Digital Joints Research Articles

Prosthetic design directives: Low-cost hands within reach.

Although three million people around the world suffer from the lack of one or both upper limbs 80% of this number is located within developing countries. While prosthetic prices soar with technology 3D printing and low cost electronics present a sensible solution for those that cannot afford expensive prosthetics. The electronic and control design of a low-cost prosthetic hand, the Touch Hand II, is discussed. This paper shows that sensorless techniques can be used to reduce design complexities, costs, and provide easier access to the electronics. A closing and opening finite state machine (COFSM) was developed to handle the actuated digit joint control state and a supervisory switching control scheme, used for speed and grip strength control. Three torque and speed settings were created to be preset for specific grasps. The hand was able to replicate ten frequently used grasps and grip some common objects. Future work is necessary to enable a user to control it with myoelectric signals (MESs) and to solve operational problems related to electromagnetic interference (EMI).

Fully automated joint space width measurement and digital X-ray radiogrammetry in early RA

ObjectivesTo study fully automated digital joint space width (JSW) and bone mineral density (BMD) in relation to a conventional radiographic scoring method in early rheumatoid arthritis (eRA).MethodsRadiographs scored by the...

Digital Joint Reconstruction with Osteotendinous Joint Allograft: Experimental Study in Rats.

Background:Fresh or frozen nonvascularized osteotendinous joint allografts (OTJA) have not been used previously, clinically or experimentally, for metacarpophalangeal joint reconstruction. Therefore, we evaluated the viability of OTJA for metatarsophalangeal joint (MTJ) reconstruction in rats.Methods:In the experimental group of 12 Lewis rats, we reconstructed the MTJ of the third digit of the hindlimb with a fresh, nonvascularized OTJA obtained from the same digit from 12 donor rats. In the control group of 6 Lewis rats, an autologous composite osteotendinous graft of the MTJ of the same digit was obtained and repositioned in situ as an auto-transplant. Weight, pain, edema, dehiscence, and wound infection were evaluated every 24 hours for 30 days postoperatively. At the end of 30 days, we evaluated digit position, flexion and extension, passive mobility, radiological bone healing, and histological grades of rejection.Results:We found no statistically different changes in weight, edema, pain, digit position, or radiological bone healing in either group. No wound dehiscence or infection was seen in any of the rats. Ten degrees of flexion and extension mobility were lost in the control group; the experimental group lost up to 30 degrees (P = 0.009). Histologically, 9 of the experimental group rats (9/12, 75%) showed rejection reactions compared with none of the controls (0%) (P = 0.009).Conclusions:Fresh nonvascularized OTJA caused an immune reaction without exposure of the graft, but with bone resorption. However, the rats maintained digital form and alignment with decreased passive flexion and extension of 10–30 degrees.

ISOLATION AND CHARACTERIZATION OF A NOVEL MARINE BRUCELLA FROM A SOUTHERN SEA OTTER (ENHYDRA LUTRIS NEREIS), CALIFORNIA, USA.

We characterize Brucella infection in a wild southern sea otter ( Enhydra lutris nereis) with osteolytic lesions similar to those reported in other marine mammals and humans. This otter stranded twice along the central California coast, US over a 1-yr period and was handled extensively at two wildlife rehabilitation facilities, undergoing multiple surgeries and months of postsurgical care. Ultimately the otter was euthanized due to severe, progressive neurologic disease. Necropsy and postmortem radiographs revealed chronic, severe osteoarthritis spanning the proximal interphalangeal joint of the left hind fifth digit. Numerous coccobacilli within the joint were strongly positive on Brucella immunohistochemical labelling, and Brucella sp. was isolated in pure culture from this lesion. Sparse Brucella-immunopositive bacteria were also observed in the cytoplasm of a pulmonary vascular monocyte, and multifocal granulomas were observed in the spinal cord and liver on histopathology. Findings from biochemical characterization, 16S ribosomal DNA, and bp26 gene sequencing of the bacterial isolate were identical to those from marine-origin brucellae isolated from cetaceans and phocids. Although omp2a gene sequencing revealed 100% homology with marine Brucella spp. infecting pinnipeds, whales, and humans, omp2b gene sequences were identical only to pinniped-origin isolates. Multilocus sequence typing classified the sea otter isolate as ST26, a sequence type previously associated only with cetaceans. Our data suggest that the sea otter Brucella strain represents a novel marine lineage that is distinct from both Brucella pinnipedialis and Brucella ceti. Prior reports document the zoonotic potential of the marine brucellae. Isolation of Brucella sp. from a stranded sea otter highlights the importance of wearing personal protective equipment when handling sea otters and other marine mammals as part of wildlife conservation and rehabilitation efforts.

