Session 12: DOS Best Paper

16. November
16:00 - 17:00
Lokale: Auditorium
Chair: Michael M Petersen and Michala Skovlund

104. Local Cefuroxime tissue concentrations in the hand after single and repeated administration – a randomized clinical study of metacarpal bone, synovial sheath and subcutaneous tissue of patients undergoing trapeziectomy
Andrea René Jørgensen 1,2, Pelle Hanberg1, Mats Bue 1,2,3, Charlotte Hartig-Andreasen 3, Nis Pedersen Jørgensen4, Maiken Stilling1,2,3
1. Aarhus Denmark Microdialysis Research Group (ADMIRE), Orthopaedic Research Unit, Aarhus University Hospital, Aarhus N, Denmark; 2. Department of Clinical Medicine, Aarhus University, Aarhus N, Denmark; 3. Department of Orthopaedic Surgery, Aarhus University Hospital, Aarhus N, Denmark; 4. Department of Infectious Diseases, Aarhus University Hospital, Aarhus N, Denmark

Background: The role of antimicrobial prophylaxis in shorter, clean soft tissue hand surgical procedures is debatable, but it is standard in hand surgeries involving bone and/or implants. A single preoperative antimicrobial administration may not provide sufficient antimicrobial coverage in all tissues for the duration of hand surgeries.
Aim: To investigate the time that the free concentration of Cefuroxime was above minimal inhibitory concentration (fT>MIC) of 4 µg/mL for Staphylococcus aureus in targeted hand tissues after single and repeated administration, enabling evaluation of need for re-administration and optimal time for initial administration.
Materials and Methods: In a prospective, unblinded randomized clinical study, 16 patients (13 female, 3 male) with a mean age of 66 years (range 51 to 80 years) underwent trapeziectomy with suspensionplasty. Before wound closure, microdialysis catheters were placed in the metacarpal bone, the synovial sheath and subcutaneous tissue. After tourniquet release, patients were randomized to intravenous administration of a single Cefuroxime dose (1,500 mg) (Group 1, n=8) or repeated (2x1,500 mg) Cefuroxime dosing with a 4-h dosing interval (Group 2, n=8). Dialysates and venous samples were taken over a period of 8 h.
Results: fT>MIC of 4 µg/mL was longer in all compartments in Group 2 (range 96–100%) than in Group 1 (range 52–75%). A mean Cefuroxime concentration of 4 µg/mL was reached in all compartments in both groups within a mean time of 6 min (range 0–27 min). In Group 1, the mean concentrations decreased below 4 µg/mL between 3 h 59 min and 5 h 38 min after administration.
Interpretation / Conclusion: A single administration of Cefuroxime 1,500 mg provided antimicrobial tissue coverage for a minimum of 3 h 59 min. Administration of Cefuroxime in hand surgeries should be done a minimum of 27 min prior to incision in order to achieve sufficient coverage in all individuals. Re-administration of Cefuroxime should be considered in hand surgeries lasting longer than approximately 4 h from the time of initial administration.

105. Poor Patient-Reported Outcomes and Satisfaction after Revisions of Medial Unicompartmental Knee Arthroplasties for unexplained pain. A cross-sectional nationwide study on patients revised for Unexplained Pain vs Aseptic Loosening
Kristine Bollerup Arndt1, Henrik Morville Schrøder2, Anders Troelsen3, Martin Lindberg-Larsen1
1. Department of Orthopaedic Surgery and Traumatology, Odense University Hospital; Department of Clinical Research, University of Southern Denmark, Odense 2. Department of Orthopaedic Surgery. Naestved Hospital, Denmark 3. Department of Orthopaedic Surgery, Clinical Orthopaedic Research Hvidovre, Copenhagen University Hospital Hvidovre, Denmark

