Osteosarcoma cell death induced by innovative scaffolds doped with chemotherapeutics.

Osteosarcoma (OS) cancer treatments include systemic chemotherapy and surgical resection. In the last years, novel treatment approaches have been proposed, which employ a drug-delivery system to prevent offside effects and improves treatment efficacy. Locally delivering anticancer compounds improves on high local concentrations with more efficient tumour-killing effect, reduced drugs resistance and confined systemic effects. Here, the synthesis of injectable strontium-doped calcium phosphate (SrCPC) scaffold was proposed as drug delivery system to combine bone tissue regeneration and anticancer treatment by controlled release of methotrexate (MTX) and doxorubicin (DOX), coded as SrCPC-MTX and SrCPC-DOX, respectively. The drug-loaded cements were tested in an in vitro model of human OS cell line SAOS-2, engineered OS cell line (SAOS-2-eGFP) and U2-OS. The ability of doped scaffolds to induce OS cell death and apoptosis was assessed analysing cell proliferation and Caspase-3/7 activities, respectively. To determine if OS cells grown on doped-scaffolds change their migratory ability and invasiveness, a wound-healing assay was performed. In addition, the osteogenic potential of SrCPC material was evaluated using human adipose derived-mesenchymal stem cells. Osteogenic markers such as (i) the mineral matrix deposition was analysed by alizarin red staining; (ii) the osteocalcin (OCN) protein expression was investigated by enzyme-linked immunosorbent assay test, and (iii) the osteogenic process was studied by real-time polymerase chain reaction array. The delivery system induced cell-killing cytotoxic effects and apoptosis in OS cell lines up to Day 7. SrCPC demonstrates a good cytocompatibility and it induced upregulation of osteogenic genes involved in the skeletal development pathway, together with OCN protein expression and mineral matrix deposition. The proposed approach, based on the local, sustained release of anticancer drugs from nanostructured biomimetic drug-loaded cements is promising for future therapies aiming to combine bone regeneration and anticancer local therapy.

A Case of Severe Acute Kidney Injury Due to an Antibiotic-Loaded Cement Spacer for Infected Knee Arthroplasty.

The treatment for periprosthetic joint infection frequently involves the placement of a high-dose antibiotic-loaded bone cement spacer (ALCS) into the debrided joint. Typical antibiotics in the spacer include aminoglycosides and vancomycin. It has been believed that systemic absorption of intraarticular antibiotics would be low and early experience suggested that the risk of acute kidney injury (AKI) from ALCS was minimal. However, recent case reports and case series have suggested a risk of acute kidney injury due to antibiotic absorption, though confounding factors are common. We report a case of severe AKI requiring hemodialysis with extremely high systemic tobramycin levels after the placement of an ALCS with increased dosing of antibiotics after previous failure to resolve a periprosthetic joint infection with a prior ALCS. There was no concomitant use of intravenous nephrotoxic antibiotics nor other confounding factors. Despite dialysis, the patient needed urgent removal of the ALCS to control tobramycin levels with subsequent resolution of the AKI. This case highlights the potentially serious nephrotoxicity of ALCS's, the importance of antibiotic type and dosing, and the value of close monitoring after ALCS placement, especially in a patient with chronic kidney disease.

A systematic review and meta-analysis of antibiotic-loaded bone cement for prevention of deep surgical site infections following primary total joint replacement.

