better results in tensile strength (59.5 %) compared to joints of type B (53.2 %). No statistically significant effect of the joint type was revealed, when processing the results of bending tests in the studied range. Therefore, the average bending strength (80.2 %) characterizes both types of joints. Moreover, the strength of these two types of joints with sufficient reliability can be characterized by the average tensile strength (56.4 %). At the same time, both types of joints correspond in strength to the standard requirements to the products with adhesive end joints. The test results vary in a relatively narrow range, which indicates a stable quality of adhesive joints with rectangular fingers made by pressing. This study demonstrates the possibility of using rectangular pressed fingers for the manufacture of joints based on them.For citation: Rubleva O.A., Gorokhovsky A.G. Experimental Evaluation of Strength of End Joints with Rectangular Pressed Fingers. Lesnoy Zhurnal [Russian Forestry Journal], 2020, no. 3, pp. 128–142. DOI: 10.37482/0536-1036-2020-3-128-142

Abstract 100: Restoration Of Proprioceptive And Cutaneous Sensation Using Regenerative Peripheral Nerve Interfaces (RPNIs) In Humans With Upper-limb Amputations

Purpose: Without meaningful and intuitive sensory feedback, even the most advanced prosthetic devices remain insensate, burdensome, and are associated with enormous cognitive demand. To provide a bidirectional motor and sensory neural interface, we have developed the Regenerative Peripheral Nerve Interface (RPNI). An RPNI consists of a free muscle graft that is reinnervated by a transected peripheral nerve. In previous human studies, RPNI’s have demonstrated stable high amplitude motor EMG signals with high signal to noise ratio for prosthetic control, and have been used to treat and prevent neuroma pain. In this study, we investigate if applying electrical stimulation through the RPNIs can produce meaningful proprioceptive and/or tactile sensations in participants with upper-limb amputations. Materials and Methods: Two distal transradial participants underwent surgical implantation of RPNIs for treatment of neuroma pain. One RPNI was created on each of the median and ulnar nerve for participant 1, while participant 2 had two RPNIs created on the ulnar nerve and one on the median nerve. The RPNIs were stimulated with a monopolar, charge balanced, biphasic square wave using intramuscular bipolar electrodes. To determine the sensory perception threshold, a stepwise increment of 0.1 mA was used at a constant 20 Hz frequency and 200 µS pulse-width. Stimulation lasted for 1 to 2 seconds for each increment. After each increment, participants were asked to report the sensations they felt. Once a sensation was felt, the amplitude was decremented until the sensation stopped, and then increased until a sensation was felt again. Amplitudes were then marked as the perception threshold. After a threshold was determined, amplitudes were increased until participants could clearly perceive the sensation. Participants then reported the location of the sensation on their phantom limb using their contralateral intact hand, and a description of the invoked sensation. Results: Stimulation of the RPNIs resulted in both participants reporting proprioceptive sensations in their phantom limb. In particular, stimulation of the median nerve RPNI activated a flexing sensation in the thumb or index finger of participant 1, while stimulation of the ulnar nerve RPNI invoked a flexing sensation of the ring or small finger. Likewise, during stimulation of ulnar nerve RPNI 1, participant 2 felt a flexed sensation at the ring finger distal interphalangeal (DIP) joint, specifically describing that only the DIP joint was being flexed on the phantom ring finger. Stimulation of the ulnar nerve RPNI 2 and the median nerve RPNI resulted in cutaneous sensations that corresponded to the dermatome of their respective nerve. Sensory stimulation thresholds remained stable across 7 and 11 months with an average amplitude of 1.27 ± 0.52 mA for participant 2, and 0.98 ± 0.04 mA for participant 1, respectively. Conclusions: These results suggest that RPNIs have the potential to restore proprioceptive and skin-referred sensory feedback that could improve prosthesis motor performance, producing a stable bidirectional interface for advanced prosthesis control.

Abstract 118: Targeted Muscle Reinnervation In The Hand: An Anatomical Study For Identification Of Target Motor Entry Points

