Ideal insertion point and projection of the infra-acetabular screw in acetabular fracture surgery.

BACKGROUND: In acetabular fracture surgery, an infra-acetabular screw (IAS) is inserted from the anterior to the posterior column through the infra-acetabular corridor to stabilize both columns. Although the IAS is useful for increasing fixation strength, proper placement requires proficiency and often results in extraosseous screw penetration. The complex anatomy of the infra-acetabular corridor and difficult intraoperative detection of the ideal insertion point and angle make proper placement of the IAS challenging. This study aimed to detect the ideal insertion point and angle of the IAS based on anatomical landmarks that can be directly identified intraoperatively. METHODS: We retrospectively reviewed the pelvic CT of 50 adults who underwent serial slice CT imaging. The pelvic inlet plane (PIP), which contains the anterior border of both the sacroiliac joint and posterior superior edge of the pubic symphysis, was used as the reference plane for the pelvic coordinate system to simulate the ideal insertion of IAS. The distance from the posterior superior edge of the pubic symphysis to the ideal insertion point of the IAS (IAS distance) and the angle and length of the IAS that could be inserted from the ideal insertion point were measured. RESULTS: The mean IAS distance was 61.0 ± 5.7 mm (57.6 ± 4.3 mm in men and 64.4 ± 4.9 mm in women). The mean angle between ideal IAS and yz-plane on the outlet view (α-angle) was 8.4 ± 6.6 ° (6.4 ± 5.6° in men and 10.5 ± 7.0° in women). The mean angle between ideal IAS and y-axis on the yz-plane (ß-angle) was 86.5 ± 10.6 ° (86.0 ± 10.3° in men and 87.0 ± 10.9° in women). The length of IAS was 97.1 ± 4.7 mm in men and 89.2 ± 3.6 mm in women. CONCLUSION: The IAS ideal insertion point detected as a distance from the pubic symphysis may aid in the proper insertion of the IAS during surgery. The insertion angle was parallel or tilted 10 ° laterally to the longitudinal axis in the pelvic outlet plane and almost perpendicular to the PIP in the sagittal plane when inserted from the ideal insertion point.

Associations among Preoperative Malnutrition, Muscle Loss, and Postoperative Walking Ability in Intertrochanteric Fractures: A Retrospective Study.

Sarcopenia and malnutrition are increasing in older adults and are reported risk factors for functional impairment after hip fracture surgery. This study aimed to investigate the associations between skeletal muscle mass loss, malnutrition, and postoperative walking ability in patients with hip fracture. We retrospectively reviewed patients who underwent intertrochanteric fracture surgery at our institute. The psoas muscle index, controlling nutritional status score, and functional ambulation category (FAC) were used to evaluate skeletal muscle mass, nutritional status, and walking ability, respectively. Six months after surgery, walking ability was assessed as either "gait disturbance" or "independent gait". Multivariate binomial logistic regression analysis, with skeletal muscle mass, nutritional status, and other factors, was used to predict the risk of being assigned to the gait disturbance group. This study included 95 patients (mean age, 85.2 years; 70 women). Sixty-six patients had low skeletal muscle mass, 35 suffered from malnutrition, and 28 had both. Malnutrition and low skeletal muscle mass were significantly associated with postoperative gait disturbance (FAC < 3). Preoperative low skeletal muscle mass and malnutrition were risk factors for postoperative poor walking ability. Further preventive interventions focusing on skeletal muscle mass and nutritional status are required.

Double plating via anterolateral and posterolateral approach for distal femoral fracture.

Although there are some reports highlighting the applicability of double plates in distal femoral fractures, there is no standard approach or fixation method for supracondylar fractures combined with posterior coronal shear fractures. We report a case of distal femoral fracture treated with a lateral locking plate and posterior buttress plate using anterolateral and posterolateral approaches from one incision. A 70-year-old man was hit by a motorcycle and had an intra-articular distal femoral fracture involving a long medial proximal spike and a single lateral condyle fragment, with the lateral condyle fragment posteriorly displaced. A 12-cm lateral skin incision was made, and the joint was developed using a para-patellar approach from the anterior to iliotibial band. Posterior buttress plate fixation was successfully performed from behind the iliotibial band using a posterolateral approach, followed by cannulated cancellous screw and lateral locking plate fixation from the anterolateral window. Combined anterolateral and posterolateral approaches from one incision enable intra-articular exposure and fixation based on fixation principles for lateral condyle fragments combined with supracondylar fracture.

Comparison of screw versus locking plate fixation via sinus tarsi approach for displaced intra-articular calcaneal fractures.

