Lower skeletal muscle mass is associated with diabetes and insulin resistance: A cross-sectional study.

AIMS: The association between skeletal muscle mass and diabetes incidence/insulin resistance/glycated hemoglobin (HbA1C) is unknown. The aim of this study was to investigate such association in clinically apparently healthy males and females. METHODS: A cross-sectional study of 372,399 Korean males and females who completed bioelectrical impedance analysis (BIA) in a health-screening programme was performed. Skeletal muscle index was used as an indicator of skeletal muscle mass. Skeletal muscle index (%) [appendicular skeletal muscle mass (kg)/body weight (kg)X100] was estimated using BIA. The study outcomes were diabetes incidence, homoeostasis model assessment of insulin resistance (HOMA-IR), and HbA1C. RESULTS: The mean age of study participants was 38.92 ± 8.54 years. Multiple logistic regression analysis revealed a significant negative association between Skeletal muscle index and diabetes incidence/HOMA-IR/HbA1C after adjusting for various confounding factors. Odds ratios (95% confidence interval (CI)) of diabetes incidence in Q2, Q3, and Q4 compared to the lowest quantile (Q1) were 0.95 (0.85-1.05), 0.88 (0.78-0.99), and 0.79 (0.69-0.9), respectively. Beta coefficients (95% CI) of HOMA-IR in Q2, Q3, and Q3 with Q1 were 0.05 (0.03-0.07), -0.06 (-0.09∼-0.04), and -0.19 (-0.22∼-0.16), respectively. Beta coefficients (95% CI) of HbA1C in Q2, Q3, and Q4 with Q1 were 0.02 (0.01-0.03), -0.001 (-0.01∼0.01), and -0.02 (-0.03∼-0.01), respectively. CONCLUSIONS: This study demonstrated negative associations of skeletal muscle mass with diabetes incidence, insulin resistance, and HbA1C levels in healthy adults.

Intra- and extra-capsular ganglia at the gastrocnemius origin and association with meniscal tears and severity of osteoarthritis of the knee joint.

BACKGROUND: The association between size of ganglia or type of ganglia (intra-articular or extra-articular) and meniscal tears or severity of the osteoarthritis (OA) is not evaluated. PURPOSE: To evaluate the prevalence, size, and location of intra- and extra-capsular ganglia at the gastrocnemius origin and to assess their associations with meniscal injury and grades of OA. MATERIAL AND METHODS: This study included 301 consecutive patients who had knee pain and had undergone magnetic resonance imaging (MRI) of the knee. We evaluated presence of ganglia at the gastrocnemius muscle origin site and diagnosed whether it was an intra-capsular located or mixed-capsular located (intra-capsular and extra-capsular) and then measured the diameter of each ganglion. After two weeks, we evaluated whether articular cartilage injury existed. The presence of a meniscal tear was also recorded. RESULTS: A total of 186 patients (93%) had intra- and extra-capsular ganglia. Intra-capsular ganglia were found in 183 cases (91%) and mixed-capsular ganglia were found in 16 cases (8%). In cases with intra- and extra-capsular ganglia, more meniscal tears were found (P = 0.029). Intra-capsular ganglia showed more meniscal tears (P = 0.021). Intra-capsular ganglia were more likely to have high-grade OA (P = 0.043). Patients who had a meniscal tear displayed larger-sized ganglia, especially of the intra-capsular type (P = 0.044). CONCLUSION: Patients with intra- and extra-capsular ganglia, especially of the intra-capsular type, are more likely to have meniscal injury and more severe OA. Patients with a meniscal tear or OA are more likely to have larger intra- and extra-capsular ganglia, especially of the intra-capsular type.

Roles of Exosome-Like Vesicles Released from Inflammatory C2C12 Myotubes: Regulation of Myocyte Differentiation and Myokine Expression.

