Nuclear scintigraphic assessment of the thoracolumbar synovial intervertebral articulations

Reasons for performing study: The results of nuclear scintigraphic examination of the thoracolumbar synovial intervertebral articulations (facet joints) have to date been poorly documented. Objectives: To establish an objective scintigraphic grading system for the facet joints; to investigate the relationship between the presence or absence of clinical signs of back pain and increased radiopharmaceutical uptake (IRU); and to compare the results of scintigraphy and radiography. Methods: Nuclear scintigraphic images of the 13th thoracic (T13) to first lumbar (L1) vertebrae were graded subjectively (visual assessment of the image) and objectively (using region of interest analysis) from 31 clinically normal horses in full work (Group N) and 65 horses with clinical evidence of thoracolumbar region pain and osteoarthritis of ≥1 facet joint (Group B). Sensitivity and specificity of IRU for detection of back pain and radiographic abnormalities were assessed. A Spearman correlation was performed to test for an association between the grade of IRU and the classification of radiographic abnormality. Results: The objective scintigraphic grades were matched by 96.7% of subjective grades. IRU was seen more commonly in Group B (61.5%) than in Group N (25.8%), and moderate or intense IRU was only seen in Group B. The strongest association between radiographic abnormalities and scintigraphy was seen in horses with intense IRU. Conclusions: Moderate or intense IRU in a facet joint is more likely to be seen in horses with back pain than in clinically normal horses. Potential relevance: Nuclear scintigraphy is a potentially useful tool in the evaluation of a horse with thoracolumbar region pain.     

Relationship between scintigraphic and radiographic evaluations of spinous processes in the thoracolumbar spine in riding horses without clinical signs of back problems

REASONS FOR PERFORMING STUDY: Radiography and scintigraphy are used to aid diagnosis of the cause of back pain, but a large variation in appearance and radiopharmaceutical uptake in fully functioning horses make diagnosis difficult. OBJECTIVES: To describe the range of and compare scintigraphic and radiographic findings in the spinous processes of horses without clinical signs of back problems. METHODS: Thirty-three apparently normal riding horses underwent scintigraphic and radiographic examinations of the spinous processes in the thoracolumbar spine. Scintigraphic images were evaluated in a continuous blue, green and red colour scale, and the level of radiopharmaceutical uptake in the spinous processes from T10-L2 was graded into none, mild, moderate or severe increased radiopharmaceutical uptake. Structural changes along the borders of the spinous processes and the width of the interspinous spaces from T10-L2 were recorded. RESULTS: Only 7 horses had no scintigraphic or radiographic findings. Nine horses had no increased radiopharmaceutical uptake, 17 had no sclerosis, 21 had no radiolucencies and 11 had normal spacing of the spinous processes (>4 mm wide). The majority of findings in 26 horses were located from T13-18 and were mild. CONCLUSIONS: The findings of a wide spectrum of scintigraphic and radiographic changes leads to the conclusion that changes within this range found in affected horses cannot be interpreted as clinically significant. POTENTIAL RELEVANCE: To determine whether scintigraphy and/or radiography can be used to separate horses with back pain from horses without clinical signs, the results from this study should be compared to the scintigraphic and radiographic findings in horses with clinical signs.     

Close, impinging and overriding spinous processes in the thoracolumbar spine: the relationship between radiological and scintigraphic findings and clinical signs

Reasons for performing study: There has been no objective study comparing radiological features of spinous processes (SPs) in the thoracolumbar region and/or scintigraphic findings with clinical signs. Objectives: To investigate the relationship between the presence or absence of clinical signs of back pain and: 1) radiological findings of close, impinging or overriding SPs; 2) increased radiopharmaceutical uptake (IRU) in the SPs; and 3) the combination of radiological findings and IRU. Also to determine the prevalence of concurrent osseous pathology. Methods: Five‐hundred and eighty‐two horses, presented for perceived back pain and poor performance, underwent comprehensive clinical investigation including diagnostic analgesia of the forelimbs, hindlimbs, back and sacroiliac joints, and radiographic and scintigraphic evaluation of the thoracolumbar spine. Radiological and scintigraphic grades were determined subjectively. Statistical analysis was performed to determine the relationships between clinical signs of back pain, radiological and scintigraphic features, age, breed, gender, discipline, height and weight. Results: Thoroughbreds (TBs) were over‐represented with thoracolumbar pain compared with Warmbloods and TB cross breeds. There was a significant association between maximum and total radiological grades of the SPs and thoracolumbar pain, between maximum and total grades of IRU and thoracolumbar pain, and between a combination of radiological and scintigraphic abnormalities and thoracolumbar pain. Horses with osteoarthritis (OA) of the synovial intervertebral articulations (SIAs) were more likely to have thoracolumbar pain than horses with lesions of the SPs alone, but the presence of OA of the SIAs and lesions of the SPs was associated with the highest likelihood of thoracolumbar pain. Conclusions and potential relevance: Fore‐ or hindlimb lameness and/or pain associated with the sacroiliac joints could mimic primary thoracolumbar pain. A combination of radiology and scintigraphy gives the most accurate prediction of thoracolumbar pain, but diagnostic analgesia is crucial for accurate diagnosis.     