The architectural and functional specifications of intrinsic muscles of the fore limb of the Egyptian Baladi goats (Capra hircus)

This study provides quantitative anatomical data on the muscle–tendon units of intrinsic muscles of the fore limb of the domesticated goat specifically; muscle mass, volume, fascicle length, tendon mass, tendon volume, and tendon rest length. From these measurements, the physiological cross sectional area (PCSA) and maximum isometric force (Fmax), in addition to tendon stress and tendon strain were calculated for each muscle. A total of 180 muscles (60 from each cadaver; 30 in each limb) were dissected to examine each muscle functional specifications and their role in limb function. The largest muscle mass was revealed to have the largest volume, long fascicle length and the highest capacity for force production. Within the functional groups of muscles, the proportion of muscle mass, muscle volume, PCSA as well as force generation was the greatest for the shoulder flexors followed by shoulder extensors. This is suitable for their role in weight bearing. The muscles working on joints of digits were having long tendons with high cross section area (CSA) and architecture index (AI) and thus were functionally suited to elastic energy storage needed for digital movement. In conclusion, architecture properties are crucial factors for determination of muscle function.

Transplantation of free proximal interphalangeal joint of the second toe with toe preservation for repair of traumatic digital arthritis

Objective To evaluate the clinical outcome of reconstruction of traumatic digital arthritis by transfer of free proximal interphalangeal joint of the second toe with toe reserving technique. Methods The study enrolled nineteen patients with traumatic digital arthritis treated from May 2013 to April 2016. The patients consisted of fifteen males and four females, and mean age was 27.3 years (range, 18-52 years). Finger involved included index fingers in 10 patients, middle fingers in seven and ring fingers in two. The joint of digit was reconstructed by transplanting the proximal interphalangeal joint of the second toe with a monitoring flap, and bone defect of the second toe was repaired with autogenous iliac bone graft. Wound was closed directly in six patients and covered by island flap from the foot dorsum in 13 patients. Evaluation indicators contained survival rate of the free joint and island flap, appearance and fracture healing of the finger and toe and motion of the proximal digital joint. Finger function was studied using the evaluation standard of upper limb function set up by hand surgery branch of Chinese Medical Association. Healing in the donor site, foot function and related complications were observed. Results All the free joint and island flap survived. Period of follow-up was 6-30 months (mean, 14 months). The fractured finger healed at 2.5 months on average, and appearance of the finger was good. Flexion range of the proximal digital joint was 63°-80°(mean, 74°) and extension range was -20°--10°(mean, -14°). Finger function was excellent in eleven patients and good in eight patients, with the excellent-good rate of 100%. Hematoma of the dorsal region of the foot occurred in one patient and the cut healed well after taking out some stitches and drainage. All fractured toe healed at 2.6 months. Except that one patient had fracture malunion with minor outward inclination, all presented good appearance of the toe without influencing walking and running. On the part of iliac, there was only one inconspicuous linear scar without any discomfort. Conclusions Transfer of free proximal interphalangeal joint of the second toe with toe preservation restores the anatomy structure and function of the digital joint. Meantime, autogenous iliac bone grafting combined with island flap from the foot dorsum for coverage of donor site defect retains the toe length and reduces injury of the donor site. Key words: Finger joint; Arthritis, traumatic; Toe phalanges; Bone transplantation

An interdigit signalling centre instructs coordinate phalanx-joint formation governed by 5'Hoxd-Gli3 antagonism.

The number of phalanges and joints are key features of digit ‘identity' and are central to limb functionality and evolutionary adaptation. Prior chick work indicated that digit phalanges and their associated joints arise in a different manner than the more sparsely jointed long bones, and their identity is regulated by differential signalling from adjacent interdigits. Currently, there is no genetic evidence for this model, and the molecular mechanisms governing digit joint specification remain poorly understood. Using genetic approaches in mouse, here we show that functional 5′Hoxd–Gli3 antagonism acts indirectly, through Bmp signalling from the interdigital mesenchyme, to regulate specification of joint progenitors, which arise in conjunction with phalangeal precursors at the digit tip. Phalanx number, although co-regulated, can be uncoupled from joint specification. We propose that 5′Hoxd genes and Gli3 are part of an interdigital signalling centre that sets net Bmp signalling levels from different interdigits to coordinately regulate phalanx and joint formation.

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.

Predictable Pattern Digital Artery Perforator Flap: An Alternative Concept in Digital Reconstruction.

