This 10-year follow-up study aims to further investigate long-term migration patterns of the uncemented Delta-TT cup and H-MAX S stem, comparing outcomes between ceramic and polyethylene liners. Given the predictive value of early RSA migration patterns at the 2-year mark for identifying implants at risk of aseptic loosening, we hypothesize that the Delta-TT cup will demonstrate good stability at the 10-year postoperative mark. Besides, it is hypothesized that migration of Delta TT-cups is comparable between ceramic and polyethylene liners. The primary objective of this study is to measure the long-term stability of the Delta TT cup, combined with either a ceramic or cross-linked polyethylene liner, by means of RSA at 10-years postoperatively. Secondary objectives are to measure long-term stability of the H-MAX S stem, by means of RSA at 10-year postoperatively. Furthermore the study aims to measure implant survival rates and patient-reported outcomes for both the Delta-TT cup and H-MAX S stem, comparing outcomes between the ceramic and polyethylene group.
Study Type
OBSERVATIONAL
Enrollment
51
Total hip prothesis with a Delta-TT cup, H MAX S Stem and a ceramic liner
Total hip prosthesis with a Delta TT cup, H MAX S stem and polyethylene liner
OLVG Hospital
Amsterdam, North Holland, Netherlands
RECRUITINGLong-term (10-year) migration pattern of the Delta-TT cup compared between a ceramic and polyethylene liner.
Measured in 3D translations and rotations by means of Radiostereometric X-ray images at 10-years postoperatively. Data will be summarized by treatment group. A mixed model analysis will be performed to assess cup migration, with liner type (polyethylene vs. ceramic) as the primary independent value. The primary outcome is the effect of the liner type on implant migration. Differences are considered significant for p-values below 0.05.
Time frame: 10 Years
Long-term (10-year) migration pattern of the H-MAX S Stem compared between a ceramic and polyethylene liner.
Measured in 3D translations and rotations by means of Radiostereometric X-ray images at 10-years postoperatively. Data will be summarized by treatment group. A mixed model analysis will be performed to assess stem migration, with liner type (polyethylene vs. ceramic) as the primary independent value. The primary outcome is the effect of the liner type on implant migration. Differences are considered significant for p-values below 0.05.
Time frame: 10 years
Implant survival of the Delta TT cup and H-MAX S stem.
Survival data will be collected from the Dutch Arthroplasty Register (LROI). The collected data includes: revision (yes/no), Reason for revision and survival in years. Differences in revision rates will be reported, but nog statistically tested since the study is not powered for survival analysis.
Time frame: 10 years
Radiographic signs of osteolysis around the Delta-TT cup.
Radiolucent lines are examined on lateral and anteroposterior X-rays. A radiolucent line is defined as such if the maximum width is equal to or greater than 1 mm. Orthopeadic surgeons will assess the radiolucent lines and will be blinded for liner type (obscured by researcher). Radiolucent lines are assessed in the three acetabular zones defined by DeLee and Charnley. A Chi-square test is used to compare the numer of cases with one or more radiolucent lines between the polyethylene liner group and the ceramix liner group. If there are fewer than 10 observed cases with one or more radiolucent lines in one of the two groups, the Fisher's exact test is used, which is valid for all sample sizes.
Time frame: 10 years
Radiographic signs of osteolysis around the H-Max S stem.
Radiolucent lines are examined on lateral and anteroposterior X-rays. A radiolucent line is defined as such if the maximum width is equal to or greater than 1 mm. Orthopeadic surgeons will assess the radiolucent lines and will be blinded for liner type (obscured by researcher). Radiolucent lines are assessed in the seven zones zones defined by Gruen. A Chi-square test is used to compare the numer of cases with one or more radiolucent lines between the polyethylene liner group and the ceramix liner group. If there are fewer than 10 observed cases with one or more radiolucent lines in one of the two groups, the Fisher's exact test is used, which is valid for all sample sizes.
Time frame: 10 years
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