Purpose: Targeted muscle reinnervation has emerged as a treatment for and prevention of symptomatic neuromas and may be beneficial in the hand. Anatomic studies establishing feasibility in the hand or landmarks to identify the motor entry points to the intrinsic muscles have not been performed. The purpose of this study was to provide details regarding the motor entry points to the intrinsic muscles, determine which motor entry points are identifiable dorsally, and develop recommended sensory to motor entry point nerve coaptations for prophylactic TMR at the time of ray amputation or for management of symptomatic neuromas. Methods: Motor entry points to the intrinsic hand muscles were dissected in five fresh latex-injected cadavers. Number of motor entry points, diameter, surface of entry, and distance from dorsal (Lister’s tubercle) and volar (hamate hook) landmarks was recorded for each target muscle. The digital sensory nerve diameters were measured for size comparison. Results: Motor entry points were identified to all nineteen intrinsic muscles through a volar approach and twelve muscles through dorsal approach. For all fingers there were at least two motor entry points consistently identified dorsally at the base of each amputation site innervating expendable muscles. Motor entry points to the thenar muscles were only reliably identified through a volar approach. Two recommended nerve coaptations for each digit amputation were identified. All had favorable sensory:MEP diameter ratio of less than 2:1. Recommended targets for index finger amputation include transfer of the radial digital nerve to the MEP to first dorsal interossei (1.46mm average diameter, 62.69% distance from Lister’s tubercle to the metacarpophalangeal joint of amputated finger; sensory:MEP diameter ratio of 1.32) and ulnar digital nerve to first palmar interossei (0.98mm, 58.32%; 1.69). The long finger radial digital nerve is best coapted to the MEP for second dorsal interossei (1.26mm, 60.11%; 1.48) and ulnar digital nerve to third dorsal interossei (1.26mm, 57.41%; 1.24). Ring finger ideal targets include the radial digital nerve to the MEP for fourth dorsal interossei (1.22mm, 62.75%; 1.46) and ulnar digital nerve to third lumbrical (1.12mm, 81.62%; 1.5). Lastly, the ideal target for the small finger radial digital nerve is to the MEP for third palmar interossei (0.76mm, 64.11%; 1.95) and ulnar digital nerve to fourth lumbrical (0.9mm, 82.04%; 1.71). Conclusion: Targeted muscle reinnervation is feasible to be performed in the hand. The intrinsic muscles have motor entry points found at consistent distances from bony landmarks both dorsally and volarly. These results can be applied clinically to assist surgeons in identifying the locations of motor entry points to the intrinsic muscles when performing targeted muscle reinnervation in the hand for both neuroma treatment and prevention.

Morphologic changes of the fifth phalange secondary to smartphone use.

The use of smart phones is now part of the daily routine throughout the world. Morphological alterations have been described associated with telephone holding technique, as well as clinically significant alterations related to their use. The objective was to determine the macroscopic morphological changes due to smartphone use in the fifth finger of the hand with which the smartphone is commonly used. University students were invited to participate. Photographs of the dorsal region of both hands were taken using a millimeter paper as background. After calibrating the ImageJ software, photographs were analyzed in pairs obtaining areas of asymmetry. Sociodemographic information and technique of use was collected through a survey. The data were analyzed using SPSS ver. 20. A total of 143 participants were included. The mean age was 20 years. No significant differences were found between the area of asymmetry and the miniferet of both fingers of the subjects compared with age, gender, BMI, daily time of use, years using a smartphone or the type of holding technique. No asymmetric changes were evident between left and right small fingers in relation to the holding technique of a smartphone in a young adult population.

Polydactyly a review and update of a common congenital hand difference.

The purpose of this review is to describe various forms of hand polydactyly and their different treatment approaches. Hand polydactyly is commonly classified as ulnar (small finger) or radial (thumb). Polydactyly can be sporadic, genetic, and/or associated with syndromic conditions. Both ulnar and radial polydactyly can be surgically treated to optimize hand aesthetics and function. Timing of surgery is based on multiple factors, most notably including safety of anesthesia and socialization of the affected child. The pediatrician should be aware of potential associated conditions, such as chondroectodermal dysplasia or Ellis-van Creveld syndrome for ulnar polydactyly. Polydactyly is a common congenital hand difference and can be broadly be classified by radial or ulnar involvement. Polydactyly warrants hand surgical referral, as surgical treatment is often indicated. Pediatricians should be aware of treatment options, as well as of commonly associated anomalies and syndromes.

P601 Development and validation of dried blood spot sampling as a tool to identify the best time point to measure predictive ustekinumab serum concentrations in patients with Crohn’s disease

