INTRODUCTION: Postoperative urinary retention (POUR) frequently complicates the course of patients following hip and knee arthroplasty. Intrathecal morphine (ITM) was identified as a significant risk factor for POUR. The objective of this study was to investigate the incidence and risk factors for POUR in fast-track total joint arthroplasty (TJA) under spinal anaesthesia (SA) with ITM. METHODS: We conducted a retrospective study of our institutional joint registry of patients who underwent primary TJA under SA with ITM between October 2017 and May 2021. Preoperative (baseline demographics) and perioperative data were collected. The primary outcome was the incidence of POUR after 8 h or earlier, either due to lack of voiding or according to patient's complaints of bladder distension. Univariate and adjusted analyses were performed to identify predictors of POUR. RESULTS: Sixty-nine patients who underwent total knee arthroplasty (TKA) and 36 patients who underwent total hip arthroplasty (THA) under SA with ITM were included in the study. POUR requiring bladder catheterisation was diagnosed in 21% of patients. Independent predictors of POUR were age over 65 years and male gender. CONCLUSIONS SA with ITM for TJA is associated with high rates of POUR in males older than 65 years of age. Other previously identified risk factors such as intraoperative fluid administration or comorbidities may not be as influential.
Humans ; Retrospective Studies ; Male ; Urinary Retention/epidemiology* ; Arthroplasty, Replacement, Knee/adverse effects* ; Anesthesia, Spinal/adverse effects* ; Female ; Arthroplasty, Replacement, Hip/adverse effects* ; Morphine/adverse effects* ; Aged ; Middle Aged ; Risk Factors ; Postoperative Complications/epidemiology* ; Injections, Spinal ; Incidence ; Analgesics, Opioid/adverse effects* ; Aged, 80 and over

BACKGROUND: The choice of unicompartmental knee arthroplasty (UKA) vs . total knee arthroplasty (TKA) in the surgical treatment of knee osteoarthritis (KOA) remains controversial. This study aimed to perform a systematic review and meta-analysis of randomized controlled trials (RCTs) to compare the clinical results of UKA and TKA for treating unicompartmental KOA. METHODS: PubMed, Embase, and the Cochrane Library were systematically searched for articles published up to January 2, 2023. The literature was rigorously screened to include only RCTs comparing UKA and TKA for unicompartmental KOA. A systematic review and meta-analysis were performed to calculate the mean difference (MD), relative risk (RR), and 95% confidence interval (CI) according to the Cochrane standards. RESULTS: Thirteen publications involving 683 UKAs and 683 TKAs were analyzed. Except for one study with a follow-up period of 15 years, all outcome measures reported were within 5 years of follow-up. Meta-analysis showed better knee recovery (MD: 1.23; 95% CI: 1.01-1.45; P  <0.001), greater knee function (MD: 1.78; 95% CI: 0.34-3.22; P  = 0.020), less pain (MD: 0.75; 95% CI: 0.43-1.06; P  <0.001), and better health status (MD: 3.75; 95% CI: 0.81-6.69; P  = 0.010) after UKA than TKA. However, considering the minimal clinically important difference values for these variables, the findings were not clinically relevant. Moreover, UKA patients had fewer complications (RR: 0.59; 95% CI: 0.45-0.78; P  <0.001) and shorter hospital stays (MD: -0.89; 95% CI: -1.57 to -0.22; P  = 0.009) than did TKA patients. There were no statistically significant differences in terms of postoperative range of movement, revision, failure, operation time, and patient satisfaction. CONCLUSIONS In terms of clinical efficacy, there was no obvious advantage of UKA over TKA in the surgical treatment of knee OA when considering the minimal clinically important difference. The main advantage of UKA over TKA is that it leads to fewer complications and a shorter length of hospital stay. It is ideal to perform prospective studies with longer follow-up periods to fully evaluate the long-term efficacy and safety of the two procedures in the future.
Humans ; Arthroplasty, Replacement, Knee/methods* ; Osteoarthritis, Knee/surgery* ; Randomized Controlled Trials as Topic ; Treatment Outcome

