Surgical strategy of the treatment of atypical femoral fractures.

The atypical femoral fracture (AFF) has been attracting significant attention because of its increasing incidence; additionally, its treatment is challenging from biological and mechanical aspects. Although surgery is often required to manage complete AFFs, clear guidelines for the surgical treatment of AFFs are currently sparse. We reviewed and described the surgical treatment of AFFs and the surveillance of the contralateral femur. For complete AFFs, cephalomedullary intramedullary nailing spanning the entire length of the femur can be used. Various surgical techniques to overcome the femoral bowing common in AFFs include a lateral entry point, external rotation of the nail, and the use of a nail with a small radius of curvature, or a contralateral nail. In the case of a narrow medullary canal, severe femoral bowing, or pre-existing implants, plate fixation may be considered as an alternative. For incomplete AFFs, prophylactic fixation depends on several risk factors, such as a subtrochanteric location, presence of a radiolucent line, functional pain, and condition of the contralateral femur; the same surgical principles as those in complete AFFs can be applied. Finally, once AFF is diagnosed, clinicians should recognize the increased risk of contralateral AFFs, and close surveillance of the contralateral femur is recommended.

Pyruvate dehydrogenase kinase 4 promotes ubiquitin-proteasome system-dependent muscle atrophy.

BACKGROUND: Muscle atrophy, leading to muscular dysfunction and weakness, is an adverse outcome of sustained period of glucocorticoids usage. However, the molecular mechanism underlying this detrimental condition is currently unclear. Pyruvate dehydrogenase kinase 4 (PDK4), a central regulator of cellular energy metabolism, is highly expressed in skeletal muscle and has been implicated in the pathogenesis of several diseases. The current study was designed to investigated and delineate the role of PDK4 in the context of muscle atrophy, which could be identified as a potential therapeutic avenue to protect against dexamethasone-induced muscle wasting. METHODS: The dexamethasone-induced muscle atrophy in C2C12 myotubes was evaluated at the molecular level by expression of key genes and proteins involved in myogenesis, using immunoblotting and qPCR analyses. Muscle dysfunction was studied in vivo in wild-type and PDK4 knockout mice treated with dexamethasone (25 mg/kg body weight, i.p., 10 days). Body weight, grip strength, muscle weight and muscle histology were assessed. The expression of myogenesis markers were analysed using qPCR, immunoblotting and immunoprecipitation. The study was extended to in vitro human skeletal muscle atrophy analysis. RESULTS: Knockdown of PDK4 was found to prevent glucocorticoid-induced muscle atrophy and dysfunction in C2C12 myotubes, which was indicated by induction of myogenin (0.3271 ± 0.102 vs 2.163 ± 0.192, ****P < 0.0001) and myosin heavy chain (0.3901 ± 0.047 vs. 0.7222 ± 0.082, **P < 0.01) protein levels and reduction of muscle atrophy F-box (10.77 ± 2.674 vs. 1.518 ± 0.172, **P < 0.01) expression. In dexamethasone-induced muscle atrophy model, mice with genetic ablation of PDK4 revealed increased muscle strength (162.1 ± 22.75 vs. 200.1 ± 37.09 g, ***P < 0.001) and muscle fibres (54.20 ± 11.85% vs. 84.07 ± 28.41%, ****P < 0.0001). To explore the mechanism, we performed coimmunoprecipitation and liquid chromatography-mass spectrometry analysis and found that myogenin is novel substrate of PDK4. PDK4 phosphorylates myogenin at S43/T57 amino acid residues, which facilitates the recruitment of muscle atrophy F-box to myogenin and leads to its subsequent ubiquitination and degradation. Finally, overexpression of non-phosphorylatable myogenin mutant using intramuscular injection prevented dexamethasone-induced muscle atrophy and preserved muscle fibres. CONCLUSIONS: We have demonstrated that PDK4 mediates dexamethasone-induced skeletal muscle atrophy. Mechanistically, PDK4 phosphorylates and degrades myogenin via recruitment of E3 ubiquitin ligase, muscle atrophy F-box. Rescue of muscle regeneration by genetic ablation of PDK4 or overexpression of non-phosphorylatable myogenin mutant indicates PDK4 as an amenable therapeutic target in muscle atrophy.

