Lag Screw Fixation of a Sagittal Fracture of the Third Carpal Bone in a Horse

A sagittal fracture of the third carpal bone of a Standardbred racehorse was repaired with lag screw fixation. Healing of the fracture was uncomplicated, and the horse made a successful return to racing. It was concluded that selected sagittal fractures of the third carpal bone may be treated successfully with lag screw fixation. Criteria for selection of cases include fragment size and orientation of the fracture plane.     

Modified Tenoscopic Method for Carpal Flexor Retinaculum Release in a Horse

Objective— To report the use of a proximolateral endoscopic portal with a distolateral instrument portal for carpal retinaculum release in a horse clinically affected with carpal canal syndrome. Study Design— Clinical report. Animals— A 4‐year‐old Thoroughbred female. Methods— Carpal canal syndrome secondary to traumatic suppurative tenosynovitis was treated by accessory carpal bone debridement and carpal retinaculum release using a tenoscopic approach to the carpal flexor synovial sheath through a proximolateral endoscope portal and a distolateral instrument portal. Results— Resolution of carpal sheath effusion and lameness occurred allowing racing 14 months later. Use of a distolateral instrument portal was not associated with complications or iatrogenic damage to neurovascular structures and reduced endoscope and instrument interference and offered easier access to the distal aspect of the carpal sheath. Conclusions— Carpal retinaculum release may be safely accomplished with a distolateral instrument portal when access to the distal aspect of the carpal sheath is needed. Clinical Relevance— The distolateral instrument portal described may be a useful alternative to a proximolateral portal when distal carpal sheath instrument access is necessary or advantageous.     

Cortical Bone Allografting in the Horse

Half and full cylindrical frozen cortical bone allografts were transplanted into groups of horses. All horses accepted, resorbed, and began replacement of their grafts to varying degrees, according to frequent radiographic and monthly histologic evaluation. Clinically, all the recipients appeared to return to varying degrees of function. This method of bone allografting is suggested as an adjunct to current methods of fracture fixation in the horse.     

Bilateral Rupture of the Palmar Carpal Ligament in a Horse Suffering from Acute Diaphragmatic Hernia

A 20-year-old Argentinian gelding was evaluated for sudden weakness, muscular tremors, tachypnea, and reluctance to move. On admission, a mild bilateral hyperextension of the carpi was noticed. On the basis of the clinical, laboratory, and ultrasonographic findings, a diagnosis of diaphragmatic hernia was made. During confinement, the hyperextension of the carpi worsened. Because radiographic examination of both carpi revealed palmar-lateral diastasis of the accessory carpal bone, bilateral rupture of the palmar carpal ligament (PCL) was suspected. Gross pathology confirmed the diaphragmatic hernia and the bilateral rupture of the PCL. Rupture of a PCL in a horse has been previously described, and conformation of the forelimb of that horse was similar to that of the horse in the case described in this article.     

Anatomo-radiographic Study on the Osteogenesis of Carpal and Tarsal Bones in Horse Fetus

The aim of this study is to point out the time of appearance of the carpal and tarsal bones in the fetal horse, considering an estimated fetal age, to follow their morphological development through to birth, and to characterize possible abnormal shape and/or delay of their ossification. The right carpal and tarsal region of 140 equine fetuses of both sexes (71 males, 69 females) and different ages (from 70 to 340 days of gestation) were examined radiographically in order to identify the sites of ossification from their earliest appearance. The times of appearance of the sites of ossification of the carpal bones are chronologically stated for each bone.     

An Additional Bone in the Carpal Region of Raptorial Birds

In a series of 4 species of owls and 12 species of diurnal raptors, an additional bone was present bilaterally in the area of the carpus. Designating the bone as an “additional bone of the raptorial carpal region” is suggested pending appropriate embryological studies to determine the origin of the bone. Generally, the bone was present in owls and in diurnal raptors with relatively short, rounded wings, but was absent in species with longer, more tapered wings. The bone lies at the cranial edge of the carpal area near the radial carpal bone, and is fixed to the surrounding skeleton by ligaments. The tendon of the tensor patagium longus muscle has one slip that attaches to the additional bone and another that passes over its craniodorsal surface en route to insertion. Awareness of the occurrence of this bone in some raptors, but not others, is essential in clinical evaluation of wing injuries, as well as in forming a prognosis for the return to soundness, the potential for release, and, therefore, the life of an injured raptor.     

