Comparison of radiography and ultrasonography to detect osteochondrosis lesions in the tarsocrural joint: A prospective study

Reasons for performing study: Lesions located on the medial malleolus of the tarsocrural joint can be difficult to image radiographically. Ultrasonography allows evaluation of articular cartilage and subchondral bone. Objectives: To compare dorso30° lateral‐plantaromedial‐oblique (DL‐PlMO) and dorso45° views to detect lesions on the medial malleolus, to validate the use of ultrasonography to show lesions in the tarsocrural joint and to compare its sensitivity to radiography. Methods: Tarsocrural joints (n = 111) with osteochondrosis were evaluated ultrasonographically and radiographically prior to arthroscopic lesion debridement. A complete radiographic examination was made and the best view to detect each lesion recorded. Longitudinal and transverse ultrasonography of the dorsal aspect of the joint was performed and the best scan plane to image each lesion recorded. Results: There were 94 joints with lesions on the distal intermediate ridge of tibia, 24 with lesions on the medial malleolus, and 4 with lesions on the lateral trochlear ridge. The sensitivity of radiography to detect lesions on the medial malleolus and distal intermediate ridge of tibia was 71 and 96%, respectively. Eighty‐two percent of lesions on the medial malleolus were better imaged on dorso30° view. The sensitivity of ultrasonography to detect lesions on the medial malleolus and distal intermediate ridge of tibia was 83 and 98%, respectively. Ultrasonography was significantly more sensitive than radiography to detect lesions on the medial malleolus and distal intermediate ridge of tibia. Conclusion: Dorso30° lateral‐plantaromedial‐oblique view was the best to image lesions on the medial malleolus. Ultrasonography was a valuable diagnostic tool to diagnose lesions in the tarsocrural joint and was more sensitive than radiography for lesions located on the medial malleolus and distal intermediate ridge of tibia. Clinical relevance: Radiographic examination should include a dorso30° view for detection of lesions on the medial malleolus and ultrasonography should be considered to diagnose osteochondrosis in the tarsocrural joints.     

Normal Radiographic and Ultrasonographic Appearance of the Adult Dromedary Camel Tarsus (One Humped Camel)

Six cadaver pelvic limbs were obtained from clinically sound dromedary camels and examined radiographically and ultrasonographically using a 7.5 MHz convex transducer. Radiographic examination was performed in dorsoplantar, lateromedial, dorsolateral‐plantaromedial oblique and plantarolateral‐dorsomedial oblique projections, and the bony structures and articulations of the tarsal joint were outlined. The tarsus was ultrasonographically investigated in four planes (dorsal, medial, lateral and plantar), and each plane was scrutinized in four levels (calcaneal tuber, tibial malleoli, base of calcaneus and proximal end of metatarsus) in both transverse and longitudinal views. Limbs were examined grossly, frozen at ?20°C and sectioned. Radiographic and ultrasonographic findings correlated well with the gross anatomy and frozen sections. The normal appearance of bony and soft structures of the tarsus described in this study provided basic reference data for ultrasonographic and radiographic investigations of tarsal disorders in the dromedary camel.     

Arthroscopic Approach and Intra-Articular Anatomy of the Plantar Pouch of the Equine Tarsocrural Joint

Arthroscopic examination of structures within the plantar pouch of the tarsocrural joint was accomplished via portals in both the plantaromedial and plantarolateral aspects of the joint. Flexion and extension of the tarsus while examining the joint through either portal allowed observation of the proximal and plantar aspects of the lateral and medial trochlear ridges, the trochlear groove, the caudal aspect of the distal tibia, and the deep digital flexor tendon (DDFT) in its sheath. From a plantarolateral portal, the plantar talocalcaneal ligament and the plantar aspect of the lateral malleolus could be observed. The caudal aspect of the medial malleolus could not be observed with flexion or extension of the joint from a plantaromedial portal, but in some horses, the caudal aspect of the lateral malleolus could be observed. The dorsolateral and dorsomedial aspects of the plantar pouch were best examined from a portal on the ipsilateral side of the joint. An instrument portal opposite either arthroscope portal allowed access to most regions of the joint except the abaxial surface of the trochlear ridge opposite the instrument.     

