SCIENTIFIC ARTICLE
Camitz Tendon Transfer Using Flexor Retinaculum as a Pulley in Advanced Carpal Tunnel Syndrome Yasunori Hattori, MD, PhD, Kazuteru Doi, MD, PhD, Sotetsu Sakamoto, MD, Kannan Kumar, MD, Satomi Koide, MD Purpose To report the outcomes of modified Camitz abductor plasty using the released flexor retinaculum as a pulley in patients with advanced carpal tunnel syndrome. Methods A retrospective review of 46 hands in 43 patients who underwent modified Camitz abductor plasty was performed. Active palmar abduction of thumb and pulp pinch strength were assessed. Patient-reported outcome measures were assessed using the Disabilities of the Arm, Shoulder, and Hand and Carpal Tunnel Syndrome instrument. As an electrophysiological assessment, compound muscle action potential (CMAP) from abductor pollicis brevis (APB) was investigated. Results At 3 months, active palmar abduction of thumb and pulp pinch strength significantly improved. Although pulp pinch strength further improved, active abduction of thumb did not improve at the final follow-up. Both the patient-reported outcome measures improved at 3 months and further improved at final follow-up. Approximately 75% of improved scores were obtained at the first 3 months after surgery and the balance of improved scores (25%) was obtained by the time of final follow-up. Useful recovery of postoperative APB-CMAP (amplitude > 1.8 mV) was obtained in 3 hands (7%) at 3 months after surgery and in 23 hands (50%) at final follow-up. There was no statistical significance of the postoperative results including active palmar abduction of thumb and improvement of patient-reported outcome measures at final follow-up between the hands with useful recovery of postoperative APB-CMAP and the hands without it. Conclusions Modified Camitz abductor plasty benefitted the early improvement of activity of daily living in patients with advanced carpal tunnel syndrome. It acted not only as an internal orthosis in patients who eventually recovered thenar muscle function but also as the sole palmar abductor of the thumb in patients who failed to recover useful thenar muscle function. (J Hand Surg Am. 2014;39(12):2454e2459. Copyright Ó 2014 by the American Society for Surgery of the Hand. All rights reserved.) Type of study/level of evidence Therapeutic IV. Key words Abductor pollicis brevis, Camitz opponensplasty, carpal tunnel syndrome.
From the Department of Orthopedic Surgery, Ogori Daiichi General Hospital, Ogori, Yamaguchi, Japan. Received for publication June 10, 2014; accepted in revised form September 2, 2014. No benefits in any form have been received or will be received related directly or indirectly to the subject of this article. Corresponding author: Yasunori Hattori, MD, PhD, Department of Orthopedic Surgery, Ogori Daiichi General Hospital, 862-3, Shimogo, Ogori, Yamaguchi-City, YamaguchiPrefecture, 754-0002, Japan; e-mail: [email protected]. 0363-5023/14/3912-0016$36.00/0 http://dx.doi.org/10.1016/j.jhsa.2014.09.008
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Ó 2014 ASSH
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Published by Elsevier, Inc. All rights reserved.
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the palmaris longus tendon has frequently been used in patients with advanced carpal tunnel syndrome (CTS). This procedure is usually performed at the time of carpal tunnel release.1e10 Several authors have reported that the Camitz transfer provides abduction rather than opposition because it results in improved abduction but weak flexion and pronation of the carpometacarpal joint of the thumb, prerequisites for opposition.6e10 This is due to the radial orientation AMITZ ABDUCTOR PLASTY USING
CAMITZ TENDON TRANSFER
of the transferred tendon, which has an axis that is suboptimal to provide opposition. Prominent bowstringing of the transferred tendon is noted. This can be overcome by modifying the direction of the transferred tendon by using the released flexor retinaculum as a pulley, described by MacDougal in 1995.6 However, the indication of simultaneous opposition transfer for advanced CTS has been a subject of controversy. Some authors have reported clinical recovery from thenar muscle atrophy after carpal tunnel release alone and have not recommended simultaneous opposition transfer.11,12 Others have reported that thenar muscle atrophy showed minimal improvement despite the recovery of sensory function, and therefore, they have stated that opposition transfer is indicated in advanced CTS.2,4 Foucher et al4 reported that significant recovery of thenar muscle bulk was recorded in only 6 of 72 hands (8.%) in which the conventional Camitz transfer was done, and their follow-up was greater than 16 months. However, it is difficult to evaluate thenar muscle recovery by observing the muscle bulk and by palpation of the thenar eminence after simultaneous opposition transfer. Moreover, it is difficult to calculate how much opposition strength is contributed from the tendon transfer and how much is from the spontaneous thenar muscle recovery. This makes the accurate assessment of the real effect of simultaneous tendon transfer difficult. We performed modified Camitz abductor plasty using flexor retinaculum as a pulley in patients with advanced CTS who have difficulty with opposition.6e10 The aim of this study was to report our postoperative outcomes of this procedure including objective strength, motion measurements, patientreported outcome measures, and an electrophysiological assessment. MATERIALS AND METHODS Patients This study was undertaken in conformity with the Declaration of Helsinki after approval of our institutional review board. Written informed consent was obtained from each patient. We surgically treated 614 consecutive hands with idiopathic CTS between January 2007 and March 2013. CTS was diagnosed with physical examination and electrophysiological assessment using compound muscle action potential (CMAP) from the abductor pollicis brevis (APB). APB-CMAP was recorded with surface electrodes by supramaximal stimulation of the median nerve at the wrist.13 Our indication of modified Camitz transfer J Hand Surg Am.
