Corticosteroid-associated osteonecrosis of the femoral head in an 87-year-old patient following treatment for COVID-19-associated pneumonia: A case report.

Coronavirus disease 2019 is known to cause severe acute respiratory syndrome, and serious cases need to be treated with corticosteroids. Herein, we report an 87-year-old woman who developed bilateral osteonecrosis of the femoral head after corticosteroid treatment for coronavirus disease 2019-related pneumonia. Sixteen months after treatment, she developed right hip pain without any evidence of trauma. A diagnosis of bilateral osteonecrosis of the femoral head was made based on sclerotic bands on plain radiographs and low-signal bands on T1-weighted magnetic resonance images. The patient underwent right total hip arthroplasty 4 months after symptom onset. Histological examination of the resected femoral head revealed pathological evidence of osteonecrosis. The postoperative course was good, and the patient can now walk unassisted. To the best of our knowledge, this is the first report of histologically proven osteonecrosis after corticosteroid therapy for coronavirus disease 2019-related disease.

The role of torsional stress in the development of subchondral insufficiency fracture of the femoral head: A finite element model analysis.

BACKGROUND: Subchondral insufficiency fracture of the femoral head generally occurs without evidence of trauma or with a history of minor trauma. Insufficient bone quality is considered one cause; however, the detailed mechanism of fracture development at the subchondral area (SA) is not understood. The aim of this study was to clarify the directions of force that cause subchondral fracture using finite element model analysis. METHODS: Two types of finite element models were generated from the CT data of femurs obtained from three individuals without osteoporosis (normal models) and another three with osteoporosis (osteoporosis models). Three directions of force, including compressive, shearing, and torsional, were applied to the femoral head. The distribution of von Mises stress (Mises stress) was evaluated at the SA, principal compressive trabeculae (PC), and principal tensile trabeculae. RESULTS: Under compressive force, the mean Mises stress value was greatest at the PC in both the normal and osteoporosis models. Under shearing force, the mean Mises stress value tended to be greatest at the SA in the normal model and at the PC in the osteoporosis model. Under torsional force, the mean Mises stress value was greatest at the SA in both types of models. CONCLUSIONS: The torsional force showed the greatest Mises stress at the SA in both the normal and osteoporosis models, suggesting the importance of torsion as a possible force responsible for subchondral insufficiency fracture development.

Side-to-side variability in the femoral neck anteversion angle: A study of the Japanese population with osteonecrosis of the femoral head.

BACKGROUND: Side-to-side variability in the femoral neck anteversion angle (FA) reportedly varies from 0.0° to 17.3°. To investigate the side-to-side variability in the FA and the relationship between the FA and the morphology of the acetabulum in the Japanese population, we performed a three-dimensional computed tomography (CT)-based study involving patients with osteonecrosis of the femoral head (ONFH). METHODS: CT data were obtained from 170 nondysplastic hips of 85 patients with ONFH. The FA and acetabular coverage parameters, including the acetabular anteversion angle, acetabular inclination angle, and acetabular sector angle in the anterior, superior, and posterior directions, were measured using three-dimensional CT. The distribution of the side-to-side variability in the FA was evaluated separately for each of the five degrees. RESULTS: The mean side-to-side variability in the FA was 6.7° ± 5.3° (range, 0.2°-26.2°). The distribution of the side-to-side variability in the FA was 0.0°-5.0° in 41 patients (48.2%), 5.1°-10.0° in 25 patients (29.4%), 10.1°-15.0° in 13 patients (15.3%), 15.1°-20.0° in 4 patients (4.7%), and >20.1° in 2 patients (2.4%). There was a weak negative correlation between the FA and anterior acetabular sector angle (r = -0.282, P < 0.001) and a very weak positive correlation between the FA and acetabular anteversion angle (r = 0.181, P < 0.018). CONCLUSIONS: The mean side-to-side variability in the FA was 6.7° ± 5.3° (range, 0.2°-26.2°) in Japanese nondysplastic hips, and about 20% of the patients had a side-to-side variability of >10°.

