Tendon transfer for triple nerve paralysis of the hand in leprosy

Transcription

1 Lepr Rev (2002) 73, 319±325 Tendon transfer for triple nerve paralysis of the hand in leprosy ELAINE MCEVITT & RICHARD SCHWARZ Green Pastures Hospital, Box 5, Pokhara, Nepal Accepted for publication 27June 2002 Summary Paralysis of ulnar, median and radial nerves is seen in less than 1% of those affected with leprosy. This condition is a particular challenge for the surgeon, physiotherapist, and patient. A retrospective chart review was conducted at the Green Pastures Hospital and Rehabilitation Centre (GPHRC) and Anandaban Leprosy Hospital (ALH) in Nepal, and results were graded by the system outlined by Sundararaj in Thirty-one patients were identi ed, and 21 charts were available for review. Excellent or good results were obtained in 93% of patients for wrist extension, 85% of patients for nger extension, 90% of patients for thumb extension, 71% of patients for intrinsic reconstruction, and 63% of patients for thumb opposition reconstruction. These results are reasonable but inferior to those obtained by Sundararaj in his study. Surgical intervention offers a very signi cant improvement in function in these very dif cult hands. Intensive physiotherapy is required both pre- and postoperatively. Introduction Hansen's disease results from infection with Mycobacterium leprae with subsequent involvement of skin, nerve, and mucosal tissue. Nerve damage occurs in 20±25% of patients. 1 In the upper limb the nerve paralysis most frequently affects the ulnar nerve. Median nerve dysfunction may occur later or develop simultaneously, most frequently affecting the distal innervation (simian hand). 2 High radial nerve involvement is least common (wrist drop), with 1% of patients having combined ulnar, median, and radial paralysis (triple nerve palsy). 1,2 The typical pattern is that of high radial nerve palsy combined with high ulnar nerve and low median nerve loss. The aim of reconstructive hand surgery in leprosy is to correct deformity and restore the primary functions of grasp and pinch. In patients with triple nerve paralysis, functioning muscles available for transfer are limited. Especially in those with high median nerve involvement, wrist fusion is occasionally indicated to stabilize the wrist joint in slight extension to allow ef cient exion of the digits. This may free wrist exor tendons for Correspondence to: R. Schwarz ( rschwarz@inf.org.np) /02/ $1.00 q Lepra 319

2 320 E. McEvitt & R. Schwarz Table 1. Grading of reconstruction of wrist, nger, and thumb Grade Description Excellent Power >3 Good Power 3 Fair Power 2 Poor Power < 2 Wrist fusion Good if hold position of 08 extension transfer for other motor functions. The typical pattern of nerve involvement allows potential tendon transfer of the pronator teres (PT), exor digitorum super cialis (FDS), exor carpi radialis (FCR), palmaris longus (PL) muscles and possibly exor carpi ulnaris (FCU). The most common pattern of reconstruction is a two-stage procedure with the reconstruction of extension of the wrist, ngers, and thumb in the rst stage, and the reconstruction of opposition and intrinsic function (MCP exion with simultaneous IP extension) in the second stage. In his series of patients, Sundararaj demonstrated that greater than 89% of patients had good or excellent results from each of the ve tendon transfer operations. Materials and methods A retrospective chart review was performed to evaluate the results of surgical reconstruction for triple nerve paralysis in leprosy patients in Nepal. Charts were reviewed at GPHRC (Green Pastures Hospital and Rehabilitation Centre) and ALH (Anandaban Leprosy Hospital). Patients were identi ed by reviewing the Operating Theatre logbooks from 1977 to 1999 to identify patients who had underwent surgery for wrist drop. Charts were reviewed for demographics, duration of deformity, pattern of nerve involvement, operations performed, and results. Table 2. Grading system for intrinsic function and thumb opposition; reconstruction results Grade Intrinsic function Opposition Excellent MP joint ex to 908 Pulp thumb to pulp of little IP joint extend fully or ring nger No claw Good MP exion to 708 Pulp of thumb to pulp of Less than 108 claw middle or index nger with IP extended Fair MP exion 50±708 or Thumb opposition only if moderate claw (10±408) IP exed Poor MP exion < 508 or severe No opposition claw > 408

