- Email: [email protected]
Flexor tendon mechanics after carpal tunnel release
12
Discussion This study confirms that the endoscopic carpal tunnel release is as effective as conventional open surgery with the advantage of earlier return to work and less pain in the CT.
THE J O U R N A L OF H A N D SURGERY VOL. 21B S U P P L E M E N T 1
The electromyogram always confirmed decompression except for the two unsuccessful cases. Minor complications were always transient, disappearing within 3 to 6 months and included superficial cellulitis, oedema, paresthesia in the ulnar digital nerve and hypothenar tenderness.
Preliminary review of 100 carpal tunnel releases by the mini-invasive technique
Flexor tendon mechanics after carpal tunnel release
G. De Fiori, R. Ajmar, D. Tunesi, P. Di Giuseppe
R. K. Brown, C. A. Peimer, J. O. M o y
Divisione di Chirurgia Plastica e Centro di Ch. della Mano, Osp G. Fornaroli, Magenta, Italy
Hand Center of Western NY, State University of N Y at Buffalo, Department of Orthopaedics, Buffalo, USA
In December 1993 we performed the first carpal tunnel release by the mini-invasive technique for carpal tunnel syndrome in the initial stage. After 100 hands treated with this method we carried out a retrospective study to determine its real validity. The mini-invasive technique summarizes advantages of the open and of the endoscopic release of carpal tunnel, allowing us to perform an external neurolysis with direct vision through a 2.5 cm palmar incision. In our experience, the technique is simple and safe. In the first 100 cases we observed very few complications, and two cases needed reoperation because of adherences to the divided transverse carpal ligament. We need a longer follow-up to assess the recurrence rate; anyway patients treated by the mini-invasive method gained early recovery of function and return to work, similar to those achieved with the endoscopic treatment.
Introduction Successful outcome after CTR results from adequate nerve decompression; but long-term clinical relief and functional recovery are variable, especially for repetitive manual workers. Digital flexor tendon bowstringing is known to increase after CTR; this may actually cause short- and long-term difficulties. There is also measurable palmar displacement of the median nerve after CTR reported by MRI, but less after endoscopic than open methods. Are there important differences of tendon mechanics between these techniques that we don't know about? We used a published cadaver model to answer questions where no published data are available.
Treatment of recalcitrant carpal tunnel syndrome with the hypothenar fat flap Ch. Mathoulin, J. B a h m
Institut de la Main, Paris, France Persistent paresthesiae with recurring symptoms are rare but incapacitating sequelae of carpal tunnel decompression and are usually due to adhesions of the nerve to the inner surface of the scar of the transected ligament, often after a lateral incision. The authors report the results of a hypothenar fat flap mobilized from the hypothenar eminence and vascularized from the branches of the ulnar artery. This technique was preferred to an ulnar dorsal flap, to the placement of a silastic sheath or to a synovial flap, due to its simplicity. An anatomical study of 15 cadavers showed the presence of constant collateral branches of the ulnar artery vascularizing the anterior hypothenar fat. Between 1991 and 1994, 29 patients were treated with this technique. Patients with incomplete division of the carpal ligament were excluded from this study. There were five men and 24 women. The average age was 53 years (34-82 years). All patients had undergone previous surgery once except four patients who had undergone two interventions. Paresthesiae were present in 89% of the cases. Tinel's sign was present in all cases. Electromyogram showed preoperative neural lesions in all cases. The average follow-up was 26 months (13-43 months). Four patients had excellent results with complete recovery of grip strength and disappearance of all pain symptoms. 23 had good results with a disappearance of pain symptoms and satisfactory recovery of grip strength and two patients had a bad result with persistent paresthesia.
Methods Digital flexor tendon excursion was measured in five freshthawed cadavers: 1. 2. 3. 4. 5.
with an intact transverse carpal ligament after single-portal endo-CTR after two-portal endo-CTR after conversion to open CTR after suturing the open palm incision.
Each forearm was transected 7 cm proximal to the radial styloid, and joints distal to the carpus were immobilized with K-wires. Specimens were mounted firmly in the vertical position with tendon pull directed in the forearm axis. Sutures were woven into each FDS, FDP and the FPL tendon and connected proximally to 900 g weights by pulleys so that markers on the sutures moved against a fixed calibrated background. Excursion of each tendon was recorded and digitized, from 70° wrist flexion to 70° extension, set in t0 ° increments, and repeated six times in each wrist for each experimental condition. Data were analysed by ANOVA with Fisher's PLSD for pairwise comparisons.
