Treatment outcomes of patients with Cutibacterium acnes-positive cultures during total joint replacement revision surgery: a minimum 2-year follow-up

INTRODUCTION Periprosthetic joint infection (PJI) is a devastating complication following total joint replacement (TJR). Cutibacterium acnes (C. acnes) is a low virulent skin commensal, commonly found during TJR revision surgery for "aseptic" causes. The purpose of the present study was to report the treatment outcomes of patients with C. acnes contamination or infection in the presence of a TJR treated with a revision surgery ± implant exchange ± prolonged (≥ 8 weeks) postoperative antibiotics. METHODS Medical records of patients with at least one positive C. acnes culture in intraoperative tissue samples or sonication fluid from a TJR revision surgery between January 2005 and December 2014 were retrospectively evaluated. The primary endpoint was infection eradication according to Delphi criteria. The diagnostic accuracy of preoperative TJR aspiration regarding the diagnosis of C. acnes PJI was also investigated. RESULTS A total of 52 TJR (28 shoulders, 17 hips, 7 knees) in 52 patients (35 males, 17 females) with an average age of 63 ± 11 (33-86) years were included. At an average follow-up of 67 ± 33 (24-127) months, the infection eradication of C. acnes PJI was 97% regardless of the surgical treatment or administration of prolonged postoperative antibiotics. The incidence of unsuspected C. acnes PJI was 28.8%. The sensitivity and specificity of preoperative joint aspiration in detecting C. acnes PJI were 59% and 88%, whereas the PPV and NNV were 83% and 67%, respectively. CONCLUSION Infection eradication of C. acnes PJI was very high at a minimum follow-up of 24 months, suggesting that C. acnes PJI could be adequately treated with a combination of revision surgery and prolonged postoperative antibiotics. The preoperative diagnosis of C. acnes PJI might be challenging with more than one-quarter of patients presenting without suspicion of C. acnes PJI. The appropriate treatment of patients with a single positive culture remains still unclear. A negative TJR aspiration should not rule out a C. acnes PJI, especially in the presence of clinical correlates of infection. LEVEL OF EVIDENCE Retrospective case-control study, Level III. IRB APPROVAL Kantonale Ethikkommission Zürich, BASEC Nr.:2017-00567

Study Protocol: Short Against Long Antibiotic Therapy for Infected Orthopaedic Sites - SALATIO Trials

Background: Few studies address the appropriate duration of post-surgical antibiotic therapy for orthopedic infections; with or without infected residual implants. We perform two similar randomized-clinical trials (RCT) to reduce the antibiotic use and associated adverse events. Methods: Two unblinded RCTs in adult patients (non-inferiority with a margin of 10%, a power of 80%) with the primary outcomes "remission" and "microbiologically-identical recurrences" after a combined surgical and antibiotic therapy. The main secondary outcome are antibiotic-related adverse events. The RCTs allocate the participants between 3 vs. 6 weeks of post-surgical systemic antibiotic therapy for implant-free infections; and between 6 vs. 12 weeks for residual implant-related infections. We need a total of 280 episodes (randomization schemes 1:1) with a minimal follow-up 12 months. We perform two interim analyses starting approximately after 1 and 2 years. The study approximatively lasts 3 years. Discussion: Both parellel RCT will enable to prescribe less antibiotics for future orthopedic infections in adult patients. Trial registration: ClinicalTrial.gov NCT05499481. Registered on 12 August 2022. Protocol version: 2 (19 May 2022

Articular cartilage and labral lesions of the glenohumeral joint: diagnostic performance of 3D water-excitation true FISP MR arthrography

OBJECTIVE: To evaluate the diagnostic performance of MR arthrography in the detection of articular cartilage and labral lesions of the glenohumeral joint using a transverse 3D water-excitation true fast imaging with steady-state precession (FISP) sequence. MATERIALS AND METHODS: Seventy-five shoulders were included retrospectively. Shoulder arthroscopy was performed within 6 months of MR arthrography. MR images were evaluated separately by two radiologists. They were blinded to clinical and arthroscopic information. Arthroscopy served as the reference standard. RESULTS: For the detection of humeral cartilage lesions, sensitivities and specificities were 86% (12/14)/89% (50/56) for observer 1 and 93%/86% for observer 2) for the transverse true FISP sequence and 64%/86% (50%/82% for observer 2) for the coronal intermediate-weighted spin-echo images. The corresponding values for the glenoidal cartilage were 60% (6/10)/88% (51/58) (80%/76% for observer 2) and 70%/86% (60%/74% for observer 2) respectively. For the detection of abnormalities of the anterior labrum (only assessed on true FISP images) the values were 94% (15/16)/84% (36/43) (88%/79% for observer 2). The corresponding values for the posterior labrum were 67% (8/12)/77% (36/47) (observer 2: 25%/74%). The kappa values for the grading of the humeral and glenoidal cartilage lesions were 0.81 and 0.55 for true FISP images compared with 0.49 and 0.43 for intermediate-weighted fast spin-echo images. Kappa values for true FISP evaluation of the anterior and posterior part of the labrum were 0.81 and 0.70. CONCLUSION: Transverse 3D true FISP MR arthrography images are useful for the difficult diagnosis of glenohumeral cartilage lesions and suitable for detecting labral abnormalities

End-stage extension of the knee and its influence on tibial tuberosity-trochlear groove distance (TTTG) in asymptomatic volunteers