BACKGROUND: The optimal treatment of displaced intra-articular calcaneal fractures (DIACF) is controversial. This study compared the fixation stability of screws and locking plates in DIACF treated via the sinus tarsi approach (STA). METHODS: We retrospectively evaluated 118 DIACF cases treated via STA and extracted data that could affect treatment outcomes. Loss of Böhler's angle after surgery was measured to compare fixation stability. RESULTS: The loss of Böhler's angles was significantly smaller in the locking plate group than in the screw group (2.6 ± 2.7º vs. 5.6 ± 5.3º, P < 0.01). There was no difference in the clinical outcomes between the groups. On multivariate logistic regression analysis, screw fixation was significantly associated with loss of Böhler's angle by> 10º (odds ratio, 8.63; 95% confidence interval, 1.16-64.4; P < 0.05). CONCLUSIONS: Locking plate fixation is more reliable than screw fixation for preventing correction loss in DIACF treated via STA. LEVEL OF EVIDENCE: III.

Effect of an Adjustable Hinged Carbon Fiber Operating Table on the Coronal Alignment of the Lumbar Spine During Oblique Lateral Interbody Fusion.

OBJECTIVE: We sought to measure the coronal alignment of the lumbar spine of patients in the right lateral decubitus position on a hinged Jackson operating table with the following 3 table positions: neutral and right and left 20-degree flexion. METHODS: We analyzed the data of 23 patients who underwent OLIF. Spinal alignment was quantified using the coronal Cobb angle from L1 to S1, measured on anterior-posterior radiographs obtained preoperatively, after induction of anesthesia, with patients in the right lateral decubitus position, for the following 3 positions of the Jackson hinged operating table: neutral, right 20-degree flexion, and left 20-degree flexion. The Cobb angle at each position, the change in the Cobb angle, and the effective range of motion (%) were obtained from neutral to right and left 20-degree flexion. Alignment was compared between the 3 positions, and the range of motion was compared between men and women. RESULTS: The Cobb angle was different in all 3 positions of the table (P < 0.0001): -7.0 ± 8.7°, neutral; 2.8 ± 7.6°, right 20-degree flexion; and -14.7 ± 7.8°, left 20-degree flexion. The change in Cobb angle and the effective range of motion were greater in women (10.9 ± 2.8° and 55%) than in men (6.7 ± 5.8° and 34%) from the neutral to right 20-degree flexion position (P = 0.0298). CONCLUSIONS: The coronal alignment of the lumbar spine of patients in the right lateral decubitus position on a flat operating table (neutral position) was convex. The right 20-degree flexion position of the hinged operating table yielded less coronal plane lumbar spine deformity, with greater deformity in women.

Interleukin-4 downregulates the cyclic tensile stress-induced matrix metalloproteinases-13 and cathepsin B expression by rat normal chondrocytes.

Mechanical stress plays a key role in the pathogenesis of cartilage destruction seen in osteoarthritis (OA). We investigated the effect of cyclic tensile stress (CTS) on the anabolic and catabolic gene expression of rat cultured normal chondrocytes using the Flexercell strain unit. The effects of interleukin (IL)-4, a chondroprotective cytokine, on the changes in gene expression induced by CTS were also investigated. CTS (7% elongation at 0.5 Hz) for 24 h did not affect the expression of aggrecan and type II collagen, whereas CTS significantly upregulated matrix metalloproteinase (MMP)-13 and cathepsin B mRNA expression by chondrocytes. IL-1beta expression was also signifi cantly upregulated by CTS up to 12 h. The upregulation of MMP-13 was observed at 3 h, which was earlier than that of IL-1beta. Furthermore, pre-treatment with IL-4 (10 ng/ml) suppressed both MMP-13 and cathepsin B induction by mechanical stress, as well as CTS-induced IL-1beta expression. Our results suggest that IL-4 might have a therapeutic value in the treatment of OA by downregulation of mechanical stress-induced MMP-13 and cathepsin B expression by chondrocytes.

Decreased levels of insulin-like growth factor-1 and vascular endothelial growth factor relevant to the ossification disturbance in femoral heads spontaneous hypertensive rats.

Ossification disturbance in femoral head reportedly is seen in the Spontaneously Hypertensive rats (SHR) between ages of 10 and 20 weeks. We investigated serum and tissue levels of insulin-like growth factor-1 (IGF-1) and vascular endothelial growth factor (VEGF) in SHR relevant to the ossification disturbance and osteonecrosis of the femoral head. Serum levels of IGF-1 and VEGF were significantly lower in SHR than in Wistar Kyoto rats (WKY) at weeks 5, 10, 15 and 20 (p<0.005). The incidence of histological ossification disturbance of the femoral head was higher in SHR (59%) than in WKY (40%) at week 20. Lower serum and local levels of VEGF in SHR appeared to be related to the incomplete ossification of the femoral heads. Immunohistochemical study showed significantly lower numbers of IGF-1 and VEGF positive chondrocytes in the femoral epiphyseal cartilage of SHR than in those of WKY at weeks 10, 15 and 20. Our results suggest that local and/or systemic levels of IGF-1 and VEGF between ages of 5 and 20 weeks might play roles in the pathogenesis of ossifi cation disturbance of the femoral head in SHR.