BACKGROUND: The use of antibiotic-loaded bone cement (ALBC) as a mean for preventing deep surgical site infections (SSI) after total joint replacement is controversial. Therefore, we have conducted a meta-analysis to evaluate the prophylactic effect of ALBC for SSI prevention in patients undergoing arthroplasty. This study was conducted to revise treatment guidelines for MRSA infections in Japan. METHODS: PubMed (Medline), Scopus, Embase, Web of Science and Cochrane library were searched for relevant articles comparing preventive effect of ALBC for patients undergoing primary total joint arthroplasty by August 2022. Primary outcome was the incidence of deep SSI. Subgroup analyses by type of surgery (total hip (THA) or knee (TKA) arthroplasty) and by causative pathogen (methicillin-resistant Staphylococcus aureus (MRSA)) were performed. RESULTS: Of the 3379 studies identified for screening, six studies involving 5745 patients were included. The use of ALBC significantly reduced the incidence of deep SSI in overall patients (risk ratio [RR] 0.60, 95% confidential interval [CI] 0.39-0.92), but the evidence level was very low. There was no significant preventive effect for ALBC compared with non-ALBC in both THA and TKA (THA, RR 0.52, 95% CI 0.23-1.16; TKA, RR 0.64, 95% CI 0.38-1.06), and for preventing MRSA-SSI (RR 0.27, 95% CI 0.03-2.41). CONCLUSIONS: Although the overall preventive effect of ALBC was significant, the evidence level was very low. Thus, the routine use of ALBC as a mean to prevent SSI in arthroplasty may not be suggested.

Finite element analysis of biomechanical effects of percutaneous cement discoplasty in scoliosis.

OBJECTIVE: To investigate the effect of bone cement on the vertebral body and biomechanical properties in percutaneous cement discoplasty (PCD) for degenerative lumbar disc disease. METHODS: Three-dimensional reconstruction of L2 ~ L3 vertebral bodies was performed in a healthy volunteer, and the corresponding finite element model of the spine was established. Biomechanical analysis was performed on the changes in stress distribution in different groups of models by applying quantitative loads. RESULTS: Models with percutaneous discoplasty (PCD) showed improved stability under various stress conditions, and intervertebral foraminal heights were superior to models without discoplasty. CONCLUSION: Cement discoplasty can improve the stability of the vertebral body to a certain extent and restore a certain height of the intervertebral foramen, which has a good development prospect and potential.

Biomechanical study between percutaneous vertebroplasty combined with cement pedicle plasty improves vertebral biomechanical stability: A finite element analysis.

OBJECTIVE: To investigate the biomechanical effects of percutaneous vertebroplasty combined with cement pedicle plasty (PVCPP) on the unstable osteoporotic vertebral fractures (OVFs) through finite element (FE) analysis. The study compares the biomechanical stability of finite element models between percutaneous vertebroplasty (PVP) and percutaneous vertebroplasty combined with cement pedicle plasty. METHODS: Two patients with unstable OVFs underwent computed tomography (CT) examination at the thoracolumbar vertebral body levels, respectively. The CT images were reconstructed into three-dimensional finite element models to simulate stress conditions across six dimensions and to evaluate the vertebral von Mises stress before and after bone cement reinforcement. RESULTS: The study found that stress distribution differed between groups mainly at the pedicle base. In the surgical vertebral bodies, the maximum stress in the PVP group decreased during flexion and left bending, while it increased in other states. In the PVCPP group, all maximum stresses decreased. In the inferior vertebral bodies, the maximum stress in the PVP group generally increased, while it decreased in the PVCPP group. In the superior vertebral bodies, postoperatively, the maximum stress in the PVP group generally increased, while it almost remained unchanged in the PVCPP group. PVP group had higher cement stress and displacement. CONCLUSION: PVCPP is an effective treatment method for patients with unstable OVFs. It can quickly relieve pain and enhance the stability of the three columns, thereby reducing the risk of some complications.

Application of antibiotic bone cement combined with lobulated perforator flap based on descending branch of the lateral circumflex femoral artery in treatment of infected traumatic tissue defects of foot.

