Simultaneous bilateral TKA in the context of fast track surgery - Do patients meet discharge criteria as anticipated?

BACKGROUND: The efficacy and safety of enhanced recovery after surgery (ERAS) protocols for patients undergoing total knee arthroplasty (TKA) have been generally proven. Previous studies investigating patients undergoing simultaneous bilateral TKA (SBTKA) focused on complications, mortality, and pain and did not examine patients' functional limitations. Therefore, the aim of this study was to investigate to what extent patients undergoing SBTKA are able to meet functional discharge criteria originally designed for their counterparts undergoing unilateral TKA (UTKA) in an ERAS setting. MATERIALS AND METHODS: All patients who received primary SBTKA between June 2015 and December 2018 were included in this retrospective analysis. For comparison, UTKA patients were matched 1:1 to SBTKA patients using Propensity Score Matching based on age, gender, and BMI. The times to achieving the rehabilitation checkpoints of walking 150 m, walking a flight of stairs, and 90° knee flexion were evaluated. RESULTS: 63 (SBTKA group) and 64 (UTKA group) patients were included. Due to the Propensity-Score-Matching there were no differences regarding age, gender, and BMI. The mean length of stay (LOS) was 9.1 days in the SBTKA and 7.6 days in the UTKA group (p = 0.003). On average, it took SBTKA patients 5.4 days to achieve an uninterrupted walking distance of at least 150 m, while it took UTKA patients 4.1 days (p < 0.001). Mean time to walking a flight of stairs was 6.3 days for SBTKA patients and 4.7 days for UTKA patients (p < 0.001). 90° flexion was achieved after 4.1 days by SBTKA patients and 3.5 days by UTKA patients (p = 0.241). CONCLUSION: The vast majority of SBTKA patients were able to achieve functional discharge criteria within their inpatient stay when allowed about 30% extra time. Therefore, functional discharge criteria in ERAS protocols designed for UTKA can be considered appropriate for SBTKA patients. LEVEL OF EVIDENCE: Therapeutic Level III.

Surfing After Hip Resurfacing Surgery.

OBJECTIVE: There is no information about surfing after hip resurfacing arthroplasty (HRA). We did a retrospective study aiming to evaluate the safety and feasibility to resume surfing-an extreme sport with high-impact physical activity-after HRA. DESIGN: Retrospective case series. SETTING: Specialist Orthopaedic Group, Mater Hospital Sydney, NSW, Australia. PATIENTS: We evaluated 45 patients who practiced surfing before the onset of pain and hip surgery. Complete clinical and radiographical follow-up and a completed questionnaire were available for 37 (82%) patients. INTERVENTIONS: Hip resurfacing arthroplasty. MAIN OUTCOME MEASURES: Postel-Merle d'Aubigne score, the Oxford hip score, the Harris hip score, and the University of California at Los Angeles activity score. Radiographical evaluation at 6 weeks, 3, and 12 months after surgery and yearly thereafter. Return to surf rates using a specific questionnaire. Complications and failures during follow-up. RESULTS: All clinical scores improved significantly after HRA. Eight of 37 (22%) patients stopped surfing after their HRA. More than 80% of patients commenced surfing within the first 6 months after surgery. During surfing, 21 patients (72%) were completely pain free. CONCLUSION: No literature exists regarding the return to a high-impact sport as surfing after HRA. Most of our patients (71%) were able to return at least to their preoperative level of surfing after surgery. No complications related to this sport activity were observed during short-term follow-up. We believe that surfing is compatible with HRA, but long-term studies are necessary to assess the influence of this extreme sport on loosening and revision rates.

The PROMISE study protocol: a multicenter prospective study of process optimization with interdisciplinary and cross-sectoral care for German patients receiving hip and knee endoprostheses.

Background and purpose - Knee and hip replacement are common and increasing procedures, and an optimized care process that could be implemented in different settings would be useful. The PROMISE trial investigates whether a new care process works equally in different German settings and how the results compare with current non-standardized care.Patients and methods - This multi-center prospective mixed-method study includes 2,000 German patients receiving arthritis-related hip or knee endoprostheses. An interdisciplinary and cross-sectoral care process was developed and implemented in 3 German hospitals with different levels of care, and corresponding rehabilitation centers were included to bridge the gap after acute care.Duration and outcome - The PROMISE trial recruited patients between May 2018 and March 2020. Follow-up will end in February 2021. Assessments are performed at: examination on clinical indication, 1 week before surgery, on the day of surgery, at the end of hospitalization, end of the rehabilitation program, and 3 months, 6 months, and 12 months after surgery. Outcomes include patient-reported outcomes, medical examination findings, and routinely collected data regarding the surgery and complications. Guideline-based interviews are conducted with selected patients and care partners. The primary endpoint is the presence of chronic pain at 12 months after surgery. Secondary endpoints are the number of recognized pre-existing conditions, physical activity at 12 months after surgery, use of medical services, quality of life, and interactions between care partners.Trial registration - The trial is registered with the German Clinical Trials Register (https://www.drks.de; DRKS00013972; March 23, 2018).

