A randomized controlled trial comparing autologous cranioplasty with custom-made titanium cranioplasty

Is Polyetheretherketone an Effective Alloplastic Material in Comparison to Titanium in Calvarial Reconstruction

INTRODUCTION AND AIM

Polyetheretherketone (PEEK) and titanium (Ti) cranioplasty implants ideal outcomes are good esthetics, long-term stability, and protection of the fragile brain tissue. However, it is unclear whether PEEK implants can offer an equal alternative to Ti implants. This work aimed to critically review papers and case series published on both Ti and PEEK Cranioplasty regarding complications, clinical outcomes, ease of use, esthetics, manufacture and availability, cost and time-saving factors, postoperative quality of life (QOL), as well as their suitability for the fronto-orbito region reconstruction.

METHODS

PubMed database was sourced for published literature in the period 2007 to the end of 2023; a further manual search for articles was carried out on the reference lists of each paper.

RESULTS

A total of 48980 papers were found during the initial search, but only 33 articles met the inclusion criteria. A total of 6023 cranial implants, with 3879 being Ti and 1205 PEEK. Titanium was the material of choice in over 64.4% of cases; however, Ti has been in application for many years compared to PEEK. Out of the 33 papers, there was 27 retrospective cohort/analysis/case series and reviews: 1 meta-analysis, 2 systematic reviews and 3 randomized control trials. Four articles commented on the QOL, 15 on esthetics, 7 discussed cost and time-saving without measurable variables, and 7 articles looked explicitly at the complex fronto-orbito region, of which 49% were primary 1-stage surgical reconstructions, 54% were reconstructed with PEEK and 7% Ti (CAD/CAM).

CONCLUSION

There is no absolute consensus for the preference of either material, however, in the fronto-orbito region, PEEK is the material of choice for ease of use, esthetics, and time-saving. However, there are no long-term studies on PEEK cranioplasty, and fewer in comparison with Ti implants. Further research is required in this field. No reliable or measurable data was found to determine the QOL, esthetics, cost, or time-saving elements.

A Single Standard Polyvinyl Chloride 3D Skull Model to Create the Polymethyl Methacrylate Cranioplasty Flap: A Novel and Low-Cost Technique

BACKGROUND

 Although, cranioplasty is a commonly performed neurosurgical procedure worldwide, the cost of available cranioplasty implants is a major issue in a low-income country like India. The aims of this study were to introduce a novel and low-cost technique using a single standard three-dimensional (3D) skull model to guide the polymethyl methacrylate (PMMA) cranioplasty flap production and to evaluate the functional and cosmetic outcomes.

METHODS

 We retrospectively evaluated 47 cases of PMMA cranioplasty in the period from February 2019 to June 2022. A single standard 3D skull model was used to make the PMMA cranioplasty flaps. The overall cost of this PMMA implant was compared with that of other available cranioplasty implants. The functional and cosmetic outcomes were evaluated postoperatively.

RESULTS

 The mean age of our patients was 37.17 ± 13.83 years and the age range was 17 to 63 years. The primary cause of surgery was trauma in the majority of cases (n = 31, 65.96%). The mean operative time was 78.55 ± 19.82 minutes. The cosmetic results were very satisfying in 46 of 47 (97.87%) patients and moderately satisfying in 1 (2.12%) patient. Overall, there were three (6.38%) complications.

CONCLUSION

 Our technique provides excellent functional and cosmetic outcomes. The overall surgical cost of these PMMA implants was lower than that of the other available cranioplasty implants. This technique is currently the most cost-effective option for cranioplasty.

Exploring complications following cranioplasty after decompressive hemicraniectomy: A retrospective bicenter assessment of autologous, PMMA and CAD implants

Cranioplasty (CP) after decompressive hemicraniectomy (DHC) is a common neurosurgical procedure with a high complication rate. The best material for the repair of large cranial defects is unclear. The aim of this study was to evaluate different implant materials regarding surgery related complications after CP. Type of materials include the autologous bone flap (ABF), polymethylmethacrylate (PMMA), calcium phosphate reinforced with titanium mesh (CaP-Ti), polyetheretherketone (PEEK) and hydroxyapatite (HA). A retrospective, descriptive, observational bicenter study was performed, medical data of all patients who underwent CP after DHC between January 1st, 2016 and December 31st, 2022 were analyzed. Follow-up was until December 31st, 2023. 139 consecutive patients with a median age of 54 years who received either PMMA (56/139; 40.3%), PEEK (35/139; 25.2%), CaP-Ti (21/139; 15.1%), ABF (25/139; 18.0%) or HA (2/139; 1.4%) cranial implant after DHC were included in the study. Median time from DHC to CP was 117 days and median follow-up period was 43 months. Surgical site infection was the most frequent surgery-related complication (13.7%; 19/139). PEEK implants were mostly affected (28.6%; 10/35), followed by ABF (20%; 5/25), CaP-Ti implants (9.5%; 2/21) and PMMA implants (1.7%, 1/56). Explantation was necessary for 9 PEEK implants (25.7%; 9/35), 6 ABFs (24.0%; 6/25), 3 CaP-Ti implants (14.3%; 3/21) and 4 PMMA implants (7.1%; 4/56). Besides infection, a postoperative hematoma was the most common cause. Median surgical time was 106 min, neither longer surgical time nor use of anticoagulation were significantly related to higher infection rates (p = 0.547; p = 0.152 respectively). Ventriculoperitoneal shunt implantation prior to CP was noted in 33.8% (47/139) and not significantly associated with surgical related complications. Perioperative lumbar drainage, due to bulging brain, inserted in 38 patients (27.3%; 38/139) before surgery was protective when it comes to explantation of the implant (p = 0.035). Based on our results, CP is still related to a relatively high number of infections and further complications. Implant material seems to have a high effect on postoperative infections, since surgical time, anticoagulation therapy and hydrocephalus did not show a statistically significant effect on postoperative complications in this study. PEEK implants and ABFs seem to possess higher risk of postoperative infection. More biocompatible implants such as CaP-Ti might be beneficial. Further, prospective studies are necessary to answer this question.

Clinical Outcomes After Cranioplasty With Titanium Mesh, Polyetheretherketone, or Composite Bone Cement: A Retrospective Study

Cranioplasty is a common neurosurgical procedure; however, the optimal material choice remains controversial. At the time of this writing, autologous bone, the preferred choice for primary cranioplasty, has a high incidence of complications such as infection and resorption, thus requiring frequent use of synthetic materials. Therefore, this study aimed to compare the clinical benefits of titanium mesh (Ti), polyetheretherketone (PEEK), and composite bone cement (CBC) in cranioplasty to provide a clear selection basis for clinicians and patients. This study retrospectively collected data from 207 patients who underwent cranioplasty with Ti (n=129), PEEK (n=54), and CBC (n=24) between January 2018 and December 2020 at Henan Provincial People's Hospital. Postoperative follow-up information after 6 months was used to compare the long-term effects of the 3 materials on the patients. There were no significant differences in the overall complication rate after cranioplasty among the 3 materials. However, subcutaneous effusion was more frequent with PEEK (24.07%) and CBC (20.83%) than with Ti (2.33%). Second, there were no significant differences in the increase in Glasgow Outcome Scale and Karnofsky Performance Status scores after cranioplasty among the 3 materials. Finally, we found that PEEK had the highest patient satisfaction and hospitalization cost, whereas the opposite was true for Ti. Although the surgical outcomes of the 3 implant materials were similar, an examination of clinical outcomes such as patient satisfaction showed significant differences, deepening people's perceptions of the 3 materials.

A Comparative Study of Titanium Cranioplasty for Extensive Calvarial Bone Defects: Three-Dimensionally Printed Titanium Implants Versus Premolded Titanium Mesh

OBJECTIVE

This study compared the complications and symmetry outcomes between 3-dimensionally printed titanium implants and premolded titanium mesh in patients with extensive calvarial bone defects.

METHODS

This retrospective analysis included patients with calvarial defects >50 cm2 undergoing cranioplasty who received either a 3-dimensionally printed titanium implant manufactured by selective laser melting techniques (N = 12) or a premolded titanium mesh customized onto a 3-dimensionally printed skull template (N = 23). Complications including intracranial infection, hardware extrusion, wound dehiscence, and cerebrospinal fluid leaks were investigated. Predictive factors affecting complications were investigated to identify the odds ratios in univariate and multivariate analyses. The symmetry was assessed by calculating the root mean square deviation, which showed the morphological deviation of the selected area compared with the mirrored image of the contralateral region.

RESULTS

The overall complication rate was 26.1% (6/23 patients) in the premolded titanium group and 16.7% (2/12 patients) in the 3-dimensionally printed group. The reoperation rates did not differ significantly between the 2 groups (3-dimensionally printed group, 16.7%, versus premolded group, 21.7%). In multivariate analysis, only the number of previous cranial operation was significantly associated with the complication rate (odds ratio, 2.42; 95% confidence interval, 1.037-5.649; P = 0.041). The mean ± SD of the root mean square deviation was significantly smaller in the 3-dimensionally printed group (2.58 ± 0.93 versus 4.82 ± 1.31 mm, P < 0.001).

CONCLUSIONS

The 3-dimensionally printed titanium implant manufactured by the selective laser melting technique showed comparable stability and improved symmetry outcomes compared with the conventional titanium mesh in the reconstruction of extensive calvarial defects.