BACKGROUND/AIMS: The complicated differentiation processes of cells in skeletal muscle against inflammation that induce muscle atrophy are not fully elucidated. Given that skeletal muscle is a secretory organ, we evaluated the effects of inflammation on myogenic signals and myokine expression, and the roles of inflammatory exosomes released by myotubes in myogenic differentiation. METHODS: Inflammation was induced by treatment of fully differentiated C2C12 myotubes with a cytokine mixture of TNF-α and INF-γ. Exosome-like vesicles (ELVs) were isolated from conditioned media of control or inflamed myotubes and incubated with myoblasts. The expression of molecular switches that contribute to myogenic differentiation, including several kinases, their downstream targets, and myokines, were evaluated using immunoblot analysis in inflamed myotubes and in myoblasts treated with ELVs. RESULTS: Inflammation activated molecular mechanisms contributing to muscle atrophy, including AMPK, p-38 MAPK and JNK, while inhibiting Akt-mediated myogenic signals. In addition, inflammation induced myostatin expression with suppression of a myostatin-counteracting myokine, decorin. Well-characterized ELVs released from inflamed myotubes induced myoblast inflammation and inhibited myogenic mechanisms while stimulating atrophic signals. CONCLUSION: Inflammation of skeletal muscle induces muscle atrophy via multiple mechanisms, including the regulation of myokines and kinases. Inflammatory ELVs are likely to contribute to inflammation-induced muscle atrophy.

Rotational and Varus Instability in Chronic Lateral Ankle Instability: In Vivo 3D Biomechanical Analysis.

We retrospectively evaluated the altered biomechanics of the talus in 15 adult patients (7 males, 8 females) with chronic lateral ankle instability when the ankle joint moved actively from full dorsiflexion to full plantarflexion under a non-weight bearing condition. CT images were taken for the unstable ankle and the contralateral normal (control) ankle. Three-dimensional surface models of both ankle joints were reconstructed from the CT data, and we used a computer simulation program to compare both ankle motions of inversion/eversion in the coronal plane, plantarflexion/dorsiflexion in the sagittal plane, and internal rotation/external rotation in the axial plane. This evaluation method provides in vivo, dynamic, and 3D results of ankle motion. In the ankles with chronic lateral instability and the controls, the average talar rotational movement of inversion (+)/eversion (-) was 19.0° and 15.5° and the internal rotation (+)/external rotation (-) was 30.4° and 20.7°, respectively. Paired t-tests revealed significant differences in the amount of inversion (+)/eversion (-) (p=0.012) and internal rotation (+)/external rotation (-) (p<0.001) between unstable and normal ankle joints. The difference of mean rotational movement in internal rotation (9.7°) was greater than that of inversion (3.5°). Rotational instability should be considered when evaluating chronic lateral ankle instability.

The effect of intra-articular autogenous bone marrow injection on healing of an acute posterior cruciate ligament injury in rabbits.

PURPOSE: The purpose was to identify the effect of intra-articular autogenous bone marrow injection on the healing of an acute posterior cruciate ligament (PCL) rupture in a rabbit model. The effect of autogenous bone marrow on the healing process was assessed serially by gross inspection, histologic examination, and immunohistochemical study of growth factors. METHODS: In both knee joints, the PCL was completely transected surgically near the femoral attachment site in 24 rabbits. Autogenous bone marrow was obtained from both tibias and delivered only to the right knee joint by direct intra-articular injection. Gross inspection, histologic examination, and immunohistochemical study of growth factors were performed at 8, 12, and 16 weeks after severing of the posterior cruciate ligament (PCL) among 8 randomly chosen specimens. The degree of healing in both marrow-stimulated and untreated control ligaments was evaluated by gross inspection using an ordinal scale consisting of 5 grades. The degree of fibroblast and vessel proliferation and alignment of collagen fibers were evaluated by histologic examination. The degree of expression of transforming growth factor ß1, epidermal growth factor receptor, and vascular endothelial growth factor was evaluated by immunohistochemical study. Statistical analysis was performed with the Mann-Whitney U test. RESULTS: In the group with marrow-stimulated ligaments, the degree of healing was higher at 8 and 12 weeks by gross examination, whereas there was no significant difference at 16 weeks between the 2 groups. According to histologic examination, the healing process was faster in the bone marrow injection group than in the control group at 8 and 12 weeks because the degree of fibroblast and vessel proliferation significantly declined and collagen fibers were arranged more regularly compared with the control group. Similar to the results of histologic examination, the results of immunohistochemical studies showed that the healing process was faster in the bone marrow injection group. However, the recovery of the PCL was completed at 16 weeks after PCL resection in both the bone marrow injection group and the control group. CONCLUSIONS: Intra-articular autogenous bone marrow injection appeared to promote the initiation of healing response in acutely injured PCLs in rabbits. CLINICAL RELEVANCE: Intra-articular autogenous bone marrow injection can be a viable option for treating acutely injured PCLs.

