Risk Factors For Avascular Necrosis Research Articles

Association between ossific nucleus volume changes and postoperative avascular necrosis risk in children with developmental dysplasia of the hip

This study aimed to investigate the correlation between ossific nucleus volume and avascular necrosis (AVN) in pediatric patients diagnosed with developmental dysplasia of the hip (DDH). Analyzing 211 cases, including 119 open reduction (OR) and 92 closed reduction (CR) procedures, we quantified ossific nucleus volume using magnetic resonance imaging (MRI). Categorizing the OR group based on ossific nucleus volume revealed no statistically significant difference in AVN incidence. Similarly, in the CR cohort, there was no significant discrepancy in AVN occurrence between subgroups with or without the ossific nucleus. Logistic regression in CR identified the international hip dysplasia institute (IHDI) grade as a significant AVN risk factor (p = 0.007). IHDI grades 3 and 4 exhibited a 6.94 times higher likelihood of AVN compared to grades 1 and 2. Across CR and OR, neither initial age nor ossific nucleus volume emerged as AVN risk factors. In conclusion, ossific nucleus volume does not pose a risk for AVN in DDH children undergoing CR or OR, emphasizing the clinical significance of IHDI grading in predicting AVN risk during CR and the importance of early intervention to prevent treatment delays.

Clinical features of pediatric femoral neck fractures and analysis of risk factors for avascular necrosis of the femoral head: A retrospective case-control study of 45 patients.

ObjectivesTo summarize the clinical features of pediatric femoral neck fractures and analyze the risk factors for avascular necrosis of the femoral head. MethodsA retrospective analysis of the case data of pediatric femoral neck fractures treated in our hospital from January 2010 to December 2022, including gender, age, fracture type, causative factors, and surgical details. The occurrence of avascular necrosis of the femoral head was recorded and risk factors were analyzed. ResultsFrom January 2010 to December 2022, a total of 45 cases of femoral neck fractures were treated in our hospital with a median age at onset of 93 months (IQR=81) and a median time from injury to surgery of 96 hours (IQR=46). Closed reduction was performed in 36 cases, while open reduction was performed in 9 cases. Avascular necrosis of the femoral head occurred in 29 cases postoperatively, while it did not occur in 16 cases. Increased time from injury to surgery and greater degree of fracture displacement were independent risk factors for avascular necrosis of the femoral head. The risk of avascular necrosis in Garden IV type femoral neck fractures was significantly higher than in Garden II and III type patients. An injury-to-surgery time exceeding 82.5 hours was identified as a critical threshold for the development of avascular necrosis of the femoral head. ConclusionPediatric femoral neck fractures have a low incidence rate and are mostly caused by high-energy trauma, often resulting in severe injuries. Therefore, actively maintaining stable vital signs and properly managing associated injuries, timely surgical intervention for femoral neck fractures, achieving good reduction and fixation of displaced fractures are crucial in the treatment of pediatric femoral neck fractures.

Risk of avascular necrosis in patients with inflammatory bowel disease: Insights from a nationwide cohort study and the impact of corticosteroid use

Background and aimCorticosteroid use is a risk factor for avascular necrosis (AVN) and inflammatory bowel disease (IBD) patients are often exposed to higher corticosteroid usage. We investigated the epidemiology and risk factors of AVN in a nationwide population-based cohort of IBD patients. MethodsPatients newly diagnosed with IBD were identified, and sex- and age-matched participants from the general population were selected in a 1:3 IBD:non-IBD ratio. We investigated newly diagnosed AVN and assessed the incidence rates and risk of AVN with multivariate Cox regression models. ResultsDuring the median follow-up period of 7.22±3.85 years, 357 (0.62 %) were newly diagnosed with AVN. The risk of AVN was higher in IBD (aHR = 1.42, 95 % CI: 1.25–1.62). Ulcerative colitis (UC) patients showed a particularly elevated risk of developing AVN. IBD patients with higher cumulative corticosteroid intake and exposed to a mean prednisolone-equivalent daily dose>20 mg for >1 month were at higher risk of AVN. In Crohn's disease (CD), longer exposure time to >20 mg prednisolone-equivalent presented a trend in increased risk. ConclusionAVN risk was higher in IBD than in those without, particularly in UC and corticosteroid use in IBD could pose a crucial role. These underscore the importance of considering the AVN etiological factors, particularly corticosteroid use.

