Background
A cranioplasty offers the neurosurgical patient restoration of skull defects caused by trauma, infections, tumors, surgeries, or congenital issues. It often follows a decompressive craniectomy.1,2 Cranial defects leave patients vulnerable to intracranial pressure dysregulation, cerebrospinal fluid (CSF) dynamic disturbance, cerebral injury, and psychosocial difficulty.3 Often unconsidered, cranioplasty plays a key role in restoring cosmesis and psychosocial difficulty.1,3The choice of implant material influences outcomes including infection rates, bone resorption, and revision surgery. Despite being biocompatible and low cost, autologous bone grafts carry resorption rates of 20%–40%, more so in pediatric and young adult patients.1,2,4 Titanium implants, despite being expensive and associated with infection or poor osseointegration, are superior in structural stability and resistance to resorption.5–7
Timing remains an integral part of cranioplasty planning. Ultra-early cranioplasty (≤30 days) offers shorter operative times and improved neurological recovery in some patients,8–10 while early cranioplasty (<90 days) has been shown to improve CSF dynamics and cognitive recovery but with a potentially elevated hydrocephalus risk.1,11 Delayed cranioplasty (≥90 days) is associated with higher rates of bone resorption and extended surgical time.1,12,13 Ultra-late repair (>180 days) has a higher complication rate.14 Despite this growing evidence base, outcome data from Kenya and sub-Saharan Africa (SSA) are nearly absent from the literature. In resource-limited settings, material availability, cost constraints, theater access, and the nature of follow-up introduce complexity that is not captured by a high-income country series. The present study describes 7 years of cranioplasty experience at a Kenyan tertiary referral center, documenting implant selection patterns, the distribution and clinical consequences of surgical timing, and predictors of infectious complications with the aim of extracting practical lessons relevant to local neurosurgical practice.
Methods
Study design and setting
This was a retrospective case series conducted at a tertiary neurosurgical referral center in Kenya. All patients who underwent cranioplasty between 2017 and December 2024 were eligible.
Inclusion and exclusion criteria
Patients were included if they: (1) underwent cranioplasty during the study period; and (2) had complete operative and postoperative records available for review. Patients were excluded if records were incomplete to the extent that primary outcomes could not be ascertained or if they underwent revision cranioplasty of a previously failed implant performed outside the study institution.
Data collection
Data were extracted from electronic and physical medical records using a structured, prepiloted data collection instrument. Variables captured included: patient demographics; indications for and timing of preceding craniectomy; cranioplasty characteristics (material, fixation, timing, and surgeon grade); perioperative factors (antibiotic prophylaxis, drain use, and vancomycin powder application); and postoperative outcomes. Two independent researchers extracted and cross-checked all data; discrepancies were resolved by consensus. A pilot test was conducted on a small subset of records to refine the data collection tool.
Missing data were handled as follows:
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Variables with ≥20% missing items were excluded from inferential analysis and reported descriptively only.
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Epilepsy history and antiepileptic drug (AED) use were identified as incompletely recorded (<50% completeness) and are therefore reported as data gaps rather than structured findings.
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Of the 106 cranioplasty procedures performed during the study period, 77 were excluded due to incomplete operative or postoperative records, leaving 29 patients with complete records for analysis.
Outcome definitions
Two infectious outcomes were distinguished: (1) infection in the postcraniectomy interval, which was defined as a documented clinical or microbiological infection of the cranial wound occurring between the index craniectomy and cranioplasty; and (2) postcranioplasty surgical site infection (SSI), which was defined as an infection meeting standard criteria within 30 days of the cranioplasty procedure. These were treated as distinct outcomes throughout. The composite primary outcome for implant comparison was any postcranioplasty complication (SSI, CSF leak, or revision surgery).
Statistical analysis
Descriptive statistics are presented as a median and interquartile range (IQR) for continuous variables and as a frequency with percentage for categorical variables. Fisher’s exact test was used for categorical comparisons given sparse cell counts. Relative risk (RR) and an odds ratio (OR) with 95% confidence intervals were calculated to describe associations. Mann-Whitney U tests were used for continuous variable comparisons by the outcome group. All analyses were performed in SPSS (version 28) and Stata (version 17).
Given the sample size of 29 patients, and a large set of missing data (77 cases), the study was substantially underpowered for comparative inference between implant groups or timing categories. The analyzed cases did not meet the estimated sample size of 100. This study is, therefore, descriptive and hypothesis-generating. No formal multivariable logistic regression was undertaken because the event rate (maximum 5 composite complications) does not meet the minimum 10-events-per-variable rule required for stable regression estimation. All P-values should be interpreted within this context.
Ethics
Ethical approval was obtained from the Kenyatta National Hospital-University of Nairobi Ethics and Research Committee (Approval reference: P573/06/2025) prior to data collection. A waiver of informed consent was granted for retrospective review of existing medical records. All data were anonymized prior to analysis. The study was conducted in accordance with the Declaration of Helsinki.