OBJECTIVE: To evaluate the clinical effectiveness of antibiotic bone cement combined with the lobulated perforator flap based on the descending branch of the lateral circumflex femoral artery (d-LCFA) in the treatment of infected traumatic tissue defects in the foot, in accordance with the Enhanced Recovery after Surgery (ERAS) concept. METHODS: From December 2019 to November 2022, 10 patients with infected traumatic tissue defects of the foot were treated with antibiotic bone cement combined with the d-LCFA lobulated perforator flap. The cohort comprised 6 males and 4 females, aged 21 to 67 years. Initial infection control was achieved through debridement and coverage with antibiotic bone cement, requiring one debridement in nine cases and two debridements in one case. Following infection control, the tissue defects were reconstructed utilizing the d-LCFA lobulated perforator flap, with the donor site closed primarily. The flap area ranged from 12 cm×6 cm to 31 cm×7 cm. Postoperative follow-up included evaluation of flap survival, donor site healing, and ambulatory function of the foot. RESULTS: The follow-up period ranged from 7 to 24 months, averaging 14 months. Infection control was achieved successfully in all cases. The flaps exhibited excellent survival rates and the donor site healed by first intention. Based on the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scale, pain and function were evaluated as excellent in 3 cases, good in 5 cases, and moderate in 2 cases. CONCLUSION: The application of antibiotic bone cement combined with the d-LCFA lobulated perforator flap is an effective treatment for infected traumatic tissue defects of the foot with the advantages of simplicity, high repeatability, and precise curative effects. The application of the d-LCFA lobulated perforator flap in wound repair causes minimal damage to the donor site, shortens hospital stays, lowers medical expenses, and accelerates patient rehabilitation, aligning with the ERAS concept. Therefore, it is a practice worth promoting in clinical use.

Enhanced bone cement distribution in percutaneous vertebroplasty using a curved guide wire: a propensity score matching analysis.

BACKGROUND: Osteoporotic vertebral compression fractures (OVCF) severely affect the quality of life in the aged population. Percutaneous vertebroplasty (PVP) alleviates pain and stabilizes vertebrae, but suboptimal bone cement distribution can cause complications. Hence, this study aimed to clarify whether a new technique for PVP, using a curved guide wire, enhances the distribution of bone cement and improves clinical outcomes in patients with OVCF. METHODS: Patients with single-segment OVCF underwent PVP or curved guide wire percutaneous vertebroplasty (C-PVP). Propensity score matching (PSM) was employed to balanced the baseline characteristics. The primary outcomes were the visual analog scale (VAS) and Oswestry disability index (ODI) scores. The secondary outcomes included assessments of bone cement distribution, bone cement injection volume, radiological parameters, and general clinical results. Additionally, Complications and adverse events were documented. RESULTS: After PSM analysis, each group comprised 54 patients, which significantly reduced baseline differences. The C-PVP group showed better clinical outcomes compared to the traditional PVP group. One month after surgery, the C-PVP group had significantly lower VAS and ODI scores (p < 0.001). These improvements persisted at six months and the final follow-up. Additionally, bone cement distribution scores were better (p < 0.001), injection volume was higher (p = 0.03), leakage was less frequent (p = 0.02), and adjacent vertebral fractures occurred less frequently (p = 0.04) in the C-PVP group. Radiological parameters and overall clinical outcomes revealed no significant differences between the two groups. CONCLUSION: The use of curved guide wire in PVP significantly improves bone cement distribution and injection volume, resulting in better clinical efficacy in patients with OVCF.

Clinical significance of modified unilateral puncture percutaneous vertebroplasty guided by 3D- printed guides in the treatment of osteoporotic vertebral compression fractures: a retrospective study.

OBJECTIVE: To investigate the clinical significance of using 3D printing guides in modified unilateral puncture percutaneous vertebroplasty (PVP) for the treatment of osteoporotic vertebral compression fractures (OVCF), and to explore a new method for preventing paravertebral vein leakage during PVP in conjunction with a previous study of the optimal puncture-side bone cement/vertebral volume ratio(PSBCV/VV%). METHODS: This retrospective study analyzed 99 patients who underwent unilateral puncture PVP between January 2023 and December 2023. Patients were divided into a guide plate group (46 patients) and a conventional group (53 patients). The guide plate group underwent modified unilateral puncture PVP with the guidance of 3D printing guides, while the conventional group underwent unilateral puncture PVP using the conventional pedicle approach. The distribution of bone cement, surgical outcomes, and the occurrence of cement leakage into paravertebral veins were observed in both groups. RESULTS: The guide plate group had significantly shorter operating time and required fewer fluoroscopies compared to the conventional group. The amount of bone cement volume (BCV) used in the guide plate group was higher, but the amount of bone cement volume on the puncture side(PSBCV), the PSBCV/VV%, and the rate of paravertebral vein leakage were lower in the guide plate group compared to the conventional group (P < 0.05). Within each group, significant improvements in anterior vertebral margin height, Cobb angle, visual analog scale (VAS) score, and Oswestry Disability Index (ODI) were observed at 1 day and 1 month postoperatively compared to preoperative values (P < 0.05). CONCLUSION: Using 3D printing guides in modified unilateral puncture PVP is a safe and effective method for treating OVCF. And it has the advantages of short operation time, less fluoroscopy, even distribution of bone cement, and a low rate of paravertebral vein leakage.

