Early active mobilization of tendon grafts using mesh reinforced suture techniques

E A R L Y A C T I V E M O B I L I Z A T I O N OF T E N D O N G R A F T S U S I N G MESH REINFORCED SUTURE TECHNIQUES K. L. SILFVERSKIOLD and E. J. MAY

From the Division of Hand Surgery, Department of Orthopaedic Surgery, Sahlgren Hospital, University of Gothenburg, Sweden The flexor digitorum profundus tendon in 11 digits with division of both flexor tendons in zone 2 was reconstructed with a palmaris longus tendon graft in a ,two-stage procedure. The distal and proximal fixation of the graft was reinforced with a polyester mesh sleeve placed around the ends of the graft during stage 1. All digits were mobilized with a combination of active extension and active and passive flexion within 3 days of the second stage. There were three ruptures, one due to faulty technique and two due to falls on outstretched hands during alcohol intoxication and football. Excluding the ruptures, the mean active composite distal and proximal interphalangeal joint range of motion 6 weeks and 6 months post-operatively was 141 ° and 136 ° respectively. The results indicate that palmaris longus tendon grafts can survive and heal during early active mobilization, with few or no adhesions of functional significance. The techniques described here represent one possible approach to the safe implementation of early active mobilization after tendon grafting procedures.

Journal of Hand Surgery (British and European Volume, 1995) 20B: 3:301 307 Results after reconstruction of flexor tendon function with free tendon grafts are still far from optimal. Although the introduction of the staged reconstruction technique with a silicone rod has improved results in severely injured digits (Hunter and Salisbury, t971), adhesions between the graft and the surrounding tissues remain a major problem. If combined with strong enough suture techniques, active mobilization started within a few days after reconstruction could be expected to minimize adhesion formation (Silfverski61d and May, 1994) and perhaps also promote healing (Lundborg et al, 1980; McDowell and Snyder, 1977). In this report we describe our initial experience using mesh reinforced suture techniques and early active mobilization after reconstruction of flexor function with free palmaris longus grafts in zone 2 injuries.

described by Hunter and Salisbury (1971) was used. At the first operation, scar excision, pulley reconstruction and capsulectomy were performed as indicated. A silicone rod (Holter-Hausner International) was inserted, extending from the fingertip to the distal forearm, and sutured to the distal FDP stump in the fingertip. The proximal end of the rod was left free. The distal and proximal ends of the palmaris longus tendon were exposed through separate incisions and a strip of Mersilene mesh (Ethicon Inc) was wrapped around each end of the tendon to form two 15 to 18 mm long mesh sleeves. A 6/0 polypropylene running suture was used to close the "seam" of each sleeve and attach it to the lateral edge of the tendon (Fig la). When necessary for extra length, the proximal mesh was placed around the intramuscular part of the tendon (after scraping it clean). With the continuity of the palmaris tendon still intact, the wounds were closed. Post-operatively the hand and wrist were immobilized in a dorsal splint for ten days before mobilization was begun. When the palmaris tendon was harvested at the second operation, 2 to 3 months after the first, the mesh reinforced ends were covered with a smooth layer of connective tissue. The mesh was also firmly attached to the tendon and thus provided a strong hold for sutures

MATERIAL AND METHODS Patients

From October 1990 to December 1991 the flexor digitorum profundus (FDP) tendon in 11 digits (ten patients) with complete division of both flexor tendons in zone 2 was reconstructed with a free palmaris longus tendon graft and mesh reinforced suture technique. The mean age of the patients was 34 years (range: 22 years to 63 years). The pre-operative condition of the digits was categorized according to a modification of Boyes (1950) original system (Table 1). There were seven grade 5 injuries, one grade 4 injury, one grade 3 injury and two grade 2 injuries. Details of patients and their injuries are shown in Table 2.

