The split tendon of flexor digitorum superficialis reunites deep to the tendon of flexor digitorum profundus, around which it forms a loop. The flexor digitorum superficialis tendons then insert into the palmar Standard anatomical terms of location deal unambiguously with the anatomy of animals, including humans. All vertebrates (including humans) have the same basic body plan — they are bilaterally symmetrical. That is, they have mirror-image left and right halves if divided down the centre. For these reasons, the basic directional terms can be considered to be those used in vertebrates.Anatomical terms of location
What are the branches of the superficial digital flexor tendon?
Distally, the superficial digital flexor tendon divides into two branches (termed “distal branches” by some authors like JM Denoix, opposite to the sagittal branch of the proximal part). The distal branches insert on the lateral and medial eminences of the middle phalanx (and also some fibers insert on the lateral aspect of the proximal phalanx).
Where do the tendons of flexor digitorum superficialis enter the hand?
As the tendons of flexor digitorum superficialis enter the hand, they course superficial to the corresponding flexor digitorum profundus tendon. Upon passing the metacarpophalangeal joint, the two tendons enter the digital flexor sheath.
What is the synovial tendon that surrounds the flexor tendon?
The flexor tendons also have synovial tendon sheaths (paratendon) that surround them in the fetlock and digital region. 10. In the digital region the flexor tendons are bound down by proximal and distal digital annular ligaments. The distal digital annular ligament is beyond the SDFT and therefore only covers the DDFT.
How are the flexor tendons bound?
In the digital region the flexor tendons are bound down by proximal and distal digital annular ligaments. The distal digital annular ligament is beyond the SDFT and therefore only covers the DDFT. 11. Tendons have elastic properties and can stretch to a certain degree but over stretching will cause damage.
Where does the superficial digital flexor insert on horse?
The SDFT divides into two branches at the distal end of the proximal phalanx. The branches insert on the lateral and medial eminences of the middle phalanx, a minority of fibres also insert on the lateral aspect of the proximal phalanx.
What does the superficial digital flexor tendon connect to?
The superficial digital flexor tendon is located in the fore and hind limbs and runs along the back of the cannon bones and connects the short pastern to the coffin bone (LLC, HorseDVM). The superficial digital flexor tendon is responsible for the stabilization and support of the fetlock joint.
Where does the deep digital flexor tendon insert in the horse?
The DDF tendon courses behind the carpus, down along the back (palmar aspect) of the cannon bone, around the back of the fetlock, around the navicular bone in the back of the foot, and inserts on the underside of the third phalanx (P3).
Where is the superficial digital flexor tendon horse?
The SDFT specifically stretches from below the knee or hock to the pastern bone2 (see figure 1) and is involved in flexing the digit. This tendon is under considerable loading stress, especially in disciplines involving high speeds or jumping, such as Three-Day Eventing.
Where does the accessory check ligament of the superficial digital flexor attach proximally in the forelimb of a horse?
The accessory ligament or inferior check ligament, joins the tendon at the middle of the metacarpus. They then continue through the bifurcation of the superficial digital flexor tendon , through the intersesamoidean groove at the fetlock joint, over the pastern and insert on the distal phalanx.
Where does the suspensory ligament insert?
The suspensory ligament separates into separate branches proximal to the fetlock joint, with insertions on each of the four sesamoid bones. Additionally, small branches insert on the proximal aspect of the first phalanx.
What does the deep digital flexor tendon do in horses?
Its main job is to flex the leg, but it also plays a support role at the heel, where the tendon fibers fan out to pass over the navicular bone. Injuries in the lower section of this tendon, from mid-pastern into the foot, are common for sport horses.
Where does the deep digital flexor tendon originate from?
medial humeral epicondyleThe deep digital flexor tendon arises as three bellies from its origin on the medial humeral epicondyle, fusing to form a common tendon just proximal to the carpus on the caudal aspect of the limb. The single tendon passes distally, enclosed in the carpal sheath, through the carpal canal.
