Polymethylmethacrylate Implants Research Articles

Feasibility of Customised Polymethyl Methacrylate Implants Fabricated Using 3D Printed Flexible Moulds for Correction of Facial Skeletal Deformities.

Use of patient specific Polymethyl methacrylate (PMMA) implants for the reconstruction of cranial defects has become a standard practice with excellent long-term results. However, for the reconstruction of midface and mandibular osseous defects other alloplastic materials are preferred but their use is limited due to high cost. This is a report of our experience with the use of low-cost patient specific PMMA implants fabricated using 3D printed moulds in the reconstruction of osseous defects involving different areas of the facial skeleton not limited to cranium. The 25 consecutive patients with craniofacial osseous defects who underwent reconstruction using customized PMMA implants were analyzed. All PMMA implants were fabricated intraoperatively with the use of 3D printed flexible moulds or templates. A total of 34 implants were used in 25 consecutive patients. Out of 34 implants 25 were used for midface and mandibular osseous defects. Most common etiology was post-traumatic deformity (n = 19) followed by tumor (n = 3), craniofacial anomalies (n = 2) and post-craniotomy (n = 1). One patient out of 25 (n = 1) had postoperative implant exposure. The follow-up was ranged from 3 to 19 months with an average of 12 months. The aesthetic outcome was found to be good to excellent with mean visual analogue score of 4.08. Polymethyl methacrylate implants fabricated intraoperatively using 3D printed moulds provide accurate and precise reconstruction at an exceptionally low cost. PMMA has an excellent moulding property with low infection rates. As shown in our study its application may be easily extended to all areas of the craniofacial skeleton.

Do Antibiotic Beads Need to be Removed?

Polymethylmethacrylate antibiotic impregnated beads can be an effective treatment for chronic osteomyelitis or an adjuvant in the treatment of open fractures. It remains unclear however whether the beads cause long-term adverse events if not removed. The purpose of this study was to determine if removal of antibiotic beads was required in order to avoid long term complications. A retrospective chart review was conducted on patients with an extremity or pelvis fracture that had implantation of polymethylmethacrylate (PMMA) antibiotic beads over a five-year period. Fifty-one patients met inclusion criteria for this study; thirty-seven patients (73%) did not have complications after surgical debridement and placement of PMMA antibiotic beads necessitating removal. Our findings suggest that polymethylmethacrylate antibiotic beads can be utilized as a means of delivering high-dose concentrations of local antibiotics and do not have to be removed in all patients.

Craneoplastía con implante de polimetilmetacrilato (PMMA) para corregir secuela de trauma. Reporte de caso

Introducción: los defectos del cráneo y las anomalías del hueso craneofacial que requieren reconstrucción son comunes en una variedad de procedimientos neuroquirúrgicos. Después de una craniectomía o de fracturas craneofaciales posteriores a traumatismos cráneoencefálicos, los pacientes pueden desarrollar defectos cosméticos importantes. Algunos de estos son la depresión de la piel y un defecto de hundimiento que lleva a una apariencia asimétrica de la cabeza, sin dejar de lado las repercusiones físicas, neurológicas y psicológicas que estas lesiones conllevan. La reconstrucción craneofacial y la craneoplastía tienen una larga historia, pero las nuevas técnicas quirúrgicas y una multitud de opciones de materiales han impulsado recientemente el avance en esta área. Los implantes de polimetilmetacrilato (PMMA) han demostrado ser estables, biocompatibles, no conductores, radiotransparentes y de bajo costo. Es así que se pueden colocar y modificar fácilmente, con lo que se elimina la morbilidad del sitio donante. Presentación del caso: en este artículo presentamos un caso de craneoplastía de defecto frontal, posterior a traumatismo, cuya reconstrucción fue realizada mediante una prótesis de polimetilmetacrilato (PMMA) en el Hospital General Xoco de la Cuidad de México. Conclusión: se reporta la reducción del tiempo quirúrgico, además de un costo de la prótesis accesible para el paciente; de esta manera, se obtuvieron resultados satisfactorios y mejoras en el contorno estético facial, en tanto se permitió cobertura y protección para el tejido encefálico.La reconstrucción craneofacial y la craneoplastía tienen una larga historia, pero las nuevas técnicas quirúrgicas y una multitud de opciones de materiales han impulsado recientemente el avance en esta área.1 Los implantes de polimetilmetacrilato (PMMA) han demostrado ser estables, biocompatibles, no conductores, radiotransparentes y de bajo costo.6 Se pueden colocar y modificar fácilmente y se elimina la morbilidad del sitio donante. En este artículo presentamos un caso de craneoplastía de defecto frontal posterior a traumatismo realizada mediante una prótesis de polimetilmetacrilato (PMMA) en el Hospital General Xoco de la Cuidad de México, con la cual se logró reducir el tiempo quirúrgico, además el costo de la prótesis fue accesible para el paciente y se obtuvieron resultados satisfactorios.

