Chapter 25 A Historical Perspective on Flexor Tendon Reconstruction and Surgical Procedures

Andrew E. Farber, DO, Daniel P. Mass, MD

Outline

Flexor tendon reconstruction is a spectrum of challenging treatment options ranging from non-operative treatment to tenolysis to single-stage and multistage reconstructive surgical procedures. Secondary tendon reconstruction is indicated in the patients whose tendon injuries are not treated at the primary or delayed primary stages, whose injuries to the tendon are too serious, or where destruction of the flexor pulleys are too extensive, which prevents primary repair of the tendon. In the presence of severe scar in the tendon gliding bed or extensive pulley damages, both patient and surgeon are to be prepared for multiple surgical procedures. This chapter starts with a concise review of the development of secondary flexor tendon reconstruction, followed by descriptions of surgical procedures and postoperative rehabilitation of tendon grafting and staged tendon reconstructions.

In the tenth century, Avicenna, an Arabian surgeon, was credited with performing the first tendon repair surgery. In Europe, however, Galen teachings resulted in infrequent tendon repair. Galen did not differentiate between nerves and tendons, noting that nerves entered muscles and muscles ended with whitish cords. Accordingly, teaching at that time (circa 150 ad) involved an intimate relationship between tendons and nerves, so much so that physicians feared severe consequences from damaging or even touching a nerve or a tendon. They further believed that suturing of a nerve or a tendon would result in pain, convulsions, and gangrene.¹

In 1752, Galen’s concept that complications are associated with tendon damage was finally refuted by the work of Albrecht von Haller,¹ who demonstrated the insensibility of tendons. In England around 1850, Syme reported success with several cases of tendon repair paving the way for modern tendon repair and reconstruction.

Development of Tendon Reconstruction

Until the 1960s, tendon lacerations in zone 2, or “no man’s land,” were treated with removal of the tendon with grafting of new tendons. Sterling Bunnell taught “it is better to remove the tendons entirely from the finger and graft in new tendons smooth throughout its length.”^2,³ Based on Bunnell’s classic work in the early twentieth century, repair of tendon lacerations in zone 2, “no man’s land,” involved removal of the tendon and grafting new tendons.³ The techniques of single-stage free tendon grafting were later refined by a number of master hand surgeons, including Pulvertaft, Graham, Littler, Boyes, and Stark.⁵^–¹⁷ Boyes’ large series of tendon grafts popularized the procedure in 1950s and 1960s.^13,^14,¹⁷

In 1963, Bassett and Carroll subsequently first described this type of two-stage flexor tendon reconstruction using a silicone implant.¹⁸ In 1965, Hunter first published his experience with tendon implants for tendon reconstruction.¹⁹ As is widely reported, Hunter further refined this process in the early 1970s, resulting in the naming of the Hunter silicone rod and staged tendon reconstruction techniques currently used.^19,²⁰ An alternative method was described by Paneva-Holevich in 1969,²¹ who sutured the proximal cut end of the flexor digitorum superficialis (FDS) tendon to the proximal cut end of the profundus tendon in the palm. At the second stage, the FDS tendon was severed as far proximal as possible and this end was brought out to be inserted at the distal phalanx as a pedicle graft. In 1982, Paneva-Holevich reported secondary repair of 324 flexor tendon injuries using pedicle FDS tendon grafting. In 39 fingers, this technique was combined with silicone rod implantation at the first stage to prepare a smooth bed for the graft.²²

Surgical Procedures

It is helpful to think of flexor tendon reconstruction as a spectrum of challenging treatment options ranging from nonoperative treatment to tenolysis to single-stage and multistage reconstructive surgical procedures. Both patient and surgeon need to be prepared for multiple surgical procedures and strict compliance with postoperative rehabilitation protocols. It is therefore imperative to carefully consider surgical and nonsurgical indications when selecting the best treatment protocol. Additionally, it is essential to discuss the range of outcomes with the patient including the likelihood of stiffness and the possible need for amputation. In some cases, doing nothing or performing a primary amputation or arthrodesis may avoid a series of painful procedures that may ultimately provide or restore minimal function.

Bunnell’s extensive work on flexor tendon injury and reconstruction resulted in the widely accepted belief that injured tendons should be removed and replaced with new tendon graft.^2,³ Bassett, Carroll, and Hunter refined this recommendation with their works on the silicone rod, which was designed to create a smooth bed for tendon grafting. These developments led to the widespread acceptance and use of the two-stage tendon reconstruction.

Over the four decades that followed, however, significant advancements in flexor tendon repair and reconstruction led to revised indications for both primary repair and secondary reconstruction. When considering secondary repair, the decision needs to be made whether to graft and reconstruct the tendons in a single stage or to perform a two-stage repair. This decision requires careful preoperative and intraoperative examinations. Regardless of the surgical technique chosen, patients should be counseled and should be prepared to participate in a complex rehabilitation program. This may preclude performing the procedure on children younger than 3 years of age.

Single-Stage Reconstruction

Preoperatively, patients considered for single-stage reconstruction with tendon grafting must display a well-healed, neurovascularly intact digit without excessive scarring. Intraoperatively, an intact, smooth tendon bed should be present with an adequate pulley system. Patients with inadequate soft tissue coverage, those with significant, dense scarring, or an inadequate pulley system generally benefit from a two-stage reconstruction. Additional indications and limitations are described next.

Although primary flexor tendon repair has become increasingly popular, select patients can still benefit from single-stage flexor tendon reconstruction.⁴^–¹⁰ Careful patient selection and intraoperative evaluation are critical to maximize the chance for a successful outcome. Boyes and others have described indications for single-stage grafting including: (1) injuries with segmental tendon loss and (2) delayed presentation resulting in the inability to perform a primary end-to-end repair. This may include injuries older than 3 to 6 weeks.^4,¹¹^–¹⁷

The hand and finger should also demonstrate at least one intact digital nerve in the affected finger, a well-healed wound without extensive scarring, adequate circulation; and near full-passive motion of all joints. Insufficient passive range of motion should be addressed with a course of hand therapy prior to considering surgical intervention. Patients should also be prepared to participate in a rigorous and complex postoperative rehabilitation program. This requirement generally excludes growing children and some elderly patients.¹⁹

Excellent surgical technique is imperative and should be carried out under loupe magnification and tourniquet control.

Only gold members can continue reading. Log In or Register to continue