Purpose: The purpose of this study was to provide a matched cohort comparison of clinical and functional outcome scores, range of motion and quality of life following unicompartmental knee arthroplasty (UKA) or total knee arthroplasty (TKA). The hypothesis was that patients receiving UKA report better results than comparable patients who receive conventional TKA.Methods: Clinical and functional results of 35 patients with medial end-stage osteoarthritis who had received a fixed-bearing UKA were compared with the results of 35 matched patients who had received a TKA from the same manufacturer by the same surgeon. Outcome scores were measured before surgery and at final follow-up using Tegner Activity Scale (TAS), range of motion (ROM) and Short Form 36 Health Survey (SF-36). The Knee Society Score (KSS) was assessed at final follow-up. The mean observation period was 2.3 years in both groups.Results: The preoperative knee scores had no statistically significant differences between the two groups. Postoperatively, however, UKAs performed significantly better regarding TAS and ROM (4 vs. 3 and 118.4 vs. 103.7, respectively). The results of the SF-36 showed significantly better results for the UKA group in the mental component summary score and in the subscale of social function.Conclusions: The present study suggests that UKA is associated with higher activity level, higher quality of life, and greater ROM when compared with TKA on comparable patients. Prolonged clinical follow-up in a larger patient cohort with a randomised-controlled study design would be beneficial to confirm these findings.Level of evidence: III.

Obesity is strongly associated with mortality and morbidity, but there is a lack of data on its impact on health-related quality of life (HRQoL) across different age groups. Therefore, this study’s objective was to determine the association between body mass index (BMI) and HRQoL in the Austrian adult population based on age groups using the 36-Item Short Form (SF-36) survey. Methods: The SF-36 survey was sent to 500 randomly assigned Austrian adults (response rate: 80.6%). This study assessed HRQoL subscale and component scores based on gender, level of education, smoking status, and alcohol consumption in 403 participants. Results: Increasing BMI is associated with a negative impact on all domains of physical health and social function. The study uncovered substantial variations in the impact of increasing BMI on HRQoL across different age groups, with a pronounced effect observed in the physical components, particularly among individuals aged 65–74. Conclusions: BMI is negatively associated with the physical aspects of HRQoL and social function, affecting various adult age groups differently. Consequently, our results emphasize assessing different age groups and possible influencing factors on HRQoL, such as BMI, for further optimization in designing prevention programs against obesity.

(1) Background: Degeneration of the hip abductor mechanism, a well-known cause of functional limitation, is difficult to treat and is associated with a reduced health-related quality of life (HRQOL). The gluteus maximus muscle flap is a treatment option to support a severely degenerative modified gluteus medius muscle. Although several reports exist on the clinical outcome, there remains a gap in the literature regarding HRQOL in conjunction with functional results. (2) Methods: The present study consists of 18 patients with a mean age of 64 (53‒79) years, operatively treated with a gluteus maximus flap due to chronic gluteal deficiency. Fifteen (83%) of these patients presented a history of total hip arthroplasty or revision arthroplasty. Pre and postoperative pain, Trendelenburg sign, internal rotation lag sign, trochanteric pain syndrome, the Harris Hip Score (HHS), and abduction strength after Janda (0‒5) were evaluated. Postoperative patient satisfaction and health-related quality of life, according to the Short Form 36 (SF-36), were used as patient-reported outcome measurements (PROMs). Postoperative MRI scans were performed in 13 cases (72%). (3) Results: Local pain decreased from NRS 6.1 (0–10) to 4.9 (0–8) and 44% presented with a negative Trendelenburg sign postoperatively. The overall HHS results (p = 0.42) and muscular abduction strength (p = 0.32) increased without significance. The postoperative HRQOL reached 46.8 points (31.3–62.6) for the mental component score and 37.1 points (26.9–54.7) for the physical component score. The physical component results presented a high level of positive correlation with HHS scores postoperatively (R = 0.88, p < 0.001). Moreover, 72% reported that they would undergo the operative treatment again. The MRI overall showed no significant further loss of muscle volume and no further degeneration of muscular tissue. (4) Conclusions: Along with fair functional results, the patients treated with a gluteus maximus flap transfer presented satisfying long-term PROMs. Given this condition, the gluteus maximus muscle flap transfer is a viable option for selected patients with chronic gluteal deficiency.