r
2455
FIGURE 1: Surgical technique of modified Camitz opponensplasty. Small arrow shows the insertion of the APB tendon. Medium arrow shows the palmaris longus tendon strip. Large arrow shows a small hole at the radial side remnant of the released flexor retinaculum.
was diminished pinch function with severe thenar muscle atrophy and no detection of preoperative APB-CMAP. Surgical technique and postoperative management All patients underwent modified Camitz transfer according to the technique described by Kato et al.10 The palmaris longus tendon was dissected in continuity with the longitudinal slip of the palmar aponeurosis. The flexor retinaculum was released close to its medial attachment. The palmaris longus tendon was passed through a small hole of the released flexor retinaculum from the undersurface of the released flexor retinaculum (Fig. 1). The palmaris longus tendon was then passed through a subcutaneous tunnel and was sutured to the insertion of the APB. The hand was placed in a short-arm thumb spica orthosis with 45 palmar abduction of the thumb and the wrist at neutral position for 4 weeks. Then active and passive range of motion exercises of thumb and wrist were started. The orthosis was removed and patients were allowed to use their hand as required. No specific postoperative rehabilitation was undertaken. Vol. 39, December 2014
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Assessment Clinical evaluation was performed before surgery, 3 months after surgery, and at final follow-up 12 to 18 months after surgery. All patients were reviewed directly by a certified hand therapist in our hospital who had not been primarily involved in the patients’ management. We recorded any subjective symptoms of paresthesia in the median nerve distribution. Pressure thresholds in the middle finger pulp were determined using the Semmes-Weinstein monofilament test. The filaments used for examination were 0.08, 0.22, 2.4, and 279 g. Active palmar abduction of the thumb (measured as the angle between the first and the second rays) was recorded. Pulp pinch strength was measured and recorded as a percentage compared with the contralateral hand. In patients who underwent surgery in both hands, pulp pinch strength was not used for analysis. Patient-reported outcomes were measured using the Japanese Society for Surgery of the Hand version of Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire14 and the Japanese Society for Surgery of the Hand version of the Carpal Tunnel Syndrome instrument (CTSI).15 Electrical investigations in all patients included APB-CMAP, which was measured from the stimulus artifact to the onset of the potential. Amplitude was measured from the baseline to the negative peak of the potential. Nobuta et al13 reported that postoperative APB-CMAP amplitude was greater than 1.8 mV in patients who obtained useful recovery of opposition after carpal tunnel release alone for advanced CTS. We used their criterion (APB-CMAP amplitude > 1.8 mV) as useful spontaneous recovery of APB function. The postoperative outcomes including active palmar abduction of thumb, DASH score improvement, and CTSI score improvement at final follow-up were compared between the hands with useful recovery of postoperative APB-CMAP and the hands without it. Complications including infection, hematoma, rupture of the transferred tendon, and prominent bowstringing of the transferred tendon were also investigated. Statistical analysis All results are presented as mean SD and were analyzed using Wilcoxon signed-ranks test or MannWhitney U test. P of .05 was established for statistical significance. RESULTS Out of 614 hands, preoperative APB-CMAP was not detectable in 140 hands. Among them, 55 hands of 52 J Hand Surg Am.
r
patients who had diminished pinch function with severe thenar muscle atrophy underwent simultaneous carpal tunnel release with modified Camitz abductor plasty. Three patients underwent this procedure in both hands. Out of these 55 hands, 46 hands of 43 patients were followed for at least 12 months and were included in this study. Of these 43 patients, there were 6 men and 37 women. Mean age was 70 10 years at the time of operation. Thirty right and 16 left hands were affected. The mean follow-up period was 14 2 months. Three months after surgery, reduction of paresthesia was observed in 36 of 46 hands (78%). At the final follow-up, complete resolution of paresthesia was observed in 34 hands (74%) and improvement in 12 hands (26%). On Semmes-Weinstein monofilament testing before surgery, 7 hands (15%) were able to perceive 2.4 g. After surgery, significant improvement was observed. Twenty-two hands (48%) perceived the 2.4-g filament at 3 months and 40 hands (87%) at final follow-up. Active palmar abduction of thumb averaged 22 before surgery and improved to 44 at 3 months. No further improvement was observed after 3 months. Pulp pinch strength averaged 53% of the contralateral hand before surgery. This improved to 64% at 3 months and further improved at final follow-up. Twenty-three patients completed both DASH and CTSI and were included for analysis. All of these patients underwent surgery in a single hand. DASH score averaged 33 points before surgery. This improved to 14 at 3 months and to 8 at final followup. Symptom severity score and function score of CTSI averaged 2.5 and 2.2, respectively, before surgery. This improved to 1.6 and 1.5 at 3 months and to 1.3 and 1.2 at final follow-up. Before surgery, APB-CMAP was undetectable in all hands. At 3 months, CMAP was detectable in 8 of 46 hands (17%). At final follow-up, the CMAP was detectable in 32 of 46 hands (70%). Latency and amplitude in these 32 hands averaged 5.2 ms and 4.4 mV, respectively. The overall results are summarized in Table 1. According to the criterion of Nobuta et al,13 useful recovery of postoperative APB-CMAP (amplitude > 1.8 mV) was obtained in 3 hands (7%) at 3 months after surgery and in 23 hands (50%) at final followup. Active palmar abduction of thumb averaged 46 in 23 hands with useful recovery of postoperative APB-CMAP, and 43 in 23 hands without it. Improvement of DASH score, CTSI symptom severity score, and CTSI function score averaged 28, 1.3, and 1.2, respectively, in 11 hands with its useful Vol. 39, December 2014
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CAMITZ TENDON TRANSFER
TABLE 1.
