Flexor tendon injuries slideshare

Dr Ajay Shah IOM,Nepal
flexors tendon injuries

1. Flexors Tendon Injuries Moderator : Assoc Prof Dr Suresh Uprety Presenter : Dr Ajay Shah (Resident) Department of Orthopedics and Trauma Surgery IOM,TUTH

2. Anatomy Superficial Group Pronator teres Flexor carpi radialis Palmaris longus Flexor digitorum superficialis Flexor carpi ulnaris Deep Group Flexor digitorum profundus Flexor pollicis longus Pronator quadratus

3. Zones of Flexors Tendon Verdan Classification Zone I: F rom middle of middle phalanx distally Zone II: F rom MCP joints to middle of middle phalanx Zone III: Central palm Zone IV: Tendons in carpal tunnel Zone V: Tendons proximal to carpal tunnel Thumb Zone TI: Distal to IP joint TII: From A1 pulley to IP joint TIII: Thenar eminence

4. Flexors Synovial sheath

5. Muscles and Tendons According to Zones

6. Carpal Tunnel

7. Neurovascular Distribution According to Zones

8. Camper’s chiasm At A1 pulley FDS tendon splits and rotates laterally then dorsally around FDP tendon Two splits tendon join together proximal to PIP joint at camper’s chiasm Functions Provides a pathway for FDP tendon Increases the stability and balance of PIP joint Prevents hyperextension of PIP joint

9. No Man’s Land Historic derivation of “no man's land” dates back to 14 th   century It was used to describe an area outside London used for executions Sterling Bunnel used this term in hand surgery who most probably derived it with his experience in the World War 1

10. He described it as no man's land because of perennial anatomical characteristics This zone has a fibro osseous digital canal where both the tendons interweave in a complex manner Multiple pulleys increase its complexity because minimal swelling of the epitenon can impair free motion of the tendon Any infection, fibrosis, scarring, overcrowding can lead to dense adhesions and hence compromising the results

11. Pulley system Digital flexors synovial sheath is reinforced by a system of fibrous pulleys 5 annular pulleys (A) A1 : 8-10 mm over MCPJ A2 : 18-20mm over proximal phalanx A3 : 2-4 mm over PIPJ A4 : 10-12mm over middle phalanx A5 : 2-4 mm over DIPJ

12. 3 Cruciform pulleys (C) C1, C2, C3 proximal to A3,A4, A5 Allow shortening of the pulley system in flexion A2 and A4 are considered most important. Their disruption leads to bowstringing, reduced mechanical efficiency and decreased flexion

13. Function of Pulley System Keep the tendon close to bone , providing an inline pull of tendon along the axis of digit and toward palm Keep the tendon adjacent to the joints, maintaining a standard lever distance from joint center of rotation Gaps between annular and cruciform ligaments are necessary to allow flexion of fingers

14. Biomechanics of Pulley If the tendon is allowed to move away from joint center of rotation and force is pulled through flexor system , lever distance increases, causing increase in work performance at joint leading to excess flexion at DIP joint Degree of flexion is directly proportional to tendon excursion and inversely proportional to moment arm

15. Tendon Nutrition Tendon nutrition 2 basic sources: Synovial fluid produced within the tenosynovial sheath Blood supply provided through longitudinal vessels in the paratenon , intraosseous vessels at the tendon insertion, and vincular circulation

16. Blood supply Suture placement in volar half of tendon Intratendinous placement of crisscross sutures disturb the microcirculation

17. Tendon healing Tendon healing is believed to occur through the activity of extrinsic and intrinsic mechanisms Extrinsic : Through the activity of peripheral fibroblasts derived from tendon sheath and seems dominant mechanism contributing to the formation of scar and adhesions. Intrinsic: Through the activity of the fibroblasts derived from the tendon

18. Phases of Tendon healing Following laceration, tendon healing proceeds through 3 sequential but overlapping phases

19. Examination General condition of patient Possibility of other injuries Neurologic examination Assessment of light touch and static two point discrimination Vascular examination CRT of volar digital pulp and nail bed is assessed When necessary, digital Allen test can be done

20. Posture of Hand Normal flexion cascade: MCP joints slightly flexed – about 30 degrees in the index, ranging to 70 degrees in the little Assure all fingers point to scaphoid area when flexed at PIPs joint When both flexor tendons of a finger are injured, the finger lies in an unnatural position of hyperextension, especially compared with uninjured finger Passive extension of the wrist does not produce the normal flexion of the finger

