EBRA Study AMISTEM-C FR

The primary endpoint is the measurement of femoral component migration by EBRA-FCA software (The Ein Bild Roentgen Analyse-femoral component analysis, Innsbruck, Austria) with an accuracy of ± 1.5 mm (95% percentile), a specificity of 100% and a sensitivity of 78% for the detection of a migration of more than 1.0 mm, referring to the RSA method. The EBRA-FCA method is based on the detection of 19 points on the bony femur and the femoral component, as well as two lines to determine the axis of the implant on successive radiographs of the front pelvis. The correction of the radiological enlargement is performed based on the known diameter of the prosthetic femoral component. Lengths are measured from anatomical reference points to ensure comparability of the radiographs. The change in the distance between the top of the greater trochanter and the shoulder of the prosthesis is used to measure the migration of the femoral component.

The survival rate according to a Kaplan Meier curve. The Kaplan-Meier method calculates the survival of the prosthesis by measuring the fraction of living subjects during a period after the procedure. Each time an expected event occurs (revision of the prosthesis, patients lost to follow-up, death, etc.), the probability of implant survival changes. This information is used to estimate the performance of the prosthesis.

During the study, the number of stem revisions and the number of patients who died or were lost to follow-up will be collected to calculate the probability of survival. The time of occurrence will be recorded for each event.

Evaluation of the Harris Hip Score The Harris Hip Score (HHS) items include an analysis of the operated hip according to pain, function, mobility, stability and deformity analysis. The Harris Hip Score will be used to assess the patient's subjective and objective improvement in the above criteria. The usefulness of this score has been studied to estimate the clinical results after THR, it is a reference score in the field of orthopedics.

The Harris hip score is scored from 0 (worst functional outcome and maximum pain) to 100 points (best functional outcome and least pain).

Merle d'Aubigné functional score The Postel and Merle d'Aubigné (PMA) score: a method for grading the functional value of the hip form a minimum of 0 to a maximum of 18 points.

Collection of intra- and postoperative complications (infection, loosening,etc)

Collection of Oxford Hip Score: It is a score composed of 12 questions evaluating the function and pain of the hip before and after arthroplasty.

The scores for the 0-48 scale can be interpreted as follows[6]:

Score 0 to 19 May indicate severe hip arthritis. It is highly likely that you may well require some form of surgical intervention, contact your family physician for a consult with an orthopaedic surgeon.

Score 20 to 29 May indicate moderate to severe hip arthritis. See your family physician for an assessment and x-ray. Consider a consult with an orthopaedic surgeon.

Score 30 to 39 May indicate mild to moderate hip arthritis. Consider seeing your family physician for an assessment and possible x-ray. You may benefit from non-surgical treatment, such as exercise, weight loss, and/ or anti-inflammatory medication.

Score 40 to 48 May indicate satisfactory joint function. May not require any formal treatment.

-Standard X-ray to identify radiolucencies and endosteal cavitations