Obesity impairs revascularization and bone healing in a mouse model of osteonecrosis.

Osteonecrosis of the femoral head (ONFH) is a devastating bone disease that is caused by a disruption of blood supply leading to necrotic cell death. Clinically, it was found that obesity has a high prevalence with ONFH. However, it remains unclear how obesity may directly affect tissue regeneration and bone healing in osteonecrosis (ON). The purpose of this study is to investigate the effects of obesity and weight loss (WL) on ON healing. In this study, we induced obesity and WL in an established surgery-induced ON mouse model via feeding a high-fat diet (HFD) and altering the diet respectively. All mice received a surgical induction of ON of distal femoral epiphysis at the age of 12 weeks. HFD was switched to normal diet (ND) after ON surgery to induce WL. Mouse body weight was recorded weekly. Mouse body composition was scanned by DEXA (Dual-energy X-ray absorptiometry) right after sacrifice at the age of 16 weeks. The distal femoral bone samples were fixed and embedded for histology such as H&E, immunohistochemistry, and TRAP staining. In this study, we found that HFD-induced obesity impaired revascularization and bone remodeling showing decreased vessel areas and reduced osteoblast and osteoclast numbers. WL could rescue obesity-induced bone healing defects. Our study is the first to test the direct effects of obesity and WL on ON bone healing. We believe our work may provide new concepts for osteonecrosis treatment in obese patients.

Risk factors for osteonecrosis of the humeral head after internal fixation of proximal humeral fractures: a systematic review and meta-analysis.

BACKGROUND: Osteonecrosis of the humeral head (ONHH) is a severe complication after the internal fixation of proximal humeral fractures (IFPHF). The risk factors remain controversial though many studies have reported. In this research, meta-analysis was used to evaluate which surgeon-level factors can be modified to lower the risk and we hope to provide evidence-based support for preventing ONHH. METHODS: Literature was retrieved from PubMed, Cochrane Library, Embase, Web of Science, and Scopus for eligible studies published up to January 2023. The pooled odds ratios (ORs) were calculated with their corresponding 95% confidence intervals (CIs) to evaluate. STATA 15.1 software was applied for data synthesis, sensitivity synthesis, and publication bias. RESULTS: 45 articles were published between 2000 and 2022, and 2482 patients were finally included. All articles were observational research, with 7 case-control studies and 38 cohort studies, and the Newcastle Ottawa Scale (NOS) score ranged from 7 to 9. The pooled results suggested that age (OR 0.32, 95% CI 0.14-0.74, P = 0.01), reduction quality (OR 0.08, 95% CI 0.01-0.44, P = 0.00), fracture type (OR 0.44, 95% CI 0.25-0.78, P = 0.01), surgical approach (OR: 4.06, 95% CI 1.21-13.61, P = 0.02) and fixation implant (OR = 0.68, 95% CI = 0.34-1.33, P = 0.02) were risk factors for ONHH after IFPHF. According to sensitivity analysis, Begg (P = 0.42) and Egger (P = 0.68) tests, the results were stable and exhibited no publication bias. CONCLUSIONS: The study showed that age, reduction quality, fracture type, surgical approach and fixation implant were risk factors for ONHH after IFPHF, while gender, varus or valgus, timely operation, injured side, and the existence of medial support have little influence on ONHH, as they could not be considered risk factors and still need further investigations.

A prediction model for osteonecrosis of femoral head after internal fixation with multiple cannulated compression screws for adult femoral neck fractures.