21. Test for flexor digitorum profundus Test for flexor digitorum superficialis Test for flexor pollicis longus Examination of individual Tendon

22. Objective of Tendon Repair Purpose of tendon suture To approximate the ends of a tendon or to fasten one end of a tendon to adjoining tendons or to bone To hold this position during healing Pinching and grasping of the uninjured surfaces should be avoided

23. Principles of Tendon Repair All flexor tendons should be repaired at whatever level they are transected . Whenever possible the repair should be done primarily. When delayed a tendon graft may be required A2 and A4 annular pulley areas of the flexor sheath should be preserved; otherwise, tendon bowstringing and flexion deformity of the finger can develop and excursion of the tendon becomes impaired. Tendon laceration of 60 % or more is treated as complete transection

24. Initally dorsal epitenon sutures are placed then core sutures and then finally volar epitenon sutures Diameter of the suture is also directly porportional to the strength of the repair 3.0 to 4.0 calliber non absorbable suture is recommended

25. Repair is supplemented with a running circumferential epitenon suture technique. Advantages: smooth repair and improves tendon gliding minimize the adhesion formation less gap formation Suture technique must withstand gap formation of 3 mm at the repair site during the initial 3 weeks following repair.

26. Strickland stressed six characteristics of an ideal tendon repair Easy placement of sutures in the tendon, Secure suture knots, Smooth juncture of tendon ends, Minimal gapping at the repair site, Minimal interference with tendon vascularity, and Sufficient strength throughout healing to permit application of early motion stress to the tendon.

27. Timing of Flexor Tendon Repair Primary tendon repair within the first 12 hours of injury can be extended to within 24 hours of injury in rare situations Delayed primary repair : within 24 hours to approximately 10 days. Secondary after 10 to 14 days Late secondary repair after 4 weeks

28. Ideal properties of suture material Non reactive Hold securely when knotted Small caliber High tensile strength Easy to handle Common material: Ethibond , Nylon, Prolene

29. Suture Configurations Tendon repair types can be divided into three groups Group 1: Simple suture Group 2 : Bunnell suture Group 3: Pulvertaft technique (fish-mouth weave )

30. An abundance of research has shown that four-strand, six-strand, and eight-strand core sutures Create stronger repairs Reduce the possibility of gap formation Permit greater active forces applied to the repaired tendons Allowing earlier active motion

31. End to End Suture Techniques Kessler technique Modification of the Mason-Allen suture. Effective for tendon repair in the fingers and palm Knots being left exposed on the tendon surface.

32. Modified Kessler technique Modifications: Only one knot inside the repair site Knot is left in the cut surface of the tendon Easier to use a monofilament suture like a 4.0 Prolene to reapproximate tendon edges

33. Kessler Tajima stitch Separate sutures are used so that the tendon ends can be passed within the flexor sheath using the free end of the suture as traction suture Knots are tied within the tendon However, use of two knots in the repaired area could lead to a high risk of early failure, suture slippage, and tendon torsion

34. Modified Kessler Tajima Suture (Strickland ) Modified by addition of Peripheral epitenon suture Core mattress suture Knots are tied within the tendon Sutures are locked with each exit from the tendon .

35. Pulvertaft Technique ( Fish mouth technique) Commonly used to suture tendons of unequal size Tendon of small diameter can be sutured to one of large diameter

36. End to Side Suture Technique Frequently used in tendon transfers when one motor must activate several tendons

37. Tendon to Bone Attachment F requently requires a pull-out technique (usually distal phalanx) For tendon to bone repairs ,core suture techniques used most often are Kessler Bunnell crisscross suture

38. Suture Anchor Tendon Attachment As effective as pull-out wire or suture but without the potential complications with fingernail that can occur with pull-out technique Two suture anchors are placed in the distal phalanx from distal-volar to proximal-dorsal To purchase in the thickest portion of the distal phalanx to provide greatest pullout strength

39. Surgical Incision Incisions should not compromise viability of skin flaps Should not create contractures or cosmetically unsightly scars Less exposure needed distally than proximally Zigzag (Brunner),mid radial ,mid ulnar or midline oblique incisions

40. Zone I Repair Contains only the FDP tendon Direct repair (primary tenorraphy ): laceration >1 cm from FDP insertion Proximal tendon retrieved by feeding tube and passed underneath A4 pulley

