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FESSH prep Congenital hand The Oberg–Manske–Tonkin classification, the Bayne–Klug and James modifications for radial longitudinal deficiency, associated syndromes and work up, prerequisites for centralisation

Radial longitudinal deficiency and the OMT classification

Last reviewed v1.0

FESSH-043Congenital hand●●○ intermediate

Regarding radial longitudinal deficiency and the classification of congenital upper-limb anomalies:

  1. 1.The Oberg–Manske–Tonkin (OMT) classification groups congenital upper-limb anomalies into malformations, deformations and dysplasias, and has been adopted by the International Federation of Societies for Surgery of the Hand in place of the Swanson classification.

  2. 2.In the James, McCarroll and Manske modification of the Bayne and Klug classification, type N denotes a normal-length radius with a normal carpus and thumb hypoplasia, type 0 a normal-length radius with radial-sided carpal anomalies, and type 4 complete absence of the radius.

  3. 3.In thrombocytopenia–absent radius (TAR) syndrome the thumbs are present despite bilateral absence of the radii, and the thrombocytopenia tends to improve during childhood.

  4. 4.A normal full blood count in infancy excludes Fanconi anaemia in a child with radial longitudinal deficiency.

  5. 5.Wrist centralisation is indicated regardless of elbow motion, because restoring forearm length compensates for a stiff elbow.

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Question ID
FESSH-043
First published
Last reviewed
Version
v1.0
Answer key and explanations — open after answering

  1. 1. The Oberg–Manske–Tonkin (OMT) classification groups congenital upper-limb anomalies into malformations, deformations and dysplasias, and has been adopted by the International Federation of Societies for Surgery of the Hand in place of the Swanson classification.

    True

    Tonkin and Oberg describe a classification that uses dysmorphological terminology and places conditions in one of three groups, malformations, deformations and dysplasias, with malformations subdivided according to whether the whole limb or the hand plate alone is affected and whether the insult involves one of the three axes of limb development or is non-axial; the IFSSH Scientific Committee for Congenital Conditions approved it as a replacement for the Swanson classification. It was proposed in 2010 by Oberg, Feenstra, Manske and Tonkin, tested for inter- and intra-observer reliability in 2013, and updated in 2014 and 2020; the authors describe it as expandable and by no means final.

    • Tonkin MA, Oberg KC. The OMT Classification of Congenital Anomalies of the Hand and Upper Limb. Hand Surg. 2015;20(3):336-42. PMID 26387992
    • Tonkin MA, Tolerton SK, Quick TJ, Harvey I, Lawson RD, Smith NC, et al.. Classification of congenital anomalies of the hand and upper limb: development and assessment of a new system. J Hand Surg Am. 2013;38(9):1845-53. PMID 23684520
    • Goldfarb CA, Ezaki M, Wall LB, Lam WL, Oberg KC. The Oberg-Manske-Tonkin (OMT) Classification of Congenital Upper Extremities: Update for 2020. J Hand Surg Am. 2020;45(6):542-547. PMID 32093994

  2. 2. In the James, McCarroll and Manske modification of the Bayne and Klug classification, type N denotes a normal-length radius with a normal carpus and thumb hypoplasia, type 0 a normal-length radius with radial-sided carpal anomalies, and type 4 complete absence of the radius.

    True

    James, McCarroll and Manske extended the radiographic Bayne and Klug types so that isolated thumb hypoplasia and carpal anomalies sit in the same spectrum as radial absence: type N has a normal-length radius and a normal carpus with thumb hypoplasia, type 0 a normal-length radius with radial-sided carpal abnormalities, type 1 more than 2 mm of radial shortening, type 2 a hypoplastic radius, type 3 a partial radius with absence of the distal physis, and type 4 complete absence of the radius. In their 196-extremity series every patient had thumb hypoplasia, 82% of type N and 0 extremities had carpal anomalies, and 44% of type 1 limbs had proximal radioulnar synostosis or radial head dislocation.

