Procedure for single-stage implant retention for chronic periprosthetic infection using topical degradable calcium-based antibiotics.

INTRODUCTION: Surgical treatment using DAIR (debridement, systemic antibiotics, and implant retention) can lead to high rates of treatment success in cases of early periprosthetic joint infection (PJI) but can fail in late-onset cases. Supplementary local antibiotic therapy is not yet generally established and lacks evidence-based proof of efficacy. The aim of this study was to analyze DAIR outcomes in recurrent PJI cases and patients who are not suitable for a two-stage exchange, using additional degradable calcium-based antibiotics. METHODS: All patients fulfilled the Infectious Diseases Society of America (IDSA) guidelines for chronic late-onset PJI but were not suitable for a multistage procedure because of their individual operation risk. A total of 42 patients (mean age, 73 years) were treated using a single-stage algorithm consisting of DAIR, followed by implantation of degradable antibiotics chosen in accordance with an antibiogram. OSTEOSET® (admixed ceftriaxone/vancomycin/tobramycin) and Herafill-Gentamycin® were used as carrier systems. The follow-up period was 23 months (± SD, 10.3). The study is based on institutional review board (IRB) approval. RESULTS: The clinical entities were chronic PJI of the hip (45.2%), knee (28.6%), and knee arthrodesis (26.2%). The bacterial spectrum was composed of Staphylococcus epidermidis (29%), Staphylococcus aureus (21%), and Enterococcus faecalis (21%). 21.4% showed a combination of two or more bacteria. In 73.8%, permanent remission was achieved, while 11.9% showed chronic PJI under implant retention. Implant retention could be achieved in 85.7%. CONCLUSION: DAIR usually shows low levels of success in difficult-to-treat cases. However, we could demonstrate the successful treatment of patients with recurrent PJI (typically considered DAIR-inappropriate) using degradable antibiogram-based topical calcium-based antibiotics. Over 70% of the cases went to remission and over 85% of the implants could be retained.

[Handling of retrieved implants in orthopedic surgery : Results of a survey within the framework of the EndoCert initiative]. / Bestandsaufnahme zum Umgang mit ausgebauten Implantaten in der orthopädischen Chirurgie : Ergebnisse einer Umfrage im Rahmen der EndoCert-Initiative.

BACKGROUND: Although investigations of retrieved medical implants can provide valuable information about the cause of the revision, there is a lack of information, which could be avoided by consequent failure analyses. In the framework of the EndoCert certification system it is obligatory to record and report incidents. OBJECTIVES: The present work examines how the willingness to report has developed in certified arthroplasty centers and which method of handling retrievals is preferred and actually used. MATERIALS AND METHODS: On the basis of a questionnaire for handling retrievals, all 508 arthroplasty centers that were certified till June 1, 2016, were included (return rate = 97.2%). RESULTS: A total of 93.3% of the centers have established an algorithm for handling of retrievals and 83.0% of the centers prefer to hand out the retrieval to the patient, while only 25.7% wish to store it in the center for research purposes. In the case of a potential incident as the cause of revision, centers prefer to forward the retrieval to damage analysis, whereby the centers act in different ways, depending on the case. An implant fracture is, e.g., considered a reportable event in most cases without temporal limitation. On the other hand, breakage or failure of surgical instruments is considered not to be reported in the case of more than half of the centers. In 2014 and 2015, approximately 71% of EPZs reported no incidents. CONCLUSIONS: According to our survey, many certified arthroplasty centers are sensitized to careful handling of retrievals. The treatment of the explanted components is conducted in different ways. The assessment of whether an incident is to be reported shows large differences. In view of the relatively high number of revision surgeries, the number of reports to the authorities appears to be low.

Total Wrist Arthroplasty.

