Foot Drop

Chairpersons : Dr. Rupakumar .C.S. Dr. Ravikiran

Presented by : Dr. Syed Imran

Definition : Inability to actively dorsiflex and evert the foot.

Introduction : Foot drop is a condition where the propulsion is partially impaired due to changes in gait.

Anatomy of leg :Two muscular septa divide leg

into three compartmentsAnterior ( Extensor) compartmentLateral ( Peroneal ) compartmentPosterior ( Flexor ) compartment

Extensor compartment

Lateral Compartment :

Posterior Compartment :

Common Peroneal NerveHalf size of tibial nerveL4,5,S1,2Enters leg antero- laterally• Branches

Sup Peroneal NerveSuperficial fibular NDeep to peroneus Longus then passes Anteroinf b/w peroneus longus and EDL

Deep peroneal NerveOblique forward deep to EDL to

front of interosseus membrane and reaches Ant.Tibial artery in proximal 1/3

Branches

Etiology :Neuromuscular diseasePeroneal NerveSciatic NerveLumbosacral plexusL5 Nerve rootSpinal cord ( poliomyelitis, tumour )Brain ( Stroke, TIA )Genetic ( CMT )Non-organic

Traumatic : Extensor and peroneal tendon injuries

Neurogenic 1. At level of common peroneal N• Direct injuries • Fractures and dislocations1. # / dislocation head / neck of fibula2. Dislocation of Sup. Tibiofibular jt3. Dislocation of knee4. Compound # upper 1/3 tibia

Pathogenic1. High skeletal tibial traction2. Tight plaster around knee joint3. High tibial osteotomy4. Total knee replacementOthersLat meniscal

cysts,Exostosis,Tumour of head of fibula

Above level of Common Peroneal N

At the thigh : # shaft femur, penetrating injuries

At the hip : Post dislocation of hip,# hip

At the gluteal region : Deep im injAt the spine : IVDP,Spina bifida,

tumours

Infective : Leprosy,poliomyelitis, GBS, Syphillis

Metabolic : DM,Beri beri, Alcoholic neuritis

Exogenous toxin : Lead, arsenic, mercury.

Classification :Seddon :1. Neurapraxia2. Axontemesis3. Neurotemesis

Sunderland

Signs and Symptoms :Weakness of dorsiflexion and

eversion of footHigh stepping gait : Foot slap

followed by heel strike, toe drag during swing phase,increased hip and knee flexion

Sensory loss

Autonomous Zone of Common peroneal N

Clinical ExaminationSigns of motor denervation :

Paralysis, loss of tone, areflexia, Insensibility to compression, atrophy

Signs of Autonomic denervation 1. Loss of sweating2. Vasomotor 3. Loss of hair4. Trophic ulceration

Diagnostic tests :Nerve conduction velocity

Electromyography

Autonomic testsSweat test : Presence of sweat

within autonomous zone indicates that complete denervation has not occurred.

Wrinkle testSkin resistance test : Increased

resistance to passage of electric current

Assessment of recovery :Tinels signMotor recoveryM0- No contractionM1- Return of contraction in proximal

gpM2 – Proximal gp + Distal gpM3- Muscles can act against resistanceM4 – All synergistic independent movts

possibleM5- Complete recovery

Sensory recoveryS0- Absence of sensibility in

autonomous areaS1- Recovery of deep cutaneous painS2- Superficial cutaneous pain +

Tactile sensibility ( some degree )S3- Throughout autonomous areaS3+ - Recovery of 2-point

discriminationS4- Complete recovery

ManagementConservativeAim : Prevention of deformity and

improvement of gait.1. Proper positioning of foot splints2. Passive movements of joints3. Electrical stimulation of muscles4. Ankle foot orthosis

AFOFunctions :1. Provide toe dorsiflexion during

swing phase2. Medial and lateral stability at

ankle during stance3. Push off stimulation during late

stance• Dynamic or static

Surgical managementNeurorrhaphyTendon transfersBony operations Choice of surgical correction depends on1. Mobility of joints2. Soft tissue and muscle contractures3. Availability of muscles and tendons for

transfer4. Bony changes5. Age

NeurorrhaphyIndications1. Clean and sharply incised nerve

injury2. Contaminated and nerve

transection with ragged ends3. Nerve injury following blunt

trauma or closed fractures4. Following closed reduction or

manipulation of fracture

TechniquesEpineural neurorrhaphyPerineural neurorrhaphyEpiperineural neurorrhaphyInterfascicular nervegrafting

