Olecranon fractures: A biomechanical comparison of three tension band wiring fixation methods on bone models.

PURPOSE: This study aimed to compare the biomechanical pull-out strength of the three different tension band wiring (TBW) methods employed to fix transverse olecranon fractures on bone models. METHODS: Three different fixation models were created in groups of seven synthetic olecranon fractured bone models. The first technique was fixed the olecranon with the traditional TBW method. The second technique was fixed the olecranon with a large intramedullary screw TBW method. The third technique was fixed the olecranon with the double-screw TBW method. The pull-out force needed for the failure of each specimen under the tensile test device was evaluated, and the results were recorded. RESULTS: We found that the lowest average pull out strength was 55.10 N (range: 35.87-65.85 ± 10.17) in the traditional TBW method, the highest pull out strength was 84.28 N (range: 63.67-117 ± 18.87) in the double-screw TBW method. The pull out strength was 70.80 N (range: 52.60-80.95 ± 10.18) in the intramedullary screw TBW method. In terms of ultimate failure loads, there was no significant difference between the intramedullary screw TBW and the double-screw TBW (p > .05) while there was a significant difference between the traditional TBW and the other two methods (p < .05). CONCLUSION: The use of screw(s) shows higher biomechanical stability than K-wires in the TBW method. Double-screws fixation gives similar results in terms of the biomechanical load to failure compared to a large intramedullary screw fixation. Both screw methods can be used as stable constructs in clinical practice. LEVEL OF EVIDENCE: III, biomechanical trial.

Comparison of two methods for coracoclavicular ligament reconstruction: A finite element analysis.

OBJECTIVE: This study aimed to compare two different tendon grafting techniques for coracoclavicular ligament reconstruction from the data obtained using finite element analysis. METHODS: Three different finite element models of the shoulder girdle were formulated using computerized tomography images: the reference model, coracoid loop technique (CLT), and drilling technique (DT) model. In all these models, forces were applied to the clavicle along three axes (x, y, and z) of the trapezius and sternocleidomastoid muscles. Thereafter, data regarding the loading values of the tendon grafts, loads on the coracoid base, and coracoclavicular vertical distance were measured. RESULTS: While the reference model yielded the lowest values for all the loading conditions as well as the shortest coracoclavicular distance, the DT model demonstrated the highest values for all the loading conditions and the largest coracoclavicular distance. CONCLUSION: Different tendon grafting techniques may offer different loading values on both bone surface and tendon graft during coracoclavicular ligament reconstruction. The drilling technique may be associated with increased loading on the tendon graft and bone surface, causing further loss of reduction and consequent complications.

The Role of Surgical Closure Position in Total Knee Arthroplasty: Flexion versus Extension-A Randomized Prospective Study.

We aimed to investigate the effect of the knee position during the surgical closure on isokinetic muscle strength, clinical score, and range of motion in total knee arthroplasty. Seventy-five eligible patients were enrolled in the study and randomly divided into two groups; wound closure was performed with the knee flexed at 90° in group 1 and knee extended in group 2. All the surgeries were performed by the same surgeon and by the same prosthesis type. All the patients received the same rehabilitation program postoperatively. The primary outcomes were the knee flexion degrees and the American Knee Society Score values at preoperative and postoperative 6 weeks, 3, and 6 months. The secondary outcome was the isokinetic muscle strength measurements of both knees before the surgery and after 6 months. There were no significant differences in the American Knee Society Scores and knee flexion degrees between the flexion and extension groups. However, a significant decrease was found in the extensor muscle strength in the extension group after 6 months of the surgery. The findings of our study are that the closing of the knee in flexion or extension does not affect the postoperative knee flexion degrees and scores in total knee arthroplasty. However, quadriceps strength recovers early if the knee closure is performed in flexion position.

Subacromial space volume in patients with rotator cuff tear: The effect of surgical repair.