Increase in Benign Squeaking Rate at Five-Year Follow-Up: Results of a Large Diameter Ceramic-on-Ceramic Bearing in Total Hip Arthroplasty.

BACKGROUND: Squeaking is an on-going complication with a variable incidence of 0.5%-20.7%. The mechanism of squeaking has not been understood completely and is most likely multifactorial in nature. Previously, we have reported on a squeaking rate of 7.3% at 2 years. Our current results show a substantial increase in the squeaking incidence from 7.3% to 17.4% with the DeltaMotion articulation at the 5-year follow-up. METHODS: Two hundred six total hip arthroplasties with a large ceramic-on-ceramic bearing were performed on 195 patients by 2 senior authors. The minimum duration of follow-up was 5 years (range 5-6.2). RESULTS: The mean Harris Hip Score remained stable at 91.7 at 5 years compared to 92 after 2 years. However, we observed an increase in the squeaking rate from 7.3% after 2 years to 17.4% after 5 years. As in previous studies, we did not find significant differences between the silent and squeaking group in relation to age, height, weight, and femoral head diameter. In contrast, others reported no significant differences regarding range of motion and gender between the silent and the squeaking hip group at 2 years of follow-up, whereas at 5 years, the squeaking group showed a significantly higher combined range of motion and a higher relative risk of squeaking in women compared to the silent group. CONCLUSION: While large diameter ceramic bearings may produce squeaking, especially in female patients, our mid-term clinical results of a large ceramic-on-ceramic bearing in total hip arthroplasty are encouraging. Nevertheless, long-term follow-up is recommended.

Venous thromboembolism in patients hospitalized for hip joint replacement surgery.

BACKGROUND: Venous thromboembolism (VTE) is a potentially life-threatening disease. Major transient risk factors include trauma, surgery, and immobilization. Patients undergoing hip joint replacement (HJR) are characterized by a high risk of postoperative VTE, but data on the time trends of VTE rates in this population are sparse. METHODS: In an analysis of the German nationwide inpatient sample, we included all hospitalizations for elective primary HJR in Germany from 2005 to 2016. Time trends of the surgical procedure, overall death rates, and VTE rates were analysed, and predictors of VTE identified. RESULTS: Overall, 1,885,839 inpatients with elective primary HJR (59.1% women, 51.4% ≥70 years) were included in the analysis. During hospitalization, VTE was documented in 11,554 (0.6%) patients. While total numbers of primary HJR increased from 145,223 in 2005 to 171,421 in 2016 (ß-(slope)-estimate 1818 [95%CI 1083 to 2553], P < 0.001), in-hospital VTE decreased from 1288 (0.9%) to 843 (0.5%) cases (ß-estimate -0.71 [95%CI -0.77 to -0.65], P < 0.001), and in-hospital death rate from 0.33% (476 deaths) to 0.29% (498 deaths) (ß-estimate -0.11 [95%CI -0.20 to -0.02], P = 0.018). Infections during hospitalization were associated with higher VTE risk than cancer and cardiovascular events. VTE events were independently associated with an increased death risk (OR 15.19 [95%CI 14.19-16.86], P < 0.001). CONCLUSIONS: While total numbers of HJR increased significantly in Germany between 2005 and 2016, in-hospital rates of VTE decreased from 0.9% to 0.5%. Patients with perioperative VTE had a 15-fold increase of in-hospital death. Cancer, cardiovascular disease and perioperative infections were associated with higher risk for VTE.

Zirconia phase transformation in retrieved, wear simulated, and artificially aged ceramic femoral heads.

Zirconia in Zirconia toughened alumina ceramic hip replacements exists in an unstable state and can transform in response to stress giving the material improved fracture toughness. Phase transformation also occurs under hydrothermal conditions such as exist in vivo. To predict the hydrothermal aging that will occur in vivo accelerated aging procedures have been used, but validation of these models requires the study of retrieved hip joints. Here 26 retrievals are analysed to determine the degree of phase transformation in vivo. These were compared with virgin heads, heads that had undergone the accelerated aging process and heads wear tested to 5 million cycles in a hip simulator. Monoclinic content and surface roughness were measured using Raman spectroscopy and white light interferometry respectively. The monoclinic content for retrieved heads was 28.5% ± 7.8, greater than twice that in virgin, aged, or wear tested heads and did not have a significant correlation with time, contrary to the predictions of the hydrothermal aging model. The surface roughness for retrieved heads in the unworn area was not significantly different to that in virgin, aged, or unworn areas of wear tested heads. However in worn areas of the retrieved heads, the surface roughness was higher than observed in wear simulator testing. These results indicate that current testing methodologies do not fully capture the operational conditions of the material and the real performance of future new materials may not be adequately predicted by current pre-clinical testing methods. © 2017 The Authors. Journal of Orthopaedic Research Published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society 35:2781-2789, 2017.