PURPOSE: Increased tibial tuberosity-trochlear groove distance (TTTG) is one potential correcting parameter in patients suffering from lateral patellar instability. It was hypothesized that end-stage extension of the knee might influence the TTTG distance on MR images. METHODS: Transverse T1-weighted MR images of the knee were acquired at full extension, 15° and 30° flexion of the knee in 30 asymptomatic volunteers. MRI parameters: slice thickness: 3 mm, matrix: 256 × 384, FOV: 150 × 150 mm. Two observers independently measured the TTTG at all positions. RESULTS: Mean TTTG for observer 1 was 15.1 ± 3.2 mm at full extension, 10.0 ± 3.5 mm at 15° flexion and 8.1 ± 3.4 mm at 30° flexion. Mean TTTG for observer 2: 14.8 ± 3.3 mm at full extension, 9.4 ± 3.0 mm at 15° flexion, 8.6 ± 3.4 mm at 30° flexion. Mean values were significantly different (p < 0.001) between full extension and 15° as well as 30° flexion for both observers. Mean values were significantly different (p < 0.001) between 15° and 30° for observer 1, but not for observer 2 (n.s.). Interobserver agreement was very good (intraclass correlation coefficient: 0.87-0.88; p < 0.001). CONCLUSIONS: The TTTG increases significantly at the end-stage extension of the knee. Therefore, the comparability of published TTTG values measured on radiographs, CT and MRI at various flexion/extension angles of the knee are limited. LEVEL OF EVIDENCE: Development of diagnostic criteria in a consecutive series of patients and a universally applied 'gold' standard, Level II

Indikationen zum Gelenkersatz : Knieendoprothese

Current demographic trends with an increasing number of older patients, have led to a rising number of patients with higher demands on performance. Osteoarthritis in younger patients caused by abnormal forms or accidents also pose new challenges for medical professionals in the orthopedic field. As a rule of thumb, all conservative therapeutic possibilities should be exhausted before starting a surgical intervention. The main aims of surgery are to reduce pain, increase mobility and quality of life. In order to qualify for total knee arthroplasty (TKA) patients must fulfil major and minor criteria; however, after TKA approximately one fifth of patients are not satisfied with the result. In order to reduce this rate, indications should be narrowly set and expectations should be thoroughly discussed with the patient prior to an intervention. The high degree of dissatisfaction must be improved by intensifying efforts in further research

Closing wedge patellar osteotomy in combination with trochleoplasty

Sulcus-deepening trochleoplasty may result in a serious patellofemoral incongruence in cases where the patella also is highly dysplastic. In such cases, a closing wedge osteotomy of the patella may be considered. The technique was used in two patients (both female, 16 1/2 and 14 years old respectively) out of 85 trochleoplasties performed. At two years follow-up, both patients showed a stable patella with correct tracking. Both considered their functional result as excellent. Postoperative radiographs showed a normal sulcus angle (135 degrees and 132 degrees) with good congruence. Closing wedge patellar osteotomy, combined with sulcus-deepening trochleoplasty, can increase patellofemoral congruence with good clinical outcome

Diagnostic accuracy of 99m^{99m}Tc-antigranulocyte SPECT/CT in patients with osteomyelitis and orthopaedic device-related infections: A retrospective analysis

OBJECTIVES Conventional imaging techniques are routinely used in the diagnostic work-up of patients with suspected osteomyelitis or orthopaedic implant-associated infections. Hybrid nuclear medicine imaging techniques are a suitable alternative to routine imaging modalities as they provide anatomical and functional information within one procedure. Our study investigated the performance of anti-granulocyte SPECT/CT using $^{99m}$Tc-labelled monoclonal antibodies in the diagnosis of osteomyelitis and orthopaedic implant-associated infections. METHODS In this retrospective analysis, we included all patients with $^{99m}$Tc-antigranulocyte SPECT/CT acquired in the context of a suspected bone and joint infection. All patients underwent routine diagnostics and/or had a clinical follow-up of at least 12 months. RESULTS 26 episodes were included. Fifteen exams were performed for suspected osteomyelitis, and 11 for suspected orthopaedic implant-associated infection. SPECT/CT was ordered most often if standard diagnostic tests or conventional imaging modalities remained inconclusive. The overall sensitivity and specificity for the diagnosis of an infection was 77.8% and 94.1%, respectively. The positive predictive value was 87.5% and the negative predictive value 88.9%. Diagnostic accuracy was 88.5%. CONCLUSIONS $^{99m}$Tc-antigranulocyte SPECT/CT imaging has a high accuracy in the diagnosis of osteomyelitis and orthopaedic implant-associated infections and is a suitable non-invasive diagnostic tool if standard diagnostic examinations are inconclusive or not applicable

Mini Review on the Impact of Mobile Parts’ Exchange During the DAIR Procedure (Debridement, Antibiotics, Irrigation, Retention) for Infected Total Joint Arthroplasties

A prosthetic joint infection (PJI) requires a combined approach (infectiology and surgery). The therapeutic DAIR approach (debridement, antibiotics, irrigation, and retention) is an option for acute and stable PJI yielding remission incidences that oscillate between 70% and 90%; in a literature mostly composed of retrospective single-center trials. DAIR can be performed with or without mobile part’s exchange during debridement. Scientific data proving the necessity of mobile part exchanges (by leaving other infected components in situ) remain scarce. In this narrative mini review, we evaluate the existing literature that analyses the benefit of exchanging mobile parts with at least ten own cases. We moreover discuss the optimal duration of concomitant targeted systemic antibiotic therapy and reveal some insights in the surgical difficulties in performing DAIR. Our conclusion tends to favor of the mobile part’s exchange whenever feasible