Discrepancies Between Objective and Subjective Outcomes of and Quality of Life During Molding Helmet Therapy for Cranial Deformities.

Positional skull deformities have been on the rise for decades and can be treated with molding helmets in early childhood. Parents often fear later cosmetic stigmatization, but also a reduced quality of life (QoL) during treatment. The aim of this study was to examine therapy results in our patient collection from a new perspective. Cranial vault asymmetry (CVA), cranial vault asymmetry index (CVAI), and cranial index (CI) were compared before and after molding helmet therapy. Correction was defined by a decrease in CVA <3.5 mm and CI <90%. Subjective therapy outcome, side effects and QoL from the parents' perspective were determined using a questionnaire. There were 25 patients included. Differences between pretherapeutic and posttherapeutic CVA, CVAI, and CI were significant (P<0.01). An objective correction according to the defined values was observed in only 12% of cases. However, 76% of parents stated that their child's skull shape was normal after therapy. There were 60 side effects reported in 23 cases. The QoL of 21 children was assessed as unimpaired during helmet therapy. Even though complete normalization was rarely observed, the parameters were significantly different after therapy, and subjective reduction in skull deformity was common.

Bone density of the cervical, thoracic and lumbar spine measured using Hounsfield units of computed tomography - results of 4350 vertebras.

INTRODUCTION: The assessment of bone density has gained significance in recent years due to the aging population. Accurate assessment of bone density is crucial when deciding on the appropriate treatment plan for spinal stabilization surgery. The objective of this work was to determine the trabecular bone density values of the subaxial cervical, thoracic and lumbar spine using Hounsfield units. MATERIAL AND METHODS: Data from 200 patients who underwent contrast-enhanced polytrauma computed tomography at a maximum care hospital over a two-year period were retrospectively analyzed. HUs were measured with an elliptical measurement field in three different locations within the vertebral body: below the upper plate, in the middle of the vertebral body, and above the base plate. The measured Hounsfield units were converted into bone density values using a validated formula. RESULTS: The mean age of the patient collective was 47.05 years. Mean spinal bone density values decreased from cranial to caudal (C3: 231.79 mg/cm3; L5: 155.13 mg/cm3; p < 0.001), with the highest values in the upper cervical spine. Bone density values generally decreased with age in all spinal segments. There was a clear decrease in values after age 50 years (p < 0.001). CONCLUSIONS: In our study, bone density decreased from cranial to caudal with higher values in the cervical spine. These data from the individual spinal segments may be helpful to comprehensively evaluate the status of the spine and to design a better preoperative plan before instrumentation.

Early detection of aseptic bone necrosis post-cranioplasty: A retrospective CT analysis using Hounsfield units.

This study examined the efficacy of computed tomography (CT)-based Hounsfield units (HU) as early predictors of aseptic bone necrosis, a serious post-cranioplasty complication after autologous cranioplasty. In total, 100 patients who underwent decompressive craniectomy and subsequent autologous cranioplasty were included. The radiodensity of the bone flap was evaluated in HU from CT scans at five follow-up timepoints. HU thresholds were established to predict the development of aseptic bone necrosis. HU demonstrated a declining trend throughout the follow-up period in all patients. Necrosis type I patients showed significant differences at all timepoints from 3 months post-procedure onwards, while necrosis type II patients displayed a significant decline in HU at every follow-up. Optimal thresholds with cut-off A (91.23% of initial HU) and cut-off B (78.73% of initial HU) were established to predict the occurrence of bone necrosis and the need for artificial bone replacement, respectively. Our findings demonstrated the utility of CT-based HU measurements as a simple, non-invasive tool for the early prediction of aseptic bone necrosis following autologous cranioplasty. By delineating specific HU thresholds, our study offers a valuable guide for orchestrating timely follow-ups and advising patients on the necessity of proactive interventions.

Clinical Evaluation of the Osteoporotic Fracture Treatment Score (OF-Score): Results of the Evaluation of the Osteoporotic Fracture Classification, Treatment Score and Therapy Recommendations (EOFTT) Study.

