Muscles of Tail & Pelvic and Stifle Joints PDF

Muscles of tail & Pelvic and stifle joints  Sacrum Degree of fusion, least in the pig, of the sacral vertebrae varies among species. Dorsal surface marked by the appropriate number of spinous processes, or much reduced or e...

Muscles of tail & Pelvic and stifle joints  Sacrum Degree of fusion, least in the pig, of the sacral vertebrae varies among species. Dorsal surface marked by the appropriate number of spinous processes, or much reduced or even absent (e.g., pig) Spinous processes may preserve their independence (e.g., dog or horse) or fuse to form a continuous crest (e.g., ruminants) Base of the sacrum Cranial and above its slightly convex articular surface is the beginning of the wide sacral canal Promontory: cranioventral part of the base has a transverse ridge Apex Caudal extremity of the sacrum Articulates with the 1st caudal vertebra Dorsal surface Median sacral crest (fusion of the spinous processes) Intermediate sacral crest: fused mamillo-articular processes Dorsal sacral foramina Pelvic surface Variable in its degree of concavity Pelvic sacral foramina Lateral sacral crest Wing of the sacrum Enlarged lateral part auricular surface  Caudal vertebrae Vertebrae of the tail after the sacral vertebrae Number of caudal vertebrae varies greatly, between and within species Greater variation than are the vertebrae of any other region 1st few resemble miniature lumbar vertebrae, the middle and later members of the series are reduced to simple rods. More cranial vertebrae of some species provide protection to the main artery of the tail in the form of: Ventral (hemal) arches Separate small chevron (V- shaped) bones connected to the undersurfaces of the bodies Paired ventral (hemal) processes  Muscles of the tail Situated around the caudal vertebrae enclosed in the strong coccygeal fascia Muscles are composed of series of fasciculi terminating into tendons. The movements of the tail are affected by pairs of coccygeal muscles which are longitudinally disposed around the coccygeal vertebrae and thus cover them completely. Extensors or levators of the tail: Dorsal in location M. sacrocaudalis dorsalis lateralis and medialis Flexors or depressors of the tail: Ventral in location M. sacrocaudalis ventralis lateralis and medialis Lateral flexors of the tail: Lateral location M. coccygeus, levator ani, intertransversarii caudae + rectococcygeus and retractor penis Extensors or levators of the tail: Epaxial muscles that form a continuous column Muscles of the tail throughout most of the vertebral column: Dorsal coccygeal muscle: serratus dorsalis, the erector spinae, transverse spinalis, interspinalis and intertransversarii. Direct continuations of the epaxial musculature of the trunk. Lie on the lumbar vertebrae, sacrum, and caudal vertebrae, and insert on the caudal vertebrae, exclusively. Extensors or levators of the tail: Muscles of the tail Sacrocaudalis dorsalis lateralis = long levator of the tail Origin: Continuation of the longissimus Tendinous origin from the mamillary processes of 1st – 6th lumbar vertebra Articular processes of the sacrum Mamillary processes of 1st 8 caudal vertebrae. Lies between the m. longissimus (laterally), and the mm. multifidus lumborum and sacrocaudalis dorsalis medialis (medially). Insertion: Mamillary processes of the 5th to last caudal vertebrae. Action: Extension or lifting of the tail, possibly also to move it to the side. Nerve: branches of the plexus caudalis dorsalis Extensors or levators of the tail: Muscles of the tail M.sacrocaudalis dorsalis medialis = short levator of the tail Origin: Direct continuation on the tail of the m. multifidus Small processes that are dorsolateral to the caudal edge of the caudal vertebrae. Lies next to the median plane on the sacrum and caudal vertebrae and extends from the seventh lumbar to the last caudal vertebrae Composed: Deep, short muscle masses Larger, superficial, long part (small tendon that spans four or five vertebrae) Insertion: Mamillary processes of the fifth through last caudal vertebrae. The superficial tendons end in common with the long tendons of