COMPARISON OF RADIOGRAPHIC AND SCINTIGRAPHIC FINDINGS OF THE SPINOUS PROCESSES IN THE EQUINE THORACOLUMBAR REGION

Back pain is common in horses, but there has been no large‐scale in‐depth study describing radiographic changes of the spinous processes, the relationship between radiographic and scintigraphic findings, and the effect of size, age, breed, or discipline. The objectives were to investigate the frequency of occurrence in horses with perceived back pain of: (1) radiographic alteration of the spinous process structure; (2) increased radiopharmaceutical uptake (IRU) in the spinous processes; and (3) to compare radiographic and scintigraphic findings; and to determine if there was breed, gender, age, bodyweight, height, or work discipline predisposition for close, impinging, or overriding spinous processes. Radiographic and scintigraphic images of the thoracolumbar spine of 604 horses were graded. A radiographic grade for each spinous process (T8–L6) was assigned (0–7). The maximum radiographic grade for each horse was defined as the highest grade assigned to any spinous process; the total radiographic grade was the sum of all grades for each horse. A scintigraphic grade for each spinous process was determined (0–3). The maximum scintigraphic grade for each horse was defined as the highest grade assigned to any spinous process; the total scintigraphic grade was the sum of all grades for each horse. Associations between radiology and scintigraphy and age, gender, breed, height, weight, and discipline were analyzed statistically. The severity of radiographic lesions of the spinous processes was associated with the severity of scintigraphic abnormalities. The caudal thoracic spine (T14–T17) was most frequently affected. There was a significant breed and age effect, with Thoroughbreds and older horses having higher total and maximum radiographic grades. The severity of the lesions of the spinous processes was significantly associated with the presence of osteoarthritis of the articular process joints. It was concluded that there is a wide range of radiographic abnormalities of the spinous processes seen in horses with or without back pain. There is an association between radiographic and scintigraphic grades of the spinous processes.     

Thoracic processi spinosi findings agree among subjective,semiquantitative, and modified semiquantitative scintigraphic image evaluation methods and partially agree with clinical findings in horses with and without thoracolumbar pain

Impinging processi spinosi in the equine thoracic spine are a common cause of poor performance in the horse. A modified semiquantitative scintigraphic image analysis has been proposed for the evaluation of equine processi spinosi. This technique showed a high inter‐ and intraobserver agreement when compared to subjective and semiquantitative image analysis. The aim of this retrospective, method comparison study was to evaluate the agreement of the modified semiquantitative scintigraphic image assessment with previous methods of interpretation and to compare these scintigraphic evaluation techniques with radiographic and clinical findings. Two hundred twenty‐three Warmblood horses that underwent scintigraphic, radiographic, and clinical examination of the thoracic spine were included in the study. Scintigraphic images were assessed using subjective, semiquantitative, and modified semiquantitative techniques. Radiographs were subjectively graded and horses were assigned to a group with or without thoracolumbar pain. Total radiographic and total scintigraphic grades were higher in horses with thoracolumbar pain (P < 0.05). Both the semiquantitative and the modified semiquantitative uptake ratios did not differ significantly in horses with or without thoracolumbar pain. The kappa agreement showed a substantial agreement between the modified semiquantitative scintigraphic and the semiquantitative scintigraphic evaluation techniques. The agreement between subjective scintigraphic and modified semiquantitative scintigraphic image evaluations was fair. There was a slight agreement between all scintigraphic techniques and radiographic findings. Limitations were the definition of thoracolumbar pain and the image analysis being restricted to the caudal thoracic processi spinosi. In conclusion, the modified semiquantitative scintigraphic image assessment obtained consistent results but did not perform better than previous evaluation methods. Further comparison to a defined diagnosis is warranted.     