Table 1--Grading of the pre-operative injury status (modified from Boyes, 1950)

Grade

Status Good Scar (soft tissue scarring requiring excision) Joint (scar and joint contracture) Nerve (scar and nerve injury) Multiple (scar, joint and nerve or multiple digit injuries with at least grade 3 status)

Operative technique

All operations were performed under axillary block in a bloodless field. A standard two-stage procedure as 301

302

THEJOURNALOF HANDSURGERYVOL.20BNo. 3 JUNE1995

Table 2--Details of patients and their range of motion (ROM) Patient

Age/Sex

Digit

Injury grading

Active R O M 6 weeks post-operatively in degrees PIP

1 2 3 4 4 5 6 7 8 9 10

Fig 1

30/M 27/M 30/M 27/M 27/M 63/M 44/M 31/F 26/M 22/M 44/M

Right ring Left small Right ring Right middle Right ring Left small Right middle Right middle Left index Right index Right small

2 4 5 5 5 5 5 5 2 5 3

0-90 0 90 0-85 0 95 0-100 20 75 0-80 0-85 0-100

DIP

PIP + DIP

0-60 0 50 0-55 0 65 0-60 0 55 0-65 20-65 0-35 Rupture 3 weeks postop Rupture 1 week postop

150 140 140 160 160 110 145 130 135

Active R O M 6 months post-operatively in degrees PIP

DIP

PIP + DIP

0-80 0-70 150 5 95 10 70 150 0-90 0-55 145 15 100 0 75 160 15-150 0-70 160 40 95 0-55 110 30-90 20-65 105 30-90 35-80 105 Rupture 3 months postop

(a) The mesh sleeve applied around the proximal, intramuscular, part of the palmaris longus at stage 1. (b) The mesh-reinforcedpalmaris longus end covered with a smooth layer of connective tissue at stage 2, ready to be attached to the distal phalanx with two 3/0 sutures.

(Fig lb). After withdrawing the silicone rod, the reversed palmaris graft was passed into its place so that what originally was the proximal end of the graft was placed distally and vice versa. The mesh reinforced end of the graft was attached to the distal phalanx with two 3/0 sutures (Fig lb), either in the usual manner with a longitudinal drill hole through the bone and tied over a dorsal button, or with a palmar cortical window and a transverse drill hole through the bone, as described by Lee (1990). For the proximal junction the following technique was used (Fig 2). After adjusting the tension, the mesh reinforced end of the graft was attached, with a few stay sutures, side to side to the proximal F D P stump just proximal to the wrist crease. Another mesh sleeve was then pulled over the junction and secured proximally to the F D P with a previously described circumferential epitendinous cross-stitch (Silfverski61d and Andersson, 1993). The two tendon ends were then sutured to each other, and the external mesh, with two lateral running suture lines of the type described by Becker et al (1979). Each suture grasp thus included the external mesh, the F D P and the mesh reinforced graft. A 5/0 polyester suture was used throughout the

procedure. All patients received prophylactic antibiotic treatment, which was started pre-operatively and continued for a total of 3 days. Post-operative treatment and follow-up

After the operation the hand was immobilized in a dorsal plaster of Paris splint from below the elbow to the level of the PIP joints or, in some cases, to the fingertips. The wrist was splinted in a neutral position and the MP joints in 50 to 70 ° of flexion. IP joint mobilization was begun on the first to third postoperative day. Dynamic flexion traction with a palmar pulley was applied to all four digits. The patients performed ten active IP joint extension exercises hourly. Full active extension was ensured by the patients unloading the tension of the rubber bands by uncoupling them proximally during the extension phase. The passive flexion produced by the rubber bands was increased by the patients pushing down the tips of the digits with their other hand. While thus flexing the IP joints passively as much as possible, the patients contracted the flexor muscles actively twice for approximately 2 to 3

EARLY TENDON GRAFT MOBILIZATION

303

a

Fig 2

The proximal tendon bond. (a) Schematically. (b) In rive, showing the proximal F D P stump on the right and a glimpse o f the palmaris graft to the left, as it disappears into the mesh sleeve.