Background: It is uncertain if patients undergoing revision of UKAs because of unexplained pain benefit from the surgery.
Aim: The aim of this study was to compare patient- reported outcome measures (PROM) and satisfaction 1 to 3 years after revision of medial unicompartmental knee arthroplasties (mUKA) for unexplained pain vs aseptic loosening.
Materials and Methods: We included 104 patients undergoing revision of mUKA's for the indications unexplained pain and aseptic loosening in the period January 1, 2018 to December 31, 2020 from the Danish Knee Arthroplasty Register. 52 patients were revised for unexplained pain and 52 for aseptic loosening. Questionnaires including PROMs (Oxford Knee Score (OKS), EQ-5D-5L, Forgotten Joint Score (FJS)) and questions about satisfaction with the surgery were sent to digitally secured mailboxes.
Results: Median OKS was 26 (IQR 22) vs 34 (IQR 12) 1 to 3 years after revisions for unexplained pain vs aseptic loosening, p=0.033. Median EQ-5D-5L Index was 0.7 (IQR 0.6) vs 0.8 (IQR 0.1) for unexplained vs aseptic loosening, p=0.014. Median FJS was 48 (IQR 10) vs 52 (IQR 14) for unexplained pain vs aseptic loosening, p=0.1. Satisfaction with the surgery (100=not satisfied; 0=very satisfied) was 55 (IQR 60) for unexplained pain vs 50 (IQR 67) for aseptic loosening, p=0.087, and patients revised for unexplained pain were less likely to find their knee problem importantly improved (p=0.032).
Interpretation / Conclusion: Patients undergoing revision of mUKAs for unexplained pain presented poor postoperative PROM scores, and PROM scores were worse compared to patients revised for aseptic loosening. This study support the evidence against revisions for unexplained pain.

106. Validity of the registration of periprosthetic joint infection after total knee arthroplasty in the Danish Knee Arthroplasty Register using microbiology data as a gold standard
Marie Anneberg1, Eskild Bendix Kristiansen1, Anders Troelsen2, Per Gundtoft3, Henrik Toft Sørensen1,4, Alma Becic Pedersen1,4
1 Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus University, Denmark; 2 Department of Orthopedic Surgery, Hvidovre Hospital, Denmark; 3 Department of Orthopedic surgery, Aarhus University Hospital, Denmark; 4 Department of Clinical Medicine, Aarhus University Denmark

Background: Periprosthetic joint infection (PJI) is a serious complication after total knee arthroplasty (TKA). Recent studies have revealed low validity of the PJI diagnosis in several joint arthroplasty registers and suggested a systematic underestimation of the incidence of PJI
Aim: To assess the validity of recording of revision due to PJI within the first year after primary TKA in the Danish Knee Arthroplasty Register (DKR), using the Danish Microbiology Database (MiBa) as gold standard.
Materials and Methods: We included patients who underwent primary TKA between January 1st, 2016, and December 31st 2018, registered to both DKR and MiBa, with matching primary operation date and side (n= 18.454). MiBa holds nationwide information on results of all microbiology samples and procedure codes via linkage to the Danish National Patient Registry. PJI was defined in DKR as first-time revision due to PJI within the first year after primary TKA, registered as “PJI suspected” or “PJI verified by microbiology”. PJI was defined in MiBa as first-time same- side knee-related revision surgery within the first year after primary TKA, accompanied by cultures taken between 24 hours before to 48 hours after revision surgery, with a minimum of two samples out of a minimum of three samples positive with the same microorganism. We estimated the sensitivity, specificity, positive and negative predictive value (PPV and NPV) of PJI diagnosis in DKR.
Results: Amongst 18,454 primary TKA patients, we identified 147 PJIs in DKR and 158 in MiBa. Validating DKR against MiBa, 94 of PJIs in DKR were true positive, 53 false positive, 64 false negative, and 18243 true negative, corresponding to a sensitivity of 59.5% (51.4 - 67.2), a specificity of 99.7% (99.6 -99.8), a PPV of 63.9% (55.6% - 71.7), and a NPV of 99.7% (99.6 - 99.7). 60/64 false negatives were found within the first 3 months after primary TKA.
Interpretation / Conclusion: Using microbiology samples as gold standard, we found 40% underrecording of revision due to PJI after TKA in DKR during 2016-2018. 36% of PJI reported to DKR had negative cultures according to MiBa, and likely partly represents culture negative PJIs, as this remains a clinical diagnosis.