Average 22-Year Results of Total Hip Arthroplasty Using Harris-Galante Prosthesis in Patients under 50 Years.

Background: The Harris-Galante (HG) prosthesis is a first-generation, cementless total hip arthroplasty (THA) prosthesis. Considering the recent increase in the demand for THA in young patients and their life expectancy, a study with a follow-up duration of longer than 20 years in a young population is needed. Therefore, we evaluated the long-term clinical and radiographic results after cementless THA using the HG prosthesis in patients younger than 50 years. Methods: A total of 61 THAs performed using the HG with a minimum follow-up of 10 years were included. There were 38 men and 11 women with an average age of 46 years and the mean follow-up duration was 22 years. Clinical evaluation included modified Harris Hip Score (HHS) and radiographic analysis consisted of cup inclination, anteversion angle, component stability, osteolysis, liner wear rate, wear-through, liner dissociation, and heterotopic ossification. Complications included recurrent dislocation, periprosthetic femoral fracture, and periprosthetic joint infection. Survivorship analysis included cup and stem revision for aseptic loosening, as well as any revision. Results: The HHS improved from 46.5 preoperatively to 81.8 postoperatively (p < 0.001). The average linear wear rate was 0.36 mm/yr. A total of 34 hips (56%) were revised: stem revision in 10 (16.4%), cup revision in 9 (14.8%), exchange limited to bearing surface in 8 (13.1%), and revision of all components in 7 (11.5%). Estimated survivorship at 34 years postoperatively was 90.9% for cup revision for aseptic loosening, 80.5% for stem revision for aseptic loosening, and 22.1% for any revision. Conclusions: THA using the HG prosthesis showed satisfactory estimated survivorship of the acetabular and femoral components at 34 years postoperatively with good clinical outcomes. Bearing-related problems, such as osteolysis and liner dissociation, accounted for 56% of revision operations and were concerns in patients younger than 50 years.

Abnormal Lipid Profiles in Nontraumatic Osteonecrosis of the Femoral Head: A Comparison with Osteoarthritis Using Propensity Score Matching.

BACKGROUND: Abnormal lipid metabolism may play an important role in the development of nontraumatic osteonecrosis of the femoral head (ON). By comparing lipid biomarkers in patients with ON and osteoarthritis (OA) after propensity score matching, we sought to reveal (1) common lipid biomarkers that are abnormal in ON regardless of the etiology and (2) specific lipid biomarkers associated with ON according to the etiology. METHODS: Among 2,268 patients who underwent primary THA, 1,021 patients were eligible for this study. According to the Association Research Circulation Osseous criteria, ON was classified as either idiopathic (n = 230), alcohol-associated (n = 293), or glucocorticoid-associated ON (n = 132). Most common cause of OA was hip dysplasia in 106 patients (47%). We investigated patient lipid profiles by assessing total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglycerides (TGs), apolipoprotein (Apo) A1 and B, lipoprotein (a) levels and ApoB/A1 ratio. Since age and body mass index affect the lipid profile, we performed propensity score matching to select 304 patients for final analysis and compared lipid profiles between the ON and OA groups. We also compared biomarkers between the ON subgroups and the OA group. RESULTS: Overall, the ON group showed lower HDL-C (p < 0.001), higher TGs (p = 0.001) levels and higher ApoB/A1 ratio (p = 0.003). Idiopathic ON patients demonstrated lower HDL-C (p = 0.032), higher TGs (p = 0.016), ApoB (p = 0.024) levels and ApoB/A1 ratio (p = 0.008). The alcohol-associated ON subgroup showed lower HDL-C (p < 0.001), higher TGs (p = 0.010) levels and ApoB/A1 ratio (p = 0.030). Finally, the steroid-associated ON subgroup demonstrated lower HDL-C (p = 0.003), higher TGs (p = 0.039), lower TC (p = 0.022), LDL-C (p = 0.021), and ApoA1 (p = 0.004) levels. CONCLUSIONS: Higher TGs and lower HDL-C levels were associated with nontraumatic ON regardless of the etiology. Additionally, idiopathic ON was associated with higher ApoB levels and ApoB/A1 ratio. Alcohol-associated ON was related to higher ApoB/A1 ratio, and steroid-associated ON paired with decreased TC, LDL-C, and ApoA1 levels. Our findings may support future efforts for prevention and management of nontraumatic ON. LEVEL OF EVIDENCE: Diagnostic Level III.