The proper digital arteries as any other axial vessel give rise to multiple cutaneous perforators either volar or dorsal along their course. Their identification is performed with Doppler flowmetry. The vasculo-cutano-tendino-osseous complex (VCTOC), which was described by the senior authors, was responsible for the vascularization of all digital anatomic structures (extensor apparatus, skin, periosteum). Their consistent appearance to well measured distances from the digital joints led the way to the present clinical study for highlighting this described anatomy in-vivo and demonstrating the predictability in digital artery perforator (DAP) flap harvest. From November 2012 to March 2014, fifteen patients underwent reconstruction with a predictable pattern digital artery perforator flap (PPDAP), based on the previously described VCTOC mapping, for digital lesions secondary to tumor extirpation. Flaps were designed as V-Y advancement or propeller type. Postoperative control concerned flap viability and digital function. Seven males and 8 females underwent elective surgery using PPDAP flaps for digital defects following tumor extirpation. The diameter of the defect ranged from 0.5 to 1.5 cm. The vast majority of the lesions were identified on the right hand, the index, the ring finger and the distal phalanx. All flaps survived without signs of venous congestion. No functional digital problems were observed during follow up (mean of 77 months). A minor wound dehiscence presented in one patient. Authors introduced the concept of a "predictable pattern" in the surgery of perforator flaps in the digits. These flaps are reliable and could be a valuable reconstructive option.

Treatment of 63 Subjects With Digital Mucous Cysts With Percutaneous Sclerotherapy Using Polidocanol.

Digital mucous cysts (digital myxoid cysts or DMCs) are benign cystic swellings typically affecting the digital distal interphalangeal joint or the proximal nail fold. Many treatment modalities exist; however, permanent scarring, wound infection, and recurrence are common. Polidocanol sclerotherapy has been reported as a potential treatment. To assess the efficacy and safety of percutaneous polidocanol sclerotherapy in the treatment of DMC. The authors performed polidocanol sclerotherapy in 63 patients (23 men and 40 women). For each patient, the DMC contents were extruded and 3% polidocanol (0.02-0.5 mL) was injected to gently refill the cyst to its previous size. Subjects were reviewed after 6 weeks and offered a second treatment if necessary, and reviewed again after 12 weeks. Changes in lesions and adverse reactions were noted. Of the 63 subjects treated, 43 (68.3%) experienced complete resolution of the cyst by 6 weeks, and 49 (77.8%) experienced complete resolution by 12 weeks. Side effects were minor and had resolved in all patients by 12-week review. Percutaneous polidocanol sclerotherapy is a simple, safe, and effective approach to treating DMC, and is suitable for office-based practice.

Biomechanics of Front and Back-of-Tablet Pointing with Grasping Hands

Considering the kinematic model of the hand allows for deeper understanding of target selection on the front and on the back of tablets. The authors found that the position where the thumb and fingers are naturally hovering when the device is held results in shortest target selection times. The authors broaden our understanding of that ergonomic optimum by analyzing the touch data as well as 3D data. That allows us to model the entire hand pose including finger angles, thumb angles, and orientation. The authors show how target acquisition with grasping hands is realized through bending the joints of the digits. For targets located very close to the palm of the grasping hand, the digit joints have to be bent till their limit, which is a less ergonomic motion that therefore requires longer selection times than pointing at targets with relaxed digits that are further away.

An Assessment of 2 Objective Measurements of Web Space Position

To describe 2 simple objective clinical methods of measuring the web position between fingers and to determine their intra-observer and inter-observer reliabilities. Two observers examined the second, third, and fourth web spaces on both hands of 30 adult healthy volunteers. The web index measured the web height as a relative ratio to constant anatomical landmarks on both fingers subtending the web. The dorsal web index took reference from the distance between the metacarpophalangeal and proximal interphalangeal joints, whereas the palmar web index was measured in relation to the distance between the most proximal basal digital and proximal interphalangeal joint creases. The intraclass correlation coefficient was used to determine intra-observer and inter-observer reliability. Intraclass correlation coefficient values for intra-observer and inter-observer reliability were greater than 0.80, indicating excellent agreement. There was no statistically significant difference between the dorsal or palmar measurement methods in terms of reliability. The dorsal or palmar measurement method may be reliably used in healthy adults to establish a web index that describes the web position. The palmar method is considered easier to perform. Diagnostic III.

