- Email: [email protected]
Can a divided digital nerve on one side of the finger be left unrepaired?
CAN A DIVIDED DIGITAL NERVE ON ONE SIDE FINGER BE LEFT UNREPAIRED?
OF THE
S. P. CHOW and C. NG From the Department of Orthopaedic Surgery, University of Hong Kong, Hong Kong
72 fingers with divided digital nerves on one side alone had their nerves repaired and the sensory recovery assessed at different intervals of up to 2 years. Another 36 fingers with similar digital nerve injuries had their divided nerves left unrepaired and sensory recovery similarly assessed for comparison. In the “repaired” group, the result continued to improve and by 2 years, 90% reached S3+ or above. In the “unrepaired” group, improvement plateaued after 6 months, and at 2 years only 6% reached S3+ or above, although all had regained some protective sensibility. Journal of
Hand Surgery (British and European Volume, 1993) 18B: 629-630
In animal experiments, collateral sprouting of sensory nerves has been well demonstrated (Diamond et al, 1976; Kinnman and Aldskogius, 1986; Kingery and Vallin, 1989). An earlier study (Chow et al, 1980) showed that in man, collateral innervation after denervation is a very dynamic process. As a result of this, the area of total anaesthesia after a digital nerve laceration was very small even at the early stage, and may be absent in children or in certain patients. It is possible therefore that after damage to a single digital nerve, collateral innervation may in the long run totally substitute for its function so that repair may not be necessary. It is also possible that the sensory recovery that follows digital nerve repair (Tupper et al 1986; Young et al 198 1; Goldie et al 1992) is due to the collateral innervation, and that the result would be the same whether the nerve was repaired or not. The idea that a divided digital nerve need not be repaired is attractive, because postoperative immobilization would no longer be necessary. In fact, recent work showed that the existence of a gap might allow neurotropism to work more effectively (Lundborg and Hansson, 1979). In 1986, we started a prospective study on unilateral severed digital nerves, comparing the result of a group in which the nerve was not repaired with a control group in which the nerve was repaired.
requirements of associated injuries. For those that were repaired, it would be done either as a primary procedure or as a delayed primary procedure within the first week of injury. Two to four epineurial sutures of S/O ethilon were inserted under magnification. The hands were immobilized in a “boxing-glove” dressing with the MP joint at 90” flexion and the IP joint extended for 1 week. Sensory recovery was assessed according to the MRC grading (Omer, 1983) by one occupational therapist at 3, 6, 18 and 24 months after injury. RESULTS
Between November 1986 and December 1988, 132 patients were admitted to the study and followed-up to end of 1990. However, in 47 patients, either the records were incomplete or the patients defaulted during followup. Thus, there were 85 patients (66 male and 19 female) with 108 digits (108 nerves) involved. 52 patients (72 digits) belonged to the “repaired” group, and 33 patients (36 digits) belonged to the “not repaired” group. 18 digits in the “repaired” group and eight digits in the “not repaired” group had significant associated injuries to tendon, bone, or joint. The results in the two groups at different stages of follow-up are shown in Tables 1 and 2. In the “repaired” group, the results continued to improve throughout the 24 months period and the percentage of digits with sensory recovery of S3+ or above rose from 4% at 3
MATERIAL AND METHOD All patients older than 16 years with lacerated digital nerves in one side of a finger distal to the MP joint were included in the study, except those involving the thumb, the radial side of the index, and the ulnar side of the little finger, where all divided nerves would be repaired. Patients were also excluded in whom skin grafting or flaps were required for skin closure and where excessive tension or a gap required nerve grafting in the repaired group. Informed consent was obtained from all patients. If patients were unwilling to leave the nerves unrepaired, then repair would be performed and the patient put in the “repaired” group. For patients in whom divided digital nerves were not to be repaired, the wound was sutured and mobilization of the finger started immediately, depending on the
Table l-Result Time after injury
3 6 12 18 24
months months months months months
in the “repaired” group at different stages Number of digits in each category of sensory recovery so
SI
s2
s3
s3+
s4
5 -
31 5 -
28 31 28 13 -
5 25 22 35 7
3 7 13 14 47
-
Number of patients: 52. Number of nerves involved: 72. Number of patients with painful neuroma= 0. 629
4 7 10 18
% of S3+ and S4 4% 14% 31% 33% 90%
630
THE JOURNAL
Table 2-Result Time after injury
in the “unrepaired” group at different stages Number
of digits in each category of sensory recovery
so
SI
s2
s3
s3+
s4
% of S3’ and S4
3 months 6 months
-
15 5
16 24
5 7
_ _
_ _
12 months 18 months 24 months
-
4 3 2
24 24 24
7 7 8
0% 0% 3% 6% 6%
1 2 2
_ _ _
Number of patients: 33. Number Number
of nerves involved: 36. of patients with painful neuroma=
2.
