Introduction: The purpose of this study was to investigate the relationship between central sensitization (CS) and neuropathic pain (NP) and whether CS and NP were associated with patient-reported outcome measures (PROMs) in patients undergoing total knee arthroplasty (TKA). Methods: A total of 312 patients who underwent primary TKA for end stage knee OA were enrolled. CS was defined as a patient with a score of 40 or higher using central sensitization inventory. NP was defined as a patient with a score of 12 or more using pain detect questionnaire. PROMs were evaluated using the WOMAC score preoperatively and at postoperative 1 year. The patients were divided into 4 groups, group 1 with CS and NP positive, group 2 with only CS positive, group 3 with only NP positive, and group 4 with CS and NP negative. Results: There were 90 patients(28.5%) with both CS and NP positive, 32 patients(10.1%) with only CS positive, and 83 patients(26.3%) with only NP positive and 107 patients(35.1%) with CS and NP negative. All WOMAC subscores were significantly inferior to group 1,2 and 3 before surgery compared to group 4 (all p<0.05). Worse preoperative WOMAC scores continued until postoperative 1 year in the group 1,2,3 compared to group 4 (all p<0.05). Conclusion: CS and NP symptom were factors related to higher postoperative pain levels and inferior PROMs in patients undergoing primary TKA. Those with both CS and NP positive showed an inferior postoperative PROM compared to only NP positive, and both CS and NP negative.

Knee ankylosis is an uncommon condition where a patients knee is fused at a certain angle usually due to infective or post-traumatic events. We describe a case report and systematic review of literature. A 54 year old patient presented with ankylosed knee due to old healed tuberculosis from 30 years ago. The left knee was fused at 30 degrees flexion with the patella fused to the femoral trochlea. Range of movement was 0 degrees. Patient requested surgical intervention due to painful ankylosis and difficulty with activities of daily living. A hinge knee system with sleeve was used. We templated the tibial canal diameter to be less than 10mm and therefore elected not to use an offset stem but instead a sleeve construct which has equivalent stability due to the 3D printed coating and milling prior to insertion.
Systematic review of the literature demonstrated that in the small number of cases that had been performed worldwide, all patients had an increased range of motion post operatively (P < 0.01). In 36 percent of cases reviewed one or more subsequent treatments were performed. At the last follow-up, range of motion had increased to a mean of 81° (P < 0.0001).
Persistent knee stiffness, flexion contracture and difficulty with soft tissue coverage after this type of surgery are serious complications which are often resistant to treatment

Objective:
The study is aimed to compare drain application versus non-drain application in total knee replacement.

Methods:
This study was conducted at one centre. It was designed as a retrospective observational cohort study to assess the use of drains in patients with primary total knee arthroplasty.

Results:
The hemoglobin level was retrievable for (67.9%) , mean 12.6 g/dl, std: 1.4 g/dl) and the post-operative HB was reported; from which the average change (drop) in the HB ranged between 0 and 4 g/dl (mean 1.6 g/dl, std: 0.93 g/dl. There was a significant difference in relation to the use of Tranexamic Acid,
The average drop in HB : was higher for those with drain, at about 1.8 g/dl , while for those without drain was 1.3 g/dl
It has significantly increased the hospital stay ; which averaged for those without drain 5.3 days , while for cases where the drain was used, averaged 10.6 days.

“Tourniquet time”: was longer for those with drain averaged 94.5 mins , while for those without drain 74.4 mins
“Frequency of dressing change” during hospital stay was higher for those with drain; mean: 1.6 times , while for those without drain averaged 0.9 times

Conclusions:
Our study indicated that closed suction drainage increases the transfusion requirements, LOS after elective knee arthroplasty and has no major benefits.
We recommend the use of Tranexamic Acid (TXA) routinely as it demonstrated less need for Post Op blood and shorter Length of Stay (LOS).

Objective: The aim of this study is to assess the effect of intravenous tranexamic acid (IV-TXA) on perioperative blood loss (BL) in primary total knee arthroplasty (TKA). Methods: A retrospective data review for patients who underwent TKA at a tertiary care institute from January 2017 to October 2018 was performed. Patients who received IV-TXA were compared to a control group (non-TXA). Patients demographics, preoperative hemoglobin (Hb) and hematocrit, postoperative (postop) day 1 hematocrit and Hb levels, blood transfusion, timing of TXA administration, postop use of drains, postop complications, length of hospital stay (LHS), and the use of anticoagulants were collected. Final postop BL loss (CBL) was calculated using “Gross formula”. Results: 67 patients were included in the study with the mean age of 65 ± 7years. Tourniquet was used in all patients. 37 (55.22%) vs 30 (44.8%) patients present in TXA vs Non-TXA group. Postop Hb (g/dL) where higher in TXA group (11.4 ± 1.5 vs. 10.7 ± 1.4, p=0.04). CBL showed no statistical significance between the two groups (p>0.05). The LHS was 7 days vs. 11 days, (p<0.001) in IV-TXA and Non-TXA group respectively. In IV-TXA group, two patients required blood transfusion postoperatively and one patient developed pulmonary embolism. In non-TXA group, one patient (2.7%) developed supraventricular tachycardia. Conclusion: Preoperative administration of TXA is associated with significant reduction in hospital length of stay. However, there was no statistical significance in the CBL and rate of blood transfusion between the two groups. More study needed to assess side-effects of TXA.

