Bone Flap Resorption: Risk Factors for the Development of a Long-Term Complication following Cranioplasty after Decompressive Craniectomy

OBJECTIVEAutologous bone cranioplasty after decompressive craniectomy entails a notable burden of difficult postoperative complications, such as infection and bone flap resorption (BFR), leading to mechanical failure. The prevalence and significance of asymptomatic BFR is currently unclear. The aim of this study was to radiologically monitor the long-term bone flap survival and bone quality change in patients undergoing autologous cranioplasty.METHODSThe authors identified all 45 patients who underwent autologous cranioplasty at Oulu University Hospital, Finland, between January 2004 and December 2014. Using perioperative and follow-up CT scans, the volumes and radiodensities of the intact bone flap prior to surgery and at follow-up were calculated. Relative changes in bone flap volume and radiodensity were then determined to assess cranioplasty survival. Sufficient CT scans were obtainable from 41 (91.1%) of the 45 patients.RESULTSThe 41 patients were followed up for a median duration of 3.79 years (25th and 75th percentiles = 1.55 and 6.66). Thirty-seven (90.2%) of the 41 patients had some degree of BFR and 13 (31.7%) had a remaining bone flap volume of less than 80%. Patients younger than 30 years of age had a mean decrease of 15.8% in bone flap volume compared with the rest of the cohort. Bone flap volume was not found to decrease linearly with the passing of time, however. The effects of lifestyle factors and comorbidities on BFR were nonsignificant.CONCLUSIONSIn this study BFR was a very common phenomenon, occurring at least to some degree in 90% of the patients. Decreases in bone volume were especially prominent in patients younger than 30 years of age. Because the progression of resorption during follow-up was nonlinear, routine follow-up CT scans appear unnecessary in monitoring the progression of BFR; instead, clinical follow-up with mechanical stability assessment is advised. Partial resorption is most likely a normal physiological phenomenon during the bone revitalization process.

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Risk factors and rates of bone flap resorption in pediatric patients after decompressive craniectomy for traumatic brain injury

Journal of Neurosurgery Pediatrics ◽

10.3171/2013.1.peds12483 ◽

2013 ◽

Vol 11 (5) ◽

pp. 526-532 ◽

Cited By ~ 74

Author(s):

Christian A. Bowers ◽

Jay Riva-Cambrin ◽

Dean A. Hertzler ◽

Marion L. Walker

Keyword(s):

Risk Factors ◽

Traumatic Brain Injury ◽

Multivariate Analysis ◽

Brain Injury ◽

Decompressive Craniectomy ◽

Pediatric Patients ◽

Skull Fracture ◽

Bone Flap ◽

Bone Flap Resorption ◽

Independent Risk Factors

Object Decompressive craniectomy with subsequent autologous cranioplasty, or the replacement of the native bone flap, is often used for pediatric patients with traumatic brain injury (TBI) who have a mass lesion and intractable intracranial hypertension. Bone flap resorption is common after bone flap replacement, necessitating additional surgery. The authors reviewed their large database of pediatric patients with TBI who underwent decompressive craniectomy followed by bone flap replacement to determine the rate of bone flap resorption and identify associated risk factors. Methods A retrospective cohort chart review was performed to identify long-term survivors who underwent decompressive craniectomy for severe TBI with bone flap replacement from January 1, 1996, to December 31, 2011. The risk factors investigated in a univariate statistical analysis were age, sex, underlying parenchymal contusion, Glasgow Coma Scale score on arrival, comminuted skull fracture, posttraumatic hydrocephalus, bone flap wound infection, and freezer time (the amount of time the bone flap was stored in the freezer before replacement). A multivariate logistic regression model was then used to determine which of these were independent risk factors for bone flap resorption. Results Bone flap replacement was performed at an average of 2.1 months after decompressive craniectomy. Of the 54 patients identified (35 boys, 19 girls; mean age 6.2 years), 27 (50.0%) experienced bone flap resorption after an average of 4.8 months. Underlying parenchymal contusion, comminuted skull fracture, age ≤ 2.5 years, and posttraumatic hydrocephalus were significant, or nearly significant, on univariate analysis. Multivariate analysis identified underlying contusion (p = 0.004, OR 34.4, 95% CI 3.0–392.7), comminuted skull fractures (p = 0.046, OR 8.5, 95% CI 1.0–69.6), posttraumatic hydrocephalus (p = 0.005, OR 35.9, 95% CI 2.9–436.6), and age ≤ 2.5 years old (p = 0.01, OR 23.1, 95% CI 2.1–257.7) as independent risk factors for bone flap resorption. Conclusions After decompressive craniectomy for pediatric TBI, half of the patients (50%) who underwent bone flap replacement experienced resorption. Multivariate analysis indicated young age (≤ 2.5 years), hydrocephalus, underlying contusion as opposed to a hemispheric acute subdural hematoma, and a comminuted skull fracture were all independent risk factors for bone flap resorption. Freezer time was not found to be associated with bone flap resorption.