3 Table 3. Results of wrist extension reconstruction Tendon transfer for triple nerve paralysis 321 Result PT-ECRB Fusion Other Excellent 5 1* Good 7 3 ± Poor 1 ± 1** No record 2 1 ± Total * PL to ECRB. ** PT to ERCL. Results were classi ed as described by Sundararaj. 1 For wrist, nger and thumb extension the grading system is shown in Table 1. Table 2 outlines the grading system for intrinsic function and for thumb opposition. Results Thirty-one patients were identi ed who had had wrist drop surgery (15 GP, 16 AN). Twenty-one charts were available for review (10 GP, 11 AN). There were 17 males and four females, and mean age was 34.6 years. The non-operated hand was normal in 35%, had ulnar/median palsy in 59% and had wrist drop in 6%. The mean years of wrist drop prior to surgery were 6. Complete involvement of the ulnar nerve occurred in 19 patients (90%), and of the median nerve (distal innervation) occurred in 18 (86%). Complete radial involvement occurred in 16 patients (76%). In the remaining patients there was incomplete paralysis of these nerves. The results of procedures for wrist extension reconstruction are shown in Table 3. Transfer of PT to ECRB was most common, and overall there were good or excellent results in 93% initially, although two of these weakened after a 4-year period. The results of nger extension are shown in Table 4. The most common transfer was FCR to EDC, which gave good or excellent results in 85%. The results for thumb extension reconstruction are shown in Table 5. Most commonly, FCR was transferred to EPL (FCR tendon split) with good or excellent results in 90%. Results for intrinsic reconstruction are outlined in Table 6. The most common operations were the FDS `lasso' procedure or transfer of FDS to the lateral bands (sublimus procedure), with good or excellent results in 71%. Table 7 presents the results for Table 4. Results of nger extension reconstruction Result FCR-EDC FDS-EDC Other Excellent (power > 3) 4 1 ± Good (power 3) Fair (power 2) ± ± ± Poor (power < 2) 1 ± 1 No record 3 ± ± Total

4 322 E. McEvitt & R. Schwarz Table 5. Results of thumb extension reconstruction Result FCR-EDC FDS-EDC Other Excellent (power > 3) 3 ± ± Good (power 3) Fair (power 2) ± ± 1 Poor (power < 2) ± ± ± No record Total Table 6. Results of intrinsic function reconstruction Result FDS-A2 FDS-LB Other Excellent (908 exion) 2 ± ± Good (708 exion) 1 2 ± Fair (508 exion) ± 1 ± Poor (< 508 exion) ± 1 ± No record ± ± 1 Total Table 7. Results of opposition reconstruction Result FDS-OPP FPL-OPP Excellent (opposition to 4/5 digit) 1 1 Good (opposition to 2/3 digit) 3 ± Fair (opposition with IP exed) ± ± Poor (no opposition) 3 ± No record 1 1 Total 8 2 Table 8. Results of tendon transfer in patients who had all ve functions reconstructed Result Patients All ve functions working 3 Wrist, nger and thumb extension only working 1 Limited intrinsic function and wrist extension only 1 patients undergoing reconstruction of thumb opposition. The most common procedure was the FDS opponensplasty with good or excellent results in 63%. In our series, ve patients underwent reconstructive surgery of all ve functions. The results for this group are shown in Table 8.

5 Tendon transfer for triple nerve paralysis 323 Nine complications were identi ed in our patient population. These were radial wrist deviation (three), tendon adhesions requiring tenolysis (three), wound infection (one), deep infection requiring removal of bone (one) and median nerve neuritis (one). Discussion Patients undergoing reconstructive surgery for triple nerve paralysis in this study presented late, with a mean duration of wrist drop of 6 years. Some of these patients had developed severe joint contractures or had resorbed digits and therefore were not considered appropriate for tendon transfers for all functions. Only eight of the 21 patients had intrinsic reconstruction and 10 patients had opposition reconstruction. Reasons for this were partial nerve involvement as noted above, refusal of further surgery, and unsuitability for further reconstruction. One option that should be kept in mind when dealing with these severely paralysed hands is that of carrying out a tenodesis of the nger extensors in combination with a pronator teres to ERCB transfer. 6 The EDC tendons are tenodesed to the ulna with the ngers straight and the wrist in 10±158 of extension. In this way the ngers extend when the wrist exes, but can ex when the wrist is extended. This allows at least functional extension of the digits when the wrist is exed. It needs to be stressed that the key to obtaining a good functional hand is good active wrist extension and that wrist arthrodesis should be considered only when other dynamic options are not available. Ninety-three percent of patients having wrist drop surgery had good or excellent results compared with 90% of patients in Sundararaj's series. Wrist arthrodesis was graded as good if the desired degree of extension was maintained postoperatively. Patients with PT to ECRB tendon transfers for wrist extension overall had better results as compared to wrist arthrodesis, both for functional wrist extension and other hand functions. As such in patients without high median nerve paralysis PT to ERCB transfer should be considered the standard procedure. In three patients excessive radial deviation occurred after tendon transfer. One of these had had PT to ECRL transfer. Brand has demonstrated that the ECRL by its more radial insertion has a signi cant moment as a radial deviator. 7 The only remaining ulnar deviator is the FCU, if present. Thus the only way to obtain balanced wrist extension is to use the transferred PT and FCU together, which would effectively weaken an already weak wrist extensor. In triple nerve palsy the FCU is usually paralysed, leading inevitably to radial deviation. The other two cases had undergone PT to ERCB transfers. ECRB as well is a weak radial deviator. Brand suggests inserting PT tendon into both ECRB and ECRL tendons, but to transfer the insertion of ECRL to the ulnar side of the wrist to give balanced extension. 7 This modi cation of the PT to ERCB transfer would probably eliminate the problems seen with radial deviation in the three patients in this study and should be strongly considered when performing this procedure. Eighty- ve percent of patients having had nger extension surgery and 90% of patients having had thumb extension surgery had good or excellent results, compared with 96% and 96% of patients in Sundararaj's series. In most cases, we use FCR as a powerful muscle with good excursion is needed. Either FCU, if present, or PL will give adequate wrist exion after FRC is transferred. Even if PL is used in a transfer procedure, the patient can rely on gravity to effect wrist exion as grasping is usually done with the hand in the prone position. On two occasions FDSwas used with similarly good results. Both FDSand FCR transfers gave good results for thumb extension as well. In all patients, a split tendon approach to both EDC and

