Muscle Variants of the Upper and Lower Limb (with Anatomical Correlation)

ABSTRACT

Several accessory muscles in the upper and lower limb have been described in the medical literature. Most are asymptomatic and represent incidental findings at imaging. In some instances, however, these muscles may become clinically relevant producing palpable swelling, entrapment of neurovascular structures, or exercise-related pain. The diagnosis of accessory muscles is based on recognition of their typical location and on cross-sectional imaging features. Familiarity with their most common location and knowledge of the possible clinical syndromes caused by these supernumerary structures may aid in diagnosis and treatment.

KEYWORDS

Muscle anatomy - accessory muscles - ultrasound - magnetic resonance imaging

REFERENCES

• 1 Sookur P A, Naraghi A M, Bleakney R R, Jalan R, Chan O, White L M. Accessory muscles: anatomy, symptoms, and radiologic evaluation.  Radiographics. 2008;  28(2) 481-499
• 2 Landry Jr S O. The phylogenetic significance of the chondro-epitrochlearis muscle and its accompanying pectoral abnormalities.  J Anat. 1958;  92(1) 57-61
• 3 Miguel M, Llusá M, Ortiz J C, Porta N, Lorente M, Götzens V. The axillopectoral muscle (of Langer): report of three cases.  Surg Radiol Anat. 2001;  23(5) 341-343
• 4 Dharap A. An unusually medial axillary arch muscle.  J Anat. 1994;  184(Pt 3) 639-641
• 5 Rizk E, Harbaugh K. The muscular axillary arch: an anatomic study and clinical considerations.  Neurosurgery. 2008;  63(4, suppl 2) 316-319 discussion 319-320
• 6 Hewitt R L. Acute axillary-vein obstruction by the pectoralis-minor muscle.  N Engl J Med. 1968;  279(11) 595-596
• 7 Flaherty G, O'Neill M N, Folan-Curran J. Case report: bilateral occurrence of a chondroepitrochlearis muscle.  J Anat. 1999;  194(Pt 2) 313-315
• 8 Loukas M, Louis Jr R G, Kwiatkowska M. Chondroepitrochlearis muscle, a case report and a suggested revision of the current nomenclature.  Surg Radiol Anat. 2005;  27(4) 354-356
• 9 Spinner R J, Carmichael S W, Spinner M. Infraclavicular ulnar nerve entrapment due to a chondroepitrochlearis muscle.  J Hand Surg [Br]. 1991;  16(3) 315-317
• 10 O'Driscoll S W, Horii E, Carmichael S W, Morrey B F. The cubital tunnel and ulnar neuropathy.  J Bone Joint Surg Br. 1991;  73(4) 613-617
• 11 Jeon I H, Fairbairn K J, Neumann L, Wallace W A. MR imaging of edematous anconeus epitrochlearis: another cause of medial elbow pain?.  Skeletal Radiol. 2005;  34(2) 103-107
• 12 Husarik D B, Saupe N, Pfirrmann C W, Jost B, Hodler J, Zanetti M. Elbow nerves: MR findings in 60 asymptomatic subjects—normal anatomy, variants, and pitfalls.  Radiology. 2009;  252(1) 148-156
• 13 Masear V R, Hill Jr J J, Cohen S M. Ulnar compression neuropathy secondary to the anconeus epitrochlearis muscle.  J Hand Surg [Am]. 1988;  13(5) 720-724
• 14 Jones M, Abrahams P H, Sañudo J R, Campillo M. Incidence and morphology of accessory heads of flexor pollicis longus and flexor digitorum profundus (Gantzer's muscles).  J Anat. 1997;  191(Pt 3) 451-455
• 15 al-Qattan M M. Gantzer's muscle. An anatomical study of the accessory head of the flexor pollicis longus muscle.  J Hand Surg [Br]. 1996;  21(2) 269-270
• 16 Tabib W, Aboufarah F, Asselineau A. Compression of the anterior interosseous nerve by Gantzer's muscle[in French].  Chir Main. 2001;  20(3) 241-246
• 17 Degreef I, De Smet L. Anterior interosseous nerve paralysis due to Gantzer's muscle.  Acta Orthop Belg. 2004;  70(5) 482-484