41. Tendon advancement (<1cm stump) Pull-out suture Free ends of sutures are passed through or around distal phalanx, tied over dorsum of fingernail with button. Removed after 6 weeks Internal suture methods Suture anchors or other methods to affix the tendon directly to the bone

42. When the diagnosis of interruption of FDP tendon is delayed, and the tendon has retracted into the palm, its vinculum has been disrupted and a decision must be made regarding repair depending upon types Type I : FDP tendon is avulsed from its insertion and retracts into palm Type II : Avulsed from its insertion but stump remains within digital sheath Type III : A vulsed bony fragment attached to tendon stump, remains within flexor sheath

43. Modified Leddy and Packer classification for FDP avulsion Type IV avulsions were first described by Robins and Dobyns in 1974. Inclusion of type V avulsions in the classification was proposed by Al- Qattan in 2001

44. Type 1, if it is within 7 to 10 days of the injury, the tendon should be threaded back into the finger and reattached with a pull-out wire into distal phalanx Type 2, despite the passage of a few months, these tendons can be reattached as well because circulation is thought to be maintained Type 3, usually fracture repair with k-wire or miniature screw fixation Type 4, fracture fixation followed by advancement of tendon to distal phalanx Type 5, FDP tendon with avulsed bone fragment is reduced using a pull-out technique, and a K-wire is placed for avulsed fragment

45. Zone II Repair Primary repair at this level frequently fails because of adhesion in the area of pulley Technical concerns during the repair procedure includes Management of lacerations of FDP and FDS tendons Appropriate orientation of the FDP with FDS slips Attachment of the FDS slips in the thin flat area Management of the flexor sheath, including annular thickening (pulleys) Postoperative management, Timing and technique for tenolysis

46. Care should be taken when FDS has been injured in area just proximal to PIP joint Care also should be taken to deliver FDP tendon through the split portion of FDS when profundus tendon has retracted proximally

47. Method of repair however is controversial but following are the different options of treatment: Repair of the FDP tendon only with debridement of the FDS stump Repair of both tendons or Repair of FDP with repair of one slip of FDS tendon Most hand surgeons prefer to repair the FDP and one slip of FDS , reasonably a good option as the repair of both slips of FDS may produce overcrowding within the sheath and pulleys and compromise the result  Coats RW, 2nd, Echevarría-Oré JC, Mass DP. Acute flexor tendon repairs in zone II. Hand Clin .  2005;21:173–9

48. Core suture with two or more strands, locking components, and buried knots is usually preferred A running, circumferential 5-0 or 6-0 suture is used to complete a smooth repair and to minimize adhesion formation to the sheath Tenolysis may be required in an estimated 18% to 25% of patients after flexor tendon repair Three months is considered to be earliest time for flexor tenolysis , assuming no improvement in motion in previous 1 to 2 months Function in the finger can be improved by 50% by tenolysis

49. Strickland technique for flexor tendon injury in Zone II

50. Zone III Repair If both tendons are lacerated, both are repaired, end to end with circumferential re-enforcing sutures Muscles bellies of lumbricals and tendon are f requently affected so additional incision often needed to expose further area If conditions permit, primary repair of sharply severed nerve is crucial If wound condition preclude tendon and nerve repair, the ends of the tendon and nerve are sutured to adjacent fascia to prevent undue retraction Lumbricals muscle bellies usually are not sutured, causes lumbrical plus finger

51. Zone IV Repair Associated with median ,ulnar nerve or ulnar/radial vessel injury If the laceration occurs beneath the transverse carpal ligament, partial or complete release of the transverse carpal ligament may be required Preserve, if possible, a portion of the transverse carpal ligament to avoid bowstringing postoperatively If it cannot be preserved, release it in a Z-lengthening configuration Best suture configuration is intratendinous one with a locking core Immobilize the wrist in about 45 degrees of flexion, 50 to 60 degrees of flexion at MCP joints and the IP joints in full extension

52. Zone V Repair In zone V, multiple tendons, nerves, and vessels frequently are injured so its important to identify the tendons accurately Properly match the tendon ends by careful attention to their location and level in the wound, their relation to neighboring structures Blood clots within the tenosynovium usually serve as clues in locating severed tendons Repairs done in the distal forearm do not absolutely require an intratendinous repair, double right-angled or mattress suture may be used Immobilize the wrist in about 45 degrees of flexion, with fingers in 50 to 60 degrees of flexion at MCP joints and the IP joints in full extension

