Lower Limb Flashcards
Mechanical back pain - define
Mechanical back pain is extremely common.
- It is characterised by pain when the spine is loaded, that worsens with exercise and is relieved by rest. - It tends to be intermittent and is often triggered by innocuous activity.
Mechanical back pain - risk factors
obesity,
poor posture,
a sedentary lifestyle with deconditioning of the paraspinal (core) muscles,
poorly-designed seating
incorrect manual handling (bending and lifting) techniques.
Disc Degeneration & Marginal osteophytosis
The nucleus pulposus of the intervertebral discs dehydrates with age.
This leads to a decrease in the height of the discs, bulging of the discs and alteration of the load stresses on the joints.
Osteophytes (bony spurs) called syndesmophytes therefore develop adjacent to the end plates of the discs. This is known as marginal osteophytosis.
Increased stress is also placed on the facet joints, which also develop osteoarthritic changes. The facet joints are innervated by the meningeal branch of the spinal nerve, so arthritis in these joints is perceived as painful.
As the disc height decreases and arthritis develops in the facet joints and vertebral bodies, the intervertebral foramina decrease in size.
This can lead to compression of the spinal nerves and is perceived as radicular or nerve pain.
what are the 4 stages of disc herniation
- Disc degeneration: chemical changes associated with ageing cause discs to dehydrate and bulge
- Prolapse: Protrusion of the nucleus pulposus occurs with slight impingement into the spinal canal. The nucleus pulposus is contained within a rim of annulus fibrosus
- Extrusion: The nucleus pulposus breaks through the annulus fibrosus but is still contained within the disc space
- Sequestration: The nucleus pulposus separates from the main body of the disc and enters the spinal canal
what nerve is affected of a paracentral hernaition of L4/L5
compression of a spinal nerve root within the intervertebral foramen.
Transverinsg nerve root (nerve root that emerges below)
Aka L5 root affected
what is risk of central herniation?
Cauda equina
directly towards spinal cord
what nerve is affected in far lateral herniation
Exiting nerve root affected (aka L4).
Nerve root that emerges at same level as intervertebral disc
Radicular leg pain
Sciatica is the name given to pain caused by irritation or compression of one or more of the nerve roots that contribute to the sciatic nerve (i.e. L4, L5, S1, S2 and S3).
The pain experienced is typically experienced in the back and buttock and radiates to the dermatome supplied by the affected nerve root. Hence it follows a path ‘from the back to the dermatome
If the nerve compression also causes paraesthesia, this will be only experienced in the affected dermatome (rather than the full path from lumbar spine to dermatome)
L4 sciatica pain distribution
anterior thigh, anterior knee, medial leg
L5 sciatica pain distribution
lateral thigh, lateral leg, dorsum of foot
S1 sciatica pain distriction
posterior thigh, posterior leg, heel, sole of foot
Causes of leg radicular?
marginal osteophytosis,
slipped disc etc
Cauda equina - what is it?
Cauda equina syndrome can develop in the context of prolapsed intervertebral disc when there is a ‘canal filling disc’ that compresses the lumbar and sacral nerve roots within the spinal canal.
Cauda equina - causes
Approx. 5% of cases of cauda equina syndrome are due to a central disc prolapse. 30 – 50 years. tumours (primary or secondary) affecting the vertebral column or meninges, spinal infection / abscess, spinal stenosis secondary to arthritis, vertebral fracture, spinal haemorrhage, late-stage ankylosing spondylitis.
Cauda equina symptoms
Bilateral sciatica Perianal numbness (saddle anaesthesia) Painless retention of urine Urinary / faecal incontinence Erectile dysfunction
Cauda equina Treatment
Cauda equina syndrome needs to be treated by surgical decompression within 48 hours of the onset of sphincter symptoms, otherwise the prognosis is poor.
The consequences of missing this diagnosis are serious and life-changing e.g. chronic neuropathic pain, impotence, having to perform intermittent self-catheterisation to pass urine, faecal incontinence or impaction requiring manual evacuation of the rectum, loss of sensation and lower limb weakness requiring a wheelchair. You do not want to miss a case of cauda equina syndrome
Spinal canal stensosis
abnormal narrowing of the spinal canal that compresses either the spinal cord or the nerve roots
Lumbar stenosis is most common, followed by cervical stenosis.
