Julia Goetz

Background: Persistent muscular deficits are a major contributor to functional limitations following total knee arthroplasty (TKA). While Enhanced Recovery After Surgery (ERAS) protocols are increasingly adopted to improve postoperative outcomes, their influence on mid-term objective muscle strength recovery remains insufficiently defined. This study aimed first, to determine whether a modified ERAS protocol enhances mid-term recovery of knee muscle strength after primary TKA and second, compare associated clinical outcomes using validated functional and patient-reported measures. Methods: The study received ethical approval from the Ethics Committee of the University of Regensburg, Germany (Reference No. 19-1470-101 on 31 July 2019) and was conducted in accordance with the principles of the Declaration of Helsinki. In this prospective, single-blinded randomized controlled trial, 58 patients undergoing primary TKA were assigned to either a modified ERAS protocol ( n = 31) or conventional perioperative care ( n = 27). Assessments were conducted at 5 days, 4 weeks, 3 months, 6 months, and 12 months postoperatively. Isokinetic muscle strength - including peak torque (Nm), total work (J), and power (W) - was measured using the Biodex ^® System 3 Dynamometer. Clinical outcomes were evaluated using the Numeric Rating Scale (NRS) for pain, Patient-Reported Outcome Measures (PROMs), and the Knee injury and Osteoarthritis Outcome Score (KOOS). Results: At 5 days postoperatively, the ERAS group demonstrated significantly higher isokinetic muscle strength and improved active knee flexion compared to the conventional group ( p < 0.05). These early differences decreased over time, with no significant differences observed between groups at 3, 6, or 12 months. Both groups demonstrated excellent mid-term outcomes, with similarly high patient satisfaction and comparable PROMs and KOOS scores at the one-year follow-up. Conclusion: The modified ERAS protocol led to significantly improved early postoperative recovery of knee muscle strength without adversely affecting short- or mid-term outcomes. Although isokinetic and clinical measures aligned across groups over time, the ERAS approach appears to be a safe and effective strategy for enhancing early functional recovery and overall patient experience following primary TKA.

Background: Depressive symptoms are prevalent among patients with osteoarthritis (OA), particularly in geriatric patients. Pain and mood are closely interconnected, with chronic joint pain contributing significantly to psychological distress. Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are established procedures that improve pain and physical function and may also influence depressive symptoms. The objective of this study was to evaluate changes in depressive symptoms following THA and TKA in geriatric patients. Methods: In this prospective pilot study, we analysed data from 143 participants enrolled in the ongoing Special Orthopaedic Geriatrics (SOG) trial, funded by the German Federal Joint Committee (G-BA). Depressive symptoms were assessed using the Geriatric Depression Scale (GDS) preoperatively and at 3 days, 7 days, 4 weeks, and 3 months after surgery. Depressive symptoms were analysed in two predefined groups: the total sample (GDS 1–15) and patients with elevated baseline symptoms (GDS 6–15). Statistical analysis included the Friedman test for repeated measures, followed by post-hoc testing. Results: In the overall cohort, median GDS scores decreased from 3 at baseline to 2 at the 3-month follow-up ( p < 0.001). In the subgroup with elevated baseline symptoms (GDS 6–15), median scores declined from 8.5 at baseline to 4 at 3 months ( p < 0.001). Improvements were observed after both THA and TKA, with changes appearing more pronounced in THA. Conclusion: THA and TKA were associated with modest improvements in depressive symptoms across the full range of baseline GDS scores. While patients with elevated baseline symptoms showed larger absolute changes, improvements were also observed in those without abnormal baseline scores. Improvements in depressive symptoms were most pronounced between the preoperative and early postoperative assessments, whereas only minor additional changes were observed during later postoperative follow-up. These findings should be interpreted as exploratory and require confirmation in larger controlled studies. Trial registration: This study is part of the Special Orthopaedic Geriatrics (SOG) trial, German Clinical Trials Register DRKS00024102. Registered on 19 January 2021.

This study investigated isokinetic muscle strength deficits in patients with advanced knee osteoarthritis (KOA) scheduled for total knee arthroplasty (TKA) to explore the relationship between objective strength measures and subjective symptoms such as pain and functional limitations. By analyzing muscle function using isokinetic dynamometry, the study aimed to provide insights into how strength deficits relate to patient-reported outcomes and whether these assessments could inform surgical decision-making. A total of 52 patients (mean age: 66.96 years, 53.85% female) with advanced KOA awaiting TKA were included. Isokinetic muscle strength of the knee, measured in peak torque (Newton-meters), work (Joules), and power (Watts), was assessed bilaterally before surgery using a Biodex dynamometer at angular velocities of 180 degrees/s and 60 degrees/s. Subjective symptoms were evaluated using standardized assessments, including the Numeric Rating Scale (NRS), Knee Injury and Osteoarthritis Outcome Score (KOOS), Short Form-12 (SF-12), Hospital Anxiety and Depression Scale (HADS-D), and EuroQol 5-Dimension 3-Level questionnaire. Findings revealed a significant strength deficit on the affected side scheduled for surgery (p < 0.050). However, correlations between isokinetic knee parameters and symptom scores were weak (|r| ≤0.5), suggesting that subjective complaints do not necessarily align with objective strength measurements. Notably, isokinetic parameters were significantly intercorrelated (p < 0.050). These results indicate that isokinetic dynamometry effectively quantifies muscle strength differences in KOA patients, yet its findings should be considered alongside clinical assessments and patient-reported symptoms to form a comprehensive evaluation of disease severity and surgical necessity.

