Available online at
ScienceDirect www.sciencedirect.com Chirurgie de la main 33 (2014) 320–324
Surgical technique
Case report: Double nerve transfer of the anterior and posterior interosseous nerves to treat a high ulnar nerve defect at the elbow Double neurotisation du nerf ulnaire par les nerfs interosseux antérieur et postérieur après perte de substance du nerf ulnaire au coude : à propos d’un cas S. Delclaux *, C. Aprédoaei, P. Mansat, M. Rongières, P. Bonnevialle Institut locomoteur, CHU de Toulouse-Purpan, place du Dr Baylac, 31059 Toulouse cedex, France Received 8 March 2014; received in revised form 29 June 2014; accepted 18 August 2014 Available online 16 September 2014
Abstract Double neurotization of the deep branch of ulnar nerve (DBUN) and superficial branch of ulnar nerve using the anterior interosseous nerve (AIN) and the recurrent (thenar) branch of the median nerve was first described by Battiston and Lanzetta. This article details the postoperative results after 18 months of a patient who underwent this technique using the posterior interosseous nerve (PIN) instead of the recurrent branch of the median nerve for sensory reconstruction. A 35-year-old, right-handed man suffered major trauma to his right upper limb following a serious motor vehicle accident. One year later, a pseudocystic neuroma of the ulnar nerve was evident on ultrasound examination and MRI. After the neuroma had been resected, the nerve defect was estimated at 8 cm. One and a half years after the initial trauma, with the patient still at M0/S0, we transferred the AIN and PIN onto the deep and superficial branches of the ulnar nerve respectively. Nerve recovery was monitored clinically every month and by electromyography (EMG) every three months initially and then every six months. At 18 months postoperative, 5th digit abduction/adduction was 28 mm. Sensation was present at the base of the 5th digit. The patient was graded M3/S2. Clear re-innervation of the abductor digiti minimi was demonstrated by EMG (motor conduction velocity 50 m/s). Given that the ulnar nerve could not be excited at the elbow, this re-innervation had to be the result of the double nerve transfer. Neurotization of the DBUN using the AIN produces functional results as early as 1 year after surgery. Using PIN for sensory neurotization is easy to perform, has no negative consequences for the donor site, and leads to good recovery of sensation (graded as S2) after 18 months. # 2014 Elsevier Masson SAS. All rights reserved. Keywords: Neurotization; Anterior interosseous nerve; Posterior interosseous nerve; Ulnar nerve
Résumé En 1999, Battiston et Lanzetta ont rapporté une nouvelle technique de double neurotisation des rameaux profond et superficiel du nerf ulnaire par le nerf interosseux antérieur (NIOA) et le rameau palmaire du nerf médian. Nous rapportons ici les résultats au recul de 18 mois obtenus chez un patient ayant bénéficié de cette technique, modifiée par l’utilisation du nerf interosseux postérieur (NIOP) pour la reconstruction sensitive. Un homme de 35 ans, droitier, fumeur, avait été victime d’un grave accident de la route avec un traumatisme important du membre supérieur droit. À un an du traumatisme, une échographie et une IRM ont montré un pseudo-névrome du nerf ulnaire. Une fois le névrome réséqué, la perte de substance du nerf était évaluée à 8 cm. Un an et demi après le traumatisme initial, et alors que le patient était toujours M0/S0, nous avons réalisé une neurotisation des rameaux profond et superficiel du nerf ulnaire, respectivement par le NIOA et le NIOP. La récupération nerveuse a été surveillée cliniquement tous les mois et par une électromyographie à 3 mois, puis tous les 6 mois. À 18 mois de la neurotisation, l’abduction/adduction du 5e doigt était de 28 mm. La sensibilité était présente à la base du 5e doigt. Le patient était alors évalué M3/S2. L’électromyogramme montrait des nets progrès de réinnervation de l’abducteur du petit doigt (vitesse conduction motrice : 50 m/s), conséquence de la neurotisation puisque le nerf ulnaire restait inexcitable au coude. La neurotisation du rameau profond du nerf ulnaire par le NIOA permet des résultats fonctionnels précoces, dès
* Corresponding author. E-mail address: [email protected] (S. Delclaux). http://dx.doi.org/10.1016/j.main.2014.08.001 1297-3203/# 2014 Elsevier Masson SAS. All rights reserved.