Total wrist arthroplasty (TWA), first performed in the late 19th Century, is still an infrequently used operation. It is most commonly indicated in patients with rheumatoid arthritis who have pan-carpal wrist involvement. It is an alternative to total wrist arthrodesis in patients who wish to preserve joint motion. Patients must lead a low-demand lifestyle and have failed non-operative measures. Complications are not insignificant and have been reported to be as high as 43%. Modern generation implants most often fail due to dislocation or loosening. Because wrist arthrodesis remains the gold standard treatment, particularly in patients with higher physical demands, it remains to be seen whether TWA will gain greater acceptance as prosthetic designs evolve.

Cathodic Electrical Stimulation Combined With Vancomycin Enhances Treatment of Methicillin-resistant Staphylococcus aureus Implant-associated Infections.

BACKGROUND: Effective treatments for implant-associated infections are often lacking. Cathodic voltage-controlled electrical stimulation has shown potential as a treatment of implant-associated infections of methicillin-resistant Staphylococcus aureus (MRSA). QUESTIONS/PURPOSES: The primary purpose of this study was to (1) determine if cathodic voltage-controlled electrical stimulation combined with vancomycin therapy is more effective at reducing the MRSA bacterial burden on the implant, bone, and synovial fluid in comparison to either treatment alone or no treatment controls. We also sought to (2) evaluate the histologic effects of the various treatments on the surrounding bone; and to (3) determine if the cathodic voltage-controlled electrical stimulation treatment had an effect on the mechanical properties of the titanium implant as a result of possible hydrogen embrittlement. METHODS: Thirty-two adult male Long-Evans rats (Harlan Laboratories, Indianapolis, IN, USA) with surgically placed shoulder titanium implants were infected with a clinical strain of MRSA (NRS70). One week after infection, eight animals received a treatment of cathodic voltage-controlled electrical stimulation at -1.8 V versus Ag/AgCl for 1 hour (STIM), eight received vancomycin twice daily for 1 week (VANCO), eight received the cathodic voltage-controlled electrical stimulation and vancomycin therapy combined (STIM + VANCO), and eight served as controls with no treatment (CONT). Two weeks after initial infection, the implant, bone, and synovial fluid were collected for colony-forming unit (CFU) enumeration, qualitative histological analysis by a pathologist blinded to the treatments each animal received, and implant three-point bend testing. RESULTS: The implant-associated CFU enumerated from the STIM + VANCO (mean, 3.7 × 10(3); SD, 6.3 × 10(3)) group were less than those from the CONT (mean, 1.3 × 10(6); SD, 2.8 × 10(6); 95% confidence interval [CI] of difference, -4.3 × 10(5) to -9.9 × 10(3); p < 0.001), STIM (mean, 1.4 × 10(6); SD, 2.0 × 10(6); 95% CI of difference, -2.1 × 10(6) to -1.8 × 10(3); p = 0.002), and VANCO (mean, 5.8 x 10(4); SD, 5.7 × 10(4); 95% CI of difference, -6.4 × 10(4) to -1.7 × 10(4); p < 0.001) group. The bone-associated CFU enumerated from the STIM + VANCO group (6.3 × 10(1); SD, 1.1 × 10(2)) were less than those from the CONT (mean, 2.8 × 10(5); SD, 4.8 × 10(5); 95% CI of difference, -9.4 × 10(4) to -5.0 × 10(3); p < 0.001) and STIM (mean, 2.6 × 10(4); SD, 2.5 × 10(4); 95% CI of difference, -4.1 × 10(4) to -1.6 × 10(3); p < 0.001) groups. The VANCO group (4.3 × 10(5); SD, 6.3 × 10(2)) also had lower bone-associated CFU as compared with the CONT (mean 95% CI of difference, -9.3 × 10(4) to -4.5 × 10(3); p < 0.001) and STIM (95% CI of difference, -4.0 × 10(4) to -1.5 × 10(3); p < 0.001) groups. In comparison to the synovial fluid CFU enumerated from the CONT group (mean, 3.3 × 10(4); SD, 6.0 × 10(4)), lower synovial CFU were reported for both the STIM + VANCO group (mean, 4.6 × 10(1); SD, 1.2 × 10(2); 95% CI of difference, -4.9 × 10(3) to -3.0 × 10(2); p < 0.001) and the VANCO group (mean, 6.8 × 10(1); SD, 9.2 × 10(1); 95% CI of difference, -4.9 × 10(3) to -2.8 × 10(2); p = 0.007). The histological analysis showed no discernable deleterious effects on the surrounding tissue as a result of the treatments. No brittle fracture occurred during mechanical testing and with the numbers available, no differences in implant flexural yield strength were detected between the groups. CONCLUSIONS: In this rodent model, cathodic voltage-controlled electrical stimulation combined with vancomycin is an effective treatment for titanium implant-associated infections showing greater than 99.8% reduction in bacterial burden on the implant, surrounding bone, and synovial fluid as compared with the controls and the stimulation alone groups. CLINICAL RELEVANCE: Cathodic voltage-controlled electrical stimulation combined with vancomycin may enable successful treatment of titanium orthopaedic implant-associated infections with implant retention. Future studies will focus on optimization of the stimulation parameters for complete eradication of infection and the ability to promote beneficial host tissue responses.

