Search

Background: Red blood cell (RBC) transfusions are commonly used in surgical patients, but accompanied by many risks such as metabolic derangement, and allergic and febrile reactions. Indications for transfusion in patients after hip or knee surgery have not been definitively evaluated and remain controversial. We performed a meta-analysis to compare the benefits and harms of restrictive versus liberal transfusion strategies in patients after hip or knee surgery., Methods: The PubMed, EMBASE, and Cochrane Library databases were searched for relevant studies through September 2015. The main clinical outcomes reported in randomized controlled trials (RCTs) included 30-day mortality, infection rate, cardiogenic complications, and length of hospital stay. The meta-analysis program of the Cochrane Collaboration (RevMan version 5.3.0) was used for data analysis. Statistical heterogeneity was assessed by both Cochran chi-squared test (Q test) and I test. Begg and Egger test were used to assess potential publication bias., Results: We identified 10 eligible RCTs, involving 3788 patients in total. In patients undergoing hip or knee surgery, we found no differences in mortality, or the incidence rates of pneumonia, wound infection, myocardial infarction, or congestive heart failure, between restrictive and liberal thresholds for RBC transfusion (P > .05)., Conclusion: Restrictive transfusion has no advantage over the liberal strategy. However, considerably less patients received blood transfusion via the restrictive strategy than with the liberal counterpart. Due to variations in the included studies, additional larger scale and well-designed studies are required to validate these conclusions.

Purpose: It is always a challenge for orthopaedic surgeons to minimise surgical incisions while ensuring excellent surgical results. We propose the minimally invasive small incision (MISI) technique and an extramedullary positioning technique in the unicompartmental knee arthroplasty (UKA) surgery. This study aimed to clarify the early postoperative clinical outcomes and component alignment between MISI and conventional minimally invasive surgical (MIS) techniques. Methods: We prospectively enrolled 60 patients who underwent MISI-UKA and 60 patients who underwent MIS-UKA as controls. Clinical parameters include the time of straight leg raising, postoperative walking time with walker assistance, hospital stay, Numerical Rating Scale (NRS) pain score and Knee Society Score (KSS). The postoperative components and lower extremity alignment were compared between the two groups with radiographic image measurement. Results: The MISI group obtained a smaller incision during knee extension (P < 0.001) but a longer tourniquet usage time than the MIS group. The MISI group lost less blood (P < 0.001). The MISI group achieved straight leg raising and walking with aid earlier after surgery, with a shorter hospital stay than the MIS group (P < 0.001). Range of motion (ROM), NRS and KSS scores revealed no significant difference between the two groups in six months postoperative follow-up (P > 0.05). Radiographic measurement results between the two groups revealed no statistical difference (P > 0.05) Conclusion: The MISI-UKA could achieve faster earlier recovery after surgery and shorter hospital stays without compromising the principles of proper prosthesis position and limb alignment compared with the conventional MIS-UKA. [ABSTRACT FROM AUTHOR]

Purpose: There is a dilemma as to whether the presence of degenerative changes of lateral meniscus is a contraindication to medial unicompartmental knee arthroplasty (UKA). Therefore, the purpose of this study is to assess the influence of preoperative MRI-detected lateral meniscal intra-substance signal abnormalities on mid-term functional outcomes following mobile-bearing UKA. Methods: We performed a retrospective review of the record on a consecutive series of patients who have undergone mobile-bearing medial UKA from September 2020 to June 2023. The mean duration of follow-up was 2.34 years. All records were collected from case system. MRI assessment of lateral meniscus was performed with the use of the Stoller's classification system. Patients were categorized into two groups (grade 0 and ≥ grade 1). Patient-reported outcomes were assessed with the use of the American Knee Society functional Score (AKSS-F), American Knee Society Objective Score (AKSS-O), and Oxford Knee Score (OKS) preoperatively and at latest follow-up. Furthermore, range of motion (ROM) and hip-knee-ankle angle (HKA) were measured in preoperative and postoperative periods. Results: A total of 92 patients (101 knees) were included in our study. No differences in AKSS-F, AKSS-O, OKS, HKA, or ROM were found between those who showed normal or abnormal signal change of lateral meniscus preoperatively (P < 0.05). Furthermore, there were also no significant differences between two groups concerning AKSS-F, AKSS-O, OKS, HKA, or ROM at latest postoperative follow-up (P < 0.05). Age and duration of disease were independent predictors of low postoperative AKSS-F and AKSS-O (P < 0.05). Nevertheless, ROM was an independent predictor of high postoperative AKKS-O (P < 0.05). Age and female were independent predictors of high postoperative OKS (P < 0.05). Conclusion: The presence of preoperative MRI-detected lateral meniscal degenerative changes did not affect mid-term functional outcomes in patients who underwent mobile-bearing medial UKA. On the basis of the results of the current study, we believe that the presence of degenerative changes of lateral meniscus is acceptable in mobile-bearing medial UKA. [ABSTRACT FROM AUTHOR]

