A Validated Chiral LC-MS/MS Method for the Enantioselective Determination of (S)-(+)- and (R)-(-)-Ibuprofen in Dog Plasma: Its Application to a Pharmacokinetic Study.

The purpose of this study was to develop a method for simultaneously separating ibuprofen enantiomers using electrospray ionization (ESI) liquid chromatography with tandem mass spectrometry (LC-MS/MS). LC-MS/MS was operated with negative ionization and multiple reaction monitoring modes; transitions were monitored at m/z of 205.1 > 160.9 for ibuprofen enantiomers, 208.1 > 163.9 for (S)-(+)-ibuprofen-d3 [internal standard 1 (IS1)], and 253.1 > 208.9 for (S)-(+)-ketoprofen (IS2), respectively. In a one-step liquid-liquid extraction, 10 µL plasma was extracted with ethyl acetate:methyl tertiary-butyl ether of 7:3. Enantiomer chromatographic separation was carried out with an isocratic mobile phase consisting of 0.008% formic acid in water-methanol (v/v) at a flow rate of 0.4 mL/min on a CHIRALCEL® OJ-3R column (150 × 4.6 mm, 3 µm). This method was fully validated for each enantiomer and results were in compliance with the regulatory guidelines of the U.S. Food and Drug Administration and the Korea Ministry of Food and Drug Safety. The validated assay was executed for nonclinical pharmacokinetic studies after oral and intravenous administration of racemic ibuprofen and dexibuprofen in beagle dogs.

Development of a Rapid LC-MS/MS Method for Simultaneous Quantification of Donepezil and Tadalafil in Rat Plasma: Its Application in a Pharmacokinetic Interaction Study after Oral Administration in Rats.

This study aimed to establish a simple and sensitive analytical method to simultaneously quantify donepezil (DPZ) and tadalafil (TAD) in rat plasma using lansoprazole (LPZ) as an internal standard (IS) by using liquid chromatography tandem mass spectrometry. The fragmentation pattern of DPZ, TAD, and IS was elucidated using multiple reaction monitoring in electrospray ionization positive ion mode for the quantification of precursor to production at m/z 380.1 → 91.2 for DPZ, m/z 390.2 → 268.1 for TAD, and m/z 370.3 → 252.0 for LPZ. The extracted DPZ and TAD from plasma using acetonitrile-induced protein precipitation was separated using Kinetex C18 (100 × 2.1 mm, 2.6 µm) column with a gradient mobile phase system consisting of 2 mM ammonium acetate and 0.1% formic acid in acetonitrile at a flow rate of 0.25 mL/min for 4 min. The selectivity, lower limit of quantification, linearity, precision, accuracy, stability, recovery, and matrix effect of this developed method was validated according to the guidelines of the U.S. Food and Drug Administration and the Ministry of Food and Drug Safety of Korea. The established method achieved acceptance criteria in all validation parameters, ensuring reliability, reproducibility, and accuracy, and was successfully implemented in a pharmacokinetic study on the co-administration of DPZ and TAD orally in rats.

Visceral adiposity and systemic inflammation in the obesity paradox in patients with unresectable or metastatic melanoma undergoing immune checkpoint inhibitor therapy: a retrospective cohort study.

BACKGROUND: The obesity paradox is a topic of increasing interest in oncology and epidemiology research. Although this phenomenon has been observed in melanoma patients receiving immune checkpoint inhibitors, little is known about its mechanism. We aim to investigate the prognostic value of obesity and its association with adiposity and systemic inflammation. METHODS: This retrospective study evaluates the data of patients who received pembrolizumab or nivolumab for unresectable or metastatic melanoma between June 2015 and April 2021. The skeletal muscle index (SMI) and visceral fat index (VFI) (cm2/m2) were calculated by dividing the cross-sectional areas of skeletal muscle and visceral fat by height squared. The systemic immune-inflammation index (SII) was defined as the total peripheral platelet count×neutrophil/lymphocyte ratio. Cox proportional hazard regression analysis was conducted to determine the association with overall survival. RESULTS: We analyzed 266 patients with a median age of 60 years (IQR 51-69 years; 135 men and 131 women). The protective effect of obesity was independent of covariates (HR 0.60; 95% CI 0.37 to 0.99; p=0.048), but disappeared after adjusting for VFI (HR 0.76; 95% CI 0.41 to 1.40; p=0.380) or SII (HR 0.71; 95% CI 0.42 to 1.18; p=0.186). An increase of 10 cm2/m2 in VFI was associated with longer overall survival after adjusting for covariates (HR 0.88; 95% CI 0.79 to 0.99; p=0.029). The prognostic value of VFI remained and predicted favorable overall survival after additional adjustment for SMI (HR 0.86; 95% CI 0.76 to 0.98; p=0.025), but disappeared with adjustment for SII (HR 0.92; 95% CI 0.82 to 1.03; p=0.142). An increase of 100×109/L in SII was associated with poor overall survival when adjusted for covariates (HR 1.08; 95% CI 1.05 to 1.11; p<0.001) or when additionally adjusted for VFI (HR 1.07; 95% CI 1.04 to 1.10; p<0.001). CONCLUSIONS: Visceral adiposity and systemic inflammation are significant prognostic factors in patients with unresectable or metastatic melanoma receiving immune checkpoint inhibitors. The prognostic impact of visceral adiposity is dependent on systemic inflammation status.