STUDY DESIGN: Multicenter prospective cohort study. OBJECTIVE: The study aims to validate the recently developed OF score for treatment decisions in patients with osteoporotic vertebral compression fractures (OVCF). METHODS: This is a prospective multicenter cohort study (EOFTT) in 17 spine centers. All consecutive patients with OVCF were included. The decision for conservative or surgical therapy was made by the treating physician independent of the OF score recommendation. Final decisions were compared to the recommendations given by the OF score. Outcome parameters were complications, Visual Analogue Scale, Oswestry Disability Questionnaire, Timed Up & Go test, EQ-5D 5 L, and Barthel Index. RESULTS: In total, 518 patients (75.3% female, age 75 ± 10) years were included. 344 (66%) patients received surgical treatment. 71% of patients were treated following the score recommendations. For an OF score cut-off value of 6.5, the sensitivity and specificity to predict actual treatment were 60% and 68% (AUC .684, P < .001). During hospitalization overall 76 (14.7%) complications occurred. The mean follow-up rate and time were 92% and 5 ± 3.5 months, respectively. While all patients in the study cohort improved in clinical outcome parameters, the effect size was significantly less in the patients not treated in line with the OF score's recommendation. Eight (3%) patients needed revision surgery. CONCLUSIONS: Patients treated according to the OF score's recommendations showed favorable short-term clinical results. Noncompliance with the score resulted in more pain and impaired functional outcome and quality of life. The OF score is a reliable and save tool to aid treatment decision in OVCF.

Management of Lumbar Pyogenic Spondylodiscitis in Germany: A Cross-Sectional Analysis of Spine Specialists.

OBJECTIVE: The incidence of pyogenic spondylodiscitis is increasing, and the disease is associated with considerable morbidity, mortality, long-term healthcare utilization and societal costs. Disease-specific treatment guidelines are lacking and there is little consensus regarding optimal conservative and surgical management. This cross-sectional survey of German specialist spinal surgeons sought to determine practice patterns and degree of consensus regarding the management of lumbar pyogenic spondylodiscitis (LPS). METHODS: An electronic survey covering provider information, diagnostic approaches, treatment algorithms, and follow-up care of patients with LPS was distributed to members of the German Spine Society. RESULTS: Seventy-nine survey responses were included in the analysis. Magnetic resonance imaging is the diagnostic imaging modality of choice for 87% of respondents; 100% routinely measure C-reactive protein in suspected LPS and 70% routinely take blood cultures before therapy initiation; 41% believe that surgical biopsy to obtain microbiological diagnosis should be carried out in all cases of suspected LPS, whereas 23% believe that surgical biopsy should only be carried out when empirical antibiotic therapy proves ineffective; 38% believe an intraspinal empyema should always be surgically evacuated, regardless of spinal cord compression. The median intravenous antibiotic duration is 2 weeks. The median total duration of the antibiotic therapy (intravenous and oral) is 8 weeks. Magnetic resonance imaging is the preferred imaging modality for follow-up of both conservatively and operatively treated LPS. CONCLUSIONS: There exists considerable variation of care in the diagnosis, management, and follow-up of LPS among German spine specialists with little agreement on key aspects of care. Further research is required to understand this variation in clinical practice and to enhance the evidence base in LPS.

Bone density of the axis (C2) measured using Hounsfield units of computed tomography.