Results Combined flexor tendon bowstringing increased 30.4% after single-portal endo-CTR and 33.0% after two-portal endoCTR (P<0.001 for each compared to intact), and was 45.9% greater after open CTR (P<0.001); notably, wound closure had no effect. This bowstringing was significantly greater than after either endo-CTR (P<0.004). From neutral to 70° wrist flexion, digital tendon bowstringing increased 49.4% and 62.2% after one- and two-portal endo-CTR, respectively (P<0.001 compared to control). Bowstringing increased 82.3% after open CTR (P<0.001); and this also was significantly more bowstringing than after either endo-CTR (P<0.02). Conclusions Digital flexor bowstringing at the carpal canal is greater after endo-CTR than that in intact wrists, but less than that after
SESSION4 open CTR. This is true in both a 0° to 70° flexion range and for the full 140° flexion-extension arc. Less consumption of flexor tendon excursion with wrist motion means better mechanical efficiency after endo-CTR compared with open release. This difference has important implications on functional outcome after CTR, and especially for those tasks performed with the wrist in flexion - in the home and at work - where tendon mechanics are dramatically worse.
Treatment of sequelae after lesions to the sensory branch of the radial nerve A. L l u c h
Institut Kaplan, Paseo Bonanova, 9. 08022 Barcelona, Spain Purpose Lesions to the sensory branch of the radial nerve (SBRN) can lead to painful neuroma, with areas of anesthesia and of skin dysesthesia. The purpose of this study is to review their clinical manifestations and propose a new method for the treatment of dysesthesia.
13
Discussion Treating the dysesthesia can be quite frustrating as it may persist despite performing a variety o f surgical procedures over the stump of the divided nerve. Symptoms may persist even in those cases where the SBRN has been completely removed to its origin at the level o f the brachioradialis muscle. The reason for failure may be that the noxious impulses are transmitted via the deep fiber~ of the intact posterior interosseous nerve (PIN). Dysesthesia appears only after isolated SBRN injuries, and not after injuries to the radial nerve proximal to the elbow level, where the fibers of the PIN are also transected. Excision of a 2 cm segment of the distal PIN was successful in treating the dysesthesia in the majority of cases. Proximal and deep relocation of the painful neuroma proved to be the easiest and most effective procedure, although we should warn about two possible causes for failure. The neuroma has a tendency to be squeezed out from under the muscle and slip back into its original place. This can be avoided by anchoring the neuroma with suture into the recipient bed. The other cause of failure is not to identify more than one neuroma in the same patient. A careful preoperative search for more than one neuroma should be done, especially in the most distal lesions.
Materials and methods There were 76 patients complaining of dysesthesia in the dorso-lateral aspect of the hand. Painful amputation neuroma were also present in 60 of the patients. There were 62 women and 14 men, ranging from 17 to 72 years old, with an average age of 41. In 32 cases the lesion occurred after trauma. In the remaining 44 it occurred as a complication of surgical procedures. The time lapse from injury until the operative treatment ranged from 2 months to 9 years, with an average of 22 months.
Surgicalprocedure Through a short transverse incision, the posterior interosseous nerve (PIN) above the interosseous membrane was divided just proximal to the extensor retinaculum. When a neuroma was present it was identified and relocated proximally under the extensor musculature, without tension in a soft bed, where it will be protected from external impacts.
Results The dysesthesia was completely relieved in all but five patients, who experienced partial relief. Pain secondary to an amputation neuroma persisted in 6 of the 60 cases. Five o f them underwent another operative procedure: to relocate the neuroma in one case and to displace an additional neuroma not seen at the first procedure in four cases. One patient refused additional treatment since he felt sufficiently relieved from the symptoms. The area of anesthesia is not a matter of concern to the patient, since it is located in a non-working surface of the hand, and it tends to diminish with time by the overlapping of neighboring nerves.
The dorsal branch of the ulnar nerve: an anatomic study with surgical application M. A. Janssen, G. J. K l e i n r e n s i n k , S. E. R. H o v i u s
Department of Plastic and Reconstructive Surgery, University Hospital Rotterdam, Dijkzigt, Department of Anatomy, Erasmus UniversityRotterdam, The Netherlands The transverse radioulnar branch of the dorsal branch of the ulnar nerve is not accurately described in various textbooks. This anatomical study concerning 15 cadaver dissections confirms the existence of nerve tissue passing through a foramen in the extensor retinaculum. Owing to its course in the wrist region this nerve branch is at risk during operative procedures in this area; in open procedures, as well as in wrist arthroscopy. In wrist arthroscopy this site is known as the R6 portal. This portal is rarely used because of iatrogenic injury risk of the dorsal branch of the ulnar nerve. Another observation was the existence of a foramen in the extensor retinaculum. The particular small branch o f the dorsal nerve pierced this foramen. We were unable to find this foramen in the anatomical textbooks. Considering the course of this branch through the extensor retinaculum toward the ulnocarpal complex it could play a role in the transport of proprioceptive information from this complex. Another aspect of this branch could be its role in chronic wrist pain. As such, it should be mentioned in selective denervation procedures like Wilhelm's technique for denervation.
