10 - Knee and Foot Disorders Flashcards
What are the signs of compartment syndrome and what are the long and short term consequences if not treated?
Signs: severe pain in limb which is excessive for degree of damage, increasing and not relieved by analgesia. Pain exacerbated by passive stretch of muscles
Short: Ischaemia due to reduced perfusion of muscles so rhabdomyolysis and acute kidney injury. Neurovascular signs later. Loss of peripheral pulses so nerves get ischemic leading to distal paraesthesia followed by loss of motor function
Long: Chronic kidney injury from rhabdomyolysis. Volkmann’s ischaemic contracture from necrosis fibrosis
What are the common causes of ankle fractures and what do you need to take into account upon assessment?
- Eversion/Inversion injury
- Consider co-morbidities and if diabetic
- Look for blisters as surgery has to be halted until clear and may turn necrotic increasing healing time
- If open need urgent surgery and irrigation to prevent osteomyelitis
What is the ring of the ankle joint and how does it help to assess ankle fracture?
- Proximal: articular surface of tibia and fibula joint by syndesmotic ligaments
- Medial: medial deltoid ligament
- Inferior: subtalar jont
- Lateral: lateral ligament complex (anterior and posterior talofibular and talocalcaneal
Likely that with a fracture there is a ligament tear so can figure if stable or not
What is talar shift?
- When there is a disruption of any two of the syndesmosis, medial or lateral ligaments. Leads to unstable ankle mortise and wiens talus
- Syndesmosis are ligaments holding the tibia and fibula together
How do you treat an ankle fracture?
- Stable: Aircast boot or fibreglass cast for comfort
- Unstable: surgical stabilisation, high risk in patients with diabetes
What is an ankle sprain, how does it heal and what is the common mechanism of injury?
- Partial or complete tear of one or more of the ligaments of the ankle joint
- Rest and time but if don’t heal can cause ankle instability
- Excessive strain of ligaments past it’s yield point. Often inversion injury of plantar flexed weight bearing foot. Anterior talofibular at risk
What are the lateral and medial ligaments of the foot?
What are risk factors for ankle sprains?
- Weak ankle muscles crossing joint
- Weak or lax ligaments due to hereditary or overstretching
- Inadequate joint proprioception
- Slow neuromuscular response to off-balance positon
- Running on uneven surfaces
- Wearing high heels or shoes with inadequate ankle support
Why does a severe ankle sprain leads to avulsion fracture of fifth metatarsal tuberosity and when do you need to be careful when diagnosing this kind of fracture?
- Peroneus brevis tendon attached to tubercle and under tension in inversion injury
- In children unfused apophysis can be seen and look llike fracture, both can exist!!
What is the mechanism of injury of achilles tendon rupture?
- Men 30-50 years mainly weekend warriors
- Forceful push off with extended knee, e.g when jumping
- Fall with foot outstretch and ankle dorsiflexed
- Falling from a height
Rupture in vascular watershed area, 6cm above insertion, as decreased thickness and vascularity here
What are the symptoms of an Achille’s tendon rupture?
Inability to stand on tip toe or push off whilst walking
How do you diagnose and treat and achille’s tendon rupture?
- Thompson’s test, MRI and ultrasound
- Two ends frayed so surgical reconstruction hard
- Conservatively with aircast boot.
- Rerupture rate and issues with overlying skin as thin and poorly vascularised
What is hallux valgus?
- Big toe lateral deviation
- Varus deviation of first metatarsal
- Valgus deviation and lateral rotation of hallux
- Prominence of metatarsal head with or without overlying callus
What is hallux valgus caused by and what are some issues?
Issues: middle aged females cosmetic issue, painful movement of 1st MTPJ
Causes: secondary to trauma, arthritis, ligament laxity (which can be inherited), tight shoes exacerbate and line of pull of EHL tendon can exacerbate
DON’T KNOW REAL REASON
What is hallux rigidus and some signs of it?
- OA of 1st MTPJ resulting in stiffness
- Can be due to stress of walking, gout or previous septic arthritis
- Pain in 1st MTPJ on walking and dorsiflexion. Walking on outside of foot, restricted dorsiflexion of toe, dorsal bunion (osteophyte)
What do the following terms mean
- Arthroplasty?
- Arthodesis?
- Excision arthroplasty?
- Osteotomy?
- Joint replacement
- Joint fusion
- Surgical removement of joint with replacement of soft tissue, e.g rolled up tendon
- Surgical cutting of bone to realign
How can you treat OA of hallux? (hallux rigidus)
- Activity modificatiom, analgesia, aids
- Orthotics preventing 1st MTPJ movement
- If conservative doesnt work, arthrodesis of 1st MTPJ or maybe arthroplasty
What is the difference between OA of ankle joint and OA of hip joint?
- Ankle nearly always secondary arthritis
- Post traumatic arthritis few years later, inflammation, joint stress, obesisty
- Few that are primary arent as bad as secondary OA and tend to be older
What is the treatment for OA of the ankle?
- Arthrodesis as patients can still walk due to mid and fore foot with no bad limp
- Ankle arthroplasty may be considered but risk of infection and loosening
What are some common deformities of the lesser toes?
What is a claw toe?
- Toes hyperextended at MTPJ and flexed at PIP
- Usually all four litte toes and may get corns
- Usually due to neurological damage, e.g cerebral palsy, stroke, diabetes or alcohol dependence.
- Due to muscle imbalance so tendons and ligaments weirdly tight
What is a hammer toe?
- Flexed at PIPJ, most commonly second toe
- Ill-fitting pointed shoes causing muscles to contract and shorten
What is a mallet toe?
Flexed at distal PIPJ for same reasons as hammer toe
What are curly toes?
- Congenital usually affecting 3,4,5th digits and usually bilateral
- Tendon of FDL or flexor digitorum brevis too tight
- Mainly asymptomatic and can have conservative treatment by stretching flexor tendons and extension. Surgery only considered after age 6 if pain