Epineural NeurorrhaphyGap can be closed end to end Without excessive tension

Perineural Neurorrhaphy

Tendon transfersWhen joints are mobile and

muscles and tendons are available for transfer

Objectives1. To provide active motor power

to replace function of paralysed muscle

2. To eliminate deforming force when antagonist is paralysed

3. To improve stability by improving muscle balance

Principles of tendon transfer1. The muscle to be transferred

should be healthy2. Muscle strength should be grade 4-

53. Free range of movement in joint4. Any bony deformity should be

corrected5. It is desirable to use synergistic

muscle as it is easier to rehabilitate

6. Joints proximal to parts to be moved should be stabilised by tendon action

7. Tendon must be attached under moderate tension

8. If tendon is split, tension must be equal at all points

9. Nerve and blood supply must not be impaired

OBER’S TECHNIQUE

Barr techniqueMake a skin incision on medial

side of ankle from insertion of tibialis posterior and post to malleolus proximally along medial border of tibia.

Split the sheath in a proximal direction until distal 5cm of muscle is mobilised.

Make second incision anteriorly beginning distally at level of ankle joint extending laterally to tibialis ant tendon .

The dissection should be between tendons of tibialis anterior and EHL preserving dorsalis pedis artery.

Make a generous window in interosseus membrane pass tibialis posterior tendon through window between bones.

Expose third cuneiform or base of third metatarsal,incise periosteum drill a hole large enough to receive tendon and anchor in bone with a wire

Two-tailed trasferTwo tailed transfer of tibialis posteriorThe tendon of tibialis posterior is

identified through a small incision over the tuberosity of the navicular bone.

The tendon is then detached from its insertion and its synovial attachments are divided.

.

five-centimetre longitudinal incision is made in the lower part of the leg close to the medial border of the tibia, about ten centimetres above the medial malleolus. The tendon of tibialis posterior is identified and pulled out.

The tendon is then split longitudinally into two “ tails “ up to the point where it will cross the tibia proximally.

Two transverse incisions are made on the dorsum of the foot, one over the extensor hallucis longus tendon and the other more laterally, over the tendons ofthe extensor digitorum longus.

A tendon tunneller (Andersen’s tunneller) is passed from the wounds in the dorsum to the wound in the leg. The tunnels are made subcutaneously.

Two separate tunnels are made for the two “ tails “ of the motor tendon.

The motor slips are pulled through. One is implanted in the tendon ofextensor hallucis longus and the other in the tendons of extensor digitorum longus.

During this stage the knee is held in flexion of about 30 degrees and the ankle in dorsiflexion of at least 10 degrees.

After operation a below-knee plaster is applied, with the foot further dorsiflexed to release any tension on the tendon sutures during healing.

Six weeks after operation the patient is started on walking training. On the average the patient needs another two weeks to learn to walk normally.

Lengthening of tendoachillesWhite techniqueUse a posteromedial incision to expose the

Achilles tendon from its insertion to approximately 10 cm proximally, preserving the sheath

Divide the posteromedial two thirds of the tendon near its insertion.

Apply a moderate dorsiflexion force to the foot, and divide the medial two thirds of the tendon approximately 5 to 8 cm proximal to the site of the distal division.  

Dorsiflex the foot so that the tendon lengthens to the desired length

Carefully close the tendon sheath and subcutaneous tissues to prevent adherence of the tendon to the overlying skin.

Apply a short leg cast with the ankle in maximal dorsiflexion.

White technique

Z-Plasty

     

Percutaneous lengthening

Percutaneous lengthening

1. Medial cut at the insertion of the tendon onto the calcaneus, through one half of the width of the tendon.

2. Make the second tenotomy proximally and medially, just below the musculotendinous junction.

3. Make the third laterally through half the width of the tendon midway between the two medial cuts.

Bony operationsWhen joints are stiff with muscle

and soft tissue contractures and bony changes ( fixed deformities)

Lambrinudi arthrodesisTriple arthrodesis

Lambrinudi arthrodesis

Lambrinudi arthrodesisRecommended for correction of

isolated fixed equinus deformity in patients older than 10 years.