Bone morphology and physical characteristics of the pro-cyclist hip joint.

PURPOSE: This study aimed to investigate the radiographic findings for the hip joint and hip range of motion in professional cyclists, and to determine their bone morphology and physical characteristics. The effects of physical characteristics on athletic performance were examined in terms of metabolic efficiency using simulation analysis. METHODS: We performed a case-control research study on 22 hips in 11 male professional cyclists (average age 28.5, height 1.73 m, weight 77.6 kg). Thirty hips in 15 healthy male volunteers were selected as controls. As radiographic evaluations, acetabular dysplasia was assessed on standardized radiographs. During physical evaluations, the hip range of motion was examined. We used simulation analysis to investigate the metabolic efficiency in the different cycling forms. RESULTS: The radiographic evaluations showed a significant difference in the incidence of acetabular dysplasia (p = 0.01): 59% (13/22 hips) in the pro-cyclist group versus 10% (3/30 hips) in the control group. The physical evaluations revealed significant differences in the hip internal rotation angle (p = 0.01), with greater ranges of internal rotation in the pro-cyclist group versus the control group. The simulation analyses showed that metabolism was reduced in the cycling form with hip internal rotation, especially in the lower extremities. CONCLUSIONS: Pro-cyclists showed a high frequency of acetabular dysplasia and superior hip internal rotation. According to the cycling model analyses, hip internal rotation allowed pedaling with reduced metabolic power.

Assessment of the Hip Flexor Muscles Shortly after Curved Periacetabular Osteotomy using Magnetic Resonance Imaging.

BACKGROUND: Curved periacetabular osteotomy requires detachment and retraction of the hip flexors. In this study, we evaluated hip flexor muscle status by magnetic resonance imaging (MRI) shortly after curved periacetabular osteotomy. METHODS: We retrospectively evaluated 60 hips of 56 patients by MRI 1 week and 3 months after curved periacetabular osteotomy performed from August 2017 to December 2019. We classified the condition of the flexors as follows: Grade 0, normal; Grade I, strain/edema; Grade II, partial tear; and grade III, complete tear. RESULTS: At 1 week after surgery, the iliacus muscle was classified as grades I and II in 12.0 and 88.0% of hips; psoas as grades 0, I and II in 22.0, 72.0, and 6.0%; sartorius muscle as grades 0, I and II in 6.0, 62.0, and 32.0%; and rectus femoris muscle as grades 0 and I in 86.0 and 14.0%, respectively. At 3 months, 82.0, 88.0, and 96.0% of psoas, sartorius, and rectus femoris muscles, respectively, had improved to grade 0, whereas the iliacus was grades I and II in 94.0 and 6.0%, respectively. These changes in the iliacus muscle at 3 months were not significantly associated with patient characteristics, radiographic data, or clinical scores. CONCLUSIONS: All the iliacus, 78% of psoas, 94% of sartorius, and 14% of rectus femoris muscles appeared abnormal on MRI 1 week after curved periacetabular osteotomy. However, at 3 months, only 18% of psoas, 12% of sartorius, and 4% of rectus femoris muscles appeared abnormal, whereas all iliacus muscles still appeared abnormal. These abnormalities did not significantly affect clinical scores.

Femoral nerve status during the anterolateral approach for total hip arthroplasty: Motor-evoked potential analysis and an influencing factor.