A study on the relationship between the rate of vertebral body height loss before balloon kyphoplasty and early adjacent vertebral fracture.

BACKGROUND: The number of patients with an osteoporotic vertebral compression fracture, which is often accompanied by lower back pain and restrained activities, is growing. Balloon kyphoplasty involves the inflation of a balloon to restore height and reduce kyphotic deformity before stabilization with polymethylmethacrylate. However, there is a great deal of debate about whether balloon kyphoplasty also increases fracture morbidity by either inducing or facilitating subsequent adjacent vertebral fractures. OBJECTIVE: To evaluate the relationship between the rate of vertebral body height loss before balloon kyphoplasty and the etiology of early adjacent vertebral fracture after augmentation. METHODS: A total of 59 patients with osteoporotic vertebral compression fractures who underwent kyphoplasty were enrolled. This study defined early adjacent segmental fractures as new fractures occurring within three months after surgery. This study included the rate of vertebral body height loss. RESULTS: Early adjacent vertebral fractures were diagnosed in nine (15%) of the 59 patients. The patients were divided into two groups, with and without adjacent vertebral fractures. There was no significant difference in terms of age, body mass index, bone mineral density, local kyphotic angle, Cobb's angle, cement volume, cement leakage, and percent height restored between the groups with fractures and without fractures. There was a statistically significant difference between the two groups in the rate of vertebral body height loss. The rate of vertebral body height loss was significantly higher in the fracture group than in the without fracture group. CONCLUSIONS: A high rate of vertebral body height loss increased the risk of early adjacent vertebral fractures after balloon kyphoplasty.

Why do subchondral cysts occur at the medial aspect of the femoral head in hip dysplasia?

INTRODUCTION: Osteoarthritis in dysplastic hips should develop from the lateral side of the acetabulum and the femoral head just below. However, the existence of subchondral cysts located more on the medial side contradicts the weight-loading theory. The aim of this study was to confirm the presence of medial cysts at the femoral head and to investigate the relationship between medial cysts and injuries of the ligamentum teres in hip dysplasia. METHODS: A retrospective analysis was conducted on 257 cases of hip dysplasia. All patients had x-rays and 3-dimensional computed tomographies (3D CT) preoperatively and 123 patients had magnetic resonance arthrographies. A comparison was performed between cases with and without medial cysts according to the severity of damage to the ligamentum teres, the presence of bony spurs around the fovea capitis, and the Tönnis grade. RESULTS: Medial subchondral cysts around the fovea capitis were found in 100 cases. Mild osteoarthritis (Tönnis grade 0 or 1) was present in 89% of cases in the medial cyst group. A significant difference between the groups was observed in the incidence of bony spurs around the fovea capitis (p < 0.05) and injuries of the ligamentum teres (p < 0.05). CONCLUSIONS: The formation of subchondral cysts at the medial femoral head in hip dysplasia may be related to damage in the ligamentum teres. Considering that subchondral cysts develop in early osteoarthritis, the progression of arthritis in hip dysplasia appears to correlate with damage to the ligamentum teres, as well as compressive pressure on the joint.

Outcome of arthroscopic single-bundle versus double-bundle reconstruction of the anterior cruciate ligament: a preliminary 2-year prospective study.

