Factors For Necrosis Research Articles

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.

Large Nipple Volume as a Risk Factor of Nipple-areola Complex Necrosis Following Nipple-sparing Mastectomy.

Nipple-areola complex (NAC) necrosis, which is caused by local ischemia, remains one of the complications associated with nipple-sparing mastectomy. Obesity, smoking, diabetes mellitus, and immediate breast reconstruction have been identified as risk factors of NAC necrosis. The current study examined the correlation between NAC necrosis and nipple volume. A total of 83 patients who underwent NSM for primary breast cancer from January 2016 to December 2019 were retrospectively analyzed. Nipple volume was determined using the formula: volume (cc) = length × width × height (mm), with measurements determined using contrast-enhanced magnetic resonance imaging. Total and partial NAC necrosis was defined as full-thickness necrosis requiring surgical procedures and epidermal necrosis managing local wound care, respectively. NAC necrosis was observed in 30 patients (36%), with 3 and 27 patients having total and partial necrosis, respectively. Large nipple volume (56% vs. 24%, p = 0.006), as well as smoking and immediate breast reconstruction (57 vs. 28%, p = 0.017; 48% vs. 20%, p = 0.009, respectively), were significantly correlated with NAC necrosis. Multivariate analysis identified nipple volume as an independent risk factor for NAC necrosis (OR, 3.75; 95% CI, 1.23-11.44; p = 0.02). Smoking (OR, 4.68; 95% CI, 1.37-15.94; p = 0.014) and immediate breast reconstruction (OR, 3.43; 95% CI, 1.05-11.23; p = 0.042) were also independently associated with NAC necrosis. This study suggested that a large nipple volume could be one of the risk factors for NAC necrosis following NSM.

Moderate-severe grade of chronic graft versus host disease and younger age (less than 45 years old) are risk factors for avascular necrosis in adult patients undergoing allogeneic hematopoietic cell transplantation.

Avascular necrosis (AVN) is a debilitating complication of allogeneic hematopoietic cell transplantation (HCT). A retrospective review of 845 patients who underwent HCT was conducted. Cumulative incidence of AVN was 6.3% at 4 years. The following risk factors were significantly associated with AVN risk on univariate analysis: age < 45 (p=0.004), moderate to severe chronic GvHD (p<0.001), reduced intensity conditioning (p=0.02), and a diagnosis of acute leukemia (p=0.045). Multivariate analysis confirmed two risk factors: younger age (<45 years), 9.0% vs 4.4% (p=0.011, hazard ratio (HR) 2.134), and moderate-severe chronic GvHD, 15.4% vs 2.1% (p<0.001, HR 4.950). A risk score model was generated assigning a score to each risk factor. A score of 1 was assigned to moderate-severe GvHD or those with age <45. Total score was calculated, thus dividing patient into three groups: low (score 0, n=349, 41.3%), intermediate (score 1, n=379, 44.9%), and high risk (score 2; n=116, 13.7%). This risk score could stratify the patients according to AVN risk (p<0.001). The risk of AVN was 1.5% in the low risk, 6.2% in the intermediate risk, and 20.8% in the high risk groups. Moderate-severe chronic GvHD and younger age (<45 years) are key risk factors for AVN following allogeneic HCT.

The value of the MTHFR polymorphisms in pathogenesis of nontraumatic necrosis of femoral head

Introduction. Among the etiological factors of non-traumatic avascular necrosis of the femoral head are the following: the prolonged use of corticosteroids, alcohol abuse, systemic lupus erythematosus, sickle cell anemia, the Legg Calve Perthes disease, ionizing radiation, cytotoxic agents, etc. At the same time necrosis of the femoral head might occur in the absence of the above factors (idiopathic necrosis). The reasons for idiopathic avascular necrosis could be a mechanical obstacle to the flow of blood, thrombotic occlusion of vessels, extravascular compression.&#x0D; The purpose of this study is to examine the role of C677T gene mutation of the MTHFR gene in the development of non-traumatic avascular necrosis of the femoral head.&#x0D; Materials and methods. During this study there was a comparative analysis of the frequency of the C677T gene allelic variants conducted in 41 patients with a verified diagnosis of non-traumatic avascular necrosis (main group) and 320 healthy individuals (control group). The survey program included the study of polymorphisms of MTHFR C677T gene by PCR.&#x0D; Results. Differences in the frequency of occurrence of C allele of C677T gene MTHFR in the heterozygous state in case of non-traumatic avascular necrosis and in its absence were not statistically significant (51.2% against 37.2% respectively, 2 = 3.014, p = 0.083). The genotype TT (T in the homozygous state) of the C677T MTHFR gene was detected in 19.5% of the main group patients. A similar index in the control group was two times lower and amounted to 9.0 percent, the differences between groups statistically significant, 2 = 4.314, p = 0.038.&#x0D; Conclusion. The study showed the importance of having the T C677T MTHFR gene in the pathogenesis of non-traumatic avascular necrosis of the femoral head. The data obtained and the analysis of the current literature suggests that this polymorphism is one of genetic predictors of non-traumatic avascular necrosis of the femoral head and other cardiovascular diseases as well.