Discussion This study confirms that the endoscopic carpal tunnel release is as effective as conventional open surgery with the advantage of earlier return to work and less pain in the CT.
THE J O U R N A L OF H A N D SURGERY VOL. 21B S U P P L E M E N T 1
The electromyogram always confirmed decompression except for the two unsuccessful cases. Minor complications were always transient, disappearing within 3 to 6 months and included superficial cellulitis, oedema, paresthesia in the ulnar digital nerve and hypothenar tenderness.
Preliminary review of 100 carpal tunnel releases by the mini-invasive technique
Flexor tendon mechanics after carpal tunnel release
G. De Fiori, R. Ajmar, D. Tunesi, P. Di Giuseppe
R. K. Brown, C. A. Peimer, J. O. M o y
Divisione di Chirurgia Plastica e Centro di Ch. della Mano, Osp G. Fornaroli, Magenta, Italy
Hand Center of Western NY, State University of N Y at Buffalo, Department of Orthopaedics, Buffalo, USA
In December 1993 we performed the first carpal tunnel release by the mini-invasive technique for carpal tunnel syndrome in the initial stage. After 100 hands treated with this method we carried out a retrospective study to determine its real validity. The mini-invasive technique summarizes advantages of the open and of the endoscopic release of carpal tunnel, allowing us to perform an external neurolysis with direct vision through a 2.5 cm palmar incision. In our experience, the technique is simple and safe. In the first 100 cases we observed very few complications, and two cases needed reoperation because of adherences to the divided transverse carpal ligament. We need a longer follow-up to assess the recurrence rate; anyway patients treated by the mini-invasive method gained early recovery of function and return to work, similar to those achieved with the endoscopic treatment.
Introduction Successful outcome after CTR results from adequate nerve decompression; but long-term clinical relief and functional recovery are variable, especially for repetitive manual workers. Digital flexor tendon bowstringing is known to increase after CTR; this may actually cause short- and long-term difficulties. There is also measurable palmar displacement of the median nerve after CTR reported by MRI, but less after endoscopic than open methods. Are there important differences of tendon mechanics between these techniques that we don't know about? We used a published cadaver model to answer questions where no published data are available.
Treatment of recalcitrant carpal tunnel syndrome with the hypothenar fat flap Ch. Mathoulin, J. B a h m
Institut de la Main, Paris, France Persistent paresthesiae with recurring symptoms are rare but incapacitating sequelae of carpal tunnel decompression and are usually due to adhesions of the nerve to the inner surface of the scar of the transected ligament, often after a lateral incision. The authors report the results of a hypothenar fat flap mobilized from the hypothenar eminence and vascularized from the branches of the ulnar artery. This technique was preferred to an ulnar dorsal flap, to the placement of a silastic sheath or to a synovial flap, due to its simplicity. An anatomical study of 15 cadavers showed the presence of constant collateral branches of the ulnar artery vascularizing the anterior hypothenar fat. Between 1991 and 1994, 29 patients were treated with this technique. Patients with incomplete division of the carpal ligament were excluded from this study. There were five men and 24 women. The average age was 53 years (34-82 years). All patients had undergone previous surgery once except four patients who had undergone two interventions. Paresthesiae were present in 89% of the cases. Tinel's sign was present in all cases. Electromyogram showed preoperative neural lesions in all cases. The average follow-up was 26 months (13-43 months). Four patients had excellent results with complete recovery of grip strength and disappearance of all pain symptoms. 23 had good results with a disappearance of pain symptoms and satisfactory recovery of grip strength and two patients had a bad result with persistent paresthesia.
Methods Digital flexor tendon excursion was measured in five freshthawed cadavers: 1. 2. 3. 4. 5.
with an intact transverse carpal ligament after single-portal endo-CTR after two-portal endo-CTR after conversion to open CTR after suturing the open palm incision.
Each forearm was transected 7 cm proximal to the radial styloid, and joints distal to the carpus were immobilized with K-wires. Specimens were mounted firmly in the vertical position with tendon pull directed in the forearm axis. Sutures were woven into each FDS, FDP and the FPL tendon and connected proximally to 900 g weights by pulleys so that markers on the sutures moved against a fixed calibrated background. Excursion of each tendon was recorded and digitized, from 70° wrist flexion to 70° extension, set in t0 ° increments, and repeated six times in each wrist for each experimental condition. Data were analysed by ANOVA with Fisher's PLSD for pairwise comparisons.