How has the introduction of new bearing surfaces altered the biological reactions to byproducts of wear and modularity?

BACKGROUND: Biological responses to wear debris were largely elucidated in studies focused on conventional ultrahigh-molecular-weight polyethylene (UHMWPE) and some investigations of polymethymethacrylate cement and orthopaedic metals. However, newer bearing couples, in particular metal-on-metal but also ceramic-on-ceramic bearings, may induce different biological reactions. QUESTIONS/PURPOSES: Does wear debris from the newer bearing surfaces result in different biological responses compared with the known responses observed with conventional metal-on-UHMWPE bearings? METHODS: A Medline search of articles published after 1996 supplemented by a hand search of reference lists of included studies and relevant conference proceedings was conducted to identify the biological responses to orthopaedic wear debris with a focus on biological responses to wear generated from metal-on-highly crosslinked polyethylene, metal-on-metal, ceramic-on-ceramic, and ceramic-on-polyethylene bearings. Articles were selected using criteria designed to identify reports of wear debris particles and biological responses contributing to prosthesis failure. Case reports and articles focused on either clinical outcomes or tribology were excluded. A total of 83 papers met the criteria and were reviewed in detail. RESULTS: Biological response to conventional UHMWPE is regulated by the innate immune response. It is clear that the physical properties of debris (size, shape, surface topography) influence biological responses in addition to the chemical composition of the biomaterials. Highly crosslinked UHMWPE particles have the potential to alter, rather than eliminate, the biological response to conventional UHMWPE. Metal wear debris can generate elevated plasma levels of cobalt and chromium ions. These entities can provoke responses that extend to the elicitation of an acquired immune response. Wear generated from ceramic devices is significantly reduced in volume and may provide the impression of an "inert" response, but clinically relevant biological reactions do occur, including granulomatous responses in periprosthetic tissues. CONCLUSIONS: The material composition of the device, the physical form of the debris, and disease pathophysiology contribute to complex interactions that determine the outcome to all wear debris. Metal debris does appear to increase the complexity of the biological response with the addition of immunological responses (and possibly direct cellular cytotoxicity) to the inflammatory reaction provoked by wear debris in some patients. However, the introduction of highly crosslinked polyethylene and ceramic bearing surfaces shows promising signs of reducing key biological mechanisms in osteolysis.

Risk of thromboembolism in shoulder arthroplasty: effect of implant type and traumatic indication.

