Extensor tendon injury & associated deformities Dr Sumer Yadav Mch – Plastic and Reconstructive surgery [email protected]
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Extensor tendon injury
& associated deformities Dr Sumer YadavMch – Plastic and Reconstructive surgery
ANATOMY OF EXTENSOR FORE ARM Proximal group: The
ECU,EDM,EDC,ECRL,ECRB tendons originate adjacent to the lateral epicondyle of the humerus and are innervated proximally
Distal group: The EPL,EIP,AbPL & EPB originate in the distal half of the forearm. There fore, a proximal laceration with loss of function in distal group probably represents a motor nerve injury.
Muscles of the Forearm lateral (Extensor Surface)
Outcropping Group Extensor Pollicis Brevis/
Abductor Pollicis Longus
Extensor pollicis longus
Medial GroupExtensor Carpi radialis
L/B
Bracioradialis
ARRANGEMENT OF EXTENSOR TENDONS AT WRIST The Extensor tendons gain entrance to
hand from the fore arm through a series of six canals, 5 fibro-osseus & 1 fibrous( the 5th dorsal compartment containing EDM)
The Communis tendons are joint distally near the MP joint by fibrous inter connections called Junturae Tendinum
The Proprius tendons( EIP&EDM) are independent finger extensors and they lie on the ulnar side of the their respective EDC tendons
EXTENSOR MECHANISM IN FINGER At the MP joint, the Extensor mechanism flattens into a
broad hood and envelops the dorsal third of proximal & middle phalanges
Fibers of the common extensor tendon blend with the fibers of lateral bands to form the central slip which inserts in the base of the middle phalanx & effects PIP joint extension
The central slip is kept in its dorsal position by the Transverse Retinacular ligament
The lateral bands are held dorsal to the axis of the PIP joint by fibers of the Triangular ligament
SORL originates on the palmer plate & flexion sheath beneath the PIP joint .These fibers move dorsally to insert in the terminal tendon. With PIP extension , fibers of the SORL tighten to assist DIP extension
MECHANICS OF HAND Two set of muscles, INTRINSIC (originating in the hand itself
& innervated by the Ulnar and Medial nerves) and EXTRINSIC (originating in the forearm & innervated by the Radial nerve) act synergistically
The extensor system prepares the hand for grasp & pinch by positioning the hand in various degrees of extension.
The most frequent activities of daily living occur in positions close to the position of function like holding a cup or writing with a pen. More specialized activities like grasping a large or a very small object occur at the extremes of extension & flexion
An Extensor tendon laceration results in the decrease in the extensor force distal to the injury. This force is then transferred to the joint proximal to the injury, resulting in a net increase of extensor force at that joint, which causes a change in that joint position leading to characteristic deformities
TENODESIS EFFECTDynamic Tenodesis is defined as the concept of movement at one joint transmitting power to an adjacent joint( usually distal)As the wrist flexes , the extensor tendons tighten and the flexor tendons relax, both actions serving to produce extension of the MP joints. The intrinsic tendons tighten with MP extension, augmenting PIP extensionThe lateral bands & the ORL are lax with PIP flexion and tighten with PIP extension. The Tenodesis effect of the ORL can be demonstrated by checking passive flexion of the DIP joint with the PIP joint in flexion and extension
ZONES OF INJURYZONE FINGER THUMBI DIP joint IP jointII Middle Phalanx Proximal PhalanxIII PIP joint MCP jointIV Proximal Phalanx MetacarpalV MCP joint Carpometacarpal
joint/ Radial StyloidVI Metacarpal VII Dorsal RetinaculamVIII Distal forearmIX Mid & Proximal forearm
Each zone in the fingers refers to an identical location. The thumb lacks a middle phalanx. Consequently the thumb zones I to V refer to different anatomic location relative to the fingers 60% of Tendon injuries occur in zone V to VIII ( MP joint to distal fore arm)Outcome is more favorable in zone V to VIII injury as compared to zone I to IV injuryMore than 50% of injuries have an associated injury such as fracture, dislocation or flexor tendon injury
CLINICAL EVALUATION
Testing for EDC, EIP & EDM musculotendinous functionThe proprius tendon to the index & little finger are capable of independent extension.Their function together can be evaluated with the middle & ring finger flexed into the palm , the proprius tendons can extend the ring & little finger
TESTING PROPRIUS TENDONS
With the middle & ring fingers flexed into the palm, the Proprius tendon can extend the index and little fingers
EPB tendon can be checked by placing a finger in the anatomical snuff box and asking the patient to extend the thumb in a flat position APL tendon can be checked by asking the patient to abduct the thumb against resistance
ZONE I INJURY Occurs at the DIP joint of the finger
or the IP joint of the thumb Mechanism of injury is usually
forced flexion of an actively extended distal joint
aka Mallet finger, Base ball finger, Dropped finger, or Extension lag
MALLET FINGER Mechanism : a blow from a thrown ball
strikes the tip of the finger--- ‘forced flexion’.
