Mechanical characterization and cytocompatibility of linoleic acid modified bone cement for percutaneous cement discoplasty.

Minimally invasive spine treatments have been sought after for elderly patients with comorbidities suffering from advanced degenerative disc disease. Percutaneous cement discoplasty (PCD) is one such technique where cement is injected into a degenerated disc with a vacuum phenomenon to relieve patients from pain. Adjacent vertebral fractures (AVFs) are however an inherent risk, particularly for osteoporotic patients, due to the high stiffness of the used cements. While low-modulus cements have been developed for vertebroplasty through the addition of linoleic acid, there are no such variations with a high-viscosity base cement, which is likely needed for the discoplasty application. Therefore, a low-modulus polymethyl methacrylate was developed by the addition of 12%vol. linoleic acid to a high-viscosity bone cement (hv-LA-PMMA). Initial experimental validation of the cement was performed by mechanical testing under compression over a period of 24 weeks, after storage in 37 °C phosphate buffer saline (PBS) solution. Furthermore, cement extracts were used to evaluate residual monomer release and the cytotoxicity of hv-LA-PMMA using fibroblastic cells. Relative to the base commercial cement, a significant reduction of Young's modulus and compressive strength of 36% and 42% was observed, respectively. Compression-tension fatigue tests at 5 MPa gave an average fatigue limit of 31,078 cycles. This was higher than another low-modulus cement and comparable to the fatigue properties of the disc annulus tissue. Monomer release tests showed that hv-LA-PMMA had a significantly higher release between 24 h and 7 days compared to the original bone cement, similarly to other low-modulus cements. Also, the control cement showed cytocompatibility at all time points of extract collection for 20-fold dilution, while hv-LA-PMMA only showed the same for extract collections at day 7. However, the 20-fold dilution was needed for both the control and the hv-LA-PMMA extracts to demonstrate more than 70% fibroblast viability at day 7. In conclusion, the mechanical testing showed promise in the use of linoleic acid in combination with a high-viscosity PMMA cement to achieve properties adequate to the application. Further testing and in vivo studies are however required to fully evaluate the mechanical performance and biocompatibility of hv-LA-PMMA for possible future clinical application.

Modification of polymethylmethacrylate bone cement with halloysite clay nanotubes.

BACKGROUND: Polymethylmethacrylate (PMMA) bone cement is used in orthopedics and dentistry to get primary fixation to bone but doesn't provide a mechanically and biologically stable bone interface. Therefore, there was a great demand to improve the properties of the PMMA bone cement to reduce its clinical usage limitations and enhance its success rate. Recent studies demonstrated that the addition of halloysite nanotubes (HNTs) to a polymeric-based material can improve its mechanical and thermal characteristics. OBJECTIVES: The purpose of the study is to assess the compressive strength, flexural strength, maximum temperature, and setting time of traditional PMMA bone cements that have been manually blended with 7 wt% HNT fillers. METHODS: PMMA powder and monomer liquid were combined to create the control group, the reinforced group was made by mixing the PMMA powder with 7 wt% HNT fillers before liquid mixing. Chemical characterization of the HNT fillers was employed by X-ray fluorescence (XRF). The morphological examination of the cements was done using a scanning electron microscope (SEM). Analytical measurements were made for the compressive strength, flexural strength, maximum temperature, and setting time. Utilizing independent sample t-tests, the data was statistically assessed to compare mean values (p < 0.05). RESULTS: The findings demonstrated that the novel reinforced PMMA-based bone cement with 7 wt% HNT fillers showed higher mean compressive strength values (93 MPa) and higher flexural strength (72 MPa). and lower maximum temperature values (34.8 °C) than the conventional PMMA bone cement control group, which was (76 MPa), (51 MPa), and (40 °C), respectively (P < 0.05). While there was no significant difference in the setting time between the control and the modified groups. CONCLUSION: The novel PMMA-based bone cement with the addition of 7 wt% HNTs can effectively be used in orthopedic and dental applications, as they have the potential to enhance the compressive and flexural strength and reduce the maximum temperatures.

