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result(s) for
"Müllner, Maximilian"
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Association of age and spinopelvic function in patients receiving a total hip arthroplasty
by
Hu, Zhouyang
,
Pumberger, Matthias
,
Müllner, Maximilian
in
692/308
,
692/499
,
Arthroplasty, Replacement, Hip - adverse effects
2023
Restricted spinopelvic mobility received attention as a contributing factor for total hip arthroplasty (THA) instability. However, it is still unknown, how the spinopelvic function is influenced by age. In identifying the patients at highest risk for altered spinopelvic mechanics the study aimed to determine the association of age on the individual segments of the spinopelvic complex and global spinal sagittal alignment in patients undergoing THA. 197 patients were included in the prospective observational study conducting biplanar stereoradiography (EOS) in standing and sitting position pre-and postoperatively. Two independent investigators assessed C7-sagittal vertical axis (C7-SVA), cervical lordosis (CL), thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence (PI), sacral slope (SS), anterior plane pelvic tilt (APPT), and pelvic femoral angle (PFA). Key segments of the spinopelvic complex are defined as lumbar flexibility (∆ LL = LL
standing
− LL
sitting
), pelvic mobility (∆ SS = SS
standing
− SS
sitting
) and hip motion (∆ PFA = PFA
standing
− PFA
sitting
). Pelvic mobility was further defined based on ∆ SS = SS
standing
− SS
sitting
as stiff (∆ SS < 10°), normal (∆ SS ≥ 10°–30°) and hypermobile (∆ SS > 30°). The patient collective was classified into three groups: (1) < 60 years (n = 56), (2) ≥ 60–79 years (n = 112) and (3) ≥ 80 years (n = 29). Lumbar flexibility (∆ LL) was decreased with increasing age between all groups (36.1° vs. 23.1° vs. 17.2°/p
1+2
< 0.000, p
2+3
= 0.020, p
1+3
< 0.000) postoperatively. Pelvic mobility (∆ SS) was decreased in the groups 2 and 3 compared to group 1 (21.0° and 17.9° vs. 27.8°/p
1+2
< 0.000, p
2+3
= 0.371, p
1+3
= 0.001). Pelvic retroversion in standing position (APPT) was higher in group 2 and 3 compared to group 1 (1.9° and − 0.5° vs 6.9°/p
1+2
< 0.000, p
2+3
= 0.330, p
1+3
< 0.000). Global sagittal spinal balance (C7-SVA) showed more imbalance in groups 2 and 3 compared to group 1 (60.4 mm and 71.2 mm vs. 34.5 mm/p
1+2
< 0.000, p
2+3
= 0.376, p
1+3
< 0.000) postoperatively. The preoperative proportion of patients with stiff pelvic mobility in group 1 was distinctly lower than in group 3 (23.2% vs. 35.7%) and declined in group 1 to 1.8% compared to 20.7% in group 3 after THA. Changes after THA were reported for groups 1 and 2 representing spinopelvic complex key parameter lumbar flexibility (∆ LL), pelvic mobility (∆ SS) and hip motion (∆ PFA), but not for group 3. This is the first study to present age-adjusted normative values for spinopelvic mobility. The subgroups with increased age were identified as risk cohort for altered spinopelvic mechanics and enhanced sagittal spinal imbalance and limited capacity for improvement of mobility after THA. This valuable information serves to focus in the preoperative screening on the THA candidates with the highest risk for abnormal spinopelvic function.
Journal Article
Does obesity affect acetabular cup position, spinopelvic function and sagittal spinal alignment? A prospective investigation with standing and sitting assessment of primary hip arthroplasty patients
by
Hipfl, Christian
,
Pumberger, Matthias
,
Müllner, Maximilian
in
Acetabulum
,
Analysis
,
Arthritis
2021
Background
Total hip arthroplasty (THA) instability is influenced by acetabular component positioning, spinopelvic function and sagittal spinal alignment. Obesity is considered as a risk factor of THA instability, but the causal relationship remains unknown. This study aimed to investigate the influence of BMI on (1) spinopelvic function (lumbar flexibility, pelvic mobility and hip motion), (2) sagittal spinal alignment pre- and postoperatively and (3) acetabular cup position postoperatively in primary THA patients in a prospective setting.
Methods
One hundred ninety patients receiving primary total hip arthroplasty were enrolled in a prospective cohort study and retrospectively analysed. All patients received stereoradiography (EOS) in standing and relaxed sitting position pre-and postoperatively. C7-sagittal vertical axis (C7-SVA), lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), anterior plane pelvic tilt (APPT), and pelvic femoral angle (PFA) were assessed. Key parameters of the spinopelvic function were defined as lumbar flexibility (∆ LL = LL
standing
− LL
sitting
), pelvic mobility (∆ PT = PT
standing
− PT
sitting
) and hip motion (∆ PFA = PFA
standing
− PFA
sitting
). Pelvic mobility was further defined based on ∆ PT as stiff, normal and hypermobile (∆ PT < 10°; 10°–30°; > 30°). The patients were stratified to BMI according to WHO definition: normal BMI ≥ 18.5–24.9 kg/m
2
(n = 68), overweight ≥ 25.0–29.9 kg/m
2
(n = 81) and obese ≥ 30–39.9 kg/m
2
(n = 41). Post-hoc analysis according to Hochberg's GT2 was applied to determine differences between BMI groups.
