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The Abductor Pollicis Longus Tendon as an Alternative Graft in Hand Surgery
SURGICAL TECHNIQUE
The Abductor Pollicis Longus Tendon as an Alternative Graft in Hand Surgery Samuel Rosas, MD,*† Carolina Mesa, MD,† Felipe Mesa, MD†
Initial treatment of damaged tendons after soft tissue trauma of the hand can be performed with primary tendon reconstruction or with tendon grafts if indicated. The most frequently used tendons are from the palmaris longus and plantaris muscles. Nonetheless, these muscles may not be present or their anatomic characteristics might not suitable for reconstructive procedures. Here, we present an alternative surgical technique for tendon reconstruction of the hand using abductor pollicis longus accessory tendons as grafts. The abductor pollicis longus can be considered an excellent choice of graft for tendon reconstruction of the hand because of its multiple bellies, ease of extraction, and limited donor site morbidity and the frequent absence of the palmaris longus tendon. (J Hand Surg Am. 2016;-(-):-e-. Copyright Ó 2016 by the American Society for Surgery of the Hand. All rights reserved.) Key words Abductor pollicis longus, graft, hand.
L
ESIONS TO TENDONS OF THE HAND resulting from hand or wrist trauma can cause great morbidity and disability on a personal as well as professional level.1e3 Most injuries involve flexor and/or extensor tendons and often additional structures near the site of trauma.1e4 Early reconstruction of these injuries, especially flexor tendons, are essential because of potential disabilities as a consequence of delayed treatment. However, the possibility of some loss of function must always be taken into consideration.1,2 Reconstruction may be performed with a primary reconstructive technique by suturing both ends of the damaged tendon5 or with a secondary reconstruction, either with a tendon graft when the muscle is functional or with a tendon transfer when the myotendinous unit does not work.5e7
From the *Department of Orthopedic Surgery, University of Miami, Miami, FL; and †Universidad CES, Antioquia, Colombia. Received for publication August 1, 2016; accepted in revised form December 10, 2016. No benefits in any form have been received or will be received related directly or indirectly to the subject of this article. Corresponding author: Samuel Rosas, MD, Department of Orthopedic Surgery, Wake Forest School of Medicine, 1 Medical Center Boulevard, Winston-Salem, NC 27157; e-mail: [email protected]. 0363-5023/16/---0001$36.00/0 http://dx.doi.org/10.1016/j.jhsa.2016.12.006
The most commonly used graft tendon is the palmaris longus (PL), which is considered the ideal donor tendon in most cases, followed by the plantaris as a second choice.7e10 Other described are use of the long extensors of the toes, the flexor digitorum superficialis, the extensor indicis proprius, and the tensor fascia latae as alternatives.6,7 These described surgical methods have returned good to optimal results, but complications can occur, such as donor site morbidity in the form of limited range of motion and/or pain, and may range from minimal to severe.5e8 Although the tendon graft of the PL is most frequently used for these reconstructions, this tendon may be absent unilaterally or bilaterally, or it may not meet the criteria of length or width to be considered an adequate graft.9e12 INDICATIONS Tendon reconstruction with the abductor pollicis longus (APL) is indicated primarily in patients with acute or chronic tendon injuries who are not amenable to primary repair or have failed it. Various tendon repair surgeries such as multiple or single, flexor or extensor reconstruction, and pulley restoration can be achieved successfully. Patients with absence of the PL
Ó 2016 ASSH
r
Published by Elsevier, Inc. All rights reserved.
