Treatment of femoral neck fractures using actis stem: complication rate in 188 uncemented hemiarthroplasties.

INTRODUCTION: Cemented hemiarthroplasty (HA) is preferred in treating dislocated femoral neck fractures in elderly, osteoporotic patients, since uncemented HA was associated with mechanical complications more frequently. Cementation can conversely cause cardiopulmonary complications, leading to demand on safe, uncemented implants addressing osteoporosis. This study is set up as a retrospective feasibility study on the use of an uncemented, collared wedge implant (Actis®, DePuy Synthes, Warsaw, IN), for HA in elderly patients, focusing on complication rate. MATERIALS AND METHODS: From 1,194 patients, treated with HA in two study centers between 2017-2022, 188 received Actis® uncemented stem with bipolar head. Complete follow-up were retrospectively collected in all patients. RESULTS: In 188 patients (f: 64.9%; age: 83.1 ± 7.7a) included, no case of intra-operative mortality was recorded. 2 day mortality was 1.1%, 30 day mortality was 7.4% and 1 year mortality was 28.2%. 2 (1.1%) intra-operative fractures did not receive surgical revision, 3 (1.6%) post-operative periprosthetic fractures caused separate admission and revision. 2 cases (1.1%) of early infection required surgical revision. CONCLUSION: Our data provide proof of concept, that Actis® Stem allows an alternative, uncemented treatment option for displaced femoral neck fractures with HA. In case of preoperative or intraoperative medial cortical bone defects, stability of this implant is deteriorated.

Performance of automated multiplex polymerase chain reaction (mPCR) using synovial fluid in the diagnosis of native joint septic arthritis in adults.

AIMS: This study aimed to assess the performance of an automated multiplex polymerase chain reaction (mPCR) technique for rapid diagnosis of native joint septic arthritis. PATIENTS AND METHODS: Consecutive patients with suspected septic arthritis undergoing aseptic diagnostic joint aspiration were included. The aspirate was used for analysis by mPCR and conventional microbiological analysis. A joint was classed as septic according to modified Newman criteria. Based on receiver operating characteristic (ROC) analysis, the area under the ROC curve (AUC) values of the mPCR and the synovial fluid culture were compared using the z-test. A total of 72 out of 76 consecutive patients (33 women, 39 men; mean age 64 years (22 to 92)) with suspected septic arthritis were included in this study. RESULTS: Of 72 patients, 42 (58%) were deemed to have septic joints. The sensitivity of mPCR and synovial fluid culture was 38% and 29%, respectively. No significant differences were found between the AUCs of both techniques (p = 0.138). A strong concordance of 89% (Cohen's kappa: 0.65) was shown. The mPCR failed to detect Staphylococcus aureus (n = 1) and Streptococcus pneumoniae (n = 1; no primer included in the mPCR), whereas the synovial fluid culture missed six microorganisms (positive mPCR: S. aureus (n = 2), Cutibacterium acnes (n = 3), coagulase-negative staphylococci (n = 2)). CONCLUSION: The automated mPCR showed at least a similar performance to the synovial fluid culture (the current benchmark) in diagnosing septic arthritis, having the great advantage of a shorter turnaround time (within five hours). Cite this article: Bone Joint J 2019;101-B:288-296.

[Change in rheumatic hip surgery]. / Wandel in der rheumatischen Hüftchirurgie.

There is a trend towards a reduction in joint-preserving hip surgery, such as synovectomy and total hip joint replacement in rheumatic patients. This is mostly due to the success of biological disease-modifying antirheumatic drugs (bDMARD) in systemic anti-rheumatic therapy. The results of hip surgery in rheumatic patients are comparable to those in non-rheumatic patients, except for prosthetic joint infections, which are higher in patients with rheumatoid arthritis. Especially in hip surgery there was a big evolution in the last few years including a broad range of minimally invasive surgical methods, such as hip arthroscopy, mini-open hip surgery and minimally invasive hip arthroplasty with bone preservation or short femoral shafts. These surgical methods also have an advantage in the treatment of typical rheumatoid pathologies and have the benefit of a rapid recovery.

Qualitative α-defensin test (Synovasure) for the diagnosis of periprosthetic infection in revision total joint arthroplasty.

AIMS: The diagnosis of periprosthetic joint infection (PJI) remains demanding due to limitations of all the available diagnostic tests. The synovial fluid marker, α-defensin, is a promising adjunct for the assessment of potential PJI. The purpose of this study was to investigate the qualitative assessment of α-defensin, using Synovasure to detect or exclude periprosthetic infection in total joint arthroplasty. PATIENTS AND METHODS: We studied 50 patients (28 women, 22 men, mean age 65 years; 20 to 89) with a clinical indication for revision arthroplasty who met the inclusion criteria of this prospective diagnostic study. The presence of α-defensin was determined using the qualitative Synovasure test and compared with standard diagnostic methods for PJI. Based on modified Musculoskeletal Infection Society (MSIS) criteria, 13 cases were categorised as septic and 36 as aseptic revisions. One test was inconclusive. RESULTS: The Synovasure test achieved a sensitivity of 69% and a specificity of 94%. The positive and negative likelihood ratios were 12.46 and 0.33, respectively. A good diagnostic accuracy for PJI, with an area under the curve of 0.82, was demonstrated. Adjusted p-values using the method of Hochberg showed that Synovasure is as good at diagnosing PJI as histology (p = 0.0042) and bacteriology with one positive culture (p = 0.0327). CONCLUSION: With its ease of use and rapid results after approximately ten minutes, Synovasure may be a useful adjunct in the diagnosis of PJI. Cite this article: Bone Joint J 2017;99-B:66-72.

