A new tilt on pelvic radiographs: a pilot study
- 249 Downloads
The aim of this study was to evaluate pelvic tilt on commonly performed measurements on radiography in primary protrusio acetabuli and developmental dysplasia of the hip.
Materials and methods
A dry assembled pelvis and spine skeleton was positioned in an isocentric skull unit and films exposed with increasing degrees of angulation of pelvic tilt. The films were then read by two independent readers for seven different measurements used to evaluate the hips and acetabular: acetabular line to ilioischial line, teardrop appearance, intercristal/intertuberous ratio, co-ordinates of femoral head, centre edge angle, acetabular depth/width ratio and acetabular angle.
There was so much variation in the protrusio results that no formal recommendation of any standard radiographic test can be given. Only the inter tuberous distance is not effected by pelvic tilt. The acetabular angles for developmental dysplasia of the hip showed the most potential with pelvic tilt below 15°.
As pelvic tilt increases, measurements used in protusio become unreliable, and computed tomography/magnetic resonance imaging are probably going to be more accurate as one can directly visualise pelvic intrusion. We recommend a lateral view to assess the degree of pelvic tilt in patients with protrusion to ensure these measurements are valid.
KeywordsPelvic tilt Protrusio acetabuli Iliosischial line Hip dysplasia Centre edge angle
- 1.Resnick D, Niwayama G. Diagnosis of bone and joint disorders. 2nd ed. Philadelphia: Saunders; 1988. p. 3582–3583.Google Scholar
- 4.Friedenberg ZB. Protrusio acetabuli in childhood. J Bone Jt Surg 1963; 45A (2): 373–378.Google Scholar
- 7.MacDonald D. Primary protrusio acetabui—report of an affected family. J Bone Jt Surg 1971; 53B: 30–36.Google Scholar
- 13.Hubbard MJS. The measurement of progression in protrusion acetabuli. Am J Roentgenol 1969; 106: 506–508.Google Scholar
- 15.Koehler A. The borderlands of the normal and early pathological in the skiagram (translated from 1st edition by A Turnbull). London: Ballieve, Tindall & Cox; 1928.Google Scholar
- 16.Sharp IK. Acetabular dysplasia. J Bone Jt Surg 1961; 43B: 268–272.Google Scholar
- 17.Hooper JC, Wyn-Jones E. Primary protrusion of the acetabulum. J Bone Jt Surg 1971; 53B: 23–29.Google Scholar
- 21.Swallow RA, Naglar E, Roebuck EJ, Whitley AS. Clark’s positioning in radiograp1hy. 11th ed. Boston: Butterworth-Heinemann; 1986. p. 134–135.Google Scholar
- 22.Warwich R, Williams P. Grays anatomy. 39rd ed. Amsterdam: Elsevier; 2005. p. 1430.Google Scholar
- 23.Sinnatamby CS. Last’s anatomy. 10th ed. Edinburgh: Churchill-Livingstone; 2003. p. 282.Google Scholar
- 25.Callaghan JJ, Salvati EA, Pellicci PM, Wilson PD, Ranawat CS. Results of revision for mechanical failure after cemented total hip replacement, 1979 to 1982. J Bone Jt Surg 1985; 67A: 1074–1085.Google Scholar
- 26.Wiberg G. Studies on dysplastic acetabula and congenital subluxation of the hip joint—with special reference to the complications of osteoarthritis. Acta Chirgica Scandinavica 1939; 58 (Suppl): 1–135.Google Scholar
- 27.Heyman CH, Herndon CH. Legg–Perthes disease. J Bone Jt Surg 1950; 32A: 767–778.Google Scholar
- 28.Murphy SB, Ganz R, Muller ME. The prognosis of untreated dysplasia of the hip. J Bone Jt Surg 1995; 77: A985–A989.Google Scholar