PURPOSE: The purpose of this study was to compare the clinical results of arthroscopic single-bundle and double-bundle anterior cruciate ligament (ACL) reconstruction. METHODS: We designed a prospective study that included patients with an isolated ACL injury. From April 2004 to February 2007, of 147 patients who underwent ACL reconstruction, 113 were included in this study. We serially obtained clinical and radiologic data preoperatively and postoperatively. We compared preoperative data and data at 2 years postoperatively in patients who had undergone single-bundle ACL reconstruction versus patients who had undergone double-bundle ACL reconstruction. There were 50 single-bundle reconstructions and 63 double-bundle reconstructions. Anteroposterior stability was assessed objectively by anterior stress radiographs with the telos device (telos, Marburg, Germany) and the maximal manual test with the KT-2000 arthrometer (MEDmetric, San Diego, CA). Rotational stability was determined by lateral pivot-shift test. The clinical results were assessed by International Knee Documentation Committee and Orthopadische Arbeitsgruppe Knie scores and Tegner activity scale. In addition, we evaluated postoperative thigh circumference and range of motion. RESULTS: Residual anteroposterior laxity determined at 2 years postoperatively by telos and KT-2000 was 1.74mm +/- 1.67mm and 1.79mm +/- 1.56mm, respectively, in the single-bundle reconstruction group and 1.63mm +/- 1.50mm and 1.61mm +/- 1.22mm, respectively, in the double-bundle reconstruction group. There were no statistically significant differences. For the lateral pivot-shift test done at 2 years postoperatively, there was no statistically significant difference. In addition, clinical results such as International Knee Documentation Committee score, Orthopadische Arbeitsgruppe Knie score, Tegner activity scale, thigh circumference, and range of motion showed no significant differences between the 2 groups. CONCLUSIONS: Double-bundle reconstruction of the ACL by a method using 2 femoral tunnel and 2 tibial tunnels showed no differences in stability results or any other clinical aspects or in terms of patient satisfaction. LEVEL OF EVIDENCE: Level II, prospective comparative study.

Long-term results of primary total knee arthroplasty with and without patellar resurfacing.

Among patients that underwent total knee arthroplasty from June, 1990 to January, 1999, 61 cases (44 patients) that could be followed for more than 10 years were included in this study. The patients were divided into a patellar retention group and a patellar resurfacing group, and were compared with regard to their clinical and radiological outcomes. In patients undergoing primary TKA, a selective patellar resurfacing protocol was used. The indications for patellar retention were a small patella, nearly normal articular cartilage, minimal preoperative patellofemoral pain, poor patellar bone quality, and young patient age. When patellar retention was performed, osteophytes of the patella were removed and marginal electrocauterization was carried out. There were 25 cases (20 patients) in the patellar retention group and 36 cases (29 patients) in the patellar resurfacing group. The mean follow-up period was 140.7 months in the patellar retention group and 149.0 months in the patellar resurfacing group. The selective patellar resurfacing with total knee arthroplasty had a favorable outcome;there were a significant difference noted between the 2 groups in the functional scores, which showed better outcomes in the patellar resurfacing group than in the patellar retention group.

Postoperative radiologic outcome comparison between conventional and computer-assisted navigation total knee arthroplasty in extra-articular tibia vara.

PURPOSE: Total knee arthroplasty (TKA) is the definite treatment for osteoarthritis. Meanwhile, significant inherent extra-articular varus angulation is associated with abnormal postoperative hip-knee-ankle (HKA) angle. Computer-assisted navigation TKA (CAS-TKA) used in patients who have severe varus deformity. The purpose of this study was to compare postoperative radiologic outcome between CAS-TKA and conventional TKA for extra-articular tibia vara. METHODS: A retrospective review of postoperative HKA on standing lower extremity views was conducted in patients who underwent TKA by a single surgeon from 2010 to 2018, including knee with conventional TKA (n = 83) and CAS-TKA (n = 246). Extra-articular tibia vara was assessed by measuring the metaphyseal-diaphyseal angle (MDA) of the tibia in preoperative standing lower extremity view. Postoperative alignment was assessed by measuring the HKA in postoperative standing lower extremity view. RESULTS: There was no significant difference in age (p = 0.063), gender (p = 0.628), body mass index (p = 0.426), preoperative range of motion (p = 0.524), preoperative HKA (p = 0.306), preoperative MDA (p = 0.523), or postoperative HKA (p = 0.416) between the two groups (conventional TKA and CAS-TKA). There was no significant difference in postoperative alignment for cases with MDA ≤4° (p = 0.351) or MDA >4° (p = 0.866) in each group. There was a positive correlation between preoperative HKA and postoperative HKA in the CAS-TKA group (p < 0.001, r = 0.243). However, there was no significant correlation between preoperative HKA and postoperative HKA in the conventional TKA group (p = 0.732). CONCLUSIONS: There was no significant difference in postoperative alignment between conventional TKA and CAS-TKA in extra-articular tibial vara even for cases with MDA >4°.

