There are many anatomical variations in and around the carpal tunnel that affect the nerves, tendons and arteries in this area. Awareness of these variations is important both during the clinical examination and during carpal tunnel release. The purpose of the present review is to highlight recognized anatomical variations within the carpal tunnel including variation in nerve anatomy, tendon anatomical variants, vascular anatomical variations and muscle anatomical variations.
LindleySGJacksonMSKleinertJM. Prevalence of anatomic variations encountered in elective tunnel release.J Hand Surg2003; 28A: 849–55.
2.
LanzU.. Anatomic variations of the median nerve in the carpal tunnel.J Hand Surg1977; 2A: 44–53.
3.
AmadioPC. Anatomic variations of the median nerve within the carpal tunnel.Clin Anat1988; 1: 23–31.
4.
JeonIHKimPTParkIHParkBCIhnJC. High bifurcation of median nerve at the wrist causing common digital nerve injury in endoscopic carpal tunnel release.J Hand Surg2002; 27B: 580–2.
5.
GutowskiKAOliverWAMehraraBJFriedmanDW. Arteriovenous malformation of a persistent median artery with a bifurcated median nerve.Plast Reconstr Surg2000; 106: 1336–9.
6.
Fernandez-GarciaS.Pi-FolgueraJ.Estallo-MatonoF.. Bifid median nerve compression due to a musculotendinous anomaly of FDS to the middle finger.J Hand Surg1994; 19B: 616–7.
7.
SzaboRMPetteyJ.. Bilateral median nerve bifurcation with an accessory compartment within the carpal tunnel.J Hand Surg1994; 19B: 1744–6.
8.
GrahamWPIII. Variations of the motor branch of the median nerve at the wrist.Plast Reconstr Surg1973; 51: 90–2.
9.
HurwitzPJ. Variations in the course of the thenar motor branch of the median nerve.J Hand Surg [Br]1996; 21: 344–6.
10.
TaleisnikJ.. The palmer cutaneous branch of the median nerve and the approach to carpal tunnel. An anatomical study.J Bone Joint Surg1973; 55A: 1212–7.
11.
PapanastasiouS.SoodM.. Aberrant position of the ulnar nerve within the carpal canal.Microsurgery2004; 24: 24–5.
12.
EskesenV.RosenornJ.OsgaardO.. Atypical carpal tunnel syndrome with compression of the ulnar and median nerves.J Neurosurg1981; 54: 668–9.
13.
GalzioRJMaglianiV.LucantoniD.D'ArrigoC.. Bilateral anomalous course of the ulnar nerve at the wrist causing ulnar and median nerve compression syndrome.J Neurosurg1987; 67: 754–6.
14.
BrandsmaJWBirkeJASimsDS. The Martin-Gruber innervated hand.J Hand Surg1986; 11A: 536–9.
15.
UchidaY.SugiokaY.. Electrodiagnosis of Martin-Gruber connection and its clinical importance in peripheral nerve surgery.J Hand Surg1992; 17A: 54–9.
16.
LeibovicSJHastingsH.. Martin-Gruber revisited.J Hand Surg1992; 17A: 47–53.
17.
NakashimaT.. An anatomical study of the Martin-Gruber anastomosis.Surg Radiol Anat1993; 15: 193–5.
18.
TaamsKO. Martin-Gruber connections in South Africa. An anatomical study.J Hand Surg1997; 22B: 328–30.
SimonettiS.KrarupC.. Unusual ulnar sensory innervation and Martin-Gruber anastomosis in a patient with a carpal tunnel syndrome.J Neurol2000; 247: 141–2.
21.
LeeK.OhC.ChungI.SunwooI.. An anatomic study of the Martin-Gruber anastomosis: Electrodiagnostic implications.Muscle Nerve2005; 31: 95–7.
KimuraI.AyyarDRLippmannSM. Electrophysiological verification of the ulnar to median nerve communications in the hand and forearm.Tohoku J Exp Med1983; 141: 269–74.
24.
MarinacciA.. The problem of unusual anomalous innervation of hand muscles: the value of electrodiagnosis in its evaluation.Bull Los Angeles Neruol Soc1964; 29: 133–42.