Avascular necrosis after surgery of developmental dysplasia of the hip in children after walking age: incidence and risk factors

Introduction Developmental dysplasia of the hip (DDH) is a common congenital anomaly in children. It includes a spectrum of anatomic abnormalities ranging from acetabular dysplasia to frank hip dislocation. Avascular necrosis (AVN) is one of the main complications associated with the treatment of DDH. It is a devastating problem that can lead to acetabular dysplasia and joint incongruity and cause premature osteoarthritis. The study aims to evaluate the incidence and risk factors of AVN after open reduction of developmental dislocation of the hip in children after walking age. Patients and methods Between the period of April 2014 and April 2019, a retrospective cohort evaluation of DDH cases was managed by surgery in the form of open reduction and pelvic osteotomy with or without femoral shortening. All grades of Tönnis classification were included. This study included 200 cases with an age range from 1 to 7 years, and the average age is 3.5 years at the time of last follow-up. The mean follow was 2.29 years, which ranged from 1 to 4 years. Plain radiography obtained in anteroposterior and frog lateral views after 1 year follow-up to diagnosis AVN as established in the literature. Results In this study, the mean time of intervention was 2.26 ± 0.97 years with an age range from 1 to 5 years. Twenty-six (13%) cases were managed only by open reduction and capsulorrhaphy, 174 (72.5%) cases had pelvic osteotomies, either Salter or Dega osteotomy, of whom 104 had femoral shortening and derotational osteotomy (59.77%). No AVN was reported in 159 (79.5%) cases, while AVN was evident in 41 (20.5%) cases. Discussion Incidence of AVN after open reduction depend on variable factor discussed in this study with total incidence of AVN 41 (20.5%) cases. This result is similar to other studies, with the incidence of AVN ranging from 15 to 30%. In the present study, the incidence of AVN increased 17 times in cases with postoperative immobilization in the hip spica more than or equal to 60° in the form of 21 cases showed AVN. Conclusion Postoperative hip immobilization in spica less than 60° as children with postoperative hip abduction more than or equal to 60° showed an increase incidence of AVN.

Risk factors for avascular necrosis of the femoral head after developmental hip dislocation reduction surgery and construction of Nomogram prediction model

BackgroundTo analyze the risk factors for the development of avascular necrosis (AVN) of the femoral head after reduction surgery in children with developmental hip dysplasia (DDH), and to establish a prediction nomogram.MethodsThe clinical data of 134 children with DDH (169 hips) treated with closure reduction or open reduction from December 2016 to December 2019 were retrospectively analyzed. Independent risk factors for AVN after DDH reduction being combined with cast external immobilization were determined by univariate analysis and multivariate logistic regression and used to generate nomograms predicting the occurrence of AVN.ResultsA total of 169 hip joints in 134 children met the inclusion criteria, with a mean age at surgery of 10.7 ± 4.56 months (range: 4–22 months) and a mean follow-up duration of 38.32 ± 27.00 months (range: 12–94 months). AVN developed in 42 hip joints (24.9%); univariate analysis showed that the International Hip Dysplasia Institute (IHDI) grade, preoperative development of the femoral head ossification nucleus, cartilage acetabular index, femoral head to acetabular Y-shaped cartilage distance, residual acetabular dysplasia, acetabular abduction angle exceeding 60°, and the final follow-up acetabular index (AI) were associated with the development of AVN (P < 0.05). Multivariate logistic regression analysis showed that the preoperative IHDI grade, development of the femoral head ossification nucleus, acetabular abduction angle exceeding 60°, and the final follow-up AI were independent risk factors for AVN development (P < 0.05). Internal validation of the Nomogram prediction model showed a consistency index of 0.833.ConclusionPreoperative IHDI grade, preoperative development of the femoral head ossification nucleus, final AI, and acetabular abduction angle exceeding 60° are risk factors for AVN development. This study successfully constructed a Nomogram prediction model for AVN after casting surgery for DDH that can predict the occurrence of AVN after casting surgery for DDH.

Avascular Necrosis in Kidney Transplant Recipients is Associated With an Increased Risk of Patient Death.

Introduction: Avascular necrosis is a debilitating osseous complication in transplant recipients. Project Aim: This program evaluation sought to describe risk factors and adverse outcomes of avascular necrosis in kidney transplant recipients. Design: This was a retrospective evaluation of all recipients of kidneys and simultaneous pancreas and kidneys between 2001 and 2018 from a single center. Controls were selected based on the incidence density, sampling at a 1:3 ratio based on the post-transplant interval. Outcomes of interest were acute rejection, death-censored graft failure, and patient mortality. Results: A total of 88 kidney recipients had avascular necrosis and were compared with 257 controls. Most of the recipient's and donors' baseline characteristics were similar between the groups, except calcineurin inhibitor-based immunosuppression was more prevalent, and non-white donors were less prevalent in the control group. Looking for risk factors for avascular necrosis, calcineurin inhibitor-based immunosuppression was associated with a lower risk for avascular necrosis in the univariate analysis, but this was not found after adjustment of multiple variables. In multivariate analysis, avascular necrosis was associated with an increased risk for patient death (hazard ratio: 1.68; 95% confidence interval: 1.16-2.44; P = .008) but not for acute rejection or death censored graft failure. Conclusion: Although limited by small sample size, this evaluation found avascular necrosis to be associated with an increased risk of patient death. This finding may be useful for the provider taking care of the patients and discussing the various outcomes after the transplant.

