CHAPTER 11 The tibia
Common Causes of Pain in the Anterior Aspect of the Lower Leg
Note: Knock-knee and bow-leg deformities are included with the knee joint.
Osteitis of the Tibia
Osteitis of the tibia occurs predominantly in children, with or without a history of previous trauma or sore throat. Pain is intense, tenderness is acute and initially well localised over the metaphyseal area, and there is inability to weightbear. There is systemic upset with fever and tachycardia, and often (but not always) a polymorph leukocytosis. Admission and investigation with repeated blood cultures is essential. Radiographs of the tibia are initially normal, often with a lag of 2 weeks or more before any abnormality is detectable (although MRI and CT scans may be affected somewhat earlier). The ESR and C-reactive protein are usually elevated at an early date. When this condition is suspected, it is customary to administer a broad-spectrum antibiotic effective against the penicillin-resistant Staphylococcus, and in large doses to achieve adequate bone levels, prior to the results of blood culture. Splintage of the affected area is often helpful, and in proven cases antibiotics are administered for 4 weeks. Surgical drainage is seldom necessary and is avoided unless failure of response to antibiotics, profound toxicity and spread of the infection make it essential.
Cellulitis from insect stings, small wounds and abrasions and hair follicle infections may sometimes cause difficulty in diagnosis.
Low-grade osteitis of the tibia (Brodie’s abscess) may give rise to chronic upper tibial pain.
Bone Tumours
The tibia is a common site for many primary bone tumours, so that radiographic examination of the tibia is essential in any case of undiagnosed leg pain.
Anterior Tibial Compartment Syndrome
This is a common complication of fractures of the tibial shaft, but may follow a period of intense lower limb activity: hence it is common in athletes. It gives rise to pain in the front of the leg. This is due to oedema and swelling within the confines of the anterior compartment, which lead in turn to ischaemia in the anterior tibial muscles. In severe cases where swelling is progressive there may eventually be muscle necrosis. The leg is diffusely swollen and tender, and the skin has a glossy appearance. Tibialis anterior and extensor hallucis longus are first affected, with weakness and later inability to extend the ankle and great toe. The dorsalis pedis pulse may be absent, and there may be sensory loss in the first web space due to ischaemic changes in the deep peroneal nerve. In high-risk and suspect cases compartment pressure monitoring is advisable. In severe cases immediate surgical decompression of the anterior tibial compartment is essential if muscle necrosis is to be avoided.
Stress Fracture of the Tibia
In this condition the onset of leg pain may be sudden or less acute. There is sharply localised bone tenderness and overlying oedema. Radiographic demonstration of the hairline fracture may be difficult, and with persistent pain repeated examination is essential. A radioisotope bone scan may be helpful in diagnosing a local ‘hot spot’. In many cases the diagnosis may not be firmly established until a small area of tell-tale callus is showing. The condition is also common in Paget’s disease where, of course, there is an easily identifiable radiological abnormality.
Medial Tibial Syndrome/Shin Splints
In this condition pain on the medial side of the shin in sportsmen may be severe, and there is usually tenderness along the posteromedial border of the lower part of the tibia. In a number of cases the symptoms may arise from stress fractures of the tibia, but in others the pathology is less clear. (Other causes include compartment syndromes, fascial hernias, interosseous membrane tears, periosteal avulsions, tendinitis, muscle sprains and periostitis.) Where symptoms are of a chronic nature, and fracture has been excluded, division of the attachments of the crural fascia may give relief.
Common Causes of Pain in the Posterior Aspect of the Lower Leg
