Flexor tendon repair

During the last 20 years there have been significant innovations in injury repair and aftercare for patients who sustain zone 2 flexor tendon injuries. Improvements in our understanding of the mechanisms of repair and the variables that impact the function of the repair site have resulted in outcome improvements. The purpose of this article is to review advances in flexor tendon surgery and to discuss current trends in the repair of zone 2 flexor tendon injuries. Copyright © 2001 by the American Society for Surgery of the Hand     

Flexor tendon repair

Healing canine flexor tendons treated with either total immobilization, delayed protected mobilization, or early protected mobilization was studied by biomechanical, microangiographic, biochemical, and histologic techniques at intervals through 12 weeks. The healing characteristics of the early mobilization tendons showed higher tensile strengths and improved gliding function than the delayed mobilization and immobilization tendons. Protected passive motion brought about accelerated changes in peritendinous vessel density and configuration, as well as increased repair site total DNA content. While adhesions obliterated the space between the tendon surface and the tendon sheath of the immobilized repairs, the mobilized tendons demonstrated coverage of the repair site by cells from the epitenon by 10 days, and a smooth, gliding surface that was maintained free of adhesions through 42 days. A series of in vitro studies demonstrated the cellular processes involved in the repair: phagocytosis of cellular debris and collagenous fragments by cells from the epitenon, and collagen synthesis primarily by endotenon cells.     

Tissue engineering solutions for tendon repair

Tendon injuries range from acute traumatic ruptures and lacerations to chronic overuse injuries, such as tendinosis. Even with improved nonsurgical, surgical, and rehabilitation techniques, outcomes following tendon repair are inconsistent. Primary repair remains the standard of care. However, repaired tendon tissue rarely achieves functionality equal to that of the preinjured state. Poor results have been linked to alterations in cellular organization within the tendon that occur at the time of injury and throughout the early stages of healing. Enhanced understanding of the biology of tendon healing is needed to improve management and outcomes. The use of growth factors and mesenchymal stem cells and the development of biocompatible scaffolds could result in enhanced tendon healing and regeneration. Recent advances in tendon bioengineering may lead to improved management following tendon injury.     

Flexor tendon repair

In 1979 Verdan wrote, "whatever the situation may be, adhesions are until now certainly not a technically avoidable accident, but rather a consequence of the physiological healing process. As long as we have no technical solution to the problem of accurately maintaining the two cut ends in an intact synovial sheath without interfering with the blood supply, adhesions will remain a biologic inevitability." Although his admonition remains applicable, advances are occurring in our understanding of tendon healing and nourishment, the pulley system, techniques of repair, and the modification of adhesions. Armed with this information, each surgeon dealing with interruptions of flexor tendons must develop a rational, systematic approach to the management of these difficult injuries. The principles of atraumatic technique, as set down many years ago by Bunnell, remain inviolate. Repair procedures should be carried out by surgeons who are thoroughly knowledgeable and well trained in the area of flexor tendon surgery. Primary or delayed primary tendon repair of both the profundus and superficialis tendons should be carried out in almost all patients in all zones of flexor tendon interruption. The use of nonabsorbable sutures with a modified Kessler or Tajima "core suture" has proved to be effective, and, whenever possible, repair of the flexor tendon sheath seems to be appropriate. A well supervised program of early motion utilizing either active or passive techniques is also beneficial in suitable individuals. The restoration of function to a digit following flexor tendon interruption may be a long and tedious undertaking, requiring strong rapport between surgeon, therapist, and patient. When initiating the care of a patient with such an injury, the surgeon should spend considerable time explaining the problems related to the particular injury, the likelihood of achieving success, and the number of procedures that may be required. A high degree of patient motivation must be established to insure the proper participation in the demanding postoperative regimen associated with these procedures. With the important advances occurring in many areas of flexor tendon surgery, it is realistic to believe that in the future the techniques described in this article will be substantially altered and modified. Results should continue to improve until the patient and surgeon can expect all digits to return to nearly full function after flexor tendon interruption.     

Investigation of locking configurations for tendon repair

PURPOSE: Locking sutures have proven beneficial to the strength of the repaired tendon. In this study we investigated the effects of 3 locks in the tendon-suture junction and their effect on repair strength. METHODS: Forty-seven fresh pig flexor tendons were transected and repaired using 4-strand repairs with 3 different configurations of locks in each tendon-suture junction: 1 exposed cross-lock, 1 embedded cross-lock, and 1 circle lock. The tendons were subjected to a linear noncyclic load-to-failure test using a tensile testing machine. The initial gap, the 2-mm gap force, and the ultimate strength were measured to compare the biomechanical performance for each repair. RESULTS: Despite noticeable differences in the configurations of locks the gap formation force and ultimate strength were not significantly different among the 3 tested locking configurations. CONCLUSIONS: An exposed cross-lock, an embedded cross-lock, and a circle lock at tendon-suture junctions had similar locking power. Circle-lock repairs without cross-locking components produce tensile strength similar to cross-locking repairs. The findings of this study suggest that the creation of cross-configurations in locking repairs used conventionally by many surgeons is not essential to repair strength and that circle locking is as efficient as cross-locking in the repair of lacerated flexor tendons.     

