What is compartment syndrome and what causes it?
- Elevated interstitial pressure within a closed fascial compartment resulting in microvascular compromise
- Causes include increased internal pressure (trauma/bleeding, muscle oedema/myositis, intracompartmental administration of fluids/drugs, re-perfusion in vascular surgery) and increased external compression (impaired consciousness, positioning in theatre, bandaging/casts, full thickness burns)
What is the pathophysiology of compartment syndrome?
- Pressure within the compartment exceeds pressure within the capillaries
- Muscles become ischaemic and develop oedema through increased endothelial permeability
- Necrosis begins in the ischaemic muscles after 4 hours
- Ischaemic nerves become neuropraxic. This may recover if relieved early, permeant damage may result after as little as 4 hours.
- Compromise of the arterial supply
Why is timely management of acute compartment syndrome crucial?
- 1hr (nerve conduction normal, muscle viable)
- 4hrs (neuropraxia in nerves, reversible, reversible muscle ischaemia)
- 8hrs (nerve axonotmesis and irreversible damage, irreversible muscle ischaemia and necrosis)
- End stage (stiff fibrotic muscle compartments, impaired nerve function, clawing of limbs and loss of function)
What are the clinical features of compartment syndrome?
- Pain (especially on stretching of the compartment)
- Shiny skin
- Autonomic responsiveness (sweating, tachycardia)
- Impaired conscious level
What is seen on examination of compartment syndrome?
- Deep nerves affected first as pressure is highest deeper in compartment
- If difference between diastolic BP and the compartment pressure is <30mmHg this is diagnostic of compartment syndrome
- Pulses present (until late stages) unless associated vascular injury
- Parasthesia and paralysis usually later
How is compartment syndrome treated?
- Open any constricting bandages
- Surgical release
- If late presentation consider non-operative treatment and splint in position of function
What are the compartments of the forearm?
- Mobile wad of three
What are the compartments of the leg?
- Deep posterior
- Superficial posterior
What are the compartments of the thigh?
What is tendinopathy?
- Chronic tendon injury of over use (repetitive loading)
- Degeneration, disorganisation of collagen fibres
- Increased cellularity
- Little inflammation
What is the pathology of tendinopathy?
- Probably not inflammation
- Deranged collagen fibres/degeneration with a scarcity of inflammatory cells
- Increased vascularity around the tendon
- Failed healing response to microtears
- Inflammatory mediators released IL-1, NO, PGs – cause apoptosis, pain and provoke degeneration through release of matrix metalloproteinases
How is tendinopathy diagnosed?
- X-ray can give information about limb to see if biomechanical problem
- US (Doppler) to see if increased flow around tendon
- MRI can show anatomical field to check tendon itself
How is tendinopathy treated?
- Activity modification
- GTN can cause localised vasodilation in area
- PRP injection (platelet derived growth factors) can stimulate healing
- Extracorporeal shockwave therapy
- Prolotherapy (additional damage to stimulate healing)
- Topaz-radiofrequency coablation (small holes made and radiofrequency to stimulate healing)
- Operative (debridement, excision of diseased tissue)