Gluteal Region, Hip & Thigh Flashcards
What are the regions of the lower limb?
- Gluteal (from hip to thigh joint)
- Thigh (from thigh to knee joint)
- Leg (from knee to ankle joint)
- Foot
What is the function of the lower limbs?
STRENGTH + STABILITY in preference to range of movement to:
- Support body weight
- Maintain upright posture
- Locomotion (gait)
- Accommodate shock loading
What are the 4 basic phases of walking?
Stance:
- Heel strike
- Support
Swing:
- Toe-off
- Swing/carry through
What is the very last thing to leave the floor when you are about to enter the swing phase? Why is this relevant?
The big toe so this is critical for walking and uses a huge muscle to propel the body forward when coming off the ground
What is the pelvic girdle?
A basin shaped rigid ring of bone that is partly formed by the axial skeleton (sacrum) to distribute weight of the axial body to the lower limbs and enables locomotion and standing
What makes up the hip joint?
Synovial deep ball and socket joint made up of the femoral head (ball) connected to the acetabulum (socket)
What would a posterior hip joint dislocation look like?
Limb would be shortened, flexed, adducted (pulled into midline) and internally rotated - more COMMON type of hip joint dislocation
What would an anterior hip joint dislocation look like?
Limb is abducted (away from midline) and externally rotated
What makes up the bony pelvis?
Sacrum and 2 hip bones connected via secondary cartilaginous joints: sacroiliac posteriorly and the pubic symphysis anteriorly
What is the function of the sacroiliac joints?
Transmit weight of body to the hip bones
What can happen if you injure your sacroiliac joint?
Pain that radiates up the back, into bum and perineal region - common in taller people
How can you injure the pelvic girdle?
High force trauma esp. when sitting down when the hip ligaments are the loosest (posterior dislocation is the most common outcome)
What are sciatic foramen?
Holes formed by borders of the sacrospinous and sacrotuberous ligaments so nerves, vessels and some tendons can pass through, there are 2 types:
- Greater: connects pelvic cavity and gluteal region (divided in half by piriformis)
- Lesser: connects to perineal and gluteal regions
What are the 3 hip bones?
- Ilium
- Ischium
- Pubis
Come together to form the acetabulum (not fused till young adulthood)
What muscles attach to the greater trochanter bony prominence of the femur? What is their role?
Gluteus medius and minimus - stabilise pelvis on lower limb during walking
What muscle attaches to the lesser trochanter bony prominence of the femur? What is its role?
Illiopsoas - powerful hip flexor
What inserts into the linea aspera?
Many powerful thigh muscles and the 3 intermuscular septa
What is the condyle of the femur?
J-shaped articular regions for the knee
What bony prominence of the femur is palpable?
Adductor tubercle
If a bony prominence of a bone is bigger, what does this generally mean?
It takes more stress and force through muscle attachments so more remodelling occurs here (Wolff’s law)
What is the weakest area of the femur?
The neck
What is the bit of the femur that breaks most commonly when osteoporotic/osteopenic elderly patients fall?
The neck
What is the acetabular labrum?
Horseshoe shaped fibrocartilage rim of tissue that surrounds the acetabulum by attaching to its bony margin making the hip joint deeper and more stable - can get impinged within joint causing pain on movement
What are the 2 membranes that cover the hip joint?
- Synovial membrane: covers the joint
2. Fibrous membrane: covers the synovial membrane
What are the 3 ligaments that cover the hip joints and its membranes?
- Illiofemoral
- Pubofemoral
- Ischiofemoral
How do the hip ligaments function?
They wrap tightly around the hip joint upon standing to reinforce and stabilize the joint whereas upon sitting they become looser allowing deep hip flexion
What is the blood supply to the hip?
It is unidirectional and circumflex arteries flowing from the base of the femoral neck, surround it, pass through the retinacular fibres of the joint capsule to the femoral head = medical emergency
What can be the result of an intra-capsular femoral neck fracture?
Disruption of blood supply to the femoral head resulting in avascular necrosis - artery of ligament of head of femur cannot compensate as it is too small
What does the common illiac artery become when it passes through the inguinal ligament?