Infection-related failure of autologous versus allogenic cranioplasty after decompressive hemicraniectomy - A systematic review and meta-analysis

Introduction

Cranioplasty is required after decompressive craniectomy (DC) to restore brain protection and cosmetic appearance, as well as to optimize rehabilitation potential from underlying disease. Although the procedure is straightforward, complications either caused by bone flap resorption (BFR) or graft infection (GI), contribute to relevant comorbidity and increasing health care cost. Synthetic calvarial implants (allogenic cranioplasty) are not susceptible to resorption and cumulative failure rates (BFR and GI) tend therefore to be lower in comparison with autologous bone. The aim of this review and meta-analysis is to pool existing evidence of infection-related cranioplasty failure in autologous versus allogenic cranioplasty, when bone resorption is removed from the equation.

Materials and methods

A systematic literature search in PubMed, EMBASE, and ISI Web of Science medical databases was performed on three time points (2018, 2020 and 2022). All clinical studies published between January 2010 and December 2022, in which autologous and allogenic cranioplasty was performed after DC, were considered for inclusion. Studies including non-DC cranioplasty and cranioplasty in children were excluded. The cranioplasty failure rate based on GI in both autologous and allogenic groups was noted. Data were extracted by means of standardized tables and all included studies were subjected to a risk of bias (RoB) assessment using the Newcastle-Ottawa assessment tool.

Results

A total of 411 articles were identified and screened. After duplicate removal, 106 full-texts were analyzed. Eventually, 14 studies fulfilled the defined inclusion criteria including one randomized controlled trial, one prospective and 12 retrospective cohort studies. All but one study were rated as of poor quality based on the RoB analysis, mainly due to lacking disclosure why which material (autologous vs. allogenic) was chosen and how GI was defined. The infection-related cranioplasty failure rate was 6.9% (125/1808) for autologous and 8.3% (63/761) for allogenic implants resulting in an OR 0.81, 95% CI 0.58 to 1.13 (Z ​= ​1.24; p ​= ​0.22).

Conclusion

In respect to infection-related cranioplasty failure, autologous cranioplasty after decompressive craniectomy does not underperform compared to synthetic implants. This result must be interpreted in light of limitations of existing studies. Risk of graft infection does not seem a valid argument to prefer one implant material over the other. Offering an economically superior, biocompatible and perfect fitting cranioplasty implant, autologous cranioplasty can still have a role as the first option in patients with low risk of developing osteolysis or for whom BFR might not be of major concern.

Trial registration

This systematic review was registered in the international prospective register of systematic reviews. PROSPERO: CRD42018081720.

Titanium Versus Autologous Bone-Based Cranioplasty: A Systematic Review and Meta-Analysis

At present, there is no gold standard when looking at reconstructive evidence for cranioplasty with the use of autologous bone as well as other synthetic materials. Titanium has been considered recently as a good option due to its unique properties such as strength and biocompatibility. Numerous studies have previously compared titanium with autologous bone for cranioplasty yet no meta-analysis has been performed within the literature to provide guidelines for craniofacial surgeons. A systematic review and meta-analysis were performed as per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A search of electronic information was conducted to identify all comparative studies of autologous bone vs. titanium implants in cranioplasty following a craniectomy. The primary outcomes were measured as re-operation rates and cosmesis, the secondary outcome measures included the incidence of complications, for example, bone resorption and infection. Five studies were selected, enrolling 323 cases. A high reoperation rate (p > 0.007) was seen in autologous cranioplasty using bone due to the significantly high resorption rate reported in this group. Cosmetic outcomes demonstrated no significant difference between the two groups examined. Finally, costs and infection rates (p > 0.18) were found to be comparable. Overall, titanium implants used in cranioplasty offer lower re-operation rates in comparison to autologous bone grafts whilst there was no major increase in adverse outcomes such as postoperative cost or rates.

Ultra-High-Molecular-Weight Polyethylene Merlon Shape: Novel Fixation of Artificial Bone for Cranioplasty

BACKGROUND

Cranioplasty is a surgical procedure widely performed for repairing cranial defects caused by external decompression surgery for cerebrovascular disease or traumatic brain injury. We devised a new cranioplasty method using artificial bone made up of ultra-high molecular-weight polyethylene, with serrated wings on the edge. We named this newly designed artificial bone as Merlon shape.

OBJECTIVE

To describe our initial experience with the Merlon shape and evaluate its usefulness and safety in cranioplasty.

METHODS

The serrated wings of the Merlon shape were preoperatively designed for solid fixation and improving cosmetic results by reducing the thickness of the artificial bone. We evaluated 25 patients who underwent cranioplasty with the Merlon shape between December 2018 and December 2021. The causes of bone defects in these patients (male: 9, female: 16; median age: 62 years) were subarachnoid hemorrhage (n = 14), cerebral infarction (n = 8), and traumatic brain injury (n = 3).

RESULTS

There were no postoperative adverse events such as infection, bone resorption, implant exposure, or graft sinking in 24 patients during an average follow-up period of 19 months. One patient experienced acute epidural hemorrhage and required reoperation.

CONCLUSION

This is the first report on the use of the ultra-high molecular-weight polyethylene Merlon shape. Our initial 4-year case series showed good outcomes with this method.

Complications and cosmetic outcomes of materials used in cranioplasty following decompressive craniectomy-a systematic review, pairwise meta-analysis, and network meta-analysis

BACKGROUND

Optimal reconstruction materials for cranioplasty following decompressive craniectomy (DC) remain unclear. This systematic review, pairwise meta-analysis, and network meta-analysis compares cosmetic outcomes and complications of autologous bone grafts and alloplasts used for cranioplasty following DC.

METHOD

PubMed, Embase, and Cochrane were searched from inception until April 2021. A random-effects pairwise meta-analysis was used to compare pooled outcomes and 95% confidence intervals (CIs) of autologous bone to combined alloplasts. A frequentist network meta-analysis was subsequently conducted to compare multiple individual materials.

RESULTS

Of 2033 articles screened, 30 studies were included, consisting of 29 observational studies and one randomized control trial. Overall complications were statistically significantly higher for autologous bone compared to combined alloplasts (RR = 1.56, 95%CI = 1.14-2.13), hydroxyapatite (RR = 2.60, 95%CI = 1.17-5.78), polymethylmethacrylate (RR = 1.50 95%CI = 1.08-2.08), and titanium (Ti) (RR = 1.56 95%CI = 1.03-2.37). Resorption occurred only in autologous bone (15.1%) and not in alloplasts (0.0%). When resorption was not considered, there was no difference in overall complications between autologous bone and combined alloplasts (RR = 1.00, 95%CI = 0.75-1.34), nor between any individual materials. Dehiscence was lower for autologous bone compared to combined alloplasts (RR = 0.39, 95%CI = 0.19-0.79) and Ti (RR = 0.34, 95%CI = 0.15-0.76). There was no difference between autologous bone and combined alloplasts with respect to infection (RR = 0.85, 95%CI = 0.56-1.30), migration (RR = 1.36, 95%CI = 0.63-2.93), hematoma (RR = 0.98, 95%CI = 0.53-1.79), seizures (RR = 0.83, 95%CI = 0.29-2.35), satisfactory cosmesis (RR = 0.88, 95%CI = 0.71-1.08), and reoperation (RR = 1.66, 95%CI = 0.90-3.08).

CONCLUSIONS

Bone resorption is only a consideration in autologous cranioplasty compared to bone substitutes explaining higher complications for autologous bone. Dehiscence is higher in alloplasts, particularly in Ti, compared to autologous bone.

Analysis of PMMA versus CaP titanium-enhanced implants for cranioplasty after decompressive craniectomy: a retrospective observational cohort study

Numerous materials of implants used for cranioplasty after decompressive craniectomy (DC) have been investigated to meet certain demanded key features, such as stability, applicability, and biocompatibility. We aimed to evaluate the feasibility and safety of biocompatible calcium-phosphate (CaP) implants for cranioplasty compared to polymethylmethacrylate (PMMA) implants. In this retrospective observational cohort study, the medical records of all patients who underwent cranioplasty between January 1st, 2015, and January 1st, 2022, were reviewed. Demographic, clinical, and diagnostic data were collected. Eighty-two consecutive patients with a mean age of 52 years (range 22-72 years) who received either a PMMA (43/82; 52.4%) or CaP (39/82; 47.6%) cranial implant after DC were included in the study. Indications for DC were equally distributed in both groups. Time from DC to cranioplasty was 143.8 ± 17.5 days (PMMA) versus 98.5 ± 10.4 days (CaP). The mean follow-up period was 34.9 ± 27.1 months. Postoperative complications occurred in 13 patients with PMMA and 6 in those with CaP implants (13/43 [30.2%] vs. 6/39 [15.4%]; p = 0.115). Revision surgery with implant removal was necessary for 9 PMMA patients and in 1 with a CaP implant (9/43 [20.9%] vs. 1/39 [2.6%]; p = 0.0336); 6 PMMA implants were removed due to surgical site infection (SSI) (PMMA 6/43 [14%] vs. CaP 0/39 [0%]; p = 0.012). In this study, a biocompatible CaP implant seems to be superior to a PMMA implant in terms of SSI and postoperative complications. The absence of SSI supports the idea of the biocompatible implant material with its ability for osseointegration.

Outcomes of Cranioplasty Strategies for High-Risk Complex Cranial Defects: A 10-Year Experience

INTRODUCTION

Although the literature contains reports of the risks and complications of calvarial vault reconstruction for acquired defects, there are few publications addressing the specific patient population who require such reconstructions in cases preceded by prior infection, radiation, massive associated soft tissue trauma, and so on. We define such clinical presentations as a hostile environment for large surface area reconstruction. Our objective is to compare the safety and efficacy of autologous bone and alloplastic reconstruction in hostile cranial defects.