Translucent Customized Cranial Implants Made of Clear Polymethylmethacrylate: An Early Outcome Analysis of 55 Consecutive Cranioplasty Cases.

Large skull reconstruction, with the use of customized cranial implants, restores cerebral protection, physiologic homeostasis, and one's preoperative appearance. Cranial implants may be composed of either bone or a myriad of alloplastic biomaterials. Recently, patient-specific cranial implants have been fabricated using clear polymethylmethacrylate (PMMA), a visually transparent and sonolucent variant of standard opaque PMMA. Given the new enhanced diagnostic and therapeutic applications of clear PMMA, we present here a study evaluating all outcomes and complications in a consecutive patient series. A single-surgeon, retrospective, 3-year study was conducted on all consecutive patients undergoing large cranioplasty with clear PMMA implants (2016-2019). Patients who received clear PMMA implants with embedded neurotechnologies were excluded due to confounding variables. All outcomes were analyzed in detail and compared with previous studies utilizing similar alloplastic implant materials. Fifty-five patients underwent cranioplasty with customized clear PMMA implants. Twenty-one (38%) were performed using a single-stage cranioplasty method (ie, craniectomy and cranioplasty performed during the same operation utilizing a prefabricated, oversized design and labor-intense, manual modification), whereas the remaining 34 (62%) underwent a standard, 2-stage reconstruction (craniectomy with a delayed surgery for cranioplasty and minimal-to-no implant modification necessary). The mean cranial defect size was 101.8 cm. The mean follow-up time was 9 months (range, 1.5-39). Major complications requiring additional surgery occurred in 7 patients (13%) consisting of 2 (4%) cerebrospinal fluid leaks, 2 (4%) epidural hematomas, and 3 (4%) infections. In addition, 3 patients developed self-limiting or nonoperative complications including 2 (4%) with new onset seizures and 1 (2%) with delayed scalp healing. This is the first reported consecutive case series of cranioplasty reconstruction using customized clear PMMA implants, demonstrating excellent results with regard to ease of use, safety, and complication rates well below published rates when compared with other alloplastic materials. Clear PMMA also provides additional benefits, such as visual transparency and sonolucency, which is material specific and unavailable with autologous bone. Although these early results are promising, further studies with multicenter investigations are well justified to evaluate long-term outcomes.

Esthetic Occipital Augmentation With Computer-Aided Design–Computer-Aided Manufacturing Prefabricated Customized Polymethyl Methacrylate Implant: Comparison of Planned and Final Results

