Accessory Carpal Bone Research Articles

Effect of perineural anesthesia on the ultrasonographic appearance of equine palmar metacarpal structures.

The purpose of this study was to describe ultrasonographic changes of the equine palmar metacarpal area attributed to the infiltration of local anesthetic solution and to determine whether these changes were noted immediately or at 24 h. The palmar metacarpal region of one forelimb in each of six horses was examined ultrasonographically with a 10-MHz linear array transducer and a 7.5-MHz curvilinear transducer. Transverse and longitudinal images were recorded at 5-cm intervals distal to the accessory carpal bone. High and low palmar and palmar metacarpal nerve blocks were performed with a 2% mepivacaine hydrochloride solution. Ultrasonographic examinations similar to the initial examination then were performed immediately, 1 h and 24 h postinjection. Cross-sectional area and mean pixel value were determined for the superficial and deep digital flexor tendons, the accessory ligament of the deep digital flexor tendon, the suspensory ligament, and the suspensory branches at each level and time period. Subjective ultrasonographic changes also were noted. No significant difference was noted in the cross-sectional area or mean pixel value of any structure at any level or time period compared to baseline. Subjective changes in the tendons and ligaments were not noted. There was mild hypoechoic swelling of the surrounding soft tissues and gas in the region of the injections. Gas could interfere with the evaluation of the origin of the suspensory ligament and the proximal portion of the accessory ligament of the deep digital flexor tendon within the first hour but was not detectable ultrasonographically at 24 h. Based on these findings, if gas interferes with an ultrasonographic examination performed temporally close to perineural anesthesia, a repeat examination at 24 h is recommended.

Arthroscopic surgery of the carpal and digital tendon sheaths

Abstract Chronic active tenosynovitis of the digital sheath can become increasingly complicated by intrathecal mass and adhesion development, annular ligament constriction, and secondary linear clefting or flattening of the tendons. Endoscopic techniques (tenoscopy) provide a minimally invasive mechanism for thorough digital sheath examination, resection of masses and adhesions, transection of the annular ligament, and debridement of frayed edges after secondary damage. Use of a torniquet, an arthroscope entry point distal to the annular ligament, and instrument portals over the proximal cul-de-sacs of the sheath provide access for tendon and tendon sheath repair. The surgery in advanced cases can be challenging but improvement in work capability and cosmetic appearances are frequently positive. Similarly, a complex form of carpal sheath tenosynovitis can develop from intrusions of bony exostoses and osteochondroma from the radius, tears of the flexor tendons, overextension of the carpus, or fracture of the accessory carpal bone. Tenoscopic examination and debridement within the carpal sheath can assist in rehabilitation. Additionally, the proximal check ligament can be easily transected using carpal sheath tenoscopic techniques. A lateral arthroscope entry proximal to the accessory carpal bone provides access to most clinically relevant regions within the carpal sheath. Instrument portals are made after spinal needle insertion to establish the most appropriate path to the lesion. Removal of bone protrusions and tenosynovial masses, debridement of flexor tendon damage, and release of the carpal retinaculum all offer better chances of improved work capability in a variety of carpal sheath diseases. The examination of the carpal sheath and its contents is more complete than that following open approaches, and a return to rehabilitation exercise programs can be quickly initiated after surgery.

Ectrodactilia em cão (Canis domestica)

O presente trabalho relata o caso de uma cadela sem raça definida, adulta, com deformidade na região distal do membro torácico esquerdo, a qual consistia de duplicidade do osso acessório do carpo, aplasia do primeiro carpiano, ausência dos ligamentos interósseos entre o terceiro e o quarto dígitos, alterações ósseas no quarto dígito e presença de um dígito supranumerário incompleto adjacente ao quarto dígito. Após análise dos defeitos concluiu-se tratar de uma malformação congênita, hereditária em cães, denominada ectrodactilia, associada à existência de um dígito supranumerário.

Dual-energy X-ray absorptiometry measurement of bone-mineral density in the distal aspect of the limbs in racing Greyhounds.