Surgical Management of Proximal Splint Bone Fractures in the Horse

Fractures of Metacarpal and Metatarsal II and IV (the splint bones) were treated in 283 horses over an 11 year period. In 21 cases the proximal portion of the fractured bone was stabilized with metallic implants. One or more cortical bone screws were used in 11 horses, and bone plates were applied in 11 horses. One horse received both treatments. Complications of screw fixation included bone failure, implant failure, radiographic lucency around the screws, and proliferative new bone at the ostectomy site. Only two of the horses treated with screw fixation returned to their intended use. Complications of plate fixation included partial fixation failure (backing out of screws), wound drainage, and proliferative bony response around the plate. Six of the 11 horses treated by plate fixation returned to their intended use. The authors recommend consideration of plate fixation techniques for repair of fractures in the proximal third of the splint bone.     

Evaluation of the Tibia as a Source of Autogenous Cancellous Bone in the Horse

A 1 cm defect was created in the proximal medial cortex of 12 tibiae, cancellous bone was removed from the site, and the bones were fractured by loading in torsion. The fractures did not occur through the donor sites and the fracture patterns and loads to fracture were similar for the treated tibiae and their untreated mates. Cancellous bone was harvested from the proximal medial aspect of both tibiae in nine adult horses. The soft tissue wounds were monitored for more than 10 days in seven horses and healing of the osseous defects was evaluated radiographically at regular intervals to month 6 in two horses. The site provided convenient access with the horses in lateral or dorsal recumbency, the anatomic landmarks were reliable, and the surgical procedure was simple and short. Complications occurred in only three incisions.     

Pancarpal Arthrodesis for Treatment of Carpal Collapse in the Adult Horse A Report of Two Cases

Two mares with multiple carpal bone fractures, malarticulation and degenerative joint disease were successfully treated with unilateral arthrodeses of the antebrachiocarpal, middle carpal, and carpometacarpal joints. Arthrodesis was achieved by removal of articular cartilage, autogenous cancellous bone graft, and double dynamic compression plating. In one horse, wedge ostectomy corrected the severe, acquired angular limb deformity. External coaptation supplemented the internal fixation. Postoperative complications were limited to cast sores that healed with treatment, although protracted in one horse. Both mares adapted to the "peg leg" condition and ambulated without pain by 3 months. The first mare treated survived for at least 2 1/2 years after surgery and has had at least one foal. The most recently treated mare will be bred next year.     

Accessory Carpal Bone Fractures in the Racing Greyhound: Classification and Pathology

Fractures of the accessory carpal bone in 35 racing Greyhounds were classified into five types. Type I fractures (27 fractures) involved the distal articular surface of the accessory carpal bone, type II (6 fractures) were of the proximal articular margin, type III (1 fracture) were at the origin of the accessorometacarpal ligaments, type IV (6 fractures) were avulsion fractures at the tendon of insertion of the flexor carpi ulnaris muscle, and type V (3 fractures) were comminuted fractures.     

A Large Frontonasal Bone Flap for Sinus Surgery in the Horse

A large frontonasal bone flap was created to treat diseases of the paranasal sinuses in 14 horses. The bone flap was made as wide as possible within the confines of the nasolacrimal duct so the floor of the frontal sinus and the dorsal and ventral conchae could be opened. These openings exposed the nasal passages, maxillary sinuses, and ventral conchal sinus thereby facilitating removal of diffuse and localized lesions from these sites. Diseases treated were ethmoid hematomas (4 horses), sinus cysts (5 horses), cryptococcal granuloma, osteoma, hemangiosarcoma, pus in the ventral conchal sinus, and periapical infection of a second molar. Four horses were euthanatized during or after surgery, one because of postsurgical pleuritis and pneumonia (horse with osteoma) and three because of their primary problems (cryptococcal granuloma, hemangiosarcoma, pus in the ventral conchal sinus). Skin suture abscesses that responded to treatment developed in four horses. Ten horses returned to their intended uses, the sinus flaps healed without blemish, and the original problems did not recur. The frontonasal flap technique provided greater access to all paranasal sinuses than methods described previously.     

Incorporation of Fresh and Cryopreserved Bone in Osteochondral Autografts in the Horse

The structural integrity of subchondral bone in fresh and frozen osteochondral autografts was investigated at month 3 in 10 horses. Two osteochondral autografts were harvested from the lateral aspect of the lateral trochlear ridge of the left talus in each of 10 anesthetized horses. Grafts were frozen in 7.5% DMSO. After 14 days, the thawed grafts were press-fitted into drill holes in the trochlear ridges of the right stifles. A fresh graft from the right hock was implanted in each left stifle. To control for the effects of surgery, a fresh graft was transferred from the right stifle to the left stifle. The end result was two grafts in each femoropatellar joint. Fresh and frozen bone grafts maintained a structurally intact support for the cartilage surface. Graft stability and surface congruency were determining factors in the outcome of the grafts. Incorporation of both types of graft was complete at month 3, but remodeling of the fresh grafts was more active.     