OBJECTIVES: This study aims to investigate the high-risk factors for osteonecrosis of the femoral head (ONFH) after internal fixation with multiple cannulated compression screws for adult femoral neck fractures and to construct a prediction model. PATIENTS AND METHODS: Between from January 2012 and December 2020, a total of 268 patients (138 males, 130 females; mean age: 53±10 years; range, 23 to 70 years) with ONFH who had complete follow-up data were included. Closed reduction in combination with open reduction were performed. All patients received internal fixation with multiple cannulated compression screws and were assigned to ONFH and non-ONFH groups. Logistic regression model was utilized to identify independent risk factors for postoperative ONFH, followed by constructing a nomogram prediction model. The predictive ability of the model was evaluated by receiver operating characteristic curve, Hosmer-Lemeshow test, and calibration curve. RESULTS: Multivariate analysis revealed that older age (odds ratio [OR]: 2.307, 95% confidence interval [CI]: 1.295-4.108], Charlson Comorbidity Index (CCI) ≥2 (OR: 2.214, 95% CI: 1.035-4.739), fracture displacement (OR: 2.426, 95% CI: 1.122-5.247), unsatisfactory reduction (OR: 2.629, 95% CI: 1.275-5.423), postoperative removal of internal fixation implant (OR: 2.200, 95% CI: 1.051-4.604) were independent risk factors for postoperative ONFH (p<0.05). The nomogram prediction model constructed based on these clinical characteristics showed high predictive value (AUC=0.807) and consistency (p>0.05). CONCLUSION: Age, comorbidity index, fracture type, reduction quality and postoperative removal of internal fixation implant are of utmost importance for postoperative ONFH in patients with femoral neck fractures. The established nomogram prediction model can accurately predict the occurrence of postoperative ONFH.

Identifying Risk Factors for Osteonecrosis After Talar Fracture.

OBJECTIVE: To identify patient, injury, and treatment factors associated with the development of avascular necrosis (AVN) after talar fractures, with particular interest in modifiable factors. DESIGN: Retrospective chart review. SETTING: 21 US trauma centers and 1 UK trauma center. PATIENT SELECTION CRITERIA: Patients with talar neck and/or body fractures from 2008 through 2018 were retrospectively reviewed. Only patients who were at least 18 years of age with fractures of the talar neck or body and minimum 12 months follow-up or earlier diagnosis of AVN were included. Further exclusion criteria included non-operatively treated fractures, pathologic fractures, pantalar dislocations, and fractures treated with primary arthrodesis or primary amputation. OUTCOME MEASUREMENTS AND COMPARISONS: The primary outcome measure was development of AVN. Infection, nonunion, and arthritis were secondary outcomes. RESULTS: In total, 798 patients (409 men; 389 women; age 18-81 years, average 38.6 years) with 798 (532 right; 264 left) fractures were included and were classified as Hawkins I (51), IIA (71), IIB (113), III (158), IV (40), neck plus body (177), and body (188). In total, 336 of 798 developed AVN (42%), more commonly after any neck fracture (47.0%) versus isolated body fracture (26.1%, P < 0.001). More severe Hawkins classification, combined neck and body fractures, body mass index, tobacco smoking, right-sided fractures, open fracture, dual anteromedial and anterolateral surgical approaches, and associated medial malleolus fracture were associated with AVN ( P < 0.05). After multivariate regression, fracture type, tobacco smoking, open fractures, dual approaches, age, and body mass index remained significant ( P < 0.05). Excluding late cases (>7 days), time to joint reduction for Hawkins type IIB-IV neck injuries was no different for those who developed AVN or not. AVN rates for reduction of dislocations within 6 hours of injury versus >6 hours were 48.8% and 57.5%, respectively. Complications included 60 (7.5%) infections and 70 (8.8%) nonunions. CONCLUSIONS: Forty-two percent of all talar fracture patients developed AVN, with talar neck fractures, more displaced fractures, and open injuries having higher rates. Injury-related factors are most prognostic of AVN risk. Surgical technique to emphasize anatomic reduction, without iatrogenic damage to remaining blood supply appears to be prudent. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Postoperative scaphoid alignment, smoking, and avascular necrosis mostly influence union rate after scaphoid reconstruction: Results from a retrospective single center study involving 370 patients.