The 2021 Association Research Circulation Osseous Classification for Early-Stage Osteonecrosis of the Femoral Head to Computed Tomography-Based Study.

BACKGROUND: The Association Research Circulation Osseous developed a novel classification for early-stage (precollapse) osteonecrosis of the femoral head (ONFH). We hypothesized that the novel classification is more reliable and valid when compared to previous 3 classifications: Steinberg, modified Kerboul, and Japanese Investigation Committee classifications. METHODS: In the novel classification, necrotic lesions were classified into 3 types: type 1 is a small lesion, where the lateral necrotic margin is medial to the femoral head apex; type 2 is a medium-sized lesion, with the lateral necrotic margin being between the femoral head apex and the lateral acetabular edge; and type 3 is a large lesion, which extends outside the lateral acetabular edge. In a derivation cohort of 40 early-stage osteonecrotic hips based on computed tomography imaging, reliabilities were evaluated using kappa coefficients, and validities to predict future femoral head collapse by chi-squared tests and receiver operating characteristic curve analyses. The predictability for future collapse was also evaluated in a validation cohort of 104 early-stage ONFH. RESULTS: In the derivation cohort, interobserver reliability (k = 0.545) and intraobserver agreement (63%-100%) of the novel method were higher than the other 3 classifications. The novel classification system was best able to predict future collapse (P < .05) and had the best discrimination between non-progressors and progressors in both the derivation cohort (area under the curve = 0.692 [0.522-0.863], P < .05) and the validation cohort (area under the curve = 0.742 [0.644-0.841], P = 2.46 × 10-5). CONCLUSION: This novel classification is a highly reliable and valid method of those examined. Association Research Circulation Osseous recommends using this method as a unified classification for early-stage ONFH. LEVEL OF EVIDENCE: Level III, diagnostic study.

Osteonecrosis of the Femoral Head: an Updated Review of ARCO on Pathogenesis, Staging and Treatment.

Non-traumatic osteonecrosis of the femoral head (ONFH) usually affects adults younger than 50 years and frequently leads to femoral head collapse and subsequent arthritis of the hip. It is becoming more prevalent along with increasing use of corticosteroids for the adjuvant therapy of leukemia and other myelogenous diseases as well as management of organ transplantation. This review updated knowledge on the pathogenesis, classification criteria, staging system, and treatment of ONFH.

Diagnosis and Treatment of Femoral Head Osteonecrosis: A Protocol for Development of Evidence-Based Clinical Practice Guidelines.

INTRODUCTION: There are many treatment options for patients who have osteonecrosis of the femoral head (ONFH) and management strategies vary widely both among and within individual countries. Although many researchers have attempted to elucidate the optimal strategies for managing this disease, the lack of large-scale randomized control trials and the lack of agreement on disease staging have curtailed the development of clear-cut guidelines. MATERIALS AND METHODS: The Association Research Circulation Osseous (ARCO) group sought to address three questions for the management of patients who have ONFH: 1) What imaging studies are most sensitive and specific for the diagnostic evaluation of patients who have ONFH?; 2) What is the best treatment strategy for preventing disease progression in patients who have pre-collapse lesions?; and 3) What is the best treatment strategy for patients who have post-collapse disease? The Patient, Intervention, Comparison, and Outcome (PICO) format was used to formulate the search strategy for each research question. A systematic review will be performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. ARCO participants have been allocated to three groups, each representing one of the PICO questions. After qualitative and quantitative analysis of the data extracted from studies pertaining to each of the three research questions, a set of evidence-based clinical practice guidelines will be proposed for the management of patients who have ONFH. DISCUSSION: It is not always clear which treatment method is optimal for the management of ONFH. Thus, many surgeons have developed and performed various procedures based on patient-specific factors. As there is no consensus on the optimal treatment for various stages of disease, it was clear that developing evidence-based clinical practice guidelines would provide more structure and uniformity to management of these patients. Therefore, the results of this systematic review will lead to the development guidelines that may improve patient-care strategies and result in better outcomes for patients who have ONFH.

