Contractures of the hip and knee

Before you decide on any operative treatment, assess the function of the patient's limbs in detail, and what he needs to do with them. He may have already achieved remarkable mobility, and although a straight leg may look better, it may not work better, especially if it needs calipers. If a child's legs are so weak and contracted that he crawls along the ground, you must get him walking, because the psychological effect of doing this will be tremendous[md]his parents will now think that he is worth educating. But if he is an adult, consider his whole future carefully first. He may be able to crawl fast and cultivate his fields on his hands and knees, but if he can only walk slowly and stiffly in calipers, he may die of starvation. So a cultivator may be better crawling, especially if his arms are too weak to use crutches, whereas a clerk, for example, may benefit from calipers. Sometimes an operation is an obvious disservice, for example lengthening a patient's Achilles tendon, when he walks on the ball of an equinus foot, and this is compensating for a short leg.

A severe polio contracture can: (1) cause the skin over a patients's joint to shrink, (2) shorten his muscles, intermuscular septa, nerves, and vessels, (3) contract his joint capsule, (4) deform his epiphyses. Undoing all this is difficult, and may be impossible, so only try to relieve milder contractures, and follow the indications we give carefully, or you may damage important structures, or cause infection or skin loss. A child's contractures are easier to correct than an adult's[md]he probably only needs a tenotomy, whereas an adult may need an osteotomy, or an arthrodesis.

The contractures of a patient's hip and knee, are often associated. You may have to release: (1) His iliotibial band, in several places down his thigh. In a young child, one or two incisions may be enough, and you may not need the complete set of four incisions described below. When you have divided it in his thigh, there may be no need to divide it at his knee. (2) The tight structures on the front of his hip, particularly, his iliopsoas. (3) The tendon of his biceps femoris in his popliteal fossa. (4) His medial hamstrings (occasionally).

You can cut tight bands and tendons in two ways: (1) You can push a long thin tenotomy knife through a small skin incision, and cut the bands by feel. This is satisfactory for the less severe contractures, provided you do it correctly, and as extensively as necessary. (2) You can cut tight structures under direct vision. In the thigh, this is the best method, especially for severe contractures, but it needs more skill and the wound may break down, so use the closed method. Behind the knee, the common peroneal nerve is very superficial, so the only safe way to divide the tendons there is by open operation.

Don't try to treat a contracted hip by manipulation and serial casting in a spica[md]surgery is better.

The knee is the most difficult of the three joints on which you may have to operate, especially in an adult, whose tibia can be rotated backwards and laterally, as well as being flexed. Be safe, and don't try to release a contracture of [mt] 90[de]. If you try, his tight popliteal vessels and nerves may be stretched; and pain, paralysis, and even gangrene may follow. Even a contracture of [lt]90[de] may be difficult. After you have released it as much as you can by tenotomy, you can obtain the final correction by one of these three methods. You can:

(1) Manipulate his knee and apply a cast.

(2) Apply a cast and wedge it; this may be useful if plaster is scarce, but manipulation and a fresh cast will give better results. A cast by either of these methods will mobilize him earlier, and is economical in the use of beds; but it will not be effective, if the operation has left him with a contracture of 45[de], or more. It also increases the risk of a stiff, painful knee, and of osteoarthritis later.

(3) Put him into Hamilton Russell traction. This will keep him in bed for 2 or 3 months, but it does have these advantages; (a) it is better if he is an adult, and his contracture is severe, (b) it reduces the risk of pain and osteoarthritis, (c) it is the only way of treating a contracture which remains [mt]45[de] after the operation, (d) it helps to control an associated contracture of his hip, (e) it is less likely to cause backward subluxation of his tibia on his femur than extension traction (78.3). Hamilton Russell traction is commonly used for treating fractures of the upper femur and hip, but Perkins traction (78.4) is better and simpler.

(4) Use reversed slings on a Thomas splint.

(5) Use skeletal traction with a pin through the lower tibia, a simple and very useful method (70.11).

ANATOMY. The common peroneal (lateral popliteal nerve) descends obliquely along the lateral side of the popliteal fossa to the head of the fibula, close to the medial margin of biceps femoris. It lies between the tendon of biceps femoris and the lateral head of gastrocnemius, and winds round the lateral surface of the neck of the fibula deep to peroneus longus.

HIP AND KNEE CONTRACTURES [s7]TREATED OPERATIVELY INDICATIONS. (1) An isolated hip contracture of [mt]30[de] at any age. (2) A child with an isolated flexion contracture of his knee of [mt]30[de]. (3) An adult with an isolated flexion contracture of his knee of [lt]90[de]. (4) Combined hip and knee contractures of [mt]30[de], provided there are no contraindications. If you have many patients, start by operating on the younger ones with lesser deformities first.

