Polymethylmethacrylate Cement Research Articles

Restoration in Vertebral Compression Fractures (VCF): Effectiveness Evaluation Based on 3D Technology.

There are few studies about anatomical reduction of the fractured vertebral body before stabilization for treatment of vertebral compression fracture (VCF). Although restoration on vertebral height has been useful, the reduction of fractured endplates is limited. The vertebra is part of a joint, and vertebral endplates must be treated like other weight-bearing joint to avoid complications. The aim of this study was to evaluate the feasibility of anatomic reduction of vertebral compression fracture, in different bone conditions, fracture types, and ages (VCF). Under methodological point of view, we followed different steps: first was the placement of two expandable titanium implants just below the fracture. Later, to push the fractured endplates into a more anatomical position, the implants were expanded. Finally, with the implants perfectly positioned, PMMA cement was injected to avoid any loss of correction. To evaluate the effectiveness of this procedure in anatomical fracture reduction, a method based on 3D CT reconstructions was developed. In this paper, we have developed the procedure in three case studies. In all of them, we were able to demonstrate the efficacy of this procedure to reduce the VCF. The percentage of correction of the kyphotic angle varied range between 49% and 62% with respect to the value after the fracture preoperative value. This was accompanied by a reduction of the pain level on the VAS scale around 50%. In conclusion, this novel approach to the vertebral fracture treatment (VCF) associated with 3D assessment have demonstrated the possibility of reducing the vertebral kyphosis angle and the vertebral endplate fractures. However, given the few cases presented, more studies are necessaries to confirm these results.

Critical Review of the State-of-the-Art on Lumbar Percutaneous Cement Discoplasty.

Interbody fusion is the gold standard surgery to treat lumbar disc degeneration disease but can be a high-risk procedure in elderly and polymorbid patients. Percutaneous Cement Discoplasty (PCD) is a minimally invasive technique developed to treat advanced stage of disc degeneration exhibiting a vacuum phenomenon. A patient-specific stand-alone spacer is created by filling the disc with polymethylmethacrylate cement, allowing to recover the disc height and improve the patient’s conditions. As it has recently been introduced in the lumbar spine, this review aims to present a transversal state-of-the-art of the surgery from its clinical practice and outcome to biomechanical and engineering topics. The literature was searched across multiple databases using predefined keywords over no limited period of time. Papers about vertebroplasty were excluded. Among 466 identified papers, the relevant ones included twelve clinical papers reporting the variations of the surgical technique, follow-up and complications, four papers reporting biomechanical ex vivo and numerical tests, and four letters related to published clinical papers. Papers presenting the operative practice are reported, as well as follow-ups up to four years. The papers found, consistently reported that PCD significantly improved the clinical status of the patients and maintained it after two years. Spine alignment was impacted by PCD: the sacral slope was significantly reduced, and disc height increased. The foramen opening correlated to the volume of injected cement. Substitutes to the acrylic cement exhibited better osteointegration and mechanical properties closer to bone tissue. Finally, limitations and risks of the surgery are discussed as well as potential improvements such as the development of new filling materials with better mechanical properties and biological integration or the investigation of the inner disc.

Cranioplasty with hydroxyapatite or acrylic is associated with a reduced risk of all-cause and infection-associated explantation

