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PRIMARY FLEXOR TENDON REPAIR IN ZONE 1
PRIMARY FLEXOR TENDON REPAIR IN ZONE 1 N. S. MOIEMEN and D. ELLIOT From the St Andrew's Centre for Plastic Surgery, Broom®eld Hospital, Chelmsford, UK
This paper presents an analysis of the results of repair of 102 complete ¯exor tendon disruptions in zone 1 which were rehabilitated by an early active mobilization technique during a 7 year period from 1992 to 1998. These injuries were subdivided into: distal tendon divisions requiring reinsertion; more proximal tendon divisions but still distal to the A4 pulley; tendon divisions under or just proximal to the A4 pulley; and closed avulsions of the ¯exor digitorum profundus tendon from the distal phalanx. Assessment by Strickland's original criteria showed good and excellent results of 64%, 60%, 55% and 67% respectively in the four groups. However, examination of the results measuring the range of movement of the distal interphalangeal (DIP) joint alone provided a more realistic assessment of the aect of this injury on DIP joint function, with good and excellent results of only 50%, 46%, 50% and 22% respectively in the four groups. Journal of Hand Surgery (British and European Volume, 2000) 25B: 1: 78±84 They included 17 female and 72 male patients with ages ranging from 7 to 71 (mean, 33) years. Nine patients with pull-o injuries of the FDP were also treated during this period and are documented in the study for comparison with the tendon divisions. Twenty-six patients with 30 complete tendon divisions in zone 1 who did not participate in the postoperative rehabilitation for the minimum period of 8 weeks or were lost to follow-up before 12 weeks were excluded from the study. Thirty-six patients with partial FDP divisions and all patients under 5 years of age were also excluded. Replantations, revascularizations and ¯exor tendon injuries with associated fractures, joint damage or signi®cant skin loss were also excluded from the study. No patients with small or moderate skin defects were excluded as these were mobilized immediately and in the normal manner while the skin problem was treated with small dressings and/or with homodigital ¯aps until epithelialization occurred. From the point of view of the operating surgeon, divisions of the FDP tendon in zone 1 fall naturally into three subgroups (Fig 1). We de®ned those divisions so close to the insertion of the tendon that it was impossible to insert a Kessler suture into the distal end of the tendon as zone 1a injuries. After exclusions, there were 14 zone 1a tendon divisions in this study. In these injuries, the tendon was repaired by reinsertion onto the distal phalanx using a 3/0 or 4/0 polypropylene (Prolene) tendon core suture passed through the bone and nail complex and tied over a button or by the alternative technique of attachment without a button tie-over (Sood and Elliot, 1996). Those tendon divisions between zone 1a and the distal edge of the A4 pulley, were de®ned as zone 1b injuries. After exclusions, there were 43 zone 1b tendon divisions in this study. These injuries were repaired using the modi®cation of the Kirchmayr/Kessler core suture in which the suture is tied with a single intratendinous knot using 3/0 or 4/0 polypropylene and a continuous epitendinous suture of 5/0 or 6/0 polypropylene or nylon (Ethilon). Repairs in zone 1b may catch on the
Since the introduction of immediate ¯exor tendon repair and early mobilization (Kelly, 1959; Kleinert et al., 1967; Siler, 1950; Verdan, 1952; 1960; Young and Harmon, 1960), research into ¯exor tendon repair has concentrated, almost exclusively, on zone 2 injuries. These injuries create problems largely as a result of loss of proximal interphalangeal (PIP) joint function whereas zone 1 injuries predominantly aect the function of the DIP joint. For this reason, it may be inappropriate and even misleading to assess zone 1 injuries using the methods used for zone 2 injuries. A number of earlier papers, including two involving the senior author (DE), which examined zone 1 injuries with such methods have, inadvertently, given a false impression that these injuries do well with the techniques of surgery and rehabilitation evolved for use on zone 2 injuries (Bainbridge et al., 1994; Brunelli and Monini, 1982; Brunelli et al., 1983; Elliot et al., 1994; Grandis and Rossello, 1988; Mantero et al., 1974; Mantero and Bertolotti, 1976; Wulle, 1992). We can only ®nd two small studies of zone 1 tendon divisions that present data in such a manner that it is possible to examine the eect of these injuries and their treatment on the DIP joint (Evans, 1990; Gerbino et al., 1991). These data suggest that tendon divisions in this zone create particular diculties of management and that our current methods of treatment do not routinely restore good DIP joint function. In this study, we have examined a larger number of zone 1 injuries to try to throw more light on the problems of tendon injuries in this zone and the adequacy of current treatment. PATIENTS AND METHOD Over a period of 7 years, from 1991 to 1998, 168 complete and partial disruptions of the ¯exor digitorum profundus (FDP) tendon in zone 1 were treated in our unit. These included 93 complete tendon divisions in 93 ®ngers in 89 patients over the age of 5 years. These patients constitute the main study group in this paper. 78
PRIMARY FLEXOR TENDON REPAIR IN ZONE 1
Fig 1 Subdivision of zone 1 ¯exor tendon injuries.
