II.

Irreducibility of the knee following complete dislocation is a rare event determined by the interposition of various capsulo-ligamentous structures in the joint space. Such cases often require urgent surgical treatment. We report the case of a healthy 70-year-old man with a sprain of the left knee that occurred after a sports trauma. The patient showed knee dislocation with multiple ligamentous injuries and articular block due to interposition of a portion of the vastus medialis muscle. After arthroscopic evaluation, we performed surgical treatment to free the muscle, regularize the medial meniscus and suture the posterior and medial capsule and ligaments; the cruciate ligaments were not treated. The most interesting aspect of the articular damage in this case was a wide detachment of the vastus medialis muscle with intra-articular dislocation. The decision to treat only the posterior lesions and allow the healing of the front ones by rehabilitation treatment was supported by full functional recovery and return to sports activity.

knee alignment and the prosthesis-bone interface of fixation [8][9][10]. Clinical and radiographic evaluation of implants, at medium and long follow-up periods, had allowed us to make precise decisions, in order to achieve certain results. Radiographs were evaluated using the Knee Society's TKA radiographic evaluation and scoring system that permits comparisons not only between different institutions but also between different implants [11,12]. Attention was placed on tibiofemoral and prosthetic alignments, implant positioning, and bone-cement or bone-prosthesis interfaces [8,9,13]. The purpose of the present study was to evaluate by radiological appearance 100 Press-Fit Condylar (PFC) total knee prostheses implanted between 1993 and 1998. AbstractThe three standard views are necessary for the radiographic evaluation of a total knee arthroplasty, by the measurement of knee alignment, components position and prosthetic interface. We radiographically evaluated 100 Press-Fit Condylar (PFC) total knee replacements in 66 women and 18 men (mean age, 69.5 years), at a mean follow-up of 5 years. The indication for implantation was osteoarthritis in 87% of the cases and rheumatoid arthritis in 11%. Radiographs were done at 3 and 6 months and then every year after implant, and each time were compared to the postoperative controls. The postoperative alignment had in 98% of the knees a valgus angle between 5°and 7°.Radiolucencies were found around the femoral component in 8% of the knees, and in the views of the tibial tray in 33%. The thicknesess of the radiolucent lines was 1 mm and was not progressive in 98% of the prostheses. One case presented aseptic loosening signs. Evaluation of total joint arthroplasty must be clinical, radiological and with annual intervals, in order to discover early failure signs. Concerning the present study, aseptic loosening is not a complication of the total knee arthroplasty evaluated for a medium follow-up of five years.

Until the early 1990's our experience in Total Knee Replacement (TKR) was based on AGC 2000, Tricon M and MG implants. Starting from 1992 we decided to use a rotating knee prosthesis. At that time in Italy there were many knee replacement devices with rotating elements: Oxford, LCS, Rotaglide and Endomodel from Link. The Endomodel rotating prosthesis was our choice and between 1992 and 1995 we implanted 142 prosthesis of this type, 128 as primary replacement and 14 as TKR revision. The overall results were good or excellent in most of our cases (Fig. 1). During this period we had 6 dislocations of the device (Fig. 2) and 4 infections: 1 from our service and 3 coming from other hospitals.