Introducing a New Biomarker Named R2*-BOLD-MRI Parameter to Assess Treatment Response in Osteosarcoma.

BACKGROUND: While histologic response to neoadjuvant chemotherapy (NChT) is the major prognostic factor for osteosarcoma treatment, evaluating that response is difficult. PURPOSE: To evaluate the feasibility of the blood oxygen level-dependent (BOLD) technique to assess the response to NChT. STUDY TYPE: Prospective. POPULATION: Twelve patients with osteosarcoma undergoing NChT. FIELD STRENGTH/SEQUENCE: 3 T; T2*-weighted BOLD, dynamic contrast-enhanced (DCE) and diffusion-weighted (DW) (b values of 0, 400, and 1400 seconds/mm2 ) sequences. ASSESSMENT: Examination was performed before treatment (first), after each cycle of treatment (second and third). At each time point, spin dephasing rates (R2*) from BOLD magnetic resonance imaging (MRI), parameters from DCE-MRI (volume transfer constant [Ktrans ], reflux rate [kep ], volume fraction of the extravascular extracellular matrix [ve ], and blood plasma volume [vp ]), and the apparent diffusion coefficient (ADC) from DW-MRI were measured. STATISTICAL TESTS: Wilcoxon's signed rank test, Spearman's correlation coefficient (ρ) were used. A P-value of <0.05 was considered statistically significant. RESULTS: The difference and relative difference of the R2* values between the first/third MRIs in the extraosseous portion were statistically significant. Only the differences in the kep values between the first/second and between the first/third MRIs in the extraosseous portion were significant. The differences in the ADCs in the extraosseous and osseous portions were not statistically significant (P = 0.151, P = 0.733 each in extraosseous portion and P = 0.569, P = 0.129 each in osseous portion). The relative difference in R2* values in the extraosseous portion between the first/third MRI (ρ = 0.706) was significantly better correlated with the pathologic grade than those of kep and ADC over the same period (ρ = 0.286 and ρ = -0.091, respectively). DATA CONCLUSION: The R2* from the BOLD MRI technique could be a useful biomarker for evaluating treatment response in osteosarcoma treated with NchT. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY: Stage 2.

A Pharmacokinetic Study of Ephedrine and Pseudoephedrine after Oral Administration of Ojeok-San by Validated LC-MS/MS Method in Human Plasma.

A sensitive and reproducible liquid chromatography-tandem mass spectrometry (LC-MS/MS) system was developed and fully validated for the simultaneous determination of ephedrine and pseudoephedrine in human plasma after oral administration of the herbal prescription Ojeok-san (OJS); 2-phenylethylamine was used as the internal standard (IS). Both compounds presented a linear calibration curve (r2 ≥ 0.99) over a concentration range of 0.2-50 ng/mL. The developed method was fully validated in terms of selectivity, lower limit of quantitation, precision, accuracy, recovery, matrix effect, and stability, according to the regulatory guidelines from the U.S. Food and Drug Administration and the Korea Ministry of Food and Drug Safety. This validated method was successfully applied for the pharmacokinetic assessment of ephedrine and pseudoephedrine in 20 healthy Korean volunteers administered OJS.

Acral malignant melanoma; emphasis on the primary metastasis and the usefulness of preoperative ultrasound for sentinel lymph node metastasis.