Current literature does not definitely demonstrate the superiority of any particular scaphoid reconstruction method. The primary goal of this retrospective single center study was to evaluate the influence of reconstruction techniques and other factors on the union rate after reconstruction of scaphoid nonunions. In the study, 370 patients with nonunions classified as stable (Mayo 1) or unstable (Mayo 2) depending on carpal alignment were included. Minimal radiological follow-up was 3 months. Bone healing after scaphoid reconstruction was evaluated using computer tomography scans in 294 and radiograms in 76 patients. Univariate and multivariate logistic regressions were applied in the analysis. Eight statistically significant factors that influenced the union rate were fixation method, type of previous operations, number of all operations, number of reconstructions, smoking, postoperative pathological lateral intrascaphoid angle (LISA>45°), avascular necrosis (AVN), and stability of nonunion. Smoking and postoperative LISA>45° significantly reduced the probability of bone fusion by approximately 4.4 and 9.5 times, respectively. Patients with reduced vascularity in the nonunion site had a 5.2 times lower chance of bone fusion. Our multivariate logistic regression model can explain 32% of failures after scaphoid reconstruction, including postoperative LISA>45°, patients' present record of smoking, and reduced vascularity in the nonunion site. However, bone graft type does not impact the union rate in general; however, in case of AVN, the tendency toward higher union rates was observed for medial femoral condyle free flaps when compared to other types of graft (non-vascularized and pedicled bone grafts considered as one group, p = 0.09).

Clinical and epidemiological features and therapeutic options of avascular necrosis in patients with sickle cell disease (SCD): a cross-sectional study.

BACKGROUND: Avascular necrosis (AVN) is a debilitating complication in sickle cell disease (SCD) patients, and its management is usually challenging. This study aims to evaluate the clinical and epidemiological features and therapeutic options of AVN in sickle cell patients in Qatar. PATIENTS AND METHODS: A cross-sectional study was conducted on a 49 SCD patients who were diagnosed with AVN and attended the hematology clinic at the National Center for Cancer care & research, Hamad Medical Corporation, Qatar between Jan-2011 to Jan2021.  Results: Forty-nine adult patients with SCD who were diagnosed with AVN were studied. The median age of the study population is 32 years, and the median age at the first AVN diagnosis was 26 years (range: 11-44 yr.). 37 (75.5%) patients suffered from multiple joints AVN while 12(24.5%) had single joint involvement. 31 (63.3%) patients had bilateral hip AVN and 18 (36.7%) had shoulder involvement. 30 patients (61%) were on Hydroxyurea treatment. Based on FICAT and Alert classification of AVN, 57 % of patients had stage III and above at first diagnosis. 20 (40.8%) were managed with a conservative approach, 11 (22.4%) received hyperbaric oxygen with good response, 6(12.2%) underwent hip core decompression and 12(24.5%) underwent hip replacement surgery. CONCLUSION: In SCD patients, AVN occurred more during the 3rd and 4th decades of life. The majority of AVN represented with advanced stage and had multiple joint involvements. We recommend adopting a low threshold of joint imaging for early detection and prevention of further complications.

Knee Osteonecrosis After SARS-CoV-2 Virus Infection.

ABSTRACT: Osteonecrosis after COVID-19 infection is a complex pathology with multifactorial origin. Factors such as infection itself with associated coagulopathy, as well as genetic mechanisms, and medications used for its treatment such as corticosteroids, may also be involved. The variability in the presentation makes diagnosis difficult, which, if done soon, can help delay progression and reduce morbidity and the need for surgery.This report presents a case of knee osteonecrosis in a female patient who did not have previous knee pathology on imaging tests. She was diagnosed by magnetic resonance imaging months after hospital admission for SARS-CoV-2 pneumonia, which required high-dose corticosteroid treatment.

Outcomes of three cannulated screws in a modified triangular transverse configuration for fixation of intra-capsular femoral neck fractures.