INTRODUCTION: The assessment of bone density is of great importance nowadays due to the increasing age of patients. Especially in regard to the surgical stabilization of the spine, the assessment of bone density is important for therapeutic decision making. The aim of this work was to record trabecular bone density values using Hounsfield units of the second cervical vertebra. MATERIAL AND METHODS: The study is a monocentric retrospective data analysis of 198 patients who received contrast-enhanced polytrauma computed tomography in a period of two years at a maximum care hospital. Hounsfield units were measured in three different regions within the C2: dens, transition area between dens and vertebral body and vertebral body. The measured Hounsfield units were converted into bone density values using a validated formula. RESULTS: A total of 198 patients were included. The median bone density varied in different regions of all measured C2 vertebrae: in the dens axis, C2 transition area between dens and vertebral body, and in the vertebral body bone densities were 302.79 mg/cm3, 160.08 mg/cm3, and 240.31 mg/cm3, respectively. The transition area from dens axis to corpus had statistically significant lower bone density values compared to the other regions (p < 0.001). There was a decrease in bone density values after age 50 years in both men and women (p < 0.001). CONCLUSIONS: The transitional area from dens axis to corpus showed statistically significant lower bone density values compared to the adjacent regions (p < 0.001). This area seems to be a predilection site for fractures of the 2nd cervical vertebra, which is why special attention should be paid here in radiological diagnostics after a trauma.

Georg Schmorl prize of the German spine society (DWG) 2022: current treatment for inpatients with osteoporotic thoracolumbar fractures-results of the EOFTT study.

AIM: Osteoporotic thoracolumbar fractures are of increasing importance. To identify the optimal treatment strategy this multicentre prospective cohort study was performed. PURPOSE: Patients suffering from osteoporotic thoracolumbar fractures were included. Excluded were tumour diseases, infections and limb fractures. Age, sex, trauma mechanism, OF classification, OF-score, treatment strategy, pain condition and mobilization were analysed. METHODS: A total of 518 patients' aged 75 ± 10 (41-97) years were included in 17 centre. A total of 174 patients were treated conservatively, and 344 were treated surgically, of whom 310 (90%) received minimally invasive treatment. An increase in the OF classification was associated with an increase in both the likelihood of surgery and the surgical invasiveness. RESULTS: Five (3%) complications occurred during conservative treatment, and 46 (13%) occurred in the surgically treated patients. 4 surgical site infections and 2 mechanical failures requested revision surgery. At discharge pain improved significantly from a visual analogue scale score of 7.7 (surgical) and 6.0 (conservative) to a score of 4 in both groups (p < 0.001). Over the course of treatment, mobility improved significantly (p = 0.001), with a significantly stronger (p = 0.007) improvement in the surgically treated patients. CONCLUSION: Fracture severity according to the OF classification is significantly correlated with higher surgery rates and higher invasiveness of surgery. The most commonly used surgical strategy was minimally invasive short-segmental hybrid stabilization followed by kyphoplasty/vertebroplasty. Despite the worse clinical conditions of the surgically treated patients both conservative and surgical treatment led to an improved pain situation and mobility during the inpatient stay to nearly the same level for both treatments.

Occurrence of adjacent segment fractures after surgical treatment of an osteoporotic vertebral fracture: a retrospective comparison between two different treatment methods.

INTRODUCTION: Osteoporotic vertebral fractures are a major healthcare problem. Vertebral cement augmentation (VCA) is frequently used as a minimally invasive surgical approach to manage symptomatic fractures. However, there is a potential risk of adjacent segment fracture (ASF), which may require second surgery. The addition of transcutaneous screw-fixation with cement augmentation superior and inferior to the fracture [Hybrid transcutaneous screw fixation (HTSF)] might represent an alternative treatment option to reduce the incidence of ASF. MATERIALS AND METHODS: We retrospectively compared surgery time, hospital stay, intraoperative complication rate and the occurrence of ASF with the need for a surgical treatment in a cohort of 165 consecutive patients receiving either VCA or HTSF in our academic neurosurgical department from 2012 to 2020. The median follow-up was 52.3 weeks in the VCA-group and 51.9 in the HTSF-group. RESULTS: During the study period, 93 patients underwent VCA, and 72 had HTSF. Of all patients, 113 were females (64 VCA; 49 HTSF) and 52 were males (29 VCA; 23 HTSF). The median age was 77 years in both groups. Median surgery time was 32 min in the VCA-group and 81 min in the HTSF-group (p < 0.0001). No surgery-related complications occurred in the VCA-group with two in the HTSF-group (p = 0.19). ASF was significantly higher in the VCA-group compared to HTSF (24 [26%] vs. 8 [11%] patients; p < 0.02). The proportion of patients requiring additional surgery due to ASF was higher in the VCA-group (13 vs. 6%), but this difference was not statistically significant (p = 0.18). Median hospital stay was 9 days in the VCA-group and 11.5 days in the HTSF-group (p = 0.0001). CONCLUSIONS: Based on this single-center cohort study, HTSF appears to be a safe and effective option for the treatment of osteoporotic vertebral compression fractures. Surgical time and duration of hospital stay were longer in the HTSF-group, but the rate of ASF was significantly reduced with this approach. Further studies are required to ascertain whether HTSF results in superior long-term outcomes or improved quality of life.

