How would you manage the painful midfoot?
How would your management of a keen sportsman with a painful foot differ from that of our experts, Mr Nick Cullen and Mr Fares Haddad?
of our experts,
Mr Nick Cullen and Mr Fares Haddad?
A 39-year-old stockbroker presented with an eight-month history of pain localised to his midfoot. There was no specific history of trauma. A keen tri-athlete, the pain had prevented him from running and cycling normally for a significant proportion of this time.
He initially took a period of rest lasting three weeks, during which time his pain almost completely settled, but the pain recurred within a fortnight of resuming training. Radiographs of his foot at this stage were normal.
This case report illustrates one of the commonest causes of midfoot pain, the metatarsal stress fracture, a fracture of normal bone that result from summation of stresses, any one of which is insufficient to produce a fracture in isolation. Most patients do not recall a specific history of trauma.
Stress fractures or 'march fractures' are not uncommon in army recruits, who undergo intensive training which transfers excessive stress to the bones of the foot which are not specifically adapted.
With the current increasing interest in sports, notably jogging, metatarsal stress fractures are being seen more frequently in normal, healthy young patients.
Patients usually describe a predisposing activity, the pain is described as an aching or soreness of the midfoot. As the intensity of the pain increases, swelling and limp are variable findings. Direct tenderness over the fractured metatarsal is not a consistent feature, but when present is diagnostic.
Clinical assessment is important for early diagnosis as radiographic changes take time to become apparent, and radiographs taken within two weeks of onset of symptoms are usually normal. After this a fine line may be visible due to bone resorption at the fracture edges. In the event of normal radiographs associated with persistent symptoms, a technetium bone scan or an MRI scan can be used to confirm the diagnosis.
In the initial management of this case, the patient was referred to physiotherapy and treated with strapping and ultrasound followed by a specific sports-directed rehabilitation programme.
This was initially successful on two occasions but his pain recurred and increased in intensity as he resumed training. On examination, the pain was localised over the dorsal and plantar aspects of the third metatarsal. There was no swelling or erythema of note. Sensation was normal. The medial arch was well formed.
Standard antero-posterior, lateral and oblique radiographs showed cortical thickening of the diaphysis of the third metatarsal. A diagnosis of stress fracture of the third metatarsal was made.
We treat most cases in a walking cast or boot until the pain subsides, usually four-six weeks, followed by limitation of exercise for a further four-six weeks. Operative intervention is rarely required.
In this case the patient was treated for six weeks in a removable walking boot, followed by four weeks' exercise limitation with avoidance of impact activities. Accommodative orthoses were provided, followed by a graduated return to running and cycling, with no recurrence of symptoms.
A careful clinical history and examination is extremely important in elucidating the cause of midfoot pain.
Stress fractures of the navicular are less common than those of the metatarsals. They tend to present with a similar history of repetitive activity in athletes, with pain or a cramping sensation over the dorsum or medial plantar arch.
Pain is specifically localised to the navicular, and can be reproduced by the patient standing on their toes, thus exerting a compressive force between the talus and forefoot.
Stress fractures of the navicular are more likely to displace if unrecognised; plain radiographs and bone scan can aid diagnosis.
An accessory navicular bone or 'Os Naviculare' may be mistaken for a stress fracture, but this often presents in adolescence, with no specific history of repetitive trauma.
Patients complain of a painful prominence on the medial border of the mid foot, sometimes associated with a tender overlying bursa, and may have an associated spastic flat foot.
Radiographically the accessory bone may appear as a separate ossicle in the tibialis posterior tendon, or may appear as a prominent medial tubercle. Higher-energy trauma to the midfoot can result in midfoot fracture-dislocations.
The magnitude of these injuries is frequently not initially recognised in view of the often subtle radiographic findings.
High-energy injuries to the foot associated with gross swelling, often out of proportion to the radiographic findings – often a chip or marginal fracture of the base of one or more metatarsals – should raise the possibility of a major midfoot dislocation, otherwise known as a Lisfranc dislocation.
These injuries can be quite debilitating and should be investigated and treated promptly. Lisfranc injuries are treated with anatomical reduction and internal fixation.
Less dramatic sprains of the midfoot, notably the first and second tarso-metatarsal joints, are being increasingly diagnosed as repetetive injuries in athletes.
Pain in the midfoot associated with paraesthesia or numbness radiating along the medial and plantar aspect of the foot are suggestive of a nerve entrapment syndrome: tarsal tunnel syndrome.
Degenerative arthrosis in the midfoot is not uncommon, it may be associated with inflammatory arthritides, or subtalar arthritis, and regrettably is a common sequel to delayed presentation of subtle Lisfranc fracture dislocations.
Radiographs are very useful in identifying the location and severity of degenerative changes. The diagnosis may be assisted with bone scans and diagnostic local anaesthetic injections.
Nick Cullen is orthopaedic specialist registrar
Fares Haddad is consultant orthopaedic and trauma surgeon at University College London Hospitals