Optimizing hook implantation angle of the clavicular hook plate: a cadaveric study.

PURPOSE: While Clavicle hook plates have demonstrated favorable results regarding bone and shoulder function, their design can potentially lead to complications due to pressure concentration at the plate's tip. This study aims to investigate the impact of different hook implantation angles on the contact surface area between the hook plate and acromion, with the goal of minimizing mismatch and maximizing contact surface area. METHODS: Twenty soft shoulder cadavers were included in the study, and the contact surface area of the hook plate was measured in different positions based on the hook implantation angle. RESULTS: The results showed variations in compatibility, width, and length of the contact surface area depending on the hook implantation angle and the medial or lateral row placement. The lateral row generally demonstrated superior compatibility (84.0% vs 46.67%, p-value < 0.001), with a broader contact area (3.55 ± 0.08 mm vs 3.09 ± 0.10 mm, p-value = 0.004) and a longer contact area (7.36 ± 0.19 mm vs 5.10 ± 0.23 mm, p-value < 0.001) at specific angles. A detailed analysis of the lateral position revealed that the zero angle of implantation resulted in the greatest contact surface area, measuring 3.91 ± 0.70 mm in width (p value = 0.083) and 8.85 ± 1.24 mm in length (p value < 0.001). CONCLUSION: Placing the hook laterally and at the zero position according to the hook implantation angle can maximize contact surface area, may reduce stress concentration, and minimize complications in hook plate fixation. Further research and consideration of anatomical variations are warranted to refine the placement technique and enhance patient outcomes. LEVEL OF EVIDENCE: Level V evidence.

The biomechanical properties of the hook plate and pull-out suture in mallet finger fractures: a cadaveric study.

A total of 32 cadaveric fingers with bony mallet injuries were fixed using either the hook plate or the pull-out suture technique. The purpose of this study was to assess the immediate postoperative biomechanical responses of the fixation techniques under different load conditions. The fingers were cyclically loaded with a force of 7 N for 3500 cycles and until construct failure. The maximum displacements of the hook plate and pull-out sutures were 0.7 mm and 0.6 mm, respectively (p = 0.556). The stiffnesses of the hook plate and pull-out suture were 1.3 N/mm and 1.1 N/mm, respectively (p = 0.515). The ultimate loads-to-failure for the hook plate and pull-out suture were 64.4 N (interquartile range [IQR] 37.7-77.7) and 44.5 N (IQR 29.7-63.5), respectively (p = 0.094). Both fixation techniques were able to withstand immediate postoperative mobilization without any difference in fracture displacement, construct stiffness or maximum load to failure.

Composition of Platelet-Rich Plasma Prepared From Knee Osteoarthritic Patients: Platelets, Leukocytes, and Subtypes of Leukocyte.

INTRODUCTION: Platelet-rich plasma (PRP) has gained increasing popularity in the orthopedic field. There has been still no consensus on PRP preparation technique, thus providing a variety of final PRP products. Different preparation techniques lead to different compositions of PRP, which include platelet concentration, the number of leukocytes, and their subtypes. Here, we studied those compositions of PRP compared to whole blood samples. METHODS: There were 335 participants who met the inclusion and exclusion criteria. Each participant underwent a blood drawing process to prepare PRP for their knee osteoarthritis treatment. We categorized baseline platelet concentration in whole blood samples into three groups: less than 2 x 105/µL (Group 1), between 2 x 105/µL and 2.99 x 105/µL (Group 2), and greater than 2.99 x 105/µL (Group 3). The primary outcome was reported as the platelet concentration in PRP and the ratio of platelet concentration in PRP compared to baseline whole blood samples. The secondary outcome was reported as the ratios of leukocyte, lymphocyte, and neutrophil in PRP compared to the baseline whole blood samples. RESULTS: The average platelet concentration in PRP was 1.26 x 106/µL (6.3 times higher compared to baseline whole blood samples). The mean platelet concentration of PRP in Group 1, Group 2, and Group 3 was 1.08 x 106/µL, 1.38 x 106/µL, and 1.71 x 106/µL, respectively (p-value = 0.0001). The platelet concentration ratio of PRP condition to the baseline whole blood was 6.9, 5.8, and 4.2 in Group 1, Group 2, and Group 3, respectively (p-value = 0.0018). The average ratio of leukocytes in PRP to whole blood was 1.5. The average ratio of lymphocytes and neutrophils in PRP to whole blood was 2.0 and 0.5, respectively.  Conclusion: Different baseline platelet concentrations in whole blood samples provided significantly different platelet concentrations in PRP. The baseline platelet concentration in whole blood also provided an inverse relation to the fold change of the platelet concentration in PRP. Subtypes of leukocytes changed from neutrophil-predominated in the baseline whole blood samples to lymphocyte-predominated in PRP.

Anatomic Study of the Medial Collateral Ligament in Thai Population: A Cadaveric Study of 56 Elbows.

Purpose: This study aims to elucidate basic anatomic and geometric features of MCL, providing more accurate and detailed information, as guidance for surgeons, to improve patient's outcome of the treatment. Methods: The anterior bundle (AB), posterior bundle (PB) and transverse bundle (TB) ligament of 56 fresh frozen Thai cadaveric elbows, were measured and recorded, comprise key ligament's geometric features, footprints and dimensions, and its relation to bony landmarks. Sagittal and coronal planes were used in respect of the anatomical position. Results: The mean distance between the center of AB origin and the apex of medial epicondyle is as follows: 2.97 ± 2.21 mm anteriorly, 4.73 ± 1.60 mm inferiorly in the sagittal plane, and 4.23 ± 1.13 mm deep from the epicondyle in the coronal plane. Its dimension is 6.23 ± 1.02 mm in width and 45.97 ± 6.75 mm in length. The ligament's insertion triangular shape has its base located 28.44 ± 3.51 mm anterior from the posterior olecranon border, and 22.52 ± 2.49 mm superior from the inferior ulnar border. The tip located 50.79 ± 4.86 mm anterior from the posterior olecranon border and 17.64 ± 2.80 mm superior from the inferior ulnar border. Conclusion: Apprehension of the precise geometries and distances of the ligament's footprint relative to key anatomical point is crucial. This stereographically comprehended data are useful for surgeon as reference points to obtain stability, motion, kinetic, and kinematic properties of the elbow. Level of Evidence: Level V evidence. Supplementary Information: The online version contains supplementary material available at 10.1007/s43465-022-00648-x.

The lateral collateral ligament complex of the elbow in a Thai population: an anatomical study of 56 cadaveric specimens.

The purpose of this study was to investigate the anatomical features of the lateral collateral complex (LCC) of the elbow in a Thai population. We dissected 56 cadaveric elbows and described the LCC three-dimensionally in sagittal and coronal planes. We found that the characteristics differed from previous reports in other ethnic populations. In the sagittal plane, the centre of the origin of the LCC was located 3 mm anteriorly and 4 mm inferiorly to the apex of the lateral humerus epicondyle, and in the coronal plane it was 4 mm deep. The vertical distance between the origin of the lateral ulnar collateral ligament (LUCL) and the lateral epicondyle and the distance from the LUCL insertion to the border of the ulnar bone differed significantly between sexes. These data may be useful for surgeons during reconstruction of injures to the LCC of the elbow.Level of evidence: V.