Comparison of Bone Cement Fixation for Stapes Prostheses with Different Materials in Endoscopic Primary Stapedectomy.

Otosclerosis is a complex skeletal condition that originates from both hereditary and environmental factors. Gradual conductive hearing loss is the main character. Aim to contrast and assess the postoperative results, such as hearing improvement, following the use of bone cement to fix the Titanium versus Teflon stapes piston. 50 patients who had endoscopic stapedotomy with different prostheses insertions were included in this prospective, randomized research. They were splitted into two groups in the: group A consisted of 25 ears in which titanium prostheses with bone cement were applied, while group B consisted of 25 ears Teflon prostheses with bone cement were used. A statistically significant difference was observed in average air conduction (better hearing) between groups A and B at 3, 6, and 12 months postoperatively based on audiometric results. When comparing groups B and A after 3, 6, and 12 months after surgery, the average air bone gap (ABG) was greater in group B, and this difference was statistically significant. Between the two groups, there was no discernible variation in any of the preoperative metrics. 96% of groups A and B were successful. Using bone cement in primary stapedotomy may help fix the procedure and reduce the chance of persistent hearing loss in patients with otosclerosis. This is especially true when titanium is used, as titanium has the ideal mass and stiffness to support acoustic transmission with a low rate of adverse effects and better average ABG.

Injectable bone cement cannulated pedicle screw for lumbar degenerative disease in osteoporosis - clinical follow-up of over 5 years.

OBJECTIVE: The aim of this study is to evaluate the clinical efficacy of injectable cemented hollow pedicle screw (CICPS) in the treatment of osteoporotic lumbar degenerative diseases through a large sample long-term follow-up study. Additionally, we aim to explore the risk factors affecting interbody fusion. METHODS: A total of 98 patients who underwent CICPS for transforaminal lumbar interbody fusion (TLIF) for osteoporotic lumbar degenerative disease from March 2011 to September 2017 were analyzed. X-ray and electronic computed tomography (CT) imaging data were collected during preoperative, postoperative, and follow-up periods. The data included changes in intervertebral space height (ΔH), screw failure, cement leakage (CL), and intervertebral fusion. The patients were divided into two groups based on their fusion status one year after surgery: satisfied group A and dissatisfied group B. Surgical data such as operation time, intraoperative bleeding volume and surgical complications were recorded, and visual analog scale (VAS) and Oswestry disability index (ODI) were used to evaluate the improvement of lumbar and leg pain. RESULTS: The mean follow-up time was 101.29 months (ranging from 70 to 128 months). A total of 320 CICPS were used, with 26 screws (8.13%) leaking, 3 screws (0.94%) experiencing cement augmentation failure, and 1 screw (0.31%) becoming loose and breaking. The remaining screws were not loose or pulled out. Female gender, decreased bone density, and CL were identified as risk factors affecting interbody fusion (P < 0.05). Early realization of interbody fusion can effectively prevent the loss of intervertebral space height (P < 0.05) and maintain the surgical treatment effect. Both VAS and ODI scores showed significant improvement during the follow-up period (P < 0.05). Binary logistic regression analysis revealed that decreased bone density and cement leakage were risk factors for prolonged interbody fusion. CONCLUSIONS: The results of long-term follow-up indicate that PMMA enhanced CICPS has unique advantages in achieving good clinical efficacy in the treatment of osteoporosis lumbar degenerative diseases. Attention should be paid to identify female gender, severe osteoporosis, and CL as risk factors affecting interbody fusion.

Trends in Cemented Fixation in Hemiarthroplasty for Hip Fractures in Canada.