Overall Results Postoperative
Final
Preoperative
3 mo
Follow-up
6.65 filament (hands)
39
24
6
4.31 filament (hands)
7
21
23
3.61 filament (hands)
0
1
17
Thumb palmar abduction ( ) (n ¼ 46)
22 5
44 5
45 6
Pulp pinch (%) (n ¼ 43)
53 24
64 22
80 21
DASH (points) (n ¼ 23)
33 14
14 12
8 12
Semmes-Weinstein test (n ¼ 46)
CTSI (n ¼ 23) Symptom severity score (points)
2.53 0.76
1.63 0.5
1.29 0.38
Function score (points)
2.22 0.63
1.46 0.42
1.19 0.43
0
8
32
Electrophysiological assessment (n ¼ 46) Detection of APB-CMAP (hands)
TABLE 2.
Comparison of Results Between Hands With or Without Useful APB-CMAP Recovery APB-CMAP Recovery (þ)
(e)
Thumb palmar abduction ( )
46 4 (n ¼ 23)
43 7 (n ¼ 23)
DASH score improvement (points)
25 11 (n ¼ 11)
22 12 (n ¼ 12)
Symptom severity score
1.25 0.53 (n ¼ 11)
1.24 0.72 (n ¼ 12)
Function score
1.20 0.54 (n ¼ 11)
0.87 0.42 (n ¼ 12)
CTSI score improvement (points)
recovery and 22, 1.2, and 0.9 in 12 hands without it. There was no statistical significance of these results between 2 groups (Table 2). There were no complications after surgery. DISCUSSION It is still controversial whether useful motor recovery is possible after carpal tunnel release alone for the patients with severe thenar muscle atrophy and whether simultaneous tendon transfer is necessary. APB-CMAP directly assess the motor function of APB, and is often undetectable in advanced CTS patients with marked thenar muscle atrophy.13,16e19 According to the criterion of Nobuta et al,13 we were able to obtain useful recovery of postoperative APB-CMAP in 23 hands (50%) at final follow-up. From these results, 50% of our patients had a potential of spontaneous useful recovery of thenar muscle function after carpal tunnel release alone. In our series, of the patients’ average age was 70 years. Overall life expectancy of the Japanese population was J Hand Surg Am.
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male, 80 years, and female, 87 years, listed by the World Health Organization in 2013.20 Healthy life expectancy in 2010 was 71 years for men and 76 years for women.21 Almost all of our patients in this series requested early functional recovery of the hand, because they lived alone or independently and their hand function was of critical importance to them. Our study showed that both DASH and CTSI scores significantly improved after surgery. The improved score of 19 points after 3 months was much greater than 10 points defined as minimal clinically important difference.22 Consequently, 77% of the improvement in the DASH score was obtained in first 3 months after surgery, Similarly, 72% of the improvement in the CTSI symptom severity score and 74% of the improvement in the CTSI function score were obtained in the first 3 months after surgery. We attributed this early improvement of activity of daily living in our patients to the recovery of sensory function due to the decompression of the median nerve and restored Vol. 39, December 2014
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CAMITZ TENDON TRANSFER
thumb palmar abduction due to tendon transfer. In electrophysiological findings, useful recovery of postoperative APB-CMAP was obtained in 3 hands (7%) at 3 months after surgery. Average active palmar abduction of thumb was 44 after 3 months and did not improve further. These findings revealed that the thumb opposition function at the first 3 months after surgery solely depended on the transferred tendon in most hands. In our series, useful recovery of postoperative APB-CMAP was obtained in 23 of 46 hands at final follow-up. Although statistical significance was not observed between patients with and without useful recovery of postoperative ABP-CMAP, it appeared that patients with detection of postoperative APBCMAP exhibited better functional results as shown in the validated outcome measurements. Our results show the usefulness of modified Camitz tendon transfer for early functional recovery in the patients with advanced CTS. However, this study had several limitations. First, this study had no control group to provide direct comparison of postoperative outcomes between advanced CTS patients treated with carpal tunnel release alone and those with combined simultaneous opponensplasty. There were 140 hands affected by CTS without detection of APB-CMAP before surgery. Among them, 85 hands underwent carpal tunnel release alone. These patients might have been candidates for the control group in this study. However, some patients did not experience diminished pinch function even with severe thenar muscle wasting because the flexor pollicis brevis produced adequate palmar abduction of thumb. Some patients did not request the reconstruction of opposition even with diminished pinch function. Some patients had systemic medical problems which precluded extensive surgery. Generally speaking, the patients who requested combined simultaneous opponensplasty were highly motivated and healthy compared with those who underwent carpal tunnel release alone. Because the characteristics between these 2 patient groups were somewhat different, we abandoned the direct comparison of their postoperative outcomes. However, a randomized controlled trial for direct comparison would confirm our conclusions. Second, the recovery of pronation of the thumb was not assessed, which is an important component of opposition. Modified Camitz tendon transfer has a potential for improving thumb pronation compared with the conventional procedure. Kato et al10 assessed the thumb pronation angle formed between the longitudinal nail axes of the J Hand Surg Am.
