Mid-Term Functional and Radiological Outcomes of Total Ankle Replacement in an Asian Cohort.

There are limited studies looking at longer-term outcomes of the total ankle replacement (TAR) in the Asian cohort. Asian ankles are smaller in size and are more varus compared to Western cohorts. Cultural differences also require increased ankle range of motion demands. Therefore, assessment of longer-term functional and radiological outcomes in the Asian cohort is warranted. Between 2007 and 2015, 43 consecutive patients received a 3-component, cementless, unconstrained, fully congruent TAR. Patients were followed up over a mean 8 (range 5-14 years). Preoperative and postoperative AOFAS ankle-hindfoot score (AOFAS-AHS), visual analogue score (VAS), physical and mental component scores of the SF-36 (PCS and MCS respectively) were calculated. European Foot and Ankle Score was also recorded at 8 years. Radiographs were reviewed postoperatively to assess implant position and study evidence of implant loosening and impingement. At 8 years, survivorship was 83.5%. Reasons for implant removal included infection (n = 2) and aseptic loosening (n = 5). AOFAS-AHS, VAS MCS at 8 years postoperatively were comparable to outcomes at 2 years postoperatively (p > .05). PCS at 8 years demonstrated improvement compared to 2 years postoperatively (49 ± 7 vs 42 ± 11, p = .048). Radiographic impingement was noted in 9 cases (20.9%). Radiological loosening was noted in 8 cases with 5 cases requiring revision surgery. At 8 years postoperatively, clinical outcomes, radiological outcomes and survivorship following TAR in an Asian cohort are satisfactory and comparable to that found in existing literature. Long-term studies are required to ascertain survivorship of TAR. Implant design with the Asian cohort in mind may yield improved outcomes.

Biodiversity of magnetotactic bacteria in the tropical marine environment of Singapore revealed by metagenomic analysis.

Most studies on the diversity of magnetotactic bacteria (MTB) have been conducted on samples obtained from the Northern or the Southern hemispheres. The diversity of MTB in tropical Asia near the geo-equator, with a close-to-zero geomagnetic inclination, weak magnetic field and constantly high seawater temperature has never been explored. This study aims to decipher the diversity of MTB in the marine environment of Singapore through shotgun metagenomics. Although MTB has been acknowledged to be ubiquitous in aquatic environments, we did not observe magnetotactic behaviour in the samples. However, we detected the presence and determined the diversity of MTB through bioinformatic analyses. Metagenomic analysis suggested majority of the MTB in the seafloor sediments represents novel MTB taxa that cannot be classified at the species level. The relative abundance of MTB (~0.2-1.69%) in the samples collected from the marine environment of Singapore was found to be substantially lower than studies for other regions. In contrast to other studies, the genera Magnetovibrio and Desulfamplus, but not Magnetococcus, were the dominant MTB. Additionally, we recovered 3 MTB genomic bins that are unclassified at the species level, with Magnetovibrio blakemorei being the closest-associated genome. All the recovered genomic bins contain homologs of at least 5 of the 7 mam genes but lack homologs for mamI, a membrane protein suggested to take part in the magenetosome invagination. This study fills in the knowledge gap of MTB biodiversity in the tropical marine environment near the geo-equator. Our findings will facilitate future research efforts aiming to unravel the ecological roles of MTB in the tropical marine environments as well as to bioprospecting novel MTB that have been adapted to tropical marine environments for biotechnological applications.

Targeted Enrichment of Low-Abundance and Uncharacterized Taxon Members in Complex Microbial Community with Primer-Free FISH Probes Designed from Next Generation Sequencing Dataset.

Methods to obtain high-quality assembled genomic information of rare and unclassified member species in complex microbial communities remain a high priority in microbial ecology. Additionally, the supplementation of three-dimensional spatial information that highlights the morphology and spatial interaction would provide additional insights to its ecological role in the community. Fluorescent in-situ hybridization (FISH) coupling with fluorescence-activated cell sorting (FACS) is a powerful tool that enables the detection, visualization, and separation of low-abundance microbial members in samples containing complex microbial compositions. Here, we have described the workflow from designing the appropriate FISH probes from metagenomics or metatranscriptomics datasets to the preparation and treatment of samples to be used in FISH-FACS procedures.