seconds each time. The strength and effect of these contractions were checked and adjusted by a therapist or a doctor so as to produce active flexion, without any passive help from rubber bands or the other hand, o f at least 80 ° in the PIP joint and at least 40 to 45 ° in the DIP joint (Fig 3b), before discharge on the third to fourth post-operative day. At night the IP joints were splinted in extension. This programme is identical to the programme we use for primary end-to-end repairs in zone 2. It has been described in greater detail previously (Silfverski61d and May, 1994). After 3 to 4 weeks the splint was removed and unassisted active flexion-extension exercises were begun. Progressive resisted exercises were started 6 to 8 weeks after the operation. Full power grip was not allowed until 3 months post-operatively. The dorsal button and pullout sutures used for the distal insertion were removed 8 weeks after the operation. After the initial in-patient period of 3 to 4 days, the patients were reviewed weekly for the first 6 weeks after the operation, then every 14 days for another 6 weeks. Apart from being called back for a 6-month review, the patients were then seen and treated as indicated by their progress. RESULTS Results in each patient are shown in Table 2. There were three ruptures, occurring 1 week, 3 weeks and 3 months post-operatively. The first was very early in the series before we understood how important it was to scrape the palmaris tendon clean of paratenon in the area where the mesh was applied. If this is not done, the mesh becomes attached to the paratenon, instead of the tendon proper, and can easily be pulled off with the paratenon when tension is applied, as happened in this patient. The two other ruptures were due to falls on outstretched hands, one during alcohol intoxication 3 weeks post-operatively and one during football 3 months post-operatively. One patient developed

inflammation around the dorsal button used for the distal fixation after swimming in a pool just before the pull-out sutures were to be removed, 7 weeks postoperatively. This settled after removal of the button and the sutures and a few days of rest. Excluding the digits in which the grafts ruptured, the mean active composite DIP and PIP joint range of motion 6 weeks and 6 months post-operatively was 141 ° and 136 ° respectively (Table 3). This amounted to 79% and 76% of the active range of motion in the corresponding digit in the opposite healthy hand. DISCUSSION The number of patients in this series was too small to draw any definite conclusions about results obtainable with these methods. Apart from the ruptures which were due either to faulty technique or to extreme stresses in connection with falls, the results were, however, very encouraging. An average recovery amounting to 79% of full "normal" active DIP and PIP range of motion, and a corresponding ratio of 85% between active and passive R O M 6 weeks post-operatively, must be considered excellent by any standards and certainly better than we previously obtained with conventional techniques, particularly since all injuries were in zone 2 and all but one had a pre-operative injury grading of 4 or 5 (ruptures not included). As can be seen in Table 2, the subsequent loss of range of motion that occurred between 6 weeks and 6 months post-operatively (a mean of 5 °) was mainly due to increasing extension deficits, primarily in three digits with grade 5 injuries. Although a common occurrence in patients immobilized post-operatively, we had hoped that early active motion would minimize this problem. Paradoxically, these flexion contractures were partly the result of a tendency for troublesome hyperextension deformities in the PIP joint in some of the more severely damaged digits, during the initial period of active movement. These were therefore treated with PIP extension block splinting. The subsequent balance

304

THE JOURNAL OF HAND SURGERY VOL. 20B No. 3 JUNE 1995

it

C Fig 3

Patient with double digit injuries of all four flexor tendons and both radiat neurovascular bundles (case 4). (a) Pre-operatively. (b) Flexing actively with rubber bands uncoupled 2 weeks after stage 2. (c and d) 3 months post-operatively after extension block splinting for PIP hyperextension problems resulted in slight PIP extension deficits.

between flexion contracture and swan neck deformity proved difficult to maintain. The mobilization programme used in this study was initially developed for primary tendon repairs (Silfverski61d and May, 1994). The combination of dynamic traction, additional passive flexion with the other hand and simultaneous active flexion (in addition to active extension) ensures that an optimal range of motion is obtained within a few days after the second stage, while minimizing the tension on the graft. The use of active flexion also ensures that tendon excursions really are proportional to the range of motion. This is not necessarily the case when passive flexion techniques are used, especially when soft and thin tendons like the palmaris or plantaris are used. As can be readily observed intra-operatively, these tend to bunch up within the synovial sheath (and even more so when parts of the sheath have been excised), instead of moving proximally when the digit is passively flexed. Adhesions are thus not prevented to the same extent as when fully active mobilization is used. This is, we believe, one of the major reasons for the still often unsatisfactory results obtained after tendon grafting even though controlled

