Poliomyelitis Treatment & Management

Treatment options for poliomyelitis include the following ^{[12, 20]} :

• Release of joint contractures
• Reestablishment of muscle balance around the joint to prevent deformities
• Muscle transplantation to replace a paralyzed muscle
• Stabilization of a relaxed or flail joint by means of (a) tenodesis, (b) fixation of ligaments, or (c) construction of artificial check ligaments
• Arthrodesis
• Osteotomies
• Limb lengthening, ^[21]  Ilizarov techniques ^[22]
• Joint replacement surgery

The surgeon managing the residual weakness of poliomyelitis and postpolio syndrome (PPS) must possess an understanding of the pathologic process in poliomyelitis, as well as the variations in the pattern of the disease in different parts of the body. Poliomyelitis causes a lower-motor-neuron disease unlike other types of neuromuscular paralysis. The neurologic problems and the pattern of paralysis following poliomyelitis are different from upper-motor-neuron paralysis or, indeed, lower-motor-neuron paralysis caused by other diseases.

Provocative poliomyelitis is paralysis following the administration of an intramuscular (IM) injection in children with acute viremia and indicates that (probably) muscle paralysis has been provoked by IM injections. Unnecessary injection must be avoided in children during acute viremic states, and use of the oral polio vaccine should be encouraged. ^[23]

The surgeon must have a solid knowledge of the pathoanatomy before embarking on operative treatment. The mainstay of management remains physiotherapy and orthotic appliances.

The priorities of management, as described by Watts, are as follows ^[24] :

• To get the patient walking
• In children, to correct factors that will create deformity with growth
• To correct factors that will obviate or reduce the need for an orthosis
• To correct upper-extremity problems
• To treat scoliosis 

Acute stage

In the acute stage of poliomyelitis, treatment is mainly medical, involving the pediatric physicians. General supportive treatment for the pyrexia and irritation, prevention of secondary respiratory infection, and treatment of any respiratory paralysis are the main aspects of therapy.

The paralyzed legs are supported by plaster splints or pillows and sandbags to keep the hip joints in 5° of flexion and in neutral rotation. The knee joint is held at 5° of flexion, and the foot is supported in a 90° position. Splinting relieves pain and spasm and prevents the development of deformities.

Recovery stage

Treatment in the recovery stage is mainly by the orthopedics department, involving physiotherapy and splinting.

The aims of treatment are as follows:

• To assist in the recovery of paralyzed muscles by remedial exercises
• To prevent deformities by the use of orthotic devices

An assessment is first made of the extent of muscle paralysis by charting the power of various groups of muscles and grading them according to the international nomenclature (Medical Research Council grading) as follows:

• 0 - Complete paralysis
• 1 - Slight flicker of contraction present
• 2 - Muscle can move a joint only when gravity is eliminated.
• 3 - Muscle can move a joint against gravity
• 4 - Muscle can move a joint against gravity and resistance
• 5 - Full normal power

Total functional assessment of the limbs is made before planning treatment. This will include the following:

• Charting the muscle power grades
• Extent of contractures and deformities
• Method of ambulation
• Shortening of the limb

Efficient physiotherapy is the mainstay of the management of this stage of poliomyelitis; exercise therapy, hydrotherapy, and electrical stimulation of muscles are essential in the management of paralytic polio. (See the images below.)

Orthotic management

Appropriate orthotic appliances are prescribed to prevent deformities due to muscle imbalance (see the image below).

The current international nomenclature for orthotic appliances describes the joints that are stabilized by the appliance (eg, what was once commonly referred to as a below-knee appliance is now referred to as an ankle-foot orthosis [AFO]). ^{[25, 26, 27, 28]}

When the muscles controlling the hip and knee have normal power and the weakness is only in the dorsiflexors or plantarflexors of the ankle or the invertors or evertors of the foot, the patient is prescribed an AFO (below-knee orthosis or caliper). When quadriceps power is 2 or below, the knee must be stabilized, and hence, a knee-ankle-foot orthosis (KAFO; full or above-knee caliper) is prescribed. If hip abduction power is poor (ie, < 2), the appliance will include a KAFO with a cane in hand to compensate for weak hip abductors.

In the recovery stage, a child who starts with a full appliance with a pelvic band may be able to manage gradually with a shorter appliance and ultimately may be able to discard it when the muscles fully recover as a result of intensive physiotherapy.

Residual-paralysis stage

The final aim should be for patients to return home and be accepted and integrated into their communities. Because overuse weakness is frequently present in these patients, the role of slowly progressive, nonfatiguing exercise in their rehabilitation is emphasized. New muscle weakness of a mild-to-moderate degree responds well to a nonfatiguing exercise program and pacing of activity, with rest periods to avoid muscle overuse. Generalized fatigue may be treated with energy conservation, weight-loss programs, and lower-extremity orthoses.