Post Covid-19 Effect on Avascular Necrosis of Hip Joint

Background and objectives: The exact course of Severe acute respiratory syndrome (SARS) -2(COVID-19) and itscomplications on multiorgan system are complex and still under studies. Musculoskeletal system has also beenaffected post covid in various forms. This study was taken up to analyse the effects of covid-19 disease on the hipbone and join tissue.Materials and Methods: Retrospective analysis of ten patients was done who had been hospitalised with covid-19infection and later complained of hip pain . They underwent MR imaging and were found to have degenerativechanges characterizing with avascular necrosis (AVN) of head of femur .One of them had history of previoussurgery of femur with PFN, doing well but developed AVN after COVID .Results: Observation of this group showed a clear correlation among the history of COVID-19 disease in thepatients, moderately severe symptoms, high levels of IgG antibodies, and the time of occurrence of joint changes.No other risk factors for AVN or autoimmune or degenerative diseases were found in the study group. The groupof patients responded well to empirical treatment with anti-inflammatory drugs ans supportive therapy, whichsubsided acute inflammatory symptoms and pain in the joints.Conclusions: It is concluded that there have been obvious musculoskeletal complications in covid patientsincluding AVN which could be attributed to the high use steroids and microembolism leading to bone necrosis.Hence more studies and long follow-up is suggested.

Post Covid-19 Effect on Avascular Necrosis of Hip Joint

Background and objectives: The exact course of Severe acute respiratory syndrome (SARS) -2(COVID-19) and itscomplications on multiorgan system are complex and still under studies. Musculoskeletal system has also beenaffected post covid in various forms. This study was taken up to analyse the effects of covid-19 disease on the hipbone and join tissue.Materials and Methods: Retrospective analysis of ten patients was done who had been hospitalised with covid-19infection and later complained of hip pain . They underwent MR imaging and were found to have degenerativechanges characterizing with avascular necrosis (AVN) of head of femur .One of them had history of previoussurgery of femur with PFN, doing well but developed AVN after COVID .Results: Observation of this group showed a clear correlation among the history of COVID-19 disease in thepatients, moderately severe symptoms, high levels of IgG antibodies, and the time of occurrence of joint changes.No other risk factors for AVN or autoimmune or degenerative diseases were found in the study group. The groupof patients responded well to empirical treatment with anti-inflammatory drugs ans supportive therapy, whichsubsided acute inflammatory symptoms and pain in the joints.Conclusions: It is concluded that there have been obvious musculoskeletal complications in covid patientsincluding AVN which could be attributed to the high use steroids and microembolism leading to bone necrosis.Hence more studies and long follow-up is suggested.

Vitamin D Deficiency and Avascular Necrosis in Patients with Sickle Cell Disease: A Retrospective Cohort Study

