Barny Fraser

Objective
To determine the ideal location of a medial tenoscopic portal in the equine carpal flexor tendon sheath (CFTS) using contrast computed tomography (CT).

Study design
Experimental cadaver study.

Animals
A total of 20 entire forelimbs from adult Standardbred horses.

Methods
Contrast media diluted in saline was injected into the CFTS from a lateral approach before manually flexing and extending the limb 20 times to disperse the contrast solution. The limbs were placed in lateral recumbency and a capped 21-gauge 1.5 inch needle was placed approximately 5 mm proximal and 32 mm caudal to the palpable distal medial radial physis into the medial aspect of the CFTS. Contrast CT was performed followed by tenoscopy using the conventional lateral approach. Gross dissection was then performed to determine if any damage was caused by needle placement. CT images were reviewed for impingement of intrathecal structures, the cephalic vein (CV) and the flexor carpi radialis tendon (FCRT).

Results
Neither intrathecal nor macroscopic superficial damage was caused by needle placement. Impingement of the FCRT and CV, identified on CT, occurred in seven specimens (35%) and one specimen (5%), respectively.

Conclusion
The location for a medial tenoscopic portal was identified in the current study.

Clinical significance
Establishment of the location of a medial tenoscopic portal may help surgeons improve triangulation, egress and visualization of structures within the carpal sheath.

A 5-year-old Anglo-Nubian wether goat presented for evaluation of carpal varus deformity. Chronic disuse muscle atrophy and marked lameness developed in the affected limb. The associated physes appeared radiographically closed; however, the opposite limb also developed mild varus deviation at the carpus. Radial wedge ostectomy and double plating of the radius with narrow 4.5 mm locking compression plates surgically corrected the deformity and associated lameness. Physiotherapy was performed to increase muscle mass development following surgery. This report discusses and describes the surgical technique used to successfully correct severe carpal varus in an adult goat.

An 11-month-old entire male Cob colt was presented for unilateral cryptorchid castration and intermittent purulent urethral discharge. Cystoscopy, trans-cutaneous and trans-rectal abdominal ultrasonography and contrast enhanced computed tomography examinations confirmed unilateral cryptorchidism, ipsilateral renal dysplasia and pyoureter with dilatation and ectopia. While nephrectomy may be a viable treatment approach for some cases of unilateral renal dysplasia, surgical intervention was not attempted in this case owing to financial constraints and the yearling was subjected to euthanasia. To the authors' knowledge, this is the first report of a case of complex congenital urogenital malformation including ipsilateral renal dysplasia, pyoureter with dilatation and ectopia and cryptorchidism, a finding which has been reported more commonly in human males.

This paper reports the diagnosis and repair of synovial fistulae between a carpal hygroma and both the antebrachiocarpal (ABC) joint and the extensor carpi radialis (ECR) tendon sheath of the left carpus in a 7‐year‐old gelding. The communication was confirmed using contrast radiography. Arthroscopy visualised the synovial fistulae and aided in the surgical repair. The gelding made a full athletic and acceptable cosmetic recovery.

The authors present a case of a racehorse with acute respiratory distress, bilateral epistaxis and laryngeal swelling following a laryngeal tie-forward procedure. An emergency tracheostomy was performed following brief endoscopic examination identifying significant pharyngeal collapse and a minimally patent airway. No cranial nerve deficits or obvious neurological abnormalities were present. Lateral radiographs ruled out a fracture and provided a preliminary diagnosis of hyperextension injury. CT 24 hours later showed marked soft tissue swelling consistent with haemorrhage associated with the ventral straight muscles, causing median septum disruption. No fractures were identified. Endoscopy four days postoperatively confirmed the haemorrhage was external to the guttural pouches consistent with ventral straight muscle rupture. The horse was treated conservatively with five weeks of box rest. The tracheostomy tube was removed 19 days postoperatively. The horse was then discharged and gradually returned to exercise, winning a race nine months later.

