Radial Carpal Bone Research Articles

Pancarpal Arthrodesis Using Antibiotic–Impregnated Calcium Sulfate Beads in a Dog with Septic Arthritis and Osteomyelitis

AbstractA 6-year-old Lurcher dog was referred for evaluation and treatment of a septic carpal arthritis, associated osteomyelitis of the radius and radial carpal bone and antebrachiocarpal luxation following a previous articular surgery 14 weeks prior to presentation. A staged approached was elected and following removal of the original implants, a pancarpal arthrodesis was performed using autologous bone graft and gentamicin-impregnated bioabsorbable calcium sulfate beads. At 12 weeks postoperatively, lameness had resolved on the operated limb and complete joint fusion was confirmed on radiographic evaluation. The purpose of this case report is to describe the successful short- and long-term outcome of a pancarpal arthrodesis using antibiotic medication–impregnated calcium sulfate beads, providing details about the surgical technique used for management of a destructive septic arthritis and osteomyelitis.

Arthroscopic repair of full-thickness cartilage defects in horses with autologous nasal chondrocytes seeded in an injectable hydrogel: from preclinical development to clinical cases

This study aimed at evaluating the ability of autologous equine nasal chondrocytes (EqNCs) embedded in a silanised hydroxypropyl methylcellulose (Si-HPMC) hydrogel to repair cartilage defects in horses. Autologous EqNCs from the nasal septum were cultured in vitro and mixed with Si-HPMC. This hybrid construct was injected arthroscopically to experimental full-thickness critical-sized cartilage defects in a pilot horse. After this preliminary test, it was implanted in 6 experimental horses and compared with microfracture (positive control) and with debridement only (negative control) using experimental defects created bilaterally on radial carpal bones and medial femoral condyles. Cartilage tissue repair was subsequently investigated arthroscopically, macroscopically and histologically 18 months after the surgical procedure. Two client-owned horses presenting with cartilage damage were also treated using hybrid EqNCs/Si-HPMC constructs. We developed an injection technique for a 3D hybrid construct of EqNC and Si-HPMC under gas arthroscopy. The in situ reticulation and adhesion properties of the construct ensured its stability after injection. The hybrid construct was well tolerated and Si-HPMC was estimated as a safe scaffold for horses. We found a better cartilage healing with our hybrid construct compared to microfracture or defect left empty characterized by an increased type II collagen content in the defects filled with the hybrid construct. In the 2 clinical cases, hybrid construct injection led to the formation of repair tissue exhibiting the gross appearance of articular cartilage and both returned to intended use. This study revealed that EqNCs/Si-HPMC constructs can support the formation of a healing tissue with hyaline cartilage features.

Morphometric studies on the appendicular bony skeleton of the ostriches (Struthio Camelus)

BackgroundMorphometric study of the bony elements of the appendicular skeleton in the ostrich was fully described and identified. The appendicular skeleton included the bones of the pectoral girdle, the wing, the pelvic girdle and the pelvic limb.ResultsThe shoulder girdle of the ostrich included the scapula and coracoid bones. The scapula appeared as a flattened spoon-like structure. The coracoid bone appeared quadrilateral in outline. The mean length of the scapula and coracoid (sternal wing) were 15.00 ± 0.23 and 10.00 ± 0.17 cm, respectively. The wing included the humerus, ulna, radius, radial carpal bone, ulnar carpal bone, carpometacarpus and phalanges of three digits. The mean length of the humerus, radius, and ulna were 33.00 ± 0.46, 10.50 ± 0.40 and 11.50 ± 0.29 cm respectively. The carpometacarpus was formed by the fusion of the distal row of carpal bones and three metacarpal bones. Digits of the wing were three in number; the alular, major and minor digits. Os coxae comprised the ilium, ischium and pubis. Their mean lengths were 36.00 ± 0.82 cm, 32.00 ± 0.20 and 55.00 ± 0.2.9 cm, respectively. The femur was a stout short bone, that appeared shorter than the tibiotarsus. The mean length of the femur, tibiotarsus, and tarsometatarsus were 30.00 ± 0.23, 52.00 ± 0.50 and 46.00 ± 0.28 cm. Tibiotarsus was the longest bone in the pelvic limb. The fibula was a long bone (44.00 ± 0.41 cm) lying along the lateral surface of the tibiotarsus. The tarsometatarsus was a strong long bone formed by the fusion of the metatarsal (II, III, IV) and the distal row of tarsal bones. It was worth mentioning that metatarsal II was externally absent in adults.ConclusionsIn the appendicular skeleton of ostrich, there were special characteristic features that were detected in our study; the clavicle was absent, the coracoid bone was composed of a sternal wing and scapular wing, the ulna was slightly longer in length than the radius. The coupled patellae i.e., the proximal and distal patella were observed; and the ostrich pedal digits were only two; viz., the third (III) and fourth (IV) digits.

