MSK week 5 Flashcards
When should surgical management be considered?
When appropriate conservative measures have failed to control the condition.
Name the four surgical strategies for management of an arthritic joint?
Arthroplasty/joint replacement
Excision or resection arthroplasty
Arthrodesis
Osteotomy
What does arthroplasty mean?
Reshaping of the joint.
Replacing half a joint is known as
Hemiarthroplasty
Why do joint replacements ultimately fail?
Loosening of components (wear particles produce an inflammatory response).
What is a psuedotumour?
Metal particles from a joint replacement causing an inflammatory granuloma which can cause muscle and bone necrosis.
What is osteolysis?
Polyethylene particles causing an inflammatory response in bone with subsequent bone reabsorption
A complication of joint replacement surgery is deep infection- how is it managed?
If caught early (first 2-3 weeks)- wash out of the joint, debridement and parenteral antibiotics for 6 weeks should suffice.
If caught after 3 weeks- bacteria form a biofilm which prevents the patients immune system from getting to it. Remove infected implants and all foreign material (inc cement)
Patient is usually left without a joint for 6 weeks with parenteral antibiotics for this time. Once the CRP has fallen and the wound has healed (infection under control) a revision joint replacement is performed.
Early local complications of joint replacement
Dislocation, infection, leg length discrepancy, nerve damage, ischaemia, bleeding, DVT.
Early general complications of joint replacement surgery
Hypovolaemia (due to blood loss) Shock Acute renal failure MI ARDS Urine/chest infection
Late local complications of joint replacement
Infection (from haematogenous spread), loosening, fracture, implant breakage, pseudotumour.
What is excision or resection arthroplasty?
Involves the removal of bone and cartilage on one or both sides of the joint. Good for smaller joints- quite disabling for larger joints.
What is arthrodesis?
Means surgical stiffening or fusion of a joint in a position of function. The remaining hyaline cartilage of the joint and subchondral bone is removed and the joint is stabilised resulting in bony union.
Pros and cons of arthrodesis
Pro- good for pain. Good for end stage disease.
Con- loss of function. May also increase pressure in surrounding areas leading to arthritic change.
What is osteotomy?
Surgical realignment of a bone which can be used for deformity correction or to redistribute load across an arthritic joint.
What is the aim of osteotomy in arthritis?
To shift the pressure from the diseased part of the joint onto the non-diseased part of the joint.
In which areas is injection into a tendon not advised?
Achilles tendon, extensor mechanism of the knee.
In which areas can injection of steroid help with inflammation?
Tennis elbow, adhesive capsulitis.
What is instability of a joint?
Abnormal motion of a joint resulting in subluxation or dislocation with pain and/or giving way.
What surgical strategies might you use for instability of a joint?
Ligament tightening/advancement
Ligament reconstruction using a tendon graft (e.g. ACL reconstruction).
In most cases, soft tissue procedures are highly unlikely to work and bony procedures are likely to be required (e.g. in patellofemoral instability-osteotomy).
What procedure would you use in carpal tunnel or cubital tunnel syndrome?
Nerve decompression.
What procedure would you use if the spinal nerve roots are being compressed by disc material or osteophytes?
Discectomy or spinal decompression.
What is osteomyelitis?
Infection of bone (includes spongy, marrow and compact bone)
What usually causes osteomyelitis?
Usually bacterial infection but can be fungal.
Describe the process of acquiring osteomyelitis
Once infected, enzymes from leucocytes cause local osteolysis (destruction of bone) and pus will form. This impairs the blood flow making the infection very difficult to eradicate. A dead fragment of bone called a sequestrum can break off and once this is present antibiotics alone will not cure the infection. New bone will form around the area of necrosis called an involucrum.
What can staph aureus infections do that others can’t?
It can infect osteocytes intracellularly making infection additionally difficult for the immune system to reach.
Who does acute osteomyelitis occur in?
Generally children (in the absence of a surgical cause) and immunocompromised adults.
What makes children so much more susceptible to bone infection than adults?
In children- the metaphysics of long bones contain torturous vessels with sluggish flow. This can allow bacteria to sit and accumulate.