Spinal cord stenesosis - causes
Spinal canal stenosis tends to affect the elderly and is often due to a combination of:
Disc bulging
Facet joint osteoarthritis
Ligamentum flavum hypertrophy
Other causes include:
Compression fractures of the vertebral bodies
Spondylolisthesis
Trauma
Spinal cord steneosis - symptoms
The symptoms depend on the region of the cord or nerve roots that are affected.
Discomfort whilst standing (95% of patients)
Discomfort or pain in the shoulder, arm or hand (for cervical stenosis) or in the lower limb (for lumbar stenosis)
Bilateral symptoms in approximately 70% of patients
Numbness at or below the level of the stenosis
Weakness at or below the level of the stenosis
Neurogenic claudication (see below)
The natural history of lumbar canal stenosis is that 70% of patients’ symptoms stay unchanged, 15% get progressively worse and 15% improve with time.
Neurogenic claudication
Neurogenic claudication (or pseudoclaudication) is a symptom rather than a diagnosis.
Neurogenic means that the problem originates in the nerve and claudication is derived from the Latin for limp (claudigo), as the patient feels a cramping pain or weakness in their legs, and therefore tends to limp.
It results from compression of the spinal nerves as they emerge from the lumbosacral spinal cord (spinal canal stenosis).
This leads to venous engorgement of the nerve roots during exercise, leading to reduced arterial inflow and transient arterial ischaemia.
The ischaemia of the affected nerve(s) results in the pain and/or paraesthesia.
Neurogenic claudication -symptoms
The patient reports pain and/or pins and needles in the legs on prolonged standing and on walking, radiating in a sciatica distribution.
Neurogenic claudication may be present in one or both legs. It is classically relieved by rest (most effective), a change in position and by flexion of the spine.
Movements that involve flexion of the waist are well tolerated such as cycling, pushing a trolley and climbing stairs.
Spondylolisthesis
Spondylolisthesis is anterior displacement of the vertebra above on the vertebra below. It is classified into various types according the underlying cause
Congenital or dysplastic: congenital instability of the facet joints
Isthmic: A defect in the pars interarticularis
Degenerative: results from facet joint arthritis and joint remodelling (age >50 years)
Traumatic: Acute fractures in the neural arch, other than the pars interarticularis
Pathological: Infection or malignancy
Iatrogenic: Caused by surgical intervention e.g. if too much lamina and facet joint is excised during a laminectomy operation Spondylolisthesis may, or may not, be associated with gross instability of the vertebral column.
Spondylolisthesis -symptoms
Some individuals remain asymptomatic, but most complain of some discomfort ranging from occasional lower back pain to incapacitating mechanical pain, sciatica from nerve root compression, and neurogenic claudication (see next page).
You should be able to recognise spondylolisthesis on an X-ray or MRI scan
Describe a lumbar puncture and how is it performed
Lumbar puncture is the withdrawal of fluid from the subarachnoid space of the lumbar cistern.
It is an important diagnostic test for a variety of central nervous system disorders including meningitis, multiple sclerosis etc.
“Lumbar puncture (LP) is performed with the patient lying on the side with the back and hips flexed (knee–chest position) (fig. 2.40). Flexion of the vertebral column facilitates insertion of the needle by spreading apart the vertebral
laminae and spinous processes, stretching the ligamenta flava. The skin covering the lower lumbar vertebrae is anesthetized, and a lumbar puncture needle is inserted in the midline between the spinous processes of the L3 and L4 (or L4 and L5) vertebrae. This can be located by finding the plane transecting the highest points of the iliac crests—the supracristal plane—this usually passes through the L4 spinous process. At these levels, there is no danger of damaging the spinal cord. After passing 4–6 cm in adults (more in obese persons), the needle “pops” through the ligamentum flavum, then punctures the dura and arachnoid, and enters the lumbar cistern. When the stylet is removed, CSF escapes and can be collected.”