Morphology of the Sternum, Pectoral Girdle and Wing of West African ‎Black-Crowned Crane (Balearica pavonina pavonina)‎

The present work was undertaken to study the gross morphological features of the sternum, pectoral girdle and wing bones of adult black-crowned crane. The bones were processed using standard techniques to highlight structural details. The sternum was triangular shaped, comprised of three borders and two surfaces. The dorsal border was slightly shallow medially having linearly arranged pneumatic foramina. The basal border was strongly convex and bears a prominent sternal crest. The cranial border was broad and transversely convex with shallow grooves on the lateral edges for articulation with the coracoid bones. There were seven pairs of ribs that articulated with corresponding sterno-costal bones. The shoulder girdle comprised of the blade-like scapula, coracoid, and the clavicles which fused proximally to form the foramen triosseum. The humerus was pneumatic tubular bone with flat expanded proximal ends and small rounded distal ends. The ulna and radius were of comparatively equal length, separated along their long axis by extended interosseous space. The carpus consisted of the ulnar carpal bone and radial carpal bone. Whereas, the carpo-metacarpal comprised of three primary bones that articulated distally with corresponding rays of digits.

Forty new specimens of Ichthyornis provide unprecedented insight into the postcranial morphology of crownward stem group birds.

Ichthyornis has long been recognized as a pivotally important fossil taxon for understanding the latest stages of the dinosaur-bird transition, but little significant new postcranial material has been brought to light since initial descriptions of partial skeletons in the 19th Century. Here, we present new information on the postcranial morphology of Ichthyornis from 40 previously undescribed specimens, providing the most complete morphological assessment of the postcranial skeleton of Ichthyornis to date. The new material includes four partially complete skeletons and numerous well-preserved isolated elements, enabling new anatomical observations such as muscle attachments previously undescribed for Mesozoic euornitheans. Among the elements that were previously unknown or poorly represented for Ichthyornis, the new specimens include an almost-complete axial series, a hypocleideum-bearing furcula, radial carpal bones, fibulae, a complete tarsometatarsus bearing a rudimentary hypotarsus, and one of the first-known nearly complete three-dimensional sterna from a Mesozoic avialan. Several pedal phalanges are preserved, revealing a remarkably enlarged pes presumably related to foot-propelled swimming. Although diagnosable as Ichthyornis, the new specimens exhibit a substantial degree of morphological variation, some of which may relate to ontogenetic changes. Phylogenetic analyses incorporating our new data and employing alternative morphological datasets recover Ichthyornis stemward of Hesperornithes and Iaceornis, in line with some recent hypotheses regarding the topology of the crownward-most portion of the avian stem group, and we establish phylogenetically-defined clade names for relevant avialan subclades to help facilitate consistent discourse in future work. The new information provided by these specimens improves our understanding of morphological evolution among the crownward-most non-neornithine avialans immediately preceding the origin of crown group birds.

Examining the Effects of the Oral Supplement Biota orientalis in the Osteochondral Fragment-Exercise Model of Osteoarthritis in the Horse.