S. Delclaux et al. / Chirurgie de la main 33 (2014) 320–324
321
la première année après la chirurgie. L’utilisation du NIOP pour la neurotisation sensitive est simple à réaliser. Elle n’entraîne aucune conséquence pour le site donneur et permet à 18 mois de recul, une récupération sensitive satisfaisante notée S2 pour ce patient. # 2014 Elsevier Masson SAS. Tous droits réservés. Mots clés : Neurotisation ; Nerf interosseux antérieur ; Nerf interosseux postérieur ; Nerf ulnaire
1. Introduction If the intrinsic muscles do not recover after high ulnar nerve palsy, the functional consequences for thumb-finger pinching and wrist locking are severe. First developed in the 1970s, nerve grafting is the most commonly used technique for cases of nerve defects. In 1999, Battiston and Lanzetta [1] reported a new double nerve transfer technique where the anterior interosseous nerve (AIN) and the palmar cutaneous branch of the median nerve were connected to the deep and superficial branches of the ulnar nerve (DBUN and SBUN). In later studies [2–4], it was shown that the DBUN and the anterior interosseous nerve had the same diameter and the same number of axons. In a cadaver study, Robert et al. [5] concluded that these two motor branches could be directly sutured together. Flores et al. [6] used the 3rd palmar common digital nerve to carry out sensory neurotization. In this article, we report on the 18-month results of a patient who underwent double nerve transfer of the AIN and the posterior interosseous nerve (PIN). 2. Material and methods 2.1. Case report A 35-year-old, right-handed man suffered major trauma to his right upper limb during a serious motor vehicle accident; this patient was a smoker. The initial assessment found soft tissue degloving of the right forearm and elbow associated with gross tears of the flexor carpi radialis and ulnaris muscles, along with the flexor digitorum superficialis and extensor digitorum muscles. The surgical report did not specify the condition of the ulnar nerve. After initial debridement and skin grafting 15 days later, the patient was transferred to his native region for followup. The skin had completely healed after 1.5 months and full wrist and elbow range of motion was achieved 1 year after the accident (Fig. 1). The patient’s main complaint was a lack of strength along with frequent electric shocks at the elbow. Anesthesia was present in the area supplied by the ulnar nerve. There was persistent hypotrophy of the intrinsic thenar and hypothenar muscles. The dorsal and palmar interossei muscles were also deficient. Grip strength was only 10 kg on the Jamar dynamometer. Froment’s sign was positive, with exaggerated flexion of the thumb interphalangeal joint. Based on the HighetZachary classification [7], the patient had M0 motor ability in the intrinsic muscles and S0 sensation in the hypothenar area. The first electromyography (EMG) performed 3 months after the accident found trivial motor and sensor response amplitudes
(sensory conduction latency 3.45 ms, motor conduction speed 37.3 m/s). An EMG performed 9 months later showed the same results along with atrophy of the intrinsic muscles. Given the lack of clinical improvement and lack of potential for re-innervation of the intrinsic muscles based on the EMG findings, ultrasonography and MRI were performed to get a better view of the ulnar nerve groove. These two imaging modalities were suggestive of pseudocystic neuroma above the ulnar nerve groove. A new surgical procedure was undertaken 1 year after the initial injury. We identified a discontinuity in the ulnar nerve and a neuroma. The initial nerve defect was 5 cm; it was 8 cm long once the neuroma had been resected (Fig. 2). Since direct suture repair was impossible, the nerve was protected with a connective tissue membrane to prepare for nerve surgery. One and a half years after the initial injury, with the patient still at M0/S0, the AIN and PIN were transferred onto the DBUN and SBUN, respectively. 2.2. Surgical technique The procedure was performed under general anesthesia with a tourniquet cuff at the base of the arm. The first surgical phase was performed with loupes; the second phase of dissection and fascicle suturing was performed under a microscope. 2.2.1. Neurotisation of SBUN by the PIN Guyon’s canal was opened to expose the ulnar nerve. Using a microscope, distal to proximal dissection was performed to separate the sensory and motor fascicles. The dissection was
Fig. 1. Clinical appearance of elbow once the skin lesions had healed.
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S. Delclaux et al. / Chirurgie de la main 33 (2014) 320–324 Table 1 Clinical recovery of intrinsic muscle function. Time after nerve transfer
3 months
6 months
18 months
Abduction/adduction distance of 5th finger
15 mm
24 mm
28 mm
Fig. 2. The ulnar nerve defect was 8 cm long.
