Orthopaedics Flashcards
What causes osteoarthritis?
Imbalance between destruction of cartilage and repair by chondrocytes, leading to rubbing together of bones.
RFs: obesity, age, occupation, trauma, female sex and family history.
What is the pattern of joint involvement in OA?
Hips
Knees
Sacro-iliac joints
Distal-interphalangeal joints in the hands (DIPs)
The carpometacarpal joint at the base of the thumb (CMC)
Wrist
Cervical spine (cervical spondylosis)
Give 4 x ray changes in OA.
L – Loss of joint space
O – Osteophytes (bone spurs)
S – Subarticular sclerosis (increased density of the bone along the joint line)
S – Subchondral cysts (fluid-filled holes in the bone)
severity of symptoms does not correlate with x ray findings.
Give 4 signs in the hands to look for in OA.
Heberden’s nodes (in the DIP joints) Bouchard’s nodes (in the PIP joints) Squaring at the base of the thumb at the carpometacarpal joint Weak grip Reduced range of motion
How is OA diagnosed?
Clinical - over 45 years old, pain associated with activity, no morning stiffness >30 mins.
What is the management for OA?
Patient education, conservative mx - wt loss, PT, OT, orthotics Analgesia - 1. PCM+ topical NSAIDs, 2. PO NSAID + PPI, 3. opiates eg codeine Topical capsaicin IA steroid injections Joint replacement
How would you counsel someone for starting ibuprofen long term?
Action - reduce prostaglandins are inflammation Timeline - mornings, with a PPI How - PO daily Length - as long as symptomatic Effect - a few weeks Tests - bloods before starting - U+Es Important SEs - GI eg gastritis and ulcers leading to bleed, renal - ATN, AKI, CKD; CVD - htn, HF, MI, stroke; exacerbating asthma CI - asthma, AKI
Give 3 reasons for joint replacement.
OA (most common) RA Septic arthritis Fracture Osteonecrosis Bone tumours
What is a hemiathroplasty?
Replacing half of the joint (eg head of femur in hip joint, this is done in patients who are not medically fit for TJR)
What is partial joint resurfacing?
Replacing part of the joint surfaces (eg only the medial joint surfaces of the knee)
How would you explain a total hip replacement to a patient?
We make a cut over the outside of the hip. The hip joint is dislocated (separated). The top of the femur, the long bone from the hip to the knee, is removed. A metal or ceramic replacement head of femur, on a metal stem, is used to replace it. The stem can either be cemented into the bone or carefully pushed into the shaft to make a tight enough fit to hold it securely in place. Uncemented stems have a rough surface that holds them tightly in place.
The socket of the pelvis is hollowed out and replaced by a metal socket, which is cemented or screwed into place. A spacer is used between the new head and socket to complete the new artificial joint.
Explain a total knee replacement.
Usually, a vertical, anterior incision is made down the front of the knee. The patella is rotated out of the way to allow access to the knee joint.
The articular surfaces (the cartilage and some of the bone) of the femur and tibia are removed. A new metal surface replaces these. They can be either cemented or pushed tightly into place.
A spacer is added between the new articular surfaces of the femur and tibia to complete the new artificial joint.
Explain a total shoulder replacement.
Usually, an anterior incision is made down the front of the shoulder, along the deltoid. The shoulder joint is dislocated (separated) to give access to both articular surfaces.
The head of the humerus is removed and replaced with a metal or ceramic ball. This replacement head is attached to the humerus either by a metal stem or screws (stemless).
The glenoid (socket) is hollowed out and replaced by a metal socket. This completes the artificial shoulder joint.
What is a reverse total shoulder replacement?
A reverse total shoulder replacement involves adding a sphere in place of the glenoid (socket) and a spacer with a cup to replace the head of the humerus. This reverses the normal ball-in-cup structure of the shoulder joint, but the joint function remains the same.
Give 5 things that are done before joint replacement surgery.
X-rays
CT or MRI scans may be required for a more detailed assessment
Pre-operative assessment (pre-op)
Consent for surgery
Bloods (including group and save and crossmatching of blood)
Medication changes if needed (e.g., temporarily stopping anticoagulation)
Venous thromboembolism assessment
Fasting immediately before surgery
The limb will be marked with the patient awake to ensure the operation is performed on the correct joint
What medications are usually given during joint replacement surgery?
General anaesthetic. Spinal anaesthetic may be used for lower limb surgery.
Prophylactic antibiotics are given before the procedure to reduce the risk of infection.
Tranexamic acid may be used to minimise blood loss during the procedure.
Give 5 things that are done after joint replacement surgery.
Analgesia
Physiotherapy to guide when and how to mobilise
VTE prophylaxis - LMWH 28 days post hip, 14 days post knee
Post-operative x-rays
Post-operative full blood count (to check for anaemia)
Monitoring for complications (e.g., deep vein thrombosis or infection)
Give 5 risks of joint replacement surgery.
Risks of the anaesthetic
Pain
Bleeding
Infection of the prosthesis - 1%. Usually staph aureus. RFs - prolonged op time, obesity and diabetes. Symptoms - fever + painful hot red swollen joint. Need to go back to surgery and have prolonged abx.
Damage to nearby structures (e.g., nerves or arteries)
Stiffness or restricted range of motion in the joint
Joint dislocation
Loosening
Fracture during the procedure
Venous thromboembolism (DVT or PE)
What is a compound fracture?
Skin is broken and broken bone is exposure to air.
What is a stable fracture?
Sections of bone remain in alignment at the fracture site.
What is a pathological fracture?
A fracture due to an abnormality in the bone eg lytic lesion.