Also in infants- the metaphases of bones are within the joint capsule and therefore they can get a co-existent septic arthritis.
Infants also have loosely applied periosteum so abscesses can spread.
What is Brodies abscess?
In children- a thin rim of sclerotic bone can grow to wall of an abscess.
It occurs in subacute osteomyelitis.
When would you get chronic osteomyelitis?
Untreated acute osteomyelitis
Where does chronic osteomyelitis tend to be?
In adults- tends to be in the axial skeleton with haematogenous spread from pulmonary or urine infections.
How can osteomyelitis be classified?
Superficial (affecting the outer surface of bone), medullary, localised (affecting the cortex and medullary bone) or diffuse (segment of bone is infected resulting in skeletal instability).
Treatment of acute osteomyelitis?
Best guess antibiotics. Unless there is an abscess which would need surgical drainage. If these fail then you may need to obtain a sample surgically and treat from there.
Treatment of chronic osteomyelitis?
Cannot be cured or eradicated by antibiotics alone.
Surgery is usually recommended to gain deep bone tissue cultures, to remove any sequestrum and to excise any infected or non-viable bone (debridement).
If debridement of the bone results in instability- the bone must be stabilised.
IV antibiotics are continued for several weeks after surgery.
Who is at particular risk of osteomyelitis of the spine?
Intravenous drug users, poorly controlled diabetics and immunocompromised patients.
What is the presentation of osteomyelitis of the spine?
Constant and unremitting back pain that is insidious with onset.
Paraspinal muscle spasm and spinal tenderness
Fever and systemic upset
Complications of spinal osteomyelitis?
Pus can exude forming an paravertebral or epidural abscess
Vertebrae may start to collapse
What investigations would you do into suspected osteomyelitis of the spine?
MRI to look for infection and soft tissue involvement.
Blood cultures may indicate the causative organism.
CT guided biopsy to obtain tissue for culture
Treatment of spinal osteomyelitis?
High dose IV antibiotics- antibiotics may be required for several months.
Indications for surgery are- no response to antibiotic therapy, progressive vertebral collapse and an inability to obtain cultures by needle biopsy.
Which organisms are likely to be found in infection of a prosthetic joint?
Staph aureus and gram negative bacilli (inc coliforms).
Some bacteria cause a more low grade response (often diagnosed up to a year after surgery and requires surgical intervention)- staph epidermis and enterococcus.
What is primary healing?
The fracture site is small (less than 1mm) and the bone simply bridges the gap with new bone from osteoblasts.
When does primary healing occur?
In hair line fractures and fractures that are fixed with a plate and screws.
What is secondary healing?
the majority of fractures heal this way. It involves an inflammatory response.
Describe the process of secondary healing?
A fracture occurs.
A haematoma occurs with injured tissues surrounding the fracture becoming inflamed
White cells (macrophages) and osteoclasts come and clear the debris away.
New blood vessels start to form and it lays down granulation tissue.
The chondroblasts then start to form cartilage (soft callus)
Osteoblasts then lay down their matrix of type 1 collagen (endochondral ossification) and calcium mineralisation of this forms the hard callus.
Remodelling occurs with organisation along lines of stress into lamellar bone.
What are the general principles for fracture management?
Save life Save limb Treat pain Maintain viable skin envelope Restore function
When is a Thomas splint used?
Femoral shaft fractures.
If a femoral shaft fracture is unstable what should you use?
Intramedullary nails.
Extra-articular distal femur fracture management
These tend to be unstable due to the pull of the gastrocnemius on the bone.
If fracture not too distal- can use IM nails.
Could also use a Thomas splint.
Intra-articular distal femur fracture
Anatomical reduction and rigid fixation. Can use plate and screws.
Management of proximal tibial fractures
Plate and screws generally.
Management of tibial shaft fractures
High risk of compartment syndrome
Operative management- IM nail or plate and screws.
Distal tibial fracture management
Ideally you want to be able to reduce it and internally fix it however generally a lot of soft tissue swelling. Can use external fixation until the swelling has gone down- then use plate and screws.