To determine those bones in the distal aspect of the limbs of Greyhounds with fatigue fractures that have the greatest left-to-right differences in bone-mineral density (BMD). Limbs obtained from 20 Greyhounds. Dual-energy x-ray absorptiometry (DXA) of the distal aspect of each limb and isolated bones from 10 dogs with a fracture of the central tarsal bone (CTB) of the right pelvic limb was performed. High-resolution scanning was performed on excised bones, and BMD measurements of CTB also were obtained from limbs of dogs without a CTB fracture. The BMD of the accessory carpal bone and calcaneus was not significantly different from the BMD of those bones in the contralateral limb. Although BMD of the CTB of the entire right pelvic limb and isolated bones from dogs with a CTB fracture was lower, compared with values for the entire left pelvic limb, values for isolated CTB from dogs without a CTB fracture were not significantly different. Metacarpal or metatarsal and thoracic or pelvic limb significantly affected BMD for measurements of the entire limb and isolated bones. Left-to-right differences in BMD were greatest for metacarpal 5. Asymmetric adaptive remodeling of metacarpal 5 can be detected by DXA. The potentially confounding effects of CTB fracture and unknown racing history made it difficult to interpret BMD changes in the CTB of these specimens. Densitometry could be developed as an in vivo assessment for risk of fractures in racing Greyhounds.

Arthroscopic removal of os centrale carpi causing wrist pain

Summary: The os centrale carpi is a relatively rare accessory carpal bone of the wrist that infrequently has been reported to cause symptoms. This report describes 2 cases where an apparently mobile os centrale carpi caused painful clicking and crepitus and where the symptoms disappeared after arthroscopic removal of the ossicles.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 16, No 5 (July), 2000: pp 537–539

MAGNETIC RESONANCE IMAGING OF NORMAL CANINE CARPAL LIGAMENTS

Magnetic resonance imaging was conducted on previously frozen left carpi from six normal dogs using a 1.5 Tesla magnet in combination with a transmit/receive wrist coil. Three-millimeter thick T1-weighted spin-echo images and 1-mm thick T2*-weighted gradient-recalled 3-D images were obtained in dorsal and sagittal planes. Carpi were embedded, sectioned, and stained. Anatomic structures on the histologic sections were correlated with the MR images. All of the carpal ligaments plus the radioulnar articular disc and the palmar fibrocartilage were identified on MR images. The accessorio-quartile ligament, which had not been well described previously in dogs, was also identified. It originated on the accessory carpal bone and inserted on the fourth carpal bone. The T2*-weighted gradient echo imaging technique provided better images than T1-weighted technique, largely because thinner slices were possible (1 mm vs. 3 mm), resulting in less volume averaging of thin ligaments with surrounding structures. Although MRI is currently the imaging modality of choice to identify ligamentous injury in humans, further studies are needed to determine if abnormalities can be detected in canine carpal ligaments using MRI.

Tenoscopic Anatomy of the Equine Carpal Flexor Synovial Sheath

To describe the tenoscopic anatomy of the carpal sheath of the flexor tendons (carpal sheath) viewed from a lateral approach. Tenoscopic observation of structures within the carpal sheath subsequently confirmed by dissection. 12 equine cadaveric forelimbs. The limbs were positioned lateral side up with the carpus slightly flexed. After distention of the carpal sheath, a portal for the arthroscope was made approximately 3 cm proximal to the distal radial physis and 2.5 cm caudal to the radius between the tendons of the ulnaris lateralis and lateral digital extensor muscles. A lateral tenoscopic approach was adequate to identify all structures within the carpal sheath. From proximal to distal, structures identified using this approach were the radial head of the deep digital flexor muscle, accessory ligament of the tendon of the superficial digital flexor muscle, distal radial physis, tendons of the superficial and deep digital flexor muscles, accessory carpal bone, antebrachiocarpal and middle carpal joints, and vincula of the tendon of the deep digital flexor muscle. A lateral tenoscopic approach offered an easy, repeatable entry into the carpal sheath and allowed good observation of all structures within the sheath except for the medial borders of the tendons of the deep and superficial digital flexor muscles. Applications of a lateral tenoscopic approach to the carpal sheath include diagnostic procedures, lavage and synovial resection for septic tenosynovitis, desmotomy of the accessory ligament of the tendon of the superficial digital flexor muscle for flexural deformity or tendinitis, and removal of osteochondromas from the distal radial metaphysis.