107. Short-term Patient-reported outcome after stemmed versus stemless total shoulder arthroplasty for glenohumeral osteoarthritis: A patient-blinded non-inferiority randomized clinical trial.
Zaid Issa1,2, Jeppe Vejlgaard Rasmussen3, Stig Brorson1,2
1. Department of Orthopaedics, Zealand University Hospital, Køge. 2. Centre for Evidence-Based Orthopaedics (CEBO). 3. Department of Orthopaedics, Herlev Gentofte hospital.

Background: Stemmed total shoulder arthroplasty (TSA) is the dominant implant in the treatment of patients with primary osteoarthritis (OA) and an intact cuff. Stemless TSA systems have been used since 2004, but information about safety and efficacy is sparse. The metaphyseal fixation of the stemless TSA may be an advantage should the need of a revision arthroplasty arise.
Aim: The purpose of the study was to compare the short-term patient-reported outcome of stemless and stemmed total shoulder arthroplasty.
Materials and Methods: We conducted a non-inferiority randomized clinical trial. Patients with symptomatic OA, computerized tomography (CT) scan-verified adequate glenoid bone stock, and no total rupture of rotator cuff tendons verified by a magnetic resonance imaging (MRI) scan were randomly allocated to a stemmed or stemless TSA. The primary outcome was the Western Ontario Osteoarthritis Shoulder (WOOS) score at 12 months. The minimal clinically important difference (MCID) of WOOS is 12.3%. we used this value to define the non-inferiority margin.
Results: Eighty patients were randomised, 38 in the stemmed TSA group and 42 in the stemless TSA group. One patient in the stemless TSA group died after the 3 months follow-up, otherwise no dropouts. Demographics were comparable in both groups. At 12 months follow-up the mean WOOS was 77.8 (SD=22.0) and median 87.1 (IQR: 66.6-94.2) in the stemmed TSA group and 86.8 (SD=16.9) and 94.2 (IQR: 82.5-98.2) in the stemless TSA group (p-value for non- inferiority test =0.045). We found a statistically significant difference in the mean WOOS of 9.0% (95% CI 0.7- 17.0) but the lower limit of the CI (e.g., 0.7) did not cross the margin of non-inferiority (e.g., -12.5).
Interpretation / Conclusion: The stemless TSA is non-inferior to the stemmed TSA in terms of patient-reported outcome measures at short term follow-up. Sparing the humeral shaft canal for later revision could be an argument for using a stemless TSA.

108. No effect of capsular closure during hip arthroscopy - one-year follow-up of a prospective randomized controlled study.
Bjarne Mygind-Klavsen1, Otto Kraemer2, Bent Lund3, Michael Krogsgaard5, Per Hölmich2, Martin Lind1, Torsten Grønbech Nielsen1, Lene Lindberg Miller1, Karen Briggs4, Marc J. Philippon4, Christian Dippmann5
1. Div. of Sports Traumatology, Dept. of Orthopedics, Aarhus University Hospital, Palle Juul-Jensens Blvd. 99, 8200 Aarhus N, Denmark. 2. Sports Orthopedic Research Center – Copenhagen (SORC-C), Department of Orthopedic Surgery, Copenhagen University Hospital, Amager-Hvidovre, Kettegård Allé 30, 2650 Hvidovre Denmark. 3. Horsens Regional Hospital, Dept. of Orthopedics, 8700 Horsens, Denmark. 4. Steadman Philippon Research Institute, Vail, CO 81657, USA. 5. Section for Sportstraumatology M51, Bispebjerg-Frederiksberg Hospital. Part of IOC Research Center Copenhagen, Bispebjerg Bakke 23, 2400 Copenhagen, Denmark.