Risk factors for avascular bone necrosis in patients with lupus nephritis

Risk factors for avascular bone necrosis in patients with lupus nephritis

Contact pressure distribution of the hip joint during closed reduction of developmental dysplasia of the hip: a patient-specific finite element analysis

BackgroundDevelopmental dysplasia of the hip (DDH) is the most common deformity of the lower extremity in children. The biomechanical change during closed reduction (CR) focused on cartilage contact pressure (CCP) has not been studied. Thereby, we try to provide insight into biomechanical factors potentially responsible for the success of CR treatment sand complications by using finite element analysis (FEA) for the first time.MethodsFinite element models of one patient with DDH were established based on the data of MRI scan on which cartilage contact pressure was measured. During CR, CCP between the femoral head and acetabulum in different abduction and flexion angles were tested to estimate the efficacy and potential risk factors of avascular necrosis (AVN) following CR.ResultsA 3D reconstruction by the FEA method was performed on a 16 months of age girl with DDH on the right side. The acetabulum of the involved side showed a long, narrow, and “flat-shaped” deformity, whereas the femoral head was smaller and irregular compared with the contralateral side. With increased abduction angle, the stress of the posterior acetabulum increased significantly, and the stress on the lateral part of the femoral head increased as well. The changes of CCP in the superior acetabulum were not apparent during CR. There were no detectable differences in terms of pressure on the femoral head.ConclusionsSevere dislocation (IHDI grade III and IV) in children showed a high mismatch between the femoral head and acetabulum. Increased abduction angle corresponded with high contact pressure, which might relate to AVN, whereas increased flexion angle was not. Enhanced pressure on the lateral part of the femoral head might increase the risk of AVN.

P0897RISK FACTORS FOR AVASCULAR BONE NECROSIS IN PATIENTS WITH LUPUS NEPHRITIS

Abstract Background and Aims Avascular necrosis of bone (AVN) is an important complication of systemic lupus erythematosus (SLE) and often causes serious physical disability. The aim of this study was to investigate the risk factors for symptomatic avascular necrosis of bone (AVN) in lupus nephritis (LN) patients. Method The records of 374 patients (43 males, 331 females) with kidney biopsy-proven LN were reviewed retrospectively. Symptomatic AVN cases were defined as those with at least one diagnosis of AVN. The patients with LN who did not have AVN were evaluated as a control group. To determine risk factors for AVN, clinical, laboratory and therapeutic variables were analyzed by logistic regression. Results Symptomatic AVN was present in 17 patients (4 males, 13 females, mean age of 27,4±6,7 years). Among the 17 patients, 28 joints presented AVN. 12 occurred in hips (2 bilateral), 6-in ankles, 4-in knees, 3-in shoulders and 1- in lumbar spine. In 9 patients AVN involved 2 or more joints. 14 patients were on steroids at the time of presentation of AVN. 2 patients were not on CS and 1 patient did not has documentation of steroid use. Meta-analysis demonstrates a significant increased risk of AVN in patients with high disease activity and class IV LN (p&amp;lt;0,005). LN patients with AVN showed an earlier onset age (p&amp;lt;0,05) and received significantly higher total cumulative corticosteroid dose. AVN was not significantly associated with use of immunosuppressive agents. Serositis, coagulation disorders, vasculitis, cigarette smoking were higher incidence in male with LN and AVN. Raynaud‘s phenomenon, autoimmune thyroiditis, arthritis, Sjögren’s syndrome, IgM anticardiolipin antibodies, antiphospholipid syndrome, Cushingoid body habitus were higher incidence in female with LN and AVN. Conclusion Many risk factors have been involved in the development of AVN in LN patients. AVN is prevalent in class IV LN and in younger patients. Since asymptomatic osteonecrosis may remain undetected, its true prevalence could be much higher than we reported. Multifocal lesions involving more than three anatomical sites are unusual. Corticosteroids are the principal risk factor, although some cases of AVN occur in relatively steroid naïve patients. Early detection of AVN is important because the prognosis depends of the stage and location of the lesion. An individual risk assessment for AVN development should be made prior to and during treatment for LN, especially in patients high dose corticosteroids.