Surgical treatment of a comminuted articular fracture of the accessory carpal bone in a thoroughbred horse

The clinical, radiographic and ultrasonographic findings in a case of a comminuted articular fracture of the accessory carpal bone of a thoroughbred chaser are described, and its surgical treatment and...

Carpal injuries in the dog

INTRODUCTION The carpus comprises the antebrachiocarpal joint, the middle carpal joint and the carpometacarpal joint. Intercarpal joints exist between individual carpal bones in each row. There are seven named carpal bones. The radial, ulnar and accessory carpal bones form the proximal row and the distal row contains the first, second, third and fourth carpal bones. The antebrachiocarpal joint accounts for 80-90% of carpal movement. The carpus depends upon the surrounding soft tissue structures for its support. The most important structures are the palmar ligaments and a fibrocartilage pad which prevent hyperextension. The major carpal ligaments are the palmar ligaments that Connect the radial and accessory carpal bones with the metacarpal bones, and the short radial collateral ligaments.

Ultrasonography as a method to determine tendon cross-sectional area

SUMMARY Ultrasonographic cross-sectional area (csa) measurements of equine superficial digital flexor (sdf) tendon were obtained to determine the feasibility of ultrasonography for csa measurement of tendon in vivo and in vitro. Ultrasonographic measurements were compared with a more traditional csa measurement method, ink-blot analysis. In addition, values for ultrasonographic sdf tendon mean echogenicity were obtained in vivo and in vitro. The left forelimb sdf tendons of 23 horses were evaluated ultrasonographically. Cross-sectional images were acquired at 4-cm intervals distal to the base of the accessory carpal bone (dacb) to the level of the proximal sesamoid bones while horses were standing squarely. After euthanasia, the left forelimbs were mounted in a materials testing system (mts) and loaded under tension to standing load. Ultrasonographic images were again acquired at the same locations. The ultrasonographic images were digitized, and values for ultrasonographic csa and mean echogenicity were obtained for each level. Immediately after mechanical testing, a 1-cm-thick transverse section of sdf tendon at 12 cm dacb was removed. Three ink blots were prepared from each end of the removed tendon section and digitized. The 6 csa values were averaged to generate a value for morphologic csa for each sdf tendon at 12 cm dacb. Standing ultrasonographic tendon csa at 12 cm dacb was consistently smallest (mean ± sd csa = 86 ± 11 mm2), followed by mts ultrasonographic csa (mean, 95 ± 12 mm2), ink-blot morphologic csa being largest (mean, 99 ± 15 mm2). Comparison of standing and mts ultrasonographic csa values at 12 cm dacb revealed a strong positive linear correlation between methods (R2 = 0.74, P = 0.001). Comparison of ink-blot csa at 12 cm dacb with standing and mts ultrasonographic csa revealed strong positive linear correlations (R2 = 0.64, P = 0.001 and R2 = 0.72, P = 0.001, respectively). For ultrasonographic mean echogenicity, standing values insignificantly exceeded mts values at each level. The authors conclude that ultrasonography is a useful technique for the noninvasive assessment of sdf tendon csa that can be applied in vivo and in vitro.

