Osteomyelitis of the tibia

The tibia is one of the most common sites for osteomyelitis, which is fortunate, because it is one of the easier bones to approach. If you operate early, drill it through a short incision. If you operate late, don't do so before firm involucrum has formed, or you will leave a gap in the bone which will need extensive reconstructive surgery to repair. A gap is particularly likely in the tibia, because so much of it is subcutaneous.

CHEPESOK was a charming little Pokot girl of about 8 with osteomyelitis of her tibia. The stock of ketamine was finished, so, rather unusually, she was given a subarachnoid (spinal) anaesthetic. Half way through the operation she sat up and said ''You will take out all the bad bone, won't you!'' LESSONS (1) These can be very rewarding patients. (2) ''Primary Anaesthesia' considers childhood a contraindication to subarachnoid anaesthesia unless you are expert (A 7.4).

OSTEOMYELITIS OF THE TIBIA Follow the general methods for osteomyelitis in Sections 7.4 to 7.6. Apply a tourniquet.

DRILLING. Make a linear incision 1 cm lateral to the anterior border of the patient's tibia, as in Fig. 7-10.

SEQUESTRECTOMY. Make the main part of the incision over his muscles rather than his bone. Make the longitudinal part of the incision 1 cm lateral to its anterior border. Proximally, don't extend it higher than his tibial tubercle. If possible, avoid taking it across his tibia where this is infected, because the scar from the incision will stick to the bone and become painful later. If necessary, curve its upper and lower ends to cross the anterior border of the bone.

Reflect his skin with his periosteum. They will probably be so closely bound together that you will be unable to separate them. Hold the skin flap lightly with skin hooks. Incise the periosteum midway between the anterior and posteromedial borders of the bone.

If the position of sinus tracks make it necessary, you can make a medial flap in the same way, with most of the length of the incision over the muscle on the medial side of his tibia.

After you have removed the sequestrum: (1) If the tissues are not too tight, you can close the wound lightly and insert a drain in its lower part. Or, (2) if the tissues are tight, you can let the skin edges fall into the wound and leave it unsutured, as in H, and I, Fig. 7-10. Healing will take longer like this. Apply a posterior slab or a long leg cast with his ankle in neutral, and his knee in 20[de] of flexion. Mark a window in it while it is still soft, cut out the window with a knife (70.2), or with a plaster saw 2 days later when it is hard. Dress the wound through this window.

If you have left a deep trough in the front of the tibia which is slow to granulate and epithelialize, graft it.

CAUTION! (1) Don't go directly anteriorly through the subcutaneous surface of his tibia. (2) Make sure your assistant retracts the skin flaps gently, because they can easily necrose.

Give him a long leg cast with a walking heel, then encourage early weight bearing with as normal a gait as possible.

DIFFICULTIES [s7]WITH OSTEOMYELITIS OF THE TIBIA If there is a VERY LARGE SKIN DEFECT IN A PATIENT'S TIBIA which is slow to heal consider making relieving incisions about 15 cm long down the medial and lateral sides of his calf, and pushing his tissues forward to cover part of the gap. Hold them in place with sutures or strapping. Graft the gap made by the relieving incisions.

If a LARGE PART OF HIS TIBIA has been destroyed, and inadequate involucrum has formed, try to get this fibula to hypertrophy before referring him. Walk him in a below-knee caliper. Later, refer him for an operation in which a length of his fibula is moved across to form a new tibia. This is done in two steps, moving one end at a time. The transposed piece of his fibula can hypertrophy greatly. Destruction would not have occurred if you had removed the sequestrum at the right time.

If: (1) you MISTAKENLY REMOVED A SEQUESTRUM before a firm involucrum had formed, or (2) the periosteum in the middle third of the shaft of the tibia is destroyed, keep him in a Sarmiento cast (81.5), to support his leg and prevent his foot going into inversion until such a time as you can refer him to have his fibula moved over under his tibia.

If osteomyelitis has COMPLETELY DESTROYED A CHILD'S TIBIA, his fibula may hypertrophy, and push his foot into varus; refer him.

Fig. 7-11 OSTEOMYELITIS OF THE FIBULA. Approach a patient's fibula between his peroneal muscles anteriorly, and his soleus posteriorly.