carried out to 5 cm proximal to the distal wrist crease. A dorsal incision was centered over the distal radio-ulnar (DRU) joint and the PIN was dissected from distal to proximal. The PIN was 1 mm in diameter distally and up to 2 mm proximal to the DRU. The PIN was retrieved in front through the interosseous membrane. The sensory fascicles to 4th and 5th fingers were then sutured to the PIN fascicles. There were no discernible differences in the diameter of the nerve branches. 2.2.2. Neurotisation of DBUN by the AIN The AIN was found at the proximal edge of the pronator quadratus muscle and was dissected as distally as possible. The AIN was 1.5 mm in diameter, whereas the motor branch of the ulnar nerve was 2 mm in diameter. The motor fascicles of the ulnar nerve were then sutured to the motor fascicles of the AIN using a microscope. All of the nerve transfers were carried out using interrupted sutures with 10–0 Ethilon and fibrin glue. 2.2.3. Postoperative care and follow-up The patient’s arm was immobilized for 21 days. Intensive physical therapy was then initiated that included electrostimulation set out by the surgeon and adjusted as the intrinsic muscles gradually recovered. Nerve recovery was monitored clinically every month; EMG was carried out at 3 months, then every 6 months until the 18th month. The follow-up was terminated at 18 months when the patient moved to another area of the country.
Fig. 3. Abduction–adduction of the 5th finger, 1 year after the nerve transfer.
point, with protective sensation being present. EMG showed clear gradual re-innervation of the abductor digiti minimi (motor conduction speed 50 m/s); this was attributed to the nerve transfer because the ulnar nerve could not be excited at the elbow. Sensory response was still lacking, but there was clear increase in the current perception threshold of the 5th finger (120 V, standard < 80 V). The patient stated that he was extremely satisfied with the procedure. We were able to reach the patient by telephone three years after the surgery. He stated that he did not wish to continue the specialized follow-up. He continued to experience improved intrinsic hand function (abduction/adduction of the 5th finger, less hypotrophy in the hypothenar eminence area). He also said that recovery of sensation in the 4th and 5th digits was occurring slowly. The QuickDASH score, determined over the telephone, was 34 out of 100.
4. Discussion 3. Results The patient experienced gradual recovery of his intrinsic hand muscles (Table 1) on the clinical and EMG front. At the 6th month, the 5th finger could be abducted/adducted 24 mm. Sensation had recovered in the palm of the hand. Eighteen months after the double nerve transfer, the 5th finger could be abducted/adducted 28 mm (Fig. 3). Sensation was present at the base of the 5th finger. The patient was graded M3/S2 at that
Post-traumatic lesions of the ulnar nerve have serious consequences for hand function. The goal for these patients is to recover the function of the intrinsic muscles as quickly as possible. Use of the sensory branch as a donor graft became popular in the 1970s. But some studies eventually reported disappointing results [8,9]. Vastamaki et al. [9] found that good functional results were rare if more than 7 cm of nerve was damaged; they
S. Delclaux et al. / Chirurgie de la main 33 (2014) 320–324
also noted that extrinsic factors (age, nerve defect, time to surgery) negatively affected the success of these grafts. Chan et al. [10] compared the outcomes of nerve transfer to nerve grafting in a patient with ulnar nerve laceration at the wrist and a 2 cm defect. Six weeks after the injury, they performed a nerve graft with the sural nerve and simultaneously transferred the AIN to the DBUN. After 18 months, maximum motor axon regeneration was obtained after simulation of the median nerve at the elbow, which indicated that the AIN transfer was superior to ulnar nerve grafting. They concluded that nerve transfer appeared to be more effective than nerve grafting, making it a good treatment option. Two cadaver studies [2,3] revealed that the AIN and DBUN had the same number of axons and the same diameter, making it possible to suture the nerves together in a satisfactory way. Robert et al. [5] reported that these two nerves were no more than 10 mm apart once the fascicles had been individualized. The two nerves could be directly sutured together in the 15 cadaver arms that were dissected. The first clinical application of this technique was described in three patients in 1974, but no sensory nerve transfer was performed. Battiston and Lanzetta [1] stated that it was impossible to directly suture the AIN and DBUN together intraoperatively. They also found that the AIN penetrated the pronator quadratus at its proximal edge. But this was not found in a later cadaver study [5]. Several authors [1,6,11] have reported satisfactory results with restoration of the hand’s intrinsic function. Haase and Chung [11] favor this technique in cases of high ulnar nerve lesions. The distal median to ulnar nerve transfer technique has been well described [12]. Battiston and Lanzetta [1] and Flores [6] transferred different nerves onto the SBUN during the same surgical