METHODS

An institutional review board-approved retrospective review of patients who underwent cranioplasty of a hostile site at the University of Alabama at Birmingham between January 2008 and December 2018 was performed. The patients were stratified into 3 groups based on the type of implant used: autogenous (bone), alloplastic (polyetheretherketone [PEEK], titanium, polymethyl methacrylate), or mixed (combination of bone and prosthetic). The primary outcome metric was a complication in the year after cranioplasty, identified by implant failure, necrosis, or infection. Statistical analysis included t tests and χ2 tests where appropriate using SPSS.

RESULTS

There were 55 total cases in this period: 27 autogenous, 23 alloplastic, and 5 mixed. The purely autogenous group had the highest complication rate (44%), and the alloplastic group had the lowest complication rate (38%), which was not statistically different between the 3 groups (P = 0.121). When stratified by specific material used for reconstruction (27 bone, 14 PEEK, 10 titanium, and 5 polymethyl methacrylate), overall complication rate was statistically significant (P = 0.009, χ2 test), with PEEK implants having the lowest complication rate (21%).

CONCLUSIONS

This analysis interestingly found that in the setting of hostile cranial defects, cranioplasties would benefit from the use of prosthetic implants instead of autologous bone grafts, not only for avoidance of donor site morbidity but also for a decrease in overall complications.

Treatment options for critical size defects - Comparison of different materials in a calvaria split model in sheep

Bone defects of the craniofacial skeleton are often associated with aesthetic and functional impairment as well as loss of protection to intra- and extracranial structures. Solid titanium plates and individually adapted bone cements have been the materials of choice, but may lead to foreign-body reactions and insufficient osseointegration. In contrast, porous scaffolds are thought to exhibit osteoconductive properties to support bone ingrowth. Here, we analyse in critical size defects of the calvaria in sheep whether different bone replacement materials may overcome those remaining challenges. In a critical size defect model, bilateral 20 × 20 × 5-mm craniectomies were performed on either side of the sagittal sinus in 24 adult female blackheaded sheep. Bony defects were randomised to one of five different bone replacement materials (BRMs): titanium scaffold, biodegradable poly(d,l-lactic acid) calcium carbonate scaffold (PDLLA/CC), polyethylene 1 (0.71 mm mean pore size) or 2 (0.515 mm mean pore size) scaffolds and polymethyl methacrylate (PMMA)-based bone cement block. Empty controls (n = 3) served as references. To evaluate bone growth over time, three different fluorochromes were administered at different time points. At 3, 6 and 12 months after surgery, animals were sacrificed and the BRMs and surrounding bone analysed by micro-CT and histomorphometry. The empty control group verified that the calvaria defect in this study was a reliable critical size defect model. Bone formation in vivo was detectable in all BRMs after 12 months by micro-CT and histomorphometric analysis, except for the non-porous PMMA group. A maximum of bone formation was detected in the 12-months group for titanium and PDLLA/CC. Bone formation in PDLLA/CC starts to increase rapidly between 6 and 12 months, as the BRM resorbs over time. Contact between bone and BRM influenced bone formation inside the BRM. Empty controls exhibited bone formation solely at the periphery. Overall, porous BRMs offered bone integration to different extent over 12 months in the tested calvaria defect model. Titanium and PDLLA/CC scaffolds showed remarkable osseointegration properties by micro-CT and histomorphometric analysis. PDLLA/CC scaffolds degraded over time without major residues. Pore size influenced bone ingrowth in polyethylene, emphasising the importance of porous scaffold structure.

Customized cost-effective polymethylmethacrylate cranioplasty: a cosmetic comparison with other low-cost methods of cranioplasty

BACKGROUND

Intraoperative hand-moulded cranioplasty and polymethylmethacrylate (PMMA) prostheses made from bone impressions are economical but the cosmetic results are less than satisfactory. Commercially available customized prostheses perform better but are prohibitively expensive. We evaluate the performance of a locally developed, low-cost customized PMMA cranioplasty prosthesis.

OBJECTIVE

To compare the cosmetic outcome of 3 types of PMMA cranioplasty as well as with objective measurements on postoperative CT scans METHODS: This study includes 70 patients who underwent cranioplasty between March 2016 and June 2020. In this period, patients had their cranioplasty prostheses made by intra-operative hand moulding (HM), by using the removed bone as a template and making a bone impression (BI) or by 3D printing the prosthesis based on a CT scan. Cosmetic outcomes were assessed by the patient and the operating surgeon on an 8-point scale. The degree of measured anthropometric asymmetry was measured on a postoperative CT scan and correlated with the cosmetic outcome.

RESULTS

Our locally produced 3D-printed cranioplasty prostheses showed a statistically better performance in cosmetic scores when compared to the HM and BI (p value < 0.001). CT anthropometric measurements significantly correlated with cosmetic outcome (p value 0.01) CONCLUSION: Our 3D cranioplasty prostheses had better cosmetic outcomes than HM and BI prostheses, and our technique is able to produce them at 10% of the cost of the currently available commercial customized prostheses.

Three dimensional custom-made PEEK cranioplasty

BACKGROUND

An optimal reconstruction of calvarial skull defects is a challenge for neurosurgeons, and the strategy used to achieve the best result remains debatable. Therefore, we conducted this study to compare the esthetic and functional outcome of custom-made three-dimensional (3D) cranioprostheses to handmade bone cement in reconstructing calvarial skull defects.

METHODS

We included 66 patients above 10 years of age with calvarial skull defects and undergoing reconstruction: 33 were enrolled in the custom-made 3D implants group and 33 in the handmade implants group in the period from August 2017 to December 2020 in the neurosurgery department of Fayoum University Hospital.

RESULTS

Complete success of the esthetic end-point was insignificantly higher in the custom-made 3D prostheses group based on the doctor's and patients' assessment (60.6% vs. 42.4%; 33.3% vs. 9.1%, P > 0.05), respectively. Complete success of the functional end-point was significantly higher in the custom-made 3D group compared to the handmade cement bone group according to the doctor's and patients' assessment (60.6% vs. 0%; 21.2% vs. 0%, P < 0.05). There were no late complications noted in the custom-made 3D prosthesis group, whereas 50% of the handmade bone group had late complications (P < 0.05). Full improvement of the symptoms of the "syndrome of trephined" was achieved in the 3D custom-made group compared to the handmade bone cement group (20% vs. 0%).

CONCLUSION

Cranioplasty using three dimensional customs made PEEK prosthesis is a reliable method which saves operative time, lowers cost and provides less complications if compared with other cranioplasty techniques. Custom-made 3D cranioprostheses are better than handmade bone cement in reconstructing calvarial defects in terms of esthetic and functional outcome as well as complications.

A Novel Titanium Cranioplasty Technique of Marking the Coronal and Squamosoparietal Sutures in Three-Dimensional Titanium Mesh as Anatomical Positioning Markers to Increase the Surgical Accuracy and Reduce Postoperative Complications

Objective: The objective of this research is to modify the titanium cranioplasty (Ti-CP) technique to increase the surgical accuracy and preliminarily verify the effectiveness and safety of this improvement.

Methods: We developed a novel technique of marking the coronal and squamosoparietal sutures in three-dimensional (3D) titanium mesh as anatomical positioning markers and designed a prospective trial in patients with a unilateral frontotemporoparietal skull defect. Patients were randomly divided into two groups by the presence or absence of the anatomical positioning markers, and the therapeutic effects of these two groups were compared.

Results: Forty-four patients were included in this study, including 28 (64%) males and 16 (36%) females. The mean age was 44.8 ± 15.2 years (range, 13–75 years). Overall postoperative complication rate of the intervention group (18%) was significantly (P = 0.03) lower than the control group (50%). Surgical accuracy of the intervention group (97.8%) was significantly (P < 0.001) higher than the control group (94%). Visual analog scale for cosmesis (VASC) of the intervention group (8.4) was significantly (P < 0.001) higher than the control group (7). The overall postoperative complication rate was 34%. Multivariate analyses showed that surgical accuracy <95.8% (OR = 19.20, 95% CI = 3.17–116.45, P = 0.001) was significantly associated with overall postoperative complications. Independent predictor of overall postoperative complications was surgical accuracy (OR = 0.57, 95% CI = 0.40–0.82, P = 0.002).

Conclusions: This novel technique for repairing frontotemporoparietal skull defects increases surgical accuracy, improves cosmetic prognosis, and reduces postoperative complications. Therefore, it is a safe and effective improvement for Ti-CP.

Two-center validation of the Oulu resorption score for bone flap resorption after autologous cranioplasty

OBJECTIVE

Autologous bone has been the gold standard of cranioplasty materials for decades. Unique to autologous cranioplasty, bone flap resorption is a poorly understood and unclearly defined complication. Even further, it has been unclear, whether the resorption process eventually stabilizes over time. Thus, the sufficient follow-up period after autologous cranioplasty is unknown. The Oulu Resorption Score (ORS) is a straight-forward classification system for the radiological interpretation of bone flap resorption. The aims of the present study were to evaluate the reliability of the ORS using intra-class correlation coefficient (ICC) and to assess the temporal progression of the resorption process.

METHODS

We identified 108 consecutive autologous cranioplasty patients treated between 2005 and 2018 in two tertiary referral centers. All 365 head CT scans the patients had undergone were evaluated using the ORS in a blinded, independent two-center setting. Intra- and inter-observer reliabilities were calculated. The ORS was applied to study the temporal progression of the resorption process.

RESULTS

The intra-observer reliability of the ORS was excellent (ICC 0.94, 95%CI 0.93-0.95). Inter-observer reliability was good-to-excellent (ICCs 0.87 and 0.89, 95%CIs 0.84-0.89 and 0.87-0.91, respectively). In scatterplot smoothing analyses, the progression of bone flap resorption appeared to stabilize 12-24 months after cranioplasty.