Association of Elevated Body Mass Index and Outcomes of Arthroscopic Treatment for Osteochondral Lesions of the Talus.

Background: Osteochondral lesions of the talus (OLTs) are a common condition found in patients with chronic ankle pain after previous ankle sprains. Surgical management is indicated after conservative management has failed. Hypothesis/Purpose: This study evaluates the influence of body mass index (BMI) on the early clinical outcomes of arthroscopic debridement and microfracture of OLTs. Methods: A total of 252 patients with symptomatic OLTs who failed conservative management underwent arthroscopic debridement and microfracture of OLTs over the affected ankle between 2007 and 2017. Patients from this cohort were divided into 2 groups based on BMI: the normal BMI group (NB Group) (BMI 18.5-25.0) and overweight and obese BMI group (OB Group) (BMI ≥25). Visual analogue scale (VAS), American Orthopaedic Foot & Ankle Society (AOFAS) hindfoot score, and the physical and mental component summaries of the 36-Item Short-Form Health Survey (PCS and MCS, respectively) were prospectively collected from the cohort during their standard postoperative outpatient follow-up. Results: The NB Group (n=105) and OB Group (n=147) were well matched demographically. The operative duration was significantly shorter for the NB Group compared to the OB Group. Patients from both groups had significant improvements in VAS, AOFAS, and PCS scores postoperatively at 6 and 24 months after surgery (P < .05). Between both groups, patients had comparable VAS, AOFAS, and PCS scores at preoperation, 6 months postoperation, and 24 months postoperation (P > .05). However, MCS in the OB Group was lower at 24 months postoperatively compared with the NB Group (P < .05). The OB Group reported better satisfaction scores (82.4% vs 72.6%, P < .05), and a greater proportion had their expectations met (88.2% vs 77.9%, P < .05). Conclusion: A BMI ≥25 was not associated with worse postoperative pain and functional outcomes, but rather was found to be associated with greater satisfaction and fulfillment. However, patients with BMI ≥25 required longer procedure duration and had poorer MCS scores at 24 months after surgery.Level of Evidence: Level III, retrospective cohort study.

Isolated Synovial Osteochondromatosis in a Completely Enclosed Suprapatellar Pouch: A Rare Case Report.

INTRODUCTION: A complete suprapatellar plica of the knee is a rare condition that separates the suprapatellar pouch from the rest of the knee cavity. Synovial osteochondromatosis is a rare benign monoarticular arthropathy affecting synovial joints that are clinically manifested as intra-articular multiple loose bodies. Isolated synovial osteochondromatosis within a concealed suprapatellar pouch caused by complete suprapatellar plica is an exceptionally rare occurrence. There is no well-documented report in literature on the diagnosis and arthroscopic approach to osteochondromatosis within a separated suprapatellar pouch. CASE REPORT: We report the case of a 61-year-old man who presented with a 3-month history of atraumatic right knee pain localized to the suprapatellar region. Pre-operative magnetic resonance imaging confirmed the presence of loose bodies at the suprapatellar region behind the complete septum. Loose bodies were concealed in a sealed suprapatellar pouch and could not be detected by routine arthroscopic examination of the knee cavity. The suprapatellar plica was punctured and loose bodies trapped within the enclosed suprapatellar compartment were arthroscopically removed. Histological examination of the loose bodies confirmed the diagnosis of osteochondromatosis. The patient postoperatively experienced complete relief of knee pain. CONCLUSION: Successful arthroscopic removal of loose bodies in the separated suprapatellar compartment requires careful study of pre-operative imaging and can effectively be performed throughthe standard anteromedial and anterolateral arthroscopic portals.

Satisfaction Rates Are Low following Revision Total Knee Arthroplasty in Asians Despite Improvements in Patient-Reported Outcome Measures.