Prosthesis loosening is the leading cause of postoperative revision in unicompartmental knee arthroplasty (UKA). The deviation of medial and lateral translational installation of the prosthesis during surgery is a common clinical phenomenon and an important factor in increasing the risk of prosthesis loosening. This study established a UKA finite element model and a bone-prosthesis fixation interface micromotion prediction model. The predicted medial contact force and joint motion of the knee joint from a patient-specific lower extremity musculoskeletal multibody dynamics model of UKA were used as boundary conditions. The effects of 9 femoral component medial and lateral translational installation deviations on the Von Mises stress of the proximal tibia, the contact stress, and the micro-motion of the bone prosthesis fixation interface were quantitatively studied. It was found that compared with the neutral position (a/A of 0.492), the lateral translational deviation of the femoral component significantly increased the tibial Von Mises stress and the bone-prosthesis fixation interface contact stress. The maximum Von Mises stress and the maximum contact stress of the fixation interface increased by 14.08% and 143.15%, respectively, when a/A was 0.361. The medial translational deviation of the femoral component significantly increased the bone-prosthesis fixation interface micro-motion. The maximum value of micromotion under the conditions of femoral neutral and medial translation deviation was in the range of 20-50 μm, which is suitable for osseointegration. Therefore, based on considerations such as the micromotion range suitable for osseointegration reported in the literature, the risk of reducing prosthesis loosening, and factors that may induce pain, it is recommended that clinicians control the mounting position of the femoral component during surgery within the safe range of 0-4 mm medial translation deviation.
Humans ; Arthroplasty, Replacement, Knee/methods* ; Finite Element Analysis ; Biomechanical Phenomena ; Knee Prosthesis ; Tibia/surgery* ; Femur/surgery* ; Stress, Mechanical ; Prosthesis Failure ; Knee Joint/surgery* ; Prosthesis Design

Although metal blocks have been widely used for reconstructing uncontained tibial bone defects, the influence of their elastic modulus on the stability of tibial prosthesis fixation remains unclear. Based on this, a finite element model incorporating constrained condylar knee (CCK) prosthesis, tibia, and metal block was established. Considering the influence of the post-restraint structure of the prosthesis, the effects of variations in the elastic modulus of the block on the von Mises stress distribution in the tibia and the block, as well as on the micromotion at the bone-prosthesis fixation interface, were investigated. Results demonstrated that collision between the insert post and femoral prosthesis during tibial internal rotation increased tibial von Mises stress, significantly influencing the prediction of block elastic modulus variation. A decrease in the elastic modulus of the metal block resulted in increased von Mises stress in the proximal tibia, significantly reduced von Mises stress in the distal tibia, decreased von Mises stress of the block, and increased micromotion at the bone-prosthesis fixation interface. When the elastic modulus of the metal block fell below that of bone cement, inadequate block support substantially increased the risk of stress shielding in the distal tibia and fixation interface loosening. Therefore, this study recommends that biomechanical investigations of CCK prostheses must consider the post-constraint effect, and the elastic modulus of metal blocks for bone reconstruction should not be lower than 3 600 MPa.
Knee Prosthesis ; Humans ; Finite Element Analysis ; Tibia/surgery* ; Elastic Modulus ; Arthroplasty, Replacement, Knee/methods* ; Stress, Mechanical ; Metals ; Prosthesis Design ; Knee Joint/surgery* ; Biomechanical Phenomena