Clinical features and diagnosis of sacroiliac joint region pain in 296 horses: 2004–2014

There has been no large‐scale study of the clinical signs of sacroiliac (SI) joint region pain and its association with lameness and/or thoracolumbar pain. Horses with a positive response to infiltration of local anaesthetic solution around the SI joint regions (SI block) and/or abnormal radiopharmaceutical uptake (RU) in the region of the SI joints were included. History, clinical signs, diagnostic imaging findings, response to SI block, and concurrent lameness and/or thoracolumbar pain were recorded. Horses (n = 296) were divided into 2 groups: SI joint region pain only (Group 1, n = 43) and SI joint region pain and concurrent source(s) of pain (Group 2, n = 253). Clinical signs in Group 1 included increased tension in the longissimus dorsi muscles (40%), restricted flexibility of the thoracolumbar region (44%), trunk stiffness during exercise (61%) and poor hindlimb impulsion (56%). When ridden 65% had a poor contact with the bit, in 81% canter quality was worse than trot, and 35% bucked or kicked out with a hindlimb during canter. In both Groups 1 and 2 clinical signs were seen in a significantly greater proportion of horses during ridden work than lungeing (P<0.0001). Following SI block, 98% of horses showed dramatic improvement in clinical signs, including greater overall movement through the trunk, increased hindlimb impulsion and better quality canter. Abnormal RU in the SI joint regions was seen in 85/180 (47%) horses. Of horses with a positive response to SI block that underwent scintigraphy, only 43% had abnormal RU. Per rectum ultrasonographic examination of the SI joint region revealed abnormalities in 41/129 (32%) horses. Clinical signs of SI joint region pain are worse when horses are ridden. Sacroiliac joint region diagnostic analgesia is a useful, safe but nonspecific block. Ultrasonography and scintigraphy can provide additional information in some horses, but negative results do not preclude SI joint region pain.     

Efficacy of tiludronate in the treatment of horses with signs of pain associated with osteoarthritic lesions of the thoracolumbar vertebral column

OBJECTIVE: To evaluate the efficacy of tiludronate for the treatment of horses with signs of pain associated with lesions of the thoracolumbar vertebral column. ANIMALS: 29 horses with clinical manifestations of pain associated with lesions of the thoracolumbar vertebral column and abnormal radiographic findings indicative of osteoarthritis of the articular processes-synovial intervertebral joints. PROCEDURES: Horses were initially examined in accordance with a standardized protocol, which included radiographic, ultrasonographic, and scintigraphic examinations. Fifteen horses were randomly assigned to receive tiludronate (1 mg/kg, IV, as a slow-rate infusion), and 14 horses received a control substance (day 0). Horses were monitored for the subsequent 120 days. Clinical evaluations were performed on days 60 and 120. Horses that had no evidence of clinical improvement on day 60 were administered tiludronate. Statistical analyses were performed to compare efficacy at day 60, improvement of dorsal flexibility at day 120, and dorsal flexibility before and 60 days after administration of tiludronate. RESULTS: Horses treated with tiludronate had significant improvement in dorsal flexibility between days 0 and 60, compared with control horses. Clinical improvement in dorsal flexibility was still evident at day 120. The percentage of positive responses was higher in the tiludronate group at 60 days. CONCLUSIONS AND CLINICAL RELEVANCE: Tiludronate had efficacy in the treatment of horses with signs of pain induced by osteoarticular lesions of the thoracolumbar vertebral column, causing a significant improvement in dorsal flexibility. Tiludronate may offer a treatment option for the management of horses with intervertebral lesions and the associated pain.     

Soft tissue- and bone-phase scintigraphy for diagnosis of navicular disease in horses

Radiography and soft tissue- and bone-phase scintigraphy were performed on 14 clinically normal horses and 35 horses in which definite, probable, or possible navicular disease had been diagnosed. The specificity of radiography and scintigraphy in revealing signs of navicular disease were nearly equal; however, the sensitivity of scintigraphy appeared to be greater than that of radiography. The greatest sensitivity and specificity were achieved when the results of radiography and scintigraphy were evaluated together. Differences in sensitivity were greatest when scintigraphy revealed lesions not detected by radiography. Although a diagnosis of navicular disease was sometimes made when only soft tissue-phase or only bone-phase scintigraphy revealed lesions, results obtained during the 2 phases generally were similar. It was concluded that scintigraphy can be a valuable aid in diagnosing navicular disease in horses, especially when radiographic findings do not support clinical findings.     