CONCLUSIONS

ORS is the only validated radiological tool for the standardized analysis of bone flap resorption after autologous cranioplasty. Evaluated using the ORS, the resorption process seemed to stabilize during the first two postoperative years after cranioplasty, suggesting that the sufficient follow-up time after autologous cranioplasty is two years.

Surface Area of Decompressive Craniectomy Predicts Bone Flap Failure after Autologous Cranioplasty: A Radiographic Cohort Study

Skull bone graft failure is a potential complication of autologous cranioplasty after decompressive craniectomy (DC). Our objective was to investigate the association of graft size with subsequent bone graft failure after autologous cranioplasty. This single-center retrospective cohort study included patients age ≥18 years who underwent primary autologous cranioplasty between 2010 and 2017. The primary outcome was bone flap failure requiring graft removal. Demographic, clinical, and radiographic factors were recorded; three-dimensional (3D) reconstructive imaging was used to perform accurate measurements. Univariate and multi-variate regression analysis were performed to identify risk factors for the primary outcome. Of the 131 patients who underwent primary autologous cranioplasty, 25 (19.0%) underwent removal of the graft after identification of bone flap necrosis on computed tomography (CT); 16 (64%) of these were culture positive. The mean surface area of craniectomy defect was 128.5 cm² for patients with bone necrosis and 114.9 cm² for those without bone necrosis. Linear regression analysis demonstrated that size of craniectomy defect was independently associated with subsequent bone flap failure; logistic regression analysis demonstrated a defect area >125 cm² was independently associated with failure (odds ratio [OR] 3.29; confidence interval [CI]: 0.249-2.135). Patient- and operation-specific variables were not significant predictors of bone necrosis. Our results showed that increased size of antecedent DC is an independent risk factor for bone flap failure after autologous cranioplasty. Given these findings, clinicians should consider the increased potential of bone flap failure after autologous cranioplasty among patients whose initial DC was >125 cm².

Subgaleal drains may be associated with decreased infection following autologous cranioplasty: a retrospective analysis

BACKGROUND

Autologous bone is often the first choice in cranioplasty following a decompressive craniectomy. However, infection is a common complication, with reported rates up to 25%. While the incidence and management of infection are well documented, the risk factors associated with infection remain less clear. The current study aims to identify predictors of infection risk following autologous cranioplasty.

METHODS

A retrospective analysis was conducted on patients who underwent decompressive craniectomy and cranioplasty using cryopreserved autologous bone flaps between 2010 and 2020. Patient demographics and factors related to both surgeries and infection rates were recorded from patient records. Logistic regressions were conducted to determine which factors were implicated in the development of infection.

RESULTS

In our cohort, 126 patients underwent autologous cranioplasty. A total of 10 patients (7.9%) developed an infection following reconstruction, with half resulting in implant failure. We did not identify any significant risk factors for infection. Regression analysis identified placement of subgaleal drain following cranioplasty as a protective factor against the development of infection (OR: 0.16, p = 0.007). On average, drains remained in for 3 days, with no difference between the length of drains for those with infection vs. those without (p = 0.757).

CONCLUSIONS

The current study demonstrates an infection rate of 7.9% in patients who receive an autologous cranioplasty following decompressive craniectomy, which is consistent with previous data. Half (4%) of patients who experienced an infection ultimately required removal of the implant. While it is common practice for neurosurgeons to use drains to prevent hematomas and fluid collections, we found that subgaleal drain placement following cranioplasty was associated with decreased infection, thus demonstrating another benefit of a commonly used tool.

Cranioplasty Following Severe Traumatic Brain Injury: Role in Neurorecovery

PURPOSE OF REVIEW

Decompressive craniectomy (DC) is a life-saving procedure performed in refractory intracranial pressure increase and mass lesion due to severe traumatic brain injury (TBI). Cranioplasty primarily intends to maintain cerebral protection and reconstruct aesthetic appearance. Also, cranioplasty can enable neurological rehabilitation and potentially augment neurological recovery. This article reviews recent studies on the effect of cranioplasty on neurological recovery in severe TBI.

RECENT FINDINGS

Recent findings suggested that cranioplasty has the potential to enhance neurological recovery after severe TBI. Cranioplasty may alleviate cognitive and functional deficits by reinstating the regular cerebrospinal fluid dynamics and improving brain perfusion. Analyses on the effects of cranioplasty timing on neurological recovery likely favor early cranioplasty. Also, materials used during cranioplasty, autologous and exogenous, were suggested to have similar effects in recovery. Although neurological therapy of TBI patients is still a serious challenge, recent findings represent the possible enhancing effect of cranioplasty on neurological recovery.

Factors predicting complications following cranioplasty

This study aimed to identify factors that predict complications following cranioplasty, by conducting a retrospective cohort study at a large tertiary care center. Electronic databases were searched to identify all patients who underwent cranioplasty at our institution. Baseline demographics, perioperative variables, and outcomes were extracted. Logistic regression analyses were conducted to identify factors associated with cranioplasty complications. Of the 92 included patients, 15 (16.3%) experienced one or more complications, with 11 (73.3%) experiencing complication within 30 days of cranioplasty. Patients aged ≤60 had decreased odds of all-cause complication (OR 0.058; 95% CI 0.008-0.434) and cranioplasty graft removal (OR 0.035; 95% CI 0.004-0.321) on multivariate analysis. Titanium mesh cranioplasties were associated with increased odds of all-cause complication (OR 19.776; 95% CI 1.021-382.901), and cranioplasty removal (OR 29.780; 95% CI 1.330-666.878). A longer craniectomy-cranioplasty interval was associated with increased odds of cranioplasty removal (OR 1.005; 95% CI 1.000-1.010). An initial craniectomy indication of cerebral infarction was associated with decreased odds of all-cause complication (OR 0.042; 95% CI 0.002-0.876) and cranioplasty removal (OR 0.032; 95% CI 0.001-0.766). Elderly patients may require more aggressive follow-up and antibiotic prophylaxis in the postoperative period following cranioplasty. Additionally, avoiding the use of titanium mesh cranioplasties and prolonged craniectomy-cranioplasty intervals may further reduce complications.

First Report of a Multicenter Prospective Registry of Cranioplasty in the United Kingdom and Ireland

BACKGROUND

There are many questions that remain unanswered regarding outcomes following cranioplasty including the timing of cranioplasty following craniectomy as well as the material used.

OBJECTIVE

To establish and evaluate 30-d outcomes for all cranial reconstruction procedures in the United Kingdom (UK) and Ireland through a prospective multicenter cohort study.

METHODS

Patients undergoing cranioplasty insertion or revision between June 1, 2019 and November 30, 2019 in 25 neurosurgical units were included. Data collected include demographics, craniectomy date and indication, cranioplasty material and date, and 30-d outcome.

RESULTS

In total, 313 operations were included, consisting of 255 new cranioplasty insertions and 58 revisions. Of the new insertions, the most common indications for craniectomy were traumatic brain injury (n = 110, 43%), cerebral infarct (n = 38, 15%), and aneurysmal subarachnoid hemorrhage (n = 30, 12%). The most common material was titanium (n = 163, 64%). Median time to cranioplasty was 244 d (interquartile range 144-385), with 37 new insertions (15%) within or equal to 90 d. In 30-d follow-up, there were no mortalities. There were 14 readmissions, with 10 patients sustaining a wound infection within 30 d (4%). Of the 58 revisions, the most common reason was due to infection (n = 33, 59%) and skin breakdown (n = 13, 23%). In 41 (71%) cases, the plate was removed during the revision surgery.

CONCLUSION

This study is the largest prospective study of cranioplasty representing the first results from the UK Cranial Reconstruction Registry, a first national registry focused on cranioplasty with the potential to address outstanding research questions for this procedure.

Three-dimensional printed hydroxyapatite bone tissue engineering scaffold with antibacterial and osteogenic ability

The development of an effective scaffold for bone defect repair is an urgent clinical need. However, it is challenging to design a scaffold with efficient osteoinduction and antimicrobial activity for regeneration of bone defect. In this study, we successfully prepared a hydroxyapatite (HA) porous scaffold with a surface-specific binding of peptides during osteoinduction and antimicrobial activity using a three-dimensional (3D) printing technology. The HA binding domain (HABD) was introduced to the C-terminal of bone morphogenetic protein 2 mimetic peptide (BMP2-MP) and antimicrobial peptide of PSI10. The binding capability results showed that BMP2-MP and PSI10-containing HABD were firmly bound to the surface of HA scaffolds. After BMP2-MP and PSI10 were bound to the scaffold surface, no negative effect was observed on cell proliferation and adhesion. The gene expression and protein translation levels of type I collagen (COL-I), osteocalcin (OCN) and Runx2 have been significantly improved in the BMP2-MP/HABP group. The level of alkaline phosphatase significantly increased in the BMP2-MP/HABP group. The inhibition zone test against Staphylococcus aureus and Escherichia coli BL21 prove that the PSI10/HABP@HA scaffold has strong antibacterial ability than another group. These findings suggest that 3D-printed HA scaffolds with efficient osteoinduction and antimicrobial activity represent a promising biomaterial for bone defect reconstruction.

Complications of Cranioplasty in Relation to Material: Systematic Review, Network Meta-Analysis and Meta-Regression

BACKGROUND

Cranioplasty is a ubiquitous neurosurgical procedure consisting of reconstruction of a pre-existing calvarial defect. Many materials are available, including polymethylmethacrylate in hand-moulded (hPMMA) and prefabricated (pPMMA) form, hydroxyapatite (HA), polyetheretherketone (PEEK) and titanium (Ti).