mobilization based on passive flexion is used. In the only comparative study of post-operative immobilization and controlled passive mobilization there was no significant difference in the final joint range of motion between the two treatment r6gimes (Tonkin et al, 1988). Results of experimental studies, using passive mobilization in dogs, have indicated that grafts of intrasynovial origin, such as digital flexor tendons, may be better adapted for survival, with less cellular necrosis and adhesion formation, in the intrasynovial milieu of a digit than grafts of extrasynovial origin, such as the palmaris longus or plantaris tendons (Abrahamsson et al, 1994; Gelberman et al, 1992; Seiler et al, 1993). Other studies have shown that extrasynovial grafts, placed in a synovial milieu and immobilized postoperatively, survive through repopulation with fibroblasts from an extrinsic source (Kleiner et al, 1986). As cellular responses and adhesion formation are related to the stress applied and the excursions obtained (Gelberman et al, 1981; Hitchcock et al, 1987; Lundborg et al, 1980; Silfverski61d et al, 1992; Silfverski61d et al, 1993; Slack et al, 1984; Woo et al, 1981) it is possible that the use of early active mobilization may alter these

EARLY TENDON GRAFT MOBILIZATION

Fig 4

305

Example of suboptimal result due to extension deficits. Patient with not quite complete amputation of the three radial digits, in which complete arterial and venous revascularization was needed to restore circulation (case 6). (a) Original trauma. (b) Before stage 2 reconstruction of middle finger FDP. The primary result in the index finger and thumb was considered acceptable. (c and d) Flexion and extension 3 months after stage 2.

Table 3--Summary of mean results (excluding ruptures)

6 weeks post-operatively (n=9)

6 months post-operatively (n=8)

141 85 79

136 87 76

Total active IP R O M (degrees) Total active/passive IP ROM (%) Total active/normal* IP ROM (%)

*Normal refers to the active range of motion in the corresponding digit of the contralateral healthy hand.

responses and produce different results. While awaiting further clarification of these questions it appears that the palmaris tendon used in our study does survive and heal well enough during early active mobilization, with few or no adhesions of functional significance. The forces on the graft during early active mobilization are difficult to assess. Urbaniak et al (1975) and Schuind et al (1992) have recorded forces of up to 35 Newtons in the long flexors during unresisted active flexion in patients undergoing surgery in the carpal tunnel. In the clinical situation the forces may be substantially larger (Lane et al, 1976). Due to their partly

fibrocartilaginous quality, normal flexor tendons provide a fairly good hold for sutures. When sutured or reinserted to bone the weak point is therefore usually the suture material (Kim, 1981; Urbaniak et al, 1975; Wade et al, 1986). With thin, soft tendons, like the patmaris or plantaris tendons, the weak point is likely to be the suture's grip in the tendon. Singer et al (1989) found that the strength of a conventional bony fixation of a flexor carpi radialis graft (also a nonfibrocartilaginous tendon) to a toe phalanx in dogs, using 3/0 polyester, was only between 15 and 23 Newtons, 5 days after operation. With a comparatively

306

flimsy tendon, like palmaris longus, the holding power is substantially less. Morrison and Schlicht (1992) described a technique in which the plantaris tendon is harvested with its bony insertion in the calcaneus to provide a secure bone to bone fixation. The tendonbone junctions in prefabricated composite grafts were, however, shown by Singer et al (1989) to deteriorate in strength initially and were not significantly stronger than a conventional graft-to-bone suture fixation 5 days after grafting. Screws with washers or barbed fixation plates have been investigated by Robertson et al (1986). They can under certain circumstances provide superior strength but in the distal phalanx they have the drawback of having to be removed. The problem of wear of the tendon against the edge of the device during motion has yet to be solved. It is in this context that the twostage mesh reinforcement technique offers significant advantages. Several studies have shown that fibroblasts and collagen grow in and around implanted polyester mesh with very little inflammatory reaction (Amis et al, 1984; Goodship et al, 1985; Park et al, 1985) and that the breaking strength of polyester-tendon bonds are equal to tendon-tendon bonds already after 3 weeks (Salisbury et al, 1974). Polyester-bone interfaces also show the same type of intimate integration, with bone growing into the mesh (Arnoczky et al, 1988). In this series the palmaris tendon was always present. When it is absent or damaged on the ipsilateral side, the contra-lateral tendon (if available), the plantaris or any other tendon of choice, can be reinforced in the same manner. We prefer to place the proximal anastomosis in the forearm/wrist level because of its relative bulkiness. By utilizing the intramuscular portion of the palmaris we always managed to obtain a long enough graft. The results of this study indicate that palmaris longus tendon grafts can survive and heal during early active mobilization, with few or no adhesions of functional significance. The techniques described here represent one possible approach to the safe implementation of early active mobilization after tendon grafting procedures. Acknowledgments The study was supported by grants from the G6teborg Medical Society, the Swedish Medical Society, the University of Gothenburg, the Greta and Einar Asker Foundation, the Bertha and Felix Neubergh Foundation and Konung Gustav V:s 80-gtrsfond.