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thumb and the index finger in tip pinch position and described significant recovery of this angle after modified Camitz tendon transfer. However, because accurate measurement of this angle was difficult, we abandoned the use of this parameter for our analysis. Third, our study was a retrospective study of case series. Fourth, because DASH14 and CTSI15 have been available in Japan since 2005 and 2007, respectively, we started to use both of these measures in June 2008. Despite the importance of these assessments, only 23 patients completed both of these measures before and after surgery and were included. REFERENCES 1. Camitz H. Surgical treatment of paralysis of opponens muscle of thumb. Acta Chir Scand. 1929;65:77e81. 2. Littler JW, Li CS. Primary restoration of thumb opposition with median nerve decompression. Plast Reconstr Surg. 1967;39(1): 74e75. 3. Braun RM. Palmaris longus tendon transfer for augmentation of the thenar musculature in low median palsy. J Hand Surg Am. 1978;3(5): 488e491. 4. Foucher G, Malizos C, Sammut D, Braun FM, Michon J. Primary palmaris longus transfer as an opponensplasty in carpal tunnel release. A series of 73 cases. J Hand Surg Eur Vol. 1991;16(1):56e60. 5. Terrono AL, Rose JH, Mulroy J, Millender LH. Camitz palmaris longus abductorplasty for severe thenar atrophy secondary to carpal tunnel syndrome. J Hand Surg Am. 1993;18(2):204e206. 6. MacDougal BA. Palmaris longus opponensplasty. Plast Reconstr Surg. 1995;96(4):982e984. 7. Park IJ, Kim HM, Lee SU, Lee JY, Jeong C. Opponensplasty using palmaris longus tendon and flexor retinaculum pulley in patients with severe carpal tunnel syndrome. Acta Orthop Trauma Surg. 2010;130(7):829e834. 8. Kang SW, Chung YG, Lee JY, Jo WL. Modified Camitz opponensplasty using transverse carpal ligament loop pulley in patients with advanced carpal tunnel syndrome. Plast Reconstr Surg. 2012;129(4):761ee763e. 9. Naeem R, Lahiri A. Modified Camitz opponensplasty for severe thenar wasting secondary to carpal tunnel syndrome: case series. J Hand Surg Am. 2013;38(4):795e798. 10. Kato N, Yoshizawa T, Sakai H. Simultaneous modified Camitz opponensplasty using a pulley at the radial side of the flexor retinaculum in severe carpal tunnel syndrome. J Hand Surg Eur Vol. 2013;39(6):632e636. 11. Mondelli M, Reale F, Padua R, Aprile I, Padua L. Clinical and neurophysiological outcome of surgery in extreme carpal tunnel syndrome. Clin Neurophysiol. 2001;112(7):1237e1242. 12. Park IJ, Kim BJ. Prognosis of carpal tunnel release with extreme thenar atrophy. J Korean Soc Surg Hand. 2002;7:52e56. 13. Nobuta S, Sato K, Komatsu T, Miyasaka Y, Hatori M. Clinical results in severe carpal tunnel syndrome and motor nerve conduction studies. J Orthop Sci. 2005;10(1):22e26. 14. Imaeda T, Toh S, Nakao Y, et al. Validation of the Japanese Society for Surgery of the Hand version of the Disability of the Arm, Shoulder, and Hand questionnaire. J Orthop Sci. 2005;10(4): 353e359. 15. Imaeda T, Uchiyama S, Toh S, et al. Validation of the Japanese Society for Surgery of the Hand version of the Carpal Tunnel Syndrome instrument. J Orthop Sci. 2007;12(1):14e21. 16. Choi SJ, Ahn DS. Correlation of clinical history and electordiagnostic abnormalities with outcome after surgery for carpal tunnel syndrome. Plast Reconstr Surg. 1998;102(7):2374e2380.
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17. Padua L, LoMonaco M, Aulisa L, et al. Surgical prognosis in carpal tunnel syndrome: usefulness of a preoperative neurophysiological assessment. Act Neurol Scand. 1996;94(5):343e346. 18. Aulisa L, Tamburrelli F, Padua R, Romanini E. Lo Monaco M, Padua L. Carpal tunnel syndrome: indication for surgical treatment based on electrophysiological study. J Hand Surg Am. 1998;23(4):687e691. 19. Nolan WB, Alkaitis D, Glickel SZ, Snow S. Results of treatment of severe carpal tunnel syndrome. J Hand Surg Am. 1992;17(6): 1020e1023.
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20. World Health Organization. World Health Statistics 2014. Available at: http://www.who.int/mediacentre/news/releases/2014/world-healthstatistics-2014/en/. Accessed June 6, 2014. 21. Salomon JA, Wang H, Freeman MK, et al. Healthy life expectancy for 187 countries, 1990e2010: a systematic analysis for the Global Burdon Disease Study 2010. Lancet. 2012;380(9859):2144e2162. 22. Sorensen AA, Howard D, Tan WH, Ketchersid J, Calfee RP. Minimal clinically important differences of 3 patinet-rated outcomes instruments. J Hand Surg Am. 2013;38(4):641e649.