r
e1
e2
APL AS ALTERNATIVE GRAFT IN HAND SURGERY
are ideal surgical candidates, because the technique described here allows for tendon grafting within or near the same surgical site as the injury, which eliminates the need to prepare and drape a second surgical site, and thus increases efficiency and diminishes surgical time. CONTRAINDICATIONS Caution must be taken in patients who were previously operated on at the donor site, because the muscle bellies of the APL might have been injured or excised. Patients with multiple injections at the site should be carefully examined when extracting the graft, because the tendons also may have been weakened or debilitated for this reason. ANATOMY The APL is composed of superficial and deep heads, or muscle bellies, each of which ends in one or more tendons.13,14 The APL is radial to the extensor pollicis brevis in the first dorsal compartment. Cadaver studies demonstrated that the presence of the APL ranges from 85% to 92%.13,15 The origin of the APL, which is not of great importance for the technique described in this article, is located on the dorsal aspect of the radius, the interosseous membrane, and the ulnar bone.15 The insertion of this muscle, which is the main focus here, has been studied in many cadaver specimens because there appear to be important differences in its anatomy.13,16e19 To summarize the findings of previously cited studies, the distal course of the APL can be defined as within the first dorsal compartment with various distal insertions of accessory tendons, such as to the trapezium, abductor pollicis brevis, opponens pollicis, and thenar muscles,13,17 in addition to the principal insertion to the volar base of the thumb metacarpal. Surgeons must consider the numerous sensory branches of the radial nerve near the site of the APL insertion. We recommend identification and careful dissection to minimize postoperative complications such as pain.
remembering that the APL courses radial to the extensor pollicis brevis at this site.13 Because there are multiple tendon bellies in most patients, we favor not excising the tendon that inserts on the first metacarpal because it conveys most of the thumb abduction properties of this muscle. All of the tendons are evaluated by traction, analyzing, and selecting the tendon that imparts least function on the carpometacarpal joint (Figs. 1, 2). The selected tendon is dissected up to its insertion site at the trapezium bone, the abductor pollicis brevis fascia, or other insertion sites in the thenar area. From there, the tendon is dissected proximally up to the myotendinous unit; here the tendon is cut and extracted through a small incision on the skin. In our experience, the average length of the APL graft is 140 mm.
SURGICAL TECHNIQUE After the patient is properly evaluated initially, the reconstructive technique is planned. The surgeon performs a transverse incision on the distal radial side of the carpus, distal to the first dorsal compartment of the extensor tendons. The branches of the superficial sensory radial nerve are dissected out. Then, the APL tendon is dissected proximally up to the bellies,
COMPLICATIONS Complications from APL tenotomy can arise from various structures. In theory, dissection of the tendons can injure branches of the superficial sensory radial nerve and cause postoperative pain. This can be avoided by careful nerve branch dissection. Because of the multiple tendinous insertions of the APL, loss of function to the thumb is a possible complication
J Hand Surg Am.
FIGURE 1: Dissection of the first dorsal compartment through a distal incision. The extensor pollicis brevis tendon is thinner and dorsoulnar to the APL tendon.
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APL AS ALTERNATIVE GRAFT IN HAND SURGERY
Average age was 48.5 6.4 years (range, 36e64 years); most patients were men (73.5%). Different kinds of tendon reconstruction were performed among the 34 patients: flexor reconstruction was performed in 10, extensor reconstruction in 13, multiple tendon reconstruction in 4 (flexors in 2 patients and extensors in another 2), and pulley reconstruction in 7. We assessed functionality through the modified Medical Research Council (mMRC) scale according to Paternostro-Sluga et al.20 Functional range of motion (ROM) was considered to be good or excellent when values of the mMRC were greater than 4, fair when values ranged from 2 to 3 and 3 to 4, and poor when values were equal to or less than 2. Among patients with flexor tendon reconstruction (n ¼ 10), ROM was considered good or excellent (values greater than 4 on the mMRC scale) in 70% and fair (values from 2 to 3 and 3 to 4 on the mMRC scale) in 20%. Only one patient showed poor results (values equal to or less than 2 on the mMRC scale) because he did not comply with rehabilitation. Among those who had one extensor tendon reconstruction (n ¼ 13), ROM was good or excellent in 69.2% and fair in 30.8%. In those with multiple tendon reconstruction (n ¼ 4), ROM was good or excellent in 50% and fair in 50%. No residual pain after 1 year of surgery occurred in these patients. In terms of daily activities, most patients returned to their previous work activities; only 2 patients with pulley reconstruction needed job reassignment because of residual pain (visual analog scale ¼ 6). Functionality of the donor APL remained intact in all patients.