months, through 14% at 6 months, to 90% at 24 months. In the “not repaired” group, there was some improvement in sensibility from 3 to 6 months. However, improvement after 6 months was minimal and even at 24 months, 94% still showed sensory recovery of S3 or below. Two digits also had a painful neuroma. These two patients were subsequently explored, the neuroma excised, and nerve grafting performed. The remaining patients refused further surgical intervention. DISCUSSION
The results of this prospective study show that the results in the group without repair of the severed digital nerve were definitely worse than those in the repaired group. The sensibility in the repaired group continued to improve for up to 2 years, whereas those that were not repaired only showed improvement during the first 6 months. Only 6% of those not repaired regained
OF HAND
SURGERY
VOL. 18B No. 5 OCTOBER
1993
2-point discrimination at 2 years follow-up compared to 90% of the repaired group, and two patients in the unrepaired group had painful digital neuromata. Surprisingly, except for these two patients, all the others declined further surgery, because the majority (94%) has regained some protective sensibility. References CHOW, S. P., LUK, D. K., NGAI, Y. Y. and HWANG, J. C. (1980). Immediate return of sensation after digital nerve repair. The Australian and New Zealand Journal of Surgery, 50: 3: 228-232. DIAMOND, J., COOPER, E., TURNER, C. and MACINTYRE, L. (1976). Trophic regulation of nerve sprouting. Science, 193: 371-377. GOLDIE, B. S., COATES, C. .I. and BIRCH, R. (1992). The long term result of digital nerve repair in no-man’s land. Journal of Hand Surgery, 17B: 1: 75-77. KINGERY, W. S. and VALLIN, J. A. (1989). The development of chronic mechanical hyperalgesia, autotomy and collateral sprouting following sciatic nerve section in rat. Pain, 38: 321-332. KINNMAN, E. and ALDSKOGIUS, H. (1986). Collateral sprouting of sensory axons in the glabrous skin of the hindpaw after chronic sciatic nerve lesion in adult and neonatal rats: A morphological study. Brain Research, 377: 73-82. LUNDBORG, G. and HANSSON, H-A. (1979). Regeneration of peripheral nerve through a preformed tissue space. Preliminary observations on the reorganisation of regenerating nerve fibres and perineurium. Brain Research, 178: 573-576. OMER, G. E. (1983). Report of the committee for evaluation of the clinical result in peripheral nerve injury. Journal of Hand Surgery, 8: 5(2): 754-759. TUPPER, J. W., CRICK, J. C. and MATTECK, L. R. (1986). Fascicular nerve repairs: A comparative study of epineurial and fascicular (perineurial) techniques. Orthopedic Clinics of North America, 19: 1: 57-69. YOUNG, L., WRAY, R. C. and WERKS, P. M. (1981). A randomized prospective comparison of fascicular and epineural digital nerve repairs. Plastic and Reconstructive Surgery. 68: 1: 89-93.