distal edge of the A4 pulley on ®nger ¯exion. Except in the earliest part of this series, the distal edge of the A4 pulley was released laterally, or ``vented'', as a routine if this was deemed necessary to achieve full free movement of a repair. In the early years of this study, there was no routine unit policy on venting pulleys and details of this feature of management were not routinely recorded. In ®ve of the zone 1b injuries, the palmar plate of the DIP joint was also injured and required surgical repair. Those tendon injuries lying immediately beneath or just proximal to the A4 pulley were de®ned as zone 1c injuries. After exclusions, there were 36 zone 1c tendon divisions in this study. The tendons in zone 1c were repaired using the same technique as for zone 1b injuries. Access to the divided tendons in this zone often requires complete or near complete division of the A4 pulley, with further pulley division sometimes being necessary to allow free movement of the repair. As with zone 1b injuries, there was no routine policy in the unit in the early years of this study on how to manage these problems of access and mobility but `venting' of the distal A4 pulley has been considered acceptable practice in the unit during most of the period of this study, both to achieve access to the site of division and to achieve a free running repair. Closed avulsions of the FDP tendon from the distal phalanx were designated as zone 1p (pull-o) injuries. After exclusions, there were nine zone 1p injuries in nine patients in this study. Six avulsions were type 2 and three were type 3 injuries (Leddy and Packer, 1977). There were no type 1 injuries. Of the type 3 injuries, all three tendon avulsions included a large fragment of bone and constituted a signi®cant intra-articular fracture of the DIP joint which required bone reattachment with interosseous wires. In the remaining six ®ngers, the tendon was reinserted using the same technique as for tendon divisions in zone 1a. The repairs were mobilized postoperatively in the variation of the controlled or early active motion
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regimen that we use routinely and have described previously (Elliot et al., 1994). Return to work was allowed at 8±12 weeks, according to occupation. All patients included in this study were followed for a minimum of 12 weeks. The results were assessed using Strickland's original criteria, which measure the total ¯exion of the proximal and the distal interphalangeal joints minus any extension lag (Strickland and Glogovac, 1980). In this classi®cation, a net range of motion of these two joints of 1758 is considered as 100% and results of ¯exor tendon repair between 85 and 100% (150±1758) are considered excellent, those between 70 and 84% (125±1498) as good and those between 50 and 69% (90±1248) as fair. Results between 0 and 49% (0±908) are regarded as poor. To allow comparison with previous papers, it was also necessary to assess our results using the modi®ed Strickland assessment in which results of ¯exor tendon repair between 75 and 100% (132±1758) are considered excellent, those between 50 and 74% (88±1318) as good, those between 25 and 49% (44±878) as fair and those between 0 and 24% (0±448) are regarded as poor (Strickland, 1985). To achieve a more accurate picture of the eect of zone 1 ¯exor injuries on DIP joint function, we have also analysed our results in terms of DIP joint range of motion alone. This necessitated devising a system of assessment similar to that of Strickland and Glogovac (1980) but using DIP measurements only and comparing them with a calculated ``normal'' value for the DIP joint range alone. Unfortunately, Strickland and Glogovac did not indicate how the ®gure of 1758 for the normal range of movement of both interphalangeal joints was determined or how much of this ®gure represents DIP joint movement. Therefore, our study was extended to include measurements of the ranges of motion of the DIP joints of all eight ®ngers of 50 normal individuals. To determine whether the movement range of the DIP joint varies between dierent individuals, these measurements were made on 320 ®ngers in ten male labourers, ten male doctors, ten female nurses and ten female medical secretaries, who represented a slightly older female population than the nurses. The average range of motion of the DIP joint for the men was 698 and for the women was 798 with an overall average for both sexes of 748. This ®gure was used as the normal range of motion of the DIP joint. The average combined range of motion of the PIP and DIP joints in this group of normal individuals was 1758, con®rming the ®gure used by Strickland and Glogovac (1980). Considering DIP joint range of motion alone, results of ¯exor tendon repair between 85 and 100% of the average (62±748) were considered excellent, as in Strickland's original assessment method for zone 2 injuries. Those between 70 and 84% (51±618) were considered as good and results between 50 and 69% (37±508) as fair. Results between 0 and 49% (0±368) were regarded as poor.
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RESULTS Table 1 shows the complete results of our series and Figure 2 shows the percentage of good and excellent results for the dierent subdivisions of zone 1 in those ®ngers with intact tendon repairs at 12 weeks from primary surgery. Figure 2 illustrates the results of assessment by the original Strickland method, the modi®ed Strickland method and for DIP joint measurements alone as compared with a normal range of DIP motion of 748. There were four zone 1 repairs in this series, which ruptured at 7, 12, 15 and 24 days after primary surgery. All four were in zone 1c. Three of these ruptures were rerepaired and the fourth was treated by two-stage tendon grafting. Of the three re-repairs one achieved an excellent outcome, one a good and one a poor result when assessed by Strickland's original criteria. When assessed by DIP motion alone, one achieved a good, one a fair and one a poor result. Four patients developed ``stuck'' FDP tendons. In two cases, tenolysis of intact
repairs was successful. In another, the tendon repair was found to have gapped under the A4 pulley. As the patient did not wish to have a tendon graft, a distal tenodesis was performed. The fourth patient, who had developed a severe ®xed ¯exion contracture of the DIP joint, was treated by arthrodesis of this joint. Two patients developed re¯ex sympathetic dystrophy, which responded well to analgesics and guanethidine blocks. There were no complications in the patients with tendon avulsions. DISCUSSION Evans (1990) discussed the eect of zone 1 profundus tendon injuries on DIP joint motion and the importance of active movement of this joint to ®ner aspects of ®nger function. She reported her own experience that patients were usually not satis®ed unless the DIP joint, as well as the PIP joint, was free of ¯exion contracture and the DIP joint ¯exed to 408 or more. We believe that a
Table 1ÐThe complete results of our series with dierent methods of assessment Methods of Assessment Original Strickland
DIPJ alone
Excellent
Good
Fair
Poor
Rupture
Excellent
Good
Fair
Poor
Rupture
All zone 1 tendon divisions Zone 1a tendon divisions Zone 1b tendon divisions Zone 1c tendon divisions
(n=93) (n=14) (n=45) (n=34)
33 6 17 10
22 3 10 9
21 5 8 8
13 0 6 7
4 0 4 0
31 5 16 10
14 2 5 7
12 1 8 3
32 6 12 14
4 0 4 0
All zone 1 tendon avulsions Type 2 FDP avulsions Type 3 FDP avulsions
(n=9) (n=6) (n=3)
2 1 1
4 4 0
1 0 1
2 1 1
0 0 0
1 0 1
1 1 0
1 1 0
6 4 2
0 0 0
Fig 2 Good and excellent results of zone 1 injuries in this study, assessed by dierent methods.
PRIMARY FLEXOR TENDON REPAIR IN ZONE 1
capability for rapid movement is also essential to achieving the full functional potential of the DIP joint. This is seen particularly in the rapid movement of the DIP joints of the index and middle ®ngers through small ranges of motion which are an integral part of ®ne pinch activities and are of particular signi®cance to hand function in skilled craftsmen and musicians. Power gripping of large diameter objects and span pinch, that is ®ve digit tip gripping as when opening the lid of a coee jar, also requires DIP joint function. We can only ®nd two papers that present data on the treatment of zone 1 injuries in such a way as to allow analysis of the eect of these injuries and their treatment on the DIP joint (Evans, 1990; Gerbino et al., 1991). Evans (1990) reported a 60% incidence of complications but did not elaborate on these problems. Gerbino et al. (1991) reported a complication rate of 35% but these included six complete failures of DIP motion, which would normally be reported as poor results and not as complications. Nevertheless, it was the high complication rates in these two papers which prompted us to reexamine zone 1 ¯exor tendon injuries. In this study, we analysed our results initially using the original Strickland method (Strickland and Glovac, 1980). Most authors have abandoned the modi®ed version of the Strickland assessment of zone 2 injuries as being too lenient and, eectively moving all results up a grade (Strickland, 1985). This eect is seen clearly in Figure 2. The Strickland modi®cation of the TAM method of assessment was introduced to eliminate the dilutional eect of a normal or near-normal range of movement of the MP joint on assessments of zone 2 injuries. This study illustrates that the same problem arises if PIP joint movements are included in the assessment of the results of treatment of zone 1 injuries (Fig 2). Inclusion of the PIP joint ranges of motion dilutes the true eect of zone 1 injuries on the DIP joint
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and, hence, their eect on the ®ner aspects of ®nger function provided by this joint. To analyse the eect of zone 1 injuries on the DIP joint, we have introduced a new method of assessment which uses the same methodology as the original Strickland method but considers the movements of the DIP joint alone. We believe this is a better indicator of the eectiveness of the treatment of zone 1 injuries. Nevertheless, the Strickland assessment is still useful in showing the eect of zone 1 injuries and their treatment on the function of the ®ngers when they are used for more basic gripping activities in which the distal interphalangeal joint motion is said only to be responsible for 15% of total ®nger ¯exion (Marin-Braun et al., 1991). In our series, 62% of the ®ngers achieved recovery of more than the 408 of DIP joint motion, which Evans (1990) believed to be necessary for unproblematic function of this joint. Although we did not experience the high rate of complications reported by either Evans (1990) or Gerbino et al. (1991), these results leave no room for complacency and the good and excellent results in our series are very much lower than those of zone 2 repairs whether or not the analysis includes the PIP joint. We have re-examined the data from the study by Gerbino et al. (1991) using the same assessment methods as in our own study (Fig 3). Examined in the conventional manner of this ®gure, the results in the two studies are comparable. Both papers also reported similar rupture rates of 4±5%. However, a striking dierence between the two studies is seen when one looks at those cases that did not rupture but had poor results. In our study, there were four of 93 (4%) injuries with ``stuck'' FDP tendons while Gerbino et al. reported six of 20 (30%) ®ngers with no movement of the DIP joint at all. Although none of these cases was explored, the authors believed this to be due to gapping of the repairs as a result of too aggressive passive extension of
Fig 3 Good and excellent results of zone 1 injuries in the literature and in this study, assessed by dierent methods.