ARCO Consensus on the Pathogenesis of Non-traumatic Osteonecrosis of the Femoral Head.

Osteonecrosis of the femoral head (ONFH) is a devastating disease frequently leading to femoral head collapse and hip arthritis. Specifically, non-traumatic ONFH primarily affects young and middle-aged adults. Although compromised local circulation of the femoral head seems to be pathognomonic for the disease, the pathogenesis is perplexing and continues to be an area of scrutiny and research. Comprehension of the pathogenesis is of crucial importance for developing and guiding treatments for the disease. Therefore, we provide an up-to-date consensus on the pathogenesis of non-traumatic ONFH.

Precontoured Plate Fixation for Incomplete Atypical Diaphyseal Fracture of Femur using Three-Dimensional Printing Rapid Prototyping: Two Cases Reports.

BACKGROUND: Reconstruction intramedullary nail spanning the whole length of the femur has been the gold standard treatment for complete atypical diaphyseal fractures of the femur (ADF). However, in cases of incomplete ADF combined with severe bowing, this approach might have complications and lead to iatrogenic complete fracture. We report two cases of incomplete ADF with severe bowing using a precontoured plate (PCP) after rapid prototyping (RP) of the deformed femurs with three-dimensional printing (3DP) technology. CASE PRESENTATION: Two patients presented with gradually worsening thigh pain, especially during walking. The patients had been using bisphosphonates for 4 and 10 years, respectively. Radiography showed an incomplete fracture in the lateral cortex of the right femur shaft. The lateral bowing angles measured in the affected femurs were 15° and 14°, and the anterior bowing angles were 20° and 16°, respectively. In bone scans, both patients showed hot uptake in the right mid-shaft of the femur. Preoperatively, the affected femur of the patient was reconstructed by 3DP RP using CT, and the plate was bent to the shape of the bone model. The ADF was fixed with a PCP using the minimally invasive plate osteosynthesis technique. Both patients were encouraged to start full weight-bearing and return to their preinjury activity level in daily life immediately after surgery. At 2 years postoperatively, radiography showed healing of the fracture site without recurrence of thigh pain and implant-related problems. CONCLUSION: Although intramedullary nailing is the standard surgical treatment for complete ADF, PCP using 3DP RP could be an effective treatment option for incomplete ADF with severely curved femur.

Does proximal femoral nail antirotation achieve better outcome than previous-generation proximal femoral nail?

BACKGROUND: There are few studies in the literature comparing the clinical outcomes and radiographic results of proximal femoral nail (PFN) and proximal femoral nail antirotation (PFNA) for pertrochanteric femoral fracture (PFF) in elderly patients. AIM: To evaluate both clinical and radiographic outcomes after fixation with PFN and PFNA in an elderly patient population. METHODS: One hundred fifty-eight patients older than 65 years with PFF who underwent fixation with either PFN or PFNA were included. Seventy-three patients underwent fixation with PFN, whereas 85 were fixed with PFNA. The mean follow-up was 2.4 years (range, 1-7 years). Clinical outcome was measured in terms of operation time, postoperative function at each follow-up visit, and mortality within one year. Radiographic evaluation included reduction quality after surgery, Cleveland Index, tip-apex distance (TAD), union rate, time to union, and sliding distance of the screw or blade. Complications including nonunion, screw cutout, infection, osteonecrosis of the femoral head, and implant breakage were also investigated. RESULTS: Postoperative function was more satisfactory in patients who underwent PFNA than in those who underwent PFN (P = 0.033). Radiologically, the sliding difference was greater in PFN than in PFNA patients (6.1 and 3.2 mm, respectively, P = 0.036). The rate of screw cutout was higher in the PFN group; eight for PFN (11.0%) and two for PFNA patients (2.4%, P = 0.027). There were no differences between the two groups in terms of operation time, mortality rate at one year after the operation, adequacy of reduction, Cleveland Index, TAD, union rate, time to union, nonunion, infection, osteonecrosis, or implant breakage. CONCLUSION: Elderly patients with PFF who underwent PFNA using a helical blade demonstrated better clinical and radiographic outcomes as measured by clinical score and sliding distance compared with patients who underwent PFN.

