Pain Relief After Total Knee Arthroplasty with Intravenous and Periarticular Corticosteroid: A Randomized Controlled Trial.

BACKGROUND: Total knee arthroplasty (TKA) is a cost-effective procedure, but it is also associated with substantial postoperative pain. The present study aimed to compare pain relief and functional recovery after TKA among groups that received intravenous corticosteroids, periarticular corticosteroids, or a combination of both. METHODS: This randomized, double-blinded clinical trial in a local institution in Hong Kong recruited 178 patients who underwent primary unilateral TKA. Six of these patients were excluded because of changes in surgical technique; 4, because of their hepatitis B status; 2, because of a history of peptic ulcer; and 2, because they declined to participate in the study. Patients were randomized 1:1:1:1 to receive placebo (P), intravenous corticosteroids (IVS), periarticular corticosteroids (PAS), or a combination of intravenous and periarticular corticosteroids (IVSPAS). RESULTS: The pain scores at rest were significantly lower in the IVSPAS group than in the P group over the first 48 hours (p = 0.034) and 72 hours (p = 0.043) postoperatively. The pain scores during movement were also significantly lower in the IVS and IVSPAS groups than in the P group over the first 24, 48, and 72 hours (p ≤ 0.023 for all). The flexion range of the operatively treated knee was significantly better in the IVSPAS group than in the P group on postoperative day 3 (p = 0.027). Quadriceps power was also greater in the IVSPAS group than in the P group on postoperative days 2 (p = 0.005) and 3 (p = 0.007). Patients in the IVSPAS group were able to walk significantly further than patients in the P group in the first 3 postoperative days (p ≤ 0.003). Patients in the IVSPAS group also had a higher score on the Elderly Mobility Scale than those in the P group (p = 0.036). CONCLUSIONS: IVS and IVSPAS yielded similar pain relief, but IVSPAS yielded a larger number of rehabilitation parameters that were significantly better than those in the P group. This study provides new insights into pain management and postoperative rehabilitation following TKA. LEVEL OF EVIDENCE: Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence.

Effects of enhanced recovery after surgery practices on postoperative recovery and length of stay after unilateral primary total hip or knee arthroplasty in a private hospital.

INTRODUCTION: Enhanced recovery after surgery (ERAS) practices improve postoperative recovery and reduce postoperative length of stay (LOS) in patients undergoing primary total hip arthroplasty (THA) or total knee arthroplasty (TKA). Our study investigated whether these promising results could be reproduced in a private hospital setting. METHODS: In total, 228 patients were included in the study cohort: the conventional group comprised 117 patients from 2012 to 2014, while the ERAS group comprised 111 patients from 2017 to 2018. All patients had undergone unilateral primary THA or TKA at a private hospital in Hong Kong. The outcome was postoperative LOS; factors affecting LOS were also investigated. RESULTS: No significant differences were found in any baseline parameters between the two groups of patients. The mean LOS was significantly shorter in the ERAS group than in the conventional group (3.28 ± 1.04 vs 5.16 ± 2.06 days, P<0.001). Moreover, a significantly greater proportion of patients could be discharged on or before postoperative day 3 in the ERAS group, compared with the conventional group (77.5% vs 13.7%, P<0.001). A significant difference in LOS was observed between general ward and private ward patients (3.06 ± 0.59 vs 3.66 ± 1.46 days, P=0.003). Sex, age, and nature of surgery (TKA vs THA) did not have significant effects on LOS. CONCLUSIONS: The ERAS practices yielded a significant improvement in postoperative LOS, compared to conventional practices, among patients who underwent unilateral primary THA or TKA in a private hospital.

Total knee arthroplasty is safe for patients aged ≥80 years in Hong Kong.