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Bone Flap Resorption in Pediatric Patients Following Autologous Cranioplasty

Operative Neurosurgery ◽

10.1093/ons/opaa452 ◽

2021 ◽

Author(s):

David S Hersh ◽

Hanna J Anderson ◽

Graeme F Woodworth ◽

Jonathan E Martin ◽

Yusuf M Khan

Keyword(s):

Risk Factors ◽

Bone Resorption ◽

Decompressive Craniectomy ◽

Pediatric Patients ◽

Bone Flap ◽

Calvarial Bone ◽

Advantages And Disadvantages ◽

Bone Flap Resorption ◽

Autologous Bone

Abstract Following a decompressive craniectomy, the autologous bone flap is generally considered the reconstructive material of choice in pediatric patients. Replacement of the original bone flap takes advantage of its natural biocompatibility and the associated low risk of rejection, as well as the potential to reintegrate with the adjacent bone and subsequently grow with the patient. However, despite these advantages and unlike adult patients, the replaced calvarial bone is more likely to undergo delayed bone resorption in pediatric patients, ultimately requiring revision surgery. In this review, we describe the materials that are currently available for pediatric cranioplasty, the advantages and disadvantages of autologous calvarial replacement, the incidence and classification of bone resorption, and the clinical risk factors for bone flap resorption that have been identified to date.

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

Journal of Neurosurgery ◽

10.3171/2017.6.jns17943 ◽

2018 ◽

Vol 129 (6) ◽

pp. 1604-1610 ◽

Cited By ~ 8

Author(s):

Griffin Ernst ◽

Fares Qeadan ◽

Andrew P. Carlson

Keyword(s):

Risk Factors ◽

Logistic Regression ◽

Bone Resorption ◽

Decompressive Craniectomy ◽

Significant Risk ◽

Bone Flap ◽

Type I ◽

Custom Implant ◽

Autologous Bone ◽

Clinically Significant

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.

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Bone Flap Resorption Following Cranioplasty after Decompressive Craniectomy: Preliminary Report

Korean Journal of Neurotrauma ◽

10.13004/kjnt.2015.11.1.1 ◽

2015 ◽

Vol 11 (1) ◽

pp. 1 ◽

Cited By ~ 11

Author(s):

Ji Sang Kim ◽

Jin Hwan Cheong ◽

Je Il Ryu ◽

Jae Min Kim ◽

Choong Hyun Kim

Keyword(s):

Decompressive Craniectomy ◽

Preliminary Report ◽

Bone Flap ◽

Bone Flap Resorption

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Initial Dead Space and Multiplicity of Bone Flap as Strong Risk Factors for Bone Flap Resorption after Cranioplasty for Traumatic Brain Injury

Korean Journal of Neurotrauma ◽

10.13004/kjnt.2018.14.2.105 ◽

2018 ◽

Vol 14 (2) ◽

pp. 105 ◽

Cited By ~ 1

Author(s):

Jeong Kyun Joo ◽

Jong-Il Choi ◽

Chang Hyun Kim ◽

Ho Kook Lee ◽

Jae Gon Moon ◽

...

Keyword(s):

Risk Factors ◽

Traumatic Brain Injury ◽

Brain Injury ◽

Dead Space ◽

Bone Flap ◽

Bone Flap Resorption

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

Journal of Neurosurgery ◽

10.3171/2015.4.jns159 ◽

2016 ◽

Vol 124 (3) ◽

pp. 710-715 ◽

Cited By ~ 42

Author(s):

Falko Schwarz ◽

Pedro Dünisch ◽

Jan Walter ◽

Yasser Sakr ◽

Rolf Kalff ◽

...