With the aging population in Asia and increase in total knee arthroplasty (TKA) utilization rates, the number of patients requiring revision TKA (rTKA) are expected to increase as well. The purpose of this study was to evaluate outcomes and satisfaction rates following rTKA in an Asian population that has unique cultural demands. Registry data of patients who underwent rTKA from 2006 to 2010 and had completed 5 years of follow-up were analyzed. Flexion range, Oxford Knee score (OKS), Knee Society score (KSS), the Short-Form 36 (SF-36), and satisfaction rates were assessed for improvement from preoperative values, as well as by the minimum clinically important difference (MCID) criterion. rTKA was performed in 163 patients. There were significant improvements seen at 2 years postoperatively and these were sustained up to 5 years. The minimal clinically important difference (MCID) criterion for KSS, OKS, and SF-36 physical component score (PCS) was met at 2 and 5 years postoperatively. The overall complication rate was 3.7% at a mean follow-up of 8.4 years. A total of 121 patients (74.2%) were satisfied at 5 years postoperatively. Within our cohort, rTKA results in significantly improved patient-reported outcome measures with a low complication rate of 3.7% at a minimum of 5-year follow-up. Despite these encouraging results, satisfaction rates remain low.

Jujuboside B promotes the death of acute leukemia cell in a RIPK1/RIPK3/MLKL pathway-dependent manner.

Initiation of necroptosis has been considered as a promising strategy for anticancer therapies, especially for eradicating apoptosis-resistant malignant cells. Jujubisode B is a natural saponins extracted from the seeds of Zizyphi Spinosi Semen, and possesses multiple pharmacological activities, including antianxiety, anti-inflammation, antiplatelet aggregation and induction of apoptosis. This study aims to explore the effect of jujuboside B on acute leukemic cells and the underlying mechanisms. Our results showed that jujuboside B inhibited leukemia cell growth in a dose-dependent manner and attenuated the clonogenic ability of U937 cells, concomitant with activation of RIPK1/RIPK3/MLKL pathway; these phenomena were evidently blocked by necroptosis inhibitor (Nec-1). With the help of Molecular Operating Environment (MOE) program, we identified that RIPK1, RIPK3 and MLKL are potential targets of jujuboside B. To the best of our knowledge, this is the first study to provide evidence that jujuboside B possesses antileukemic activity via a mechanism involving activation of RIPK1/RIPK3/MLKL pathway.

Recurrent surgical site infection after anterior cruciate ligament reconstruction: A case report.

BACKGROUND: Surgical site infections following anterior cruciate ligament (ACL) reconstruction are an uncommon but potentially devastating complication. In this study, we present an unusual case of recurrent infection of the knee after an ACL reconstruction, and discuss the importance of accurate diagnosis and appropriate management, including the issue of graft preservation versus removal. CASE SUMMARY: A 33-year-old gentleman underwent ACL reconstruction using a hamstring tendon autograft with suspensory Endobutton fixation to the distal femur and an interference screw fixation to the proximal tibia. Four years after ACL reconstruction, he developed an abscess over the proximal tibia and underwent incision and drainage. Remnant suture material was found at the base of the abscess and was removed. Five years later, he re-presented with a lateral distal thigh abscess that encroached the femoral tunnel. He underwent incision and drainage of the abscess which was later complicated by a chronic discharging sinus. Repeated magnetic resonance imaging revealed a fistulous communication between the lateral thigh wound extending toward the femoral tunnel with suggestion of osteomyelitis. Decision was made for a second surgery and the patient was counselled about the need for graft removal should there be intra-articular involvement. Knee arthroscopy revealed the graft to be intact with no evidence of intra-articular involvement. As such, the decision was made to retain the ACL graft. Re-debridement, excision of the sinus tract and removal of Endobutton was also performed in the same setting. Joint fluid cultures did not grow bacteria. However, tissue cultures from the femoral tunnel abscess grew Enterobacter cloacae complex, similar to what grew in tissue cultures from the tibial abscess five years earlier. In view of the recurrent and indolent nature of the infection, antibiotic therapy was escalated from Clindamycin to Ertapenem. He completed a six-week course of intravenous antibiotics and has been well for six months since surgery, with excellent knee function and no evidence of any further infection. CONCLUSION: Prompt and accurate diagnosis of surgical site infection following ACL reconstruction, including the exclusion of intra-articular involvement, is important for timely and appropriate treatment. Arthroscopic debridement and removal of implant with graft preservation, together with a course of antibiotics, is a suitable treatment option for extra-articular knee infections following ACL reconstruction.

