You are in: eMedicine Specialties > Orthopedic Surgery > HAND AND UPPER EXTREMITY Flexor TenolysisArticle Last Updated: Apr 8, 2008AUTHOR AND EDITOR INFORMATIONSection 1 of 11
  Author: W Jay Gorum II, MD, Consulting Surgeon, Gorum Orthopedics and Associates W Jay Gorum II is a member of the following medical societies: American Academy of Orthopaedic Surgeons Coauthor(s): Cato T Laurencin, MD, PhD, University Professor, Lillian T Pratt Distinguished Professor and Chairman, Department of Orthopaedic Surgery, The University of Virginia Editors: Michael S Clarke, MD, Clinical Associate Professor, Department of Orthopedic Surgery, University of Missouri-Columbia School of Medicine; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Thomas R Hunt III, MD, John D Sherrill Professor and Director of Orthopaedic Surgery, Surgeon in Chief of UAB Highlands Hospital, Director of Hand and Upper Extremity Fellowship, University of Alabama at Birmingham; Dinesh Patel, MD, FACS, Associate Clinical Professor of Orthopedic Surgery, Harvard Medical School; Chief of Arthroscopic Surgery, Department of Orthopedic Surgery, Massachusetts General Hospital; Harris Gellman, MD, Consulting Surgeon, Broward Hand Center, Voluntary Clinical Professor of Orthopedic Surgery and Plastic Surgery, Departments of Orthopedic Surgery and Surgery, University of Miami School of Medicine Author and Editor Disclosure Synonyms and related keywords: tendon adhesion, tendon anatomy, tendon lacerations INTRODUCTIONSection 2 of 11
  Flexor tenolysis is a procedure used to remove adhesions from tendons and is designed to improve active digital flexion. History of the ProcedureDespite attempts to develop surgical and rehabilitation techniques to maximize flexor tendon function following surgical repair, postoperative tendon adhesions remain a problem and a significant source of morbidity. In these cases, appropriately timed flexor tenolysis of nongliding adhesions can markedly improve function of the digit. ProblemPrecise digital function requires smooth gliding of flexor tendons within their sheath. Tendon adhesions following injury or repair limit gliding, thereby decreasing the active range of motion of the digit as compared to the passive range of motion.1 FrequencyThe occurrence of flexor tendon adhesions depends on the degree and location of soft tissue injury. Crush injuries and disruption in zone II are frequently complicated by tendon adhesions. EtiologyViolation of the tendon surface, whether traumatic disruption or from attempts at surgical treatment, results in production of adhesions through the normal inflammatory response. The limited space between the profundus and superficialis tendons and the theca is a primary contributor to the problem. Once adhesions develop, tendon gliding within this confined space is affected and active digital motion is diminished. PathophysiologyThe process by which flexor tendons heal is debatable. The conventional theory is that peripheral fibroblasts from the surrounding connective tissue invade the zone of injury and serve as a source of reparative cells. In this theory, the tendon itself is believed to have no intrinsic ability for repair. New evidence seems to indicate that the epitenon cells migrate into and across the zone of injury along a fibrin lattice and that collagen fibers, formed by the epitenon and endotenon fibroblasts, bridge the laceration site.2 Vascularization of the repair zone is from within the proximal end of the tendon by proliferation of vascular channels.3 These studies suggest that the tendon possesses the intrinsic ability to participate in the healing process.4, 5 Peripheral adhesions attach to the repairing tendon, potentially limiting tendon excursion during flexion and extension. Although adhesions may add strength to the healing tendon, it is unlikely that adhesions are an essential component of the reparative process. ClinicalPatients present following tendon injury or repair with a complaint of decreased motion of the digit. On physical examination, a significant decrease of active range of motion compared to passive range of motion is demonstrated, especially in flexion. INDICATIONSSection 3 of 11