OBJECTIVE

To perform a network meta-analysis (NMA) to assess the relationship between materials and complications of cranioplasty.

METHODS

PubMed/MEDLINE, Google Scholar, EMBASE, Scopus, and The Cochrane Library were searched from January 1, 1990 to February 14, 2021. Studies detailing rates of any of infections, implant exposure, or revision surgery were included. A frequentist NMA was performed for each complication. Risk ratios (RRs) with 95% CIs were calculated for each material pair.

RESULTS

A total of 3620 abstracts were screened and 31 full papers were included. Surgical revision was reported in 18 studies and occurred in 316/2032 cases (14%; 95% CI 11-17). PEEK had the lowest risk of re-operation with a rate of 8/157 (5%; 95% CI 0-11) in 5 studies, superior to autografts (RR 0.20; 95% CI 0.07-0.57), hPMMA (RR 0.20; 95% CI 0.07-0.60), Ti (RR 0.39; 95% CI 0.17-0.92), and pPMMA (RR 0.14; 95% CI 0.04-0.51). Revision rate was 131/684 (19%; 95% CI 13-25; 10 studies) in autografts, 61/317 (18%; 95%CI 9-28; 7 studies) in hPMMA, 84/599 (13%; 95% CI 7-19; 11 studies) in Ti, 7/59 (9%; 95% CI 1-23; 3 studies) in pPMMA, and 25/216 (12%; 95% CI 4-24; 4 studies) in HA. Infection occurred in 463/4667 (8%; 95% CI 6-11) and implant exposure in 120/1651 (6%; 95% CI 4-9).

CONCLUSION

PEEK appears to have the lowest risk of cranioplasty revision, but further research is required to determine the optimal material.

Complications of cranioplasty following decompressive craniectomy for traumatic brain injury: systematic review and meta-analysis

BACKGROUND

Decompressive craniectomy (DC) is a common neurosurgical intervention for severe traumatic brain injury (TBI), as well as malignant stroke, malignancy and infection. DC necessitates subsequent cranioplasty. There are significant demographic differences between TBI and non-TBI patients undergoing cranioplasty, which may influence their relative risk profiles for infection, aseptic bone flap resorption (aBFR) and re-operation.

OBJECTIVE

Perform a meta-analysis to determine the relative infection, aBFR and re-operation risk profiles of TBI patients as compared to other indications for DC.

METHODS

A systematic review and meta-analysis was performed in accordance with the PRISMA guidelines. PubMed, MEDLINE, EMBASE and Google Scholar were searched until 26/11/2020. Studies detailing rates of infection, re-operation and/or aBFR in specific materials and the post-TBI population were included, while studies in paediatrics or craniosynostosis repair were excluded.

RESULTS

Twenty-six studies were included. There was no difference in relative risk of infection between TBI and non-TBI cohorts (RR 0.81, 95% CI 0.57-1.17), with insignificant heterogeneity (I² = 33%). TBI was a risk factor for aBFR (RR 1.54, 95% CI 1.25-1.89), with no significant heterogeneity (I² = 13%). TBI was a risk factor for re-operation in the autologous sub-group (RR 1.49, 95% CI 1.05-2.11) but not in the alloplastic sub-group (RR = 0.86, 95% CI 0.34-2.18). Heterogeneity was insignificant (I² = 11%).

CONCLUSION

TBI is a risk factor for aBFR and re-operation following cranioplasty. Use of an alloplastic graft for primary cranioplasty in these patients may partially mitigate this increased risk.

AK, Faujdar DS. Bony Union and Flap Resorption in Cranioplasty with Autologous Subcutaneous Pocket Preserved Bone Flap: Early Report on an Ambidirectional CT Scan-Based Study

Introduction Absence of sufficient number of prospective randomized controlled studies and comparatively small sample size and short follow-up period of most of the studies, available so far, have left ambiguity and lack of standardization of different aspects of cranioplasty.

Materials and Methods This is an early report of a computed tomography scan image-based ambidirectional study on cranioplasties performed with autologous subcutaneous pocket preserved bone flaps. Retrospective arm compared bony union and factors influencing it between cranioplasties and craniotomies. Patients with poor bony union and aseptic resorption were followed up in the prospective arm.

Results Retrospective arm of the study, followed up for five years (mean 32.2 months), comprised 42 patients as cases (Group 1) and 29 as controls (Group 2). Twenty-seven individuals (64.3%) in Group 1 had good bony union, as compared with 20 (68.9%) good unions in Group 2 out of the 29 patients. Four patients (9.5%) in Group 1 showed evidence of flap resorption, a finding absent in any patient in Group 2. Age, sex, smoking habits, superficial skin infection, and method of fixation did not appear to have any implication on bony union. Craniotomies done using Gigli saws fared better as compared with those done with pneumatic saw with lesser flap size–craniectomy size discrepancy, though it was not statistically significant. Fifteen patients have been included in the Prospective arm at the time of submission of this article.

Conclusion Ours is a study with a small sample size, unable to put its weight on any side, but can surely add some more data to help the Neurosurgeons in choosing the best for their patients.

Syndrome of the trephined: A rare challenge in head & neck reconstruction

BACKGROUND

Syndrome of the trephined (ST) refers to the rare, reversible event of neurological deterioration following craniectomy. ST is also known as "sinking skin flap syndrome" and typically occurs in the weeks to months following operation. The mechanism underlying syndromic onset is poorly understood. Changes to cerebrospinal fluid flow, alteration of temperature-related perfusion, and scarring at the intracranial surgical site have all been proposed. Patients present with a variety of symptoms related to paradoxical increased intracranial pressure. Sometimes falsely attributed as a consequence of the initial cranial insult, ST is more specifically a symptomatic process resulting as direct consequence of the craniectomy procedure. With timely identification and subsequent cranioplasty, the associated neurological dysfunction can be corrected - this rectification being the primary confirmatory feature of the syndrome.

CASE

A 59-year-old female was seen with regards to a wound of the temporoparietal scalp, with exposed cranial implant. She had suffered a traumatic brain injury and underwent craniectomy after a motor vehicle accident 10 years prior. Her injury was complicated by necrosis of her cranial bone flap after reimplantation and at least 10 subsequent attempts to reconstruct her wound. When delayed cranial reconstruction was attempted on two separate occasions, the patient suffered severe syndrome of the trephined and required hospitalization for symptoms of impending herniation. Ultimately, she required revision and replacement of titanium mesh and latissimus dorsi free flap for soft tissue coverage of the titanium mesh.

CONCLUSION

This case presents a unique surgical challenge in that chronic infection was perpetuated by the replacement of implant material in the wound. Soft tissue reconstruction alone was not possible given the patient's severe ST. Free tissue transfer was required in order to bring vascularized myofascial tissue to prevent recolonization of the newly implanted mesh and allow the cranial wound to heal.

Complications following titanium cranioplasty compared with nontitanium implants cranioplasty: A systematic review and meta-analysis

Decompressive craniectomy is widely used to treat medically refractory intracranial hypertension. There were still few studies focusing on the complications between titanium cranioplasty with non-titanium materials cranioplasty. Our systematic review and meta-analysis aimed to assess the complications following titanium cranioplasty and to make a comparison with nontitanium materials. A systematic review was used to review titanium cranioplasty characters in recent articles. A systematic literature review and meta-analysis were performed by using PubMed/MEDLINE, Scopus, the Cochrane databases and Embase for studies reporting on cranioplasty procedures that compared complication outcomes between titanium with non-titanium materials. The final 15 studies met inclusion criteria and represented 2258 cranioplasty procedures (896 titanium, 1362 nontitanium materials). Overall complications included surgical site infection, hematoma, implant exposure, seizure, cerebrospinal fluid leak, imprecise fitting. Titanium cranioplasty was associated with a significant decrease in overall complications rate (OR, 0.72; P = 0.007), hematoma rate (OR, 0.31; P = 0.0003) and imprecise fitting rate (OR, 0.35; P = 0.04). However, it also suggested that titanium cranioplasty can be greatly increased implant exposure rate (OR, 4.11; P < 0.00001). Our results confirmed the advantages of titanium cranioplasty in reducing complications including hematoma, imprecise fitting, and also suggested that clinicians should pay more attention to postoperative implant exposure. With new synthetic materials emerging, it would also be interesting to study the cost-effect and functional outcomes associated with cranioplasty materials.

Titanium reinforced calcium phosphate improves bone formation and osteointegration in ovine calvaria defects: a comparative 52-weeks study

In a 52-week ovine calvaria implantation model, the restoration of cranial defects with a bare titanium mesh (Ti-mesh) and a titanium mesh embedded in a calcium phosphate (CaP-Ti) were evaluated in seven animals. During the study, no major clinical abnormalities were observed, and all sheep presented a normal neurologic assessment. Blood and CSF analysis, made at termination, did not show any abnormalities. No indentation of the soft tissue was observed for either test article; however, the Ti-mesh burr-hole covers were associated with filling of the calvarial defect by fibrous tissue mainly. Some bone formation was observed at the bottom of the created defect, but no significant bone was formed in the proximity of the implant. The defect sites implanted with CaP-Ti were characterized by a moderate degradation of the calcium phosphate that was replaced by mature bone tissue. Calcium-phosphate-filled macrophages were observed in all animals, indicating that they might play a vital role in osteogenesis. The newly formed bone was present, especially at the bony edges of the defect and on the dura side. Integration of the titanium mesh in a calcium phosphate improved bone formation and osteointegration in comparison to a bare titanium mesh.

