Introduction. The goal of treating artificial joint infection is to relieve the infection quickly and re-establish joint function, but many patients have underlying diseases, and treatment is often made problematic by the diversity of the causative bacteria. In this study we assessed the factor that enabled revision arthroplasty in patients with infection after artificial hip arthroplasty, including bipolar hip arthroplasty, in our hospital. Subjectives and Methods. The subjects were the 16 patients (16 hips) with infection after hip arthroplasty who were treated in our hospital during the past 10 years. There were 7 males and 9 females, and their mean age was 69.8 years. Primary total hip arthroplasty had been performed in 6 hips, revision hip arthroplasty in 8 hips, and bipolar hip arthroplasty in 2 hips. Infected implants were removed as soon as possible and delayed reimplantations with an interval antibiotic spacer were attempted in all patients. 9 hips were successful in reimplantation (reimplantation group) and 7 hips were impossible (No reimplantation group). In this study we investigated age, complications, body mass index (BMI), body temperature, pain, rate of resistant bacteria, number of hip surgery prior to infection and clinical manifestations compared to two groups. Results. Age, rate of resistant bacteria, body temperature and number of surgery were not significantly different compared to two groups. In no reimplantation group BMI was significantly low. Also, local heat, redness and fistula as clinical manifestations had been observed in most no reimplantation hips. Conversely there were no associations with the presence or absence of swelling, tenderness and pain in initial consultation. Discussion. Garvin et al. have reported a two-stage reimplantation success rate for infected artificial joints of 91%. However, our results comparatively showed lower successful rate. It is suggested that lower BMI, presence of local heat, redness and fistulation were risk factors for reimplantation. Especially, these clinical manifestations means that the infection widely invade to subcutaneous tissue. Therefore, we should performed debridement and antibiotic treatment more carefully

Aims. Sickle cell disease (SCD) is an autosomal recessive inherited condition that presents with a number of clinical manifestations that include musculoskeletal manifestations (MM). MM may present differently in different individuals and settings and the predictors are not well known. Herein, we aimed at determining the predictors of MM in patients with SCD at the University Teaching Hospital, Lusaka, Zambia. Methods. An unmatched case-control study was conducted between January and May 2019 in children below the age of 16 years. In all, 57 cases and 114 controls were obtained by systematic sampling method. A structured questionnaire was used to collect data. The different MM were identified, staged, and classified according to the Standard Orthopaedic Classification Systems using radiological and laboratory investigations. The data was entered in Epidata version 3.1 and exported to STATA 15 for analysis. Multiple logistic regression was used to determine predictors and predictive margins were used to determine the probability of MM. Results. The cases were older median age 9.5 (interquartile range (IQR) 7 to 12) years compared to controls 7 (IQR 4 to 11) years; p = 0.003. After multivariate logistic regression, increase in age (adjusted odds ratio (AOR) = 1.2, 95% confidence interval (CI) 1.04 to 1.45; p = 0.043), increase in the frequency of vaso-occlusive crisis (VOC) (AOR = 1.3, 95% CI 1.09 to 1.52; p = 0.009) and increase in percentage of haemoglobin S (HbS) (AOR = 1.18, 95% CI 1.09 to 1.29; p < 0.001) were significant predictors of MM. Predictive margins showed that for a 16-year-old the average probability of having MM would be 51 percentage points higher than that of a two-year-old. Conclusion. Increase in age, frequency of VOC, and an increase in the percentage of HbS were significant predictors of MM. These predictors maybe useful to clinicians in determining children who are at risk. Cite this article: Bone Joint Open 2020;1-6:175–181

Instability after TKA can result from ligament imbalance, attenuation of soft tissues, or ligament disruption. Flexion instability has been reported after both CR and PS TKA. However, the clinical manifestations of flexion instability can be quite variable. Symptoms of flexion instability include pain and swelling after activity. Bracing occasionally can be helpful. Revision options to treat flexion instability include tibial insert exchange and revision to increase constraint. However, more favorable results have been reported using implants with varus-valgus constraint. Constrained mechanisms include a varus-valgus constrained PS post or hinge. The constrained post relies on the mechanical function of the post to provide stability which may deform or wear in-vivo leading to recurrent instability if used for a completely deficient collateral ligament. The hinge, which provides more rigid constraint, is indicated for collateral ligament deficiency. However, the additional constraint also results in greater bone-implant interface stresses, which may be mitigated by use of stem fixation to minimise risk of loosening

