Summary
Normal skeletal variants are a common occurrence in clinical practice and may lead to misinterpretation. As part of a case control study investigating the carpal tunnel, our asymptomatic and voluntary participant underwent magnetic resonance (MR) imaging of both wrists from the metacarpal bases to the distal radiocarpal joint. The imaging techniques included spin echo (SE), turbo spin echo (TSE) and fast field echo (FFE) sequences using 4 mm-slice thickness. As an incidental finding bipartite hamulus was detected bilaterally. The anomaly was evident in both hamuli with similar MRI characteristics. The congenital origin was further supported by the absence of trauma or surgery to the wrists. In this case report the authors discuss the anatomical variant, bilateral bipartite hook of the hamate, and demonstrate the reliability of contiguous slices of MR axial slices in displaying an anatomical variant of the carpus. This normal variant of the hamate is not commonly encountered in MR imaging of the wrist and can be misinterpreted as fracture or post-traumatic sequelae. Images of the normal hamulus are presented for comparison.
Résumé
Les variations squelettiques normales sont fréquemment rencontrées en pratique clinique et peuvent conduire à des erreurs d'interprétation. Lors d'une étude contrôle concernant le canal carpien, des sujets asymptomatiques et volontaires ont subi une imagerie par résonance magnétique (IRM) des deux poignets depuis les bases des métacarpiens jusqu'à l'interligne radio-carpien. Les techniques d'imagerie utilisaient des coupes de 4 mm en spin-écho (SE), en turbo spin-écho (TSE) et en écho de champ rapide (FFE). Fortuitement, nous avons trouvé un hamulus bipartite bilatéral. L'anomalie était évidente sur les deux hamulus et présentait les mêmes caractéristiques IRM. L'origine congénitale a été retenue en l'absence de traumatisme ou de chirurgie des poignets. Dans le cas rapporté, les auteurs discutent la variante anatomique, un hamulus bipartite de l'hamatum, et montrent la fiabilité des coupes axiales IRM contiguës pour décrire une variante anatomique du carpe. Cette variante normale de l'hamatum est rarement rencontrée en IRM du poignet et pourrait être prise par erreur comme une fracture ou une séquelle post-traumatique. Les images d'un hamulus normal sont présentées pour comparaison.
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References
Baird DB, Friedenberg ZB (1968) Delayed ulnar nerve palsy following a fracture of the hamate. J Bone Joint Surg 50A: 570–2
Bianchi S, Abdelwahab IF, Federici E (1990) Unilateral os hamuli proprium simulating a fracture of the hook of the hamate: A case report. Bull Hosp Joint Dis Inst 50: 205–208
Bogart FB (1932) Variations of the bones of the wrist. Am J Roentgenol 50: 638–646
Boyes JH (1970) Bunnell's Surgery of the hand. JB Lippincott, Philadelphia, p 592
Bray TJ, Swafford AR, Brown RL (1985) Bilateral fracture of the hook of the hamate. J Trauma 25: 174–175
Buchberger W, Schon G, Strasser K, Jungwirth W (1991) High-resolution ultrasonography of the carpal tunnel. J Ultrasound Med 10: 531–537
Burgess RC (1990) Anatomic variations of the midcarpal joint. J Hand Surg 15A: 129–131
Carter PR, Eaton RG, Littler JW (1977) Ununited fracture of the hook of the hamate. J Bone Joint Surg 59A: 5, 583–88
Delaney TJ, Eswar S (1992) Carpal coalitions. J Hand Surg 17A: 28–31
Doman AN, Marcus NW (1990) Congenital bipartite scaphoid. J Hand Surg 15A: 869–73
Dwight T (1907) A clinical atlas: Variations of the bones of the hands and feet. JB Lippincott, Philadelphia, pp 8–11
Gerscovich EO, Greenspan A (1990) Os Centrale Carpi. Skeletal Radiol 598: 143–145
Greene MH, Hadied AM (1981) Bipartite hamulus with ulnar tunnel syndrome: A case report and literature review. J Hand Surg 6A: 605–609.