Meniscal translocation and deformation throughout the range of motion of the equine stifle joint: an in vitro cadaveric study

Reason for performing study: By study of the translocation and deformation of equine menisci throughout the range of motion, it may be possible to identify potential mechanical factors in the pathogenesis of injury to the cranial horn of the medial meniscus. Objective: To quantitatively document meniscal translocation and deformation using radiographic and MR imaging, and to evaluate for potential variation between the medial and lateral menisci. Methods: Radiographic markers were embedded in the periphery of the menisci in 6 cadaver stifles. Proximal‐distal radiographs were taken at 15° intervals ranging from full flexion (30°) to full extension (160°). Magnetic resonance imaging sequences of 3 additional cadaver stifles were obtained in axial and sagittal planes at the predetermined stifle angles. Results: A significantly greater overall mean cranial‐caudal translocation (1.6 times) of the lateral meniscus relative to the medial was seen from full extension to full flexion (P = 0.002). The cranial horn of the medial meniscus was the least mobile of the 4 horns, yet a significant cranial displacement relative to the cranial horn of the lateral meniscus was seen in the terminal 10° of extension. MRI images revealed a significantly greater axial compressive strain in the cranial horn of the medial meniscus relative to the cranial horn of the lateral meniscus in the terminal 10° of extension (P = 0.017). Conclusion: The equine menisci exhibit a cranial‐caudal translocation over the tibia throughout the range of motion. While the cranial horn of the medial meniscus is the least mobile of the 4 horns, it undergoes significant cranial translocation and axial compression in the terminal 10° of extension. Potential relevance: Hyperextension of the stifle may place the cranial horn of the medial meniscus at risk of injury and thus explain the higher prevalence of meniscal tears at this location.     

Determination of Pelvic Limb Alignment in the Large‐Breed Dog: A Cadaveric Radiographic Study in the Frontal Plane

Objectives— To report a method for radiographic determination of the mechanical axis of the canine pelvic limb and its relationship to the joints and bone axes. To report reference ranges for the relationships between the axes of the pelvic limb and for joint position relative to the pelvic limb axis. Study Design— Cadaveric radiographic anatomic study. Animals— Pelvic limbs (n=101) from normal midsized to large breed dogs; tibiae (n=105) from dogs with cranial cruciate ligament disease (previous study). Methods— Extended full‐limb radiography was performed and images analyzed to determine: mechanical joint reference angles (femur, tibia), pelvic limb axis, tibiofemoral and metatarsotibial angle, mechanical axis—femur/metatarsus angle, and mechanical axis deviation (MAD) of the stifle/tarsus. Results— Mean mechanical angles were: lateral proximal femoral (103.7°±5.4°), lateral distal femoral (98.6°±2.5°), medial proximal tibial (92.2°±1.8°), medial distal tibial (95.9°±2.2°), tibiofemoral (9.1° varus ±2.8°), metatarsotibial (0.6° valgus ±2.1°). Mean mechanical axis—femur and—metatarsus angles were 5.6° (±1.7°) and 2.9° (±1.5°), respectively. Mean MAD of the stifle and tarsus were 3.6% (±1.1%) and 1.2% (±0.6%), respectively. Tibial angles were not different between dogs with and without cranial cruciate ligament disease. Conclusions— Mechanical axes of the canine pelvic limb and their relationship to the joints can be determined by full‐limb radiography. Clinical Relevance— Techniques and reference ranges may be useful for diagnosis, surgical planning, and postoperative assessment of pelvic limb deformities.     

Occult subchondral osseous cyst-like lesions of the equine tarsocrural joint

OBJECTIVE: To report the clinical signs, diagnosis, management, and outcome of horses with occult sub-chondral osseous cyst-like lesions of the tarsocrural joint. DESIGN: Retrospective study. ANIMALS: Twelve horses with subchondral osseous cyst-like lesions (SOCLs) in the tarsocrural joint. METHODS: Information about history, examination findings, diagnostic techniques, and surgical procedures as obtained from medical records. Outcome was determined by patient re-evaluation and telephone communication with the referring veterinarian, owner, or trainer. RESULTS: Horses were aged from 3 to 29 years. Lameness (2 weeks to 1 year) varied from moderate to severe. Synovial fluid analyses (9 horses) yielded changes consistent with suppurative inflammation and positive bacterial culture was obtained in 4 horses. Eight of 9 horses that had intra-articular analgesia had a dramatic reduction in lameness. No abnormalities were detected on tarsal radiographs in 10 horses. Scintigraphy identified foci of increased radiopharmaceutical uptake in the distal tibia or talus of all horses, and the lesion was further characterized by computed tomography in 7 horses. SOCLs were identified in the medial malleolus (5), intertrochlear groove of the talus (4), lateral malleolus (2), and distal intermediate ridge of the tibia (1). One horse was euthanatized, 6 horses had surgical debridement, and 5 horses were managed conservatively. Four horses treated surgically (67%) returned to soundness. Conservatively treated horses continued to exhibit lameness but 2 were sufficiently sound for light pleasure riding. CONCLUSIONS: Occult lesions of the tarsus not visible on radiographs can be detected by computed tomography and scintigraphy and may be a source of lameness. CLINICAL RELEVANCE: SOCL, possibly of septic origin, should be a differential diagnosis for persistent lameness localized to the tarsocrural joint without radiographic abnormalities. Surgical debridement of the lesions may offer the best prognosis for a return to athletic soundness.     

