Lower Leg and Foot

Lower Leg and Foot

Exam

·        Look: swelling, deformity, muscle wasting.  Deformities include:

o  Hallux valgus: lateral deviation of the MTP joint of the big toe (bunion). Causes: biomechanical, pointed shoes or wearing heals, flat foot (flattening of the longitudinal arch) 

o  Hammer toe: Extended at the MTP joint, hyperflexed at the PIP joint, extended at the DIP joint (cf boutonniere deformity of the finger) 

o  Claw toes: fixed flexion deformity: extended at MTP joints, and flexed at PIP and DIP joints. Due to imbalance of extensors and flexors (eg previous polio)

o  Crowding of the toes: rheumatoid arthritis

o  Sausage deformity of the toes: psoriasis, ankylosing spondylitis and Reiter‟s disease

o  Inspect transverse and longitudinal arch:

§  Pes Planus: Flat feet. May be valgus and eversion deformity. Normal when a child is learning to walk. If the arch forms when walking on toes then OK

§  Pes cavus: Accentuated longitudinal arches: idiopathic, spina bifida or previous polio ® ­weight on head of metatarsals ® pain.

o  Calluses over the metatarsal heads on the plantar surface occur with subluxation of these joints

·        Feel and move:

o  Swelling around the lateral and medial malleoli (don‟t confuse with pitting oedema)

o  Hold midfoot and test dorsiflexion (normal ~ 20º) and plantar flexion (~ 50º)

o  Subtalar joint: test inversion and eversion.  Look for tenderness more than range of movement

o  Midtarsal (midfoot) joints allow rotation when hindfoot fixed

o  Squeeze MTP joints: tenderness common in early rheumatoid arthritis 

o  Very tender first MTP joint Þ ?gout

o  IP joints typically affected in sero-negative arthritis

o  Palpate Achilles tendon for nodules and Achilles tendonitis

o  Palpate inferior heal for plantar fasciitis (can occur with seronegative-arthropathies)

 Lower Leg and Foot Injury

·        Ankle anatomy:

o  Lateral malleolus of the fibula is firmly attached to tibia by the anterior and posterior inferior tibio-fibular ligaments

o  Talus is held in place by deltoid ligament on medial side and calcaneo-fibular ligament on lateral side

o  Commonest ankle injury occurs when the talus is rotated, fracturing one or both malleoli and rupturing the ligaments

·        Fracture of the Tibia

o  Most common site of open fractures 

o  Clinical: Skin may be undamaged or obviously divided. Foot rolled outwards, leg bruised and swollen. Need to assess circulation and sensation in toes

o  Treatment:

§  Closed fractures need to be observed for compartment syndrome and soft tissue damage. Obtain fracture alignment and start weight bearing early

§  Open fractures require immediate antibiotics, debridement, then stabilization and rehab

·        Distal fibial fracture:

o  Check even, clear joint space around the ankle

o  Check ankle joint is not subluxed

o  Check ligaments on the other side (eg Deltoid).  If damaged Þ unstable

o  Classified as A, B, C1 or C2

o  If stable, cast for symptomatic relief for 6 weeks

·        Diastasis:

o  = Dislocation where no true joint exists

o   Separation of the distal tibia and fibula. Talus goes with the fibula. Leads to incongruity of the tibial-talus joint

·        Ruptured deltoid: always exclude proximal fibular fracture (Maisoneuve Fracture)

·        Dislocation of the ankle: reduce urgently (ie before lengthy transport) otherwise ischaemia of overlying skin

·        Achilles Tendon Rupture:

o   Mechanism: Forced dorsiflexion against resistance (eg jumping, due to a forward lunge in squas â€“       an eccentric injury

o   Presentation:

·        Lie on stomach with foot over end of the bed. Foot normally slightly plantar-flexed. If rupture ® neutral position

·        Swelling plus defect felt in tendon. Squeezing is positive (Simmond‟s test). Foot doesn‟t move when calf is squeezed

o   Management: Hold the ends together until healed – either surgical or conservative.

·        Conservative: Casting for both: 4 weeks in full flexion below the knee cast then a further 3 weeks with foot half way to neutral. Walking with heeled shoe for a further 8 weeks but not bare-foot. Physio + ultrasound to reduce swelling. Rerupture rate 20%

§  Operative:

·        Makes the tendon heal at the right length, doesn‟t heal any faster 

·        Indicated if: a re-rupture, late presentation (> 48 hours), open wound, or if strong healing necessary (eg athlete)

·        Risk: poor skin healing

§  Nothing vigorous for 6 months post injury

·        Ruptured plantaris: severe pain, unable to bear weight

·        March Fractures: in the shaft of the 2^nd and 3^rd metatarsals, following excessive walking. X-rays may be normal. Conservative treatment unless severe, in which case cast

·        Lisfranc Dislocation of the 1^st TMT joint – may impair blood supply to the medial foot

·        Metatarsalgia: caused by:

o   Freiberg‟s infarction: collapse and reformation of the epiphyses of the 2^nd and 3^rd metatarsal heads

o   Neuroma of the digital nerve

o   Synovitis

o   Sesamoid fracture

o   Injury

o   Pes cavis