Medizinische Universität Graz Austria/Österreich - Forschungsportal - Medical University of Graz
Gewählte Publikation:
Pfann, M.
Radiographical analysis of 100 total hip replacements with the collarless Corail® stem and a 36 mm ceramic on ceramic bearing with a mean followup of 6,3 years - a retrospective study
Humanmedizin; [ Diplomarbeit ] Graz Medical University; 2017. pp.
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- Autor*innen der Med Uni Graz:
- Betreuer*innen:
- Holzer Lukas
- Leithner Andreas
- Maurer-Ertl Werner
- Altmetrics:
- Abstract:
- Background: In 2016 the Corail® cementless hydroxyapatite (HA) coated hip stem celebrated its 30th anniversary. There is limited data on the midterm results with the use of the collarless version of the Corail® stem. Objectives: In this study we focused on the stem’s subsidence and the presence of radiolucent lines, especially in combination with a 36 mm ceramic-on-ceramic (CoC) hard bearing. Study Design & Methods: This retrospective single center study included 100 total hip replacements (THR) in 94 patients. There were 46 males and 48 females, who underwent THR. The collarless Corail® KS and KHO stems (DePuySynthes Inc., Warsaw, IN, USA) were combined with a Pinnacle® cementless cup (DePuySynthes Inc., Warsaw, IN, USA) and a 36 mm CoC bearing (CeramTec GmbH, Plochingen, Germany). Radiographical analyses were performed independently by two orthopaedic senior surgeons for following parameters: Radiolucent lines (RLL) according to Gruen and Johnston, stress shielding, osteolysis, heterotope ossifications. Biomechanical offset status, leg length, CCD-angle, as well as inclination and anteversion of the cup that were measured by using MediCAD classic®. Hip stem migration was measured with EBRA-FCA® (Einzel-Bild-Röntgen-Analyse-Femoral Component Analysis). Results: Stress shielding was detected in three cases, osteolysis in one. Brooker heterotopic ossification grade 1 was found in eleven, grade 3 in two cases. Especially zone 1 (39%), 8 (32%) and 14 (18%) according to Gruen and Johnston were affected by radiolucent lines. Leg length discrepancies revealed a mean correction from 3,9 mm preoperatively (range: 0,0 – 20,0) to a mean of 4,3 mm (range: 0,0 – 13,0) postoperatively. The mean preoperative acetabular offset measured 35,7 mm (range: 27,0 – 68,0), the mean postoperative offset 31,7 mm (range: 26,0 – 51,0). The mean preoperative femoral offset changed from 39,1 mm (range: 13,0 – 60,0) to 43,3 mm (range: 30,0 – 55,0) postoperatively. The average CCD-angle measured 125,6° preoperatively (range: 102,3 – 141,4) and changed to 135,0° postoperatively (range: 129,2 – 142,8). The average anteversion of the Pinnacle cup measured 20,2° (range: 9,5 - 28,7) and the mean inclination measured 44,3° (range: 30,0 - 62,6). There was no cup with less than 9,5° of anteversion and no cup with a steeper inclination of 62,6°. The EBRA-FCA® measurement revealed an average stem subsidence of 0,26 mm after six months, 0,34 mm after one year, 0,51 mm after two years, 0,53 mm after four years, 0,46 mm after six and 0,60 mm after 8 years. Two stems were revised. One due to aseptic loosening of the stem and the second due to biomechanical discrepancy. One patient complaint of a painless and well-functioning squeaking hip joint without index for revision surgery, but regular follow-up intervals are planned. No other adverse events occurred. Conclusion: The data of this retrospective analysis indicate a stable osseointegration of the cementless hydroxyapatite coated collarless Corail® hip stem despite the use of a challenging large 36 mm hard-on-hard ceramic bearing couple. Subsidence data show less than 0,70 millimeters six years after primary implantation. The obtained results using the collarless Corail® stem with a 36 mm CoC bearing are encouraging with regards to migration and osseointegration of the stem.