Keyword(s):

Risk Factors ◽

Bone Resorption ◽

Decompressive Craniectomy ◽

Bone Substitute ◽

Older Patients ◽

Artificial Bone ◽

Flap Necrosis ◽

Discrimination Analysis ◽

Bone Necrosis

OBJECT 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.

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Risk factors of aseptic bone resorption: a study after autologous bone flap reinsertion due to decompressive craniotomy

Journal of Neurosurgery ◽

10.3171/2013.1.jns12860 ◽

2013 ◽

Vol 118 (5) ◽

pp. 1141-1147 ◽

Cited By ~ 56

Author(s):

Pedro Dünisch ◽

Jan Walter ◽

Yasser Sakr ◽

Rolf Kalff ◽

Albrecht Waschke ◽

...

Keyword(s):

Risk Factors ◽

Multivariate Analysis ◽

Decompressive Craniectomy ◽

Perioperative Complications ◽

Bone Flap ◽

Type Ii ◽

Flap Necrosis ◽

Bone Necrosis ◽

Increased Risk ◽

Autologous Bone

Object In patients who have undergone decompressive craniectomy, autologous bone flap reinsertion becomes necessary whenever the cerebral situation has consolidated. However, aseptic necrosis of the bone flap remains a concern. The aim of this study was to report possible perioperative complications in patients undergoing autologous bone flap reinsertion and to identify the risk factors that may predispose the bone flap to necrosis. Methods All patients admitted to the authors' neurosurgical department between September 1994 and June 2011 and who received their own cryoconserved bone flap after decompressive craniectomy were studied. The grade of the bone flap necrosis was classified into 2 types. Type II bone necrosis was characterized by aseptic resorption with circumscribed or complete lysis of tabula interna and externa requiring surgical revision. To define predisposing factors, a multivariate analysis was performed using bone necrosis as the dependent variable. Results Among the 372 patients (mean age 48.6 years, 57.4% males) who received 414 bone flaps during the observation period, 134 (36.0%) had a diffuse traumatic brain injury, 69 (18.5%) had subarachnoid hemorrhage, 58 (15.6%) had cerebral infarction, 56 (15.1%) had extraaxial bleeding, 43 (11.6%) had intracerebral bleeding, and 12 (3.2%) had a neoplasm. Surgical relevant Type II bone flap necrosis occurred in 85 patients (22.8%) and 91 bone flaps, after a median time of 15 months (interquartile range [IQR], 10–33 months). In a multivariate analysis with Type II necrosis as the dependent variable, bone flap fragmentation with 2 (OR 3.35, 95% CI 1.59–7.01, p < 0.002) or more fragments (OR 24.00, 95% CI 10.13–56.84, p < 0.001), shunt-dependent hydrocephalus (OR 1.76, 95% CI 0.99–3.12, p = 0.04), and a younger age (OR 0.98, 95% CI 0.96–0.99, p = 0.004) was associated with a higher risk for the development of an aseptic bone flap necrosis. Conclusions In patients undergoing bone flap reinsertion after craniotomy, aseptic bone necrosis is an underestimated problem during long-term follow-up. Especially in younger patients with an expected good neurological recovery and a fragmented bone flap, an initial allograft should be considered because of an increased risk for aseptic bone flap necrosis.

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LONG-TERM OUTCOME OF SUBCUTANEOUSLY PRESERVED AUTOLOGOUS CRANIOPLASTY

Neurosurgery ◽

10.1227/01.neu.0000350870.69891.86 ◽

2009 ◽

Vol 65 (3) ◽

pp. 505-510 ◽

Cited By ~ 41

Author(s):

Alireza Shoakazemi ◽

Thomas Flannery ◽

Robert Scott McConnell

Keyword(s):