Primer-free FISH probes from metagenomics/metatranscriptomics data permit the study of uncharacterised taxa in complex microbial communities.

Methods for the study of member species in complex microbial communities remain a high priority, particularly for rare and/or novel member species that might play an important ecological role. Specifically, methods that link genomic information of member species with its spatial structure are lacking. This study adopts an integrative workflow that permits the characterisation of previously unclassified bacterial taxa from microbiomes through: (1) imaging of the spatial structure; (2) taxonomic classification and (3) genome recovery. Our study attempts to bridge the gaps between metagenomics/metatranscriptomics and high-resolution biomass imaging methods by developing new fluorescence in situ hybridisation (FISH) probes-termed as R-Probes-from shotgun reads that harbour hypervariable regions of the 16S rRNA gene. The sample-centric design of R-Probes means that probes can directly hybridise to OTUs as detected in shotgun sequencing surveys. The primer-free probe design captures larger microbial diversity as compared to canonical probes. R-Probes were designed from deep-sequenced RNA-Seq datasets for both FISH imaging and FISH-Fluorescence activated cell sorting (FISH-FACS). FISH-FACS was used for target enrichment of previously unclassified bacterial taxa prior to downstream multiple displacement amplification (MDA), genomic sequencing and genome recovery. After validation of the workflow on an axenic isolate of Thauera species, the techniques were applied to investigate two previously uncharacterised taxa from a tropical full-scale activated sludge community. In some instances, probe design on the hypervariable region allowed differentiation to the species level. Collectively, the workflow can be readily applied to microbiomes for which shotgun nucleic acid survey data is available.

Early Functional, Radiological Outcomes and Satisfaction Rates of Total Ankle Arthroplasty in an Asian Population.

BACKGROUND: Few studies have outlined the outcomes and complications in Asians undergoing total ankle arthroplasty. This study reports the functional, radiological outcomes and satisfaction rates in our Asian population. METHODS: Patients who underwent primary total ankle arthroplasty from 2007 to 2013 were recruited. Outcomes evaluated were the AOFAS Ankle-Hindfoot Score (AHS), Visual Analogue Scale (VAS), and the Short Form 36 (SF-36)questionnaire. Outcome scores were collected prospectively up to 2 years. Patient satisfaction was evaluated on a 6-point scale based on North American Spine Society Low Back Pain Instrument and classified as satisfied or unsatisfied. RESULTS: Forty-one patients underwent primary total ankle arthroplasty. All patients experienced improvements in AHS, VAS, and Mental Component Summary score of the SF-36 at both 6-month and 2-year postoperative interval. The mean AHS score improved from 35 ± 19 points preoperatively to 64 ± 24 at 6 months (P<.001) and 72 ± 26 at 24 months (P <.001). VAS scores improved from 7 ± 2 preoperatively to 3 ± 3 (P < .001) at 6 and 24 months. The Physical Component Summary (PCS) of the SF-36 has an established minimum clinically important difference (MCID) of 5. The mean improvement in PCS in our cohort met this MCID for the PCS; 63% and 71% of patients were satisfied with the procedure at 6 months and 2 years postoperatively, respectively. Revision rate in this series was 9.7%. CONCLUSION: Total ankle arthroplasty has good patient satisfaction rates, with favorable early clinical outcome in Asian patients. LEVELS OF EVIDENCE: Therapeutic, Level II.

