An Original Study A Reliable and Simple Solution for Recalcitrant Carpal Tunnel Syndrome: echniques The Hypothenar Fat Pad Flap T Cesare Fusetti, MD, Guido Garavaglia, MD, Christophe Mathoulin, MD, & John Gianfranco Petri, MD, and Stefano Lucchina, MD Abstract estimated. Persistent symptoms are usually attributed The incidence of failure in open carpal canal tun- to an inadequate distal ligament release or a severe, nel decompression is underestimated. Recurrence chronic, irreversible nerve compression. Recurrent is often the result of scarring of the median nerve. symptoms often result from scarring of the median echnologies Conservative treatment or careful neurolysis is usu- nerve, which is fixed to the radial leaf of the divided T ally insufficient. transverse carpal ligament. These adhesions interfere The hypothenar fat pad flap interposes adipose tis- sue from the hypothenar eminence and could offer a with the physiologic gliding of the median nerve dur- solution for patients with recalcitrant carpal tunnel syn- ing wrist motion. Simple neurolysis is insufficient to drome. We reviewed the results of using this procedure prevent new scar formation or relieve hyperesthesia in 20 patients with recalcitrant carpal tunnel syndrome and analyzed subjective and objective results, compli- rthopedic cations, and pitfalls. For 18 patients, pain disappeared “The surgical incision for O completely. Two-point discrimination improved from an expanded range to normal in 16 of the 20 patients. HTFPF should be more Quick DASH (Disabilities of the Arm, Shoulder, and Hand) scores improved significantly. ulnarly placed to harvest The hypothenar fat pad flap, a technically simple procedure, prevents median nerve readher- ence, produces excellent results, and should be the flap more easily... ” included among the tools any surgeon uses for carpal tunnel surgery. and allodynia. Various procedures have been described for recalcitrant CTS (RCTS), but many are technically demanding and may require the sacrifice of normal tis- arpal tunnel syndrome (CTS), the most sue and muscles. common entrapment neuropathy, afflicts up The hypothenar fat pad flap (HTFPF) procedure to 10% of the general population. Many car- was initially described by Cramer.1 This pedicled fat Cpal tunnel releases are performed annually, pad flap is locally available, its mobilization is safe, and the procedure is regarded as simple and fast, with its results reliable, and its postoperative complications the risk that its potential complications may be under- rare. In this article, we describe the technique and pre- Dr. Fusetti is Consultant, Hand Surgery Unit, Department of Orthopaedics and Traumatology, and Dr. Garavaglia is Chief, Department of Orthopaedics and Traumatology, Ospedale San Giovanni, Bellinzona, Switzerland. Dr. Mathoulin is Professor and Consultant, Clinique Jouvenet, Hand Surgery Unit, Institut de la Main, Paris, France. Dr. Petri is Chief, Department of Orthopaedics and Traumatology, and Dr. Lucchina is Consultant, Hand Surgery Unit, Ospedale San Giovanni, Bellinzona, Switzerland. Address correspondence to: Cesare Fusetti, MD, FMH-EBHS, Hand Surgery Unit, FMH-EBHS, Department of Orthopaedics and Traumatology, Ospedale San Giovanni, CH-6500, Bellinzona, Switzerland (tel, 41-91-811-8082; fax, 41-91-811-8083; e-mail, [email protected]). Am J Orthop. 2009;38(4):181-186. Copyright, Quadrant HealthCom Figure 1. Median nerve (arrows) is adherent to radial leaf of Inc. 2009. All rights reserved. divided transverse ligament. April 2009 181 A Reliable and Simple Solution for Recalcitrant Carpal Tunnel Syndrome Figure 2. Deep branch of ulnar artery, running along deep Figure 3. Cadaver dissection shows transverse arterial motor branch of ulnar nerve, is dissected and ligated branches to fat pad arising from medial side of ulnar artery. (Mathoulin’s artifice). Copyright 2009, Mathoulin, Dorn. Flap is pedicled on superficial branches of ulnar artery after section of deep branch of ulnar artery. sent our results in the form of a case series involving 20 consecutive patients with RCTS. and Hand) questionnaire was used to evaluate disabil- ity and to monitor changes in symptoms and function MATERIALS AND METHODS over time. The optional High-Performance Sport/ Between June 2004 and June 2006, 20 patients with Music or Work modules were not used. RCTS were managed with HTFPF and followed at our Mean preoperative Quick DASH score was 75.8 institution for at least 12 months (mean, 13 months; (median, 79.5; range, 68.2-88.6). Significant palmar range, 12-24 months). There were 12 women and 8 hypersensitivity or allodynia was present in all 20 men. Mean age was 56 years (range, 38-85 years). patients; nocturnal tingling and/or pain was present in 18 All procedures were performed by Dr. Fusetti. Four patients. All patients felt that their condition had wors- of the 20 patients had previously undergone open ened after the first operation. carpal tunnel decompression by the same surgeon; the On clinical examination, 12 of the 16 referred other 16 patients were referred to our institution