OA - what is it
Clinical syndrome comprising joint pain accompanined by functional limitation and reduced QOL
Affeted joints: hips, knees, cervical spine, lumbar spine, small joints of hands
Chronic disease without sysemic invovlement
○ No invovlement of eyes, skin, etc
○ Non inflammatory
Risk factros leads to excessive/uneven loading of joint = damage to hyaline cartialge covering articular surface
Hyaline cartialge becomes swollen due to increased proteogylcan synthesis by chondrocytes
Increased numbers of chondrocytes differentiating from chondroprogenitor cells (adult chondrocytes do not proliferate)
This is an attempty to repair the cartialge damage and can last for several years
Proteogylcan content falls, causing cartialge to soften and lose elasticity
Flaking and fibirliiation (vertical clefts) develop along normally smooth articular suface
Cartialge becomes eroded down the subchdonral bone = loss of joint space
Surface changes in cartilage alter distribuiton of biomechnaicl forces and trigger further active changes in tissues
Subchondral bone: eburnation (manifests as subchondral sclerosis on X rays)
vascualr invasion and increased cellularity
Become thickened
Denser at areas of pressure
Traumatised subchondral bone = cystic degeneration to form subchondral bone cysts
Osseous necrosis secondary to chronic impaction (pressure) or to intrusion of synovial fluid
Areas along articular margin, osseous metaplasia of CT occurs = irregular outgrowth of new bone (osteophytes)
OA - symptoms
Deep aching joint pain, exacerbated by use
Reduce range of motion and crepitus (grinding)
Stiffness during rest - morning stiffness <1 hour
Joint stiffness
Pain in hip, gluteal, and groin regions radiating to the knee via obturator nerve
Mechanical pain - accentuated by mobilisation or weight bearing
Crepitus - grating sound or crunching/crackling sensation on movement of joint
Reduced mobility
OA on an xX ray - 4 signs
JOBS Reudced joint space Subchonrdal scleoriss Bone cysts Osteophytes
what is primary OA
Unknown cause
Risk factors- age, Female, ehtnicity (african-american, american indican, hispanic), FH, Nuttirion (high vit C and E some protection against OA)
what is secondary OA
known precipitating cause
obesity
Trauma - sports and occuptaitonal risk factors
Malalignment e.g. developemtn of dysplasia of hip
Infection - septic arthritis, TB
Inflammatroy arthritis -RA, ankylosing spondylitis
Metabolic disroders affecting joints - gout
Haematolgical disorders e.g. haemophilia with haemarthrosis - bleeding into joints
Endocrine abnromalities - Diabetes with neurovascualr impairment - can lead to chronic malaginment of articular surfaces (charcot joint)
OA treatment
Weight reudction if overweight
Activity modification - avoid that precipiate symtpoms
Walking aid
Muscle strenghthening exercises
Orthotic footwear can reablacne a misalined load through a joint
Analgesia (paracetamol) and anti-inflammatories (NSAIDs, COX-2 inhibitors)
Nutritional supplements - glucosamine and chondrotin sulfate
Steroid injections - reduce swelling, alleviate shoulder stiffness and pain
Hyaluroninc acid injections into joint - viscosupplementation - may increase lubrication and possibly promote cartilage repair (evidence is limiting)
Total hip replacemnt = cure
Replaces damaged surfaces with implants and helps to relieve pain and restore mobility
Fracture of femoral neck - what does leg look like
If fracture is displaced, affected leg: shortened, abducted and externally rotated.
Exacerbation of pain on palpation of greater trochanter and pain is exacerbated by rotation of the hip
what happens in an intracapsular fracture
Weight reudction if overweight
Activity modification - avoid that precipiate symtpoms
Walking aid
Muscle strenghthening exercises
Orthotic footwear can reablacne a misalined load through a joint
Analgesia (paracetamol) and anti-inflammatories (NSAIDs, COX-2 inhibitors)
Nutritional supplements - glucosamine and chondrotin sulfate
Steroid injections - reduce swelling, alleviate shoulder stiffness and pain
Hyaluroninc acid injections into joint - viscosupplementation - may increase lubrication and possibly promote cartilage repair (evidence is limiting)
Total hip replacemnt = cure
Replaces damaged surfaces with implants and helps to relieve pain and restore mobility
Intracapsular fracture - treatment
Treated by surgical replacement of femoral head - hemiarthroplasty (femoral head only) or total hip replacement (head and acetabular cup)
Intracapsular fracture - risks factors
Elderly - postmenapasual women with osteoporotic bone
Minor fall
describe extracapsular fracture
Extracapsular - retinacular arterial supply to femoral head likely to remain intact
- Intertrochanteric - Subtrochanteric - Affect young and middle aged population
Sign tramuatic force - RTC
dislocation of hip
Head of femur being fully displaced out of cup-shaped acetabulum of pelvis
May be congenital
Developmental dysplasia of hip (DDH) / congenital dislocation of the hip (CDH)
May be traumatic - severe injury in 16-40 year old in high speed RTCs. Lots of force needed to dislocate normal hip
90% of dislocations = posterior
Posterior dislocation of hip - what does limb look like
shortened, and held in positon of flexion, adduction and internal (medial) rotation
Sciatic nerve palsy - 8-20% cases
Anterior dislocation of hip - limb look like and potential risk
Limb is held in a position of external rotation, Abduction with slight flexion
Femoral nerve palsies can be present , but are uncommon
Describe central dislocation
Central dislocation
Head of femur is driven into pelvis through acetabulum
Always a fracture-dislocation
Femoral head is palpable on rectal examination - high risk of intrapelvic haemorrhage due to disruption of pelvic venous plexuses
Can be life threatening injury
Femoral neck fracture
High velocity trauma - falls from a height, or RTC.
