Foot drop

General overview of Foot drop

1. COURSE OF COMMON PERONEAL NERVE FOOT DROP AND it's management Dr. Manas Kanti Sarkar. 2 nd yr. PGT BMCH

2. ANATOMY OF COMMON PERRONEAL NERVE LUMBO SACRAL PLEXUS [VENTRAL RAMI OF (L1 –S3) IN LOWER LIMB.] SCIATIC NERVE(WIDEST 2 cm in diameter ) 1)TIBIAL – VENTRAL BRANCH (L4-S3) 2)COMMON PERONEAL-DORSAL BR.(L4-S2) SUPERFICIAL DEEP BOTH HAVE TERMINATING MEDIAL LATERAL DIVISIN

3. COURSE Smaller terminal br. Of sciatic nerve conveys fibres from dorsal branch of ventral rami. IN POPLITTEAL FOSSA Nv. enter the fossa beneath long head of biceps femoris and slopes down laterally along the medial margin of biceps tendon. At the lateral angle of the popliteal fossa it crosses superficial to plantaris, lat. Head of gastrocnemius and on reaching the back it rests on the fleshy sheet of soleus(where it can be rolled against bone) Finally nerve curves forward on the lateral side of neck of fibula deep to peroneus longus tendon divided into 2 terminal branches- i ) superficial & ii)deep. BRANCHES- A) CUTANEOS- *LATERAL CUTANEOU S NERVE OF CALF. *SURAL COMMUNICATING. B)ARTICULAR- 3 branches *SUPERIOR LATERAL GENICULAR *INFERIOR LATERAL GENICULAR * RECURRENT GENICULAR.

4. *** SUPERFICIAL PERONEAL NERVE*** ARISE FROM- Superficial division of common peroneal nerve on the lat. Side of neck of fibula. COURSE- Initially deep to peroneus longus & passes downward between peroneus longus and brevis(supplies both muscles) &pierce the deep fascia behind the ant. Inter muscular septum at the jn. b/n upper two third and lower third and divide into med. & lat. Br above the ankle joint & appear on the dorsum of foot. BRANCHES – Muscular (peroneus longus and Brevis) cutaneous

5. ***DEEP PERONEAL NERVE*** COURSE- After winding round the neck of fibula pierces the ant inter muscular septum appear in the ant extensor compartment Deep to EDL & superficial to IOM. $In prox. third –intervenes TA EDL. $In middle third TA . EHL $In distal third EHL& EDL

6. BRANCHES OF DEEP PERONEAL NERVE: MUSCULAR: All four muscles of ant crural compartment- TIBIALIS ANT. EHL EDL PERONEUS TERTIUS. ARTICULR: ANKLE JOINT

7. NERVE SUPPLY OF DORSUM OF FOOT

8. FOOT DROP- PARALYSIS OF MUSCLES OF EXTENSOR AND PERONEAL COMPARTMENT CAUSES PLANTIFLEXION AND INVERSION OF FOOT ALONG WITH CERTAIN DEGREE OF FLATTENING OF LONGITUDINAL ARCH, WHICH IS NORMALLY MAINTAINED SOME EXTENT BY TIBIALIS ANTERIOR AND PERONEUS LONGUS. FOOT BEING ELEVATED TO ALLOW THE DROPPED TOES TO CLEAR THE GROUND,SO THE PATIENT WALKS IN A HIGH STEPPING GAIT.

9. Causes Injury to the peroneal nerve 1. Fracture head ,neck of fibula. 2. prolonged external pressure as application of tight plaster cast. 3 . severe varus injuries of knee.( injury of postero lateral corner of knee) 4. surgical procedure like – HTO. KNEE PROSTHESIS. 5 . knee dislocation. 6.weight loss. 7. sports specific nerve entrapment in runners. SCIATIC NERVE INJURY CAUSING COMMON PERONEAL NERVE PALSY 1. fracture dislocation of hip. 2.penetrating injury in the proximal buttock. 3.shaft femur fracture. 4.Hip exposure.

10. Neurological conditions that can contribute to foot drop include: stroke multiple sclerosis (MS) cerebral palsy Charcot-Marie-Tooth disease Conditions that cause the muscles to progressively weaken or deteriorate may cause foot drop: muscular dystrophy amyotrophic lateral sclerosis (Lou Gehrig’s disease) polio

11. Rupture of Anterior Tibialis Compartment Syndrome Diabetes Alcohol Abuse

12. Vulnerability of Peroneal Nerve Anatomy around the neck of fibula implicated as the main reason for susceptibility nerve injury – fibular tunnel formed by peroneus longus blending with crural fascia anteriorly & posteriorly with fibular neck and soleus muscle. Dynamic contraction of these muscles causes repeatative stretching of nv. Funiculi of the peroneal nerve - larger and less connective tissue Fewer autonomic fibers, so in any injury, motor and sensory fibers bear the brunt of the trauma. More superficial course, especially at the fibular neck

13. MUSCLES in MAINTAING NEUTRAL POSITION OF FOOT. DORSIFLEXORS TIBIALIS ANTERIOR EXTENSOR HALLUCIS LONGUS EXTENSOR DIGITORUM LONGUS PERONEUS TERTIUS EVERTORS PERONEUS LONGUS PERONEUS BREVIS

14. SYMPTOMS Difficulty in lifting the foot. Pain, weakness numbness along the distribution of nerve.

15. SIGN INS- EQUINOUS DEFORMITY , CLAWING OF TOES , WASTING OF MUSCLES. MOTOR- INABILITY TO DORSIFLEX THE FOOT AND TOES SENSORY LOSS- LATERAL ASPECT OF LEG AND DORSUM OF FOOT.