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the ®ngers during early rehabilitation. It is more likely that the problem was impingement of the repaired tendons on the repaired A4 pulley, preventing ¯exion of the DIP joint, as these authors pursued a policy of closing the tendon sheath. We believe that our policy of leaving the sheath open, with liberal venting of the pulley as necessary to achieve a full passive range of motion of the repairs before closing the skin of the ®ngers, is a better technique when operating within the narrow con®nes of the tendon sheath in zone 1. Unfortunately, this retrospective study does not allow us to con®rm this as our present policy was evolved during the period of this work. Evans reported results of 83 complete zone 1 tendon divisions repaired by 25 dierent surgeons and referred to her for rehabilitation. The techniques of repair were not detailed but the rehabilitation was standardized. The ®rst 63 patients, examined retrospectively, were treated by a passive mobilization regimen which was changed to a more complicated passive regimen before examining a further 20 patients prospectively. Comparison of our results with those of Evans' study was more complicated as her results were reported using the modi®ed Strickland method and only the mean value of the range of motion of the DIP joint was given for each of the two parts of her study. Therefore, we have re-assessed our results and those of Gerbino et al. by these methods (Figs 3 and 4). As can be seen from these ®gures, the revised regimen of mobilization used by Evans in the second part of her study improved the results over those achieved using the original method of mobilization. However, this intensive, complicated and therapistdependent regimen appears to have little advantage over simply allowing the patients to move their ®ngers actively within a splint which limits full extension. All
THE JOURNAL OF HAND SURGERY VOL. 25B No. 1 FEBRUARY 2000
three studies show similar, and not impressive, restoration of DIP joint function. The fourth subgroup of tendon injury in zone 1 is that of closed avulsion of the tendon from the distal phalanx. Our results of treatment of these injuries during this period are included for comparison with the tendon divisions, in particular those divisions in zone 1a (Table 1 and Fig 2). Although one would expect those type 3 avulsion injuries, which have pulled o signi®cant fragments of bone and which constitute intra-articular fractures to have bad results, it is uncertain why the type 2 avulsions also have much worse results than zone 1a tendon divisions. However, meaningful interpretation requires larger numbers of cases in both groups. All four ruptures in this series presented within 48 hours and three were re-repaired within a further 24 hours. One achieved an excellent result, one a good result and one a poor result. As for zone 2 ®nger ¯exor tendon and FPL ruptures, immediate re-repair, although not easy, is the best option of treatment for patients who present quickly after rupture and who wish to have active DIP joint motion (Allen et al., 1987; Harris et al., 1999; Sirotakova and Elliot, 1999; Small et al., 1989). The alternative is to accept the loss of movement of the DIP joint and ignore the rupture. If this treatment option is chosen, it is sometimes necessary to either splint the DIP joint in slight ¯exion for a period of 4±6 weeks or carry out a distal tenodesis of the ¯exor tendon if the ®nger is seen to be developing a ¯ail joint with hyperextension when pressure is applied to the ®ngertip. Over and above the general diculties of operating in zone 1, it has become evident from our increased scrutiny of the zone during this study that the local anatomy of the ¯exor tendon and its sheath are not
Fig 4 Mean range of motion of the DIP joint alone in the literature and in this study.
PRIMARY FLEXOR TENDON REPAIR IN ZONE 1
constant throughout the length of the zone and the consequences of tendon division at dierent levels within the zone demand subtle dierences of management by the operating surgeon. In this respect, we identi®ed three subgroups of zone 1. Zone 1a injuries requires re-insertion of the profundus tendon into the distal phalanx. Although the repair will move very little during subsequent ®nger movement, the reinsertion causes slight shortening of the profundus tendon, the consequences of which are unknown. Zone 1b injuries overlie the palmar plate of the DIP joint which may be injured primarily or scarred later during healing, resulting in joint contracture. At worst, this can create a hook ®nger with serious dysfunction and is less amenable to palmar plate release than that of the PIP joint. Zone 1b repairs may also impinge on the distal edge of the A4 pulley, with loss of full ¯exion. Treatment of both zone 1a and 1b injuries requires division of the A5 pulley to achieve repair, the implications of which have not been studied. Zone 1c injuries mostly lie under the A4 pulley. However, in a previous study from this unit, it was found that the whole of the attachment of the FDS tendon was proximal to the A4 pulley in 30% of ®ngers examined (Kwai Ben and Elliot, 1998). Because the interface of zones 1 and 2 was de®ned by Verdan and Michon (1961) as the distal end of attachment of the FDS tendon to the middle phalanx, some divisions of the FDP tendon just proximal to the A4 pulley will be included in zone 1. We have come to realize that zone 1c injuries frequently require complete division of the A4 pulley for access and/or free excursion of the tendon repair. Comparison of our results with those of Evans (1990) and Gerbino et al. (1991) does not identify any detrimental eect of A4 division on the ultimate function of the ®nger in terms of range of motion, which has been, and still remains, the conventional measure of ®nger function after ¯exor tendon repair. The eect of zone 1 ¯exor tendon repairs, with or without A4 pulley division, on the power of ®nger ¯exion is not known. However, the work of Savage (1990), and of Tomaino et al. (1998) would suggest that we need no longer consider this pulley to be sacrosanct, a view expressed by Kleinert et al. in 1975. Subdivision of zone 1 is useful in identifying the surgical diculties of particular parts of the zone 1 injury. It did not have a prognostic bene®t in this study, other than con®rming that only the most proximal zone 1 injuries under the A4 pulley, de®ned as zone 1c, are likely to result in loss of PIP range of motion and therefore to aect power gripping of small and moderate-size objects. However, our policy of pulley venting was intended to eliminate any dierences between the subgroups and may have eliminated dierences which could be important in future studies examining other methods of management, particularly of the tendon sheath and A4 pulley. All three series reporting on the treatment of zone 1 tendon divisions by conventional suturing with a Kessler