Clinical manifestations and treatments of Protobothrops mucrosquamatus bite and associated factors for wound necrosis and subsequent debridement and finger or toe amputation surgery

Introduction Protobothrops mucrosquamatus bite induces wound necrosis, coagulopathy, thrombocytopenia, rhabdomyolysis, and acute renal failure. The severity of the hematological derangements and associated factors for wound necrosis and subsequent surgery and the appropriate management of these conditions have not been well characterized. Although severe renal failure requiring hemodialysis has been reported following P. mucrosquamatus bite, the culprit snake may be erroneously classified. Materials and methods A total of 186 patients with P. mucrosquamatus bites were retrospectively evaluated. They were categorized into group 1 (patients receiving debridement or finger/toe amputation) and group 2 (all other patients) to identify the associated factors for surgery. Characteristic data were compared between groups 1 and 2 and between definite and suspected cases. Results No differences were observed between definite and suspected cases in terms of symptomatology and management. Of the 186 patients, 7 (3.8%) were asymptomatic, 179 (96.2%) experienced tissue swelling and pain, and 107 (57.5%) had local ecchymosis. Coagulopathy, thrombocytopenia, and renal impairment were found in 13 (7%), 19 (10.2%), and 7 (3.8%) patients, respectively. None of the patients required transfusion therapy or hemodialysis. Furthermore, no systemic bleeding or death occurred. Antivenom was administered to all 179 envenomed patients at a median of 1.5 h post-bite. The median total dose of the specific antivenom was 5.5 vials. In multivariate logistic regression analysis, finger as the bite site, bullae and blister formation, and wound infection were significantly associated with wound necrosis; whereas finger as the bite site and bullae and blister formation were related to debridement or finger/toe amputation. Discussion and conclusions Protobothrops mucrosquamatus envenomation mainly exerts effects on local tissue. Systemic effects are uncommon and generally nonsevere and transient after the treatment with the specific antivenom. We speculated that severe renal failure requiring hemodialysis is not a typical finding of P. mucrosquamatus envenomation. Patients with finger as the bite site and bullae or blister formation should be carefully examined for wound necrosis, secondary infection, and subsequent surgery. Further evaluations of the efficacy of antivenom against local tissue effects and the effect of selective antibiotics in the management of bite wound infection are urgently required. Although the antivenom manufacturer suggested a skin test prior to use, we believed that it could be omitted because it does not accurately predict the allergic responses.

FEMORAL NECK FRACTURE TREATED WITH CANNULATED SCREWS: IS REDUCTION THE KEY POINT?

Background: In middle-aged patients, treatment of femoral neck fractures is still debated between osteosynthesis and replacement. Describing predictive factors is essential to choose the appropriate treatment for each patient. The aim of this study was to describe risk factors for avascular necrosis (AVN) of the femur head in patients with femoral neck fractures treated with three cannulated screws. Methods: We conducted a retrospective study of 91 patients between January of 2011 and February of 2017. Fractures were classified according to Garden and Pauwels classifications, fracture displacement was measured in millimetres (mm), quality of reduction was classified as anatomical or not anatomical; all post-operative radiographs were classified with Garden Alignment Index (GAI). Demographic data were recorded and analyzed. Results: AVN was found in six cases (6.6%). The Garden Classification ([Formula: see text]), GAI classification ([Formula: see text]), fracture displacement in mm ([Formula: see text]) and anatomical reduction ([Formula: see text]) were significantly associated with AVN. The most important risk factor for AVN was suboptimal reduction in axial view evaluated with GAI ([Formula: see text]). One case of AVN occurred in patients with GAI considered excellent (71.42%); no AVN occurred in patients with anatomical reduction (47.2%). Conclusions: Anatomical reduction in patients with femoral neck fractures treated with cannulated screws is mandatory. The degree of displacement before surgery influences the outcome but post-operative anatomical reduction, especially in the lateral view, is the most important predictive factor for the outcome: decreasing the Lateral Garden Angle (LGA) from 180∘increases significantly the risk for AVN.