CLINICAL RELEVANCE OF ABNORMAL SCINTIGRAPHIC FINDINGS OF ADULT EQUINE RIBS

Horses with cranial rib abnormalities may exhibit severe acute lameness and may have unusual gait deficits characterized by forelimb abduction during protraction at the walk. Horses with caudal rib abnormalities may resent being saddled and ridden. In a retrospective evaluation of 20 horses with a documented rib lesion, 25 sites of increased radiopharmaceutical uptake were found in one or more ribs. Thirteen (52%) scintigraphic lesions involved the first rib; four were located immediately dorsal to the sternal articulation, eight were near the costochondral junction and one was at the costovertebral junction. Six (24%) scintigraphic rib lesions involved ribs 2–8; one was located immediately dorsal to the sternal articulation, three were at the costovertebral junction and two were near the costochondral junction. Six (24%) scintigraphic rib lesions involved the mid‐portion (five) or costovertebral junction (one) of ribs 9–18. The 20 horses were divided into three groups based on the clinical relevance of the scintigraphic findings. Group 1 (n=3) horses had clinical signs attributed to a rib abnormality; Group 2 (n=6) horses had a rib abnormality that was a plausible explanation for clinical signs; Group 3 (n=11) horses had clinical signs that could not be attributed to a rib abnormality. For horses with cranial rib abnormalities, a modified lateral scintigraphic image with the ipsilateral limb pulled caudally and a left (right) 45° caudal–right (left) radiograph facilitated the diagnosis.     

Comparison of radiography and ultrasonography for the diagnosis of osteochondritis dissecans in the equine femoropatellar joint

Reasons for performing study: Osteochondritis dissecans (OCD) lesions of the femoropatellar (FP) joint are diagnosed routinely by radiography, but lesions located in the trochlear groove or without accompanying subchondral bone changes can be difficult to visualise. Ultrasonography allows evaluation of articular cartilage and subchondral bone in the FP joint. Objectives: To document the radiographic and ultrasonographic appearance of OCD lesions in the equine FP joint, grade ultrasonographic lesions and compare their accuracy in the diagnosis of these lesions. Methods: The medical records of all horses diagnosed with FP OCD between 1995 and 2006 were assessed. Inclusion criteria included availability of both radiographic and ultrasonographic images. Lesion characteristics were evaluated in each trochlear ridge and trochlear groove. For assessment of the accuracy (sensitivity and specificity) of both imaging techniques in the diagnosis of OCD, only cases with an arthroscopic or necropsy examination were studied. Results: Twenty‐one horses were included. OCD lesions were diagnosed by radiography (30/32 joints) and ultrasound (32/32 joints). The lateral trochlear ridge (LTR, 91%) and the medial trochlear ridge (MTR, 17%) were involved on radiography. The localisation on ultrasound examination was similar (97% LTR, 25% MTR). All but one lesion seen on radiography were also detected with ultrasound; 2 LTR and 3 MTR lesions, not seen on radiography were diagnosed by ultrasound and confirmed at arthroscopy or necropsy. The specificity was 100% regardless of the site and imaging procedure except for the distal third of the MTR (94% for ultrasound). The sensitivity varied, depending on lesion site. Conclusion: Ultrasonography is a valuable diagnostic tool to diagnose OCD lesions in the FP joint and more sensitive than radiography for lesions affecting the MTR of the distal femur. Clinical relevance: Ultrasound should be considered as a useful adjunct to radiography for diagnosing equine FP OCD, especially in cases of high clinical suspicion but equivocal radiographic findings. Images can be generated immediately when digital radiography is not available, permitting an immediate on‐site diagnosis.     