FIGURE 2: The APL tendon selected as a graft. Forceps place traction on distal insertion. Through the proximal incision, the tendon is dissected proximally to its myotendinous junction.
that has not occurred in our experience. The anatomic characteristics of the APL with multiple distal insertions enable safe extraction of a tendon graft without compromising thumb function. We recommend that surgeons avoid harvesting the tendon that inserts on the first metacarpal to decrease the already minimal possibility of altering thumb function and carpometacarpal joint stability. PEARLS AND PITFALLS This technique has several advantages that make it a good choice for tendon reconstruction, such as that multiple APL tendons are present in most patients, the length is predictable, the donor tendon is in the same operating field, and if dissected with care, the procedure will not cause functional deformities. Use of the APL is convenient when the PL is not available for tendon repair. Although this technique has many advantages, it also has a few disadvantages, such as that the length of the APL is shorter than the PL; the bellies of the APL must be dissected and evaluated to ensure that the donor tendon is not a major contributor to thumb abduction, which could lengthen the procedure; and the superficial radial nerve may be injured during the dissection. If the PL is not found or if more than one tendon graft is required for a multiple tendon reconstruction, use of an accessory tendon of the APL is an excellent choice because it is in the same operative field, it is a relatively constant finding, and it has few donor complications.
COMPLICATIONS Careful review of this series demonstrated that of 34 patients operated on with this technique, there was only one complication. That patient was a male who sustained a flexor tendon injury necessitating reconstruction. He was noncompliant in following up with postoperative therapy, and at 24 months he sustained a rupture of the grafted tendon. Only 2 of the 34 patients required job reassignment because of postoperative pain. The diagnosis of those patients was pulley reconstruction; they sustained the injuries at work and had workers’ compensation claims pending at the latest follow-up.
CASE SERIES We obtained data from a series of 34 patients operated on with this technique; patients were periodically assessed up to 1 year after surgery. J Hand Surg Am.
e3
REFERENCES 1. Daniels JM II, Zook EG, Lynch JM. Hand and wrist injuries: part I. Nonemergent evaluation. Am Fam Physician. 2004;69(8): 1941e1948.
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Vol. -, - 2016
e4
APL AS ALTERNATIVE GRAFT IN HAND SURGERY
2. Hermann BF. Ligament injuries of the hand and wrist. Clin Occup Environ Med. 2006;5(2):323e331, vii. 3. Morgan RL, Linder MM. Common wrist injuries. Am Fam Physician. 1997;55(3):857e868. 4. Daniels JM II, Zook EG, Lynch JM. Hand and wrist injuries: part II. Emergent evaluation. Am Fam Physician. 2004;69(8):1949e1956. 5. Chu PJ, Lee HM, Hou YT, Hung ST, Chen JK, Shih JT. Extensortendons reconstruction using autogenous palmaris longus tendon grafting for rheumatoid arthritis patients. J Orthop Surg Res. 2008;3:16. 6. Alagoz MS, Uysal AC, Tuccar E, Tekdemir I. Morphologic assessment of the tendon graft donor sites: palmaris longus, plantaris, tensor fascia lata. J Craniofac Surg. 2008;19(1):246e250. 7. Boyes JH, Stark HH. Flexor-tendon grafts in the fingers and thumb: a study of factors influencing results in 1000 cases. J Bone Joint Surg Am. 1971;53(7):1332e1342. 8. Jakubietz MG, Jakubietz DF, Gruenert JG, Zahn R, Meffert RH, Jakubietz RG. Adequacy of palmaris longus and plantaris tendons for tendon grafting. J Hand Surg Am. 2011;36(4):695e698. 9. Sebastin SJ, Lim AY, Bee WH, Wong TC, Methil BV. Does the absence of the palmaris longus affect grip and pinch strength? J Hand Surg Br. 2005;30(4):406e408. 10. Thompson NW, Mockford BJ, Cran GW. Absence of the palmaris longus muscle: a population study. Ulster Med J. 2001;70(1):22e24. 11. Mbaka GO, Ejiwunmi AB. Prevalence of palmaris longus absence—a study in the Yoruba population. Ulster Med J. 2009;78(2):90e93. 12. Sebastin SJ, Puhaindran ME, Lim AY, Lim IJ, Bee WH. The prevalence of absence of the palmaris longus—a study in a Chinese
J Hand Surg Am.
