Early vs late cranioplasty: what is better?

Improved rehabilitation efficiency after cranioplasty in patients with sunken skin flap syndrome: a case series

PURPOSE

Sunken Skin Flap Syndrome (SSFS) is an uncommon, delayed complication after craniectomy characterized by a functional plateau or decline with variable neurologic symptoms, improving after cranioplasty. SSFS negatively impacts the rehabilitation course, with subjective reports of functional improvement after cranioplasty. However, no studies have assessed the impact of cranioplasty on functional recovery rate. This case series aims to analyze SSFS manifestations and management while awaiting cranioplasty. Also, to assess the role of cranioplasty on rehabilitation outcomes and recovery rate in SSFS patients.

METHODS

Four patients were identified with SSFS in inpatient rehabilitation. Each patient had unique clinical manifestations, with multiple strategies used for symptomatic control. Patients spent an average of 23 days in rehabilitation with SSFS symptoms before cranioplasty. After cranioplasty, all patients had SSFS symptom resolution. Comparing change in functional independence measure (FIM) scores and FIM efficiency pre-and post-cranioplasty rehabilitation course, a mean improvement of 23 and 0.72 occurred after cranioplasty, respectively.

CONCLUSION

A diagnosis of SSFS should be considered in craniectomy patients exhibiting functional decline or plateau with associated neurological symptoms. This study suggests that FIM and FIM efficiency increases in SSFS patients after cranioplasty, supporting prompt cranioplasty to improve functional outcomes and minimize rehabilitation delays.

Post-traumatic decompressive craniectomy: Prognostic factors and long-term follow-up

Background

Decompressive craniectomy (DC) is still controversial in neurosurgery. According to the most recent trials, DC seems to increase survival in case of refractory intracranial pressure. On the other hand, the risk of postsurgical poor outcomes remain high. The present study aimed to evaluate a series of preoperative factors potentially impacting on long-term follow-up of traumatic brain injury (TBI) patients treated with DC.

Methods

We analyzed the first follow-up year of a series of 75 TBI patients treated with DC at our department in five years (2015-2019). Demographic, clinical, and radiological parameters were retrospectively collected from clinical records. Blood examinations were analyzed to calculate the preoperative neutrophil-to-lymphocyte ratio (NLR). Disability rating scale (DRS) was used to classify patients' outcomes (good outcome [G.O.] if DRS ≤11 and poor outcome [P.O.] if DRS ≥12) at 6 and 12 months.

Results

At six months follow-up, 25 out of 75 patients had DRS ≤11, while at 12 months, 30 out of 75 patients were included in the G.O. group . Admission Glasgow Coma Scale (GCS) >8 was significantly associated with six months G.O. Increased NLR values and the interval between DC and cranioplasty >3 months were significantly correlated to a P.O. at 6- and 12-month follow-up.

Conclusion

Since DC still represents a controversial therapeutic strategy, selecting parameters to help stratify TBI patients' potential outcomes is paramount. GCS at admission, the interval between DC and cranioplasty, and preoperative NLR values seem to correlate with the long-term outcome.

Earlier cranioplasty following posttraumatic craniectomy is associated with better neurological outcomes at one-year follow-up: a two-centre retrospective cohort study

PURPOSE

Cranioplasty (CP) after decompressive craniectomy (DC) is routinely performed for reconstructive purposes and improves rehabilitation. However, the optimal timing of CP remains controversial. This study aimed to assess differences in clinical outcomes following different timings of CP in patients with traumatic brain injury.

MATERIALS AND METHODS

Patients with traumatic brain injury who underwent CP after DC in Zhongnan Hospital of Wuhan University from 1 January 2010 to 1 May 2017, and in Affiliated Hospital of Guizhou Medical University from 1 January 2015, to 1 May 2017, were retrospectively reviewed. According to the timing of CP, patients were divided into an 'early group' (3-6 months) and a 'late group' (6-12 months). The clinical characteristics of patients and postoperative complications occurred within 1-year follow-up were analysed. The neurological function was assessed with Barthel Index (BI).