Risk Factors for Fat Necrosis after Stereotactic Partial-Breast Irradiation (S-PBI) for Early-Stage Breast Cancer on a Phase I Clinical Trial

Risk Factors for Fat Necrosis after Stereotactic Partial-Breast Irradiation (S-PBI) for Early-Stage Breast Cancer on a Phase I Clinical Trial

Abstract P5-16-04: Evaluation of autologous fat grafting local morbidity (fat necrosis and biopsy rates) in breast reconstruction after breast cancer: A retrospective study on 257 patients in Oscar Lambret Center

Abstract Background.Autologous fat grafting (AFG) is a widely used procedure in breast reconstruction after breast cancer. Indications are in constant increase but there is a lack of dataabout global morbidity, especially fat necrosis and management of local complications. The purpose of this study was to evaluate the complications rate in term of abnormal clinical examination or imaging and the proportion of additional explorations. Methods. We retrospectively reviewed the computerized files of consecutive patients who underwent AFG for breast reconstruction after breast cancer or for preventive surgery and aesthetic sequelae after lumpectomy in the Oscar Lambret center between January 2013 and December 2016. Fat grafts were harvested with a fat trap then processed and injected according the Coleman technique. We collected demographics, operative details, local complications, incidence of palpable masses and/or suspicious breast imaging findings leading to additional explorations (breast imaging or biopsy), and locoregional cancer recurrence. Descriptive statistics were generated. Results. Over a 4-year period, 257 women underwent autologous fat grafting for breast reconstruction and aesthetic sequelae after lumpectomy. Their mean age was 50 years [range 28-75], the mean BMI was 25 [range 18-44], 26% (n=66) were smoking and 74% (n=190) underwent radiotherapy. A total of 303 breasts were operated by 270 mastectomies (89%) or33 lumpectomies (11%). The reconstruction was delayed in 63% (n=171) and the main techniques used were breast implant (44%, n=119) and autologous latissimus dorsi (31%, n=84). The mean number of fat grafting procedures was 1,9 per patient [range 1-7] with a mean volume of 181 mL [range 30-535]. The mean time interval between cancer diagnosis and first fat graft session was 56 months [range 3-285], and the follow-up ranged from 0 to 51 months (mean=16). The prevalence of donor site complications was 6% (n=16) and infections was 2% (n=5). Sixty six (25,6%) patients had a clinically palpable lesion and 54 (21%) underwent additional imagings, mostly by ultrasounds (53 patients, 98%) except the usual follow-up. Twenty one biopsies (8%) were performed and showed 16 benign results (76,2%) and 5 malignant results (23,8%) leading to 6,2% of fat necrosis and 1,9% of locoregional recurrence after AFG in our study.Tobacco (p=0.45), BMI (p=0.95), radiotherapy (p=0.56) and amount of fat grafted ( p=0.09) didn't appear to be risk factors for fat necrosis. Conclusions. A good knowledge of local complications by surgeons and radiologists enables to avoid systematic and repeated further imaging explorations. Multicentric, prospective studies with long term follow up and evaluation of patients reported outcomes are needed to evaluate anxiety generated by biopsies and costs generated by repeated imagings. Key words: autologous fat grafting, breast cancer, local morbidity, fat necrosis. Citation Format: Hannebicque K, Renaudeau C, Giard S, Regis C, Boulanger L, Bogart E, Le Deley M-C, Ceugnart L, Chauvet M-P. Evaluation of autologous fat grafting local morbidity (fat necrosis and biopsy rates) in breast reconstruction after breast cancer: A retrospective study on 257 patients in Oscar Lambret Center [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-16-04.

