Lateral unstable fractures of the femoral neck represent a controversial problem for the surgical treatment, due to the difficulty in achieving an adequate mechanically stable bone-devices system. Compression hip screw alone has proven to be inadequate, while in association with the trochanteric stabilizing plate (TSP) it offers better results. The authors analyse functional results and complications of a series of 87 lateral unstable fractures of the femoral neck (type A2 and A3 of the AO classification). Weight bearing was allowed 48 hours after surgery. The most important complications reported were: persistent trochanteric pain (12 cases) shaft medialization and device mobilization (2 cases) shortening of more than 2cm (3 cases). All complications were reported in A3 type fractures. Our data confirm the efficacy of the TSP the treatment of lateral unstable fractures of the femoral neck (type A2) because it stabilizes the lateral cortex. In A3 type fractures, intramedullary devices offers better results than compression hip screw and TSP in terms of complications rate and stability.
Patella resurfacing in revision total knee arthroplasty is a controversial issue. While performing revision TKA we must consider some different situations: previously resurfaced patella or not, in case of resurfaced patella, if it is fix or loosened, in case of loosened patella is there a bone loss or not. If patella wasn’t previously resurfaced, we can preserve natural patella performing at least a regularization of its osteophytes, or we can realize a primary resurfacing. If patella was previously resurfaced and still well fixed, we preserve domed component if not grossly damaged. Its revision is performed if it is damaged or not congruent. If patella was previously resurfaced and loosened the two possibilities are the revision or the retention of the bony patella. In case of previously resurfaced and loosened patella, with severe bone loss, we can preserve the bony shell, or we can realize revision with the use of cortical grafting or we can performa patelloplasty, or complete patellectomy. Finally, in these cases it’s possible the revision with tantalum patella. Outcomes of patella resurfacing in revision total knee arthroplasty are usually fair: low functional and pain scores, quadricipite leverage loss, worse patellar tracking, anterior pain, patellar fractures, knee stiffness.
This study presents the results of 1188 original and innovative posteriorly stabilized TKA procedures in which the femoral bone stock is preserved with a shallow compartment insofar as possible. The TKA procedure is directly derived from Insall’s original technique, except for the posterior stabilisation design, where a third median condyle starts working at 30° of knee flexion. A total of 1188 primary TKA procedures were consecutively performed in a university hospital. Average follow-up was 30 months (0–168 months). The implants were cemented (except for 35 femoral components) and the patella resurfaced (except for nine cases). Clinical results were assessed using the IKS Score. The quality of the implantation was analysed on long-leg X-rays (1175 preoperative and 883 postoperative long-leg films available at follow-up). The results showed that 95% of patients were very satisfied or at least satisfied. Knee score and functional scores were 44 and 54 preoperatively and 90 and 78 postoperatively. Mean range of motion was 116°. On X-ray analysis, the average mechanical femorotibial angle was 179° postoperatively. Survival of the implant for revision was 94.2% at 14 years. We performed 83 re-operations (nine patellar fractures, 14 infections, 12 cases of stiffness and 11 clunck syndromes), including 33 component revisions. Clinical results compared favourably with the literature. This original posterior stabilisation design confirmed the good and excellent results at follow-up. We obtain good range of motion, and no revision was due to polyethylene wear.
The problem of early mechanical stability and late biological osseointegration of the tibial component is still a debated issue in total knee arthroplasty. We are among those authors that stress the necessity of cementing the tibial component to avoid the risk of failure due to the high torque stresses at this interface. In fact while on the femoral edge a good stability can be achieved even in uncemented implants, the stability of traditional tibial components is harder to obtain even in cemented implants. To solve this problem it has been proposed to use additional devices such as screws, pegs or keels to better fix the tibial plateau. Tantalum monobloc tibial tray is a new answer to this problem. It consists in a cement-less tibial tray made of porous tantalum with monobloc polyethylene. Chemical, physical and biological properties of the raw tantalum are very similar to those of titanium. Porosity of the processed material is 80% (2–3 times compared to plasma spray, beads and fiber mesh coatings) and pores, which diameter is 650 mm, are fully interconnected in the whole bulk of the implant. This trabecular spongy structure, that is not a coating, allows the bone at the interface to deeply grow into the pores, and to achieve optimal stability. In addiction, the fusion of polyethylene into the tantalum mesh completely abolish the back side wear problem. With this technology is yet in use an acetabular component, with which we have a 5 years experience in 150 implants, and now is available a new tibial plateau; the first implant in Europe was performed in our department. Despite our short series and follow up (6 implants in 2 months) the properties of porous tantalum, already tested in acetabular implants, represent an alternative to the traditional ways of tibial tray fixation.
Aseptic loosening is one of the most frequent cause of total knee arthroplasty (TKA) failure; it is related to a fatigue-type wear which can rapidly break up a tibial polyethylene (PE) inlay. PE debris production is the result of this wear and depend on contact stress between the components. This crucial parameter is more related to conformity than to load tranfer. That is why mobile bearing TKA seems to represent a valid solution to the PE debris production. In fact this implant offers great tibio-femoral conformity without an increased risk of loosening due to increased axial torque. Mobile bearing TKA also eneables the surgeon to self correct tibial component malrotation. On the other hand this implant could lead to new problems such as bearing dislocation or breakage and a possible new wear pattern at the PE-tibial metal tray interface. We performed 100 consecutive cemented posterior stabilised TKA using randomly in 50 cases a mobile bearing and in 50 cases the same implant with a fixed bearing. The mean follow up was 15 months. The results in mobile bearing group are the following. Hospital for Special Surgery (HSS) score improved from 38 to 91 after the surgery. Preoperative Range of Movement (ROM) was 71 while the post op value was 107. No lucencies >
1 mm were observed. There were no statistically significant differences among the mobile bearing group and the fixed bearing one. Despite our short follow up, this implant offers the same good clinical results if compared to other devices, and allows the surgeons to correct errors in positioning the implant. In future we have to consider that this possibility will lead to an abnormal load stresses distribution and to a higher risk of late loosening.
