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The present study aimed to describe the normal cross sectional anatomy and magnetic resonance imaging of pastern and coffin joints in dromedary camel. This study was conducted on twelve distal limbs (fore and hind) of fresh cadavers from three adult camels of both sexes. The specimens appeared normal without orthopedic disorders. Twelve distal limbs were scanned using a 1 Tesla MRI scanner and then injected with colored latex to be sectioned into sagittal, dorsal and transverse slices. Cross anatomical sections were matched with their corresponding MR images for identification and evaluation of the clinically relevant anatomical structures that appeared with different signal intensities on MRI scans. The present study showed that all major soft tissues in pastern and coffin joints of camel were clearly depicted on MR images, however, the palmar/plantar ligaments of pastern joint and ligaments of navicular cartilage could not be identified on MR images. The annotated cross anatomical sections with the corresponding MR images could be used as a normal reference for interpretation of some clinical diseases in pastern and coffin joints of camel.

Made available in DSpace on 2020-12-10T17:02:41Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-11-01. Added 1 bitstream(s) on 2021-07-15T14:36:55Z : No. of bitstreams: 1 S0102-09352019000601791.pdf: 1072900 bytes, checksum: a79c42439324c4f8793e6eb1c22fd042 (MD5) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) The tenectomy of the medial head of the deep digital flexor (TMHDDF) is a minimally studied surgery used in cases of dorsal subluxation of the proximal interphalangeal joint of the hindlimb in horses. The TMHDDF was evaluated in six healthy horses by the degree of lameness, perimeter of the surgical site, the angle of the distal articular joints, and the linear and angular measures of the hoof. Thus, TMHDDF of the right hindlimb was performed and the contralateral limb was used as a control. Both, right and left limbs were evaluated before surgery, as well as at 15, 30, and 60 days after surgery aiming to evaluate the effects of the surgical procedure in healthy limbs. Data were compared by analysis of variance regarding days and limbs. Values below the significant level (P< 0.05) were analyzed using the Tukey's test. TMHDDF caused a mild increase of the toe length and the height of lateral heel (0.2cm in both), as well as a decrease of the angle of the proximal interphalangeal joint (2 degrees) when comparing the left hindlimb to the right hindlimb, 30 and 60 days after surgery. Overall, TMHDDF did not cause significant changes in the evaluated variables up to the 60 days of surgery. Univ Oeste Santa Catarina, Xanxere, SC, Brazil Univ Estadual Paulista, Botucatu, SP, Brazil Univ Estadual Paulista, Botucatu, SP, Brazil FAPESP: 2009/12159-9

Objective To describe the presence of fragments in the dorsal proximal interphalangeal (PIP) joint and to report flat racing performance after surgical treatment. Study design Retrospective study. Sample population Thirty-nine affected thoroughbred flat racehorses and 169 age- and sex-matched maternal siblings. Methods Medical records from 2000 to 2015 were reviewed for thoroughbred horses that underwent arthroscopic removal of osteochondral fragments in the dorsal aspect of the PIP joint. The horses' 2-year-old year, 3-year-old year, and career athletic performances were compared with their matched siblings. Results Thirty-nine thoroughbred horses were included, varying in age from 4 months to 4 years, with osteochondral fragments in 42 PIP joints. Hind limbs (92%) were more commonly affected than forelimbs (8%). Fragments were located within the origin of the collateral ligament of the distal sesamoid (navicular) bone. After surgery, the likelihood of starting a race did not differ between treated horses (27/39 [69%]) and maternal siblings (129/169 [76%], P = .15). Race earnings did not differ between treated horses and their siblings during their 2-year-old year (P = .66), 3-year-old year (P = .43), or career (P = .60). Conclusion Removing osteochondral fragments from the origin of the collateral ligament of the distal sesamoid bone did not impair the ability to race or earning potential for affected thoroughbred racehorses compared with their maternal siblings. Clinical significance Fragments from the dorsal aspect of the PIP joint in racehorses can be removed arthroscopically resulting in a good clinical outcome and future flat racing performance comparable to matched controls.

