The pathologies of the hip (epiphisiolysis, Perthes, congenital dysplasia) cause invalidating outcomes in young patients. In the years many authors searched for the golden standard if total hip arthroplasty is necessary. From Smith-Petersen to McKee, to Amstutz the saving of the femoral neck has been the main objective, with the longevity of the system. Therefore the combination metal-metal has been used for articular components, because the friction of metallic components creates sub-micron metallic particles causing only minimal foreign body reactions andvery low wear rates. Our study group (Arthro Surgery Group) has implanted, from April 2003, 28 cementless resurfacing hip prosthesis with metal-metal articular components. The average follow-up has been of 6 months (from 3 months to 1 year). In all cases, the Harris Hip Score has been good or excellent (from 77 to 100), and radiographic exams didn’t show signs of radiolucence or resorption. This type of prosthesis allows moreover an minimum-invasive approach to the hip and a second line of defense in case of revision.
In cementless joint arthroplasty, the first goal is the stabilization of the prosthetic components, due to bone ingrowth. In the past, to achieve the best fixation, the orthopaedic surgeons used osteoconductive materials (HA, TriCa-Ph). To accelerate the fixation process, we have developed an osteoinductive procedure with growth factors. A product born from cancellous bone (BMP’s), bone marrow (stem cells) and plateled-rich plasma (growth factors) is applicated to the tridimensional fixation surface (spongiosametall) of the prosthesis. Since June 2003, we have treated 15 arthroplasties with this procedure (11 THA, 4 TKA). The average duration of clinical follow-up was 6 month (Range from 2 to 9 months). In case of THA, the average Harris Hip Score was 96(Range from 91 to 100). In case of TKA, the average of HSS scoring was 90(Range from 85 to 100). The radiographic exams were good. DEXA and RSA evaluations are in course. In our opinion, the OSTEOKIN system is one of the most valuable growth factors system, to use always in arthroplasty surgery.
The improvement of the anchorage surfaces of the total hip arthroplasty (THA) has allowed a better bone integration of the stem and of the cup more durable in the time and often more advanced to the duration of those articular components subject to wear. In case of lesion of one of these components, our study group (Arthro Surgery Group) has created a standard protocol for the revisions of total hip arthroplasty with well fixed stems and shells (PIT-STOP). We operated 22 patients with THA more than 10 years ago after the first implantation. The average HARRIS HIP SCORE post-op is 92 in 1 year follow-up. The X-rays exams are excellent. In case of wear of the polyethylene liner or of the head, we proceed to the substitution of the components if available and if the fixation mechanism is not damaged. In case of old designed THA, with articular components not available (polyethylene liner for the cup and ceramic or metal head), we use the liner fixation by cementation into the well fixed original metal back and a new head. If an alteration or an anomalous size of the neck is evidenced, we put on a metallic special device of measure adapted (taper case) on which we put a new ceramic head. In case of fracture of a ceramic head, we remove all the fragments and put on the prosthetic neck a new ceramic head with the metallic special device (taper case), after many washing and radical sinoviectomy.
