The surgical installation accuracy of the components in unicompartmental knee arthroplasty (UKA) is an important factor affecting the joint function and the implant life. Taking the ratio of the medial-lateral position of the femoral component relative to the tibial insert (a/A) as a parameter, and considering nine installation conditions of the femoral component, this study established the musculoskeletal multibody dynamics models of UKA to simulate the patients' walking gait, and investigated the influences of the medial-lateral installation positions of the femoral component in UKA on the contact force, joint motion and ligament force of the knee joint. The results showed that, with the increase of a/A ratio, the medial contact force of the UKA implant was decreased and the lateral contact force of the cartilage was increased; the varus rotation, external rotation and posterior translation of the knee joint were increased; and the anterior cruciate ligament force, posterior cruciate ligament force and medial collateral ligament force were decreased. The medial-lateral installation positions of the femoral component in UKA had little effect on knee flexion-extension movement and lateral collateral ligament force. When the a/A ratio was less than or equalled to 0.375, the femoral component collided with the tibia. In order to prevent the overload on the medial implant and lateral cartilage, the excessive ligament force, and the collision between the femoral component and the tibia, it is suggested that the a/A ratio should be controlled within the range of 0.427-0.688 when the femoral component is installed in UKA. This study provides a reference for the accurate installation of the femoral component in UKA.
Humans ; Arthroplasty, Replacement, Knee ; Knee Joint/surgery* ; Knee Prosthesis ; Gait ; Rotation

OBJECTIVE: To compare the short-term effectiveness of "SkyWalker" robot-assisted total knee arthroplasty (TKA) and traditional TKA. METHODS: A clinical data of 54 patients (54 knees) with TKA who met the selection criteria between January 2022 and March 2022 was retrospectively analyzed. Among them, 27 cases underwent traditional TKA (traditional operation group) and 27 cases underwent "SkyWalker" robot-assisted TKA (robot-assisted operation group). There was no significant difference between the two groups ( P>0.05) in terms of gender, age, body mass index, osteoarthritis side, disease duration, and preoperative Knee Society Score (KSS), Western Ontario and McMaster University Osteoarthritis Index (WOMAC), visual analogue scale (VAS) score, hip-knee-ankle angle (HKA), lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), and posterior proximal tibial angle (PPTA). The operative time, intraoperative bleeding volume, surgery-related complications, the KSS, WOMAC, and VAS scores before operation and at 6 months after operation, and Forgotten Joint Score (FJS) at 6 months after operation were recorded. X-ray films were taken to review the prosthesis position and measure HKA, LDFA, MPTA, and PPTA. The differences of the clinical and imaging indicators between before and after operation were calculated and statistically analyzed. RESULTS: The operations were completed successfully in both groups. There was no significant difference in the operative time and intraoperative bleeding volume between the two groups ( P>0.05). After operation, 1 case of incision nonunion and 1 case of heart failure occurred in the traditional operation group, while no surgery-related complications occurred in the robotic-assisted operation group. The incidences of surgical complications were 7.4% (2/27) in the traditional operation group and 0 (0/27) in the robotic-assisted operation group, with no significant difference ( P=0.491). Patients in both groups were followed up 6 months. KSS score, WOMAC score, VAS score, and ROM significantly improved in both groups at 6 months after operation when compared with preoperative ones ( P<0.05). There was no significant difference between the two groups ( P>0.05) in the differences between the pre- and post-operative values of the clinical indicators and FJS scores at 6 months after operation. X-ray films showed that the lower extremity force lines of the patients improved and the knee prostheses were in good position. Except for LDFA in the robot-assisted operation group, HKA, LDFA, MPTA, and PPTA significantly improved in both groups at 6 months after operation when compared with the preoperative ones ( P<0.05). There was no significant difference between the two groups in the differences between the pre- and post-operative values of the radiological indicators ( P>0.05). CONCLUSION The "SkyWalker" robot-assisted TKA is one of the effective methods for the treatment of knee osteoarthritis and had good short-term effectiveness. But the long-term effectiveness needs to be further studied.
Humans ; Arthroplasty, Replacement, Knee/methods* ; Knee Joint/surgery* ; Knee Prosthesis ; Osteoarthritis, Knee/surgery* ; Retrospective Studies ; Robotics ; Treatment Outcome