procedure to restore both sensation and motor activity. Battiston and Lanzetta used an end-to-end suture of the palmar cutaneous branch of the median nerve, while Flores used an end-to-side suture of the 3rd palmar common digital nerve. But using the palmar cutaneous branch of the median nerve can lead to dysesthesia in the thenar eminence area. Battiston and Lanzetta did not find any occurrences of neuroma or significant discomfort in their patients. Flores found no sensory deficit in the region corresponding to the 3rd palmar common digital nerve. Both studies used the Highet-Zachary classification [7] as modified by Mackinnon and Dellon [8] to evaluate their functional outcomes. After a follow-up of 30 months, Battiston and Lanzetta found 86% of M4 and S3 scores, which corresponded to good results. Flores [6] reported scores of M3/M4 and S3/S4 in his five patients, 7 months after the surgery. Based on these two aforementioned studies, we decided to treat our patient with double nerve transfer so as to allow motor recovery and protective sensation restoration in the hypothenar eminence area. We used the PIN dissected from the posterior side of the wrist. This nerve was then passed in front of the interosseous membrane and sutured end-to-end to the SBUN. The advantage of this technique is that there are no negative sensory consequences at the donor site. Eighteen months after the surgery, the sensory recovery was still slow, but the patient
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had regained some sensation at the base of the 5th finger (graded S2) and an objective increase in the current perception threshold on EMG. At that point, the intrinsic function of the hand had also gradually recovered. The abduction/adduction distance of the 5th finger increased from 15 mm at the 3rd month to 28 mm at the 18th month. The motor/sensory assessment, which was initially graded M0/S0, had reached M3/S2 18 months after the surgery. This study presents a retrospective assessment of a patient with 18 months of follow-up. One of the weaknesses of the current study is that only one patient was evaluated over a limited time period. Nevertheless, it confirms the good results of double nerve transfer that have already been described in other published studies. We have described a new nerve transfer technique for the SBUN using end-to-end suture of the PIN, without sequelae for the donor site. 5. Conclusion The double transfer of the PIN and AIN nerves onto the SBUN and DBUN led to functional recovery within the first year after the surgical procedure. The motor nerve transfer technique has been well described. But this is the first published description of the PIN being transferred (end-to-end suture) to restore sensory function. This is a reliable option without sequelae for the donor site. We found no significant differences in the diameter of the PIN and SBUN. A more detailed cadaver study could reinforce this finding. Disclosure of interest The authors declare that they have no conflicts of interest concerning this article. References [1] Battiston B, Lanzetta M. Reconstruction of high ulnar nerve lesions by distal double median to ulnar nerve transfer. J Hand Surg Am 1999;24:1185–91. [2] Ustün ME, Og˘ün TC, Büyükmumcu M, Salbacak A. Selective restoration of motor function in the ulnar nerve by transfer of the anterior interosseous nerve. An anatomical feasibility study. J Bone Joint Surg Am 2001;83:549–52. [3] Wang Y, Zhu S, Zhang B. Anatomical study and clinical application of transfer of pronator quadratus branch of anterior interosseous nerve in the repair of thenar branch of median nerve and deep branch of ulnar nerve. Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi 1997;11:335–7. [4] Wang Y, Zhu S. Transfer of a branch of the anterior interosseous nerve to the motor branch of the median nerve and ulnar nerve. Chin Med J (Engl) 1997;110:216–9. [5] Robert M, Blanc C, Gasnier P, Le Nen D, Hu W. Neurotisation of the deep branch of ulnar nerve with anterior interosseous nerve: anatomic study. Chir Main 2011;30:406–9. [6] Flores LP. Distal anterior interosseous nerve transfer to the deep ulnar nerve and end-to-side suture of the superficial ulnar nerve to the third palmar common digital nerve for treatment of high ulnar nerve injuries: experience in five cases. Arq Neuropsiquiatr 2011;69:519–24. [7] Zachary RB, Holmes W. Primary suture of nerves. Surg Gynecol Obstet 1946;82:632–51. [8] Mackinnon SE, Dellon AL. Surgery of the peripheral nerve. New York: Thieme; 1988: 119.
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[9] Vastamäki M, Kallio PK, Solonen KA. The results of secondary microsurgical repair of ulnar nerve injury. J Hand Surg Br 1993;18: 323–6. [10] Chan KM, Olson JL, Morhart M, Lin T, Guilfoyle R. Outcomes of nerve transfer versus nerve graft in ulnar nerve laceration. Can J Neurol Sci 2012;39:242–4.
[11] Haase SC, Chung KC. Anterior interosseous nerve transfer to the motor branch of the ulnar nerve for high ulnar nerve injuries. Ann Plast Surg 2002;49:285–90. [12] Brown JM, Yee A, Mackinnon SE. Distal median to ulnar nerve transfers to restore ulnar motor and sensory function within the hand: technical nuances. Neurosurgery 2009;65:966–77.