Bone cement repair of malleus handle fractures: Intraoperative video and case report of two patients.

Isolated malleus fractures are a rare occurrence with few reported cases in the literature. Symptoms include sudden otalgia, hearing loss, tinnitus and aural fullness. Work-up and diagnosis are based on a combination of thorough anamnesis and careful otoscopic evaluation or high-resolution computer tomography. We present two cases of isolated malleus handle fractures who were diagnosed based on a combination of pneumatic otoscopy and tympanometry. Both fractures were surgically repaired using hydroxyapatite bone cement as showcased in the supplemental video material. Post-operative audiometry showed improvement in the pure-tone-average of both patients as well as normalisation of tympanometry. Isolated malleus fracture should be suspected in cases of sudden hearing loss and tinnitus following digital manipulation of the outer ear canal together with a conductive hearing loss with a mostly high-frequent air-bone-gap and hypercompliant tympanometry with hypermobility of the tympanic membrane on pneumatic insufflation. Surgical repair of the fracture using bone cement has good hearing outcomes and leads to improvement in auditory symptoms.

Exclusive endoscopic management of incus long process major defects: conventional incus interposition versus malleostapediopexy.

PURPOSE: The aim of the current study is to compare the surgical and audiometric results of conventional incus interposition (IP) versus malleostapediopexy (MS) in incus long process large defects. METHODS: A total of 71 patients (incus IP group n = 37, MS group n = 34) were enrolled in this study. All patients enrolled in the current study underwent ossiculoplasty via an exclusive endoscopic transcanal approach. Pre- and postoperative audiometric measurements and air-bone gap (ABG) values were compared, and if the postoperative ABG value was less than 20 dB, ossiculoplasty was considered successful. Graft success rates and complications were also compared. RESULTS: The average auditory gain was 14.7 ± 4.2 dB in the incus IP group and 18.3 ± 5.1 dB in the MS group. The auditory gain was significantly greater in the MS group relative to the incus IP group (p = 0.012). Ossiculoplasty success (postoperative ABG value < 20 dB) rate was 70.3% in the incus IP group patients and 88.2% in the MS group patients (p < 0.001). There was no significant difference in terms of graft success rate between groups (p > 0.05) and the overall graft uptake rate was 91.5% (65/71). CONCLUSION: Malleostapediopexy-bridging of malleus and stapes using bone cement-is an effective, reasonable, and more efficient technique in terms of auditory outcomes relative to the conventional incus interposition in endoscopic transcanal management of incus long process major defects.

Novel technique utilizing polymethylmethacrylate cement for the treatment of pulsatile tinnitus caused by different sigmoid sinus pathologies.

PURPOSE: Sigmoid sinus anomalies such as dehiscence or diverticula may present with pulsatile tinnitus (PT) and low-frequency hearing loss. Occasionally, these symptoms are severe, necessitating resurfacing of the affected area to restore a normal-appearing sinus wall. This study describes three cases wherein we managed PT attributed to sigmoid sinus anomalies using polymethylmethacrylate (PMMA) bone cement, a novel material. METHODS: Three patients with PT without any history of illnesses initially underwent cortical mastoidectomy to expose the affected area and resurface the sinus wall. Subsequently, PMMA bone cement was used to reconstruct any bony defects causing PT symptoms. Viscosity of the bone cement was altered based on specific characteristics and causes of the affected area. Additionally, we performed the water occlusion test (WOT), audiological assessment, the Tinnitus Handicap Inventory score (THI), and temporal computed tomography, both pre- and postoperatively, to assess the extent of PT. RESULTS: Preoperatively, all three patients had tinnitus that dissipated with pressure on the neck and the water occlusion test (WOT), with no reported vertigo, trauma, or ear infections. Moreover, all three cases had a severe handicap according to the THI. In contrast, all cases had reduced PT and a significantly decreased THI score postoperatively, as well as no recurrence or complications and no instances of increased intracranial hypertension at the 12-month follow-up. CONCLUSION: All cases showed promising results, emphasizing the sustained benefits of this novel intervention for the management of PT.