6 324 E. McEvitt & R. Schwarz EPL was used without supplying a separate muscle for thumb extension. We have found that this gives very adequate function, as usually when one needs to extend the ngers as for a pregrasp action the thumb also needs to be extended. As such, we would not recommend a separate transfer for thumb extension in triple nerve palsy. Good or excellent results were obtained in 71% of patients having intrinsic reconstruction and 63% of patients having thumb opposition surgery compared with 93% and 89% of patients in Sundararaj's series. Although our results are poorer than those reported, we had very few (seven MCP exion, eight opposition) for whom we had follow-up. With this small number, our results may not re ect the true outcome. Results for patients undergoing combined ulnar and median nerve paralysis in Anandaban hospital (with and without radial nerve paralysis) demonstrate a 94% success rate (unpublished data). These results are similar to Shah's results with combined lasso/opponens operations. 8 The reasons for the signi cantly worse results when radial nerve palsy is also present are not clear. It should be noted that in both pure ulnar and ulnar/median paralysis, PIP extension is effected by the radially innervated EDC when the `lasso' transfer is activated to produce MCP exion. In triple nerve palsy, however, the PIP extension is carried out by another tendon transfer, which will not be as effective. This would contribute to inferior results seen in the triple nerve palsy. Other reasons may be the late presentation of patients, or possibly inexperience with this type of lesion at our centres. FPL transfer, as described by Davis, 9 was only used for opposition reconstruction in two patients in this series. The FPL is divided at the inter-phalangeal joint, re-routed up Guyon's canal and across the palm to insert into the exor pollicus brevis insertion. Inter-phalangeal joint fusion is carried out through a dorsal incision. This technique has the advantage of not sacri cing any additional motor units as transfers, and has been used by the senior author in other patients with excellent results. The results from this study reinforce the importance of early intervention and treatment of nerve paralysis in leprosy. Sundararaj has previously shown that good functional outcomes can be obtained in this patient population. Intensive follow-up and physiotherapy are key to maintaining a successful reconstruction. With multiple transfers, it can be quite dif cult for the patient to remember to use all muscles correctly and requires ongoing encouragement and training. Many of the patients were lost to follow-up for a variety of reasons, principally that of the cost and dif culty of travel and lack of free time. More proactive follow-up of these patients may improve long-term results of these patients by ensuring that all transfers are being utilized and correcting secondary deformities before they become irreversible. Limitations of this study are the small numbers of patients and the retrospective design. Sundararaj's grading system has the advantage of simplicity and objectivity, but does not include functional assessment. Inclusion of tests of function would perhaps give a better indication of overall performance of the transfers. With the more complete hand assessments established at our institutions in recent years this will be possible in the future. For future study, a comparison of single versus multiple transfers for thumb and nger extension would be helpful to determine if a separate transfer for thumb extension is advantageous. Brand's suggestion of including ECRL in the PT to ERCB transfer with ulnar reinsertion of ECRL also needs objective assessment. In conclusion, we recommend that patients with wrist drop have a tendon transfer for reconstruction rather than wrist fusion if feasible. Asingle tendon for both nger and thumb extension reconstruction gives excellent results in our hands. Intensive postoperative follow-up and physiotherapy are key to a successful outcome in this severe disability.

7 Tendon transfer for triple nerve paralysis 325 References 1 Sundararaj GD, Mani K. Surgical reconstruction of the hand with triple nerve palsy. J Bone Joint Surg (Br), 1984; 66: 260± McDowell F, Enna CD. Surgical rehabilitation in leprosy. Williams and Wilkins, Baltimore, Cuinard RG, Boyes JH, Stark HH, Ashworth CR. Tendon transfers for radial nerve palsy: use of super cialis tendons for digital extension. J Hand Surg, 1978; 3: 560± Raskin KB, Wilgis EF. Flexor carpi ulnaris transfer for radial nerve palsy: functional testing of long term results. J Hand Surg, 1995; 20: 737± Chotigavanich C. Tendon transfer for radial nerve palsy. Bull Hosp Jt Dis Orthop Inst, 1990; 50: 1±10. 6 Warren G. Tendon transfers for triple nerve palsy. In: Conolly B (ed) Atlas of hand surgery. Churchill Livingstone, London, 1998, pp 241± Brand PW. Clinical mechanics of the hand. C.V. Mosby, St Louis, 1985, pp 200± Shah A. Multiple super cialis replacement for opponens and lumbriacl replacement: One stage correction of leprous claw hand. J Hand Surg, 1984; 9-B: 285± Davis TR, Barton NJ. Median nerve palsy. In: Green DP, Hotchkiss RN, Pederson WC (eds) Operative hand surgery. Churchill Livingstone, New York, 1993, pp 1497±1525.