BACKGROUND: Femoral nerve palsy is an uncommon but serious complication during the anterolateral approach for total hip arthroplasty. One of the reported reasons for femoral nerve palsy is retractor-induced intraoperative damage after retractor placement on the anterior wall of the acetabulum. The present study aimed to clarify the femoral nerve status during anterolateral approach total hip arthroplasty using motor-evoked potential analysis and to identify risk factors influencing the nerve status. METHODS: From June 2019 to September 2020, 32 hips in 31 patients underwent primary total hip arthroplasty via the anterolateral approach. The integrity of the femoral nerve was tested by the motor-evoked potential at three time points: preoperatively as a control (first period), immediately after retractor placement on the anterior wall of the acetabulum (second period), and after the procedure (third period). In the second period, the hips were divided into the following two groups: a <50% femoral nerve amplitude group and a ≥50% group. The iliopsoas muscle volume was evaluated by measuring the muscle cross-sectional area on preoperative computed tomography images, and compared between the two groups. RESULTS: The mean amplitude of the femoral nerve was significantly reduced from 100% in the first period to 35% in the second period (p < 0.01), but then significantly recovered to 54% in the third period (p < 0.01). In 26 (81%) hips, the femoral nerve amplitude was <50% in the second period. The muscle cross-sectional area of the iliopsoas muscle in the <50% group was significantly smaller than that in the ≥50% group (p < 0.05). CONCLUSIONS: The mean amplitude of the femoral nerve was significantly reduced to 35% in the second period, and the iliopsoas muscle volume was considered to influence this femoral nerve status.

Measurement of particulate matter 2.5 in surgical smoke and its health hazards.

PURPOSE: Surgical smoke is generated during the cauterization, coagulation, and incision of biological tissues by electrocautery, ultrasonic coagulation, incising devices, and lasers. Surgical smoke comprises water, water vapor, steam, and some particulate matter, including bacteria, viruses, cell fragments, and volatile organic compounds, which can pose health risks to the operating room personnel. In this study, we measured the concentration of particulate matter 2.5 (particles with a diameter of ≤ 2.5 µm) in surgical smoke. METHODS: We used digital dust counters for real-time monitoring of particulate matter 2.5 generated intraoperatively in breast and gastrointestinal surgeries performed at our hospitals between 2019 and 2020. RESULTS: Concentrations of particulate matter 2.5 were measured in surgical smoke generated when performing 14 different surgeries. Immediately after electrocautery, the concentration of particulate matter 2.5 increased to 2258 µg/m3 and then, when we stopped using the devices, it decreased rapidly to the initial levels. Interestingly, the concentrations increased after each intermittent electrocautery procedure. Higher concentrations of particulate matter 2.5 were observed during breast surgeries than during laparoscopic procedures. CONCLUSION: Surgical smoke poses potential health risks to operating room personnel by contaminating their breathing zone with high concentrations of particulate matter 2.5. A local exhaust ventilation system is needed to reduce exposure.

Mechanical Influence of Pubic Nonunion on the Stress Distribution After Curved Periacetabular Osteotomy: Patient-Specific Three-Dimensional Finite Element Analysis.

BACKGROUND: Pubic nonunion after curved periacetabular osteotomy (CPO) reportedly occurs in 1%-17% of patients and causes pubic pain in 21%. Furthermore, pubic nonunion is associated with a risk of ischial ramus stress fracture, but the mechanical influence of pubic nonunion has not been fully clarified. METHODS: Patient-specific finite element (FE) analysis was performed using Mechanical Finder software. Three FE models (pre-CPO, union, and nonunion models) were constructed from preoperative and postoperative computed tomographic data. The contact area (mm2) and contact pressure (MPa) in the hip joint as well as the equivalent stress (MPa) at the ischial ramus were evaluated among the 3 FE models. RESULTS: Patient-specific FE models were generated using 18 consecutive hips treated with CPO. The mean contact pressure in the hip joint was not significantly different between the union and nonunion models (0.50 ± 0.10 vs 0.50 ± 0.09 MPa, P = .88). However, the mean equivalent stress at the ischial ramus in the nonunion models was 1.7 times higher than that in the union models (1.13 ± 0.77 vs 0.64 ± 0.45 MPa, P < .01). CONCLUSION: FE analysis revealed that pubic nonunion did not affect the mechanical distribution in the hip joint itself but increased the mean equivalent stress at the ischial ramus. This finding suggests the importance of achieving pubic union after CPO to avoid the risk of ischial ramus stress fracture.

Formation of polycyclic aromatic hydrocarbons, benzofuran, and dibenzofuran in fuel-rich oxidation of toluene using a flow reactor.

