The purpose of this prospective randomized study is to compare the quality of treatment between cemented versus uncemented hydroxyapatite coated femoral stems in Total Hip Arthroplasty (THA) in patients who suffers from dislocated femoral neck fractures.

Our hypothesis is that an uncemented option spares the patient the operative load of the cementing procedure, i e risk of fatty embolism and inflammatory response, which in turn also perhaps reduces the postoperative cognition strain and improves mobilization parameters.

If the uncemented option has the same excellent fixation in poor bone stock, as in the case of these osteopenic fractures, and also has the same good clinical outcome, it would be a viable standard option for the treatment of dislocated femoral neck fractures.

Corail-SP study. A prospective randomized study to compare the quality of treatment between cemented versus uncemented hydroxyapatite coated femoral stems in Total Hip Arthroplasty (THA) in patients who suffers from dislocated femoral neck fractures.

Femoral neck fractures often occurs among the fragile elderly patients who have a higher degree of co-morbidity. The 3-month mortality is 13%. The incidence of risk of fracture complications when using osteosyntheses are as high as 30-40%, mainly due to non union, which leads to impairments in quality of life, locomotion and pain.

For that reason more patients nowadays are submitted to a cemented hemiarthroplasty or a total hip arthroplasty directly after their injury - at the same time the problem with fatty embolism syndrome has been recognized. When cementing during surgery, the bone marrow is pushed into the blood stream, which can affect the cardiopulmonary function and even the mental functions.

As a measure for reducing those risks an uncemented hip arthroplasty is sometimes used instead.

The pros and cons with uncemented fixation is poorly examined which this study will try to scrutinize.

100 patients with dislocated (Garden classification III-IV) femoral neck fractures who have the clinical indication of undergoing a Total Hip Arthroplasty are asked and included at Mölndals Hospital (part of Sahlgrenska University Hospital).

Randomization to either; an inversed hybrid arthroplasty with an uncemented hydroxyapatite coated Corail stem and a cemented Marathon cup (DePuy), alternatively to, a totally cemented option with a Lubinus SPII stem and a IP cup (Link).

Preoperatively:

Patient questionnaires regarding cognitive and social status, hip function, quality of life (QoL), activity level. Standard hip and pelvis X-ray. Blood sample for biomarkers.

Peroperatively:

Pulmonary artery catheter measurements of pulmonary artery pressure, cardiac output, ejection fraction of the right ventricle. Surgeon's questionnaire regarding prosthesis components, duration of surgery, blood group, bleeding volume, oxygen saturation. Half of the patients are marked with tantalum pellets for radiostereometric analysis (RSA). Biomarkers.

Postoperatively:

Standard X-ray. On the patients marked with tantalum pellets RSA is performed. Bone density scan (DXA). Measurements regarding cognition, ADL, mobilization. Eventual confusion is noted. Biomarkers every second day until discharge from hospital. Eventual wound infections or thromboembolic episodes are noted.

Follow up:

Outpatient return visits to physician 3, 6 months, 1, 2, 5, 7, 10 years postoperatively. Standard X-ray, RSA, DXA, Patient questionnaires regarding patient's satisfaction, QoL, activity level, hip function. Biomarkers.

Eventual gains with an uncemented prosthesis:

Reduced fatty embolism risk, reduced inflammatory response, reduced generalized symptoms/confusion, faster mobilization, shorter surgery.

Inclusion Criteria:

• Patients who are acutely admitted to hospital with dislocated femoral neck fractures, that in clinical praxis are in the need of hip prosthesis surgery, are recruited in the study. The fracture shall not engage the lesser nor the greater trochanters.
• Patients who wants to participate in the study and who can consider participation for at least 1 year.
• Coming from independent dwelling conditions.
• Not dementia.
• Circa 60-85 years of age.
• Circa 50 patients in each arm/group shall be included at Mölndal's Hospital (part of Sahlgrenska University Hospital).

Exclusion Criteria:

• Patients who have difficulties in understanding the intent of the study.
• Rheumatic disorders (RA, Bechterew, SLE).
• Cortison treatment.
• Stroke with remaining weakness or neurological disorders with affection of locomotion.
• Dementia.
• Grave obesity with BMI >=30-35.
• Delay between time of injury and time of surgery exceeding 72 hours.