The Effect of Pulley Reconstruction on Maximum Flexion,Bowstringing,and Gliding Coefficient in the Setting of Zone II Repair of FDS and FDP: A Cadaveric Investigation

Abstract

Purpose

The purpose of this experiment was to determine the effect of A2 pulley reconstruction on gliding coefficient (GC), bowstringing, and proximal interphalangeal (PIP) joint maximum flexion angle after zone II repair of flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP) lacerations.

Methods

Fresh frozen cadaver forearms were mounted, and the wrist and MCP joints fixed. FDS and FDP tendons were dissected free, and sequential loads were applied while digital images were captured. The dissected digit with intact native A2 pulley, FDS, and FDP tendons was used as the control (group 1). Zone II lacerations followed by four-stranded repair of FDP plus epitendinous suture and repair of FDS were then performed, and the data recorded (group 2). A2 pulley excision and reconstruction with a loop of palmaris longus autograft was then completed and the specimens sequentially loaded and photographed (group 3). Using the digital images, GC, bowstringing, and maximum flexion angle were calculated.

Results

No difference in maximum flexion angle was observed across the three testing conditions. Zone II laceration and subsequent FDS and FDP tendon repair significantly increased the GC for group 2 specimens; however, pulley reconstruction alleviated some of this increase for group 3. Bowstringing was significantly greater after pulley reconstruction, with a mean increase of 1.9 mm at maximum flexion for group 3 specimens relative to group 1 controls.

Discussion

Strong flexor tendon repairs are needed to prevent gap formation and subsequent triggering; however, the increased bulk from these large repairs can itself produce deleterious triggering, as well as tendon abrasion. Pulley reconstruction, in the setting FDP and FDS repair (group 3), significantly reduced the GC relative to tendon repair alone (group 2). While bowstringing was significantly greater after pulley reconstruction (group 3), it averaged only 1.9 mm over group 1 specimens and did not compromise maximum flexion angle compared to the uninjured controls (group 1) or the isolated tendon repair digits (group 2).

Keywords

A2 pulley Flexor tendon Flexor tendon repair Pulley reconstruction Zone II

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References

Arora

Fritz

Zimmermann

. Reconstruction of the digital flexor pulley system: a retrospective comparison of two methods of treatment. J Hand Surg. 2007;32E:60–6.

Bowers

Kuzma

Bynum

. Closed traumatic rupture of finger flexor pulleys. J Hand Surg. 1994;19A:782–7.

Boyer

Stickland

Engles

. Flexor tendon repair and rehabilitation: state of the art in 2002. Instr Course Lect. 2003;52:137–61.

Bunata

. Primary pulley enlargement in zone 2 by incision and repair with an extensor retinaculum graft. J Hand Surg. 2010;35A:785–90.

Bunata

Kosmopoulos

Simmons

. Primary tendon sheath enlargement and reconstruction in zone 2: an in vitro biomechanical study on tendon gliding resistance. J Hand Surg. 2009;34A:1436–43.

Clark

Skeete

Amadio

. Flexor tendon pulley reconstruction. J Hand Surg. 2010;35A:1685–9.

Coert

Uchiyama

Amadio

. Flexor tendon-pulley interaction after tendon repair. A biomechanical study. J Hand Surg. 1995;20B:573–7.

Gelberman

Boyer

Brodt

. The effect of gap formation at the repair site on the strength and excursion of intrasynovial flexor tendons. An experimental study on the early states of tendon-healing in dogs. J Bone Joint Surg. 1999;81:975–82.

Harris

Foster

. The aetiology of acute rupture of flexor tendon repairs in zones 1 and 2 of the fingers during early mobilization. J Hand Surg. 1999;24B:275–80.

10.

Hasslund

Jacobson

Dadali

. Adhesions in a murine flexor tendon graft model: autograft versus allograft reconstruction. J of Orthop Res. 2008;26:824–33.

11.

Kapandji

. Reconstructive augmentation of the metacarpal tendons. Ann Chir Main. 1983;2:281–2. French.

12.

Lilly

Misser

. Complications after treatment of flexor tendon injuries. J Am Acad Orthop Surg. 2006;14:387–96.