This study aimed to evaluate the most common primary metastatic location of acral malignant melanoma and to evaluate the usefulness of preoperative ultrasound for sentinel lymph node metastasis. Ninety-eight Korean acral malignant melanoma patients were enrolled. Acral malignant melanoma was present in 76 lower limbs and in 22 upper limbs. The most common origin location was the sole (33.7%). The most common location of primary metastasis was loco-regional recurrence (22/34, 64.7%). The sensitivity, specificity, positive predictive value, and negative predictive value of preoperative sentinel lymph node ultrasound was 29.1%, 94.6%, 63.6%, and 80.5%, respectively. We postulate the unusefulness of preoperative ultrasound for sentinel lymph node metastasis in acral malignant melanoma.

What is the reason of the high fibular head in the Discoid Lateral Meniscus?

The purpose of this study was to assess the factors associated with high fibular head in symptomatic discoid lateral meniscus (DLM). Eighty-seven patients with complete DLM (discoid group) and 80 normal subjects (control group) were included prospectively. Plain X-rays and MRI were analyzed for level and angle of the fibular head and thickness and type of Wrisberg ligament. Multivariate regression analysis was performed to find the factors associated with levels of the fibular head and DLM. The angle of the fibular head was the only factor associated with level of the fibula in the discoid group (odds ratio : 3.0, p=0.007). The 13.6mm cut off value for fibular level had 70.5% sensitivity and 77.0% specificity for diagnosis of DLM. A high fibular head was associated with larger angle and type of fibular head. Level of evidence : Level II.

Superthin SCIP Flap for Reconstruction of Subungual Melanoma: Aesthetic Functional Surgery.

BACKGROUND: This study aimed to use a superthin, free superficial circumflex iliac artery perforator (SCIP) flap in functional surgery for treating subungual melanoma and to evaluate its outcomes. METHODS: Forty-one patients with primary subungual melanoma of less than or equal to 2-mm thickness who were treated with functional surgery were prospectively enrolled. After oncologic resection, a thin SCIP flap was harvested along the trans-superficial fat layer and transferred to the defect with further thinning by primary defatting. Complications and oncologic outcomes were investigated. Postoperative functional status was assessed, using the Quick Disabilities of the Arm, Shoulder and Hand questionnaire for finger cases and the Foot Function Index for toe cases, and was compared with that of patients treated with amputation. RESULTS: The SCIP flap was inset with a final thickness ranging from 1.5 to 4 mm after defatting. Total flap failure occurred in one patient. Complete wound healing was achieved within 3 weeks postoperatively in most cases (90.2 percent). The majority of patients achieved satisfactory contour without needing secondary debulking. Two recurrences developed during a mean follow-up period of 31 months: one local recurrence and one in-transit recurrence. The 3-year disease-free survival was 97.1 percent. Mean scores for the Quick Disabilities of the Arm, Shoulder and Hand questionnaire and the Foot Function Index following functional surgery were significantly lower than those following amputation. CONCLUSION: The superthin SCIP flap might serve as a valuable reconstruction option, providing aesthetically thin coverage and reliable outcomes, in functional surgery for treating early-stage subungual melanoma. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Magnetic resonance imaging of posterolateral plica of the elbow joint: Asymptomatic vs. symptomatic subjects.

BACKGROUND: Magnetic resonance imaging (MRI) may be useful to diagnose a posterolateral plica syndrome of the elbow joint because this syndrome has less clear clinical features. The purposes of this study were to document mediolateral and sagittal dimensions of a posterolateral synovial fold and to determine the proportion of subjects with the posterolateral plica in asymptomatic elbows. We also aimed to determine whether the dimensions of the posterolateral synovial fold and the prevalence of the plica differ between symptomatic and asymptomatic subjects. MATERIALS AND METHODS: This retrospective review of prospectively collected data included 50 asymptomatic elbows (asymptomatic group) and 14 elbows with arthroscopically confirmed posterolateral plicae (plica group). The mediolateral and sagittal dimensions of the posterolateral synovial fold were measured. In addition, the criteria for the prevalence of posterolateral plica was determined with conventional MRI as synovial fold dimension ≥ 3 mm and coverage of radial head by synovial fold ≥ 30%. RESULTS: The plica group showed larger posterolateral synovial fold dimensions compared to the asymptomatic group. The median mediolateral and sagittal dimensions of the synovial fold in the asymptomatic group were 3.8 mm and 4.7 mm, respectively. Dimensions in the plica group were 7.0 mm and 7.4 mm, respectively. When the presence of posterolateral plica was determined using the dimension criteria, there was no difference in the prevalence of the plica between the asymptomatic and the plica group. However, using the coverage criteria, the prevalence of posterolateral elbow plica was significantly greater in the plica group than the asymptomatic group (64% vs. 18%; p < 0.001). CONCLUSIONS: The patients who underwent arthroscopic surgery for posterolateral plica syndrome had larger dimensions of the posterolateral synovial fold and higher prevalence of the posterolateral plica on conventional MRI compared to the asymptomatic subjects.