Comparable bone penetration between antibiotic-loaded and plain bone cement in total knee arthroplasty.

INTRODUCTION: One of the main concerns around the use of antibiotic-loaded bone cement (ALBC) is the potential reduction in the mechanical properties of the cement when antibiotics are admixed. The purpose of this study was to determine whether there is a difference between plain cement and ALBC in terms of radiological intrusion into the bone in total knee arthroplasties (TKAs). METHODS: Prospective randomized study of 80 consecutive patients who underwent TKA. Depending on the cement used, patients were divided into two groups by a computer-generated randomization programme: the cement without antibiotic (Group 1) or the ALBC (Group 2). Cement intrusion was measured in postoperative radiographs in eight different regions in the tibial component and six regions in the femoral component. RESULTS: The average cement intrusion was similar in both groups (p = nonsignificance [n.s.]). Group 1 (plain cement) had an average cement intrusion in the femur of 1.4 mm (±0.4) and 2.4 mm (±0.4) in the tibia. In Group 2 (ALBC), the average cement intrusion in the femur came to 1.6 (±0.5) and 2.4 mm (±0.5) in the tibia. In 80% of the patients, the cement intrusion in the tibia averaged a minimum of 2 mm, being similar in both groups (p = n.s.). CONCLUSION: There are no differences in bone intrusion when comparing plain cement to ALBC. Therefore, the use of ALBC in primary TKA may be indicated, achieving optimal bone penetration. LEVEL OF EVIDENCE: Level I.

Antibiotic-loaded bone cement is associated with a reduction of the risk of revision of total knee arthroplasty: Analysis of the Catalan Arthroplasty Register.

PURPOSE: The purpose of this study was to analyse the impact on peri-prosthetic joint infection (PJI) rate and prosthetic survival using antibiotic-loaded bone cement (ALBC) versus plain cement during total knee arthroplasty (TKA). METHODS: A retrospective cohort study was conducted. The main data source was the Catalan Arthroplasty Register (RACat). TKAs with surgery date between 1 January 2011 and 31 December 2020 were analysed and followed up until 31 December 2023. The main variable of interest was the type of cement (ALBC vs. plain cement), and several endpoints (septic revision, aseptic revision, and all-cause revision) were considered. The analysed outcomes were revision rates, survival rates and risk factors' hazard ratios (HR). RESULTS: A total of 22,781 TKAs were analysed, 13,125 (57.6%) of them with plain cement and 9656 (42.4%) with ALBC. The septic revision rate was lower in the ALBC group after 3 months of follow-up (0.52% vs. 0.78%, p value = 0.04). Prosthetic survival with respect to the aseptic revision endpoint was also higher for the ALBC group during the whole follow-up period (~158 months). Regarding risk factors for infection, ALBC showed a protective effect, HR: 0.53 (0.44, 0.63), while sex (being male) and the analysed comorbidities increased the risk. CONCLUSIONS: ALBC is associated with a reduction in both the septic revision and the aseptic revision rate after TKA, and thus with higher prosthetic survival. LEVEL OF EVIDENCE: Level III, Therapeutic, retrospective.

Effect of prophylactic infusion of norepinephrine on the prevention of hypotension during vertebroplasty: a randomized clinical trial.