Background: Valgus malalignment is one of the most common reasons for the progression of osteoarthritis in the lateral compartment of the knee after mobile-bearing unicompartmental knee arthroplasty (UKA). The arithmetic hip-knee-ankle angle (aHKA) of the Coronal Plane Alignment of the Knee (CPAK) classification could reflect the constitutional alignment of the arthritic knee. The purpose of this study was to observe the relationship between the aHKA and valgus malalignment after mobile-bearing UKA. Methods: This retrospective study was conducted using 200 knees undergoing UKA from January 1, 2019, to August 1, 2022. These radiographic signs, including preoperative hip–knee–ankle angle (HKA), mechanical proximal tibial angle (MPTA), mechanical lateral distal femoral angle (LDFA), and postoperative HKA, were measured using standardized weight-bearing long-leg radiographs. Patients with postoperative HKA > 180° and postoperative HKA ≤ 180° were classified as the valgus group and non-valgus group, respectively. The aHKA was calculated as 180° + MPTA − LDFA in this study, which had the same meaning as that (aHKA = MPTA − LDFA) in the CPAK classification. The Spearman correlation analysis, the Mann–Whitney U test, the chi-square test, the Fisher's exact test, and multiple logistic regression were used in the study. Results: Of the 200 knees included in our study, 28 knees were classified as the valgus group, while 172 knees were in the non-valgus group. The mean ± standard deviation (SD) of aHKA (all groups) was 177.04 ± 2.58°. In the valgus group, 11 knees (39.3%) had a value of aHKA > 180°, while 17 knees (60.7%) had a value of aHKA ≤ 180°. In the non-valgus group, 12 knees (7.0%) had a value of aHKA > 180°, while 160 knees (93.0%) had a value of aHKA ≤ 180°. In Spearman correlation analysis, aHKA was positively correlated with postoperative HKA (r = 0.693, p < 0.001). In univariate analysis, preoperative HKA (p < 0.001), LDFA (p = 0.02), MPTA (p < 0.001), and aHKA (p < 0.001) showed significant differences between the valgus and non-valgus groups. Variables with p < 0.1 in univariate analysis were further analyzed using multiple logistic regression analysis, and the variable-aHKA (> 180° vs ≤ 180°, odds ratio (OR) = 5.899, 95% confidence interval (CI) = 1.213 to 28.686, and p = 0.028) was expressed as the risk factor of postoperative valgus malalignment. Conclusion: The aHKA is correlated with the postoperative alignment of mobile-bearing UKA and a high aHKA (> 180°) will increase the risk of postoperative valgus malalignment. Therefore, mobile-bearing UKA should be performed with caution in patients with preoperative aHKA > 180°. [ABSTRACT FROM AUTHOR]