INTRODUCTION: Total knee arthroplasty (TKA) is an efficacious operation that improves pain and function in patients with knee arthritis. Because of the population ageing trend in Hong Kong, there is a need to determine the safety profile of TKA in older patients. This study examined the age of patients who underwent TKA in the past 10 years in Hong Kong; the aim was to investigate the mortality safety profile and clinical outcomes of TKA in patients aged ≥80 years. METHODS: This study included all patients who underwent primary TKA in the Hospital Authority (HA) from 2010 to 2019. Incidences of 30-day, 90-day, and 1-year mortality were established. Clinical outcomes of patients aged ≥80 years in one cluster of HA hospitals were assessed. RESULTS: Between 2010 and 2019, 25 040 TKA procedures were conducted in all HA hospitals; 2491 were conducted in patients aged ≥80 years. The median age at operation was higher during 2015-2019 than during 2010-2014 (70 vs 69 years; P<0.001); furthermore, an increase was observed in the proportion of patients aged ≥80 years at the time of operation. Incidences of 30-day, 90-day, and 1-year mortality were 0.156%, 0.35%, and 1.09%, respectively. CONCLUSIONS: In this first study to examine the safety profile of TKA in older patients in Hong Kong, the mean age at the time of TKA and proportion of patients aged ≥80 years have steadily risen in the past decade. Even in older patients, TKA is a reasonably safe procedure.

Preoperative optimization to prevent periprosthetic joint infection in at-risk patients.

Periprosthetic joint infection (PJI) remains an important complication with devastating consequences after total joint arthroplasties. With the increasing number of arthroplasties worldwide, the number of PJI will increase correspondingly with a significant economic burden to our healthcare system. It is likely impossible to completely eradicate PJI; hence, assessment and optimization of its risk factors to preventing such a disastrous complication will be the key. There are many strategies to prevent PJI in the preoperative, intraoperative, or postoperative phases. The preoperative assessment provides a unique opportunity to screen and diagnose underlying comorbidities and optimize modifiable risk factors before elective surgeries. In this review, we will focus on current literature in preoperative assessment of various modifiable risk factors and share the experience and practical approach in our institution in preoperative optimization to reduce PJI in total joint arthroplasties.

Universal haemoglobin A1c screening reveals high prevalence of dysglycaemia in patients undergoing total knee arthroplasty.

INTRODUCTION: Diabetes mellitus is an established modifiable risk factor for periprosthetic joint infection (PJI). Haemoglobin A1c (HbA1c) is a glycaemic marker that correlates with diabetic complications and PJI. As diabetes and prediabetes are frequently asymptomatic, and there is increasing evidence to suggest a correlation between dysglycaemia and osteoarthritis, it is reasonable to provide HbA1c screening before total knee arthroplasty (TKA). The aim of the present study was to determine the prevalence of dysglycaemia in patients who underwent TKA and investigate whether HbA1c screening and optimisation of glycaemic control before TKA affects the incidence of PJI after TKA. METHODS: Patients who underwent primary TKA before and after routine HbA1c screening was introduced in our unit were reviewed. Prediabetes and diabetes were defined according to the American Diabetes Association. Patients with HbA1c ≥7.5% were referred to an endocrinologist for optimisation of glycaemic control before TKA. The incidence PJI, defined according to the Musculoskeletal Infection Society criteria, was recorded. RESULTS: A total of 729 patients (934 knees) had HbA1c screening before TKA. Of them, 17 (2.3%) and 184 (25.2%) patients had known prediabetes and diabetes, respectively, and 265 (36.4%) and 12 (1.6%) had undiagnosed prediabetes and diabetes, respectively. The incidence of PJI was significantly lower in all patients who received HbA1c screening compared with those who did not (0.2% vs 1.02%, P=0.027). CONCLUSION: Screening for HbA1c before TKA provides a cost-effective opportunity to identify undiagnosed dysglycaemia. Patients identified as having dysglycaemia receive modified treatment, significantly reducing the rate of PJI when compared with historical controls.

Blood transfusions in total knee arthroplasty: a retrospective analysis of a multimodal patient blood management programme.