BACKGROUND: Intra-capsular femoral neck fractures (FNF) are commonly encountered in trauma settings and are associated with high rates of morbidity and mortality. One of the most used methods of FNF treatment is the use of multiple cannulated screws. Many different screw constructs are reported in the literature, with no evidence of superiority of one construct over others. We present a series of patients treated by one senior surgeon with three cannulated screws positioned in a specific configuration. MATERIALS AND METHODS: We conducted a retrospective monocentric analysis. All charts of patients hospitalized between January 2004 and June 2022 for an intra-capsular femoral neck fracture treated by three cannulated screws by the same senior surgeon were retrieved and analyzed. The clinical and radiological evaluations were performed by two independent researchers. Functional status of patients was assessed using the modified Harris Hip score (mHHS). Complications such as secondary displacement, non-union, avascular necrosis (AVN) and femoral neck shortening were all recorded. RESULTS: A total of 38 patients met the inclusion criteria. There were 17 males and 21 females with an average age of 66.3 ± 13.6 years and a follow-up period of 16 ± 20 months. Bone union was observed in 34 (89.5%) patients. Mild shortening was observed in two patients (5.2%) with no functional limitation. Four patients (10.5%) underwent reoperations, three due to another fall and one due to AVN four years post-fracture fixation. CONCLUSION: In our series, we demonstrate that the use of three cannulated screws in a triangular transverse configuration for fixation of intra-capsular femoral neck fractures provides excellent results with low rates of femoral neck shortening, AVN or non-union.

Time to reconsider post arthroscopic osteonecrosis of the knee: a systematic review.

The etiology of post-arthroscopic osteonecrosis of the knee (PAONK) is still unknown. The aims of this systematic review were to analyze the main characteristics of patients who developed osteonecrosis after arthroscopy. We considered for inclusion in the review case reports, case series, retrospective and prospective clinical trial, that involved patients who developed osteonecrosis of the knee within 1 year of arthroscopy for meniscal lesion or anterior cruciate ligament rupture with or without chondropathy. In all cases, there was a pre-operative magnetic resonance imaging that excluded the presence of osteonecrosis. We used the MINORS criteria to estimate the risk of bias. A total of 13 studies that involved 125 patients were included in the review. Only 14 out of 55 patients performed the pre-operative MRI after the "window period", which we considered 6 weeks between the onset of symptoms and positive MRI findings. A diagnosis of PAONK was made for 55 patients within 1 year of surgery. Of these, 29% was treated conservatively, while 71% repeated surgery. Osteonecrosis after knee arthroscopy is a reality and surgeon shouldn't underestimate the persistence or re-emergence of symptoms after arthroscopy. It may be due to subchondral insufficiency fractures in osteopenic bone, without evidence of necrosis. However, there are not elements enough to differentiate clinical and radiological characteristics of PAONK from SPONK. Terminology should be simplified, distinguishing subchondral insufficiency fractures of the knee as a precursor of primary osteonecrosis of the knee.

The Hertel classification can't predict the risk of humeral head osteonecrosis after osteosynthesis using an anterolateral approach.

BACKGROUND: Proximal humeral fractures can progress to osteonecrosis of the humeral head. Hertel developed a binary classification system (12 subtypes) and demonstrated that some patterns have more risk to develop osteonecrosis. Hertel described the prevalence and the risk factors for Humeral head osteonecrosis after osteosynthesis using a Deltopectoral approach. Few studies have evaluated the prevalence and the capacity of Hertel's classification to predict Humeral Head osteonecrosis following osteosynthesis of proximal Humeral fractures through the anterolateral approach. The objectives of this study were to correlate osteonecrosis predictors established by the Hertel classification with the risk of developing osteonecrosis and its prevalence after osteosynthesis using the anterolateral approach. METHODS: This was a retrospective study of patients who underwent osteosynthesis of proximal humerus fractures using an anterolateral approach. Patients were divided into two groups: high risk for necrosis (group 1) and low risk for necrosis (group 2) according to Hertel's criteria. The overall prevalence of osteonecrosis and the prevalence in each group were calculated. A radiological examination was performed in the true anteroposterior (Grashey), scapular, and axillary views, before and after the operation (minimum 1 year after surgery). A Kaplan-Meier curve was used to assess the pattern of the temporal evolution of osteonecrosis. The groups were compared using the Chi-square test or Fisher's exact test. The unpaired t-test (parametric variables - age) and the Mann-Whitney test (non-parametric time between trauma and surgery) were used. RESULTS: In total, 39 patients were evaluated. The postoperative follow-up time was 14.5 ± 3.3 months. The time to onset of necrosis was 14.1 ± 3.9 months. Sex, age, and time between trauma and surgery did not influence the risk of necrosis. Type 2, 9, 10, 11, and 12, or fractures with posteromedial head extension less than or equal to 8 mm, or diaphysis deviation greater than 2 mm, as well as grouping did not influence the risk for osteonecrosis. CONCLUSIONS: Hertel's criteria were not able to predict the development of osteonecrosis after osteosynthesis of proximal humerus fractures performed through the anterolateral approach. The total prevalence of osteonecrosis was 17.9% with a tendency toward an increased incidence after 1 year of surgical treatment.