PROPOSE: To investigate the molecular mechanisms underlying the protective effects of ischemic preconditioning (IPC) in patients undergoing total knee arthroplasty. METHODS: GSE21164 was extracted from an online database, followed by an investigation of differentially expressed genes (DEGs) between IPC treatment samples at 2 time points (T0T and T1T). Function and pathway enrichment analyses were performed on the DEGs. A protein-protein interaction network was constructed to identify hub genes according to 5 different algorithms, followed by enrichment analysis. In addition, long noncoding RNAs (lncRNAs) were identified between the T0T and T1T samples. Furthermore, a competing endogenous RNA network was predicted based on the identified lncRNA-messenger RNA (mRNA), lncRNA-microRNA (miRNA), and mRNA-miRNA relationships revealed in this study. Finally, a drug-gene network was investigated. Statistical analyses were performed using GraphPad Prism 8.0. Differences between groups were determined using an unpaired t-test. p < 0.05 was considered significant. RESULTS: A total of 343 DEGs at T0 and 10 DEGs at T1 were identified and compared with their respective control groups, followed by 100 DEGs between T0T and T1T. Based on these 100 DEGs, protein-protein interaction network analysis revealed 9 hub genes, mainly with mitochondria-related functions and the carbon metabolism pathway. Six differentially expressed lncRNAs were investigated between T0T and T1T. A competing endogenous RNA network was constructed using 259 lncRNA-miRNA-mRNA interactions, including alpha-2-macroglobulin antisense RNA 1-miR-7161-5p-iron-sulfur cluster scaffold. Finally, 13 chemical drugs associated with the hub genes were explored. CONCLUSION Iron-sulfur cluster scaffold may promote IPC-induced ischemic tolerance mediated by alpha-2-macroglobulin antisense RNA 1-miR-7161-5p axis. Moreover, IPC may induce a protective response after total knee arthroplasty via mitochondria-related functions and the carbon metabolism pathway, which should be further validated in the near future.
Humans ; Arthroplasty, Replacement, Knee ; Ischemic Preconditioning ; RNA, Long Noncoding/genetics* ; Protein Interaction Maps ; MicroRNAs/genetics* ; RNA, Messenger/genetics* ; Gene Regulatory Networks

PURPOSE: End-stage knee osteoarthritis (OA) patients are the primary candidates for total knee arthroplasty (TKA). However, most morphological refinements of TKA prosthesis are based on anatomical data from the knees of healthy individuals. This study aimed to determine whether differences exist in key bony morphological characteristics of the distal femur and proximal tibia between osteoarthritic knees and healthy knees. METHODS: This was a retrospective cross-sectional observational study with a case-control design. Patients who were aged ≥ 50 years, had no history of trauma, fracture, or surgery in the studied knee, and had no obvious knee flexion contracture were included in this study by CT scans. Patients who met the American College of Rheumatology clinical criteria for knee OA were included in the study group. Kellgren-Lawrence grade III or IV knees were studied (for bilateral cases, the more severely affected knee was chosen). Patients who presented with unilateral knee pain or trauma were included in the control group, with CT scans from the opposite (asymptomatic) knee used for analyzing. The studied knee had a Kellgren-Lawrence grade of 0 or I and showed no abnormalities upon physical examination. Archived knee CT scans from 160 patients were divided into 2 groups: the study group (80 moderate-to-severe OA knees) and the control group (80 healthy knees). After 3-dimensional reconstruction and virtual cutting using a CT workstation, 13 morphological parameters of the distal femur and proximal tibia were compared between the 2 groups using independent-samples t-tests. RESULTS: No significant group differences in the femoral anteroposterior dimension (p = 0.797), height of the lateral femoral condyle (p = 0.268), posterior condylar angle (p = 0.240), tibial anteroposterior dimension (p = 0.536), or tibial lateral anteroposterior dimension (p = 0.702) were observed. However, the femoral mediolateral dimension (p = 0.002), distal femoral aspect ratio (femoral mediolateral dimension/femoral anteroposterior dimension) (p < 0.001), height of the femoral trochlear groove (p < 0.001), height of the medial femoral condyle (p < 0.001), tibial mediolateral dimension (p = 0.001), proximal tibial aspect ratio (tibial mediolateral dimension/tibial anteroposterior dimension) (p = 0.004), tibial medial anteroposterior dimension (p = 0.005), and tibial asymmetry ratio (tibial medial anteroposterior dimension/tibial lateral anteroposterior dimension) (p = 0.006) were all significantly greater in the study group. CONCLUSION Knees with moderate-to-severe OA are significantly wider than healthy knees, and OA is a risk factor for increased tibial platform asymmetry. When refining the morphological parameters of TKA prostheses, the specific bony morphological characteristics of OA knees should be taken into account to reduce the potential risk of femoral or tibial component underhang and facilitate optimal balance between tibial component fit and rotational alignment.
Humans ; Osteoarthritis, Knee/pathology* ; Male ; Female ; Cross-Sectional Studies ; Retrospective Studies ; Arthroplasty, Replacement, Knee ; Middle Aged ; Aged ; Case-Control Studies ; Prosthesis Design ; Knee Prosthesis ; Femur/anatomy & histology* ; Tibia/anatomy & histology* ; Tomography, X-Ray Computed ; Knee Joint/diagnostic imaging*