13.
14. 15.
16. 17.
18.
19.
20.
r
population and a review of the literature. J Hand Surg Br. 2005;30(5):525e527. Bravo E, Barco R, Bullon A. Anatomic study of the abductor pollicis longus: a source for grafting material of the hand. Clin Orthop Relat Res. 2010;468(5):1305e1309. van Oudenaarde E. Structure and function of the abductor pollicis longus muscle. J Anat. 1991;174:221e227. Tewari J, Mishra PR, Tripathy SK. Anatomical variation of abductor pollicis longus in Indian population: a cadaveric study. Indian J Orthop. 2015;49(5):549e553. Walsh AC. Variations in the abductor pollicis longus tendon; a study in 74 arms. Can Med Assoc J. 1955;73(9):741e743. Roy AJ, Roy AN, De C, et al. A cadaveric study of the first dorsal compartment of the wrist and its content tendons: anatomical variations in the Indian population. J Hand Microsurg. 2012;4(2): 55e59. Choi SJ, Ahn JH, Lee YJ, et al. de Quervain disease: US identification of anatomic variations in the first extensor compartment with an emphasis on subcompartmentalization. Radiology. 2011;260(2): 480e486. Rousset P, Vuillemin-Bodaghi V, Laredo JD, Parlier-Cuau C. Anatomic variations in the first extensor compartment of the wrist: accuracy of US. Radiology. 2010;257(2):427e433. Paternostro-Sluga T, Grim-Stieger M, Posch M, et al. Reliability and validity of the Medical Research Council (MRC) scale and a modified scale for testing muscle strength in patients with radial palsy. J Rehabil Med. 2008;40(8):665e671.
Vol. -, - 2016
The Abductor Pollicis Longus Tendon as an Alternative Graft in Hand Surgery Samuel Rosas, MD,*† Carolina Mesa, MD,† Felipe Mesa, MD†
Initial treatment of damaged tendons after soft tissue trauma of the hand can be performed with primary tendon reconstruction or with tendon grafts if indicated. The most frequently used tendons are from the palmaris longus and plantaris muscles. Nonetheless, these muscles may not be present or their anatomic characteristics might not suitable for reconstructive procedures. Here, we present an alternative surgical technique for tendon reconstruction of the hand using abductor pollicis longus accessory tendons as grafts. The abductor pollicis longus can be considered an excellent choice of graft for tendon reconstruction of the hand because of its multiple bellies, ease of extraction, and limited donor site morbidity and the frequent absence of the palmaris longus tendon. (J Hand Surg Am. 2016;-(-):-e-. Copyright Ó 2016 by the American Society for Surgery of the Hand. All rights reserved.) Key words Abductor pollicis longus, graft, hand.