Introduction Sickle cell disease (SCD) is an inherited hemoglobinopathy with complex systemic involvement. Avascular necrosis (AVN) is a devastating complication among patients with SCD. Vitamin D deficiency (VDD) is commonly found in SCD patients, but there is limited research on the potential role of VDD as a risk factor for AVN in SCD patients. This study aimed to assess the association between VDD and AVN and determine the patterns, risk factors, diagnosis, and treatment of AVN in SCD patients. Methods We conducted a retrospective cohort study of consecutive SCD patients diagnosed with VDD from January 2020 to December 2022 at Prince Sultan Medical Military City (PSMMC) in Riyadh, Saudi Arabia. Patients meeting the following criteria were included: (1) adults and children with confirmed SCD through hemoglobin electrophoresis and (2) tested for VDD. Patients who underwent bone marrow transplant were excluded. The main outcome measured was the occurrence of AVN. VDD was diagnosed in patients with 25-hydroxyvitamin D levels below 30 nmol/L. Magnetic resonance imaging was used to stage and confirm AVN diagnosis. Associations were assessed using the chi-square test, and logistic regression was performed to control for confounding. Results The study included 711 eligible SCD patients, with 271 (38%) being children. VDD affected 301 out of 711 patients (42.3%). Among these, 212 (70.4%) were adults (&amp;gt;18 years old). VDD was observed in 32.2% of children and 48.1% of adults. Of the total cohort, 127 (17.9%) patients experienced AVN, including 18 children. Among patients with VDD, 89 developed AVN, while VDD affected 212 patients without AVN. The time between VDD diagnosis and AVN presentation ranged from 3 to 12 months. Male patients accounted for 52% of AVN cases. The average age at AVN diagnosis was 30.9 ± 11 years. The most common clinical presentation of AVN was chronic joint pain in over 95% of patients. Other presentations included limping in 3.9% of patients and limited joint movement in one patient. Affected joints included the hip (86%), shoulder (16.5%), knee (4.7%), and sacroiliac joint (0.7%). Bilateral joint involvement was present in 50.4% of AVN patients. The majority of patients (76.4%) were diagnosed with advanced stage AVN (III/IV). Treatment of patients with AVN included joint replacement in 44 (34.6%) patients, while the remaining 83 patients managed with conservative therapy such as pain control and physiotherapy. Patients with a history of VDD were significantly associated with a higher risk of AVN (p &amp;lt; 0.001), as seen in Table 1. Multivariate logistic regression showed SCD patients with VDD had 9.79 times the odds of AVN compared to SCD patients without VDD (OR 9.79; 95% CI: 5.25-18.26). Other statistically significant risk factors for AVN included frequent vaso-occlusive crises (three or more episodes per year), older age, history of acute chest syndrome, and low hemoglobin F levels. Conclusion AVN is a significant cause of morbidity in our SCD cohort, with most patients having advanced AVN disease. VDD is an independent risk factor for AVN in patients with SCD. Well-designed randomized trials are needed to determine the effect of vitamin D supplementation in reducing AVN in children and adults with SCD.

Risk factor analysis of femoral avascular necrosis after operation for Tönnis grade IV developmental dysplasia of the hip.

We explored the risk factors for avascular necrosis (AVN) after surgery using open reduction, pelvic osteotomy, and femoral osteotomy for Tönnis grade IV developmental dysplasia of the hip (DDH). In this retrospective study, we collected data of patients with Tönnis grade IV DDH treated with open reduction and pelvic osteotomy combined with femoral osteotomy from January 2012 to May 2020. The patients were divided into the AVN group and non-AVN group using the Kalamchi-MacEwen classification system. The clinical and imaging data of the two groups were collected, and the possible risk factors were included in the analysis. Univariate and multivariate logistic regression analyses were used to identify the independent risk factors and odds ratios of AVN. In all, 254 patients (mean age; 2.6±0.9 years, 278 hips) were included. The mean follow-up time was 3.8±1.5 years. A total of 89 hips (32%) were finally classified as AVN (Kalamchi-MacEwen II-IV). Univariate analysis showed significant associations with AVN for age (p=0.006), preoperative femoral neck anteversion (FAV) (p<0.001), femoral osteotomy length to dislocation height ratio (FDR) <1 (p<0.001), and the epiphyseal ossific nucleus diameter to the neck diameter ratio (ENR) <50% (p=0.009). Multivariate logistic regression analysis showed that only excessive preoperative FAV (OR: 1.04; 95% CI: 1.02-1.05; p<0.001) and FDR<1 (OR: 3.58; 95% CI: 2.03-6.31; p<0.001) were independent risk factors for femoral head necrosis. Excessive preoperative FAV and FDR<1 are important risk factors for femoral AVN after open reduction, pelvic osteotomy, and femoral osteotomy for Tönnis grade IV DDH. For children with DDH with high dislocation and excessive FAV, clinicians should fully evaluate their condition and design more personalized treatment programs to prevent AVN.

Risk factors related with avascular necrosis after internal fixation of femoral neck fractures in children: a systematic review and meta-analysis.

