Managing chronic polio

The children of the developing world pay a high price for acquiring their natural immunity. A survey from Ghana showed seven in every thousand to be lame, and although nearly 90% of these children could walk without mechanical aid, many of them had scoliosis and needed calipers.

Poliomyelitis destroys the anterior horn cells of a patient's spinal cord. This causes a flaccid lower motor paralysis, without impairing sensation. The flexor and extensor muscles of a normal limb are arranged so that they oppose one another's action. Polio can weaken both groups mildly or severely, equally or unequally. When, as is usual, the muscle groups are involved unequally, it is commonly his extensors which are most affected. When this happens, his stronger flexors pull his limb into a flexion contracture. If all the muscles of his limb are weak, he has a flail limb. If he is a child, growth will cause further deformity. All this can happen in varying degrees to his hips, his knees, or his ankles, on one or both sides, to cause many patterns of paralysis. His arms are less commonly affected, and are usually less of a disability, so we say nothing about them here, nor do we discuss the effects of polio on the spine.

These are your opportunities: (1) Do all that you can to promote the immunization campaigns that should now be taking place in your district in response to WHO's expanded programme of immunization (EPI). (2) Try to prevent contractures developing immediately after the acute phase of the illness. (3) If they do develop, use serial plasterings, traction, or tenotomies to release some of the milder ones. More complex operations, such as osteotomies, arthrodeses, and tendon transfers, are tasks for an expert, so are all operations on the arms and spine, on the rare occasions when these are necessary. (4) Provide patients with the necessary calipers, crutches, and plaster splints. (5) Follow them up for many years, if necessary, and help them to find places in schools, and to find jobs. As always in medicine, but particularly in polio, consider a patient's total needs. Never treat a single joint without considering the other joints in his limb, his other limb, and the adaptations that he has already made to his disability.

Your results should be good if: (1) you operate carefully on the right indications, (2) you give him simple calipers, and (3) you are able to provide the necessary physiotherapy and follow-up. These last two are likely to be your main constraints. The methods we describe are adapted from those of Huckstep. In some countries they are mostly done by orthopaedic assistants.

Huckstep RL. ''Poliomyelitis: A Guide for Developing Countries, including appliances and rehabilitation' ELBS version. Churchill Livingstone, 1975.[-3] Nicholas D, et al. ''Is poliomyelitis a serious problem in the developing countries?[md]The Danfa Experience'. British Medical Journal 1977;1:1009[nd]12. Fig. 27-3 CHRONIC POLIO. A, a patient with a weak hip or knee may be able to walk by putting his hand on his thigh, or by locking it in hyperextension, using the extensors of his hip (B). C, if his whole leg is weak, he will have to use a stick. D, if he has severe contractures of both knees, he may crawl on the ground. E, an adult ''crawler' seated. Note the large callosities on his knees. Kindly contributed by Ronald Huckstep.

A GENERAL METHOD FOR CHRONIC POLIO A patient with chronic polio can have any of the following patterns of paralysis:

THE HIP [s7]IN CHRONIC POLIO A MILDLY WEAK HIP (common) needs no treatment, especially if he also has a mild equinus deformity of his ankle, which helps to compensate for the shortening caused by his hip.

A FLEXION AND ABDUCTION CONTRACTURE OF THE HIP (common) due to weakness of its extensors and adductors.

If an adult or child has an isolated flexion contracture of his hip of [lt]30[de], he is probably walking adequately, and needs no treatment, provided he has no other serious contractures. The stability of his hip may even be improved, and shortening compensated for, by a small adduction and flexion contracture.

If an adult or child has an isolated flexion contracture of [mt]30[de], consider releasing it.

A FLAIL HIP (fairly common) due to paralysis of all its muscles. Give him a pair of crutches.

DISLOCATION OR SUBLUXATION OF THE HIP (rare) may occur in a flail hip. Reduce his dislocation, and put him into an abduction spica (77.3). Give him crutches. Occasionally, he may need an osteotomy, an arthrodesis, or a psoas transfer. Reducing a dislocated hip can be difficult. Some surgeons would leave a flail hip because it so easily redislocates.

If his dislocation is recurrent, it may be best left untreated. Unfortunately, most dislocations are recurrent, because there are no functioning muscles left around the hip to hold it in place.

Fig. 27-4 MORE POLIO DEFORMITIES OF THE KNEE. The common and most treatable ones are the flexion contractures shown by patients D, and E, in the previous figure. A patient can also have a valgus deformity (A, in the present figure), a hyperextension deformity (genu recurvatum) (B), a rotation deformity (C), or posterior subluxation (D). All these are much less easily treated. Kindly contributed by Ronald Huckstep.

THE KNEE [s7]IN CHRONIC POLIO Not all weak knees need a complete caliper. Some patients may be able to manage with a knee splint.

A FLEXION CONTRACTURE OF THE KNEE (common) due to weakness of its extensors.

If a patient has an isolated flexion contracture of his knee of [lt]30[de], apply serial casts for a child (27.2), and skin traction for an adult.

CAUTION ! Never put a cast on a knee (or any other joint) while it is held under tension, or osteoarthritis will follow (27.2).