Uncertain But Not Unregulated: Medical Product Regulation in the Light of Three-Dimensional Printed Medical Products

As applications of three-dimensional (3D) printed medical products are being translated into clinical practice, stakeholders are increasingly concerned about whether current regulatory frameworks are able to regulate such products. With more additive manufacturing (AM) and 3D printed medical products being brought into clinical use and the assumption that usage will be more widespread in the future, a (perceived) lack of or inadequacy of regulation by some stakeholders is often depicted as a hindrance to the comprehensive translation of AM and 3D printed medical products into clinical use. This article addresses this uncertainty by analyzing existing medical product regulations and their applicability to AM and 3D printed medical products to assess the degree of regulatory oversight they administer. It concludes that there are specific legal questions that need to be clarified, but the products are not expected to "disrupt" existing legal frameworks.

Long-term follow-up of custom-made porous hydroxyapatite cranioplasty in adult patients: a multicenter European study. Can we trust self-reported complications?

BACKGROUND

Cranioplasty is a surgical intervention aiming to re-establish the integrity of skull defects. Autologous bone and different heterologous materials are used for this purpose, with various reported related complications. The aim of the study was to evaluate the complication rate in a multicentric cohort of patients underwent porous hydroxyapatite (PHA) cranioplasty implantation and to assess the validity of company post-market clinical analysis.

METHODS

Authors analyzed a company based register of 6279 PHA cranioplasty implanted all over the world. In these adult patients only self-reported complications were available. We then obtained the data of adult patients treated with custom-made porous HA prostheses (CustomBone Service) in 20 institutions from different European countries through an on-site interview with the physicians in charge of the patients (494 patients). The endpoints were the incidence of adverse events and of related implant removal.

RESULTS

The groups of patients had similar demographics characteristics. The average follow-up was 26.7 months. A significantly higher number of complications was recorded in the group of patients underwent onsite interview. Thirty-nine complications were reported (7.89%) with an explantation rate of 4.25% (21 cases) in the series, compared to the data reported from the Company (complications rate of 3.3% and explantation rate of 3.1%). The most common complications were infection (4.86%), hematomas (1.22%), fractures (1.01%), mobilization (0.4%) and scar retraction (0.4%).

CONCLUSIONS

Our data confirm that porous HA cranioplasty is at least as effective as other heterologous materials to repair cranial defects. Another interesting finding is that self-reporting complicantions by surgeons does not give a precise picture of the real rate of complications of the devices. These data in future studies need to be re-confirmed with on-site interviews.

Comparison of complications in cranioplasty with various materials: a systematic review and meta-analysis

Objective: Meta-analysis to evaluate complications in the use of autogenous bone and bone substitutes and to compare bone substitutes, specifically HA, polyetheretherketone (PEEK) and titanium materials.Methods: Search of PubMed, Cochrane, Embase and Google scholar to identify all citations from 2010 to 2019 reporting complications regarding materials used in cranioplasty.Results: 20 of 2266 articles met the inclusion criteria, including a total of 2913 patients. The odds of overall complication were significantly higher in the autogenous bone group (n = 214/644 procedures, 33.2%) than the bone substitute groups (n = 116/436 procedures, 26.7%, CI 1.29-2.35, p < 0.05). In bone substitutes groups, there was no significant difference in overall complication rate between HA and Ti (OR, 1.2; 95% CI, 0.47-3.14, p = 0.69). PEEK has lower overall complication rates (OR, 0.51; 95% CI, 0.30-0.87, p = 0.01) and lower implant exposure rates (OR, 0.17; 95% CI, 0.06-0.53, p = 0.002) than Ti, but there was no significant difference in infection rates and postoperative hematoma rates.Conclusions: Cranioplasty is associated with high overall complication rates with the use of autologous bone grafts compared with bone substitutes. PEEK has a relatively low overall complication rates in substitutes groups, but still high infection rates and postoperative hematoma rates. Thus, autologous bone grafts should only be used selectively, and prospective long-term studies are needed to further refine a better material in cranioplasty.

Oxysterols as promising small molecules for bone tissue engineering: Systematic review

BACKGROUND

Bone tissue engineering is an area of continued interest within orthopaedic surgery, as it promises to create implantable bone substitute materials that obviate the need for autologous bone graft. Recently, oxysterols – oxygenated derivatives of cholesterol – have been proposed as a novel class of osteoinductive small molecules for bone tissue engineering. Here, we present the first systematic review of the in vivo evidence describing the potential therapeutic utility of oxysterols for bone tissue engineering.

AIM

To systematically review the available literature examining the effect of oxysterols on in vivo bone formation.

METHODS

We conducted a systematic review of the literature following PRISMA guidelines. Using the PubMed/MEDLINE, Embase, and Web of Science databases, we queried all publications in the English-language literature investigating the effect of oxysterols on in vivo bone formation. Articles were screened for eligibility using PICOS criteria and assessed for potential bias using an expanded version of the SYRCLE Risk of Bias assessment tool. All full-text articles examining the effect of oxysterols on in vivo bone formation were included. Extracted data included: Animal species, surgical/defect model, description of therapeutic and control treatments, and method for assessing bone growth. Primary outcome was fusion rate for spinal fusion models and percent bone regeneration for critical-sized defect models. Data were tabulated and described by both surgical/defect model and oxysterol employed. Additionally, data from all included studies were aggregated to posit the mechanism by which oxysterols may mediate in vivo bone formation.

RESULTS

Our search identified 267 unique articles, of which 27 underwent full-text review. Thirteen studies (all preclinical) met our inclusion/exclusion criteria. Of the 13 included studies, 5 employed spinal fusion models, 2 employed critical-sized alveolar defect models, and 6 employed critical-sized calvarial defect models. Based upon SYRCLE criteria, the included studies were found to possess an overall “unclear risk of bias”; 54% of studies reported treatment randomization and 38% reported blinding at any level. Overall, seven unique oxysterols were evaluated: 20(S)-hydroxycholesterol, 22(R)-hydroxycholesterol, 22(S)-hydroxycholesterol, Oxy4/Oxy34, Oxy18, Oxy21/Oxy133, and Oxy49. All had statistically significant in vivo osteoinductive properties, with Oxy4/Oxy34, Oxy21/Oxy133, and Oxy49 showing a dose-dependent effect in some cases. In the eight studies that directly compared oxysterols to rhBMP-2-treated animals, similar rates of bone growth occurred in the two groups. Biochemical investigation of these effects suggests that they may be primarily mediated by direct activation of Smoothened in the Hedgehog signaling pathway.

CONCLUSION

Present preclinical evidence suggests oxysterols significantly augment in vivo bone formation. However, clinical trials are necessary to determine which have the greatest therapeutic potential for orthopaedic surgery patients.

Risk factors for bone flap resorption after autologous bone cranioplasty: Protocol for a systematic review and meta-analysis

BACKGROUND

One of the most common complications following autologous cranioplasty is bone flap resorption (BFR). Severe BFR can lead to revision surgery with implantation of synthetic bone flap and also necessarily lead to higher hospital expenses. This study aims to perform a meta-analysis to summarize available evidence regarding risk factors of BFR requiring a second surgery in patients with autologous cranioplasty.

METHODS

Cohort, case-control, and cross-sectional studies that report the incidence and risk factors of BFR among patients with autologous cranioplasty, published in English, will be considered for selection. Three databases from inception to May 2020 will be searched. The process of data selection, quality assessment, and data extraction will be assessed by 2 authors independently. The study quality will be assessed by Newcastle-Ottawa Scale (NOS) and Agency for Healthcare Research and Quality checklist.The statistical analysis of this meta-analysis will be calculated by Review manager version 5.3.

RESULTS

The results of this systematic review and meta-analysis will be disseminated through academic conferences and expected to publish in a peer-reviewed journal CONCLUSION:: This study will offer high-quality evidence about risk factors for BFR after autologous cranioplasty.

REGISTRATION NUMBER

INPLASY202050063.

Comparison of two different titanium cranioplasty methods: Custom-made titanium prostheses versus precurved titanium mesh

Background:

The aim of this study was to compare the results of two different titanium cranioplasties for reconstructing skull defects: standard precurved mesh versus custom-made prostheses.

Methods:

Retrospective analysis of 23 patients submitted to titanium cranioplasty between January 2014 and January 2019. Ten patients underwent delayed cranioplasty using custom-made prostheses; and 13 patients were treated using precurved titanium mesh (ten delayed cranioplasties, and three single-stage resection- reconstructions). Demographic, clinical, and radiological data were recorded. Results and complications of the two methods were compared, including duration of surgery, cosmetic results (visual analog scale for cosmesis [VASC]), and costs of the implants.

Results:

Complications: one epidural hematoma in the custom-made group, one delayed failure in precurved group due to wound dehiscence with mesh exposure. There were no infections in either group. All custom-made prostheses perfectly fitted on the defect; eight of 13 precurved mesh prostheses incompletely covered the defect. Custom-made cranioplasty obtained better cosmetic results (average VASC 94 vs. 68), shorter surgical time (141min vs. 186min), and -fewer screws was needed to fix the prostheses in place (6 vs. 15). However, satisfactory results were obtained using precurved mesh in cases of small defects and in single-stage reconstruction. Precurved mesh was found to be cheaper (€1,500 vs. €5,500).

Conclusion:

Custom-made cranioplasty obtained better results and we would suggest that this should be a first choice, particularly for young patients with a large cranial defect. Precurved mesh was cheaper and useful for single-stage resection-reconstruction. Depending on the individual conditions, both prostheses have their place in cranioplasty therapies.

A retrospective descriptive study of cranioplasty failure rates and contributing factors in novel 3D printed calcium phosphate implants compared to traditional materials

BACKGROUND

Failure rates with cranioplasty procedures have driven efforts to improve graft material and reduce reoperation. One promising allograft source is a 3D-printed titanium mesh with calcium phosphate filler. This study evaluated failure rates and pertinent characteristics of these novel 3D-grafts compared to traditional materials.