L
ESIONS TO TENDONS OF THE HAND resulting from hand or wrist trauma can cause great morbidity and disability on a personal as well as professional level.1e3 Most injuries involve flexor and/or extensor tendons and often additional structures near the site of trauma.1e4 Early reconstruction of these injuries, especially flexor tendons, are essential because of potential disabilities as a consequence of delayed treatment. However, the possibility of some loss of function must always be taken into consideration.1,2 Reconstruction may be performed with a primary reconstructive technique by suturing both ends of the damaged tendon5 or with a secondary reconstruction, either with a tendon graft when the muscle is functional or with a tendon transfer when the myotendinous unit does not work.5e7
From the *Department of Orthopedic Surgery, University of Miami, Miami, FL; and †Universidad CES, Antioquia, Colombia. Received for publication August 1, 2016; accepted in revised form December 10, 2016. No benefits in any form have been received or will be received related directly or indirectly to the subject of this article. Corresponding author: Samuel Rosas, MD, Department of Orthopedic Surgery, Wake Forest School of Medicine, 1 Medical Center Boulevard, Winston-Salem, NC 27157; e-mail: [email protected]. 0363-5023/16/---0001$36.00/0 http://dx.doi.org/10.1016/j.jhsa.2016.12.006
The most commonly used graft tendon is the palmaris longus (PL), which is considered the ideal donor tendon in most cases, followed by the plantaris as a second choice.7e10 Other described are use of the long extensors of the toes, the flexor digitorum superficialis, the extensor indicis proprius, and the tensor fascia latae as alternatives.6,7 These described surgical methods have returned good to optimal results, but complications can occur, such as donor site morbidity in the form of limited range of motion and/or pain, and may range from minimal to severe.5e8 Although the tendon graft of the PL is most frequently used for these reconstructions, this tendon may be absent unilaterally or bilaterally, or it may not meet the criteria of length or width to be considered an adequate graft.9e12 INDICATIONS Tendon reconstruction with the abductor pollicis longus (APL) is indicated primarily in patients with acute or chronic tendon injuries who are not amenable to primary repair or have failed it. Various tendon repair surgeries such as multiple or single, flexor or extensor reconstruction, and pulley restoration can be achieved successfully. Patients with absence of the PL
Ó 2016 ASSH
r
Published by Elsevier, Inc. All rights reserved.
r
e1
e2
APL AS ALTERNATIVE GRAFT IN HAND SURGERY
are ideal surgical candidates, because the technique described here allows for tendon grafting within or near the same surgical site as the injury, which eliminates the need to prepare and drape a second surgical site, and thus increases efficiency and diminishes surgical time. CONTRAINDICATIONS Caution must be taken in patients who were previously operated on at the donor site, because the muscle bellies of the APL might have been injured or excised. Patients with multiple injections at the site should be carefully examined when extracting the graft, because the tendons also may have been weakened or debilitated for this reason. ANATOMY The APL is composed of superficial and deep heads, or muscle bellies, each of which ends in one or more tendons.13,14 The APL is radial to the extensor pollicis brevis in the first dorsal compartment. Cadaver studies demonstrated that the presence of the APL ranges from 85% to 92%.13,15 The origin of the APL, which is not of great importance for the technique described in this article, is located on the dorsal aspect of the radius, the interosseous membrane, and the ulnar bone.15 The insertion of this muscle, which is the main focus here, has been studied in many cadaver specimens because there appear to be important differences in its anatomy.13,16e19 To summarize the findings of previously cited studies, the distal course of the APL can be defined as within the first dorsal compartment with various distal insertions of accessory tendons, such as to the trapezium, abductor pollicis brevis, opponens pollicis, and thenar muscles,13,17 in addition to the principal insertion to the volar base of the thumb metacarpal. Surgeons must consider the numerous sensory branches of the radial nerve near the site of the APL insertion. We recommend identification and careful dissection to minimize postoperative complications such as pain.
remembering that the APL courses radial to the extensor pollicis brevis at this site.13 Because there are multiple tendon bellies in most patients, we favor not excising the tendon that inserts on the first metacarpal because it conveys most of the thumb abduction properties of this muscle. All of the tendons are evaluated by traction, analyzing, and selecting the tendon that imparts least function on the carpometacarpal joint (Figs. 1, 2). The selected tendon is dissected up to its insertion site at the trapezium bone, the abductor pollicis brevis fascia, or other insertion sites in the thenar area. From there, the tendon is dissected proximally up to the myotendinous unit; here the tendon is cut and extracted through a small incision on the skin. In our experience, the average length of the APL graft is 140 mm.
SURGICAL TECHNIQUE After the patient is properly evaluated initially, the reconstructive technique is planned. The surgeon performs a transverse incision on the distal radial side of the carpus, distal to the first dorsal compartment of the extensor tendons. The branches of the superficial sensory radial nerve are dissected out. Then, the APL tendon is dissected proximally up to the bellies,
COMPLICATIONS Complications from APL tenotomy can arise from various structures. In theory, dissection of the tendons can injure branches of the superficial sensory radial nerve and cause postoperative pain. This can be avoided by careful nerve branch dissection. Because of the multiple tendinous insertions of the APL, loss of function to the thumb is a possible complication
J Hand Surg Am.
