Lateromedial Radiographs Research Articles

Evaluation of digital radiographic measurements for the diagnosis of acute laminitis.

Traditional radiographic measurements of distal phalanx (Pd) displacement based on the outer hoof wall are not useful for diagnosis of acute laminitis. We hypothesised that the distance between the inner hoof wall and Pd ('lamellar lucent zone'; LLZ) measured on lateromedial digital radiographs would be increased in horses with acute and subacute laminitis compared with healthy horses. Retrospective cohort study and in vivo experimental study. Forelimb radiographs from 32 healthy and 18 laminitic mixed-breed horses were analysed retrospectively. Laminitis was defined by at least two clinical signs (acute multi-limb lameness, increased digital pulse amplitude and/or persistently warm hooves) for ≤3 days (acute), or >3 and ≤14 days (subacute) duration, without overt palmar rotation (≥3°), remodelling, or distal displacement of the Pd. Some laminitic limbs initially classified as acute were subsequently radiographed later in hospitalisation and also included as subacute. Twelve measurements including LLZ at proximal, middle, and distal locations were performed on 126 forelimb radiographs that met the criteria for acute laminitis (n = 39), subacute laminitis (n = 23) or healthy control (n = 64). A mixed effects linear regression model was used for comparisons and a receiver-operator characteristic (ROC) curve was created for select measurements. Three horses were serially radiographed to study the impact of magnification and obliquity. The mean [95% confidence interval] LLZ (mm) was increased in acute and subacute laminitis compared with control in the proximal (acute = 8.8 [8.4-9.2]; subacute = 9 [8-9.9]; control = 7.3 [7-7.7]), middle (acute = 8.9 [8.5-9.3]; subacute = 9.1 [8.2-10]; control = 6.9 [6.5-7.2]), and distal (acute = 9.1 [8.5-9.7]; subacute = 10.2 [9.1-11.3]; control = 7.5 [7.2-7.8]) dorsal lamellar regions (p < 0.001). At a cut-off of >7.5 mm for middle LLZ, sensitivity was 87% [73%-94%] and specificity 91% [81%-96%] for diagnosis of acute laminitis. Using the ratio of middle LLZ to distal phalanx cortical length, sensitivity was 95% [81%-99%] and specificity was 95% [87%-99%] (cut-off >0.11). Magnification and obliquity affected absolute LLZ measurements but did not alter LLZ ratios. No histological confirmation of laminitis. LLZ measurements are potentially useful for radiographic diagnosis of acute and subacute laminitis.

Equine Talocalcaneal subluxation

A Quarter horse filly was evaluated for a two-week old wound of the right hind cannon bone after the mare stepped on her. A sequestrum was noted radiographically and was surgically debrided. After continued follow-up a left hind varus deformity was noted and was corrected with a lateral transphyseal screw in the distal left tibia. After the varus deformity was improved, a lateromedial radiograph was taken of the distal left tibia and tarsus and talocalcaneal subluxation was seen. The same view was taken of the right tarsus and the same deformity was noted. After finding no case reports on the condition with information on treatment or surgical correction, humane euthanasia was elected. A few months later, the same owner brought a two-month-old colt out of the same mare to the hospital for an elective procedure. Tarsal radiographs were taken due to the owner's previous experience, although the colt had no clinical history or any traumatic incidents. A lateromedial view of the right tarsus revealed talocalcaneal subluxation.

Changes in aspects of hoof and distal limb conformation in foals by radiographic evaluation

This study investigated age-related radiographic changes in the distal parts of the forelimbs by radiographic evaluation and identified the radiographic changes associated with diseases specific to foals. The hoof angle (HA), distal phalanx angle (P3A), distal phalanx palmer angle (P3PA), distal interphalangeal joint angle (DIPJA), and metacarpophalangeal joint angle (MPJA) on lateromedial radiographs of forelimbs were measured on the day after birth (Day 1); at 1, 2, 4, 6, and 8 weeks of age; and then at monthly intervals until 12 months of age. HA and P3A significantly increased from 1 day to 4 weeks and 4 weeks to 3 months of age. The P3PA increased dramatically from 1 day to 1 week, 1 week to 2 weeks, and 2 weeks to 8 weeks of age, and then decreased after 3 months of age. DIPJA significantly decreased from 1 day to 2 weeks of age before increasing from 3 to 5 months of age. MPJA increased with age until 4 weeks, slightly decreased from 2 to 4 months of age, and then gradually decreased from 4 to 6 months of age. The findings indicate that foals' forelimbs typically show flexion of the fetlock and a broken backward hoof-pastern axis just after birth, an upright fetlock until 4 months of age, and a change to a mature conformation after 6 months of age. Physiological variants were correlated with the occurrence of common foal diseases during the radiographic evaluation periods.