    • James MA, McCarroll HR, Manske PR. The spectrum of radial longitudinal deficiency: a modified classification. J Hand Surg Am. 1999;24(6):1145-55. PMID 10584934
    • Bayne LG, Klug MS. Long-term review of the surgical treatment of radial deficiencies. J Hand Surg Am. 1987;12(2):169-79. PMID 3559066

  3. 3. In thrombocytopenia–absent radius (TAR) syndrome the thumbs are present despite bilateral absence of the radii, and the thrombocytopenia tends to improve during childhood.

    True

    Toriello characterises TAR syndrome by absent radii with the presence of thumbs and congenital or early-onset thrombocytopenia that tends to resolve in childhood, which distinguishes it from the usual rule that the severity of thumb deficiency parallels the severity of radial deficiency. Albers showed that TAR results from compound inheritance of a rare null allele (usually the 1q21.1 microdeletion) and a low-frequency regulatory SNP in RBM8A, explaining 53 of 55 cases. Recognising TAR matters for surgical timing, because operating during the thrombocytopenic period carries a bleeding risk; Fishman found the proximal ulna to be less dysplastic in TAR than in other type 4 deficiencies, although elbow motion still needs assessment.

    • Toriello HV. Thrombocytopenia-absent radius syndrome. Semin Thromb Hemost. 2011;37(6):707-12. PMID 22102274
    • Albers CA, Paul DS, Schulze H, Freson K, Stephens JC, Smethurst PA, et al.. Compound inheritance of a low-frequency regulatory SNP and a rare null mutation in exon-junction complex subunit RBM8A causes TAR syndrome. Nat Genet. 2012;44(4):435-9, S1-2. PMID 22366785
    • Fishman FG, January AM. Increasing Severity of Radial Longitudinal Deficiency Correlates With the Degree of Proximal Ulnar Hypoplasia. J Hand Surg Am. 2024;50(9):1123.e1-1123.e6. PMID 38970602

  4. 4. A normal full blood count in infancy excludes Fanconi anaemia in a child with radial longitudinal deficiency.

    False

    Fanconi anaemia is a recessive DNA-repair disorder with diverse congenital malformations, progressive pancytopenia and a predisposition to haematological malignancy and solid tumours; the marrow failure usually appears later in childhood, so the blood count can be normal when the limb anomaly presents. Auerbach describes the chromosomal breakage test with diepoxybutane or other cross-linking agents as the unique cellular marker for the diagnosis, which can identify the pre-anaemic patient. Maschke's review requires a renal ultrasound, echocardiogram and full blood count in every child with radial longitudinal deficiency regardless of severity, because the systemic associations (Fanconi anaemia, Holt–Oram syndrome, VACTERL) may be life-threatening; a normal count is part of the work-up but not exclusionary.

    • Auerbach AD. Fanconi anemia and its diagnosis. Mutat Res. 2009;668(1-2):4-10. PMID 19622403
    • Maschke SD, Seitz W, Lawton J. Radial longitudinal deficiency. J Am Acad Orthop Surg. 2007;15(1):41-52. PMID 17213381

  5. 5. Wrist centralisation is indicated regardless of elbow motion, because restoring forearm length compensates for a stiff elbow.

    False

    VanHeest states that wrist centralisation is indicated in children with complete absence of the radius who have an elbow range of motion greater than 90 degrees and a stable medical condition; a radially deviated wrist allows a child with a stiff, extended elbow to reach the mouth, so straightening the wrist can worsen function when elbow flexion is inadequate. Bhat's algorithm lists elbow stiffness as a crucial factor in decision-making, and elbow (proximal ulnar) involvement increases with the severity of the deficiency. The long-term problems of centralisation, recurrent radial deviation and reduced ulnar growth, further temper the indication.

    • VanHeest A. Wrist centralization using the dorsal rotation flap in radial longitudinal deficiency. Tech Hand Up Extrem Surg. 2010;14(2):94-9. PMID 20526162
    • Bhat AK, Pai G M. An Algorithm for Management of Radial Longitudinal Deficiency. J Hand Surg Asian Pac Vol. 2024;29(6):508-518. PMID 39544041