Objective Cranioplasty remains an essential procedure following craniectomy but is associated with high morbidity. We investigated factors associated with outcomes following first alloplastic cranioplasty. Methods A single-centre, retrospective cohort study of patients undergoing first alloplastic cranioplasty at a tertiary neuroscience centre (01 March 2010–01 September 2021). Patient demographics and craniectomy/cranioplasty details were extracted. Primary outcome was all-cause explantation. Secondary outcomes were explantation secondary to infection, surgical morbidity and mortality. Multivariable analysis was performed using Cox proportional hazards regression or binary logistic regression. Results Included were 287 patients with a mean age of 42.9 years [SD = 15.4] at time of cranioplasty. The most common indication for craniectomy was traumatic brain injury (32.1%, n = 92). Cranioplasty materials included titanium plate (23.3%, n = 67), hydroxyapatite (22.3%, n = 64), acrylic (20.6%, n = 59), titanium mesh (19.2%, n = 55), hand-moulded PMMA cement (9.1%, n = 26) and PEEK (5.6%, n = 16). Median follow-up time after cranioplasty was 86.5 months (IQR 44.6–111.3). All-cause explantation was 12.2% (n = 35). Eighty-three patients (28.9%) had surgical morbidity. In multivariable analysis, the risk of all-cause explantation and explantation due to infection was reduced with the use of both hydroxyapatite (HR 0.22 [95% CI 0.07–0.71], p = .011, HR 0.22 [95% CI 0.05–0.93], p = .040) and acrylic (HR 0.20 [95% CI 0.06–0.73], p = .015, HR 0.24 [95% CI 0.06–0.97], p = .045), respectively. In addition, risk of explantation due to infection was increased when time to cranioplasty was between three and six months (HR 6.38 [95% CI 1.35–30.19], p = .020). Mean age at cranioplasty (HR 1.47 [95% CI 1.03–2.11], p = .034), titanium mesh (HR 5.36 [95% CI 1.88–15.24], p = .002), and use of a drain (HR 3.37 [95% CI 1.51–7.51], p = .003) increased risk of mortality. Conclusions Morbidity is high following cranioplasty, with over a tenth requiring explantation. Hydroxyapatite and acrylic were associated with reduced risk of all-cause explantation and explantation due to infection. Cranioplasty insertion at three to six months was associated with increased risk of explantation due to infection.

Core Decompression and Bone Marrow Aspiration Concentrate Grafting for Osteonecrosis of the Femoral Head.

Core decompression (CD) with bone marrow aspiration concentrate (BMAC) is a technique that may improve outcomes in osteonecrosis of the femoral head (ONFH). The primary aim of this study was to evaluate the radiographic progression free survival (PFS) of CD augmented with BMAC. Secondary aims were to determine the survivorship with conversion (CFS) to total hip arthroplasty (THA) as an endpoint, determine prognostic factors, and characterize the cellular quality of the BMAC. A retrospective cohort study of 61 femoral heads (40 patients) was performed. Patient demographics, comorbidities, BMI, smoking status, etiology, location and extent of ONFH were recorded. The primary endpoint was radiographic progression of ONFH and secondarily, conversion to THA. Additional aims were to determine predictive factors for progression and report the cellular characteristics of the BMAC. Data obtained were compared to the results of a prior randomized controlled trial comparing CD alone versus CD with polymethylmethacrylate cement (PMMA) augmentation. Radiographic PFS of CD with BMAC at 2 and 5 years was 78.3% and 53.3%, respectively. The risk of progression was lower in the CD with BMAC group compared to CD alone (HR0.45, p = 0.03), however this difference no longer remained statistically significant on multivariate analysis. Conversion to total hip arthroplasty free survival (CFS) of CD with BMAC at both 2 and 5 years was 72.1% and 54.6%, respectively with no differences compared to the control groups (CD alone, CD and PMMA). The predictive factors for progression were obesity (BMI ≥ 30) and the extent of the disease as quantified by either percentage involvement, necrotic index or modified necrotic index. No differences in PFS or CFS between CD with BMAC compared to CD alone or CD with PMMA were identified. Independent statistically significant predictors of progression-free survival or conversion to THA are BMI ≥ 30 and the extent of ONFH. Further research with an adequately powered randomized controlled trial is needed. 3.

Time to revisit contraindications of vertebroplasty- A retrospective study of osteoporotic burst fracture operated with vertebroplasty and short segment fixation

