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BACKGROUND AND PURPOSE: Aseptic prosthesis loosening, caused by wear particles, is one of the most common causes of arthroplasty failure. Extensive and over‐activated osteoclast formation and physiological functioning are regarded as the mechanism of prosthesis loosening. Therapeutic modalities based on inhibiting osteoclast formation and bone resorption have been confirmed to be an effective way of preventing aseptic prosthesis loosening. In this study, we have investigated the effects of sophocarpine (SPC, derived from Sophora flavescens) on preventing implant loosening and further explored the underlying mechanisms. EXPERIMENTAL APPROACH: The effects of SPC in inhibiting osteoclastogenesis and bone resorption were evaluated in osteoclast formation, induced in vitro by the receptor activator of NF‐κB ligand (RANKL). A rat femoral particle‐induced peri‐implant osteolysis model was established. Subsequently, micro‐CT, histology, mechanical testing and bone turnover were used to assess the effects of SPC in preventing implant loosening. KEY RESULTS: In vitro, we found that SPC suppressed osteoclast formation, bone resorption, F‐actin ring formation and osteoclast‐associated gene expression by inhibiting NF‐κB signalling, specifically by targeting IκB kinases. Our in vivo study showed that SPC prevented particle‐induced prosthesis loosening by inhibiting osteoclast formation, resulting in reduced periprosthetic bone loss, diminished pseudomembrane formation, improved bone‐implant contact, reduced bone resorption‐related turnover and enhanced stability of implants. Inhibition of NF‐κB signalling by SPC was confirmed in vivo. CONCLUSION AND IMPLICATIONS: SPC can prevent implant loosening through inhibiting osteoclast formation and bone resorption. Thus, SPC might be a novel therapeutic agent to prevent prosthesis loosening and for osteolytic diseases.

The recovery of indium from waste indium tin oxide (ITO) target has great significance for the economy and environment. Based on our previous study on the optimization of acid leaching technique, the present study focuses on tin removal via zinc substitution and indium recovery from a tin-free leach solution. The results show that when the amount of added zinc powder and reaction time increase, the tin removal effect can be improved. The optimal conditions obtained are as follows: additional content of zinc powder from 20 g/L to 25 g/L, reaction temperature of 60 °C, and reaction time from 3 h to 4 h. Under this condition, the tin removal rate exceeds 98%, and the tin content in the tin removal solution is lower than 0.05 g/L. After tin removal, the substitution time could be reduced from 3–5 d to 1–2 d by neutralizing the residual acid by using alkaline residue and maintaining the pH value less than 2. The indium recovery rate is also improved when this condition is used. The indium content in the tin residue is reduced to lower than 0.1% and the acid-insoluble β-SnO2 could be obtained via the strong nitric acid leaching of the indium-containing tin residue. Indium could be recovered from ITO with a high purity of 99.995% via electrorefining.

Ceramic bearing surfaces have been introduced to prevent osteolysis after total hip arthroplasty (THA), but little is known about the difference in clinical and radiological results between pure alumina and sandwich alumina bearings. The purpose of this study was to analyze the results obtained with third-generation alumina-on-alumina THA with two different designs both in liner and femoral stem fixation after a minimum follow-up of 4.2 years.The results of 195 primary alumina-on-alumina THAs in 167 patients were evaluated. The procedures were performed between January 1998 and October 2006. Three patients died and 11 patients were lost to follow-up, leaving a total of 153 patients (181 hips) available for study. In the 88 group A patients, 107 hips were implanted using pure alumina bearings with cementless femoral stems. These patients were followed for (6.84 ± 1.49) years. In the 65 group B patients, 74 hips were implanted using sandwich alumina ceramic bearings with cemented femoral stems. These patients had a follow-up period of (7.73 ± 1.60) years. Patients in both groups were evaluated clinically and radiographically.One ceramic liner fracture occurred in group A and five took place in group B (P0.05), four of them revised for liner fracture. In each group, one acetabular shell migration happened without liner breakage and two hips developed deep infections, and all these six hips received revisions. Nine femoral components loosened in group B, with seven undergoing revisions. Kaplan-Meier survivorship at 5 years for revision of any component for any reason in group A was 96.26% compared to 90.54% in group B (P0.05). Better function was determined in group A (average Harris hip scores: 92.13 ± 2.85) than in group B (average Harris hip scores: 86.03 ± 4.21) and the difference was significant (P0.05). Squeaking was not recorded in either group.The sandwich design of the acetabular bearings can not reduce the migration rate in ceramic bearings but increase the liner fracture rate compared to pure ceramic liners. The high loosening rate in fluted and taped designed cemented stems with sandwich liners warrant caution to their use.

