Outcome of modified Bunnell's procedure in the management of leprotic claw hand deformity

Saurabh Jain; Sunil Rajan; Deepak Singal

doi:10.4103/0975-7341.165252

ORIGINAL ARTICLE

Year : 2014 | Volume : 7 | Issue : 2 | Page : 139-144

Outcome of modified Bunnell's procedure in the management of leprotic claw hand deformity

Saurabh Jain¹, Sunil Rajan², Deepak Singal³
¹ Department of Orthopaedics, Mahavir Hospital, Indore, Madhya Pradesh, India
² Department of Orthopaedics, Bundelkhand Medical College, Sagar, Madhya Pradesh, India
³ Department of Orthopaedics, MGMMC and MY Hospital, Indore, Madhya Pradesh, India

Date of Web Publication

14-Sep-2015

Correspondence Address:
Dr. Saurabh Jain
Mahavir Hospital, Footi Khothi, Indore, Madhya Pradesh
India

Source of Support: None, Conflict of Interest: None

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DOI: 10.4103/0975-7341.165252

Abstract

Clawing, partial or total due to leprosy affects greatly, hand's ability for fine movements, grip and skilful use along with loss of tactile sensation of hand, which usually precedes the motor weakness. We reviewed and evaluated the functional results of Modified Bunnel's procedure in management of 20 patient of leprosy with 28 claw hand deformity. After mean followup of 18 months (range 12-38 months) results were excellent in 10 (35%) cases, good in 12 (42.8%), fair in 4 (14.2%) and poor in 2 (7.1%). 97% of the patients (27/28) had improvement in the grip except one case (3%). Swan-neck deformity, flexion contracture, check-rein deformity and insufficient finger flexion was seen in none of the cases whereas superficial minus deformity of ring finger was seen in only 1 case. Modified Bunnel's procedure is simple to perform and gives superior results as it gives least possible adhesions, provides straight course for the tendon and good leverage with normal angle, with better cosmetic results and patient satisfaction.

Keywords: Claw hand, leprosy, modified bunnels procedure

How to cite this article:
Jain S, Rajan S, Singal D. Outcome of modified Bunnell's procedure in the management of leprotic claw hand deformity. J Orthop Traumatol Rehabil 2014;7:139-44

How to cite this URL:
Jain S, Rajan S, Singal D. Outcome of modified Bunnell's procedure in the management of leprotic claw hand deformity. J Orthop Traumatol Rehabil [serial online] 2014 [cited 2023 Mar 27];7:139-44. Available from: https://www.jotr.in/text.asp?2014/7/2/139/165252

Introduction

Leprosy, primarily a disease of peripheral nerves and its Schwann cells, is among the oldest known disease to mankind, associated with social stigma. ^[1] About 60% sufferers have varying degree of motor or sensory deficit in the peripheral nerves, isolated ulnar nerve being the most commonly involved, causing partial clawing with the involvement of ring and little fingers. Additional involvement of median nerve causes total clawing with involving all four fingers, with loss of action of intrinsic muscles (lumbricals, interossei, thenar, and hypothenar) of hand, thumb opposition and abduction, lateral movement of fingers, flattening of carpal arches, and unopposed action of long flexor and extensors. Thus, the patient is unable to simultaneously flex the metacarpophalangeal joint and extend the interphalangeal (IP) joint, greatly affecting the hand's ability for fine movements, grip, and skillful use along with loss of tactile sensation of hand, which usually precedes the motor weakness. ^[2],[3]

With adequate control of infection to noninfectious state by multi-drug therapy, surgical techniques have changed, from debridement and partial amputation to reconstructive surgery with the restoration of intrinsic muscles function. We reviewed and evaluated the functional outcome of modified Bunnell's procedure in the management of patient of leprosy with partial or total claw hand deformity.

Materials and Methods

Twenty-eight claw hands in 20 prospective patients of leprosy, who underwent reconstructive surgery unilaterally or bilaterally via modified Bunnell's procedure, were included in the study. Patients were initially clinical examined and classified as per Dharmendra's classification. ^[4] Cases having multidrug therapy <1-year, patients with lepra reaction, positive skin and nasal smear, stiff and contracted joints, and follow-up <1-year were excluded.

Preoperatively, grasp was subjectively assessed by dynamometer and muscle strength charting as well as sensory function examination were done and preoperative photograph of the hand taken [Figure 1]. Unassisted, assisted, and contracture angle was calculated for each finger. ^[5],[6] Metacarpal and IP joints were made supple by exercises and massage.