53. Postoperative Rehabilitation

54. Immobilization Indication for immobilization after flexor tendon surgery is usually not required, exceptions Children or adults unable to cooperate with hand therapy Unstable bone repair Concerns about the effect of tension on microneurovascular repairs . Unwilling to adhere to strict early mobilisation protocols

55. Passive Motion Protocol Modified Kleinert : Active extension, passive flexion by rubber bands. Duran: Controlled Passive Motion Methods

56. Modified kleinert

57. Duran Protocol

58. Flexor Tendons Reconstruction When FDS and FDP tendons have been divided in the critical area of the pulleys, flexor tendon grafting may be indicated if Injuries resulting in segmental tendon loss Neglected >3 to 6 weeks with tendon degeneration and scar within the tendon sheath i.e. chronic flexor tendon injuries If a gap cannot be closed because of myocontracture Large section of tendon has been damaged in Zone II injury Delayed presentation of FDP avulsion injuries associated with significant tendon retraction

59. Requirements before tendon graft Skin is pliable; Any wounds are well healed Tissues through which tendon is expected to glide must be relatively free of scar Edema has subsided Joints allow a full passive range of motion Sensation in the finger is normal or at least one digital nerve is intact

60. Boyes preoperative classification helps to identify the severity of injury, with higher grades portending worse outcomes

61. Single-Stage Tendon Graft Considered when the flexor tendon sheath is relatively intact and unscarred and the pulley system is competent Attempt can be made to dilate collapsed pulleys with urethral dilators However , if unsuccessful, a two-stage procedure with pulley reconstruction should be undertaken Age is a strong prognostic factor. Results are best in patients 10 to 30 years old, and worst results in very young and in patients older than 50 years Bora FW Jr : Profundus tendon grafting with unimpaired sublimis function in children . Clin Orthop Relat Res 1970;71 (71 ):118-123.

62. Two-Stage Tendon Graft Indications Crushing injuries associated with fracture or skin damage Damaged pulley system Excessive scarring of the tendon bed Failure of previous operations Stiff joints

63. First stage Excision of tendon and scar from the flexor tendon bed Preserving or reconstructing the flexor pulley system Dacron-impregnated silicone rod is inserted to maintain the tunnel in the area of excised tendons until passive motion and sensitivity have been restored to the digit Second stage Done when the finger is soft, supple, and well healed with mobile joints Earliest time for the second stage is about 8 weeks, but usually 3 months is required, depending on the patient’s needs and the surgeon’s judgment Consists of Rod removal Tendon graft insertion

64. Pulley Reconstruction Goal To enable maximum excursion and strength with controlled gliding of flexor tendons To minimize friction Two main techniques are Weaving the pulley graft through remaining pulley rim Creating a new pulley loop around bone

65. Graft Choices Palmaris longus tendon Plantaris tendon Extensor Digitorum longus to 2 nd 3 rd or 4 th toes Flexor digitorum longus to 2 nd toe Flexor digitorum superficialis Intrasynovial grafts (FDS and toe flexors) have better morphologic and functional characteristics than that of extrasynovial grafts. Extrasynovial grafts have been thought to lead to more adhesions Flexor tendon grafting to the hand: An assessment of the intrasynovial donor tendon. A preliminary single-cohort study. J Hand Surg Am 2000; 25(4 ):721-730 .

66. Complications Short term : Infection Injury to neurovascular structures or pulley system Abnormal scarring Long term : Adhesion Rupture Joint contracture Triggering Rarer complications Lumbrical plus finger Quadrigia effect

67. Adhesions Most common complication despite early motion protocols Higher risk with Z one II injuries Treatment Physical therapy Tenolysis when patients progressive gain in digital motion has plateaued, usually 3- 6 months after repair Adhesion formation with restriction of tendon excursion and the need for tenolysis has reported rates from 12 % to 47 % LaSalle WB, Strickland JW: An evaluation of the two-stage flexor tendon reconstruction technique. J Hand Surg Am 1983;8(3 ):263-267 .

68. Tendon rupture Noted by the patient as “popping” in the hand 7-10 days postop when tensile strength is weakest MRI may help in diagnosis Treatment If < 1cm of scar is present, resect the scar and perform primary repair If > 1cm of scar is present, perform tendon graft if the sheath is intact and allows passage of a pediatric urethral catheter or vascular dilator, perform primary tendon grafting if the sheath is collapsed, place Hunter rod and perform staged graft

69. References Campbells Operative Orthopaedics,13 th edition Green Operative Hand Surgery, 7 th edition Apleys system of Orthopedics,9 th edition Articles