ScienceDirect www.sciencedirect.com Chirurgie de la main 33 (2014) 320–324
Surgical technique
Case report: Double nerve transfer of the anterior and posterior interosseous nerves to treat a high ulnar nerve defect at the elbow Double neurotisation du nerf ulnaire par les nerfs interosseux antérieur et postérieur après perte de substance du nerf ulnaire au coude : à propos d’un cas S. Delclaux *, C. Aprédoaei, P. Mansat, M. Rongières, P. Bonnevialle Institut locomoteur, CHU de Toulouse-Purpan, place du Dr Baylac, 31059 Toulouse cedex, France Received 8 March 2014; received in revised form 29 June 2014; accepted 18 August 2014 Available online 16 September 2014
Abstract Double neurotization of the deep branch of ulnar nerve (DBUN) and superficial branch of ulnar nerve using the anterior interosseous nerve (AIN) and the recurrent (thenar) branch of the median nerve was first described by Battiston and Lanzetta. This article details the postoperative results after 18 months of a patient who underwent this technique using the posterior interosseous nerve (PIN) instead of the recurrent branch of the median nerve for sensory reconstruction. A 35-year-old, right-handed man suffered major trauma to his right upper limb following a serious motor vehicle accident. One year later, a pseudocystic neuroma of the ulnar nerve was evident on ultrasound examination and MRI. After the neuroma had been resected, the nerve defect was estimated at 8 cm. One and a half years after the initial trauma, with the patient still at M0/S0, we transferred the AIN and PIN onto the deep and superficial branches of the ulnar nerve respectively. Nerve recovery was monitored clinically every month and by electromyography (EMG) every three months initially and then every six months. At 18 months postoperative, 5th digit abduction/adduction was 28 mm. Sensation was present at the base of the 5th digit. The patient was graded M3/S2. Clear re-innervation of the abductor digiti minimi was demonstrated by EMG (motor conduction velocity 50 m/s). Given that the ulnar nerve could not be excited at the elbow, this re-innervation had to be the result of the double nerve transfer. Neurotization of the DBUN using the AIN produces functional results as early as 1 year after surgery. Using PIN for sensory neurotization is easy to perform, has no negative consequences for the donor site, and leads to good recovery of sensation (graded as S2) after 18 months. # 2014 Elsevier Masson SAS. All rights reserved. Keywords: Neurotization; Anterior interosseous nerve; Posterior interosseous nerve; Ulnar nerve
Résumé En 1999, Battiston et Lanzetta ont rapporté une nouvelle technique de double neurotisation des rameaux profond et superficiel du nerf ulnaire par le nerf interosseux antérieur (NIOA) et le rameau palmaire du nerf médian. Nous rapportons ici les résultats au recul de 18 mois obtenus chez un patient ayant bénéficié de cette technique, modifiée par l’utilisation du nerf interosseux postérieur (NIOP) pour la reconstruction sensitive. Un homme de 35 ans, droitier, fumeur, avait été victime d’un grave accident de la route avec un traumatisme important du membre supérieur droit. À un an du traumatisme, une échographie et une IRM ont montré un pseudo-névrome du nerf ulnaire. Une fois le névrome réséqué, la perte de substance du nerf était évaluée à 8 cm. Un an et demi après le traumatisme initial, et alors que le patient était toujours M0/S0, nous avons réalisé une neurotisation des rameaux profond et superficiel du nerf ulnaire, respectivement par le NIOA et le NIOP. La récupération nerveuse a été surveillée cliniquement tous les mois et par une électromyographie à 3 mois, puis tous les 6 mois. À 18 mois de la neurotisation, l’abduction/adduction du 5e doigt était de 28 mm. La sensibilité était présente à la base du 5e doigt. Le patient était alors évalué M3/S2. L’électromyogramme montrait des nets progrès de réinnervation de l’abducteur du petit doigt (vitesse conduction motrice : 50 m/s), conséquence de la neurotisation puisque le nerf ulnaire restait inexcitable au coude. La neurotisation du rameau profond du nerf ulnaire par le NIOA permet des résultats fonctionnels précoces, dès
* Corresponding author. E-mail address: [email protected] (S. Delclaux). http://dx.doi.org/10.1016/j.main.2014.08.001 1297-3203/# 2014 Elsevier Masson SAS. All rights reserved.