Bacground: The use of cemented fixation is widely recommended in hip arthroplasty for hip fractures, although it is not used universally. Methods: We describe the trends in cementing prevalence in hemiarthroplasty for hip fractures in Canada for patients ≥55 years old between April 2017 and March 2022. Results: The national prevalence of cemented fixation increased from 43% in 2017/18 to 58% in 2021/22, but there was a large variety of both the baseline prevalence and the trends across the country and between individual hospitals. The proportion of surgeons only performing cementless fixation fell from 30% to 21% between 2018/19 and 2021/22. Conclusions: As cemented fixation is now universally recommended, more coordination is needed to track these trends and to help drive implementation of this evidence-based practice across Canada.

Biomechanical evaluation of screw and cement placement strategies for treating medial uncontained tibial defects in total knee arthroplasty: A finite element analysis.

Total knee arthroplasty faces challenges in the management of medial uncontained tibial defects, affecting prosthesis stability and implant survival. The use of screws and bone cement is a preferred approach; however, optimal screw insertion techniques lack consensus in the existing literature. The present study aimed to address this gap by exploring optimal screw and cement placement strategies, focusing on their biomechanical implications. The present study conducted a finite element analysis using a knee prosthesis model with a defined uncontained tibial defect. Various parameters were systematically adjusted, including the number of screws (1, 2 or 3 screws), screw lengths (10, 18, 30 or 40 mm), lateral-medial screw positions (2, 4 or 6 mm laterally) and abduction rotation angles (0, 5, 10 or 15 degrees). These adjustments were made to evaluate their specific and combined impacts on the vertical displacement and abduction angles of the tibial tray. The results revealed that incorporating three-screw reinforcement markedly reduced vertical displacement, while the single screw in the middle position exhibited superior performance in preventing the deformation of abduction angles compared to scenarios with two screws at anterior and posterior positions without a middle screw. Longer screws and smaller abduction angles contributed to decreased movement of the tibial component. Furthermore, the lateral adjustment of the screw position led to an increase in vertical displacement values, reaching ~1.5% when shifted 6 mm laterally. On the whole, the finite element analysis in the present study suggests that, for the treatment of medial uncontained tibial defects, three-screw reinforcement is advantageous for larger defects. Longer screws and a smaller abduction angle are deemed favorable. Moreover, the results underscore the superiority of medial screw placement over lateral placement. It is imperative to note that further clinical validation is essential to corroborate the biomechanical implications observed herein.

Evaluating the physico-chemical properties of water-based and 2% lidocaine hydrochloride-based aluminum-free glass polyalkenoate cements for distal radius fixation.

Lidocaine hydrochloride is used as an anesthetic for clinical applications. This study considers the effects of the substitution of 2% lidocaine hydrochloride for deionized (DI) water on the rheological, mechanical, ion release, pH and injectable properties of two formulations of aluminum-free glass polyalkenoate cements (GPCs) using two distinct poly(acrylic) acids (PAA), E9 and E11, which have different molecular weights (Mw). The substitution of 2% lidocaine hydrochloride demonstrated increased injectability, but did not affect mechanical properties. The mechanical properties increased with time, as expected, and, in general, E9-based GPCs displayed significantly higher strengths over E11-based GPCs. With respect to ion release, which includes calcium (Ca), strontium (Sr), zinc (Zn) and silicon (Si); all ions displayed a steady and consistent increased release over time. Ca and Sr showed similar ion release patterns, whereby the GPC made with E11 PAA and lidocaine hydrochloride released significantly more ions than all other compositions likely due to similar chemical kinetics. However, Zn is also divalent in nature, but displayed only one significant difference across the GPC series at all time points, which was attributed to its higher electronegativity allowing for increased participation in the setting reaction. Finally, an analysis of the pH confirmed an increase in pH with time, suggesting that H+ ions were attacking the glass structure to allow for ion release. After 1 and 7 days, water-based GPCs environments achieved a higher pH than lidocaine hydrochloride-based GPCs, indicating that the lidocaine hydrochloride may be releasing additional protons upon bond formation with PAA.

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.

Contact Dermatitis from Biomedical Devices, Implants and Metals- Trouble from Within.

