Biomechanical aspects of plating osteosynthesis of transverse clavicular fracture with and without inferior cortical defect

OBJECTIVE: To find out whether superior or anterior plating osteosynthesis of clavicular fractures with and without inferior cortical defect provides more stability. DESIGN: The bearing of maximal bending moment of the osteosyntheses was determined by applying a load from a universal testing machine. BACKGROUND: A plate is recommended for internal fixation of the clavicular fracture. Stability of the osteosynthesis depends on placing of the plate at anterior or superior aspect of the clavicle. Whereas, the pattern of the fracture also influences stability. METHODS: Pairs of fresh cadaveric clavicles were used. The fractures were created at middle clavicle. Both superior and anterior plating fixation of both patterns of the fractures were performed. A compression load was applied at lateral end of the clavicle and maximal bending moment was calculated. RESULTS: For fractures without inferior cortical defect, the superior plating could withstand 12.05 (SD, 1.74) Nm and 8.69 (SD, 1.56) Nm for the anterior plating. For the fractures with inferior cortical defect, the superior plating could withstand 7.87 (SD, 2.58) Nm, but 10.26 (SD, 2.19) Nm for the anterior plating. CONCLUSIONS: The superior plating of the fracture without inferior cortical defect provides more stability against the bending moment than the anterior plating (P = 0.008). Whereas, the anterior plating of the fracture with inferior cortical defect provides more stability (P = 0.025). RELEVANCE: When plating a clavicular fracture without inferior cortical defect is performed, the plate should be placed at superior aspect of the clavicle for achieving more stability of the osteosynthesis against the bending moment. On the other hand, when the fracture has an inferior cortical defect, the plate should be placed at the anterior aspect of the clavicle.     

Vertical pelvic ring displacement in pelvic ring injury: Measurements in pelvic outlet radiograph and in cadavers

Background:Vertical pelvic ring displacement (VPRD) is a serious injury and needs assessment. Pelvic outlet radiographs are routinely taken. However, relationship of radiographic and actual VPRD is still in question. Thus, measurement of VPRD from pelvic radiographs was studied.Results:Radiographic VPRD from outlet and anteroposterior pelvic views at 10 mm actual displacement were 20.12 ± 1.98 and 4.08 ± 3.76 mm, at 20 mm were 40.31 ± 1.97 and 9.94 ± 7.27 mm and at 30 mm were 58.56 ± 2.53 and 11.29 ± 2.89 mm. Statistical analyses showed that radiographic VPRD from pelvic outlet view is 1.95 times of actual displacement with strong correlation at 0.992 coefficient and strongly significant regression analysis (P < 0.001) with 0.984 of R² value. Whereas, the measurement from anteroposterior pelvic radiograph was not strongly significant.Conclusion:Pelvic outlet radiograph provides efficient measurement of VPRD with 2 times of actual displacement.     

Acetabular roof arc angles and anatomic biomechanical superior acetabular weight bearing area

Background:

Acetabular fracture involves whether superior articular weight bearing area and stability of the hip are assessed by acetabular roof arc angles comprising medial, anterior and posterior. Many previous studies, based on clinical, biomechanics and anatomic superior articular surface of acetabulum showed different degrees of the angles. Anatomic biomechanical superior acetabular weight bearing area (ABSAWBA) of the femoral head can be identified as radiographic subchondral bone density at superior acetabular dome. The fracture passes through ABSAWBA creating traumatic hip arthritis. Therefore, acetabular roof arc angles of ABSAWBA were studied in order to find out that the most appropriate degrees of recommended acetabular roof arc angles in the previous studies had no ABSAWBA involvement.

Materials and Methods:

ABSAWBA of femoral head was identified 68 acetabular fractures and 13 isolated pelvic fractures without unstable pelvic ring injury were enrolled. Acetabular roof arc angle was measured on anteroposterior, obturator and iliac oblique view radiographs of normal contralateral acetabulum using programmatic automation controller digital system and measurement tools.