Proximal fragment is abduacted due to pull of gluteus medius and maximus on greater trochanter and flexed due to action of iliopsoas on lesser trochanter
Distal segment is adducted into a varus deformity due to action of adductor muscles (adductor magnus, gracilis) and extended due to pull of gastrocnemius on posterior femur
Patient: tense swollen thigh
Femoral neck fracture - complications
Blood loss in closed femoral shaft fracutres: 1000-1500mL and pateint may develop hypovalaemic shock
Blood close in open femoral shaft fractures: may be double
Complications due to invovlement of neighbourin neurovascualr structures within fracture site are rare
Femoral neck fracture - treatment
surgical fixation
Femoral neck fracture -risk factors
Young children: non-accidental injury (child abuse) should be considered
Elderly with osteoporotic bones or patents with bone metastases or other bone lesions (bone cysts), can occur following a low velocity injury i.e. falling over from standing position
Distal Femoral Fractures
Young patients: high energy sporting injury, sig displacement of fracture fragments. Pic below you can see unfused epihyses in proximal tibia
Elderly: assocation with osteoporotic bone, fall from stanidng
Popliteal artery may beocme invovled if there is sig displacement of fracture
Careful assessment of neurovascular status of limb before, and after, reduction of fracture is essnetial
Tibial platateu fracture
High energy injuries
Axial (top to bottom) loading with varus or valgus angulation (an abnormal medial or lateral flexion load) of the knee
Asoscaited with meniscal tears and ACL injuries
Fractures affecting articulating surface of tibia within the knee joint
○ Unicondylar - affecting one condyle
○ Bicondylar - affecting both tibial condyles
○ Affecting lateral tibial condyle most common
Articular cartialge is always damaged
Most patients will develop a degree of post traumatic osteoarhritis in affected joint
Patella fracture- cause
1% of all skeletal injuries
Direct impact injury - knee against dashboard
Eccentrci conctraction of the quadriceps (muscle is contracting but joint is extending)
Age 20-50 years
Patella Fracture - examination and blood supply
Most important blood supply is via inferior pole
Examination: palpable defect in patella and haemarthrosis (blood in joint)
If extensor mechanism is disrupted (fracture completely splits the patella distal to insertion of quadriceps tendon), patient will be unable to perform a straight leg raise (keep knee extending and flexing at hip)
Patella Fracture - treatment
Reqire reduction an surgical fixation
Undisposed patellar fracutres: protected whilst healing takes palce through splingitn and using crutches, do not usually require surgical fixation
8% of population the patella is bipartite (2 parts) and can be mistaken for a patella fracture on X ray
Develops because there is failure of union of secondary ossifcation centre with the main body of patella
○ Normal anatomical variant
Patella Dislocation
Patella completely displaced out of its normal alignment
Subluxation is partial displacement
Dislocate laterally
Patella usuall held in correct position by contraction of inferior, almost horizontal, fires of vastus medialis, vastus medialis obliquus (VMO)
Role of VMO - stabilise patella within trochlear groove and to control tracking of patella when knee is flexed and extended
Role of VMO
stabilise patella within trochlear groove and to control tracking of patella when knee is flexed and extended
