BACKGROUND: Increasingly, acetabular retroversion is recognized in patients undergoing hip arthroplasty. Although prosthetic component positioning is not determined solely by native acetabular anatomy, acetabular retroversion presents a dilemma for component positioning if the surgeon implants the device in the anatomic position. QUESTIONS/PURPOSES: We asked (1) whether there is a difference in ROM between surface replacement arthroplasty (SRA) and THA in the retroverted acetabulum, and (2) does increased femoral anteversion improve ROM in the retroverted acetabulum? METHODS: Using a motion analysis tracking system, we determined the ROM of eight cadaveric hips and then created virtual CT-reconstructed bone models of each specimen. ROM was determined with THA and SRA systems virtually implanted with (1) the acetabular component placed in 45° abduction and matching the acetabular anteversion (average 23° ± 4°); (2) virtually retroverting the bony acetabulum 10°; and (3) after anteverting the THA femoral stem 10°. RESULTS: SRA resulted in ROM deficiencies in four of six maneuvers, averaging 25% to 29% in the normal and retroverted acetabular positions. THA restored ROM in all six positions in the normal acetabulum and in four of the six retroverted acetabula. The two deficient positions averaged 5% deficiency. THA with increased femoral stem anteversion restored ROM in five positions and showed only a 2% deficiency in the sixth position. Compared with the intact hip, ROM deficits were seen after SRA in the normal and retroverted acetabular positions and to a lesser extent for THA which can be improved with increased femoral stem anteversion. CONCLUSION: Poor ROM may result after SRA if acetabular retroversion is present.
BACKGROUND: Increasingly, acetabular retroversion is recognized in patients undergoing hip arthroplasty. Although prosthetic component positioning is not determined solely by native acetabular anatomy, acetabular retroversion presents a dilemma for component positioning if the surgeon implants the device in the anatomic position. QUESTIONS/PURPOSES: We asked (1) whether there is a difference in ROM between surface replacement arthroplasty (SRA) and THA in the retroverted acetabulum, and (2) does increased femoral anteversion improve ROM in the retroverted acetabulum? METHODS: Using a motion analysis tracking system, we determined the ROM of eight cadaveric hips and then created virtual CT-reconstructed bone models of each specimen. ROM was determined with THA and SRA systems virtually implanted with (1) the acetabular component placed in 45° abduction and matching the acetabular anteversion (average 23° ± 4°); (2) virtually retroverting the bony acetabulum 10°; and (3) after anteverting the THA femoral stem 10°. RESULTS:SRA resulted in ROM deficiencies in four of six maneuvers, averaging 25% to 29% in the normal and retroverted acetabular positions. THA restored ROM in all six positions in the normal acetabulum and in four of the six retroverted acetabula. The two deficient positions averaged 5% deficiency. THA with increased femoral stem anteversion restored ROM in five positions and showed only a 2% deficiency in the sixth position. Compared with the intact hip, ROM deficits were seen after SRA in the normal and retroverted acetabular positions and to a lesser extent for THA which can be improved with increased femoral stem anteversion. CONCLUSION: Poor ROM may result after SRA if acetabular retroversion is present.
Authors: Amir A Jamali; Kiril Mladenov; Dominik C Meyer; Alberto Martinez; Martin Beck; Reinhold Ganz; Michael Leunig Journal: J Orthop Res Date: 2007-06 Impact factor: 3.494
Authors: R Stephen J Burnett; Gregory J Della Rocca; Heidi Prather; Madelyn Curry; William J Maloney; John C Clohisy Journal: J Bone Joint Surg Am Date: 2006-07 Impact factor: 5.284
Authors: Anisha B Patel; Rohan R Wagle; Molly M Usrey; Matt T Thompson; Stephen J Incavo; Philip C Noble Journal: J Arthroplasty Date: 2009-12-21 Impact factor: 4.757
Authors: Thomas P Schmalzried; Mauricio Silva; Mylene A de la Rosa; Eui-Sung Choi; Vincent A Fowble Journal: Clin Orthop Relat Res Date: 2005-12 Impact factor: 4.176
Authors: Reinhold Ganz; Javad Parvizi; Martin Beck; Michael Leunig; Hubert Nötzli; Klaus A Siebenrock Journal: Clin Orthop Relat Res Date: 2003-12 Impact factor: 4.176