Retained activity in the gastrocnemius-soleus, combined with inactive dorsiflexors and peroneals, causes the footdrop deformity.

The posterior talus abuts the undersurface of the tibia, and the posterior ankle joint capsule contracts to create a fixed equinus deformity

In the Lambrinudi procedure, a wedge of bone is removed from the plantar distal part of the talus so that the talus remains in complete equinus at the ankle joint, while the remainder of the foot is repositioned to the desired degree of plantar flexion

The Lambrinudi arthrodesis is not recommended for a flail foot or when hip or knee instability requires a brace

A good result depends on the strength of the dorsal ankle ligaments

TechniqueWith the foot and ankle in extreme

plantar flexion, make a lateral radiograph, and trace the film.

Cut the tracing into three pieces along the outlines of the subtalar and midtarsal joints; from these pieces, the exact amount of bone to be removed from the talus can be determined with accuracy before surgery.

Expose the sinus tarsi through a long lateral curved incision.

Section the peroneal tendons by a Z-shaped cut, open the talonavicular and calcaneocuboid joints, and divide the interosseous and fibular collateral ligaments of the ankle to permit complete medial dislocation of the tarsus at the subtalar joint.

With a small power saw (more accurate than a chisel or osteotome), remove the predetermined wedge of bone from the plantar and distal parts of the neck and body of the talus. Remove the cartilage and bone from the superior surface of the calcaneus to form a plane parallel with the longitudinal axis of the foot.

Make a V-shaped trough transversely in the inferior part of the proximal navicular and denude the calcaneocuboid joint of enough bone to correct any lateral deformity.

Firmly wedge the sharp distal margin of the remaining part of the talus into the prepared trough in the navicular, and appose the calcaneus and talus.

Insert smooth Kirschner wires for fixation of the talonavicular and calcaneocuboid joints.

Suture the peroneal tendons, close the wound in the routine manner, and apply a cast with the ankle in neutral or slight dorsiflexion.

ComplicationsAnkle instability Residual varus or valgus

deformities caused by muscle imbalance

Pseudarthrosis of the talonavicular joint.

Triple arthrodesisThe most effective stabilizing

procedure in the foot is triple arthrodesis fusion of the subtalar, calcaneocuboid, and talonavicular joints

Triple arthrodesis limits motion of the foot and ankle to plantar flexion and dorsiflexion.

Indications1. To obtain stable and static realignment of the

foot 2. To remove deforming forces3. To arrest progression of deformity 4. To eliminate pain 5. To eliminate the use of a short leg brace or to

provide sufficient correction to allow fitting of a long leg brace to control the knee joint

6. To obtain a more normal-appearing foot. Generally, triple arthrodesis is reserved for severe deformity in children 12 years old and older; occasionally, it may be required in children 8 to 12 years old with progressive, uncontrollable deformity.

Make an oblique incision centered over the sinus tarsi in line with the skin creases on the lateral side of the foot, beginning dorsolaterally at the lateral border of the tendons of the long toe extensors at the level of the talonavicular joint

Continue the incision posteriorly, angling plantarward and ending at the level of the peroneal tendons. Carefully protect the extensor and peroneal tendons, and carry the incision sharply down through the sinus tarsi to the extensor digitorum brevis muscle

Incise the capsules of the talonavicular, calcaneocuboid, and subtalar joints circumferentially to obtain as much mobility as possible. If this release allows the foot to be placed in a normal position, removal of large bony wedges is not required. If correction is impossible after soft-tissue release, appropriate bony wedges are removed

Cut the removed bone into small pieces to be used for bone grafting. Place most of the bone graft around the talonavicular joint and in the depth of the sinus tarsi.

Correction is maintained with internal fixation, usually smooth Steinmann pins or Kirschner wires.

Close the muscle pedicle of the extensor digitorum brevis over the sinus tarsi to reduce the dead space.

Close the wound over a suction drain, and apply a well-padded, short leg cast.

AftertreatmentWalking with crutches or a

walker, with touch-down weight bearing on the operated foot, is allowed as tolerated. The cast and pins or wires are removed at 6 to 8 weeks, and a short leg walking cast is applied and worn until union is complete, usually 4 weeks more.

Thank You