BACKGROUND: Transient hypotension is a common occurrence during the implantation of bone cement. This placebo-controlled randomized clinical trial study investigated the effect of prophylactic infusion of norepinephrine on the incidence of hypotension in senior patients who underwent vertebroplasty. METHODS: The trial recruited patients who were greater than or equal to 65 years of age, had an American Society of Anesthesiologist physical status classification of I to III, and underwent vertebroplasty from August 2020 to August 2021 at the Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine in China. The patients were randomly grouped according to whether they received either a norepinephrine infusion of 0.05 µg/kg/min or an equivalent volume of saline 10 min before implantation of bone cement. Intraoperative hemodynamics were monitored continuously by the MostCare system at the following 7 time points: 10 min before implantation of bone cement and immediately, 30 s, 1, 3, 5, and 10 min after implantation of bone cement. We also recorded the number of hypotensive episodes and the total number of vasopressors after implantation of bone cement. Multivariable logistic regression was used to assess the risk factors associated with hypotension after implantation of bone cement. RESULTS: A total of 63 patients were randomized to the control group (n = 31; median [IQR] age, 74 [69-79] years) and the norepinephrine group (n = 32; median [IQR] age, 75 [71-79] years). The incidence of hypotension in the norepinephrine group was significantly lower than that in the control group after implantation of bone cement (12.5% vs. 45.2%; relative risk [RR], 3.61 [95% CI, 1.13-15.07]; P = 0.005). Moreover, the median (IQR) number of hypotensive episodes (0 [0-0] vs. 0 [0-2]; P = 0.005) and the total number of vasopressors (0 [0-0] vs. 0 [0-1]; P = 0.004) in the norepinephrine group were significantly lower than those in the control group. Furthermore, compared with the baseline, the MAP significantly decreased at 1 min (P = 0.007) and 3 min (P < 0.001) after bone cement implantation in the control group. However, the MAP at 3 min in the norepinephrine group was significantly higher than that in the control group (P < 0.001). The incidence of complications was not different between the groups. In multivariable logistic regression, the FRAIL score (OR, 2.29; 95% CI, 1.21-4.31) was identified as a risk factor associated with hypotension. CONCLUSION: Prophylactic infusion of norepinephrine before bone cement implantation can stabilize hemodynamics and reduce the incidence of hypotension after implantation of bone cement.

Reverse total shoulder arthroplasty with proximal bone loss: a biomechanical comparison of partially vs. fully cemented humeral stems.

BACKGROUND: The appropriate amount of cementation at the time of reverse total shoulder arthroplasty with significant proximal bone loss or resection is unknown. Extensive cementation of a humeral prosthesis makes eventual revision arthroplasty more challenging, increasing the risk of periprosthetic fracture. We analyzed the degree of subsidence and torque tolerance of humeral components undergoing standard cementation technique vs. our reduced polymethyl methacrylate (PMMA) protocol. Reduced cementation may provide sufficient biomechanical stability to resist physiologically relevant loads, while still permitting a clinically attainable torque for debonding the prosthesis. METHODS: A total of 12 cadaveric humeri (6 matched pairs) underwent resection of 5 cm of bone distal to the greater tuberosity. Each pair of humeri underwent standard humeral arthroplasty preparation followed by either cementation using a 1.5-cm PMMA sphere at a location 3 cm inferior to the porous coating or standard full stem cementation. A 6-degree-of-freedom robot was used to perform all testing. Each humeral sample underwent 200 cycles of abduction, adduction, and forward elevation while being subjected to a physiologic compression force. Next, the samples were fixed in place and subjected to an increasing torque until implant-cement separation or failure occurred. Paired t tests were used to compare mean implant subsidence vs. a predetermined 5-mm threshold, as well as removal torque in matched samples. RESULTS: Fully and partially cemented implants subsided 0.49 mm (95% CI 0.23-0.76 mm) and 1.85 mm (95% CI 0.41-3.29 mm), respectively, which were significantly less than the predetermined 5-mm threshold (P < .001 and P < .01, respectively). Removal torque between fully cemented stems was 45.22 Nm (95% CI 21.86-68.57 Nm), vs. 9.26 Nm (95% CI 2.59-15.93 Nm) for partially cemented samples (P = .021). Every fully cemented humerus fractured during implant removal vs. only 1 in the reduced-cementation group. The mean donor age in our study was 76 years (range, 65-80 years). Only 1 matched pair of humeri belonged to a female donor with comorbid osteoporosis. The fractured humerus in the partially cemented group belonged to that donor. CONCLUSION: Partially and fully cemented humeral prostheses had subsidence that was significantly less than 5 mm. Partially cemented stems required less removal torque for debonding of the component from the cement mantle. In all cases, removal of fully cemented stems resulted in humeral fracture. Reduced cementation of humeral prostheses may provide both sufficient biomechanical stability and ease of future component removal.