BACKGROUND: Synovectomy has been introduced into total knee arthroplasty (TKA) with the aim of relieving pain and inflammation of the synovium. However, there are no long-term, comparative data to evaluate the effect of synovectomy in TKA. This study was aimed at assessing pain, function, and complications in patients undergoing synovectomy during TKA for osteoarthritis (OA) at long-term follow-up. METHODS: This was a prospective randomized controlled trial of 42 consecutive patients who underwent staged bilateral TKA. Patients undergoing the first-side TKA were allocated to receive TKA with or without synovectomy followed by a 3-month washout period and crossover to the other strategy for the opposite-side TKA. The overall efficacy of both strategies was evaluated by determination of blood loss, the Knee Society score (KSS), and knee inflammation conditions during a 3-month postoperative period. The postoperative pain, range of motion (ROM), and complications were sequentially evaluated to compare the two groups until 10 years after surgery. RESULTS: At the 10-year follow-up, both groups had a similarly significantly improved ROM (114.88 ± 9.84° vs. 114.02 ± 9.43°, t  = 0.221, P  = 0.815) and pain relief with no differences between the two groups (1.0 [1.0] vs. 1.0 [1.5], U  = 789.500, P  = 0.613). Similar changes in total blood loss, KSS, and knee inflammation were found in both groups during 3 months postoperatively ( P  > 0.05). Additionally, there was no significant difference regarding complications and satisfaction between the two groups ( P  > 0.05). CONCLUSIONS: Synovectomy in conjunction with TKA for primary OA does not seem to provide any benefit regarding postoperative pain, ROM, and satisfaction during a 10-year follow-up. In addition, it may not result in more blood loss and increased incidence of long-term complications. Based on our long-term findings, it should not be performed routinely. TRIAL REGISTRATION Chinese Clinical Trial Registry, ChiCTR-INR-16008245; https://www.chictr.org.cn/showproj.aspx?proj=13334 .
Humans ; Arthroplasty, Replacement, Knee/methods* ; Synovectomy/methods* ; Osteoarthritis, Knee/surgery* ; Prospective Studies ; Pain, Postoperative ; Inflammation/etiology* ; Range of Motion, Articular ; Knee Joint/surgery* ; Treatment Outcome ; Knee Prosthesis/adverse effects*

OBJECTIVE: To investigate the clinical efficacy of unicompartmental knee arthroplasty (UKA) in the treatment of knee osteoarthritis in patients over 75 years old. METHODS: The clinical efficacy of primary fixed platform UKA in patients with osteoarthritis, was retrospectively analyzed from October 2014 to November 2020. Age, body mass index (BMI), range of motion (ROM), preoperative joint function score, the quality of life score and other preoperative indicators were measured by propensity score matching (PSM). The patients were divided into elderly group (≥75 years old) and control group (<75 years old). Oxford knee score(OKS), Western Ontario McMaster Universities osteoarthritis index(WOMAC), Short Form-12 including physical component summary (PCS), mental component summary(MCS), minimal clinically important difference(MCID ) and clinical complications were evaluated preoperatively and postoperatively. RESULTS: A total of 514 patients were analyzed, 428 patients fulfilled the inclusion criteria. A propensity-score matching study was conducted to eliminate confounding factors. After 1∶2 propensity match, there were 84 patients in elderly group (≥75 years), age ranged from 75 to 88 years old, with an average of (78.79±3.08) years old, and 168 patients in control group (<75 years), age ranged from 47 to 74 years old, with an average of (64.10±5.96)years old. The follow-up duration of two groups ranged from 12 to 84 months with an average of (29.35±16.52) months in elderly group, and 12 to 85 months with an average of (31.83±17.34) months in control group. There was only significant difference in age between the elderly and control groups preoperatively (P<0.01). Postoperatively, the elderly group showed significantly higher WOMAC (P<0.01) and lower SF-12 PCS scores (P<0.01) as compared to the control group. There was no significant difference between the elderly group and the control group in knee range of motion, OKS and the proportion of each scoring system reaching the minimum clinical difference value (P>0.05). In the aspect of preperative complications, the elderly group exhibited more surgical site complications and postoperative delirium compared to control group(P<0.05). The differences in other indicators including deep vein thrombosis, acute urinary retention, cardiovascular events, cerebrovascular events and radiolucent lines around prothesis were not statistically significant(P>0.05). CONCLUSION UKA in the treatment of elderly patients over 75 years old with knee osteoarthritis was safe and feasible, and could obtain satisfactory short-term efficacy.
Humans ; Aged ; Aged, 80 and over ; Middle Aged ; Osteoarthritis, Knee/surgery* ; Knee Prosthesis ; Retrospective Studies ; Propensity Score ; Quality of Life ; Knee Joint/surgery* ; Arthroplasty, Replacement, Knee/methods* ; Treatment Outcome