If a patient has an isolated flexion deformity of his knee of [mt]30[de] but [lt]90[de], consider releasing it surgically (27.6). The operation described in Fig. 27-8 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.

If an adult has a flexion deformity of [mt]90[de], correction is going to be difficult, and he may subsequently have a stiff painful knee. If he has one contracted knee, either leave him alone, or consider referring him for an osteotomy or an arthrodesis. Don't ever consider straightening two contracted knees in an adult.

A VALGUS DEFORMITY OF THE KNEE (common) is usually associated with a flexion contracture, for which he needs a surgical release and a caliper. If necessary, bend his caliper, or fit it with a valgus knee strap, to prevent it rubbing against his knee.

If a small child has a severe valgus deformity of his knee, refer him for an osteotomy, or stapling of his medial epiphysis by an expert.

LATERAL ROTATION OF THE TIBIA ON THE FEMUR, or LATERAL SUBLUXATION OF THE KNEE (common). He usually also has a flexion contracture of his knee. You may be able to correct rotation and subluxation at the same time that you correct his flexion contracture. More often, the deformity is structural by the time you see him, and cannot be corrected by simple tenotomies. If rotation and subluxation are his only deformities, they are usually asymptomatic, and do not require specific treatment.

A HYPEREXTENSION DEFORMITY OF THE KNEE (genu recurvatum, fairly common) is due to early weight-bearing on a weak knee.

If a child's knee has less than 10[de] of hyperextension, leave it untreated.

If a child has [mt]10[de] of hyperextension, fit him with an above knee caliper with a posterior strap.

If an adult has a hyperextended knee, leave him untreated, provided it is not getting worse, or causing complications. Otherwise, he may need an osteotomy.

COMBINED HIP AND KNEE CONTRACTURES. If these are less than 30[de] and he is walking, leave them. If they are [mt] 30[de], consider releasing them, provided there are no contraindications.

FLAIL KNEE. He may be able to walk adequately without a caliper, if he has good hip extensors, and if his foot is in a good position.

THE ANKLE [s7]IN CHRONIC POLIO AN EQUINUS DEFORMITY OF THE ANKLE (very common) due to paralysis of its extensors.

If he is a child and flexion of his knee allows you to bring his ankle up into neutral, correct his deformity by serial casting (27.2). If he has a greater degree of deformity than this, do a tenotomy.

If he is an adult, the decision as to whether an operation would improve him is difficult, and depends on: (1) the degree of equinus of his ankle, (2) the power in his knee and hip, (3) the condition of his other leg, (4) whether he can or cannot use crutches, and (5) whether he will need calipers after surgery and can get them.

A CALCANEUS DEFORMITY OF THE ANKLE (rare) due to weakness of his calf muscles.

If his calcaneus deformity is mild, a lace-up boot may be all he needs.

If his calcaneus deformity is more severe, fit him with a below-knee caliper with a front stop.

A VALGUS DEFORMITY OF THE ANKLE (common) is usually associated with some degree of equinus.

If his valgus deformity is mild, correcting his equinus deformity and fitting him with a caliper will probably be enough.

If his valgus deformity is severe, consider referring him for transfer of his peroneal tendons, and perhaps a triple arthrodesis.

A VARUS DEFORMITY OF THE ANKLE (rare) is due to weakness of the evertors of his foot. His foot is inverted and his forefoot may be adducted.

If his varus deformity is mild, fit him with a below-knee caliper.

If his deformity is severe, you will probably have to refer him for soft tissue correction, or a subtaloid triple arthrodesis.

AN ADDUCTION DEFORMITY OF THE FOREFOOT. Try several manipulations as in L, Fig. 27-2. You will probably have to refer him for surgical correction.

A CAVUS FOOT. You may need to refer him for tenotomy, tendon transfer, or arthrodesis of his toes. Surgery is complex, so that scarce orthopaedic skills are probably be best reserved for other patients.

COMBINED DEFORMITIES [s7]IN CHRONIC POLIO A common pattern is a flexion deformity of his hip and knee, and an equinus deformity of his ankle. Provided there are no contraindications (27.6, 27.7), treat these as if they were isolated deformities. If they are all severe enough to need release, consider releasing his hip and knee first, and then his ankle. Refer him if you can.

SHORTENING [s7]IN CHRONIC POLIO Apparent shortening is due to tilting of his pelvis, as the result of an adduction or abduction deformity of his hip. True shortening is a real shortening of his leg, and in polio is due to the failure of a paralysed leg to grow.

If necessary, correct an abduction contracture of the hip, a flexion contracture of the knee, or an equinus contracture of the ankle.

If his shortening makes walking difficult (usually [mt] 4 cm), raise his short leg with a clog or with boots. If necessary, fit calipers.

DIFFICULTIES [s7]WITH CHRONIC POLIO If he BREAKS HIS FEMUR OR HIS TIBIA, fit him with a cast, use the opportunity to correct any deformity, and keep him walking. His knee and ankle are unlikely to be functional, so stiffness will not be a problem. Perkins traction (78.4) may be useful for a short period initially.