THE CONTRAINDICATIONS to any release operation are: (1) Weak arms. The patient will need crutches, so he must have two strong arms, especially if both his legs and his trunk are weak. There are exceptions to this rule, and a really determined adult, or child, sometimes manages surprisingly well with limited weakness in one or both his arms, provided his trunk is strong. (2) A patient with mild contractures, who is walking reasonably well, is probably best left as he is. This includes a patient with: (a) a contracture of his hip alone of 30[de] or less, especially if it also has a mild abduction deformity, which may increase its stability and compensate for shortening. (b) An isolated knee contracture in a child[md]treat him with fortnightly manipulations under anaesthesia. (3) An adult who is earning his living as a ''crawler', and is happy to go on doing so; leave him. (4) Don't operate on any patient unless you can provide him with calipers.

CAUTION ! Scar tissue is not stable for at least 6 months, so when you correct contractures, you must find some way of maintaining the position of his limb for at least 6 months, or longer, if there is still muscle imbalance, or much scar tissue.

Fig. 27-7 CUTTING THE ILIOTIBIAL BAND. A, the position of the incisions. B, the structures to be cut. Kindly contributed by Ronald Huckstep.

TENOTOMY [s7]FOR THE HIP AND KNEE DIVIDING THE ILIOTIBIAL BAND. Use a narrow tenotomy knife, or an old cataract knife, or a No 11 scalpel blade altered as in Fig. 27-10, so that only its tip is sharp. Operate under full sterile precautions, and prepare both his legs, even if you are only going to operate on one of them. Squeeze all blood out of the incisions periodically during the operation, and at the end. His hip incision may bleed considerably.

Release his hip and knee before you release his ankle. The structures you are going to divide must be tense, as you divide them, so keep his hip in as much extension and adduction as you can, while you cut. Feel the tight structures through his skin, to make sure that you have left no tight bands undivided.

First incision. Make this on the outer side of his thigh, about 2 cm above his knee. You can usually feel his tensor fascia lata as a tight band. Push the knife horizontally into the outer side of his thigh, just behind the tight band, until it just touches the lateral side of his femur. Rotate its blade, so that its cutting edge is upwards; then cut all the subcutaneous structures anterior to the blade, and lateral to his femur. Provided you make the incision in the right place, and only cut anteriorly, you will not cut anything important. Don't cut posteriorly, or you may cut his popliteal artery, or his lateral popliteal nerve.

Second and third incisions. Make these one third and two-thirds of the way down the outer side of his thigh. Some surgeons only make one incision in the middle of the thigh. Feel for his tensor fasciae latae, and push the knife in along its posterior border down to the bone, exactly as for the first incision. Then rotate it through 90[de] and cut anteriorly and laterally to the outer side of the shaft of his femur.

If you cannot feel his tensor fasciae latae, insert the knife where you think it should be and cut exactly the same way. There are other tight structures to be cut, including his vastus lateralis.

The fourth incision is the one which releases his hip. Make it one finger's breadth below his anterior superior iliac spine.

CAUTION ! (1) Don't damage his femoral vessels and nerve. Don't push the knife further medially than a point 2 cm lateral to his mid-inguinal point (where you can feel the artery). (2) Feel for his inguinal ligament, and take care not to divide that.

Push the knife in subcutaneously, below his anterior superior iliac spine, from a lateral to a medial direction, so that its flat surface is in the plane of the skin just caudal to his anterior superior iliac spine. Stop 2 cm lateral to his mid- inguinal point (see above). Then rotate it 90[de], so that its edge faces backwards, and cut all the tight subcutaneous structures.

If his contracture is severe, cut all tight structures lateral to the branches of his femoral nerve. Cut right down to the front of the trochanter of his femur.

When you have cut the tight structures anteriorly, twist the knife so that it cuts laterally, and cut all the tight structures on the antero-lateral side of his hip.

CAUTION ! (1) When the tip of the knife is deep, angle it caudally, so that its blade is parallel with his inguinal ligament, and will not cut it. (2) Don't cut further back than the coronal plane of the anterior part of his hip joint. Leave the abductors posterior to this, to give lateral stability to his hip. (3) Keep his hip in as much adduction and extension as you can, while you divide the tight structures. Feel them through his skin during the operation, and don't leave any tight deforming bands behind.

Fig. 27-8 OPEN BICEPS TENOTOMY to release a contracture of the knee. A, the site of the incision. B, be quite sure you find the patient's lateral popliteal nerve, before you cut anything. C, his biceps femoris tendon divided. Kindly contributed by Ronald Huckstep.

OPEN BICEPS FEMORIS TENOTOMY [s7]FOR A POLIO CONTRACTURE INDICATIONS. This is only indicated if his knee contracture is [mt]30[de] but [lt]90[de]. The method which follows is a very limited open tenotomy suitable for a patient: (1) who needs a bit more extension, so that he can be put into skin traction, and (2) whose biceps femoris tendon is tight, but not his semitendinosus and semimembranosus tendons, which are attached medially. Feel his tendons when his knee is extended to its limit. If all his tendons are tight and need surgical release, refer him.

METHOD. Make an incision on the lateral side of his knee, as shown in Fig. 27-8. Feel for, and find his biceps tendon under direct vision, hook it out of the wound, and cut it.