BACKGROUND: Patellofemoral joint (PFJ) degeneration has traditionally been regarded as a contraindication to unicompartmental knee arthroplasty (UKA). More recently, some researchers have proposed that PFJ degeneration can be ignored in medial UKA, and others have proposed that this change should be reviewed in PFJ degenerative facets and severity. This study aimed to systematically evaluate the effect of PFJ degeneration on patient-reported outcome measures (PROMs) and revision rates after medial UKA. METHODS: Electronic databases (PubMed, Embase, Web of Science, etc.) were searched for studies assessing the influence of PFJ degeneration on medial UKA. A random-effects meta-analysis was conducted for the Oxford knee score (OKS), Knee society score (KSS), and revision rates and stratified by PFJ degenerative facets (medial/lateral/trochlear/unspecified), severe PFJ degeneration (bone exposed), and bearing type (mobile/fixed). Heterogeneity was assessed by the Cochran Q test statistic and chi-squared tests with the I-squared statistic. RESULTS: A total of 34 articles with 7007 knees (2267 with PFJ degeneration) were included (5762 mobile-bearing and 1145 fixed-bearing and 100 unspecified). Slight to moderate degenerative changes in the medial and trochlear facets did not decrease the OKS and KSS, and only lateral facets significantly decreased the OKS (mean difference [MD] = -2.18, P   <  0.01) and KSS (MD = -2.61, P   <  0.01). The severity degree of PFJ degeneration had no additional adverse effect on the OKS, KSS, or revision rates. For mobile-bearing UKA, only lateral PFJ degeneration significantly decreased the OKS (MD = -2.21, P  < 0.01) and KSS (MD = -2.44, P  < 0.01). For fixed-bearing UKA, no correlation was found between PROMs/revision rates and PFJ degeneration. CONCLUSION For medial mobile-bearing UKA, slight to moderate degenerative changes in the PFJ, except lateral facet, did not compromise PROMs or revision rates. For medial fixed-bearing UKA, although it might not be conclusive enough, PROMs or revision rates were not adversely affected by PFJ degeneration (regardless of the facet).
Humans ; Arthroplasty, Replacement, Knee ; Patellofemoral Joint/surgery* ; Treatment Outcome ; Osteoarthritis, Knee/surgery* ; Knee Prosthesis ; Bone Diseases ; Knee Joint/surgery* ; Retrospective Studies

Humans ; Arthroplasty, Replacement, Knee ; Follow-Up Studies ; Cohort Studies ; Treatment Outcome ; Minimally Invasive Surgical Procedures ; Knee Joint/surgery* ; Knee Prosthesis ; Osteoarthritis, Knee/surgery*