BackgroundTo evaluate the safety and efficacy of vertebroplasty with short segmented cement augmented pedicle screws fixation for severe osteoporotic vertebral compression fractures (OVCF) with posterior/anterior wall fracture patients. MethodsA retrospective study of 48 patients of DGOU type-4 (vertebra plana) OVCF with posterior/anterior wall fracture, were treated by vertebroplasty and short segment PMMA cement augmented pedicle screws fixation. Radiological parameters (kyphosis angle and compression ratio) and clinical parameters Visual analogue scale (VAS) and Oswestry disability index (ODI) were analysed. ResultsA significant improvement was noted in VAS (preoperative, 7.90±0.60; final follow-up 2.90±0.54) and ODI (77.10±6.96 to 21.30±6.70), (P<0.05). Neurological improvement was noted in all patients. Kyphosis corrected significantly from preoperative 23.20±5.90 to 5.30±1.40 postoperative with 5% (3.30±2.95) loss of correction at final follow-up. Anterior vertebral height restored significantly from 55.80±11.9% to 87.6±13.1% postoperative with 4.5±4.0% loss at final follow-up. Two cases of cement leakage were found, but both patients were asymptomatic. One patient had implant backout, one had Screw breakage and two had proximal junction kyphosis at final follow-up. No iatrogenic dural or nerve injury. ConclusionsTreatment with vertebroplasty with cement augmented screw fixation and direct decompression is a great option in treating such a complex situation in fragile age with fragile bones because. Vertebroplasty is a viable option for restoring vertebral anterior columns in patients who are considered as contraindications for vertebroplasty, like DGOU-4. It provides anterior support avoiding corpectomy, minimise blood loss, and also the duration of surgery. The addition of short segment fixation gives adequate support with less stress risers at the junctional area.

Contribution of Minimally Invasive Bone Augmentation With PMMA Cement in Primary Fixation of Schatzker Type II Tibial Plateau Fractures.

Background: The most common type of fracture of the lateral tibial plateau is the Schatzker type II split-depressed fracture. Minimally invasive surgery using balloon reduction appears to be very promising compared to the gold standard using a bone tamp. This surgery aims to have the best reduction and stabilization to benefit from an early passive and active rehabilitation to avoid stiffening and muscle wasting. Using a balloon for fracture reduction has allowed the use of semi-liquid Injectable Bone Cement (IBC) fillers. These fillers can be phosphocalcic or polymethyl methacrylate (PMMA). The latest recommendations on these IBCs in spinal surgery increasingly rule out phosphocalcic fillers because of their low mechanical strength. Questions/purposes: 1) What is the mechanical influence of IBC filling (PMMA) regarding the split and depression components of a Schatzker type II fracture? 2) What is the mechanical influence of osteosynthesis regarding the split and depression components of a Schatzker type II fracture with or without PMMA filing in three different kinds of percutaneous fixations? Methods: This biomechanical study was performed on 36 fresh frozen tibia/fibula specimens. Six groups were formed according to the type of percutaneous osteosynthesis or possible PMMA filling. Mechanical strength tests were carried out using a Unicompartmental Knee prosthesis and displacement components were measured on either side of the separation on the anterolateral facet by optical method. Results: We found a significant difference between cementless and cemented osteosynthesis for depression fracture stabilization (difference −507.56N with 95% confidence interval [−904.17; −110.94] (p-value = 0.026)). The differences between the different types of osteosynthesis were not significant (p-value = 0.58). There was a significant difference between osteosynthesis without cement and osteosynthesis with cement on separation (difference −477.72N [−878.52; −76.93] (p-value = 0.03)). The differences between the different types of fixations were not significant regarding separation (p-value = 0.99). Conclusion: PMMA cement significantly improves primary stability, regardless of the type of osteosynthesis for a Schatzker type II plateau fracture. Filling with PMMA cement during tuberoplasty seems to be a very promising strategy in association with percutaneous osteosynthesis to allow rapid recovery after surgery.

Management of Giant Cell Tumor of Talus With Extended Intralesional Curettage and Reconstruction Using Polymethylmethacrylate Cement.

An 18-year-old man presented with complaints of pain and swelling around the left ankle region. Local examination revealed diffuse, hard, mildly tender swelling with ill-defined margins over the medial aspect of the left ankle joint just below the medial malleolus. Radiographic and computed tomographic assessment revealed osteolytic lesion with moderately defined margins. Provisional diagnosis of Campanacci grade 2 giant cell tumor was made, which was later confirmed on histopathology. Extended intralesional curettage and reconstruction with polymethylmethacrylate cement was done under spinal anesthesia. Full weight bearing was allowed at 4 weeks when the below knee back slab was removed. Radiographic assessment was done every 3 months during the first year of follow-up and then every 6 months. No evidence of recurrence of tumor, collapse of talus, or avascular necrosis was found during follow-up. Managing such rare form of bone tumors with extended intralesional curettage and bone cement is an appropriate treatment and gives good functional results.Level of Evidence: Level V.