Taper corrosion and Trunionnosis are recognized as a major complication of hip replacement surgery presenting in a variety of clinical manifestations commonly referred to as Adverse Local Tissue Reactions. Metal debris is produced through Mechanically Assisted Crevice Corrosion with several implicating factors including mixed alloy components, taper design, head offset, femoral head size, and taper impaction techniques (including magnitude of force, control of alignment and environmental factors). Our project has focused singularly on taper impaction techniques and surgeon controlled factors, as we believe the process of head impaction unto a trunnion is non-standardized, which often times dooms the trunionn to failure. We have contemplated a standardization process, such that given the right tool, the surgeon can control the quality of the taper interlock, which may produce a “cold weld” or perfect taper interlock, eliminate micro motion, mechanically assisted crevice corrosion, and trunionnosis. We have considered four specific problems with current head to trunionn impaction techniques: 1. The magnitude of applied force is uncontrolled, haphazard, and non-standardized. 2. Non-axial application of force is the norm, which produces canting, leading to micro-motion and tribocorrosion. 3. The transfer of energy from the head to the trunionn interface is highly inefficient, such that the energy produced by the surgeon is mostly dissipated in a non-constrained system. 4. No in vitro studies exist to guide surgeons as to the magnitude of force required for a proper interlock. Regardless of the design, including taper angles, larger heads, offset heads, mixed alloy components, shorter and slimmer trunionns there is a widespread problem with the process of head impaction onto the trunionn and the engagement of the modular taper interface that dooms the trunionn interface to failure. The deficiencies noted in current techniques are addressed with a simple tool and minor modification of the femoral stem. We present a new concept/apparatus for head to trunionn taper assembly that fully controls the magnitude and direction of assembly force within a constrained, dry and contaminant free environment. This tool allows application of a perfectly axial and high insertional forces without risk of damage to the femoral stem/bone interface to obtain a cold weld and perfect taper interlock with no chance for canting, micro motion and tribocorrosion. The concept has been verified through several prototypes and can be adopted in order to standardize the process of taper assembly, making this procedure independent of surgeon skill and strength, and minimizing the incidence of trunionnosis

Aim. Spinal implant-associated infections (SIAI) require combined surgical and antimicrobial treatment and prolonged hospital stay. We evaluated the clinical, laboratory, microbiological and radiological characteristics and treatment approaches in patients with SIAI. Method. Consecutive adult patients with SIAI treated between 2015 and 2017 were prosepctively included. SIAI was defined by: (i) significant microbial growth from intraoperative tissue or sonication fluid, (ii) intraoperative purulence, secondary wound dehiscence or implant on view, (iii) radiographic evidence of infection and fever (>38°C) without other recognized cause, increasing back pain or neurologic impairment, (iv) peri-implant tissue inflammation in histopathology. Results. A total of 60 patients were included, median age was 66 years (range, 28–91 years), 29 (48%) were males. The most common reason for spinal stabilization was spinal canal stenosis in 20 patients (33%) followed by vertebral degenerative disease in 14 (23%). 31 patients (52%) had one or more previous spine surgeries (range, 1–4 interventions). The anatomic site of spinal instrumentation was lumbar/sacral in 26 (43%), cervical in 23 patients (38%), thoracic in 11 (18%). The median number of fused segments was 5 (range, 1–14). Clinical manifestations included wound healing disturbance in 41 patients (68%), increasing back pain in 15 (25%), neurologic impairment in 12 patients (20%) and fever in 14 (23%). Serum CRP was abnormal (>10mg/l) in 46/59 patients (78%). Most (n=54) infections were postsurgical, 5 were hematogenous and 1 was contiguous. Imaging showed epidural, intraspinal or paravertebral abscess in 21/42 patients (50%), implant failure in 9 (21%) and implant loosening in 3 cases (7%). Monomicrobial infection was observed in 41 (68%), polymicrobial in 16 (27%) patients and culture-negative infection in 3 episodes (5%). Predominant causative pathogens were S. aureus (n=19), coagulase-negative staphylococci (n=18) and gram-negative rods (n=16). Surgery was performed in all patients including debridement and implant retention in 39 patients (65%), partial implant exchange in 10 (17%) and complete exchange in 11 (18%). Antimicrobial treatment included biofilm-active substances in 52 patients (87%). The median duration of antimicrobial therapy was 11,7 weeks (range, 6–12 weeks). 14 patients (23%) recieved suppressive therapy for a median duration of 9 months (range 3–12 months). Conclusions. Most SIAI were seen in lumbar/sacral segments and wound healing disturbance and increasing back pain were the most common manifestations. In 95% the causative pathogen was isolated, predominantly staphylococci. In half of the episodes, abscesses were present. All patients underwent surgery and biofilm-active antibiotics were administered in 87%