Results
Standing cup inclination was significant higher in the obese group compared to the normal BMI group (45.3° vs. 40.1°;
p
= 0.015) whereas standing cup anteversion was significantly decreased (22.0° vs. 25.3°;
p
= 0.011). There were no significant differences for spinopelvic function key parameter lumbar flexibility (∆ LL), pelvic mobility (∆ PT) and hip motion (∆ PFA) in relation to BMI stratified groups. The obese group demonstrated significant enhanced pelvic retroversion compared to the normal BMI group (APPT − 1.8° vs. 2.4°;
p
= 0.028). The preoperative proportion of stiff pelvic mobility was decreased in the obese group (12.2%) compared to normal (25.0%) and overweight (27.2%) groups. Spinal sagittal alignment in C7-SVA and PI-LL mismatch demonstrated significantly greater imbalance in the obese group compared to the normal BMI group (68.6 mm vs. 42.6 mm,
p
= 0.002 and 7.7° vs. 1.2°,
p
= 0.032, respectively) The proportion of patients with imbalanced C7-SVA was higher in the obese (58.5%) than in the normal BMI group (44.1%).
Conclusions
The significantly increased spinal sagittal imbalance with altered pelvic mechanics is a potential cause for the reported increased risk of THA dislocations in obese patients. Consequently, the increased spinal sagittal imbalance in combination with normal pelvic mobility need to be taken into account when performing THA in obese patients.
Journal Article
Serratia marcescens prosthetic joint infection: two case reports and a review of the literature
by
Adelhoefer, Siegfried
,
Müllner, Maximilian
,
Gonzalez, Marcos R.
in
Adolescent
,
Aged
,
Analysis
2023
Background
Despite some studies on Gram-negative bacteria as difficult to treat pathogens in periprosthetic joint infections, there are no detailed analyses on
Serratia
periprosthetic joint infections. As such, we present two cases of
Serratia
periprosthetic joint infections and summarize all known cases to date in the course of a PRISMA criteria-based systematic review.
Case presentation
Case 1: a 72-year-old Caucasian female with Parkinson’s disease and treated breast cancer developed periprosthetic joint infection caused by
Serratia marcescens
and
Bacillus cereus
, following multiple prior revisions for recurrent dislocations of her total hip arthroplasty. Two-stage exchange was performed, and the patient remained free of
Serratia
periprosthetic joint infection recurrence at 3 years. Case 2: an 82-year-old Caucasian female with diabetes and chronic obstructive pulmonary disease presented with a chronic parapatellar knee fistula after undergoing multiple failed infection treatments at external clinics. After performing two-stage exchange and gastrocnemius flap plastic for combined
Serratia marcescens
and
Proteus mirabilis
periprosthetic joint infection, the patient was released without any signs of infection, but was subsequently lost to follow-up. Review: a total of 12 additional
Serratia
periprosthetic joint infections were identified. Merged with our two cases, the mean age of 14 patients was 66 years and 75% were males. Mean length of antibiotic therapy was 10 weeks with ciprofloxacin most commonly used (50%). Mean follow-up was 23 months. There was a total of four reinfections (29%), including one case of
Serratia
reinfection (7%).
Conclusions
Serratia
is a rare cause of periprosthetic joint infection affecting elderly with secondary diseases. While the overall reinfection rate was high, the risk of
Serratia
periprosthetic joint infection persistence was low. Treatment failure in patients may be attributable to the host, rather than the
Serratia
periprosthetic joint infection itself, thus challenging current concepts on Gram-negatives as a uniform class of difficult-to-treat pathogens.
Level of evidence
: Therapeutic level IV
Journal Article
The arthroscopic popliteus bypass reconstruction for posterolateral instabilities of the knee - clinical results > 2 year follow up
2020
Aims and Objectives:
Injuries of the posterior cruciate ligament (PCL) are most often accompanied by injuries of the posterolateral corner (PLC) and the ligamentum collaterale fibulare (LCL). This leads to a combined dorsal- and external rotational instability. Prior to this study a novel arthroscopic technique was developed to treat posterolateral injuries (Popliteus Bypass Graft). To date, there are no long term results reported for arthroscopic techniques to treat these injuries. This study evaluated the clinical outcome of patients undergoing this surgery with a minimum follow up of 2 years.