Radiographic analysis of the dorsal hoof wall thickness in clinically normal draft horses.

To evaluate the radiographic thickness of the dorsal hoof wall in normal draft horse feet. 33 adult draft horses with no history of laminitis, no clinically obvious lameness, and visibly unremarkable front feet were included. This was a prospective, descriptive study of clinically normal draft horses' front feet. Lateromedial radiographs were acquired of the front feet. A ratio of the dorsal hoof wall thickness to the length of the distal phalanx (DHWP3 ratio) was calculated. The dorsal hoof wall thickness to length of the distal phalanx was calculated as 0.33 ± 0.03 (range of 0.28 to 0.39) in this population of draft horses. With very few exceptions, the heterogeneous population of draft horses evaluated in this study had a DHWP3 ratio greater than previously published values in lighter breeds (< 0.30).

A detailed radiographic description and correlated magnetic resonance imaging findings of an infrequently identified articular indentation of the articular margin of the distal phalanx

SummaryBackgroundEquine veterinarians frequently obtain lateromedial radiographs of the feet. During assessment, one infrequently encounters a triangular‐shaped articular indentation of the articular surface of the distal phalanx (P3). To the authors’ knowledge, there are no detailed radiographic or MRI descriptions of this specific articular indentation in the literature so far.ObjectivesThe main purpose of this study was to give a detailed morphological description of this radiographical identified articular indentation.Study designDescriptive study.MethodsAll LM and DP radiographs of the feet of horses presented at our hospital between August 2016 and August 2019 were retrospectively reviewed for presence of an articular indentation. Following selection, patient information, patient history, clinical findings, MRI‐finding and surgical details were retrieved. In total, 30 horses were included of which 12 underwent magnetic resonance imaging. Radiographs and MRI results were evaluated for the precise location, shape and extent of the articular indentation and for signs of degenerative joint disease of the DIPJ.ResultsFour different indentation types were identified radiographically. Concomitant low field MRI proved to be a useful and excellent imaging modality for evaluation of this rare articular indentation and its surrounding subchondral bone. MRI findings were various and ranged from slight subchondral contour deviations to obvious OCLL (Osseous Cyst Like Lesions). Furthermore, MRI identified some additional indentation related OCLLs that were not noted on plain radiographs.Main limitationsThe limited number of horses that were included and the absence of complementary histopathology.ConclusionsArticular indentations are typically identified in the third quarter of the articular margin of P3 and may have underlying OCLLs. Since OCLLs are known to be a potential cause of future unsoundness, careful radiographic assessment is advised if an indentation is encountered. If needed, Standing Low‐Field MRI can give additional and detailed information.

First phalanx exostosis in traditional equestrian horses in Western Libya.

Background:Orthopedic diseases involving the forelimb fetlock joint of horses other than those used in professional racing have not been widely reported in the literature. One of these problems is the exostosis on the proximal forelimb phalanx (P1), which has not been reported previously in Western Libya.Aim:The study aimed to investigate the prevalence of P1 exostosis in traditional equestrian horses (known locally as Sarj horses) of different breeds in Libya that participated in a special social event and described its clinical findings radiographic appearance.Methods:The current study involved 60 horses admitted to private veterinary clinics with varied fetlock orthopedic problems. The studied horses were aged between 6 and 11 years old and galloped on hard grounds. Clinical and radiographic examinations were carried out on all horses. Lateromedial radiographs for one or both forelimb fetlock joints were acquired for each horse.Results:Clinical examination revealed that 21 horses (35%) had hard non-painful swelling on the dorsal aspect of fetlock with joint stiffness during flexion. In 19 of them, the swelling was bilateral. No forelimb lameness was noticed. Radiographically, hard swelling was diagnosed as bone exostosis, with various sizes, on the proximo-dorsal aspect of P1. There was also a new bone formation on the disto-dorsal part of third metacarpal bone in two cases.Conclusion:This study has documented the first report on bone exostosis on the proximo-dorsal aspect of the forelimb proximal phalanx as a common problem in Sarj horses that galloped on hard grounds in Western Libya. Although this bone lesion did not cause lameness in all reported cases, further investigations are warranted to identify its histopathological nature, potential etiology, and proper treatment.