Less than 1% of children develop femoral neck fractures (FNF), making them uncommon. However, they may have dangerous side effects, like avascular necrosis. Even though several risk factors for postoperative avascular necrosis have been identified, there is still debate regarding them. In this investigation, a meta-analysis was performed to examine the potential causes of postoperative avascular necrosis in children with FNF. We conducted a thorough literature search to find risk factors for avascular necrosis (AVN) after internal fixation of pediatric FNF. Until December 2022, we searched several databases, including PubMed, Embase, Cochrane Library, Web of Science, CNKI, Orthosearch, and Sinomed. Software Zotero 6.0 and Stata 17.0 were used to organise and synthesise the data. Finally, a sensitivity and publication bias test was carried out. Our study includes a total of 15 case-control studies involving 814 patients. The risk of postoperative AVN increased with age at fracture encounter (95% CI: 0.64-1.88, P = 0.0003), initial fracture displacement (95% CI: 1.87-9.54, P = 0.0005), and poor fracture reduction (95% CI:1.95-22.34, P = 0.0024) were risk factors for postoperative AVN. There was no significant relationship between gender and postoperative AVN (95% CI: 0.52-1.31, P = 0.41). Conversely, Postoperative AVN and reduction methods have no connection with each other (95% CI: 0.77-2.66, P = 0.25), procedure time (95% CI: 0.43-2.99, P = 0.16), or injury mechanism (95% CI: 0.32-2.26, P = 0.75). The incidence of post-operative AVN varies between Delbet fracture types (95% CI: 0.15-0.31, P < 0.0001), with the overall trend being that the incidence of post-operative AVN is highest for type II, lowest for type IV, and close for types I and III, but it is not clear which type of fracture is the independent risk factor. Funnel plots indicate no significant publication bias. In line with this study, About 26% of children who underwent surgery for a femoral neck fracture suffered postoperative AVN. The main risk factors for AVN were the child's age, the initial displacement of the fractures, and poorly reduced fractures. The risk of AVN did not significantly correlate with gender, the time of the procedure, reduction methods or the mechanism of injury. The overall trend in the incidence of postoperative AVN for the different Delbet types of fracture is that the incidence of postoperative AVN is highest for type II, lowest for type IV, and close for types I and III, but it is not clear which type of fracture is the independent risk factor.

Complications and Outcomes of the Internal Fixation of Non-displaced Femoral Neck Fracture in Old Patients: A Two-Year Follow-Up.

Background Fractures of the proximal femur are amongst the most common injuries in the elderly population. While there is a clear consensus regarding the management of displaced femoral neck fractures, the management of non-displaced fractures is less clear. Both fixation and arthroplasty are valid treatment options. Internal fixation is a less invasive procedure, but it carries the risks of non-union and avascular necrosis (AVN) of the femoral head. The literature describes varying complication rates associated with these risks. We aim to describe a series of elderly patients above the age of 65 years with non-displaced fractures of the femoral neck who were treated with internal fixation. Our objectives are to determine the union rate and complications in this group and to elucidate the factors that influence these outcomes. Methods We conducted a retrospective review of all patients aged 65 years and older who presented with femoral neck fractures at our level 1 trauma unit between 2018 and 2020. Fractures were classified using the Garden classification system, and only those with Garden 1 or 2 fractures (non-displaced) were included. Preoperative radiographs or intraoperative fluoroscopy images were used to classify fractures using the Pauwels classification. Serial postoperative radiographs and clinical notes (up to 24 months postoperatively) were reviewed to assess the union rate and the development of complications. Both non-union and AVN were analysed for their associations with age, sex, Pauwels grade and comorbidities. A subgroup analysis of the complications was performed to elucidate their association with age groups (<80 and >80 years) and types of fixations (dynamic hip screws {DHS} and cannulated screws). Results A total of 148 patients, consisting of 60 males and 88 females, were included in the analysis. The patients had a mean age of 78.5 years (ranging from 65 to 98 years). The union rate without any degree of AVN was 90.7%, with six non-unions (4.05%) and six patients experiencing AVN (4.05%). No difference in outcome was detected between the two groups based on age. High (type 2 or 3) Pauwels grade (p = 0.05) and treatment with cannulated screws (p = 0.02) were indicated as significant factors for non-union. All patients who developed AVN were noted to have a comorbidity that is known to predispose them to AVN. Conclusion Our series shows a union rate of 90.7%, which is comparable to the union rates reported in other published literature. Our results suggest that age does not independently influence the outcome of fixation for these fractures. We conclude that fractures with vertical orientation (Pauwels grade 2 or 3), when treated with cannulated screws, are more likely to result in non-union. AVN is the second most common complication after non-union, which is also associated with other risk factors for AVN.