A novel antibacterial zirconia-containing PMMA bone cement

A non-leaching antibacterial bone cement has been developed and evaluated. Chlorine- and bromine-containing furanone derivatives were synthesized and covalently coated onto the surface of zirconia filler particles, followed by mixing into a conventional poly(methyl methacrylate) bone cement. Flexural strength and bacterial viability were used to evaluate the modified cements. Effects of coated antibacterial moiety content, coated zirconia loading and halogen on furanone were investigated. Results showed that the experimental cement showed significant enhanced antibacterial function against bone-associated Gram-positive Staphylococcus aureus as well as Gram-negative Pseudomonas aeruginosa, as compared to commercial PMMA cement. The cement also exhibited a comparable flexural strength to and 3–14% higher flexural modulus than commercial PMMA bone cement. Increasing antibacterial moiety content and filler loading significantly enhanced antibacterial activity. Increasing antibacterial moiety content slightly increased both flexural strength and modulus of the modified cement. Increasing filler loading slightly increased flexural strength up to 7% loading and then decreased. The bromine-containing furanone modified cement showed a higher antibacterial activity than its chlorine counterpart. Antibacterial agent leaching tests exhibited that the modified experimental cement showed no leachable antibacterial components to surroundings. Within the limitations of this study, this experimental poly(methyl methacrylate) cement may find potential applications in orthopedics for reducing in-surgical and post-surgical infection after further investigations are conducted.

Influence of Different Nanometals Implemented in PMMA Bone Cement on Biological and Mechanical Properties.

Cemented arthroplasty is a common process to fix prostheses when a patient becomes older and his/her bone quality deteriorates. The applied cements are biocompatible, can transfer loads, and dampen vibrations, but do not provide antibacterial protection. The present work is aimed at the development of cement with antibacterial effectivity achieved with the implementation of nanoparticles of different metals. The powders of Ag, Cu with particles size in a range of 10–30 nm (Cu10) and 70–100 nm (Cu70), AgCu, and Ni were added to PMMA cement. Their influence on compression strength, wettability, and antibacterial properties of cement was assessed. The surface topography of samples was examined with biological and scanning electron microscopy. The mechanical properties were determined by compression tests. A contact angle was observed with a goniometer. The biological tests included an assessment of cytotoxicity (XTT test on human cells Saos-2 line) and bacteria viability exposure (6 months). The cements with Ag and Cu nanopowders were free of bacteria. For AgCu and Ni nanoparticles, the bacterial solution became denser over time and, after 6 months, the bacteria clustered into conglomerates, creating a biofilm. All metal powders in their native form in direct contact reduce the number of eukaryotic cells. Cell viability is the least limited by Ag and Cu particles of smaller size. All samples demonstrated hydrophobic nature in the wettability test. The mechanical strength was not significantly affected by the additions of metal powders. The nanometal particles incorporated in PMMA-based bone cement can introduce long-term resistance against bacteria, not resulting in any serious deterioration of compression strength.

Insertion des vis au cours des différentes phases de prise du ciment acrylique : conséquences sur leur résistance à l’arrachage

BackgroundFor large bone defects, after curettage of aggressive bone tumors; such as giant-cell tumors, cementation with supplement internal fixation was used to prevent subsequent collapse of cement-bone constructs. The purpose of this study is to compare the pull-out strength of cement augmented screws between inserting screws in the working phase or hard phase of bone cement. HypothesisTiming at which completed screw insertion takes place affecting the pull-out strength of cement augmented screws. MethodsPull-out strength was compared between screws; inserted within the working phases of cement, and after the cement was hardened in high viscos cement blocks. Each group consists of 10 cortex screws, 10 cancellous screws and 10 locking screws. The pull-out strength test was followed using the instructions of ASTM F543–13e1 Standard Specification and Test Methods, for Metallic Medical Bone Screws. ResultsScrews that were inserted in the working phases of cement had significantly higher pull-out strength, than those inserted in hard cement (p=0.021). The pull-out strength was statistically significant in difference among the types of screws (p<0.001), with locking screws having the highest pull-out strength. Furthermore, the pull-out strength of locking screws revealed no significant difference when either; inserted during the working or hardened phases of bone cement. ConclusionInsertion of screws during the working periods of PMMA cement had higher pull out strength compared to the hard phase of cement. Hence, we recommend performing internal fixation before cementation after curettage of aggressive bone tumors. However, if the surgeon prefers to pack the cement first, for benefit of avoiding residual bone defects, we suggest using a locking plate system to achieve comparable pull-out strength. Level of evidenceIn-vitro study.

