Carpal collateral ligament desmopathy in three horses.

The radiographic and ultrasonographic findings in three horses with severe damage to the collateral ligaments of the carpus, associated with degenerative joint disease, are described. The horses remained lame despite prolonged rest and medical management, primarily because of the progression of the joint disease. Ultrasonography was found to be an accurate method for diagnosing the injury to the ligaments and is recommended as part of a routine examination in suspected carpal injuries.

Comparison of radiography and scintigraphy in the diagnosis of dental disorders in the horse.

Scintigraphy, with 99mTechnetium methylenediphosphonate (99mTc-MDP) and 99mTc-labelled leucocytes, was compared to radiography in the diagnosis of dental disease in the horse in a prospective case-controlled study, comprising 30 horses with clinical signs of dental disease and 30 control horses. In each case, right and left lateral, ventral and dorsal soft tissue and bone phase scintigraphic images were obtained after i.v. injection of 1 GBq/100 kg bwt 99mTc-MDP, using a gamma camera. The same views were acquired in 10 horses with clinical signs of dental disease and 12 control horses after injection of 99mTc-labelled leucocytes. Standard radiographic projections of the paranasal sinuses and of the apices of the maxillary and mandibular teeth were obtained. The scintigraphs and radiographs were assessed subjectively by 2 board-certified surgeons and one board-certified radiologist, with extensive experience of equine radiology, from who the clinical history was withheld. Sensitivity, specificity and kappa, as a measure of agreement, were calculated for the different methods. Bone phase images were also scored subjectively on a scale from 0 to 3 on the basis of isotope uptake over the teeth. Regions of interest were defined over the teeth, and normal teeth compared to diseased counterparts. Total scintigraphic counts were related to the age of the animal and to the disease process. Differences in density ratios between left and right teeth were evaluated using the Mann-Whitney Test. Dental disease was confirmed in 22 horses at surgery or postmortem examination. Horses with dental disease showed a significant increase in scintigraphic activity over the affected tooth compared to the contralateral tooth, with a typical pattern for different diseases. The sensitivity of scintigraphy with 99mTc-MDP proved to be excellent (95.5%), whereas the specificity was moderate (86.4%). In contrast, radiography had excellent specificity (95.0%) and a low sensitivity (51.5%). The greatest sensitivity and specificity were achieved by evaluating radiographs and scintigrams together. The objective scintigraphic density ratios were found to be significantly different between diseased and control horses. The results of this study suggest that, if a density ratio of 1.5 or greater between a suspected diseased tooth and its contralateral number is regarded as abnormal, only 1% false positive diagnoses and 20% false negative diagnoses will occur. In contrast, scintigraphy with 99mTc-labelled leucocytes was not very successful, due to the lack of anatomical detail provided by this technique, which made identification of the diseased tooth impossible. Accurate radiographic interpretation of dental disease presents difficulties, both in terms of missed diagnoses and mistaken diagnoses. Scintigraphy complements radiographic examination of dental structures by providing information important for accurate diagnosis and is, therefore, conceived to be essential for selection of the appropriate treatment for dental disease.

Endoscopic examination of the tarsal sheath of the lateral digital flexor tendon in horses.

This study was designed to develop a reliable technique for endoscopic examination of the tarsal sheath of the lateral digital flexor tendon of horses. The anatomy of the tendon sheath and associated structures was studied in detail in cadavers before determining portals for the insertion of an arthroscope into the sheath. Approaches into the sheath through the proximal pouch and through the flexor retinaculum, at the level of the sustentaculum tali, were performed and compared in cadavers. The proximal pouch portal permitted visualisation only of the proximal half of the sheath, while the approach through the retinaculum allowed examination of the entire sheath. The normal endoscopic appearance of the tarsal sheath was studied. The endoscopic approach was subsequently used to examine and treat 5 horses with tarsal sheath tenosynovitis, including 2 cases of chronic, traumatic tenosynovitis and 3 of subacute septic tenosynovitis. Four of these horses had fragmentation of the sustentaculum tali. The technique allowed adequate examination of the sheath and debridement of adhesions and lesions within the lumen of the sheath. Fragments dorsal to the medioplantar edge of the sustentaculum tali could not be visualised endoscopically and had to be removed after widening of the wound. All 5 horses survived. Follow-up enquiries (8-31 months) revealed that the horses were all reported to be sound. Four were performing at their previous level of activity, 1 was used for hacking. The 2 cases presented with chronic tenosynovitis had residual sheath distension with no associated loss of function. A prospective study, including longer term follow-up investigation, is currently being performed.