Efficacy of BRAF Inhibitors in Asian Metastatic Melanoma Patients: Potential Implications of Genomic Sequencing in BRAF-Mutated Melanoma.

BACKGROUND: The BRAF inhibitors vemurafenib and dabrafenib are currently the standard treatment for metastatic melanoma with BRAF V600 mutations. However, given the rarity of noncutaneous melanoma, including acral and mucosal subtypes, the efficacy of BRAF inhibitors for this subset of patients has not been extensively investigated. Acquired resistance generally appears 6 to 8 months after treatment with a BRAF inhibitor, and the mechanism of resistance is not well established. METHODS: We examined treatment outcomes for patients diagnosed with metastatic melanoma and treated with BRAF inhibitors at Samsung Medical Center between April 2013 and December 2015. We analyzed genomic alterations in selected patients using targeted sequencing. RESULTS: Twenty-seven patients with a median age of 49 years (range 23-82 years) with metastatic melanoma and treated with a BRAF inhibitor were identified. Of these patients, 19 (70.3%) had noncutaneous melanoma, including acral and mucosal melanoma. All patients had BRAFV600E mutations. The median progression-free survival of all patients was 9.2 months (95% confidence interval, 1.6-16.7), and the objective response rate was 78.9% in the mucosal/acral melanoma group and 75.0% in the cutaneous melanoma group. Three (11.1%) patients achieved complete response, and 19 (70.4%) showed a partial response. Targeted sequencing in five patients demonstrated NF1 mutations in three patients who did not respond to BRAF inhibitors. CONCLUSION: BRAF inhibitors were an effective therapeutic option for Korean patients with metastatic melanoma harboring a BRAF V600 mutation regardless of melanoma subtype (acral/mucosa versus cutaneous).

Fate of subchondral fatigue fractures of femoral head in young adults differs from general outcome of fracture healing.

PURPOSE: The purpose of this study is to report the clinical course of fatigue-type subchondral fractures of the femoral head in young healthy adults. MATERIALS/METHODS: We retrospectively reviewed 28 consecutive patients (34 hips) who had a clear history of a sudden increase in physical activity without trauma on the hip and pelvis, and were diagnosed as having a fatigue-type subchondral fracture of the femoral head. The diagnosis was made primarily on the basis of sequential plain radiographs and magnetic resonance images. RESULTS: Of the 34 hips, 19 hips with no bony collapse experienced gradual disappearance of subjective pain a few months after onset, and there were no recurrences. Other 2 hips that showed bony collapse, but preserved the articular margin, also experienced no definite deterioration of collapse or arthritic change and did not need surgical intervention. In the remaining13 hips with bony collapse and destroyed articular margin or arthritic change, hip pain gradually worsened necessitating surgery. CONCLUSIONS: The current findings suggest that a subchondral fatigue fracture of the femoral head could show a different severity of subchondral injury over time. In the collapsed subchondral fatigue fractures, especially when combined with head incongruency, the hip pain was aggravated enough to require surgical intervention.

Treatment outcome of PD-1 immune checkpoint inhibitor in Asian metastatic melanoma patients: correlative analysis with PD-L1 immunohistochemistry.