the m. sacrocaudalis dorsalis lateralis Action: Extension of the tail and possibly lateral flexion. Nerve: Branches of the plexus caudalis dorsalis Flexors or depressors of the tail: Muscles of the tail M.sacrocaudalis ventralis lateralis = long depressor of the tail Consists of numerous long, individual parts that are arranged like those of the long levator and that end by means of long tendons from the sixth to the last segment. Origin: Ventral surface of the body of the last lumbar vertebra and from the sacrum Ventral surfaces and roots of the transverse processes of the caudal vertebrae. Insertion: Ventral lateral tubercle of the proximal end of the sixth through last caudal vertebrae. Action: Flexion of the tail and occasionally lateral movement. Nerve: Branches of the plexus caudalis ventralis. Flexors or depressors of the tail: Muscles of the tail M.sacrocaudalis ventralis medialis = short depressor of the tail Consists of segmental, short individual parts extending from the last sacral vertebra throughout the length of the tai Origin: Starting from the last sacral vertebra on the ventral surface and running from each vertebra to the next. Insertion: Ventrolateral process of each vertebra. Action: Flexion of the tail and occasionally, lateral movement. Nerve: Branches of the plexus caudalis ventralis.  Sacrocaudalis dorsalis medialis Sacrocaudalis dorsalis lateralis Sacrocaudalis ventralis lateralis Sacrocaudalis ventralis medialis (plus dessous la lateralis) Sacrocaudalis ventralis medialis Sacrocaudalis dorsalis lateralis Sacrocaudalis dorsalis medialis Sacrocaudalis ventralis lateralis Lateral flexors of the tail: Muscles of the tail M.intertransversarii DORSAL caudal Between the sacrum and the middle of the tail. Consists of short individual parts Origin: Dorsal sacroiliac ligament (lateral part of the 3rd sacral vertebra), and forms muscle belly that ends on the transverse process of the 5th-6th caudal vertebra by means of a long tendon. In its course it receives supplementary fibers from the transverse processes of the first few caudal vertebrae. Insertion: Transverse process of the fifth and sixth caudal vertebra. Action: With the intertransversarius ventralis caudalis, lateral flexion of the tail. Nerve: Branches of the plexus caudalis ventralis. Lateral flexors of the tail: Muscles of the tail M.intertransversarii VENTRAL caudal Origin: Ventral to the transverse processes, begins at the third caudal vertebra. Composed of segments, and, at the base of the tail, is smaller than the dorsal muscle. Ventrally covered by the long tendons of the long depressor of the tail. Between ventral and dorsal intertransversarii: 3rd-5th caudal vertebra: separated by coccygeal m. Remaining separated by a intermuscular septum of the caudal fascia. Insertion: Ventral surface of each caudal vertebra. Action: Lateral flexion of the tail. Nerve: Same as for the m. intertransver- sarius dorsalis caudalis. Branches of the plexus caudalis ventralis. Il est sous le sacrocaudalis ventral lateralis et medialis  Sacroiliac joint Combined synovial and fibrocartilaginous joint Combine firmness of attachment with some shock-absorbent capacity Capable of slight motion. It transmits the weight of the trunk to the hindlimbs during standing and the thrust of the limbs to the trunk during progression Joint capsule: Unites the margins between the crescent- shaped auricular surfaces on the wings of the sacrum and ilium Sacroiliac synchondrosis: Fibrocartilage firmly uniting the ilium and sacrum are firmly united Located craniodorsal to the synovial portion of the joint.  Ventral sacroiliac ligament Mostly covered by the iliacus muscle 2 groups (carnivorous) with the joint capsule between them: Cranial group: Run medially and caudally from the ilium to the sacrum. Caudal group: Shorter fascicles that run medially and cranially. Dorsal sacroiliac ligaments More extensive than the ventral sacroiliac ligament Divided into short and long parts. Short part: Well developed in carnivorous Solid fibrous beams that attach themselves dorsally to the auricular surface of the ilium bone as well as the part near the dorsocranial iliac spine, sometimes dorsocaudal (Dogs) and go to the border of the sacrum, on the part that corresponds to the first transverse sacral processes.  