after patients presented an incision scar placed too radi- previous open carpal tunnel surgery (mean time since ally along the axis of the third metacarpal. In 8 last failed operation, 17 months; range, 6-42 months). patients, the incision was along the axis of the fourth Nine patients were in a worker’s compensation group; metacarpal. All patients had marked irritation signs 4 of these 9 patients lost their jobs because of pro- (Tinel, Phalen, and Durkan signs). The 2-point Weber longed absence from work. Patients with RCTS after discrimination test averaged 9 mm (range, 5-14 mm). endoscopic decompression or after internal fixation of In 3 patients, there was complete numbness. Thenar a distal radius fracture were excluded. muscle atrophy was present in 7 patients. Mean grip All patients met the inclusion criteria for RCTS strength with the Jamar dynamometer test was 27 kg (Table). For all patients, conservative treatment (range, 8-42 kg). by an experienced hand therapist over at least 6 All patients underwent preoperative nerve con- months (range, 6-17 months) had failed, and 2 duction studies. After the first operation, 17 patients patients needed psychological support. Six patients had their conduction parameters worsen, 1 had experienced probatory unsuccessful infiltration of unchanged parameters, and 2 had normal parameters. the carpal tunnel. Two patients had 1 failed case Seven patients had abolished conduction parameters. and another patient had 2 failed cases of neurolysis Denervation signs of the thenar muscles were present without flap interposition. in 3 patients. Subjective complaints were evaluated. The short- Informed preoperative written consent for the surgi- ened Quick DASH (Disabilities of the Arm, Shoulder, cal procedure was obtained from each patient. Table. Inclusion Criteria for Recalcitrant Carpal Tunnel Syndromea 1. Persistent or recurrent carpal tunnel syndrome after adequate open surgical decompression. 2. Failure of conservative treatment. 3. No other major wrist surgery. 4. Preoperative median nerve hypersensitivity at wrist without clinical evidence of damage to the palmar cutaneous branch of median nerve or intraoperative findings of median nerve adherence to the transverse carpal ligament. aAdapted from Strickland et al.25 182 The American Journal of Orthopedics® C. Fusetti et al H preop 3 months 6 months Figure 4. Flap can be advanced over median nerve (black Figure 5. Subjective complaints (preoperative, 3 months, 6 arrow) and placed palmar to nerve and dorsal to radial leaf months). (white arrow) of transverse ligament. Note ulnar neurovascular bundle (white star). with a desensitization program begins after removal Surgical Technique of the stitches. Nocturnal wrist splinting is continued With general anesthesia, loupe magnification, and for 2 additional weeks; heavy lifting and sport are not pneumatic tourniquet, a linear incision is made 0.5 cm allowed for 8 weeks. from the previous scar on its ulnar side, in line with the ulnar border of the third digit. The incision is then RESULTS curved at the wrist crease and continued along the Our study results appear in Figures 5 and 6. In 16 flexor carpi ulnaris tendon. The remnants of the trans- patients, the median nerve adhered to the radial leaf verse carpal ligament are opened on its ulnar side, and of the divided transverse carpal ligament (Figure 1); in the median nerve is identified (Figure 1). A cleavage the other 4 patients, the scar did not allow the surgeon plane is developed by sharp dissection starting from an to identify an evident cleavage plane between the epi- unscarred region. Epineurolysis of the median nerve is neural surface and the remnants of the transverse car- performed only when the scar does not allow identifi- pal ligament. One patient had an associated neuroma of cation of an evident dissection plane. the palmar branch of the median nerve, with no clinical Initial subdermal dissection of the hypothenar fat is preoperative evidence. The neuroma was excised in continued as far as the insertion of the palmaris brevis association with HTFPF. Ligature of the deep branch muscle with identification of the ulnar neurovascular of the ulnar artery was necessary in 4 patients. bundle. The ulnar pedicle need not be dissected unless Subjective complaints and objective data were the flap cannot be mobilized over the median nerve. recorded by all 20 patients for follow-up evaluations Distally, care is taken not to injure the digital nerves 3, 6, and 12 months after surgery. Quick DASH to the ring and small fingers while the undermining scores were obtained at 3 and 12 months. Two continues medially to the midpalm. Deep mobilization patients were also evaluated 24 months after HTFPF, of the flap is possible after excision of a segment of during decompression of the contralateral symptom- the ulnar leaf of the transverse carpal ligament. The atic carpal tunnel. flap is then elevated until the ulnar nerve and artery are visualized. At this point, flap mobility is tested to determine if the flap can be advanced easily over the median nerve.