Radiographic anatomy of the tarsocrural joint of the dog

The normal radiographic anatomy of the proximal hock joint of the dog is discussed. The choice of projection depended on the site to be examined. Examination of the lateral trochlear ridge of the talus required a number of projections including the fully extended and fully flexed mediolateral, plantaromedial-dorsolateral oblique and a flexed dorsoplantar using a horizontal beam. The best radiographic projection for examination of the medial side of the joint was the plantarodorsal projection while the mediolateral projection showed the dorsal and plantar edges and gave some general information of changes around the joint.     

Radiography and Standing Computed Tomography of an Osteochondritis Dissecans Lesion Found at the Dorsodistolateral Aspect of the Calcaneus in a 3-Year-Old Horse

An incidental osteochondritis dissecans (OCD) lesion was found in a left tarsus of a 3-year-old Freiberger stallion presented for a prepurchase examination. The lesion was best visualized on the dorsomedial-plantarolateral oblique and dorsoplantar projections. A standing computed tomographic examination confirmed a fragmentation of the dorsodistolateral aspect of the calcaneus. In suspected OCD lesions at the distal aspect of the talus or calcaneus, a dorsoplantar projection of the tarsus improves lesion localization and could be added to the standard radiographic protocol during OCD screenings. Computed tomography allowed more detailed evaluation of a not previously described calcaneal origin of this uncommon presumed OCD lesion in the equine tarsus.     

Fractures of the lateral malleolus of the tibia in 16 horses.

Clinical and radiological features of 16 horses with fractures of the lateral malleolus of the tibia are reported. The paper describes surgical techniques used, results obtained and discusses justification for removal. Fourteen fractures were unilateral and two bilateral. There was no left:right disparity. The history included a known traumatic incident in 14 cases. All animals had a tarsocrural joint effusion and 10 had palpable thickening of the lateral collateral ligaments. Crepitus was also palpable in 10 horses. The fracture was identified in all dorsoplantar and 14 of 18 dorsomedial-plantarolateral oblique radiographic projections. Nine fractures were simple and 9 comminuted. All fractures were removed via a tarsocrural arthrotomy. Approaches were dorsolateral in 14 joints, plantarolateral in 3 and dorsolateral and plantarolateral in 1. After an ascending exercise programme horses returned to work 6 months after surgery: 15 horses were free of lameness after 17-62 months, with 13 animals performing at a level similar to pre-injury standard.     

Osteochondral fragmentation of the palmarolateral/plantarolateral aspect of the distal phalanx in four horses: A novel location

Four horses presenting for lameness were diagnosed with unilateral osteochondral fragmentation (OCF) of the palmarolateral/plantarolateral aspect of the distal phalanx within the distal interphalangeal joint (DIPJ). Histological evaluation of one case supported a diagnosis of osteochondritis dissecans (OCD), with patient age and history from two cases suggesting a traumatic origin. Lesion appearance on conventional radiography, computed tomography (CT), nuclear scintigraphy and magnetic resonance imaging (MRI) are described. Fragmentation was best identified on dorsal 65° proximal-palmaro/plantarodistal oblique (D65°PrPDiO/D65°PrPlDiO) and dorsal 65° proximal-palmaro/plantarodistal lateral oblique (D65°Pr45°L-PDiMO/D65°Pr45°L-PlDiMO) radiographic projections of the foot, but articular pathology appeared more severe on cross-sectional imaging modalities. In all cases, lameness was refractory to conservative management. Arthroscopic evaluation of the DIPJ was performed in three horses, although the lesion was inaccessible in two. In one horse, access to the lesion was possible due to increased joint laxity, presumably due to concurrent soft tissue injury. One horse was euthanased after failed conservative management, one was pasture sound following palmar digital neurectomy 12 months after initial presentation, one returned to racing and one was lost to follow-up. Osteochondral fragmentation at this location has not previously been described, treatment options are limited and the prognosis appears to be poor.     