Factors of fat necrosis after breast reconstruction with autologous fat graft

Objective To investigate the related factors of fat necrosis nodules after autologous fat grafting for breast reconstruction. Methods Different methods of purification, number of operations, and history of breast radiation were analyzed. The relationship between fat graft and necrosis were compared. A total of 48 patients undergoing autologous transplantation for breast reconstruction after radical mastectomy between January 2015 and June 2017 in Chinese Academy of Medical Sciences were retrospectively analyzed, and 51 breasts were used. Results After surgery, 9 cases of palpable nodules were found in the breast, including 8 cases in the centrifuge group and 1 case in the sedimentation group. There were 20 cases of multiple hypoechoic nodules in breast ultrasound, including 13 cases in the centrifugation group and 7 cases in the sedimentation group. The incidence of breast nodules in the centrifuge group was 33.33%, and the incidence of fat liquefaction cysts was 54.17%; the incidence of breast nodules in the sedimentation group was 3.7%, and the incidence of fat liquefaction cysts was 25.93%. In this study, there were 4 cases of breast fat filling surgery, 18 cases of fat graft for 2 times, 23 cases of breast fat filling for 3 times, and 6 cases of fat filling for 4 times; the more time of fat graft surgery, the higher of the fat necrosis incidence. There were 21 cases of breasts with radiotherapy history, 30 cases of breast without radiotherapy history, 7 cases of nodules after autologous fat transplantation and breast reconstruction in radiotherapy group, 2 cases of nodules that could be touched after autologous fat transplantation without breast reconstruction, and 2 cases with radiotherapy. The incidence of fat necrosis after fat transplantation breast reconstruction was higher than those without radiotherapy. Conclusions The incidence of fat necrosis after fat-purified with centrifugation autologous grafting for breast reconstruction is higher than that by sedimentation method. The higher rate of fat necrosis is observed after breast reconstruction with autologous fat grafting in radiotherapy than that without radiotherapy. Key words: Adipocytes; Transplantation; Fat necrosis; Nodules; Breast reconstruction

Cemento-Osseous dysplasia-related jaw necrosis − a case report and literature review

Abstract: Osteonecrosis of the jaw (ONJ) is most commonly related to medications such as anti-resorptives and anti-angiogenics or head and neck radiotherapy. However, in addition to these, alternative causes of ONJ have also been reported including; infection, chemical toxicity, trauma and vascular ischaemia, but this list is not exhaustive. It is well accepted that cemento-osseous dysplasia (COD) can increase the risk of infection, poor healing and osteomyelitis due to the reduced vascularity. However, necrotic and exposed COD has not been widely reported. This case report describes a patient with COD-related necrosis in the anterior mandible and hence provides an additional member to the ever growing list of potential predisposing factors for jaw necrosis CPD/Clinical Relevance: Cemento-osseous dysplasia is a well recognized and benign condition commonly diagnosed from radiographs. The condition carries an increased risk of osteomyelitis and slow healing following oral surgery and, at its extreme, can cause osteonecrosis of the jaw, which remains an important condition of which the general dental practitioner (GDP) should be aware.

GW29-e1908 Clinical risk factors for transmural intestinal necrosis in acute mesenteric venous thrombosis

GW29-e1908 Clinical risk factors for transmural intestinal necrosis in acute mesenteric venous thrombosis

Sa1391 - Risk Factors for Walled-Off Necrosis Associated with Severe Acute Pancreatitis: A Multicenter Retrospective Observational Study

Sa1391 - Risk Factors for Walled-Off Necrosis Associated with Severe Acute Pancreatitis: A Multicenter Retrospective Observational Study

Time trend and risk factors of avascular bone necrosis in patients with systemic lupus erythematosus: methodological issues

Time trend and risk factors of avascular bone necrosis in patients with systemic lupus erythematosus: methodological issues

Identifying Risk Factors for Fat Necrosis after Autologous Fat Transplantation to the Breast

Identifying Risk Factors for Fat Necrosis after Autologous Fat Transplantation to the Breast

An analysis of clinical and dosimetric factors for postradiation nasopharyngeal necrosis in intensity-modulated radiotherapy for nasopharyngeal carcinoma