Accepted: 4 May 1993 Professor S. P. Chow, Department Mary Hospital, Hong Kong. 0
1993 The British
of Orthopaedic
Surgery,
Society for Surgery of the Hand
University
of Hong
Kong,
Queen
OF THE
S. P. CHOW and C. NG From the Department of Orthopaedic Surgery, University of Hong Kong, Hong Kong
72 fingers with divided digital nerves on one side alone had their nerves repaired and the sensory recovery assessed at different intervals of up to 2 years. Another 36 fingers with similar digital nerve injuries had their divided nerves left unrepaired and sensory recovery similarly assessed for comparison. In the “repaired” group, the result continued to improve and by 2 years, 90% reached S3+ or above. In the “unrepaired” group, improvement plateaued after 6 months, and at 2 years only 6% reached S3+ or above, although all had regained some protective sensibility. Journal of
Hand Surgery (British and European Volume, 1993) 18B: 629-630
In animal experiments, collateral sprouting of sensory nerves has been well demonstrated (Diamond et al, 1976; Kinnman and Aldskogius, 1986; Kingery and Vallin, 1989). An earlier study (Chow et al, 1980) showed that in man, collateral innervation after denervation is a very dynamic process. As a result of this, the area of total anaesthesia after a digital nerve laceration was very small even at the early stage, and may be absent in children or in certain patients. It is possible therefore that after damage to a single digital nerve, collateral innervation may in the long run totally substitute for its function so that repair may not be necessary. It is also possible that the sensory recovery that follows digital nerve repair (Tupper et al 1986; Young et al 198 1; Goldie et al 1992) is due to the collateral innervation, and that the result would be the same whether the nerve was repaired or not. The idea that a divided digital nerve need not be repaired is attractive, because postoperative immobilization would no longer be necessary. In fact, recent work showed that the existence of a gap might allow neurotropism to work more effectively (Lundborg and Hansson, 1979). In 1986, we started a prospective study on unilateral severed digital nerves, comparing the result of a group in which the nerve was not repaired with a control group in which the nerve was repaired.
requirements of associated injuries. For those that were repaired, it would be done either as a primary procedure or as a delayed primary procedure within the first week of injury. Two to four epineurial sutures of S/O ethilon were inserted under magnification. The hands were immobilized in a “boxing-glove” dressing with the MP joint at 90” flexion and the IP joint extended for 1 week. Sensory recovery was assessed according to the MRC grading (Omer, 1983) by one occupational therapist at 3, 6, 18 and 24 months after injury. RESULTS
Between November 1986 and December 1988, 132 patients were admitted to the study and followed-up to end of 1990. However, in 47 patients, either the records were incomplete or the patients defaulted during followup. Thus, there were 85 patients (66 male and 19 female) with 108 digits (108 nerves) involved. 52 patients (72 digits) belonged to the “repaired” group, and 33 patients (36 digits) belonged to the “not repaired” group. 18 digits in the “repaired” group and eight digits in the “not repaired” group had significant associated injuries to tendon, bone, or joint. The results in the two groups at different stages of follow-up are shown in Tables 1 and 2. In the “repaired” group, the results continued to improve throughout the 24 months period and the percentage of digits with sensory recovery of S3+ or above rose from 4% at 3
MATERIAL AND METHOD All patients older than 16 years with lacerated digital nerves in one side of a finger distal to the MP joint were included in the study, except those involving the thumb, the radial side of the index, and the ulnar side of the little finger, where all divided nerves would be repaired. Patients were also excluded in whom skin grafting or flaps were required for skin closure and where excessive tension or a gap required nerve grafting in the repaired group. Informed consent was obtained from all patients. If patients were unwilling to leave the nerves unrepaired, then repair would be performed and the patient put in the “repaired” group. For patients in whom divided digital nerves were not to be repaired, the wound was sutured and mobilization of the finger started immediately, depending on the
Table l-Result Time after injury
3 6 12 18 24
months months months months months
in the “repaired” group at different stages Number of digits in each category of sensory recovery so
SI
s2
s3
s3+
s4
5 -
31 5 -
28 31 28 13 -
5 25 22 35 7
3 7 13 14 47
-
Number of patients: 52. Number of nerves involved: 72. Number of patients with painful neuroma= 0. 629
4 7 10 18
% of S3+ and S4 4% 14% 31% 33% 90%
630
THE JOURNAL
Table 2-Result Time after injury
in the “unrepaired” group at different stages Number
of digits in each category of sensory recovery
so
SI
s2
s3
s3+
s4
% of S3’ and S4
3 months 6 months
-
15 5
16 24
5 7
_ _
_ _
12 months 18 months 24 months
-
4 3 2
24 24 24
7 7 8
0% 0% 3% 6% 6%
1 2 2
_ _ _
Number of patients: 33. Number Number
of nerves involved: 36. of patients with painful neuroma=
2.