Vol. 39, December 2014
Camitz Tendon Transfer Using Flexor Retinaculum as a Pulley in Advanced Carpal Tunnel Syndrome Yasunori Hattori, MD, PhD, Kazuteru Doi, MD, PhD, Sotetsu Sakamoto, MD, Kannan Kumar, MD, Satomi Koide, MD Purpose To report the outcomes of modified Camitz abductor plasty using the released flexor retinaculum as a pulley in patients with advanced carpal tunnel syndrome. Methods A retrospective review of 46 hands in 43 patients who underwent modified Camitz abductor plasty was performed. Active palmar abduction of thumb and pulp pinch strength were assessed. Patient-reported outcome measures were assessed using the Disabilities of the Arm, Shoulder, and Hand and Carpal Tunnel Syndrome instrument. As an electrophysiological assessment, compound muscle action potential (CMAP) from abductor pollicis brevis (APB) was investigated. Results At 3 months, active palmar abduction of thumb and pulp pinch strength significantly improved. Although pulp pinch strength further improved, active abduction of thumb did not improve at the final follow-up. Both the patient-reported outcome measures improved at 3 months and further improved at final follow-up. Approximately 75% of improved scores were obtained at the first 3 months after surgery and the balance of improved scores (25%) was obtained by the time of final follow-up. Useful recovery of postoperative APB-CMAP (amplitude > 1.8 mV) was obtained in 3 hands (7%) at 3 months after surgery and in 23 hands (50%) at final follow-up. There was no statistical significance of the postoperative results including active palmar abduction of thumb and improvement of patient-reported outcome measures at final follow-up between the hands with useful recovery of postoperative APB-CMAP and the hands without it. Conclusions Modified Camitz abductor plasty benefitted the early improvement of activity of daily living in patients with advanced carpal tunnel syndrome. It acted not only as an internal orthosis in patients who eventually recovered thenar muscle function but also as the sole palmar abductor of the thumb in patients who failed to recover useful thenar muscle function. (J Hand Surg Am. 2014;39(12):2454e2459. Copyright Ó 2014 by the American Society for Surgery of the Hand. All rights reserved.) Type of study/level of evidence Therapeutic IV. Key words Abductor pollicis brevis, Camitz opponensplasty, carpal tunnel syndrome.
From the Department of Orthopedic Surgery, Ogori Daiichi General Hospital, Ogori, Yamaguchi, Japan. Received for publication June 10, 2014; accepted in revised form September 2, 2014. No benefits in any form have been received or will be received related directly or indirectly to the subject of this article. Corresponding author: Yasunori Hattori, MD, PhD, Department of Orthopedic Surgery, Ogori Daiichi General Hospital, 862-3, Shimogo, Ogori, Yamaguchi-City, YamaguchiPrefecture, 754-0002, Japan; e-mail: [email protected]. 0363-5023/14/3912-0016$36.00/0 http://dx.doi.org/10.1016/j.jhsa.2014.09.008
2454
r
Ó 2014 ASSH
r
Published by Elsevier, Inc. All rights reserved.
C
the palmaris longus tendon has frequently been used in patients with advanced carpal tunnel syndrome (CTS). This procedure is usually performed at the time of carpal tunnel release.1e10 Several authors have reported that the Camitz transfer provides abduction rather than opposition because it results in improved abduction but weak flexion and pronation of the carpometacarpal joint of the thumb, prerequisites for opposition.6e10 This is due to the radial orientation AMITZ ABDUCTOR PLASTY USING
CAMITZ TENDON TRANSFER
of the transferred tendon, which has an axis that is suboptimal to provide opposition. Prominent bowstringing of the transferred tendon is noted. This can be overcome by modifying the direction of the transferred tendon by using the released flexor retinaculum as a pulley, described by MacDougal in 1995.6 However, the indication of simultaneous opposition transfer for advanced CTS has been a subject of controversy. Some authors have reported clinical recovery from thenar muscle atrophy after carpal tunnel release alone and have not recommended simultaneous opposition transfer.11,12 Others have reported that thenar muscle atrophy showed minimal improvement despite the recovery of sensory function, and therefore, they have stated that opposition transfer is indicated in advanced CTS.2,4 Foucher et al4 reported that significant recovery of thenar muscle bulk was recorded in only 6 of 72 hands (8.%) in which the conventional Camitz transfer was done, and their follow-up was greater than 16 months. However, it is difficult to evaluate thenar muscle recovery by observing the muscle bulk and by palpation of the thenar eminence after simultaneous opposition transfer. Moreover, it is difficult to calculate how much opposition strength is contributed from the tendon transfer and how much is from the spontaneous thenar muscle recovery. This makes the accurate assessment of the real effect of simultaneous tendon transfer difficult. We performed modified Camitz abductor plasty using flexor retinaculum as a pulley in patients with advanced CTS who have difficulty with opposition.6e10 The aim of this study was to report our postoperative outcomes of this procedure including objective strength, motion measurements, patientreported outcome measures, and an electrophysiological assessment. MATERIALS AND METHODS Patients This study was undertaken in conformity with the Declaration of Helsinki after approval of our institutional review board. Written informed consent was obtained from each patient. We surgically treated 614 consecutive hands with idiopathic CTS between January 2007 and March 2013. CTS was diagnosed with physical examination and electrophysiological assessment using compound muscle action potential (CMAP) from the abductor pollicis brevis (APB). APB-CMAP was recorded with surface electrodes by supramaximal stimulation of the median nerve at the wrist.13 Our indication of modified Camitz transfer J Hand Surg Am.