25.
StreibEW. Ulnar-to-median nerve anastomosis in the forearm: electromyographic studies.Neurology1976; 29: 1534–7.
26.
ManginiU.. Flexor pollicis longus muscle: Its morphology and clinical significance.J Bone Joint Surg1960; 42A: 467–70.
27.
LinburgRMComstockBE. Anamalous tendon slips from the flexor pollicis longus to the flexor digitorum profundus.J Hand Surg1979; 4: 79–83.
StahlS.StahlS.CalifE.. Failure of flexor pollicis longus repair caused by anomalous flexor pollicis longus to index flexor digitorum profundus interconnections: A case report.J Hand Surg2005; 30A: 483–6.
30.
TakamiH.TakahashiS.AndoM.. The Linburg Comstock anomaly: A case report.J Hand Surg1996; 21A: 251–2.
31.
LombardiRMWoodMBLinscheidRL. Symptomatic restrictive thumb-index flexor tenosynovitis: Incidence of musclotendionous anomalies and results of treatment.J Hand Surg1988; 13A: 325–8.
32.
SlaterRR. Flexor tendon anomalies in a patient with carpal tunnel syndrome.J Hand Surg2001; 26B: 373–6.
33.
BilginSSOlcaySEDerincekA.AdiyamanS.DemirtasAM. Can simple release relieve symptoms of carpal tunnel syndrome caused by a persistent median artery?Arch Orthop Trauma Surg2004; 124: 154–6.
34.
OlaveE.PratesJCGabrielliC.PardiP.. Median artery and superficial palmar branch of the radial artery in the carpal tunnel.Scand J Plast Reconstr Surg Hand Surg1997; 31: 13–6.
35.
BarfredT.HojlundAPBertheussenK.. Median artery in carpal tunnel syndrome.J Hand Surg [Am]1985; 10: 864–7.
36.
KeleH.VerhegenR.ReimersCD. Carpal tunnel syndrome caused by thrombosis of the median artery: the importance of high-resolution ultrasonography for diagnosis. Case report.J Neurosurg2002; 97: 471–3.
37.
GassnerEMSchockeM.PeerS.SchwabeggerA.JaschkeW.BodnerG.. Persistent median artery in the carpal tunnel: Color Doppler ultrasonographic findings.J Ultrashound Med2002; 21: 455–61.
38.
ZeissJ.Guilliam-HaidetL.. MR demonstration of anomalous muscles about the volar aspect of the wrist and forearm.Clinical Imaging1996; 20: 219–21.
39.
SiegP.JacobsenHCHakimSGHermesD.. Superficial ulnar artery: Course or blessing in harvesting fasciocutaneous forearm flaps.Head Neck2006; 28: 447–52.
40.
ThomaA.YoungJE. The superficial ulnar artery “trap” and the free forearm flap.Ann Plast Surg1992; 28: 370–2.
41.
FatahMFNancarrowJDMurrayDS. Raising the radial artery forearm flap: The superficial ulnar artery “trap.”Br J Plast Surg1985; 38:394–5.
42.
ReimannAFDaselerEHAnsonBJBeatonLE. The palmaris longus muscle and tendon. A study of 1600 extremities.Anat Rec1944; 89: 495–505.
43.
ButlerB.BigleyEC. Aberrant index lumbrical tendinous origin associated with carpal-tunnel syndrome. A case report.J Bone Joint Surg1971; 53A: 160–2.
KonoH.. Acute carpal tunnel syndrome caused by anomalous muscle bellies: A case report.Hand Surg2003; 8: 141–3.
46.
KostakogluN.BormanH.KecikA.. Anomalous flexor digitorum superficialis muscle belly: An unusual case of mass in the palm.Br J Plast Surg1997; 50: 654–6.
47.
AmeteweeK.HarrisA.SamuelM.. Acute carpal tunnel syndrome produced by anomalous flexor digitorum superficialis indicis muscle.J Hand Surg1985; 10: 1:83–4.
48.
HuttonP.KernohanJ.BirchR.. An anomalous flexor digitorum superficialis indicis muscle presenting as carpal tunnel syndrome.Hand1981; 13: 1:85–6.
