Conversion From Knee Arthrodesis Back to Arthroplasty: A Particular Challenge in Combination With Fungal Periprosthetic Joint Infection.

A 58-year-old female treated at an outside facility with knee arthrodesis due to persistent periprosthetic joint infection fulfilled all prerequisites for a conversion back to arthroplasty, as part of a 2-stage revision. Owing to the detection of Candida parapsilosis, the treatment concept was converted to a three-stage procedure. A scheduled spacer exchange with additional amphotericin B-loaded polymethylmethacrylate was conducted as an intermediate revision before reimplantation. Conversion in the setting of fungal periprosthetic joint infection presents a challenge, and successful treatment hinges on the use of proper antifungal and antimicrobial protocols, advanced surgical techniques, and a multidisciplinary team approach. At the 3-year follow-up, successful infection eradication as measured by the Delphi-based consensus definition was achieved with a range of motion of 0°-100°

MedShapeNet -- A Large-Scale Dataset of 3D Medical Shapes for Computer Vision

Prior to the deep learning era, shape was commonly used to describe the objects. Nowadays, state-of-the-art (SOTA) algorithms in medical imaging are predominantly diverging from computer vision, where voxel grids, meshes, point clouds, and implicit surface models are used. This is seen from numerous shape-related publications in premier vision conferences as well as the growing popularity of ShapeNet (about 51,300 models) and Princeton ModelNet (127,915 models). For the medical domain, we present a large collection of anatomical shapes (e.g., bones, organs, vessels) and 3D models of surgical instrument, called MedShapeNet, created to facilitate the translation of data-driven vision algorithms to medical applications and to adapt SOTA vision algorithms to medical problems. As a unique feature, we directly model the majority of shapes on the imaging data of real patients. As of today, MedShapeNet includes 23 dataset with more than 100,000 shapes that are paired with annotations (ground truth). Our data is freely accessible via a web interface and a Python application programming interface (API) and can be used for discriminative, reconstructive, and variational benchmarks as well as various applications in virtual, augmented, or mixed reality, and 3D printing. Exemplary, we present use cases in the fields of classification of brain tumors, facial and skull reconstructions, multi-class anatomy completion, education, and 3D printing. In future, we will extend the data and improve the interfaces. The project pages are: https://medshapenet.ikim.nrw/ and https://github.com/Jianningli/medshapenet-feedbackComment: 16 page

The Modified Harrington Procedure for Metastatic Peri-Acetabular Bone Lesion Using a Novel Highly Porous Titanium Revision Shell with Long Lever Arm Screw

Background and Objectives: Peri-acetabular metastases often lead to significant pain and functional impairment. Surgical interventions, including the Harrington procedure, aim to address these challenges. This study evaluates a modified Harrington procedure using the MUTARS® PRS® (Pelvic Revision Shell) with an 8 mm fixation screw for severe acetabular defects resulting from metastatic lesions. Materials and Methods: Retrospective analysis of 12 patients treated between January 2020 and December 2023 was conducted. The procedure involved using the novel MUTARS® PRS® with an 8 mm in diameter dome screw (length 70–100 mm). Outcome measures included implant positioning changes, complication rates, functional outcomes, implant longevity, and patient survival. Radiological assessments were performed postoperatively, with follow-ups at 3, 6, 12 months, and annually thereafter. Results: Average follow-up was 15 ± 11 months, with 67% patient survival at 1 year and 44% at 2 years. Implant survivorship remained 100%. Harris Hip Score improved significantly from 37 ± 22 preoperatively to 75 ± 15 at the last follow-up. No revisions involving implant components were reported. Complications occurred in 5 of 12 patients. Overall, PRS® demonstrates effective osseous ingrowth, high primary stability, immediate full weight-bearing, and low complication rates. Conclusions: PRS® integrates facilitating osseous ingrowth for preferable long-term outcomes, while efficiently transmitting the weight-bearing load to the intact aspect of the pelvis using a long 8 mm lever screw, enhancing the primary stability of the construct. It proves to be an effective and reproducible technique for managing destructive metastatic lesions of the acetabulum and peri-acetabular region, even in irradiated bone

Erratum to \u27Conversion From Knee Arthrodesis Back to Arthroplasty: A Particular Challenge in Combination With Fungal Periprosthetic Joint Infection\u27 [Arthroplasty Today 6 (2020) 1038-1044].

[This corrects the article DOI: 10.1016/j.artd.2020.10.007.]

Three-stage revision arthroplasty for the treatment of fungal periprosthetic joint infection: outcome analysis of a novel treatment algorithm : a prospective study.