Recently, polycyclic aromatic hydrocarbons (PAHs) and oxygenated PAHs (OPAHs) have been attracting considerable attention owing to their high toxicity. Understanding their formation mechanism during combustion processes is important to control their emission. However, there are few studies that have quantitatively investigated OPAH formation in the fuel-rich oxidation of hydrocarbons, despite the availability of several studies on PAH formation. In this study, benzofuran and dibenzofuran as OPAHs were quantified in the fuel-rich oxidation of toluene using a flow reactor at atmospheric pressure in a temperature range of 1050-1350 K at equivalence ratios from 3.0 to 12.0 and residence times from 0.2 to 1.5 s. In addition to benzofuran and dibenzofuran, 4 types of monocyclic aromatic hydrocarbons and 19 types of PAHs were also evaluated. The experimental data obtained in this study were compared with those of the ethylene oxidation performed in our previous study. The existing kinetic model for PAH growth was modified based on several theoretical studies to predict the behavior of OPAHs with furan structures. The modified model showed significant improvements in the prediction of benzofuran and dibenzofuran formation. Based on the rate of production and sensitivity analysis using the modified model, the dominant reaction pathways of benzofuran and dibenzofuran were investigated.

Magnetic Resonance Imaging Assessment of Abductor Muscles Shortly After Curved Periacetabular Osteotomy.

BACKGROUND: Curved periacetabular osteotomy (CPO) is performed via an anterior approach without detachment of the hip abductor muscles. This study aimed to evaluate the abductor muscle status shortly after CPO on magnetic resonance imaging (MRI). METHODS: We prospectively evaluated 38 hips in 38 patients 1 week and 3 months after CPO between October 2017 and July 2019. The status of the abductor muscles was assessed on MRI using the following criteria: grade 0, normal; grade I, strain/edema; grade II, partial tear; and grade III, complete tear. We also evaluated associations between muscle status and patients' characteristics. RESULTS: One week after CPO, the gluteus maximus was classified as grade 0 in all patients. The gluteus medius was grade 0 in 84.2% of patients and grade I in 15.8%. The gluteus minimus was grade I in 55.3% of patients and grade II in 44.7%. Three months after CPO, both the gluteus maximus and gluteus medius were grade 0 in all patients, while the gluteus minimus was still grade I in 47.4%. There were no significant differences between patients with a grade 0 and grade I gluteus minimus at 3 months after CPO in patients' characteristics (age and body mass index) or clinical scores (Harris Hip Score and Japanese Orthopedics Association score). CONCLUSION: Both the gluteus minimus and medius showed abnormal appearances on MRI 1 week after CPO, whereas only the gluteus minimus showed abnormalities 3 months after CPO. This abductor muscle status did not affect the postoperative Harris Hip Score or Japanese Orthopedics Association score.

Leg Length Change After Curved Periacetabular Osteotomy and Its Impact on the Clinical Outcomes.

BACKGROUND: Curved periacetabular osteotomy (CPO) is one of the periacetabular osteotomies for the treatment of acetabular dysplasia. Several complications have been described after CPO, however, there have been no reports on the leg length change (LLC). This study aimed to investigate the LLC after CPO and its impact on the clinical outcomes. METHODS: This study was a retrospective review of 70 consecutive hips in 67 patients with symptomatic acetabular dysplasia who underwent CPO between March 2016 and April 2019. Preoperative and postoperative leg lengths were measured using anteroposterior radiographs, and the clinical outcomes were evaluated based on the Harris hip score (HHS) and Medical Outcomes Survey 36-item Short Form Health Survey (SF-36). RESULTS: The mean LLC (and standard deviation) after CPO was -0.08 ± 3.10 mm. The mean HHS significantly improved from 73.5 points to 91.9 points (P < .001). The physical component and role component scores of SF-36 significantly improved from 35.1 to 46.1 (P < .001) and from 39.5 to 47.0 (P < .001), respectively. No significant differences were found between the preoperative and postoperative mental component scores of SF-36. In addition, among 70 hips, 35 hips exhibited leg length elongation (0 to plus 6.82 mm) after CPO, whereas 35 hips exhibited leg length shortening (0 to minus 6.23 mm). No significant differences were found in HHS and SF-36 between the leg elongation group and leg shortening group. CONCLUSION: The mean LLC after CPO was -0.08 ± 3.10 mm, and this change does not affect the postoperative clinical outcomes.