Dorsal sacroiliac ligaments Long part: Appears on the ilium dorsocaudally to the short part, to which it is united. Carnivorous and Pigs: Ends on the last sacral transverse processes Ungulates: Continues with the sacral attach of the sacrosciatic ligament. In ruminants (and horses) extends considerably annexing a great part of the sacrosciatic ligament, in order to cover the spinal muscles and attach on median sacral crest. Limits the tilting movements of the ilium on the sacrum and interlocks even more tightly the pelvis to the vertebral column. Components: Funicular part: spread to the median sacral crest Membranous part: It goes to the lateral border of the sacrum and of the first coccygean vertebrae, covering the spinal muscles.  Hip joint Diarthrodial articulation between the femoral head and acetabulum Ball-and-socket configuration provides stability while allowing a wide range of joint motion Primary stabilizers: Ligament of the head of the femur Joint capsule Dorsal acetabular rim Secondary stabilizers: Joint fluid (hydrostatic pressure) Periarticular muscles: deep, middle, and superficial gluteal muscles, iliopsoas, quadratus femoris, gemelli, internal obturator, and external obturator muscles Axes through the femur and os coxae meet at the hip joint in a cranially open angle ~95 degrees  Acetabular lip Provides secondary stabilization of the hip joint and comprises a thin, fibrocartilaginous band that extends laterally from the dorsal acetabular rim. Ventrally, this fibrocartilaginous band extends across the acetabular notch as the transverse acetabular ligament.  Joint capsule Attachments: Medially from the edge of the acetabular lip Laterally, on the neck of the femur The fibrous coat has various thickenings but no definite ligaments. Orbicular zone: Most distinct thickening in the dorsal part that causes a horizontal bulging of the synovial membrane Other ligaments: Iliofemoral ligament (cranially) Ischiofemoral ligament (caudally)  Ligament of the head of the femur (round ligament) Short, thick, flattened cord that extends from the fovea in the head of the femur to the acetabular fossa. Largely intraarticular and not weight-bearing but is still covered by synovial membrane. Acetabular attachment is wide as it blends with the periosteum of the acetabular fossa and the transverse acetabular ligament. In and peripheral to the rectangular acetabular fossa there is usually a small quantity of fat J’ai passé vascularization hip joint ad proximal femure  Stifle joint Flexion-extension and rotation are the primary types of motion about the stifle joint. ROM ~140 degrees Complex condylar synovial joint: Femorotibial joint (or condyloid part of the joint): 1. Main spheroidal part formed by the thick, roller-like condyles of the femur articulating with the flattened condyles of the tibia 2. Separation of its articular surfaces by intra-articular fibrocartilages (menisci) Femoropatellar joint: 3. Located between the patella and the trochlea of the femur. 4. Improve the efficiency of the extensor mechanism by increasing the moment arm of the quadriceps muscle  Bones of the Stifle Joint 3 major articular areas: one each on the medial and lateral femoral condyles third within the femoral trochlea on the cranial surface Medial and lateral femoral condyles separated by the intercondyloid fossa. Caudal articular surface of the condyles continuous with articular facets on adjacent epicondyles that articulate with the fabellae Medial and lateral fabellae: small sesamoid bones in the tendons of origin of the gastrocnemius muscle  Bones of the Stifle Joint Femoral trochlear (patellar) surface: Grooved articular surface of the cranial femur Continuous with the articular surfaces of the femoral condyles. Patella articulates with the femoral trochlea. Proximal articular surface of the tibia: Triangular in cross-section Proximal articular surface is divided into medial and lateral condyles, Intercondylar eminence: A sagittal, nonarticular area separates