83
type of core suture and circumferential support suture and mobilized in current active or passive mobilizing regimes have results which are worse than those of zone 2 injuries both in terms of total range of movement of the ®nger and also in terms of their particular eect on the adjacent DIP joint. We suspect that the increase in diameter of the tendon as a result of suturing, in particular the bunching of the tendon which is an inherent risk of ¯exor tendon suture, and the associated diculty in avoiding problems of tendon gliding in the much more con®ned space of zone 1 may be critical factors. Although less frequently used than in earlier times, the techniques of pull-out suture described by Brunelli (1958) and by Mantero et al. (1973) in Italy, or the modi®cation using the Jennings barbed wire suture used in Strasbourg (Marin Braun et al., 1991), oer alternative methods of treatment of zone 1 tendon divisions. These sutures are, essentially modi®cations of the original Bunnell technique and similar to the suture technique which we, and most others, use for zone 1a tendon divisions and for FDP avulsion injuries. However, these authors also used pull-out sutures for more proximal tendon divisions both in zone 1 and distal zone 2. While still prone to the problem of tendon bunching, these suture techniques involve less surgical invasion of the zone 1 sheath and leave less suture material in this restricted space so may have advantages in this respect. Unfortunately, all the earlier studies reporting results with these techniques were analysed using assessments which include or depend on the ranges of motion of all three joints of the ®nger, so give very little indication of the true eect of the injuries and their treatments on the DIP joint (Brunelli and Monini, 1982; Brunelli et al., 1983; Grandis and Rossello, 1988; Montero et al., 1974; Mantero and Bertolotti, 1976; Marin Braun et al., 1991; Wulle, 1992). With these assessments, good and even excellent results may be achieved with no DIP movement at all if the MP and PIP ranges of movement are normal. A more recent study of zone 1 repairs by the Mantero technique (Guinard et al., 1999) examined the results of treatment using the original Strickland assessment and reported good and excellent results in 23 of 24 (96%) of cases. Unfortunately, direct comparison of DIP joint function with our results and those of Evans (1990) and of Gerbino et al. (1991) is impossible. However, as these results are considerably better than those in the studies using the Kessler and circumferential suture repair technique, further examination of the Brunelli and/or Mantero techniques may be warranted. Guinard et al. (1999) presented a patients' evaluation of the results of treatment for the ®rst time in the literature of ¯exor tendon injuries. The patients considered the results to be less favourable than did the surgeons. This suggests that the observation of Evans (1990) that 408 of DIP joint ¯exion is necessary for patient satisfaction is a minimum necessity and that our assessment of treatment of this injury has not been
84
suciently stringent in the past to alert us to the inadequacy of our treatments of zone 1 injuries. Acknowledgments The authors wish to thank Dianne Harris, the Hand Research Coordinator, for her help in the data collection and the other hand consultants in the unit for allowing us to report on their patients.
References Allen BN, Frykman GK, Unsell RS, Wood VE (1987). Ruptured ¯exor tendon tenorrhaphies in zone 2: repair and rehabilitation. Journal of Hand Surgery, 12A: 18±21. Bainbridge LC, Robertson C, Gillies D, Elliot D (1994). A comparison of postoperative mobilization of ¯exor tendon repairs with ``passive ¯exionactive extension'' and ``controlled active motion'' techniques. Journal of Hand Surgery, 19B: 517±521. Brunelli G (1958). La suture tendineuse avec lacet de nylon appuye sans ``pullout''. Acta Orthopaedica Belgica, 24: 178±179. Brunelli G, Monini L (1982). Technique personelle de suture des tendons ¯eÂchisseurs des doigts avec mobilisation immeÂdiate. Annales de Chirurgie de la Main, 1: 92±96. Brunelli G, Vigasio A, Brunelli F (1983). Slip-knot ¯exor tendon suture in zone 2 allowing immediate mobilisation. The Hand, 3: 352±358. Elliot D, Moiemen NS, Flemming AFS, Harris SB, Foster AJ (1994). The rupture rate of acute ¯exor tendon repairs mobilized by the controlled active motion regimen. Journal of Hand Surgery, 19B: 607±612. Evans RB (1990). A study of the zone 1 ¯exor tendon injury and implications for treatment. Journal of Hand Therapy, 133±148. Gerbino PG, Saldana MJ, Westerbeck P, Schacherer TG (1991). Complications experienced in the rehabilitation of zone 1 ¯exor tendon injuries with dynamic splinting. Journal of Hand Surgery, 16A: 680±686. Grandis C, Rosello MI (1988). Dieci anni di esperienza con il pull-out intertendineo nella chirurgia dei tendini ¯essori al canale digitale (zona 1±2). [Ten years experience with intertendinous pull-out in ¯exor tendon surgery at the digital canal (zones 1±2)]. Rivista di Chirurgia della Mano, 25: 43±49. Guinard D, Montanier D, Thomas D, Corcella D, Moutet F (1999). The Mantero ¯exor tendon repair in zone 1. Journal of Hand Surgery, 24B: 148±151. Harris SB, Harris D, Foster AJ, Elliot D (1999). The aetiology of acute rupture of ¯exor tendon repairs in zones 1 and 2 of the ®ngers during early mobilization. Journal of Hand Surgery, 24B: 275±280. Kelly AP (1959). Primary tendon repairs. A study of 789 consecutive tendon severances. Journal of Bone and Joint Surgery, 41A: 581±598. Kleinert HE, Kutz JE, Ashbell T, Martinez E (1967). Primary repair of lacerated ¯exor tendons in ``No Man's Land''. Journal of Bone and Joint Surgery, 49A: 577. Kleinert HE, Forshew FC, Cohen MJ. Repair of zone 1 ¯exor tendon injuries. In: AAOS symposium on tendon surgery in the hand. St Louis, Mosby, 1975: 115±122. Kwai Ben I, Elliot D (1998). ``Venting'' or partial lateral release of the A2 and A4 pulleys after repair of zone 2 ¯exor tendon injuries. Journal of Hand Surgery, 23B: 649±654.