Augmentation of the occiput is an esthetic procedure that is gaining more popularity but is not well reported in the literature. The aim of this retrospective study on a case series of patients was to describe the use of computer-aided design-computer-aided manufacturing prefabricated polymethyl methacrylate (PMMA) implants in esthetic occipital augmentation. Furthermore, comparison between the surgical outcome and the digital planning was carried out to ascertain the replicability of the surgical planning. We performed a retrospective study of a case series of patients who underwent occipital augmentation with computer-aided design-computer-aided manufacturing prefabricated implants. Customized PMMA occipital implants were fabricated and were inserted via a bicoronal approach with patients under general anesthesia. The patients' 1-week postoperative cone-beam computed tomography image was superimposed onto the preoperative virtual planning images, and the positions of the actual implant and virtual implant were compared. A total of 15 patients who were treated at Charm Clinic, Taipei, Taiwan, and received occipital implants for esthetic purposes were included in this study. The percentage overlap of the occipital implant ranged from 87.8% to 99.99% (mean, 95.71%). One patient experienced partial wound dehiscence, which recovered after wound revision and suturing. In another patient, mild hematoma developed, which resolved spontaneously. Although no formal questionnaire was administered, all patients expressed satisfaction with the cosmetic outcome. The use of prefabricated PMMA posterior calvarial implants showed a rate of replicability of 87.8% to 99.99% (mean, 95.71%) compared with the preoperative virtual planning, and we recommend it as a feasible method for esthetic occipital augmentation.

Discussion of Elective Sonolucent Cranioplasty for Real-Time Ultrasound Monitoring of Flow and Patency of an Extra- to Intracranial Bypass.

Discussion of Elective Sonolucent Cranioplasty for Real-Time Ultrasound Monitoring of Flow and Patency of an Extra- to Intracranial Bypass.

The impact of implant material and patient age on the long-term outcome of secondary cranioplasty following decompressive craniectomy for severe traumatic brain injury

BackgroundSecondary cranioplasty (CP) is considered to support the neurological recovery of patients after decompressive craniectomy (DC), but the treatment success might be limited by complications associated to confounders, which are not yet fully characterized. The aim of this study was to identify the most relevant factors based on the necessity to perform revision surgeries.MethodsData from 156 patients who received secondary CP following DC for severe traumatic brain injury (TBI) between 1984 and 2015 have been retrospectively analyzed and arranged into cohorts according to the occurrence of complications requiring surgical intervention.ResultsCox regression analysis revealed a lower revision rate in patients with polymethylmethacrylate (PMMA) implants than in patients with autologous calvarial bone (ACB) implants (HR 0.2, 95% CI 0.1 to 1.0, p = 0.04). A similar effect could be observed in the population of patients aged between 18 and 65 years, who had a lower risk to suffer complications requiring surgical treatment than individuals aged under 18 or over 65 years (HR 0.4, 95% CI 0.2 to 0.9, p = 0.02). Revision rates were not influenced by the gender (p = 0.88), timing of the CP (p = 0.53), the severity of the TBI (p = 0.86), or the size of the cranial defect (p = 0.16).ConclusionsIn this study, the implant material and patient age were identified as the most relevant parameters independently predicting the long-term outcome of secondary CP. The use of PMMA was associated with lower revision rates than ACB and might provide a therapeutic benefit for selected patients with traumatic cranial defects.

Follow-Up Study: One-Step Salvage of Infected Prosthetic Breast Reconstructions Using Antibiotic-Impregnated Polymethylmethacrylate Plates and Concurrent Tissue Expander Exchange.

Periprosthetic infections represent major complications in breast reconstruction, frequently leading to expander-implant loss. No consensus regarding a management algorithm for attempted salvage currently exists. This study assessed outcomes of the authors' salvage protocol using an antibiotic-impregnated polymethylmethacrylate implant with expander device exchange. A retrospective chart review identified infected implant-based breast reconstruction cases treated between 2009 and 2017. Of 626 cases initially identified, a total of 62 cases had severe prosthetic infections, and underwent either prosthetic salvage (n = 45) or immediate explantation (n = 17). All the prosthetic salvage patients received intravenous antibiotics followed by surgical débridement, insertion of polymethylmethacrylate plates, device exchange, and postoperative antibiotics. After clinical resolution of infection, tissue expansion was performed, with the polymethylmethacrylate plates remaining in situ until exchanged for permanent implants. The authors' study demonstrated a primary infection clearance rate of 82.2 percent (n = 37). Compared to the traditional explantation group, a significantly higher percentage of the salvage patients completed final reconstruction (84.4 percent versus 35.3 percent; p < 0.001). Fewer patients abandoned reconstruction efforts after infection clearance (2.2 percent versus 58.8 percent; p < 0.001). The majority of cases (78.8 percent) that succeeded the salvage protocol ultimately received implant-based reconstruction; 62.5 percent that failed the salvage protocol still went on to receive autologous tissue reconstruction. Sustained local antibiotic delivery using polymethylmethacrylate implants and expander device exchange can successfully salvage an infected breast expander/implant. Compared with the traditional explantation approach, more patients complete final reconstruction. Other benefits include preserved skin envelope integrity and possibly improved long-term aesthetic outcomes. Therapeutic, III.

