A comparative study of two methods of controlled mobilization of flexor tendon repairs in zone 2

A COMPARATIVE STUDY OF TWO METHODS OF CONTROLLED MOBILIZATION OF FLEXOR TENDON REPAIRS IN ZONE 2 E H. P E C K , C. A. B U C H E R , 3. S. W A T S O N and A. R O E

From Withington Hospital, Manchester and the University of Salford, Salford, UK

This prospective study compares subjects following primary repair of flexor tendons in zone 2 using either controlled active motion or a modified Kleinert regime. A matched pairs design was employed, subjects being matched for gender, age and injury characteristics. Twenty-six pairs of subjects with 92 tendon injuries in 52 digits were assessed 12 weeks postoperatively in respect of range of motion and dehiscence. Outcomes were defined using the Strickland criteria. No statistically significant differences in respect of range of motion were demonstrated between the groups. Incidence of rupture, however, was significantly less in the modified Kleinert group (7.7%) than in the controlled active motion group (46%).

Journal of Hand Surgery (British and European Volume, 1998) 23B: 1." 41-45 The aim of modern postoperative treatment regimes for the management of flexor tendon injuries in zone 2 is to modify peritendinous adhesions by promoting excursion at the repair site whilst respecting the healing process (Citron and Forster, 1986). A wide range of rehabilitation approaches have been based upon this principle. However, there remains no universally accepted regime guaranteed to achieve favourable results following flexor tendon repair at this level (Chow et al, 1987; 1988; Duran and Houser, 1975; Edinburg et al, 1987; Lister et al, 1977; May et al, 1992: Slattery and McGrouther, 1984; Small et al, 1989). In 1989 Small et al documented a series of patients who were managed under the "Belfast regime" of early active motion which allowed protected active flexion of the digit following conventional suturing of the tendons by modified Kessler technique. Variations of this controlled active motion programme are now accepted by many Centres in the United Kingdom as an appropriate and safe approach to the management of these zone 2 injuries in preference to previously employed Kleinert style regimes (Bainbridge et al, 1994; Cullen et al, 1989; Elliot et al, 1994; Small et at, 1989). Our experience in dealing with this type of injury has left us with the impression that early active motion (or

controlled active motion as it is now known) may be inappropriate for our particular patient group. We were reluctant to introduce a controlled active motion programme routinely in this unit without evaluating its safety and effectiveness. This study was designed to compare the controlled active motion method of management with the modified Kleinert technique already in use in this unit (Peck et al, 1996). PATIENTS AND METHODS In this unit we have audited the outcomes of our zone 2 injuries prospectively since 1993. As part of this study we have detailed two groups each of 26 patients (Group 1 and Group 2). These comprised 22 male and 4 female patients per group with ages ranging from 3 to 45 years (mean age Group 1, 23.9 years and Group 2, 23.5 years). Digits with complete divisions of flexor digitorum profundus (FDP) with or without concomitant flexor digitorum superficiafis (FDS) injuries were included in this study. Multidigit tendon injuries, fractures, large skin defects and crush injuries were excluded (Table 1). Fifty-two digits were surgically explored as an emergency within 24 hours of injury and FDP tendons were repaired using a modified Kessler

Table 1--Details of injuries

Group 1 Modified Kleinert Injuries FDP FDP & DN FDP & FDS FDP & Prt FDS FDP, FDS & DN FDP, Part FDS & DN Total

Group 2 Controlled active motion

No. of digits

Injuries

5

FDP FDP & DN FDP & FDS FDP & Prt FDS FDP, FDS & DN FDP, Part FDS & DN Total

1

6 2 12 0 26

DN = Digital Nerve 41

No. of digits 5 1 6 2 12 0 26

42

THE JOURNAL OF HAND SURGERY VOL. 23B No. 1 FEBRUARY 1998

technique. 3/0 Prolene was used for the core suture and 6/0 Prolene or 6/0 nylon for epitendinous repair. FDS tendons were repaired with horizontal mattress sutures of 6/0 prolene. Smooth gliding of the repairs through the pulley system was ensured at the end of each operation. Postoperatively the affected hands were protected overnight in a plaster of Paris dorsal protective splint. GROUP 1