condyles Medial and lateral intercondylar tubercles: Projections atop the intercondylar eminence  Bones of the Stifle Joint Cranial intercondyloid area: Depression cranial to the intercondylar eminence Attachment site for the cranial cruciate ligament and the cranial meniscal ligaments Caudal intercondyloid area: Smaller depression caudal to the intercondylar eminence Attachment site for the caudal meniscal ligaments Popliteal notch: Caudal-most aspect Separates the tibial condyles Caudal cruciate ligament attaches to the lateral edge of the popliteal notch. Extensor groove: Small notch at the cranial margin of the lateral tibial condyle that extends to the margin of the articular surface of the lateral condyle. Long digital extensor tendon runs through this groove.  Bones of the Stifle Joint Tibial tuberosity: Cranioproximal process that serves as the attachment for the patellar ligament, as well as for parts of the biceps femoris and sartorius muscles Cranial border of the tibia (formerly called the tibial crest) extends distally from the tibial tuberosity. Facies articularis fibularis: Articulation of the fibular head and caudolateral surface of the tibial condyle  Capsule of the Stifle Joint The joint capsule of the femorotibial joint is composed by two sacs, a medial and a lateral, freely connected with joint capsule of femoropatellar joint, the third sac constituting the joint capsule of the stifle joint. In dogs, the femoropatellar sacs are considerably smaller than the femoropatellar. Both femorotibial sacs are partly divided by the menisci into femoromeniscal and tibiomeniscal parts. Femorotibial sacs are divided into femoromeniscal and tibiomeniscal parts by the menisci. Distal to the patella, the synovial and fibrous layers of the joint capsule are separated by the infrapatellar fat pad (extrasynovial) Synovial, protecting and fibrocartilaginous structures of stifle joint: Corpus adiposum infrapatellare (7): fatty tissue under lig.patellae Bursa infrapatellaris (8): under lig. Patellaea tibial tuberosity Recessus suprapatellaris (9): behind and above patella Recessus subextensorius (10): around tendon of m.ext.dig.longus Recessus subpopliteus (11): around tend on of m.popliteus Meniscusmedialis (12): fibrocartilage between femur and tibia Meniscuslateralis (13): fibrocartilage between femur and tibia  Capsule of the Stifle Joint Lateral femorotibial joint: 3 subpouches Small extension traverses laterally between the head of the fibula and the lateral condyle of the tibia Distally through the extensor groove, Partially surrounds the tendon of origin of the popliteal muscle at the level of the lateral femoral condyle and serves as a synovial bursa. A small synovial bursa is frequently located between the patellar ligament and the tibial tuberosity, just proximal to the attachment of the ligament.  Patella Largest sesamoid bone Ossification in the tendon of insertion of the quadriceps muscle Ovate in shape and slightly curved to articulate with the femoral trochlea. Base: Blunt, proximal portion Apex: slightly pointed distal surface Patellar ligament: part of the tendon of the quadriceps femoris muscle between the patella and its insertion on the tibial tuberosity  Meniscus C-shaped disks of fibrocartilage located between the condyles of the femur and the tibia Functional extension of the tibia, are held in place by ligaments and soft tissue attachments Cranial and caudal meniscal horns are firmly attached to bone via the ligaments (cranial and caudal meniscotibial ligaments) Coronary ligament: Anchors meniscal body to the tibia and femur, which varies between medial and lateral menisci. Medial meniscus is firmly attached to the medial collateral ligament and the joint capsule via the coronary ligament Lateral meniscus lacks these attachments.  