Tenolysis is technically demanding and should not be entered into lightly. No absolute indications for tenolysis exist. Each case must be treated individually, taking into account the details of the initial injury, the initial surgical treatment, the postoperative therapy program, and patient-specific factors. Patient selection is paramount. Patient factors, such as motivation and the ability to follow an intensive postoperative rehabilitation program, age, occupational needs, neurovascular status of the digit, and the presence of joint contracture, help guide the decision-making process. However, flexor tenolysis is recommended whenever active flexion of the digit is significantly less than passive flexion of the digit and all attempts at improvement through therapy have been exhausted. Among orthopedic surgeons, no consensus exists regarding the exact timing of the procedure. Weeks et al demonstrated that 22 weeks following a tendon graft, most patients achieved maximum active motion of the digit.6 Therefore, they recommended operating at that time. Rank et al advocate waiting 6-9 months before considering flexor tenolysis.7 Green and Strickland support a minimum of 3 months prior to operative intervention.8 Significant improvement in active flexion after tenolysis can be confidently expected only in children older than 11 years.9 RELEVANT ANATOMYSection 4 of 11
Two flexor tendons exist within the theca (the enclosed tendon sheath) that participate in flexion of the digit. These tendons originate in the forearm and pass through the carpal canal at the wrist. The flexor digitorum superficialis (FDS) inserts into the base of the middle phalanx and flexes the metacarpophalangeal (MP) and proximal interphalangeal (PIP) joints. The flexor digitorum profundus (FDP), or deep flexor tendon, inserts into the base of the distal phalanx. It serves to flex all 3 joints in the finger. The deep flexor tendons, except for the FDP to the index digit, usually function as a unit due to proximal interconnections. This is in contrast to the independent function of the FDS tendons. The flexor retinaculum is a fibrous sheath that surrounds the flexor tendons and provides mechanical advantage, preventing bowstring of the flexor tendons and aiding in flexion of the digit. Five annular (A) and 3 cruciate (C) bands make up the pulley system. Moving from distal to proximal in the phalanx, the A5 pulley overlies the distal interphalangeal (DIP) joint. C3, A4, and C2 are over the middle phalanx. A3 covers the PIP joint. C1 and A2 are found over the proximal phalanx, and A1 is over the metacarpophalangeal joint. A4 and A2 pulleys arise from bone alone and, thus, are the strongest and most critical of the pulley. A1, A3, and A5 arise from the volar plate and bone. C3 often is an oblique band. It is just distal to the A4 pulley on the middle phalanx. A4 is a broad structure and lies over the middle one third of the middle phalanx. C2 originates at the base of the middle phalanx and is a thin band that crisscrosses. C1 also crisscrosses and overlies the distal portion of the proximal phalanx. A2 is the largest pulley, spanning the proximal half of the proximal phalanx. Some disagreement exists regarding the exact vascular supply to the flexor tendons. From the forearm to the palm, blood supply is generally believed to be provided by segmental vessels from the paratenon, which give rise to longitudinal intratendinous vessels that travel with the tendons. At about the level of the midproximal phalanx, the vincula begin to contribute. A short vinculum and a long vinculum exist for each of the flexor tendons. These vincula enter the tendons on their dorsal surface. In addition, many investigators believe that the synovial fluid within the enclosed theca also contributes nourishment to the flexor tendons. CONTRAINDICATIONSSection 5 of 11
Tenolysis is absolutely contraindicated in patients with active infection, motor-tendon problems secondary to denervation, and unstable underlying fractures requiring fixation and immobilization. Relative contraindications include extensive adhesions, immature previous scars, and severe posttraumatic underlining arthrosis. WORKUPSection 6 of 11
Lab Studies
Imaging Studies
Histologic FindingsCells in the injury zone resemble myofibroblast and synthesize collagen, primarily types III and I. Cells from the epitenon are present, regulating the initiation of a-procollagen and phagocytosis of collagen debris. These cells are active in protein synthesis. Metalloproteinases have been implicated as a factor in the regulation of collagen synthesis. Glycosaminoglycans appear after 2 weeks. Fibronectin has been identified in tendon and the sheath synovium. TREATMENTSection 7 of 11