CAUTION ! Be sure that it is his biceps tendon, and only his biceps tendon. Be careful you have not got his lateral popliteal nerve with it. They both look very similar. Look for muscle fibres being inserted into the tendon before you cut it. Be sure the nerve has not stuck to the back of the tendon.

Put your finger into the wound, and feel for any other tight structures which need cutting. You may need to cut the posterior part of his iliotibial band, and his lateral intermuscular septum. Sometimes, the anterior part of the deep fascia lata also needs cutting.

Put him into skin traction, or into a well-padded cast.

CASTING AND MANIPULATION. If the contracture of his knee is [lt]45[de], apply a cast. If it is [mt]45[de], Russell traction is better, but you can apply a cast, if necessary.

Apply a well-padded cast with his knee just short of the full extension to which it is capable. It must not be under any tension, or it will be painful and .

CAUTION ! NEVER put a knee into a cast under tension, or wedge a cast to correct a knee contracture, or its articular cartilage may necrose, and early painful osteoarthritis may follow, in what was previously a painless mobile joint.

Check the hip incision again (if you have released his hip at the same time), as soon as you have applied the cast, and squeeze out any clot which has formed, under full sterile precautions. Pad the incision and apply light adhesive strapping.

Every two weeks, remove the cast, and manipulate his hip and knee, until his knee is in at least 5[de] of hyperextension, and there is [lt]10[de] of flexion deformity (''fixed flexion') in his hip. Manipulate him as in Section 27.2, and spend 5 to 10 minutes on each joint. Be sure to flex his knee fully, and to rotate his tibia medially and laterally, to maintain these very important movements. Correct or avoid backward subluxation of his knee. If necessary, correct the lateral rotation of his tibia on his femur.

After each manipulation apply a well-padded above- knee cast, with his ankle firmly dorsiflexed. As always, don't put his knee under tension!.

As soon as the flexion deformity in his knee is less than about 40[de], fix a walking piece on the bottom of his cast, and encourage him to walk with crutches.

Leave the final cast on for 2 weeks, and then replace it by an above knee caliper, with its posterior strap loose. Tell him to wear it day and night for 2 or 3 weeks, until the risk of recurrence of a flexion contracture of his knee is less. Later, he can wear it by day only, for up to 6 months, when the tendency for the contracture to recur will have passed, or indefinitely if he needs it to stabilize his knee.

If possible, provide him with physiotherapy, or assisted exercises, after the cast has been removed. If the postoperative care is not properly done, he may end up with a stiff, painful knee, in which his tibia is subluxed posteriorly on his femur.

HAMILTON RUSSELL TRACTION. If he is an adult, and his contracture is [mt]45[de] after the operation, Russell traction for 2 or 3 months, as in C, Fig. 27-9, is better than casting and manipulation.

Every day, stretch his knee and hip passively. As his contracture improves, make the traction more longitudinal, so that it becomes more like extension, or straight leg traction (78.3). You will probably not need to manipulate him under anaesthesia, except for the last 15[de] of a flexion contracture, which may be difficult to correct, and require a cast in addition. Apply a plaster backslab to his ankle, to prevent an equinus deformity recurring during prolonged Russell traction. Also, stretch his ankle passively each day to correct any deformity, or prevent it.

REVERSED SLINGS are an alternative to Russell traction. Put him into a Thomas splint. Put slings under his calf and his thigh. Pass a sling round the splint, and his knee as shown in A, Fig. 27-9. Lead the cords from this to pulleys. Apply light skin traction of about 2 kg to stabilize his leg.

GET HIM MOBILE out of bed and into a chair as soon as possible. If he is a child, you can usually do this in a few days. If he is an adult, full mobilization may take a month or two. Prop him up gradually in bed or a chair, before he tries to get up. He may need crutches or a caliper; crutches must fit properly, as shown in Fig. 77-1.

DIFFICULTIES [s7]RELEASING POLIO CONTRACTURES OF THE KNEE If his KNEE IS PAINFUL and stiff, (which, so it is said, should never happen if he has been properly treated), reassure him that this is (alas!) a common complication, and that his knee will slowly recover some, or all, its movement in a few weeks or months. His pain will probably go, even if his knee does not regain its full movement. If pain and stiffness persist, try intensive physiotherapy or Hamilton Russell traction. An arthrodesis is necessary occasionally.

Fig. 27-9 ''REVERSED SLINGS' AND HAMILTON RUSSELL TRACTION for contractures of the knee. A, a cross-section of the knee, showing how a reversed sling is passed round it. B, the principle of reversed slings. C, Hamilton Russell traction. Force ''x' is the resultant of forces ''y' and ''z'. Angle ''w' is normally about 45[de] when Russell traction is set up. As a knee contracture improves, it slowly becomes less. Prevent an equinus deformity with a backslab. This method of traction can also be used to treat fractures of the hip and femur. Kindly contributed by Hugh Roberts.