S. Delclaux et al. / Chirurgie de la main 33 (2014) 320–324
321
la première année après la chirurgie. L’utilisation du NIOP pour la neurotisation sensitive est simple à réaliser. Elle n’entraîne aucune conséquence pour le site donneur et permet à 18 mois de recul, une récupération sensitive satisfaisante notée S2 pour ce patient. # 2014 Elsevier Masson SAS. Tous droits réservés. Mots clés : Neurotisation ; Nerf interosseux antérieur ; Nerf interosseux postérieur ; Nerf ulnaire
1. Introduction If the intrinsic muscles do not recover after high ulnar nerve palsy, the functional consequences for thumb-finger pinching and wrist locking are severe. First developed in the 1970s, nerve grafting is the most commonly used technique for cases of nerve defects. In 1999, Battiston and Lanzetta [1] reported a new double nerve transfer technique where the anterior interosseous nerve (AIN) and the palmar cutaneous branch of the median nerve were connected to the deep and superficial branches of the ulnar nerve (DBUN and SBUN). In later studies [2–4], it was shown that the DBUN and the anterior interosseous nerve had the same diameter and the same number of axons. In a cadaver study, Robert et al. [5] concluded that these two motor branches could be directly sutured together. Flores et al. [6] used the 3rd palmar common digital nerve to carry out sensory neurotization. In this article, we report on the 18-month results of a patient who underwent double nerve transfer of the AIN and the posterior interosseous nerve (PIN). 2. Material and methods 2.1. Case report A 35-year-old, right-handed man suffered major trauma to his right upper limb during a serious motor vehicle accident; this patient was a smoker. The initial assessment found soft tissue degloving of the right forearm and elbow associated with gross tears of the flexor carpi radialis and ulnaris muscles, along with the flexor digitorum superficialis and extensor digitorum muscles. The surgical report did not specify the condition of the ulnar nerve. After initial debridement and skin grafting 15 days later, the patient was transferred to his native region for followup. The skin had completely healed after 1.5 months and full wrist and elbow range of motion was achieved 1 year after the accident (Fig. 1). The patient’s main complaint was a lack of strength along with frequent electric shocks at the elbow. Anesthesia was present in the area supplied by the ulnar nerve. There was persistent hypotrophy of the intrinsic thenar and hypothenar muscles. The dorsal and palmar interossei muscles were also deficient. Grip strength was only 10 kg on the Jamar dynamometer. Froment’s sign was positive, with exaggerated flexion of the thumb interphalangeal joint. Based on the HighetZachary classification [7], the patient had M0 motor ability in the intrinsic muscles and S0 sensation in the hypothenar area. The first electromyography (EMG) performed 3 months after the accident found trivial motor and sensor response amplitudes
(sensory conduction latency 3.45 ms, motor conduction speed 37.3 m/s). An EMG performed 9 months later showed the same results along with atrophy of the intrinsic muscles. Given the lack of clinical improvement and lack of potential for re-innervation of the intrinsic muscles based on the EMG findings, ultrasonography and MRI were performed to get a better view of the ulnar nerve groove. These two imaging modalities were suggestive of pseudocystic neuroma above the ulnar nerve groove. A new surgical procedure was undertaken 1 year after the initial injury. We identified a discontinuity in the ulnar nerve and a neuroma. The initial nerve defect was 5 cm; it was 8 cm long once the neuroma had been resected (Fig. 2). Since direct suture repair was impossible, the nerve was protected with a connective tissue membrane to prepare for nerve surgery. One and a half years after the initial injury, with the patient still at M0/S0, the AIN and PIN were transferred onto the DBUN and SBUN, respectively. 2.2. Surgical technique The procedure was performed under general anesthesia with a tourniquet cuff at the base of the arm. The first surgical phase was performed with loupes; the second phase of dissection and fascicle suturing was performed under a microscope. 2.2.1. Neurotisation of SBUN by the PIN Guyon’s canal was opened to expose the ulnar nerve. Using a microscope, distal to proximal dissection was performed to separate the sensory and motor fascicles. The dissection was
Fig. 1. Clinical appearance of elbow once the skin lesions had healed.
322
S. Delclaux et al. / Chirurgie de la main 33 (2014) 320–324 Table 1 Clinical recovery of intrinsic muscle function. Time after nerve transfer
3 months
6 months
18 months
Abduction/adduction distance of 5th finger
15 mm
24 mm
28 mm
Fig. 2. The ulnar nerve defect was 8 cm long.