Arthrodesis was achieved in two foals through the placement of three 4.5 mm cortical lag screws. Two screws were placed in a standard transarticular fashion from the dorsal aspect of P1 (glide hole) to the palmar aspect of P2 (thread hole). A third transarticular lag screw was placed from the dorsal aspect of P2 (glide hole) to the palmar aspect of P1 (thread hole). Both foals were comfortable and considered suitable for light work. Crossed transarticular lag screw fixation of P1 and P2 in cases of PIPJ arthrodesis in foals is a simple and useful method offering good stability for fusion and future athletic soundness.

The proximal interphalangeal (pastern) joint is the diarthrodial articulation of the proximal and middle phalanges (referred to as P1 and P2 respectively) and is a low motion, high load joint.The middle phalanx is a compact bone, enclosed distally within the hoof capsule and coronary band. Numerous soft tissue structures cross the joint, including the common digital extensor tendon dorsally and the deep digital flexor tendon on the palmar aspect. The superficial digital flexor, along with the straight distal sesamoidean ligament, inserts on the distal palmar aspect of P1 and the proximal palmar aspect of P2. Sagittal support for the joint is provided by medial and lateral collateral ligaments which attach to collateral tubercles proximally and distally. Together, these soft tissue structures prevent over extension of the distal limb, and provide stability.

A three-month-old foal was presented with subluxation of the proximal interphalangeal joint in both forelimbs. The condition, which was considered to represent an unusual manifestation of breakdown of the suspensory apparatus, appeared to have developed as a consequence of extreme overexertion, 10 days previously. This had resulted in rupture of the palmar supporting structures of the joint; namely, the superficial distal sesamoidean ligament, the insertion of the superficial digital flexor tendon and the palmar joint capsule. Severe laxity of the flexor tendons had been present in the neonatal period, and it is postulated that this might have contributed to the development of the condition by weakening the suspensory apparatus, and placing increased strain on the suspensory ligament and its associated structures.

Summary Arthrodesis of the pastern joint was performed in six horses with a history of acute trauma and in 10 horses with a history of chronic lameness of one to six months duration. Five surgical techniques were employed: curettage of the joint, lag screw compression and immobilisation in a plaster cast curettage, compression using a T plate and immobilisation; drilling, lag screw compression and immobilisation; lag screw compression and immobilisation; and curettage and immobilisation. Pre- and postoperative clinical course are described together with significant radiographical findings. The best results were achieved by luxating the joint to curette the articular cartilage, followed by fixation and compression with either lag screws or a T plate and immobilisation in a plaster cast.

When the foot impacts with the ground the pastern joint dorsiflexes into the close-packed position (Figure 1) and, normally, remains in that position until the foot lifts-off from the ground. The close-packed position is that position of a joint in which the two joint surfaces have maximum surface area in contact with each other. It is the position of greatest congruity of the joint surfaces. It is true, though the argument will not be developed here, that as the joint dorsiflexes, the bones spin around their long axes from medial to lateral (Figure 2). There is, then, a twisting or screw-like motion of the pastern joint as it dorsiflexes. This spinning occurs because the medial part of the joint is larger than the lateral part. Again, without

SummaryThe objectives were to measure sagittal plane kinematics and kinetics of the forelimb pastern joint during the stance phase at the trot. Sagittal plane video (200 Hz) and force (1,000 Hz) recordings were analyzed from four trials of six sound horses trotting in hand. Kinematic and force data were used to calculate net joint moments and joint powers. The pastern joint showed maximal flexion (155.3 ± 11.0°) at 34% stance and maximal extension (190.2 ± 3.8°) at 93% stance. Energy was absorbed on the palmar aspect throughout stance, with peak energy absorption occurring in the second half of the stance. It was concluded that the primary function of the pastern joint was to act as an energy damper.