The femoral artery which supplies the anterior thigh compartment and branches off again to form the deep femoral artery which supplies the posterior thigh compartment and also gives off the lateral and medial femoral circumflex arteries which go back up to supply the femoral head
What is the ligamentum teres? What is its blood supply?
A ligament of the head of the femur which runs from the acetabulum to the femoral head and offers joint support containing a tiny artery supplying the joint articular surface
How can you tell if a scan is of a female pelvis?
Pelvic inlet rounder with softer angles between the sacrum and ileum
Wider base of ileum
Genitalia (soft tissue shadows)
What is Shenton’s line?
A dashed line that can be drawn over the arch of the femoral neck and continued along the pelvic ring medially - simple way to tell if a patient has a subtly non-displaced hip fracture as the arch will not be nice and continuous
Why will an extracapsular (interotrochanteric) fracture not disrupt the blood supply?
The fracture goes between the greater and less trochanter so circumflex arteries can still get to femoral head as they have come off the femoral artery distal to the fracture site
What is the different between valgus and varus deformities of the joints?
Valgus = distal part of limb directed AWAY from midline (increased angle > 130 degrees) - BOWED knees
Varus = distal part of limb directed TOWARDS midline (decreased angle < 130 degrees) - KNOCKED knees
Where does the hip joint deformity normally show?
Between the femoral head and neck
Where else on the lower limb can a joint deformity form?
Knee
Toes
What are the main features of limb compartments?
They are wrapped in a deep fascia so are a sealed unit that often contain muscles with the same function, innervated by one nerve and often have a major blood supply
What is the problem with having sealed limb compartments?
Increased pressure via injury, inflammation or bleeding may compress blood vessels and nerves and kill the tissues supplied/innervated by these
What is the fascia lata?
Lower limb fascia that collectively surrounds all the compartments forming a tight contouring following covering - saphenous vein runs superficial to it
What is the iliotibial tract (ITT)?
Lateral thickening of fascia lata that acts as a muscle attachment point (much of gluteus maximum inserts into it) assisting knee extension + stability - inflammation of IT tract can cause lateral knee pain
What are the compartments of the thigh, their function, innervation and blood supply?
- Anterior: hip flexor/knee extension - femoral n. (L2-4) + femoral artery
- Medial: hip adductors - obturator n. (L2-4) + obturator artery
- Posterior: hip extension/knee flexion - sciatic n. (L4-S3) -> tibial n. (L5-S1) + branches of deep femoral (profunda femoris)
What is the function of the gluteal muscles?
Bring about hip/trunk extension and pelvic stabilisation when walking so critical when stair climbing and arising from chairs:
- Medius/minimus: contract on L when R leg is off ground preventing pelvis tilting towards unsupported R side
- Maximus keeps trunk tipping forward when walking
What are the 3 main gluteal muscles and their innervation?
- Gluteus maximus (inf. gluteal n. L5-S2)
- Gluteus medius (sup. gluteal n. L4-S1)
- Gluteus minimus (sup. gluteal n. L4-S1)
What are the attachments of the gluteus maximus?
Proximal: illium, sacrum + sacral ligaments
Distal: femur + IT tract
What can occur if the superior gluteal nerve is not functioning?
Trendelenburg sign where the gluteus medius/minimus muscles do not work so there is a lurch when walking towards the unsupported side that is off the ground
What can occur if the inferior gluteal nerve is not functioning?
Gluteus maximum is not working so the patient will be lurching backward when their weaker limb is on the floor so may complain that getting out of chairs is difficult too
Where is the sacral plexus?
Posterior lateral pelvic wall near the key landmark muscle the PIRIFORMIS (divides greater sciatic foramen into supra + infra piriform parts)
What branches does the sacral plexus give off (from superior to inferior)?
- Lumbosacral trunk (L4-5) P+A
- Sup. gluteal n. (L4-S1) P
- Inf. gluteal n. (L5-S2) P
- ALL then form the sciatic n. (L4-S3) -> common fibular n. P + tibial n. A
- Pudendal n. (S2-4) A
- Sympathetic chain A
- Nerves to levator ani (S4) A
What do the lateral rotators do? What innervates them?