Can rectal washout reduce anastomotic recurrence after anterior resection for rectal cancer? A review of the literature.

Local recurrence rates of rectal cancer after anterior resection remain high, despite the continued efforts of surgeons to devise preventive measures. Anastomotic recurrence, a form of local recurrence, may be caused by the implantation of exfoliated cancer cells during resection, and rectal stump washout has been proposed as a way to reduce the risk of this occurring. In this review article, we explore the mechanism of anastomotic recurrence after low anterior resection for rectal cancer, and examine the history and effectiveness of rectal washout on reducing recurrence rates, with a focus on washout solutions, procedures, and devices. Despite the lack of evidence from randomized trials, rectal washout with normal saline or diluted iodine is performed almost routinely during low anterior resection. Clamping is usually done using cross-clamps, linear staplers, tourniquets, and other devices. Although viable cancer cells may be shed into the rectal lumen during surgical resection, their impact on anastomotic recurrence remains uncertain. However, washout poses little or no harm to patients, and appears acceptable as a routine procedure. Randomized controlled trials or large observational studies may help to clarify the best practices for rectal washout.

[A Case of Long-Term Survival after Chemotherapy and Ablation Therapy Using Various Approaches for Multiple Colon Cancer Liver Metastases].

A 58-year-old man with unresectable sigmoid colon cancer and multiple liver metastases(H2, more than 30)received chemotherapy for 2 years. Subsequently, the patient was diagnosed with stenosis of the primary lesion and 5 bilobar, metastatic tumors. Simultaneous resection was unsuitable because of the performance status and comorbidities of the patient. The first surgery consisted of laparoscopic-assisted sigmoidectomy, laparoscopic microwave coagulation therapy(MCT), and percutaneous radiofrequency ablation(RFA). Percutaneous RFA was additionally performed after 2 months. Since 2 liver metastases(S3 and S8)were inadequately treated, 3 courses of P-mab plus FOLFIRI were administered. Finally, laparoscopic- assisted RFA was performed. Subsequently, serum CEA reduced from 288.3 ng/mL to the normal level. We used fusion imaging US, sonazoid US, laparoscopic convex probe, and ICG fluorescence imaging for ablation therapy. Chemotherapy and ablation therapy using various approaches can control unresectable multiple liver metastases and prolong survival by more than 3 years.

[A Patient with Multiple Colorectal Liver Metastases for Whom Partial Splenic Embolization Contributed Extremely to Maintain Multidisciplinary Treatment].

After approximately 2.5 years of chemotherapy at the referred hospital, a 69-year-old man with double colon cancer and unresectable liver metastases(H3)sought consultation. A total of 8 liver metastases were deemed resectable; however, the disease was progressive. He received 2 courses of mFOLFOX6 plus Bmab before hepatectomy. Seven weeks after starting chemotherapy, Grade 4 thrombocytopenia occurred, which required platelet transfusion. Ten weeks after, curative parenchymal- preserving hepatectomy was performed under platelet transfusion. Hematologic examination including bone marrow aspiration showed no significant abnormalities, including normal megakaryocyte formation. Therefore, the patient was diagnosed with thrombocytopenia due to sinusoidal obstruction syndrome associated with past chemotherapy including oxaliplatin. Partial splenic embolization(PSE)was performed 8 weeks after the first hepatectomy. The infarcted splenic ratio was 79.5%, and the infarcted splenic volume was 444.3 mL. Curative resection of the primary colorectal cancer and the 2nd hepatectomy for the newly developed recurrent liver lesions was successfully performed at 2 weeks and 19 weeks after PSE, respectively. Platelet transfusion was never required in the perioperative period of the 2 operations performed after the PSE. Forty-five months after the initial treatment, the patient is alive with no recurrent tumors and normal tumor marker levels.