Predictors of Midterm Outcomes after Medial Unicompartmental Knee Arthroplasty in Asians.

BACKGROUND: This study was designed to evaluate predictors of good outcomes following medial unicompartmental knee arthroplasty (UKA) in Asian patients. METHODS: Registry data of patients who underwent primary unilateral medial UKA from 2006 to 2011 were collected. Outcomes studied were the Oxford Knee Score (OKS) and the Physical Component Score (PCS) of the Short Form 36 (SF-36) questionnaire. These outcome scores were collected prospectively, pre- and postoperatively up to 5 years. Good outcome was defined as an overall improvement in score greater than or equal to the minimal clinically important difference (MCID). The MCID for the OKS was 5 while the MCID for the PCS was 10. Regression analysis was used to identify predictors of good outcomes following medial UKA. RESULTS: Primary medial UKA was performed in 1,075 patients. Higher (poorer) preoperative OKS (odds ratio [OR], 1.27; p < 0.001), lower (poorer) preoperative PCS (OR, 1.08; p < 0.001), lower (poorer) preoperative Knee Society Knee Score (KSKS; OR, 1.02; p < 0.001) and higher (better) preoperative SF-36 Mental Component Score (MCS; OR, 1.02; p < 0.001) were significant predictors of good outcomes. CONCLUSIONS: Patients with poorer OKS, PCS and KSKS and better SF-36 MCS preoperatively tended to achieve good outcomes by the MCID criterion at 5 years following the index surgery.

Total hip arthroplasty for surgical management of advanced tuberculous hip arthritis: Case report.

Tuberculosis (TB) arthritis of the hip is a debilitating disease that often results in severe cartilage destruction and degeneration of the hip. In advanced cases, arthrodesis of the hip confers benefits to the young, high-demand and active patient. However, many of these patients go on to develop degenerative arthritis of the spine, ipsilateral knee and contralateral hip, necessitating the need for a conversion to total hip arthroplasty. Conversion of a previously fused hip to a total hip arthroplasty presents as a surgical challenge due to altered anatomy, muscle atrophy, previous surgery and implants, neighbouring joint arthritis and limb length discrepancy. We report a case of advanced TB arthritis of the hip joint in a middle-aged Singaporean Chinese gentleman with a significant past medical history of miliary tuberculosis and previous hip arthrodesis. Considerations in pre-operative planning, surgical approaches and potential pitfalls are discussed and the operative technique utilized and post-operative rehabilitative regime of this patient is described. This case highlights the necessity of pre-operative planning and the operative technique used in the conversion of a previous hip arthrodesis to a total hip arthroplasty in a case of TB hip arthritis.

Bicompartmental versus total knee arthroplasty for medial and patellofemoral osteoarthritis.

PURPOSE: To compare the outcome of bicompartmental knee arthroplasty (BKA) versus total knee arthroplasty (TKA) in patients with medial and patellofemoral knee osteoarthritis. METHODS: Records of 17 women and 10 men with medial and patellofemoral osteoarthritis of the knee who underwent BKA (n=15) or TKA (n=12) were reviewed. All surgeries were performed by the same surgeon. Patient haemoglobin level, length of hospital stay, range of motion, and visual analogue score for pain were recorded, as were the Knee Society Score, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and the SF-36 score. RESULTS: Patients treated with BKA were younger than those treated with TKA (mean age, 52 vs. 60 years; p=0.006). BKA resulted in longer mean operating time (99 vs. 85 minutes, p=0.025), less mean intra-operative blood loss (reduction in haemoglobin level) [1.2 vs. 2.4 g/dL, p=0.003), and greater mean postoperative range of movement (125 vs. 116 degrees, p=0.019). The mean Knee Society scores, WOMAC, and SF-36 scores in both groups were not significantly different. There was no instance of implant loosening, peri-prosthetic fractures, patellar subluxation, and dislocation. CONCLUSION: Short-term outcome of BKA and TKA was comparable.