Results of zone I and zone II flexor tendon repairs in children

/

Results of Zone I and Zone II Flexor Tendon Repairs in Children

1

Stephen J. O’Connell, MD, Ranch0 Mirage, CA, Michael M. Moore, MD, Little Rock, AR, James W. Strickland, MD, Indianapolis, IN, G. Thomas Frazier, MD, Little Rock, AR, Paul C. Dell, MD, Gainesville, FL In a combined

study of three hand surgery

had sustained

flexor

critical

evaluation.

months). function

following

resulting

results when of function.

postrepair

with

into three groups: were

profundus profundus

with

Immobilization Digital

analyzed

motion

repairs

zone

a modest

years of growth.

studied.

less favorably

of Hand

Surgery

in zone motion

program

II flexor

improvement (J Hand

Digits

with

profundus

associated

compared

with

in digital

motion

was found

digital

isolated when

of

Isolated

comparable

immobilization

in an appreciable

or early motion

digital

performance

function.

II achieved

or following

digitorum

11-l 5 years.

of normal

in digital

excellent

in zone

for

3-144

of age, the effect

changes

I returned repairs

return

the effect

when

for

deterioration

and superficialis

was not significantly nerve tendon patients

and/or

palmar

lacerations. returned

In after

Surg 1994;19A:48-52.)

From the Desert Orthopaedic Center, Eisenhower Medical Center, Ranch0 Mirage, CA, Little Rock, AR, Indiana University School of Medicine, Indianapolis, IN, and Department of Orthropaedics, University of Florida, Gainesville, FL. Received for publication Oct. 1, 1991; accepted in revised form June 10, 1993. No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article. Reprint requests: Stephen J. O’Connell, MD, Director of Hand Surgery, Desert Orthopaedic Center. Eisenhower Medical Center, 39000 Bob Hope Drive, Lakeview Building, Ranch0 Mirage, CA 92270. The Journal

to determine

(range,

years, and

the percentage

less than 4 weeks of immobilization

fared

than 16 years who

was 24 months

for longer than 4 weeks resulted following

younger

O-5 years, 6-10

and superficialis

The difficulty in returning satisfactory digital motion following flexor tendon interruption in children is well recognized. There is, however, little information in the hand surgery literature that documents the results of primary flexor tendon repair in zones I and II in these patients. Furthermore, no effort has been made to determine the optimum period of

48

period

and the long-term

an early passive

in the three age groups

lacerations

78 patients

I or zone II of 95 digits were available

follow-up

immobilization,

All

managed

treated

many digits, several

Data

and combined

3 or 4 weeks.

plate

repair.

growth.

practices,

in zone

was assessed to determine

of postrepair

from

profundus

different

The average

of all digits

periods

injuries

lacerations

Patient age was divided

Performance varying

tendon

postoperative immobilization and importance of early mobilization. Alterations in digital function resulting from growth have not been studied. This study represents the combined efforts of three hand surgical practices to retrospectively analyze digital function following zone I and II primary flexor tendon repairs in children less than 16 years of age. Because the three centers had different policies with regard to the length of postrepair immobilization, sufficient numbers were available to allow meaningful comparisons between those tendons that were mobilized early and those that were subjected to 3. 4, 5, and 6 weeks of immobilization. In addition, the children were subdivided into three age groups (O-5,6- 10, and 1 I- 15 years of age) to elucidate the effect of age on final functional results. Several patients with long-term follow-up data were evaluated in an effort to assess the effect of growth on digital performance following flexor tendon repair.