13.

Lin

Amadio

. Biomechanical analysis of finger flexor pulley reconstruction. J Hand Surg. 1989;14B:278–82.

14.

Lin

Amadio

. Biomechanical studies of running suture for flexor tendon repair in dogs. J Hand Surg. 1988;13A:553–8.

15.

Lister

Kleinert

Kutz

. Primary flexor tendon repair followed by immediate controlled mobilization. J Hand Surg. 1977;2A:441–51.

16.

Mih

. Flexor tendon pulley reconstruction. Oper Tech Orthop. 1998;8:116–9.

17.

Mitsionis

Bastidas

Grewal

. Feasibility of partial A2 and A4 pulley excision: effect on finger flexor tendon biomechanics. J Hand Surg. 1999;24A:310–4.

18.

Nishida

Amadio

Bettinger

. Flexor tendon-pulley interaction after pulley reconstruction: a biomechanical study in a human model in vitro. J Hand Surg. 1998;23A:665–72.

19.

Nishida

Seiler

Amadio

. Flexor tendon-pulley interaction after annular pulley reconstruction: a biomechanical study in a dog model in vivo. J Hand Surg. 1998;23A:279–84.

20.

Okutsu

Ninomiya

Hiraki

. Three-loop technique for A2 pulley reconstruction. J Hand Surg. 1987;12A:790–4.

21.

Paillard

Amadio

Zhao

. Pulley plasty versus resection of one slip of the flexor digitorum superficialis after repair of both flexor tendons in zone II: a biomechanical study. J Bone Joint Surg. 2002;84A:2039–45.

22.

Saldana

Chow

Gerbino

. Further experience in rehabilitation of zone II flexor tendon repair with dynamic traction splinting. Plast Reconstr Surg. 1991;87:543–6.

23.

Seiler

Uchiyama

Ellis

. Reconstruction of the flexor pulley: the effect of the tension and source of the graft in an in vitro dog model. J Bone Joint Surg. 1998;80A:699–703.

24.

Silva

Brodt

Boyer

. Effects of increased in vivo excursion on digital range of motion and tendon strength following flexor tendon repair. J Orthop Res. 1999;17:777–83.

25.

Strickland

. Flexor tendon injuries: II. Operative technique. J Am Acad Orthop Surg. 1995;3:55–62.

26.

Strickland

. Development of flexor tendon surgery: twenty-five years of progress. J Hand Surg. 2000;25A:214–35.

27.

Strickland

. The scientific basis for advances in flexor tendon surgery. J Hand Ther. 2005;18:94–110.

28.

Tanaka

Amadio

Zhao

. Gliding resistance versus work of flexion-two methods to assess flexor tendon repair. J of Orthop Res. 2003;21:813–8.

29.

Tanaka

Amadio

Zhao

. Gliding characteristics and gap formation for locking and grasping tendon repairs: a biomechanical study in a human cadaver model. J Hand Surg. 2004;29A:6–14.

30.

Tanaka

Amadio

Zhao

. The effect of partial A2 pulley excision on gliding resistance and pulley strength in vitro. J Hand Surg. 2004;29A:877–83.

31.

Tang

. Clinical outcomes associated with flexor tendon repair. Hand Clin. 2005;21:199–210.

32.

Tang

Wang

. Effect of pulley integrity on excursions and work of flexion in healing flexor tendons. J Hand Surg. 2001;26A:347–53.

33.

Taras

Gray

Culp

. Complications of flexor tendon injuries. Hand Clin. 1994;10:93–109.

34.

Widstrom

Doyle

Johnson

. A mechanical study of six digital pulley reconstruction techniques: Part II. Strength of individual reconstructions. J Hand Surg. 1989;14A:826–9.

35.

Widstrom

Johnson

Doyle

. A mechanical study of six digital pulley reconstruction techniques: Part I. Mechanical effectiveness. J Hand Surg. 1989;14A:821–9.

36.

Zhao

Amadio

Momose

. Remodeling of the gliding surface after flexor tendon repair in a canine model in vivo. J Orthop Res. 2002;20:857–62.