Risk factors for avascular necrosis in patients with systemic lupus erythematosus: a multi-center cohort study of Chinese SLE Treatment and Research Group (CSTAR) Registry XXII

BackgroundAvascular necrosis is a common organ damage in SLE patients, which can influence patients’ life quality. Conflicting results exist in risk factors of AVN in SLE patients. The aim of this study was to illustrate risk factors predicting the occurrence of avascular necrosis (AVN), also known as osteonecrosis, in systemic lupus erythematosus (SLE) patients in Chinese SLE Treatment and Research Group (CSTAR), a multi-center cohort of Chinese SLE patients.MethodsSLE patients in CSTAR without existing AVN at registration were included. At least two follow-ups and an observation period of no less than 2 years for AVN event were required. Univariate and multivariate Cox regression analyses were used to evaluate risk factors for AVN in SLE patients. Coefficient B was transformed to risk score for the development of a risk stratification model.ResultsOne hundred six (2.59%) of 4091 SLE patients were diagnosed AVN during follow-ups of no less than 2 years. Multi-variate Cox regression analysis suggested that SLE onset age ≤ 30 (HR 1.616, p 0.023), arthritis (HR 1.642, p 0.018), existing organ damage (SDI ≥ 1) at registration (HR 2.610, p < 0.001), positive anti-RNP (HR 1.709, p 0.006), and high glucocorticoid maximum daily dose at registration (HR 1.747, p 0.02) were independent risk factors. A risk stratification system was developed according to the risk factors, and patients were divided into high risk (3–6) and low risk (0–2). The AUC of 0.692 indicated moderate discrimination. The calibration curve in internal validation was drawn.ConclusionPatients with SLE onset age ≤ 30, arthritis, existing organ damage (SDI ≥ 1) at registration, positive anti-RNP, and high glucocorticoid maximum daily dose at registration are at high risk for AVN and require attention.

Avascular Necrosis in Renal Transplant Patients

Kidney transplant recipients are at increased risk for avascular necrosis due to steroid use and accompanying comorbidities. Concerning risk factors, uncertainty still exists. We evaluated the clinical characteristics and risk factors of avascular necrosis in kidney transplant recipients. Symptomatic avascular necrosis was found by magnetic resonance imaging in 33 of 360 kidney transplant patients between 2005 and 2021. The patients' clinical characteristics, biochemical testing, and medications were evaluated. We found the frequency of avascular necrosis to be 9.7% during the follow-up period. If the total steroid dosage used was more than 4 g in the first 3 months, the risk of developing avascular necrosis increased 4.08 times, and the presence of cytomegalovirus disease increased the risk by 4.03 times. Avascular necrosis was observed bilaterally in 60.6% of cases and at the femoral head in 66.7%. The frequency of avascular necrosis was highest in the first and second years posttransplant. We found that avascular necrosis appears most frequently in the first 2 years after kidney transplant and the most important risk factors are cumulative steroid dose and cytomegalovirus disease. In the follow-up of kidney transplant patients, it is important to use low-dose steroid doses if possible. Of note, preventing the development of cytomegalovirus disease by screening and prophylaxis for cytomegalovirus is also important in reducing the development of avascular necrosis.

P838 Increased Risk of Avascular Necrosis in Patients With Inflammatory Bowel Disease: a nationwide population based cohort study

Abstract Background Avascular necrosis (AVN) is bone death due to disruption of blood supply causing disability and significant morbidity. Although considered multi-factorial, corticosteroid use is a well-known risk factor. Not only is AVN more prevalent in Inflammatory bowel disease (IBD), but IBD patients are often exposed to higher corticosteroids usage. Therefore, we aimed to investigate epidemiology and risk factors of avascular necrosis in Asian IBD patients. Methods We conducted a nationwide population-based cohort using Korean National Health Insurance Service (NHIS) database from January 2007 to December 2020. Newly diagnosed IBD patients were defined according to the International Classification of Diseases, 10th revision (ICD-10), and at least one prescription of IBD-specific medications. 1:3 sex-, age- matched subjects from the general population were selected. We investigated newly diagnosed AVN using the ICD-10 code and the incidence rates and risk of AVN were assessed with multivariate cox regression models. Results A total of 62,417 IBD population was identified, where ulcerative colitis (UC) comprised of 44,106. Age at diagnosis was younger in Crohn's disease (CD) than in UC (30±15 years and 43±16.3 years). UC population revealed greater number of comorbidities such as hypertension (16.7% and 7.1% for UC and CD, respectively), diabetes mellitus (12.4% and 9.5%), dyslipidemia (27.6% and 25.2%), and cerebrovascular diseases (4.5% and 2.5%). During the mean follow-up period of 6.75 years, 54,591 (87.5%) of the total IBD patients were exposed to systemic steroids (86.4% and 90.1% for UC and CD, respectively). Approximately 76.8% in the IBD group were prescribed with ≥10 mg/day of corticosteroids with mean duration of 16.3±35.1 days. A total of 100 (0.16%) newly diagnosed AVN cases were observed in the IBD population. Time from the index date to AVN diagnosis was 4.47±3.29 years. Compared to the non-IBD controls, the incidence of AVN was significantly increased in IBD subjects (adjusted hazard ratio [aHR] with 95% confidence interval [CI], 1.28 [1.01-1.63]). UC patients in particular were at an elevated risk for developing AVN (aHR with 95% CI, 1.39 [1.07-1.80]), whereas risk analysis for CD patients demonstrated results that were statistically not significant (aHR with 95% CI, 1.00 [0.63-1.57]). Table 1 Incidence rates and risk ratios of AVN in patients with IBD Conclusion Risk of AVN was elevated in Korean IBD patients compared to non-IBD population, especially for UC. Physicians dealing with IBD patients should be aware of etiological factors of AVN along with corticosteroid use. Future study is needed to investigate on the mechanisms associated with AVN in IBD.