Technique for repair of the subscapularis tendon

Patients with sudden loss of active motion after an external rotation or hyperextension injury should be viewed with a high index of suspicion for a subscapularis tear. Exaggerated external rotation and the presence of a positive lift off or belly press test on physical examination combined with appropriate imaging studies will lead to an early diagnosis. Careful surgical repair combined with a thoughtful rehabilitation program will lessen both the length and degree of disability from this clinical entity.     

Current techniques for primary flexor tendon repair

Flexor tendon lacerations still represent a challenging problem to hand surgeons, particularly in zone 2. There has been a considerable improvement in therapeutic modalities during the past 30 years, following a better understanding of the tendon healing process. It is now universally accepted that flexor tendon repair must be performed in emergency, by mean of a direct primary suture, and followed by a immediate rehabilitation protocol. More recently, the benefits of early active motion has been demonstrated. Early axial loading of the repair enhances intrinsic callus formation, reduces peritendinous adhesion, and could attenuate the fragilization of the callus during the first three weeks. However, active motion generates a heavier stress on the repair. The initial resistance of the repair thus appeared to be the critical point. This has motivated a large number of investigations about the suture technique itself, with in vitro and in vivo evaluations. The results of these studies did precise the concept of "locking" and "grasping" sutures, and demonstrated the superiority of four strands sutures. These experimental results cannot be ignored by surgeons dealing with flexor tendon repairs.     

Cutting or round-bodied needles for tendon repair

We carried out a biomechanical study comparing tensile strength after using round-bodied or cutting needles for tendon repair. Swine tendons were repaired in three groups: Group 1 core suture repair only; group 2 core and circumferential suture repair; and group 3 isolated circumferential suture repair. The tendons were tested at longitudinal stress to failure at 5mm/minute. No significant differences were found between the round-bodied and cutting needles in any group. Equal numbers in the core suture repair group failed by suture pullout when comparing cutting and round-bodied needles. We conclude that the choice of needle has no effect on the outcome of tendon repair if there is consistency of surgeon's skill and experience.     

Cobb repair for tibialis posterior tendon rupture

The tibialis posterior is the main dynamic stabilizer of the hindfoot against a valgus deformity. Its rupture results in hindfoot valgus with a considerable biomechanical disturbance and functional loss in the affected foot. A new method of reconstruction of this tendon is described which involves the use of half the tendon of tibialis anterior.     

Principles of tendon repair

Tendon injuries in the hand are common; they are usually open injuries requiring surgical intervention. In this article we discuss tendon injuries in terms of approach to repair beginning at the time of diagnosis through to the rehabilitation programmes and outcome measures commonly used in the UK. In general tendon injuries should be considered using Verdan's zones for both extensor and flexor injuries. Flexor tendons require a high strength repair and usually warrant a core suture with epitendinous reinforcement bearing in mind the importance of not disrupting glide with unnecessary suture bulk. Extensor tendons more proximally can be treated in the same way but distally require only a running suture in the flattened tendon ends. All tendon injuries require a period of protected mobilization with splinting aiming to protect the repair but reduce stiffness in other joints.     

自体腱鞘移植在修复肌腱及腱周组织严重损伤中的应用

目的　探索自体腱鞘移植在屈肌腱伴腱周组织严重损伤时 ,重建指屈肌腱背侧或环周腱鞘缺损的方法和效果。方法　对 2 1例 2 5指 区指屈肌腱伴腱周组织严重损伤者 ,取自体腕伸肌腱腱鞘作游离移植 ,修复缺损的指屈肌腱背侧或环周腱鞘 ;并按肌腱损伤时间的早晚 ,同时作肌腱修复术、肌腱移植术或肌腱粘连松解术。术后共随访到 2 4指 ,平均随访 10个月。结果　根据 Strickland评价标准 ,优 7指 ,良 11指 ,中 5指 ,差 1指 ;优良率为 75 %。结论　用游离自体腱鞘移植重建指屈肌腱背侧腱鞘或环周腱鞘 ,可提高肌腱修复术在治疗肌腱伴腱周组织严重损伤中的疗效。