Pass between the pelvic bones, ligaments and proximal femur to support the hip by helping keep hip joint surfaces together and laterally rotate the hip - innervated by L4-S2
What are the 5 lateral rotator muscles?
- Piriformis
- Gemelli (Sup. + Inf.)
- Quadratus femoris
- Obturator internus
In a posterior approach to hip replacement surgery, what muscle group is separated?
Lateral rotators
What does the sciatic nerve (L4-S3) do? When can it become damaged?
Passes distally in posterior thigh compartment, emerges from under piriformis muscle and supplies posterior compartment of thigh, leg + foot so its vulnerable to damage via compression, intramuscular injection, posterior dislocation + hip replacement
What are the 2 safe zones of the gluteal region where an intermuscular injection will avoid the sciatic nerve?
- Vertical line through highest point of illiac crest and horizontal line midway between this and the ischial tuberosity -> inject in the LUQ
- Vertical line through highest point of illiac crest and line from PSIS to greater trochanter -> inject into most lateral part (preferred method as ischial tuberosity palpation is uncomfortable for patients)
What are the hip flexor muscles?
Illiopsoas (L1-3):
- Psoas major (lumbar vertebrae + attaches to lesser trochanter)
- Illiacus (inner surface of illiac bone + attaches to lesser trochanter)
What can go wrong with the iliopsoas hip flexors?
- Hip flexion can exacerbate back pain due to psoas major attachment to lumbar vertebrae
- Illiacus attachment to lesser trochanter makes it subject to avulsion fractures
- Illiopsoas tendonitis causes groin pain
What is a psoas abscess?
An abscess that begins in the psoas major muscle, tracks down the fibrous sheath covering this muscle and producing a femoral triangle swelling that can mimic a hernia
What are the 4 adductor muscles in the medial thigh compartment? What do they do and what is their innervation?
All adduct the hip attaching to the medial aspect of the femur and innervated by the obturator n. (L2-4) including:
Superficial: 1. Pectineus (also femoral n.) 2. Adductor longus Deep: 3. Adductor magnus 4. Adductor brevis
When does the femoral artery become the popliteal artery?
When it passes through the adductor hiatus (hole in all 4 adductor muscles) to go behind the knee so that it does not pass in front of our knee which always bends and would damage it
What are the 4 quadriceps muscles in the anterior thigh compartment? What do they do and what is their innervation?
All involved in knee extension and innervated by the femoral n. (L2-4) including:
- Rectus femoris (only 1 attached to hip bone so also involved in hip flexion)
- Vastus intermedius
- Vastus lateralis
- Vastus medialis
What can go wrong with quadriceps muscle group?
Loss of function = weak/absent knee extension so patient will have difficulty getting out of chairs
Muscle/tendon rupture = pain + palpable sulcus (if proximal quadriceps tendon ruptures)
What does the sartorius muscle do?
Part of the anterior thigh compartment so is also involved with hip flexion and knee extension LIKE the quadriceps muscles
What supplies the tensor facia lata muscle?
Sup. gluteal n. (L4-S1) because its more lateral even though it is classed as an anterior thigh compartment muscle
What does the patella ligament test?
L3-4 spinal nerves
What are the 3 hamstring muscles in the posterior thigh compartment? What do they do and what is their innervation?
Originate from ischial tuberosity and attach to tibia/fibula - all involved in hip extension and knee flexion/rotation innervated by the tibial part of the sciatic n. (L5-S2) including:
- Semitendinosus (top)
- Semimembranosus (deep)
- Biceps femoris: long + short head (common fibular n. (L5-S1)
What will occur if you rupture the hamstrings?
Pain
Bruising (ecchymosis)
What do injuries would compromise the quadriceps muscle function but not directly affect them?
Fracture of patella or rupture of the patella ligament that connects the patella to the tibial tuberosity bone, also causing an avulsion fracture - both aid the quadricep muscle group in carrying out function as they are connected to it
Where does the sciatic nerve exit the gluteal region?
Inferior the piriformis muscle
What can occur at the ischial tuberosity and what might this cause?
Ischial tuberosity bursitis - hamstring muscles attach here so this can cause pain when carrying out their functions