Results:

Average medial, anterior and posterior acetabular roof arc angles of the ABSAWBA of 94 normal acetabulum were 39.09 (7.41), 42.49 (8.15) and 55.26 (10.08) degrees, respectively.

Conclusions:

Less than 39°, 42° and 55° of medial, anterior and posterior acetabular roof arc angles involve ABSAWBA of the femoral head. Application of the study results showed that 45°, 45° and 62° from the previous studies are the most appropriate medial, anterior and posterior acetabular roof arc angles without involvement of the ABSAWBA respectively.     

Lipid peroxidation,glutathione, vitamin E,and antioxidant enzymes in synovial fluid from patients with osteoarthritis

Aim: To compare levels of lipid peroxidation and antioxidants in synovial fluid from primary knee osteoarthritis (OA) patients with severe cartilage damage undergoing total knee replacement with those in the synovial fluid from injured knee joint patients with intact cartilage undergoing knee arthroscopy. Methods: Thirty‐two OA patients and 10 injured knee joint patients were recruited. Lipid peroxidation (thiobarbituric acid reactive substances [TBARs]), iron and glutathione (GSH) were measured using a colorimetric method. Vitamin E was measured with high‐performance liquid chromatography (HPLC). Activities of antioxidant enzymes (glutathione peroxidase [GPx], superoxide dismutase [SOD]) were analyzed with the use of a kinetic method. Results: TBARs, iron and GSH levels in synovial fluid were not significantly different between OA patients and injured knee joint patients. Antioxidant enzymes such as GPx and SOD activities also indicated no significant difference. Only vitamin E level was significantly lower in the synovial fluid of OA patients than in that of the injured knee joint patients. Conclusions: Oxidative stress may have a role in pathogenesis of knee osteoarthritis. Vitamin E supplementation may have a role in the management of patients.     

A new classification for combined greater tuberosity fracture and anterior shoulder dislocation: A study of fracture configurations and displacement after reduction

Objective: The aim of this study was to propose a new classification of combined greater tuberosity (GT) fractures and anterior shoulder dislocation and studied the degree of displacement, functional outcomes, and need for additional surgery after reduction.Methods: A cross-sectional study was conducted. We evaluated radiographs of patients treated for combined GT fractures and anterior shoulder dislocation. Three morphologies were proposed; type 1 (a small avulsion), type 2 (GT fractures without articular head involvement), and type 3 (GT associated with articular head fractures). Two orthopedic surgeons independently measured all radiographs and classified fractures into three types. Patients were interviewed by telephone to assess functional outcomes (the simple shoulder test (SST) and EQ-5D-5L), and additional shoulder surgery was also performed.Results: There were 52 eligible patients; 32 were male (61.5%) and the mean age was 57.3 · 17.1 years. Most cases were low-energy injuries (61.5%). Of all the cases, 32.7% were type I, 59.6% type II, and 7.7% type III cases. There were differences in the degree of displacement in each group at pre, post-reduction (both horizontal and vertical planes) and at two weeks post-reduction for HD (p < 0.05). Type III had more displacement than type I at pre- and post-reduction with a P value of less than 0.05. Type III also had higher rates of displacement than type II at post-reduction and at two-week postreduction (vertical plane). The intra and inter-rater reliabilities of measurement (ICC > 0.8) were in good to excellent agreement with the kappa value (>0.9). Three out of 52 cases (5.8%) required an additional surgery after closed reduction. Patients had good functional outcomes (SST score of 8) with an excellent utility index of EQ-5D-5L (0.9).Conclusion: This new classification exhibited good-to-excellent intra-and inter-rater reliabilities, with an ability to determine injury type. Type III seems to be linked to higher risk of fracture displacement and may require additional surgery.Level of Evidence: Level IV, Diagnostic Study     

Posterior acetabular arc angle of unstable posterior hip fracture–dislocation

Purpose

Posterior hip fracture–dislocation needs stability evaluation. A previous study in the normal acetabulum has shown that the coronal posterior acetabular arc angle (PAAA) could be used to assess an unstable posterior hip fracture. Our study was designed to assess PAAA of unstable posterior hip fracture–dislocation and whether posterior acetabular wall fracture involves the superior acetabular dome.

