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

INTRODUCTION: Premature ovarian insufficiency (POI) refers to loss of ovarian activity before the age 40 years. POI has significant detrimental effects on health (infertility, cardiovascular diseases, type 2 diabetes, reduced bone density, dementia), well-being and longevity. This summary is a practical toolkit for health-care professionals (HCPs) looking after women with POI. METHOD: A workgroup comprising specialists in gynaecology, reproductive medicine, endocrinology, genetics and family medicine reviewed relevant guidelines and literature on POI to establish recom-mendations for the diagnosis and management of POI in Singapore. RESULTS: A summary to assist HCPs manage POI was produced, outlining: (1) the aetiology and conse-quences of POI; (2) making the diagnosis; (3) hormone therapy (HT) prescribing options including for those with additional medical conditions; (4) counselling women with POI about HT; and (5) long-term management of POI. CONCLUSION Timely diagnosis and management of POI is vital to prevent long-term adverse consequences, except infertility. HT is the mainstay of treatment and there are no alternatives as effective. Contraindications are very few; estrogen-sensitive cancer is the main contraindication, and caution in prescribing may be needed with established coexisting cardiovascular disease. Estrogen dosage is higher than when treating normal menopause, and as a result, the patient might require more progestogen for endometrial protection. Minimising cardiovascular risk factors by following a healthy lifestyle is important. POI is a significant public health issue and it is imperative that women have affordable access to appropriate HT. Large-scale research on POI in Asian women is needed.
Humans ; Primary Ovarian Insufficiency/drug therapy* ; Female ; Estrogen Replacement Therapy ; Singapore ; Adult

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

The orientation of the acetabular cup in hip joint anteroposterior radiograph is a key factor in evaluating the postoperative outcomes of total hip arthroplasty (THA). Currently, measurement of the acetabular cup anteversion angle primarily relies on manual drawing of auxiliary lines by orthopedic surgeons and calculations using scientific calculators. This study proposes an automated computer-aided measurement method for the acetabular cup anteversion angle based on hip joint anteroposterior radiograph. The proposed method segments hip prosthesis images using an improved Otsu algorithm, identifies feature points at the acetabular cup opening by combining circle-fitting theory and the cup's geometric characteristics, and fits an ellipse to the cup opening to calculate the anteversion angle. A total of 104 hip joint anteroposterior radiographs, including 71 right-sided and 81 left-sided prostheses, were analyzed. Two orthopedic surgeons independently measured the postoperative anteversion angles, and the results were compared with computer-generated measurements for correlation analysis. Spearman and Pearson correlation analyses demonstrated significant correlations between the proposed method and manual measurements for both the right group ( r = 0.795, P < 0.01) and the left group ( r = 0.859, P < 0.01). This method provides a reliable reference for orthopedic surgeons to assess postoperative prognosis.
Humans ; Acetabulum/anatomy & histology* ; Arthroplasty, Replacement, Hip/methods* ; Algorithms ; Hip Prosthesis ; Hip Joint/diagnostic imaging* ; Radiography ; Image Processing, Computer-Assisted/methods*

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

Stent migration is one of the common complications following transcatheter valve implantation. This study aims to design a "drum-shaped" balloon-expandable aortic valve stent to address this issue and conduct a mechanical analysis. The implantation process of the stent was evaluated using a method that combines numerical simulation and in vitro experiments. Furthermore, the fatigue process of the stent under pulsatile cyclic loading was simulated, and its fatigue performance was assessed using a Goodman diagram. The process of the stent migrating toward the left ventricular side was simulated, and the force-displacement curve of the stent was extracted to evaluate its anti- migration performance. The results showed that all five stent models could be crimped into a 14F sheath and enabled uniform expansion of the native valve leaflets. The stress in each stent was below the ultimate stress, so no fatigue fracture occurred. As the cell height ratio decreased, the contact area fraction between the stent and the aortic root gradually decreased. However, the mean contact force and the maximum anti-migration force first decreased and then increased. Specifically, model S5 had the smallest contact area fraction but the largest mean contact force and maximum anti-migration force, reaching approximately 0.16 MPa and 10.73 N, respectively. The designed stent achieves a "drum-shaped" change after expansion and has good anti-migration performance.
Stents ; Prosthesis Design ; Heart Valve Prosthesis ; Humans ; Aortic Valve/surgery* ; Stress, Mechanical ; Transcatheter Aortic Valve Replacement/instrumentation*

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 analyze the short-term effectiveness and safety of personalized three-dimensional (3D) printed customized prostheses in severe Paprosky type Ⅲ acetabular bone defects. METHODS: A retrospective analysis was conducted on 8 patients with severe Paprosky type Ⅲ acetabular bone defects and met the selection criteria between January 2023 and June 2024. There were 3 males and 5 females, with an average age of 64.6 years ranged from 56 to 73 years. All primary replacement prostheses were non-cemented, including 1 ceramic-ceramic interface, 1 ceramic-polyethylene interface, and 6 metal-polyethylene interfaces. The time from the primary replacement to the revision was 4 days to 18 years. The reasons for revision were aseptic loosening in 5 cases, revision after exclusion in 2 cases, and repeated dislocation in 1 case. The preoperative Harris score was 39.5±3.7 and the visual analogue scale (VAS) score was 7.1±0.8. The operation time, intraoperative blood loss, hospital stay, and complications were recorded. The hip function was evaluated by Harris score, and the degree of pain was evaluated by VAS score. The acetabular cup abduction angle, anteversion angle, rotational center height, greater trochanter height, and femoral offset were measured on X-ray film. RESULTS: The operation time was 95-223 minutes, with an average of 151.13 minutes. The intraoperative blood loss was 600-3 500 mL, with an average of 1 250.00 mL. The hospital stay was 13-20 days, with an average of 16.88 days. All 8 patients were followed up 2-12 months, with an average of 6.4 months. One patient had poor wound healing after operation, which healed well after active symptomatic treatment. One patient had lower limb intermuscular vein thrombosis, but no thrombosis was found at last follow-up. No serious complications such as aseptic loosening, infection, dislocation, and periprosthetic fracture occurred during the follow-up. At last follow-up, the Harris score was 72.0±6.2 and the VAS score was 1.8±0.7, which were significantly different from those before operation ( t=-12.011, P<0.001; t=16.595, P<0.001). On the second day after operation, the acetabular cup abduction angle ranged from 40° to 49°, with an average of 44.18°, and the acetabular cup anteversion angle ranged from 19° to 26°, with an average of 21.36°, which were within the "Lewinneck safety zone". There was no significant difference in the rotational center height, greater trochanter height, and femoral offset between the healthy side and the affected side ( P>0.05). CONCLUSION The use of personalized 3D printed customized prostheses for the reconstruction of severe Paprosky type Ⅲ acetabular bone defects can alleviate pain and enhances hip joint function, and have good postoperative prosthesis position, without serious complications and have good safety.
Humans ; Printing, Three-Dimensional ; Male ; Female ; Middle Aged ; Acetabulum/surgery* ; Aged ; Retrospective Studies ; Hip Prosthesis ; Prosthesis Design ; Arthroplasty, Replacement, Hip/instrumentation* ; Reoperation ; Treatment Outcome

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