It tears the extensor tendon from its insertion +/- dorsal tip of distal phalanx
Clinically , there is extensor lag with localized DIP joint tenderness . The athlete is unable to extend the DIP
Investigation : radiographs to rule out fracture with volar subluxation
MALLET FINGER Management : continuous splint immobilization for 4
to 6 weeks in full extension Indications for surgery: open injuries, closed injuries
in a person who will be unable to work with a splint on e.g. health care worker and a large dorsal fragment with palmar subluxation of the distal fragment
Complications : skin ulceration is most common. Compensatory Swan neck deformity is known to occur.
Chronic Mallet injuries with compensatory swan neck deformity are reconstructed with SORL reconstruction techniques . Those chronic deformities which are painful, arthritic, and interfere with hand function are treated with DIP fusion
Zone I injury: Surgical Intervention
Placement of a permanent buried suture can be avoided by :
A. The tendon ends are incorporated with the interrupted skin sutures
B. The proximal end of the divided tendon is advanced into the insertion site with the use of a pull out suture tied over a bolster on the finger pad
Zone I injury: Surgical Intervention
Technique of extensor tendon repair at the DIP joint , in which the skin and the tendon are simultaneously approximated
SORL Reconstruction A. A Mallet deformity with compensatory swan neck deformityB&C. The Tendon graft is fixed to the distal phalanx with a pull out suture.The graft is passed between the flexor tendon sheath & the neurovascular bundles palmar to the PIP joint. The graft is tensioned & anchored into the shaft of the proximal phalanxSORL reconstruction is advocated for correction of a swan neck deformity which is secondary to a mallet finger
ZONE II INJURY Extensor tendon width is greater in zone II than
zone I & the extensor mechanism has two lateral bands which extend the distal phalanx
Lacerations of less than 50% of the tendon cut can be treated by skin closure alone, rest are repaired by a pull out suture technique
Typically seen in conjunction with sharp lacerations, saw injuries, and crushing injuries
The DIP is splinted in extension for 4 to 6 weeks Turrent Exostosis is a mass of bone formed
secondary to a periosteum injury in a zone II laceration. This mass limits DIP flexion and resection is the treatment of choice
Doyle’s repair : Sharp laceration of zone II repaired with a running suture and over sewn by a Silverskiold cross stitch
ZONE III INJURY Disruption of the extensor apparatus at or just proximal to
the PIP joint results in a loss of extensor power at the PIP joint
Forced flexion of the PIP joint damages the central slip of the extensor tendon
After central slip disruption the triangular ligament stretches over time shifting the lateral bands in a volar direction
The head of the proximal phalanx ‘buttonholes’ through the extensor mechanism, creating the Boutonniere deformity
Lateral bands falling volar become PIP joint flexors instead of extensors while continuing to exert an extensor force on the DIP joint
Boutonniere deformity can be acute –(closed or open) and chronic
Boutonniere Deformity Right hand Ring finger [email protected]
Patho mechanics of Boutonniere deformity: A. Attenuation of the central slip results in unopposed flexion at the PIP joint; B. With PIP flexion the lateral bands drift palmar( due to decreased support from the stretched triangular ligament) to the axis of rotation at the PIP joint [email protected]
Chronic Boutonniere Deformity Burton & Melchior classification: Stage 1: supple, passively
correctable deformity Stage 2: fixed contracture:
contracted lateral bands Stage 3: fixed contracture: joint
fibrosis, collateral ligament & palmar plate contractures
Treatment plan in Boutonniere deformity Acute closed Boutonniere injuries:
extension splinting of PIP joint Acute open Boutonniere injuries: primary
repair ( Doyle’s, Snow’s, Aiche’s methods) Chronic Boutonniere deformity: Stage 1 &
2- therapy regimen of active assisted extension of the PIP joint combined with passive flexion of the DIP joint . Stage 3 – options include Tenotomy, Tendon grafting, Tendon relocation
Burton & Melchior’s guidelines for Boutonniere surgery Boutonniere reconstruction are most successful on
supple joints. If necessary, a joint release can be performed as a first stage.