Background: Despite numerous scientific investigations, the tribological advantages of mobile bearing inserts have not been sustainably confirmed or refuted for modern knee prostheses in clinical studies. The purpose of this study was to compare fixed and mobile bearing inserts in order to draw conclusions regarding clinical benefits. Methods: The present prospective single center cohort study of 2 non-randomized stratified groups consisted of 67 patients. All included patients received cemented total knee arthroplasty (Attune®) due to osteoarthritis. 34 patients were treated with a mobile and 33 patients with a fixed insert. The WOMAC score and the Visual Analogue Scale was used for the subjective assessment of success, while the Knee-Society-Score was used considering the Range of Motion for the objective assessment. The subjective and the clinical scores showed improvements for both compared groups postoperatively at 2 years of minimum follow-up. Results: The overall postoperative results of the WOMAC score, the Knee-Society-Score and the Visual Analogue Scale presented no statistically difference between the compared groups (p > 0,05). The postoperative ROM showed a superior improvement of 13.2° ± 18.4° in the mobile-bearing group versus 4.9° ± 18.4° (p = 0.017) in the fixed-bearing group. The flexion of the knee joint was 114° ± 10.1° for the mobile-bearings and 109.2° ± 7.2° for fixed bearings (p = 0.012). Conclusion: According to the findings, both inserts showed overall promising postoperative results, in terms of objective as well as subjective parameters, without clinically relevant significant differences, except for ROM, which was superior in the mobile bearing group. The present clinical trial has been registered at the ISRCTN registry with the reverence number ISRCTN15117998 on 04/04/2022.

Background: To evaluate the function of the abductor mechanism after a gluteus maximus flap transfer due to a degeneration of the muscles after hip arthroplasty, we analyzed the post-operative functional outcome as well as radiographic effects in muscle tissue. Methods: This present study included six consecutive patients operatively treated with a gluteus maximus flap due to chronic gluteal deficiency after total hip arthroplasty. All patients presented a preoperative severe limp, hip abductor deficiency and a history of conservative treatment without the relief of symptoms. MRI scans were performed pre- and postoperatively to evaluate the muscle volume and grade of degeneration of the abductor mechanism. For clinical evaluation, the Harris hip score (HHS) was applied pre- and postoperatively. Moreover, the intensity of pain, the Trendelenburg sign, the internal rotation lag sign and the abductor muscle force were measured before and after surgery. Results: Overall, the evaluation of the Magnetic Resonance Imaging (MRI) showed no significant changes in total muscle volume during the follow-up period. Separate measurements presented a significant growth of muscle volume for the gluteus minimus and tensor fascia lata compared to preoperative imaging during the follow-up period. The amount of fat volume decreased for all the measured muscles with statistical significance for the gluteus minimus, the gluteus medius and the tensor fascia lata. No further muscle degeneration and no flap necrosis were measured. The postoperative HHS results were not statistically significant compared to the preoperative results. Conclusions: Besides fair clinical results, the radiological measurements indicate that the flap transfer enables functional muscular tissue recovery and prevents further degeneration. Given these conditions, the gluteus maximus muscle flap transfer represents a viable treatment option for patients with chronic gluteal deficiency in selected patients.

Aims: Reconstruction of bone defects is a key challenge in orthopaedic surgery. While autologous bone grafts are considered the gold standard, osseous allografts are increasingly used as an alternative as they allow for treatment of large bone defects. However, they may be associated with an increased risk of postoperative infections. This study aims to analyze the frequency of and risk factors for implant-associated infections after bone allograft transplantation. Methods: All patients who underwent reconstruction with bone allografts at a single orthopaedic and trauma unit between 2003 and 2023 were retrospectively included. Data on demographics, disease-associated parameters, risk factors at index surgery, and development of implant-associated infections during follow-up were documented. Potential risk factors for development of implant-associated infections during follow-up were investigated with logistic regression models. Results: A total of 220 patients were included (46.8% males; median age at surgery 46.5 years [IQR: 22–67]; n = 23 with implant-associated infections during follow-up). Factors independently associated with subsequent implant-associated infections were smoking ( p = 0.001), BMI ( p = 0.015) and radiotherapy ( p = 0.013). Gender, age, preoperative chemotherapy, allograft material, preoperative C-reactive protein, hemoglobin and reason for surgery (tumor, n = 104; trauma, n = 13; revision, n = 103) were not associated with implant associated infection. Conclusion: Independent risk factors for implant-associated infections following bone allograft surgery included active smoking, high BMI and radiotherapy (in case of tumor). These factors should be taken into consideration when planning bone allograft reconstruction.