References ABRAHAMSSON, S. O., GELBERMAN, R. H. and LOHMANDER, S. L. (1994). Variations in cellular proliferation and matrix synthesis in intrasynovial and extrasynovial tendons: An in vitro study in dogs. Journal of Hand Surgery, 19A: 2: 259-265. AMIS, A. A., CAMPBELL, J. R., KEMPSON, S. A. and MILLER, J. H. (1984). Comparison of the structure of neotendons induced by implantation of carbon or polyester fibres. Journal of Bone and Joint Surgery, 66B: 1: 131-139. ARNOCZKY, S. P., TORZILLI, P. A., WARREN, R. F. and ALLEN, A. A. (1988). Biologic fixation of ligament prostheses and augmentations: An evaluation of bone ingrowth in the dog. American Journal of Sports Medicine, 16: 2:106 112. BECKER, H., ORAK, F. and DUPONSELLE, E. (1979). Early active motion

THE JOURNAL OF HAND SURGERY VOL. 20B No. 3 JUNE 1995 following a beveled technique of flexor tendon repair: Report on fifty cases. Journal of Hand Surgery, 4: 5: 454-460. BOYES, J. H. (1950). Flexor-tendon grafts in the fingers and thumb: An evaluation of end results. Journal of Bone and Joint Surgery, 32A: 3: 489-499. GELBERMAN, R. H., AMIEL, D., GONSALVES, M., WOO, S. and AKESON, W. H. (1981). The influence of protected passive mobilization on the healing of flexor tendons: A biochemical and microangiographic study. The Hand, 13: 2:120 128. GELBERMAN, R. H., CHU, C. R., WILLIAMS, C. S., SEILER, J. G. and AMIEL, D. (1992). Angiogenesis in healing autogeous flexor-tendon grafts. Journal of Bone and Joint Surgery, 74A: 8:1207 1216. GOODSHIP, A. E., WILCOCK, S. A. and SHAH, J. S. (1985). The development of tissue around various prosthetic implants used as replacements for ligaments and tendons. Clinical Orthopaedics and Related Research, 196: 61-68. HITCHCOCK, T. F., LIGHT, T. R., BUNCH, W. H., KNIGHT, G. W., SARTORI, M. J., PATWARDHAN, A. G. and HOLLYFIELD, R. L. (1987). The effect of immediate constrained digital motion on the strength of flexor tendon repairs in chickens. Journal of Hand Surgery, 12A: 4: 590 595. HUNTER, J. M. and SALISBURY, R. E. (1971). Flexor-tendon reconstruction in severely damaged hands. Journal of Bone and Joint Surgery, 53A: 5: 829-858. KIM, S. (1981). Further evolution of the grasping technique for tendon repair. Annals of Plastic Surgery, 7: 2:113-119. KLEINER, J. B., AMIEL, D., ROUX, R. D. and AKESON, W. H. (1986). Origin of replacement cells for the anterior cruciate ligament autograft. Journal of Orthopaedic Research, 4: 4: 466-474. LANE, J. M., BLACK, J. and BORA, F. W. (1976). Gliding function following flexor-tendon injury. Journal of Bone and Joint Surgery, 58A: 7: 985-990. LEE, H. (1990). Double loop locking suture: A technique of tendon repair for early active mobilization: Part h Evolution of technique and experimental study. Journal of Hand Surgery, 15A: 6: 945-952. LUNDBORG, G., HOLM, S. and MYRHAGE, R. (1980). The role of the synovial fluid and tendon sheath for flexor tendon nutrition. Scandinavian Journal of Plastic and Reconstructive Surgery, 14: 99-107. MCDOWELL, C. L. and SNYDER, D. M. (1977). Tendon healing: An experinaental model in the dog. Journal of Hand Surgery, 2: 2: 122-126. MORRISON, W. A. and SCHLICHT, S. M. (1992). The plantaris tendon as a tendo-osseus graft: Part II. Clinical studies. Journal