Methods

Using coronal computed tomography (CT) of the acetabulum and 3D reconstruction of the lateral pelvis, we measured coronal, vertical PAAA and posterior acetabular wall depth of 21 unstable posterior hip fracture–dislocations and of 50 % normal contralateral acetabula. Posterior acetabular wall fracture was assessed to determine whether the fracture involved the superior acetabular dome and then defined as a high or low wall fracture using vertical PAAA in reference to the centroacetabulo–greater sciatic notch line.

Results

The coronal PAAA of unstable posterior hip fracture–dislocations and of 50 % of the posterior acetabular wall of normal the contralateral acetabulum were 54.48° (9.09°) and 57.43° (5.88°) and corresponded to 15.06 (4.39) and 15.61 (2.01) mm of the posterior acetabular wall without significant difference (p > 0.05). The vertical PAAA of unstable posterior hip fracture–dislocation was 101.67° (20.44°). There were 16 high posterior acetabular wall fractures with 35.00 (16.18) vertical PAAA involving the acetabular dome and 5 low wall fractures. High posterior wall fractures resulted in four avascular necroses of the femoral head, three sciatic nerve injuries and one osteoarthritic hip.

Conclusion

Coronal and vertical PAAA of unstable posterior hip fracture–dislocations were 54.48° and 101.67°. Vertical PAAA assesses high or low posterior acetabular wall fracture by referring to the centroacetabulo–greater sciatic notch line. High posterior wall fracture seems to be the most frequent and is involved with many complications.     

Benefit of Adding Fibular Osteotomy to Open-Wedge,Valgus, Distal Tibial Osteotomy for Correcting Varus Ankle Arthritis: An In Vitro Study

Early-stage varus ankle arthritis can usually be treated with a medial, open-wedge, valgus, distal tibial osteotomy; however, the value of adding a fibular osteotomy has been debated. We sought to determine the increase in the maximum medial osteotomy gap and correction angle provided by fibular osteotomy. In 3 sequential experiments on 12 fresh cadaveric legs, we first performed a medial open-wedge, valgus, distal tibial osteotomy alone. Second, we added a transverse fibular osteotomy. Finally, we added a blocked fibular osteotomy. In each experiment, we measured the maximum corrected osteotomy gap and the maximum correction angle. Correction was defined as the absence of lateral cortex diastasis and talocrural joint incongruity. The mean ± standard deviation maximum osteotomy gaps and correction angles were 8.40 ± 1.6 mm and 10.70° ± 3.3° for the tibial osteotomy alone, 15.70 ± 4.6 mm and 20.20° ± 5.6° for the tibial plus transverse fibular osteotomy, and 16.67 ± 3.7 mm and 20.56° ± 4.6° for the tibial plus transverse plus blocked fibular osteotomies, respectively. The corresponding median maximum correction angles were 10° (range 8° to 18°), 19.5° (range 14° to 30°), and 20° (range 14° to 28°). The osteotomy gap and correction angle in the distal tibial and transverse fibular osteotomy were significantly greater than those in the distal tibial osteotomy alone (p < .001 for both) but not in the distal tibial and blocked fibular osteotomy (p = .62 for the gap and p = .88 for the correction angle). Our data support the clinical use of adjunct transverse fibular osteotomies. The blocked fibular osteotomy provided no additional benefit.     

Measurement technique of calcaneal varus from axial view radiograph

Background:

Medial displaced posterior calcaneal tubercle creates varus deformity of an intraarticular calcaneal fracture. The fracture involves posterior calcaneal facet and the calcaneal body so we developed a measurement technique representing the angle between posterior facet and long axis of calcaneus using lateral malleolus and longitudinal bone trabeculae of posterior calcaneal tubercle as references to obtain calcaneal varus angle.