Mineralized collagen-modified PMMA cement enhances bone integration and reduces fibrous encapsulation in the treatment of lumbar degenerative disc disease.

As a minimally invasive surgery, percutaneous cement discoplasty (PCD) is now contemplated to treat lumbar disc degeneration disease in elder population. Here, we investigated whether the osteogenic mineralized collagen (MC) modified polymethylmethacrylate (PMMA) cement could be a suitable material in PCD surgery. Injectability, hydrophilicity and mechanical properties of the MC-modified PMMA (PMMA-MC) was characterized. The introduction of MC did not change the application and setting time of PMMA and was easy to be handled in minimally invasive operation. Hydrophilicity of PMMA-MC was greatly improved and its elastic modulus was tailored to complement mechanical performance of bone under dynamic stress. Then, PCD surgery in a goat model with induced disc degeneration was performed with implantation of PMMA-MC or PMMA. Three months after implantation, micro-computed tomography analysis revealed a 36.4% higher circumferential contact index between PMMA-MC and bone, as compared to PMMA alone. Histological staining confirmed that the surface of PMMA-MC was in direct contact with new bone, while the PMMA was covered by fibrous tissue. The observed gathering of macrophages around the implant was suspected to be the cause of fibrous encapsulation. Therefore, the interactions of PMMA and PMMA-MC with macrophages were investigated in vitro. We discovered that the addition of MC could hinder the proliferation and fusion of the macrophages. Moreover, expressions of fibroblast-stimulating growth factors, insulin-like growth factor, basic fibroblast growth factor and tumor necrosis factor-β were significantly down-regulated in the macrophages cocultured with PMMA-MC. Together, the promoted osteointegration and reduced fibrous tissue formation observed with PMMA-MC material makes it a promising candidate for PCD surgery.

Effect of Induced Membrane Formation Followed by Polymethylmethacrylate Implantation on Diabetic Foot Ulcer Healing When Revascularization Is Not Feasible.

No study has investigated the role of induced membrane (IM) formation in treating diabetic foot ulcer (DFU). This retrospective study was aimed (1) at evaluating the potential role of a two-staged surgical approach, comprising polymethylmethacrylate (PMMA) implantation and IM formation, in the treatment of DFU and (2) at comparing the results of those with routine wound debridement in patients with DFUs and nonrevascularized peripheral arterial disease (PAD). Fifty patients with infected DFUs who were not candidates for vascular interventions were enrolled between February 2016 and April 2018 and assigned to the PMMA group (n = 28) and conventional group (n = 22). The healing rate, major amputation rate, duration of healing, frequency of debridement procedures, patient survival rate, and reulceration of DFUs were determined. The Mann-Whitney U test, independent sample t-test, and χ2 or Fisher exact test were used in statistical analysis. Overall clinical outcomes were statistically different between the groups (Z = −2.495, P = 0.013). In the PMMA group, 16 patients (57.1%) with intact IM formation achieved ulceration healing at 13.1 ± 3.7 weeks with a mean number of debridements of 1.3 ± 0.4, which were significantly different compared to those values in 5 patients of the conventional group (22.7%, P = 0.014; healing duration: 26.4 ± 7.8 weeks, P = 0.016; mean number of debridements: 3.6 ± 0.5, P ≤ 0.001). At a mean 16.8 ± 4.3-month follow-up, patient survival rates were 92.9% and 68.2% in the PMMA and conventional groups, respectively (P = 0.032). The major amputation rate and reulceration of DFUs were similar between the groups. The two-staged surgical approach is an available, effective modality for improving healing of DFUs. This study provides preliminary information of IM formation followed by PMMA implantation in the management of DFUs in PAD when revascularization is not feasible.