Biomechanical restoration of metastatic cancer-induced peri-acetabular bone defects by ablation-osteoplasty-reinforcement-internal fixation technique (AORIF): To screw or not to screw?

BackgroundMinimally invasive percutaneous polymethyl methacrylate cement augmentation procedures offer numerous clinical advantages for patients with periacetabular osteolytic metastatic bone defects in contrast to open reconstructive procedures that are associated with many complications. Several techniques, such as Ablation-Osteoplasty-Reinforcement-Internal Fixation (AORIF), cementoplasty alone, and screw fixation alone are currently used. There is no consensus on optimal skeletal reinforcement of diseased bones. The purpose of this study was to determine the most effective technique of percutaneous acetabular augmentation for joint preservation, with respect to resilience on cyclic loading and fracture pattern at maximal load to failure. MethodsFive cohorts of hemipelvis composite bones with uniform periacetabular defects and various types of reinforcement techniques were utilized to simulate osteolytic metastasis in the weight bearing dome of the acetabulum. Five groups of hemipelves underwent finite element analysis and biomechanical testing for load to failure, energy absorption to failure, stress relaxation on cyclic loading, and fracture locations. ResultsThe combination of screws and bone cement augmentation demonstrated significant higher energy absorption than the cement or screw only groups (p < 0.05), and better protection of acetabulum from displaced intraarticular fractures than the screws alone oror cement only groups (p < 0.05). Resilience to cyclic loading was higheest in the screw with cement fixation group than the screw only repair (p < 0.01), though not the cement fixation only group. InterpretationThese data support the hypothesis that cementoplasty combined with screw augmentation such as the AORIF technique provides the best protection of acetabulum from massive metastatic cancer-induced acetabular fractures compared to augmentation with screws or cement alone.

Tailored therapeutic release from polycaprolactone-silica hybrids for the treatment of osteomyelitis: antibiotic rifampicin and osteogenic silicates.

The treatment of osteomyelitis, a destructive inflammatory process caused by bacterial infections to bone tissue, is one of the most critical challenges of orthopedics and bone regenerative medicine. The standard treatment consists of intense antibiotic therapies combined with tissue surgical debridement and the application of a bone defect filler material. Unfortunately, commercially available candidates, such as gentamicin-impregnated polymethylmethacrylate cements, possess very poor pharmacokinetics (i.e., 24 hours burst release) and little to no regenerative potential. Fostered by the intrinsic limitations associated with conventional treatments, alternative osteostimulative biomaterials with local drug delivery have recently started to emerge. In this study, we propose the use of a polycaprolactone-silica sol-gel hybrid material as carrier for the delivery of rifampicin, an RNA-polymerase blocker often used to treat bone infections, and of osteostimulative silicate ions. The release of therapeutic agents from the material is dual, offering two separate and simultaneous effects, and decoupled, meaning that the kinetics of rifampicin and silicate releases are independent from each other. A series of hybrid formulations with increasing amounts of rifampicin was prepared. The antibiotic loading efficacy, as well as the release profiles of rifampicin and silicates were measured. The characterization of cell viability and differentiation of rat primary osteoblasts and antibacterial performance were also performed. Gram-positive Staphylococcus aureus and Gram-negative Pseudomonas aeruginosa and Escherichia coli were selected due to their high occurrence in bone infections. Results confirmed that rifampicin can be successfully loaded within the hybrids without significant degradation and that it is possible to tailor the antibiotic release according to need. Once in a physiological environment, the rapid release of silicates was associated with optimal cell proliferation and the overexpression of osteoblastic differentiation. Simultaneously, rifampicin is delivered over the course of several weeks with significant inhibition of all tested strains. In particular, the materials caused a growth reduction of 7-10 orders of magnitude in Staphylococcus aureus, the major strain responsible for osteomyelitis worldwide. Our data strongly suggest that PCL/silica hybrids are a very promising candidate to develop bone fillers with superior biological performance compared to currently available options. Thanks to their unique synthesis route and their dual tailored release they can promote bone regeneration while reducing the risk of infection for several weeks upon implantation.