BACKGROUND: Total knee arthroplasty (TKA) can reduce severe joint pain and improve functional disability in hemophilia. However, the long-term outcomes have rarely been reported in China. Therefore, this study aimed to evaluate the long-term outcomes and complications of TKA in Chinese patients with hemophilic arthropathy. METHODS: We retrospectively reviewed patients with hemophilia who underwent TKA between 2003 and 2020, with at least 10 years of follow-up. The clinical results, patellar scores, patients' overall satisfaction ratings, and radiological findings were evaluated. Revision surgery for implants during the follow-up period was recorded. RESULTS: Twenty-six patients with 36 TKAs were successfully followed up for an average of 12.4 years. Their Hospital for Special Surgery Knee Score improved from an average of 45.8 to 85.9. The average flexion contracture statistically significantly decreased from 18.1° to 4.2°. The range of motion (ROM) improved from 60.6° to 84.8°. All the patients accepted patelloplasty, and the patients' patellar score improved from 7.8 preoperatively to 24.9 at the last follow-up. There was no statistically significant difference in clinical outcomes between the unilateral and bilateral procedures, except for a better ROM at follow-up in the unilateral group. Mild and enduring anterior knee pain was reported in seven knees (19%). The annual bleeding event was 2.7 times/year at the last follow-up. A total of 25 patients with 35 TKAs were satisfied with the procedure (97%). Revision surgery was performed in seven knees, with 10- and 15-year prosthesis survival rates of 85.8% and 75.7%, respectively. CONCLUSIONS TKA is an effective procedure for patients with end-stage hemophilic arthropathy, which relieves pain, improves knee functions, decreases flexion contracture, and provides a high rate of satisfaction after more than ten years of follow-up.
Humans ; Arthroplasty, Replacement, Knee/methods* ; Hemophilia A/surgery* ; Follow-Up Studies ; Retrospective Studies ; Treatment Outcome ; Knee Joint/surgery* ; Range of Motion, Articular ; Arthritis/complications* ; Pain ; Contracture/surgery* ; Surgeons ; Knee Prosthesis

Humans ; Arthroplasty, Replacement, Knee/adverse effects* ; Surgical Wound Infection/etiology* ; Retrospective Studies ; Risk Factors ; Arthroplasty, Replacement, Hip/adverse effects* ; Prosthesis-Related Infections/etiology*

Humans ; Arthroplasty, Replacement, Knee/adverse effects* ; Arthroplasty, Replacement, Hip/adverse effects* ; Reoperation ; Prosthesis-Related Infections ; Retrospective Studies

BACKGROUND: Despite the advent of innovative knee prosthesis design, a consistent first-option knee implant design in total knee arthroplasty (TKA) remained unsettled. This study aimed to compare the clinical effects among posterior-stabilized (PS), cruciate-retaining (CR), bi-cruciate substituting (BCS), and bi-cruciate retaining designs for primary TKA. METHODS: Electronic databases were systematically searched to identify eligible randomized controlled trials (RCTs) and cohort studies from inception up to July 30, 2021. The primary outcomes were the range of knee motion (ROM), and the secondary outcomes were the patient-reported outcome measures (PROMs) and complication and revision rates. Confidence in evidence was assessed using Confidence in Network Meta-Analysis. The Bayesian network meta-analysis was performed for synthesis. RESULTS: A total of 15 RCTs and 18 cohort studies involving 3520 knees were included. The heterogeneity and inconsistency were acceptable. There was a significant difference in ROM at the early follow-up when PS was compared with CR (mean difference [MD] = 3.17, 95% confidence interval [CI] 0.07, 7.18) and BCS was compared with CR (MD = 9.69, 95% CI 2.18, 17.51). But at the long-term follow-up, there was no significant difference in ROM in any one knee implant compared with the others. No significant increase was found in the PROMs and complication and revision rates at the final follow-up time. CONCLUSIONS At early follow-up after TKA, PS and BCS knee implants significantly outperform the CR knee implant in ROM. But in the long run, the available evidence suggests different knee prostheses could make no difference in clinical outcomes after TKA with extended follow-up.
Humans ; Arthroplasty, Replacement, Knee ; Posterior Cruciate Ligament/surgery* ; Network Meta-Analysis ; Osteoarthritis, Knee/surgery* ; Knee Joint/surgery* ; Knee Prosthesis ; Range of Motion, Articular