Results Combined flexor tendon bowstringing increased 30.4% after single-portal endo-CTR and 33.0% after two-portal endoCTR (P<0.001 for each compared to intact), and was 45.9% greater after open CTR (P<0.001); notably, wound closure had no effect. This bowstringing was significantly greater than after either endo-CTR (P<0.004). From neutral to 70° wrist flexion, digital tendon bowstringing increased 49.4% and 62.2% after one- and two-portal endo-CTR, respectively (P<0.001 compared to control). Bowstringing increased 82.3% after open CTR (P<0.001); and this also was significantly more bowstringing than after either endo-CTR (P<0.02). Conclusions Digital flexor bowstringing at the carpal canal is greater after endo-CTR than that in intact wrists, but less than that after
SESSION4 open CTR. This is true in both a 0° to 70° flexion range and for the full 140° flexion-extension arc. Less consumption of flexor tendon excursion with wrist motion means better mechanical efficiency after endo-CTR compared with open release. This difference has important implications on functional outcome after CTR, and especially for those tasks performed with the wrist in flexion - in the home and at work - where tendon mechanics are dramatically worse.
Treatment of sequelae after lesions to the sensory branch of the radial nerve A. L l u c h
Institut Kaplan, Paseo Bonanova, 9. 08022 Barcelona, Spain Purpose Lesions to the sensory branch of the radial nerve (SBRN) can lead to painful neuroma, with areas of anesthesia and of skin dysesthesia. The purpose of this study is to review their clinical manifestations and propose a new method for the treatment of dysesthesia.
13
Discussion Treating the dysesthesia can be quite frustrating as it may persist despite performing a variety o f surgical procedures over the stump of the divided nerve. Symptoms may persist even in those cases where the SBRN has been completely removed to its origin at the level o f the brachioradialis muscle. The reason for failure may be that the noxious impulses are transmitted via the deep fiber~ of the intact posterior interosseous nerve (PIN). Dysesthesia appears only after isolated SBRN injuries, and not after injuries to the radial nerve proximal to the elbow level, where the fibers of the PIN are also transected. Excision of a 2 cm segment of the distal PIN was successful in treating the dysesthesia in the majority of cases. Proximal and deep relocation of the painful neuroma proved to be the easiest and most effective procedure, although we should warn about two possible causes for failure. The neuroma has a tendency to be squeezed out from under the muscle and slip back into its original place. This can be avoided by anchoring the neuroma with suture into the recipient bed. The other cause of failure is not to identify more than one neuroma in the same patient. A careful preoperative search for more than one neuroma should be done, especially in the most distal lesions.
Materials and methods There were 76 patients complaining of dysesthesia in the dorso-lateral aspect of the hand. Painful amputation neuroma were also present in 60 of the patients. There were 62 women and 14 men, ranging from 17 to 72 years old, with an average age of 41. In 32 cases the lesion occurred after trauma. In the remaining 44 it occurred as a complication of surgical procedures. The time lapse from injury until the operative treatment ranged from 2 months to 9 years, with an average of 22 months.
Surgicalprocedure Through a short transverse incision, the posterior interosseous nerve (PIN) above the interosseous membrane was divided just proximal to the extensor retinaculum. When a neuroma was present it was identified and relocated proximally under the extensor musculature, without tension in a soft bed, where it will be protected from external impacts.
Results The dysesthesia was completely relieved in all but five patients, who experienced partial relief. Pain secondary to an amputation neuroma persisted in 6 of the 60 cases. Five o f them underwent another operative procedure: to relocate the neuroma in one case and to displace an additional neuroma not seen at the first procedure in four cases. One patient refused additional treatment since he felt sufficiently relieved from the symptoms. The area of anesthesia is not a matter of concern to the patient, since it is located in a non-working surface of the hand, and it tends to diminish with time by the overlapping of neighboring nerves.
The dorsal branch of the ulnar nerve: an anatomic study with surgical application M. A. Janssen, G. J. K l e i n r e n s i n k , S. E. R. H o v i u s
Department of Plastic and Reconstructive Surgery, University Hospital Rotterdam, Dijkzigt, Department of Anatomy, Erasmus UniversityRotterdam, The Netherlands The transverse radioulnar branch of the dorsal branch of the ulnar nerve is not accurately described in various textbooks. This anatomical study concerning 15 cadaver dissections confirms the existence of nerve tissue passing through a foramen in the extensor retinaculum. Owing to its course in the wrist region this nerve branch is at risk during operative procedures in this area; in open procedures, as well as in wrist arthroscopy. In wrist arthroscopy this site is known as the R6 portal. This portal is rarely used because of iatrogenic injury risk of the dorsal branch of the ulnar nerve. Another observation was the existence of a foramen in the extensor retinaculum. The particular small branch o f the dorsal nerve pierced this foramen. We were unable to find this foramen in the anatomical textbooks. Considering the course of this branch through the extensor retinaculum toward the ulnocarpal complex it could play a role in the transport of proprioceptive information from this complex. Another aspect of this branch could be its role in chronic wrist pain. As such, it should be mentioned in selective denervation procedures like Wilhelm's technique for denervation.