carried out to 5 cm proximal to the distal wrist crease. A dorsal incision was centered over the distal radio-ulnar (DRU) joint and the PIN was dissected from distal to proximal. The PIN was 1 mm in diameter distally and up to 2 mm proximal to the DRU. The PIN was retrieved in front through the interosseous membrane. The sensory fascicles to 4th and 5th fingers were then sutured to the PIN fascicles. There were no discernible differences in the diameter of the nerve branches. 2.2.2. Neurotisation of DBUN by the AIN The AIN was found at the proximal edge of the pronator quadratus muscle and was dissected as distally as possible. The AIN was 1.5 mm in diameter, whereas the motor branch of the ulnar nerve was 2 mm in diameter. The motor fascicles of the ulnar nerve were then sutured to the motor fascicles of the AIN using a microscope. All of the nerve transfers were carried out using interrupted sutures with 10–0 Ethilon and fibrin glue. 2.2.3. Postoperative care and follow-up The patient’s arm was immobilized for 21 days. Intensive physical therapy was then initiated that included electrostimulation set out by the surgeon and adjusted as the intrinsic muscles gradually recovered. Nerve recovery was monitored clinically every month; EMG was carried out at 3 months, then every 6 months until the 18th month. The follow-up was terminated at 18 months when the patient moved to another area of the country.
Fig. 3. Abduction–adduction of the 5th finger, 1 year after the nerve transfer.
point, with protective sensation being present. EMG showed clear gradual re-innervation of the abductor digiti minimi (motor conduction speed 50 m/s); this was attributed to the nerve transfer because the ulnar nerve could not be excited at the elbow. Sensory response was still lacking, but there was clear increase in the current perception threshold of the 5th finger (120 V, standard < 80 V). The patient stated that he was extremely satisfied with the procedure. We were able to reach the patient by telephone three years after the surgery. He stated that he did not wish to continue the specialized follow-up. He continued to experience improved intrinsic hand function (abduction/adduction of the 5th finger, less hypotrophy in the hypothenar eminence area). He also said that recovery of sensation in the 4th and 5th digits was occurring slowly. The QuickDASH score, determined over the telephone, was 34 out of 100.
4. Discussion 3. Results The patient experienced gradual recovery of his intrinsic hand muscles (Table 1) on the clinical and EMG front. At the 6th month, the 5th finger could be abducted/adducted 24 mm. Sensation had recovered in the palm of the hand. Eighteen months after the double nerve transfer, the 5th finger could be abducted/adducted 28 mm (Fig. 3). Sensation was present at the base of the 5th finger. The patient was graded M3/S2 at that
Post-traumatic lesions of the ulnar nerve have serious consequences for hand function. The goal for these patients is to recover the function of the intrinsic muscles as quickly as possible. Use of the sensory branch as a donor graft became popular in the 1970s. But some studies eventually reported disappointing results [8,9]. Vastamaki et al. [9] found that good functional results were rare if more than 7 cm of nerve was damaged; they
S. Delclaux et al. / Chirurgie de la main 33 (2014) 320–324
also noted that extrinsic factors (age, nerve defect, time to surgery) negatively affected the success of these grafts. Chan et al. [10] compared the outcomes of nerve transfer to nerve grafting in a patient with ulnar nerve laceration at the wrist and a 2 cm defect. Six weeks after the injury, they performed a nerve graft with the sural nerve and simultaneously transferred the AIN to the DBUN. After 18 months, maximum motor axon regeneration was obtained after simulation of the median nerve at the elbow, which indicated that the AIN transfer was superior to ulnar nerve grafting. They concluded that nerve transfer appeared to be more effective than nerve grafting, making it a good treatment option. Two cadaver studies [2,3] revealed that the AIN and DBUN had the same number of axons and the same diameter, making it possible to suture the nerves together in a satisfactory way. Robert et al. [5] reported that these two nerves were no more than 10 mm apart once the fascicles had been individualized. The two nerves could be directly sutured together in the 15 cadaver arms that were dissected. The first clinical application of this technique was described in three patients in 1974, but no sensory nerve transfer was performed. Battiston and Lanzetta [1] stated that it was impossible to directly suture the AIN and DBUN together intraoperatively. They also found that the AIN penetrated the pronator quadratus at its proximal edge. But this was not found in a later cadaver study [5]. Several authors [1,6,11] have reported satisfactory results with restoration of the hand’s intrinsic function. Haase and Chung [11] favor this technique in cases of high ulnar nerve lesions. The distal median to ulnar nerve transfer technique has been well described [12]. Battiston and Lanzetta [1] and Flores [6] transferred different nerves onto the SBUN during the same surgical