Avascular Necrosis of HIP After Active Covid-19 Infection

AbstractBackground and objectives: The exact course of SARS -2(COVID-19) and its complications on multiorgan systemare complex and still under studies. Musculoskeletal system has also been affected post covid in various forms.This study was taken up to analyse the effects of covid-19 disease on the hip bone and join tissue.Materials and Methods: Retrospective analysis of ten patients was done who had been hospitalised with covid-19infection and later complained of hip pain. They underwent MR imaging and were found to have degenerativechanges characterizing with avascular necrosis (AVN) of head of femur .One of them had history of previoussurgery of femur with PFN, doin well but developed AVN after covid.Results: Observation of this group showed a clear correlation among the history of COVID-19 disease in thepatients, moderately severe symptoms, high levels of IgG antibodies, and the time of occurrence of joint changes.No other risk factors for AVN or auto-immune or degenerative diseases were found in the study group. The groupof patients responded well to empirical treatment with anti-inflammatory drugs ans supportive therapy, whichsubsided acute inflammatory symptoms and pain in the joints.Conclusions: It is concluded that there have been obvious musculoskeletal complications in covid patientsincluding AVN which could be attributed to the high use steroids and microembolism leading to bone necrosis.Hence more studies and long follow-up is suggested.

Relative frequency of avascular necrosis of the hip as indication for primary Total Hip Arthroplasty in the USA vs. India

IntroductionBackground: Primary total hip arthroplasty (THA) is performed for a variety of pathologies. Osteoarthritis (OA) is the most common indication for THA in the United States of America (USA). The study aims to establish the incidence of indications for THA in the USA as compared to India and to assess whether Avascular Necrosis (AVN) of the Hip is a more frequent indication for THA in India than in the USA. MethodsThe National Inpatient Sample database (USA) and two Indian databases (one national and one regional) were analyzed to identify all patients who underwent primary THA within the databases. The relative frequencies of each indication for THA were determined. The patients' demographics and risk factors for AVN of the hip were recorded and assessed. The data were then compared across the patients in the USA and the patients in India. Results225,061 primary THA patients were identified in the USA database and 20,288 in the Indian database. The proportion of primary THA performed for AVN in the American database (5.97%) was significantly lower than the proportion of THA performed for AVN in the Indian database (51.8%). ConclusionThe relative frequency of AVN as an indication for THA is significantly higher in India than in the USA. It is important to recognize the differences in relative indications for THA between world populations, as outcomes after THA among Eastern populations of the world may not be equivalent to ones seen in their Western counterparts.

Risk Factors for Avascular Necrosis After Closed Reduction for Developmental Dysplasia of the Hip.

Background:Avascular necrosis (AVN) is a major complication after closed reduction for developmental dysplasia of the hip. The factors that predispose to AVN remain controversial. The purpose of this study was to analyze the risk factors, especially patient factors, such as age at reduction, grade of dislocation, and ossific nucleus development, related to AVN.Materials and Methods:We retrospectively reviewed children with dysplasia of the hip treated by closed reduction between 1997 and 2006. AVN was evaluated using Salter criteria and Kalamchi and MacEwen classification. Related factors were analyzed.Results:One hundred and eight children (140 hips) with an average age of 16.6 months at closed reduction (range: 6-24 mo) were included in the study. For an average duration of 10.1 years (range 7–16 y) of follow-up, 44 hips (31.4%) developed AVN. Grade II or higher AVN occurred in 14 hips (10%). The incidence of AVN increased with the grade of dislocation (P=0.022) and underdevelopment of the ossific nucleus (P<0.001). Underdevelopment of the ossific nucleus was also found to be positively correlated with the dislocation grade (P=0.047). The age at the time of reduction, sex, and side were not significant factors. Children who underwent secondary operation were all older than 1 year at reduction.Conclusions:High-grade dislocation correlates with the underdevelopment of the ossific nucleus. Patients with these 2 characteristics are predisposed to AVN. As underdevelopment of the ossific nucleus occurred regardless of age, it is not advisable to delay reduction because it does not alter the AVN rate, and instead, it increases the secondary operation rate.Level of Evidence:Level IV case series.