Compared with total knee arthroplasty, unicondylar knee replacement has the advantage of preserving the knee tissue structure and motor function to the greatest extent. Pre-clinical in-vitro test is an important tool to evaluate the safety and effectiveness of unicondylar knee prostheses, and it is also a key focus of the product registration process. Through collection, comparison, and analysis of current regulations, technical standards, guidelines, and related research literature, this paper expounds on the relevant research methods for the pre-clinical in-vitrotesting of unicondylar knee prostheses. At the same time, in conjunction with current evaluation requirements and experience, the study discusses the focus of pre-clinical performance research for unicondylar knee prostheses during the registration process to clarify the performance evaluation requirements of this product category. This aims to provide a reference for the pre-clinical performance research of unicondylar knee prostheses and to standardize industry testing standards.
Knee Prosthesis ; Arthroplasty, Replacement, Knee ; Humans ; Prosthesis Design ; Materials Testing

OBJECTIVE: To evaluate the early effectiveness of navigation-free robot-assisted total knee arthroplasty (TKA) compared to traditional TKA in the treatment of knee osteoarthritis combined with extra-articular deformities. METHODS: The clinical data of 30 patients with knee osteoarthritis combined with extra-articular deformities who met the selection criteria between June 2019 and January 2024 were retrospectively analyzed. Fifteen patients underwent CORI navigation-free robot-assisted TKA and intra-articular osteotomy (robot group) and 15 patients underwent traditional TKA and intra-articular osteotomy (traditional group). There was no significant difference in age, gender, body mass index, affected knee side, extra-articular deformity angle, deformity position, deformity type, and preoperative knee range of motion, American Knee Society (KSS) knee score and KSS function score, and lower limb alignment deviation between the two groups ( P>0.05). The operation time, intraoperative blood loss, and complications of the two groups were recorded and compared. The knee range of motion and lower limb alignment deviation were recorded before operation and at 6 months after operation, and the knee joint function was evaluated by KSS knee score and function score. RESULTS: There was no significant difference in operation time between the two groups ( P>0.05); the intraoperative blood loss in the robot group was significantly less than that in the traditional group ( P<0.05). Patients in both groups were followed up 6-12 months, with an average of 8.7 months. The incisions of all patients healed well, and there was no postoperative complication such as thrombosis or infection. At 6 months after operation, X-ray examination showed that the position of the prosthesis was good in both groups, and there was no loosening or dislocation of the prosthesis. The knee joint range of motion, the lower limb alignment deviation, and the KSS knee score and KSS function score significantly improved in both groups ( P<0.05) compared to preoperative ones. The changes of lower limb alignment deviation and KSS function score between pre- and post-operation in the robot group were significantly better than those in the traditional group ( P<0.05), while the changes of other indicators between pre- and post-operation in the two groups were not significant ( P>0.05). CONCLUSION Compared to traditional TKA, navigation-free robot-assisted TKA for knee osteoarthritis with extra-articular deformities results in less intraoperative blood loss, more precise reconstruction of lower limb alignment, and better early effectiveness. However, long-term effectiveness require further investigation.
Humans ; Arthroplasty, Replacement, Knee/methods* ; Osteoarthritis, Knee/surgery* ; Robotic Surgical Procedures/methods* ; Male ; Female ; Retrospective Studies ; Range of Motion, Articular ; Middle Aged ; Aged ; Treatment Outcome ; Osteotomy/methods* ; Knee Joint/physiopathology* ; Operative Time