Arthroscopic treatment of iliopsoas tendinitis after total hip arthroplasty with acetabular cup malposition: Two case reports.

BACKGROUND: Optimal treatment for iliopsoas tendinitis after total hip arthroplasty (THA) with cup malposition, iliopsoas release alone or with cup revision, is controversial, particularly in young, active patients. Moreover, arthroscopic iliopsoas tendon (IPT) release in these patients has been rarely described, and midterm effects of this procedure on THA longevity and groin pain recurrence remain unclear. We performed arthroscopic IPT release after THA and report midterm outcomes in two young patients with acetabular cup malposition. CASE SUMMARY: In the two patients, groin pain started early after THA. Physical examination revealed nonspecific findings, and laboratory tests showed no evidence of infection. Radiography and computed tomography showed reduced acetabular component anteversion angle and anterior cup prominence of more than 16 mm. For therapeutic diagnosis, ultrasonography-guided lidocaine with steroid was injected into the IPT sheath. In both patients, groin pain improved initially but worsened after a few months. Therefore, the patients underwent arthroscopic IPT release under spinal anesthesia. Arthroscopy revealed synovitis with fibrous tissues around the IPT and various lesions related to the implants after THA. IPT tenotomy and debridement with biopsy were performed; histopathologic studies showed chronic inflammation with synovial hyperplasia. Both patients were encouraged to start walking immediately after surgery, and they returned to complete daily function early after surgery. They experienced no recurrence of groin pain or any implant-related problems 5 years postoperatively. CONCLUSION: Arthroscopic IPT release for cup malposition produced excellent midterm outcomes without recurrence of groin pain and implant-related problems.

Feasibility of the Inner-Side-Out Use of the LC-DCP for Periprosthetic Femoral Fracture in Total Hip Arthroplasty.

BACKGROUND: The optimal technique for plate fixation to treat type B and C periprosthetic femoral fractures (PFFs) is unclear. The purpose of this study is to evaluate the radiographic results of inner-side-out limited contact dynamic compression plate (LC-DCP) to treat PFFs during or after total hip arthroplasty (THA). METHODS: This retrospective study comprised of four men and six women with an average age of 64.7 years who underwent open reduction and internal fixation with an inner-side-out LC-DCP technique to treat PFFs; the reduction was maintained preliminary with the use of contoured plate and cables, and the grooves on the undersurface of LC-DCP for limited contact was used to hold and prevent the cables from slippage during tightening the cables. There were five intraoperative and five postoperative PFFs after THA. According to the Vancouver classification, the intraoperative PFFs included type B2 in two, B3 in one and C3 in two patients while postoperative PFFs were categorized into type B1 in one, type B2 in two and type C in two patients. The mean follow-up duration was 5.9 years (range 1-10.4). We evaluated radiographic union and complications after index operation. RESULTS: All patients demonstrated radiographic bone union at an average follow-up duration of 4.4 months (range 3-8). Two patients showed stem subsidence after revision THA and one patient demonstrated a subsequent peri-implant fracture around the distal end of plate after union of the initial PPF; one patient underwent re-revision THA for stem loosening while another patient went through refixation for the peri-implant fracture. There was no nonunion, infection, nerve injury, or dislocation. CONCLUSION: The inner-side-out LC-DCP technique showed satisfactory radiographic outcome. In certain situations where locking plates are not available, this technique might be a useful alternative for treating type B and C PFFs.

