Trauma and orthopaedics (7): General Flashcards
OA is characterised by
progressive loss of articular cartilage and remodelling of the underlying bone.
causes of OA
- Degradation of cartilage and remodelling of bone due to an active response of chondrocytes in the articular cartilage and the inflammatory cells in the surrounding tissues.
- The release of enzymes from these cells break down collagen and proteoglycans, destroying the articular cartilage.
- The exposure of the underlying subchondral bone results in sclerosis, followed by reactive remodelling changes that lead to the formation of osteophytes and subchondral bone cysts.
- The joint space is progressively lost over time.
RF for OA
obesity, advancing age, female gender, and manual labour occupations.
most common joints affected by OA
- small joints of hands and feet
- hip
- knee
presentation of OA
- insidius
- chronic
- gradually worsening
- pain and stiffness worsened with activity
- relived by rest
- joint deformity
- reduced range of meovement
characteristic signs of OA
- Bouchard nodes (swelling of PIPJs) or
- Heberden nodes (swelling of DIPJs) in the hands
- Fixed flexion deformity or varus malalignment in the knees.
Feel for crepitus throughout the range of movement. Movement of the joint is generally reduced and painful.
investigation for OA
primarily a clinical diagnosis
- blood tests to exclude inflammatory or infective causes
- X-ray - to confirm diagnosis and exclude fractures
X-ray findings of OA
LOSS
- Loss of joint space
- Osteophytes
- Subchondral cysts
- Subchondral sclerosis
conservative management of OA
weight loss
physio (strengthening exercise)
local heat/ice packs
joint supports
medical management of OA
Paracetamol and topical NSAIDs are the mainstay of most medical management for OA, alongside the conservative measures.
+- steroid injection (typically mixed with local anaesthetic)
surgical management of OA
surgical management choice will depend on the site affected. Options include:
- Osteotomy
- Arthrodesis (joint fusion)
- Arthroplasty
general complications after orthopaedic surgery
- malunion/ nonunion
- Nerve dysfunction
- infection (open fracture)
- secondary osteoarthritis
- fat embolism
- VTE
how long do artifical joints last
more than 10-15 years. However, they may be affected by loosening, wear and dislocation.
Some patients may require further surgery and replacement of the artificial joint at some point.
other options than joint replacement
analgesia, steroid injections and physiotherapy.
indication of joint replacement
Osteoarthritis is the most common indication for an elective joint replacement. It is not usually performed until symptoms are severe and not manageable with conservative treatments.
Joints may also require replacement for:
- Fractures
- Septic arthritis
- Osteonecrosis
- Bone tumours
- Rheumatoid arthritis
options for joint replacement
- Total joint replacement – replacing both articular surfaces of the joint
- Hemiarthroplasty – replacing half of the joint (e.g., the head of the femur in the hip joint)
- Partial joint resurfacing – replacing part of the joint surfaces (e.g., only the medial joint surfaces of the knee)
total hip replacement (THR) method
Usually, a lateral incision over the outer aspect of the hip is used. The hip joint is dislocated (separated) to give access to both articular surfaces.
The head of the femur 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 shaft of the femur or carefully pushed into the shaft to make a tight enough fit to hold it securely in place. Uncementedstems have a rough surface that holds them tightly in place.
The acetabulum (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.
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 femurand 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.
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
joint replacement surgery requires either
general anaesthetic or spinal anaesthetics
prophylactic Abx
Tranexamic acid to minimise blood loss
after joint replacement surgeyr
- Analgesia
- Physiotherapy to guide when and how to mobilise
- VTE prophylaxis
- Post-operative x-rays
- Post-operative full blood count (to check for anaemia)
- Monitoring for complications (e.g., deep vein thrombosis or infection)
VTE prophylaxis
LMWH for:
- 28 days post elective hip replacement
- 14 days post elective knee replacement
Other measures that may be used for VTE prophylaxis after joint replacement surgery are:
- Aspirin
- DOACs (e.g., rivaroxaban)
- Anti-embolism stockings
risk of joint replacement
- Risks of the anaesthetic
- Pain
- Bleeding
- Infection – infection of the prosthesis can be highly problematic (see below)
- 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)
most common organism which causes prosthetic joint infection
staphylococcus areus
Risk factors for prosthetic joint infection are:
- Prolonged operative time
- Obesity
- Diabetes
Symptoms include:
- Fever
- Pain
- Swelling
- Erythema
- Increased warmth
Compartment syndrome
is where the pressure within a fascial compartment is abnormally elevated, cutting off the blood flow to the contents of that compartment.
Fascial compartments involve m
muscles, nerves and blood vessels surrounded by fascia. Fascia is a sheet of strong, fibrous connective tissue that encases the contents of the compartment. It is not able to stretch or expand.
compartment syndrome can be classified as
acute or chronic
Acute compartment syndrome
is usually associated with an acute injury, where bleeding or tissue swelling (oedema) associated with the injury increases the pressure within the compartment.
presentation of acute compartment syndrome
Acute compartment syndrome most often affects one of the fascial compartments in the legs, but it can also affect the forearm, feet, thigh and buttocks.