16. GAIT CYCLE Swing phase (SW): The period of time when the foot is not in contact with the ground. In those cases where the foot never leaves the ground (foot drag) - phase when all portions of the foot are in forward motion. Initial contact (IC): when the foot initially makes contact with the ground; represents beginning of the stance phase - foot strike. Terminal contact (TC): when the foot leaves the ground - end of the stance phase or beginning of the swing phase - foot off. .

17. FOOT DROP Drop foot SW: Greater flexion at the knee to accommodate the inability to dorsiflex - stair climbing movement. Drop foot IC: Instead of normal heel-toe foot strike, foot may either slap the ground or the entire foot may be planted on the ground all at once. Drop foot TC: Terminal contact is quite different - inability to support their body weight – walker can be used

18. IMAGING X-Ray : Post-Traumatic - tibia/fibula and ankle - any bony injury. Anatomic dysfunction (eg . Charcot joint) High resolution Ultrasonography : Helpful in diagnosing masses around peroneal nerve Additional advantage of allowing for dynmic examination with muscle contraction, joint motion and palpation of tender area. Magnetic Resonance: to detect Tumor or a compressive mass lesion to the peroneal nerve.

19. Electromyogram This study can confirm the type of neuropathy, establish the site of the lesion, estimate extent of injury, and provide a prognosis. Sequential studies are useful to monitor recovery of acute lesions.

20. TREATMENT Depends on the underlying cause. If cause is successfully treated foot drop may improve or even disappear. Medical treatment - Painful Paresthesia Sympathetic block A mitriptyline Nortriptyline Pregabalin

21. SPECIFIC TREATMENT Braces or splint Brace on the ankle and foot or splint that fits into the shoe can help to hold the foot in the normal position

22. Physical Therapy Exercises that strengthen the leg muscles M aintain the range of motion in knee and ankle Improve gait problems associated with foot drop.

23. Nerve Stimulation S timulating the nerve (peroneal nerve) improves foot drop especially if it caused by a stroke.

24. SURGICAL REPAIR When nerve insult is the cause - restore the nerve continuity – by Autogenous interfascicular nerve grafting is the preferred technique for bridging the gap. MINIMUM GAP CAN BE SUTURED- SCIATIC NERVE 15CM & CPN 12CM. INDICATION - If failing to show any clinical and electrophysiological evidence of recovery 3 months or more after the injury: CRITICAL LIMIT OF DELAY- SCIATIC NOT >(12-15)& CPN NOT>12 MONTHS. In the mean time patient is put on a foot drop splint or srung caliper to improve the gait. AFTER CARE- Hip spica 6 wks (suture removal after 10 days) Hinged knee brace 6wks physiotherapy and exercises.

25. WHEN THE NERVE DOES NOT RECOVER AND FUNCTION IS SUFFICICINTLY IMPAIRED 1.BARR procedure(1947); Tendon tibialis posterior is freed from its insertion and transferred through IOM and insertion of tendon on medial cuneiform on the dorsum of foot. it is necessary to stabilize the hind foot by triple arthrodesis. advantage Provide active dorsiflexion of ankle joint and improve gait.

26. 2.SRINIVASAN et al (1968) Distal end of Tibialis posterior tendon is splitted into 2 halves one half inserting to EHL other half to EDL & peroneus brevis with ankle held in ankle held in 10 degree of dorsiflexion knee in 30 degree flexion . they also recommend TENDO ACHILLIS lengthening by Z plasty . Walking commenced at 6 weeks. After cast removal.

27. Neurotendinous transposition Lateral head of gastrocnemius is transposed to the tendons of the anterior muscle group with simultaneous transposition of the proximal end of deep peroneal nerve. The nerve is sutured to the motor nerve of the gartrocnemius .

28. N.B.- AFTER TENDON TRANSFER Cast and Non-Weight Bearing ambulation for 6 weeks PHYSIOTHERAPY To correct gait abnormalities CHRONIC AND CONTRACTURE CASES Achilles tendon lengthening In patients whom foot drop is due to neurologic and anatomic factors (polio, Charcot joint ) - Arthrodesis Subtalar Stabilizing procedure or Triple Arthrodesis can be done.

29. COMPLICATIONS Surgical procedure- wound infection may occur. Nerve graft failure In tendon transfer procedures- recurrent deformity In arthrodesis or fusion procedures- pseudoarthrosis , delayed union, or nonunion.

30. Thank you