Epidemiology and risk factors of coccyx fracture: A study using national claim database in South Korea.

INTRODUCTION: Coccyx fracture usually is a low-energy trauma caused by a backward fall onto a slippery floor of ice. The exact epidemiology of the coccyx fracture is not known. Moreover, the effects of seasonality and weather on the fracture incidence have not been reported. The purpose of this study was to evaluate the annual incidence, gender-preponderance, age-distribution, seasonal variation and climatic risk factors of the coccyx fracture. METHODS: We identified coccyx fractures, which occurred in South Korea from 2010 to 2018, using nationwide data of Korean Health Insurance Review and Assessment Service (HIRA). International Classification of Diseases-10th Revision (ICD-10) code S322 was used for the identification. Annual incidence of the coccyx fracture was calculated, and the fractures were correlated with gender, age, month of diagnosis and climatic factors. RESULTS: A total of 238,906 patients were diagnosed with coccyx fracture with an average of 26,545 patients at year. Male to female ratio was 1:2.6. The annual incidence of coccyx fracture was 119.75/100,000 persons in 2018; 33.44/100,000 in male and 86.30/100,000 in female. The incidence rate was the highest at puberty (age of 10-14 years) in male, and at menopause (age of 50-54 years) in female. The incidence was frequent in winter followed by summer. The incidence of coccyx fracture was negatively correlated with the temperature (Pearson correlation factor= -0.67, P<0.01) in winter, while it was positively correlated with the temperature in summer (Pearson correlation coefficient = 0.66, p<0.01). In generalized linear model, old age, female gender, recent year, summer and winter, low temperature and high amount of precipitation appeared as risk factors for coccyx fracture. CONCLUSIONS: The epidemiologic patterns of coccyx fracture were comparable to other osteoporotic fractures. Findings of our study can be used for epidemiological awareness and prevention campaigns of coccyx fracture.

Guidelines for clinical diagnosis and treatment of osteonecrosis of the femoral head in adults (2019 version).

Osteonecrosis of the femoral head (ONFH) is a common and refractory disease in orthopaedic clinics. The number of patients with ONFH is increasing worldwide every year. There are an estimated 8.12 million patients with nontraumatic osteonecrosis in China alone. Treatment of nontraumatic osteonecrosis has always been a clinical challenge for orthopaedic surgeons. To further standardize diagnosis and treatment of ONFH, these guidelines provide not only basic diagnosis, treatment, and evaluation systems for ONFH but also expert advice and standards in many aspects, including epidemiology, aetiology, diagnostic criteria, pathological staging, prevention and treatment options, and postoperative rehabilitation. The aetiological factors of ONFH can currently be divided into two major categories: traumatic and nontraumatic; however, the specific pathological mechanism of ONFH is not completely clear. Currently, the staging system of ONFH formulated by the Association Research Circulation Osseous is widely used in clinical practice. Based on the changes in the intraosseous blood supply at different stages, the corresponding nonsurgical and surgical treatments are recommended, and when there are risk factors for possible ONFH, certain preventive measures to avoid the occurrence of osteonecrosis are recommended. These guidelines provide brief classification criteria and treatment regimen for osteonecrosis. Specification of the aetiology, treatment plan based on comprehensive consideration of the different stages of osteonecrosis, hip function, age, and occupation of the patients are important steps in diagnosis and developing treatment strategies. TRANSLATIONAL POTENTIAL OF THIS ARTICLE: New advances in the epidemiology, etiology, pathophysiology, imaging, diagnosis and treatment of ONFH have been renewed in this revision. This guideline can be used for reference by orthopedic professionals and researchers, and for standardized diagnosis and treatment management under the clinical guidance, which is conducive to the prevention, treatment and further research of ONFH, improving the diagnosis and treatment level, making patients' symptoms under good control, and improving their quality of life.

The 2019 Revised Version of Association Research Circulation Osseous Staging System of Osteonecrosis of the Femoral Head.