Immediate Post-Operative Reconstruction of Calvarial Bone by Cranioplasty Prosthesis in Calvarial Bone Fibrous Dysplasia

Objectives: Immediate post-operative reconstruction of calvarial bone by cranioplasty prosthesis in calvarial bone fibrous dysplasia. An easy and economical method for reconstruction of the defect. Methods: Surgical excision of right parietal cranial space occupied lesion was performed followed by fabrication of immediate postoperative period cranioplasty prosthesis by using clear heat polymerized polymethylmethacrylate. Results: The cranial defect created during excision of calvarial bone fibrous dysplasia was immediately replaced by cranioplasty prosthesis which was fabricated in the immediate post-operative period using heat polymethylmethacrylate. Conclusions: Polymethylmethacrylate is a very reliable thermoplastic material that can be prefabricated or even placed immediately after post-operative period to produce a suitable prosthesis. Polymethylmethacrylate implants have been outmoded by computer-aided design and computer-aided manufacturing and newer 3-dimensional printed implants, but these newer methods are accompanied by higher expenses and timing issues.

Comparative Cost-Effectiveness of Cranioplasty Implants.

The aim of this study was to compare operative duration and total hospital costs incurred for patients undergoing elective cranioplasty with a variety of materials, including manually shaped autogenous bone graft and titanium mesh, custom patient-specific titanium mesh, polymethyl methacrylate (PMMA) acrylic, and polyetheretherketone (PEEK) implants. A single-centre retrospective chart review was used. Patient demographics, defect characteristics, total operative time, and length of hospital stay were obtained. Total costs were sourced from Sunnybrook and standardized to the 2014 to 2015 year. Bivariate and age-controlled multivariate analyses were performed with (n = 119) and without (n = 101) outliers. When outliers were removed, an age-controlled analysis revealed that autogenous implants resulted in an operative time of 178 ± 37 minutes longer than manually shaped titanium implants (P < .01). The average cost of cranioplasty was CAD$18 335 ± CAD$10 265 for manually shaped titanium implants, CAD$31 956 ± CAD$31 206 for custom patient-specific titanium implants, CAD$20 786 ± CAD$13 075 for PMMA, CAD$14 291 ± CAD$5562 for autogenous implants, and CAD$27 379 ± CAD$4945 for PEEK implants (P = .013). When outliers were removed, cranioplasty with PMMA and PEEK incurred greater costs, CAD$4442 ± CAD$2100 and CAD$13 372 ± CAD$2728, respectively, more than manually shaped titanium implants (P < .01). Manually shaped titanium mesh is the most cost-effective implant choice for small cranial defects. Large unknown defects and frontal paranasal sinus defects are most effectively treated with autogenous bone or titanium mesh. Despite prolonged operative duration and inpatient admission, total costs were not significantly increased. Both PMMA and PEEK implants were significantly more costly, which may be a result of higher complications necessitating reoperation.