Purpose: Gap balance is critical in Oxford unicompartmental knee arthroplasty (OUKA) surgery; the effect of lower limb positioning on gap balance judgements has not been reported. There are two mean operative positions for OUKA patients, the hanging leg (HL) and the supine leg (SL) position. This study aimed to investigate the gap balance achieved by current UKA surgical techniques by using a force sensor, to compare the differences in gap balance between the two different positions, and to test whether the difference in gap balance leads to different outcomes in terms of component alignment and early post-operative clinical outcomes. Methods: This prospective study included 97 knees (76 patients), who underwent OUKA from June 1, 2020, to July 31, 2021, of which 67 knees underwent UKA in the supine leg position and the other 30 in the hanging leg position. When the operator was satisfied with the gap balance, the contact forces between the trial and the spacer block were measured at 90° of knee flexion (flexion gap) and 20° of knee flexion (extension gap) using a pre-developed matrix flexible force sensor. X-rays were reviewed three to five days after surgery. Knee Society Scores (KSS) were obtained at the six month follow-up. Results: Compared to the HL group, the contact force at the flexion gap was higher in the SL group: 55.15N (SD 43.36N) vs. 34.25N (SD 27.56N) (p < 0.05), whereas in the extension gap, there was no significant difference, 90.19 N (SD 43.36N) in the SL group and 86.72N (SD 43.08N) in the HL group (ns.). The contact force was greater in the extension gap than in the flexion gap in both groups (p < 0.01). The gap balance difference in the HL group was 52.46N (SD 31.33N), which was greater than that of the SL group at 35.03N (SD 19.50N) (p < 0.05). There were no significant differences in component alignment or lower limb mechanical alignment between the two groups. There was no significant difference in pre-operative and post-operative KSS between the two groups, while post-operative KSS was significantly higher in both groups compared to the pre-operative period. Conclusion: The intra-operative contact forces between the flexion and extension gaps differed in the two groups; the hanging leg position appeared to produce a greater difference in the judgement of gap balance than the supine leg position, but this difference did not adversely affect the alignment of the component or the early post-operative clinical outcome. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to assess the difference between flexion and extension contact forces—gap balance—after Oxford mobile-bearing medial unicompartmental knee arthroplasty (UKA) performed by surgeons with varying levels of experience. Methods: Surgeons in a training programme performed UKAs on fresh frozen cadaveric specimens (n = 60). Contact force in the medial compartment of the knee was measured after UKA during extension and flexion using a force sensor, and values were clustered using an unsupervised machine learning (k-means algorithm). Univariate analysis was performed with general linear regression models to identify the explanatory variable. Results: The level of experience was predictive of gap balance; surgeons were clustered into beginner, mid-level and experienced groups. Experienced surgeons' mean difference between flexion and extension contact force was 83 N, which was significantly lower (p < 0.05) than that achieved by mid-level (215 N) or beginner (346 N) surgeons. Conclusion: We found that the lowest mean difference between flexion and extension contact force after UKA was 83 N, which was achieved by surgeons with the most experience; this value can be considered the optimal value. Beginner and mid-level surgeons achieved values that were significantly lower. This study also demonstrates that machine learning can be used in combination with sensor technology for improving gap balancing judgement in UKA. [ABSTRACT FROM AUTHOR]

Background: This study aimed to assess the radii of the distal and posterior articular surfaces of the medial femoral condyle in a Chinese population and provide detailed parameters of the knee joint for the future design of UKA components.Methods: This study included 500 consecutive Chinese patients who underwent knee MRI from Jan 2019 to Jan 2020. The two most appropriate circles were used to reveal the distal and posterior joint surfaces in the sagittal plane of the MRI images. The radius of the circle representing the distal articular surface in the sagittal plane was measured as R1, and the radius of the posterior articular surface was measured as R2. The distance between the centers of the two rotation circles was recorded as d. An independent t test was used to compare the differences between men and women. The Pearson correlation coefficient was calculated to analyze the correlation between R1 and R2. SPSS v19.0 software was used for statistical analysis.Results: The average values of R1, R2, R1/R2 and d were calculated. Scatter plots were constructed to show the trend of changes in the radius of the distal and posterior articular surfaces of the femoral condyle. R1, R2 and d differed significantly between men and women (p < 0.05). Correlation analysis showed that R1 was positively correlated with R2 (r = 0.61, p < 0.05).Conclusions: The data of the radii of the distal and posterior articular surfaces of the medial femoral condyle were provided. In the UKA design, the relationships between the radii of the distal and posterior articular surfaces should be taken into account. [ABSTRACT FROM AUTHOR]

Purpose: The argument that patellofemoral osteoarthritis (PFOA) is a contraindication to unicompartmental knee arthroplasty (UKA) remains to be resolved. The purpose of this study was to perform a meta-analysis to determine whether PFOA affects functional outcomes and survivorship after medial UKA. Methods: A literature search was performed in PubMed, Medline, Cochrane Library and Web of science to identify studies published in English (the last search was updated on June 1, 2020). The primary outcome measure was the Oxford Knee Score (OKS), whereas the secondary outcomes included range of motion (ROM) and the revision rate. Patients with patellofemoral joint narrowing or cartilage lesions as assessed intraoperatively or by radiography were assigned to the PFOA group. Results: A total of 8 studies involving 3504 patients and 3975 knees were included in this meta-analysis. No patients had a severe lateral patellar groove. The results showed that there was no significant difference in the OKS, revision rate and ROM between PFOA patients and patients without PFOA. Conclusions: No significant difference in functional outcomes and survivorship was found between patients with and without PFOA. Patients with PFOA assessed by radiographs or intraoperatively but without a lateral patellar groove should be considered candidates for medial UKA. [ABSTRACT FROM AUTHOR]

