Metacarpophalangeal Region Research Articles

Postcranial anatomy of Dsungaripterus weii (Pterosauria: Ornithocheiroidea) from the Lower Cretaceous of Wuerho, China

ABSTRACT Ornithocheiroidea was a globally diverse group of pterosaurs during the Cretaceous. However, well-documented ornithocheiroids are highly derived, hampering our understanding on the morphological evolution of this clade. Dsungaripterus weii Young, 1964 from the Lower Cretaceous Tugulu Group (Valanginian) of the Junggar Basin is an iconic early member of Ornithocheiroidea. Dsungaripterus is known from numerous three-dimensionally preserved specimens, ranging from isolated bones to partially articulated individuals. Here we provide a comprehensive description of the postcranium of Dsungaripterus. We find that Dsungaripterus has many autapomorphies in the postcranial skeleton parallelling its unique skull, including the asynchronous fusion between the sacrum and pelvis and a posterodorsal fossa of the humerus with a paper-thin bone wall. Dsungaripterus also displays some plesiomorphic features of Ornithoecheiroidea, for example, limb bones with relatively thick bone walls, variably reduced pneumatic features in cervical vertebrae and appendicular skeletons, absence of spinoprezygapophyseal and spinopostzygapophyseal ridges in middle-series cervical vertebrae, at least one metacarpal articulating with the distal syncarpal, and a distally displaced adductor ridge on the femur. Additionally, Dsungaripterus possesses some unexpected features possibly convergent with other members of Ornithocheiroidea. Although the postcranial skeletons of Dsungaripterus are represented by osteologically mature specimens, notable morphological variation is present. Functional reconstructions of several aspects of the postcranial skeleton of Dsungaripterus are elucidated, including the arrangement of the metacarpophalangeal region during terrestrial locomotion. Niche partitioning between the two dsungaripterids from the Tugulu Group of Wuerho, Dsungaripterus and Noripterus, is supported by their distinct dentitions, neck morphology, and limb proportions.

Computed Tomographic Evaluation of the Sagittal Ridge of the Third Metacarpal Bone in Young Thoroughbred Racehorses: A Longitudinal Study.

Metacarpophalangeal joint region pain is a common cause of lameness in racehorses. Radiological abnormalities in the sagittal ridge (SR) of the third metacarpal bone have been associated with joint effusion, lameness and reduced sales prices. The aims were to describe computed tomographic (CT) appearance of the SR in racehorses, and to document the progression of these findings over three assessments. Forty yearlings were enrolled at the first examination (time 0). Re-examinations were performed twice, approximately six months apart on 31 (time 1) and 23 (time 2) horses, respectively. Computed tomographic examinations of both metacarpophalangeal regions were performed with the horses in a standing position. Computed tomographic reconstructions were analysed subjectively and objectively. The mean Hounsfield Unit values (Hus) of eight radial segments and location, size and shape of hypoattenuating lesions were recorded. Mean Hus at time 1 were higher than at time 0. There was no difference between mean HU at times 1 and 2. The mean HU values of the dorsal half were higher in the right forelimbs and in fillies. Hypoattenuation was identified in 33/80 (41.3%) limbs at time 0, in 22/62 (35.5%) limbs at time 1 and in 14/46 (30.4%) limbs at time 2. All hypoattenuations were located in the dorsodistal aspect of the SR. The most common shapes were hypoattenuating lesions elongated proximodistally and those extending towards trabecular bone. An increase in attenuation of the SR occurred in the first six months of training. Hypoattenuating lesions could decrease in size and could resolve during early training. In this population, these lesions were not associated with lameness.

Standing magnetic resonance imaging findings in the metacarpophalangeal region of 76 horses and metatarsophalangeal region of 24 horses

Standing magnetic resonance imaging findings in the metacarpophalangeal region of 76 horses and metatarsophalangeal region of 24 horses

Standing computed tomography of the equine limb using a multi‐slice helical scanner: Technique and feasibility study

SummaryComputed tomography (CT) is an important cross‐sectional diagnostic modality for lameness localised to the equine distal limb. The necessity of general anaesthesia to perform CT scans has limited its use in the equine orthopaedic field. Therefore, many attempts have been made to perform CT of the distal limb in standing horses. This retrospective report aims to describe the technical set‐up and the feasibility of using a multi‐slice helical CT unit recently introduced into the equine market. The medical records of the patients undergoing a standing CT in the period between March 2019 and January 2020 were reviewed. The imaged anatomical region and the image quality were assessed. Thirty‐two horses met the inclusion criteria, and the following anatomical areas have been imaged: front foot/pastern (n = 14), metacarpophalangeal joint (n = 11), front proximal suspensory ligament (n = 2), carpus (n = 2), metatarsophalangeal joint (n = 2) and tarsus (n = 1). In 97% of the cases, excellent imaging quality was obtained. Motion artefact is the main cause of poor image quality. The feet and the metacarpophalangeal region can be easily imaged. Imaging the proximal anatomical regions of the limb is more challenging but achievable.