PMMA-cement anterior column reconstruction in surgical treatment of spondylodiscitis

Introduction: and research questionThis paper explains how antibiotic loaded cement can be used in surgical treatment of spondylodiscitis to reconstruct the anterior column of the spine. Material and methods35 consecutive surgical procedures performed for spondylodiscitis were collected over a 11-year period and charts were reviewed. Most infections were caused mainly by staphylococcus spp (n = 16), streptococcus spp (n = 8) and pseudomonas spp (n = 4). Most patients had long standing but unsuccessful antibiotic therapy (median 42 days). Other indications included instability, neurologic deficit, abscess, and patients were generally in very poor medical condition. ResultsAnterior debridement was followed by a partial cavity filling with surgical high viscosity PMMA cement in all cases. Cement was a high viscosity gentamycin loaded cement, that was placed in the cavity created by debridement under the direct eye control. In 25 cases, a part of the cavity was filled with freeze dried cancellous bone allograft rehydrated in rifampicin. Spine was further stabilized with an anterior plate in 15 cases, with short (+1/+1) posterior instrumentation in 5 cases, and a long (≥ +2/+2) posterior instrumentation in 11 cases. In four patients, spine was left un-instrumented. Immediate, unrestricted mobilization was always authorized after surgery. None of the patients were reoperated neither for mechanical failure nor for infection relapse. ConclusionThis report supports the idea that surgical bone cement is an efficient gap filler when used through anterior approach. For small as well as for large defects, it can help to reconstruct the anterior column and locally control the infection in combination with additional stabilization and optimal intravenous and oral antibiotic treatment.

Dual-functional porous and cisplatin-loaded polymethylmethacrylate cement for reconstruction of load-bearing bone defect kills bone tumor cells

Malignant bone tumors are usually treated by resection of tumor tissue followed by filling of the bone defect with bone graft substitutes. Polymethylmethacrylate (PMMA) cement is the most commonly used bone substitute in clinical orthopedics in view of its reliability. However, the dense nature of PMMA renders this biomaterial unsuitable for local delivery of chemotherapeutic drugs to limit the recurrence of bone tumors. Here, we introduce porosity into PMMA cement by adding carboxymethylcellulose (CMC) to facilitate such local delivery of chemotherapeutic drugs, while retaining sufficient mechanical properties for bone reconstruction in load-bearing sites. Our results show that the mechanical strength of PMMA-based cements gradually decreases with increasing CMC content. Upon incorporation of ≥3% CMC, the PMMA-based cements released up to 18% of the loaded cisplatin, in contrast to cements containing lower amounts of CMC which only released less than 2% of the cisplatin over 28 days. This release of cisplatin efficiently killed osteosarcoma cells in vitro and the fraction of dead cells increased to 91.3% at day 7, which confirms the retained chemotherapeutic activity of released cisplatin from these PMMA-based cements. Additionally, tibias filled with PMMA-based cements containing up to 3% of CMC exhibit comparable compressive strengths as compared to intact tibias. In conclusion, we demonstrate that PMMA cements can be rendered therapeutically active by introducing porosity using CMC to allow for release of cisplatin without compromising mechanical properties beyond critical levels. As such, these data suggest that our dual-functional PMMA-based cements represent a viable treatment option for filling bone defects after bone tumor resection in load-bearing sites.