procedure to restore both sensation and motor activity. Battiston and Lanzetta used an end-to-end suture of the palmar cutaneous branch of the median nerve, while Flores used an end-to-side suture of the 3rd palmar common digital nerve. But using the palmar cutaneous branch of the median nerve can lead to dysesthesia in the thenar eminence area. Battiston and Lanzetta did not find any occurrences of neuroma or significant discomfort in their patients. Flores found no sensory deficit in the region corresponding to the 3rd palmar common digital nerve. Both studies used the Highet-Zachary classification [7] as modified by Mackinnon and Dellon [8] to evaluate their functional outcomes. After a follow-up of 30 months, Battiston and Lanzetta found 86% of M4 and S3 scores, which corresponded to good results. Flores [6] reported scores of M3/M4 and S3/S4 in his five patients, 7 months after the surgery. Based on these two aforementioned studies, we decided to treat our patient with double nerve transfer so as to allow motor recovery and protective sensation restoration in the hypothenar eminence area. We used the PIN dissected from the posterior side of the wrist. This nerve was then passed in front of the interosseous membrane and sutured end-to-end to the SBUN. The advantage of this technique is that there are no negative sensory consequences at the donor site. Eighteen months after the surgery, the sensory recovery was still slow, but the patient
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had regained some sensation at the base of the 5th finger (graded S2) and an objective increase in the current perception threshold on EMG. At that point, the intrinsic function of the hand had also gradually recovered. The abduction/adduction distance of the 5th finger increased from 15 mm at the 3rd month to 28 mm at the 18th month. The motor/sensory assessment, which was initially graded M0/S0, had reached M3/S2 18 months after the surgery. This study presents a retrospective assessment of a patient with 18 months of follow-up. One of the weaknesses of the current study is that only one patient was evaluated over a limited time period. Nevertheless, it confirms the good results of double nerve transfer that have already been described in other published studies. We have described a new nerve transfer technique for the SBUN using end-to-end suture of the PIN, without sequelae for the donor site. 5. Conclusion The double transfer of the PIN and AIN nerves onto the SBUN and DBUN led to functional recovery within the first year after the surgical procedure. The motor nerve transfer technique has been well described. But this is the first published description of the PIN being transferred (end-to-end suture) to restore sensory function. This is a reliable option without sequelae for the donor site. We found no significant differences in the diameter of the PIN and SBUN. A more detailed cadaver study could reinforce this finding. Disclosure of interest The authors declare that they have no conflicts of interest concerning this article. References [1] Battiston B, Lanzetta M. Reconstruction of high ulnar nerve lesions by distal double median to ulnar nerve transfer. J Hand Surg Am 1999;24:1185–91. [2] Ustün ME, Og˘ün TC, Büyükmumcu M, Salbacak A. Selective restoration of motor function in the ulnar nerve by transfer of the anterior interosseous nerve. An anatomical feasibility study. J Bone Joint Surg Am 2001;83:549–52. [3] Wang Y, Zhu S, Zhang B. Anatomical study and clinical application of transfer of pronator quadratus branch of anterior interosseous nerve in the repair of thenar branch of median nerve and deep branch of ulnar nerve. Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi 1997;11:335–7. [4] Wang Y, Zhu S. Transfer of a branch of the anterior interosseous nerve to the motor branch of the median nerve and ulnar nerve. Chin Med J (Engl) 1997;110:216–9. [5] Robert M, Blanc C, Gasnier P, Le Nen D, Hu W. Neurotisation of the deep branch of ulnar nerve with anterior interosseous nerve: anatomic study. Chir Main 2011;30:406–9. [6] Flores LP. Distal anterior interosseous nerve transfer to the deep ulnar nerve and end-to-side suture of the superficial ulnar nerve to the third palmar common digital nerve for treatment of high ulnar nerve injuries: experience in five cases. Arq Neuropsiquiatr 2011;69:519–24. [7] Zachary RB, Holmes W. Primary suture of nerves. Surg Gynecol Obstet 1946;82:632–51. [8] Mackinnon SE, Dellon AL. Surgery of the peripheral nerve. New York: Thieme; 1988: 119.
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[9] Vastamäki M, Kallio PK, Solonen KA. The results of secondary microsurgical repair of ulnar nerve injury. J Hand Surg Br 1993;18: 323–6. [10] Chan KM, Olson JL, Morhart M, Lin T, Guilfoyle R. Outcomes of nerve transfer versus nerve graft in ulnar nerve laceration. Can J Neurol Sci 2012;39:242–4.
[11] Haase SC, Chung KC. Anterior interosseous nerve transfer to the motor branch of the ulnar nerve for high ulnar nerve injuries. Ann Plast Surg 2002;49:285–90. [12] Brown JM, Yee A, Mackinnon SE. Distal median to ulnar nerve transfers to restore ulnar motor and sensory function within the hand: technical nuances. Neurosurgery 2009;65:966–77.