RESULTS

A total of 100 patients (58 cases in early group and 42 cases in late group) were included. The median interval between DC and CP was 135 days and 225 days in the early and late CP groups, respectively. The overall complication rate after CP was 16%, and no significant difference in complication rate was observed between the early and late CP groups (17.2% vs.14.3%, p = 0.69). The neurological function was improved in early CP group (pre-CP 85.77 ± 11.61 vs. post-CP 95.34 ± 9.02, p < 0.001, but not in late CP group (pre-CP 82.74 ± 22.82 vs. post-CP 88.93 ± 22.86, p = 0.22). In addition, a significantly higher proportion of patients in the early CP group showed neurological functional improvement in comparison with the late CP group (early vs. late: 74.1% vs. 57.1%, p = 0.04). Multivariate analysis further demonstrated that the timing of CP is an independent predictor for neurological outcomes (OR = 0.32, 95% CI 0.13-0.82, p = 0.02).

CONCLUSION

Early CP (3-6 months) following posttraumatic DC was associated with better neurological outcomes than late CP (>6 months).

Ultra-Early Cranioplasty versus Conventional Cranioplasty: A Retrospective Cohort Study at an Academic Level 1 Trauma Center

The goal of this study was to ascertain the efficacy, safety, and comparability of ultra-early cranioplasty (CP; defined here as <30 days from the original craniectomy) to conventional cranioplasty (defined here as >30 days from the original craniectomy). A retrospective review of CPs performed at our institution between January 2016 and July 2020 was performed. Craniectomies initially performed at other institutions were excluded. Seventy-seven CPs were included in our study. Ultra-early CP was defined as CP performed within 30 days of craniectomy whereas conventional CP occurred after 30 days. Post-operative wound infection rates, rate of return to the operating room (OR) with or without bone flap removal, operative length, and rate of post-CP hydrocephalus were compared between the two groups. Thirty-nine and 38 patients were included in the ultra-early and conventional CP groups, respectively. The average number of days to CP in the ultra-early group was 17.70 ± 7.75 days compared to 95.70 ± 65.60 days in the conventional group. The mean Glasgow Coma Scale upon arrival to the emergency room was 7.28 ± 3.90 and 6.92 ± 4.14 for the ultra-early and conventional groups, respectively. The operative time was shorter in the ultra-early cohort than that in the conventional cohort (ultra-early, 2.40 ± 0.71 h; conventional, 3.00 ± 1.63 h; p = 0.0336). The incidence of post-CP hydrocephalus was also lower in the ultra-early cohort (ultra-early, 10.3%; conventional, 31.6%; p = 0.026). No statistically significant differences were observed regarding post-operative infection, return to the OR, or bone flap removal. Our study shows that ultra-early CP can significantly reduce the rate of post-CP hydrocephalus, as well as operative time in comparison to conventional CP. However, the timing of CP post-DC should remain a patient-centered consideration.

Cranioplasty: A Multidisciplinary Approach

Decompressive craniectomy (DC) is an operation where a large section of the skull is removed to accommodate brain swelling. Patients who survive will usually require subsequent reconstruction of the skull using either their own bone or an artificial prosthesis, known as cranioplasty. Cranioplasty restores skull integrity but can also improve neurological function. Standard care following DC consists of the performance of cranioplasty several months later as historically, there was a concern that earlier cranioplasty may increase the risk of infection. However, recent systematic reviews have challenged this and have demonstrated that an early cranioplasty (within three months after DC) may enhance neurological recovery. However, patients are often transferred to a rehabilitation unit following their acute index admission and before their cranioplasty. A better understanding of the pathophysiological effects of cranioplasty and the relationship of timing and complications would enable more focused patient tailored rehabilitation programs, thus maximizing the benefit following cranioplasty. This may maximise recovery potential, possibly resulting in improved functional and cognitive gains, enhancement of quality of life and potentially reducing longer-term care needs. This narrative review aims to update multi-disciplinary team regarding cranioplasty, including its history, pathophysiological consequences on recovery, complications, and important clinical considerations both in the acute and rehabilitation settings.

Microsurgical scalp reconstruction and cranioplasty refined

Introduction: Microsurgical free flap scalp reconstruction is commonly the only reconstructive option in certain challenging patient cohorts. We describe the technical refinements that have streamlined our ap-proach to microsurgical scalp reconstruction and cranioplasty. Methods: Virtual surgical planning for multiple failed cranioplasty cases involves fashioning an implant with a 3 mm offset. Intramuscular dissection of the latissimus dorsi (LD) vascular pedicle, distal to its bifurcation, is routinely performed, and can increase pedicle length by up to 4 cm without the need for tedious dissec-tion in the axilla. Anastomoses to the superficial temporal vessels distal to their bifurcation in the parietal scalp are reliable and safe. The sequence of surgery is in reverse to the conventional sequence, with the free flap vascularised before craniectomy/cranioplasty is performed to decrease the duration of synthetic im-plant exposure. Results: Thirty-nine cases were performed in 35 patients over a five-year period. An LD-based free flap in various permutations was the commonest free flap option (n = 31). The superficial temporal artery and vein were choice recipient vessels in 82 per cent and 74 per cent of cases, respectively, with the former demon-strating higher anatomical consistency. Complications included free flap venous congestion successfully salvaged (n = 1), infected polymethylmethacrylate cranioplasty requiring explantation (n = 1), subdural haematoma requiring craniotomy for evacuation (n = 1) and free flap donor site haematoma (n = 2). Conclusion: Our technical refinements offer a streamlined and reliable procedure of complex scalp recon-struction and cranioplasty.