Use of a flexed dorsoplantar radiographic view of the talocrural joint to evaluate lameness in two dogs.

A flexed dorsoplantar radiographic view of the talocrural joint was a useful additional view to diagnose abnormalities of the lateral trochlear ridge of the talus of 2 dogs. This view outlined the subchondral bone of both trochlear ridges of the talus and the apposing cochlea tibiae of the distal portion of the tibia. The tarsus was flexed at the level of the talocrural joint, and an x-ray beam was centered on the joint. With this additional view, fractures of the lateral trochlear ridge were readily diagnosed. This view would help to demonstrate osteochondral lesions of the lateral trochlear ridge.     

An In Vitro Biomechanical Comparison of Dynamic Condylar Screw Plate Combined with a Dorsal Plate and Double Plate Fixation of Distal Diaphyseal Radial Osteotomies in Adult Horses

Objective— To compare stiffness and strength of a dynamic condylar screw plate combined with dorsal broad dynamic compression plate (DCS–bDCP) fixation with double broad dynamic compression plate (dbDCP) fixation used to repair oblique distal fractures of adult equine radii. Study Design— Experimental. Sample Population— Adult equine radii (n=10 pair). Methods— An unconstrained three‐dimensional loading–measurement system was used to determine stiffness of a 50 mm long intact, and then DCS–bDCP or dbDCP‐plated osteotomized/ostectomized segment of radii when subjected to a nondestructive sequence of compression, torsion, and lateral‐to‐medial (LM), medial‐to‐lateral (ML), cranial‐to‐caudal (CrCa), and caudal‐to‐cranial (CaCr) bending. Uniform load over the entire length of construct identified its weakest characteristics during torsion and LM and CrCa bending to failure. Results— No difference was observed between osteotomized/ostectomized DCS–bDCP and dbDCP construct stiffness for all 6 loading modes, and strength for all 3 failure loads. Ostectomized DCS–bDCP and dbDCP construct stiffness was significantly lower than osteotomized radii, the latter approaching intact for axial, LM, and CrCa bending. Most frequent failure was bone fracture through exit site of a screw located adjacent to osteotomy/ostectomy. Conclusions— DCS–DCP and dbDCP constructs had comparable strength and stiffness when repairing osteotomies/ostectomies in equine adult radius bone. Fracture reduction increased stiffness that approached intact bone for loads that placed the unplated side in compression. Clinical Relevance— DCS–bDCP and dbDCP constructs are comparable in stiffness and strength when applied to oblique distal diaphyseal osteotomies/ostectomies in equine radius bone. However, the DCS's localized effect on distal epiphyseal structure because of additional bone removal remains to be investigated under in vivo articular loading conditions.     

ULTRASONOGRAPHIC EVALUATION OF TARSOCRURAL JOINT CARTILAGE IN NORMAL ADULT HORSES

Ultrasonographic examination of the tarsus was performed on four clinically and radiographically normal limbs of adult horses. Particular attention was paid to the articular cartilage surfaces of the trochlear ridges of the talus and the distal intermediate ridge of the tibia. Two separate measurements of articular cartilage thickness were acquired from a longitudinal view at each site. Anatomy was confirmed with post mortem dissection. Ultrasonography was found to be a practical method for imaging the articular cartilage over the trochlear ridges of the talus and distal intermediate ridge of the tibia. The cartilage appeared as a hypoechoic band overlying the hyperechoic subchondral bone. The mean cartilage thickness over the lateral and medial trochlear ridges of the talus and the distal intermediate ridge of the tibia were 0.57 mm, 0.58 mm and 0.7 mm respectively. These measurements may have value for comparison to thickened cartilage and lesions of osteochondrosis and abnormally thinned cartilage of osteoarthritis. Ultrasound examination was not helpful in evaluating the proximal and distal intertarsal and tarsometatarsal joints, the close proximity of the articular surfaces obscured visualization of the articular cartilage.     