Osteoarthritis (OA) is a common problem in horses. Several oral supplements have been proposed as treatments for horses with OA. The object of this study was to evaluate the use of the oil extract from the seeds of Biota orientalis (BO) for the treatment of experimentally induced OA in horses. OA was induced in 16, 2–5 year old horses in one middle carpal joint on Day 0; the other limb underwent a sham operation. Once daily oral treatment with BO or placebo was initiated on Day 0 and continued to Day 70. All horses were exercised 5 days a week starting on Day 14 through Day 70. The horses were evaluated every other week for lameness and serum GAG concentration as well as weekly synovial fluid assessment. Magnetic resonance imaging was performed on Day 7 and 70. Radiographic changes were assessed on Day 0, 14, and 70. On Day 70 tissue from the middle carpal joint was assessed macroscopically and histologically. All outcome parameters were compared between treatment groups to identify effects of treatment. Compared to placebo a significant decrease was found in synovial fluid prostaglandin E2 concentration and white blood cell counts in horses treated with BO. There was a significant reduction in radiographic scores for subchondral lysis of the radial carpal bone, osteophyte formation, subchondral sclerosis of the radial carpal bone, and total radiographic score for the horses treated with BO. There was no significant difference between treatment groups in clinical lameness findings, MRI findings, macroscopic grading or histologic grading. This study suggests a significant anti-inflammatory effect from oral BO that should be further investigated in clinical OA.

Multibody Computer Model of the Entire Equine Forelimb Simulates Forces Causing Catastrophic Fractures of the Carpus during a Traditional Race.

Simple SummaryPalios are traditional horseraces held in the main square of few Italian cities. Due to peculiar features of such circuits, adapted to the square architecture and thus characterized by tight curves and unconventional footing surface, horses involved are at particular risk of accidents. Prevention of catastrophic musculoskeletal injuries is a significant issue and matter of debate during these events. In particular, the negotiation of the curves in the city circuits is a significative concern. An experiment was set up to build a model of entire forelimb at the point of failure in the context of a turn comparable to that in a Palio circuit. The model was informed by live data and the output compared to post-mortem findings obtained from a horse that sustained a catastrophic fracture of the carpus during this competition. The objective of this study is to determine the magnitude and distribution of internal forces generated across the carpus under which the catastrophic injury has occurred and describe related post-mortem findings.A catastrophic fracture of the radial carpal bone experienced by a racehorse during a Palio race was analyzed. Computational modelling of the carpal joint at the point of failure informed by live data was generated using a multibody code for dynamics simulation. The circuit design in a turn, the speed of the animal and the surface characteristics were considered in the model. A macroscopic examination of the cartilage, micro-CT and histology were performed on the radio-carpal joint of the limb that sustained the fracture. The model predicted the points of contact forces generated at the level of the radio-carpal joint where the fracture occurred. Articular surfaces of the distal radius, together with the proximal articular surface of small carpal bones, exhibited diffuse wear lines, erosions of the articular cartilage and subchondral bone exposure. Even though the data in this study originated from a single fracture and further work will be required to validate this approach, this study highlights the potential correlation between elevated impact forces generated at the level of contact surfaces of the carpal joint during a turn and cartilage breakdown in the absence of pre-existing pathology. Computer modelling resulted in a useful tool to inversely calculate internal forces generated during specific conditions that cannot be reproduced in-vivo because of ethical concerns.

Incidence of carpal fractures and risk factors for recurrent fractures after arthroscopic removal of carpal chip fracture fragments in Thoroughbred racehorses.