Characteristics of Patients with Trephine Syndrome: A Retrospective Study

Objectives:

This study retrospectively investigated the prevalence and clinical features of trephine syndrome, which is a late complication of craniectom, in patients who underwent craniectomy decompression.

Methods:

Trephine syndrome was defined as an increase of ≥2 points in the functional independent measure (FIM) score at 7 days after cranioplasty compared with that 3 days before cranioplasty. Patients who underwent craniectomy at Kawasaki Medical School Hospital between January 1, 2010, and March 15, 2020, were included in the study.

Results:

During the observation period, 102 patients underwent craniectomy decompression; 71 of them later underwent cranioplasty. In total, 12 and 59 patients were assigned to the trephine and non-trephine syndrome groups, respectively. The patients in the trephine syndrome group were significantly younger than those in the non-trephine syndrome group (P<0.05). The mean durations±standard deviations (in days) from craniectomy decompression to cranioplasty were 57.1±38.9 and 83.6±69.3 for the trephine and non-trephine syndrome groups, respectively (P<0.05). Improvements in the FIM motor scores were greater than the improvements in the cognitive scores for all but one case (P<0.05). The frequency with which patients experienced exacerbation (worsened consciousness and sudden anisocoria) after hospitalization was significantly higher in the trephine syndrome group than in the non-trephine syndrome group (P<0.05).

Conclusions:

Performing cranioplasty as early as possible in young patients may lead to functional improvement. In the trephine syndrome group, the improvement in motor FIM score was greater than that of the cognitive score. Moreover, post-hospitalization exacerbation was more frequent in the trephine syndrome group.

Trends and Outcomes of Cranioplasty Alone Versus Single-Stage Composite Scalp and Calvarial Reconstruction

BACKGROUND

Cranioplasty is a critical intervention to restore the calvarium using autologous or alloplastic materials with single-stage composite scalp and calvarial reconstruction reserved for complex cases. This study aims to identify 30-day outcomes in scalp and calvarial reconstruction using the American College of Surgeons National Surgical Quality Improvement Program database.

METHODS

The authors conducted a retrospective analysis of the 2010 to 2018 American College of Surgeons National Surgical Quality Improvement Program database. Adult patients who underwent cranioplasty were identified using current procedural terminology coding and included by exposure type (autologous, alloplastic, composite, or other). Subjects with missing exposure or outcome data were excluded. Primary outcome was 30-day reoperation, whereas secondary outcomes were 30-day unplanned readmission and transfusion. Univariate analysis was completed to assess differences in demographics, comorbidities, and postoperative complications. Multivariable logistic regression was used to control for confounders.

RESULTS

In total, 1719 patients underwent cranioplasty (mean age 54.7 ± 15.3 years, 43.5% male), including 169(9.8%) autologous, 1303(75.8%) alloplastic, 32(1.9%) composite, and 215(12.5%) other procedures. Cranioplasty procedures were associated with 30-day complication and mortality rate of 16.5% and 2.4%, respectively. Composite cranioplasty was associated with decreased 30-day reoperation (adjusted odds ratios 0.11, 95% confidence interval 0.014-0.94, P = 0.044). There was no statistically significant difference in readmission between cranioplasty groups. Alloplastic cranioplasty was associated with decreased odds of postoperative transfusion (adjusted odds ratios 0.47, 95% confidence interval 0.27-0.84, P = 0.01).

CONCLUSIONS

Cranioplasty is an increasingly common procedure. Alloplastic cranioplasty is associated with decreased 30-day transfusion requirement, whereas single-stage composite reconstruction is a viable option and associated with decreased 30-day reoperation with no difference in readmission.