Overexpression of PD-L1 has been shown to be associated with better clinical responses to PD-1/PD-L1 blockade in melanoma. However, the utility of PD-L1 immunostaining as a predictive biomarker for anti-PD-1 treatment remains unclear, especially in melanoma of acral/mucosal origin. Materials and methods We collected and reviewed the medical records of 37 patients with metastatic melanoma who were treated with the anti-PD-1 antibodies pembrolizumab or nivolumab between January and December 2015. Patients with histologically diagnosed malignant melanoma and whose pretreatment tumor specimens were available for immunohistochemical staining of PD-L1 expression in tumor or immune cells were included. Results Of 37 patients, 26 patients had either acral or mucosal melanoma. The overall response rate was 10.8 % (95 % CI, 0.8-20.8 %). The response rate to PD-1 inhibitor was 11.5 % (95 % CI, 0-23.8 %) in acral/mucosal melanoma and that for cutaneous melanoma was 9.1 % (95 % CI, 0-26.1 %). Of these 37 patients, 18 had pre-treatment tumor specimens available for PD-L1 staining. Of 18 patients, 10 (55.5 %) were of acral/mucosal origin. In all patients with acral melanoma, the overall response rate (ORR) was 16.7 % (1 of 6 patients) and disease control rate (DCR) was 50 % (3 of 6 patients). In the PDL-1(+) melanoma group (1 % cut-off value), ORR was 20 % (2/10) and DCR was 80 %; for PDL-1 (-) group, ORR was 12.5 % (1/8) and DCR of 37.5 %. In the PDL-1 (+) group by 5 % cut-off value, ORR was 33.3 % (2/6) and DCR was 83.3 %; for patients with PDL-1 (-), ORR was 8.3 % (1/12) and DCR was 50 %. The median PFS was 6.8 months in PDL-1(+) group and 1.9 months in PDL-1(-) group (p = 0.149). Anti-PD-1 treatment was very well tolerated without serious adverse events of grade 3 or 4 in all patients. Conclusions The treatment outcome to PD-1 antibody was not different in acral/mucosal melanoma when compared with cutaneous melanoma. The immunohistochemical PD-L1 expression seemed to be correlated with better clinical outcomes of anti-PD-1 treatment in limited cases.

How accurate is anatomic limb alignment in predicting mechanical limb alignment after total knee arthroplasty?

BACKGROUND: Anatomic limb alignment often differs from mechanical limb alignment after total knee arthroplasty (TKA). We sought to assess the accuracy, specificity, and sensitivity for each of three commonly used ranges for anatomic limb alignment (3-9°, 5-10° and 2-10°) in predicting an acceptable range (neutral ± 3°) for mechanical limb alignment after TKA. We also assessed whether the accuracy of anatomic limb alignment was affected by anatomic variation. METHODS: This retrospective study included 314 primary TKAs. The alignment of the limb was measured with both anatomic and mechanical methods of measurement. We also measured anatomic variation, including the femoral bowing angle, tibial bowing angle, and neck-shaft angle of the femur. All angles were measured on the same full-length standing anteroposterior radiographs. The accuracy, specificity, and sensitivity for each range of anatomic limb alignment were calculated and compared using mechanical limb alignment as the reference standard. The associations between the accuracy of anatomic limb alignment and anatomic variation were also determined. RESULTS: The range of 2-10° for anatomic limb alignment showed the highest accuracy, but it was only 73 % (3-9°, 65 %; 5-10°, 67 %). The specificity of the 2-10° range was 81 %, which was higher than that of the other ranges (3-9°, 69 %; 5-10°, 67 %). However, the sensitivity of the 2-10° range to predict varus malalignment was only 16 % (3-9°, 35 %; 5-10°, 68 %). In addition, the sensitivity of the 2-10° range to predict valgus malalignment was only 43 % (3-9°, 71 %; 5-10°, 43 %). The accuracy of anatomical limb alignment was lower for knees with greater femoral (odds ratio = 1.2) and tibial (odds ratio = 1.2) bowing. CONCLUSIONS: Anatomic limb alignment did not accurately predict mechanical limb alignment after TKA, and its accuracy was affected by anatomic variation. Thus, alignment after TKA should be assessed by measuring mechanical alignment rather than anatomic alignment.

Comparison of Medial and Lateral Meniscus Root Tears.