The outcomes of total hip replacement in osteonecrosis versus osteoarthritis: a systematic review and meta-analysis.

PURPOSE: This systematic review and meta-analysis aimed to compare the outcomes of THA in patients with osteonecrosis (ON) and those with osteoarthritis (OA). METHODS: Four databases were searched from inception till December 2022 for original studies that compared the outcomes of THA in ON and OA. The primary outcome was the revision rate; the secondary outcomes were dislocation and Harris hip score. This review was conducted in line with PRISMA guidelines, and the risk of bias was assessed using the Newcastle-Ottawa scale. RESULTS: A total of 14 observational studies with 2,111,102 hips were included, with a mean age of 50.83 ± 9.32 and 55.51 ± 8.95 for ON and OA groups, respectively. The average follow-up was 7.25 ± 4.6 years. There was a statistically significant difference in revision rate between ON and OA patients in favour of OA (OR: 1.576; 95%CI: 1.24-2.00; p-value: 0.0015). However, dislocation rate (OR: 1.5004; 95%CI: 0.92-2.43; p-value: 0.0916) and Haris hip score (HHS) (SMD: - 0.0486; 95%CI: - 0.35-0.25; p-value: 0.6987) were comparable across both groups. Further sub-analysis adjusting for registry data also showed similar results between both groups. CONCLUSION: A higher revision rate, periprosthetic fracture and periprosthetic joint infection following total hip arthroplasty were associated with osteonecrosis of the femoral head compared with osteoarthritis. However, both groups had similar dislocation rates and functional outcome measures. This finding should be applied in context due to potential confounding factors, including patient's age and activity level.

The incidence, risk factors, and outcomes of symptomatic avascular necrosis of bone among Chinese pediatric patients with acute lymphoblastic leukemia.

BACKGROUND: Avascular necrosis (AVN) of bone is a debilitating complication of pediatric patients with acute lymphoblastic leukemia (ALL). While it is extensively studied and reported in Western population, studies focused on Orientals are limited. This study aims to evaluate the incidence, risk factors, and clinical outcomes of AVN among Chinese children with ALL. METHODS: This study is a retrospective, territory-wide population-based cohort study of pediatric patients with ALL enrolled on one of the three consecutive ALL study protocols (ALL-IC-BFM 2002, CCLG-ALL 2008, and CCCG-ALL 2015). RESULTS: A total of 24 out of 533 pediatric subjects with ALL (4.5%) had symptomatic AVN. Age was the single most important risk factor associated with the development of AVN. Only three patients were below age of 10 at the time of diagnosis of ALL. The incidences of AVN in patients aged above and below 10 years were 18.2% ± 3.6% and 0.8% ± 0.5%, respectively, and were significantly different (p < 0.005). Treatment protocol, immunophenotype, and gender were not predictive of AVN. Among the 24 patients, five required orthopedic interventions in view of progressive and severe disease. For subjects with hip joints involvement, follow-up assessments showed 12 of 22 hip joints had radiological progression over a median duration of 3.63 years. Seventeen of them did not have pain at the latest follow-up and among patients with pain (n = 7), five did not experience any limitation on activities of daily living while two required use of walking aids or wheelchair. CONCLUSION: The incidence of symptomatic AVN in Chinese ALL patients was comparable to other studies in Western population. Adolescent age more than 10 years old was recognized to be the most important factor for development of AVN. Significant proportion of patients had radiological progression over time with a small percentage of subjects had daily activities affected.