Purpose: The objective of this study was to measure resected surfaces of the medial tibial plateau and to provide accurate anatomical parameters for the Chinese population and improve the unicompartmental knee arthroplasty (UKA) component design in the future.Methods: This study measured different dimensions of the medial tibial plateau on MRIs of 1000 consecutive healthy Chinese people without knee deformity. The anteroposterior (AP) dimension and mediolateral dimensions at defined points (recorded as WA, WB, WC) of the medial tibial plateau were measured. The aspect ratio (WB/AP, recorded as AR) was also recorded. The measured results were grouped to compare with the dimensions of the Oxford Phase III tibial component. An independent t test was used to compare the differences between the males and females.Results: The Oxford Phase III tibial component showed mediolateral overhang or undersize for the whole range of measured anteroposterior dimensions of the resected medial tibial plateau. A total of 71.3% patients' resected surface did not match the Oxford Phase III tibial component well. The study also found a decrease in the aspect ratio (WB/AP) with an increase in the AP dimension in the medial tibial plateau.Conclusions: There is a difference between the morphology of the Chinese knee joint and the configuration of the Oxford Phase III tibial components. The results of this study provided accurate anatomical parameters for Chinese and guidelines for designing UKA components suitable for the Chinese population.Level Of Evidence: Retrospective comparative study, Level III. [ABSTRACT FROM AUTHOR]

Background: The aim of this prospective study was to evaluate the effectiveness of extracorporeal shock wave therapy (ESWT) in normalizing the symptoms and imaging features of primary bone marrow edema syndrome (BMES) of the knee.Methods: This study compared the outcomes of ESWT (Group A) (n = 20) and intravenously applied prostacyclin and bisphosphonate (Group B) (n = 20) in the treatment of BMES of the knee in our department between 2011 and 2013. The Visual Analog Scale for pain (VAS, 100 mm), the Western Ontario and McMaster University Osteoarthritis Index (WOMAC), the SF-36 scores and MRI scans as well as plain radiographs were obtained before and after therapy between two groups.Results: Compared with Group B, we found greater improvement in VAS, the WOMAC Osteoarthritis Index and SF-36 score at 1, 3 and 6 months post-treatment in Group A (P < 0.05). Furthermore, MRI scans showed a higher incidence of distinct reduction and complete regression of bone marrow edema at 6 months in Group A (95 vs. 65 %; P = 0.018). The MRI at 1 year follow-up showed complete regression in all patients in Group A. However, two cases in Group B continued to normalize over the subsequent follow-up period.Conclusions: ESWT can produce rapid pain relief and functional improvement. It may be an effective, reliable, and non-invasive technique for rapid treatment of BMES of the knee.Trial Registration: Research Registry UIN 528, September 03, 2015. [ABSTRACT FROM AUTHOR]

Purpose: The lower limb misalignment as calculated by radiography has an evident effect on the development and progression of knee osteoarthritis (OA). However, whether the knee malalignment has an influence on ankle alignment is unknown. The purpose of this study was to discuss the correlation between knee and ankle alignment in varus and valgus gonarthrosis.Methods: This is a retrospective study of 149 patients with symptomatic varus and valgus knee OA who intend to take total knee arthroplasty (TKA) between January and October 2013. A protocol for the measurement of knee-ankle alignment and angles on full-length standing anteroposterior radiographs of the lower extremity was outlined in detail with step-by-step instructions. Two observers measured the angles chosen. The Pearson's correlation tests were used for the statistical analysis.Results: Pearson's correlation test results for unilateral varus or valgus gonarthrosis showed that the varus or valgus deformity of the knee can influence the tilt angle and tibiotalar angle of the ankle in operative side signficantly(p<0.05), and the tilt angle of the ankle can also be affected in nonoperative side (p<0.05). Moreover, the tilt angle of the bilateral ankle can be simultaneously affected in bilateral varus gonarthrosis (p<0.05).Conclusion: These findings suggest that the varus and valgus deformity of the knee can induce the tilt of the ankle and influence the ankle alignment, which may further accelerate the degeneration of the ankle. Moreover, the knee alignment in the nonoperative side can also result in the change of ankle alignment at the same time. [ABSTRACT FROM AUTHOR]