Introduction: Numbers of total hip arthroplasty (THA) are steadily rising and patients expect faster mobility without pain postoperatively. The aim of enhanced recovery after Surgery (ERAS) programs in a multidisciplinary setup was to keep pace with the needs of quality and quantity of surgical THA-interventions and patients’ expectations. Methods: 194 patients undergoing THA procedures were investigated after single-blinded randomization to ERAS (98) or conventional setup group (96). Primary outcome variable was mobilization measured with the Timed Up and Go Test (TUG) in seconds. Secondary outcome variables were floor count and walking distance in meters as well as rest, mobilization and night pain on a numerous rating scale (NRS). All variables were recorded preoperatively and daily until the sixth postoperative day. To assess and compare clinical outcome and patient satisfaction, the PPP33-Score and PROMs were used. Results: No complications such as thromboembolic complications, fractures or revisions were recorded within the first week postoperatively in either study group. Compared to the conventional group, the ERAS group showed significantly better TUG (p < 0.050) and walking distance results after surgery up to the sixth, and floor count up to the third postoperative day. On the first and second postoperative day, ERAS patients showed superior results (p < 0.001) in all independent activity subitems. Regarding the evaluation of pain (NRS), PPP33 and PROMS, no significant difference was shown (p > 0.050). Conclusion: This prospective single-blinded randomized controlled clinical trial was able to demonstrate excellent outcome with comparable pain after ERAS THA versus a conventional setup. Therefore, ERAS could be used in daily clinical practice.

Purpose: Total knee arthroplasty (TKA) combined with the concept of enhanced recovery is of continued worldwide interest, as it is reported to improve early functional outcome and treatment quality without increasing complications. The aim of the study was to investigate isokinetic knee muscle strength after cemented TKA in combination with an enhanced recovery after surgery (ERAS) compared to a conventional setup.Methods: In the single blinded prospective randomized study, 52 patients underwent navigated primary cemented TKA within an ERAS (n = 30) or a conventional setup (n = 22). Preoperatively, five days and four weeks after surgery isokinetic knee muscle strength with BIODEX‐type measuring device (peak torque in Nm, work in Joules and power in Watt) and subjective patient‐related outcome measures (PROMs) were investigated.Results: The ERAS group showed significantly better outcomes in knee flexion at 180°/s (peak torque (Nm) p = 0.047, work (J) p = 0.040 and power (W) p = 0.016) 5 days postoperatively. The isokinetic measuring at knee extension 60°/s and 180°/s demonstrated no significant difference. The PROMs showed that patients were satisfied with the postoperative results in both groups. After 4 weeks, there was no longer a significant difference in isokinetic measuring at knee extension and flexion between the ERAS and conventional group.Conclusions: TKA with the concept of ERAS improves excellent isokinetic outcome and patient satisfaction. The isokinetic muscle strength measurement can help patients and surgeons to modify expectations and improve patient satisfaction.

Aims: Periprosthetic joint infections (PJIs) are rare, but represent a great burden for the patient. In addition, the incidence of methicillin-resistant Staphylococcus aureus (MRSA) is increasing. The aim of this rat experiment was therefore to compare the antibiotics commonly used in the treatment of PJIs caused by MRSA. Methods: For this purpose, sterilized steel implants were implanted into the femur of 77 rats. The metal devices were inoculated with suspensions of two different MRSA strains. The animals were divided into groups and treated with vancomycin, linezolid, cotrimoxazole, or rifampin as monotherapy, or with combination of antibiotics over a period of 14 days. After a two-day antibiotic-free interval, the implant was explanted, and bone, muscle, and periarticular tissue were microbiologically analyzed. Results: Vancomycin and linezolid were able to significantly (p < 0.05) reduce the MRSA bacterial count at implants. No significant effect was found at the bone. Rifampin was the only monotherapy that significantly reduced the bacterial count on implant and bone. The combination with vancomycin or linezolid showed significant efficacy. Treatment with cotrimoxazole alone did not achieve a significant bacterial count reduction. The combination of linezolid plus rifampin was significantly more effective on implant and bone than the control group in both trials. Conclusion: Although rifampicin is effective as a monotherapy, it should not be used because of the high rate of resistance development. Our animal experiments showed the great importance of combination antibiotic therapies. In the future, investigations with higher case numbers, varied bacterial concentrations, and changes in individual drug dosages will be necessary to be able to draw an exact comparison, possibly within a clinical trial. Cite this article: Bone Joint Res 2022;11(3):143–151.