The position of x‐ray beam‐centring affects radiographic measurements of palmar angle and sole thickness on radiographs of the equine thoracic distal limb

SummaryBackgroundDifferent locations of x‐ray beam centring on the equine distal limb for lateromedial and dorsopalmar radiographs of the equine digit may affect clinically relevant radiographic measurements.ObjectivesTo evaluate the effects of two different locations of x‐ray beam centring on lateromedial and dorsopalmar radiographic measurements of the equine digit and to assess intra‐ and inter‐observer variability of measurements.Study designProspective, observational and method comparison.MethodsComparisons were made of nine measurements on orthogonal radiographs acquired from 24 unshod equine feet at two locations of x‐ray beam centring: coronary band and hoof–ground interface. Radiographic measurements were obtained by three observers of varied equine veterinary experience and made in triplicate by a board‐certified veterinary radiologist.ResultsRadiographs acquired with x‐ray beam centred at the coronary band and hoof–ground interface produced differences in the mean measurements of palmar angle, defined as the angle created by the palmar processes of the distal phalanx relative to the ground surface, on the lateromedial projection (p = 0.002), and medial (p &lt; 0.001) and lateral (p &lt; 0.001) sole thickness on the dorsopalmar projection. There was less variability of palmar angle (p = 0.039) and more superimposition of the palmar processes (p &lt; 0.001) with the x‐ray beam centred at the hoof–ground interface.Main limitationsThe study population was homogeneous and only included horses without outwardly visible abnormalities of the foot. Anatomic measurements were not used for comparison due to the nonterminal nature of the study.ConclusionsCentring the x‐ray beam at the hoof–ground interface produces more repeatable and smaller radiographic measurements of palmar angle and sole thickness when compared to centring the x‐ray beam centred at the coronary band. The distal phalangeal palmar processes are more superimposed with the more distal x‐ray beam centring. The strong inter‐ and intraobserver variability support the use of these nine radiographic measurements by practitioners of all levels of experience.

In vitro assessment of the motion of equine proximal sesamoid bones relative to the third metacarpal bone under physiologic midstance loads.

To assess the motion of the proximal sesamoid bones (PSBs) relative to the third metacarpal bone (MC3) of equine forelimbs during physiologic midstance loads. 8 musculoskeletally normal forelimbs (7 right and 1 left) from 8 adult equine cadavers. Each forelimb was harvested at the mid-radius level and mounted in a material testing system so the hoof could be moved in a dorsal direction while the radius and MC3 remained vertical. The PSBs were instrumented with 2 linear variable differential transformers to record movement between the 2 bones. The limb was sequentially loaded at a displacement rate of 5 mm/s from 500 N to each of 4 loads (1.8 [standing], 3.6 [walking], 4.5 [trotting], and 10.5 [galloping] kN), held at the designated load for 30 seconds while lateromedial radiographs were obtained, and then unloaded back to 500 N. The position of the PSBs relative to the transverse ridge of the MC3 condyle and angle of the metacarpophalangeal (fetlock) joint were measured on each radiograph. The distal edge of the PSBs moved distal to the transverse ridge of the MC3 condyle at 10.5 kN (gallop) but not at lower loads. The palmar surfaces of the PSBs rotated away from each other during fetlock joint extension, and the amount of rotation increased with load. At loads consistent with a high-speed gallop, PSB translations may create an articular incongruity and abnormal bone stress distribution that contribute to focal subchondral bone lesions and PSB fracture in racehorses.