Aim. The purpose of this study is to evaluate the safety profile and impact on functional results of surgical debridement performed in the early postoperative by comparing them with patients that undergone uncomplicated total joint arthroplasty. Method. This is a retrospective case-control study. Patients that underwent debridement with prosthesis preservation for suspected acute postoperative infection of total hip or knee arthroplasty between 2010–2014 were included. Controls were randomly selected (1:2 ratio) from a list of primary arthroplasty patients in the same time period matching for articulation, age, gender, ASA score, BMI and follow-up time. Infection status, success of treatment and medical-surgical complications were investigated and all patients were assessed using Hip disability and Osteoarthritis Outcome Score(HOOS) or Knee injury and Osteoarthritis Outcome Score(KOOS). Results. Twenty-nine patients were included at a mean follow-up of 42.3 (18–66) months. Infection was confirmed in all but one patient. There was one related death (multiorgan failure) and three cases progressed to chronic infection requiring further two-stage revision – overall success rate was 86.2%. No other medical-surgical complications related to the procedure were noted. Of the 25 that achieved infection eradication, only 19 were available to functional evaluation. Two had unrelated complications that preclude functional evaluation (one periprosthetic fracture and one contralateral amputation) and four patients died from unrelated causes (all of them without evidence of infection relapse after at least two years follow-up). Comparing functional result of the 19 patients available with 38 uncomplicated controls, there were no significant differences between groups: Pain– 91.7±86.5 vs. 87.5±14.2; Other symptoms– 90.6±7.7 vs. 88.6±9.2; Activities of day living– 85.7±8.6 vs. 82.7±15.3; Sport– 62.3±13.2 vs. 56.6±16.1; Quality of life– 78.4±16.3 vs. 77±14.6. Conclusions. Early diagnosis of acute periprosthetic infection can be extremely difficult because clinical manifestations can be very subtle. On one hand, waiting for obvious findings may delay proper therapeutic intervention leading to chronicity. On the other hand, fear of adding morbidity frequently delays decision. The results of this study demonstrate that early surgical debridement is safe, effective and brings no long-term deleterious implications on functional results. The authors believe that when facing a complicated wound healing in early postoperative period, a low threshold to assume a possible infection diagnosis is beneficial

INTRODUCTION. The uncertainty of the biological effects of wear and corrosion from Metal-on-metal (MoM) implants has initiated a debate on their safety and use. Generally, the release of wear particles from MoM hip implants can clinically manifest in aseptic osteolysis. In our study, the effect of MoM-wear particles and particle originated Co and Cr ions on mesenchymal stromal cells (MSCs) was investigated [1]. The lead hypotheses were that (1) dissociated Co and Cr, originated from MoM-wear particles, accumulate in the bone marrow and (2) apparently impair the osteogenic function of local MSCs. This impairment could be one element contributing to the manifestation of periprosthetic osteolyses. METHODS. The study was approved by the local ethical committee (EA1/194/13); all donors gave written informed consent. Blood (B), Synovial fluid (SF) periprosthetic tissue (PT) and bone marrow (BM) were collected from patients with at least one osteolytic lesion, undergoing a revision of a MoM hip implant. Patients undergoing primary THA served as controls. Metal wear particles were isolated from PT by enzymatic digestion and their size and shape characterized by transmission electron microscopy (TEM). Local and systemic levels of Co and Cr were analyzed by graphite furnace atomic absorption spectroscopy. MoM-MSCs and control-MSCs were isolated from BM for in vitro assessment of their viability, proliferation, migration and multilineage differentiation. In addition, control-MSCs were in vitro exposed to Co and Cr ions and assessed for their viability, proliferation and osteogenic differentiation. RESULTS. We confirmed the presence of nanoscaled particles that appeared heterogeneous in size and shape (mean diameter: 34.7 ± 16.2 nm; n = 64). Second, we confirmed the exposure to Co and Cr and quantified its particulate and dissociated amounts. Local metal levels exceed systemic ones by several magnitudes and dissociated Co and Cr was found in periprosthetic compartments including BM (peak BM Co concentration: 977 µg/L, peak BM Cr concentration: 2,875 µg/L; n = 10). While in vivo exposure to MoM-wear did not influence MSCs' viability, proliferation, migration capacity, adipogenic- and chondogenic differentiation, it decreased osteogenic matrix mineralization and cellular ALP activity (FIGURE 1). In vitro exposure of control-MSCs to Co(II) and Cr(III) ions, at concentrations detected in BM, confirmed the decrease in osteogenic matrix mineralization and ALP activity (FIGURE 2). DISCUSSION. We found that extensive amounts of Co and Cr occurred in their dissociated state within the periprosthetic region (SF, PT, BM), indicating that vast amounts of particulate wear in degraded. Our work represents an important piece in the puzzle of the clinical manifestation of periprosthetic osteolysis: dissociated Co and Cr at clinically relevant concentrations impair the bone forming function of MSCs. The study's data indicate an influence of MoM-wear on BM residing MSCs' osteogenic differentiation that is relevant for maintaining vital bone structure, thus confirming the lead hypothesis. The use of CoCrMo alloys for articulating surfaces in hip implants needs critical reconsideration. For figures/tables, please contact authors directly.

