Septic arthritis of the hip

If a patient has an acutely tender hip in varying degrees of flexion, and fever, suspect that it is infected. The general methods for septic arthritis are described in Section 7.16. An important sign is spasm of his hip muscles. Test for this by rolling his thigh as in Fig. 7-17. If this is acutely painful, suspect that his hip is infected. If he has septic arthritis or osteomyelitis banging his greater trochanter lightly with your clenched fist will be painful; if he has deep inguinal adenitis or pyomyositis it will not, see Sections 5.12 and 7.1. In septic arthritis or osteomyelitis the epiphysis of his femur may become indistinct, or even absent on an X-ray, but it often reappears. This is not an indication for removing it.

Many doctors, and even many general surgeons, are afraid to open the hip joint, and look on this as a specifically ''orthopaedic' procedure. The hip does however require exploring and draining just like any other joint. The problem is that it lies a little deeper than the others. There are three operations you may need to do, but only the first is common. Be prepared to: (1) Drain pus in septic arthritis. (2) Remove the head of a patient's femur, when this has been destroyed as the result of infection. (3) Do Girdlestone's operation in chronic septic arthritis to remove the head and neck of his femur.

Here we are only concerned with septic arthritis of the hip. If you don't treat a patient early, any of these things may happen to it:

(1) He may may develop a flexion contracture of his hip, which will be a great disability, if you let it become permanent. You can prevent and treat this in two ways: (a) You can apply extension (skin) traction to his lower leg (70.10). This is very effective prevention, so do it routinely. (b) If a contracture has started to develop, you can extend his leg by laying him on his front for some time each day[md]if he will tolerate it. Few patients, especially children, will do this for long if their head faces the wall. So make sure his bed faces the centre of the ward.

(2) His upper femoral epiphysis may slip off the shaft of his femur, and become a dead sequestrum in his hip joint, as in Fig. 7-14. Later in the course of the disease there is a useful test to find out if it is slipping. Bend his knee to 90[de] and then flex his hip, as in B, Fig, 7-17. If his leg goes into external rotation as you do this, the head of his femur may have slipped. Confirm it by taking a frog-leg X-ray view, as in Fig. 77-9. If it has slipped and is forming a sequestrum, you will have to open his hip joint and remove it, as described below.

(3) His hip joint may be destroyed. When this happens, there are two possibilities: (a) Fusion of his hip in the position of function. If you decide that this will be best for him, achieve this position by applying a spica in the position described in Section 7.17, until his hip has fused. (b) If the head and neck of his femur have been partly destroyed, he may benefit if their remains are removed by Girdlestone's operation (7.19). This will give him a much more comfortable joint with some movement.

(4) The infection may extend into his acetabulum and involve the bones of his pelvis. When this has happened, there is little you can do, except drain the pus. His osteitis usually settles.

To explore and drain the hip you can approach it anteriorly or posteriorly. If you can safely anaesthetize a prone patient (A 16.12), the posterior approach is easier, because it allows better drainage. If you cannot do this, use the anterior one, and anaesthetize him in the supine position.

Fig. 7-18 THE ANTERIOR APPROACH TO THE HIP. A, the incision. B, the muscles retracted. C, preparing to incise the capsule.

1, the anterior superior iliac spine. 2, the pubic tubercle. 3, the femoral vein, artery and nerve from medial to lateral in this order. 4, sartorius. 5, rectus femoris. 6, the ascending branch of the lateral circummflex vessels. 7, the exposed surface of the ilium. 8, gluteus medius and tensor fascia lata. 9, the incision in the capsule.

SPECIAL METHODS FOR THE HIP For the methods of aspiration, and the positions of rest and function, see Section 7.17.

THE RELIEF OF SPASM. If the patient is a child, apply up to 1/7th of his body weight of extension (skin) traction, depending on his weight. This will relieve the spasm of his muscles, and will prevent him developing a flexion contracture.

THE ANTERIOR APPROACH [s7]TO THE HIP (really the anterolateral approach, 7-18) ANAESTHESIA. Ketamine, or general anaesthesia with spontaneous respiration.

POSITION. Lay him supine, but tilt him to the other side by putting a sandbag under his affected hip.

ASPIRATION is useful to check that pus is present. If you don't find it, but think that he probably has got septic arthritis, explore his hip anyway.

INCISION. Cut from the mid-point of his iliac crest to his anterior-superior iliac spine. Extend the incision distally down his leg for 10 or 12 cm. Divide his superficial and deep fascia. Use a periosteal elevator to separate his gluteus medius and tensor fascia lata from his iliac crest. Continue the dissection distally between his tensor fascia lata posterolaterally, and his sartorius and rectus femoris anteromedially. Divide the ascending branch of his lateral circumflex vessels between ligatures.

Insert two bone levers on each side round the upper shaft of his femur and retract his muscles. You will now see the capsule of his hip joint. Check that it is his joint by aspirating. Now open the joint with a cruciate incision. Ask an unsterile assistant to grasp the patient's ankle and externally rotate his hip. You will see the head of his femur moving inside his acetabulum. If you want better access to the joint, insert levers round the neck of his femur. If you suspect osteomyelitis, drill at least 4 holes into the neck and upper shaft of his femur.

Insert a corrugated drain from the joint to the surface, and leave it in for 5 to 7 days. Don't suture the capsule. Bring his muscles together lightly with a few ''0' chromic catgut sutures. Close the fascia over his iliac crest. Close his skin with ''0' monofilament.

POSTOPERATIVELY, apply 2 to 5 kg of skin traction up to his mid thigh, with his leg in in 1 to 15[de] of abduction and minimal flexion. Raise the foot of his bed.

Fig. 7-19 EXPLORING THE HIP THROUGH OBER'S POSTERIOR APPROACH. A, incise patient's gluteus maximus. B, separate its fibres. C, be careful not to injure the sciatic nerve. D, incise the hip joint.

THE POSTERIOR APPROACH [s7]TO THE HIP (OBER'S APPROACH) Intubate the patient and control his ventilation. Lie him on his side, slightly inclined towards the prone position. Find the tip of his great trochanter. Cut medially from it for 5 cm in line with the fibres of his gluteus maximus. Cut through his skin and superficial fascia.

Separate the fibres of his gluteus maximus using your index finger and the end of a curved haemostat, until you meet the capsule of his hip joint. Open the incision with retractors.

If you find pus in the muscles of his buttock, before you reach his hip, stop. He has pyomyositis. If you go further and open a normal hip through an abscess in his muscles, you will probably infect it.

Ask an assistant to take hold of his ankle and rotate his hip internally, so as to increase the space between his trochanter and his acetabulum.

Make a small incision in the distended capsule of his hip joint and widen it with a haemostat.

CAUTION ! (1) His sciatic nerve leaves his buttock half way between his greater trochanter and his ischial tuberosity. There is no need to incise or dissect this far medially. (2) The capsule of the hip joint is only a finger's breadth wide between the posterior aspect of the greater trochanter and the posterior margin of the acetabulum.

If his upper femoral epiphysis has slipped and is forming a sequestrum, remove it. Approach his hip posteriorly as above. Modify this by carrying the incision down his greater trochanter. Remove the loose head of his femur with large bone forceps, and as much of its neck as is necrotic.

POSTOPERATIVELY, reduce the tendency of his hip to slide proximally by putting him into traction for 6 weeks postoperatively, while fibrous tissue forms to limit movement. He will have an unstable hip and will need a crutch, but he should be pain-free and he will be able to walk.