Correlation of quantitative computed tomography derived bone density values with Hounsfield units of a contrast medium computed tomography in 98 thoraco-lumbar vertebral bodies.

INTRODUCTION: Vertebral fractures in patients with bone density reduction are often a major challenge for the surgeon, as reduced bone density can lead to screw loosening. Several options are available to determine bone density preoperatively. In our study, we investigated the correlation of Hounsfield units (HU) of a contrast medium computed tomography (CT) to the bone density values of a quantitative computed tomography (QCT) and computed a formula to estimate bone density values using HU. MATERIALS AND METHODS: In our retrospective data analysis, we examine 98 vertebral bodies from 35 patients who received a contrast medium CT of the spine and a QCT, performed no longer than 1 month apart. The determined HU from the contrast medium CT were compared with the bone density values of the QCT and examined for correlations. Linear logistic regression was used to estimate bone density values base on HU. RESULTS: A strong correlation was found between the HU measured in the CT and the bone density values (r = 0.894, p < 0.001), irrespective of patients' gender. We also found no correlation differences when the HU were measured at different levels. Bland-Altman plot demonstrated good agreement between the two measurements. The following formula was developed to estimate bone density values using HU: QCT-value = 0.71 × HU + 13.82. CONCLUSIONS: Bone density values correlate well to HU measured in contrast medium CT. Using simple formula, the bone density of a contrast medium CT of vertebral bodies can be estimated based on HU without additional examinations and unnecessary costs.

Correlation of Bone Density Values of Quantitative Computed Tomography and Hounsfield Units Measured in Native Computed Tomography in 902 Vertebral Bodies.

OBJECTIVE: Due to the increasing age of patients, the evaluation of bone density is crucial, especially in preparation for spinal surgery. The aim of this study was to determine bone density using a computed tomography (CT) and to correlate Hounsfield units (HU) with bone density values of a quantitative computed tomography (QCT). METHODS: The study is a monocentric, retrospective data analysis. We examined 902 vertebral bodies from a total of 369 patients who received a CT of the thoracolumbar spine in the period from 2015 to 2019 and compared the HU with values of a QCT. A general equation for calculation the QCT values was established. RESULTS: We found a significant correlation between the Hounsfield units and the corresponding QCT-values (r = 0.944, P < 0.001). We also demonstrated that the calculated QCT values are independent of patient sex (P < 0.942). Furthermore, we could not demonstrate differences in the correlation of the 3 measured levels (axial, sagittal, and coronary) to the QCT values. The QCT-values can be calculated on the basis of a native CT of the lumbar spine using the equation: QCT = 17.8 + 0.7 × HU. CONCLUSIONS: The equation allows calculating bone density values without the need for an additional QCT and without further radiation exposure or costs. With this measuring method it is possible to obtain additional information from a computed tomography.

Assessment of Skin Flaps Above Cranial Defects Following Craniectomy: A Proposed Classification System.