METHODS

Sixty patients were retrospectively identified who underwent a cranioplasty between January 2015-December 2017. Specific data points related to graft failure were collected for all surgical admissions, from the primary injury to their most recent. These included, but were not limited to, initial physical exam findings, vitals, comorbid conditions, surgery length, estimated blood loss, incision type, and need for revision. Failure rates of 3D-printed allografts were compared to traditional grafts.

RESULTS

A total of 60 subjects were identified who underwent 71 unique cranioplasty procedures (3D = 13, Synthetic = 12, Autologous = 46). There were 14 total failures, demonstrating a 19.7% overall failure rate. Specifically, 15.4% (n = 2) of 3D, 19.6% (n = 9) of autologous, and 25.0% (n = 3) of synthetic grafts required revision. Patients receiving 3D-grafts had the shortest overall mean surgery times (200.8 ± 54.3 min) and lowest infection rates (7.7%) compared to autologous (210.5 ± 47.9 min | 25.0%) and synthetic models (217.6 ± 77.3 min | 8.7%), though significance was unable to be determined. Tobacco use and trap-door incisions were associated with increased failure rates relative to straight or curved incisions in autologous grafts. Cranioplasties performed less than 3 months after craniectomy appeared to fail more often than those performed at least three months after craniectomy, for the synthetic group.

CONCLUSION

We concluded that 3D-printed cranioplasty grafts may lead to lower failure rates and shorter surgery times compared to traditional cranioplasty materials in our limited population. 3D-implants hold promise for cranial reconstruction after TBI.

Establishment and Characteristic Analysis of a Dog Model for Autologous Homologous Cranioplasty

Objective

The aim of this study is to establish a large animal (dog) model that can be referred clinically for autologous homologous cranioplasty.

Methods

Our large skull defect dog model was established by emulating the decompressive craniectomy with 22 adult beagle dogs. The autologous bones were taken out from the dogs and divided into two groups, the freeze-drying (FD) group and the single freezing (SF) group. They were then stored in the bone bank at -20°C after being irradiated with 25 KGy. Three months later, the bones were reimplanted. After operation, we closely watch the experimental objects for four more months examining the infection and survival of the bone graft.

Results

Through macroscopic observation, it was found that, among 44 cranial flaps (bilateral) from the rest of the 22 dogs, grade A cranial flaps accounted for 86.4% (19/22) in the SF group and only 31.8% (7/22) in the FD group. Although osteogenic osteoclast, Harvard tube, neovascularization, and angiogenic factors were found through the pathological results, including an electron microscope and calmodulin tracer, it could be verified by using X-CT and micro-CT that early bone resorption could be still found even in grade A bone flap.

Conclusion

By using the common clinical method to preserve the cranial flaps, we established an experimental dog model of autologous cranioplasty for a large area of cranial defect. It was proved that this model could reproduce the infections and bone resorption which typically happened in clinical autologous homologous cranioplasty. As a conclusion, the established model can be used as an effective experimental tool for further research to improve the success rate of autologous homologous cranioplasty.

Three-Dimensional CAD in Skull Reconstruction: A Narrative Review with Focus on Cranioplasty and Its Potential Relevance to Brain Sciences

In patients suffering from severe traumatic brain injury and massive stroke (hemorrhagic or ischemic), decompressive craniectomy (DC) is a surgical strategy used to reduce intracranial pressure, and to prevent brainstem compromise from subsequent brain edema. In surviving patients, cranioplasty surgery helps to protect brain tissue, and correct the external deformity. The aesthetic outcome of cranioplasty using an asymmetrical implant can negatively influence patients physically and mentally, especially young patients. Advancements in the development of biomaterials have now made three-dimensional (3-D) computer-assisted design/manufacturing (CAD/CAM)-fabricated implants an optimal choice for the repair of skull defects following DC. Here, we summarize the various materials for cranioplasty, including xenogeneic, autogenous, and alloplastic grafts. The processing procedures of the CAD/CAM technique are briefly outlined, and reflected our experiences to reconstruct skull CAD models using commercial software, published previously, to assess aesthetic outcomes of regular 3-D CAD models without contouring elevation or depression. The establishment of a 3-D CAD model ensures a possibility for better aesthetic outcomes of CAM-derived alloplastic implants. Finally, clinical consideration of the CAD algorithms for adjusting contours and their potential application in prospective healthcare are briefly outlined.

Three-Dimensional CAD in Skull Reconstruction: A Narrative Review with Focus on Cranioplasty and Its Potential Relevance to Brain Sciences

In patients suffering from severe traumatic brain injury and massive stroke (hemorrhagic or ischemic), decompressive craniectomy (DC) is a surgical strategy used to reduce intracranial pressure, and to prevent brainstem compromise from subsequent brain edema. In surviving patients, cranioplasty surgery helps to protect brain tissue, and correct the external deformity. The aesthetic outcome of cranioplasty using an asymmetrical implant can negatively influence patients physically and mentally, especially young patients. Advancements in the development of biomaterials have now made three-dimensional (3-D) computer-assisted design/manufacturing (CAD/CAM)-fabricated implants an optimal choice for the repair of skull defects following DC. Here, we summarize the various materials for cranioplasty, including xenogeneic, autogenous, and alloplastic grafts. The processing procedures of the CAD/CAM technique are briefly outlined, and reflected our experiences to reconstruct skull CAD models using commercial software, published previously, to assess aesthetic outcomes of regular 3-D CAD models without contouring elevation or depression. The establishment of a 3-D CAD model ensures a possibility for better aesthetic outcomes of CAM-derived alloplastic implants. Finally, clinical consideration of the CAD algorithms for adjusting contours and their potential application in prospective healthcare are briefly outlined.

Tailored Three-Dimensionally Printed Triply Periodic Calcium Phosphate Implants: A Preclinical Study for Craniofacial Bone Repair

Finding alternative strategies for the regeneration of craniofacial bone defects (CSD), such as combining a synthetic ephemeral calcium phosphate (CaP) implant and/or active substances and cells, would contribute to solving this reconstructive roadblock. However, CaP's architectural features (i.e., architecture and composition) still need to be tailored, and the use of processed stem cells and synthetic active substances (e.g., recombinant human bone morphogenetic protein 2) drastically limits the clinical application of such approaches. Focusing on solutions that are directly transposable to the clinical setting, biphasic calcium phosphate (BCP) and carbonated hydroxyapatite (CHA) 3D-printed disks with a triply periodic minimal structure (TPMS) were implanted in calvarial critical-sized defects (rat model) with or without addition of total bone marrow (TBM). Bone regeneration within the defect was evaluated, and the outcomes were compared to a standard-care procedure based on BCP granules soaked with TBM (positive control). After 7 weeks, de novo bone formation was significantly greater in the CHA disks + TBM group than in the positive controls (3.33 mm3 and 2.15 mm3, respectively, P=0.04). These encouraging results indicate that both CHA and TPMS architectures are potentially advantageous in the repair of CSDs and that this one-step procedure warrants further clinical investigation.

Cranioplasty length of stay: Relationship with indication, surgical decision-making factors, and sex

Objectives

Cranioplasty is being performed more often due to rising rates of decompressive craniectomy. Hospital length of stay is a quality metric which has not been directly studied after cranioplasty. This study aims to identify factors associated with length of stay after cranioplasty to better understand their outcomes.

Patients and methods

A retrospective review was conducted at a single academic center from 2007 to 2015 for all patients >18 years of age who received cranioplasty. Baseline data from 148 patients were recorded including demographics, clinical characteristics, and surgeon decision-making factors for cranioplasty. Post-operative complications within 30 days after cranioplasty were recorded in addition to disposition and discharge data. Weibull accelerated failure time models were used to identify significant associations with length of stay after cranioplasty.

Results

The overall post-operative complication rate was 27.0%, and the most frequent indication for craniectomy was traumatic brain injury. The majority (72.3%) of patients returned home, compared to other disposition, and median length of stay was 2.0 days (interquartile range = 2.0). Average length of stay was 7.7 days in men, as compared with 2.4 days in women, and even upon adjusting for covariate effects, length of stay was longer in men than in women irrespective of post-operative complications. When time-to-cranioplasty fell between 0 and 30 days, average length of stay was 19.2 days, as compared with 10.3 days when time-to-cranioplasty fell between 30 and 90 days, and 2.5 days when time-to-cranioplasty was >90 days. After adjustment for covariate effects, the association between time-to-cranioplasty and length of stay was maintained only in patients without post-operative complications.

Conclusions

Length of stay can inform our understanding of outcomes after cranioplasty. In our study, length of stay was associated with sex, indication for craniectomy, and surgical decision-making (time-to-cranioplasty and implant material), but time-to-cranioplasty was only associated in patients without post-operative complications. These relationships should be seen not as direct causation, but rather as tools to add to our understanding of this relatively complicated procedure.

Evaluation of titanium mesh cranioplasty and polyetheretherketone cranioplasty: protocol for a multicentre, assessor-blinded, randomised controlled trial

INTRODUCTION

Cranioplasty is a common surgery in neurosurgery department. However, restoring the integrity of skull brings many challenges to surgeons, and the selection of ideal implant materials is throughout the history of cranioplasty. Although titanium mesh was still preferred by many neurosurgeons in cranial reconstruction, the new polyetheretherketone (PEEK) material, for example, is gaining popularity for craniofacial reconstruction today. There remain limited data that compare the outcome of PEEK cranioplasty and titanium mesh cranioplasty. It is necessary to conduct a study to compare outcome of different materials for cranioplasty.