Medial Meniscus Firmly attached to the tibia through the cranial and caudal meniscotibial ligaments Peripherally attached to the joint capsule (and indirectly to the tibia and femur) and the medial collateral ligament through the coronary ligament Abaxial border blends into the medial collateral ligament Intermeniscal ligament is located between the cranial horns of the lateral and medial menisci Cranial meniscotibial ligament of the medial meniscus runs from the cranial axial border of the medial meniscus to the cranial intercondyloid area immediately cranial to the intermeniscal ligament Caudal meniscotibial ligament of the medial meniscus runs from the caudal axial border of the medial meniscus to attach to the caudal intercondyloid area of the tibia  Lateral Meniscus Less firmly attached to the tibia than is the medial meniscus. Less extensive attachment to the joint capsule than does the medial meniscus because the popliteus muscle tendon is interposed between the joint capsule and the lateral meniscus. Cranial meniscotibial ligament of the lateral meniscus attaches to the cranial intercondyloid area of the tibia Caudal meniscotibial ligament of the lateral meniscus runs from the caudal axial border of the lateral meniscus to attach in the popliteal notch Meniscofemoral ligament of the lateral meniscus, (femoral ligament) runs dorsally from the caudal axial border of the lateral meniscus to attach within the intercondylar fossa of the femur as it blends into the medial femoral condyle.  Intracapsular ligaments Transverse ligament: connects cranial angles of the two meniscus Meniscofemoral ligament: from medial femoral condyle’s caudal axial surface to caudal end of lateral meniscus Meniscotibial ligament: from cranial and caudal ends of both meniscus to tibia L.craniale menisci laterale: area intercondylaris cranialis lateralis L.craniale menisci mediale: area intercondylaris cranialis medialis L.caudale menisci laterale: incisur apoplitea L.caudale menisci mediale: area intercondylaris caudalis The cruciate ligaments are located within the stifle joint (intra-articular), but because they are covered by synovium, they are considered to be extrasynovial. Cranial cruciate ligament: Dog: from lateral femoral condyle’s caudal axial surface to area intercondylaris cranialis of tibia Equine: from lateral femoral condyle’s caudal axial surface to area intercondylaris centralis of tibia Caudal cruciate ligament: from medial femoral condyle’s cranial axial surface to area intercondylaris caudalis and incisura poplitea of tibia  Cruciate ligaments Cranial cruciate ligament: Primary restraint against cranial tibial translation (cranial drawer). Resists hyperextension of the stifle joint. Twists to limit internal rotation but notsignificant for external rotation. Has variable impact on varus and valgus angulation. 2 Bundles: Craniomedial band – Taut in extension & flexion Caudolateral band – Taut in extension Caula cruciate ligament: Main restraint against caudal tibial translation (caudal drawer). Limits internal tibial rotation by twisting with Cranial Cruciate Ligament. Secondary restraint against hyperextension. Helps limit varus and valgus angulation in flexion.  Extracapsular ligaments Retinaculum patellae: from fascia lata and aponeurosis of muscles, covers stifle Lig. patellae: Continuation of m. quadriceps femoris’s tendon, the patella is a sesamoid bone in the tendon before patellar ligament inserts on tibial tuberosity Lateral collateral l.: from lateral epicondyle of femur to head of fibula, a lesser part to lateral condyle of tibia; underneath there is the tendon of m. popliteus Medial collateral l.: from medial epicondyle of femur to distal part of tibia’s medial condyle; it also attaches strongly to medial meniscus Interspecies differences of the stifle Transverse lig. of stifle: not present in horse and bovine Medial patellar lig.: present in horse and bovine Intermediate patellar lig.: present in horse and bovine Lateral patellar lig.: present in horse and bovine Stifle of the horse 1, Adductor; 2, vastus medialis; 3, rectus femoris; 4, vastus lateralis 5, outline of patella; 6, outline of patellar fibrocartilage 7, 8, and 9, medial, intermediate, and lateral patellar ligaments 10, joint capsule over medial ridge of femoral trochlea 11 and 11ʹ, medial and lateral collateral ligaments 12 and 12ʹ, medial and lateral femorotibial joint capsules, 13 and 13ʹ, medial and lateral menisci 14, distal infrapatellar bursa