An orthosis is a device that externally supports an existing body part, with the objective of supporting, correcting, or compensating for skeletal deformity or weakness. There are currently many various types of orthoses, and the range of devices available to the prescriber continues to increase with the advent of new materials such as carbon fiber, as well as advances in manufacturing techniques. ^{[25, 26]}

Orthoses are available for all parts of the body and aid in conservative and definitive treatment for many deformities. The thermoplastic leaf spring AFO, or drop foot splint, is a good example of an orthosis commonly used. It assists dorsiflexion and uses three-point pressure to stabilize the ankle joint.

Hip and knee contractures greater than 30°

In general, hip and knee contractures exceeding 30° will all require surgical treatment, unless one or both arms are weak in addition to bilateral lower-limb paralysis, making the use of crutches difficult or impossible. In a young child with fairly recent contractures, the most important single factor responsible for the deformity is tightness of the tensor fasciae latae and iliotibial band. In the older child or adult, however, other ligamentous and tendinous structures play an important part and must be divided as well.

The iliotibial band contracture produces flexion deformities of the hip and knee on the same side. The Soutter release involves the soft-tissue release on the anterolateral aspect of the hip joint, whereby the tensor fasciae latae and gluteus maximus are released from their origins, as they contribute to the formation of the iliotibial band. The Yount release involves excision of the thickened anterolateral fascia lata so that the knee contracture is better corrected. (See the image below.)

The percutaneous method of division is highly satisfactory for less severe contractures, provided that it is done correctly and as extensively as necessary. Care must be taken to avoid damaging the femoral and popliteal arteries, as well as the common peroneal nerve. The biceps, however, should always be divided under direct vision because of the risk of damaging the adjacent lateral popliteal nerve.

Tendon transfer to reestablish muscle power

In the selection of a tendon to transfer, the muscle should be sufficiently strong to supplement the power of a paralyzed muscle. The nerve and blood supply of the transferred muscle should be preserved in order to avoid iatrogenic weakness.

For efficiency, the transferred tendon should be securely attached (with tension) close to the insertion of a paralyzed tendon and should be routed in a direct line between its origin and the new insertion. The transferred tendon loses its power by one grade.

The transferred tendon should also be retained in its own sheath, avoiding tunnels in fascia or bone or an interosseous membrane so as to minimize adhesions.

The joint across which the muscle acts must be in a satisfactory position; all contracted structures must be released before the tendon transfer.

When possible, an agonist muscle, with the same range of excursion of its tendon, should be chosen.

Muscle transplantation to replace paralyzed muscle

In muscle transplant procedures, unlike tendon transfer procedures, both the origin and the insertion of a muscle are detached along with its neurovascular pedicle. This procedure is not as popular as tendon transfer, because of the difficulty in finding a normal muscle to transplant, donor-side morbidity, the technical difficulty of the procedure, and the shortage of microvascular surgeons in developing nations, where residual polio is still seen.

Stabilization of relaxed or flail joint

Tenodesis, fixation of ligaments, and construction of artificial check ligaments are used to restrict the range of movement or to eliminate abnormal motion of a joint. With few exceptions, these procedures have been discarded; deformity in the opposite direction may occur, and the tendon or artificial check ligaments may stretch with time. This technique can still be helpful in skeletally immature patients.

Arthrodesis

Arthrodesis is used to correct a deformity, relieve pain in arthritic joints, and reduce the number of joints across which a weak muscle is acting. Arthrodesis is more popular than tenodesis. In skeletally immature patients, extra-articular arthrodeses can be performed, allowing continued growth of the skeleton. ^[29] (See the image below.)

Osteotomies

The osteotomy most commonly performed in this setting is a supracondylar distal femoral flexion osteotomy to correct recurvatum deformity at the knee. ^[24]

Limb lengthening

Often, poliomyelitis is unilateral, causing limb-length inequality, which occasionally requires limb lengthening. In leg lengthening for patients with poliomyelitis, callus maturation is slow, and patients tend to develop contractures despite physiotherapy, bracing, or joint fixation. Concomitant and secondary surgery are frequently required to treat associated problems or residual deformities. Lengthening along an intramedullary locked nail can significantly shorten the treatment time with relatively few complications. ^{[21, 30]}

Joint replacement surgery

In patients with postpolio residual deformities, joint replacement can be indicated. In one study, pain and knee scores improved following total knee arthroplasty (TKA) in patients with a history of poliomyelitis and antigravity quadriceps strength, but there was less pain relief in patients with less than antigravity quadriceps strength. ^{[31, 32]}

Recurrence of instability and progressive functional deterioration are possible in all knees affected by poliomyelitis that have undergone total knee replacement, but they appear to occur more commonly in more severely affected knees.

In a review of the outcome of TKA in patients with poliomyelitis, the revision rate was found to be higher. ^[33] Quadriceps power was found to be an important prognostic factor. The authors recommended the use of a constrained knee prosthesis. 