Abstract Background Therapeutic drug monitoring of ustekinumab (UST), a monoclonal antibody directed against the p40 subunit of IL12/23, can serve as a tool to identify underexposed Crohn’s disease (CD) patients, as UST concentrations have been linked to treatment response. Drug concentrations are most often measured when a patient is losing response. To reduce the risk of loss of response, drug concentrations could be measured upfront to predict the chance of achieving response later on and optimising treatment if necessary. Identification of the optimal time point to measure UST levels that have a predictive value for long-term outcome requires studies with multiple sampling. Dried blood spot (DBS) sampling allows convenient and remote collection of a blood drop through a small finger prick. The current study aimed to develop and validate the DBS method in order to identify the best time point to measure UST concentrations to predict long-term outcome in CD patients and explore the pharmacokinetic profile. Methods UST concentrations (0.2–80 μg/ml) were spiked in citrated whole blood and 40 μl was spotted onto protein saver cards. After punching a 6mm disc, DBS was extracted and the UST concentration was measured with an in-house developed MA-UST56A2D11/MA-UST56C1H12 ELISA. The extraction efficiency, accuracy, precision and the effect of anti-UST antibodies on UST detection were evaluated. Additionally, the effect of the spotted blood volume, the stability of the DBS card at room temperature (RT) and DBS extract at -20°C was examined. To evaluate the correlation between UST in DBS extracts and serum, DBS and serum were simultaneously collected from 8 UST-treated CD patients at two different time points. Results Spiking UST to citrated whole blood and subsequent spotting and extraction revealed an average extraction efficiency of 65 ± 9% (n = 11). The accuracy and imprecision of all concentrations tested were 92–109% and 11–18%, respectively. Addition of anti-UST antibodies to spiked UST samples caused a similar decrease in UST concentration in DBS extracts as in serum. Spotted blood volumes between 15 and 50 μl demonstrated similar recoveries. Storing the DBS card at RT for up to 2 weeks and DBS extract at -20°C for 2 months did not impair recovery. UST concentrations in DBS extracts (range: 0.55–12.1 μg/ml) from CD patients correlated strongly with those in serum (Pearson r = 0.982, p < 0.0001). Conclusion DBS is a robust method that facilitates multiple sampling for the determination of UST concentrations in CD patients. To explore the pharmacokinetic profile of UST and identify the best time point during induction to predict the long-term outcome, a prospective study in which multiple DBS are collected in active CD patients initiating UST is warranted.

Morphometric Assessment of the Residual Width of the Distal Hamate Articular Surface after Graft Harvest for Hemi-hamate Arthroplasty.

The hemi-hamate arthroplasty (HHA) can restore joint congruity and stability in chronic fracture-dislocations of the proximal interphalangeal joint (PIPJ). Purpose of this study was to compare the width of the distal hamate articular surface (DHAS) to the width of the base of the middle phalanges (P2) of the fingers. We hypothesized the dimensions of the width of the DHAS would be similar to those of P2, leaving a small amount of residual DHAS width after autograft harvest. Fifty-nine CT scans of the hand without any bony pathology were evaluated. Three observers measured the following parameters and compared: (a) Width of the DHAS in the axial and coronal planes; (b) Width of the P2 articular bases of all four fingers; (c) Maximum capitate length (MaxCap) in the coronal plane. The residual DHAS on the coronal plane after graft harvest (bone remaining on the radial and ulnar aspects each, not accounting for saw blade or osteotomy width thickness) among all patients was 1.3, 0.9, 1.4, and 2.4 mm for the index, long, ring and small fingers respectively. There was a strong correlation between DHAS and MaxCap r=0.76. There is likely to be a very small amount of residual hamate articular surface width left after the graft is harvested if the entire base of P2 is reconstructed.

Demonstrator of a Low-Cost Hand Prosthesis

Upper limb absence has an impact on both physical and mental health of a human being. Nowadays, the costs of commercial, externally powered prosthetic hands range between 25.000 € and 70.000 €. A first demonstrator of a lightweight low-cost prosthetic hand is produced with 3D-printing technology (Fused Deposition Modeling). Due to integration of single-axis solid-state joints the five fingers can be printed in one piece. Thermoplastic polyurethane is used for this purpose. The flexion of all fingers is achieved by moving cords which are positioned on the palmar side of each finger. Two twisted string actuators are integrated to allow the movement of the thumb and the remaining four fingers. These actuators consist of two polyethylene strands which are twisted along their main axis by a DC motor, providing a tensile force to bend the fingers. In order to achieve simultaneous but differential actuation of the four fingers (small finger, ring finger, middle finger and index finger), a differential mechanism is used. The thumb is driven by a separate unit. In order to open the hand, the elasticity of the joints’ material is taken advantage of. With the developed mechanics it is possible to perform precision and cylindrical grasps with an opposed thumb. Weights up to 260 g can be held according to the shape and size of an object. To increase the adaption to different sizes and weights of objects, the design should be modified. It can be concluded, that the presented device is a promising basis for a lightweight, low-cost prosthetic hand in the future.

Quantitative examination of isolated finger flexion associated with function of the flexor digitorum superficialis.