An investigation of the shape of the hoof capsule in hindlimbs, its relationship with the orientation of the distal phalanx and comparison with forelimb hoof capsule conformation

SummaryThere is limited information documenting hind foot conformation. The objectives of the study were to describe the shape of the hoof capsule of hindlimbs from the lateral aspect in horses of variable breeds, and, within horses, to compare the conformation of the hoof capsule of forelimbs and hindlimbs and determine the orientation of the distal phalanx within the hoof capsule in hindlimbs. Lateral photographs of the fore and hind feet (n = 225) and lateromedial radiographs of the hind feet (n = 29) were obtained. Differences among breed and shoeing status groups were assessed using multivariable mixed‐effects linear regression models. Angular parameters and ratios of linear measurements were compared between fore and hind feet; angular radiological variables and photographic parameters of the hind feet were compared. The mean dorsal hoof wall angle for hind feet (50.9°±3.7°) was smaller than forefeet (51.8°±3.9°) (P = 0.04). The mean heel angles for hind feet (36.4°±9.6°) were smaller than forefeet (40.1°±9.3°; P &lt; 0.001). Dorsal hoof wall (P &lt; 0.001) and heel (P = 0.002) angles were larger in unshod than shod feet. In the hind feet, the dorsal hoof wall was parallel to the dorsal aspect of the distal phalanx. The median angle of the distal phalanx to the horizontal (angle S) was 0.6° (interquartile range: −1.4, 2.3°). There was a positive relationship between angle S and the hoof wall angle (W); each 1° increase in angle S was associated with 0.6° increase in angle W (P &lt; 0.001). Angle S was also positively associated with photographic heel angle; each degree increase in the angle S was associated with 1.8° increase in the heel angle (P &lt; 0.001). It was concluded that the angle of the distal phalanx to the horizontal in hindlimbs is smaller than published values for forelimbs. The orientation of the distal phalanx in hindlimbs is correlated with external characteristics of the hoof capsule.

Hoof conformation in Icelandic competition horses and its interrelationship with hoof pathologies and tölt performance

In order to improve the four-beat-rhythm and forelimb action of the tölt in Icelandic horses (ICE), special shoeing techniques are applied particularly in the front hooves by increasing hoof length and height, or by adding weight to the distal limbs. Although regulations limit dorsal hoof wall length (LDHW) in competition ICE, their shoeing often deviates from a biomechanically optimal distal limb conformation. This study aimed to qualitatively and quantitatively describe current shoeing practices of ICE in competition. Moreover, the influence of LDHW on the occurrence of deviations from a standard hoof conformation, as well as on tölt performance was investigated. At four European competition sites, hoof dimensions of 133 randomly selected ICE were measured manually, and limb conformation and hoof balance were described. Dorsopalmar/-plantar and lateromedial radiographs of the left front and hind hooves were taken of each horse. Various parameters related to hoof dimensions and balance were measured on radiographs using the Metron-Hoof-Pro software.Flares of the dorsal hoof wall had the highest prevalence of all investigated hoof deformities. Multiple logistic regression analysis revealed that longer LDHW was associated with the occurrence of toe flares (P = 0.045), a broken hoof pastern axis (P = 0.003), and asymmetry of the quarter wall heights (P = 0.015). However, horses with a longer LDHW achieved higher scores in competition. In spite of its positive effect on tölt performance, a long LDHW is not recommendable as it may be associated with a higher prevalence of certain hoof deformities.