From August 1993 to August 1994 all patients (Group 1) followed a modified Kleinert regime of management using controlled passive motion (Duran and Houser, 1975) and controlled mobilization (Lister et al, 1977). In addition modifications to the Kleinert technique described by Knight (1987) were employed with the aim of achieving maximum range of motion at the distal interphalangeal joint in order to encourage excursion of the profundus tendon on superficialis (McGrouther and Ahmed, 1981). On the first postoperative day the affected hands were positioned in a dorsal, thermoplastic splint with the wrist in 40 ° of flexion and the metacarpophalangeal joints in 60 ° of flexion. A dressmaker's hook was attached to the nail of the affected digit with superglue and the elastic band traction applied with the minimum tension required to return the finger to flexion (Citron and Forster, 1987). The patient was asked to perform two passive flexion exercises of all the digits followed by two active extension exercises every half hour. The modified traction (Fig 1) was applied as soon as the patient was able to achieve an adequate range of passive flexion of the digit and a further two active extension exercises from the maximally flexed position were added to the half hourly regime. At 3 weeks the traction but not the hook was removed and active motion of the fingers commenced; if the active flexion of the interphalangeal joints deteriorated the traction was reapplied and the patient requested to continue with the early regime in conjunction with active exercise. GROUP 2

From November 1994 to November 1995 all patients undergoing flexor tendon repair in zone 2 followed a regime of controlled active motion described by the Belfast group (Small et al, 1989) with modification described by Elliot et al (1994). A dorsal thermoplastic splint was applied on the first postoperative day with the wrist and MCP joints positioned in 30 ° of flexion. Antigrab bars were added to discourage inadvertent use of the hand (Fig 2). The patients were asked to perform two passive flexion exercises of the digit followed by two active extension and two active flexion exercises every half hour. The importance of full active interphalangeal joint extension was reinforced and the aim of the exercise regime was to achieve 25% of the full range of active flexion by the end of the first week. This was increased to full range of motion by the end of the third week.

Fig 1

Dorsal splint and Knight traction applied every half hour to encourage extension from m a x i m u m flexion of the digit.

All patients

Certain features were common to the two treatment protocols. In the event of a flexion contracture at the interphalangeal joints a palmar gutter splint (Fig 3) was applied at night. Previous studies have shown that these splints are not deleterious to the tendon repair and do not increase the incidence of dehiscence (May et al, 1992;

"~!~:;:'~::',...."

Fig 2

Splint position and antigrab bar.

k~

~ ". ~ ' ~

43

MOBILIZATION OF TENDON REPAIRS

weeks and the patients were dissuaded from performing heavy manual activity until 12 weeks after repair. Patients were required to attend a special clinic for review by the surgeons and physiotherapists twice weekly for the first 4 weeks and once weekly thereafter. A recent audit of this type of injury (Peck et al, 1996) has shown that patients who comply with such attendance requirements are more likely to achieve an excellent or good result as defined by Strickland's criteria (Strickland and Glogovac, 1980). Details of the incidence and reasons for rupture and subsequent re-repairs were recorded throughout the study. Measurements of interphalangeal joint motion were undertaken at 12 weeks and reported in terms of the formula described by Strickland and Glogovac (1980). This method "was regarded to be the most demanding set of criteria for evaluation of digital performance" (Chow et al, 1987). In addition it allows effective comparison of our results with other studies (Bainbridge et al, 1994; Baktir et al, 1996; Cullen et al, 1989; Elliot et al, 1994; Small et al, 1989). We acknowledge that not all patients achieve a definitive result at this stage but experience has shown us that in this unit many patients fail to attend appointments after 12 weeks and are subsequently lost to follow-up. Patients from each group were matched retrospectively for age, gender and injury characteristics. Data relating to rupture rates and outcomes were subject to statistical analysis, using the McNemar and Wilcoxon matched pairs sign rank test respectively. RESULTS

Fig 3

Palmar splint applied at night.

Peck et al, 1996). They are designed to prevent further loss of extension at these joints. Active motion of the wrist commenced at 4 weeks and protective splintage was removed at 6 weeks for free active exercise and light functional activity but retained at night and when in at risk situations for a period of 8 weeks in total. Passive stretching of any residual contractures commenced at 6

The rupture rate for Group 1 (modified Kleinert) expressed as a percentage of digits was 7.7%. Group 2 (controlled active motion) exhibited fi significantly higher rate of rupture, 46% (P = 0.006) (Table 2). Two patients in Group 1 ruptured the tendons 2 weeks following repair (Fig 4). One patient ruptured the tendon whilst sleeping and the other could give no reason to account for the dehiscence. In Group 2, twelve patients ruptured a total of t 8 tendons in 12 digits. These ruptures occurred between 1 and 4 weeks from the date of repair (Fig 4). Three patients' tendons ruptured during the first week, four during the second week, two during the third week, and three during the fourth week after surgery. Two patients suffered ruptures whilst performing pre-

Table 2---Ruptures Group 1 Modified Kleinert

Digits 2 (7.7%)

Group 2 Controlled active motion

Tendons Re-repairs Re-ruptures Digits Tendons (Tendons) 2 2 0 12 (46%) 18

Re-repairs Re-ruptures (Tendons) 10 5

44

THE JOURNAL OF HAND SURGERY VOL. 23B No. 1 FEBRUARY 1998

Ruptures group 1 : modified Kleinert

2.__. 1.5 =.