Diagnostic findings and prognosis following arthroscopic treatment of subtle osteochondral lesions in the shoulder joint of horses: 15 cases (1996-1999)

OBJECTIVE: To determine clinical, scintigraphic, radiographic, and arthroscopic findings and results of treatment in horses with lameness attributable to subtle osteochondral lesions of the shoulder joint. DESIGN: Retrospective study. ANIMALS: 15 horses. PROCEDURE: Medical records were reviewed, and results of physical examination, scintigraphy, radiography, arthroscopy, and treatment were recorded. RESULTS: Severity of lameness ranged from grade 1 to 4. Response to shoulder flexion or extension was variable. Twelve horses had a narrow upright foot. Intra-articular anesthesia of the shoulder joint localized the cause of the lameness to the shoulder joint in 9 of 10 horses. Scintigraphic abnormalities were detected in 4 of 6 horses. Radiographic lesions were subtle and included glenoid sclerosis, focal glenoid lysis, small glenoid cysts, and alterations in the humeral head contour. Arthroscopic evaluation confirmed clefts in the glenoid cartilage, glenoid cysts, a humeral head cyst, fibrillation of the humeral head cartilage, cartilage fragmentation, or a nondisplaced fracture of the humeral head. After treatment, 12 horses returned to their previous level of performance, 1 was sound for light riding, 1 remained lame, and 1 was euthanatized because of chronic lameness. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that a combination of physical examination, scintigraphy, and radiography is necessary to diagnose subtle osteochondral lesions of the shoulder joint in horses. Arthroscopy can be used to confirm the diagnosis and treat cartilage and subchondral bone lesions. Young and middle-aged horses with subtle osteochondral lesions of the shoulder joints have a good prognosis for return to performance following arthroscopic treatment.     

Palmar or plantar process fractures of the distal phalanx in riding horses: 22 cases (1994–2003)

No case series exists in the literature describing palmar/plantar process fractures (PPFs) of the distal phalanx in a nonracehorse population. We aim to describe the distribution of these injuries, together with their clinical, radiographic and scintigraphic features. In a retrospective case study, horses were selected based on radiographic evidence of a PPF. Data were collected relating to clinical and lameness examination, radiography, scintigraphy, management and follow‐up information. Oblique and flexed oblique radiographic views of the distal phalanx are the most sensitive in detecting PPFs of the distal phalanx and this study concluded that fractures of palmar or plantar process are likely to be missed in horses showing mild lameness if oblique radiographic views of the palmar process are not included.     

Pain associated with the sacroiliac joint region: a clinical study of 74 horses

REASONS FOR PERFORMING STUDY: There has been no large study of horses with suspected sacroiliac (SI) joint region pain in which the clinical diagnosis has been supported by either abnormal radiopharmaceutical activity in the SI joint region or by periarticular infiltration of local anaesthetic solution. OBJECTIVES: To describe the clinical features of horses with SI joint region pain, to document the age, breed, sex, discipline, size and conformation of affected horses and to compare these with the author's (SD) normal case population and to document the results of infiltration of local anaesthetic solution around the SI joint region. METHODS: Horses were selected for inclusion in the study based upon the exclusion of other causes of lameness or poor performance, together with clinical signs suggestive of SI joint pain and abnormal radiopharmaceutical activity in the SI joint region and/or a positive response to periarticular infiltration of local anaesthetic solution. RESULTS: Sacroiliac joint region disease was identified in 74 horses between November 1997 and March 2002. Dressage and showjumping horses appeared to be at particular risk (P < 0.001). Affected horses were generally slightly older than the normal clinic population (P < 0.0001), taller at the withers (P < 0.0001) and of greater bodyweight (P < 0.01). There was a significant effect of breed (P < 0.001), with a substantially higher proportion of Warmblood horses (51%) in the SI pain group compared to the normal clinic population (29%). There was no correlation between conformation and the presence of SI joint region pain. The tubera sacrale appeared grossly symmetrical in most (95%) horses. Poor development of the epaxial muscles in the thoracolumbar region and asymmetry of the hindquarter musculature were common. Twenty-six horses (35%) showed restricted flexibility of the thoracolumbar region and 10 (16%) had an exaggerated response to pressure applied over the tubera sacrale. Fourteen horses (19%) were reluctant to stand on one hindlimb for prolonged periods. The majority of horses (75%) had a straight hindlimb flight and only 18% moved closely behind or plaited. In all horses restricted hindlimb impulsion was the predominant feature; invariably this was most obvious when the horse was ridden. Stiffness, unwillingness to work on the bit and poor quality canter were common. Sacroiliac joint region pain was seen alone (47%), or in conjunction with thoracolumbar pain (16%), hindlimb lameness (20%), forelimb lameness (7%) or a combination of problems (10%). Seventy-three horses (99%) had abnormalities of the SI joint region identified using nuclear scintigraphy. Infiltration of local anaesthetic solution around the SI joint region produced profound improvement in gait in all 34 horses in which it was performed. CONCLUSIONS AND POTENTIAL RELEVANCE: Careful clinical examination combined with scintigraphic evaluation of the SI joint region and local analgesia can enable a more definitive diagnosis of SI joint region pain than has previously been possible.     