Sclerosing osteomyelitis of Garré: A confusing clinical diagnosis.

We describe a rare case of sclerosing osteomyelitis of Garré in a 63-year-old woman with uncontrolled right thigh pain. She had suffered from lower back pain and radiating pain on the right lower leg for a year and 4 months and so had spine surgery 8 months ago. But the right thigh pain persisted, and the levels of C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) remained abnormal. Right femur radiographs showed cortical thickening on the proximal femur. Magnetic resonance images showed T2 hypersignal intensity lesions in the proximal femur. Under suspicion of osteoid osteoma or sclerosing osteomyelitis, surgery was performed with biopsy, bone curettage, and drilling. The culture was negative, and the biopsy showed chronic osteomyelitis. Despite surgery, the levels of CRP and ESR still remained abnormal. After using venous antibiotics, the pain subsided and CRP and ESR levels turned to normal. Followed by 6 weeks of oral antibiotics, pain was relieved after 1-year follow-up.

Evidence-Based Recommendations on the Pharmacological Management of Osteoarthritis and Chronic Low Back Pain: An Asian Consensus

The overall burden of chronic musculoskeletal pain in Asian countries will continue to increase as the population ages, as will the demand for safe and effective pain management. Currently available Asian guidelines are mostly outdated and targeted only to primary care. Implementation of international guidelines may be unsuitable for Asian patients due to cultural, local economic and regulatory factors. With the aim of developing Asian-specifi c consensus recommendations for the pharmacological management of osteoarthritis (OA) pain and chronic low back pain (cLBP), we convened to review and discuss recent available evidence for pharmacotherapy, clinical experiences, and current practice challenges they face in the region, including challenges in opioid use. Taking these into consideration, we provided general recommendations for the overall assessment and management of OA pain and cLBP. The strength of the recommendations regarding the use of pharmacological agents was assessed using the Grades of Recommendation Assessment, Development and Evaluation (GRADE) system. Where evidence is confl icting or limited, we made no recommendation pending the availability of further evidence. We recommend topical non-steroidal anti-infl ammatory drugs (NSAIDs) as a fi rst-line pharmacological treatment of OA pain, while oral NSAIDs should be considered as a fi rst-line pharmacological treatment of cLBP. Acetaminophen has been commonly used as the fi rst-line treatment for OA pain and cLBP, but its long-term use is not recommended based on recent evidence. These consensus recommendations are not prescriptive, and serve as a guide for decision-making in clinical practice. The optimal management of OA pain and cLBP should ultimately be individualized to each patient.

Comparison of two-dimensional fast spin echo T2 weighted sequences and three-dimensional volume isotropic T2 weighted fast spin echo (VISTA) MRI in the evaluation of triangular fibrocartilage of the wrist.

OBJECTIVE: To compare image quality of three-dimensional volume isotropic T2 weighted fast spin echo (3D VISTA) and two-dimensional (2D) T2 weighted images (T2WI) for evaluation of triangular fibrocartilage (TFC) and to investigate whether 3D VISTA can replace 2D T2 WI in evaluating TFC injury. METHODS: This retrospective study included 69 patients who received wrist MRIs using both 2D T2 WI and 3D VISTA techniques for assessment of wrist pathology, including TFC injury. Two radiologists measured the signal-to-noise ratio (SNR) and the contrast-to-noise ratio (CNR) of the two sequences. The anatomical identification score and diagnostic performance were independently assessed by two interpreters. The diagnostic abilities of 3D VISTA and 2D T2 WI were analysed by sensitivity, specificity and accuracy for diagnosing TFC injury using surgically or clinically confirmed diagnostic reference standards. RESULTS: 17 cases (25%) were classified as having TFC injury. 2 cases (12%) were diagnosed surgically, and 15 cases (88%) were diagnosed by physical examination. 52 cases (75%) were diagnosed as having intact TFC. 8 of these cases (15%) were surgically confirmed, while the others were diagnosed by physical examination and clinical findings. The 3D VISTA images had significantly higher SNR and CNR values for the TFC than 2D T2 WI images. The scores of 3D VISTA's total length, full width and sharpness were similar to those of 2D T2 WI. We were unable to find a significant difference between 3D VISTA and 2D T2 WI in the ability to diagnose TFC injury. CONCLUSION: 3D VISTA image quality is similar to that of 2D T2 WI for TFC evaluation and is also excellent for tissue contrast. 3D VISTA can replace 2D images in TFC injury assessment. Advances in knowledge: 3D VISTA image quality is similar to that of 2D T2 WI for TFC evaluation and is also excellent for tissue contrast. 3D VISTA can replace 2D images in TFC injury assessment.