THE JOURNAL OF HAND SURGERY VOL. 25B No. 1 FEBRUARY 2000 Leddy JP, Packer JW (1977). Avulsion of the profundus insertion in athletes. Journal of Hand Surgery, 2: 66±69. Mantero R, Bertolotti P, Badoini C (1973/4). Il pull-out in ``no man's land'' e al canale digitale nelle lesioni dei ¯essori (metodo personale). Rivista di Chirurgia della Mano, 11: 119±130. Mantero R, Bertolotti P, Badoino C, Ferrari GL (1974/5). Revisione critica di 20 anno di esperienza sul trattamento delle lesioni dei ¯essori. Rivista di Chirurgia della Mano, 12: 87±110. Mantero R, Bertolotti P (1976). La mobilisation preÂcoce dans le traitement des leÂsions des tendons ¯eÂchisseurs au canal digital. Annales de Chirurgie de la Main, 30: 889±896. Marin Braun F, Foucher G, Buch-Jaeger N, Sammut D (1991). ReÂparation du ¯eÂchisseur profond et du long ¯eÂchisseur du pouce par la `®xation en rappel'. ReÂsultats d'une seÂrie de soixante-dix-sept cas. Annales de Chirurgie de la Main, 10: 13±21. Savage R (1990). The mechanical eect of partial resection of the digital ®brous ¯exor sheath. Journal of Hand Surgery, 15B: 435±442. Siler VE (1950). Primary tenorrhaphy of the ¯exor tendons in the hand. Journal of Bone and Joint Surgery, 32A: 218±225. Sirotakova M, Elliot D (1999). Early active mobilization of primary repairs of the ¯exor pollicis longus tendon. Journal of Hand Surgery, 24B: 647±653. Small JO, Brennen MD, Colville J (1989). Early active mobilization following ¯exor tendon repair in zone 2. Journal of Hand Surgery, 14B: 383±391. Sood MK, Elliot D (1996). A new technique of attachment of ¯exor tendon to the distal phalanx without a button tie-over. Journal of Hand Surgery, 21B: 629±632. Strickland JW (1985). Results of ¯exor tendon surgery in zone 2. Hand Clinics, 1: 167±179. Strickland JW, Glogovac SV (1980). Digital function following ¯exor tendon repair in zone 2: a comparison of immobilization and controlled passive motion techniques. Journal of Hand Surgery, 5: 537±543. Tomaino M, Mitsionis G, Basitidas J, Grewal R, Pfaee J (1998). The eect of partial excision of the A2 and A4 pulleys on the biomechanics of ®nger ¯exion. Journal of Hand Surgery, 23B: 50±52. Verdan CE. ReÂparation primaire des ¯eÂchisseurs en dehors des coulisses osteo®breuses des doigts. In: Chirurgie reÂparatrice et fonctionnelle des tendons de la main. Paris, L'Expansion Scienti®que FrancËaise, 1952, 174±176. Verdan CE (1960). Primary repair of ¯exor tendons. Journal of Bone and Joint Surgery, 42A: 647±657. Verdan CE, Michon J (1961). Le traitement des plaies des tendons ¯echisseurs des doigts. Revue de Chirugie OrthopeÂdique et ReÂparatrice de L'Appareil Moteur, 47: 290±296. Wulle C (1992). Flexor tendon suture in zone 1 and distal zone 2 by the Mantero technique. Annals of Hand and Upper Limb Surgery, 11: 200±206. Young RES, Harmon JM (1960). Repair of tendon injuries of the hand. Annals of Surgery, 151: 562±566.
Received: 5 August 1999 Accepted after revision: 10 September 1999 D. Elliot MA FRCS, St Andrew's Centre for Plastic Surgery, Broom®eld Hospital, Court Road, Broom®eld, Chelmsford, Essex CM1 7ET, UK. # 2000 The British Society for Surgery of the Hand DOI: 10.1054/jhsb.1999.0319, available online at http://www.idealibrary.com on
This paper presents an analysis of the results of repair of 102 complete ¯exor tendon disruptions in zone 1 which were rehabilitated by an early active mobilization technique during a 7 year period from 1992 to 1998. These injuries were subdivided into: distal tendon divisions requiring reinsertion; more proximal tendon divisions but still distal to the A4 pulley; tendon divisions under or just proximal to the A4 pulley; and closed avulsions of the ¯exor digitorum profundus tendon from the distal phalanx. Assessment by Strickland's original criteria showed good and excellent results of 64%, 60%, 55% and 67% respectively in the four groups. However, examination of the results measuring the range of movement of the distal interphalangeal (DIP) joint alone provided a more realistic assessment of the aect of this injury on DIP joint function, with good and excellent results of only 50%, 46%, 50% and 22% respectively in the four groups. Journal of Hand Surgery (British and European Volume, 2000) 25B: 1: 78±84 They included 17 female and 72 male patients with ages ranging from 7 to 71 (mean, 33) years. Nine patients with pull-o injuries of the FDP were also treated during this period and are documented in the study for comparison with the tendon divisions. Twenty-six patients with 30 complete tendon divisions in zone 1 who did not participate in the postoperative rehabilitation for the minimum period of 8 weeks or were lost to follow-up before 12 weeks were excluded from the study. Thirty-six patients with partial FDP divisions and all patients under 5 years of age were also excluded. Replantations, revascularizations and ¯exor tendon injuries with associated fractures, joint damage or signi®cant skin loss were also excluded from the study. No patients with small or moderate skin defects were excluded as these were mobilized immediately and in the normal manner while the skin problem was treated with small dressings and/or with homodigital ¯aps until epithelialization occurred. From the point of view of the operating surgeon, divisions of the FDP tendon in zone 1 fall naturally into three subgroups (Fig 1). We de®ned those divisions so close to the insertion of the tendon that it was impossible to insert a Kessler suture into the distal end of the tendon as zone 1a injuries. After exclusions, there were 14 zone 1a tendon divisions in this study. In these injuries, the tendon was repaired by reinsertion onto the distal phalanx using a 3/0 or 4/0 polypropylene (Prolene) tendon core suture passed through the bone and nail complex and tied over a button or by the alternative technique of attachment without a button tie-over (Sood and Elliot, 1996). Those tendon divisions between zone 1a and the distal edge of the A4 pulley, were de®ned as zone 1b injuries. After exclusions, there were 43 zone 1b tendon divisions in this study. These injuries were repaired using the modi®cation of the Kirchmayr/Kessler core suture in which the suture is tied with a single intratendinous knot using 3/0 or 4/0 polypropylene and a continuous epitendinous suture of 5/0 or 6/0 polypropylene or nylon (Ethilon). Repairs in zone 1b may catch on the
Since the introduction of immediate ¯exor tendon repair and early mobilization (Kelly, 1959; Kleinert et al., 1967; Siler, 1950; Verdan, 1952; 1960; Young and Harmon, 1960), research into ¯exor tendon repair has concentrated, almost exclusively, on zone 2 injuries. These injuries create problems largely as a result of loss of proximal interphalangeal (PIP) joint function whereas zone 1 injuries predominantly aect the function of the DIP joint. For this reason, it may be inappropriate and even misleading to assess zone 1 injuries using the methods used for zone 2 injuries. A number of earlier papers, including two involving the senior author (DE), which examined zone 1 injuries with such methods have, inadvertently, given a false impression that these injuries do well with the techniques of surgery and rehabilitation evolved for use on zone 2 injuries (Bainbridge et al., 1994; Brunelli and Monini, 1982; Brunelli et al., 1983; Elliot et al., 1994; Grandis and Rossello, 1988; Mantero et al., 1974; Mantero and Bertolotti, 1976; Wulle, 1992). We can only ®nd two small studies of zone 1 tendon divisions that present data in such a manner that it is possible to examine the eect of these injuries and their treatment on the DIP joint (Evans, 1990; Gerbino et al., 1991). These data suggest that tendon divisions in this zone create particular diculties of management and that our current methods of treatment do not routinely restore good DIP joint function. In this study, we have examined a larger number of zone 1 injuries to try to throw more light on the problems of tendon injuries in this zone and the adequacy of current treatment. PATIENTS AND METHOD Over a period of 7 years, from 1991 to 1998, 168 complete and partial disruptions of the ¯exor digitorum profundus (FDP) tendon in zone 1 were treated in our unit. These included 93 complete tendon divisions in 93 ®ngers in 89 patients over the age of 5 years. These patients constitute the main study group in this paper. 78
PRIMARY FLEXOR TENDON REPAIR IN ZONE 1
Fig 1 Subdivision of zone 1 ¯exor tendon injuries.