Aims: Fungal periprosthetic joint infections (fPJIs) are rare complications, constituting only 1% of all PJIs. Neither a uniform definition for fPJI has been established, nor a standardized treatment regimen. Compared to bacterial PJI, there is little evidence for fPJI in the literature with divergent results. Hence, we implemented a novel treatment algorithm based on three-stage revision arthroplasty, with local and systemic antifungal therapy to optimize treatment for fPJI. Methods: From 2015 to 2018, a total of 18 patients with fPJI were included in a prospective, single-centre study (DKRS-ID 00020409). The diagnosis of PJI is based on the European Bone and Joint Infection Society definition of periprosthetic joint infections. The baseline parameters (age, sex, and BMI) and additional data (previous surgeries, pathogen spectrum, and Charlson Comorbidity Index) were recorded. A therapy protocol with three-stage revision, including a scheduled spacer exchange, was implemented. Systemic antifungal medication was administered throughout the entire treatment period and continued for six months after reimplantation. A minimum follow-up of 24 months was defined. Results: Eradication of infection was achieved in 16 out of 18 patients (88.8%), with a mean follow-up of 35 months (25 to 54). Mixed bacterial and fungal infections were present in seven cases (39%). The interval period, defined as the period of time from explantation to reimplantation, was 119 days (55 to 202). In five patients, a salvage procedure was performed (three cementless modular knee arthrodesis, and two Girdlestone procedures). Conclusion: Therapy for fPJI is complex, with low cure rates according to the literature. No uniform treatment recommendations presently exist for fPJI. Three-stage revision arthroplasty with prolonged systemic antifungal therapy showed promising results. Cite this article: Bone Jt Open 2021;2(8):671-678

Facing multidrug-resistant pathogens in periprosthetic joint infections with self-administered outpatient parenteral antimicrobial therapy-A prospective cohort study.

A key factor in the successful management of periprosthetic joint infection (PJI) besides the surgical regime is a consistent antimicrobial therapy. Recently, oral versus intravenous (IV) antibiotics for bone and joint infection trial demonstrated the noninferiority of oral antimicrobial therapy compared to IV, implying that an early transition to oral administration is reasonable. It is likely that the international consensus meeting of musculoskeletal Infections and the European Bone and Joint Infection Society will consider these findings. However, rising levels of antimicrobial resistance are challenging and recommendations for dealing with multidrug-resistant (MDR) pathogens resistant to oral antibiotics are lacking. This study focuses on establishing guidance towards their management in PJI. From December 2015 to June 2019, patients with MDR pathogens were included in a single-center prospective cohort study and treated with self-administered outpatient parenteral antimicrobial therapy (S-OPAT) based on a two-stage revision strategy. Demographics, pathogens, antimicrobial agents, and outcomes were recorded. A total of 1738 outpatient days in 26 patients were analyzed. The incidence of pathogens resistant to oral antibiotics in PJI was 4%, most frequently encountered were staphylococcus epidermidis. The Kaplan-Meier-estimated infection-free survival after 3 years was 90% (95% confidence interval, 84.6%-95.5%). We recorded adverse events in 6 of 54 (11%) S-OPAT episodes (3.45/1000 S-OPAT days). (i) S-OPAT in two-stage revision arthroplasty to counter increasing numbers of MDR pathogens resistant to oral agents can achieve a high infection eradication rate and (ii) should therefore be taken into account at the next society\u27s consensus treatment updates

Does the Implementation of the PRO-IMPLANT Foundation Treatment Algorithm Improve the Outcome of Chronic Periprosthetic Knee Infections? Mid-Term Results of a Prospective Study.

BACKGROUND: Several treatment options for chronic periprosthetic joint infections have been published in the current literature, with an on-going discussion to determine effective management algorithms. OBJECTIVES: To compare outcomes of the two-stage exchange procedure in revision TKA prior to and after implementation of the PRO-IMPLANT Foundation treatment algorithm. The primary endpoints were defined as (i) revisions during the interval time, (ii) duration of the interval time and (iii) successful PJI eradication. MATERIAL AND METHODS: Between 02/2013 and 09/2016, 122 patients were included in a single-centre cohort analysis. 55 patients were treated according to the previously used algorithm (K1) and 67 according to the PRO-IMPLANT Foundation algorithm (K2). A minimum follow-up period of 3 years was set as the inclusion criterion. Successful eradication of infection was defined in accordance with the consensus criteria by Diaz-Ledezma et al. RESULTS: Successful eradication was achieved in 42 (67%) patients in K1 and 47 (85.5%) in K2 (p ≤ 0.005). The mean interval time was 88 days (range 51 - 353) in K1 and 52 days (range 42 - 126) in K2 (p ≤ 0.005). In K1, a mean of 0.8 (range 0 - 6) revisions were necessary during the interval period compared with 0.5 (range 0 - 4) in K2 (p = 0.066). CONCLUSION: Implementation of the PRO-IMPLANT treatment algorithm led to significant improvement in the outcome of periprosthetic joint infections. During mid-term follow-up, infection eradication was highly successful, with decreases in the interval time as well as the number of revisions