Symptomatic osteonecrosis in French survivors of childhood and adolescent leukemia: a clinical and MRI study of LEA cohort.

Osteonecrosis (ON) is a known complication of acute leukemia (AL) management, affecting 1%-10% of young patients and resulting in long-term morbidity. Widespread access to MRI over the past decade has allowed earlier detection and more accurate assessment. This study investigated clinical and MRI features of the 129 (2.5%) patients with symptomatic ON retrospectively recruited from the French LEA (Leucémies de l'Enfant et de l'Adolescent, or child and adolescent leukemias) cohort (n = 4,973). We analyzed data concerning ON risk factors, multifocal involvement, severe lesions detected by MRI, and patient quality of life (QoL). ON patients tended to be >10 years old at the time of AL diagnosis (odds ratio [OR]: 22.46; p < 10-6), female (OR: 1.8; p = 0.002), or treated for relapse (OR: 1.81; p = 0.041). They more frequently suffered from other sequelae (p < 10-6). Most necroses involved weight-bearing joints, and they were multifocal in 69% of cases. Double-blinded review of MRIs for 39 patients identified severe lesions in 14, usually in the hips. QoL of adolescents and adults was poor and permanently impacted after onset of ON. In conclusion, age >10 at time of AL diagnosis, female sex, and relapse occurrence were risk factors for multifocal ON; MRI revealed severe ON in a third of the patients considered; and ON was associated with persistently poor QoL affecting multiple domains. Future studies should include prospective data addressing ON management and seek to identify genetic markers for targeted screening enabling early ON detection and treatment.

Kienböck's disease: preventing disease progression in early-stage disease.

Currently Kienböck's disease remains an 'unsolved' problem in hand surgery. Different factors have been associated with the avascular necrosis of the lunate. Mechanical, vascular and biological factors, alone or in combination, may have an influence in the aetiopathogenesis and determine the progress of the disease and even the results of the treatment. This is especially relevant in the early stages, in which conservative or surgical treatment may modify the natural history of the disease, maintaining the lunate structure and thus preserving the joint surfaces. There are multiple surgical treatments for Kienböck's disease in the early stages, before lunate collapse; each one is based on one of the possible factors that can cause avascular necrosis of the lunate. The objective is not only to treat symptoms but to prevent progression. This article is a review of the most frequent treatments used in the early stages and a personal view of the authors.Level of evidence: V.

Tool parameters to minimize temperature changes in bone drilling.

BACKGROUND: Drilling is a common technique used in orthopedic surgery procedures but causes increases in temperature that can lead to cell damage and death. The extent of this depends largely on the magnitude of the increase in temperature. The commonly accepted limit to prevent osteonecrosis is less than 47 °C for 60 s. There is controversy when it comes to the optimal drilling parameters that limit temperature increases and cell death. In addition to this, less research has been done on the drilling effects in the osteochondral area of joints. Osteochondral tissue damage can interfere with the daily lives of patients and if severe enough will need to be treated. We hypothesize that increasing tool speed and drill bit size will increase temperature that could be above the osteonecrosis limit. METHODS: Ex-vivo experiments were conducted on porcine shoulder joints that tested the thermal effects of different tool speeds and drill bit sizes. A thermal camera was used to record and measure real time temperature changes while drilling. Three drill bit sizes and five tool speeds were used. Statistical analyses includes Welch's ANOVA with Games-Howell Post Hoc analyses, multivariate linear regression, and surface response regression were used to explore the association of tool speeds and drill bit size on temperature. RESULTS AND CONCLUSIONS: All the tool speed and drill bit size combinations lead to an increase in temperature that were under the commonly accepted limit. The highest temperature reached was 44 °C with a tool speed of 1150 RPM and 3070 RPM and drill bit size 5.159 mm. It was found that increasing the tool speed increased the temperature change and increasing the drill bit size increased the temperature change.