Allergic contact dermatitis is characterized by its appearance of red, raised and infiltrated, scaling or scabbed skin and intense pruritus, and distinguished from irritant contact dermatitis by its specific immune process and histopathology. Many contact allergens are low molecular weight chemicals including metals such as nickel, cobalt, and chromium, preservatives, and adhesives. When such materials are used internally in biomedical devices, they are similarly capable of causing sensitization and an inflammatory response. Sometimes the reaction remains internal, and presents as swelling, pain, stiffness, decreased range of motion, and internal itching around the implant. Such reactions may, in some cases, also extend to include a localized or, rarely, systemic contact dermatitis indicative of the same process. This review will present an overview of reported skin and local internal reactions to orthopedic implants, which are the largest category of implanted internal metal devices. Immune reactions to smaller categories of medical appliances include cardiac devices and vascular stents, neuromodulation devices, diabetic appliances, Nuss bar surgery for pectus excavatum, and dental and spinal implants. We will review the available diagnostic tools, the consensus on interpretation, and reported strategies for treatment.

Mechanical Properties, Drug Release, Biocompatibility, and Antibacterial Activities of Modified Emulsified Gelatin Microsphere Loaded with Gentamicin Composite Calcium Phosphate Bone Cement In Vitro.

Bone defects are commonly addressed with bone graft substitutes; however, surgical procedures, particularly for open and complex fractures, may pose a risk of infection. As such, a course of antibiotics combined with a drug carrier is often administered to mitigate potential exacerbations. This study involved the preparation and modification of emulsified (Em) crosslinking-gelatin (gel) microspheres (m-Em) to reduce their toxicity. The antibiotic gentamicin was impregnated into gel microspheres (m-EmG), which were incorporated into calcium phosphate bone cement (CPC). The study investigated the effects of m-EmG@CPC on antibacterial activity, mechanical properties, biocompatibility, and proliferation and mineralization of mouse progenitor osteoblasts (D1 cells). The average size of the gel microspheres ranged from 22.5 to 16.1 µm, with no significant difference between the groups (p > 0.05). Most of the oil content within the microspheres was transferred through modification, resulting in reduced cytotoxicity. Furthermore, antibiotic-impregnated m-EmG did not compromise the intrinsic properties of the microspheres and exhibited remarkably antibacterial effects. After combining with CPC (m-EmG@CPC), the microspheres did not significantly hinder the CPC reaction and produced the main product, hydroxyapatite (HA). However, the compressive strength of the largest microsphere content of 0.5 wt.% m-EmG in CPC decreased significantly from 59.8 MPa of CPC alone to 38.7 MPa of 0.5m-EmG@CPC (p < 0.05). The 0.5m-EmG@CPC composite was effective against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) in drug release and antibacterial tests. Compared with m-EmG alone, the 0.5m-EmG@CPC composite showed no toxicity to mouse fibroblast cells (L929). Additionally, the proliferation and mineralization of mouse osteoblastic osteoprogenitor cells (D1 cells) did not have a negative impact on the 0.5m-EmG@CPC composite over time in culture compared with CPC alone. Results suggest that the newly developed antibacterial 0.5m-EmG@CPC composite bone cement did not negatively affect the performance of osteoprogenitor cells and could be a new option for bone graft replacement in surgeries.

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.

Cement loaded with high-dose gentamicin and clindamycin does not reduce the risk of subsequent infection after aseptic total hip or knee revision arthroplasty: a preliminary study.