METHODS/DESIGN

In this multicentre, assessor-blinded, randomised controlled study, we will randomise 140 patients in a 1:1 ratio to PEEK cranioplasty versus titanium cranioplasty. Eligible patients are adults who were diagnosed with cranial defect (due to severe traumatic brain injury, ischaemic stroke, haemorrhagic stroke, infiltrative tumour and so on), the defect size is over 25 cm², and they need to agree to participate in this trial. Instead of standard examinations, the enrolled patients receive neurological, motor, cognitive function and cerebral hemodynamics examinations as well as cosmetic evaluation. The procedures are repeated 3, 6 months after cranioplasty. The primary outcome, defined as infection or implant exposure after surgery, is the implant failure rate within 6 months. Secondary outcomes include postoperative complication rates, neurological outcomes, motor function, cerebral hemodynamics, cosmetic outcome and the total cost over a 6-month period.

ETHICS AND DISSEMINATION

This trial protocol has been approved by Biomedical Research Ethics Committee of West China Hospital of Sichuan University. All patients will be fully informed the implant materials, potential complications after surgery, responsibilities during the trial, and they will sign the informed consent before joining in this trial. If the patient's cognitive function is impaired, the patient's next of kin would be carefully informed. The results will be disseminated through academic conferences, student theses and will be published in a peer-reviewed journal.

TRAIL REGISTRATION NUMBER

ChiCTR1900024625; Pre-results.

Postcranioplasty seizures following decompressive craniectomy and seizure prophylaxis: a retrospective analysis at a single institution

OBJECTIVE

Cranioplasty is a relatively simple and less invasive intervention, but it is associated with a high incidence of postoperative seizures. The incidence of, and the risk factors for, such seizures and the effect of prophylactic antiepileptic drugs (AEDs) have not been well studied. The authors' aim was to evaluate the risk factors that predispose patients to postcranioplasty seizures and to examine the role of seizure prophylaxis in cranioplasty.

METHODS

The records of patients who had undergone cranioplasty at the authors' medical center between 2009 and 2014 with at last 2 years of follow-up were retrospectively reviewed. Demographic and clinical characteristics, the occurrence of postoperative seizures, and postoperative complications were analyzed.

RESULTS

Among the 583 patients eligible for inclusion in the study, 247 had preexisting seizures or used AEDs before the cranioplasty and 336 had no seizures prior to cranioplasty. Of these 336 patients, 89 (26.5%) had new-onset seizures following cranioplasty. Prophylactic AEDs were administered to 56 patients for 1 week after cranioplasty. No early seizures occurred in these patients, and this finding was statistically significant (p = 0.012). Liver cirrhosis, intraoperative blood loss, and shunt-dependent hydrocephalus were risk factors for postcranioplasty seizures in the multivariable analysis.

CONCLUSIONS

Cranioplasty is associated with a high incidence of postoperative seizures. The prophylactic use of AEDs can reduce the occurrence of early seizures.

Polymethylmethacrylate patient-matched implants (PMMA-PMI) for complex and revision cranioplasty: analysis of long-term complication rates and patient outcomes

Objective: Cranioplasty (CP) is associated with high complication rates and patient-matched implants (PMI) are frequently used for CP. However, only limited data are available regarding complication rates of PMI-based CP after complex or failed primary CP. Here we report our experience with the use of polymethylmethacrylate (PMMA) PMI for this purpose.Method: We analyzed all patients with complex or failed primary CP and subsequent implantation of PMMA-PMI between 2010 and 2015 at our institution.Results: A total of 67 patients (29 females, 38 males) with a mean age of 43 years (range: 13-74 years) were included in the study. Primary PMI-CP was performed in 18 patients with destructive or osteolytic bone tumors. Secondary PMI-CP was performed in 49 patients. Complications occurred in 14 patients with an overall complication rate of 21.7% during a mean follow-up of 39.7 ± 23.4 month. Approximately two-thirds of the patients reported a good quality of life after the initial event and subsequent CP. The majority of patients (>90%) was satisfied with the cosmetic result.Conclusion: Surgical CP with PMMA-PMI appears to be a suitable method for patients with failed or complex CP. Complication rates are comparable to those reported for primary CP.

Subcutaneous bone flap storage after emergency craniectomy: cost-effectiveness and rate of resorption

OBJECTIVEDecompressive craniectomy is used for uncontrolled intracranial pressure in traumatic brain injury and malignant hemispheric stroke. Subcutaneous preservation of the autologous bone flap in the abdomen is a simple, portable technique but has largely been abandoned due to perceived concerns of resorption. The authors sought to characterize their experience with subcutaneous preservation of the bone flap and cranioplasty.METHODSThe authors performed a retrospective single-institution review of subcutaneous preservation of the autologous bone flap after decompressive craniectomy from 2005 to 2015. The primary outcome was clinically significant bone resorption, defined as requiring a complete mesh implant at the time of cranioplasty, or delayed revision. The outcome also combined cases with any minor bone resorption to determine predictors of this outcome. Logistic regression modeling was used to determine the risk factors for predicting resorption. A cost comparison analysis was also used via the 2-sided t-test to compare the cost of cranioplasty using an autologous bone flap with standard custom implant costs.RESULTSA total of 193 patients with craniectomy were identified, 108 of whom received a cranioplasty. The mean time to cranioplasty was 104.31 days. Severe resorption occurred in 10 cases (9.26%): 4 were clinically significant (2 early and 2 late) and 6 demonstrated type II (severe) necrosis on CT, but did not require revision. Early resorption of any kind (mild or severe) occurred in 28 (25.93%) of 108 cases. Of the 108 patients, 26 (24.07%) required supplemental cranioplasty material. Late resorption of any kind (mild or severe) occurred in 6 (5.88%) of 102 cases. Of these, a clinically noticeable but nonoperative deformity was noted in 4 (3.92%) and minor (type I) necrosis on CT in 37 (37%) of 100. Bivariate analysis identified fragmentation of bone (OR 3.90, 95% CI 1.03-14.8), shunt-dependent hydrocephalus (OR 7.97, 95% CI 1.57-40.46), and presence of post-cranioplasty drain (OR 9.39, 95% CI 1.14-1000) to be significant risk factors for bone resorption. A binary logistic regression optimized using Fisher's scoring determined the optimal multivariable combination of factors. Fragmentation of bone (OR 5.84, 95% CI 1.38-28.78), diabetes (OR 7.61, 95% CI 1.37-44.56), and shunt-dependent hydrocephalus (OR 9.35, 95% CI 1.64-56.21) were found to be most predictive of resorption, with a C value of 0.78. Infections occurred in the subcutaneous pocket in 5 (2.60%) of the 193 cases and after cranioplasty in 10 (9.26%) of the 108 who underwent cranioplasty. The average cost of cranioplasty with autologous bone was $2156.28 ± $1144.60 (n = 15), and of a custom implant was $35,118.60 ± $2067.51 (3 different sizes; p < 0.0001).CONCLUSIONSCraniectomy with autologous bone cranioplasty using subcutaneous pocket storage is safe and compares favorably to cryopreservation in terms of resorption and favorably to a custom synthetic implant in terms of cost. While randomized data are required to definitively prove the superiority of one method, subcutaneous preservation has enough practical advantages with low risk to warrant routine use for most patients.

Comparison between the different types of heterologous materials used in cranioplasty: a systematic review of the literature

INTRODUCTION

The choice of heterologous materials for cranioplasty after decompressive craniectomy is still difficult. The aim of this study is to examine the association between material of choice and related complications to suggest the best treatment option.

EVIDENCE ACQUISITION

A systematic review was performed for articles reporting cranioplasty comparing the following heterologous implants: titanium, poli-methyl-methacrylate (PMMA), polyetheretherketone (PEEK) and hydroxyapatite (HA). Extracted data included implant materials and incidence of the most frequent complications.

EVIDENCE SYNTHESIS

The final selection resulted in 106 papers but according to our rules only 27 studies were included in the final analysis. Among a total of 1688 custom-made prosthesis implanted, 649 were titanium (38.49%), 298 PMMA (17.56%), 233 PEEK (13.82%), and 508 were HA (30.13%). A total of 348 complications were recorded out of 1688 reported patients (20.64%). In the titanium group, 139 complications were recorded (21.42%); in the PMMA group 57 (19.26%), in the PEEK group 49 (21.03%) and in the HA group 103 (20.3%). If we examine a summary of the reported complications clearly related to cranioplasty (postoperative infections, fractures and prosthesis displacement) versus type of material in multicentric and prospective studies we can see how HA group patients have less reported infections and cranioplasty explantation after infections than PMMA, PEEK and titanium. On the contrary HA patients seem to have a higher number of prosthesis displacement again if compared with the other materials. Since these data are not derived from a statistically correct analysis they should be used only to help to differentiate the properties of the various heterologous cranioplasties.

CONCLUSIONS

The ideal material for all heterologous cranioplasty has not yet been identified. The choice of material should be based on the clinical data of patients, such as the craniectomy size, presence of seizures, possibility of recovery, good long-term outcome associated with a cost analysis.

Use of Stock Titanium Mesh Plates in Cranioplasty

Craniofacial surgeons are often confronted with major defects of the calvarium. These most commonly are post-traumatic but could also be consequent upon neurosurgical procedures, infection, or tumor removal. There are several options available to reconstruct these defects including autogenous, heterogeneous, and alloplastic material. The goal is to have a method that is easy, cost-effective, with minimal complications, and long-lasting. In our unit we review 100 cases of the use of stock titanium mesh during a 5-year period. Complications occurred in 5 patients (5%) with 3 exposures, 1 late seroma and 1 case requiring repositioning of the plate following trauma. None of the patients required removal of the plate.