[Management of prosthetic joint infections]. / Management von Prothesen-infektionen.

Infections of prosthetic joints with biofilm-forming pathogens are one of the most devastating complications for patients and surgeons. Although the incidence is low they result in massive restrictions in the quality of life and mobility for patients as well as high costs for the treatment. Crucial for an adequate management of prosthetic joint infections are primarily comprehensive diagnostics to be able to exclude an aseptic loosening and secondarily in the presence of an infection to identify the pathogen responsible for forming the biofilm. The correct grading of the infection is crucial for selecting the appropriate form of infection management. Established standards in surgical treatment as well as in microbiology have be considered.

Biomechanical stability of tape augmentation for anterior talofibular ligament (ATFL) repair compared to the native ATFL.

PURPOSE: Current methods of anterior talofibular ligament (ATFL) reconstruction fail to restore the stability of the native ATFL. Therefore, augmented anatomic ATFL reconstruction gained popularity in patients with attenuated tissue and additional stress on the lateral ankle ligament complex. The aim of the present study was to evaluate the biomechanical stability of the InternalBrace (Arthrex Inc., Naples, FL, USA), a tape augmentation designed to augment the traditional Broström procedure. METHODS: Twelve (12) fresh-frozen human anatomic lower leg specimens were randomized into two groups: a native ATFL (ATFL) and a tape augmentation group (IB). Dual-energy X-ray absorptiometry (DEXA) scans were carried out to determine bone mineral density (BMD) of the specimens. The ligaments were stressed by internally rotating the tibia against the inverted fixated hindfoot. Torque at failure (Nm) and angle at failure (°) were recorded. RESULTS: The ATFL group failed at an angle of 33 ± 10°. In the IB group, construct failure occurred at an angle of 46 ± 16°. Failure torque reached 8.3 ± 4.5 Nm in the ATFL group, whereas the IB group achieved 11.2 ± 7.1 Nm. There was no correlation between angle at ATFL or IB construct failure or torque at failure, respectively, and BMD for both groups. CONCLUSION: This study reveals that tape augmentation for ATFL reconstruction shows similar biomechanical stability compared to an intact native ATFL in terms of torque at failure and angle at failure. BMD did not influence the construct stability. Tape augmentation proved an enhanced initial stability in ATFL reconstruction which may allow for an accelerated rehabilitation process. LEVEL OF EVIDENCE: II.

Comparison of Broström technique, suture anchor repair, and tape augmentation for reconstruction of the anterior talofibular ligament.

PURPOSE: Recently, tape augmentation for Broström repair has been introduced in order to improve the primary stability of the reconstructed anterior talofibular ligament (ATFL). The biomechanical effect of tape augmentation suture anchor (SA) repair is not known yet. The aim of the present study was to compare construct stability of the traditional Broström (TB) repair compared with a stand alone SA repair (SutureTak, Arthrex) and SA repair combined with tape augmentation (InternalBrace, Arthrex) internal brace (IB) of the ATFL. METHODS: Eighteen fresh-frozen human anatomic lower leg specimens were randomly assigned to three different groups: TB group, SA group, and IB augmentation group. In vivo torsion conditions in ankle sprain were carried out quasi-statically (0.5°/s). Torque (Nm) required to resist as well as the rotary displacement (°) of the load frame was recorded. Intergroup differences for age, bone mineral density (BMD), angle at failure, and torque at failure were analysed using ANOVA. RESULTS: In the TB group, ATFL reconstruction failed at an angle of 24.1°, in the SA group failure occurred at 35.5°, and in the IB group it failed at 46.9° (p = 0.02). Torque at failure reached 5.7 Nm for the TB repair, 8.0 Nm for the SA repair, and 11.2 Nm for the IB group (p = 0.04). There was no correlation between angle at ATFL failure, torque at failure, and BMD for the SA or IB groups. CONCLUSION: The present biomechanical study reveals statistically superior performance in terms of angle at failure as well as failure torque for the IB group compared to the other reconstruction methods. BMD did not influence the construct stability in the SA repair groups.

Effects of selenium coating of orthopaedic implant surfaces on bacterial adherence and osteoblastic cell growth.

The aim of this study was to evaluate whether coating titanium discs with selenium in the form of sodium selenite decreased bacterial adhesion of Staphylococcus aureus and Staph. epidermidis and impeded osteoblastic cell growth. In order to evaluate bacterial adhesion, sterile titanium discs were coated with increasing concentrations of selenium and incubated with bacterial solutions of Staph. aureus (ATCC 29213) and Staph. epidermidis (DSM 3269) and stained with Safranin-O. The effect of selenium on osteoblastic cell growth was also observed. The adherence of MG-63 cells on the coated discs was detected by staining with Safranin-O. The proportion of covered area was calculated with imaging software. The tested Staph. aureus strain showed a significantly reduced attachment on titanium discs with 0.5% (p = 0.011) and 0.2% (p = 0.02) selenium coating. Our test strain from Staph. epidermidis showed a highly significant reduction in bacterial adherence on discs coated with 0.5% (p = 0.0099) and 0.2% (p = 0.002) selenium solution. There was no inhibitory effect of the selenium coating on the osteoblastic cell growth. Selenium coating is a promising method to reduce bacterial attachment on prosthetic material.