[Purpose] Isolated finger flexion associated with function of the flexor digitorum superficialis has been qualitatively assessed using standard and modified tests. The purpose of this study was to quantify isolated finger flexion in healthy participants. [Participants and Methods] We assessed 100 volunteers (mean age: 44.6 years) without upper limb dysfunction using the standard and modified flexor digitorum superficialis tests. The sum of the isolated active flexion angles of the metacarpophalangeal and proximal interphalangeal joints of the test finger was also calculated, with the other three fingers held in an extended position with our original jig. [Results] The mean isolated flexion angles were, respectively, 152.4° and 154.8° for the right and left index fingers, 161.1° and 160.4° for the middle fingers, 160.6° and 158.2° for the ring fingers, 129.4° and 134.6° for the independent flexor digitorum superficialis function, 85.8° and 74.7° for the common flexor digitorum superficialis function, and 75.8° and 71.2° for absent flexor digitorum superficialis function in the small finger. The functional variations of the flexor digitorum superficialis of the small fingers showed symmetry in 65.0% of the fingers but asymmetry in 35.0%. [Conclusion] The data obtained in this study provide normal reference values for the examination of independent movement disorders of the fingers.

Schaaf-Yang Syndrome: An Example of Genomic Imprinting and Expanding Phenotype

Schaf-Yang Syndrome is a rare genetic condition, produced by a mutation in the MAGEL2 gene, located at the level of chromosome 15, in the Prader-Willi Syndrome region, with which it shares some physical similarity. The phenotype is variable and ranges from fetal akinesia to an important neurobehavioral phenotype and contractures of the small finger joints that are very characteristic. The gene has a maternal imprint and the phenotype will only be expressed when the mutated allele has been transmitted parentally. We present the case of a 2-and-a-half-year-old male from Ecuador, whose most prominent signs were in the beginning a marked macroglossia that gave a certain rough facial appearance, as well as bilateral camptodactyly of the 3rd and 4th fingers. The history of a previous sister who died at age 8 with a diagnosis of hypothyroidism, and clinical similarity to this new baby, led the clinical orientation to the screening of a potentially autosomal recessive condition. The genetic tests performed as part of the differential diagnosis where to pathologies such as Becwith-Wiedeman Syndrome, Mucopolysaccharidosis and Congenital Hypothyroidism. The clinical elements of this case are compared with those described in the literature with this rare genetic syndrome, and the clinical evolution of dysmorphic patterns in young children is emphasized in order to achieve a better diagnostic certainty. We emphasize the features of macroglossia as a probably expanding phenotype in this rare condition. The presentation of this clinical case shows that the factors that alter the segregation of simple mutations such as the case of the genetic imprint, found in this patient, constitute an event that hinders the interpretation of inheritance patterns and should always be taken into account in genetic counseling.

Progressing Flexion Deformity of the Middle, Ring, and Small Fingers With a Rare Congenital Anatomic Difference of Flexor Digitorum Profundus.

A flexion deformity caused by a congenital anomaly of the flexor digitorum profundus (FDP) of the middle, ring, and small fingers is extremely rare, and it has previously been described only in isolated case reports. Hence, there has been no consensus with regard to the clinical presentation, etiology, and treatment. We retrospectively analyzed our 10 cases (5 male individuals and 5 female individuals) for congenital FDP abnormalities. We obtained radiography, computed tomography, and magnetic resonance imaging on our patients. Nerve studies were performed in 7 of 10 patients, except for 3 patients below 5 years of age who were unable to co-operate. We used the grading criteria (Wang classification) to evaluate the restricted extension of the affected fingers and the active flexion function. An abnormal fibrous cord was seen intraoperatively in the proximal part of the belly of the FDP that was destined for the affected fingers. It originated from a bony prominence on the proximal part of the ulna. On resection of the aberrant cord, extension of the affected fingers was immediately improved. Pathologic examination of the removed aberrant cord revealed dense fibrous connective tissue. Nerve conduction studies and electromyography revealed that there was no substantial damage to the median and/or ulnar nerves. Plain radiography revealed no bone or joint anomalies. Computed tomography showed a slight bony prominence at the proximal part of the ulna. However, magnetic resonance imaging indicated a demonstrably abnormal fibrous cord in the FDP that originated from a bony prominence at the proximal part of the ulna and extended toward the middle, ring, and small fingers. On the basis of the Wang classification criteria for functional evaluation, 7 were moderate, and 3 were severe. Patients were followed-up for 2 to 36 months with a mean follow-up of 16 months. The postoperative outcomes were excellent in 8 cases and fair in 2 cases. The flexion and extension functions were regained, and there was no relapse of deformity. On the basis of its pathologic features, we recommend that this condition be treated by resection of the abnormal cord. Level IV.