Figure 1: Preoperative photography of 35 years male showing leprotic claw hand

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Operative Procedure

All patients were operated under general anesthesia in supine position under a pneumatic tourniquet. In cases of total clawing, an incision of 3 cm was made mid-laterally on radial aspect of ring and little finger extending from mid-shaft of proximal phalanx to proximal interphalangeal (PIP) joint and tendon strip of flexor digitorum superficialis (FDS) was detached, near to insertion as possible without injuring the flexor digitorum profundus (FDP) tendon, whereas only ring finger's FDS was detached in case of isolated ulnar claw hand.

Further, a 4 cm transverse incision was made at proximal palmar crease deep to the palmar fascia, and the slips of FDS tendons pulled out through this incision gently. In cases of the total claw hand each of the two slips were further divided to make four equal strips, whereas in ulnar clawing, the ring finger's FDS was split into two and were kept wet with saline.

A 2.5 cm longitudinal incision just lateral to mid-lateral line was made along the proximal segment of fingers except the donor's finger, that is, on index and middle finger in cases of the total claw hand finger and in little finger in case of ulnar clawing. In the index finger, it was on the ulnar side whereas for middle, ring, and little it was on the radial side to secure adduction of the index finger. In each finger, extensor aponeurotic expansion was cleaned from lateral band to the edge of the middle band to avoid damage to the expansion and periosteum [Figure 2].

Figure 2: Intraoperative photographs of 36-year male patient with claw hand treated by modified Bunnell's procedure showing (a) transverse incision at proximal palmar crease with slips of flexor digitorum superficialis tendon and (b) longitudinal incision at proximal segment of each finger with each slip into pulled in distal incision

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The tunneller was then passed through the lumbrical canal, anterior to transverse metacarpal ligament, and each slip was gently pulled into the distal incision by the tunneller. In this way, all the four tendons were pulled distally for each finger in the case of total clawing and in ring and little finger in cases of ulnar clawing.

Hand was then kept on the positioning splint with 80° flexion at metacarpophalangeal joints (MCP) joint, extension at IP joint, and 30° flexion at the wrist and was tied with a sterile bandage to avoiding any displacement. The slips were then sutured with 5/0 silk, a minimum of three sutures to the edge of the dorsal expansion along the axis of lumbricals, taking the slack and putting it under no tension. After burying the suture ends in all the four fingers, the tourniquet was released and bleeders caught and ligated. Layered closure was done without overlap and tension.

Postoperatively, below elbow slab was given, keeping hand in lumbrical position. The finger was left open dorsally, but slab extended right to the tip of fingers ventrally. Intravenous antibiotics were given for 3 days followed by oral antibiotics for 5 days.

Suture removal was done after 2 weeks and slab was removed after 3 weeks. In 1 ^st week after slab removal, elbow, wrist and MCP joint, flexion and extension exercise began without flexing the IP joint and a finger extension splint for each finger with IP joint in full extension was given [Figure 3]. Next week patient was encouraged lumbrical action, by contracting the transplanted muscle. At 3 ^rd week, patient encouraged to flex PIP joint along with wax bath and exercises.

Figure 3: Postoperative photograph of the patient after modified Bunnell's procedure (a) immediate postoperative with below elbow slab with hand in lumbrical position and (b) 3 weeks postoperative with finger extension splint for each finger with interphalangeal joint in full extension and allowing elbow, wrist, and metacarpophalangeal joints, flexion, and extension exercise without flexing the interphalangeal joint

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Assisted, unassisted, and contracted angle and the grasp were assessed postoperatively [Figure 4]. Results were graded as per scoring system by brand. ^[5]

Figure 4: Six months postoperative follow-up photographs after modified Bunnell's procedure showing excellent results (a) open hand assessment and (b) grasp

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Results

Twenty-eight claw hands in 20 patients of leprosy were included in the study of which there were 14 males (70%) and 6 females (30%). Average age of involvement was 33.6 years (range 19-49 years). Left hand involvement was seen in 8 cases (40%) whereas 4 (20%) had right hand involvement and 8 (40%) of them had bilateral involvement making total number of cases to 28. 10 (50%) patients had lepromatous leprosy whereas 10 (50%) had tuberculoid leprosy. Complete claw hand (high ulnar and low median) was seen in 17 (60.7%) and partial claw hand (ulnar nerve) was seen in 11 (39.3%) cases. Mean follow-up was 18 months (range 12-38 months). 8 had associated planter ulcer, 6 had depressed nasal bridge, and 2 had foot drop.

Duration of diseases was <3 years in 10 (50%) cases, whereas 10 (50%) had more than 3 years duration. Mean duration of disease was 3.5 years (range 2-7 years).