PURPOSE: The aim of this study was to quantify the prophylactic effect of high-dose gentamicin and clindamycin antibiotic-loaded bone cement (ALBC) during revision total hip (rTHA) or knee (rTKA) arthroplasty for aseptic reasons. The hypothesis was that the raw surgical site infection (SSI) rate is lower when this particular cement is used in comparison with cement loaded with standard-dose gentamicin during rTHA or rTKA for aseptic reasons. METHODS: This retrospective study included 290 consecutive patients undergoing aseptic rTHA or rTKA. Two consecutive cohorts were defined: the first (control group) involved 145 patients where ALBC with gentamicin only was used; the second (study group) involved 145 patients where ALBC with high-dose gentamicin and clindamycin was used. The primary endpoint was the raw SSI rate after 24 months. RESULTS: The raw SSI rate was 8/145 (6%) in the control group and 13/145 (9%) in the study group (odds ratio 0.62, p = 0.26). There was a significant impact of the presence of any risk factor on the SSI rate (15/100 versus 6/169, odds ratio = 4.25, p = 0.002), but no significant impact of any individual risk factor. No complication or side effect related to ALBC was observed in either group. CONCLUSION: These results do not support the routine use of gentamicin and clindamycin ALBC for fixation of revision implants after rTHA and rTKA for aseptic reasons.

Curettage of lesion combined with reconstruction of intramedullary nail and bone cement for the treatment of subtrochanteric metastatic tumors of the femur.

This study investigated subtrochanteric femoral metastases using a retrospective approach by analyzing data from 109 patients with bone metastases (2015-2019). Surgical methods were compared: curettage with intramedullary nail and bone cement versus prosthetic reconstruction. Post-surgical assessments included joint function, bone metastasis-related serum markers, and complications. Univariate and multivariate logistic regression analysis was used to screen independent risk factors affecting patients' prognosis. R language was used to construct a nomogram model for predicting patients' 1- and 2-year survival, which was validated through ROC curves and the calibration chart. Patients treated with curettage showed superior postoperative outcomes, exhibiting significantly higher Karnofsky Performance Status (KPS) scores (80.00 vs. 70.00, P < 0.001) and Musculoskeletal Tumor Society Scores (MSTS) (23.86 ± 2.57 vs. 21.67 ± 3.24, P < 0.001). Both methods demonstrated comparable efficacy in pain control (VAS: 3.00 vs. 3.00, P > 0.05) and bone metabolism impact (ALP: 85.93 ± 14.44 vs. 83.19 ± 21.19; CTX-I: 3.03 ± 1.56 vs. 3.15 ± 1.75; PINP: 10.30 ± 4.41 vs. 11.57 ± 3.90; all P > 0.05). Cox regression identified treatment regimen, age, diabetes, and pre-treatment KPS score as significant survival factors (all P < 0.05). The nomogram model demonstrated high accuracy in predicting one-year and two-year survival (AUC: 0.821 and 0.790, respectively). In conclusion, curettage with intramedullary nail and bone cement enhances postoperative functional recovery and quality of life for subtrochanteric femoral metastases patients, representing a promising treatment method.

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.

Adamantinoma of the ulna: A case report and literature review.

INTRODUCTION AND IMPORTANCE: Adamantinomas are rare, low-grade, malignant skeletal tumors accounting for only 0.33-0.48 % of primary malignant bone tumors. CASE PRESENTATION: An 11-year-old boy with adamantinoma of the ulna was treated with en bloc resection, kryptonite bone cement, and plate fixation. The surgery resulted in marked pain relief and good functional recovery. No evidence of recurrence was observed for 5 years postoperatively, and the Musculoskeletal Tumor Society score was 93. CLINICAL DISCUSSION: This case of an 11-year-old previously treated for an aneurysmal bone cyst (ABC) illustrates the complexity of diagnosing adamantinoma, especially in atypical locations like the ulna. The successful use of en bloc resection and synthetic bone graft highlights the importance of accurate diagnosis and advanced surgical methods in achieving favorable outcomes in pediatric orthopedic oncology. CONCLUSION: Ulnar adamantinomas are rare and can be difficult to diagnose. The successful treatment of this tumor, as described in this case report, can help guide the management of similar cases in the future.

[Therapeutic effect of calcaneal beak-like fracture secondary to calcaneal osteomyelitis caused by diabetic foot].