Aims:
Intraoperative acquisition of representative tissue samples are essential during revision arthroplasty of the infected total knee arthroplasty (TKA). While the number of intraoperative tissue samples to identify the organism are well described in the literature, there is still a paucity of evidence regarding the location of positive intraoperative samples and its correlation to postoperative outcome.

Material and Methods:
Forty-two patients who had failed one-stage revision TKA for periprosthetic joint infection (PJI) were identified between January 2010 to December 2017. From the same time interval, a control group of patients who had a successful one-stage revision TKA without any revision surgery for the management of PJI were randomly selected. The location of positive intraoperative tissue samples were categorized as 1) soft tissue, 2) interface between bone and prosthesis and 3) intramedullary. Statistical analyses were performed to analyze if the location of tissue samples affects the postoperative outcome.

Results:
A positive intraoperative intramedullary sample was associated with a higher risk of re-infection after one-stage revision TKA (p=0.0009). Weight >100 kg and higher CCI (p < 0.05) were also significant predictors for failure. The presence of polymicrobial organism was not a statistically significant risk factor for predicting failure of the one-stage revision TKA (p=0.468).

Conclusion:
This is the first study identifying that positive intramedullary sample has significant impact on the outcome and may benefit from longer postoperative antibiotic therapy for the treatment of one-stage exchange arthroplasty with intraoperative intramedullary positive culture.

Background: SPECT/CT combines scintigraphy with a CT scan forming a 3D-reconstruction of bone-tracer uptake patterns. It has become a fundamental component of the work-up of a painful total knee arthroplasty (TKA). The addition of an arthrogram is purported to improve its diagnostic yield.
Objectives: The aim of this study was to assess the enhancement of a SPECT CT’s sensitivity and specificity for diagnosing aseptic loosening in a painful total knee replacement with addition of an arthrogram.
Methods: PubMed, Embase and Scopus were searched in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Included studies compared results of SPECT/CT +/- arthrogram against an appropriate reference standard for diagnosing TKA aseptic loosening. The quality of included studies was independently assessed using the QUADAS-2 tool.
Results: 160 abstracts were identified by our search strategy. Of these, six studies compromising 472 patients met our inclusion criteria. All included studies used operative findings or a period of clinical and radiological observation as reference standards. SPECT/CT arthrogram was more sensitive in identifying aseptic loosening of knee prostheses, it also provided greater specificity for excluding its diagnosis.
Conclusion: The amalgamated results of included studies of use of SPECT/CT demonstrate it is the best test in helping out rule aseptic loosening in patients with painful TKAs (specificity 97% versus 85%). It is also a more sensitive test (sensitivity 78% versus 75%) Considering the potential morbidity of injection of contrast into the prosthetic joint, addition of arthrogram to SPECT/CT is not beneficial and potentially harmful.

Introduction: The studies on the relationship between central sensitization (CS) and patient-reported outcome measures (PROMs) including postoperative pain are still lacking in patients undergoing unicompartmental knee arthroplasty (UKA). Therefore, the purpose of this study was to investigate whether CS was associated with postoperative pain and PROMs after (UKA). Methods: Between 2014 and 2019, 122 cases (122 patients) of UKA performed by a single surgeon were included in this study with a minimum follow-up of two years. CS was evaluated preoperatively using a Central Sensitization Inventory (CSI). Based on the CSI score of 40, it was divided into CS and non-CS groups. There were 96 patients (78.7%) in non-CS group, while the CS group consisted of 26 patients (21.3%). PROMs were also evaluated by the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score and forgotten joint score (FJS). Results: The CSI score of the CS group was 45, and the average of the non-CS group was 22. The preoperative WOMAC pain, function and total score were significantly worse in the CS group (Pain: 18.4 vs 15.8, Function 46.0 vs 36.2, Total: 69.9 vs 56.0, all p<0.05). This trend continued at 2 years after surgery (Pain: 3.4 vs 1.6, Function 14.8 vs 8.8, Total: 19.6 vs 11.4, all p<0.05). FJS at 2 years after surgery was also significantly lower in the CS group than in the non-CS group (64.4 vs 72.8, p<0.05). Conclusion: CS is an associated factor for persistent postoperative pain and greater knee joint awareness in patients undergoing UKA.