Radiographic method for evaluation of tarsus morphometry

The equine tarsus is the most common area of the hind limb associated with lameness. Tarsal function is probably directly related to its conformation. Previous conformational measurement methods and radiological data are either limited or too specific to explain the complex tarsus conformation in different loading conditions. This study aimed to develop a consistent method to evaluate equine tarsal conformation from lateromedial radiographs. Twenty cadaveric hind limbs from 15 adult horses of different breeds were cut at the distal one third of the tibia. Hind limbs mounted in a loading rig and positioned with the metatarsus vertical were digitally radiographed. The zero-degree lateromedial (ZLM) was defined by vertical and horizontal landmarks including overlapping of the lateral and medial trochlea of the talus and a contact point between the dorsal edges of lateral and medial borders of the distal central tarsal bone. Radiographs missing these features were retaken to achieve consistent ZLM views. Specific radiographic features were selected as landmarks to develop tarsal parameters based on their clarity and their being consistently identifiable. The intra-rater repeatability of ten measurable morphometric parameters was evaluated with each radiograph measured twice with an interval of at least one month and Bland-Altman plots developed from this data. Repeat measurements did not differ significantly (Intraclass correlation coefficients (ICC) ranged from 0.731-0.966). This study provides a base for evaluation of the tarsal conformation by radiography.

Achilles tendon rupture in camel (Camelus dromedarius): Radiographic and Ultrasonographic findings

This study describes the clinical presentation of Achilles tendon rupture and evaluates the utility of radiography and ultrasonography in the diagnosis of such disorder in dromedary camels. Seventeen camels were included in this study based on the clinical, radiographic and ultrasonographic evidence of Achilles tendon rupture. The clinical, radiographic and sonographic findings of studied camels differ according to the type, duration, and location of the tendon rupture. Complete and incomplete rupture of the Achilles tendon was precisely diagnosed in five (29.4%) and twelve (70.6%) camels respectively; ruptured deep and superficial parts of the Achilles tendon were recorded in 10 (58.8%) and 2 (11.8%) camels respectively. Clinically, the camels exhibited an acute non-weight-bearing lameness (second to fourth-grade lameness), with swelling in the tendon near the calcaneus. Radiographs revealed swelling of the soft tissues surrounding the Achilles tendon just proximal to the calcaneal tuberosity in most of the camels with the presence of avulsion fracture of the calcaneus in few cases (n=2). Ultrasonographically, the ruptured part was precisely diagnosed as swollen, oedematous, heterogeneous structure with the presence of anechoic or hypoechoic areas (core lesion). In conclusion, lateromedial radiographs and ultrasonography were helpful in diagnosis and differential diagnosis of different types of Achilles tendon rupture and subsequent clinical decision and surgical interference in dromedary camels.

Issue 1

This study describes the clinical presentation of Achilles tendon rupture and evaluates the utility of radiography and ultrasonography in the diagnosis of such disorder in dromedary camels. Seventeen camels were included in this study based on the clinical, radiographic and ultrasonographic evidence of Achilles tendon rupture. The clinical, radiographic and sonographic findings of studied camels differ according to the type, duration, and location of the tendon rupture. Complete and incomplete rupture of the Achilles tendon was precisely diagnosed in five (29.4%) and twelve (70.6%) camels respectively; ruptured deep and superficial parts of the Achilles tendon were recorded in 10 (58.8%) and 2 (11.8%) camels respectively. Clinically, the camels exhibited an acute non-weight-bearing lameness (second to fourth-grade lameness), with swelling in the tendon near the calcaneus. Radiographs revealed swelling of the soft tissues surrounding the Achilles tendon just proximal to the calcaneal tuberosity in most of the camels with the presence of avulsion fracture of the calcaneus in few cases (n=2). Ultrasonographically, the ruptured part was precisely diagnosed as swollen, oedematous, heterogeneous structure with the presence of anechoic or hypoechoic areas (core lesion). In conclusion, lateromedial radiographs and ultrasonography were helpful in diagnosis and differential diagnosis of different types of Achilles tendon rupture and subsequent clinical decision and surgical interference in dromedary camels.

Achilles tendon rupture in camel (Camelus dromedarius): Radiographic and Ultrasonographic findings