Comparison of radiography, scintigraphy and ultrasonography in the diagnosis of a case of temporomandibular joint arthropathy in a horse.

Diagnosis of temporomandibular joint disease in the horse presents a challenge to the equine veterinarian. This case report illustrates a combined imaging approach using radiography, scintigraphy and ultrasonography in a horse with severe arthropathy of the left temporomandibular joint. Radiographs were inconclusive. Scintigraphy with Tc99m methylenediphosphonate localised, but failed to characterise the disease process; ultrasonography was the only imaging method which both localised and characterised the lesion. Ultrasonography proved to be a relatively cheap, technically easy to perform and non-invasive method for the assessment of the disease.

Septic osteitis of the distal phalanx: findings and surgical treatment in 18 cases.

Eighteen cases of septic osteitis of the distal phalanx were diagnosed clinically and confirmed at surgery over a 6 year period (1990-1996). Focal bone lysis was the most common radiographic finding. Sequestra were identified in 4 horses, one of which was associated with a fractured plantar process. All the horses were treated surgically with open debridement. The septic process recurred in 4 horses: one was subjected to euthanasia due to navicular bursa infection, secondary to a pathological fracture, the other 3 horses responded to further debridement. A pathological fracture occurred in another horse. All the survivors were not lame 3 months post operatively, although complete healing took 1-12 months. Long term follow up was available in 14 cases. One was retired, all the other horses were back in work at a similar level of performance. This series indicates that surgical treatment of septic pedal osteitis carries a fair to good prognosis despite a high rate of post operative complications and convalescence period of up to 12 months.

Gross and ultrasonographic anatomy of the carpal flexor tendon sheath in horses.

This study was undertaken to establish the gross anatomy and the ultrasonographic appearance of the carpal digital flexor tendon sheath (carpal sheath) and the palmar carpal region in normal horses. The isolated forelimbs from 15 horses were used to study the morphology of the sheath and associated structures, including a detailed study of the location of the main blood vessels and nerves in that region. These limbs and the forelimbs of five live, sound horses were also examined ultrasonographically. The examination yielded good soft tissue detail of the tendons and ligaments, synovial and perisynovial tissues and larger blood vessels. There was a good correlation between the ultrasonographic and gross anatomical appearance of the limbs. The sheath cavity was only identified after it had been distended with water, and the various synovial recesses at the level of the carpal canal were poorly imaged.

Endoscopic examination of the carpal flexor tendon sheath in horses.

This study was undertaken to design a safe technique to examine the carpal flexor tendon sheath (carpal sheath) of horses endoscopically, using an arthroscope. The limbs from 15 horses were used to study the normal anatomy of the carpal sheath and related structures, establish a safe approach and endoscopic technique, and determine the normal endoscopic appearance of the sheath. Major arteries, veins and nerves, present within and around the sheath, left few 'safe' areas to insert the endoscope. Several portals were assessed and a distal lateral approach was found to be safest and to allow adequate visualisation of most of the sheath. The surgical technique and normal endoscopic findings are described in detail and discussed.

Ultrasonographic examination of the femorotibial articulation in horses: imaging of the cranial and caudal aspects.

The aim of this study was to determine the normal ultrasonographic features of the cranial and caudal aspects of the femorotibial articulation and, in particular, to establish a method of examining the menisci, cruciate and meniscal ligaments ultrasonographically. Twenty hindlimbs isolated post mortem from 10 horses were used to study the normal ultrasonographic and gross anatomy of the femorotibial joint. Five stifles from 3 normal, live horses were also examined with B-mode, real-time ultrasound imaging. The results of the anatomical study are presented. The joint surfaces, menisci, cruciate and meniscal ligaments could be imaged adequately in all the specimens. No obvious variations in shape or echotexture, that might impair visualisation of potential lesions, were observed. The authors suggest that ultrasonography is a potential, noninvasive means of diagnosing soft tissue lesions in the femorotibial joint.

The use of arthroscopy in the treatment of septic arthritis in two Highland calves.

Septic polyarthritis is a common condition in the young bovine animal. Systemic antibacterial treatment is often not sufficient to eliminate the infection, particularly in the subacute or chronic stages. More invasive procedures, including joint drainage and arthrotomy, are often unsatisfactory, either because of the failure to cure the condition or because of the associated complications. This article describes the use of arthroscopy in the treatment of infectious arthritis and osteomyelitis in two calves. In one case, two joints were explored and debrided successfully during the same intervention. The advantages of this technique to treat septic arthritis in the bovine are described and discussed. The use of diagnostic ultrasonography to confirm joint involvement is also described.