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.     

SCINTIGRAPHIC AND RADIOGRAPHIC APPEARANCE OF THE SACROILIAC REGION IN HORSES WITH GAIT ABNORMALITIES OR POOR PERFORMANCE

Nuclear bone scintigraphy is commonly used in the diagnosis of sacroiliac disease in horses. The aim of the present retrospective study was to determine if there was an association between radiopharmaceutical uptake pattern and radiographic appearance of the sacroiliac region in horses. Seventy-nine horses undergoing bone scintigraphy with Tc-99 m-HDP and radiography of the pelvis because of lameness or poor performance were studied. Subjective and semiquantitative methods were used to characterize and compare radiopharmaceutical uptake between horses. Ventrodorsal radiographs of the region were obtained and were evaluated. Subjectively, 70 horses (88.6%) had an abnormal uptake pattern. In nine horses, the sacroiliac region was normal (11.4%). There was no association between subjective evaluation of the scintigraphic images and semiquantitative methods. There was a significant association between radiopharmaceutical uptake and conformation (T- or Y-like form) and shape (butterfly-, wing-, leaf-, or horn-like) of the sacrum. The radiopharmaceutical uptake of the tubera sacralia was significantly higher in males (left side P =0.002, right side P =0.003). In conclusion, the conformation of the sacrum may play an important role in the scintigraphic appearance and may be the cause of increased radiopharmaceutical uptake.     

Radiographic Examination of the Equine Vertebral Column

A method is described for routine radiography of the horse's thoracolumbar (TL) spine from T2 to L3 in the standing position. Stocks were used for restraint, and the x-ray tube, which was mounted on an overhead gantry, was linked automatically to a cassette holder on the far side of the animal. A crosshatch grid with an ultra-fast system of screens and film was employed to provide adequate radiographic quality. An aluminum wedge filter (dodger) was used to help compensate for the marked variation in spine thickness. For radiography of the caudal lumbar spine and lumbosacral region, it was necessary to anesthetize the horse and make radiographs in the ventrodorsal position. Exposures of up to 150 kV and 400 mAs were required for heavy horses weighing up to 750 kg. Scatter radiation was kept to a minimum by using crossed high-ratio grids and by putting additional lead on the back of the cassette to prevent back scatter.     

Clinical assessment and grading of back pain in horses

BackgroundThe clinical presentation of horses with back pain (BP) vary considerably with most horse''s willingness to take part in athletic or riding purpose becoming impossible. However, there are some clinical features that are directly responsible for the loss or failure of performance.ObjectivesTo investigate the clinical features of the thoracolumbar region associated with BP in horses and to use some of the clinical features to classify equine BP.MethodsTwenty-four horses comprised of 14 with BP and 10 apparently healthy horses were assessed for clinical abnormality that best differentiate BP from normal horses. The horses were then graded (0–5) using the degree of pain response, muscular hypertonicity, thoracolumbar joint stiffness and overall physical dysfunction of the horse.ResultsThe common clinical features that significantly differentiate horses with BP from non-BP were longissimus dorsi spasm at palpation (78.6%), paravertebral muscle stiffness (64.3%), resist lateral bending (64.3%), and poor hindlimb impulsion (85.7%). There were significantly (p < 0.05) higher scores for pain response to palpation, muscular hypertonicity, thoracolumbar joint stiffness and physical dysfunction among horses with BP in relation to non-BP. A significant relationship exists between all the graded abnormalities. Based on the cumulative score, horses with BP were categorized into mild, mild-moderate, moderate and severe cases.ConclusionsBP in horse can be differentiated by severity of pain response to back palpation, back muscle hypertonicity, thoracolumbar joint stiffness, physical dysfunctions and their cumulative grading score is useful in the assessment and categorization of BP in horses.     