Accuracy of radiographic measurement techniques for the Taylor spatial frame mounting parameters

Aim!#!The correction accuracy of the Taylor Spatial Frame (TSF) fixator depends considerably on the precise determination of the mounting parameters (MP). Incorrect parameters result in secondary deformities that require subsequent corrections. Different techniques have been described to improve the precision of MP measurement, although exact calculation is reportedly impossible radiologically. The aim of this study was to investigate the accuracy of intraoperative and postoperative radiographic measurement methods compared to direct MP measurement from TSF bone mounting.!##!Methods!#!A tibial Sawbone® model was established with different origins and reference ring positions. First, reference MPs for each origin were measured directly on the frame and bone using a calibrated, digital vernier calliper. In total 150 MPs measured with three different radiographic measurement techniques were compared to the reference MPs: digital radiographic measurements were performed using soft-copy PACS images without (method A) and with (method B) calibration and calibrated image intensifier images (method C).!##!Results!#!MPs measured from a non-calibrated X-ray image (method A) showed the highest variance compared to the reference MPs. A greater distance between the origin and the reference ring corresponded to less accurate MP measurements with method A. However, the MPs measured from calibrated X-ray images (method B) and calibrated image intensifier images (method C) were intercomparable (p = 0.226) and showed only minor differences compared to the reference values but significant differences to method A (p < 0,001).!##!Conclusion!#!The results demonstrate that MPs can be accurately measured with radiographic techniques when using calibration markers and a software calibration tool, thus minimizing the source of error and improving the quality of correction

Tibiocalcaneal arthrodesis using the Ilizarov fixator in compromised hosts: an analysis of 19 patients

Introduction!#!Salvage of joint destruction of the tibiotalar and subtalar joint with necrosis or infection of the talus in compromised hosts is a challenging problem. In these cases, tibiocalcaneal arthrodesis using the Ilizarov external fixator represents a possible alternative to amputation. This retrospective study presents the results and complications of this salvage procedure.!##!Materials and methods!#!Between 2005 and 2015, 19 patients were treated with tibiocalcaneal arthrodesis using the Ilizarov external fixator. Ten patients received tibiocalcaneal arthrodesis due to an acute or chronic infection with joint destruction. The other nine patients presented posttraumatic necrosis of the talus or Charcot arthropathy. In addition to demographic data, the time spent in the fixator, the major and minor complications and the endpoint of the consolidation were evaluated retrospectively. Furthermore, clinical outcomes were measured using the modified American Orthopedic Foot and Ankle Society (AOFAS) score.!##!Results!#!The average time spent in the fixator was 22 (range 14-34) weeks. The average follow-up in 17 patients was 116 (range 4-542) weeks. Two patients were lost to follow-up. Complete osseous consolidation was achieved in 14 out of 19 patients. One patient presented partial consolidation, and in four patients, pseudarthrosis could be detected. The mean modified AOFAS score at the final follow-up was 53 out of 86 possible points.!##!Conclusion!#!Tibiocalcaneal arthrodesis using the Ilizarov fixator is a possible salvage procedure even in compromised hosts. However, the healing rates are below the rates reported in the literature for tibiotalar arthrodesis in comparable clinical situations

Facing multidrug-resistant pathogens in periprosthetic joint infections with self-administered outpatient parenteral antimicrobial therapy

A key factor in the successful management of periprosthetic joint infection (PJI) besides the surgical regime is a consistent antimicrobial therapy. Recently, oral versus intravenous (IV) antibiotics for bone and joint infection trial demonstrated the noninferiority of oral antimicrobial therapy compared to IV, implying that an early transition to oral administration is reasonable. It is likely that the international consensus meeting of musculoskeletal Infections and the European Bone and Joint Infection Society will consider these findings. However, rising levels of antimicrobial resistance are challenging and recommendations for dealing with multidrug-resistant (MDR) pathogens resistant to oral antibiotics are lacking. This study focuses on establishing guidance towards their management in PJI. From December 2015 to June 2019, patients with MDR pathogens were included in a single-center prospective cohort study and treated with self-administered outpatient parenteral antimicrobial therapy (S-OPAT) based on a two-stage revision strategy. Demographics, pathogens, antimicrobial agents, and outcomes were recorded. A total of 1738 outpatient days in 26 patients were analyzed. The incidence of pathogens resistant to oral antibiotics in PJI was 4%, most frequently encountered were staphylococcus epidermidis. The Kaplan–Meier-estimated infection-free survival after 3 years was 90% (95% confidence interval, 84.6%–95.5%). We recorded adverse events in 6 of 54 (11%) S-OPAT episodes (3.45/1000 S-OPAT days). (i) S-OPAT in two-stage revision arthroplasty to counter increasing numbers of MDR pathogens resistant to oral agents can achieve a high infection eradication rate and (ii) should therefore be taken into account at the next society's consensus treatment updates