This study describes the clinical presentation of Achilles tendon rupture and evaluates the utility of radiography and ultrasonography in the diagnosis of such disorder in dromedary camels. Seventeen camels were included in this study based on the clinical, radiographic and ultrasonographic evidence of Achilles tendon rupture. The clinical, radiographic and sonographic findings of studied camels differ according to the type, duration, and location of the tendon rupture. Complete and incomplete rupture of the Achilles tendon was precisely diagnosed in five (29.4%) and twelve (70.6%) camels respectively; ruptured deep and superficial parts of the Achilles tendon were recorded in 10 (58.8%) and 2 (11.8%) camels respectively. Clinically, the camels exhibited an acute non-weight-bearing lameness (second to fourth-grade lameness), with swelling in the tendon near the calcaneus. Radiographs revealed swelling of the soft tissues surrounding the Achilles tendon just proximal to the calcaneal tuberosity in most of the camels with the presence of avulsion fracture of the calcaneus in few cases (n=2). Ultrasonographically, the ruptured part was precisely diagnosed as swollen, oedematous, heterogeneous structure with the presence of anechoic or hypoechoic areas (core lesion). In conclusion, lateromedial radiographs and ultrasonography were helpful in diagnosis and differential diagnosis of different types of Achilles tendon rupture and subsequent clinical decision and surgical interference in dromedary camels.

Achilles tendon rupture in camel (Camelus dromedarius): Radiographic and Ultrasonographic findings

This study describes the clinical presentation of Achilles tendon rupture and evaluates the utility of radiography and ultrasonography in the diagnosis of such disorder in dromedary camels. Seventeen camels were included in this study based on the clinical, radiographic and ultrasonographic evidence of Achilles tendon rupture. The clinical, radiographic and sonographic findings of studied camels differ according to the type, duration, and location of the tendon rupture. Complete and incomplete rupture of the Achilles tendon was precisely diagnosed in five (29.4%) and twelve (70.6%) camels respectively; ruptured deep and superficial parts of the Achilles tendon were recorded in 10 (58.8%) and 2 (11.8%) camels respectively. Clinically, the camels exhibited an acute non-weight-bearing lameness (second to fourth-grade lameness), with swelling in the tendon near the calcaneus. Radiographs revealed swelling of the soft tissues surrounding the Achilles tendon just proximal to the calcaneal tuberosity in most of the camels with the presence of avulsion fracture of the calcaneus in few cases (n=2). Ultrasonographically, the ruptured part was precisely diagnosed as swollen, oedematous, heterogeneous structure with the presence of anechoic or hypoechoic areas (core lesion). In conclusion, lateromedial radiographs and ultrasonography were helpful in diagnosis and differential diagnosis of different types of Achilles tendon rupture and subsequent clinical decision and surgical interference in dromedary camels.

Achilles tendon rupture in camel (Camelus dromedarius): Radiographic and Ultrasonographic findings

This study describes the clinical presentation of Achilles tendon rupture and evaluates the utility of radiography and ultrasonography in the diagnosis of such disorder in dromedary camels. Seventeen camels were included in this study based on the clinical, radiographic and ultrasonographic evidence of Achilles tendon rupture. The clinical, radiographic and sonographic findings of studied camels differ according to the type, duration, and location of the tendon rupture. Complete and incomplete rupture of the Achilles tendon was precisely diagnosed in five (29.4%) and twelve (70.6%) camels respectively; ruptured deep and superficial parts of the Achilles tendon were recorded in 10 (58.8%) and 2 (11.8%) camels respectively. Clinically, the camels exhibited an acute non-weight-bearing lameness (second to fourth-grade lameness), with swelling in the tendon near the calcaneus. Radiographs revealed swelling of the soft tissues surrounding the Achilles tendon just proximal to the calcaneal tuberosity in most of the camels with the presence of avulsion fracture of the calcaneus in few cases (n=2). Ultrasonographically, the ruptured part was precisely diagnosed as swollen, oedematous, heterogeneous structure with the presence of anechoic or hypoechoic areas (core lesion). In conclusion, lateromedial radiographs and ultrasonography were helpful in diagnosis and differential diagnosis of different types of Achilles tendon rupture and subsequent clinical decision and surgical interference in dromedary camels.