Medical therapyMaximize therapy. Surgery is performed only after all efforts to regain motion through medical therapy have failed. Surgical therapyThe surgical technique consists of sharply releasing the adherent scar through a liberal midaxial or Brunner incision. Every effort should be made to preserve the pulley system, but the surgeon should be prepared to perform a staged tendon reconstruction with pulleys if required.10 Preoperative detailsExamine the hand to verify that the skin and soft tissue are mature without evidence of active inflammation. Review and document all measurements of active and passive extension and flexion. These values are necessary for comparison of preoperative and postoperative function. Review preoperative radiographs to ensure joint preservation. Intraoperative detailsLocal anesthesia is supplemented with intravenous analgesia and tranquilizing drugs. This allows the patient to demonstrate improvement in active motion following tenolysis. Without this active patient participation, success of the procedure is less predictable. Surgical exposure is through either a midaxial or Brunner zigzag incision. Avoid touching the epitenon with forceps; this becomes a potential site for more adhesions and scar. Complete visualization of the flexor tendon sheath and mobilization of the neurovascular bundles facilitate evaluation and comprehensive adhesion release. Meticulous dissection is required during this procedure. The tendon border enveloped in the scar tissue must be defined to fully resect adhesions. Using sharp dissection, preferably with a Beaver blade, the profundus tendon is separated from the superficialis tendon. Differentiating scar from the pulley system is often difficult, though active participation by the patient during the procedure can help. The pulley system, especially A2 and A4 pulleys, must be preserved. The patient is asked periodically to flex the digit in order to evaluate the adequacy of the tenolysis. If the patient is able to fully flex the digit within passive limits, the surgery is considered successful. Hemostasis is obtained, and the wound is closed with 5-0 Prolene, dressed, and splinted.11, 12, 13 In unusual circumstances, pulley reconstruction may be required. If the quality of the tendon or tendons is poor or continuity cannot be maintained, a 2-staged reconstruction is required. In stage 1, a Hunter rod (either passive or active) is implanted and the pulleys are reconstructed. Typically, 3-6 months later, stage 2 is performed. The rod is removed, and a tendon graft or transfer performed.14 Postoperative detailsEarly motion, usually within 24 hours postoperatively, is the cornerstone of successful tenolysis. Pain can be a significant limiting factor in the postoperative period. A postoperative regimen that combines effective analgesia with motion is employed. In difficult cases, an indwelling brachial catheter can provide pain relief while preserving motor function. 15 Formal hand therapy is usually obtained 3-5 days per week initially then slowly tapered. The surgeon must carefully monitor this process and adjust the therapy program as needed. Strickland advocates use of transcutaneous electrical nerve stimulation (TENS) units.16 Other adjunctive modalities may include continuous passive motion (CPM), muscle stimulation, splinting, and biofeedback.17, 18, 19, 20 Follow-upClose follow-up is mandatory to evaluate for complications and for advancement in range of motion. Having a close working relationship with a hand therapist facilitates the patient's chance of a successful outcome. COMPLICATIONSSection 8 of 11
Though not a complication per se, the most common failure of tenolysis is recurrent and progressive digital stiffness and contracture. Treatment revolves around therapy, including dynamic splinting. Revision tenolysis may occasionally be required. Prior to considering another operation, the surgeon must have firmly in mind the reasons for failure of the other procedures. In addition, the tendon may rupture in 8-15% of cases. Reflex sympathetic dystrophy, now termed complex regional pain syndrome, requires a multidisciplinary approach that includes, but is not limited to, physical modalities; oral and/or injected pharmacologic agents; and neurologic, psychiatric, and psychological involvement. Infection occurs in 1-7% of cases and may be related to very early motion. OUTCOME AND PROGNOSISSection 9 of 11
There is improvement in active range of motion following tenolysis in 59-90% of cases, no improvement in 5-33% of cases, worsening of symptoms in 8% of cases, and rupture in 8-15% of cases. FUTURE AND CONTROVERSIESSection 10 of 11
Current controversies include the following:
Progress will continue in defining a tendon repair technique that will impart adequate strength to the repair to allow immediate active range of motion, thereby diminishing the likelihood of adhesion formation without risking tendon rupture. REFERENCESSection 11 of 11
Article Last Updated: Apr 8, 2008 |