PURPOSE: Transfusion is associated with increased perioperative morbidity and mortality in patients undergoing total knee arthroplasty (TKA). Patient blood management (PBM) is an evidence-based approach to maintain blood mass via haemoglobin maintenance, haemostasis optimisation, and blood loss minimisation. The aim of the present study was to assess the effectiveness of a multimodal PBM approach in our centre. METHODS: This was a single-centre retrospective study of patients who underwent primary TKA in Queen Mary Hospital in Hong Kong in 2013 or 2018, using data from the Clinical Data Analysis and Reporting System and a local joint registry database. Patient demographics, preoperative haemoglobin, length of stay, readmission, mean units of transfusion, postoperative prosthetic joint infection, and mortality data were compared between groups. RESULTS: In total, 262 and 215 patients underwent primary TKA in 2013 and 2018, respectively. The mean transfusion rate significantly decreased after PBM implementation (2013: 31.3%; 2018: 1.9%, P<0.001); length of stay after TKA also significantly decreased (2013: 14.49±8.10 days; 2018: 8.77±10.14 days, P<0.001). However, there were no statistically significant differences in readmission, early prosthetic joint infection, or 90-day mortality rates between the two groups. CONCLUSION: Our PBM programme effectively reduced the allogeneic blood transfusion rate in patients undergoing TKA in our institution. Thus, PBM should be considered in current TKA protocols to reduce rates of transfusions and related complications.

Non-surgical treatment of knee osteoarthritis.

Knee osteoarthritis is one of the most common degenerative diseases causing disability in elderly patients. Osteoarthritis is an increasing problem for ageing populations, such as that in Hong Kong. It is important for guidelines to be kept up to date with the best evidence-based osteoarthritis management practices available. The aim of this study was to review the current literature and international guidelines on non-surgical treatments for knee osteoarthritis and compared these with the current guidelines in Hong Kong, which were proposed in 2005. Internationally, exercise programmes for non-surgical management of osteoarthritis have been proven effective, and a pilot programme in Hong Kong for comprehensive non-surgical knee osteoarthritis management has been successful. Long-term studies on the effectiveness of such exercise programmes are required, to inform future changes to guidelines on osteoarthritis management.

Bacteriology and risk factors associated with periprosthetic joint infection after primary total knee arthroplasty: retrospective study of 2543 cases.

INTRODUCTION: Periprosthetic joint infection after total knee arthroplasty is a serious complication. This study aimed to identify risk factors and bacteriological features associated with periprosthetic joint infection after primary total knee arthroplasty performed at a teaching hospital. METHODS: We reviewed 2543 elective primary total knee arthroplasties performed at our institution from 1993 to 2013. Data were collected from the Hong Kong Hospital Authority's Clinical Data Analysis and Reporting System, the Infection Control Team, and the joint replacement division registry. The association between potential risk factors and periprosthetic joint infection was examined by univariable analysis and multivariable logistic regression. Univariable analyses were also performed to examine the association between potential risk factors and bacteriology and between potential risk factors, including bacteriology, and early-onset infection. RESULTS: The incidence of periprosthetic joint infection in our series was 1.34% (n=34). The incidence of early-onset infection was 0.39% (n=24). Of the periprosthetic joint infections, 29.4% were early-onset infections. In both univariable and multivariable analyses, only rheumatoid arthritis was a significant predictor of periprosthetic joint infection. Methicillin-sensitive Staphylococcus aureus was the most common causative organism. We did not identify any significant association between potential risk factors and bacteriology. Periprosthetic joint infection caused by skin flora was positively associated with early-onset infection but the association was not statistically significant. CONCLUSION: The incidence of periprosthetic joint infection after elective primary total knee arthroplasty performed at our institution from 1993 to 2013 was 1.34%. Rheumatoid arthritis was a significant risk factor for periprosthetic joint infection.

Knocking out or pharmaceutical inhibition of fatty acid binding protein 4 (FABP4) alleviates osteoarthritis induced by high-fat diet in mice.