OBJECTIVE: To investigate the effectiveness of digital three-dimensional (3D) printing osteotomy guide plate assisted total knee arthroplasty (TKA) in treatment of knee osteoarthritis (KOA) patients with femoral internal implants. METHODS: The clinical data of 55 KOA patients who met the selection criteria between July 2021 and October 2023 were retrospectively analyzed. Among them, 26 cases combined with femoral implants were treated with digital 3D printing osteotomy guide plate assisted TKA (guide plate group), and 29 cases were treated with conventional TKA (control group). There was no significant difference in gender, age, body mass index, side, Kellgren-Lawrence classification, preoperative visual analogue scale (VAS) score, Hospital for Special Surgery (HSS) knee score, knee range of motion, and other baseline data between the two groups ( P>0.05). The operation time, intraoperative blood loss, incision length, postoperative first ambulation time, surgical complications; VAS score, knee HSS score, knee range of motion before operation, at 1 week and 3 months after operation, and at last follow-up; distal femoral lateral angle, proximal tibial medial angle, hip-knee-ankle angle and other imaging indicators at last follow-up were recorded and compared between the two groups. RESULTS: The operation time, incision length, intraoperative blood loss, and postoperative first ambulation time in the guide plate group were significantly lower than those in the control group ( P<0.05). In the control group, there were 1 case of incision rupture and bleeding and 1 case of lower limb intermuscular venous thrombosis, which was cured after symptomatic treatment. There was no complication such as neurovascular injury, incision infection, or knee prosthesis loosening in both groups. Patients in both groups were followed up 12-26 months, with an average of 16.25 months. The VAS score, HSS score, and knee range of motion improved at each time point after operation in both groups, and further improved with time after operation, the differences were significant ( P<0.05). The above indicators in the guide plate group were significantly better than those in the control group at 1 week and 3 months after operation ( P<0.05), and there was no significant difference between the two groups at last follow-up ( P>0.05). At last follow-up, the distal femoral lateral angle, the proximal tibial medial angle, and the hip-knee-ankle angle in the guide plate group were significantly better than those in the control group ( P<0.05). CONCLUSION The application of digital 3D printing osteotomy guide plate assisted TKA in the treatment of KOA patients with femoral implants can simplify the surgical procedures, overcome limitations of conventional osteotomy guides, reduce surgical trauma, achieve individualized and precise osteotomy, and effectively restore lower limb alignment and knee joint function.
Humans ; Arthroplasty, Replacement, Knee/instrumentation* ; Osteoarthritis, Knee/surgery* ; Osteotomy/instrumentation* ; Male ; Retrospective Studies ; Female ; Printing, Three-Dimensional ; Femur/surgery* ; Middle Aged ; Bone Plates ; Range of Motion, Articular ; Aged ; Treatment Outcome ; Surgery, Computer-Assisted/methods* ; Knee Prosthesis ; Knee Joint/surgery* ; Operative Time

OBJECTIVE: To review the research progress of intelligent remote follow-up modes in the application after hip and knee arthroplasty. METHODS: Extensive literature on this topic published in recent years both domestically and internationally was reviewed, and the application of intelligent remote follow-up modes after hip and knee arthroplasty was summarized and analyzed. RESULTS: The intelligent remote follow-up mode is a novel follow-up method based on network information technology. Patients who undergo hip and knee arthroplasty require long-term follow-up and rehabilitation guidance after operation. Traditional outpatient follow-up is relatively time-consuming and inconvenient for some patients in terms of travel and transportation, which makes the application of intelligent remote follow-up modes increasingly widespread worldwide. The inherent attributes of remote interaction and instant feedback of this mode make it particularly valued in the field of hip and knee arthroplasty. Artificial intelligence (AI)-based voice follow-up systems and virtual clinics have significant advantages in improving follow-up efficiency, reducing human resource costs, and enhancing patient satisfaction. CONCLUSION The existing intelligent follow-up system has formed a standardized protocol in remote follow-up and rehabilitation guidance. However, there are still shortcomings in the formulation of personalized rehabilitation plans and the gerontechnological adaptation of human-computer interaction. In the future, it is necessary to construct a multimodal data fusion platform and establish technical application guidelines for different rehabilitation stages.
Humans ; Arthroplasty, Replacement, Knee/rehabilitation* ; Arthroplasty, Replacement, Hip/rehabilitation* ; Artificial Intelligence ; Follow-Up Studies ; Telemedicine