The Use of Erythromycin and Colistin Cement in Total Knee Arthroplasty Does Not Reduce the Incidence of Infection: A Randomized Study in 2,893 Knees With a 9-year Average Follow-Up.

BACKGROUND: One of the most severe complications of primary total knee arthroplasty (TKA) is prosthetic joint infection. Currently, the use of antibiotic-loaded cement for the prevention of infection is still controversial. The aim of the present study was to evaluate if the use of antibiotic-loaded cement reduces the infection rate in primary TKA in long-term follow-up (more than 5 years average follow-up). METHODS: This study is the follow-up extension of a prospective randomized study, with 2,893 cemented TKA performed between 2005 and 2010 at our institution. There were 2 different cohorts depending on which bone cement was used: without antibiotics (control group) or those loaded with erythromycin and colistin (study group). All patients received the same systemic prophylactic antibiotics. The patients were followed for a minimum of twelve months. The diagnosis of prosthetic joint infection was done according to Zimmerli criteria. RESULTS: In 1,452 patients, the prosthetic components were fixed using bone cement without antibiotics, whereas in 1,441 patients, bone cement was loaded with erythromycin and colistin. Both groups were comparable in terms of all the possible risk factors studied. We found a total of 53 deep infections, with a mean rate of 1.8%. There were no differences between the groups as to whether bone cement with or without antibiotics had been used (P = .58). The average duration of follow-up was 8.7 years. In terms of prosthetic revision due to aseptic loosening, there were no differences between groups (P = .32), with 33 revision arthroplasties in the control group and 37 in the study group. Moreover, we analyzed the erythromycin resistance rate, with no differences between both groups (P = .6). CONCLUSIONS: The use of erythromycin and colistin-loaded bone cement in TKA did not lead to a decrease in the rate of infection in long-term follow-up, a finding that suggests that its use would not be indicated in the general population.

Antibiotic Laden Bone Cement Does Not Reduce Acute Periprosthetic Joint Infection Risk in Primary Total Knee Arthroplasty.

BACKGROUND: Periprosthetic joint infection (PJI) can be a serious complication of total knee arthroplasty (TKA). A method believed to decrease the incidence of PJI is antibiotic-laden bone cement (ALBC). Current clinical practice guidelines do not recommend ALBC in primary TKA. The purpose of this study was to compare ALBC to plain cement (PC) in preventing PJI in primary TKA. METHODS: This retrospective analysis included 109,242 Medicare patients in the American Joint Replacement Registry who underwent a cemented primary TKA from January 2017 to March 2021, and had at least 1 year of follow-up. Patients who received ALBC were compared to patients who received PC. Demographic and case-specific variables such as age, sex, race, body mass index, Charlson Comorbidity Index, anesthesia type, and operative time were used to create propensity scores. A logistic regression was run to predict the probability of receiving ALBC. Also, a multivariate model was run on the full unstratified population, using the same covariates as were used to create the propensity model. The primary outcome was differences in PJI rates. RESULTS: Logistic regression analysis showed that a higher preoperative diagnosis of osteoarthritis, higher Charlson Comorbidity Index, higher body mass index, women, race, and anesthesia requirements increased a patient's probability of receiving ALBC. In the full unstratified multivariate model, ALBC did not show a statistically significant difference in risk of revision for infection compared to PC. CONCLUSIONS: The use of ALBC in primary TKA has not been shown to be more efficacious in preventing PJI within the population of Medicare patients in the United States. However, this study is limited given it is a retrospective database study that may inherently have biases and the large dataset has a potential for overpowering the findings.

Cure State Sensing of Polymethylmethacrylate Using a Vibrating Axial Probe.