Results
Patient characteristics
A total of 29 patients with complete records were identified and included. The cohort was predominantly male (26/29, 89.7%) with a median age of 32 years (IQR of 22–40; range of 6–67). Baseline hemoglobin was 15.1 g/dL (IQR of 13.8–15.7; mean 14.7 ± 1.7) and serum albumin was 43.8 g/L (IQR of 40.5–44.7). A pre-existing cranial wound/infection was reported in 6/29 cases (20.7%) (Table 1).
Operative characteristics
The most common indication for the preceding craniectomy was trauma (24/29, 82.8%), including a severe traumatic brain injury in 7 cases. The operative intent of cranioplasty was overwhelmingly cosmetic as cited in more than two-thirds of procedures (20/29, 69.0%). When stratified by timing to cranioplasty, cosmetic indications were the most frequent in every group, particularly in the ultra-late (11/15) and delayed (4/5) categories. The median interval from craniectomy to cranioplasty was 194 days (IQR of 79.5–303; range of 0–655 days). The majority of procedures were ultra-late (>180 days, 15/29, 51.7%), with relatively few ultra-early (4/29, 13.8%) or early (3/29, 10.3%) cases. With respect to cranioplasty characteristics, defects were most commonly unilateral with 41.4% (12/29) occurring on the right and 34.5% (10/29) occurring on the left and the rest being frontal. Titanium was the most frequently used implant (17/29, 58.6%), followed by autologous bone (8/29, 27.6%) and PMMA (3/29, 10.3%). Rigid fixation with screws and/or plates was used in 65.5% of cases. All patients received preoperative antibiotic prophylaxis. Cefazolin was used in 86.2% of cases and other antibiotics in the remaining cases. Adjunctive infection prevention measures were widely adopted. For example, vancomycin irrigation or powder was applied in 86.2% (25/29) of procedures. CSF leak or dural breach was uncommon (3/29, 10.3%), while drain placement was used in approximately two-fifths of cases (12/29, 41.4%). Most procedures were performed by neurosurgical residents (21/29, 72.4%) (Table 2).
Postoperative outcomes
The median hospital stay was 8 days (IQR of 6–11; range of 4–35). Postoperative complications are summarized in Table 3. The composite complication rate (SSI, CSF leak, or revision surgery) was 17.2% (5/29). We did not document deaths, hydrocephalus, hematoma, subdural fluid collection, or bone resorption.Three patients (10.3%) developed infection in the postcraniectomy interval, which is distinct from the single postcranioplasty SSI (3.4%). The SSI occurred in the ultra-early group and was the only case to require revision surgery. Complications by the timing group were ultra-early at 3/4 (75%), which was the most diverse complication profile and included the sole SSI, CSF leak, and revision: early at 2/3 (66.7%), which was driven entirely by seizures; delayed at 0/5 (0%); and ultra-late at 5/15 (33.3%), which was predominantly seizures with no SSI or CSF leak.
Implant material and outcomes
For this analysis, patients were grouped as autologous (N = 8) or synthetic (titanium, PMMA, and the mixed construct; N = 21). Composite complication rates were 12.5% (1/8) in the autologous group and 19.0% (4/21) in the synthetic group. Effect estimates were imprecise and Fisher’s exact test (used given the sparse cell counts) was not significant ((RR of 0.66; 95% CI of 0.09–5.02; P = 0.677), (OR of 0.61; 95% CI of 0.06–6.44)). Confidence intervals were wide for all outcomes, which reflect the small sample size. These findings do not support a conclusion of equivalence or superiority between groups; they reflect an absence of statistical power (Table 4).
Predictors of infection
A pre-existing cranial wound or infection was strongly associated with infection in the postcraniectomy interval: 3/6 (50%) patients with this finding developed infection, compared with 0/22 of those without this finding (Fisher’s exact of P = 0.006; RR of 23.00; OR of 45.00). No other examined predictor, including CSF leak, drain insertion, surgeon grade, fixation method, or implant material, reached statistical significance (Table 5a).
Among continuous predictors, length of stay was longer in patients who developed postcraniectomy infection (median of 16 vs 8 days; Mann-Whitney of P = 0.075), although this did not reach significance. Other continuous variables including age, hemoglobin, and craniectomy-to-cranioplasty interval showed no meaningful association with infection (Table 5b).
The single SSI case also had the longest operative duration (360 minutes). Despite vancomycin powder or solution being used in 86.2% of cases (including the SSI case), near-universal uptake of this intervention precluded any meaningful analysis of its effect.
Discussion
This study describes real-world cranioplasty practice at a Kenyan tertiary referral center. The findings are organized mainly around 3 themes: implant use, surgical timing and infectious complications. The key finding with statistical support is that a pre-existing cranial wound or infection is strongly associated with infectious complications in the postcraniectomy period. Observations relating to implant type and timing are descriptive and hypothesis-generating only; the observations are constrained by the sample size of 29 patients after a significant removal of incompletely reported documented cases. Young males with post-traumatic head injury predominate the series, which is consistent with established global and regional epidemiological patterns.15–17 The concentration of cranioplasty in young adult males reflects the incidence of road traffic accidents as a leading cause of severe traumatic brain injury in Kenya.17 Titanium accounted for 58.6% of the material used, a pattern consistent with its growing global use that is attributed to favorable structural profiles and reduced re-operation rates.18–21 Autologous bone, used in 27.6% of cases, remains relevant in cost-constrained settings despite published rates of resorption of up to 40% in pediatric populations.22,23 The absence of bone resorption in this series may reflect limited long-term follow-up duration and the predominantly adult age profile.