Cellular imaging of human atherosclerotic lesions by intravascular electric impedance spectroscopy.

BACKGROUND: Newer techniques are required to identify atherosclerotic lesions that are prone to rupture. Electric impedance spectroscopy (EIS) is able to provide information about the cellular composition of biological tissue. The present study was performed to determine the influence of inflammatory processes in type Va (lipid core, thick fibrous cap) and Vc (abundant fibrous connective tissue while lipid is minimal or even absent) human atherosclerotic lesions on the electrical impedance of these lesions measured by EIS. METHODS AND RESULTS: EIS was performed on 1 aortic and 3 femoral human arteries at 25 spots with visually heavy plaque burden. Severely calcified lesions were excluded from analysis. A highly flexible micro-electrode mounted onto a balloon catheter was placed on marked regions to measure impedance values at 100 kHz. After paraffin embedding, visible marked cross sections (n = 21) were processed. Assessment of lesion types was performed by Movats staining. Immunostaining for CD31 (marker of neovascularisation), CD36 (scavenger cells) and MMP-3 (matrix metalloproteinase-3) was performed. The amount of positive cells was assessed semi-quantitatively. 15 type Va lesions and 6 type Vc lesions were identified. Lesions containing abundant CD36-, CD31- and MMP-3-positive staining revealed significantly higher impedance values compared to lesions with marginal or without positive staining (CD36 + 455 ± 50 Ω vs. CD36- 346 ± 53 Ω, p = 0.001; CD31 + 436 ± 43 Ω vs. CD31- 340 ± 55 Ω, p = 0.001; MMP-3 + 400 ± 68 Ω vs. MMP-3- 323 ± 33 Ω, p = 0.03). CONCLUSIONS: Atherosclerotic lesions with abundant neovascularisation (CD31), many scavenger receptor class B expressing cells (CD36) or high amount of MMP-3 immunoreactivity reveal significantly higher impedance values compared to lesions with marginal or no detection of immunoreactivity. Findings suggest that inflammatory processes in vulnerable plaques affect the impedance of atherosclerotic lesions and might therefore be detected by EIS.

Electric impedance spectroscopy of human atherosclerotic lesions.

OBJECTIVE: The aim of this in vitro study was to investigate the feasibility of a new highly flexible microelectrode on human tissue and its potential of differentiating atherosclerotic lesions by electric impedance spectroscopy (EIS). METHODS: Electric impedance measurements (EIM) were performed on 148 spots of 7 aortic and 6 femoral human arteries at 1kHz, 10kHz and 100kHz. RESULTS: According to the AHA classification 33 (25%) grade I lesions (PI), 34 (26%) grade II (PII), 21 (16%) grade III (PIII), 21 (16%) grade IV (PIV), 13 (10%) grade Va (PVa) and 10 (8%) grade Vb (PVb) could be identified by histology. At 1kHz, 10kHz and 100kHz the mean electric impedance (MEI) of PI, PII, PIII and PIV was statistically not different. At 100kHz the MEI of PVa showed significantly higher values compared to the MEI of PI (455+/-66Omega vs. 375+/-47Omega, p=0.05), PII (455+/-66Omega vs. 358+/-63Omega, p=0.007), PIII (455+/-66Omega vs. 342+/-52Omega, p=0.003), PIV (455+/-66Omega vs. 356+/-41Omegap=0.013) and the MEI of PVb was significantly increased compared to the MEI of PI (698+/-239Omega vs. 375+/-47Omega, p<0.001), PII (698+/-239Omega vs. 358+/-63Omegap<0.001), PIII (698+/-239Omega vs. 342+/-52Omegap<0.001), PIV (698+/-239Omega vs. 356+/-41Omegap<0.001), PVa (698+/-239Omega vs. 455+/-66Omega, p<0.001). Performing ROC analyses for the detection of grouped PVa/PVb lesions, the largest AUC was found at 100kHz with a cut-off value of 441Omega presenting a sensitivity of 74% and a specificity of 94%. CONCLUSIONS: EIM could be performed on human aortic and femoral tissue. The results show that EIS has the potential to distinguish between different plaque types.