OBJECTIVE: The assessment of the skin flap above cranial defects (SCD) following craniectomy is routine in neurosurgical practice, and a change in the consistency of the skin flap may indicate raised intracranial pressure or the occurrence of a complication necessitating intervention. The purpose of this study was to develop a clinically useful classification system based on clinical assessment of the degree of skin flap bulging or sinking and its firmness. PATIENTS AND METHODS: This was a prospective single-center study. The SCDs of consecutive patients who underwent craniectomy were assessed daily by two trained independent examiners. The consistency of the flap and its bulging or sinking in comparison with the level of the cranium were noted. Testing conditions including the positioning of the patient and examiner were standardized. RESULTS: A total of 520 examinations were conducted in 24 patients during their hospital stay. There was 100% interrater reliability (Cohen's κ = 1.0). In 66.6% of all patients (n = 16/24), a change of the SCD classification in comparison with that recorded on the previous day was noted. CONCLUSIONS: The SCD classification facilitates the reproducible and objective assessment of SCDs, enabling reliable monitoring over time and between individuals.

Prospective randomized comparison of early versus newer-generation vertebral access devices for kyphoplasty.

INTRODUCTION: Kyphoplasty is an established method of treating osteoporotic vertebral body compression fractures. In recent years, several techniques to enhance the efficiency and outcomes of this surgery have been developed and implemented in clinical practice. In the present study, we assess the impact of two new access instruments on overall operation time and the administered dose area product in comparison with the standard access instrument used in our clinical practice. The two newer comparator devices have been designed with the intention of streamlining intraoperative workflow by omitting several procedural steps. MATERIALS AND METHODS: This was a single-center prospective randomized trial investigating three distinct access instruments compatible with the Joline Allevo balloon catheter system. Specifically, two newer access devices marketed as being able to enhance surgical workflow (Joline RapidIntro Vertebra Access Device with a trocar tip and Joline SpeedTrack Vertebra Introducer Device with a short, tapered tip) were compared with the older, established Joline Vertebra Access Device from the same firm. Consecutive eligible and consenting patients scheduled to undergo kyphoplasty for osteoporotic vertebral compression fracture refractory to conservative, medical treatment during the period May 2012-August 2015 were randomized to receive surgery using one of the three devices. Besides the use of the trial instruments, all other preoperative, intraoperative and postoperative care was delivered according to standard practice. RESULTS: 91 kyphoplasties were performed on 65 unique patients during the study period. The median operation time across the three groups was 29 min (IQR 22.5-35.5) with a median irradiation time of 2.3 min (IQR 1.2-3.4). The median patient age was 74 years (IQR 66-80). The groups did not significantly differ in terms of age (p = 0.878), sex (p = 0.37), T score (p = 0.718), BMI (p = 0.285) or the applied volume of cement (p = 0.792). There was no significant difference between the treatment groups with respect to surgical duration (p = 0.157) or dose area product (p = 0.913). CONCLUSIONS: Although use of the two newer-generation access instruments were designed to involve fewer unique steps per operation, their use was not associated with reduction in surgical duration, irradiation time or dose area product administered compared with the older, established vertebral access device. Care should be taken to evaluate the impact of new instruments on key surgery-related parameters such as surgical duration and radiation exposure and claims made about new instruments should be assessed a structured fashion.

Cement-augmented anterior odontoid screw fixation in elderly patients with odontoid fracture.

OBJECTIVES: Osteoporotic bone predisposes to hardware loosening in patients with odontoid fracture treated with anterior odontoid screw fixation. Cement augmentation is an established method to increase screw anchorage in such cases. The aim of this study was to determine the intra- and perioperative surgical complications of this technique and a comparison with a non-cement augmented group. PATIENTS AND METHODS: During the period January 2012 to November 2017, 24 elderly patients with odontoid fractures and reduced bone mineral density were treated with cement-augmented anterior odontoid screw fixation. Demographic and clinico-anatomical parameters were contemporaneously recorded. A comparison group of 28 elderly patients treated with odontoid screw fixation without cement-augmentation was used to determine the difference of bone fusion rate and whether cement-augmentation extended surgery duration. RESULTS: 24 patients (18 female, 6 male) were treated with cement-augmented anterior odontoid screw fixation during the study period. The median patient age was 84 years (IQR 81-86 years). In 6/24 cases, asymptomatic cement leakage occurred. Five of these cases involved prevertebral cement leakage into the longus colli muscle. In the other case, cement leaked into the C2/3 joint. There was no significant difference in the time required to perform cement-augmented anterior screw fixation compared to fixation without cement-augmentation (median 65 min versus 56.5 min; p = .119). After a median follow-up of 11 months, the bony-fusion rate in the cement-augmented group was 75% (15/24 patients) versus 50% in the non-cement-augmented group (11/28 patients; p = .096). Revision surgery was necessary in none of the cases in the cement-augmented group and in three cases in the non-cement-augmented group (10.7%; p=.048). CONCLUSION: Additional cement augmentation for anterior odontoid fracture repair is a feasible and safe procedure in elderly patients with reduced bone mineral density. Moreover, given that cement-augmentation was associated with a trend towards a higher rate of medium-term bony fusion and a lower revision surgery rate, it is a treatment strategy that should be considered in the management of elderly patients with type IIb odontoid fractures.

