Orthopaedic
CASE 67: SuDDen CalF pain
history
A 31-year-old man attends the emergency department complaining of pain affecting his left calf. He was playing squash when he suddenly felt as though he had been hit on the back of the ankle. A loud snapping sound accompanied the pain.
examination
Examination of the left foot and ankle reveals no obvious deformity. There is tenderness over the calf and posterior aspect of the ankle. There is a full passive range of movement of the foot, ankle and knee joints. There are normal foot pulses, and neurological examination is unremarkable.
Figure 67.1 normal leg being tested.
Questions
•What clinical test is being demonstrated on a normal leg in Figure 67.1?
•What is the likely diagnosis in this patient?
•What investigation can be performed if the diagnosis is in question?
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100 Cases in Surgery
ANSWER 67
The clinical test that is being demonstrated is the ‘Simmonds test’. It describes the absence of ankle plantar flexion when the calf is compressed. This picture demonstrates normal plantar flexion with calf compression on the right leg.
Failure of plantar flexion indicates that the patient has ruptured his Achilles tendon. The history of sudden pain affecting the calf during sporting activity is typical. Other examination findings may include a palpable gap in the Achilles tendon and an inability to actively plantar flex the ankle (i.e. the patient is unable to stand on ‘tip-toes’). The latter feature may be misleading, as the deep flexors of the foot can compensate for this movement.
An ultrasound scan can confirm a gap in the Achilles tendon when the diagnosis is in doubt. Serial ultrasound scans can also be used to assess healing of the tendon. There is debate as to the best way to treat this injury. Non-surgical management involves immobilizing the leg in a plaster of Paris cast, with the foot initially in full plantar flexion. While this avoids the risks of surgery, it delays functional rehabilitation and results in a greater risk of the tendon re-rupturing. The tendon can be repaired surgically, which is thought to result in a stronger tendon repair. This may be more appropriate for patients who require a greater level of sporting activity.
KEY POINTS
•ultrasound can be used to detect damage to the achilles tendon.
•Simmonds test is diagnostic of an achilles tendon rupture.
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Orthopaedic
CASE 68: leFt Knee injury
history
A 22-year-old woman is brought to the emergency department by ambulance. Her friend says that they had been out drinking and that she had fallen off a 4-foot wall, landing directly on her left knee. Her knee swelled up immediately and she has not attempted to walk since the injury. She is normally fit and healthy. She takes a combined oral contraceptive pill, smokes 10–20 cigarettes a day and works in a supermarket.
examination
Her observations are normal. There is no evidence of a head injury. Her left knee is diffusely swollen and there is evidence of bruising. The skin is intact. The medial and lateral joint lines are not tender. The patient is unable to actively extend the knee. The knee feels otherwise stable. The hip and ankle joints are unremarkable, and the pedal pulses and foot sensation are normal.
INVESTIGATIONS
plain x-rays of the left knee are taken and are shown in Figures 68.1 and 68.2.
Figure 68.2 plain x-ray of the left knee.
Figure 68.1 plain x-ray of the left knee.
Questions
•What injury has this woman sustained?
•How should it be managed?
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100 Cases in Surgery
ANSWER 68
The x-rays show that the patient has a fractured patella (arrows in Figures 68.3 and 68.4).
Figure 68.4 patella fracture (lateral).
Figure 68.3 patella fracture (anterior-posterior).
This type of fracture typically occurs with direct trauma to the knee. It is possible, however, to sustain a similar injury by an indirect mechanism, such as by vigorous jumping that leads to rapid flexion of the knee against a fully contracted quadriceps muscle. An indirect injury tends to result in less displacement and comminution of the fracture.
The patella is a large sesamoid bone. The upper border is connected to the quadriceps tendon and the lower pole is connected to the patella tendon, which inserts into the tibial tuberosity. In order to actively extend the knee, the whole unit must remain in continuity. It is, therefore, very important when examining knee injuries to ensure the extensor mechanism is intact by feeling for any palpable gap and by getting the patient to actively extend the knee.
Patella fractures can be managed conservatively or operatively. If the extensor mechanism is disrupted and/or there is a greater than 3 mm gap in the fracture site, surgical fixation is often necessary. If the extensor mechanism is intact and there is a small gap in the fracture site, more common with the indirect injuries, then a cylinder plaster of Paris cast is more appropriate.
It is worth noting that a bipartite patella occurs in 1 per cent of the population, and it is not uncommon for patients to be misdiagnosed with a patella fracture. The diagnosis of a patella fracture is supported if there is a plausible mechanism of injury and the appropriate examination findings are present.
KEY POINT
•bipartite patella occurs in 1 per cent of the population, and can be mistaken for a patella fracture.
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