Titanium allergy or not? “Impurity” of titanium implant materials

For patients suffering from allergies to nickel, chrome and cobalt, titanium implants are the implants of choice. Nevertheless, titanium implant sensitivity has been reported in the form of “allergies” and an increasing number of patients are confused. This paper aims to use spectral analysis as a diagnostic tool for analyzing different titanium implant alloys in order to determine the percentage of the alloy components and additions that are known to cause allergies. Different materials, such as sponge titanium, TiAl6Nb7, Ti21SRx, TiAl6V4 [forged alloy], TiAl6V4 [cast alloy], TMZF, pure titanium [c. p. 1] and iodide titanium were analyzed for the presence of the elements that have been associated with allergic reactions using spectral analysis. All the implant material samples contained traceable amounts of Be, Cd, Co, up to a maximum of 0.001 percent by weight [wt.%], Cr up to 0.033 wt.%, Cu up to 0.007 wt.%, Hf up to 0.035 wt.%, Mn up to 0.007 wt.%, Ni up to 0.031 wt.%, and Pd up to 0.001 wt.%. This paper demonstrates that all the investigated implant material samples contained a low but consistent percentage of components that have been associated with allergies. For example, low nickel contents are related to the manufacturing pro- cess and are completely dissolved in the titanium grid. Therefore, they can virtually be classified as “impurities”. Under certain circumstances, these small amounts may be sufficient to trigger allergic reactions in patients suffering from the corresponding allergies, such as a nickel, palladium or chrome allergy.

Is overweight or obesity a perioperative risk factor in total hip replacement?

Introduction: A large proportion of patients who undergo total hip replacement (THR) are obese. Aim of the present study is to investigate the influence of Body Mass Index (BMI) on compli-cations following THR in a single surgeon in the short term follow-up. Material and method: This study was based on the retrospective review of charts and BMIs from 171 patients who had undergone THR between April 2005 and March 2006 at our hospital. All operations were per-formed by a single surgeon. All patients were followed up 6 weeks after operation. Results: 27 / 171 patients (15.8%) were found to have com-plications. Systemic minor complications in-cluded arrythmia in 1 case, urinary tract infec-tion in two cases, ileus in two cases, renal in-sufficiency in 3 cases, confusion in 2 cases and anaemia in 14 cases (8.2%) requiring blood tr- ansfusion. There was one case of pulmonary embolism as a major systemic complication. Local minor complications included one single dislocation and 1 superficial wound infection. Body mass index ranged from 20.8 to 46.7 with a mean of 28.6. Hospital length of stay ranged from 10 to 42 days with a mean of 13. The leng- th of operation time between obese and non- obese patients varied significantly in our study. There was no increased risk for complications and length of hospital stay. Discussion: We can conclude that there are no economic or medical reasons for excluding obese patients from THR as there is no increased risk for complications and length of hospital stay.

Experiences in total knee arthtroplasty after distal femoral varus osteotomy

Introduction: There is only little information available about total knee arthroplasty (TKA) following distal femoral varus osteotomy (DFVO). The aim of our study was to show our experiences and mid-term results of TKA after a previous DFVO. Material and method: In a retrospective study we identified 36 consecutive patients who had undergone TKA after a previous distal femoral varus osteotomy. The average duration of follow-up after the TKA was 8.2 years (min: 5.0, max: 9.2). X-rays were taken in 2 planes before TKA, 1 week after TKA and at latest follow-up. Tibiofemoral alignment was measured on weightbearing long-leg anteroposterior radiographs. Ra- diolucent lines at latest follow-up were documented. Functional evaluations were performed preoperatively and postoperatively (at the time of latest follow-up). Results: The mean Knee Society knee score in- creased from 42 points before the arthroplasty to 91.3 points after the arthroplasty. The mean Knee Society function score increased from 27.4 points preoperatively to 93.2 points postoperatively. The mean overall Knee Society score increased from 91.3 points preoperatively to 163.4 points postoperatively. The mean radiographic alignment was 4.5? of valgus (10? of varus to 19? of valgus) before TKA and 3.1? of valgus (range, 3? of varus to 6? of valgus) at the time of latest follow-up. Postoperative complications included one deep vein thrombosis with non-lethal pulmonary embolism, one wound infection requiring revision and one septic loosening. Discussion: It is possible to perform TKA following DFVO with good mid-term results. In comparison to the literature there is no higher risk of complications in TKA following DFVO in comparison to primary TKA.