We aimed to investigate the recent incidence of carpal fractures and the risk factors for recurrent ipsilateral fractures after arthroscopic removal of clinically active unilateral carpal chip fracture fragments in Thoroughbred racehorses. The findings for horses managed under the Japan Racing Association that developed carpal bone fractures between 2014 and 2018 were retrospectively reviewed. The proportion of cases that developed a recurrent carpal fracture in the originally affected joint was calculated, and the risk factors for recurrent fractures were analysed. In total, 2858 carpal fractures were recorded in the study period (incidence, 0.8%). Of the 554 horses that resumed racing after the treatment of the unilateral major carpal chip fracture, 144 had a recurrent fracture (26.0%). Chip fractures of the third carpal bone (odds ratio [OR]: 3.7) or a combination of the distal end of the radius and intermediate carpal bone (OR: 3.0) were associated with a significantly higher risk of recurrent fractures than the distal aspect of the radial carpal bone. The incidence of carpal fractures remained similar to that reported in Japan in the 1990s. The rate of recurrent ipsilateral fractures differed among lesion sites.

Surface topography as a tool to detect early changes in a posttraumatic equine model of osteoarthritis.

The equine model of posttraumatic osteoarthritis (OA) mimics certain aspects of the naturally occurring disease, both in horses and humans. The objective of this study was to assess articular cartilage degeneration in a posttraumatic OA model using the established macroscopic and microscopic scoring systems and compare them with a novel surface topography analysis. OA was induced in the carpal joint of 15 (n = 15) mixed breed horses. Surface changes on the articular cartilage were characterized using osteochondral blocks from the third carpal bone (C3) and radial carpalbone using surface topography, standard histological grading, and gross evaluation of the joints. Significant differences were observed between OA and non-OA joints for gross evaluation scores. Microscopic scores of hematoxylin and eosin and Safranin O and Fast Green-stained sections demonstrated no differences between OA and non-OA joints. However, articular cartilage from the induced OA joint had significantly greater surface topography measurements compared with the sham treatment group, consistent with the changes seen on gross evaluation of joints. No significant correlations were noted between surface roughness measurements, histological assessment, and gross evaluation scores. The results suggest that surface topography analysis may provide a reliable objective approach to assess early changes in the cartilage surface in OA.

Slab fractures of the third carpal bone involving both radial and intermediate facets and outcomes after surgical repair in racing Quarter Horses.

Characteristics and outcomes after surgical repair of third carpal bone (C3) slab fractures involving both radial and intermediate facets in racing Quarter Horses are unknown. To describe the pre- and intraoperative characteristics of C3 slab fractures of both radial and intermediate facets in Quarter Horses and to report on the long-term outcomes after internal fixation. Retrospective case series. Case records were collected from racehorses with C3 slab fractures between 2008 and 2020. Inclusion criteria required arthroscopic-guided repair of C3 slab fractures involving both radial and intermediate facets in Quarter Horses. Routine C3 slab fractures (single facet), fractures in other breeds or those repaired with other techniques were excluded. Outcomes were obtained by standardised questionnaire. Data were presented as mean±SD or as proportions with 95% confidence interval (CI). Of 22 Quarter Horses with C3 slab fractures involving both radial and intermediate facets, 91% (CI 79%-100%; n=20) were collapsing and 91% (CI 79%-100%; n=20) had avulsion of the medial palmar intercarpal ligament. Articular cartilage erosion and osteochondral fracture of the radial carpal bone was observed in 91% (CI 79%-100%; n=20) and 41% (CI 20%-62%; n=9) cases respectively. At 5.5±3.9years after surgery, 86% (CI 72%-100%; n=19) were alive and used for breeding or retirement. Of 18 horses with follow-up >1year, 39% (CI 16%-61%; n=7) resumed some athletic activity. Cases were referred specifically for surgical repair and horses with fractures considered too severe for surgical intervention or euthanasia at owner request were not included. Questionnaire responses are susceptible to recall bias. Horses with C3 slab fractures of both radial and intermediate facets that are repaired have a favourable prognosis for retirement, breeding and potentially low-level athletic activity.