1

O

0.5

d Z

0

1 a

2 3 4 Weeks post repair

5

Ruptures group 2: controlled active motion 4 ~" 3 ._e =.2

~6 d

1

Z

0 1

b Fig 4

2 3 4 Weeks post repair

5

Ruptures in (a) Group 1 and (b) Group 2.

scribed exercises. Two patients could not recall an exact cause and were not aware that their tendons had ruptured. A further two tendons ruptured whilst sleeping and the remainder were performing inadvisable activities, the details of which are listed in Table 3. Re-repairs undertaken in Group 1 did not subsequently re-rupture. In Group 2, ten profundus tendons were re-repaired and of these five went on to rupture a second time. During this study 11 of 26 digits managed under the controlled active motion regime developed some degree of flexion contracture of the PIP joint compared with eight of 26 digits managed under the modified Kleinert regime. At 12 weeks the vast majority of these were minor contractures of 20 ° or less. In Group 1, 22 digits out of 26 achieved good or excellent results. Twelve digits were graded as excellent and ten as good. Four digits were recorded as fair and there were no patients with a poor result. In Group 2, 18 of 26 digits were graded as good or excellent. Eleven achieved an excellent result and seven were graded as good. Two were recorded as fair and six as poor. Statistical analysis demonstrated that the rehabilitation programme did not influence the outcome of these injuries (P=0.191).

DISCUSSION Several authors (Bainbridge et al, 1994; Baktir et al, 1996; Cullen et al, 1989; Elliot et al, 1994; Savage and Risitano, 1989; Silfverski61d and May, 1994; Small et al, 1989) have shown that controlled active motion can be successfully applied without an increase in the rupture rates and with favourable outcomes. Our experience of the controlled active motion regime in the management of flexor tendon injury in other zones supports this view. This study of zone 2 injuries has demonstrated an unacceptably high rupture rate for the controlled active motion group. Analysis of the reasons for the ruptures indicates that some responsibility for the high rates of rupture must lie with the patients in this study. In several of the reported cases the repairs did not withstand the excessive forces applied (Table 3) and the patients clearly failed to comply with comprehensive warnings against any functional activity in the early stages after repair. It is not possible to provide a definitive reason for so many tendons rupturing; however, we suggest that some patients may take advantage of the freedom of motion which the controlled active motion regime allows. In contrast, the use of a Kleinert style regime may deter some patients from purposeful or inadvertent overactivity by the presence of elastic band traction. This may offer increased protection to the repaired tendon at a vulnerable point in the healing process and so offer some explanation for the lesser rate of ruptures experienced in Group 1. Small et al (1989) suggested that the modified Kleinert regimes result in an increased tendency to flexion contracture of the PIP joints, attributable to prolonged flexion of the digits in traction. A palmar pulley system (Slattery and McGrouther, 1984) enhances differential gliding of the profundus tendon on the superficialis (McGrouther and Ahmed, 1981) but positions the digit in a greater amount of flexion thus accentuating the problem in some patients. Our regime addresses the complication of flexion contracture by maintaining the digit in minimal flexion and by careful monitoring of these injuries in special outpatient clinics. The early application of a palmar gutter Table 3~Reasons for rupture

Group ] Modified Kleinert No specific incident Whilst sleeping

Group 2 Controlled active motion Celebrating Christmas Eve During a fight Whilst sleeping No specific incident During arrest by police No specific incident Opening a door Playing with daughter Whilst sleeping Squeezing a cloth Whilst exercising

MOBILIZATION OF TENDON REPAIRS

45

Table ~-Results Group 1 Modified Kleinert Excellent Good Fair Poor

46% 38% 15% 0

Group 2 Controlled active motion 42% 27% 7.7% 23%

splint at night was also designed to reduce the incidence of severe flexion deformity. The incidence of flexion contracture in our series indicates that neither regime was immune from this complication and that consequently both groups require similar supervision. It has been suggested that Kleinert splints are more expensive to construct and that patients following traction regimes require greater supervision (Small et al, 1989). In our study both groups of patients were managed in splints constructed from the same material and the modified traction does not require an expensive pulley system as it is made of elastic bands and safety pins. This study demonstrated that there were no significant differences in range of motion between controlled active motion and a modified Kleinert regime and that good results were achieved from both methods. We acknowledge that these results are pertinent to the unit under investigation but suggest that other centres may wish to consider them when determining postoperative protocols. We strongly support the philosophy that every patient must be managed according to their individual needs and the variable characteristics of injury; surgical findings and lifestyles must be acknowledged in determining any treatment programme. We believe that a modified Kleinert regime retains an imPortant role in the management of flexor tendon repairs in zone 2.