Evaluation of the Effect of Cranioplasty Using Different Prosthetic Materials on Functional Improvement in Patients with Post-traumatic Brain Injury: A Protocol

Background: Cranioplasty is considered an essential step for restoring defects in the skull, generally due to the esthetic appearance, safety of the brain, or handling the adverse effect of the Trephined Syndrome (TS) or sinking skin flap syndrome. Moreover, many studies saw the unexpected enhancement of cognitive and motor function after cranioplasty. These favorable progressive effects can be helpful in further therapy preparations in association with cranioplasty effects. Nevertheless, the proof is mainly restricted to case studies that do not target comparison between different materials in post-traumatic brain injury (P-TBI) people even though it is helpful but not enough.&#x0D; Objectives: To comparatively evaluate the effect of cranioplasty using autologous bone graft, polymethylmethacrylate (PMMA), titanium, and bone cement on cognitive and functional improvement in patients with P-TBI.&#x0D; Methodology: 40 subjects will be allocated into four groups. Group A (10 using Autologous bone graft) Group B (10 using PMMA), Group C (10 using Titanium), and Group D (10 using Bone cement). Glasgow Coma Scale (GCS) and Mini-Mental State Examination (MMSE) will be used for cognitive improvement. For functional improvement, Muscle power and Barthel index will be used. The data will be compared before and after cranioplasty.&#x0D; Expected Results: Cognitive and functional improvement will be present after cranioplasty. But the effect of cranioplasty using autologous bone graft, polymethylmethacrylate (PMMA), titanium, and bone cement has to be evaluated &amp; compared to assess the patient’s cognitive and functional improvement and provide desired intervention as required.&#x0D; Conclusion: This study will comparatively evaluate the effect of cranioplasty using different prosthetic materials and determine which material is better for patients' cognitive and functional improvement.

A Customized Knee Antibiotic-Loaded PMMA Spacer: A Preliminary Design Analysis.

A preliminary design of customized antibiotic-loaded poly-methyl-methacrylate (ALPMMA) spacer characterized by an appropriate footprint according to the specific patient’s anatomy and a reliable mechanical response to severe functional loads (i.e., level walking and 45° bent knee) is reported. The targeted virtual prototyping process takes origin from a novel patented 3D geometrical conceptualization characterized by added customization features and it is validated by a preliminary FEM-based analysis. Mechanical and thermomechanical properties of the antibiotic-doped orthopedic PMMA cement, which will be used for the future prototype manufacturing, were measured experimentally by testing samples taken during a real day-running orthopedic surgery and manufactured according to the surgeon protocol. FEM analysis results indicate that small area is subjected to intensive stresses, validating the proposed geometry from the mechanical point of view, under the two loading scenarios, moreover the value of safety margins results positive, and this is representative of the lower stress magnitude compared to the critical material limits. The experimental data confirm that the presence of antibiotic will last during the surgeon period moreover, the temperature dependent modulus of the bone cement is slightly affected by the body range temperature whereas it will drastically drop for higher temperature out the range of interest. A complete customization, according to a patient anatomy, and the corresponding real prototype spacer will be manufactured by 3D printing techniques, and it will be validated by destructive testing during the second stage of this activity before commercialization.

Angle-stable polyaxial locked plating with and without polymethylmethacrylate cement augmentation for proximal humeral fractures in elderly.

Objectives This study aims to evaluate the outcomes of proximal humeral fracture (PHF) fixation with a polyaxial locking plate (PLP) osteosynthesis alone versus cement-augmented PLP (PLP-CA) in an elderly population.Patients and methods Between May 2015 and June 2018, a total of 101 patients (17 males, 84 females; mean age: 74.5±8.1 years; range, 60 to 94 years) aged ≥60 years with an acute PHF who underwent osteosynthesis with PLP or PLP-CA were retrospectively analyzed. The patients were divided into two groups as the PLP (n=53) and PLP-CA (n=48). Clinical outcomes, Constant-Murley Scores (CMS), Disabilities of the Arm, Shoulder and Hand (DASH) scores, and Short Form-12 (SF-12) scores were compared between the groups.Results The overall mean follow-up was 28.1±11.1 months. No clinically relevant differences in the mean duration of surgery, mean intraoperative X-ray image intensifier time or postoperative in-hospital stay were found between the groups. A higher complication rate was observed in the PLP group (20.8% in PLP vs. 10.4% in PLP-CA; p<0.05). There was no statistically significant difference for this (t-test, p=0.08848). The CMS for the operated side did not show any significant differences between the groups. Also, no statically significant difference was seen in the SF-12. A slightly improved DASH score was found for the PLP group (p=0.02908).Conclusion During follow-up PLP-CA osteosynthesis yielded nearly similar functional outcomes to PLP fracture fixation, despite with an overall lower rate of complication regarding secondary loss of reduction and screw cut-out. The polymethylmethacrylate cement augmentation can decrease morbidity in this patient group.