Achilles tendon rupture in camel (Camelus dromedarius): Radiographic and Ultrasonographic findings

This study describes the clinical presentation of Achilles tendon rupture and evaluates the utility of radiography and ultrasonography in the diagnosis of such disorder in dromedary camels. Seventeen camels were included in this study based on the clinical, radiographic and ultrasonographic evidence of Achilles tendon rupture. The clinical, radiographic and sonographic findings of studied camels differ according to the type, duration, and location of the tendon rupture. Complete and incomplete rupture of the Achilles tendon was precisely diagnosed in five (29.4%) and twelve (70.6%) camels respectively; ruptured deep and superficial parts of the Achilles tendon were recorded in 10 (58.8%) and 2 (11.8%) camels respectively. Clinically, the camels exhibited an acute non-weight-bearing lameness (second to fourth-grade lameness), with swelling in the tendon near the calcaneus. Radiographs revealed swelling of the soft tissues surrounding the Achilles tendon just proximal to the calcaneal tuberosity in most of the camels with the presence of avulsion fracture of the calcaneus in few cases (n=2). Ultrasonographically, the ruptured part was precisely diagnosed as swollen, oedematous, heterogeneous structure with the presence of anechoic or hypoechoic areas (core lesion). In conclusion, lateromedial radiographs and ultrasonography were helpful in diagnosis and differential diagnosis of different types of Achilles tendon rupture and subsequent clinical decision and surgical interference in dromedary camels.

Achilles tendon rupture in camel (Camelus dromedarius): Radiographic and Ultrasonographic findings

This study describes the clinical presentation of Achilles tendon rupture and evaluates the utility of radiography and ultrasonography in the diagnosis of such disorder in dromedary camels. Seventeen camels were included in this study based on the clinical, radiographic and ultrasonographic evidence of Achilles tendon rupture. The clinical, radiographic and sonographic findings of studied camels differ according to the type, duration, and location of the tendon rupture. Complete and incomplete rupture of the Achilles tendon was precisely diagnosed in five (29.4%) and twelve (70.6%) camels respectively; ruptured deep and superficial parts of the Achilles tendon were recorded in 10 (58.8%) and 2 (11.8%) camels respectively. Clinically, the camels exhibited an acute non-weight-bearing lameness (second to fourth-grade lameness), with swelling in the tendon near the calcaneus. Radiographs revealed swelling of the soft tissues surrounding the Achilles tendon just proximal to the calcaneal tuberosity in most of the camels with the presence of avulsion fracture of the calcaneus in few cases (n=2). Ultrasonographically, the ruptured part was precisely diagnosed as swollen, oedematous, heterogeneous structure with the presence of anechoic or hypoechoic areas (core lesion). In conclusion, lateromedial radiographs and ultrasonography were helpful in diagnosis and differential diagnosis of different types of Achilles tendon rupture and subsequent clinical decision and surgical interference in dromedary camels.

An investigation into the association between plantar distal phalanx angle and hindlimb lameness in a UK population of horses

SummaryLow heels are the most common hoof conformational abnormality seen in both the front and hind feet of horses. A low/negative distal phalanx angle in the front feet has been associated with palmar heel injuries but only recently has the significance of low/negative angles in the hind feet received attention. A study including a greater number of horses more representative of the UK horse population would be useful to UK equine practitioners. Our null hypothesis was that the plantar distal phalanx angle does not differ between horses with and without hindlimb lameness. For this prospective case‐controlled study, horses presenting for orthopaedic complaints underwent a complete lameness assessment. The plantar distal phalanx angulation (PDPA), the angle between a line parallel to solar surface contacting the ground and the solar margin of the distal phalanx, was calculated from lateromedial radiographs. Horses were included in the study if hindlimb lameness was definitively localised by diagnostic anaesthesia. Student's t‐tests and multivariable linear regression models were used for statistical analysis. One hundred and eighty‐two horses met the inclusion criteria, 132 with hindlimb lameness and 50 controls. The mean left PDPA for HLL group was −1.0° vs. +1.8° for the controls. The mean right PDPA for HLL group was −1.1° vs. +1.4° in controls (both P&lt;0.001). Lameness was most frequently localised to the stifle (59% of horses), followed by the distal tarsal joints and the proximal suspensory region. A limitation of the study was that the control group included some forelimb lame horses. It was concluded that horses with hindlimb lameness, including lameness localised to the stifle, were more likely to have negative PDPAs. While Pezzanite et al. (2019) previously reported a relationship between negative/neutral PDPA and tarsal/metatarsal lameness, this study is the first to find a relationship to stifle lameness, which may reflect differences in the populations of horses examined. Further kinematic studies are required to determine whether it is a cause or effect relationship.