r
2455
FIGURE 1: Surgical technique of modified Camitz opponensplasty. Small arrow shows the insertion of the APB tendon. Medium arrow shows the palmaris longus tendon strip. Large arrow shows a small hole at the radial side remnant of the released flexor retinaculum.
was diminished pinch function with severe thenar muscle atrophy and no detection of preoperative APB-CMAP. Surgical technique and postoperative management All patients underwent modified Camitz transfer according to the technique described by Kato et al.10 The palmaris longus tendon was dissected in continuity with the longitudinal slip of the palmar aponeurosis. The flexor retinaculum was released close to its medial attachment. The palmaris longus tendon was passed through a small hole of the released flexor retinaculum from the undersurface of the released flexor retinaculum (Fig. 1). The palmaris longus tendon was then passed through a subcutaneous tunnel and was sutured to the insertion of the APB. The hand was placed in a short-arm thumb spica orthosis with 45 palmar abduction of the thumb and the wrist at neutral position for 4 weeks. Then active and passive range of motion exercises of thumb and wrist were started. The orthosis was removed and patients were allowed to use their hand as required. No specific postoperative rehabilitation was undertaken. Vol. 39, December 2014
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CAMITZ TENDON TRANSFER
Assessment Clinical evaluation was performed before surgery, 3 months after surgery, and at final follow-up 12 to 18 months after surgery. All patients were reviewed directly by a certified hand therapist in our hospital who had not been primarily involved in the patients’ management. We recorded any subjective symptoms of paresthesia in the median nerve distribution. Pressure thresholds in the middle finger pulp were determined using the Semmes-Weinstein monofilament test. The filaments used for examination were 0.08, 0.22, 2.4, and 279 g. Active palmar abduction of the thumb (measured as the angle between the first and the second rays) was recorded. Pulp pinch strength was measured and recorded as a percentage compared with the contralateral hand. In patients who underwent surgery in both hands, pulp pinch strength was not used for analysis. Patient-reported outcomes were measured using the Japanese Society for Surgery of the Hand version of Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire14 and the Japanese Society for Surgery of the Hand version of the Carpal Tunnel Syndrome instrument (CTSI).15 Electrical investigations in all patients included APB-CMAP, which was measured from the stimulus artifact to the onset of the potential. Amplitude was measured from the baseline to the negative peak of the potential. Nobuta et al13 reported that postoperative APB-CMAP amplitude was greater than 1.8 mV in patients who obtained useful recovery of opposition after carpal tunnel release alone for advanced CTS. We used their criterion (APB-CMAP amplitude > 1.8 mV) as useful spontaneous recovery of APB function. The postoperative outcomes including active palmar abduction of thumb, DASH score improvement, and CTSI score improvement at final follow-up were compared between the hands with useful recovery of postoperative APB-CMAP and the hands without it. Complications including infection, hematoma, rupture of the transferred tendon, and prominent bowstringing of the transferred tendon were also investigated. Statistical analysis All results are presented as mean SD and were analyzed using Wilcoxon signed-ranks test or MannWhitney U test. P of .05 was established for statistical significance. RESULTS Out of 614 hands, preoperative APB-CMAP was not detectable in 140 hands. Among them, 55 hands of 52 J Hand Surg Am.
r
patients who had diminished pinch function with severe thenar muscle atrophy underwent simultaneous carpal tunnel release with modified Camitz abductor plasty. Three patients underwent this procedure in both hands. Out of these 55 hands, 46 hands of 43 patients were followed for at least 12 months and were included in this study. Of these 43 patients, there were 6 men and 37 women. Mean age was 70 10 years at the time of operation. Thirty right and 16 left hands were affected. The mean follow-up period was 14 2 months. Three months after surgery, reduction of paresthesia was observed in 36 of 46 hands (78%). At the final follow-up, complete resolution of paresthesia was observed in 34 hands (74%) and improvement in 12 hands (26%). On Semmes-Weinstein monofilament testing before surgery, 7 hands (15%) were able to perceive 2.4 g. After surgery, significant improvement was observed. Twenty-two hands (48%) perceived the 2.4-g filament at 3 months and 40 hands (87%) at final follow-up. Active palmar abduction of thumb averaged 22 before surgery and improved to 44 at 3 months. No further improvement was observed after 3 months. Pulp pinch strength averaged 53% of the contralateral hand before surgery. This improved to 64% at 3 months and further improved at final follow-up. Twenty-three patients completed both DASH and CTSI and were included for analysis. All of these patients underwent surgery in a single hand. DASH score averaged 33 points before surgery. This improved to 14 at 3 months and to 8 at final followup. Symptom severity score and function score of CTSI averaged 2.5 and 2.2, respectively, before surgery. This improved to 1.6 and 1.5 at 3 months and to 1.3 and 1.2 at final follow-up. Before surgery, APB-CMAP was undetectable in all hands. At 3 months, CMAP was detectable in 8 of 46 hands (17%). At final follow-up, the CMAP was detectable in 32 of 46 hands (70%). Latency and amplitude in these 32 hands averaged 5.2 ms and 4.4 mV, respectively. The overall results are summarized in Table 1. According to the criterion of Nobuta et al,13 useful recovery of postoperative APB-CMAP (amplitude > 1.8 mV) was obtained in 3 hands (7%) at 3 months after surgery and in 23 hands (50%) at final followup. Active palmar abduction of thumb averaged 46 in 23 hands with useful recovery of postoperative APB-CMAP, and 43 in 23 hands without it. Improvement of DASH score, CTSI symptom severity score, and CTSI function score averaged 28, 1.3, and 1.2, respectively, in 11 hands with its useful Vol. 39, December 2014
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TABLE 1.