Baktir A, Turk C Y, Kabak S, Sahin V, Kardas Y (1996) Flexor tendon repair in zone 2 followed by early active mobilization. Journal of Hand Surgery, 21B: 624--628. Chow J A, Thomes L J, Dovelle S, Milnor W H, Seyfer A E, Smith A C (1987). A combined regime of controlled motion following flexor tendon repair in "no man's land". Plastic and Reconstructive Surgery, 79: 447453. Chow J A, Thomas L J, Dovelle S, Monsivais J, Milnor W H, Jackson J P (1988). Controlled motion rehabilitation after flexor tendon repair and grafting: A multi centre study. Journal of Bone and Joint Surgery, 70B: 392-395. Citron N D, Forster A (1987). Dynamic splinting following flexor tendon repair. Journal of Hand Surgery, 12B: 96100. Cullen K W, Tolhurst P, Lang P, Page R E (1989). Flexor tendon repair in zone 2 followed by controlled active mobilisation. Journal of Hand Surgery, 14B: 392-395. Duran R J, Houser R G. Controlled passive motion following flexor tendon repair in zones 2 and 3. In: American Academy of Orthopaedic Surgeons: Symposium on tendon surgery in the hand. St Louis, Mosby, 1975: 105-114. Edinburg M, Widgerow A D, Biddulph S L (1987). Early post operative mobilization of flexor tendon injuries using a modification of the Kleinert technique. Journal of Hand Surgery, 12A: 34-38. Elliot D, Moiemen N S, Flemming A F S, Harris S B, Foster A J (1994). The rupture of acute flexor tendon repairs mobilized by the controlled active motion regimen. Journal of Hand Surgery, I9B: 607-612. Knight S L (1987). A modification of the Kleinert splint for mobilisation of digital flexor tendons. Journal of Hand Surgery, 12B: 179 181. Lister G D, Keinert H E, Kutz J E, Atasoy E (1977). Primary flexor tendon repair followed by immediate controlled mobilization. Journal of Hand Surgery 2: 441451. McGrouther D A, Ahmed M R (1981). Flexor tendon excursions in "No-Man's Land." The Hand, 13: 129-141. May E, Silfverski61d K; Sollerman C (1992). Controlled mobilization after flexor tendon repair in zone II: A prospective comparison of three methods. Journal of Hand Surgery, 17A: 942-952. Peck F, Bficher C A, Watson J S, Roe A E (1996). An audit of flexor tendons in zone II and its influence on management. Journal of Hand Therapy, 9: 306-308. Savage R, Risitano G (1989). Flexor tendon repair using a "six strand"-method of repair and early active mobilisation. Journal of Hand Surgery, 14B: 396-399. Silfverski61d K L~ May E J (1994). Flexor tendon repair in zone II with a new suture technique and an early mobilization program combining passive arid active flexion. Journal of Hand Surgery, 19A: 53-60. Slattery P G, McGrouther D A (1984). A modified Kleinert controlled mobilization splint following flexor tendon repair. Journal of Hand Surgery, 9B: 217-218. Small J O, Brennen M D, Colville J (1989). Early active mobilization following flexor tendon repai r in zone 2. Journal of Hand Surgery, 14B: 383-391. Strickland J W, Glogovac S V (1980) Digital function following flexor tendon repair in zone n. A comparison of immobilization and controlled passive motion techniques. Journal of Hand Surgery, 5:537 543.

References Bainbridge L C, Robertson C, Gillies D, Elliot D (i994). A comparison of postoperative mobilization of flexor tendon repairs with "passive flexion-active extension" and "controlled active motion techniques". Journal of Hand Surgery 19B: 517-521.

Received: 14 March 1997 Accepted after revision:26 May 1997 Ms F. H. Peck, PlasticSurgeryUnit, Withington Hospital, ManchesterM20 2LR, UK. © 1997The British Societyfor Surgeryof the Hand