The Journal

Materials and Methods One hundred one patients under 16 years of age who had suffered flexor tendon lacerations within the fibroosseous canal (zone 1 or II) in 121 digits were identified. Digits with associated fractures, crush injuries, revascularization, or skin loss were omitted from the initial study group, and 23 patients were deleted because of insufficient postrepair follow-up time or data. Seventy-eight patients with flexor tendon lacerations in 95 digits were available for critical evaluation at an average postrepair follow-up period of 24 months (range. 3-144 months). Primary flexor tendon repair had been performed on 21 index, 20 middle, 26 ring, and 28 small fingers. The study group included 10 zone I isolated profundus tendon lacerations, 30 zone II isolated profundus tendon interruptions, and 55 zone II superficialis and profundus lacerations. Thirty-four digits had incurred concomitant digital nerve lacerations while 19 digits suffered division of both digital nerves. Partial or complete laceration of the paimar plate occurred in 19 digits. All associated structures were repaired in conjunction with flexor tendon suture. These surgical procedures were performed or supervised by one of eight attending surgeons from three hand surgical centers. Immediate primary repair was performed on the day of injury in 37 of 95 digits while 58 of 95 underwent delayed primary repair after an average of 5 days (range. O-76 days). Nonabsorbable suture was used for several tendon repair techniques (Kessler 44%. Bunnell 22%, modified Tajima 26%, miscellaneous 8%). Postoperative treatment included the use of an early range of motion program in 19 digits. Six digits were treated with the Kleinert dynamic motion program. and I3 digits were mobilized with a modified Duran passive motion program. The remaining 76 digits were managed by immobilization of the digits in a cast or splint for 3-6 weeks after tendon repair. Above-elbow immobilization was used in some young or noncompliant patients. Following the immobilization process the children were allowed unrestricted motion of the digits. The percentage of normal digital function that was recovered following flexor tendon repair was determined by a computation of total active motion (TAM) as described by Glogovac and Strickland.’ [TAM = proximal interphalangeal + distal interphaiangeal active flexion - extension deficit)/175 x 1001. Each digit was assigned a functional rating according to the classification system developed by the International Federation of Hand Societies.

of Hand

Surgery

/ Vol.

19A No.

1 lanuary

1994

49

Those digits achieving 75-100% of normal digital function were graded as excellent, 50-74% good, 25-49% fair, and O-24% poor. Patients were further divided into three age groups for closer scrutiny: birth to 5 years (23 patients: 27 digits, 6-10 years (23 patients; 33 digits), and 1l-15 years (32 patients: 35 digits).

Results Functional evaluation of all digits after an average postrepair follow-up period of 24 months revealed a percentage TAM averaging 69%. Primary tendon repairs managed by an early active or passive mobilization program returned an average TAM of 77%. There was no significant difference in motion return between the two methods of early mobilization. Comparable results were achieved following 3 weeks (TAM = 76%) or 4 weeks (TAM = 72%) of digital immobilization following repair, while immobilization beyond 4 weeks resulted in the deterioration of digital function (TAM 5 weeks = 62%. 6 weeks = 41%) (Fig. I). No difference in tendon repair technique or suture material was observed. In addition, no tendon ruptures were identified. All profundus repairs in zone I achieved excellent results (Fig. 2), whether they were managed by early mobilization (TAM = 90%) or 3 weeks of immobiiization (TAM = 94%). Isolated zone II profundus repairs achieved comparable results when managed by an early motion program (TAM = 78%;) or immobilization for 3 weeks (TAM = 71%) or 4 weeks (TAM = 76%). However. immobilization longer than 4 weeks resulted in an appreciable deterioration of digital function (TAM 5 weeks = 67%, 6 weeks = 43%). Similarly, good functional results were achieved following zone II flexor digitorum superficialis and flexor digitorum profundus repairs when postoperative management included an early motion program (TAM = 72%) or immobilization for 3 weeks (TAM = 72%) or 4 weeks (TAM = 71%). A significant deterioration of digital function again occurred after prolonged immobilization (TAM 5 weeks = 58%). 6 weeks = 40%) (Table I). The children were divided into three age groups (O-5 years, 6-10 years, and 1l-15 years) to study the effect of age on ultimate digital function following primary flexor tendon repair. In an effort to make meaningful comparisons between these groups, children whose digits were immobilized for longer than 4 weeks were eliminated since a larger proportion of the younger children were treated with prolonged immobilization and this form of treatment generally yields inferior functional results. Analysis of those digits with primary zone II repair of the

50

O’Connell

et al. / Zone

90

I and II Flexor Tendon

1



77%

in Children

76%

EPM

Figure 1. Functional

Repair

72%

4 Wks

3 Wks

results: postoperative

6 Wks

5 Wks

immobilization.