Management of ankle fractures
Isolated distal fibular or minimally displaced medial malleolus are stable and can be treated conservatively.
Bimalleolar fractures are unstable- talar shift.
Distal fibular fractures can also cause talar shift causing a substantial increase in joint force.
Talar shift- needs ORIF
Management of proximal humeral head fractures
It is difficult to hold fragments with external fixation.
Conservative management for most if elderly.
Internal fixation in younger patients.
What is the risk of fixing a humeral shaft injury?
Risk radial nerve injury as it runs in the radial groove.
Conservative measures are equally effective as surgical. So surgical is preserved for non union, pathological poly trauma with high energy injury and not tolerating brace.
Olecranon fracture management
Often due to an avulsion fracture from triceps tendon. Fix with plate and screws unless patient has low demand.
How does the forearm act causing multiple fractures?
It is a ring structure so you generally get two fractures rather than one.
If the radius is fractured in isolation suspect-
Dislocation of the distal-radial ulnar joint- Galeazzi fracture.
If the ulna is fractured in isolation suspect
A dislocation of the radial head- monteggia fracture.
How would you treat Monteggia and Galeazzi fractures?
If both bone fractured- ORIF
If Monteggia or Galaezzi- ORIF fractured bone once reduced- distal ulnar or radial head should reduce.
What is a colles fracture?
A fracture of the distal radius however it is still extraarticular, with dorsal angulation and dorsal displacement.
What is a complication of a Colles fracture?
Median nerve compression.
Management of a Colles fracture?
Reduce in patients who require hands e.g. concert pianist. Hold together with wires pr a plate and screws.
Elderly patients may function adequately without it.
What do volar penetrating hand injuries risk damage too?
Flexor tendons, digital nerves and arteries.
What do dorsal penetrating hand injuries risk damage too?
Extensor tendons
Treatment of complete or partial tendon injuries in the hand?
Surgical repair.
Extensor tendon injury treatment?
Usually require surgical repair with splint age in extension for 6 weeks.
What is mallet finger?
Injury to the very end of the finger meaning it sits in fixed flexion (caused by avulsion (body structure is forcibly detached) of the extensor tendon at its attachment) The patient will have pain and won’t be able to extend their finger.
Management of flexor tendon injuries?
Surgically corrected then held in a flexed position.
Criteria (Ottawa) to get an Xray for an ankle fracture?
Any severe localised tenderness (bony tenderness) of the distal tibia and fibula
Unable to weight bear for 4 steps
Stable ankle fracture treatment
Walking cast or splintage for 6 weeks.
Generally fibula fractures with no medial fracture or rupture of the deltoid ligament are stable.
Unstable fracture management
Distal fibular fractures with rupture of the deltoid ligament (suspected by bruising and tenderness medially)
Or any evidence of talar shift
Open reduction internal fixation
Fractures occurring from a fall from height?
Calcaneal fractures.
Likely mechanism of injury in a talar fracture? Treatment
Forced dorsiflexion from rapid deceleration (RTA)
Displaced fractures need closed or open reduction and screw fixation.
What is a lisfranc fracture?
Fracture at the base of the 2nd metatarsal is associated with dislocation of this too with or without dislocation of the other MTP joints too. (the ligament from the medial cuneiform no longer holds them in place).
Symptoms of lisfranc fracture and management?
Pain, bruising and unable to weight bare.
Closed or open reduction with screws.
Mechanism of injury for the 5th MTP fracture
Inversion injury with an avulsion fracture at the insertion of the peroneus braves tendon.
Treatment of a 5th MTP fracture?
Heal well with a walking cast, supportive bandaging or wearing a stout boot for 6-8 weeks.
Treatment of 1st MTP fracture?
Rare- however internally fixed.
Fracture of the other MTPs?
Often minimally displaced and therefore can be managed conservatively with a cast. Displaced ones should be stabilised with K wires.
Management of toe fractures?
Stout boot
Intra-articular fractures of the base and pharynx may benefit from reduction and fixation if the fractures are big.
Open toe fractures management?
Debridement.