What is in the digital flexor tendon sheath horse?
The digital flexor tendon sheath (DFTS) is a synovial cavity occupying the distal third of the palmar metacarpus/plantar metatarsus and the palmar/plantar pastern, to the level of the middle phalanx.
Where does the lateral digital extensor insertion?
Extensor digitorum muscleOriginLateral epicondyle of humerus (common extensor tendon)InsertionExtensor expansions of digits 2-5ActionMetacarpophalangeal / Interphalangeal joints 2-5: Finger extensionInnervationPosterior interosseous nerve (C7, C8)1 more row•May 11, 2020
What is a superficial tendon?
The forelimb superficial digital flexor tendon (SDFT) is an energy-storing tendon that is highly susceptible to injury during activities such as galloping and jumping, such that it is one of the most commonly reported causes of lameness in the performance horse.
What does SDFT mean in horses?
The superficial digital flexor tendon (SDFT) is the more commonly injured of the flexor tendons, accounting for 75–93% of clinical cases; research suggests that lesions typically occur at the mid-metacarpal level in the 'core' or central region of the SDFT.
How many branches does the digital flexor tendon have?
Distally, the superficial digital flexor tendon divides into two branches (termed “distal branches” by some authors like JM Denoix, opposite to the sagittal branch of the proximal part).
Where does the SDFT tendon come from?
On equine thoracic limb, the superficial digital flexor tendon (SDFT) arises from the superficial digital flexor muscle at the level of the carpus. Then the tendon combines with the accessory ligament (superior check ligament), passes distally on the caudal aspect through the carpal canal.
What tendon wraps around the manica flexoria?
On the metacarpus, the superficial digital flexor tendon wraps around the deep digital flexor tendon, forming the manica flexoria. On the level of the middle phalanx, the superficial digital flexor tendon is enclosed with the deep digital flexor tendon into the digital sheath.
Where is the superficial digital flexor tendon?
What is the superficial digital flexor tendon? The superficial digital flexor tendon extends from the back of the bottom of the femur (thigh bone), down the back of the lower leg (as a component of the common calcanean (Achilles) tendon, together with the tendon of the gastrocnemius (calf) msucle and the combined tendon of the biceps femorus, ...
How long does it take for a dog to recover from digital flexor tendon surgery?
The prognosis following surgery is excellent, with most dogs returning to full activity within two to three months. Most dogs have no further problems with their superficial digital flexor tendon, although re-luxation can occur in rare cases.
How to treat superficial digital luxation?
The treatment for superficial digital luxation is a surgical procedure in which the torn retinaculum is sutured back together, thereby restoring the tendon to its correct location. If the groove at the point of the heel bone (tuber calcanei) is found to be absent or abnormally shallow, it will be deepened to further increase stability.
Abstract
Clinical case presentations detail unique and clinically relevant anatomical features about the equine forelimb. Proximal forelimb cases highlight the shoulder and elbow, and distal forelimb cases highlight the carpus, metacarpus, phalanges, navicular bursa, and laminar support structures.
Clinical case
A 5-year-old Warmblood gelding presented for swelling on the palmar aspect of the mid-metacarpus of the right thoracic limb. The swelling had been present for 24 hours and was first noted when the horse returned from a weekend horseshow and the trainer removed the shipping bandages.
Anatomical features in equids
The major anatomical structures in the metacarpus/-tarsus include the extensor tendons, superficial and deep digital flexor tendons, the accessory (inferior check) ligament of the deep digital flexor tendon, and the suspensory ligament. Clinically relevant differences between the thoracic and pelvic limbs are discussed.
Traumatic Disruption of the Suspensory Apparatus
Disruption of the suspensory apparatus is usually an acute racing injury from a comminuted fracture of the proximal sesamoid bones—i.e., a “breakdown injury” in racehorses—or a laceration of the suspensory apparatus. It can also occur as a chronic problem in older horses due to degeneration of the SL ( Fig. 14.5-5 ).
