BackgroundThe surface texture, localization, and magnitude of the surface material applied to the femoral stem can facilitate bone ingrowth and influence the survival of total hip arthroplasties. Clinical and radiographic studies have shown superior bone ingrowth in proximally porous-coated stems with a diaphyseal grit-blasted surface in comparison to a smooth diaphyseal surface. Surface textures—especially porous surface material—have been suggested to have a sealing effect against migration of polyethylene debris along the implant-bone interface and to reduce the inflammatory response, leading to a prolonged implant survival.Patients and methodsBetween 2004 and 2006, we conducted a randomized, controlled trial (RCT) involving 50 patients with non-inflammatory arthritis. They received either a distally tapered, extended coated stem or a straight, proximally coated stem. During surgery, tantalum markers were inserted into the greater and lesser trochanter. Implant migration was evaluated at 3, 12, and 24 months postoperatively by radiostereometric analysis. The primary endpoint was stem migration 2 years after surgery.ResultsAll femoral components in both groups showed pronounced distal translation, with the highest rate of translation occurring between 0 and 3 months. After 2 years, the mean distal translation was 2.67 (95% CI: –3.93 to –1.42) mm for the tapered, extended coated stem and 1.80 (–2.45 to –1.15) mm for the straight, proximally coated stem. Half of the tapered, extended coated stems and two-thirds of the straight, proximally coated stems had migrated more than 1 mm. No difference between the 2 stems could be seen with regard to translation or rotation at any time point. After 2 years, 2 hips have been reoperated due to mechanical loosening of the stem.InterpretationAn excessive amount of migration of both stem types was seen 2 years postoperatively. It is of vital importance to follow this patient cohort since radiostereometric analysis is known to be predictive of late implant failure, especially in this study where pronounced early migration was observed. We recommend longer follow-up of both stem types.

Ninety-seven revisions of total hip replacements are reviewed with a median time of observation of 47 months. Satisfactory pain relief was obtained in 86%. There were six complete failures which were reduced to three by further surgery. One hip became infected and was excised. In 12 cases the revisions were complicated by peroperative fractures and in five by dislocations. Radiographic analysis disclosed a high percentage of periarticular ossification and 25 cases of radiographic loosening of the femoral implant. The clinical results of revision of failed total hip replacement have been uncertain and in infected cases some authors have recommended excision arthroplasty Revision arthroplasty took place in an ordinary operating theatre. The exchange prosthesis was inserted

In a series of 213 consecutive total hip replacements a.m. Lubinus, the clinical course after 72 revisions and 141 primary procedures was compared after 5 years. The revised THRs were uncemented Ring prostheses. Dislocation and peroperative fracture were more common in the revision group. Two failures because of aseptic loosening occurred in the revision group and 3 in the control group. No excisional arthroplasty was required, and no infections occurred. Radiographic evaluation of prosthetic positioning, component loosening, calcar resorption, and paraarticular ossification disclosed only slightly inferior results in the revision group. Clinically, the revised cases were not inferior to the primary ones. Revision of the uncemented hip seems less difficult than of the cemented hip.

Thirty-eight St. Georgs hinged-knee arthroplasties were studied with a follow-up of 2.5-8 years; 86.8% of the patients obtained an excellent or a good result, and 7.9% of the arthroplasties were failures. There was an infection rate of 3.8% and 3.8% loose prostheses. Among the failures there were two infected arthroplasties. One was arthrodesed, resulting in a pseudoarthrosis and one was successfully revised. One traumatic loosening lead to arthrodesis. It is concluded that hinged-knee arthroplasty under special circumstances may be a useful procedure.