FIGURE 1: Dissection of the first dorsal compartment through a distal incision. The extensor pollicis brevis tendon is thinner and dorsoulnar to the APL tendon.
r
Vol. -, - 2016
APL AS ALTERNATIVE GRAFT IN HAND SURGERY
Average age was 48.5 6.4 years (range, 36e64 years); most patients were men (73.5%). Different kinds of tendon reconstruction were performed among the 34 patients: flexor reconstruction was performed in 10, extensor reconstruction in 13, multiple tendon reconstruction in 4 (flexors in 2 patients and extensors in another 2), and pulley reconstruction in 7. We assessed functionality through the modified Medical Research Council (mMRC) scale according to Paternostro-Sluga et al.20 Functional range of motion (ROM) was considered to be good or excellent when values of the mMRC were greater than 4, fair when values ranged from 2 to 3 and 3 to 4, and poor when values were equal to or less than 2. Among patients with flexor tendon reconstruction (n ¼ 10), ROM was considered good or excellent (values greater than 4 on the mMRC scale) in 70% and fair (values from 2 to 3 and 3 to 4 on the mMRC scale) in 20%. Only one patient showed poor results (values equal to or less than 2 on the mMRC scale) because he did not comply with rehabilitation. Among those who had one extensor tendon reconstruction (n ¼ 13), ROM was good or excellent in 69.2% and fair in 30.8%. In those with multiple tendon reconstruction (n ¼ 4), ROM was good or excellent in 50% and fair in 50%. No residual pain after 1 year of surgery occurred in these patients. In terms of daily activities, most patients returned to their previous work activities; only 2 patients with pulley reconstruction needed job reassignment because of residual pain (visual analog scale ¼ 6). Functionality of the donor APL remained intact in all patients.
FIGURE 2: The APL tendon selected as a graft. Forceps place traction on distal insertion. Through the proximal incision, the tendon is dissected proximally to its myotendinous junction.
that has not occurred in our experience. The anatomic characteristics of the APL with multiple distal insertions enable safe extraction of a tendon graft without compromising thumb function. We recommend that surgeons avoid harvesting the tendon that inserts on the first metacarpal to decrease the already minimal possibility of altering thumb function and carpometacarpal joint stability. PEARLS AND PITFALLS This technique has several advantages that make it a good choice for tendon reconstruction, such as that multiple APL tendons are present in most patients, the length is predictable, the donor tendon is in the same operating field, and if dissected with care, the procedure will not cause functional deformities. Use of the APL is convenient when the PL is not available for tendon repair. Although this technique has many advantages, it also has a few disadvantages, such as that the length of the APL is shorter than the PL; the bellies of the APL must be dissected and evaluated to ensure that the donor tendon is not a major contributor to thumb abduction, which could lengthen the procedure; and the superficial radial nerve may be injured during the dissection. If the PL is not found or if more than one tendon graft is required for a multiple tendon reconstruction, use of an accessory tendon of the APL is an excellent choice because it is in the same operative field, it is a relatively constant finding, and it has few donor complications.
COMPLICATIONS Careful review of this series demonstrated that of 34 patients operated on with this technique, there was only one complication. That patient was a male who sustained a flexor tendon injury necessitating reconstruction. He was noncompliant in following up with postoperative therapy, and at 24 months he sustained a rupture of the grafted tendon. Only 2 of the 34 patients required job reassignment because of postoperative pain. The diagnosis of those patients was pulley reconstruction; they sustained the injuries at work and had workers’ compensation claims pending at the latest follow-up.