An Arthritic joint usually precludes soft tissue reconstruction. The surgeon should consider either a PIP joint fusion or Arthroplasty with extensor tendon reconstruction
Boutonniere deformity rarely compromise PIP flexion & grip strength. Do not trade extension at the PIP joint for a stiff finger & a weak hand
Goal of Boutonniere reconstruction is to rebalance the extensor system by reducing extensor tone at the DIP joint and increasing tone at the PIP joint
Splinting is an important component of the post operative care; it may be necessary for several months
A Bunnell splint is applied to maintain extension at the PIP joint. The strap over the PIP joint is progressively tightened until the PIP joint is fully extended. The patient is encouraged to flex the DIP [email protected]
Reconstruction of Boutonnière
A. The boutonniere deformity with the lateral bands & ORL volar to the PIP joint
B. Dorsal zigzag incisionC. The ORL is separated from the lateral
bands & a tenotomy of the lateral bands is done distal to the central slip insertion
D. If active PIP extension is still not possible, the lateral bands are suture together, dorsal to the PIP joint
E. Sequence of eventsF. The PIP joint is fixed with a
transarticular K wireG. The mechanics of the reconstruction
Central slip laceration with sufficient tendon to repair with core suture & over sew with silverskiold epitendinous suture
When the tendon laceration is distal, leaving a small stump of central slip; the core suture can be passed through a trough in the base of the middle phalanx
Snow’s technique of central slip reconstruction ( distally based flap)
Aiche’s technique of central slip reconstruction (central halves of lateral bands)[email protected]
Littler’s tendon graft technique: a thin graft is woven through the base of the middle phalanx and through the extensor tendon to restore extensor tone to the PIP joint
Extensor Tenotomy for Supple Boutonniere deformity
Dolphin or Fowler procedure: The lateral bands are released distal to the insertion of the central slips . The lateral resulting proximal migration of the extensor mechanism reduces tension at the DIP joint & increases extensor tension at the PIP joint
Post burn Boutonniere Defomity Primary damage is that of the central slip, leading
to the sliding of the lateral bands below the axis of rotation of the PIP joint
The lateral bands thus become PIP joints Flexors rather than extensors, and the PIP joint is flexed up to 90 degrees
The absence of Central slip allows the system to move proximally resulting in excessive pull on DIP joint causing its hyper extension
Before surgery its necessary to its necessary to eliminate the related contractures of other hand joints
There is a constant battle between the options of Tendoplasty vs Arthrodesis
Pseudo Boutonniere Deformity Flexion deformity of PIP joint, often
following an axial load injury Hyper extension injury to PIP joint Volar plate avulsion on X-ray with
volar PIP joint tenderness More common than Boutonniere
deformity Protected immobilization required
ZONE IV INJURY Partial zone IV injury is more common than
a complete laceration because the extensor mechanism is flat & it curves around the proximal phalanx
Often associated with a proximal phalanx fracture
Treatment is repair with modified Kessler’s suture using 4-0 braided polyester
Within 1 week of repair the patient is started on passive extension & active flexion
ZONE V INJURY A complete division of the extensor mechanism
in this zone is uncommon owing to the width of the tendon
A partial laceration with division of the central tendon is common because of the tendon’s prominence over the metacarpal head
The central tendon is repaired with a grasping suture & the hand is splinted in wrist extension & 30 degrees of MP flexion. The IP joint is allowed active motion
Sagittal band injury can also occur in zone V, can be either open or closed . Treatment of open injuries is straight forward exploration & repair
HUMAN BITE INJURIES Partial extensor tendon injuries over the MP joint
(zone V) are often caused by a punch to an opponent’s mouth, so called clench fist injury or fight bites
The tendon injury is proximal to the skin laceration because the MP joint is flexed at the time of injury
Bacterial growth consists of Streptococcus, Staphylococcus, Bacteroides & E.Corrodens
Treatment consists of prompt surgical exploration of the wound. The extensor tendon should be split longitudinally and the MP joint opened, cultured,& irrigated with antibiotic solution. Repair of lacerations is deferred ( usually 7 to 10 days) until the infection is cleared
Closed Sagittal band injuries (Extensor tendon subluxation) Result from direct blow, from forced MP joint
flexion or from daily activities such as flicking the finger or crumpling the paper
Symptoms range from pain & loss of MP joint motion to extensor tendon snapping or catching during finger flexion
Acute injuries that are 2 -3 week old can be treated with extension splinting of the MP joint
Patients who fail splint treatment or who have an injury more than 3 weeks old should be treated with direct repair of the Sagittal band
ZONE VI INJURY Have a better prognosis than distal injuries
because decreased surface area & increased subcutaneous tissue lessens adhesion formation and also there is greater tendon excursion with no complex tendon imbalances
Modified Bunnel or Kessler’s core suture supplanted with epitendinous sutures is the standard treatment
Complications after zone VI repair are loss of flexion, loss of extension, & tendon rupture in the order of frequency
ZONE VII INJURY There is almost always an associated injury
to the extensor Retinaculum Point in favor of excision of Retinaculum are
that it improves exposure & prevents friction between bulky repairs and the retinaculum while its preservation prevents bow stringing or subluxation of the extensor tendons
Treatment is same as zone VI in acute cases
Chronic injuries of zone VII Most common cause is attritional rupture
e.g. EPL rupture after distal radius fracture or with Rheumatoid Arthritis
Management is difficult as there is no Para Tenon in this region leading to retraction of the proximal tendon. Also, since the ends are frayed, end to end repair is not possible without unacceptable shortening of the musculotendinous unit & a loss of flexion
Tendon transfer or a graft is the standard treatment
Reconstruction after EPL rupture
Reconstructive options:1. The Palmaris longus tendon is
used as a intercalated graft2. EIP is transferred to the distal
end of EPL3. The Palmaris longus is
transferred around the radial side of the wrist to the EPL
ZONE VIII INJURY Includes ruptures of musculotendinous
junction and muscle belly lacerations Repair of these injuries is complicated
by the difficulty of placing sutures in the thin fascia overlying the muscle
When repair is not feasible, a side to side tendon transfer provides the best means to restore tendon function
ZONE IX INJURY Penetrating trauma in this region can be
accompanied by nerve injuries making assessment difficult
A proximal forearm laceration with a loss of distal muscle group function is probably a motor nerve injury rather than a tendon division
Multiple interrupted absorbable sutures are used to repair the Epimysium & fibrous intramuscular septum.