Fabrication and characterization of a bioactive polymethylmethacrylate-based porous cement loaded with strontium/calcium apatite nanoparticles.

Polymethylmethacrylate (PMMA)-based cements are used for bone reparation due to their biocompatibility, suitable mechanical properties, and mouldability. However, these materials suffer from high exothermic polymerization and poor bioactivity, which can cause the formation of fibrous tissue around the implant and aseptic loosening. Herein, we tackled these problems by adding Sr2+ -substituted hydroxyapatite nanoparticles (NPs) and a porogenic compound to the formulations, thus creating a microenvironment suitable for the proliferation of osteoblasts. The NPs resembled the structure of the bone's apatite and enabled the controlled release of Sr2+ . Trends in the X-ray patterns and infrared spectra confirmed that Sr2+ replaced Ca2+ in the whole composition range of the NPs. The inclusion of an effervescent additive reduced the polymerization temperature and lead to the formation of highly porous cement exhibiting mechanical properties comparable to the trabecular bone. The formation of an opened and interconnected matrix allowed osteoblasts to penetrate the cement structure. Most importantly, the gas formation confined the NPs at the surface of the pores, guaranteeing the controlled delivery of Sr2+ within a concentration sufficient to maintain osteoblast viability. Additionally, the cement was able to form apatite when immersed into simulated body fluids, further increasing its bioactivity. Therefore, we offer a formulation of PMMA cement with improved in vitro performance supported by enhanced bioactivity, increased osteoblast viability and deposition of mineralized matrix assigned to the loading with Sr2+ -substituted hydroxyapatite NPs and the creation of an interconnected porous structure. Altogether, our results hold promise for enhanced bone reparation guided by PMMA cements.

Cement augmentation of suture anchors in the proximal humerus during rotator cuff repair improves pullout strength: a systematic review

ImportanceRotator cuff pathology is a growing concern in the ageing population. If cement augmentation of suture anchors improves pullout strength, its application can potentially be applied in cases of poor bone quality to prevent anchor failure.ObjectiveTo evaluate the biomechanical benefits and fixation strength of cement-augmented versus non-augmented suture anchors in the proximal humerus during rotator cuff repair (RCR).Evidence reviewA systematic review of PubMed, Embase and Cochrane Library was performed to identify all published articles reporting on biomechanical analysis of suture anchors in the shoulder in a cadaveric model. Inclusion criteria required fresh-frozen specimens, placement in the footprint of the proximal humerus, and comparative assessment of fixation constructs with or without polymethylmethacrylate (PMMA) or bioabsorbable composite cement augmentation. Biomechanical testing procedure, cement augmentation method and pullout force were assessed.FindingsAfter review of 105 abstracts, seven full manuscripts met inclusion criteria. Six of seven studies reported statistically significant differences in mean pullout force between augmented (three PMMAs, three composites, one PMMA vs composite) and non-augmented anchors. Of two studies evaluating cycles to failure, both found a significant increase in the augmented versus non-augmented anchors. Of two studies stratifying by anchor position, both investigations identified significant differences in mean pullout strength between augmented and non-augmented anchors at the posteromedial and anterolateral anchor positions.Conclusions and relevanceCement augmentation of suture anchors in cadaveric humeri for RCR improves pullout strength regardless of cement type used or anchor position. Cement augmentation may provide a viable option for future clinical application.Level of evidenceIV, systematic review.

Intracardiac polymethylmethacrylate cement embolism.

A 56-year-old man who underwent a recent elective L5 kyphoplasty for a mild-moderate compression fracture presented to the emergency department with dyspnea and right-sided chest pain that significantly worsened with movement. Chest x-ray and computed tomography scan demonstrated a possible intracardiac foreign body for which the patient was taken to surgery (Figure 1). The patient underwent a median sternotomy that immediately revealed a 10.1 × 0.2-cm foreign body (Figure 2, A) perforating the right atrium (Figure 2, B), transgressing the pericardium into the pleural space (Figure 2, C), and puncturing the lung.