months, through 14% at 6 months, to 90% at 24 months. In the “not repaired” group, there was some improvement in sensibility from 3 to 6 months. However, improvement after 6 months was minimal and even at 24 months, 94% still showed sensory recovery of S3 or below. Two digits also had a painful neuroma. These two patients were subsequently explored, the neuroma excised, and nerve grafting performed. The remaining patients refused further surgical intervention. DISCUSSION
The results of this prospective study show that the results in the group without repair of the severed digital nerve were definitely worse than those in the repaired group. The sensibility in the repaired group continued to improve for up to 2 years, whereas those that were not repaired only showed improvement during the first 6 months. Only 6% of those not repaired regained
OF HAND
SURGERY
VOL. 18B No. 5 OCTOBER
1993
2-point discrimination at 2 years follow-up compared to 90% of the repaired group, and two patients in the unrepaired group had painful digital neuromata. Surprisingly, except for these two patients, all the others declined further surgery, because the majority (94%) has regained some protective sensibility. References CHOW, S. P., LUK, D. K., NGAI, Y. Y. and HWANG, J. C. (1980). Immediate return of sensation after digital nerve repair. The Australian and New Zealand Journal of Surgery, 50: 3: 228-232. DIAMOND, J., COOPER, E., TURNER, C. and MACINTYRE, L. (1976). Trophic regulation of nerve sprouting. Science, 193: 371-377. GOLDIE, B. S., COATES, C. .I. and BIRCH, R. (1992). The long term result of digital nerve repair in no-man’s land. Journal of Hand Surgery, 17B: 1: 75-77. KINGERY, W. S. and VALLIN, J. A. (1989). The development of chronic mechanical hyperalgesia, autotomy and collateral sprouting following sciatic nerve section in rat. Pain, 38: 321-332. KINNMAN, E. and ALDSKOGIUS, H. (1986). Collateral sprouting of sensory axons in the glabrous skin of the hindpaw after chronic sciatic nerve lesion in adult and neonatal rats: A morphological study. Brain Research, 377: 73-82. LUNDBORG, G. and HANSSON, H-A. (1979). Regeneration of peripheral nerve through a preformed tissue space. Preliminary observations on the reorganisation of regenerating nerve fibres and perineurium. Brain Research, 178: 573-576. OMER, G. E. (1983). Report of the committee for evaluation of the clinical result in peripheral nerve injury. Journal of Hand Surgery, 8: 5(2): 754-759. TUPPER, J. W., CRICK, J. C. and MATTECK, L. R. (1986). Fascicular nerve repairs: A comparative study of epineurial and fascicular (perineurial) techniques. Orthopedic Clinics of North America, 19: 1: 57-69. YOUNG, L., WRAY, R. C. and WERKS, P. M. (1981). A randomized prospective comparison of fascicular and epineural digital nerve repairs. Plastic and Reconstructive Surgery. 68: 1: 89-93.
Accepted: 4 May 1993 Professor S. P. Chow, Department Mary Hospital, Hong Kong. 0
1993 The British
of Orthopaedic
Surgery,
Society for Surgery of the Hand
University
of Hong
Kong,
Queen