Ultrasonographic cross-sectional area and mean echogenicity of the superficial and deep digital flexor tendons in 50 trained Thoroughbred racehorses

SUMMARY Fifty Thoroughbred horses were examined. All horses had been in race training for a minimum of 4 months before examination and had worked at racing speed; 24 horses had raced. All horses were clinically sound at the time of examination. Ultrasonography was performed, using a 7.5-MHz transducer with built-in fluid offset. Videotaped images of the palmar soft tissue structures were obtained at 4, 8, 12, 16, 20, and 24 cm distal to the base of the accessory carpal bone (dacb). Images were digitized, and each image was calibrated. Values for cross-sectional area (csa) and mean echogenicity (me) were then determined from the cross-sectional images of the superficial digital flexor (sdf) and the deep digital flexor (ddf) tendons, using an image-analysis program. The sdf tendons were compared between right and left forelimbs at each level, and from proximad to distad on each limb, as were the ddf tendons. The relation between the sdf and ddf tendons for the same forelimb was determined at each level. There were no significant differences in csa or me at equivalent levels of the left and right sdf tendons. Mean (± sd) csa was 1.01 (± 0.12) cm2 at 4 cm dacb, 0.95 (± 0.14) cm2 at 12 cm dacb, and 1.12 (± 0.15) cm2 at 24 cm dacb. Adjusted me was 2.34 (± 0.34) at 4 cm dacb, 2.03 (± 0.38) at 12 cm dacb, and 2.04 (± 0.35) at 24 cm dacb. The left and right ddf tendons did not have significant differences in csa or me at any level. Cross-sectional area was 1.13 (± 0.18) cm2 at 4 cm dacb, 1.01 (± 0.12) cm2 at 12 cm dacb, and 1.75 (± 0.29) cm2 at 24 cm dacb. Adjusted me was 2.60 (± 0.46) at 4 cm dacb, 2.49 (± 0.49) at 12 cm dacb, and 2.50 (± 0.44) at 24 cm dacb. At all levels, the left and right sdf tendons were smaller and less echoic than the ddf tendons of the same limb. The sdf and ddf tendons had an hourglass shape, with smallest csa at 12 cm dacb. Mean echogenicity generally decreased for the sdf and ddf tendons from proximad to distad on the limb. These results indicate that for clinically normal trained Thoroughbred racehorses, there should be no significant difference in csa or echogenicity between the left and right sdf tendons at equivalent distances dacb. There should be no significant differences in the left and right ddf tendons at equivalent levels dacb. The sdf tendon is usually smaller and less echoic than the corresponding ddf tendon at each level.

OS centrale carpi simulating a scaphoid waist fracture

The os centrale carpi is a relatively rare accessory carpal bone, and its presence may be confused with a scaphoid fracture. A case is presented which simulated an un-united scaphoid fracture on the plain X-ray film. However, CT in the sagittal plane showed two rounded fragments on the dorsum of the scaphoid with smooth, regular cortical margins differing from an acute scaphoid fracture. Their volume combined with the volume of the scaphoid is more than that of a completely normal scaphoid. There is no evidence of degeneration in the two rounded fragments and scaphoid. Because of these features, the diagnosis of soft tissue injury with an incidental finding of an os centrale carpi was suggested.

Accessory carpal bone fractures in the horse

Summary The clinical signs, the radiographic appearance, and the treatment of two cases of fracture of the accessory carpal bone are described. The fractures were in the vertical plane. Surgical intervention consisted out of fixation of the fracture with two lag screws. Follow-up information revealed that one horse became sound and returned to complete athletic activity whereas the other horse remained lame. A brief literature review is given and the surgical treatment and the complications are discussed.

Sonographic brightness of the flexor tendons and ligaments in the metacarpal region of horses