Introduction: Infection after Unicompartmental Knee Arthroplasty (UKA) is a rare but severe complication, with a lower incidence compared to a Total Knee Arthroplasty (TKA). Scant evidence exists regarding treatment of periprosthetic joint infection (PJI) after UKA, particularly with Debridment, Irrigation, polyethylene liner exchange with Implant Retention (DAIR). The purpose of this study is to present the results of the largest multicenter clinical review of joint infection after UKA treated with DAIR.
Materials and Methods: In this retrospective study, data were collated between January 2016 and December 2019. Twenty patients had early infections and were submitted to DAIR and intravenous antibiotic therapy followed by oral treatment.
Results: DAIR showed an overall survivorship free from septic reoperation of 84.2%, with an overall survivorship free from all-cause reoperation of 78.95%. DAIR had higher success rates compared to earlier published data for UKA, and significantly better survival than DAIR in TKA.
Three patients underwent a second DAIR procedure successfully: one of these patients had a TKA for medial osteoarthritis and one was lost at follow-up (FU). No recurrences were evident at the last FU.
Conclusion: Following UKA a significantly higher proportion of the knee joint remains of native tissue. This may explain lower rate of infection in comparison to TKA, but may alter the response to the rare challenge of infection. Surgeons might wish to adopt a slightly different strategy than in TKA infection, with more emphasis on the less invasive and potentially more successful DAIR procedure.

Purpose: Unicompartmental knee arthroplasty (UKA) is an effective treatment for late knee osteoarthritis (OA). However, its indications remain controversial. Young age (< 60 years) has been associated with worse outcomes. The goal of this systematic review and meta-analysis is to study the effect of age on UKA outcomes. Methods: The primary objective was to compare the UKA revision rate in young patients with that of old patients, using the age thresholds of 60 and 55 years. Secondary objectives were patient-reported outcome measures (PROMs) and implant design. PubMed, Ovid, Web of Science, Google Scholar, and Cochrane library were searched in June 2021. This review was conducted in accordance with the PRISMA guidelines (PROSPERO: CRD42021248322). Results: A total of 12 observational studies with 6,448 knees were included. A mean MINORS score of 19 was assigned to the review. The mean age of patients was 64.32 years, with follow-up ranging from 0.2 to 15 years. There was no significant difference in revision rate, incident or PROMs between young and old patients in the analysis for each age threshold. Further sub-analysis adjusting for implant type in mobile- and fixed-bearing prostheses also showed similar results between those above and under 60 and 55 years. Conclusion: Young age was not associated with a higher revision rate or lower functional scores. Thus, this review provides evidence that performing UKA at a younger age (< 60 years) should not be considered suboptimal. However, this finding should be applied in context, as other confounding factors need to be explored.

Rice bodies are materials with an amorphous nucleus and a fibrin layer found floating in the synovial space and bursa. These bodies have often been detected in patients with rheumatoid disorder and tuberculous infection. Other etiologies include non-tuberculous mycobacterial and fungal infection, juvenile arthritis, the onset of adult Still’s disease, systemic lupus erythematosus, seronegative arthritis, and non-specific arthritis. Although the etiology and pathogenesis of rice bodies are not yet fully understood, it has been hypothesized that they might be caused by chronic inflammation originating from the synovium. However to the best of our knowledge, rice body formation in Bacillus cereus periprosthetic joint infection has not been previously reported. Bacillus cereus is a widespread organism in nature and a member of the B. cereus group of catalase positive, aerobic, spore-forming, Gram-positive bacilli. B. cereus found in blood is often dismissed as a contaminant in the absence of repeated isolation from multiple cultures. Soft tissue and bone infection due to B. cereus have been associated with trauma, intravenous drug use, and an immunocompromised state. We report a case of very late periprosthetic infection of the knee joint caused by B. cereus, which occurred 9 years after total knee replacement in the absence of recent trauma or intervention. Patient underwent right knee arthrotomy washout and change of insert and subsequently done removal of implant and fusion of right knee. This is rare case of very late prosthetic joint infection by B. cereus, necessitating caution to differentiate true infection from contamination of B. cereus.

Introduction: The medial unicompartmental knee arthroplasty (mUKA) is a successful treatment for endstage, symptomatic anteromedial osteoarthritis/osteonecrosis. Aim: To describe the evolution and the outcome of a cohort of patients that underwent mUKA. Methods: 116 mUKA were performed by one of the authors in a select cohort of 105 patients since 2017 to 2022, with a minimum of 4 months follow-up. The data were collected and kept confidentially. Results: There were 102 (87.9%) cemented and 14 (12,1%) cementless implants. Age average was 66.7, mostly women 86 (74,1%) and mostly left knees operations (50,9%). The Oxford knee score improved from a preoperative mean of 23,4 to 42,3 at the last follow-up with an average range-of-motion of 0.1-126.7º. There were 3 (2,6%) complications: popliteal artery injury and infection in the same patient, and meniscal bearing oversizing in another. In the first patient, popliteal artery laceration was repaired by end-to-end vascular bypass with a large saphenous vein autograft and the infection was treated with a two-stage revision to total knee arthroplasty. Revision UKA was performed in the other patient. We acknowledge some limitations to the study. It is a small cohort and a short time follow-up. The strengths are that includes a consecutive series of both cemented and cementless mUKA, both performed with the same indications and recommended surgical technique by the same nondesigner surgeon. Conclusion: Further research is needed to assess the potential long-term benefits of mUKA. Appropriate patient selection and execution of surgical technique are crucial to optimizing patient results.