S D Steppacher1, T D Lerch2, K Gharanizadeh3, E F Liechti4, S F Werlen5, M Puls6, M Tannast7, K A Siebenrock8. 1. Department of Orthopaedic Surgery and Traumatology, Inselspital, University of Bern, Bern, Switzerland. Electronic address: simon.steppacher@insel.ch. 2. Department of Orthopaedic Surgery and Traumatology, Inselspital, University of Bern, Bern, Switzerland. Electronic address: till.lerch@bluewin.ch. 3. Department of Orthopaedic Surgery and Traumatology, Inselspital, University of Bern, Bern, Switzerland. Electronic address: kaveh.gharani@gmail.com. 4. Department of Orthopaedic Surgery and Traumatology, Inselspital, University of Bern, Bern, Switzerland. Electronic address: emanuel.liechti@gmail.com. 5. Department of Radiology, Sonnenhof Clinic, Bern, Switzerland. Electronic address: stefan.werlen@sonnenhof.ch. 6. Department of Orthopaedic Surgery and Traumatology, Inselspital, University of Bern, Bern, Switzerland. Electronic address: marcpuls@bluewin.ch. 7. Department of Orthopaedic Surgery and Traumatology, Inselspital, University of Bern, Bern, Switzerland. Electronic address: moritz.tannast@insel.ch. 8. Department of Orthopaedic Surgery and Traumatology, Inselspital, University of Bern, Bern, Switzerland. Electronic address: klaus.siebenrock@insel.ch.
Abstract
OBJECTIVE: Acetabular rim trimming is indicated in pincer hips with an oversized lunate surface but could result in a critically decreased size of the lunate surface in pincer hips with acetabular malorientation. There is a lack of detailed three-dimensional anatomy of lunate surface in pincer hips. Therefore, we questioned how does (1) size and (2) shape of the lunate surface differ among hips with different types of pincer impingement? METHOD: We retrospectively compared size and shape of the lunate surface between acetabular retroversion (48 hips), deep acetabulum (34 hips), protrusio acetabuli (seven hips), normal acetabuli (30 hips), and hip dysplasia (45 hips). Using magnetic resonance imaging (MRI) arthrography with radial slices we measured size in percentage of the femoral head coverage and shape using the outer (inner) center-edge angles and width of lunate surface. RESULTS: Hips with retroversion had a decreased size and deep hips had normal size of the lunate surface. Both had a normal shape of the outer acetabular rim. Protrusio hips had an increased size and a prominent outer acetabular rim. In all three types of pincer hips the acetabular fossa was increased. CONCLUSION: Size and shape of the lunate surface differs substantially among different types of pincer impingement. In contrast to hips with protrusio acetabuli, retroverted and deep hips do not have an increased size of the lunate surface. Acetabular rim trimming in retroverted and deep hips should be performed with caution. Based on our results, acetabular reorientation would theoretically be the treatment of choice in retroverted hips.
OBJECTIVE: Acetabular rim trimming is indicated in pincer hips with an oversized lunate surface but could result in a critically decreased size of the lunate surface in pincer hips with acetabular malorientation. There is a lack of detailed three-dimensional anatomy of lunate surface in pincer hips. Therefore, we questioned how does (1) size and (2) shape of the lunate surface differ among hips with different types of pincer impingement? METHOD: We retrospectively compared size and shape of the lunate surface between acetabular retroversion (48 hips), deep acetabulum (34 hips), protrusio acetabuli (seven hips), normal acetabuli (30 hips), and hip dysplasia (45 hips). Using magnetic resonance imaging (MRI) arthrography with radial slices we measured size in percentage of the femoral head coverage and shape using the outer (inner) center-edge angles and width of lunate surface. RESULTS: Hips with retroversion had a decreased size and deep hips had normal size of the lunate surface. Both had a normal shape of the outer acetabular rim. Protrusio hips had an increased size and a prominent outer acetabular rim. In all three types of pincer hips the acetabular fossa was increased. CONCLUSION: Size and shape of the lunate surface differs substantially among different types of pincer impingement. In contrast to hips with protrusio acetabuli, retroverted and deep hips do not have an increased size of the lunate surface. Acetabular rim trimming in retroverted and deep hips should be performed with caution. Based on our results, acetabular reorientation would theoretically be the treatment of choice in retroverted hips.
Authors: Markus S Hanke; Simon D Steppacher; Corinne A Zurmühle; Klaus A Siebenrock; Moritz Tannast Journal: Clin Orthop Relat Res Date: 2016-10 Impact factor: 4.176
Authors: Benjamin Fritz; Christoph A Agten; Franca K Boldt; Patrick O Zingg; Christian W A Pfirrmann; Reto Sutter Journal: Eur Radiol Date: 2019-03-22 Impact factor: 5.315
Authors: Corinne A Zurmühle; Helen Anwander; Christoph E Albers; Markus S Hanke; Simon D Steppacher; Klaus A Siebenrock; Moritz Tannast Journal: Clin Orthop Relat Res Date: 2016-12-05 Impact factor: 4.176
Authors: Christoph E Albers; Andrea Schwarz; Markus S Hanke; Karl-Philipp Kienle; Stefan Werlen; Klaus A Siebenrock Journal: Clin Orthop Relat Res Date: 2017-04 Impact factor: 4.176
Authors: Silvio Pflugi; Rakesh Vasireddy; Till Lerch; Timo M Ecker; Moritz Tannast; Nane Boemke; Klaus Siebenrock; Guoyan Zheng Journal: Int J Comput Assist Radiol Surg Date: 2017-11-29 Impact factor: 2.924