Editorial Commentary: Spontaneous Insufficiency Fracture of the Knee, Formerly Known as Spontaneous Osteonecrosis of the Knee, May Benefit From Combined Mosaicplasty and High Tibial Osteotomy: Better Together.

Spontaneous insufficiency fracture of the knee (SIFK) previously termed spontaneous osteonecrosis of the knee (SONK) is a painful knee condition that can occur spontaneously from unknown causes. Histology confirms that a subchondral insufficiency fracture is the true finding and osteonecrosis is a secondary and end-stage finding of the SIFK spectrum of disease. SIFK demonstrates a subchondral fracture and bone marrow edema (BME) on MRI and if left untreated, it can lead to collapse. SONK is most often diagnosed in middle-aged and older patients and is more common in females. It is usually found in the medial femoral condyle. Approximately one-third of patients progressed to total knee arthroplasty. Factors that contributed to disease progression included baseline arthritis, older age, location of the insufficiency fracture, meniscal extrusion, and varus malalignment. Positive outcomes have been reported when SIFK is treated with a combination of mosaicplasty (MOS) and high tibial osteotomy (HTO). And just as like MOS and HTO work better together, we need to collaborate to find solutions. We too are better together.

Is early mobilization a viable option after intramedullary nailing of 4-parts proximal humerus fractures?

INTRODUCTION: After centromedullary nailing (CMN) of 4-parts (4P) cephalo-tuberositary fractures of the proximal humerus (PH), shoulder immobilization for a few weeks is usual, although no scientific justification does support this attitude, nor the duration of immobilization. The objective of this study was to assess the impact of early mobilization after CMN of PH 4P fractures on clinical, radiological outcomes and complication rates. The hypothesis was that early mobilization would not lead to a deterioration in results or an increase in the complication rate. MATERIALS AND METHODS: All patients operated on for a 4P-PH fracture by CMN in our institution between 2010 and 2018 were included retrospectively. 2 groups were formed according to the duration of post-operative immobilization of the shoulder: 0-2 weeks (group A) and 3-6 weeks (group B). All patients had a clinical examination (Range of motion ROM and Constant score) and X-rays of the shoulder at least 24 months of follow-up. 58 patients (average age 66 years (39-89)) were included, with 25 in group A and 33 in group B. RESULTS: The average follow-up was 38.5 (24-73) months. The active ROM at the last follow-up was: active anterior elevation 149° (80°-180°) in group A versus 134 (60°-180°) in group B (p = 0.099); active external rotation 145° (15°-70°) in group A versus 42° (15-70°) in group B (p = 0.6). The Absolute Mean Constant score was 78.29 for Group A (45-100) versus 68.59 points (45-96) for Group B (p = 0.065). Regarding complications: in group A, we found 2 retractile capsulitis, 2 pseudarthrosis and 2 osteonecrosis of the humeral head. In group B, we found 5 retractile capsulitis, 1 infection of the surgical site, 3 osteonecrosis of the humeral head and 1 pseudarthrosis. CONCLUSION: Early mobilization after CMN of 4P-PH fractures did not lead to an increase in the complications rate and in particular secondary displacements or osteonecrosis. There was a trend toward improved clinical outcomes with early mobilization, although this trend was not statistically significant. EVIDENCE LEVEL: IV, retrospective study.

Long-term outcomes after humeral head replacement and total shoulder replacement for osteonecrosis of the humeral head: a mean follow-up of 8 years.

