www.sportex-medicine.com

6. FRACTURE OF THE FIFTH METATARSAL Two types of fracture occur at the base of the 5th metatarsal. An avulsion fracture of the tip of the styloid process is the more com- mon (76%) of the two types and usually occurs as result of inver- sion injury to the foot. Abnormal tension in the peroneal brevis muscle which is inserted here is often implicated. The transverse fracture (Jones fracture) through the shaft of distal to the insertion of peroneus brevis is less common (4%) but can be significantly dis- abling.

Clinical picture The pain is very localised to site of fracture and can be reproduced by active eversion of the foot against force. In the early stage of the fracture, the foot may be swollen, but usually it would appear normal. Patients will generally walk in the clinic limping or have an antalgic gait (ie. when the patient alters their gait to try and avoid pain). Rest and compression bandage reduces the symptoms.

Investigations ● Plain radiographs (Fig.10) ● Isotope bone scan

Treatment ● Immobilisation in either a walking or non-weight bearing below the knee cast, depending on the type and extent of the fracture ● Surgery (Fig.11) - often the preferred option to reduce the risk of non-union and not to render peroneus brevis ineffective

7. STRESS FRACTURE OF THE CALCANEUM These fractures occur at any age and usually follow an insidious onset of heel pain. It is more commonly seen in endurance sport especially running. There is usually an increase in activity or inten- sity. It occurs in children and is known as Sever’s disease (Fig.12). It is in fact an apophysitis of the growing bone. Diagnosis is usu- ally based on history as plain radiograph is often not very helpful.

Clinical picture There is pain in the heel which is aggravated by impact or weight bearing activity. The history and site of pain is often vague and is the delaying factor in making the diagnosis. The tenderness is localised to medial and lateral aspect of the heel, and is often diag- nosed and treated as chronic plantar fasciitis (CPF). Clinically pain can be reproduced by squeezing the heel. Rest makes the condition better and is therefore usually not painful first thing in the morn- ing or after a period of rest. This should differentiate it from CPF.

Figure 12: Sever’s disease

Investigations ● Plain radiograph (lateral view) will show a classical sclerotic appearance at the posterior margin the heel ● MRI scan is the investigation of choice (Fig.13)

Treatment ● Shock absorbing heel pads to reduce the impact ● Foot orthoses ● Non-weight bearing on crutches for 4-6 weeks

8. SINUS TARSI SYNDROME (rehabilitation focus follows) Sinus tarsi syndrome (STS) was first described by O’Connor in 1958 as a condition characterised by unremitting pain in the lateral ankle area, usually following a sprain. It can also occur following aseptic synovial inflammation, ankle/subtalar ligament injury, osteoarthritis, rheumatoid arthritis, peroneal tenosynovitis, and peroneal nerve entrapment. Non-traumatic causes are ganglion cyst, abnormally pronating feet, gout, tarsal tunnel syndrome, heel spur syndrome and sciatica.

Other conditions to consider in this region

- Os naviculare syndrome - tibialis anterior enthesiitis - tibialis posterior tendonitis/enthesiitis - first ray subluxation - Lisfranc subluxation/dislocation - anterior impingement syndrome

Figure 10: Plain radiograph of fracture of the 5th metatarsal

14 SportEX

Figure 11: Internal stabilisation of the 5th metatarsal bone