Osteomyelitis secondary to trauma involving the proximal end of the radius in horses: five cases (1987-2001)

OBJECTIVE: To determine clinical, radiographic, and scintigraphic abnormalities in and treatment and outcome of horses with trauma-induced osteomyelitis of the proximal aspect of the radius. DESIGN: Retrospective study. ANIMALS: 5 horses. PROCEDURE: Data collected from the medical records included signalment; history; horse use; degree of lameness; radiographic, ultrasonographic, and scintigraphic findings; treatment; and outcome. RESULTS: Duration of lameness prior to referral ranged from 14 to 60 days. Mean severity of lameness was grade 3 of 5, and all horses had a single limb affected. All horses had signs of pain during elbow joint manipulation and digital palpation over the lateral aspect of the proximal end of the radius. Radiographic lesions consisted of periosteal proliferation, osteolysis, and subchondral bone lysis. Scintigraphy in 3 horses revealed intense pharmaceutical uptake diffusely involving the proximal end of the radius. Two horses had sepsis of the elbow joint. All horses were treated with antimicrobials long-term; 1 horse was also treated by local perfusion of the radial medullary cavity through an indwelling cannulated screw. At follow-up, all horses had returned to their previous function. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that osteomyelitis of the proximal end of the radius can result from a traumatic injury to the antebrachium. Because lesions may be an extension of septic arthritis, a thorough examination of the wound area and elbow joint is recommended. Prolonged systemic antimicrobial treatment can result in a successful outcome.     

The range and prevalence of pathological abnormalities associated with lameness in working horses from developing countries

Reasons for performing study: Lameness is highly prevalent in working horses, but published reports on the associated pathological abnormalities are lacking. With over 42 million horses in developing countries and the majority used for work, lameness has major welfare implications. Objectives: To describe the range and prevalence of pathological abnormalities associated with lameness in working horses. Methods: A standard lameness assessment was adapted for field use in working equids. Data on pathological abnormalities and pain responses in the feet, limbs and spine were collected through observation, palpation, manipulations and gait assessment in working horses from India (n = 110) and Pakistan (n = 117). Lameness at the walk was scored on a scale of 0–4 (sound‐nonweightbearing). Results: All horses examined were lame. Overall, 98% showed a gait abnormality in all 4 limbs and 87% had at least one limb scoring 3 or 4 on the lameness scale. Multiple pathological abnormalities within each limb were associated with lameness, with similar results in both countries. Chronic foot pathology was seen in every horse; 94% horses showed signs of chronic joint disease; 83% had digital flexor tendonitis in at least one limb. Lameness and pathological abnormalities were associated with specific pain responses in the feet, limbs and spine. Conclusions: The extremely high prevalence of multilimb lameness and its association with pain is of great concern. The multiple pathological abnormalities present in working horses makes lameness complex to address. Potential relevance: The results of this detailed study of lameness should facilitate the identification of risk factors and the implementation of interventions to reduce the prevalence of lameness in working equids.     

Scintigraphic and radiographic evaluation of appendicular skeletal lesions in cold-stunned Kemp's ridley sea turtles

Osteolytic appendicular skeletal lesions in eight-stranded, cold-stunned Kemp's ridley sea turtles (Lepidochelys kempii) were evaluated using radiography and skeletal scintigraphy. Radiographic studies were performed monthly in most animals. Follow-up scintigraphy was performed 45-120 days after the initial exams in six turtles. Radiographically, lesions slowly progressed from an early osteolytic process contained to either the proximal or distal end of long bones, to a later stage characterized by thickening of the affected bone, sclerosis, and remodeling of the lesion borders. In seven turtles, the initial scintigrams were characterized by at least one focus of abnormal radiopharmaceutical uptake that correlated with a lytic site noted in radiographs. In five turtles, scintigraphic lesions were characterized by asymmetric radiopharmaceutical uptake rather than by increased intensity of uptake. Scintigraphic studies obtained more than 4 months after the appearance of clinical and radiographic signs had minimal, if any, abnormal radiopharmaceutical uptake, despite the persistence of abnormal radiographic findings. Skeletal scintigraphy is an effective method for more precisely determining if and when these animals can be returned to the wild. Animals were released if normal radiopharmaceutical uptake was seen during initial examination, or if decreased uptake was noted between serial examinations. In four of the turtles, resolution of abnormal scintigraphic findings permitted an objective decision to discontinue antibiotic and antifungal therapy. Seven of the eight turtles were released after correlation of the clinical signs with the imaging findings. Radiographs, however, are still needed to facilitate the correct identification of lesions with scintigraphy.