The effect of plate fixation on supination and pronation of the feline antebrachium: a model of pancarpal arthrodesis

BackgroundPancarpal arthrodesis is purported to limit supination and pronation of the feline antebrachium. The objective of this study was to investigate whether plate fixation of the radius to the carpus and metacarpus limits supination and pronation of the ulna relative to the radius as a model for pancarpal arthrodesis in the cat. Eight feline cadaveric forelimbs were rotated from supination to pronation in a testing jig and CT (computed tomography) was performed in the neutral, supinated and pronated positions. A locking plate was then secured dorsally to the radius, radial carpal bone and metacarpal III of each of the limbs. CT was repeated in each of the testing positions following plate application. The radius and ulna of the control specimens, and the radius, ulna and plate of the plated specimens were then segmented using software. Alignment of the bones to the radius in the control specimens, and to the plate in the plated specimens was used to compare the changes in degrees of movement of the ulna relative to the radius in dorsal, sagittal and transverse planes.ResultsBased on the results of the paired t test, there was no significant difference in degrees of movement, or total range of motion between control and plated specimens in supinated and pronated testing conditions.ConclusionThe results of this ex-vivo study indicate that under the testing conditions employed, plate fixation of the radius to the carpus and metacarpus does not limit supination and pronation of the feline antebrachium.

Kinematics of the Feline Antebrachiocarpal Joint from Supination to Pronation.

Cats rely on their forelimb mobility for everyday activities including climbing and grooming. Supination and pronation of the forelimb in cats are considered to primarily involve the antebrachium, rather than the carpus. Therefore, our null hypothesis was that there would be no movement of the carpal bones (radial carpal bone, ulnar carpal bone and accessory carpal bone) relative to the ulna during supination and pronation. Eight feline cadaveric forelimbs were rotated from supination to pronation in a jig and computed tomography was performed in the neutral, supinated and pronated positions. The individual carpal bones were segmented from computed tomography images of the supinated and pronated scans in each of the eight specimens. A feline ulna coordinate system was established and used to quantify the translations and rotations between bones of the proximal carpal row and antebrachium. After the carpus was rotated from the initial supinated position into pronation, there was significant translation (x, y and z axes) and rotation (x and y axes) of the proximal row of carpal bones based on absolute magnitude values. Given the differences in translations and rotations of the proximal row of carpal bones, our null hypothesis was rejected. The proximal row of carpal bones translate and rotate independently from the ulna in the cat during pronation of the antebrachium. This may have future implications in the diagnosis and management of feline carpal injuries involving the antebrachiocarpal joint.

Surgical repair of radial carpal bone fractures in two racehorses

SummaryA 3‐year‐old Standardbred gelding (Case 1) and a 2‐year‐old Thoroughbred gelding (Case 2) were referred for surgical evaluation of a left radial carpal bone (RCB) fracture, sustained during training. Clinical findings at the time of initial examination included a palpable effusion within the left middle carpal joint in both horses and marked signs of pain and reduced range of motion on flexion of the affected carpus. In both horses, the RCB fracture was evident on the following radiographic views of the carpus: dorsolateral–palmaromedial oblique (30° off lateromedial) and flexed lateromedial. An additional loose wedge‐shaped osteochondral fragment at the proximal articular surface of the RCB could be seen in Case 2. Both horses underwent surgical reduction and repair of the fracture between 1 and 2 days following the initial injury, which consisted of arthroscopic removal of any intra‐articular osteochondral fragments, and arthroscopic assisted‐interfragmentary compression via a standard dorsomedial and dorsolateral approach to the antebrachiocarpal joint (ACJ) and middle carpal joints (MCJ). The two horses returned to function as racehorses, 6 months (Case 1) and 16 months (Case 2) after surgery. The RCB is a relatively uncommon site for large carpal fractures in horses. The clinical presentation and findings from this report were similar to that of third carpal bone (C3) slab fractures, confirming that surgical repair is indicated in selected cases of RCB fractures.

A 10-year study of arthroscopic surgery in racing Thoroughbreds and Quarter Horses with osteochondral fragmentation of the carpus.