The meniscus root plays an essential role in maintaining the circumferential hoop tension and preventing meniscal displacement. Studies on meniscus root tears have investigated the relationship of osteoarthritis and an anterior cruciate ligament tear. However, few studies have directly compared the medial and lateral root tears. To assess the prevalence of meniscal extrusion and its relationship with clinical features in medial and lateral meniscus root tears, we performed a retrospective review of the magnetic resonance imaging (MRI) results of 42 knee patients who had meniscus posterior horn root tears and who had undergone arthroscopic operations. The presence of meniscal extrusion was evaluated and the exact extent was measured from the tibial margin. The results were correlated with arthroscopic findings. Clinical features including patients' ages, joint abnormalities, and previous trauma histories were evaluated. Twenty-two patients had medial meniscus root tears (MMRTs) and twenty patients had lateral meniscus root tears (LMRTs). Meniscal extrusion was present in 18 MMRT patients and one LMRT patient. The mean extent of extrusion was 4.2mm (range, 0.6 to 7.8) in the MMRT group and 0.9mm (range, -1.9 to 3.4) in the LMRT group. Five patients with MMRT had a history of trauma, while 19 patients with LMRT had a history of trauma. Three patients with MMRT had anterior cruciate ligament (ACL) tears, while 19 patients with LMRT had ACL tears. The mean age of the patients was 52 years (range: 29-71 years) and 30 years (range: 14-62 years) in the MMRT and LMRT group, respectively. There was a significant correlation between a MMRT and meniscal extrusion (p<0.0001), and between an ACL tear and LMRT (p<0.0001). A history of trauma was significantly common in LMRT (p<0.0001). LMRT patients were significantly younger than MMRT patients (p<0.0001). Kellgren-Lawrence (K-L) grade differed significantly between MMRT and LMRT group (p<0.0001). Meniscal extrusion is common in patients with MMRTs. However, it is rare in patients with LMRTs, which are more commonly associated with a history of trauma and ACL tears.

Relationship between mechanical axis-derived and anatomic landmark-derived femoral rotation in TKA: a three-dimensional CT study.

We sought to determine the relationship between the mechanical axis-derived and the anatomic landmark-derived femoral rotational axes using three dimensional computed tomographic images of 20 lower extremities. The mechanical axis-derived femoral rotational axis was created on the distal articular surface of the femur using coronal mechanical limb axis and the reconstructed images of the femur. Then, we measured the angular difference between mechanical axis-derived and anatomic landmark-derived femoral rotational axes. The mechanical axis-derived femoral rotational axis was externally rotated with a mean of 2.2° (range, 0 to 4.7°; SD, 1.0) compared with the surgical epicondylar axis. Our findings should be considered to obtain a proper femoral rotational axis in total knee arthroplasty.

Preoperative rib cartilage imaging in 3-dimensional chest computed tomography for auricular reconstruction for microtia.

BACKGROUND: There are several methods that may be used to confirm the status of rib cartilage, such as physical examinations or chest radiography, for subjects with microtia. However, these methods are limited because of clinicians' inability to gain accurate information about the rib cartilage. We performed 3-dimensional chest computed tomography to preoperatively evaluate the accuracy of rib cartilage imaging. METHODS: A total of 37 patients preparing for auricular reconstruction using a rib cartilage graft underwent preoperative 3-dimensional rib cage computed tomography (3-D rib CT). The 3-D rib CT was performed in cases of secondary revisional reconstruction, those with a history of surgery using rib cartilage, in those with a history of trauma related to the rib cage, older patients with question of calcification of rib cartilage, or those with a suspected rib cartilage anomaly on physical examination. Preoperatively, the appropriateness of using the rib cartilage were evaluated. RESULTS: With the aid of the 3-D rib CT, successful autogenous auricular reconstruction was achieved in 36 patients. Framework fabrication in combination with a porous polyethylene implant and autogenous rib cartilage was performed in the remaining patient as planned preoperatively. By analyzing the 3-D rib CT image preoperatively, auricular reconstruction using a recycled rib cartilage graft with newly harvested rib cartilage was performed successfully in 13 of 14 secondary revisional cases. Based on preoperative CT images, modified surgical planning in terms of cartilage harvest and framework fabrication was needed in 8 of 11 patients who had a history of operation using rib cartilage and in 3 of 5 subjects with suspected rib cage anomalies on physical examination. Successful reconstruction was achieved using the modified surgical plan. CONCLUSIONS: A preoperative 3-D rib CT helps in surgical planning for autogenous auricular reconstruction for microtia, especially in patients with suspicious rib cartilage status.

MRI findings with arthroscopic correlation for tear of discoid lateral meniscus: comparison between children and adults.