Can Cranioplasty Be Considered a Tool to Improve Cognitive Recovery Following Traumatic Brain Injury? A 5-Years Retrospective Study

Cranioplasty (CP) is a neurosurgical intervention of skull repairing following a decompressive craniectomy. Unfortunately, the impact of cranioplasty on cognitive and motor function is still controversial. Fifteen TBI subjects aged 26–54 years with CP after decompressive craniectomy were selected in this observational retrospective study. As per routine clinical practice, a neuropsychological evaluation carried out immediately before the cranioplasty (Pre CP) and one month after the cranioplasty (T0) was used to measure changes due to CP surgery. This assessment was performed each year for 5 years after discharge in order to investigate long-term cognitive changes (T1-T5). Before cranioplasty, about 53.3% of subjects presented a mild to severe cognitive impairment and about 40.0% a normal cognition. After CP, we found a significant improvement in all neuropsychological test scores. The more significant differences in cognitive recovery were detected after four years from CP. Notably, we found significant differences between T4 and T0-T1, as well as between T5 and T0-T1-T2 in all battery tests. This retrospective study further suggests the importance of CP in the complex management of patients with TBI showing how these patients might improve their cognitive function over a long period after the surgical procedure.

The Boundless World of Cranioplasty: A Multicenter Retrospective Study and Therapeutic Flow-Chart Patient-Specific Based

BACKGROUND

Cranioplasty is both a functional and aesthetical therapeutic option. In the clinical scenario every cranioplasty's material is potentially qualified to achieve the goal of calvarian reconstruction but there is a lack of agreement about the optimum choice, especially between the heterologous ones. The choice of cranioplasty widely depends on surgeon's personal preferences. In this retrospective multicentric study a comparative analysis of hydroxyapatite or titanium cranioplasties was carried on analyzing the main factors considered by the surgeon to choose a material rather than another one. Our results and data were compared with those reported in the scientific literature and a flow-chart regarding the therapeutic approach in the choice of the most suitable cranioplasty was proposed and discussed.

METHODS

The authors present a multicentric study considering 2 groups of patients who underwent 2 different kinds of cranioplasty: hydroxyapatite and titanium. The outcomes measures included the surgical timing and the maintenance of post-operative subgaleal drain.

RESULTS

A total of 40 patients that had cranioplasty treatment were evaluated. The surgical technique was analyzed. In patients that underwent titanium cranioplasty we observed a reduction in the operative times and in subgaleal drain maintenance. In relation to the age, comorbidity, and neurological status a score, called most suitable material (MSM), was elaborated and a therapeutic algorithm is proposed.

CONCLUSIONS

This study confirms the known advantages and drawback of titanium and hydroxyapatite prostheses. Thanks to the lessons learned from our experience on this field, we elaborated the MSM score that coupled with the therapeutic flow-chart proposed could address the choice of the MSM for a specific patient.

Effect of cranioplasty timing on the functional neurological outcome and postoperative complications

BACKGROUND

The optimal timing for performing cranioplasty and its effect on functional outcome remains debatable. Multiple confounding factors may come into role; including the material used, surgical technique, cognitive assessment tools, and the overall complications. The aim of this study is to assess the neurological outcome and postoperative complications in patients who underwent early versus late cranioplasty.

METHODS

A retrospective cohort study was conducted to investigate the neurological outcome and postoperative complications in patients who underwent cranioplasty between 2005 and 2018 at a Level l trauma center. Early and late cranioplasties were defined as surgeries performed within and more than 90 days of decompressive craniectomy, respectively. The Glasgow Outcome Score (GOS) and modified Rankin scale (mRS), recorded within 1 week of cranioplasty, were used to assess the neurological outcome.

RESULTS

A total of 101 cases of cranioplasty were included in the study. The mean age of the patients was 31.4 ± 13.9 years. Most patients (n = 86; 85.1%) were male. The mean GOS for all patients was 4.0 ± 1.0. The mean mRS was 2.2 ± 1.78. Hydrocephalus was noted in 18 patients (early, n = 6; late, n = 12; P = 0.48). Seizures developed in 28 patients (early, n = 12; late, n = 16; P = 0.77).

CONCLUSION

The neurological outcome in patients who underwent early versus late cranioplasty is almost identical. The differences in the rates of overall postoperative complications between early versus late cranioplasty were statistically insignificant. The optimal timing for performing cranioplasty is mainly dependent on the resolution of cerebral swelling.