Preoperative deformity was mild (mean contracture <5°) in 4 (14.2%) cases, moderate (mean contracture between 5° and 10°) in 16 (57.3%), and severe (contracture >10°) in 8 (28.5%) cases.

Results were excellent in 10 (35%) cases, good in 12 (42.8%), fair in 4 (14.2%), and poor in 2 (7.1%) cases as per brand scoring system. ^[5]

Mean unassisted angle in little, ring, middle, and index finger improved from preoperative 86.3°, 80.75°, 76.81°, and 87.4° to postoperatively 52.6°, 33.75°, 41.8°, and 38.3°, respectively. Mean assisted angle in little, ring, middle, and index finger improved from preoperative 66.0°, 69.25°, 45.0°, and 78.3° to postoperatively 30.7°, 23.0°, 28.6°, and 23.8°, respectively. Mean contracted angle in little, ring, middle, and index finger improved from preoperative 4.4°, 5.0°, 6.3°, and 6.6° to postoperatively 1.57°, 1.75°, 1.8°, and 0°, respectively [Table 1].

Table 1: Mean unassisted, assisted, and contracture angles of little, ring, middle, and index fingers before modified Bunnell's procedure and after surgery

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Of the 12 patients with no grasp preoperatively, after surgery grasp improved to firm grasp in 7 patients and 4 patients to weak grasp as measured subjectively by the dynamometer, whereas in one patient there was no improvement in grasp. Of the 12 patients with weak grasp, preoperatively, all except one had grasp improved to firm grasp after surgery, whereas four cases who had firm grasp preoperative had same grasp postoperatively, with correction in deformity [Table 2]. Finally, 97% of the patients (27/28) had improvement in the grip except one case (3%) [Figure 4].

Table 2: Improvement in grasp before modified Bunnell's procedure and after surgery

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Postoperative infection was seen in one case which healed with an extended course of antibiotic whereas two had under correction [Figure 5]. Swan-neck deformity, flexion contracture, and insufficient finger flexion was seen in none of the cases whereas superficial minus deformity of ring finger was seen in only one case.

Figure 5: Three-week postoperative follow-up photograph of the patients after modified Bunnell's procedure showing superficial infection which healed on antibiotics

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Discussion

Clawing of hand, which affects the grip, the appearance of hand and ability to hold objects, are very common in leprosy, due to its involvement in ulnar and median nerve. As with other reported series of Brand ^[5] and Fritschi et al. ^[6] our series also had the high ulnar and low median nerve paralysis in 45% cases, whereas 55% had high ulnar paralysis and none of our patients had ulnar, median, and radial nerve involvement. In our series, 50% cases were of lepromatous leprosy, in which nerve involvement is earlier and extensive. We excluded the patients with antileprotic treatment <1-year to prevent lepra reaction, which may lead to poor operative results. ^[7]

For the prognostic purpose, the angle of contracture was graded as mild <5°, moderate 5°-10°, and severe >10°. In our series, preoperative deformity was mild in 4 (14.2%) cases, moderate in 16 (57.3%), and severe in 8 (28.5%) cases. Higher the grade, the remote were the results. Patients having preoperative angle as 0 (7%) were the ideal cases to be operated upon with best results. Most commonly little finger had some degree of contracture probably because it was most neglected during physiotherapy and while using hand, lateral three fingers are more frequently and forcibly used than the little finger. Other causes of contracture leading to poor results are capsule contracture, disuse, dryness of nonsweating skin or skin maceration. Fritschi et al. described musclotendinous contracture occurring in small muscles, especially in lepramatous leprosy as the cause of contracture, but in our series we did not come across any such cause. ^[6]

Surgeries to correct claw hand are based on the principle that the long finger extensors can extend IP joints, provided that hyperextension of the MCP is prevented. This stabilization of MCP can be done by capsuloplasty (Zancolli), tenodesis (Riordan), bone block (Mikhail), arthrodesis, or tendon transfers that actively extend the IP joints and flex the MCP. ^[8]

The typical indication for the bone block, capsule plication or tenodesis is long-standing lesions with fibrosis and in muscular paralysis of central origin rather than peripheral nerve lesions such as leprosy. Though these are simpler procedures with success in correcting claw deformity and increasing synchronous movement between fingers when no muscle is available for transfer, they do not improve the grip strength and needs active and timely physiotherapy and exercises. Further, these are passive procedures which can never produce the active phase of intrinsic action in grasp and pinch, as they do not provide a prime flexor of MCP. In leprosy, these procedures are not successful because of strong un-paralyzed muscles, which can be easily used for intrinsic muscle replacement by tendon transfer adding a positive voluntary action. Thus, in leprosy, as suitable muscles are available, tendon transfers should be the choice for restoration of grip strength.