Osteochondral fragmentation of the carpus is a common cause of lameness in racehorses. Prognosis following arthroscopic removal of the fragments was reported in 1987, but little is known of recent success rates. To identify associations between the severity and location of osteochondral fragments in the carpus, and to describe the racing performance of horses pre- and post-surgery in Thoroughbreds and Quarter Horses. To identify factors associated with a horse racing post-surgery. Retrospective study of clinical records (2006-2016). Surgical and racing records for racehorses undergoing arthroscopic surgery of the carpus were collated during the 10-year study period. Signalment, location of osteochondral fragmentation and grade of defect left after removal and debridement identified and racing performance pre- and post-surgery were described, stratified by breed. Logistic regression analysis was used to identify factors associated with unsuccessful return to racing. In total, 828 horses (n=416 Quarter Horses; n=412 Thoroughbreds) underwent 880 carpal arthroscopies after fragments were found on radiography. Sixty-five percent (n=289) and 27% (n=118) of the lesions were bilateral in Quarter Horses and Thoroughbreds respectively (P<0.001). In both breeds, the most commonly affected bone was the dorsodistal radial carpal bone (n=320/659; 48.6%). Overall, 82% (n=686; n=358 Quarter Horses, n=328 Thoroughbreds) of horses raced post-surgery, with 69.5% (n=476; n=228 Quarter Horses, n=248 Thoroughbreds) racing at the same or a higher level of competition. Factors associated with horses not returning to racing post-surgery were increasing horse age, female horses, and a lesion grade of 4, while racing pre-surgery was protective. This study does not include a control population for comparison. There were significant differences between the location and severity of lesions in Quarter Horses, when compared to Thoroughbreds. The majority of horses return to racing following surgery, although performance was influenced by lesion severity. The Summary is available in Portuguese - see Supporting information.

Lateral manus translation for limb-sparing surgery in 18 dogs with distal radial osteosarcoma in dogs.

To describe and report outcomes after lateral translation of the manus for limb-sparing management of distal radial osteosarcoma in dogs. Retrospective case series. Eighteen client-owned dogs. The distal aspect of the affected radius and associated neoplastic tissues were excised. The distal aspect of the ulna was preserved except for its medial cortex, which was removed en bloc with the radial segment. The manus was translated laterally to place the radial carpal bone in contact with the distal aspect of the ulna. A limb-sparing or locking compression plate was placed on the remaining proximal radius and the 3rd metacarpal bone. A 3.5-mm SOP (string of pearls) plate was placed on the lateral aspect of the proximal ulna and the 4th metacarpal bone. Dogs were administered chemotherapy. Data were collected to assess surgical and oncologic outcomes. Limb function was subjectively assessed. The percentage of radius removed ranged from 43% to 94% (median 54%). Complications developed in 12 limbs, with infection in 10, biomechanical complications in 6, and local recurrence in 4. Limb function was subjectively assessed as acceptable. Median disease-free interval was 219 days, and median survival time was 370 days. Outcomes after lateral translation of the manus compared favorably to other limb-sparing techniques for dogs with distal radial osteosarcoma, particularly in dogs requiring excision of a large segment of the radius. The lateral manus translation provides an alternative limb-sparing technique that does not require an allograft, endoprosthesis, or autograft.

Bilateral radial carpal bone luxation and its treatment in a dog

Bilateral radial carpal bone luxation and its treatment in a dog

Diagnostic investigation of an unusually large osseous cyst‐like lesion of the radial carpal bone

SummaryA 10‐year‐old Irish Sports Horse presented for intermittent, fluctuating lameness of the left forelimb. Nuclear scintigraphy, radiography and computed tomography identified a large osseous cyst‐like lesion (OCLL) occupying approximately 50% of the radial carpal bone with an articular communication to the antebrachiocarpal joint. A transcortical surgical approach was used to curette the lining of the lesion prior to injection with triamcinolone acetonide. This imaging report describes the detailed diagnostic findings of an unusually extensive OCLL in the radial carpal bone.