Suture repair of muscle lacerations have virtually no tensile strength. Post op treatment is 4 weeks of cast immobilization
Swan Neck Deformity Cause : Volar plate rupture at the PIP with often accompanying
triangular ligament rupture. Pathology :Lateral bands drift dorsally and exacerbate the
hyperextension at the PIP joint. They become ineffective in extension at the DIP joint and the unopposed action of the profundus causes flexion at the DIP joint.
Clinically : Causes “jamming” dislocations Immediately noticeable, if not immobilized will become surgical
finger. Treatment: involves SORL reconstruction
SURGICAL ASPECTSZONE SUTURE TECHNIQUE SUTURE MATERIALI & II Splint only none Skin with tendon (simple) 5-0 monofilament Tendon suture (Cross stitch) 6-0 monofilament Pull out tendon 4-0 monofilamentIII,IV & V Grasping tendon suture 4-0 braided synthetic +/- simple or cross stitch 6-0 monofilamentVI,VII & VIII Grasping core suture 4-0 braided synthetic + epitenon 6-0 monofilament Multiple slips to same digit 4-0 braided synthetic sutured together
Regional anaesthesia Brachial plexus block ( above
the clavicle): Inter scalene – anterior or posterior Supra clavicular – Classic, Plump bob, Para scalene, Inter strernocleidomastoid, Subclavian perivascular
Regional anaesthesia Infra clavicular approach- Para
coracoid, lateral Axillary block
LOCAL BLOCKS Wrist blocks Median nerve block
Superficial branch of Radial block
Ulnar nerve block
LOCAL BLOCKS
Technique of giving a dorsal digital block
DIGITAL NERVE BLOCKS Ring block Volar block Dorsal block Flexor tendon sheath
TOURNIQUET
A penrose drain can be used as a finger tourniquetFor the upper limb as a whole a tourniquet is kept at a pressure of 150 -250 mm of Hg for a period ranging from 45 mins to 2 hours
Techniques
A.Horizontal mattress; B.Figure of 8; C.Kessler’s; D.Modified Bunnell
D
Thin flat tendons repaired in pairs
When the core diameter of two tendon slips makes a core grasping suture technically difficult , the two sips can be incorporated into one repair, A. FIGURE OF EIGHT, B. MODIFIED GRASPING [email protected]
Suture technique for flat broad tendons
Flat , broad tendons of zone III, IV & V are repaired by A. core suture, B. cross stitch suture [email protected]
IMPORTANT POINTS IN EXTENSOR TENDON REPAIR Extensor tendon suture technique vary according to the
location of the injury & the size of the tendon. Distal to the MP joint, in zone I to V, the extensor tendon
is wide and flat. In zone VI to VIII, the tendon is narrow and thick.
A grasping technique is used when the tendon is large enough to allow placement of sutures.
Suture technique should be chosen to maximize strength & minimize shortening of the tendon.
Extensor retinaculum when involved should be preserved
The highest priority of extensor tendon injury is not regaining full extension. The goal is to increase motion in the functional range of the patient’s normal activities.
COMPLICATIONS Most common complication after tendon repair
is the formation of adhesions between the repair site, adjacent skin and the bone. The adhesions can restrict joint flexion as well as extension.
Treatment includes Tenolysis, Capsulotomy or Collateral ligament release
Gapping Disruption Non healing skin site Scarring Decreased Joint mobility
PHYSIOTHERAPY Zone I & II injuries are treated with a static
Splint. Only 1 to 2 mm of tendon excursion is necessary for DIP flexion, a fact that makes adhesions at the injury site less of a problem.
Early motion rehabilitation protocols are recommended for injuries in zone III to VIII
The patient actively flexes the finger followed by passive extension with rubber band traction
Children & non cooperative patients are best treated with immobilization
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