distal edge of the A4 pulley on ®nger ¯exion. Except in the earliest part of this series, the distal edge of the A4 pulley was released laterally, or ``vented'', as a routine if this was deemed necessary to achieve full free movement of a repair. In the early years of this study, there was no routine unit policy on venting pulleys and details of this feature of management were not routinely recorded. In ®ve of the zone 1b injuries, the palmar plate of the DIP joint was also injured and required surgical repair. Those tendon injuries lying immediately beneath or just proximal to the A4 pulley were de®ned as zone 1c injuries. After exclusions, there were 36 zone 1c tendon divisions in this study. The tendons in zone 1c were repaired using the same technique as for zone 1b injuries. Access to the divided tendons in this zone often requires complete or near complete division of the A4 pulley, with further pulley division sometimes being necessary to allow free movement of the repair. As with zone 1b injuries, there was no routine policy in the unit in the early years of this study on how to manage these problems of access and mobility but `venting' of the distal A4 pulley has been considered acceptable practice in the unit during most of the period of this study, both to achieve access to the site of division and to achieve a free running repair. Closed avulsions of the FDP tendon from the distal phalanx were designated as zone 1p (pull-o) injuries. After exclusions, there were nine zone 1p injuries in nine patients in this study. Six avulsions were type 2 and three were type 3 injuries (Leddy and Packer, 1977). There were no type 1 injuries. Of the type 3 injuries, all three tendon avulsions included a large fragment of bone and constituted a signi®cant intra-articular fracture of the DIP joint which required bone reattachment with interosseous wires. In the remaining six ®ngers, the tendon was reinserted using the same technique as for tendon divisions in zone 1a. The repairs were mobilized postoperatively in the variation of the controlled or early active motion
79
regimen that we use routinely and have described previously (Elliot et al., 1994). Return to work was allowed at 8±12 weeks, according to occupation. All patients included in this study were followed for a minimum of 12 weeks. The results were assessed using Strickland's original criteria, which measure the total ¯exion of the proximal and the distal interphalangeal joints minus any extension lag (Strickland and Glogovac, 1980). In this classi®cation, a net range of motion of these two joints of 1758 is considered as 100% and results of ¯exor tendon repair between 85 and 100% (150±1758) are considered excellent, those between 70 and 84% (125±1498) as good and those between 50 and 69% (90±1248) as fair. Results between 0 and 49% (0±908) are regarded as poor. To allow comparison with previous papers, it was also necessary to assess our results using the modi®ed Strickland assessment in which results of ¯exor tendon repair between 75 and 100% (132±1758) are considered excellent, those between 50 and 74% (88±1318) as good, those between 25 and 49% (44±878) as fair and those between 0 and 24% (0±448) are regarded as poor (Strickland, 1985). To achieve a more accurate picture of the eect of zone 1 ¯exor injuries on DIP joint function, we have also analysed our results in terms of DIP joint range of motion alone. This necessitated devising a system of assessment similar to that of Strickland and Glogovac (1980) but using DIP measurements only and comparing them with a calculated ``normal'' value for the DIP joint range alone. Unfortunately, Strickland and Glogovac did not indicate how the ®gure of 1758 for the normal range of movement of both interphalangeal joints was determined or how much of this ®gure represents DIP joint movement. Therefore, our study was extended to include measurements of the ranges of motion of the DIP joints of all eight ®ngers of 50 normal individuals. To determine whether the movement range of the DIP joint varies between dierent individuals, these measurements were made on 320 ®ngers in ten male labourers, ten male doctors, ten female nurses and ten female medical secretaries, who represented a slightly older female population than the nurses. The average range of motion of the DIP joint for the men was 698 and for the women was 798 with an overall average for both sexes of 748. This ®gure was used as the normal range of motion of the DIP joint. The average combined range of motion of the PIP and DIP joints in this group of normal individuals was 1758, con®rming the ®gure used by Strickland and Glogovac (1980). Considering DIP joint range of motion alone, results of ¯exor tendon repair between 85 and 100% of the average (62±748) were considered excellent, as in Strickland's original assessment method for zone 2 injuries. Those between 70 and 84% (51±618) were considered as good and results between 50 and 69% (37±508) as fair. Results between 0 and 49% (0±368) were regarded as poor.
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RESULTS Table 1 shows the complete results of our series and Figure 2 shows the percentage of good and excellent results for the dierent subdivisions of zone 1 in those ®ngers with intact tendon repairs at 12 weeks from primary surgery. Figure 2 illustrates the results of assessment by the original Strickland method, the modi®ed Strickland method and for DIP joint measurements alone as compared with a normal range of DIP motion of 748. There were four zone 1 repairs in this series, which ruptured at 7, 12, 15 and 24 days after primary surgery. All four were in zone 1c. Three of these ruptures were rerepaired and the fourth was treated by two-stage tendon grafting. Of the three re-repairs one achieved an excellent outcome, one a good and one a poor result when assessed by Strickland's original criteria. When assessed by DIP motion alone, one achieved a good, one a fair and one a poor result. Four patients developed ``stuck'' FDP tendons. In two cases, tenolysis of intact
repairs was successful. In another, the tendon repair was found to have gapped under the A4 pulley. As the patient did not wish to have a tendon graft, a distal tenodesis was performed. The fourth patient, who had developed a severe ®xed ¯exion contracture of the DIP joint, was treated by arthrodesis of this joint. Two patients developed re¯ex sympathetic dystrophy, which responded well to analgesics and guanethidine blocks. There were no complications in the patients with tendon avulsions. DISCUSSION Evans (1990) discussed the eect of zone 1 profundus tendon injuries on DIP joint motion and the importance of active movement of this joint to ®ner aspects of ®nger function. She reported her own experience that patients were usually not satis®ed unless the DIP joint, as well as the PIP joint, was free of ¯exion contracture and the DIP joint ¯exed to 408 or more. We believe that a
Table 1ÐThe complete results of our series with dierent methods of assessment Methods of Assessment Original Strickland
DIPJ alone
Excellent
Good
Fair
Poor
Rupture
Excellent
Good
Fair
Poor
Rupture
All zone 1 tendon divisions Zone 1a tendon divisions Zone 1b tendon divisions Zone 1c tendon divisions
(n=93) (n=14) (n=45) (n=34)
33 6 17 10
22 3 10 9
21 5 8 8
13 0 6 7
4 0 4 0
31 5 16 10
14 2 5 7
12 1 8 3
32 6 12 14
4 0 4 0
All zone 1 tendon avulsions Type 2 FDP avulsions Type 3 FDP avulsions
(n=9) (n=6) (n=3)
2 1 1
4 4 0
1 0 1
2 1 1
0 0 0
1 0 1
1 1 0
1 1 0
6 4 2
0 0 0
Fig 2 Good and excellent results of zone 1 injuries in this study, assessed by dierent methods.