OBJECTIVE: To explore clinical effect of vancomycin calcium sulfate combined with internal fixation on calcaneal beak-like fracture secondary to calcaneal osteomyelitis caused by diabetic foot. METHODS: From April 2018 to October 2021, a retrospective analysis was performed on 5 patients with calcaneal bone osteomyelitis secondary to diabetic foot, including 2 males and 3 females, aged from 48 to 60 years old;diabetes course ranged from 5 to 13 years;the courses of diabetic foot disease ranged from 18 to 52 days;5 patients were grade Ⅲ according to Wagner classification. All patients were treated with debridement, vancomycin bone cement implantation, negative pressure aspiration at stageⅠ, vancomycin calcium sulfate and internal fixation at stageⅡfor calcaneal beak-like fracture. Surgical incision and fracture healing time were recorded, and the recurrence of osteomyelitis was observed. American Orthopedic Foot Andankle Society (AOFAS) score and exudation at 12 months after operation were evaluated. RESULTS: Five patients were successfully completed operation without lower extremity vascular occlusion, and were followed up for 16 to 36 months. The wound healing time after internal fixation ranged from 16 to 26 days, and healing time of fractures ranged from 16 to 27 weeks. AOFAS score ranged from 65 to 91 at 12 months after operation, and 2 patients got excellent result, 2 good and 1 fair. Among them, 1 patient with skin ulcer on the back of foot caused by scalding at 5 months after operation (non-complication), was recovered after treatment;the wound leakage complication occurred in 2 patients, and were recovered after dressing change. No osteomyelitis or fracture occurred in all patients. CONCLUSION: Vancomycin calcium sulfate with internal fixation in treating calcaneal osteomyelitis secondary to calcaneal osteomyelitis caused by diabetic foot could not only control infection, but also promote fracture healing, and obtain good clinical results.

Static study and numerical simulation of the influence of cement distribution in the upper and lower adjacent vertebrae on sandwich vertebrae in osteoporotic patients: Finite element analysis.

Objective: We analyzed the influence of the location of the upper and lower cement on the sandwich vertebrae (SV) by computer finite element analysis. Materials and Methods: A finite element model of the spinal segment of T11-L1 was constructed and 6 mL of cement was built into T11 and L1 simultaneously. According to the various distributions of bone cement at T11 and L1, the following four groups were formed: (i) Group B-B: bilateral bone cement reinforcement in both T11 and L1 vertebral bodies; (ii) Group L-B: left unilateral reinforcement in T11 and bilateral reinforcement in L1; (iii) Group L-R: unilateral cement reinforcement in both T11 and L1 (cross); (iv) Group L-L: unilateral cement reinforcement in both T11 and L1 (ipsilateral side). The maximum von Mises stress (VMS) and maximum displacement of the SV and intervertebral discs were compared and analyzed. Results: The maximum VMS of T12 was in the order of size: group B-B < L-B < L-R < L-L. Group B-B showed the lowest maximum VMS values for T12: 19.13, 18.86, 25.17, 25.01, 19.24, and 20.08 MPa in six directions of load flexion, extension, left and right lateral bending, and left and right rotation, respectively, while group L-L was the largest VMS in each group, with the maximum VMS in six directions of 21.55, 21.54, 30.17, 28.33, 19.88, and 25.27 MPa, respectively. Conclusion: Compared with the uneven distribution of bone cement in the upper and lower adjacent vertebrae (ULAV), the uniform distribution of bone cement in the ULAV reduced and uniformed the stress load on the SV and intervertebral disc. Theoretically, it can lead to the lowest incidence of sandwich vertebral fracture and the slowest rate of intervertebral disc degeneration.

Related factors of severe osteoporotic vertebral compression fracture and clinical outcomes of percutaneous kyphoplasty: A retrospective study.

