Frykman classification of distal radius fractures

vigente

Two-axis morphology label based on radiocarpal and distal-radioulnar joint involvement plus an associated distal-ulna or ulnar-styloid fracture; type numbers are not an ordinal severity or treatment scale.

Índice de referência, não é suporte à decisão clínica. O RadCommons apresenta conteúdo de referência reescrito a partir de critérios publicados e com link para a fonte primária. Confira sempre a publicação primária vigente. Não é um dispositivo médico nem substitui o julgamento clínico. O radiologista responsável pelo laudo permanece o autor e o responsável.

Escala de categorias

I II III IV V VI VII VIII

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Procedência e vigência

Órgão emissor: Frykman / historical orthopedic classification
Versão: 1967
Ano: 1967
Família: léxico
Tipo de lógica: flat
Modalidade: XR, CT
Fonte primária: Fracture of the distal radius including sequelae—shoulder-hand-finger syndrome, disturbance in the distal radio-ulnar joint and impairment of nerve function · doi:10.3109/ort.1967.38.suppl-108.01
Última verificação: 2026-07-24
Última checagem: 2026-07-24

Lógica de decisão

Forma estruturada (flat). Uma futura calculadora a lê; as categorias abaixo são a superfície legível.

Return the two observed axes with the Roman type. The scheme does not encode displacement, comminution, stability, treatment, or calibrated prognosis, and its limited reliability must remain visible to downstream agents.

Mostrar a lógica estruturada (JSON)

{
  "categories": [
    "I",
    "II",
    "III",
    "IV",
    "V",
    "VI",
    "VII",
    "VIII"
  ],
  "applicability": {
    "use_for": "Morphologic description of a distal radius fracture using joint-surface extension and the presence or absence of an associated distal-ulna or ulnar-styloid fracture.",
    "historical_basis": "Conventional wrist radiographs; CT may change recognition of radiocarpal or sigmoid-notch extension but must not be assumed when it was not obtained.",
    "required_inputs": [
      "radiocarpal_joint_involvement",
      "distal_radioulnar_joint_or_sigmoid_notch_involvement",
      "associated_distal_ulna_or_ulnar_styloid_fracture",
      "imaging_modality_and_adequacy"
    ]
  },
  "axes": {
    "articular_pattern": [
      {
        "value": "neither_joint",
        "paired_types": [
          "I",
          "II"
        ]
      },
      {
        "value": "radiocarpal_only",
        "paired_types": [
          "III",
          "IV"
        ]
      },
      {
        "value": "distal_radioulnar_only",
        "paired_types": [
          "V",
          "VI"
        ]
      },
      {
        "value": "both_radiocarpal_and_distal_radioulnar",
        "paired_types": [
          "VII",
          "VIII"
        ]
      }
    ],
    "associated_ulna_fracture": [
      {
        "value": "absent",
        "parity": "odd",
        "types": [
          "I",
          "III",
          "V",
          "VII"
        ]
      },
      {
        "value": "present",
        "parity": "even",
        "types": [
          "II",
          "IV",
          "VI",
          "VIII"
        ]
      }
    ]
  },
  "mapping_table": [
    {
      "articular_pattern": "neither_joint",
      "ulna_fracture": "absent",
      "outcome_code": "I"
    },
    {
      "articular_pattern": "neither_joint",
      "ulna_fracture": "present",
      "outcome_code": "II"
    },
    {
      "articular_pattern": "radiocarpal_only",
      "ulna_fracture": "absent",
      "outcome_code": "III"
    },
    {
      "articular_pattern": "radiocarpal_only",
      "ulna_fracture": "present",
      "outcome_code": "IV"
    },
    {
      "articular_pattern": "distal_radioulnar_only",
      "ulna_fracture": "absent",
      "outcome_code": "V"
    },
    {
      "articular_pattern": "distal_radioulnar_only",
      "ulna_fracture": "present",
      "outcome_code": "VI"
    },