Which ligaments are bound down by the flexor tendons?
In the digital region the flexor tendons are bound down by proximal and distal digital annular ligaments. The distal digital annular ligament is beyond the SDFT and therefore only covers the DDFT. 11. Tendons have elastic properties and can stretch to a certain degree but over stretching will cause damage.
What are the fibers in a tendon?
13. Tendons consist of regularly arranged fiber bundles that consist of living cells and an extracellular collagen matrix produced by the cells. The collagen fibers, not the cells, are responsible for the strength and elasticity of the tendon.
Which ligament binds the sesamoid bones together?
A fibrocartilagenous intersesamoidean ligament binds the sesamoid bones together so that the proximal sesamoids form a groove for the flexor tendons. The flexor tendons are held in this groove by the palmar annular ligament. 8. At the fetlock the SDFT forms a thin sleeve (manica flexorum) around the DDFT.
Which ligament attaches to the sesamoid bones?
SDFT and its check ligament. But ….. remember that only the suspensory ligament attaches to the sesamoid bones while the flexor tendons slide over them, so the suspensory lig. is the main structure supporting the fetlock. Excessive stretching of these tendons -> inflammation = swelling = bowed tendon.
Which tendon is most often damaged in performance horses?
The tendons most often damaged in performance horses are the superficial digital flexor (SDFT) and the suspensory ligament (SL) which is the same as the interosseous tendon. In contrast, the deep digital flexor tendon (DDFT) has a lower incidence of damage.
Which muscle joins the digital extensor tendon?
The branches of the interosseous muscle (suspensory ligament) join the common digital extensor tendon before its insertion on the extensor process of the distal phalanx. A minor branch inserts on the middle phalanx and some fibres insert on the hoof cartilages.
Where does the single tendon pass?
The single tendon passes distally, enclosed in the carpal sheath, through the carpal canal. In the mid-metacarpal region, the tendon is enforced by an accessory ligament ( inferior check ligament ). At the metacarpophalangeal (fetlock) joint, the DDFT passes though the manica flexoria and over the sesamoid groove.
What is the digital extensor?
The common digital extensor tendon is surrounded by the extensor retinaculum and a protective synovial sheath. The tendon sheath begins approximately 10cm proximal to the carpus, extending distally to the level of the metacarpus.
What are tendons made of?
Tendons are composed of bundles of collagen, predominantly type I, surrounding parallel rows of fibroblasts known as tenocytes. Tenocytes synthesize the collagen fibres that they surround. Many collagen fibres make up a fascicle. Within the fascicle, collagen fibres are parallel with a ‘crimp’ waveform. This arrangement allows lateral cohesion between fibres, preventing slippage between fibres or fibrils. The ‘crimp’ straightens when the tendon is loaded and then recoils when the load is removed; this allows the elastic function of tendons. There are no muscles in the equine digit, instead there are the tendons of insertion of the two extensor muscles and the two flexor muscles of the digit.
Which tendons are surrounded by synovial sheaths?
Flexors. The digital flexor tendons are surrounded by synovial sheaths, which serve a protective function; allowing frictionless movement as the tendons traverse the bony prominences of the carpus and metacarpophalangeal (fetlock) joint. Carpal Sheath. Arises approximately 10cm proximal to the carpus and extends to mid-metacarpal region.
Where does SDFT come from?
The SDFT arises from the superficial digital flexor muscle at the level of the carpus. At this level, the tendon combines with the accessory ligament ( superior check ligament ). The tendon passes distally on the caudal aspect of the limb, running through the carpal canal to the metacarpus.
Which muscle group is the calcaneal tendon?
The common calcaneal tendon is the continuation of the ‘hamstring’ group of muscles ( biceps femoris, abductor cruris caudalis, semitendinosus, semimembranosus, gastrocnemius and SDFT) on the caudal aspect of the proximal limb. The synovial fluid-filled calcanean bursa lies between the SDFT and the calcanean tuberosity .