Orthopaedics - knee & leg Flashcards
Knee OA risk factors
Genetic factors
Increasing age, female, obesity & low bone density
Local factors – previous joint injury, occupational/recreational stresses on the joint, reduced surrounding muscle strength, joint laxity/malalignment
Knee OA clinical features
Pain – felt around the knee, can radiate to the thigh & hip, exacerbated by exercise, relieved by rest
Often have bilateral disease, associated joint stiffness which can result in reduced function
Examination – reduced range of movement, evidence of muscle wasting, crepitus
Knee OA investigations
Plain film radiograph – AP and lateral views (skyline view can be useful to assess for any patellar involvement)
Blood tests – infective causes
MRI – ligamentous injury
Knee OA initial management
Lifestyle modifications – weight loss, regular exercise, smoking cessation
Adequate pain control – ensure ongoing mobility and quality of life
Physiotherapy
Knee OA surgical management
Total knee replacement is standard treatment for advanced OA – majority will function for at least 10 years
10% of patients only requires a partial knee replacement – used for disease localised to a single compartment (faster recovery times)
Patellofemoral OA
OA affecting the articular cartilage along the trochlear groove and on the underside of the patella
Risk factors – patella dysplasia, previous patella fracture
Patellofemoral OA clinical features & management
Anterior knee pain, specifically worse with activities that put pressure on the patella eg. climbing a flight of stairs
Joint stiffness and swelling
Skyline view on plain film radiographs
Conservative management first, then patellofemoral replacement may be required (other parts involved = total knee replacement)
ACL tear clinical features
History of twisting the knee whilst weight-bearing
Majority occur without contact and patient is unable to weight bear
Rapid joint swelling (ligament is highly vascular -> haemarthrosis) & significant pain
Specific tests – Lachman test (more sensitive) and anterior draw test
ACL tear investigations
Plain film radiograph (AP and lateral) – exclude bony injuries
- Segond fracture (bony avulsion of the lateral proximal tibia) is pathognomic of ACL injury
MRI scan is gold-standard
ACL tear management
Immediate management – RICE (rest, ice, compression & elevation)
Conservative – rehab, cricket pad knee splint can be applied for comfort
Surgical reconstruction of ACL involves the use of a tendon/artificial graft – not performed acutely but after PT for a period of months
Acute surgical repair of the ACL – re-suturing the ends of the torn ligament together
ACL tear complications
Post-traumatic OA
PCL tear
Typically occur in high-energy trauma, such as a direct blow to the proximal tibia during a RTA
Result in immediate posterior knee pain, instability of the joint and a positive posterior draw test
MRI scan is gold standard
Can often be treated conservatively with a knee brace and physiotherapy (may require surgery id doesn’t get better)
Iliotibial band syndrome
Inflammation of the band (branch of longitudinal fibres that form the shared aponeurosis of tensor fascia latae & gluteus maximus)
Most common cause of lateral knee pain
Iliotibial band syndrome risk factors
Regular exercise – repetitive flexion and extension (runners, weightlifters, cyclists)
Anatomical risk factors – genu varum, excessive internal tibial torsion, foot pronation and hip abductor weakness
Iliotibial band syndrome clinical features
Lateral knee pain, exacerbated by exercise
Assess for any previous trauma or features of OA
Examination may often be unremarkable, only with pain localising to lateral aspect of the knee
Special tests – Nobles and Renne
Iliotibial band syndrome management
Advise to modify their activity & use of simple analgesics during periods of acute pain
Longer-term management – local steroid injections, PT
Surgical – only if patients remain symptomatic/functionally limited after 6 months
- Release of the iliotibial band from its attachments from the patella
MCL tear clinical features
Typically occurs after trauma to the lateral aspect of the knee
Isolated medial collateral ligaments tears – usually direct below in a valgus stress direction
Non-contact MCL injuries occur less commonly & often arise from a valgus stress with external rotation force
Patient may report hearing a ‘pop’ with immediate medial joint line pain, delayed swelling
Increased laxity when testing the MCL
MCL tear investigations
Plain film radiograph – exclude any fracture
MRI – gold standard
MCL tear management
Dependent on the grade of injury:
1) Grade I – RICE with analgesia as the mainstay, strength training as tolerated, aim to return to full exercise within around 6 weeks
2) Grade II – analgesia with a knee brace and weight-bearing/strength training as tolerated, should aim to return to full exercise within around 10 weeks
3) Grade III – analgesia with a knee brace and crutches, patients should aim to be able to return to full exercise within around 12 weeks
MCL tear complications
Instability in the joint
Damage to the saphenous nerve
Meniscal tear clinical features
Tearing sensation in their knee, associated with an intense sudden-onset pain, knee swells slowly
Knee may be locked in flexion
Examination – joint line tenderness, significant joint effusion, limited knee flexion
- Specific tests: McMurray’s & Apley’s grind test
Meniscal tears investigations
Plain film radiographs – exclude a fracture
MRI – gold standard investigation to confirm a meniscal tear
Meniscal tears management
Immediate management – RICE
Larger tears/remaining symptomatic: arthroscopic surgery is indicated
Meniscal tears complications
Secondary OA
Knee arthroscopy – risk of DVT, damage to local structures