Should We Check the Routine Postoperative MRI for Hematoma in Spinal Decompression Surgery?

BACKGROUND: A postoperative magnetic resonance imaging (MRI) is performed as a routine to assess decompression of the spinal cord as well as to evaluate postoperative complications. The purpose of this study is to analyze the efficacy of postoperative MRI for hematoma in spinal decompression surgery. METHODS: Between January 1, 2008 and January 31, 2015, 185 patients who underwent postoperative MRI after spinal decompression surgery were included in this study. We checked the history of the use of an anticoagulant or antiplatelet agent, withdrawal period, blood platelet count, and prothrombin time (international normalized ratio [INR]). We measured the total amount of suction drainage and duration until removal. We retrospectively reviewed the presence of hematoma and thecal sac compression. Postoperative prognosis was evaluated by a visual analog scale (VAS) and the Oswestry Disability Index (ODI). RESULTS: Hematomas were found on postoperative MRI scans in 97 out of 185 patients (52.4%). Thirty patients had a thecal sac compressing hematoma: 7 in the cervical spine, 1 in the thoracic spine, and 22 in the lumbar spine. The occurrence of hematoma did not show significant difference according to the use of an anticoagulant (p = 0.157). The blood platelet count, prothrombin time (INR), and suction drainage duration did not have a statistically significant correlation with the occurrence of hematoma (p = 0.562, p = 0.506, and p = 0.429, respectively). The total amount of suction drainage was significantly different according to the presence of hematoma (p = 0.022). The total 185 patients had a significant decrease in the postoperative VAS score (p < 0.001), and the diminution of VAS score was not significantly different according to the occurrence of hematoma (p = 0.243). Even in the cases of thecal sac compressing hematoma, the reduction of VAS score was not significantly different (p = 0.689). CONCLUSIONS: Postoperative MRI for hematoma in spinal decompression surgery has little effect on prognosis or management. Therefore, indiscriminate postoperative MRI should be avoided and MRI should be performed depending on the patient's status.

Simultaneous Bilateral Fracture of Femoral Neck in Korea: A Case Report.

Unilateral femoral neck factures are common and their incidence is increasing. However, simultaneous bilateral femoral neck fractures are rare. Although cases of simultaneous bilateral femoral neck fractures have been reported, most were caused by strong muscle contractions during electroconvulsive therapy. Simultaneous bilateral femoral neck fractures caused by a simple fall are an extremely rare injury; therefore, limited literature is available, and no case has been reported in Korea. We report herein a case of simultaneous bilateral femoral neck fractures caused by a simple fall. An 83-year-old woman visited the emergency department with bilateral hip joint pain and gait disturbance, which developed 1 day after a fall. Tenderness and severe limitation in left hip joint range of motion and mild limitation in right hip joint range of motion were observed on a physical examination. A Garden type IV femoral neck fracture in the left hip joint and a Garden type I femoral neck fracture in the right hip joint were observed on plain radiography. She underwent right screw fixation and left bipolar hemiarthroplasty 2 days after admission. The patient could walk using a walker 4 weeks postoperatively. Bone union in the right femoral neck was observed at the 3 month follow-up. No specific findings were observed at the left hip hemiarthroplasty site.

Biomechanical effect of the C2 laminar decortication on the stability of C2 intralaminar screw construct and biomechanical comparison of C2 intralaminar screw and C2 pars screw.