Identification of the CXCL12–CXCR4/CXCR7 axis as a potential therapeutic target for immunomodulating macrophage polarization and foreign body response to implanted biomaterials

Host recognition and immune-mediated foreign body response (FBR) to biomaterials can compromise the performance of implanted medical devices. Macrophage participation and polarization play vital roles in regulating the development of FBR; therefore, research is ongoing to use macrophages to regulate FBR. At the implantation site, the chemokine CXC chemokine ligand 12 (CXCL12) is upregulated and mediates the recruitment of innate immune cells (e.g., macrophages and monocytes) that participate in FBR. In this study, polymethyl methacrylate (PMMA) was used to induce FBR in vivo. The results indicated that PMMA induced macrophage M1 polarization, both in vitro and in vivo. The expression of CXC chemokine receptor type 7 (CXCR7), the receptor of CXCL12, was significantly higher on macrophages following PMMA implantation. In contrast, the expression of CXCR4 (another receptor of CXCL12) was significantly lower. The inhibition of CXCR7 and promotion of CXCR4 led to macrophage polarization switching from the M1 to M2 phenotype and prominent restriction of FBR. In terms of mechanism, Western blot results showed that STAT1/3/6, ERK1/2, p38 and NF-κB signaling pathways participated in the complex mechanism by which the CXCL12–CXCR4/CXCR7 axis mediated macrophage polarization. Overall, our results demonstrate that targeting the CXCL12–CXCR4/CXCR7 axis may allow for a more selective method of immunomodulating FBR, improving biomaterial biocompatibility without the need for broad immunosuppression.

296 Increased Penis Circumference and Quality of Life

Men who believe they have a thin penis produce an unsatisfactory quality of sexual life. This work aims to determine if the increase of the penis in circumference brings gains in the quality of life. To determine if the increase of the circumference of the penis up to 5 cm brought an improvement in the quality of life of the 64 patients attended between 2015 to 2017. In this study, we followed 64 patients who performed the procedure in 2015, and 23 patients (35.94%) answered the questionnaire by email, whatsapp or telephone spontaneously. Among its different therapeutic functions, the use of polymethyl methacrylate (PMMA) for more than two decades has been highlighted in the replacement of lost volumes with the aging and filling of wrinkles and wrinkles. It is considered a permanent biomaterial, although its reliability is widely discussed. The implant used was PMMA (10%) in the 20 ml volume under local anesthesia (xylocaine), 20 days after postectomy and allergy test. Outpatient. After subcutaneous PMMA implantation, the mechanical traction should be used for 30 days. Being the daily use minimum of 6 hours. It should be used at intervals of 1 hour every 2 hours of use.

Correction of Poland Syndrome (Chest Hypoplasia) Using Polymethylmethacrylate Implant

Poland anomaly (PA), also known as Poland syndrome, was first described by Alfred Poland as a unilateral underdevelopment or absence of the chest muscle, often associated with deformities such as syndactyly and chest wall deformity [1,2] Poland syndrome is characterized by a variable clinical presentation. The classical deformity consists of unilateral hypoplasia or aplasia of the sternocostal head of pectoralis major muscle and ipsilateral hand malformations. In addition, hypoplasia or aplasia of the breast is observed on the affected side in women.

Abstract: Patient-Specific Implants for Cranioplasty: Is There an Ideal Implant?

INTRODUCTION: While the ideal synthetic material for cranioplasty remains elusive, the use of prefabricated alloplastic implants has many proposed advantages. Custom implants that fit a patient’s specific defect can reduce operative time and improve contour. Polymethyl-methacrylate (PMMA) has a long history of use for large cranioplasty defects. However, advances in 3D printing have led to an increased popularity of polymer alloplastic materials such as polyether-ketone-ketone (PEKK) implants. No direct comparisons of PMMA and PEKK exist in the literature. We present a retrospective analysis of PMMA and PEKK patient-specific implants at a single institution. Methods: A retrospective chart review was performed identifying patients undergoing patient-specific implant (PSI) cranioplasty at Northwestern Memorial Hospital between January 2013 and July 2017. Medical records were reviewed for patient characteristics, indications, surgical details, implant type, and post-operative complications. Patients were divided into groups based on cranioplasty type (PMMA vs PEKK). Comparisons between groups were made using the student’s t test and Fisher exact test. RESULTS: 74 patients underwent PSI cranioplasty during the study period. Thirty-five (47.3%) had PMMA implants and 39 (52.7%) had PEEK implants. Patients were 51% male with an average age of 44. There were no differences between groups except for follow up length (17 months vs 7 months, p=0.002). Plastic surgery involvement was more common in patients with a history of infectious complications (46% v 26%). The overall failure rate for PSI cranioplasty was 14.3%. There was no difference in failure rate when comparing PMMA to PEKK (14.7% vs 13.9%, p>0.05). There was no significant difference in complications between PMMA and PEKK (41.0% vs 34.3%, P>0.05). Infection rates were equivalent between groups (17.1% vs 16.7%). Delayed wound healing was also equivalent (8.8% vs 13.9%, p>0.05). When reviewing the 10 failures, 7 occurred in patients with prior infection, 5 in patients with a history of radiation, and 3 with both. CONCLUSION: PMMA and PEKK have similar complication profiles for patient-specific implant cranioplasty. Complication rates remain high for both materials, with wound healing and infectious complications and radiation carrying high risk of implant failure.