Glasgow Coma Scale ◽

Abdominal Wall ◽

Decompressive Craniectomy ◽

Glasgow Coma Scale Score ◽

Bone Flap ◽

Term Outcome ◽

Long Term Outcome ◽

The Mean

Abstract OBJECTIVE Decompressive craniectomy for intracranial hypertension mandates later cranioplasty. Autologous cranioplasties can be preserved either by freezing or placement in a subcutaneous pocket. There are few data on the long-term follow-up of patients treated in such a fashion. METHODS A retrospective study was conducted on 100 consecutive patients who underwent decompressive craniectomy and placement of the bone flap in a subcutaneous pocket in the abdominal wall between 2000 and 2005. Initial diagnosis, Glasgow Coma Scale score on admission, complications, and Glasgow Outcome Score were recorded. RESULTS Of the 100 patients who underwent autocranioplasty, the primary diagnosis was traumatic brain injury (76%), subarachnoid hemorrhage (17%), primary intracerebral hemorrhage (3%), and tumor (4%). The mean age of the sample was 39 years (age range, 10–72 years). The mean follow-up duration was 25 months. The average Glasgow Coma Scale score on admission was 7. Eight patients died before replacement of the bone flap. The average time between craniectomy and replacement of bone flap was 42 days. The mean Glasgow Outcome Score was 4 at the time of the 1-year follow-up evaluation. Seven of the 79 patients (9%) for whom 1-year review data were available had a cosmetic result that was unacceptable and required removal of the flap (bone flap infections in 5 patients, unacceptable bone flap resorption in 2 patients) CONCLUSION Our study indicates that storage of a cranioplasty flap in a subcutaneous pouch in the abdominal wall has a favorable long-term outcome.

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Cranioplasty with autogenous bone flaps cryopreserved in povidone iodine: a long-term follow-up study

Journal of Neurosurgery ◽

10.3171/2016.8.jns16204 ◽

2017 ◽

Vol 127 (6) ◽

pp. 1449-1456 ◽

Cited By ~ 9

Author(s):

Jian Zhang ◽

Fei Peng ◽

Zhuang Liu ◽

Jinli Luan ◽

Xingming Liu ◽

...

Keyword(s):

Bone Resorption ◽

Povidone Iodine ◽

Bone Flap ◽

Autogenous Bone ◽

Type I ◽

Type Ii ◽

Type Iii ◽

Bone Flap Resorption

OBJECTIVEThe aim of this study was to investigate the long-term therapeutic efficacy of cranioplasty with autogenous bone flaps cryopreserved in povidone iodine and explore the risk factors for bone resorption.METHODSClinical data and follow-up results of 188 patients (with 211 bone flaps) who underwent cranioplasty with autogenous bone flaps cryopreserved in povidone-iodine were retrospectively analyzed. Bone flap resorption was classified into 3 types according to CT features, including bone flap thinning (Type I), reduced bone density (Type II), and osteolysis within the flaps (Type III). The extent of bone flap resorption was graded as mild, moderate, or severe.RESULTSShort-term postoperative complications included subcutaneous or extradural seroma collection in 19 flaps (9.0%), epidural hematoma in 16 flaps (7.6%), and infection in 8 flaps (3.8%). Eight patients whose flaps became infected and had to be removed and 2 patients who died within 2 years were excluded from the follow-up analysis. For the remaining 178 patients and 201 flaps, the follow-up duration was 24–122 months (mean 63.1 months). In 93 (46.3%) of these 201 flaps, CT demonstrated bone resorption, which was classified as Type I in 55 flaps (59.1%), Type II in 11 (11.8%), and Type III in 27 (29.0%). The severity of bone resorption was graded as follows: no bone resorption in 108 (53.7%) of 201 flaps, mild resorption in 66 (32.8%), moderate resorption in 15 (7.5%), and severe resorption in 12 (6.0%). The incidence of moderate or severe resorption was higher in Type III than in Type I (p = 0.0008). The grading of bone flap resorption was associated with the locations of bone flaps (p = 0.0210) and fragmentation (flaps broken into 2 or 3 fragments) (p = 0.0009). The incidence of bone flap collapse due to bone resorption was higher in patients who underwent ventriculoperitoneal (VP) shunt implantation than in those who did not (p = 0.0091).CONCLUSIONSBecause of the low incidence rates of infection and severe bone resorption, the authors conclude that cranioplasty with autogenous bone flaps cryopreserved in povidone-iodine solution is safe and effective. The changes characteristic of bone flap resorption became visible on CT scans about 2 months after cranioplasty and tended to stabilize at about 18 months postoperatively. The bone resorption of autogenous bone flap may be classified into 3 types. The rates of moderate and severe resorption were much higher in Type III than in Type I. The grade of bone flap resorption was associated with bone flap locations. Fragmented bone flaps or those implanted in patients treated with VP shunts may have a higher incidence of bone flap collapse due to bone resorption.

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