Primary Uncemented Partly Ti-coated Total Hip Prosthesis With and Without HA, and Alumina-on-alumina Articulation

University Hospital of North Norway400 enrolled

Overview

Both HA coated and certain uncoated femoral stems have good results in general. On the cup side the results are more variable, either with or without HA. HA may delaminate from the prosthesis, damage the articulation, witch may lead to osteolysis and aseptic loosening. The investigators are investigating whether a well working uncemented hip prosthesis design with HA coating, will perform without HA in the long run, when the investigators use pure Ti macrostructure and alumina on alumina articulation. Hypothesis: The bone ingrowth will be equal when the surface has almost equal roughness in Ti and HA version. This means that HA on Ti is not necessary with a well functioning prosthesis design. 0-hypothesis:The two prosthesis perform equal in survival, clinically (HHS),radiographic and in patient satisfaction at 2, 5, 10, 15 and 20 years.

Investigate survival of the implants and possible biological consequences. Clinical outcome with Harris Hip Score. Radiographic outcome with a modified protocol after JRC, JBJS 1990. Patient satisfaction with the hip prosthesis (five categories). Grit blasted TiAL6V4 + pure Ti versus grit blasted TiAL6V4 + pure Ti +HA, with almost the same roughness. Screw cup, double tapered stem, partly double coated cup, proximally double coated stem. Prospective RCT. Multicenter ( Three hospitals). Selected surgeons. Non-inferiority-design. At present 569 hips (391 patients, 178 bilateral) are randomized into the study. Inclusion of patients into the study stopped in January 2013. 548 hips have completed follow ups at an average of 2 years, 301 hips have completed follow ups at an average of 5 years and 60 hips at 8-10 years.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Enrollment

400

Eligibility

Sex: ALLMin age: 18 YearsMax age: 70 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Primary or secondary osteoarthrosis. * Both gender, less than seventy years. * Patients operated for FCF and patients with previous osteotomies are included. Exclusion Criteria: * Treatment with Prednisolon. * Osteomyelitis. * Serious infections illnesses. * Cancer or metastasis. * Rheumatoid arthritis. * Osteonecrosis after use of alcohol or medicaments. * Kidney illnesses. * Metabolic bone diseases. * Earlier hip arthrodesis. * Allergic reactions on implants. * Patients who do not cooperate on rehabilitation.

Outcomes

Primary Outcomes

Survival with revision as endpoint.

Time frame: 5-20 years

Secondary Outcomes

Clinical outcome with Harris Hip Score.

Time frame: 10-30 years

Radiographic outcome.

The radiographic evaluation will be carried out postoperatively, 2, 5, 10, 15 and 20 years after the operations with the same protocol modified after Johnston et al, JBJS Am. 1990;72: page 166. We judge and compare a.p pelvic x-rays calibrated on the computer.

Time frame: 10-30years

Patient satisfaction with the hip prosthesis.

At the consultations we ask the patient if he/she is satisfied with the hip. The patient may answer i 5 categories (dissatisfied, not satisfied, satisfied, very satisfied and very much satisfied). We also have registrations on early and late complications, leg length discrepancy, Trendelenburg lurch etc.