• 18 Zeiss J, Guilliam-Haidet L. MR demonstration of anomalous muscles about the volar aspect of the wrist and forearm.  Clin Imaging. 1996;  20(3) 219-221
• 19 Schuurman A H, van Gils A PG. Reversed palmaris longus muscle on MRI: report of four cases.  Eur Radiol. 2000;  10(8) 1242-1244
• 20 Depuydt K H, Schuurman A H, Kon M. Reversed palmaris longus muscle causing effort-related median nerve compression.  J Hand Surg [Br]. 1998;  23(1) 117-119
• 21 Timins M E. Muscular anatomic variants of the wrist and hand: findings on MR imaging.  AJR Am J Roentgenol. 1999;  172(5) 1397-1401
• 22 Harvie P, Patel N, Ostlere S J. Prevalence and epidemiological variation of anomalous muscles at Guyon's canal.  J Hand Surg Br. 2004;  29(1) 26-29
• 23 Harvie P, Patel N, Ostlere S J. Ulnar nerve compression at Guyon's canal by an anomalous abductor digiti minimi muscle: the role of ultrasound in clinical diagnosis.  Hand Surg. 2003;  8(2) 271-275
• 24 Dimitriou C, Natsis K. Accessory abductor digiti minimi muscle causing ulnar nerve entrapment at the Guyon's canal: a case report.  Clin Anat. 2007;  20(8) 974-975
• 25 Spiess A M, Gursel E. Entrapment of the ulnar nerve at Guyon's canal by an accessory abductor digiti minimi muscle.  Plast Reconstr Surg. 2006;  117(3) 1060-1061
• 26 Al-Qattan M M. Ulnar nerve compression at the wrist by the accessory abductor digiti minimi muscle: wrist trauma as a precipitating factor.  Hand Surg. 2004;  9(1) 79-82
• 27 Elias L S, Schulter-Ellis F P. Anomalous flexor superficialis indicis: two case reports and literature review.  J Hand Surg [Am]. 1985;  10(2) 296-299
• 28 Kostakoğlu N, Borman H, Keçik A. Anomalous flexor digitorum superficialis muscle belly: an unusual case of mass in the palm.  Br J Plast Surg. 1997;  50(8) 654-656
• 29 Schön R, Kraus E, Boller O, Kampe A. Anomalous muscle belly of the flexor digitorum superficialis associated with carpal tunnel syndrome: case report.  Neurosurgery. 1992;  31(5) 969-970 discussion 970-971
• 30 Sanger J R, Krasniak C L, Matloub H S, Yousif N J, Kneeland J B. Diagnosis of an anomalous superficialis muscle in the palm by magnetic resonance imaging.  J Hand Surg [Am]. 1991;  16(1) 98-101
• 31 Martinoli C, Bianchi S, Gandolfo N, Valle M, Simonetti S, Derchi L E. US of nerve entrapments in osteofibrous tunnels of the upper and lower limbs.  Radiographics. 2000;  20(Spec No.) S199-S213
• 32 Pirola E, Hébert-Blouin M N, Amador N, Amrami K K, Spinner R J. Palmaris profundus: one name, several subtypes, and a shared potential for nerve compression.  Clin Anat. 2009;  22(6) 643-648
• 33 Gama C. Extensor digitorum brevis manus: a report on 38 cases and a review of the literature.  J Hand Surg [Am]. 1983;  8(5 Pt 1) 578-582
• 34 Rodríguez-Niedenführ M, Vázquez T, Golanó P, Parkin I, Sañudo J R. Extensor digitorum brevis manus: anatomical, radiological and clinical relevance. A review.  Clin Anat. 2002;  15(4) 286-292
• 35 Dostal G H, Lister G D, Hutchinson D, Mogan J V, Davis P H. Extensor digitorum brevis manus associated with a dorsal wrist ganglion: a review of five cases.  J Hand Surg [Am]. 1995;  20(1) 35-37
• 36 Ouellette H, Thomas B J, Torriani M. Using dynamic sonography to diagnose extensor digitorum brevis manus.  AJR Am J Roentgenol. 2003;  181(5) 1224-1226
• 37 Anderson M W, Benedetti P, Walter J, Steinberg D R. MR appearance of the extensor digitorum manus brevis muscle: a pseudotumor of the hand.  AJR Am J Roentgenol. 1995;  164(6) 1477-1479
• 38 Tubbs R S, Salter E G, Oakes W J. Dissection of a rare accessory muscle of the leg: the tensor fasciae suralis muscle.  Clin Anat. 2006;  19(6) 571-572
