56.9 Syme’s amputation

This is a disarticulation of a patient’s ankle, adapted so that the stump can bear his weight. All the bones of his foot are removed, and his malleoli are sawn off, so that the end of his tibia is flat. A large full thickness heel flap is removed subperiosteally from his calcaneus, and brought forward to make a solid covering for the end of his tibia. He can walk about his house on it without a prosthesis or crutches, even though his leg is about 5 cm short. He can also wear a simple and durable elephant boot. His distal tibial epiphysis is preserved, so it is good amputation if he is a child.

Figure 56.14: SYME’S AMPUTATION. Fig. 56-14 SYME’S AMPUTATION. A shows the incision and B, the completed stump immediately after suture. C, shows how the stump can be held in place with strapping postoperatively. Ultimately, the stump should look like D. E, the patient’s ankle joint has been exposed and its ligaments cut. F, his foot has been further plantar flexed and its Achilles tendon is about to be cut. G, extreme flexion allows his calcaneus to be dissected out of its surrounding tissues subperiosteally. H, the lower end of the tibia is being sawn through. I, shows a cross section of his ankle joint with the tibialis anterior tendon (1), the great saphenous vein (2), the tibialis posterior tendon (3), the flexor digitorum longus tendon (4), the tibial nerve (5), the posterior tibial artery and vein (6), the plantaris tendon (7), the Achilles tendon and its overlying bursa (8), the small saphenous vein (9), the flexor hallucis longus tendon (10), the peroneus longus and brevis tendons (11), the extensor digitorum tendon (12), and the tendon ofextensor hallucis tongus (13). After Campbell with kind permission.

This is an excellent amputation if it is well done, but it is also the most difficult of the amputations described here. If you are not skilled, amputating below his knee would be wiser. However, if a Syme’s amputation fails, a below knee amputation is always possible.

A patient’s posterior tibial vessels run into his foot just behind his medial malleolus. If you cut them too high, they cannot supply his heel flap. So: (1) Shell out his calcaneus from under the periosteum when you dissect the flap. If you can preserve the periosteum a useful piece of new bone will form in it. (2) Cut the vessels as far distally as you can. (3) Be sure to keep the heel flap correctly aligned postoperatively, so that the patient can walk on it.