Materials and Methods:
In the ongoing study, 47 patients with posterolateral instabilities of the knee were treated with an arthroscopic reconstruction of the popliteus bypass graft in combination with a PCL reconstruction. Patients with a minimum follow up of 2 years were included in this study. The clinical outcome was evaluated by subjective and objective scores for stability, pain and activity level: Lysholm, Tegner, KOOS, Dial test, subjective scores (0-10) for function (0 good, 10 poor) und pain (0 no pain, 10 intense pain). The dorsal stability was measured with the rolimeter.
Results:
At the time of the abstract submission 17 patients where evaluated. The mean age at the time of the operation was 36.8 (±15.5) years, the mean BMI was 27.7 (±5.5). The mean time from the injury to the treatment was 6.9 (±5.3) months. The mean follow up time was 46.35 (±12.7) months. The mean postoperative Lysholm score was 88.7 (± 13.4). The mean Tegner score was 6.0 (±2.2) preoperative and changed to 5.3 (±2.2) postoperative. The KOOS score was evaluated for pain 87.2 (±19.5), symptoms 92.5 (±11.1), daily activity 89.2 (±16.9), function 73.1 (±28.9) and life quality 78.5 (±21.7). The mean Rolimeter measurement for the uninjured knee was 7.16mm (±2.2) compared to the operated side with 8,18mm (±1.7). The VAS score for function was 1.6 (±2.1) and 1.6 (±2.2) for pain.
Conclusion:
The arthroscopic reconstruction of posterolateral injuries provides good clinical and subjective results after a minimum follow up of 2 years.
Journal Article
Two-stage exchange for PJI with co-existing cerclages for fracture: higher rates of early re-infections and difficult to treat microbes
2023
IntroductionPeriprosthetic joint infections (PJI) with osteosynthesis material for contemporaneous fractures are a challenging, yet poorly described condition. This study will analyze PJI with co-existing fractures treated with cerclages and two-stage exchange.Materials and methodsPatients with and without cerclages for coexisting periprosthetic fractures, undergoing two-stage exchange for PJI of hip or knee, between 06/2013 and 02/2016, were compared concerning baseline characteristics and re-infection rate in the course of a 2 year follow-up. All patients were treated with a standardized two-stage protocol. A PJI was defined according to the EBJIS criteria. All foreign material, including cerclages, was sent in for sonication for microbiological analysis.ResultsNinety-six patients treated with two-stage exchange for PJI could be included. Co-existing fractures treated with cerclage were identified in nine patients (9.3%, study group). Diaphyseal femoral simple in five cases (AO2A3) and proximal intertrochanteric in three cases (AO1A3) were the leading fracture locations. In one patient, cerclage implantation was performed prior to prosthesis explantation, in six, during prosthesis explantation, and in two, in the course of prosthesis reimplantation. The study group showed a significantly higher rate of difficult to treat microbes (44.4%; 8.0%; p = .001), Charlson Comorbidity Index (5.4; 3.7; p = .033), relapse infections with the same microbe (22.2%; 1.1%; p = .001), and early-onset infections (< 30 days) (11.1%; 1.1%; p = .046), than the comparison two-stage exchange group without fractures. In contrast, age (72.5 study group; 68.2 comparison group; p = .224), rate of revisions for PJI in the past (55.5%; 51.7%; p = .827), and total re-infection rate (22.2%; 10.3%; p = .287) did not show a difference.ConclusionPJI with co-existing cerclages for fractures were associated with multi-resistant microbes, relapse by the same microbe and early-onset re-infections. Cerclages might be considered a potential source of re-infection during a two-stage exchange. However, statistical weaknesses and a small study group must be considered limitations of the study.
Journal Article
Establishing and Evaluating Trustworthy AI: Overview and Research Challenges
by
Inti Gabriel Mendoza Estrada
,
Veas, Eduardo
,
Fessl, Angela
in
Artificial intelligence
,
Interdisciplinary studies
,
Synthesis
2024
Artificial intelligence (AI) technologies (re-)shape modern life, driving innovation in a wide range of sectors. However, some AI systems have yielded unexpected or undesirable outcomes or have been used in questionable manners. As a result, there has been a surge in public and academic discussions about aspects that AI systems must fulfill to be considered trustworthy. In this paper, we synthesize existing conceptualizations of trustworthy AI along six requirements: 1) human agency and oversight, 2) fairness and non-discrimination, 3) transparency and explainability, 4) robustness and accuracy, 5) privacy and security, and 6) accountability. For each one, we provide a definition, describe how it can be established and evaluated, and discuss requirement-specific research challenges. Finally, we conclude this analysis by identifying overarching research challenges across the requirements with respect to 1) interdisciplinary research, 2) conceptual clarity, 3) context-dependency, 4) dynamics in evolving systems, and 5) investigations in real-world contexts. Thus, this paper synthesizes and consolidates a wide-ranging and active discussion currently taking place in various academic sub-communities and public forums. It aims to serve as a reference for a broad audience and as a basis for future research directions.