Poster Presentation NZ Association of Plastic Surgeons & NZ Society for Surgery of the Hand

Radiological prevalence of type 1 and type 2 lunates in the asymptomatic population. (1450)

Sam Hamilton 1 , Trudy Hong 1 , James Leong 1
  1. Plastic and Reconstructive Surgery , Monash Health, Melbourne, VIC, Australia


The lunate is the ‘keystone’ of the wrist. In 1993 Viegas et al1 first described two distinct lunate morphologies. Key features of Type 1 are the single distal facet that articulates with the capitate, whereas Type 2 is characterised by two facets articulating the capitate and hamate. Assessment can be completed radiographically or under direct visualization2. MRI has been reported as the most accurate imaging modality for identifying lunate morphology2. Lunate types have an impact on kinematics of the wrist and clinical presentations of wrist pathology3. We aim to establish the radiological prevalence of lunate types.



After ethics approval was obtained (Monash Health Reference RES-21-0000-023L), participants were recruited in a prospective manner. 14 high resolution MRIs of the wrist were completed on asymptomatic participants. Assessment of lunate morphology was completed in the coronal plane. A review of the literature was also completed.



50% of the study population have Type 2 lunates. Type 2 lunates have varied prevalence published in the literature, ranging from 46.2 to 68.2%4.



Coronal MRI has been established as an accurate way to assess lunate types2. Type 2 lunates lend additional stability to the carpus and can help protect against the progression of degenerative lunate pathology. Understanding the underlying anatomy assists with clinical decision making, including suggested operative interventions, and expected outcomes following surgery4.


  1. Viegas SF, Patterson RM, Hokanson JA, et al. Wrist anatomy: incidence, distribution, and correlation of anatomic variations, tears, and arthrosis. J Hand Surg Am. May 1993;18(3):463-475. doi: 10.1016/0363-5023(93)90094-j.
  2. McLean JM, Bain GI, Watts AC, et al. Imaging recognition of morphological variants at the midcarpal joint. J Hand Surg Am. Jul-Aug 2009;34(6):1044-1055. doi: 10.1016/j.jhsa.2009.03.002.
  3. Pang EQ, Douglass N, Kamal RN. Association of Lunate Morphology With Carpal Instability in Scapholunate Ligament Injury. Hand (N Y). Jul 2018;13(4):418-422. doi: 10.1177/1558944717709073.
  4. Kim BJ, Kovacevic D, Lee YM, et al. The Role of Lunate Morphology on Scapholunate Instability and Fracture Location in Patients Treated for Scaphoid Nonunion. Clinics in orthopedic surgery. 2016; 8(2): 175-80. doi:10.4055/cios.2016.8.2.175
  5. Rhee PC, Jones DB, Moran SL, Shin AY. The effect of lunate morphology in Kienböck disease. J Hand Surg Am. 2015;40(4):738-44. doi: 10.1016/j.jhsa.2014.12.024.