OBJECTIVE: The aim of this study was to evaluate the effect of the rotator cuff tear repair on subacromial space volume. METHODS: We retrospectively identified 21 eligible patients (5 males and 16 females; mean age: 56.4 (range; 46-71) years) who had shoulder arthroscopy for unilateral full-thickness small to medium rotator cuff tear and normal controlateral shoulder joint. The mean follow-up time was 16.1 (range; 12-25) months. Preoperative and postoperative 1 year bilateral shoulder MRIs and Constant scores were reviewed. Subacromial volume was calculated by using Osirix software. Pre-, postoperative and healthy side (contralateral control group) subacromial volumes were recorded. Paired sample and t-tests were used to compare the pre- and postoperative groups. Independent sample t-tests were used to compare the healthy and pre- and postoperative groups. The correlation between the changes in the subacromial volume and the shoulder Constant score were analyzed using Pearson correlation analyses. RESULTS: The mean subacromial volume of the preoperative group was 2.95 cm3 (range; 1.53-4.23) and the postoperative group was 3.59 cm3 (range; 2.12-4.84). The volume increase was statistically significant (p < 0.05). The mean subacromial volume of the control group was 3.93 cm3 (range; 2.77-5.03), and the difference between the preoperative group and the control group was statistically significant. There was no significant difference found between the postoperative group and the control group (p = 0.156). There was no significant correlation found between the volume and the constant score changes (r = 0.170, p = 0.515). CONCLUSION: The subacromial space volume significantly decreases in full-thickness rotator cuff tears smaller than 3 cm and the surgical repair increases the subacromial volume significantly. LEVEL OF EVIDENCE: Level IV; Diagnostic Study.

Evaluation of the plate location used in clavicle fractures during shoulder abduction and flexion movements: a finite element analysis.

PURPOSE: Plate fixation is a commonly used surgical method in clavicular fracture treatment. The main purpose of this treatment is making the painless shoulder girdle and bring the functions to the optimum level. Plate fixation position still remains controversial. We aimed to investigate the effect of the plate position in clavicle midshaft fractures during shoulder movements. METHODS: A normal anatomical shoulder joint was modeled using computed tomography images. A fracture line was created on the clavicle. Plate was placed superior to the clavicle in group 1 and anterior in group 2. The impacts of joints, plates, screws, ligaments and clavicle have been shown during 150° flexion and abduction movements of the shoulder by finite element analysis. Analyzes were made non-linear using ANSYS (version 18) and the same boundary conditions were applied in all models. RESULTS: The load values in the plate, screws, ligaments, and clavicle were higher in group 1 than group 2 during abduction and flexion movements. Especially the load on the ac ligament was excessive. Load value in the glenohumeral joint was found similar both groups. The load values in the flexion movement were higher than the abduction movement in both groups. CONCLUSIONS: Anterior clavicle plating provides less stress on material and shoulder girdle, compared to superior plating, during shoulder abduction and flexion movements.

A Radiographic Dye Method for Intraoperative Evaluation of Syndesmotic Injuries.

BACKGROUND: The Chertsey test has been recently defined as an intraoperative test for the detection of the syndesmotic injuries by the application of intra-articular contrast. However, no study has investigated the reliability and comparative analysis of the Chertsey test. The purpose of this study was to explore the diagnostic accuracy of the Chertsey test in predicting syndesmosis instability of the injured ankle, with correlation to preoperative computed tomography (CT) findings. METHODS: A total of 39 patients who were operated on due to the unilateral ankle fracture and had no complaint on the contralateral ankle joint were included in the study. An intraoperative Chertsey test was performed on all ankle fractures and bilateral ankle CT was obtained preoperatively. Ankles were classified as Chertsey +, Chertsey -, and contralateral control group. The morphology categorization, width, and volume of the syndesmotic region were measured on axial images of the CT. Mann-Whitney U test was used to compare the data. Intraobserver and interobserver agreements were accessed by calculating the intraclass correlation coefficient (ICC) for radiologic parameters and the Chertsey test. RESULTS: The Chertsey test was positive in 13 (33.3%) of 39 ankle fractures. Patients with a positive Chertsey test showed a significant increase in syndesmotic width and volume compared with Chertsey - and control group. However, there was no significant difference between Chertsey - and the control group. All the ICC values were excellent for both radiologic measurements and test. CONCLUSION: The Chertsey test is a reliable and useful test that can be used intraoperatively in the diagnosis of syndesmotic injuries. LEVEL OF EVIDENCE: III, comparative series.