Synovial fluid lubricin increases in canine cruciate ligament rupture

Purpose: Loss of effective joint lubrication contributes to cartilage breakdown in post-traumatic osteoarthritis (PTOA). There are two major lubricants in synovial fluid: hyaluronic acid (HA), which confers viscous properties, and lubricin, which enables low friction boundary lubrication. The absence of functional lubricin results in severe, early onset of polyarthropathy in humans and lubricin knockout mice. Several studies have reported that lubricin decreases in experimental rodent models of PTOA; however, it is unclear whether similar losses are observed in naturally occurring, large animal models of joint injury and osteoarthritis (OA) progression. Naturally occurring cranial cruciate ligament rupture in the dog closely mimics anterior cruciate ligament injury in humans with respect to the development of joint instability and secondary osteoarthritic changes, making this a valuable translational model to study the role of lubricin in PTOA. Here, we investigated lubricin and pro-inflammatory cytokines in canine cranial cruciate ligament rupture (RCCL) and the relationship of these molecules to radiographic evidence of osteoarthritis. Methods: Stifle synovial fluid samples from 30 adult dogs (age 2.5-11 yrs; n=13 neutered males, 14 neutered females, 2 intact males and 1 intact female) sustaining rupture of the cranial cruciate ligament were obtained at the time of surgery and stored in liquid N2 for biobanking purposes. Medical histories, physical examination, and surgical data were obtained from patient medical records, including age, duration of injury prior to presentation, presence of concurrent meniscal injury and whether or not meniscectomy was performed. Stifle synovial fluid samples were also obtained from a cohort of 13 clinically healthy research Beagles (age 2.5 to 5 yrs; intact males). Synovial fluid lubricin levels were quantified using a lubricin sandwich ELISA, and pro-inflammatory cytokines (IL-2, IL-6, IL-8, TNF-α) were measured using a multiplex cytokine panel (Meso Scale Diagnostics, LLC). Pre-operative lateromedial and craniocaudal stifle radiographs were randomized, blinded and scored by two independent observers. A stifle OA scoring system was modified slightly from Innes et al, which evaluated: joint effusion, osteophytosis, intra-articular mineralization, and a global OA score. T-tests were used to analyze biochemical differences between healthy and RCCL joints (α=0.05), and Spearman’s rank-order correlations were performed to determine associations between lubricin and pro-inflammatory cytokines. Results: Lubricin concentrations were nearly six-fold greater in RCCL joints (mean ± SEM = 0.07 ± 0.02 mg/mL) as compared to healthy controls (mean ± SEM = 0.68 ± 0.06mg/mL) (Fig 1A), and this elevation persisted for more than one year after injury (Fig 1B). No significant differences in synovial fluid pro-inflammatory cytokines (IL-2, IL-6, IL8, and TNF-α) were detected between RCCL and healthy joints; however, pro-inflammatory cytokines were all correlated with one another. Duration of injury did not correlate with lubricin concentrations (Spearman’s test, ρ=-0.0205). Lubricin concentrations correlated with the presence of OA, but no associations between the severity of radiographic OA and lubricin levels were detected. Additionally, lubricin levels were not correlated with any of the pro-inflammatory cytokines measured (Table 1). Conclusions: Lubricin was significantly and persistently elevated in joints with RCCL. Interestingly, although pro-inflammatory cytokines in synovial fluid levels were correlated with one another, lubricin levels did not correlate with any pro-inflammatory cytokines. A limitation of this study is that dogs presented with varying degrees of OA and durations of injury prior to surgery, with many animals presenting with a history of lameness or injury of longer than one month. However, to our knowledge, this is the first study to demonstrate that synovial fluid lubricin is significantly increased in a translational, large animal model of knee joint instability. Lubricin may have value as a potential biomarker for knee instability (and perhaps osteoarthritis progression). Lubricin may also be elevated as a protective mechanism in joint instability; however, more mechanistic studies are required to determine the role of elevated synovial fluid lubricin in knee injuries.View Large Image Figure ViewerDownload Hi-res image Download (PPT)