Approach to paralytic hand IOM Peripheral Nerve

Paralytic Hand

1. Approach to paralytic hand Presenter : Anjan Dhoj Lama Moderator : Dr Nischal Ghimire

2. Contents Principle of tendon transfer Radial nerve palsy Ulnar nerve palsy Median nerve palsy

3. Principle of tendon transfer Definition : tendon of a functioning muscle is detached from its insertion and reattached to another tendon or bone to replace the function of a paralysed muscle or injured tendon. The transferred tendon remains attached to the parent muscle with an intact neurovascular pedicle. Aim : restore the functional motion of the hand , not just a movement.

4. Indications Paralysed muscle. Nerve injury : peripheral or brachial plexus High cervical quadriplegia Neurological disease Nerve repair with early transfer as internal splint Injured muscle tendon unit. (ruptured or avulsed) Balancing deformed hand. (cerebral palsy , RA) Congenital anomalies. ( hypoplastic thumb)

5. Principle of tendon transfer

6. Patient factors Age : not too young and elderly. Motivated to co-operate with post-op physiotherapy. Ability to understand nature and limitation of surgery including aesthetic goals.

7. Recipient factors . No open wound. Stable and supple soft tissues. No induration and edema. Stable underlying skeleton. Area of action to be sensate. Full PROM of joints to be powered. Tissue equilibrium should be achieved .

8. Donor factors

9. Amplitude Length through which muscle can contract is its amplitude. This depends on length of muscle and muscle fiber. Muscle Amplitude Finger flexors 60 - 70 mm Finger extensors 40 - 50 mm Wrist flexors and extensors 30 - 40 mm Brachioradialis 20 - 30 mm Amplitude can be increased by: Freeing fascial attachment to donor tendons. Inserting tendon closer to joint being moved. Tenodesis effect during active movement.

10. Power Power is the innate strength of muscle i.e. tension the muscle can develop. Potential force is maximum when the muscle is at its resting length. Assess power by MRC grading. Only grade 5 muscle is satisfactory. Donor muscle strength should be maximized pre-operatively by physiotherapy. Power is directly propotional to the cross sectional area of muscle. 3.65 kg/cm2 of cross sectional area.

11. Power Muscles Strength APL , EPL , EPB , PL ¼ Finger extensors ½ FCR,wrist extensors, finger flexors, pronator teres 1 Brachio radialis , FCU 2 MRC grading No movement is obsereved . 1 Only a trace or flicker of movement is seen or felt in the muscle, or fasciculation is observed. 2 Movement is possible only if the resistance of gravity is removed. 3 Movement against gravity is possible but not against resistance of the examiner. 4 Muscle strength is reduced but muscle contractioncan move against gravity and resistance. 5 Muscle contracts normally against full resistance.

12. One tendon – one function Transfer of one musculo -tendon unit to restore multiple functions will result in compromised strength and movement. Exception : single motor to restore same movement in more than one digit.

13. Synergistic muscle Muscle that act together to pperform a function or when a particular function is being performed.

14. Line of transfer Should approximate the pull of original tendon if possible. End to end transfer is superior than end to side transfer. Acute angle should be avoided. Change of direction of 40 degree will result in a clinically significant loss of force. If direction change is unavoidable , smooth structure should act as a pulley.

15. Expendable Transfer should not cause loss of an essential function. Use of a muscle must not create an important new deficit. Expendability is not absolute. Pronator teres Pronator quadratus ECRL ECRB, ECU FCR is a more appropriate transfer to provide finger extension in manual labour . FCU provide important function of flexion.

16. Secondary factors Donor muscle should be independently innervated and not act in concert with other motors. All transfers should be sutured at maximum tension in position that reverses their proposed activity. Availability or necessity of antagonist. Brachioradialis is an effective wrist extensors only if triceps is functioning to resists its normal elbow flexor action.

17. Radial nerve palsy Most common site : Humeral shaft Proximal third of dorsoradial forearm High radial nerve palsy Low radial nerve palsy Loss of Wrist extension Thumb extension and abduction MCP extension Loss of Thumb extension and abduction MCP extension

18. Closed fracture associated with radial nerve palsy Burkhalter early tendon transfer indication To act as a substitute during regrowth of nerve , avoiding use of external splints. Act as a helper as reinnervation proceeds. To intervene when the results of nerve repair are considered poor or nerve is irreparable.

19. One strong wrist flexor should be retained. FCU is retained. FCU is major wrist flexor. Normal wrist motion : dorsoradial extension to volar-ulnar flexion. Wrist position for power grip is ulnar deviation. Muscular attachments along the ulnar shaft. In an attempt to balance the wrist and decrease radial deviation pronator teres is transferred to centrally located ECRB.

20. Tendon transfer Restoration of wrist extension Restoration of thumb extension Restoration of finger extension Brand PT to ECRB PL to EPL FCR to EDC Jones PT to ECRB PL to EPL FCR to EDC Boyes PT to ECRB FDS of ring to EPL FDS to long finger to EDC

21. Low ulnar nerve palsy Paralysis of Weakness of pinch Adductor pollicis and first dorsal interosseous Weakness of grip Most of finger intrinsics Clawing of ring and little finger All of intrinsic fingers

22. Normal tightness of MCP joint of the ring and little finger may limit clawing of these fingers and enable the long extensors to extend their IP joints. Troublesome clawing Dynamic procedure : tendon transfer Static procedure : Zancolli capsulodesis EI splitted two slips to radial sid e of extensor aponeurosis of each finger. Done if Bouvier’s test is positive.

23. Omer MCP arthrodesis + FDS of ring finger splitted into two slips then inserted to Insertion of adductor pollicis Two split and inserted to radial side of extensor aponeurosis of ring and little finger. Alternate : BR Burkhalter Insertion directly into PP diaphysis has the a dvantage of grater lever arm beyond the MCP joint. Tendon used : BR , ECRL, FDS of ring finger.

24. High ulnar nerve palsy Functional deficit : low ulnar nerve palsy +FDP ring and little finger +FCU. Tendon transfer : FDS of ring finger involving not done. Restoring DIP flexions Suturing profundus of these fingers to that of long finger. ECRB to FPL of long, ring and little finger.

25. Low median nerve palsy Functional deficits Loss of opposition of thumb. Paralysis of two radial lumbricals . Loss of sensibility over sensory distribution of nerve. Treatment Restoration of thumb opposition. Restoration of sensibility by a neurovascular island graft.

26. High median ulnar nerve palsy Functional deficits Loss of pronation of forearm. Loss of flexion of wrist. Loss of flexion of index and ring fingers. Loss of flexion and opposition of thumb. Loss of sensibility over sensory distribution of nerve. Treatment IP joint flexion Side to side suture of FDP ECRL / ECU to FPL Thumb oppsoiton EI to first MCP Sensibility NV island graft

27. Combined low median and ulnar nerve palsy Functional deficit Complete anaesthesia of palm. Loss of function of all intrinsics of fingers and thumb. Skin and joint contractures develop and fixed law hand results . Treatment Brown Omer Clawing ECRL FDS / ECRL / EI+EDM Adduction EI FDS middle or ring finger/ECRL

28. Combined high median and ulnar nerve palsy Treatment Arthrodesis of MCP joint of thumb. Zancolli capsulodesis . Release of flexor tendon sheath. Tendon transfer ECRL to FDP BR to FPL ECU to EPB

29. References Campbells operative orthopaedics , 13 th edition.