Morphological and morphometrical studies on the carpal bone of blue bull (boselephus tragocamelus)

The present study has been carried out on the carpal bones of six blue bull. The carpal bones consisted of six short bones arranged in two transverse rows one above the other. The bones of the proximal row from medial to lateral were radial carpal or scaphoid, intermediate carpal or semilunar, ulnar carpal or cuneiform and accessory carpal or pisiform. The bones of the distal row were second and third fused carpal or os magnum and fourth carpal or unciform. The radial carpal bone was the medial-most of the proximal row and presented six surfaces. The intermediate carpal bone was wedge shaped, being wide in front and constricted in middle. The ulnar carpal bone was irregular in outline and situated lateral to the intermediate carpal. The accessory carpal was a short, medially curved bone. It was placed behind the ulnar carpal. In the distal row, the fused second and third carpal bone was situated medially and was larger than fourth carpal. The fourth carpal bone was smaller of the two bones of the distal row. It was roughly quadrilateral in outline and decreased in thickness cranio-caudally.

Current Concepts in Radial Club Hand.

Radial club hand is a complex congenital abnormality of the radial or pre-axial border of the upper extremity. It has a wide range of phenotypes from hypoplasia of the thumb to complete absence of the radius and the first ray. Centralization with tendon transfer is a popular method for maintaining the correct position of radial club hand. On the other hand, various corrections were devised, e.g. radialization after distraction to emphasize the fact that the head of the ulna is positioned under the radial carpal bones and is no longer placed in a slot in the center of the carpus, microvascular epiphysis transfer, gradual correction using Ilizarov method, for Bayne Type III or Type IV. We should pay attention to the recurrence of radial deformity or circulatory impairment with the tension. Lunate excision or ulnar shortening can be selected for tension-free correction. Radialization can be indicated for avoiding the recurrence of radial flexion. However, we should pay attention of the radial protrusion of the ulnar head. For avoiding the recurrence of radial deformity or circulatory impairment, gradual correction using Ilizarov external fixation can be indicated, especially in the cases with severe radial deviation or with short forearm. In the mild cases, Bayne Type I or Type II, radius lengthening is accompanied by a soft-tissue distraction or release at the ulnar carpal joint with keeping wrist and forearm motion without producing growth plate damage.

Laterality and grip strength influence hand bone micro-architecture in modern humans, an HRpQCT study.

It is widely hypothesized that mechanical loading, specifically repetitive low-intensity tasks, influences the inner structure of cancellous bone. As such, there is likely a relationship between handedness and bone morphology. The aim of this study is to determine patterns in trabecular bone between dominant and non-dominant hands in modern humans. Seventeen healthy patients between 22 and 32 years old were included in the study. Radial carpal bones (lunate, capitate, scaphoid, trapezium, trapezoid, 1st, 2nd and 3rd metacarpals) were analyzed with high-resolution micro-computed tomography. Additionally, crush and pinch grip were recorded. Factorial analysis indicated that bone volume ratio, trabeculae number (Tb.N), bone surface to volume ratio (BS.BV), body weight, stature and crush grip were all positively correlated with principal components 1 and 2 explaining 78.7% of the variance. Volumetric and trabecular endostructural parameters (BV/TV, BS/BV or Tb.Th, Tb.N) explain the observed inter-individual variability better than anthropometric or clinical parameters. Factors analysis regressions showed correlations between these parameters and the dominant side for crush strength for the lunate (r2 = 0.640, P < 0.0001), trapezium (r2 = 0.836, P < 0.0001) and third metacarpal (r2 = 0.763). However, despite a significant lateralization in grip strength for all patients, the endostructural variability between dominant and non-dominant sides was limited in perspective to inter-individual differences. In conclusion, handedness is unlikely to generate trabecular patterns of asymmetry. It appears, however, that crush strength can be considered for endostructural analysis in the modern human wrist.