Metachronous extraskeletal (soft tissue) epithelioid osteogenic sarcoma: a case report

BackgroundMetachronous osteosarcoma is a rare form of osteosarcoma. The occurrence of metachronous tumor in soft tissue is exceedingly rare. The pathogenesis of metachronous osteosarcoma, as to whether it represents multiple true primaries or metastatic disease, is still obscure.Case presentationA 49-year-old Indian man presented with progressively increasing swelling in his left hand of 2 months’ duration. An X-ray showed a soft tissue lesion. Contrast-enhanced computed tomography showed a soft tissue mass lesion, with peripheral enhancement and central necrotic areas in radial palmar soft tissue overlying second metacarpophalangeal region with no obvious bony osteolysis. Possibilities of acute abscess, resolving hematoma, or aggressive soft tissue mass lesion were suggested. An incision biopsy showed morphological features of epithelioid osteosarcoma, which was confirmed on immunohistochemistry. A detailed history revealed that our patient was diagnosed as having osteosarcoma of his right leg 3 years previously. Based on history, radiology, morphology, and immunohistochemistry, a final diagnosis of extraskeletal (soft tissue) epithelioid osteogenic sarcoma of the left hand occurring as a metachronous tumor 3 years after diagnosis of primary osteosarcoma in the right leg was given.ConclusionThis is probably the first reported case of extraskeletal (soft tissue) epithelioid osteosarcoma occurring as a metachronous tumor 3 years after diagnosis of primary osteosarcoma in the right leg. The prognosis of metachronous skeletal osteosarcoma is poor as compared to that of relapse limited to lungs. In late metachronous osteosarcoma, combined-modality therapy comprising surgery and aggressive chemotherapy may affect long-term survival. Lifelong follow-up of surviving patients with osteosarcoma is necessary and if metachronous osteosarcoma is discovered, it should be treated with curative intent.

Challenging Dogma: Optimal Treatment of the "Fight Bite".

Background: The optimal treatment of human bites to the dorsal metacarpophalangeal region (ie, "fight bite") in the absence of gross purulence is controversial. Few studies have compared the outcomes of operative debridement with expectant wound care and oral antibiotics. Methods: We performed a retrospective chart review of all patients evaluated at a Level 1 trauma center over a 10-year period. We compared demographic and clinical characteristics of patients across treatment and outcome groups using the Fisher exact test. Logistic regression models were used to describe the relationships between the outcome and treatment variables. Results: We identified 115 patients with a mean age of 29 years. The mean follow-up was 51.8 days. Seventy-two (63%) patients were treated with antibiotics only. Thirty-two (28%) patients were treated with irrigation in the emergency department (ED) and expectant wound care. Eleven (9%) patients were treated with irrigation and debridement in the operating room. No demographic variables were found to correlate with the treatment selected. A 12% complication rate (major and minor) was observed. After adjusting for duration of follow-up and days to presentation, neither the treatment rendered nor the antibiotics selected influenced the rate of complications. Time to presentation >24 hours was the only variable associated with higher complication rate (P = .003). Conclusions: Not all fight bites require operative intervention. Irrigation in the ED with expectant wound care and oral antibiotics can be sufficient for patients presenting within 24 hours of injury in the absence of gross purulence.

Treatment of Single Cords in Dupuytren Disease with Collagenase Clostridium Histolyticum: Study of a Cohort with Follow-up at 1 Year

Objective The purpose of the present work was to assess the effectiveness of collagenase Clostridium histolyticum in patients with Dupuytren disease with single cords and assess the recurrence rate in the first year after the treatment. Material and Methods In this classic cohort study, a total of 53 patients (50 of them male) with a mean age of 68 years were studied who had been diagnosed with Dupuytren disease located in the metacarpophalangeal joint, in single cords, with more than 40° of extension loss. They were given an injection of collagenase C. histolyticum and later manipulation under locoregional anesthesia. The loss of extension was evaluated after a week and at the 1st, 3rd, 6th and 12th months. The effectiveness was analyzed with basis on the results of the Student t-test for paired data, as well as those of the effect size (ES) test. Results An important and statistically significant correlation was found for the loss of cord extension in the metacarpophalangeal joint (t = 32.113; p < 0.01; ES = 4.11; standardized response mean [SRM] = 4.15). Conclusion Collagenase is an injectable treatment, which is not very aggressive compared with surgery and is effective for the loss of extension in the metacarpophalangeal region secondary to single cord in Dupuytren disease during the first year.