CASE SERIES We obtained data from a series of 34 patients operated on with this technique; patients were periodically assessed up to 1 year after surgery. J Hand Surg Am.
e3
REFERENCES 1. Daniels JM II, Zook EG, Lynch JM. Hand and wrist injuries: part I. Nonemergent evaluation. Am Fam Physician. 2004;69(8): 1941e1948.
r
Vol. -, - 2016
e4
APL AS ALTERNATIVE GRAFT IN HAND SURGERY
2. Hermann BF. Ligament injuries of the hand and wrist. Clin Occup Environ Med. 2006;5(2):323e331, vii. 3. Morgan RL, Linder MM. Common wrist injuries. Am Fam Physician. 1997;55(3):857e868. 4. Daniels JM II, Zook EG, Lynch JM. Hand and wrist injuries: part II. Emergent evaluation. Am Fam Physician. 2004;69(8):1949e1956. 5. Chu PJ, Lee HM, Hou YT, Hung ST, Chen JK, Shih JT. Extensortendons reconstruction using autogenous palmaris longus tendon grafting for rheumatoid arthritis patients. J Orthop Surg Res. 2008;3:16. 6. Alagoz MS, Uysal AC, Tuccar E, Tekdemir I. Morphologic assessment of the tendon graft donor sites: palmaris longus, plantaris, tensor fascia lata. J Craniofac Surg. 2008;19(1):246e250. 7. Boyes JH, Stark HH. Flexor-tendon grafts in the fingers and thumb: a study of factors influencing results in 1000 cases. J Bone Joint Surg Am. 1971;53(7):1332e1342. 8. Jakubietz MG, Jakubietz DF, Gruenert JG, Zahn R, Meffert RH, Jakubietz RG. Adequacy of palmaris longus and plantaris tendons for tendon grafting. J Hand Surg Am. 2011;36(4):695e698. 9. Sebastin SJ, Lim AY, Bee WH, Wong TC, Methil BV. Does the absence of the palmaris longus affect grip and pinch strength? J Hand Surg Br. 2005;30(4):406e408. 10. Thompson NW, Mockford BJ, Cran GW. Absence of the palmaris longus muscle: a population study. Ulster Med J. 2001;70(1):22e24. 11. Mbaka GO, Ejiwunmi AB. Prevalence of palmaris longus absence—a study in the Yoruba population. Ulster Med J. 2009;78(2):90e93. 12. Sebastin SJ, Puhaindran ME, Lim AY, Lim IJ, Bee WH. The prevalence of absence of the palmaris longus—a study in a Chinese
J Hand Surg Am.
13.
14. 15.
16. 17.
18.
19.
20.
r
population and a review of the literature. J Hand Surg Br. 2005;30(5):525e527. Bravo E, Barco R, Bullon A. Anatomic study of the abductor pollicis longus: a source for grafting material of the hand. Clin Orthop Relat Res. 2010;468(5):1305e1309. van Oudenaarde E. Structure and function of the abductor pollicis longus muscle. J Anat. 1991;174:221e227. Tewari J, Mishra PR, Tripathy SK. Anatomical variation of abductor pollicis longus in Indian population: a cadaveric study. Indian J Orthop. 2015;49(5):549e553. Walsh AC. Variations in the abductor pollicis longus tendon; a study in 74 arms. Can Med Assoc J. 1955;73(9):741e743. Roy AJ, Roy AN, De C, et al. A cadaveric study of the first dorsal compartment of the wrist and its content tendons: anatomical variations in the Indian population. J Hand Microsurg. 2012;4(2): 55e59. Choi SJ, Ahn JH, Lee YJ, et al. de Quervain disease: US identification of anatomic variations in the first extensor compartment with an emphasis on subcompartmentalization. Radiology. 2011;260(2): 480e486. Rousset P, Vuillemin-Bodaghi V, Laredo JD, Parlier-Cuau C. Anatomic variations in the first extensor compartment of the wrist: accuracy of US. Radiology. 2010;257(2):427e433. Paternostro-Sluga T, Grim-Stieger M, Posch M, et al. Reliability and validity of the Medical Research Council (MRC) scale and a modified scale for testing muscle strength in patients with radial palsy. J Rehabil Med. 2008;40(8):665e671.
Vol. -, - 2016