OBJECTIVES: Adipokines play roles in the pathogenesis of osteoarthritis (OA). Fatty acid binding protein 4 (FABP4) is a novel adipokine that is closely associated with obesity and metabolic diseases. The aim of this study was to discover the potential role of FABP4 in OA. METHODS: Seventy-two FABP4 knockout mice (KO) in C57BL/6N background and wild-type littermates (WT) (male, 6-week-old) were fed with a high-fat diet (HFD, 60% calorie) or standard diet (STD, 11.6% calorie) for 3 months, 6 months and 9 months (n = 6 each). In the parallel study, forty-eight 6-week-old male WT mice were fed with HFD or STD, and simultaneously treated with daily oral gavage of selective FABP4 inhibitor BMS309403 (15 mg/kg/d) or vehicle for 4 months and 6 months (n = 6 each). Serum FABP4 and cartilage oligomeric matrix protein (COMP) concentration was quantified. Histological assessment of knee OA and micro-CT analysis of subchondral bone were performed. RESULTS: HFD induced obesity in mice. After 3 months and 6 months of HFD, KO mice showed alleviated cartilage degradation and synovitis, with significantly lower COMP, modified Mankin OA score, and MMP-13/ADAMTS4 expression. After 6 months and 9 months of HFD, KO mice showed less osteophyte formation and subchondral bone sclerosis. Chronic treatment of BMS309403 for 4 months and 6 months significantly alleviated cartilage degradation, but had no effects on the subchondral bone. Knocking out or pharmaceutical inhibition of FABP4 did not have significant effects on lean mice fed with STD. CONCLUSIONS: Knocking out or pharmaceutical inhibition of FABP4 alleviates OA induced by HFD in mice.

A review of the clinical approach to persistent pain following total hip replacement.

Total hip arthroplasty is effective in reducing pain and improving functional outcome for a variety of hip pathologies. Approximately 27% patients, however, complain of pain at 6 months' follow-up following surgery. The pain may worsen over time and can become severe and chronic in around 4% of patients who ultimately require revision surgery. Therefore, it is important for clinicians to comprehensively assess patients undergoing total hip arthroplasty in order to identify the underlying pathology of a painful hip and then offer prompt treatment. Causes of hip pain after total hip arthroplasty are analysed in this article, as well as the systematic approach to evaluation and appropriate diagnostic investigations.

Why do Hong Kong patients need total hip arthroplasty? An analysis of 512 hips from 1998 to 2010.

INTRODUCTION: The number of patients undergoing total hip replacement surgeries has increased as a result of a rise in the ageing population. This study reviewed the demographics and disease spectrum leading to primary total hip replacement in the Chinese population from 1998 to 2010. METHODS: This case series was conducted in a university teaching hospital in Hong Kong. Data from the prospective joint registry of all patients who underwent primary total hip replacement from January 1998 to December 2010 were reviewed. Patients' age and sex, diagnosis, as well as the Harris Hip Scores before operation and at the last follow-up were described. RESULTS: There were 512 primary total hip replacements performed on 419 patients (43.4% males) during the study period. All had clinical follow-up for at least 2 years. The mean age of the patients was 57.6 (standard deviation, 16.6) years. In males, the main aetiology was osteonecrosis (50.9%), ankylosing spondylitis (19.5%), and post-traumatic arthritis (8.5%). For females, it was osteonecrosis (33.0%), primary osteoarthritis (18.8%), and post-traumatic arthritis (15.8%). Alcohol-induced (52.5%) and idiopathic (40.7%) was the most common cause of osteonecrosis in males and females, respectively. The mean preoperative Harris Hip Score and that at last follow-up was 43.9 (standard deviation, 18.3) and 89.7 (standard deviation, 13.0), respectively. CONCLUSIONS: Osteonecrosis was the most common aetiology leading to total hip replacement although there were different causes in both sexes leading to it. The clinical result in terms of Harris Hip Score was good for all patients who required total hip replacement.

Efficacy and safety of hylan G-F 20 injection in treatment of knee osteoarthritis in Chinese patients: results of a prospective, multicentre, longitudinal study.