BACKGROUND: The Association Research Circulation Osseous (ARCO) presents the 2019 revised staging system of osteonecrosis of the femoral head (ONFH) based on the 1994 ARCO classification. METHODS: In October 2018, ARCO established a task force to revise the staging system of ONFH. The task force involved 29 experts who used a web-based survey for international collaboration. Content validity ratios for each answer were calculated to identify the levels of agreement. For the rating queries, a consensus was defined when more than 70% of the panel members scored a 4 or 5 rating on a 5-point scale. RESULTS: Response rates were 93.1%-100%, and through the 4-round Delphi study, the 1994 ARCO classification for ONFH was successfully revised. The final consensus resulted in the following 4-staged system: stage I-X-ray is normal, but either magnetic resonance imaging or bone scan is positive; stage II-X-ray is abnormal (subtle signs of osteosclerosis, focal osteoporosis, or cystic change in the femoral head) but without any evidence of subchondral fracture, fracture in the necrotic portion, or flattening of the femoral head; stage III-fracture in the subchondral or necrotic zone as seen on X-ray or computed tomography scans. This stage is further divided into stage IIIA (early, femoral head depression ≤2 mm) and stage IIIB (late, femoral head depression >2 mm); and stage IV-X-ray evidence of osteoarthritis with accompanying joint space narrowing, acetabular changes, and/or joint destruction. This revised staging system does not incorporate the previous subclassification or quantitation parameters, but the panels agreed on the future development of a separate grading system for predicting disease progression. CONCLUSION: A staging system has been developed to revise the 1994 ARCO classification for ONFH by an expert panel-based Delphi survey. ARCO approved and recommends this revised system as a universal staging of ONFH.

Identification of Factors Related to Functional Decline of Korean Older Adults After Hip Fracture Surgery: A Cross-Sectional Study.

Reducing functional decline is an essential treatment goal in older adults after hip fracture surgery. The current study examined different effects of functional decline-related factors according to activities of daily living (ADL) and instrumental ADL (IADL) in older adults after hip fracture surgery. A total of 120 participants were included. In quantile regression, preoperative walking and fear of falling were significantly associated with ADLs in the 25th percentile ADL group. Fear of falling was the only significant factor in the poorest IADL group (25th percentile). Efforts should be made to reduce fear of falling after hip fracture surgery. Preoperative walking status was significant in patients with poor ADL after hip fracture surgery; therefore, walking status should be taken into consideration when planning rehabilitation care in this group, so that the best possible ADL outcomes can be attained. [Research in Gerontological Nursing, 12(6),312-320.].

Etiologic Classification Criteria of ARCO on Femoral Head Osteonecrosis Part 1: Glucocorticoid-Associated Osteonecrosis.

BACKGROUND: Glucocorticoid usage, a leading cause of osteonecrosis of the femoral head (ONFH), and its prevalence was reported in 25%-50% of non-traumatic ONFH patients. Nevertheless, there have been no unified criteria to classify glucocorticoid-associated ONFH (GA-ONFH). In 2015, the Association Research Circulation Osseous addressed the issue of developing a classification scheme. METHODS: In June 2017, a task force was set up to conduct a Delphi survey concerning ONFH. The task force invited 28 experts in osteonecrosis/bone circulation from 8 countries. Each round of the Delphi survey consists of questionnaires, analysis of replies, and feedback reports to the panel. After 3 rounds of the survey, the panel reached a consensus on the classification criteria. The response rates were 100% (Round 1), 96% (Round 2), and 100% (Round 3), respectively. RESULTS: The consensus on the classification criteria of GA-ONFH included the following: (1) patients should have a history of glucocorticoid use >2 g of prednisolone or its equivalent within a 3-month period; (2) osteonecrosis should be diagnosed within 2 years after glucocorticoid usage, and (3) patients should not have other risk factor(s) besides glucocorticoids. CONCLUSION: Association Research Circulation Osseous established classification criteria to standardize clinical studies concerning GA-ONFH.

Etiologic Classification Criteria of ARCO on Femoral Head Osteonecrosis Part 2: Alcohol-Associated Osteonecrosis.