of Hand Surgery, 17B: 4: 471-475. PARK, J. P., GRANA, W. A. and CHITWOOD, J. S. (1985). A high-strength dacron augmentation for cruciate ligament reconstruction: A two-year canine study. Clinical Orthopaedics and Related Research, 196: 175-185. ROBERTSON, D. B., DANIEL, D. M. and BIDEN, E. (1986). Soft tissue fixation to bone. American Journal of Sports Medicine, 14: 5: 398-403. SALISBURY, R. E., MASON, A. D., LEVINE, N. S., PRUITT, B. A. and WADE, C. W. R. (1974). Artificial tendons: Design, application, and results. Journal of Trauma, 14: 7:580 586. SCHUIND, F., GARCIA-ELIAS, M., COONEY, W. P. and AN, K.-N. (1992). Flexor tendon forces: In vivo measurements. Journal of Hand Surgery, 17A: 2: 291-298. SEILER, J. G., GELBERMAN, R. H., WILLIAMS, C. S., WOO, S. L-Y., DICKERSIN, G. R., SOFRANKO, R. et al. (1993). Autogenous flexortendon grafts: A biomechanical and morphological study in dogs. Journal of Bone and Joint Surgery, 75A: 7: 104-114. SILFVERSKIOLD, K. L. and ANDERSSON, C. H. (1993). Two new methods of tendon repair: An an vitro evaluation of tensile strength and gap formation. Journal of Hand Surgery, 18A: 1:58 65. SILFVERSKIOLD, K. L. and MAY, E. J. (t994). Flexor tendon repair in zone II with a new suture technique and an early mobilization program combining passive and active flexion. Journal of Hand Surgery, 19A: 1: 53-60. SILFVERSKIOLD, K. L., MAY, E. J. and TORNVALL, A. H. (1992). Flexor digitorum profundus tendon excursions during controIted motion after flexor tendon repair in zone II: A prospective clinical study. Journal of Hand Surgery, 17A: 1:122 131. SILFVERSKIOLD, K. L., MAY, E. J. and TORNVALL, A. H. (1993). Tendon excursions after flexor tendon repair in zone n: Results with a new controlled-motion program. Journal of Hand Surgery, 18A: 3: 403-410. SINGER, D., DOI, K., MORRISON, W. A., GUMLEY, G., O'BRIEN, B. M.-C., HURLEY, J. V. and WILLIAMS, J. F. (t989). Comparative study of the use of prefabricated bone tendon grafts and conventional tendon grafts in flexor tendon reconstruction. Journal of Hand Surgery, 14A: 5: 830-836. SLACK, C., FLINT, M. H. and THOMPSON, B. M. (1984). The effect of tensional load on isolated embryonic chick tendons in organ culture. Connective Tissue Research, 12: : 229 247. TONKIN, M., HAGBERG, L., LISTER, G. and KUTZ, J. (1988). Postoperative management of flexor tendon grafting. Journal of Hand Surgery, 13B: 3: 277-281.

EARLY T E N D O N G R A F T MOBILIZATION U R B A N I A K , J. R., CAHILL, J. D. and M O R T E N S O N , R. A. Tendon Suturing Methods: Analysis of Tensile Strengths. In (Ed): A A O S Symposium on Tendon Surgery in the Hand. St. Louis, CV Mosby, 1975:70 80. WADE, P. J. F., MUIR, I. F. K. and H U T C H E O N , L. L. (1986). Primary flexor tendon repair: The mechanical limitations of the modified Kessler technique. Journal of Hand Surgery, 11B: t : 71-76. WOO, S. L-Y., GELBERMAN, R. H., COBB, N. G., AMIEL, D., L O T H I N G E R , K. and AKESON, W. H. (1981). The importance of con-

307 trolled passive mobilization on flexor tendon healing. Acta Orthopaedica Scandinavia, 52:615 622.

Accepted: 1 November 1994 K. L. Silfverski61d,12 Wolseley Road, Blackwood, South Australia 505l, Australia. © 1995 The British Society for Surgery of the Hand