Summary Sonographic observations were made of the image mean gray scale (mgs) of the flexor tendons and ligaments in the left and right metacarpal regions of each of 10 clinically normal horses. In images made in the dorsal and sagittal planes, the mgs was measured at multiple sites in the superficial digital flexor tendon (sdft), deep digital flexor tendon (ddft), accessory ligament (al), and suspensory ligament (sl), and at single sites in the medial and lateral limbs of the sl, and the palmar ligament. Relative sonographic brightness of each tendon and ligament was calculated by dividing the value of its mgs by the mean value for the mgs of images of 3 soft tissue equivalent phantoms. When a multivariate repeated-measures of anova of the relative brightness values was statistically significant (P ≤ 0.05), Tukey's method of multiple comparisons was used to determine which values were significantly different from each other. In the dorsal plane, the sl was significantly brighter than the ddft, sdft, and al; relative brightnesses of the ddft and sdft were similar, as were those of the sdft and al. In the sagittal plane, the sl again was the significantly brightest structure, followed by the al, and similar brightnesses of the ddft and sdft. In dorsal images made 25 cm distal to the accessory carpal bone, relative brightnesses of the sdft, ddft, and the medial and lateral limbs of the sl were similar. In images made 30 cm distal to the accessory carpal bone, relative brightness of the palmar ligament was significantly (P < 0.05) less than that of the sdft and ddft in the dorsal plane, but not in the sagittal plane, where it was significantly greater. Relative brightness values represented a unique sonographic characteristic of each structure and, in the future, may provide further insights into tendon and ligament structure and function.

Bilateral os centrale carpi: A rare congenital variant

Accessory carpal bones are found in 2% of the population. 1 Os centrale is a rare example of one of these anomalies and is either an accessory bone or an empty space found between the scaphoid, the trapezoid, and the capitate on x-ray films of the hand. It is important because it may be mistaken for a scaphoid fracture.

Fractures of the accessory carpal bone

Equine Veterinary EducationVolume 2, Issue 4 p. 188-190 Fractures of the accessory carpal bone Sue J. Dyson, Sue J. Dyson Animal Health Trust, PO Box 5, Newmarket, Suffolk, UK.Search for more papers by this author Sue J. Dyson, Sue J. Dyson Animal Health Trust, PO Box 5, Newmarket, Suffolk, UK.Search for more papers by this author First published: December 1990 https://doi.org/10.1111/j.2042-3292.1990.tb01441.xCitations: 18AboutPDF ToolsExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume2, Issue4December 1990Pages 188-190 RelatedInformation

The osseous repair of a horizontal fracture of the accessory carpal bone in a Thoroughbred racehorse

Equine Veterinary EducationVolume 2, Issue 4 p. 173-176 The osseous repair of a horizontal fracture of the accessory carpal bone in a Thoroughbred racehorse Deidre M. Carson, Deidre M. Carson Beaufort Cottage Stables, High Street, Newmarket, Suffolk, UK.Search for more papers by this author Deidre M. Carson, Deidre M. Carson Beaufort Cottage Stables, High Street, Newmarket, Suffolk, UK.Search for more papers by this author First published: December 1990 https://doi.org/10.1111/j.2042-3292.1990.tb01436.xCitations: 4AboutPDF ToolsExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume2, Issue4December 1990Pages 173-176 RelatedInformation

Giant cell tumor of the accessory carpal bone in a dog

Giant cell tumor of the accessory carpal bone in a dog

Unilateral osteonecrosis in a patient with bilateral os centrale carpi

Accessory carpal bones, although uncommon, are usually of no clinical significance. This report describes a patient who had bilateral presence of the accessory bone called the os centrale carpi. The patient was seen with disabling pain in the dominant right wrist and both radiologic and pathologic findings showed osteonecrosis and secondary degenerative arthritis. His left wrist was asymptomatic and the accessory ossicle was normal in appearance. We have not been able to discover any cases in the literature describing the development of unilateral osteonecrosis in a patient with bilateral os centrale capri.

Characteristics of Accessory Carpal Bone Fractures in 50 Racing Greyhounds

Fifty racing greyhounds with fracture of the accessory carpal bone presented to the Veterinary Teaching Hospitals at The University of Sydney (n = 35) and Colorado State University (n = 15) were reviewed for the purpose of identifying the frequency of the various fracture types, and to suggest possible factors which predispose to the injuries. All but three fractures occurred while the dogs were racing. All dogs raced on elliptical tracks in a counterclockwise direction, and this was implicated in the pathogenesis and anatomical distribution of these fractures.