Overall Results Postoperative
Final
Preoperative
3 mo
Follow-up
6.65 filament (hands)
39
24
6
4.31 filament (hands)
7
21
23
3.61 filament (hands)
0
1
17
Thumb palmar abduction ( ) (n ¼ 46)
22 5
44 5
45 6
Pulp pinch (%) (n ¼ 43)
53 24
64 22
80 21
DASH (points) (n ¼ 23)
33 14
14 12
8 12
Semmes-Weinstein test (n ¼ 46)
CTSI (n ¼ 23) Symptom severity score (points)
2.53 0.76
1.63 0.5
1.29 0.38
Function score (points)
2.22 0.63
1.46 0.42
1.19 0.43
0
8
32
Electrophysiological assessment (n ¼ 46) Detection of APB-CMAP (hands)
TABLE 2.
Comparison of Results Between Hands With or Without Useful APB-CMAP Recovery APB-CMAP Recovery (þ)
(e)
Thumb palmar abduction ( )
46 4 (n ¼ 23)
43 7 (n ¼ 23)
DASH score improvement (points)
25 11 (n ¼ 11)
22 12 (n ¼ 12)
Symptom severity score
1.25 0.53 (n ¼ 11)
1.24 0.72 (n ¼ 12)
Function score
1.20 0.54 (n ¼ 11)
0.87 0.42 (n ¼ 12)
CTSI score improvement (points)
recovery and 22, 1.2, and 0.9 in 12 hands without it. There was no statistical significance of these results between 2 groups (Table 2). There were no complications after surgery. DISCUSSION It is still controversial whether useful motor recovery is possible after carpal tunnel release alone for the patients with severe thenar muscle atrophy and whether simultaneous tendon transfer is necessary. APB-CMAP directly assess the motor function of APB, and is often undetectable in advanced CTS patients with marked thenar muscle atrophy.13,16e19 According to the criterion of Nobuta et al,13 we were able to obtain useful recovery of postoperative APB-CMAP in 23 hands (50%) at final follow-up. From these results, 50% of our patients had a potential of spontaneous useful recovery of thenar muscle function after carpal tunnel release alone. In our series, of the patients’ average age was 70 years. Overall life expectancy of the Japanese population was J Hand Surg Am.
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male, 80 years, and female, 87 years, listed by the World Health Organization in 2013.20 Healthy life expectancy in 2010 was 71 years for men and 76 years for women.21 Almost all of our patients in this series requested early functional recovery of the hand, because they lived alone or independently and their hand function was of critical importance to them. Our study showed that both DASH and CTSI scores significantly improved after surgery. The improved score of 19 points after 3 months was much greater than 10 points defined as minimal clinically important difference.22 Consequently, 77% of the improvement in the DASH score was obtained in first 3 months after surgery, Similarly, 72% of the improvement in the CTSI symptom severity score and 74% of the improvement in the CTSI function score were obtained in the first 3 months after surgery. We attributed this early improvement of activity of daily living in our patients to the recovery of sensory function due to the decompression of the median nerve and restored Vol. 39, December 2014
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thumb palmar abduction due to tendon transfer. In electrophysiological findings, useful recovery of postoperative APB-CMAP was obtained in 3 hands (7%) at 3 months after surgery. Average active palmar abduction of thumb was 44 after 3 months and did not improve further. These findings revealed that the thumb opposition function at the first 3 months after surgery solely depended on the transferred tendon in most hands. In our series, useful recovery of postoperative APB-CMAP was obtained in 23 of 46 hands at final follow-up. Although statistical significance was not observed between patients with and without useful recovery of postoperative ABP-CMAP, it appeared that patients with detection of postoperative APBCMAP exhibited better functional results as shown in the validated outcome measurements. Our results show the usefulness of modified Camitz tendon transfer for early functional recovery in the patients with advanced CTS. However, this study had several limitations. First, this study had no control group to provide direct comparison of postoperative outcomes between advanced CTS patients treated with carpal tunnel release alone and those with combined simultaneous opponensplasty. There were 140 hands affected by CTS without detection of APB-CMAP before surgery. Among them, 85 hands underwent carpal tunnel release alone. These patients might have been candidates for the control group in this study. However, some patients did not experience diminished pinch function even with severe thenar muscle wasting because the flexor pollicis brevis produced adequate palmar abduction of thumb. Some patients did not request the reconstruction of opposition even with diminished pinch function. Some patients had systemic medical problems which precluded extensive surgery. Generally speaking, the patients who requested combined simultaneous opponensplasty were highly motivated and healthy compared with those who underwent carpal tunnel release alone. Because the characteristics between these 2 patient groups were somewhat different, we abandoned the direct comparison of their postoperative outcomes. However, a randomized controlled trial for direct comparison would confirm our conclusions. Second, the recovery of pronation of the thumb was not assessed, which is an important component of opposition. Modified Camitz tendon transfer has a potential for improving thumb pronation compared with the conventional procedure. Kato et al10 assessed the thumb pronation angle formed between the longitudinal nail axes of the J Hand Surg Am.