Computer Aided Diagnosis Based Hand Thermal Image Analysis: A Potential Tool for the Evaluation of Rheumatoid Arthritis

The aim of the study was to evaluate the potential of the thermogram in diagnosing rheumatoid arthritis and to compare the implementation of k-means algorithm and fuzzy c means algorithm using a computer aided diagnostic tool for classification of rheumatoid arthritis (RA) and normal based on the feature extracted from the segmented thermal image. The skin surface temperature measurement, thermal image segmentation based on k-means and fuzzy c-means algorithm and the feature extraction were used in this study. The average skin surface temperature measured at the second meta carpo-phalangeal (MCP) and MCP3 in RA patients (35.40 ± 0.6 °C and 35.52 ± 0.7 °C, respectively) were significantly higher (p < 0.01) than those measured in normal subjects (33.66 ± 0.2 °C and 33.74 ± 0.2 °C, respectively). The mean difference in temperature between RA patients and healthy controls in the MCP2 and MCP3 region was found to be 1.74 and 1.78 °C respectively. The receiver operating characteristics (ROC) curve depicted a sensitivity of 86.6% and specificity of 79% achieved in the MCP region of the hand thermal image. Thermal image segmentation using the k-means algorithm provided better segmentation results compared to the fuzzy c-means algorithm in diagnosing the disease. Therefore, the computer aided diagnostic based thermography method could be used as a validated quantification method for interpreting and evaluating arthritis.

Flag flap - Kite flap Dorsal metacarpal flap

The flag flap is a pedicled dorsal digital flap, combining a skin paddle (the “flag”) and a vascular pedicle (the flag “pole”). Its vascularisation depends on the dorsal metacarpal arteries (DMCA). It has been described in 1963, by Holevitch [1] with harvest of a cutaneovascular pole; it has been brilliantly modified in 1979 by Foucher et al. [2–4] under the form of a unipedicled “kite” flap, although we would like to point out that Vilain has been using it since 1952 [5]. Usually harvested from the dorsum of the metacarpophalangeal region of the index finger, this flap is reliable, but it is more uncertain and less movable at the level of the other digits. Owing to its small size, it proves useful in hand traumatology because it does not sacrifice any major vascular axis. The kite flap is considered as a sensory flap (presence of a nerve supply) with a two-point discrimination, which can be assessed from 11 to 16 mm [1–6].

Reliability and repeatability of thermographic examination and the normal thermographic image of the thoracolumbar region in the horse.

Thermographic imaging is an increasingly used diagnostic tool. When performing thermography, guidelines suggest that horses should be left for 10-20 mins to 'acclimatise' to the thermographic imaging environment, with no experimental data to substantiate this recommendation. In addition, little objective work has been published on the repeatability and reliability of the data obtained. Thermography has been widely used to identify areas of abnormal body surface temperature in horses with back pathology; however, no normal data is available on the thermographic 'map' of the thoracolumbar region with which to compare horses with suspected pathology. To i) investigate whether equilibration of the thermographic subject was required and, if so, how long it should take, ii) investigate what factors affect time to equilibration, iii) investigate the repeatability and reliability of the technique and iv) generate a topographic thermographic 'map' of the thoracolumbar region. A total of 52 horses were used. The following investigations were undertaken: thermal imaging validation, i.e. detection of movement around the baseline of an object of constant temperature; factors affecting equilibration; pattern reproducibility during equilibration and over time (n = 25); and imaging of the thoracolumbar region (n = 27). A 1 degrees C change was detected in an object of stable temperature using this detection system, i.e the 'noise' in the system. The average time taken to equilibrate, ie. reach a plateau temperature, was 39 mins (40.2 in the gluteal region, 36.2 in lateral thoracic region and 40.4 in metacarpophalangeal region). Only 19% of horses reached plateau within 10-20 mins. Of the factors analysed hair length and difference between the external environment and the internal environment where the measurements were being taken both significantly affected time to plateau (P<0.05). However, during equilibration, the thermographic patterns obtained did not change, nor when assessed over a 7 day period. A 'normal' map of the surface temperature of the thoracolumbar region has been produced, demonstrating that the midline is the hottest, with a fall off of 3 degrees C either side of the midline. This study demonstrates that horses may not need time to equilibrate prior to taking thermographic images and that thermographic patterns are reproducible over periods up to 7 days. A topographical thermographic 'map' of the thoracolumbar region has been obtained. Clinicians can obtain relevant thermographic images without the need for prior equilibration and can compare cases with thoracolumbar pathology to a normal topographic thermographic map.