Background: Capsular management during hip arthroscopic procedures has recently been a hot topic in treatment of Femoroacetabular impingement (FAI) patients. Current cohort studies have demonstrated good outcomes in favor of capsular closure, however one randomized controlled trial did not demonstrate any significant differences in outcome after capsular closure versus unrepaired capsulotomy in FAI patients.
Aim: The aim of this controlled, randomized multicenter trial was to evaluate the effect of capsular closure in relation to subjective postoperative outcomes and revision rates in patients undergoing hip arthroscopy for FAI.
Materials and Methods: All eligible FAI patients from four surgical centers in Denmark, referred for hip arthroscopy (n = 200) were randomly assigned to either closure or no closure of the interportal capsulotomy at termination of the arthroscopic procedure. The capsular closure was performed with 2-3 absorbable sutures, using the “Quebec City Slider” knot tying technique. The Copenhagen Hip and Groin Outcome Score (HAGOS) was primary outcome and scores were collected from The Danish Hip Arthroscopy Registry preoperatively and at one-year follow-up.
Results: Baseline epidemiological and morphological characteristics were comparable between the treatment groups, except for a higher percentage of females in the capsular closure group (66% vs. 48%). Both groups significantly improved after surgery (p < 0.05). At one-year follow-up, there was no difference between treatment groups in any of the HAGOS domainscores (p > 0.05). The revision rates after one year were identical in both groups (n=5), however, two patients in the non-closure group were treated with a total hip replacement.
Interpretation / Conclusion: This controlled, randomized multicenter trial demonstrated no evidence for improved outcome of capsular closure after interportal capsulotomy in hip arthroscopic treatment of FAI-patients.

109. Effects of a progressive rehabilitation and care program across sectors for older adults following hip fracture surgery
Inge Hansen Bruun1,2, Charlotte Suetta 3,4, Jonas A. Ipsen 1,2, Lars T.Pedersen 1,2,5, Birgitte Nørgaard 6, Bjarke Viberg7,8,9
1. Department of Physical Therapy and Occupational Therapy, Lillebaelt Hospital, University Hospital of Southern Denmark, Kolding, Denmark; 2. Department of Regional Health Research, University of Southern Denmark, Odense; 3. Geriatric Research, Department of Geriatric and Palliative Medicine, Copenhagen University Hospital, Bispebjerg and Frederiksberg, Copenhagen, Denmark ; 4. Institute of Clinical Medicine, University of Copenhagen, Denmark ; 5. Department of Health Education, University College South Denmark, Esbjerg,; 6. Department of Public Health, User Perspectives and Community-based Interventions, University of Southern Denmark, Odense, Denmark; 7. Department of Orthopaedic Surgery and Traumatology. Lillebaelt Hospital, University Hospital of Southern Denmark, Kolding, Denmark ; 8. Department of Orthopaedic Surgery and Traumatology. Odense University Hospital, Odense; 9. Department of Clinical Research, University of Southern Denmark, Odense, Denmark

Background: Approximately half of the home-dwelling hip fracture patients can expect reduced functional level after one year. One issue contributing to this may be a lack of cooperation between the hospital and municipality concerning rehabilitation.
Aim: To assess the effect of a continuous and progressive rehabilitation and care program across sectors for home-dwelling hip fracture patients above 65 years.
Materials and Methods: A cluster-randomized stepped-wedge trial was carried out in Hospital Lillebaelt and the six municipalities within the hospitals’ catchment area. The intervention group received a progressive strength-training program initiated in the hospital and continuing after discharge by the municipality’s physiotherapists for 12 weeks using an empowerment-based approach. The intervention also included a follow-up visit by a nurse three days after discharge. The control group received the usual rehabilitation and care. The primary outcome was Timed Up and Go (TUG) measured eight weeks after surgery. Secondary outcomes were 30-day mortality, readmission rate, and New Mobility sum-score (NMS).
Results: In total, 336 patients were included, 168 (116 women) in the intervention group and 171 (108 women) in the control group. The mean age was 80, the mean Hindsoe-score was 8.7, and 50% were admitted due to a femoral neck fracture. There were no baseline differences between the groups regarding age, sex, comorbidity, fracture, and mobility. Eight weeks after surgery, TUG was significantly higher in the intervention group (median 14.3 (IQR10-20) compared to median 13.9 (IQR 12- 22) in the control group (p=0.038). The same applies to the NMS; for the intervention group, the median NMS sum-score was 6 (IQR 4-7) and 5.5 (IQR 4-7) in the control group (p=0.042). There were no significant differences in 30-day mortality (p=0.57) and readmission rate (p=0.15) between the groups.
Interpretation / Conclusion: A cross-sectorial strength-training program demonstrated a significant increase in mobility in terms of TUG and NMS compared to usual rehabilitation and care. The program was designed as a real-life program and will therefore be easy to implement elsewhere.