OBJECTIVE: To study the efficacy and safety of single intra-articular injection of 6-mL hylan G-F 20 in Chinese patients with symptomatic knee osteoarthritis. DESIGN: Prospective case series. SETTING: Six government hospitals in Hong Kong. PATIENTS: Patients with primary knee osteoarthritis were recruited from six government hospitals from 1 October 2010 to 31 May 2012. All patients received 6-mL intra-articular injection of hylan G-F 20. MAIN OUTCOME MEASURES: Pain visual analogue scale, functional visual analogue scale, and 5-point Likert scale on change of pain and function were assessed. Adverse events were checked. Radiographs were taken pre-injection and at 3 months and 1 year. RESULTS: A total of 110 knees of 95 patients with primary knee osteoarthritis were treated. The mean age of the patients was 62 (standard deviation, 9.8) years. All patients completed 1 year of follow-up. The mean pain visual analogue scale, functional visual analogue scale, and Likert value for pain and function showed statistically significant improvements at 6 weeks, 3 months, 6 months, and 1 year compared with the pre-injection values. No significant correlations were found between changes in visual analogue scale and age, body mass index, pre-injection radiological osteoarthritis severity, serum erythrocyte sedimentation rate, or C-reactive protein. Serial radiographs did not show any changes in the radiological severity of knee osteoarthritis. Overall, 16.4% of the patients experienced mild and self-limiting adverse events. CONCLUSION: Hylan G-F 20 is a safe and effective therapy to relieve pain and improve function for up to 1 year in Chinese patients with knee osteoarthritis.

Strontium exerts dual effects on calcium phosphate cement: Accelerating the degradation and enhancing the osteoconductivity both in vitro and in vivo.

Calcium phosphate cements (CPCs) have long been used as osteoconductive bone substitutes in the treatment of bone defects. However, the degradation rate of CPC is typically too slow to match the new bone growth rate. It is known that strontium increases the solubility of hydroxyapatite as well as exerts both anabolic and anticatabolic effects on bone. Therefore, we hypothesized that the incorporation of strontium would accelerate the degradation rate and enhance the osteoconductivity of CPC. In this study, Three groups, CPC (0% Sr-CPC), 5% Sr-CPC, and 10% Sr-CPC, were prepared, with the total molar ratio for Sr/(Sr+Ca) in the cement powder phase being 0, 5, and 10%, respectively. In the immersion test, less residual weight was observed in both 5% Sr-CPC and 10% Sr-CPC groups than CPC group. In addition, a higher osteoblastic cell proliferation rate and alkaline phosphatase activity were obtained in the strontium groups. In a rat femur bone defect model comparing CPC with 10% Sr-CPC, at 2 weeks postoperation, early endochondral ossification was found in the 10% Sr-CPC group, whereas only fibrous tissue was observed in control group; at 4-16 weeks postoperation, progressive osteoconduction toward the cement was observed in both groups. At 32 weeks, a higher peri-cement bone area and reduced cement area were noted in the 10% Sr-CPC group. In conclusion, in the 10% Sr-CPC group, strontium exerts dual effects on CPC: accelerating degradation rate and enhancing osteoconductivity, as shown here both in vitro and in vivo.

Reduction of bladder activity on FDG PET/CT scan in patients with urinary bladder carcinoma. A prospective study with a patient-friendly protocol.

UNLABELLED: Oral hydration with large volume of fluid, high dose of diuretics and maximum bladder distension are frequently required to achieve an adequate urinary FDG clearance in an FDG PET/CT protocol for bladder cancer or pelvic tumour evaluation. Although most patients tolerated these procedures for eliminating urinary FDG activity, these procedures may be still unpleasant. AIM: Is there a more patient-friendly protocol which is less burdensome and yet provides a satisfactory FDG clearance in urine? In this study, we established a patient-friendly FDG PET/CT protocol without compromising urinary FDG clearance. PATIENTS, METHODS: 23 patients with biopsy-proven urinary bladder cancers were recruited to evaluate the effectiveness of this patient-friendly protocol on reducing urinary bladder FDG activity. The patient-friendly protocol includes encouraging patients to take a tolerable amount of fluid, delaying the administration of low dose diuretic, shortening the urine holding time and using delayed imaging. RESULTS: All of the patients tolerated this patient-friendly procedure well. In addition, the patient-friendly protocol was effective in reducing FDG activity in the urine. One hundred percent of primary bladder cancer were visualized on the FDG PET/CT images using this patient-friendly protocol. CONCLUSIONS: This patient-friendly FDG PET/CT protocol is less intrusive yet effective in reducing urinary FDG activity.

The emerging role of endothelin-1 in the pathogenesis of subchondral bone disturbance and osteoarthritis.