Greulich WW, Pyle Sl (1992) Radiographic atlas of skeletal development of the hand and wrist, 2nd ed. Standford University Press, Standford, pp 112–166
Hart V, Gaynor V (1941) Roentgenographic study of the carpal canal. J Bone Joint Surg 23A: 382–383
Healy C, Watson JD, Longstaff A, Cambell MJ (1990) Magnetic resonance imaging of the carpal tunnel. J Hand Surg 15B: 243–248
Howard FM (1961) Ulnar nerve palsy in wrist fractures. J Bone Joint Surg 43A:1197–1201
Kaplan EB (1965) Functional and surgical anatomy of the hand, 2nd edn. Lippincott, Philadelphia, pp 122–125
Keats TE (1992) Atlas of normal roentgen variants that may simulate disease, 5th edn. Mosby, St. Louis, pp 443–445
Kohler A, Zimmer EA (1993) Borderlands of normal and early pathologic findings in skeletal radiography, 4th edn. Thieme, Stuttgart, pp 102–105
Kursunoglo-Brahme S, Gundry CR, Resnick D (1989) Advanced imaging of the wrist. Radiol Clin North Am 28: 307–320
Llewellyn Bowen T (1973) Injuries of the hamate bone. Hand 5: 235–38
Mesgarzadeh M, Schneck CD, Elonakdarpour A (1989) Carpal Tunnel: MR Imaging. Part I. Normal anatomy. Radiology 171: 743–748
Middleton WD, Kneeland JB, Kellman GM, et al (1987) MR Imaging of the carpal tunnel: normal anatomy and preliminary findings in the carpal tunnel syndrome. AJR 148: 308–316
Norman A, Nelson J, Green S (1985) Fractures of the hook of the hamate: Radiographic signs. Radiology 154: 49–53
Paul LW, Juhl JH (1987) Paul and Juhl's essentials of radiologic imaging, 5th edn. Lippincott, Philadelphia, pp 278–279
Pierre-Jerome C, Bekkelund Sl, Husby G, et al (1996) MRI of anatomical variants of the wrist in women. Surg Radiol Anat 18:1–5
Pierre-Jerome C, Shahabpour M, Osteaux M (1989) Bilateral MR Imaging of the wrist. Evaluation of pre and postoperative carpal tunnel syndrome. Radiology 173: 504
Pfitzner W (1895) Beitrage zur Kenntnis des menschlichen Extremitätenskelets. VI Variationen in Aufbau der Handskelets. Morphol Arbeit von Schwalbe. Z Morphol 4: 347–570
Resnick D, Nwayama G (1988) Diagnosis of bone and joint disorders, 2nd edn. Saunders, Philadelphia, pp 293, 2771
Seeger LL, Bassett LW, Gold RH (1988) Bilateral congenital absence of the hook of the hamate. Skeletal Radiol 464: 85–86
Stoller DW (1993) Magnetic resonance imaging in orthopaedics and sports medicine. Lippincott, Philadelphia, pp 663–806
Tountas CP, Bergman RA (1993) Anatomic variations of the upper extremity, 1st edn. Churchill Livingstone, New York, p 21
Williams PL, Warwick R, Dyson M, Bannister LH (1989) Gray's Anatomy, 37th edn. Churchill Livingstone, Edinburgh, p 421
Wilson JN (1954) Profiles of the carpal canal. J Bone Joint Surg 36A: 127–132
Zlatkin M, Greenan T (1992) Magnetic resonance imaging of the wrist. Magnet Res Quart 8: 2
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Pierre-Jerome, C., Roug, I.K. MRI of bilateral bipartite hamulus: a case report. Surg Radiol Anat 20, 299–302 (1998). https://doi.org/10.1007/BF01628496
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DOI: https://doi.org/10.1007/BF01628496