PRIMARY FLEXOR TENDON REPAIR IN ZONE 1
capability for rapid movement is also essential to achieving the full functional potential of the DIP joint. This is seen particularly in the rapid movement of the DIP joints of the index and middle ®ngers through small ranges of motion which are an integral part of ®ne pinch activities and are of particular signi®cance to hand function in skilled craftsmen and musicians. Power gripping of large diameter objects and span pinch, that is ®ve digit tip gripping as when opening the lid of a coee jar, also requires DIP joint function. We can only ®nd two papers that present data on the treatment of zone 1 injuries in such a way as to allow analysis of the eect of these injuries and their treatment on the DIP joint (Evans, 1990; Gerbino et al., 1991). Evans (1990) reported a 60% incidence of complications but did not elaborate on these problems. Gerbino et al. (1991) reported a complication rate of 35% but these included six complete failures of DIP motion, which would normally be reported as poor results and not as complications. Nevertheless, it was the high complication rates in these two papers which prompted us to reexamine zone 1 ¯exor tendon injuries. In this study, we analysed our results initially using the original Strickland method (Strickland and Glovac, 1980). Most authors have abandoned the modi®ed version of the Strickland assessment of zone 2 injuries as being too lenient and, eectively moving all results up a grade (Strickland, 1985). This eect is seen clearly in Figure 2. The Strickland modi®cation of the TAM method of assessment was introduced to eliminate the dilutional eect of a normal or near-normal range of movement of the MP joint on assessments of zone 2 injuries. This study illustrates that the same problem arises if PIP joint movements are included in the assessment of the results of treatment of zone 1 injuries (Fig 2). Inclusion of the PIP joint ranges of motion dilutes the true eect of zone 1 injuries on the DIP joint
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and, hence, their eect on the ®ner aspects of ®nger function provided by this joint. To analyse the eect of zone 1 injuries on the DIP joint, we have introduced a new method of assessment which uses the same methodology as the original Strickland method but considers the movements of the DIP joint alone. We believe this is a better indicator of the eectiveness of the treatment of zone 1 injuries. Nevertheless, the Strickland assessment is still useful in showing the eect of zone 1 injuries and their treatment on the function of the ®ngers when they are used for more basic gripping activities in which the distal interphalangeal joint motion is said only to be responsible for 15% of total ®nger ¯exion (Marin-Braun et al., 1991). In our series, 62% of the ®ngers achieved recovery of more than the 408 of DIP joint motion, which Evans (1990) believed to be necessary for unproblematic function of this joint. Although we did not experience the high rate of complications reported by either Evans (1990) or Gerbino et al. (1991), these results leave no room for complacency and the good and excellent results in our series are very much lower than those of zone 2 repairs whether or not the analysis includes the PIP joint. We have re-examined the data from the study by Gerbino et al. (1991) using the same assessment methods as in our own study (Fig 3). Examined in the conventional manner of this ®gure, the results in the two studies are comparable. Both papers also reported similar rupture rates of 4±5%. However, a striking dierence between the two studies is seen when one looks at those cases that did not rupture but had poor results. In our study, there were four of 93 (4%) injuries with ``stuck'' FDP tendons while Gerbino et al. reported six of 20 (30%) ®ngers with no movement of the DIP joint at all. Although none of these cases was explored, the authors believed this to be due to gapping of the repairs as a result of too aggressive passive extension of
Fig 3 Good and excellent results of zone 1 injuries in the literature and in this study, assessed by dierent methods.
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the ®ngers during early rehabilitation. It is more likely that the problem was impingement of the repaired tendons on the repaired A4 pulley, preventing ¯exion of the DIP joint, as these authors pursued a policy of closing the tendon sheath. We believe that our policy of leaving the sheath open, with liberal venting of the pulley as necessary to achieve a full passive range of motion of the repairs before closing the skin of the ®ngers, is a better technique when operating within the narrow con®nes of the tendon sheath in zone 1. Unfortunately, this retrospective study does not allow us to con®rm this as our present policy was evolved during the period of this work. Evans reported results of 83 complete zone 1 tendon divisions repaired by 25 dierent surgeons and referred to her for rehabilitation. The techniques of repair were not detailed but the rehabilitation was standardized. The ®rst 63 patients, examined retrospectively, were treated by a passive mobilization regimen which was changed to a more complicated passive regimen before examining a further 20 patients prospectively. Comparison of our results with those of Evans' study was more complicated as her results were reported using the modi®ed Strickland method and only the mean value of the range of motion of the DIP joint was given for each of the two parts of her study. Therefore, we have re-assessed our results and those of Gerbino et al. by these methods (Figs 3 and 4). As can be seen from these ®gures, the revised regimen of mobilization used by Evans in the second part of her study improved the results over those achieved using the original method of mobilization. However, this intensive, complicated and therapistdependent regimen appears to have little advantage over simply allowing the patients to move their ®ngers actively within a splint which limits full extension. All
THE JOURNAL OF HAND SURGERY VOL. 25B No. 1 FEBRUARY 2000
three studies show similar, and not impressive, restoration of DIP joint function. The fourth subgroup of tendon injury in zone 1 is that of closed avulsion of the tendon from the distal phalanx. Our results of treatment of these injuries during this period are included for comparison with the tendon divisions, in particular those divisions in zone 1a (Table 1 and Fig 2). Although one would expect those type 3 avulsion injuries, which have pulled o signi®cant fragments of bone and which constitute intra-articular fractures to have bad results, it is uncertain why the type 2 avulsions also have much worse results than zone 1a tendon divisions. However, meaningful interpretation requires larger numbers of cases in both groups. All four ruptures in this series presented within 48 hours and three were re-repaired within a further 24 hours. One achieved an excellent result, one a good result and one a poor result. As for zone 2 ®nger ¯exor tendon and FPL ruptures, immediate re-repair, although not easy, is the best option of treatment for patients who present quickly after rupture and who wish to have active DIP joint motion (Allen et al., 1987; Harris et al., 1999; Sirotakova and Elliot, 1999; Small et al., 1989). The alternative is to accept the loss of movement of the DIP joint and ignore the rupture. If this treatment option is chosen, it is sometimes necessary to either splint the DIP joint in slight ¯exion for a period of 4±6 weeks or carry out a distal tenodesis of the ¯exor tendon if the ®nger is seen to be developing a ¯ail joint with hyperextension when pressure is applied to the ®ngertip. Over and above the general diculties of operating in zone 1, it has become evident from our increased scrutiny of the zone during this study that the local anatomy of the ¯exor tendon and its sheath are not
Fig 4 Mean range of motion of the DIP joint alone in the literature and in this study.