Custom CAD/CAM implants for complex craniofacial reconstruction in children: Our experience based on 136 cases✰

BackgroundCAD-CAM patient-specific implants offer cerebral protection and improved facial balance without the disadvantages of autologous bone grafting such as donor site morbidity and unpredictable resorption. Several alloplastic materials are available, but titanium, polymethylmethacrylate (PMMA), and polyetheretherketone (PEEK) are the current popular choices. We reviewed our experience of applying different alloplastic CAD-CAM materials in the reconstruction of complex pediatric craniofacial deformities. MethodsA retrospective review was performed of all pediatric patients who underwent a complex inlay or onlay implant craniofacial reconstruction using CAD-CAM PEEK, PMMA, or titanium implants at a single institution. Demographics, cost, operative time, complications, and outcomes were assessed. ResultsBetween 2003 and 2014, 136 patients (69 male; 67 female; mean age 11.5 years (3–22 years); mean follow-up 30 months) had custom patient-specific craniofacial reconstruction with PEEK (n = 72), PMMA (n = 42), and titanium (n = 22) implants (inlay = 93; onlay = 43). Indications included congenital anomalies (26.5%), decompressive craniectomies (25.0%), craniofacial syndromes (25.7%), tumor defects (14.0%), and post-trauma (6.6%). Implant cost varied significantly for PEEK ($7703 CAD) and PMMA ($8328 CAD) compared with that for titanium ($11,980 CAD) (p < 0.0005). Six patients (4.4%) required surgery due to infection consisting of irrigation and antibiotic administration with successful implant salvage in three patients. All infections occurred in the PEEK group. Five patients (3.7%) ultimately had implants removed due to infection (n = 3), late exposure (titanium; n = 1), or late fracture (PMMA; n = 1). ConclusionsCAD-CAM alloplast reconstruction in the management of complex pediatric craniofacial deformities is effective although expensive. Implant infection does not always require explantation. A reconstruction algorithm is presented.

Self-engineered Acry C plants in nonpenetrating glaucoma surgery.

BACKGROUND:Analysis of safety and efficacy of self-engineered polymethylmethacrylate (Acry C) implants in nonpenetrating glaucoma surgery (NPGS) for control and maintenance of intraocular pressure (IOP) in primary open angle glaucoma (POAG) patients.MATERIALS AND METHODS:This was a hospital-based randomized study. Fifty eyes of 50 POAG patients were divided into 3 groups based on preoperative IOP range. NPGS was done with polymethylmethacrylate implants made from haptics of intraocular lenses. All patients were followed up after 1 day, 1 week, 1 month, 3 months, 6 months, and 12 months. Preoperative IOP range was from 25.62 ± 1.72 to 41.66 ± 1.15 mmHg. Postoperative success was defined as IOP <21 mmHg at 1 month in the absence of additional antiglaucoma medication or other treatment.RESULTS:A significant reduction in IOP was observed postsurgery in all three groups, changing from a preoperative mean of 25.62 ± 1.72 mmHg, 34.38 ± 2.27 mmHg, and 41.66 ± 1.15 mmHg to a postoperative mean of 13.27 ± 2.13 mmHg, 16.50 ± 2.74 mmHg, and 17.66 ± 1.52 mmHg, respectively (P < 0.001) at 12 months. No significant difference was seen with change in position of the implant, i.e., convexity facing limbus or fornix. No intraoperative complications were observed. The main postoperative complication was failure of filtration in 1 case (3.44%) from Group 1, 5 cases (27.78%) from Group 2, and all 3 cases (100%) from Group 3 at 1 month postoperatively. Thus, 9 eyes (41%) required postoperative antiglaucoma medications following which the IOP was controlled.CONCLUSION:NPGS with Acry-C implants is a safe and cost-effective (<1 US dollar) procedure for control of IOP in POAG patients especially those with moderately elevated IOPs.