A Comparative Study of the Effects of Early Versus Late Cranioplasty on Cognitive Function

Cranioplasty (CP) after decompressive craniectomy (DC) is associated with neurological improvement. We evaluated neurological recovery in patients who underwent late CP (more than 6 months after DC) in comparison with early CP. This prospective study of 51 patients investigated neurological function using the Addenbrooke's Cognitive Examination Revised (ACE-R), Mini-Mental State Examination (MMSE), Barthel Index (BI), and Modified Rankin Scale (mRS) prior to and after CP. Most patients with traumatic brain injury (74%) were young (mean age 33.4 ± 12.2 years) and male (33/51; 66%). There were general improvements in the patients' cognition and functional status, especially in the late-CP group. The ACE-R score increased from the time point before CP to 3 days after CP (51 ± 28.94 versus 53.1 ± 30.39, P = 0.016) and 90 days after CP (51 ± 28.94 versus 58.10 ± 30.43, P = 0.0001). In the late-CP group, increments also occurred from the time point before CP to 90 days after CP in terms of the MMSE score (18.54 ± 1.51 versus 20.34 ± 1.50, P = 0.003), BI score (79.84 ± 4.66 versus 85.62 ± 4.10, P = 0.028), and mRS score (2.07 ± 0.22 versus 1.74 ± 0.20, P = 0.015). CP is able to improve neurological outcomes even more than 6 months after DC.

Effects of Cranioplasty After Decompressive Craniectomy on Neurological Function and Cerebral Hemodynamics in Traumatic Versus Nontraumatic Brain Injury

After decompressive craniectomy (DC), cranioplasty (CP) can help to normalize vascular and cerebrospinal fluid circulation besides improving the patient's neurological status. The aim of this study was to investigate the effects of CP on cerebral hemodynamics and on cognitive and functional outcomes in patients with and without a traumatic brain injury (TBI). Over a period of 3 years, 51 patients were included in the study: 37 TBI patients and 14 non-TBI patients. The TBI group was younger (28.86 ± 9.71 versus 45.64 ± 9.55 years, P = 0.0001), with a greater proportion of men than the non-TBI group (31 versus 6, P = 0.011). Both groups had improved cognitive outcomes (as assessed by the Mini-Mental State Examination) and functional outcomes (as assessed by the Barthel Index and Modified Rankin Scale) 90 days after CP. In the TBI group, the mean velocity of blood flow in the middle cerebral artery ipsilateral to the cranial defect increased between the time point before CP and 90 days after CP (34.24 ± 11.02 versus 42.14 ± 10.19 cm/s, P = 0.0001). In conclusion, CP improved the neurological status in TBI and non-TBI patients, but an increment in cerebral blood flow velocity after CP occurred only in TBI patients.

Cranioplasty: A Comprehensive Review of the History, Materials, Surgical Aspects, and Complications

Cranioplasty is a common neurosurgical procedure performed to reconstruct cranial defects. The materials used to replace bone defects have evolved throughout history. Cranioplasty materials can be broadly divided into biological and synthetic materials. Biological materials can be further subdivided into autologous grafts, allografts, and xenografts. Allografts (bony materials and cartilage from cadavers) and xenografts (bony materials from animals) are out of favor for use in cranioplasty because of their high rates of infection, resorption, and rejection. In autologous cranioplasty, either the cranial bone itself or bones from other parts of the body of the patient are used. Synthetic bone grafts have reduced the operation time and led to better cosmetic results because of the advancement of computer-based customization and three-dimensional printing. Aluminum was the first synthetic bone graft material used, but it was found to irritate neural tissue, induce seizures, and dissolve over time. Acrylic, in the form of methyl methacrylate, is the most widely used material in cranioplasty. Hydroxyapatite is a natural component of bone and is believed to enhance bone repair, resulting in decreased tissue reactions and promoting good osteointegration. Polyetheretherketones are light and nonconductive and do not interfere with imaging modalities. The complication rates of cranioplasty are high, and surgical site infection is the most common complication. The effect of cranioplasty timing on cognitive function remains debatable. However, the timing of cranioplasty is independent of neurologic outcomes. In this article, the history, materials, complications, and evolution of current practices used in cranioplasty are comprehensively reviewed.

Custom-Made Porous Hydroxyapatite Cranioplasty in Patients with Tumor Versus Traumatic Brain Injury: A Single-Center Case Series

BACKGROUND

Cranioplasty is a common neurosurgical procedure with the goal of restoring skull integrity. Custom-made porous hydroxyapatite prostheses have long been used for cranial reconstruction in patients with traumatic brain injury. We present a large consecutive series of 2 groups of patients undergoing cranioplasty with hydroxyapatite custom bone and compare the adverse events (AEs) between the 2 groups.