    {
      "articular_pattern": "both_radiocarpal_and_distal_radioulnar",
      "ulna_fracture": "absent",
      "outcome_code": "VII"
    },
    {
      "articular_pattern": "both_radiocarpal_and_distal_radioulnar",
      "ulna_fracture": "present",
      "outcome_code": "VIII"
    }
  ],
  "assignment_steps": [
    "Inspect the distal radius for extension into the radiocarpal articular surface.",
    "Separately inspect the sigmoid notch for extension into the distal radioulnar joint.",
    "Choose exactly one of the four articular patterns; involvement of both joints must map to VII or VIII rather than either single-joint row.",
    "Then apply the associated distal-ulna or ulnar-styloid axis: absent gives the odd member and present gives the even member of the pair."
  ],
  "nonordinal_rule": "Roman numerals encode a two-axis combination. A higher number must not be translated into greater displacement, comminution, instability, urgency, prognosis, or a stronger treatment indication.",
  "missing_or_conflicting_input_behavior": [
    "If either joint surface cannot be assessed, return Frykman type unresolved and identify the missing surface rather than choosing the nearest row.",
    "If CT contradicts radiographs about joint extension, use the best-supported final morphology, name the modality that changed the assignment, and retain the initial uncertainty in the report.",
    "Do not treat an unconfirmed tiny ossicle as an associated ulnar fracture; state uncertainty and seek prior imaging or additional views when clinically material."
  ],
  "outside_model_but_required_for_care": [
    "fracture_displacement_and_direction",
    "radial_height_and_shortening",
    "radial_inclination_and_tilt",
    "articular_step_off_or_gap",
    "comminution",
    "DRUJ_congruity_and_stability",
    "carpal_or_ligament_injury",
    "open_injury",
    "neurovascular_and_soft_tissue_findings",
    "bone_quality",
    "patient_age_function_and_goals"
  ],
  "reliability_evidence": [
    {
      "study": "Andersen_1996",
      "population": "55_radiograph_sets_four_expert_observers",
      "result": "Frykman_interobserver_agreement_fair_and_most_intraobserver_results_fair_to_moderate",
      "implication": "not_warranted_as_the_sole_basis_for_treatment_direction"
    },
    {
      "study": "Kleinlugtenbelt_2017",
      "population": "51_displaced_fractures_four_experienced_surgeons",
      "conventional_radiograph_ICC": {
        "intraobserver": "0.57_fair",
        "interobserver": "0.45_fair"
      },
      "radiograph_plus_CT_ICC": {
        "intraobserver": "0.51_fair",
        "interobserver": "0.28_poor"
      },
      "implication": "CT_changed_accuracy_of_some_assignments_but_did_not_improve_Frykman_reliability"
    }
  ],
  "output_contract": [
    "report_Frykman_type",
    "spell_out_radiocarpal_and_DRUJ_involvement",
    "state_presence_or_absence_of_associated_ulna_or_ulnar_styloid_fracture",
    "state_modality_and_any_unresolved_surface",
    "separately_report_displacement_comminution_alignment_stability_and_soft_tissue_findings",
    "do_not_emit_a_treatment_or_numeric_risk_from_type_alone"
  ],
  "supporting_sources": [
    {
      "role": "original_classification",
      "doi": "10.3109/ort.1967.38.suppl-108.01",
      "pmid": "4175195"
    },
    {
      "role": "primary_reliability_study",
      "doi": "10.1016/S0363-5023(96)80006-2",
      "pmid": "8842946"
    },
    {
      "role": "prospective_CT_reliability_study_and_open_type_table",
      "doi": "10.1080/17453674.2017.1338066",
      "pmid": "28612669",
      "pmcid": "PMC5694815"
    }
  ],
  "source_locator": "Frykman 1967, PMID 4175195 and DOI 10.3109/ort.1967.38.suppl-108.01, original classification; Kleinlugtenbelt et al. 2017, PMC5694815, Table 3 for all eight mappings, Tables 4-5 and Frykman Results for reliability; Andersen et al. 1996, PMID 8842946, abstract for standalone-treatment limitation."
}