Littlers, Fowlers, and Brands procedures are indicated when patient is cooperative, seek earlier advice, and joints are quite supple, but are met with unsatisfactory results because of tendency for reversal of metacarpal arch due to dorsal pull and they needs very cooperative patients, who are ready for extensive physiotherapy, else potential power is dissipated resulting in useless hand. Hence, these procedures are complicated by the difficulty in rehabilitation and reports of median nerve compression due to crowding of the carpal tunnel. ^[9],[10]

Therefore, for the patients, like ours, who had lower economic status, presenting deformity for a longer duration, seeking advice late with stiff joints, flexor digitorum sublimis transfer, that is, modified Bunnell's procedure is more suitable operation which has the advantage of retaining flexor tendon superficialis tendons of the other fingers for better power grip and the avoiding swan neck deformity. ^[8]

Finger flexors and the wrist flexors and extensors are strong in leprosy, and there is no habitual flexion of the wrist, hence, we performed modified Bunnell's procedure, which removes the powerful flexor of the PIP joints and converted it, into an extensor of the same joints and evaluated the results of in 20 patients (28 hands) of post leprotic claw hand deformity.

Results were excellent to good results in 78.5% cases (22/28) and fair to poor in 21.5% (6/28) which are comparable to others studies. ^{[11],[12],[13],[14]} Ozkan found Bunnell's procedure more effective in correcting claw hand deformity in comparison to zancolli lasso's procedure. Poor results were due to less cooperative patients, extensor tendon laxity, joint stiffness, and patients returning to work earlier, more so ever, patients with angle of contracture more than 10°, results were expected to poor.

Preoperatively, 42.8% (12/28) of patients had no or very weak grip, 42.8% (12/28) had weak to moderate, and 14.4% (4/28) had firm grasp, which improved to 78.5% (22/28) having firm grip, 17.8% (5/28) had weak group, and only one case having no improvement in grip.

Reported complications due to Bunnell's transfer are: Swan-neck deformity, flexion posture of the distal interphalangeal joint, check-rein deformity or flexion contracture, intrinsic plus deformity, and insufficient finger flexion. However, in our study, 3% showed sepsis after suture removal on 3 ^rd week which healed on antibiotics in next 7-10 days and recurrence was found in two cases due to formation of adhesions and edema resulting in stiffness of fingers. None of our patients developed intrinsic plus, swan-neck deformity, check-rein deformity or flexion contracture hand because as our follow-up is short, and transposition was not done in hypermobile joints. A longer follow-up of these cases is needed to rule out these complications.

Burkhalter used the bony attachment in transferring split sublimis of the ring finger as a modification of the Stiles-Bunnell's transfer. ^[15] But, in leprosy bony to tendon transfer may lead poor results because of neuropathic joints and osteoporotic bones.

Proper tensioning of the tendon slips which are being sutured at the new insertion sites is critical for a better outcome. ^[16],[17] Among many methods suggested for equal and balanced tensioning of four tendon slip when the hand is in neutral position with respect to adduction or abduction of the wrist, we used Fritshi splint method, although it lacked scientific background. ^[18] As the techniques was same in all patients, we speculate the reason for less power in two patients, as inadequate tension in these cases, and thus, strongly feel that further scientific studies regarding proper tensioning and balancing is needed. Finally, it is the experience of the operating surgeon that helps to decide as to the tension that is to be kept on each slip so that maximum deformity correction is obtained without compromising the functional capabilities of the hand.

One disadvantage of taking the flexor digitorum sublimis tendon is weakening in the grasp and contributing to the position of the acute tip flexion position. Reason being that superficialis is the flexor of PIP joint and it is converted to act as extensor, thus the two muscles (superficialis and profundus) instead of acting synergically, act in opposite direction to each other.

Overall modified Bunnell's procedure is simple to perform and gives superior results as it gives least possible adhesions, provides a straight course for the tendon, and good leverage with a normal angle of approach. After surgery is it easy to re-educate the patient with better cosmetic results. The patient gets much more satisfaction as far as the functional improvement is concerned after this operation and mentally more satisfied. As all the intrinsic actions can be achieved by using FDS for all four fingers, which are attached on radial as well ulnar side to adduct and abduct as well. The only prerequisites for the Bunnell's procedure include availability of FDS along with working FDP.

Patient selection, preoperative and postoperative physiotherapy, and following the principles laid by Bunnell's procedure along with proper tensioning and surgeon's experience are essential for successful treatment of clawing and obtaining better functional and cosmetic results.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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