Clinical and Prognostic Features of Patients With Esophageal Cancer and Multiple Primary Cancers: A Retrospective Single-institution Study.

OBJECTIVE: To investigate the clinical and prognostic characteristics of patients with esophageal cancer and multiple primary cancers. SUMMARY BACKGROUND DATA: Patients with esophageal cancer frequently have multiple primary cancers, the presence of which may complicate physicians' decision-making because the clinical and prognostic features of such patients remain unknown. METHODS: This retrospective single-institution study included 538 consecutive patients who had undergone resection of esophageal cancer. The Cox proportional hazard model was used to compute the hazard ratio (HR) for mortality. RESULTS: At the time of surgery, 163 patients (30%) had multiple primary cancers (77, metachronous; 86, synchronous). Multiple primary cancers were significantly associated with alcohol use and tobacco smoking (Brinkman index). Patients with synchronous cancers had significantly shorter overall survival than those without multiple primary cancers (log-rank P = 0.032; univariate HR = 1.53, 95% confidence interval 1.02-2.17, P = 0.040; multivariate HR: 1.61; 95% confidence interval: 1.08-2.36; P = 0.020). Patients with metachronous cancers had similar prognoses to those without multiple primary cancers. The prognostic effect of synchronous cancers on overall survival was particularly prominent in patients with Stage I esophageal cancer (log-rank P = 0.0002). CONCLUSIONS: Multiple primary cancers are associated with a history of tobacco and alcohol use, supporting the concept of field cancerization. Synchronous multiple primary cancers may be an independent predictor of poorer long-term survival in patients undergoing resection of esophageal cancers.

Risk factors for pulmonary morbidities after minimally invasive esophagectomy for esophageal cancer.

BACKGROUND: Pulmonary morbidities after esophagectomy are still common and are a major cause of surgery-related mortality. The relationship between minimally invasive esophagectomy (MIE) and pulmonary morbidities is not clear. The current study aimed to examine the incidence of pulmonary morbidities after MIE and to clarify the associated risk factors. METHODS: Between May 2011 and December 2016, 184 patients underwent MIE for esophageal cancer. Clinical data were prospectively collected and analyzed. Patient- and surgery-related factors, relating to pulmonary complications, were compared between the complicated and uncomplicated cases. RESULTS: The incidence of any pulmonary morbidity following MIE was 17.9%. Univariate analysis showed that past heavy smoking [Brinkman index (BI) ≥ 1000], presence of neoadjuvant therapy, advanced clinical stage (stage III, IV), and intraoperative bleeding ≥ 600 g were candidates for being postoperative pulmonary morbidity risk factors. Multivariate analysis suggested that BI ≥ 1000 and advanced clinical stage were independent risk factors for causing pulmonary morbidities. CONCLUSIONS: Past heavy smoking and advanced stage are independent risk factors for pulmonary morbidities after MIE. When performing MIE for such cases, various preoperative precautions and careful postoperative monitoring are necessary.

Missing RRI Interpolation Algorithm based on Locally Weighted Partial Least Squares for Precise Heart Rate Variability Analysis.

The R-R interval (RRI) fluctuation in electrocardiogram (ECG) is called heart rate variability (HRV), which reflects activities of the autonomic nervous system (ANS) and has been used for various health monitoring services. Accurate R wave detection is crucial for success in HRV-based health monitoring services; however, ECG artifacts often cause missing R waves and deteriorate the accuracy of HRV analysis. The present work proposes a new missing RRI interpolation technique based on Just-In-Time (JIT) modeling. In the JIT modeling framework, a local regression model is built by weighing samples stored in the database according to the distance from a query and output is estimated only when an estimate is requested. The proposed method builds a local model and estimates missing RRI only when an RRI detection error is detected. Locally weighted partial least squares (LWPLS) is adopted for local model construction. The proposed method is referred to as LWPLS-based RRI interpolation (LWPLS-RI). The performance of the proposed LWPLS-RI was evaluated through its application to RRI data with artificial missing RRIs. We used the MIT-BIH Normal Sinus Rhythm Database for nominal RRI dataset construction. Missing RRIs were artificially introduced and they were interpolated by the proposed LWPLS-RI. In addition, MEAN that replaces the missing RRI by a mean of the past RRI data was compared as a conventional method. The result showed that the proposed LWPLS-RI improved root mean squared error (RMSE) of RRI by about 70% in comparison with MEAN. In addition, the proposed method realized precise HRV analysis. The proposed method will contribute to the realization of precise HRV-based health monitoring services.