METHODS

We examined a series of consecutive patients who underwent cranioplasty using custom-made porous hydroxyapatite implants following tumor resection and traumatic brain injury at a single center between March 2003 and May 2018. The implants were designed and produced according to the surgeon's specifications and based on the patient's computed tomography scan data obtained through a standardized protocol. AEs were recorded.

RESULTS

Information on 38 patients with tumor and 39 patients with traumatic brain injury was collected and analyzed. A significant difference in the timing of surgery was found between the 2 groups; single-stage surgery was performed in 84% of patients in the tumor versus 8% of those in the traumatic brain injury group (P < 0.0001). The rate of AEs was not significantly different between the 2 groups (P = 0.4309) and was not related to the timing of surgery.

CONCLUSIONS

Custom-made hydroxyapatite cranioplasty is a solution for cranial reconstruction in patients with cranial tumors. The low incidence of AEs in a consecutive series of patients with either trauma or tumors demonstrates that these prostheses represent a safe solution independent of the characteristics of cases.

[Modern aspects of reconstructive surgery of skull defects]

The aim of this study is to systematize the modern methods used for reconstruction of extensive and complex skull defects. Special attention is paid to computer technologies, including 3D imaging and CAD/CAM. Laser-based stereolithography is thoroughly reviewed among other additive technologies. We present our view of the problem associated with proper timing of cranioplasty and choice of materials for it. Complications of skull defect reconstruction are also discussed.

Timing for cranioplasty to improve neurological outcome: A systematic review

INTRODUCTION

Cranioplasty is a surgical technique applied for the reconstruction of the skullcap removed during decompressive craniectomy (DC). Cranioplasty improves rehabilitation from a motor and cognitive perspective. However, it may increase the possibility of postoperative complications, such as seizures and infections. Timing of cranioplasty is therefore crucial even though literature is controversial. In this study, we compared motor and cognitive effects of early cranioplasty after DC and assess the optimal timing to perform it.

METHODS

A literature research was conducted in PubMed, Web of Science, and Cochrane Library databases. We selected studies including at least one of the following test: Mini-Mental State Examination, Rey Auditory Verbal Learning Test immediate and 30-min delayed recall, Digit Span Test, Glasgow Coma Scale, Glasgow Outcome Scale, Coma Recovery Scale-Revised, Level of Cognitive Functioning Scale, Functional Independence Measure, and Barthel Index.

RESULTS

Six articles and two systematic reviews were included in the present study. Analysis of changes in pre- and postcranioplasty scores showed that an early procedure (within 90 days from decompressive craniectomy) is more effective in improving motor functions (standardized mean difference [SMD] = 0.51 [0.05; 0.97], p-value = 0.03), whereas an early procedure did not significantly improve neither MMSE score (SMD = 0.06 [-0.49; 0.61], p-value = 0.83) nor memory functions (SMD = -0.63 [-0.97; -0.28], p-value < 0.001). No statistical significance emerged when we compared studies according to the timing from DC.

CONCLUSIONS

It is believed that cranioplasty performed from 3 to 6 months after DC may significantly improve both motor and cognitive recovery.

Bioinspired Collagen Scaffolds in Cranial Bone Regeneration: From Bedside to Bench

Calvarial defects are common reconstructive dilemmas secondary to a variety of etiologies including traumatic brain injury, cerebrovascular disease, oncologic resection, and congenital anomalies. Reconstruction of the calvarium is generally undertaken for the purposes of cerebral protection, contour restoration for psychosocial well-being, and normalization of neurological dysfunction frequently found in patients with massive cranial defects. Current methods for reconstruction using autologous grafts, allogeneic grafts, or alloplastic materials have significant drawbacks that are unique to each material. The combination of wide medical relevance and the need for a better clinical solution render defects of the cranial skeleton an ideal target for development of regenerative strategies focused on calvarial bone. With the improved understanding of the instructive properties of tissue-specific extracellular matrices and the advent of precise nanoscale modulation in materials science, strategies in regenerative medicine have shifted in paradigm. Previously considered to be simple carriers of stem cells and growth factors, increasing evidence exists for differential materials directing lineage specific differentiation of progenitor cells and tissue regeneration. In this work, we review the clinical challenges for calvarial reconstruction, the anatomy and physiology of bone, and extracellular matrix-inspired, collagen-based materials that have been tested for in vivo cranial defect healing.