BACKGROUND: Osteoporosis is the most common disease in postmenopausal women and the elderly, which can lead to vertebral compression fracture. OBJECTIVE: To investigate the related factors of severe osteoporotic vertebral compression fracture (SOVCF) and evaluate the long-term outcomes of percutaneous kyphoplasty (PKP) for treating SOVCF through comparison with mild OVCF (MOVCF). METHODS: From September 2015 to March 2019, 294 osteoporotic vertebral compression fracture (OVCF) patients treated with PKP were analyzed. Compression of the anterior margin of the fractured vertebral body beyond 2/3 of the original height was defined as SOVCF. Baseline data, clinical and imaging findings before and after surgery and at the last follow-up were recorded. Numerical Rating Scale (NRS) was used to evaluate low back pain, the Oswestry Disability Index (ODI) was used to evaluate activity of daily life. Anterior vertebral height (AVH) and local kyphosis angle (LKA) was used to evaluate radiographic outcomes. During the follow-up, patients with recurrent back pain were examined by MRI to identify new fractures and the incidence of adjacent vertebral fracture (AVF) was recorded. Age, sex, body mass index (BMI), dual energy X-ray absorptiometry based T value, duration of symptom, history of trauma, steroid use, and fracture site were collected for univariate logistic regression analysis Variables with a P-value of less than 0.05 were then included in multivariate analysis to determine the related factors for SOVCF. RESULTS: Logistic regression analysis indicated that longer duration of symptom (OR = 1.109, 95%CI: 1.038-1.185, P= 0.002), lower T value (OR = 0.332, 95%CI: 0.139-0.763, P= 0.001), and steroid use (OR = 31.294, 95%CI: 1.020-960.449, P= 0.049) were related factors of SOVCF. Compared with the MOVCF group, the SOVCF group had longer operation time (57.3 ± 13.51 minutes vs 44.9 ± 8.13 minutes, P< 0.001), more radiation exposure (39.9 ± 7.98 times vs 25.5 ± 4.01 times, P< 0.001), and higher cement leakage rate (55.81% vs 18.73%, P< 0.001). At the last follow-up, the SOVCF group had higher NRS (2.28 ± 0.85 vs 1.30 ± 0.71, P< 0.001), and ODI (16.23 ± 4.43 vs 12.88 ± 3.34, P< 0.001). After operation and at the last follow-up, the SOVCF group had higher LKA and lower AVH (all P< 0.05). The AVF rate at the last follow-up was higher in the SOVCF group at the last follow-up (4.78% vs 18.60%, P< 0.001). CONCLUSION: Lower T value, longer duration of disease, and steroid use were related factors of SOVCF. Compared with MOVCF, PKP for SOVCF had longer operation time, more radiation exposure, and higher cement leakage rate, and the long-term outcomes were worsen.

Rheological Analysis and Evaluation of Measurement Techniques for Curing Poly(Methyl Methacrylate) Bone Cement in Vertebroplasty.

Vertebroplasty is a minimally invasive surgical procedure used to treat vertebral fractures, which conventionally involves injecting poly(methyl methacrylate) (PMMA) bone cement into the fractured vertebra. A common risk associated with vertebroplasty is cement leaking out of the vertebra during the injection, which may occur due to a lack of understanding of the complex flow behavior. Therefore, experiments to quantify the cement's flow properties are necessary for understanding and proper handling of the bone cement. In this study, we aimed to characterize the behavior of PMMA bone cement in its curing stages to obtain parameters that govern the flow behavior during injection. We used rotational and oscillatory rheometry for our measurements, as well as a custom-made injector setup that replicated a typical vertebroplasty setting. Our results showed that the complex viscoelastic behavior of bone cement is significantly affected by deformations and temperature. We found that the results from rotational tests, often used for characterizing the bone cement, are susceptible to measurement artifacts caused by wall slip and "ridge"-like formations in the test sample. We also found the Cox-Merz rule to be conditionally valid, which affects the use of oscillatory tests to obtain the shear-thinning characteristics of bone cement. Our findings identify important differences in the measured flow behavior of PMMA bone cement when assessed by different rheological methods, an understanding that is crucial for its risk-free usage in downstream medical applications.