Hip and knee Flashcards
Features of hip dislocation presentation
90% posterior, normally in high-impact (e.g. RTC)
10% sciatic nerve injury
Radiographic features of hip dislocations
posterior acetabulum
Head of femur superior to acetabulum
Femur in internal rotation + adduction
Affected femoral head may appear smaller
Which femoral fractures can disrupt blood supply
Intracapsular (i.e. proximal to intertrochanteric line)
- Subcapital, transcervical
Management of extracapsular #NOF
Retain head + neck because blood supply preserved
DHS or intramedullary nail
Medical management of osteoporosis!
Garden classification of femoral fractures
1 + 2 better than 3+4
Intracapsular # NOF management options
Non-operative: Medically moribund
Operative:
- Retaining head + neck (3 screws or DHS)
- Garden I + II, DHS (it rhymes!)
- More controversial for elderly
- Replacement:
- Young, active –> THR
- Elderly, low functional baseline –> hemiarthroplasty
Medical management of osteoporosis!
Complications of hip replacement
Anaesthetic, bleeding, infection
Malunion
Leg length discrepancy
Fat embolus
VTE/pressure sores
Dislocation
Investigation of #NOF
Bloods: FBC, U+E, clotting, G+S, LFT
X: AP + lateral hip X-ray, X-rays of other images (incl CT head); CXR
ECG:
Complications of internal fixation of fractures
Non-union
AVN
Loss of reduction
Poor prognostic factors for mortality in #NOF
Delirium/dementia
Poor social/physical f(x)
Delay in surgery
Post-op chest infection, wound infection
Heart failure
Complications of #NOF
Chest infection
DVT/PE
Post-traumatic arthritis (related to AVN)
Early features of hip OA
Exercise-induced groin/anterior-medial thigh pain
Loss of internal rotation
Difficulty bending down e.g. shoelaces
May be referred pain to knee!
Presentation of greater trochanteric bursitis
Tenderness over greater trochanter + pain on lying/walking
Normal ROM
Evidence on US/MRI
Management of greater trochanteric bursitis
Self-limiting
Steroid injections if recurring
Surgical lengthening of fascia lata/removalof bony spur if intractable
Presentation of avulsion fractures of the hip
Young aptients (tendon > bone)
Pain first felt when kicking/twisting against resistance
Tenderness over rectus femoris origin
Types of avulsion fractures
Rectus femoris + AIIS
Tendon fascia lata/sartorius + ASIS
Hamstrings + ischium
Sources of referred hip pain
Lumbar spine spondylosis
Lumbar radiculopathy
Spinal stenosis
Sacro-iliac joint dysfunction
Mechanism for knee dislocation
High-impact e.g. RTC
Low-impact: athletic w/ rotational component, morbid obesity is a risk factor
Associated injuries knee dislocations
Vascular (5-15%)
Common peroneal nerve (25%)
Fractures (60%)
Ligaments
Features of patellar dislocation
Usually direct blow/sudden twist, often dislocates laterally
Intense pain w/ effusion
Management of patellar dislocation
Closed reduction
Post-reduction X-ray –> check reduction + for patellar #
Immobilisation in plaster/cast
Rehab w/ quad strengthening exercises
Causes of recurrent patellar subluxation
Tight lateral retinaculum –> pulls knee laterally (medial pain!)
Girls with valgus knees
Patella alta
Joint laxity
Hypotrophic lateral femoral condyle
Collateral ligament injury presentation
Valgus/varus stress on knee (direct blow on fixed foot)
Effusion + tenderness over affected ligament
Management of knee collateral ligament tear
Medial (more common) > normally managed conservatively (rest + support in hinged knee brace)
Lateral may need surgery if unstable/other ligamentous injury
Cruciate ligament tear presentation
Twisting injury to the knee or dashboard injury
Pain, effusion, positive draw tests
Haemarthrosis
Manage with rest + physio + consider reconstruction (more difficult with PCL)
Mechanism for meniscal tears
Adduction + internal rotation for lateral
Twisting/blow to flexed knee for medial
Presentation of meniscal tears
Unable to walk, or only on tiptoe
Knee ‘locking’/’clicking’ (limited extension) due to lodging of torn fragment OR knee giving way
McMurray test +ve
IX: MRI to guide management
Typical injury trid of the knee
ACL + medial collateral + medial meniscus
Differential diagnosis dep on timing of knee swellign
Immediate: fracture (haemarthrosis)
Minutes-hours: ACL tear likely
Within 24h: Synovial effusion, ACL tear less likely, possible meniscal tear
Epidemiology of tibial shaft fractures
Most common long bone fracture in adults
Commonly young males
Most commonly open fracture
Management of closed tibial shaft fractures
Assess fo compartment syndrome
Interlocking intramedullary nailing
Presentation of patellofemoral pain syndrome
Young atheletes, often associated with increase in training load
Patellar tracking/malalignment (ask for Hx of trauma or subluxation)
Symptoms: Patella aching after prolonged sitting or stairs
Signs: Medial retropatellar tenderness and tenderness on patellofemoral compression
Management of patellar tendinopathy or patellofemoral pain syndrome
Rest, physio +/- NSAIDs
Superficial bursitis presentation
Pain/swelling anterior to patella (can be prepatellar or infrapatellar bursa) and exacerbated by kneeling
Common overuse injury
Knee bursitis management
Must not be aspirated so as not to seed infx!