PRIMARY FLEXOR TENDON REPAIR IN ZONE 1
constant throughout the length of the zone and the consequences of tendon division at dierent levels within the zone demand subtle dierences of management by the operating surgeon. In this respect, we identi®ed three subgroups of zone 1. Zone 1a injuries requires re-insertion of the profundus tendon into the distal phalanx. Although the repair will move very little during subsequent ®nger movement, the reinsertion causes slight shortening of the profundus tendon, the consequences of which are unknown. Zone 1b injuries overlie the palmar plate of the DIP joint which may be injured primarily or scarred later during healing, resulting in joint contracture. At worst, this can create a hook ®nger with serious dysfunction and is less amenable to palmar plate release than that of the PIP joint. Zone 1b repairs may also impinge on the distal edge of the A4 pulley, with loss of full ¯exion. Treatment of both zone 1a and 1b injuries requires division of the A5 pulley to achieve repair, the implications of which have not been studied. Zone 1c injuries mostly lie under the A4 pulley. However, in a previous study from this unit, it was found that the whole of the attachment of the FDS tendon was proximal to the A4 pulley in 30% of ®ngers examined (Kwai Ben and Elliot, 1998). Because the interface of zones 1 and 2 was de®ned by Verdan and Michon (1961) as the distal end of attachment of the FDS tendon to the middle phalanx, some divisions of the FDP tendon just proximal to the A4 pulley will be included in zone 1. We have come to realize that zone 1c injuries frequently require complete division of the A4 pulley for access and/or free excursion of the tendon repair. Comparison of our results with those of Evans (1990) and Gerbino et al. (1991) does not identify any detrimental eect of A4 division on the ultimate function of the ®nger in terms of range of motion, which has been, and still remains, the conventional measure of ®nger function after ¯exor tendon repair. The eect of zone 1 ¯exor tendon repairs, with or without A4 pulley division, on the power of ®nger ¯exion is not known. However, the work of Savage (1990), and of Tomaino et al. (1998) would suggest that we need no longer consider this pulley to be sacrosanct, a view expressed by Kleinert et al. in 1975. Subdivision of zone 1 is useful in identifying the surgical diculties of particular parts of the zone 1 injury. It did not have a prognostic bene®t in this study, other than con®rming that only the most proximal zone 1 injuries under the A4 pulley, de®ned as zone 1c, are likely to result in loss of PIP range of motion and therefore to aect power gripping of small and moderate-size objects. However, our policy of pulley venting was intended to eliminate any dierences between the subgroups and may have eliminated dierences which could be important in future studies examining other methods of management, particularly of the tendon sheath and A4 pulley. All three series reporting on the treatment of zone 1 tendon divisions by conventional suturing with a Kessler
83
type of core suture and circumferential support suture and mobilized in current active or passive mobilizing regimes have results which are worse than those of zone 2 injuries both in terms of total range of movement of the ®nger and also in terms of their particular eect on the adjacent DIP joint. We suspect that the increase in diameter of the tendon as a result of suturing, in particular the bunching of the tendon which is an inherent risk of ¯exor tendon suture, and the associated diculty in avoiding problems of tendon gliding in the much more con®ned space of zone 1 may be critical factors. Although less frequently used than in earlier times, the techniques of pull-out suture described by Brunelli (1958) and by Mantero et al. (1973) in Italy, or the modi®cation using the Jennings barbed wire suture used in Strasbourg (Marin Braun et al., 1991), oer alternative methods of treatment of zone 1 tendon divisions. These sutures are, essentially modi®cations of the original Bunnell technique and similar to the suture technique which we, and most others, use for zone 1a tendon divisions and for FDP avulsion injuries. However, these authors also used pull-out sutures for more proximal tendon divisions both in zone 1 and distal zone 2. While still prone to the problem of tendon bunching, these suture techniques involve less surgical invasion of the zone 1 sheath and leave less suture material in this restricted space so may have advantages in this respect. Unfortunately, all the earlier studies reporting results with these techniques were analysed using assessments which include or depend on the ranges of motion of all three joints of the ®nger, so give very little indication of the true eect of the injuries and their treatments on the DIP joint (Brunelli and Monini, 1982; Brunelli et al., 1983; Grandis and Rossello, 1988; Montero et al., 1974; Mantero and Bertolotti, 1976; Marin Braun et al., 1991; Wulle, 1992). With these assessments, good and even excellent results may be achieved with no DIP movement at all if the MP and PIP ranges of movement are normal. A more recent study of zone 1 repairs by the Mantero technique (Guinard et al., 1999) examined the results of treatment using the original Strickland assessment and reported good and excellent results in 23 of 24 (96%) of cases. Unfortunately, direct comparison of DIP joint function with our results and those of Evans (1990) and of Gerbino et al. (1991) is impossible. However, as these results are considerably better than those in the studies using the Kessler and circumferential suture repair technique, further examination of the Brunelli and/or Mantero techniques may be warranted. Guinard et al. (1999) presented a patients' evaluation of the results of treatment for the ®rst time in the literature of ¯exor tendon injuries. The patients considered the results to be less favourable than did the surgeons. This suggests that the observation of Evans (1990) that 408 of DIP joint ¯exion is necessary for patient satisfaction is a minimum necessity and that our assessment of treatment of this injury has not been
84
suciently stringent in the past to alert us to the inadequacy of our treatments of zone 1 injuries. Acknowledgments The authors wish to thank Dianne Harris, the Hand Research Coordinator, for her help in the data collection and the other hand consultants in the unit for allowing us to report on their patients.
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Received: 5 August 1999 Accepted after revision: 10 September 1999 D. Elliot MA FRCS, St Andrew's Centre for Plastic Surgery, Broom®eld Hospital, Court Road, Broom®eld, Chelmsford, Essex CM1 7ET, UK. # 2000 The British Society for Surgery of the Hand DOI: 10.1054/jhsb.1999.0319, available online at http://www.idealibrary.com on