EPM, early passive motion.

.5 100 5

90

= 80 +0 6460 'k50 gi40 a930 Ek20 is-10 cf

O

POOR Classification

I

1 n Zone I FDP

Zone II FDP H Zone II FDP + FDS

1

Figure 2. Results of flexor tendon repairs in children.

Table 1. Functional

Results Immobilization

Tendon Repaired FDP FDP FDS/FDP Total

Zone 1 2 2

FDP, flexor digitorum profundus;

Digits 10 30 55 95

Early Motion 3 7 9 19

FDS, flexor digitorum

3 Weeks 7 11 20 38

superficialis.

4 Weeks

5 Weeks

7 14 17

3 4 7

6 Weeks 6 8 14

The Journal

of Hand

Surgery

/ Vol.

19A No. 1 January

1994

51

Age Group (_wws)

Digits

TAM

study after an average postrepair follow-up period of 63 months, the average TAM was found to have increased to 86% (Table 4). This represented an average 17% improvement from their previous examination 18-120 months prior.

O-S 6-10 I l-15

8 15 20

70% 67%, 76%

Discussion

43

72%

Table 2. Functional Results Zone II FDS/FDP Repair: Early Motion or 3-4 Weeks Immobilization .~~ _~~ ~_

Total

FDS, flexor digitorum superficialis: FDP, flexor digitorum profundus.

flexor digitorum superficialis and the flexor digitorum profundus tendons indicated that there was no significant age-related functional difference regardless of whether treated with an early mobilization program or 3-4 weeks of immobilization following tendon repair (Table 2). Fifty-seven digits with associated nerve and/or palmar plate lacerations fared less favorably (TAM = 66%) when compared to isolated tendon interruptions (38 digits, TAM = 74%) (Table 3). Thirteen patients with flexor tendon repairs in 14 digits returned for evaluation at least 18 months following their last office examination. These patients had been followed for an average of 6 months following their flexor tendon repair and had an average TAM of 69% at the time of their last examination. When the children returned to participate in this

Table 3. Functional Associuted

Injury

Results Digits

TAM

38 57

74% 66%

31 I7 4 3

64% 59% 78% 80%

2

97%

Isolated tendon laceration Associated nerve and/or palmar plate laceration Single digital nerve laceration Both digital nerve lacerations Palmar plate laceration Palmar plate and single nerve laceration Palmar plate and both nerve lacerations

~~

_________.

Table 4. Functional Results: Long-term Follow-up No. of Digits* I2 2 Average

Previous Examination (months) 5 II 6

Previolts TAM 66% 84% 69%

* Total number of digits = 14.