BACKGROUND: Although alcohol is a leading risk factor for osteonecrosis of the femoral head (ONFH) and its prevalence reportedly ranges from 20% to 45%, there are no unified classification criteria for this subpopulation. In 2015, Association Research Circulation Osseous decided to develop classification criteria for alcohol-associated ONFH. METHODS: In June of 2017, Association Research Circulation Osseous formed a task force to conduct a Delphi survey. The task force invited 28 experts in osteonecrosis/bone circulation from 8 countries. Each round of the Delphi survey included questionnaires, analysis of replies, and feedback reports to the panel. After 3 rounds of the survey, consensus was reached on the classification criteria. The response rates for the 3 Delphi rounds were 100% (round 1), 96% (round 2), and 100% (round 3). RESULTS: The consensus on the classification criteria of alcohol-associated ONFH included the following: (1) patients should have a history of alcohol intake >400 mL/wk (320 g/wk, any type of alcoholic beverage) of pure ethanol for more than 6 months; (2) ONFH should be diagnosed within 1 year after alcohol intake of this dose; and (3) patients should not have other risk factor(s). CONCLUSION: ARCO-established classification criteria to standardize clinical studies concerning AA-ONFH.

CT-based Navigation System Using a Patient-Specific Instrument for Femoral Component Positioning: An Experimental in vitro Study with a Sawbone Model.

PURPOSE: The intraoperative version of the femoral component is usually determined by visual appraisal of the stem position relative to the distal femoral condylar axis. However, several studies have suggested that a surgeon's visual assessment of the stem position has a high probability of misinterpretation. We developed a computed tomography (CT)-based navigation system with a patient-specific instrument (PSI) capable of three-dimensional (3D) printing and investigated its accuracy and consistency in comparison to the conventional technique of visual assessment of the stem position. MATERIALS AND METHODS: A CT scan of a femur sawbone model was performed, and pre-experimental planning was completed. We conducted 30 femoral neck osteotomies using the conventional technique and another 30 femoral neck osteotomies using the proposed technique. The femoral medullary canals were identified in both groups using a box chisel. RESULTS: For the absolute deviation between the measured and planned values, the mean two-dimensional anteversions of the proposed and conventional techniques were 1.41° and 4.78°, while their mean 3D anteversions were 1.15° and 3.31°. The mean θ1, θ2, θ3, and d, all of which are parameters for evaluating femoral neck osteotomy, were 2.93°, 1.96°, 5.29°, and 0.48 mm for the proposed technique and 4.26°, 3.17°, 4.43°, and 3.15 mm for the conventional technique, respectively. CONCLUSION: The CT-based navigation system with PSI was more accurate and consistent than the conventional technique for assessment of stem position. Therefore, it can be used to reduce the frequency of incorrect assessments of the stem position among surgeons and to help with accurate determination of stem anteversion.

Synergistic Effects of Beta Tri-Calcium Phosphate and Porcine-Derived Decellularized Bone Extracellular Matrix in 3D-Printed Polycaprolactone Scaffold on Bone Regeneration.

Bone-derived extracellular matrix (ECM) is widely used in studies on bone regeneration because of its ability to provide a microenvironment of native bone tissue. However, a hydrogel, which is a main type of ECM application, is limited to use for bone graft substitutes due to relative lack of mechanical properties. The present study aims to fabricate a scaffold for guiding effective bone regeneration. A polycaprolactone (PCL)/beta-tricalcium phosphate (ß-TCP)/bone decellularized extracellular matrix (dECM) scaffold capable of providing physical and physiological environment are fabricated using 3D printing technology and decoration method. PCL/ß-TCP/bone dECM scaffolds exhibit excellent cell seeding efficiency, proliferation, and early and late osteogenic differentiation capacity in vitro. In addition, outstanding results of bone regeneration are observed in PCL/ß-TCP/bone dECM scaffold group in the rabbit calvarial defect model in vivo. These results indicate that PCL/ß-TCP/bone dECM scaffolds have an outstanding potential as bone graft substitutes for effective bone regeneration.