The dominance of ultra-late procedures (51.7%, >180 days) is a substantive lesson. In a high-income country series, early cranioplasty (<90 days) is increasingly favored for its association with improved CSF dynamics, cerebral compliance, and neurological recovery11,24,25; ultra-late repair (>180 days) has been linked to higher complication rates in the pooled analysis.14 In this cohort, however, most cases fall in the ultra-late category. We subjectively anticipate that plausible causes of this preference include theater scheduling delays, implant procurement lead times and affordability, infection-related postponement, and patient follow-up gaps that are common in resource-limited systems. Notably, the delayed group (>90–180 days) had zero documented complications, and the ultra-late group had a complication profile driven predominantly by seizures rather than surgical complications.
The lesson for neurosurgical practice is not simply to operate earlier but to identify and address the specific system-level barriers that force ultra-late reconstruction. Our institution is heavily dependent on evidence-based practice although the evidence practiced is imported from regions with different structural settings. Future region-specific guidelines must address these drivers rather than importing time recommendations derived from settings where early surgery is logistically feasible. The single robust finding, the association between a pre-existing cranial wound or infection and subsequent postcraniectomy infection (*P=*0.006), is clinically meaningful and actionable. In practice, this suggests that patients presenting for cranioplasty with a history of cranial wound complication warrant heightened preoperative risk stratification, optimization of any residual infection prior to reconstruction, and potentially more intensive postoperative surveillance.26,27
The role of vancomycin powder could not be assessed in this series given near-universal uptake (86.2%), including in the single SSI case. Evidence remains mixed: one large retrospective series reported a significant reduction in SSI with intrawound vancomycin in cranioplasty,28 while a 2025 systematic review found only a nonsignificance toward benefit.29 The single infected case had no drain. Interestingly, at least one relatively large autologous cranioplasty series found the opposite of what many would assume: that placement of subgaleal drain was a protective factor against infection.30 Appropriately powered prospective data are needed.
Limitations
Several limitations must be acknowledged. First, and most critically, severe attrition of the dataset from the collected 106 cases to a sample of 29 patients makes this dataset insufficient for comparative inference. All between-group analyses are descriptive only and should not be used to draw conclusions about implant superiority or optimal timing. Second, the retrospective design introduces selection and information bias; data quality is dependent on the completeness of existing records. Third, follow-up was not standardized across patients, and the duration and completeness of postoperative surveillance varied. Fourth, preoperative epilepsy status and AED use were not systematically recorded, which preclude meaningful interpretation of the seizure outcome. Fifth, patient-reported outcome measures and quality-of-life assessments were not available, limiting evaluation of the functional and psychosocial impact of cranioplasty. Finally, as a single-center study, findings may not be generalizable across SSA settings with differing resources, patient populations, and surgical volumes.
Future directions
The findings of this study support a call for a prospective, multicenter cranioplasty registry at an institutional level and across SSA to avoid the pitfalls met in analysis of these data. Such a registry will enable adequately powered analysis of factors involving cranioplasty and provide answers for questions that remain unanswered by the current evidence base, which is predominantly high-income setting based.
Conclusion
We present 3 practical lessons for cranioplasty in the Kenyan setting. First, titanium is the most common implant used in cranioplasty and performed well clinically. Comparisons could not be made with statistical significance, but results align with evidence favoring synthetic implants where feasible. Second, most cranioplasties were done ultra-late (>180 days) and can be presumed to be due to structural or economical barriers or clinical preference. The lesson would be not to just apply global evidence by recommending earlier surgery but to also fix the system-level barriers that may contribute to this preference compared to the higher income settings. Third, a pre-existing cranial wound or infection remains a statistically significant predictor of postoperative infection. Such patients need better preoperative optimization and postoperative surveillance to mitigate infectious morbidity. These 3 findings provide a modest but practical framework component for improving cranioplasty practice in this region. A larger multicenter prospective research base is needed to build on these observations and develop region-specific guidelines.
Acknowledgments
None
Ethical Approval
Ethical approval for this study was granted by the Kenyatta National Hospital-University of Nairobi Ethics and Research Committee (Approval reference: P573/06/2025) prior to data collection. The study was conducted in accordance with the Declaration of Helsinki.
Informed Consent
A waiver of individual informed consent was granted by the Institutional Ethics and Research Committee, as the study involved retrospective review of existing medical records. All records were de-identified prior to analysis.
Data Availability
The de-identified dataset generated and analysed during this study is available from the corresponding author on reasonable request.
Conflict of Interest
None
Funding
None