Risk Factors for Adjacent Fractures After Cement-Augmented Thoracolumbar Pedicle Screw Instrumentation.

BACKGROUND: The aim of our study was to identify factors that influence the occurrence of adjacent fractures in patients with cement-augmented pedicle screw instrumentation. METHODS: Data were retrospectively collected from medical charts and operative reports for every surgery in which cement-augmented instrumentation was used in our hospital of 4 consecutive years. A total of 93 operations were included and examined for gender, age, T-score, number of fused segments, number of implanted screws, broken screws, loosening of screws, leakage and distribution pattern of cement, pre- and postoperative kyphosis angle, revision surgery and adjacent fractures in follow-up. Categorical data were compared using the χ2 test or by Fisher's exact test, as appropriate. Continuous variables conforming to a normal distribution were compared using Student's t test. Otherwise the Mann-Whitney U test was applied. A P-value of <.05 was considered statistically significant. A trend was defined as a P < .2. RESULTS: The mean age was 68.1 years with a mean T-score of -3.12. Nineteen adjacent fractures occurred during follow-up and the median follow-up was 12 months (range, 1-27). Patients showed a higher risk for adjacent fractures following revision surgery (P = .016). Most fractures occurred superior to the instrumented level (P = .013) and in the first 12 months. Difference of T-score between the group "no adjacent fracture" and the group "adjacent fracture" was 0.7 (P = .138). Another trends were found in greater age (P = .119) and long instrumentations (P = .199). CONCLUSIONS AND CLINICAL RELEVANCE: Revision surgeries are associated with a higher risk of adjacent fractures. In these cases, prophylactic kyphoplasty of the superior vertebra should be considered. This study is a retrospective, nonrandomized cohort/follow-up study. LEVEL OF EVIDENCE: 3.

Cement-augmented anterior odontoid screw fixation for osteoporotic type II odontoid fractures in elderly patients: prospective evaluation of 11 patients.

PURPOSE: Osteoporosis is considered to be a relative contraindication for anterior screw fixation of odontoid fractures because of reduced screw purchase. In the presence of osteoporosis, the most frequent mode of implant failure is via cut-out through the anterior wall of C2. Under in vitro conditions, cement-augmented odontoid screws show significant biomechanical advantages as compared to non-augmented screws. Against this background, we present our prospectively collected data on cement-augmented anterior screw fixation of osteoporotic odontoid fractures in elderly patients. METHODS: 11 patients (8 female, 3 male, median age 83 years, range 73-89 years) with an isolated, osteoporotic type II odontoid fracture were treated. After closed reduction and standard anterior approach to the C2/3 level, a self-tapping, short-threaded 3.5-mm lag screw was placed. High-viscosity polymethylmethacrylate cement was injected via a cannulated Jamshidi needle into the base of the C2 vertebral body around the screw shaft and the screw was further tightened. Thin slice CT reconstructions for follow-up evaluation were done consistently postop and 12 months after surgery. RESULTS: Anatomic fracture reposition was achieved in all patients. Cement application was uneventful and well controllable. Cement leakage towards the fracture gap was not detectable. There were no major perioperative complications and no early revision surgeries. After 1 year, thin slice CT with three-dimensional reconstruction demonstrated solid osseous healing of the odontoid fracture in 8 out of 10 patients. CONCLUSIONS: Additional cement augmentation for anterior odontoid fracture repair is technically easy and safe. In elderly people with osteoporotic odontoid fractures, the procedure seems to be a useful supplementary option.

