[Total hip arthroplasty with the cementless spiron femoral neck prosthesis].

OBJECTIVE: Cementless total hip arthroplasty with preservation of femoral neck and natural load transmission. Restoration of joint function and alleviation of pain.

INDICATIONS: Osteoarthritis of the hip or femoral head necrosis in younger patients.

CONTRAINDICATIONS: Patients biologically > 65 years. Destructed or discontinued femoral neck. Pathologic hip formation: short femoral neck, severe enhanced or reduced CCD angle. Body mass index (BMI) > 30 (relative contraindication). Manifest osteoporosis. Necessity of immediate full weight bearing. Heavy smoking (relative contraindication). Ongoing chemotherapy.

SURGICAL TECHNIQUE: Anterolateral approach to the hip joint. Exposition of the femoral neck and resection of the femoral head at its lateral margin. Preparation of the acetabulum and insertion of a common acetabular component. Positioning of the center pin into the femoral neck. Face milling of the femoral neck butt. Preparation of the femoral neck with the Spiron drill bit. Insertion of the Spiron prosthesis. Trial reduction with a trial head. Substitution by the definitive head (cone 12/14 mm). Wound closure.

POSTOPERATIVE MANAGEMENT: Low centred X-ray of the pelvis and cross table view of the hip joint. Physiotherapy and partial weight bearing for 6 weeks. Prevention of deep vein thrombosis until achievement of full weight bearing.

RESULTS: A total of 28 Spiron prosthesis were implanted in 26 patients (15 men, 11 women, mean age 51 years [range 34-64 years], mean BMI 28 kg/m(2) [range 21-39 kg/m(2)]) from August 2009 to January 2012. Diagnoses: 13 cases of primary osteoarthritis, 8 cases of secondary osteoarthritis, 5 cases of femoral head necrosis, and 2 cases of posttraumatic osteoarthritis. The mean surgery length was 93 min (range 70-121 min), the mean hospital stay was 9 days (range 6-16 days). Blood transfusion was not necessary in any of the cases. There were no immediate complications such as deep vein thrombosis, surgery requiring secondary bleeding, wound infection, nerve palsy, or dislocation of the hip. Postoperative radiologic examinations showed an average leg lengthening of 3 mm (range -10-19 mm). No varus deviation of the prosthesis was observed. The Harris Hip Score improved from 55.4 points (range 33.5-76.9 points) preoperative to 90.5 points (range 75.7-99.9 points) 3 months postoperative. In 1 case with aseptic loosening, replacement surgery was performed without complications.