A new axially vibrating sensor based on an audio voice coil transducer and a lead zirconate titanate (PZT) piezoelectric disc microphone was developed as a probe for the measurement of in vitro rheological fluid properties, including curing progress for polymethylmethacrylate (PMMA) mixtures with important uses as bone cement in the field of orthopedics. The measurement of the vibrating axial sensor's acoustic spectra in PMMA undergoing curing can be described by a damped harmonic oscillator formalism and resonant frequency (ca. 180 Hz) shift can be used as an indicator of curing progress, with shifts to the blue by as much as 14 Hz. The resonant frequency peak was measured in 19 different 4.0 g PMMA samples to have a rate of shift of 0.0462 ± 0.00624 Hz·s-1 over a period of 400 s while the PMMA was in a dough state and before the PMMA transitioned to a hard-setting phase. This transition is unambiguously indicated by this sensor technology through the generation of a distinct circa 5 kHz high-Q under-damped ring-down response.

Passive Biotelemetric Detection of Tibial Debonding in Wireless Battery-Free Smart Knee Implants.

Aseptic loosening is the dominant failure mechanism in contemporary knee replacement surgery, but diagnostic techniques are poorly sensitive to the early stages of loosening and poorly specific in delineating aseptic cases from infections. Smart implants have been proposed as a solution, but incorporating components for sensing, powering, processing, and communication increases device cost, size, and risk; hence, minimising onboard instrumentation is desirable. In this study, two wireless, battery-free smart implants were developed that used passive biotelemetry to measure fixation at the implant-cement interface of the tibial components. The sensing system comprised of a piezoelectric transducer and coil, with the transducer affixed to the superior surface of the tibial trays of both partial (PKR) and total knee replacement (TKR) systems. Fixation was measured via pulse-echo responses elicited via a three-coil inductive link. The instrumented systems could detect loss of fixation when the implants were partially debonded (+7.1% PKA, +32.6% TKA, both p < 0.001) and fully debonded in situ (+6.3% PKA, +32.5% TKA, both p < 0.001). Measurements were robust to variations in positioning of the external reader, soft tissue, and the femoral component. With low cost and small form factor, the smart implant concept could be adopted for clinical use, particularly for generating an understanding of uncertain aseptic loosening mechanisms.

Reconstruction Strategy for Upper Extremity Defects After Bone Tumor Resection Based on 3D Customized Bone Cement Mold.

BACKGROUND: Reconstructing bone defects in the upper extremities and restoring their functions poses a significant challenge. In this study, we describe a novel workflow for designing and manufacturing customized bone cement molds using 3D printing technology to reconstruct upper extremity defects after bone tumor resection. METHODS: Computer tomography data was acquired from the unaffected upper extremities to create a detachable mold, which can be customized to fit the joint precisely by shaping the bone cement accordingly. Fourteen patients who underwent reconstructive surgery following bone tumor resection in the proximal humerus (13 cases) or distal radius (1 case) between January 2014 and December 2022 were retrospectively evaluated. The medical records of this case series were reviewed for the demographic, radiological, and operative data. Metastasis, local recurrence, and complication were also reviewed. Additionally, Musculoskeletal Tumor Society Score (MSTS) and Visual Analogue Scale (VAS) were used to assess clinical outcomes. RESULTS: The mean follow-up period was 49.36 ± 15.18 months (range, 27-82 months). At the end of follow-up, there were no cases of metastasis or recurrence, and patients did not experience complications such as infection, dislocation, or implant loosening. Two cases complicated with subluxation (14.3%), and 1 case underwent revision surgery for prosthetic fracture (7.1%). The average MSTS score was 23.2 ± 1.76 (77.4%, range, 66.7%-86.7%), and the postoperative VAS score was 1.86 ± 1.03 (range, 1-4), which was significantly lower than that before surgery (average preoperative VAS score was 5.21 ± 2.00 (range, 2-8)) (P < .001). CONCLUSION: Customized 3D molds can be utilized to shape bone cement prostheses, which may serve as a potential alternative for reconstructing the proximal humerus and distal radius following en bloc resection of bone tumors. This reconstruction strategy offers apparent advantages, including precise matching of articular surfaces and comparatively reduced costs.