Digit mechanics in relation to endpoint compliance during precision pinch

This study investigates the mechanics of the thumb and index finger in relation to compliant endpoint forces during precision pinch. The objective was to gain insight into how individuals modulate motor output at the digit endpoints and joints according to compliance-related sensory feedback across the digits. Thirteen able-bodied subjects performed precision pinch upon elastic resistance bands of a customized apparatus instrumented with six degree-of-freedom load-cells. Compliance levels were discretely adjusted according to the number of bands connected. Subjects were provided visual feedback to control the rate of force application. Fifteen repetitions of low-to-moderate force (<20N) pinches were analyzed at each of five compliance levels, during which force and motion data were collected. Joint angles and moments normalized by pinch force magnitude were computed. Second-order polynomials were used to characterize joint mechanics as a function of compliance. The joint degrees-of-freedom (DOFs) at the finger showed greater dependence on compliance for angular position while the thumb joint DOFs demonstrated greater dependence for normalized joint moment. The digits also adjusted coordination of their endpoint forces according to compliance. Overall, the finger may be altering its position to increase load to the joints of the thumb with changing compliance. These findings describe naturally emergent changes in digit mechanics for compliant precision pinch, which involves motor execution in response to endpoint sensory feedback. Identifying and understanding these motor patterns may provide theoretical basis for restoring and rehabilitating sensorimotor pathologies of the hand.

Range of movement in ray I of manus and pes and the prehensility of the autopodia in the Early Permian to Late Cretaceous non-anomodont Synapsida.

The mobility of ray I was analysed in seventy-eight Early Permian to Late Cretaceous specimens of non-mammalian Synapsida and one extant mammal. In all non-mammaliamorph Synapsida investigated, ray I formed a digital arcade. The first phalanx was maximally extendable to the zero position in the metapodiophalangeal joint I. Metapodiale I was the functional equivalent to a basal phalanx of digits II–V. In contrast, there was no digital arcade in ray I in Mesozoic Mammaliamorpha. Phalanx 1 I was dorsally extendable and metapodiale I was functionally part of the metapodium. During the propulsion phase, autopodial rotation occurred in the majority of Synapsida with abducted limb posture. Regarding ray I, the reduction of autopodial rotation can be estimated, e.g., from the decrease of lateral rotation and medial abduction of the first phalanx in the metapodiophalangeal joint I. Autopodial rotation was high in Titanophoneus and reduced in derived Cynodontia. In Mammaliamorpha the mobility of the first ray suggests autopodial rolling in an approximately anterior direction. Most non-mammaliamorph Therapsida and probably some Mesozoic Mammaliamorpha had prehensile autopodia with an opposable ray I. In forms with a pronounced relief of the respective joints, ray I could be opposed to 90° against ray III. A strong transverse arch in the row of distalia supported the opposition movement of ray I and resulted in a convergence of the claws of digits II–V just by flexing those digits. A tight articular coherence in the digital joints of digits II–V during strong flexion supported a firm grip capacity. Usually the grip capacity was more pronounced in the manus than in the pes. Prehensile autopodia of carnivorous Therapsida may have been utilized to hold prey while biting, thus helping to avoid fractures of the laterally compressed fangs.

Thoracic Limb Morphology of the Ring-tailed Lemur (Lemur catta) Evidenced by Gross Osteology and Radiography.

There is limited information available on the morphology of the thoracic limb of the ring-tailed lemur (Lemur catta). This study describes the morphology of the thoracic limb of captive ring-tailed lemurs evidenced by gross osteology and radiography as a guide for clinical use. Radiographic findings of 12 captive ring-tailed lemurs are correlated with bone specimens of three adult animals. The clavicle is well developed. The scapula has a large area for the origin of the m. teres major. The coracoid and hamate processes are well developed. The lateral supracondylar crest and medial epicondyle are prominent. The metacarpal bones are widely spread, and the radial tuberosity is prominent. These features indicate the presence of strong flexor muscles and flexibility of thoracic limb joints, which are important in arboreal quadrupedal locomotion. Furthermore, an ovoid ossicle is always seen at the inter-phalangeal joint of the first digit. Areas of increased soft tissue opacity are superimposed over the proximal half of the humerus and distal half of the antebrachium in male animals as a result of the scent gland. Knowledge of the morphology of the thoracic limb of individual species is important for accurate interpretation and diagnosis of musculoskeletal diseases.

(v) Ligament injuries of the hand

Abstract Ligamentous injuries of the digital joints of the hand can give rise to significant disability. While many can be managed conservatively, operative treatment is often necessary, particularly in complete ligamentous ruptures and late presenting cases. This article describes the management of the commoner and less common injuries.