BACKGROUND: Discoid lateral meniscus is more susceptible to tear than normal meniscus. A comparison study for tear types of discoid lateral meniscus between children and adults has not been reported. PURPOSE: To compare tear type of surgically proven discoid lateral meniscus between adults and children, and to analyze diagnostic performance for tear type of discoid lateral meniscus using magnetic resonance imaging (MRI). MATERIAL AND METHODS: Knee MR examinations of 53 children and 84 adults who had discoid lateral menisci identified at arthroscopic surgery were retrospectively evaluated with consensus by two radiologists for tear type including displacement of torn meniscus. MRI findings were compared with surgery as the reference standard. The difference of tear type and displacement of torn meniscus between children and adults in arthroscopic finding was analyzed using the Fisher's exact test or the Chi-squared test with Bonferroni's correction. RESULTS: At arthroscopy, complex tear (children, n = 22; adults, n = 56) and peripheral tear (children, n = 17; adults, n = 8) differed significantly between children and adults (P = 0.006 for complex tear, P = 0.002 for peripheral tear). Displacement of torn meniscus was seen in 28 cases of children and 41 cases of adults, not a statistically significant difference. In children, the positive predictive value (PPV) for horizontal tears was 90%, for peripheral tears 60%, and for complex tears 57%. PPV in adults for horizontal tears was 78%, peripheral tears 25%, and for complex tears 89%. CONCLUSION: Complex tears were more commonly found in adults than children and peripheral tears were more commonly found in children than adults. MRI has a high PPV for diagnosing the type of tear in discoid lateral meniscus for horizontal tears in children and adults and for complex tears in adults.

Diagnostic criterion to distinguish between incomplete and complete discoid lateral meniscus on MRI.

PURPOSE: To determine a new cutoff value that can further distinguish between the incomplete and complete discoid lateral meniscus (DLM). MATERIALS AND METHODS: Twenty-one cases of incomplete DLM and 42 cases of complete DLM without tear were included. In all, 105 patients with normal lateral menisci were included as a control group. We measured the ratio of the shortest width of the lateral meniscus to the longest width of the tibia (ratio 1) and the ratio of the shortest width of the medial meniscus to the shortest width of the lateral meniscus (ratio 2). RESULTS: By applying a cutoff value of ratio 1 as 0.32 between two incomplete and complete DLM groups, the proportion of the complete and incomplete DLM diagnosed cases among the true cases were 84% and 94%, respectively. By applying a cutoff value of ratio 2 as 0.40 between two incomplete and complete DLM groups, the proportion of the complete and incomplete DLM diagnosed cases among the true cases were 84% and 75%, respectively. CONCLUSION: A cutoff value of 0.32 using the ratio of the shortest width of the lateral meniscus and the longest width of the tibia are probably useful to help distinguish between complete DLM and incomplete DLM. Additionally, the new ratio using the width of the medial meniscus is also useful to improve distinguishing between the types of DLM.

Single-bundle transtibial posterior cruciate ligament reconstruction using a bioabsorbable cross-pin tibial back side fixation.

PURPOSE: The purpose of this study was to examine a developed surgical technique by performing a mid-term evaluation of clinical and stability results and complications. METHODS: Thirty patients who underwent transtibial posterior cruciate ligament (PCL) reconstruction using a bioabsorbable cross-pin tibial back side fixation method were enrolled in this prospective study. Lysholm and International Knee Documentation Committee (IKDC) knee scales were used to evaluate clinical outcomes. Stability was evaluated using a Telos device with a 150 N force at 90 degrees of knee flexion. Follow-up magnetic resonance imaging (MRI) was also performed in 20 (66.7%) patients, and complications were evaluated. Those with complication by MRI were assigned to an abnormal MRI group. RESULTS: The follow-up period was 47 (range, 25-62) months. On comparing preoperative and final follow-up clinical results, Lysholm and IKDC knee scale scores were found to have improved significantly (P < 0.001). The mean side-to-side difference in posterior translation measured using a Telos device was 13.4 ± 3.1 mm (range 10-20 mm) preoperatively and 3.2 ± 1.5 mm (range 1-7 mm) at last follow-up, which represented a significant improvement in stability (P < 0.001). Five patients showed cyst formation in the tibial tunnel and two patients showed a significant signal increase at the anterior portion of the tibial tunnel, which was believed to indicate a pro-cystic status. The normal and abnormal MRI groups had similar Lysholm and IKDC knee scale scores and stress radiographs (P > 0.05). CONCLUSIONS: Single-bundle transtibial PCL reconstruction using a bioabsorbable cross-pin tibial back side fixation was found to produce satisfactory clinical and stability results. However, despite these satisfactory results, a potential complication of tibial cyst formation was observed. LEVEL OF EVIDENCE: Case series, Level IV.