Cranioplasty after decompressive craniectomy: is there a rationale for an initial artificial bone-substitute implant? A single-center experience after 631 procedures.

OBJECTIVE: The complication rate for cranioplasty after decompressive craniectomy is higher than that after other neurosurgical procedures; aseptic bone resorption is the major long-term problem. Patients frequently need additional operations to remove necrotic bone and replace it with an artificial bone substitute. Initial implantation of a bone substitute may be an option for selected patients who are at risk for bone resorption, but this cohort has not yet been clearly defined. The authors' goals were to identify risk factors for aseptic bone flap necrosis and define which patients may benefit more from an initial bone-substitute implant than from autograft after craniectomy. METHODS: The authors retrospectively analyzed 631 cranioplasty procedures (503 with autograft, 128 with bone substitute) by using a stepwise multivariable logistic regression model and discrimination analysis. RESULTS: There was a significantly higher risk for reoperation after placement of autograft than after placement of bone substitute; aseptic bone necrosis (n = 108) was the major problem (OR 2.48 [95% CI1.11-5.51]). Fragmentation of the flap into 2 or more fragments, younger age (OR 0.97 [95% CI 0.95-0.98]; p < 0.001), and shunt-dependent hydrocephalus (OR 1.73 [95% CI1.02-2.92]; p = 0.04) were independent risk factors for bone necrosis. According to discrimination analysis, patients younger than 30 years old and older patients with a fragmented flap had the highest risk of developing bone necrosis. CONCLUSIONS: Development of bone flap necrosis is the main concern in long-term follow-up after cranioplasty with autograft. Patients younger than 30 years old and older patients with a fragmented flap may be candidates for an initial artificial bone substitute rather than autograft.

Risk factors for reoperation after initial burr hole trephination in chronic subdural hematomas.

BACKGROUND: The optimal management of chronic subdural hematomas remains a challenge. Twist drill craniotomy or burr hole trephination are considered optimal initial treatments, but the reoperation rate for hematoma recurrence and other complications is still high. Therefore, evaluation of possible risk factors for initial treatment failure is crucial. In this context, we performed a study to define a possible subpopulation that may benefit from a more invasive initial treatment regime. METHODS: We retrospectively reviewed the medical charts of 193 patients with 250 chronic subdural hematomas who had undergone burr hole trephination as first-line therapy in our institution between January 2005 and October 2012. To identify risk factors for reoperation, a multivariable logistic regression analysis was performed with reoperation as the dependent variable. Surgical complications, including acute rebleeding, infection and chronic hematoma recurrence, were analyzed separately using a logistic regression model. RESULTS: The mean age of the cohort was 71.4 years. The male/female ratio was 137:56. Reoperation was necessary in 56 cases (29%) for recurrent hematomas and surgical complications. Predictors for reoperation for surgical complications were midline shift (odds ratio [OR] (per mm) 1.16, 95% confidence interval [CI]: 1.05-1.29, p=0.006), arterial hypertension (OR 5.44, 95% CI: 1.45-20.41, p=0.012) and bilateral hematomas (OR 4.22, 95% CI: 1.22-14.58, p=0.023). There was a trend toward a higher risk of surgically-relevant hematoma recurrence in patients with prior treatment with vitamin K antagonists (OR 1.76, 95% CI: 0.75-4.13, p=0.191). CONCLUSION: Burr hole trephination is the therapy of choice in most chronic subdural hematomas, but the rate of recurrent hematomas is high. Every hematoma should be treated individually especially in relation to midline-shift and pre-existing conditions. Further prospective studies evaluating types of treatment and hematoma density are needed.