The prevalence and risk factors for delayed union of the superior pubic ramus at one year after curved periacetabular osteotomy: its risk factor and outcome.

PURPOSE: Curved periacetabular osteotomy (CPO) has been developed for the treatment of acetabular dysplasia. While several studies have reported its good clinical results, the complications of CPO include delayed union and nonunion of the superior pubic ramus. The purpose of this study is to investigate the prevalence of delayed union of the pubis one year after CPO, and to determine the risk factors for this complication. METHODS: The study examined 113 hips that underwent CPO between 2008 and 2012. Delayed union was assessed based on the anteroposterior radiography one year after CPO. A superior pubic ramus union group (U group) and a delayed union group (D group) were retrospectively compared regarding patient characteristics, clinical evaluations, and radiographic parameters. RESULTS: Delayed union rate was 16.8%. The D group contained a significantly greater proportion of smokers (p < 0.001). The gap at the pubic osteotomy site on CT coronal images was significantly larger in the D group (p < 0.001), and the cut-off value for the risk of nonunion was larger than 5.1 mm. Multivariate regression analysis indicated that smoking (OR 10.7, 95% CI 2.1-55.4) and a gap at the superior pubic ramus >5.1 mm (OR 16.5, 95% CI 3.7-73.7) were significantly associated with delayed union as independent risk factors. CONCLUSION: The prevalence of delayed union one year after CPO was 16.8%. Smoking and a gap larger than 5.1 mm at the pubic osteotomy site are risk factors for delayed union after CPO.

Incidence of delayed union one year after peri-acetabular osteotomy based on computed tomography.

BACKGROUND: Pubic bone nonunion and delayed union are reported as post-operative complications after peri-acetabular osteotomy (PAO). However, few studies have determined the incidence of delayed union using computed tomography (CT) scans. This study aimed to determine the incidence of delayed union at one year after PAO using X-ray and CT scans. METHODS: We performed a retrospective review of 150 hips in 132 consecutive patients with acetabular dysplasia who underwent PAO between January 2012 and June 2016 and evaluated 107 hips for which pelvic CT scans taken at one year after PAO were available. Clinical evaluations included age at surgery, weight, body mass index (BMI) and history. Radiographic evaluations were to assess pubic, ischial and iliac delayed union at one year post-operatively. RESULTS: Based on X-ray analysis, the incidence of delayed union in the pubic, ischial and iliac bones was 11.2% (12 hips), 5.6% (6 hips) and 0% (0 hips), respectively, and20.6% (22 hips), 8.4% (9 hips) and 0% (0 hips), respectively, based on CT scans. CONCLUSION: The incidence of delayed union of the pubis and ischium at one year after PAO according to CT scans was higher than that based on X-ray imaging. CT scans are useful in patients with some symptoms at the osteotomy site. LEVEL OF EVIDENCE: Level III.

Percutaneous transluminal plasty: a novel approach for refractory anastomotic stricture after esophagectomy.

Anastomotic stricture is often observed after esophagectomy. Surgical treatment is considered for refractory stricture to conservative treatments. However, it is not established what type of surgery is safe and effective. In this report, we present a novel approach, percutaneous transluminal plasty, for refractory anastomotic stricture reconstructed via the subcutaneous route in esophagectomy. We believe that the effectiveness and safety of this technique is considerably good and can become a good alternative for refractory stricture after esophagectomy.