Objective To investigate the influencing factors for postradiation nasopharyngeal necrosis (PRNN) by analyzing clinical characteristics, prognosis, and dosimetry of PRNN after initial intensity-modulated radiotherapy (IMRT) for nasopharyngeal carcinoma (NPC). Methods A retrospective analysis was performed among 1217 patients with NPC who received initial IMRT from 2001 to 2013. Twenty-one patients were diagnosed with PRNN by clinical symptoms, endoscopy, magnetic resonance imaging, and pathological evidence (not including local recurrence). The clinical characteristics and prognosis were summarized and the radiotherapy plans were reassessed for dosimetric evaluation. Results In the 21 patients with PRNN, 17 were male and 4 female; one patient was in stage T2, 3 in stage T3, and 17 in stage T4. The median volume of gross tumor was 83 cm3. All patients received radiotherapy with a prescribed dose of 73.92 Gy except one patient with stage T2 disease who received a prescribed dose of 69.96 Gy. The time to PRNN after radiotherapy ranged between 1.8 and 21.9 months (median time=6.2 months). The incidence of massive nasopharyngeal bleeding was 48%(10/21). In the 21 patients, 6 recovered form PRNN, 15 remained ill, and 8 patients died, consisting of 4 who died of massive nasopharyngeal bleeding, 3 of cachexia with multiple organ failure, and 1 of multiple bone metastases. Conclusions PRNN is one of the severe adverse reactions after IMRT for NPC. The development of PRNN is related to advanced T stage, large tumor volume, poor nutritional status, infection, radiotherapy dose, and intense treatment. Massive nasopharyngeal bleeding and cachexia are the primary causes of death in patients with PRNN. Key words: Nasopharyngeal neoplasms/three-dimensional radiotherapy; Radiation nasopharyngeal necrosis; Factor analysis

Cirrhosis is a risk factor for total hip arthroplasty for avascular necrosis

Background and purpose — There are limited data on risk factors for avascular necrosis of the hip, but cirrhosis has been proposed as a risk factor. We examined the association between cirrhosis and incidence of total hip arthroplasty for avascular necrosis.Methods — We used nationwide healthcare data to identify all Danish residents diagnosed with cirrhosis in 1994–2011, and matched them 1:5 by age and sex to non-cirrhotic reference individuals from the general population. We excluded people with a previous total hip arthroplasty, a previous hip fracture, or a previous diagnosis of avascular necrosis. We used stratified Cox regression to estimate the hazard ratio (HR) for cirrhosis patients relative to reference individuals, adjusting for potential confounders. We used the cumulative incidence function to compute 5-year risks.Results — We included 25,421 cirrhosis patients and 114,052 reference individuals. Their median age was 57 years, and 65% were men. 45 cirrhosis patients and 44 reference individuals underwent total hip arthroplasty for avascular necrosis. Cirrhosis patients’ HR for a total hip arthroplasty for avascular necrosis was 10 (95% CI: 6–17), yet their 5-year risk of avascular necrosis was only 0.2%. For the reference individuals, the 5-year risk was 0.02%.Interpretation — Cirrhosis is a strong risk factor for avascular necrosis of the hip, but it is rare even in cirrhosis patients.

Clinical effect of 7.5 mm QWIX screw fixation of femoral neck fracture

Objective To evaluate the clinical effect of femoral neck fracture fixed with 7.5mm QWIX screws and to find out risk factors for avascular necrosis of the femoral head postoperatively. Methods From January 2009 and March 2013, 53 patients underwent closed or open reduction of femoral neck fracture with 7.5mm QWIX screws. Healing process of fracture, complications of internal fixation, Harris hip score and avascular necrosis of the femoral head were followed up. The data reviewed were age, gender, injury patterns, fracture type, preoperative waiting time, reduction ways, reduction condition, and others. Unilateral and multivariate Logistic analysis were applied to identify factors for avascular necrosis of the femoral head. Results All patients were followed up for 2-5 years (mean, 3.4 years). There was no non-union at follow-up, and all the screws were in the original site without loosening, cut-out or penetration. Mean Harris score was 91.2 points (range, 68 to 100 points) 2 years after operation, including 42 excellent, 6 good, 1 fair and 4 poor results with the excellent-good rate of 91%. Four patients (8%) had avascular necrosis 12 to 15 months after operation. With Logistic regression analysis, fracture anatomic type was identified as the only factor for avascular necrosis of the femoral head. Conclusions The 7.5 mm QWIX fixation screw provides rigid fixation, high healing rate and low incidence of avascular necrosis of the femoral head, appearing to be a good hardware to repair femoral neck fracture. Avascular necrosis of the femoral head is associated with the anatomic type of femoral neck fracture after operation. Key words: Femoral neck fractures; Internal fixators; Femur head necrosis; 7.5 mm QWIX screws