Safety of surgical hip dislocation in femoral head fracture and dislocation (FHFD) and avascular necrosis risk factor analysis of FHFD: midterm results confirmed by SPECT/CT and MRI

BackgroundThe study aim was to report the treatment outcomes of trochanteric flip osteotomy (TFO) with surgical hip dislocation (SHD) for femoral head fracture and dislocation (FHFD) and to investigate the risk factors for avascular necrosis (AVN) of the femoral head.MethodsThe data of 34 patients (29 men, 5 women; mean age 37.9 years) diagnosed with FHFD and treated with TFO with SHD between May 2009 and February 2018 with an average follow-up period of 5.1 years (range 2.8–10.5 years) were analyzed. Clinical outcomes were evaluated using the Merle d'Aubigné–Postel score and Thompson–Epstein Scale. Radiologic outcomes were classified according to the Matta classification. AVN was confirmed using magnetic resonance imaging or single-photon emission computed tomography/computed tomography. The occurrence of complications was examined, and factors influencing complications, AVN.ResultsRegarding the Pipkin’s classification, there were 7 patients with type II, 2 patients with type III, and 25 patients with type IV fractures. Posterior wall fractures accompanied all associated acetabular fractures in the patients with Pipkin type IV fractures. Radiologically, the union of acetabular and femoral head fractures was observed within 6.1 months on average (range 4–10 months) in 32 patients, except two patients who developed femoral head AVN. Clinically, the average Merle d'Aubigné–Postel score was 14.4 points (range 8–17 points), and 22 patients had good or excellent results on the Thompson–Epstein Scale. Two patients developed femoral head AVN with both having displaced femoral neck fractures associated with FHFD. AVN was significantly correlated with femoral neck fractures (P = 0.000).ConclusionTFO with SHD is a safe and useful approach for the treatment of FHFD. Particular attention should be paid when treating femoral head fractures associated with displaced femoral neck fractures because of the high risk of AVN development.

The British Orthopaedic Surgery Surveillance study: slipped capital femoral epiphysis: the epidemiology and two-year outcomes from a prospective cohort in Great Britain.

AimsThe aim of this study was to inform the epidemiology and treatment of slipped capital femoral epiphysis (SCFE).MethodsThis was an anonymized comprehensive cohort study, with a nested consented cohort, following the the Idea, Development, Exploration, Assessment, Long-term study (IDEAL) framework. A total of 143 of 144 hospitals treating SCFE in Great Britain participated over an 18-month period. Patients were cross-checked against national administrative data and potential missing patients were identified. Clinician-reported outcomes were collected until two years. Patient-reported outcome measures (PROMs) were collected for a subset of participants.ResultsA total of 486 children (513 hips) were newly affected, with a median of two patients (interquartile range 0 to 4) per hospital. The annual incidence was 3.34 (95% confidence interval (CI) 3.01 to 3.67) per 100,000 six- to 18-year-olds. Time to diagnosis in stable disease was increased in severe deformity. There was considerable variation in surgical strategy among those unable to walk at diagnosis (66 urgent surgery vs 43 surgery after interval delay), those with severe radiological deformity (34 fixation with deformity correction vs 36 without correction) and those with unaffected opposite hips (120 prophylactic fixation vs 286 no fixation). Independent risk factors for avascular necrosis (AVN) were the inability of the child to walk at presentation to hospital (adjusted odds ratio (aOR) 4.4 (95% CI 1.7 to 11.4)) and surgical technique of open reduction and internal fixation (aOR 7.5 (95% CI 2.4 to 23.2)). Overall, 33 unaffected untreated opposite hips (11.5%) were treated for SCFE by two-year follow-up. Age was the only independent risk factor for contralateral SCFE, with age under 12.5 years the optimal cut-off to define ‘at risk’. Of hips treated with prophylactic fixation, none had SCFE, though complications included femoral fracture, AVN, and revision surgery. PROMs demonstrated the marked impact on quality of life on the child because of SCFE.ConclusionThe experience of individual hospitals is limited and mechanisms to consolidate learning may enhance care. Diagnostic delays were common and radiological severity worsened with increasing time to diagnosis. There was unexplained variation in treatment, some of which exposes children to significant risks that should be evaluated through randomized controlled trials.Cite this article: Bone Joint J 2022;104-B(4):519–528.