Arthroscopic treatment of fractures of the lateral malleolus of the tibia: 26 cases

Reasons for performing the study: A minimally invasive arthroscopic technique for removal of fractures of the lateral malleolus of the tibia is considered to be beneficial but data to this effect are required. Hypothesis: Arthroscopic removal of fractures of the lateral malleolus of the tibia is technically feasible, provides a comprehensive evaluation of the tarsocrural joint and enables removal of remote comminuted fragments and disrupted short collateral ligaments. The technique is associated with low patient morbidity, requires only short periods of hospitalisation and affords a good prognosis to affected horses. Methods: The case records of all horses that underwent arthroscopic removal of a fractured lateral malleolus of the tibia, admitted to a referral hospital, were evaluated retrospectively. Follow‐up information was obtained from race records and by telephone questionnaire. Results: Fractures were successfully removed arthroscopically in all cases following dissection from the short lateral collateral ligaments. Significant post operative complications occurred in only one horse. All other horses recovered well from surgery and of 22 horses with long‐term follow‐up, 18 returned to their previous use. Conclusion: Arthroscopic removal of fractures of the lateral malleolus of the tibia is technically demanding, but can be performed with minimal complications and with low patient morbidity and short periods of hospitalisation. The majority of horses are able to successfully return to work following the procedure. Potential relevance: The advantages of arthroscopic removal compared to removal via arthrotomy make this the technique of choice for treatment of fractures of the lateral malleolus of the tibia.     

PSITTACINE SKULL RADIOGRAPHY

The psittacine skull is a complex anatomic structure, frequently traumatized but difficult to adequately image with standard radiographic procedures. Multiple views including a ventrodorsal, a lateral, and complementary oblique projections are necessary to fully evaluate potential skull fractures in the avian patient. Magnification radiography is a relatively easy procedure that aids the review of small osseous structures. Familiarity with psittacine skull anatomy greatly facilitates radiographic interpretation of cranial trauma.     

PSITTACINE SKULL RADIOGRAPHY

The psittacine skull is a complex anatomic structure, frequently traumatized but difficult to adequately image with standard radiographic procedures. Multiple views including a ventrodorsal, a lateral, and complementary oblique projections are necessary to fully evaluate potential skull fractures in the avian patient. Magnification radiography is a relatively easy procedure that aids the review of small osseous structures. Familiarity with psittacine skull anatomy greatly facilitates radiographic interpretation of cranial trauma.     

Radiographic assessment of cattle hoofs (ungulae) of the Nellore breed: Reference standards

The purpose of this work was to determine a radiographic standard of normality for lateral and medial ungulae in 3‐year‐old bovine females of the Nellore breed. Twenty‐six cows underwent radiographic exposure of the medial and lateral ungulae of the hindlimbs and forelimbs; abaxioaxial projections were used. The images were analyzed; distances were measured between the dorsal surface of the distal phalanx and the surface of the hoof capsule. The two angles formed, i.e., an angle between the dorsal surface of the distal phalanx and a line parallel to the sole (inner), and an angle between the dorsal surface of the hoof and a line parallel to the sole (outer), were also recorded. The results suggested a standard of normality for the proximal, middle and distal distances of the ungulae of the forelimbs: 0.96 ± 0.12 cm. For the measurement of hindlimbs, except for the distal distances of the side ungulae, the suggested value was 1.02 ± 0.14 cm; for the distal measurement of the lateral ungulae of the hindlimbs, the value was 1.09 ± 0.12 cm. For inner and outer angles, the values were 36.45° ± 4.4° for the medial ungulae of the forelimbs and 42.50° ± 3.8° for other ungulae of the forelimbs and hindlimbs (standard deviations of the values suggested for the angles should be used as variations between different animals, limbs and ungulae; they should not be used between angles of the same ungula).     

奶牛跗关节的关节内窥镜径路及滑膜形态

应用关节内窥镜对奶牛跗关节的进镜部位和滑膜形态进行了研究。结果表明 ,跗关节可选 3个进镜部位 :背内侧囊在关节前方较突出部位 ,靠近趾内侧伸肌健 ,向外为跖背侧静脉和腓浅神经 ;跖内侧囊和跖外侧囊一般选在最突出的部位 ,跖外侧囊尽量靠前以避开足底外侧静脉 ,跖内侧囊不要靠后以防伤及深屈肌腱。关节不同部位的滑膜绒毛也不同 ,关节囊小且突起小的部位 ,关节滑膜绒毛一般呈短柱状或丝状 ;关节囊大的部位 ,一般呈菜花状或膜状 ,也有长丝状绒毛。在背内侧囊见有从未报道的拱桥状绒毛。靠近关节软骨处和关节固有韧带里面没有绒毛