BACKGROUND: There have been no reports of biomechanical stability of C1-2 constructs after decortication of the C2 lamina. In addition, few studies have compared the stability of C2 laminar screw and pars screw constructs. OBJECTIVE: To compare the biomechanical stability of 3 different C1-2 construct conditions (C2 pars screw, C2 intralaminar screw, C2 intralaminar construct with C2 laminar decortication). METHODS: Fourteen fresh-frozen cadaveric cervical specimens (C1-3) were used. In 7 specimens, pure moments of 1.5 Nm were applied in flexion/extension, lateral bending, and axial rotation. Each specimen was tested in the normal state, in the destabilized state (after odontoidectomy and resection of transverse atlantal ligament), and after application of constructs. After kinematic study, these 7 specimens underwent axial pullout strength testing of pars screw and 50% decorticated C2 intralaminar screws. In another 7 specimens, insertion torque and pullout strength were measured to compare the pars screw and intact C2 intralaminar screw. RESULTS: : There were no statistically significant differences between the intact C2 intralaminar and 50% decorticated C2 intralaminar screw constructs in terms of range-of-motion limitations. The C2 pars screw construct was significantly superior to the C2 laminar screw construct in lateral bending (P < .01) and axial rotation (P < .01) and equivalent to the C2 laminar screw construct in flexion/extension (P = .42). There was no significant pullout strength difference between the 3 kinds of C2 screw. CONCLUSION: The C1 lateral mass-C2 pars screws construct was stronger than the C1 lateral mass-C2 intralaminar screw construct. Decortication of C2 laminar (up to 50%) did not affect the immediate stability of the C1-2 construct.

Risk factors for intrauterine constraint are associated with ultrasonographically detected severe fibrosis in early congenital muscular torticollis.

BACKGROUND/PURPOSE: The etiology of congenital muscular torticollis (CMT) remains controversial. Ultrasonographically, severe fibrosis involving the entire sternocleidomastoid muscle (SCM; type 3 or 4) fibrosis has been associated with poor clinical outcomes and indicates a chronic state of the condition. The purpose of this study was to test whether or not type 3 or 4 fibrosis detected early after birth is associated with factors related to prolonged intrauterine constraint. METHODS: Sixty-seven patients (age, <3 months) with CMT were classified into 4 different ultrasonographic types according to the severity of SCM fibrosis. The odds ratio for the relationship between probability of type 3 or 4 and factors related to intrauterine constraint were calculated by a multivariate logistic regression model. RESULTS: None were classified as type 4. Twenty-three patients (34%) had a history of breech presentation, and 21 (91.3%) of them were delivered by elective cesarean section without likelihood of birth trauma. Compared with normal pregnancy, breech presentation and oligohydramnios showed a 6.7 or 7.5 times higher probability for type 3 fibrosis, respectively. CONCLUSION: Risk factors for intrauterine constraint appear to be associated with ultrasonographically detected severe fibrosis involving the entire SCM muscle in early presenting CMT.

Lower hip bone mass and proximal femur fractures in elderly patients: more valuable than lumbar vertebrae bone mineral density.

A decreased bone mineral density, such as osteoporosis, has been considered a factor closely associated with proximal femur fractures. We studied the relationship between osteoporosis and proximal femur fractures. Dual energy radiograph absorptiometry was used to measure the bone mineral density of 121 patients with a femur neck fracture and 134 patients with an intertrochanteric fracture. The bone density of the femoral neck, Ward's triangle, and the trochanteric region were measured. Two hundred seventeen normal patients who had undergone a bone mineral density test and were found to have no proximal femur fracture were used as the control group. Comparative analysis was performed after the patients were subdivided into different groups depending on sex and fracture type. The bone mineral density of the lumbar vertebra in patients with a proximal femur fracture was not significantly different from that of the control group, but the bone mineral density of the proximal femur in patients with a proximal femur fracture was significantly less than that of the control group. The bone mineral density of the group with an intertrochanteric fracture was lower than that of the femur neck fracture group. However, the difference was statistically insignificant. In bone mineral density comparisons, no significant differences were observed between the displaced and undisplaced femur neck fracture group and between the stable and the unstable intertrochanteric fracture group. The bone mineral density of elderly patients with a proximal femur fracture was significantly less than that of normal individuals. However, femur neck fractures in elderly men were less likely to be associated with a decreased bone mineral density. Little correlation between bone mineral densities of the proximal femur and fracture location (neck vs intertrochanter) and type (nondisplaced vs displaced neck, stable vs unstable intertrochanter) was found.