Final Follow-Up (months) 52 I35 63

Final TAM 86% 83% 86%

In 1958, Bell and associates reported on 60 flexor tendon lacerations in children between 13 months and 10 years of age.’ Thirty-nine zone II injuries were treated with 37 tendon grafts and two primary repairs followed by 3’/2 weeks of immobilization. Primary repair resulted in one good and one fair result. The final results were felt to be directly proportional to the initial injury. In 1960, Lindsay and McDougall” reported on 31 zone I and II flexor tendon injuries treated by immediate or delayed primary repair of the profundus tendon followed by 4-5 weeks of immobilization. The digits were evaluated by the measurement of the distance between the digital pulp and the distal palmar crease as proposed by Boyes.’ Satisfactory motion was gained in 70%~of the acute repairs and 50% of the delayed primary repairs. However, determination of the TAM of the patients in this series revealed only a 45% average return of normal digital function. During the 1964 Bunnell lecture, Wakefield’ reported that most hand injuries in children were the result of sharp lacerations. Clinical diagnosis was often difficult because of an unreliable history and physical examination. He recommended exploration of questionable injuries with primary repair of flexor tendon lacerations in the digital sheath of children less than 4 years of age. Because of poor results following primary repair of zone 1 and II flexor tendon lacerations in children older than 4 years of age, he recommended that tendon grafting be performed in these children. In 1974, Arons evaluated 12 children from 3 months to 12 years of age after delayed primary repair of single flexor tendons in zone II. Using Boyes” evaluation criteria, he reported 10 good and 2 fair results following zone I1 profundus repairs.h In 1974, Entin’ recommended excision of flexor digitorum superficialis in primary repair of the profundus tendon in zone II injuries. StricklandX could find no significant age-related motion difference in a 1975 review of 17 zone I and zone II primary tendon repairs. In this series, the motion results of primary repair and tendon grafting were similar. In 1981, Vahvanen’ and associates reported 22 zone II primary repairs in children with 17 good, 3 fair, and 2 poor results according to Boyes’4 criteria. They also

52

O’Connell

et al. / Zone I and II Flexor Tendon Repair in Children

recommended excision of the superficialis tendon in zone I and primary repair of the profundus tendon only. In our study, primary flexor tendon repairs in zone I or zone II in children achieved satisfactory functional results. Previous reports of flexor tendon injuries in children used the evaluation criteria of Boyes.4 We chose to evaluate our patients with the criteria described by Glogovac and Strickland,’ which eliminates the usually normal metacarpophalangeal motion. We believe this method is the most accurate assessment of digital motion recovered following flexor tendon repair. We found no agerelated variation in digital function from birth up to 16 years of age. It was interesting to note that in a small group of patients (13 patients with 14 digits) who returned at least 18 months following their last examination, there was an average 17% improvement in their digital TAM. Whether this represents an improvement secondary to growth or the lengthening or rupture of adhesions is difficult to assess. This information is encouraging and hopefully indicates that in many children improvement in digital performance can be expected with the passage of time. We could find no benefits of early mobilization protocols in children. Problems with patient compliance are well appreciated and may account for this variation when compared with the favorable results achieved by early mobilization in the adult patient. It does, however, appear that it is important that

postrepair immobilization not be continued beyond 4 weeks where a strongly prejudicial influence on ultimate digital performance was found.

References 1. Strickland JW, Glogovac SV. Digital function following flexor tendon repair in Zone II: a comparison of immobilization and controlled passive motion techniques. J Hand Surg 1980;5:537-43. 2. Bell JL, Mason ML, Koch SL, Stromberg WB. Injuries to flexor tendons of the hand in children. J Bone Joint Surg 1958;40A: 1220-30. 3. Lindsay WK, McDougall EP. Direct digital flexor tendon repair. Plast Reconstr Surg 1960;26:613-21. 4. Boyes JH. Flexor tendon grafts in the fingers and thumb: an evaluation of end results. J Bone Joint Surg 1950;32A:489-98. 5. Wakefield AR. Hand injuries in children. J Bone Joint Surg 1964;46A: 1226-34. 6. Arons MS. Purposeful delay of the primary repair of cut flexor tendons in “some-man’s_land” in children. Plast Reconstr Surg 1974;53:638-42. In: 7. Entin MA. Flexor tendon surgery in children. AAOS Symposium on tendon surgery in the hand. St. Louis, MO: Mosby, 1975: 132-44. 8. Strickland JW. Bone, nerve, and tendon injuries of the hand in children. Pediatr Clin North Am 1975;22: 451-63. 9. Vahvanen V, Gripenberg L, Nuutinen P. Flexor tendon injury of the hand in children: a long-term followup study of 84 patients. Stand J Plast Reconstr Surg 1981;15:43-8.