Model-based roentgen stereophotogrammetric analysis using elementary geometrical shape models: 10 years results of an uncemented acetabular cup component

Abstract

BackgroundNon-cemented acetabular cup components demonstrated different clinical performance depending on their surface texture or bearing couple. However, clinical osseointegration needs to be proved for each total joint arthroplasty (TJA) design. Aim of this study was to detect the in vivo migration pattern of a non-cemented cup design, using model-based roentgen stereophotogrammetric analysis with elementary geometrical shape models (EGS-RSA) to calculate early cup migration.MethodsInterchangeable applicability of the model-based EGS-RSA method next to gold standard marker-based RSA method was assessed by clinical radiographs. Afterwards, in vivo acetabular cup migration for 39 patients in a maximum follow up of 120 months (10 years) was calculated using model-based EGS-RSA.ResultsFor the axes with the best predictive capability for acetabular cup loosening, mean (±SD) values were calculated for migration and rotation of the cup. The cup migrated 0.16 (±0.22) mm along the cranio-caudal axis after 24 months and 0.36 (±0.72) mm after 120 months, respectively. It rotated − 0.61 (±0.57) deg. about the medio-lateral axis after 24 months and − 0.53 (±0.67) deg. after 120 months, respectively.ConclusionsInterchangeable applicability of model-based EGS-RSA next to gold standard marker-based RSA method could be shown. Model-based EGS-RSA enables an in vivo migration measurement without the necessity of TJA specific surface models. Migration of the investigated acetabular cup component indicates significant migration values along all the three axes. However, migration values after the second postoperative year were within the thresholds reported in literature, indicating no risk for later aseptic component loosening of this TJA design.

A prospective and consecutive study assessing short-term clinical and radiographic outcomes of Chinese domestically manufactured 3D printing trabecular titanium acetabular cup for primary total hip arthroplasty: evaluation of 236 cases

“…However, when dealing with cases with poor bone quality or quantity in primary THA such as osteoporosis, radiation-induced bone necrosis, and bone defects, the above-mentioned techniques may only provide limited initial stability. At the same time, some studies have reported galvanic effects of traditional cup and failures due to debonding of sintered titanium beads and titanium coating (6)(7)(8)24).…”

“…It has demonstrated good clinical outcomes and mid-to long-term survival rates in primary THA (4,5). While surface manufacturing techniques like plasma spraying, high-temperature sintering, and electrophoretic deposition have been used to produce favorable surfaces for bone ingrowth in non-cemented cups, there have been numerous reports documenting failures attributed to debonding of sintered titanium beads and coating (6)(7)(8).…”

Migration patterns of acetabular cups: a systematic review and meta-analysis of RSA studies

“…Unfortunately, we were unable to analyze pooled proximal migration beyond the 5-year timepoint as only 8 RSA studies reported proximal migration at 10 years. 3 of the 8 long-term cohorts reported increasing migration between 5 and 10 years [19,25,31], suggesting that more long-term RSA studies are required to investigate the patterns of continued migration.…”

Minimum ten-year follow-up of a randomized trial comparing acetabular component fixation of two porous in-growth surfaces using radiosteriometric analysis

“…Pijls et al 23 demonstrated a clinically relevant association between early migration of acetabular components and late revision in a meta-analysis of RSA studies. Nevertheless, there is a paucity of long-term RSA data 24 - 29 validating the ability of early RSA migration data to predict long-term clinical success. Our study is one of very few studies which have reported long-term RSA migration data of cementless acetabular components beyond ten years.…”