Introduction:. Skeletal involvement in non-Hodgkin lymphoma in HIV/AIDS is rarely reported. The bone lesions can have a spectrum of radiological features. Aims:. The aim of the study was to review the radiological features of non-Hodgkin lymphoma (NHL) involving the bone in HIV positive patients. Methodology:. All cases of NHL involving bone in HIV positive patients diagnosed histopathologically were recorded retrospectively between September 2002 and December 2013. Clinical manifestations, radiological features and haematological investigations were analysed from the patients' records. Histopathological subtypes were analysed from slides. Results:. 105 Cases of lymphoma involving bone were recorded. Of these, 46 patients met the criteria of being HIV positive and diagnosed with NHL involving bone. The male to female ratio was equal, the age ranged from 14 to 51 years (average 35 years), the absolute CD 4 count ranged from 17 to 307 (average 100). The sites of involvement were:- vertebrae (22), ribs (8), pelvis (6), femur (3), mandible (3), humerus (2), sternum (1) and clavicle (1). Vertebral involvement was multifocal with a large extradural soft tissue mass in 17 cases and solitary in 5 cases. Pathological fractures were seen in 4 cases of long bone involvement. Most patients presented with a high grade large B cell non-Hodgkin lymphoma with CD20 immunopositivity. Conclusion:. Primary bone lymphoma is a rare disease, accounting for approximately 3% of all primary bone malignancies and 4% to 7% of all extranodal lymphomas in the general population. The prevalence of primary and secondary bone lymphoma is very high in HIV positive patients. The disease is very aggressive, presenting in patients with low CD 4 count and the prognosis is poor. The radiologic patterns can be lytic, blastic or subtle changes, solitary or multifocal. The diagnosis of skeletal NHL is made on histopathology

Various reports confirm that elevations in serum markers associated with skeletal muscle injury exist and can occur after orthopaedic surgery in the absence of overt clinical manifestations of myocardial injury. The purpose of this study is to measure the influence surgical approach on these serum markers following primary Minimally Invasive THA. Consecutive enrollment of 30 patients into three different groups of 10 was performed. The MIS Modified Watson Jones THA is an approach using an inter-muscular plane, the Mini Posterior is a trans-muscular approach with some muscle detachment and repair, while the MIS II Incision THA is an inter-muscular approach anteriorly and a trans-muscular approach posteriorly. Blood samples for total creatine kinase (CK), creatine phospho-kinase (CPK), and serum myoglobin were obtained at screening and the morning before surgery as a baseline, immediately post-operatively in the recovery room and 8, 16, 24, 36, 48, and 72 hours post-operatively. Hemoglobin and hematocrit was obtained pre-operatively, 16, 36, and 72 hours (±6 hours) post-operatively. Cardiac troponin-I was measured the morning before surgery (pre-operatively) and 16 hours following surgery to monitor any contributory effect of myocardial injury. We report measurable and reproducible trends in serum enzyme levels consistent with skeletal muscle damage due to THA. Troponin-I remained normal in all but one case throughout the entire study indicating no myocardial contribution to measured serum enzyme levels. While these trends may have slight correlation with surgical approach, they were not statistically significant. We conclude that all three procedures do affect serum enzyme markers and are safe from this standpoint, but no surgical approach appears to affect the degree of muscle trauma more or less than another

During the pandemic of COVID-19, some patients with COVID-19 may need emergency surgeries. As spine surgeons, it is our responsibility to ensure appropriate treatment to the patients with COVID-19 and spinal diseases. A protocol for spinal surgery and related management on patients with COVID-19 has been reviewed. Patient preparation for emergency surgeries, indications, and contraindications of emergency surgeries, operating room preparation, infection control precautions and personal protective equipments (PPE), anesthesia management, intraoperative procedures, postoperative management, medical waste disposal, and surveillance of healthcare workers were reviewed. It should be safe for surgeons with PPE of protection level 2 to perform spinal surgeries on patients with COVID-19. Standardized and careful surgical procedures should be necessary to reduce the exposure to COVID-19.

Little information is available about several important aspects of the treatment of melioidosis osteomyelitis and septic arthritis.

We undertook a retrospective review of 50 patients with these conditions in an attempt to determine the effect of location of the disease, type of surgical intervention and duration of antibiotic treatment on outcome, particularly complications and relapse.

We found that there was a 27.5% risk of osteomyelitis of the adjacent bone in patients with septic arthritis in the lower limb. Patients with septic arthritis and osteomyelitis of an adjacent bone were in hospital significantly longer (p = 0.001), needed more operations (p = 0.031) and had a significantly higher rate of complications and re-presentation (p = 0.048).

More than half the patients (61%), most particularly those with multifocal bone and joint involvement, and those with septic arthritis and osteomyelitis of an adjacent bone who were treated operatively, needed more visits to theatre.

Cite this article: Bone Joint J 2015;97-B:277–82.