Carotenodermia in a Horse

This case report describes an 11-year-old Appaloosa gelding that was examined because of yellow–orange tinting of the skin of the muzzle, eyelids, sheath, anus, and perianal region without discoloration of the sclera or mucus membranes. The horse was reported to preferentially eat dandelions which were plentiful in the pasture. Physical examination was normal, except for the discolored skin. A serum chemistry panel was normal. Carotenodermia was suspected. Serum carotenoid concentrations were higher in the affected horse as compared with concentrations in two horses with depigmented skin of normal color that were on grass pasture in the same geographic area. The horse remained systemically healthy and the abnormal skin color had almost disappeared when he was examined 7 weeks later. Carotenodermia can occur in horses and can be differentiated from jaundice because the sclera remains unaffected. Veterinarians should be aware that the condition is benign and spontaneously resolves after stopping carotenoid intake.     

门源马骨营养状况的检测

对门源县 3 8匹马的骨营养状况指标进行了检测。结果发现 :门源马的血清钙浓度为 2 .68mmol L ,血清无机磷浓度为 1.3 6mmol L ,血清碱性磷酸酶活性为 66.0 4IU L ,血清羟脯氨酸含量为 15 .2 6μmol L ,均处于正常的范围。按性别组间比较 ,公马的血清钙浓度显著高于母马的 (P <0 .0 5 ) ,其他各项指标均无显著性差异 (P >0 .0 5 )。     

Changes in Third Carpal Bone Articular Cartilage After Synovectomy in Normal and Inflamed Joints

Objective —To determine if arthroscopic synovectomy in normal and inflamed joints had temporal or site-related effects on articular cartilage.
Study Design —Alterations in equine third carpal bone articular cartilage were studied at two time periods: groups 1 and 2 (6 weeks) and groups 3 and 4 (2 weeks) after synovectomy in normal (groups 2 and 4) and inflamed carpi (groups 1 and 3).
Animal Population —16 carpi from eight horses.
Methods —Biochemical and biomechanical properties of dorsal and palmar articular cartilage were determined by radiolabeling, proteoglycan (PG) extraction, chromatography, electrophoresis, and indentation testing.
Results —Synovectomy in inflamed joints produced the greatest concentration of newly synthesized PG in articular cartilage by 2 weeks. Synovectomy in normal joints produced significantly greater newly synthesized PG in articular cartilage by 6 weeks. Endogenous PG was only significantly greater in inflamed joints after 6 weeks. Dorsal sites had greater newly synthesized and endogenous PG in some groups. Chromatographic profiles of newly synthesized PG demonstrated early and late PG peaks. Electrophoresis of late PG peak showed a toluidine blue-positive band that comigrated with human A1D1 PG monomer in the two groups with the most newly synthesized PG. This band was reactive with monoclonal antibody 1C6 specific for the hyaluronic acid-binding region of aggrecan. For the material properties evaluated, only Poisson's ratio was significantly decreased between groups as a function of time (6 weeks < 2 weeks), and this was most pronounced in the thicker dorsal sites.
Conclusions —Synovectomy in inflamed joints produced site-specific, significantly greater responses in articular cartilage as compared with synovectomy in normal joints.
Clinical Relevance —Synovectomy may not be beneficial to the articular cartilage in inflamed joints.     

Laparoscopic Adhesiolysis in a Horse

Objective —The purpose of this report was to describe the use of laparoscopy as a method of treatment for abdominal adhesions in the horse.
Clinical Report —Unilateral ovariectomy for removal of a granulosa cell tumor was performed through a diagonal paramedian approach in a 14-year-old Arabian mare. Progressive incisional swelling and hemorrhage culminated in acute incisional dehiscence with herniation of ileum on the sixth postoperative day. Septic peritonitis that responded to parenteral antibiotic therapy was identified 7 days after hernia repair. Seven days later, the mare had signs of abdominal pain, and adhesions of small intestine to the paramedian incision were identified on rectal palpation. Transrectally assisted laparoscopic adhesiolysis was performed. No further complications occurred.
Clinical Relevance —Laparoscopic adhesiolysis may provide better observation of adhesions and reduced postoperative morbidity compared with laparotomy.