Solitary osteochondromas are a relatively infrequent cause of lameness in the horse, most commonly occurring in the caudal distal radial metaphysis, with sparse reports in other locations. Their presence adjacent to a synovial sheath frequently results in intra-thecal tendinous laceration and resultant synovial effusion. Surgical excision in combination with arthroscopic debridement of the tendinous pathology offers the best prognosis for soundness. This report details the successful treatment of a caudodistal tibial osteochondroma using a combination of open surgical excision and tarsal sheath tenoscopy.

Patellar luxation associated with traumatic injury is rare in the horse, and surgical correction has not been adequately described. This case report describes the clinical findings associated with traumatic lateral patellar luxation in a 2-day-old cob colt, and the technique used for successful surgical repair. A combination of computed tomography (CT), radiography and ultrasound was used to diagnose lateral luxation of the patella due to a complete tear of the vastus medialis muscle. All patellar ligaments were intact and no congenital abnormalities associated with the patellar luxation were present. Surgical correction of the patellar luxation was achieved using a lateral release of the patella performed by transection of the lateral femoropatellar ligament along with overlying fascia, and stabilisation of the patella by medial imbrication of the medial patellar ligament and parapatellar fascia to the distal tendon of the sartorius muscle. Radiographs at 18 weeks of age showed the patella in a normal position in a well-developed trochlear groove. At 1 year of age the foal was walking and trotting sound, with normal range of motion of the affected stifle.

Information available on duodenal impactions is limited. The authors present a case of a horse showing clinical signs likely indicating a small intestinal lesion, with anterior enteritis and a strangulating lesion as the most likely differentials. Due to diagnostics not strongly indicating either, the horse was initially monitored. With no clinical improvement after nasogastric decompression, anterior enteritis was considered unlikely and intervention was required. Exploratory laparotomy revealed an intraluminal obstruction oral to the duodenocolic ligament indicating a duodenal impaction. Manual decompression dislodged, broke apart and pushed the obstruction into the caecum. Postoperatively, ultrasonography revealed numerous intraluminal short linear hyperechoic foci consistent with foreign material, and gastroscopy revealed extensive grade 4 squamous ulceration. From the third day postoperatively droppings were passed containing hawthorn twigs, seeds and husks, concluding that was a duodenal hawthorn impaction. The horse responded well to surgical treatment and rehabilitated with no further abnormalities.

Placing a sterile glass ball or marble into the uterine lumen is a popular method to suppress unwanted oestrous behaviour in mares. This is in spite of the original report of Nie et al. (2003), which detailed the lack of efficacy of the technique. Recent reports in the literature have described a number of untoward problems associated with the technique. This paper describes two further cases, one involving fragmentation of marbles in the uterine lumen and a second describing the laparoscopic removal of a marble after it had tracked through the endometrium and became pedunculated between the myometrium and serosa. The inefficiency of suppressing oestrus with glass balls, combined with the potential problems their placement may cause, argue strongly that this practice should be considered unethical.

Pre-surgical investigation of digital flexor tendon sheath pathology remains challenging with current standard imaging techniques. The aim of this prospective, anatomical, pilot study was to describe the anatomy of the equine hind limb digital flexor tendon sheath using a combination of computed tomography (CT) and computed tomographic contrast tenography in clinically normal cadaver limbs. Ten pairs of hind limbs with no external abnormalities were examined from the level of the tarsometatarsal joint distally. Limbs initially underwent non-contrast CT examination using 120 kVp, 300 mAs, and 1.5 mm slice thickness. Sixty millilitres of ioversol iodinated contrast media and saline (final concentration 100 mg/ml) were injected using a basilar sesamoidean approach. The computed tomographic contrast tenography examination was then repeated, before dissection of the specimens to compare gross and imaging findings. The combined CT and computed tomographic contrast tenography examinations provided excellent anatomical detail of intra-thecal structures. The borders of the superficial and deep digital flexor tendons, and the manica flexoria were consistently identifiable in all limbs. Detailed anatomy including that of the mesotenons, two of which are previously undescribed, and the plantar annular ligament were also consistently identifiable. Dissection of all 10 pairs of limbs revealed there to be no pathology, in accordance with the imaging findings. In conclusion, the combination of CT and computed tomographic contrast tenography may be useful adjunctive diagnostic techniques to define digital flexor tendon sheath pathology prior to surgical exploration in horses.