Mounting evidence suggests reconceptualizing osteoarthritis (OA) as an inflammatory disorder. Trauma and obesity, the common risk factors of OA, could trigger the local or systemic inflammatory cytokines cascade. Inflammatory bone loss has been well documented; yet it remains largely unknown about the link between the inflammation and hypertrophic changes of subchondral bone seen in OA, such as osteophytosis and sclerosis. Amid a cohort of inflammatory cytokines, endothelin-1 (ET-1) could stimulate the osteoblast-mediated bone formation in both physiological (postnatal growth of trabecular bone) and pathological conditions (bone metastasis of prostate or breast cancer). Also, ET-1 is known as a mitogen and contributes to fibrosis in various organs, e.g., skin, liver, lung, kidney heart and etc., as a result of inflammatory or metabolic disorders. Subchondral bone sclerosis shared the similarity with fibrosis in terms of the overproduction of collagen type I. We postulated that ET-1 might have a hand in the subchondral bone sclerosis of OA. Meanwhile, ET-1 was also able to stimulate the production of matrix metalloproteinase (MMP)-1 and 13 by articular chondrocytes and synoviocytes, by which it might trigger the enzymatic degradation of articular cartilage. Taken together, ET-1 signaling may play a role in destruction of bone-cartilage unit in the pathogenesis of OA; it warrants further investigations to potentiate ET-1 as a novel diagnostic biomarker and therapeutic target for rescue of OA.

Local application of strontium in a calcium phosphate cement system accelerates healing of soft tissue tendon grafts in anterior cruciate ligament reconstruction: experiment using a rabbit model.

BACKGROUND: Healing of soft tissue tendon grafts within the bone tunnel in anterior cruciate ligament (ACL) reconstruction is known to be slower than that of bone-patellar tendon-bone grafts. There are attempts to accelerate healing of the graft within the bone tunnel. One of the methods is the use of strontium-enriched calcium phosphate cement (Sr-CPC). Early results in animal studies have been encouraging, although it is not known whether the accelerated healing was solely caused by the effect of strontium within the cement or by the calcium phosphate cement (CPC) itself. HYPOTHESIS: There would be differences between Sr-CPC and conventional CPC in terms of the effect on healing of soft tissue tendon grafts within the bone tunnels in ACL reconstruction. STUDY DESIGN: Controlled laboratory study. METHODS: A total of 30 single-bundle ACL reconstruction procedures were performed in 15 rabbits with the use of an Achilles tendon allograft. The graft on the left limb was coated with Sr-CPC, while that on the right limb was coated with CPC. Three animals each were sacrificed for histological and histomorphometric analyses at 3, 6, 9, 12, and 24 weeks after surgery. RESULTS: In the Sr-CPC group, early formation of Sharpey fibers was present at 6 weeks after surgery, while early remodeling of a graft-fibrocartilage-bone junction was noted at 12 weeks. In the CPC group, early formation of Sharpey fibers was only found at 9 to 12 weeks after surgery. At 24 weeks, a direct enthesis was found in both groups. According to the histomorphometric score, graft healing in the Sr-CPC group took place 3 weeks faster than that in the CPC group at and before 12 weeks; however, there was no difference between the groups at 24 weeks. CONCLUSION: The local application of strontium in a CPC system leads to accelerated graft healing within the bone tunnels. CLINICAL RELEVANCE: The use of Sr-CPC to enhance graft-bone healing may improve the clinical results of ACL reconstruction using soft tissue tendon grafts.

Bony ankylosis of the knee secondary to heterotopic ossification after total knee arthroplasty: a case report.

We report a case of bony ankylosis of the knee secondary to severe and extensive heterotopic ossification over 9 years after primary total knee arthroplasty in a 71-year-old woman.

Review article: Venous thromboembolism after total joint replacement.

Venous thromboembolism can occur in up to 84% of cases following total joint replacement. It can result in pain, swelling, chronic post-thrombotic syndrome, and pulmonary embolism. Its prevention is vital to the success of the surgery. To achieve a safe and effective prophylaxis, a combination of mechanical and pharmacologic agents should be used. New generation of thromboprophylactic agents target different factors of the coagulation pathway.