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thumb and the index finger in tip pinch position and described significant recovery of this angle after modified Camitz tendon transfer. However, because accurate measurement of this angle was difficult, we abandoned the use of this parameter for our analysis. Third, our study was a retrospective study of case series. Fourth, because DASH14 and CTSI15 have been available in Japan since 2005 and 2007, respectively, we started to use both of these measures in June 2008. Despite the importance of these assessments, only 23 patients completed both of these measures before and after surgery and were included. REFERENCES 1. Camitz H. Surgical treatment of paralysis of opponens muscle of thumb. Acta Chir Scand. 1929;65:77e81. 2. Littler JW, Li CS. Primary restoration of thumb opposition with median nerve decompression. Plast Reconstr Surg. 1967;39(1): 74e75. 3. Braun RM. Palmaris longus tendon transfer for augmentation of the thenar musculature in low median palsy. J Hand Surg Am. 1978;3(5): 488e491. 4. Foucher G, Malizos C, Sammut D, Braun FM, Michon J. Primary palmaris longus transfer as an opponensplasty in carpal tunnel release. A series of 73 cases. J Hand Surg Eur Vol. 1991;16(1):56e60. 5. Terrono AL, Rose JH, Mulroy J, Millender LH. Camitz palmaris longus abductorplasty for severe thenar atrophy secondary to carpal tunnel syndrome. J Hand Surg Am. 1993;18(2):204e206. 6. MacDougal BA. Palmaris longus opponensplasty. Plast Reconstr Surg. 1995;96(4):982e984. 7. Park IJ, Kim HM, Lee SU, Lee JY, Jeong C. Opponensplasty using palmaris longus tendon and flexor retinaculum pulley in patients with severe carpal tunnel syndrome. Acta Orthop Trauma Surg. 2010;130(7):829e834. 8. Kang SW, Chung YG, Lee JY, Jo WL. Modified Camitz opponensplasty using transverse carpal ligament loop pulley in patients with advanced carpal tunnel syndrome. Plast Reconstr Surg. 2012;129(4):761ee763e. 9. Naeem R, Lahiri A. Modified Camitz opponensplasty for severe thenar wasting secondary to carpal tunnel syndrome: case series. J Hand Surg Am. 2013;38(4):795e798. 10. Kato N, Yoshizawa T, Sakai H. Simultaneous modified Camitz opponensplasty using a pulley at the radial side of the flexor retinaculum in severe carpal tunnel syndrome. J Hand Surg Eur Vol. 2013;39(6):632e636. 11. Mondelli M, Reale F, Padua R, Aprile I, Padua L. Clinical and neurophysiological outcome of surgery in extreme carpal tunnel syndrome. Clin Neurophysiol. 2001;112(7):1237e1242. 12. Park IJ, Kim BJ. Prognosis of carpal tunnel release with extreme thenar atrophy. J Korean Soc Surg Hand. 2002;7:52e56. 13. Nobuta S, Sato K, Komatsu T, Miyasaka Y, Hatori M. Clinical results in severe carpal tunnel syndrome and motor nerve conduction studies. J Orthop Sci. 2005;10(1):22e26. 14. Imaeda T, Toh S, Nakao Y, et al. Validation of the Japanese Society for Surgery of the Hand version of the Disability of the Arm, Shoulder, and Hand questionnaire. J Orthop Sci. 2005;10(4): 353e359. 15. Imaeda T, Uchiyama S, Toh S, et al. Validation of the Japanese Society for Surgery of the Hand version of the Carpal Tunnel Syndrome instrument. J Orthop Sci. 2007;12(1):14e21. 16. Choi SJ, Ahn DS. Correlation of clinical history and electordiagnostic abnormalities with outcome after surgery for carpal tunnel syndrome. Plast Reconstr Surg. 1998;102(7):2374e2380.
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17. Padua L, LoMonaco M, Aulisa L, et al. Surgical prognosis in carpal tunnel syndrome: usefulness of a preoperative neurophysiological assessment. Act Neurol Scand. 1996;94(5):343e346. 18. Aulisa L, Tamburrelli F, Padua R, Romanini E. Lo Monaco M, Padua L. Carpal tunnel syndrome: indication for surgical treatment based on electrophysiological study. J Hand Surg Am. 1998;23(4):687e691. 19. Nolan WB, Alkaitis D, Glickel SZ, Snow S. Results of treatment of severe carpal tunnel syndrome. J Hand Surg Am. 1992;17(6): 1020e1023.
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20. World Health Organization. World Health Statistics 2014. Available at: http://www.who.int/mediacentre/news/releases/2014/world-healthstatistics-2014/en/. Accessed June 6, 2014. 21. Salomon JA, Wang H, Freeman MK, et al. Healthy life expectancy for 187 countries, 1990e2010: a systematic analysis for the Global Burdon Disease Study 2010. Lancet. 2012;380(9859):2144e2162. 22. Sorensen AA, Howard D, Tan WH, Ketchersid J, Calfee RP. Minimal clinically important differences of 3 patinet-rated outcomes instruments. J Hand Surg Am. 2013;38(4):641e649.
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