Erbium-169 labeled hydroxyapatite particulates for use in radiation synovectomy of digital joints – a preliminary investigation

Abstract Erbium-169 [T 1/2 = 9.4 d, E β( max ) = 342 keV (45%) and 351 keV (55%), E γ = 110.5 KeV (0.0014%)] is the most preferred radionuclide for radiation synovectomy (RSV) of digital joints. Radiolabeled particulates of appropriate size, wherein the radionuclide is irreversibly attached to the preformed particles, offer distinct advantages as the radiopharmaceuticals for use in RSV over other radiotherapeutic agents in terms of minimal leakage of radioactivity from the joint cavity. Hyroxyapatite (HA) particles, regarded as one of the most suitable carrier moiety for radiosynoviortheses applications, have been envisaged for labeling with 169Er with an aim to developing an agent for RSV of digital joints. Erbium-169 was produced with a specific activity of 415 ± 23 MBq/mg and radionuclidic purity of 99.22 ± 0.17% (both at the end of bombardment) by thermal neutron irradiation of enriched (98.2% in 168Er) erbium target at a flux of ∼ 8 · 1013 n/cm2 s for 21 d. HA particles (1–10 micrometer size), synthesized in-house, were labeled with 169Er in high yield and radiochemical purity (&gt; 99%) using 5 mg of HA particulates at pH 7.5. The radiolabeled particulates showed excellent in vitro stability in normal saline and human serum. Biodistribution and imaging studies (using 171Er-HA) carried out in normal Wistar rats following intra-articular injection of 169Er-HA particulates in the knee joint showed near-complete retention of injected radioactivity within the synovial cavity with almost no activity leaching out to the other organs/tissue.

Arthrodesis of the Thumb Interphalangeal Joint and Finger Distal Interphalangeal Joints With a Headless Compression Screw

To study the results of using a small, headless compression screw (AcuTwist) for thumb interphalangeal (IP) joint and finger distal interphalangeal (DIP) joint arthrodeses. Between November 2007 and January 2012, 48 primary arthrodeses of the thumb IP joint or DIP joint in the other digits were performed in 29 consecutive patients with AcuTwist devices. Indications for arthrodesis included 19 cases of osteoarthritis in 25 fingers, 3 cases of lupus in 9 fingers, 2 cases of post-traumatic osteoarthritis in 2 fingers, and 1 case and finger each of acute trauma, neuromuscular disorder, postinfectious osteoarthritis, boutonniere deformity, and Dupuytren contracture. Charts were reviewed for clinical data, and radiographs were assessed for alignment and healing. Age averaged 59 years and follow-up averaged 12 months (range, 2-50 mo). Union occurred in 43 out of 46 fingers (94%). There were no cases of nail deformity, wound complications, tip hypersensitivity, or clinically notable malalignment. Three arthrodeses failed to fuse, including 2 asymptomatic nonunions and 1 fixation loss requiring revision with autograft. The complication rate was 9%. Distal digital joint arthrodesis with the AcuTwist resulted in a fusion rate of 94% with a complication rate of 9%. Our rate of fusion compares favorably with prior series using other methods of fixation. Therapeutic IV.

Open Data Institute/Institute of Direct and Digital Marketing joint event

Open Data Institute/Institute of Direct and Digital Marketing joint event

Open Versus Percutaneous Release for the Treatment of Trigger Thumb

The purpose of this retrospective study was to compare the outcomes and complications of conventional open surgical release and percutaneous needle release in the treatment of trigger thumb. The study comprised 87 patients with trigger thumb who were treated with either open pulley (n=52) or percutaneous (n=32) release between 2008 and 2011. All patients were reevaluated at a mean follow-up of 22.7±9.6 months (range, 9-44 months). Main outcome measures were the rate of recurrence, pain on movement or tenderness over the pulley, infection rate, digital nerve injury, tendon bowstringing, joint stiffness or loss of thumb range of motion, and patient satisfaction. The groups were statistically similar regarding age, sex, laterality, dominant side involvement, and trigger thumb grade on initial admission. At final follow-up, no patient had recurrence, tendon bowstringing, joint stiffness, or loss of thumb range of motion. No patients in the open pulley release group and 2 (5.7%) patients in the percutaneous release group had a digital nerve injury (P=.159). No statistical difference was found in the infection rate between groups (P=.354). A total of 98.1% of patients in the open pulley release group and 97.1% of patients in the percutaneous release group were satisfied with treatment (P=.646). Both techniques resulted in similar therapeutic efficacy, and the rate of potential complications was also statistically similar in each group. Although statistically insignificant, the authors believe that the 5.7% rate of iatrogenic digital nerve injury seen in the percutaneous release group is clinically significant and serious. Therefore, they advocate using open surgical release of trigger thumb.