Proteoglycan Composition and Biosynthesis in Superficial and Deep Digital Flexor Tendons of Standardbred Horses

SummaryProteoglycan (PG) levels and their respective biosynthesis were determined in explant cultures taken from the mid-metacarpal (MMC) and metacarpophalangeal (MCP) regions of normal equine superficial and deep digital flexor tendons. Five standard-bred horses (2-5 years old) were used and explants dissected from the MMC and MCP regions of the superficial and deep digital flexor tendons. The explants (3 mm2) were cultured in Ham’s F12 media supplemented with 1% FBS. After 24 h, Na2S35SO4 was added and the culture continued for a further 48 h. The media was removed and the explants were lyophilized and weighed. The explants and media were then subject to papain digestion and the DNA and sulphated glycosaminoglycans (S-GAG) concentrations and incorporation of [35S] sulphate into PGs determined by established methods.The MMC regions of the superficial and deep digital flexor tendons contained less PGs than the MCP regions and these were predominantly small. The MCP regions, not only contained higher concentrations of PGs, but these were of larger hydrodynamic size. The incorporation of [35S] sulphate into PGs was also higher in explants from the MCP region. These data indicate that in those regions of equine flexor tendon, subjected to both, compression and tension, PG content and biosynthesis is higher than in regions which only transmit tensional loads. These findings are consistent with the adaptive role of tenocytes to the nature and level of the mechanical stresses imposed upon them.The proteoglycans (PGs) and DNA content and their biosynthesis were determined in cultures of expiants obtained from the mid-metacarpal (MMC) and metacarpophalangeal (MCP) regions of normal superficial and deep digital flexor tendons of five standard bred horses (2– years old). It was shown that the MMC region of the superficial and deep flexor tendon contained less PGs than the MCP regions. Moreover, the biosynthesis of PGs was enhanced in the MCP explants and the size of these molecules was larger than made by cells of the MMC region.

A XERORADIOGRAPHIC STUDY OF OSTEOCHONDROSIS IN THE METACARPOPHALANGEAL REGION OF TWO FOALS

Using xeroradiographic techniques, both metacarpophalangeal regions of six quarter horse foals were radiographed at 1 day of age and at 2-week intervals until they were 6 weeks old, and then at 4-week intervals until they were 12 months old. Lateromedial and dorsopalmar xeroradiographs of each metacarpophalangeal region were made per examination; dorsomedial-palmarolateral projections of the left metacarpophalangeal joint of foal 6 were also made. The foals were weighed and measured at the withers immediately prior to each examination. Representative xeroradiographs were selected to demonstrate progression of the osteochondrosis (OCH) lesions in two of these foals. Radiographic evidence of osteochondrosis in the metacarpophalangeal region was first detected at 10 weeks and followed through 12 months of age. In one foal the lesions were bilaterally symmetric and involved the dorsoproximal aspect of the sagittal ridge of metacarpal 3; in the other, the left medial proximal sesamoid bone was affected. One of the sagittal ridge lesions progressed to osteochondritis dissecans by 26 weeks; the other sagittal ridge lesion and that of the sesamoid bone healed spontaneously, but residual radiographic evidence of the disease persisted throughout the study in both foals.

A XERORADIOGRAPHIC STUDY OF THE DEVELOPING QUARTERHORSE FOREDIGIT AND METACARPOPHALANGEAL REGION FROM SIX TO TWELVE MONTHS OF AGE