Rahman et al found TKA using a rotating hinge prosthesis to be effective in pain relief; the hinge provided stability to correct instability. ^[34]

DeDeugd et al found no problems with hip instability or loosening after total hip arthroplasty (THA) at 10-year follow-up. ^[35]  Patients with poliomyelitis undergoing THA showed similar results on the affected and unaffected sides in terms of overall survivorship and complications. 

Sonekatsu et al found no loosening or osteolysis or dislocations after THA at 8-year follow-up. ^[36]

Sobrón et al found THA to yield significant clinical improvement in patients with paretic limbs after postpolio residual paralysis. ^[37]

In a long-term study of clinical and radiologic outcomes of unconstrained THA (minimum follow-up, 84 months), Buttaro et al found that all patients improved in function and had pain relief. ^[38]

Shoulder arthroplasty has been used successfully in patients with poliomyelitis with shoulder arthritis. In a study of seven polio patients who were treated with shoulder arthroplasty (one reverse arthroplasty, two hemiarthroplasties, and four total arthroplasties), Werthel et al found it to yield pain relief and improved movement; however, radiographic instability was noted, which remained asymptomatic. ^[39]  

Ilizarov techniques

There are many drawbacks to using conventional approaches for the treatment of complex foot deformities, such as the increased risk of neurovascular injury, soft-tissue injury, and shortening of the foot. An alternative approach that can eliminate these problems is the Ilizarov method. Pin-tract problems, contractures, residual deformity, and recurrence of deformity can complicate the Ilizarov method. ^[22]

In a study involving 25 patients with knee extension and ankle dorsiflexion dysfunction who were treated with ankle arthrodesis and tibial lengthening with an external fixator followed by plating and bone grafting, Wu et al found that gait improved significantly in all patients. ^{[40, 41]} Complete bone healing was noted in all patients, with an average healing time of 4 months after plating. In a study by Kirienko et al, foot and ankle deformities in 27 patients were treated with the Ilizarov method with concomitant treatment of limb-length discrepancy; simultaneous deformity correction and limb-length equalization were achieved. ^[42]

Management of fractures in poliomyelitis patients

Survivors of polio are still present in several parts of the world. Fractures that occur in these patients can be difficult to treat because of poor bone quality and deformities. Locking plates, nails, an external fixator, or various combinations thereof can be used to treat these fractures. ^[43]  Wang et al used locking plates to treat distal femoral fractures in 19 postpolio patients and found that bony union and good function could be achieved but that delayed union and minimal callus could occur. ^[44]

Fractures in poliomyelitic patients pose several challenges in terms of implant size and fracture union. A 2020 study observed similar functional and radiologic results in comparison with nonpoliomyelitic limbs. ^[45]  

In a study of 65 patients with 74 femoral fractures,  60% of the patients did not regain their previous ambulatory capacity. ^[46] Nine patients (16%) had undergone reoperation. This paper highlighted a guarded prognosis for regaining preinjury ambulatory status. 

In a study from China, adults with polio (age >48.2 years) were shown to have a higher risk of hip fracture (adjusted hazard ratio [HR], 3.59). This finding calls for a customized hip fracture prevention program to be started early in middle age. ^[19]

Treatment of spinal deformity

Spinopelvic correction and scoliosis correction can be achieved with various techniques. In a study by Li et al, an S2-alar-iliac screw construct, when compared with the Galveston technique and iliac screw fixation, was found to be associated with a shorter operating time, reduced blood loss, and a similar degree of correction. ^[47] Patient age at the time of surgery and grade higher than 2 on the SRS-Schwab classification were significant risk factors for complications.

An individualized approach to rehabilitation management is critical in patients with PPS. Interventions may include rehabilitation management strategies, adaptive equipment, orthotic equipment, gait/mobility aids, and a variety of therapeutic exercises. The progression of muscle weakness in PPS is typically slow and gradual; however, there is also variability in both the natural history of weakness and the functional prognosis. ^[48]

Many patients with PPS require revision of orthotic devices such as braces, canes, and crutches or may use new, lighter orthotic devices to treat new symptoms. Common issues include genu recurvatum, knee pain, back pain, degenerative arthritis, or arthralgia. Surgery for scoliosis or fractures may also be necessary to treat new conditions. ^{[15, 49]}

Nonsurgical treatments for PPS were examined in a 2015 Cochrane review by Koopman et al. ^[50] The reviewers concluded that intravenous (IV) immunoglobulin (IVIg), Iamotrigine, muscle-strengthening exercises and static magnetic fields may be beneficial but that at present, it is impossible to draw definite conclusions about their effectiveness.

Mortality due to postpolio syndrome

With the exception of poliomyelitis patients with respiratory failure, long-term mortality following poliomyelitis appears to increase 20 years after recovery from the acute illness. ^[51]  Contracting severe paralytic poliomyelitis at a young age seems to increase long-term mortality.

Spinal deformity

Polio and PPS can result in paralytic spinal deformity. Godzik et al found that surgery had a high complication rate but also noted significant improvement in outcome scores. ^[52]