BACKGROUND: Prior research about symptomatic venous thromboembolism (VTE) after shoulder arthroplasty has not determined whether procedure type (hemiarthroplasty, total shoulder arthroplasty, or reverse shoulder arthroplasty) or surgical indication (traumatic or elective) represent risk factors for VTE after shoulder replacement. QUESTIONS/PURPOSES: We therefore asked whether the risk of symptomatic VTE events and mortality within 90 days of shoulder arthroplasty was influenced by (1) procedure type, and (2) surgical indication (traumatic or elective). METHODS: We performed a retrospective database review of symptomatic VTE events and mortality within 90 days of shoulder arthroplasty in a large (30-hospital) integrated healthcare system over a 5-year period, from January 2005 to December 2009. We compared the likelihood of VTE and death in patients undergoing reverse shoulder arthroplasties (RSAs), total shoulder arthroplasties (TSAs), and hemiarthroplasties (HAs), and we compared the likelihood of VTE and death in patients who underwent elective shoulder arthroplasties with those who underwent shoulder arthroplasty in the setting of acute trauma. RESULTS: In the 2574 eligible shoulder arthroplasties identified during the study period, VTE developed in 1.01% of patients (deep vein thrombosis 0.51% and pulmonary embolism 0.54%). With the numbers available, no differences were observed in rates of VTE or mortality by procedure type. A trend toward increased VTE occurred more frequently in patients having surgery for traumatic indications than after elective surgery (1.71% versus 0.80%; p = 0.055). A higher likelihood of 90-day mortality was observed in trauma patients compared with elective (odds ratio = 7.4; 95% CI, 2.4-25.2). CONCLUSIONS: VTE occurred infrequently in this study sample. These data support future risk and benefit assessment of routine pharmacologic VTE prophylaxis in the perioperative treatment of patients undergoing shoulder arthroplasty, especially in all RSA and traumatic HA subsets, where the risk of VTE may be higher.

First metatarsophalangeal hemiarthroplasty for hallux rigidus.

There is a paucity of objective information in the literature about first metatarsophalangeal (MTP) hemiarthroplasty. The authors postulate that it is a reasonable treatment option for severe hallux rigidus in selected patients. Twenty-two elective first MTP hemiarthroplasties were performed on 20 patients that met the inclusion criteria. Pre- and postoperative evaluations were done using the American Orthopaedic Foot and Ankle Society (AOFAS) forefoot score, visual analogue scale (VAS) pain score, range of motion (ROM) measurements, and radiographs. Average ROM and dorsiflexion improved by 15° and 8°, respectively. VAS pain scores improved from 5 to 2.5 after six weeks. Painless ambulation occurred after six weeks, with maximum improvement by six months. After 24 months, two patients had pain at the surgical site interfering with function, leading to an unsatisfactory result that required conversion to arthrodesis. First MTP hemiarthroplasty for severe hallux rigidus can be considered an alternative to fusion in properly selected patients who wish to maintain a functional range of motion.

Acetabular revision with extensive allograft impaction and uncemented hydroxyapatite-coated implants. Results after 9 (7-11) years follow-up.

This is a clinical and radiographic review of 87 hips in 79 patients 9 (7-11) years after acetabular revision with extensive use of morselized allograft firmly impacted into localized defects as well as the entire acetabular cavity, followed by insertion of an uncemented hydroxyapatite-coated cup with supplementary screw fixation. The 9-year survival rate for the acetabular implant was 90.5% (95% CI, 83.4%-97.6%) with revision for any reason as end point and 94% (95% CI, 89%-99.1%) with revision for aseptic loosening as end point. Acetabular revision with massive allograft impaction and hydroxyapatite-coated implants show very promising results. The limited contact between implant and host bone does not seem to compromise implant survival in the 7- to 11-year perspective.

[Storage of autologous hemocomponents in patients before endoprosthesis of great joints].

Storage of autologous hemocomponents in patients prepared for elective surgery is the method of choice for adequate preparation before surgery. Autogenic erythrocytes and blood plasma increase infectious safety and efficacy of postoperative transfusion therapy. Up-to-date storage of autologous hemocomponents is indispensable condition for effective treatment of orthopedic patients.