Categorias num relance

Cat.	Significado	Conduta	Risco	Fonte
I	Type I, neither joint involved, no associated ulna fracture Distal radius fracture with no extension into either the radiocarpal joint or the distal radioulnar joint, and without an associated distal-ulna or ulnar-styloid fracture.	Use Type I only as the two-axis morphology label. Separately report displacement, shortening, angulation, comminution, stability, soft-tissue and neurovascular findings, and patient factors before any treatment decision.	Type I is not synonymous with stable or low risk. Plain radiographs can underestimate articular extension, and Frykman type does not provide a calibrated prognosis or treatment-failure probability.	okfonte Kleinlugtenbelt et al. 2017, PMC5694815, Table 3 (Type I extra-articular), Frykman Results and Tables 4-5 (limited reliability); Andersen et al. 1996, PMID 8842946, abstract (classification alone should not direct treatment).
II	Type II, neither joint involved, associated ulna fracture Distal radius fracture with no extension into either the radiocarpal or distal radioulnar joint, with an associated distal-ulna or ulnar-styloid fracture. The associated ulna finding changes the odd Type I to even Type II.	Describe the associated ulna or styloid fracture and assess DRUJ congruity and stability separately. Type II does not specify displacement, instability, fixation need, or the clinical significance of the ulnar component.	The even-number modifier does not supply an event probability or automatically increase severity. Prognosis depends on morphology and clinical variables that Frykman does not encode.	okfonte Kleinlugtenbelt et al. 2017, PMC5694815, Table 3 (Type II extra-articular with ulnar fracture); Frykman 1967, PMID 4175195; Andersen et al. 1996, PMID 8842946, reliability and standalone-use limitation.
III	Type III, radiocarpal joint only, no associated ulna fracture Distal radius fracture extending into the radiocarpal joint but not the distal radioulnar joint, without an associated distal-ulna or ulnar-styloid fracture.	Report the radiocarpal articular step-off or gap, displacement and comminution separately and verify the sigmoid notch. Type III identifies a joint surface but does not choose operative versus nonoperative care.	Radiocarpal involvement is morphologically important, but Type III is not a calibrated arthritis, instability, functional-outcome, or surgical-benefit score.	okfonte Kleinlugtenbelt et al. 2017, PMC5694815, Table 3 (Type III intra-articular into radiocarpal joint) and reliability Results; Andersen et al. 1996, PMID 8842946.
IV	Type IV, radiocarpal joint only, associated ulna fracture Distal radius fracture extending into the radiocarpal joint but not the distal radioulnar joint, with an associated distal-ulna or ulnar-styloid fracture. The ulna component changes III to IV.	Characterize radiocarpal congruity, displacement, comminution and the ulna or styloid injury independently. The Type IV label does not establish DRUJ instability or prescribe fixation of either bone.	Type IV combines radiocarpal and ulna morphology without quantifying prognosis. The numeral must not be interpreted as a validated severity rank or patient-specific risk estimate.	okfonte Kleinlugtenbelt et al. 2017, PMC5694815, Table 3 (Type IV radiocarpal involvement with ulnar fracture), Tables 4-5; Frykman 1967, PMID 4175195.
V	Type V, distal radioulnar joint only, no associated ulna fracture Distal radius fracture extending into the distal radioulnar joint at the sigmoid notch but not the radiocarpal joint, without an associated distal-ulna or ulnar-styloid fracture.	State sigmoid-notch involvement and assess DRUJ congruity and stability directly; also report displacement and any occult radiocarpal extension. Type V is descriptive and does not determine reduction or fixation strategy.	DRUJ-surface involvement does not yield a numeric instability or functional-outcome probability. The limited reliability of Frykman assignment should remain visible when the sigmoid notch is equivocal.	okfonte Kleinlugtenbelt et al. 2017, PMC5694815, Table 3 (Type V intra-articular into radioulnar joint) and Frykman reliability Results; Andersen et al. 1996, PMID 8842946.
VI	Type VI, distal radioulnar joint only, associated ulna fracture Distal radius fracture extending into the distal radioulnar joint but not the radiocarpal joint, with an associated distal-ulna or ulnar-styloid fracture. The ulna component changes V to VI.	Describe the sigmoid-notch extension, DRUJ congruity and stability, and the associated ulna injury separately. Type VI does not state displacement, instability, urgency, or whether an ulnar fragment requires treatment.	Type VI is a morphology combination without a calibrated complication or outcome probability. Even numbering denotes the ulna axis, not a validated increase in severity.	okfonte Kleinlugtenbelt et al. 2017, PMC5694815, Table 3 (Type VI radioulnar involvement with ulnar fracture), Tables 4-5; Frykman 1967, PMID 4175195.
VII	Type VII, both joints involved, no associated ulna fracture Distal radius fracture extending into both the radiocarpal and distal radioulnar joints, without an associated distal-ulna or ulnar-styloid fracture. Joint involvement alone does not require comminution.	Characterize both articular surfaces, step-off or gap, displacement, comminution, DRUJ congruity and stability, and soft-tissue injury. Type VII does not prescribe surgery or a specific construct.	Both joints are involved, but VII is not defined as 'most fragmented' and is not a numeric severity or prognostic category. Outcome depends on features outside the Frykman axes.	okfonte Kleinlugtenbelt et al. 2017, PMC5694815, Table 3 (Type VII radiocarpal plus radioulnar joints) and Results; original Frykman citation PMID 4175195; Andersen et al. 1996, PMID 8842946.
VIII	Type VIII, both joints involved, associated ulna fracture Distal radius fracture extending into both the radiocarpal and distal radioulnar joints, with an associated distal-ulna or ulnar-styloid fracture. The ulna component changes VII to VIII; comminution is not part of the definition.	Report both articular surfaces and the associated ulna injury, plus displacement, comminution, alignment, DRUJ stability and soft tissues. Type VIII alone does not mandate surgery or define the operative approach.	VIII is the even member of the both-joints pair, not an automatic 'most severe' designation. Frykman supplies no calibrated prognosis, and study agreement remained limited even with CT.	okfonte Kleinlugtenbelt et al. 2017, PMC5694815, Table 3 (Type VIII both joints with ulnar fracture), Tables 4-5 and Frykman Results; Andersen et al. 1996, PMID 8842946.

Histórico de versões

Data	Evento	Detalhe	Situação
1967-01-01	published	Frykman published the eight-type distal-radius fracture classification in Acta Orthopaedica Scandinavica Supplementum 108.	confirmado

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