It usually presents after an acute injury, particularly:
- Bone fractures
- Crush injuries
Acute compartment syndrome presents with the 5 P’s:
- P – Pain “disproportionate” to the underlying injury, worsened by passive stretching of the muscles
- P – Paresthesia
- P – Pale
- P – Pressure (high)
- P – Paralysis (a late and worrying feature)
what is not a feature of compartment syndrome
Note that pulseless is not a feature, differentiating it from acute limb ischaemia. The pulses may remain intact depending on which compartment is affected.
key characteristic of compartment syndrome
Disproportionate pain is a key characteristic of compartment syndrome. The pain is so severe that pain medications are not effective. If you see a patient with disproportionate pain after an injury in your exams, the diagnosis is probably compartment syndrome.
investigation for compartment syndrome
Needle manometry
- Is made by measurement of intracompartmental pressure measurements. Pressures in excess of 20mmHg are abnormal and >40mmHg is diagnostic
- Compartment syndrome will typically not show any pathology on an x-ray
initial management of compartment syndrome
- Escalating to the orthopaedic registrar or consultant
- Removing any external dressings or bandages
- Elevating the leg to heart level
- Maintaining good blood pressure (avoiding hypotension)
definitive management of acute compartment syndrome
Emergency fasciotomy
Emergency fasciotomy
ASAP
involves a surgical operation to cut through the fascia, down the entire length of the compartment, and release the pressure. The compartment is explored to identify and debride any necrotic muscle tissue. The wound is left open and covered with a dressing.
after fasciotomy
- repeated trips back to theatre to explore for necrotic tissue which needs debridement
- as swelling improved wound can be gradually closed- several weeks
- skin graft may be required
Osteomyelitis
refers to inflammation in a bone and bone marrow, usually caused by bacterial infection.
can be acute or chronic
most common mode of infection for osteomylitis
Haematogenous spread
other Mode of infection for osteomyelitis
direct contamination of the bone, for example, at a fracture site or during an orthopaedic operation.
organism which causes osteomyelitis
Staphylococcus aureus
RF for osteomyelitis
The key risk factors for developing osteomyelitis are:
- Open fractures
- Orthopaedic operations, particularly with prosthetic joints
- BIG PROBLEM
- Diabetes, particularly with diabetic foot ulcers
- Peripheral arterial disease
- IV drug use
- Immunosuppression
The typical presentation of osteomyelitis is with
- Fever
- Pain and tenderness
- Erythema
- Swelling
The presentation of osteomyelitis can be quite non-specific, with generalised symptoms of infection such as fever, lethargy, nausea and muscle aches.
investigations for osteomyelitis
MRI best for establishing diagnosis (x-ray only shows later signs)
blood tests (WBC, CRP, blood culture)
bone culture
management of osteomyelitis
Management involves a combination of:
- Surgical debridement of the infected bone and tissues
- Antibiotic therapy
antibiotic therapy for osteomyelitis
- 6 weeks of flucloxacillin, possibly with rifampicin or fusidic acidadded for the first 2 weeks
alternative to penicillin
- Clindamycin in penicillin allergy
- Vancomycin or teicoplanin when treating MRSA
antibiotic for chronic osteomyelitis
Usually requires 3 months or more of antibiotics.
Osteomyelitis associated with prosthetic joints (e.g., a hip replacement) may require complete revision surgery to replace the prosthesis.
sarcomas
Sarcomas are cancers originating in the muscles, bones or other types of connective tissue
bone sarcoma
- Osteosarcoma – the most common form of bone cancer
- Chondrosarcoma – cancer originating from the cartilage
- Ewing sarcoma – a form of bone and soft tissue cancer most often affecting children and young adults
soft tissue sarcoma
- Rhabdomyosarcoma – originating from skeletal muscle
- Leiomyosarcoma – originating from smooth muscle cancer
- Liposarcoma – originating from adipose (fat) tissue)
presenation of sarcoma
depends on location and size
- A soft tissue lump, particularly if growing, painful or large
- Bone swelling
- Persistent bone pain
investigations of sarcoma
- X-ray for bony lumps
- US for soft tissue
- CT or MRI for better visualisation
- biospy
staging of sarcoma
TNM
most common location for sarcoma to metastasis to
lungs
Sarcoma treatment
will depend on the type, location, size and stage of the sarcoma. This may involve:
- Surgery (surgical resection is the preferred treatment)
- Radiotherapy
- Chemotherapy
- Palliative care
septic arthritis
refers to the infection of a joint.
It requires a high index of suspicion and can affect both native and prosthetic joints.
main causative organism of septic arthritis
S. aureus (most common in adults),
Neisseria gonorrhoea (more common in sexually active patients)
Salmonella (especially in those with sickle cell disease).
mode of infection of septic arthritis
- haematogenous spread e.g. recent cellulitis, UTI, chest infection
- direct inoculation e.g. via adjacent osteomyelitis
complications of septic arthritis
- full blown sepsis
- irreversible cartilage damage leading to OA
- osteomyelitis
RF for SA
- pre-existing joint disease e.g. RA
- DM or immunosuppression
- CKD
- joint prosthesis
- IVDU
presentation of SA
- single swollen joint, red and warm
- severe pin
- pyrexia
- unable to weight bear
investigations for SA
- routine bloods (FBC, CRP, urate, blood cultures (at least two separate samples)
- joit aspiration and fluid analysis (gram stain and culture)
- preferably joint sample sent prior to starting antibiotics (unless pt septic)
management of septic arthritis
- Sepsis 6
- antibiotics administered for 4-6 weeks
- infected native joints- irrigation and debridement (washout) in theatre
- prosthetic joint- washout and then revision surgery of joint