INTRODUCTION: The purpose of this study was to compare the outcomes and complications after humeral head replacement (HHR) and total shoulder replacement (TSR) in patients with osteonecrosis of the humeral head (ONHH). MATERIALS AND METHODS: Twenty-six patients who underwent shoulder replacement (13 HHRs and 13 TSRs) for nontraumatic ONHH were included. The mean follow-up period was 96.4 months. The visual analog scale (VAS) pain score, the University of California at Los Angeles (UCLA) score, the American Shoulder and Elbow Surgeon (ASES) score, and range of motion (ROM) at the final follow-up evaluation were used for the assessment of clinical outcomes. RESULTS: The mean VAS pain score, UCLA score, and ASES score showed significant improvement from 6.3, 11.6, and 35.0 before surgery to 2.2, 28.9, and 82.6 at the final follow-up evaluation (all p < 0.001). No significant differences regarding all clinical scores and ROMs were observed between the HHR group and the TSR group, except that a greater abduction angle was observed in the HHR group compared with the TSR group (123.1° versus 96.9°, p = 0.014). Two patients in the TSR group underwent multiple reoperations due to periprosthetic joint infection. No revision surgeries were performed for glenoid erosion following HHR or aseptic glenoid loosening following TSR. CONCLUSIONS: The findings of this study showed satisfactory clinical and radiological outcomes with implant longevity for both HHR and TSR in patients with nontraumatic ONHH. The HHR group had a greater abduction angle compared with the TSR group.

Etiology of avascular necrosis of the hip and shoulder. Screening for Gaucher disease.

INTRODUCTION: Avascular necrosis (AON) of the hip and shoulder is a little studied disease and the predisposing risk factors for its development are not well known. A high percentage of patients are diagnosed with idiopathic osteonecrosis. This study aims to investigate the prevalence of potential etiological factors for AON and to screen for Gaucher disease among patients with idiopathic AON. MATERIAL AND METHODS: This retrospective, single-center, observational study was conducted on patients who had at least one episode of AON of the hip or shoulder at the Hospital de Poniente (Almería, Spain) from January 2010 to December 2019. Clinical and analytical data were collected. Patients whose medical record described no etiological factors for this disease were screened for Gaucher disease. RESULTS: The study sample consisted of 81 patients, of whom 58 were male. The mean age at presentation of AON was 45.9 years. They presented with unilateral hip necrosis (n=43), bilateral hip necrosis (n=34), bilateral hip and unilateral shoulder necrosis (n=3), and unilateral shoulder necrosis (n=1). The most frequent potential etiological factors were smoking (46.9%) and obesity (17.3%). Screening for Gaucher disease was performed in ten patients, all of whom tested negative. CONCLUSIONS: In our study population, the main potential etiological factors the onset of AON of the shoulder or hip were smoking and obesity. A high percentage of patients were diagnosed with idiopathic AON. We believe that a more exhaustive study of less frequent risk factors should be carried out in these cases.

Talar neck and body fracture outcomes: a multicentre retrospective review.

PURPOSE: Talar neck and body fractures are uncommon injuries that are challenging to manage with high reported complication rates, including post-traumatic arthritis, avascular necrosis, and poor functional outcomes. The aim of this study was to assess the complication rates for patients with talus fractures across three major trauma centres (MTCs) in England. METHODS: A retrospective analysis was performed of prospectively collected trauma databases. Data were collected from three English MTCs. Patients with talar neck and/or body fractures sustained between August 2015 and August 2019 were identified and their clinical course reviewed radiologically and clinically. Isolated process fractures, osteochondral defects and paediatric patients were excluded. Patients were analysed by fracture type and for definitive treatment method with separation into non-operative and operative management groups. Procedure type was identified in the operative group. Superficial infection, deep infection, non-union, avascular necrosis, post-traumatic arthritis and removal of metalwork rates were analysed. RESULTS: Eighty-five patients with talar neck and/or body fractures were included. Seventy-five patients received operative management, 10 non-operative. The overall AVN rate was 5.9% (five patients), overall post-traumatic arthritis rate was 18.8% (16 patients), deep infection rate 1.2% (one patient), non-union rate 4.7% (four patients). Removal of metalwork rate was 9.4% (eight patients). CONCLUSION: Our reported outcomes and complication rates are generally lower than those previously described. This may be a result of improved techniques, a higher frequency of open reduction with direct visualisation or by surgery occurring in centralised specialist centres.