Histopathological Evaluation of Polymethyl Methacrylate and Hydroxyapatite Implants for Fracture Healing in Rabbits

Experimentally created mid diaphyseal fractures in 24 rabbits were treated by intramedullary pinning with K-wires, polymethyl methacrylate (PMMA) implants and intramedullary pinning after stuffing with hydroxyapatite (HA) paste and the histopathological changes were recorded. Healing process was not progressive, in control group, as indicated by presence of only a few osteocytes in the matrices, discontinuity in the epithelial layer and extensive vacuolation with occasional presence of giant cells. In PMMA group, healing pattern by endochondral method of ossification was evident by day 30 and day 60, normal structure of bone with remarkably high osteoid formation and osteocytes proliferation were observed. In HA group, vacuolation and discrete presence of osteocytes separated by interlacing trabeculae when compared to the other two groups were more pronounced. By day 60, endosteal vascularization could be depicted under high power. To conclude, of all the three groups healing was better in PMMA group when compared to the other two groups. Keywords: polymethyl methacrylate (PMMA), hydroxyapatite (HA), endosteal vascularization, endochondral ossification, vacuolation Cite this Article Harsha Vardhan K, Devi Prasad V, Sreenu M et al. Histopathological evaluation of polymethyl methacrylate and Hydroxyapatite implants for fracture healing in rabbits. Research & Reviews: Journal of Veterinary Science and Technology. 2017; 6(3): 3–6p.

Outcomes of Cranioplasty with Preformed Titanium versus Freehand Molded Polymethylmethacrylate Implants.

Cranioplasty reshapes the neurocranium and viscerocranium after craniectomy. Different materials have been used for cranioplasty. However, no consistent data are yet available comparing these different materials regarding indications, complications, and outcome. We report our experience with preformed titanium implants and freehand molded polymethylmethacrylate (PMMA) implants for cranioplasty. This retrospective single-center analysis included 120 consecutive cranioplasty patients who had been operated between 2006 and 2013. A total of 60 patients (27 women, 33 men; mean age: 54 years) had received a preformed titanium implant and 60 patients (22 women, 38 men; mean age: 46 years) a freehand molded PMMA implant. We evaluated all demographic and procedure-related data, indications, and outcome. The longest follow-up was 5.5 years. The most frequent indications for cranioplasty were trauma (n = 48 [40%]), malignant infarction (n = 27 [23%]), tumor (n = 22 [18%]), spontaneous intracerebral or aneurysmal subarachnoid hemorrhage (n = 16 [13%]), revision surgery (n = 5 [4%]), and empyema (n = 2 [2%]). PMMA implants were more often associated with wound-healing disorders (p < 0.023; odds ratio [OR]: 10.53) and epidural hematoma (p < 0.03; OR: 8.46), resulting in a significantly higher re-operation rate (p < 0.005). Precise fitting was radiologically confirmed in 98% of titanium implants but in only 71% of PMMA implants (p < 0.001). Magnetic resonance imaging of patients with titanium implants (n = 4) did not show any relevant artifacts. Cranioplasty with preformed titanium implants seems to be superior to freehand molded PMMA implants regarding surgical morbidity, revision rate, and aesthetic results.