The purpose of the project was to provide a reference for radiographic anatomy of the developing equine foredigit and metacarpophalangeal region. Using xeroradiographic techniques, both foredigits and metacarpophalangeal regions of six Quarter Horse foals were radiographed at 1 day of age and then at 2‐week intervals until the foals were 6 weeks old. The foals were then radiographed at 4‐week intervals until they were 12 months old. The period from birth to 6 months has been described in a previous report. This paper deals with the period from 6 to 12 months of age. Lateromedial and dorsopalmar xeroradiographs of each foredigit and metacarpophalangeal region and a dorsal 65° proximal‐palmarodistal oblique view of the distal part of the digit were made at each examination. Foals were weighed and were measured at the withers immediately prior to each examination. Representative xeroradiographs were selected and appropriately labeled to demonstrate normal radiographic anatomy of these regions. Earliest radiographic visualization of distal epiphyseal ossification in metacarpal 2 and metacarpal 4 was extremely variable and ranged from 4 to 38 weeks. It was not possible to determine accurately the ages at which distal physes of the small metacarpal bones closed. In one foal, three of four of these physes were closed at 26 weeks, while in another foal, none had closed when last radiographed at 54 weeks. Radiographic closure of the proximal physis of the middle phalanx ranged from 18 to 30 weeks (mean = 26 weeks). Radiographic closure of the proximal physis of the proximal phalanx ranged from 22 to 38 weeks (mean = 30 weeks). Radiographic closure of the distal physis of metacarpal 3 ranged from 18 to 38 weeks (mean = 29 weeks).

Local Anesthetics and Nuclear Medical Bone Images of the Equine Fore Limb

The effects of two local anesthetic agents on the diagnostic quality of nuclear medical bone images (NMBIs) of distal parts of the equine fore limb were investigated. Local effects on bone uptake of technetium 99m methylene diphosphonate (99mTc-MDP) 4 and 24 hours after perineural and intraarticular injection of mepivacaine hydrochloride and bupivacaine hydrochloride were evaluated in the carpal and metacarpophalangeal regions of 12 horses and ponies. Neither mepivacaine hydrochloride nor bupivacaine hydrochloride significantly altered the diagnostic quality of the NMBIs. The injection and subsequent action of local anesthetics do not appear to influence local bone uptake of 99mTc-MDP significantly.

A XERORADIOGRAPHIC STUDY OF THE DEVELOPING EQUINE FOREDIGIT AND METACARPOPHALANGEAL REGION FROM BIRTH TO SIX MONTHS OF AGE

The purpose of the project was to provide a reference for radiographic anatomy of the developing equine foredigit and metacarpophalangeal region. Using xeroradiographic techniques, both foredigits and meta‐carpophalangeal regions of six Quarter Horse foals were radiographed at one day of age and at two‐week intervals until the foals were six weeks old. The foals were then radiographed at four‐week intervals until they were 12 months old. This report deals specifically with the first six months of postnatal development. Lateromedial and dorsopalmar xeroradiographs of each foredigit and metacarpophalangeal region and a dorsal 65° proximal‐palmarodistal oblique view of the distal part of the digit were made for each examination. The foals were weighed and measured at the withers immediately prior to each examination. Representative xeroradiographs were selected and appropriately labeled to demonstrate normal radio‐graphic anatomy of these regions. First radiographic appearance of distal epiphyseal ossification in metacarpal 2 and metacarpal 4 was extremely variable and ranged from four to 38 weeks. Radiographic closure of the proximal physis of the middle phalanx ranged from 18 to 30 weeks (mean = 26 weeks). Radiographic closure of the proximal physis of the proximal phalanx ranged from 22 to 38 weeks (mean = 30 weeks). Radiographic closure of the distal physis of metacarpal 3 ranged from 18 to 38 weeks (mean = 29 weeks). When xeroradiographic physeal closure times were compared with scintigraphic closure times from a companion study, results correlated very well. A crena marginis solearis was observed in ten of 12 forelimbs (83.3%); its first radiographic appearance ranged from four to 22 weeks (mean = 11–12 weeks). A consistent groove in the hoof wall, which formed near the time of birth and moved distally at about 3 mm per week, was noted. The groove's distance from the proximal hoof border may be useful in age estimation of foals less than 18–20 weeks old.

XERORADIOGRAPHIC ANATOMY OF THE EQUINE DIGIT AND METACARPOPHALANGEAL REGION

The purpose of the project was to use xeroradiography to provide a reference for radiographic anatomy of the equine digit and metacarpophalangeal region. The left foredigits and metacarpophalangeal joints of a mature horse and a 30‐day‐old foal were radiographed, using xeroradiographic techniques. Fifteen xeroradiographs, illustrating standard projections of each area, were selected and appropriately labeled to demonstrate normal radiographic anatomy of these regions. These xeroradiographs have been used successfully for several years to teach radiographic anatomy of these areas to first‐year veterinary students at North Carolina State University.

Rheumatoid changes in the metacarpophalangeal region as a cause of Bunnell's sign.

Rheumatoid changes in the metacarpophalangeal region as a cause of Bunnell's sign.