May be treated with topical NSAIDs or steroid injection
Pathophysiology of Baker’s cysts
Primary: Herniation of joint synovium
Secondary:Fluid buildup in semimembranosus bursa following chronic effusions in knee OA
Management of Baker’s cyst
Rule out DVT/popliteal aneurysm
Analgesia
Presentation of knee OA
Most common in black women, esp if >55 and high BMI
Knee pain on initiating movement, esp following inactivity (stairs, uneven ground)
Varus deformity
Crepitus + limited ROM
Management of knee OA
NSAIDs
Weight loss
Quadriceps exercises
Osteotomy if young, active
TKR (if night pain or significant life impact)
Signs of pelvic fracture
Leg length discrepancy
Abdominal distension
PV/urethral bleeding
PR: haematoma, # line, rupture
Loin bruising
Perineal/scrotal haematoma
NOF mortality
1 month: 10%
1 year: 30%
Management of pelvic fracture
External fixation with pelvic binder
Consider IR embolisation
Insertions of ACL
Lateral condyle to intercondyloid eminence of tibia
Anterior attachment on tibia
Insertions of PCL
Medial condyle of femur to posterior intercondyloid eminence of tibia
Posterior attachment on tibia
Evaluation of hip screw placement
Tip-apex distance, determined under fluoroscopy
Risks of knee replacement
Bleeding
Infection
Fracture
Soft tissue damage
NOT dislocation
Late features of hip OA
Loss of ext rotation/abduction
Limb shortening
Fixed flexion/rotation
Management of acutely locked knee
Get MRI first!
Do not force
Function of ACL
Prevents FEMUR subluxing posteriorly on tibia (or tibia anteriorly on femur)
Blood supply to femoral head
Medial circumflex artery
Lateral lesser extent
Shapes of mensici
Medial: More crescent-shaped
Lateral: More circular
Blood supply from outside>in –> central avascular
Inspection of hip
360d view
Increased lumbar lordosis - ?fixed flexion deformity 2ry to OA
Walking aids and gait - esp antalgic, Trendelenburg (abductor weakness)
Trendelenburg test (abductor weakness)
Leg length discrepancy
Trendelenburg test
Standing on one leg, feel ASIS movement
ASIS moves down = weak hip abductors ON CONTRALATERAL SIDE
Assessing leg length discrepancy
True - bony deformity e.g. due to fracture
ASIS > medial malleolus
Assess w/ flexed knees to find where discrepancy is
Apparent - joint deformity - e.g. fixed flexion due to OA/pain
Xiphisternum>medial malleolus
Modified Thomas’ test
One hand under lumbar spine
Both knees up to chest actively, then passive from examiner to compare flexion
Extend normal hip then abnormal hip
If abnormal hip not extending fully OR lumbar spine pressure reduced then test + ve
Indicates fixed flexion deformity, note femur angle
Special tests hip
FABER - flexion, abduction, external rotation, press down on knee - indicates intra-articular pathology
FADIR - flexion, adduction, internal rotation - indicates femoro-acetabular impingement
SLR - for sciatica, reproduces pain
Causes of varus and valgus deformities
Valgus - usually RA
Varus: - OA medial degeneration
Special tests knee
Leg lag test - Quad weakness
Anterior draw/Lachman’s: ACL
Posterior sag: PCL
Collaterals: Valgus/varus stress
Mensici: Joint line tenderness, McMurray’s
