Foot Drop Dr. Ravikiran Chairpersons : Dr. Rupakumar .C.S. 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 compartments Anterior ( Extensor) compartment Lateral ( Peroneal ) compartment Posterior ( Flexor ) compartment

Extensor compartment

Lateral Compartment :

Posterior Compartment :

Common Peroneal Nerve Half size of tibial nerve L4,5,S1,2 Enters leg antero- laterally Branches

Sup Peroneal Nerve Superficial fibular N Deep to peroneus Longus then passes Anteroinf b/w peroneus longus and EDL

Deep peroneal Nerve Oblique forward deep to EDL to front of interosseus membrane and reaches Ant.Tibial artery in proximal 1/3 Branches

Etiology : Neuromuscular disease Peroneal Nerve Sciatic Nerve Lumbosacral plexus L5 Nerve root Spinal 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 dislocations # / dislocation head / neck of fibula Dislocation of Sup. Tibiofibular jt Dislocation of knee Compound # upper 1/3 tibia

Pathogenic High skeletal tibial traction Tight plaster around knee joint High tibial osteotomy Total knee replacement Others Lat 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 inj At the spine : IVDP,Spina bifida, tumours

Infective : Leprosy,poliomyelitis, GBS, Syphillis Metabolic : DM,Beri beri, Alcoholic neuritis Exogenous toxin : Lead, arsenic, mercury.

Classification : Seddon : Neurapraxia Axontemesis Neurotemesis

Sunderland

Signs and Symptoms : Weakness of dorsiflexion and eversion of foot High 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 Examination Signs of motor denervation : Paralysis, loss of tone, areflexia, Insensibility to compression, atrophy Signs of Autonomic denervation Loss of sweating Vasomotor Loss of hair Trophic ulceration

Diagnostic tests : Nerve conduction velocity

Electromyography

Autonomic tests Sweat test : Presence of sweat within autonomous zone indicates that complete denervation has not occurred. Wrinkle test Skin resistance test : Increased resistance to passage of electric current

Assessment of recovery : Tinels sign Motor recovery M0- No contraction M1- Return of contraction in proximal gp M2 – Proximal gp + Distal gp M3- Muscles can act against resistance M4 – All synergistic independent movts possible M5- Complete recovery

Sensory recovery S0- Absence of sensibility in autonomous area S1- Recovery of deep cutaneous pain S2- Superficial cutaneous pain + Tactile sensibility ( some degree ) S3- Throughout autonomous area S3+ - Recovery of 2-point discrimination S4- Complete recovery

Management Conservative Aim : Prevention of deformity and improvement of gait. Proper positioning of foot splints Passive movements of joints Electrical stimulation of muscles Ankle foot orthosis

AFO Functions : Provide toe dorsiflexion during swing phase Medial and lateral stability at ankle during stance Push off stimulation during late stance Dynamic or static

Surgical management Neurorrhaphy Tendon transfers Bony operations Choice of surgical correction depends on Mobility of joints Soft tissue and muscle contractures Availability of muscles and tendons for transfer Bony changes Age

Neurorrhaphy Indications Clean and sharply incised nerve injury Contaminated and nerve transection with ragged ends Nerve injury following blunt trauma or closed fractures Following closed reduction or manipulation of fracture

Techniques Epineural neurorrhaphy Perineural neurorrhaphy Epiperineural neurorrhaphy Interfascicular nervegrafting

Epineural Neurorrhaphy Gap can be closed end to end Without excessive tension

Perineural Neurorrhaphy

Tendon transfers When joints are mobile and muscles and tendons are available for transfer Objectives To provide active motor power to replace function of paralysed muscle To eliminate deforming force when antagonist is paralysed To improve stability by improving muscle balance

Principles of tendon transfer The muscle to be transferred should be healthy Muscle strength should be grade 4-5 Free range of movement in joint Any bony deformity should be corrected It is desirable to use synergistic muscle as it is easier to rehabilitate

Joints proximal to parts to be moved should be stabilised by tendon action Tendon must be attached under moderate tension If tendon is split, tension must be equal at all points Nerve and blood supply must not be impaired

ober’s Technique

Barr technique Make 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 trasfer Two tailed transfer of tibialis posterior The 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 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 tendoachilles White technique Use 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 Medial cut at the insertion of the tendon onto the calcaneus, through one half of the width of the tendon. Make the second tenotomy proximally and medially, just below the musculotendinous junction. Make the third laterally through half the width of the tendon midway between the two medial cuts.

Bony operations When joints are stiff with muscle and soft tissue contractures and bony changes ( fixed deformities) Lambrinudi arthrodesis Triple arthrodesis

Lambrinudi arthrodesis

Lambrinudi arthrodesis Recommended 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

Technique With 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.

Complications Ankle instability Residual varus or valgus deformities caused by muscle imbalance Pseudarthrosis of the talonavicular joint.

Triple arthrodesis The 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.

Indications To obtain stable and static realignment of the foot To remove deforming forces To arrest progression of deformity To eliminate pain 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 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 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.

Aftertreatment Walking 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.

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