• 39 Chason D P, Schultz S M, Fleckenstein J L. Tensor fasciae suralis: depiction on MR images.  AJR Am J Roentgenol. 1995;  165(5) 1220-1221
• 40 Montet X, Sandoz A, Mauget D, Martinoli C, Bianchi S. Sonographic and MRI appearance of tensor fasciae suralis muscle, an uncommon cause of popliteal swelling.  Skeletal Radiol. 2002;  31(9) 536-538
• 41 Stoane J M, Gordon D H. MRI of an accessory semimembranosus muscle.  J Comput Assist Tomogr. 1995;  19(1) 161-162
• 42 Duc S R, Wentz K U, Käch K P, Zollikofer C L. First report of an accessory popliteal muscle: detection with MRI.  Skeletal Radiol. 2004;  33(7) 429-431
• 43 Sobel M, Levy M E, Bohne W H. Congenital variations of the peroneus quartus muscle: an anatomic study.  Foot Ankle. 1990;  11(2) 81-89
• 44 Chepuri N B, Jacobson J A, Fessell D P, Hayes C W. Sonographic appearance of the peroneus quartus muscle: correlation with MR imaging appearance in seven patients.  Radiology. 2001;  218(2) 415-419
• 45 Saupe N, Mengiardi B, Pfirmann C WA, Vienne P, Seifert B, Zanetti M. Anatomic variants associated with peroneal tendon disorders: MR imaging findings in volunteers with asymptomatic ankles.  Radiology. 2007;  242 509-517
• 46 Donley B G, Leyes M. Peroneus quartus muscle. A rare cause of chronic lateral ankle pain.  Am J Sports Med. 2001;  29(3) 373-375
• 47 Sobel M, Geppert M J, Olson E J, Bohne W H, Arnoczky S P. The dynamics of peroneus brevis tendon splits: a proposed mechanism, technique of diagnosis, and classification of injury.  Foot Ankle. 1992;  13(7) 413-422
• 48 Witvrouw E, Borre K V, Willems T M, Huysmans J, Broos E, De Clercq D. The significance of peroneus tertius muscle in ankle injuries: a prospective study.  Am J Sports Med. 2006;  34(7) 1159-1163
• 49 Peterson D A, Stinson W, Lairmore J R. The long accessory flexor muscle: an anatomical study.  Foot Ankle Int. 1995;  16(10) 637-640
• 50 Sammarco G J, Stephens M M. Tarsal tunnel syndrome caused by the flexor digitorum accessorius longus. A case report.  J Bone Joint Surg Am. 1990;  72(3) 453-454
• 51 Cheung Y Y, Rosenberg Z S, Colon E, Jahss M. MR imaging of flexor digitorum accessorius longus.  Skeletal Radiol. 1999;  28(3) 130-137
• 52 Seipel R, Linklater J, Pitsis G, Sullivan M. The peroneocalcaneus internus muscle: an unusual cause of posterior ankle impingement.  Foot Ankle Int. 2005;  26(10) 890-893
• 53 Mellado J M, Rosenberg Z S, Beltran J, Colon E. The peroneocalcaneus internus muscle: MR imaging features.  AJR Am J Roentgenol. 1997;  169(2) 585-588
• 54 Lorentzon R, Wirell S. Anatomic variations of the accessory soleus muscle.  Acta Radiol. 1987;  28(5) 627-629
• 55 Yu J S, Resnick D. MR imaging of the accessory soleus muscle appearance in six patients and a review of the literature.  Skeletal Radiol. 1994;  23(7) 525-528
• 56 Palaniappan M, Rajesh A, Rickett A, Kershaw C J. Accessory soleus muscle: a case report and review of the literature.  Pediatr Radiol. 1999;  29(8) 610-612
• 57 Paul M A, Imanse J, Golding R P, Koomen A R, Meijer S. Accessory soleus muscle mimicking a soft tissue tumor. A report of 2 patients.  Acta Orthop Scand. 1991;  62(6) 609-611
• 58 Bianchi S, Abdelwahab I F, Oliveri M, Mazzola C G, Rettagliata P. Sonographic diagnosis of accessory soleus muscle mimicking a soft tissue tumor.  J Ultrasound Med. 1995;  14(9) 707-709
• 59 Cheung Y, Rosenberg Z S. MR imaging of the accessory muscles around the ankle.  Magn Reson Imaging Clin N Am. 2001;  9(3) 465-473