Post-Polio Limb Deformity and Shortening: When to Operate, and When Not To

India has been polio-free since 2014, but many adults who had polio in childhood still live with a weak, short or deformed leg. Some have managed for decades with a stick, a hand pressed on the thigh or a heavy caliper. Reconstruction can often make walking easier, reduce the need for a brace or improve fit and appearance – but in polio, operating on the wrong thing can make walking worse. Careful evaluation is everything.

Why polio limbs deform

Polio destroys the nerve cells that control certain muscles while leaving sensation intact. Unbalanced muscles pull joints into fixed positions as the child grows, and a weak leg grows less, so it ends up shorter. Common problems include:

• Hip: flexion–abduction–external rotation contracture
• Knee: flexion contracture, or the opposite – back-knee (genu recurvatum) – and valgus
• Leg: external tibial torsion
• Foot: equinus, cavovarus, calcaneus or flail foot
• Limb length difference of varying degree
• Thin, osteoporotic bone and weak or absent muscles

Evaluation protocol

1. Detailed muscle charting – the strength of every muscle group (graded 0 to 5), especially the quadriceps, hip extensors and abductors, and ankle muscles
2. Gait analysis – how the patient actually stabilises the knee and hip while walking
3. Contractures measured at hip, knee and ankle
4. Full-length standing X-rays with blocks to measure leg-length difference; foot X-rays
5. Spine and pelvis assessment (scoliosis, pelvic obliquity)
6. Bone quality and general health, including breathing capacity
7. Screening for post-polio syndrome – new fatigue, weakness or pain decades later
8. The patient's goals, work, current brace and how much they depend on it

The golden rule: understand the compensations

Many polio patients walk by using a deformity to their advantage:

• Weak quadriceps are often compensated by a slightly pointed foot (equinus) or a back-knee, which locks the knee straight. Fully correcting the equinus, or the recurvatum, can remove that lock and make the knee buckle.
• A hand pushing on the thigh is doing the quadriceps' job.
• A mild limb shortening can help a weak leg swing through.

So the question is never only "what is deformed?" but "what is this deformity doing for the patient?"

When surgery helps

• Fixed contractures that prevent standing straight or brace fitting
• Severe deformity or significant shortening limiting walking, with enough muscle power to use the corrected limb
• Foot deformities causing pain, callus or instability
• Patients who wish to reduce dependence on a caliper, where muscle strength makes this realistic

When not to operate

• When correction would remove a compensation the patient relies on, without a plan to replace it (for example, an orthosis)
• When muscle power is too weak to benefit from a straighter or longer leg
• In active post-polio syndrome or poor general health
• When expectations cannot be met, or the patient cannot complete a long treatment and rehabilitation

Sometimes the best advice is a better orthosis or shoe raise rather than surgery.

Surgical options

Soft-tissue release and tendon procedures. Contracture releases at hip, knee and ankle; tendon lengthening; and tendon transfers that move a working muscle to replace a paralysed one (only useful if the donor muscle is strong enough).

Bone correction (osteotomy). Supracondylar femoral osteotomy for knee flexion or valgus; tibial osteotomy for torsion and recurvatum; foot osteotomies or fusion (such as triple arthrodesis) for a stable plantigrade foot.

Gradual correction with the Ilizarov method or a hexapod frame. Ideal for multi-plane deformities, stiff knees and fragile soft tissues, because correction is slow and adjustable. A hexapod (computer-guided) frame is useful for complex combined deformities.

Limb lengthening. Shortening can be corrected with:

• A frame alone (Ilizarov or hexapod)
• Lengthening over a nail (LON) – shorter frame time
• Lengthening and then plating (LAP) – the frame is removed early and a plate holds the bone
• Combined deformity correction and lengthening in one stage

Polio bone is often thin, so implant choice and protection of the new bone need care, and knee and ankle stiffness must be prevented with daily physiotherapy. Lengthening is often combined with correcting the knee or foot so that the patient gains both length and stability.

After surgery

Rehabilitation is long and essential: physiotherapy, gait training, and often a lighter orthosis than before. The patient and family must be ready for months of follow-up.

Realistic goals

The aims are a straighter, more stable and better-balanced limb, easier walking, less dependence on hand support, a lighter brace or none, and better footwear. Paralysed muscles cannot be restored, and every plan is built around the muscles that work.

For doctors: Please refer with a muscle chart, standing full-length radiographs with leg-length measurement, and a short walking video. These three things decide most of the plan.