To explore the intermediate outcomes of third-generation alumina-on-alumina total hip arthroplasty (THA).A consecutive series of 165 primary alumina-on-alumina total hip arthroplasties were performed in 135 patients. Three patients died and 13 patients lost follow-up so that a total of 119 patients (146 hips) were available for study. The mean patient age was 53.4 ± 11.0 years old (range: 26 - 79). Hydroxyapatite. (HA)-coated press-fit acetabular cups were used in all cases. At femoral side, 123 cases were implanted with HA-coated uncemented stems and 23 cases implanted with high polished double taped cemented stems. All patients were evaluated clinically and radiographically after a minimal follow-up duration of 60 months.The preoperative mean Harris hip score of 49.6 ± 7.9 points improved to 91.7 ± 3.0 points at the last follow-up (P0.05). The 5-year survival for any reason lead to revision was 96.6%. Five hips were under revision, 1 for acetabular shell loosening and migration, 1 for Vancouver B2 periprosthetic fracture, 1 for fracture of pure alumina liner and 2 for infections. All other prostheses demonstrated no radiographic evidence of loosening. No periprosthetic osteolysis was found. There were 2 cases of dislocations and 2 patients presented postoperatively with "squeaking-like" hips.The clinical and radiographic outcomes after primary THA with third-generation ceramic-on-ceramic bearing surfaces are favorable after a minimal follow-up duration of 5 years. The modified alumina-on-alumina bearing implants offer a better option for younger and active patients.

Periprosthetic femoral fractures following total hip arthroplasty are getting more prevalent. The aim of this study was to evaluate the clinical results of combined use of uncemented extensively porous coated femoral components with onlay cortical strut allografts in revision of Vancouver type B2 and B3 periprosthetic femoral fractures.Thirteen hips after total hip arthroplasty in 13 patients who suffered a Vancouver B2 or B3 periprosthetic fracture were treated with an uncemented extensively porous coated femoral component combined with onlay cortical strut allografts. Each patient was assigned a Harris hip score, and a visual analog scale (VAS) score for pain and satisfaction. Radiographs were examined for component stability, fracture site and allograft-host union and allograft reconstruction.At an average of 5.3-year follow-up, no patient required repeat revision. The average Harris hip score was (71.8 +/- 6.3) points, the pain VAS score was (16.6 +/- 4.3) points, and the patient satisfaction VAS score was (81.5 +/- 5.7) points. Radiographic examination showed no detectable loosening of the prostheses, and 12 cases were presented fixation by osseointegration and the other one was stable fibrous ingrown fixation. All fractures united for (5.2 +/- 1.4) months in average. And all onlay strut allografts united to host bone for about (11.5 +/- 2.6) months.Combined use of uncemented, long stemmed, extensively porous coated implant with cortical onlay strut allografts can achieve good clinic results and high rate of union for both fracture site and allograft-host bone junction. This technique could be used routinely to augment fixation and healing of Vancouver B2 and B3 periprosthetic fractures.

To determine the variation in femoral stress after insertion of Elite cemented femoral prosthesis.Three-dimentional finite element models of the normal human femur and Elite femoral prosthesis were developed through CT scan. With the application of hip joint loading, quantitatively measure stress changes of an intact femur with corresponding femur inserted with Elite implants were measured.Compared with intact femur, insertion of Elite implants into the femoral canal decreased the proximal femoral stresses level, especially in calcar femoral, femur wall and tuberositas. However, the stress in the prosthesis distal end.Insertion of Elite implants induced significant stress shielding in the proximal femur, especially at calcar femoral, femur wall and tuberositas. However, stress concentrates in the prosthesis distal end.