Materials and Methods:

52 axial view calcaneal radiographs of 26 volunteers were studied. Angles between posterior facet and long axis of calcaneus were measured using the measurements 1 and 2. Angle of measurement 1, as gold standard, was obtained from long axis and posterior facet of calcaneus whereas measurement 2 was obtained from a line, perpendicular to apex curve of lateral cortex of the lateral malleolus and a line parallel to the longitudinal bone trabeculae of posterior calcaneal tubercle. No more than 3° of difference in the angle of both measurements was accepted. Reliability of the measurement 2 was statistically tested.

Results:

Angles of measurement 1 and 2 were 90.04° ± 4.00° and 90.58° ± 3.78°. Mean of different degrees of both measurements was 0.54° ± 2.31° with 95% of confidence interval: 0.10°-1.88°. The statistical analysis of measurement 1 and 2 showed more than 0.75 of ICC and 0.826 of Pearson correlation coefficient.

Conclusion:

Technique of measurement 2 using lateral malleolus and longitudinal bone trabeculae of posterior calcaneal tubercle as references has strong reliability for representing the angle between long axis and posterior facet of calcaneus to achieve calcaneal varus angle.     

Effects of tobacco smoking on alpha-2-macroglobulin and some biochemical parameters in Thai males

This cross-sectional study was carried out among smokers and nonsmokers from suburban and urban residential areas in Bangkok, Thailand. One hundred eighty-six smokers and 102 nonsmokers, who voluntarily participated in the study, were investigated. The levels of alpha-2-macroglobulin (A2M), albumin, total protein, and other biochemical and hematological parameters as well as body mass index (BMI) measurements were taken. The levels of A2M, BUN and WBC counts were significantly higher in smokers than nonsmokers. Total protein and albumin concentrations were significantly lower in smokers than nonsmokers, but the levels of other biochemical parameters did not differ between the two groups. The relationship between BMI and median A2M levels in the smoker and nonsmoker groups showed the higher the BMI, the lower the serum A2M levels. Smokers had a higher percentage of hyperalpha-2-macroglobulinemia than nonsmokers. A2M concentrations correlated inversely with BMI, BUN, albumin, total cholesterol, triglycerides, and the quantity of cigarettes smoked for the total period of smoking (cigarette pack-years). Multiple regression analysis revealed that albumin and cigarette pack-years were the most closely related variables to A2M concentrations among smokers. These findings suggest cigarette smoking affects inflammation markers, increasing A2M and WBC and decreasing albumin. This effect may be the mechanism responsible for the development of chronic disease states associated with smoking since cigarette smoke contains many toxic compounds harmful to health.     

Decreased retinol transport proteins in Thai post-menopausal women with osteoporosis

High vitamin A ingestion or high serum retinol have been postulated to increase the risk of fractures and osteoporosis by reduced bone mineral density (BMD). Retinol is carried and transported to the tissues bound to retinol binding protein 4 (RBP4) and transthyretin (TTR). The relationships between retinol, retinol transport protein, retinol binding protein 4 (RBP4) and transthyretin (TTR) and BMD and osteoporosis are unclear. To examine the association between retinol and RBP4 and TTR and osteoporosis, 73 osteoporotic and 71 normal Thai postmenopausal women were studied. RBP4 and retinol levels did not differ between the groups. Serum TTR was significantly higher in control than osteoporotic subjects (89.47 and 144.53 microg/ml, respectively, p = 0.003, Mann-Whitney U test). TTR was positively correlated with BMD at several sites, such as the total radius bone (r = 0.172, p = 0.008, Spearman rank test). Osteoporosis risk was analyzed with binary logistic regression. Lean elderly Thais with lower TTR levels had a higher risk of osteoporosis. RBP4 and retinol levels had no relationship with disease status among Thai post-menopausal women. These results suggest calcium, minerals, vitamins and the retinol transport protein, transthyretin may be involved in the pathogenesis of osteoporosis.