Case study

Sunil 23 yrs male

h/o trauma to his rt knee 1 yr back Work site injury Trauma with heavy cutting machine Rushed to hospital with in 1 hour Mild contamination of wound present Difficulty in using the limb from very

beginning on wards

Surgical intervention with in 6 hours of the injury

Post op immobilized on pop Moderate wound infection post op Discharged after 2 weeks Pop removed after 6 weeks After that on AFO

Wounds fully heald Parasthesia of antero lateral aspect of foot

and leg Mild improvement in sensory symtoms but

not much improvement in power of the leg

No history of diabetes mellitus, skin diseases or any history suggestive of immuno supressed status

Patients history does not give any points in favour of long bone fractures

Local examination[knee,foot,ankle and leg]

Gait –high stepping Foot drop present Wasting of leg muscles Trophic changes of the skin and nails

Heald surgical scar on the lateral aspect of knee exending about 3 cm above the upper pole of patellae to about 5cm below the head of fibula

On palpation scar is not adhered to the deeper tissue

Fibula head –mild thickening present Other bony areas palpated normally

No abnormal thickenings of the peroneal nerve at the fibular neck level

Tinnel sign postive 5cm below the fibular head Passive movements of the knee and ankle are of full

range Active dorsiflexion and eversion of the foot is absent No limb length discrepansy No knee joint instability

B/l hip, b/l knee, opposite foot and ankle ,spine all with in normal limits

No abnormal thickening of nerves palpated any where in the body

Neurology

Tone-decreased Bulk- decreased[3cm wasting] Power-TA,EDL,EHL,PERONEI,-GRADE 0 or

grade 1 DTR-Knee present,ankle absent Sensory blunting over the anero latral aspect

of foot and leg Sensory bluntig over the first web space also

Blood investigations with in normal limits NCS-severe proneal nerve injury below the

neck of fibula No evoked response of the anterior and

lateral muscle groups on stimulation Faradic stimulation produce no response Galvanic stimulation –twitching of the muscle

groups present

Diagnosis ???

Foot drop

Anatomy of sciatic nerve

Thickest nerve on the body Root value L4,5S123 Thru gret sciatic notch –middle thigh divide to

common peroneal and tibial part- Cpn –lateral angle of the popliteal fosae-neck

of th efibula-superficial and deep part Superficial-pronei muscles and skin over the

antero lateral front of leg dorsum of the foot

Deep-anterior compartment muscles,--medial and lateral terminal branch

Medial -1st web space Lateral-end as a ganglion after supplying Ext

dig brevis and 2nd dorsal interossei

Tibial part –posterior compartment,cutaneous distribution of the entire sole of the foot

Causes of foot drop

General –leprosy Local –spine-bifida,tumrs,disc prolapse Hip –posterior dislocation ,# around hip,#of

acetabulam,THR[.5 to 3%]` Gluteal region-IM injections Thigh -#sof,penetrating and gun shot injury

Knee –forcible inversion of the knee Dislocation of the knee # lateral condyle of tibia Dislocation of superior tibiofibular joint Tight plaster around the knee Poor padding during traction UT skeletal traction Tumours and cysts Direct injury-gun shot,incised or penetrating

High lesion

Both tibial and C P N paralysed

Low lesion

Complete or incoplete Complete-anterolaterl muscles of the leg

sensory loss including first web space Incomplete-pronei are paralysed sensory

loss of outer leg and foot OR vice versa

Discussion !!!!!!

Nerve repair

End to end repair Autologous interfascicular nerve grafting –

Ideal• Mobilization and end to end neuroraphy even

up to 12cm gap is possible

splintage -knee in 20* flexion,ankle in 90*for night time

Day time –foot drop apliances=-dynamic[spring shoe]static[back stop shoe]

Great care should be given to avoid injuries to the insensitive skin and to prevent trophic ulcers

-

.>1 year—established foot drop

Complete foot drop-OBER/BARR PROCEDURE

Incomplete –[commonest] loss of dorsiflexors and presence of evertors---combined tib poster and pero brevis anerior transposition

Other surgeries may be used

Tendo achillis lengthening –fixed equinus Sub talar stabilization-fixed varus Triple arthrodesis –fixed varus at sub talar

joint Amputation may be prefered to a flail

deformed insensitive skin

Points to be remembered

CPN-most vulnerable nerve for traction stress

Between two bony points –fibula and pelvis-no soft tissue structures effectively protect the nenve from traction

```

After repair long leg cast is not enough Line of sutures often seprtate unless a spica

cast is given Motor recovery is far more important than

sensory recovery bcos the autonomous zone on dorsum of foot is very small

Even in very ideal setups recovery is only up to 60 to 70 %

A 2nd operation to resuture the nerve after initial failure to obtain motor recovery is rarely indicated

Useful motor function in the personal nerd is not to be expected when suture has been delayed 12 months after the initial surgery`

Your contributions!!!!!!!!!!!!

Thanks to all

Dr Mthew K M