An Assessment of 3.5mm Reconstruction Plate Fixation in Olecranon Fractures

Background: Olecranon process is a large, curved eminence comprising of the proximal and posterior part of the ulna. It lies subcutaneously which makes it more vulnerable to injury. Due to intra-articular extension of fractures, anatomical reduction and early mobilization should be achieved in every case and usually managed surgically. Aims and Objectives: To access the results of reconstruction plate in fracture olecranon.Materials &Methods: This was a prospective study consisted of 25 cases of olecranon fractures which were managed by open reduction and internal fixation using 3.5mm reconstruction plate. Patients were followed up every month till 6 months. At each follow up visit clinical and radiological parameters were assessed: Final assessment was done at 6 months using the Mayo Elbow Performance Score.Result: According to the AO classification, Type A-1 – 7 cases, A-3 – 1case, B-1 – 13 cases, B-3 – 1 case, C-1 – 1 case, C-2 – 1 case, C-3 – 1 case. An adequate reduction was maintained in all fractured olecranon until union. Average radiological union time was 12 weeks in 72% cases, 15 weeks in 16% cases, 18 weeks in 8% cases and > 18 weeks in 4% cases. The results were graded as per the criteria laid by Rogers et al as excellent in 84% cases, good in 12% and unsatisfactory in 4% cases. 2 cases developed superficial infection and 1 deep infection and 1 delayed union.Conclusion: Open reduction and internal fixation of fracture of olecranon with 3.5mm reconstruction plate is based on sound biomechanical principle with a good functional outcome and a low incidence of complications.

Biomechanical analysis of two medial buttress plate fixation methods to treat Pauwels type III femoral neck fractures

Background Femoral neck fractures in young people are usually Pauwels Type III fractures. The common treatment method are multiple parallel cannulated screws or dynamic hip screw sliding compression fixation. Due to the huge shear stress, the rate of complications such as femoral head necrosis and nonunion is still high after treatment. The aim of our study was to compare the stabilities of two fixation methods in fixating pauwels type III femoral neck fractures. Methods All biomimetic fracture samples are fixed with three cannulated screws combined with a medial buttress plate. There were two fixation groups for the buttress plate and proximal fracture fragment: Group A, long screw (40 mm); Group B, short screw (6 mm). Samples were subjected to electrical strain measurement under a load of 500 N, axial stiffness was measured, and then the samples were axially loaded until failure. More than 5 mm of displacement or synthetic bone fracture was considered as construct failure. Results There were no significant differences in failure load (P = 0.669), stiffness (P = 0.842), or strain distribution (P > 0.05) between the two groups. Conclusions Unicortical short screws can provide the same stability as long screws for Pauwels Type III Femoral Neck Fractures.

Acromion-axillary Nerve Distance and Its Relation to the Humeral Length in the Prediction of the Axillary Nerve Position During the Anterolateral Deltoid-splitting Approach in the Treatment of Proximal Humerus Fractures: a Clinical Study

Background Because of the broad anatomical variation in the course of the axillary nerve, several cadaveric studies have investigated the acromion-axillary nerve distance and its association with the humeral length to predict the axillary nerve location. This study aimed to analyze the acromion-axillary nerve distance (AAND) and its relation to the arm length (AL) in patients who underwent internal plate fixation for proximal humerus fractures.Methods The present prospective study involved 37 patients (15 female, 22 male; the mean age = 51 years, age range = 19 to 76) with displaced proximal humerus fractures who were treated by open reduction and internal fixation. After anatomic reduction and fixation was achieved, the following parameters were measured in each patient before wound closure without making an extra incision or dissection: (1) the distance from the anterolateral edge of the acromion to the course of axillary nerve was recorded as the acromion-axillary nerve distance and (2) the distance from the anterolateral edge of the acromion to the lateral epicondyle of the humerus was recorded as arm length. The ratio of AAND to AL was then calculated and recorded as the axillary nerve index.Results The mean AAND was 6 ± 0.36 cm (range = 5.5–6.6), and the mean arm length was 32.91 ± 2.9 cm (range = 24–38). The mean axillary nerve ratio was 0.18 ± 0.02 (range = 0.16 to 0.23). There was a significant moderate positive correlation between AL and AAND (p = 0.006; r = 0.447). The axillary nerve location was predictable in only 18% of the patients.Conclusion During the anterolateral deltoid-splitting approach to the shoulder joint, 5.5 cm from the anterolateral edge of the acromion could be considered as a safe zone for the prevention of possible axillary nerve injury.

A Study to Analyse Correlation of Plate Position With Flexor Pollicis Longus Tendon Attrition In Patients Managed With Volar Plating

Background: Purpose of this study was to study association of flexor pollicis longus tendon (FPL) attrition using Ultrasonography with plate position on radiographs in patients managed with volar locked compression plate fixation (LCP) in distal radius fractures. Methods: Status of flexor pollicis longus tendon was analysed by ultrasonography in patients who underwent volar locked compression plating a minimum of one year follow up. Soong’s criteria were used to assess the plate position and then correlated with the ultrasonography findings of flexor pollicis longus. Results: There were 45 patients included in our study, of which 28 belonged to Soong’s grade zero, 10 were grades one and 7 were grade two. Flexor pollicis longus attrition was noted in 5 cases with grade two plating. Conclusion: Amongst the cases with grade 2 of Soong’s criteria, attritional changes were seen in 72 percent of patients , which warrants a proper follow up to identify any impending signs of tendon rupture and to make early intervention to prevent rupture.

Peculiar Periprosthetic Fracture Involving Trochanteric Region Along With Shaft of Femur in a 68-Year Male Treated With Locking Plate Fixation and Additional Augmentation with Cable – A Case Report and Review of Literature

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Variation of the palmar cutaneous branch of the median nerve identified within the tendon sheath of the flexor carpal radialis

Purpose: During volar plate fixation of distal radius fractures, we have encountered patients with an anomalous course of the palmar cutaneous branch (PCB) of the median nerve within the sheath of the flexor carpi radialis (FCR) tendon. The purpose of this study was to assess the frequency and location of variations of the PCB within the sheath of the FCR tendon.Methods: This retrospective study enrolled 83 patients who underwent volar locking plate fixations through a modified Henry approach for distal radius fractures from July 2018 to April 2020. When we encountered an anomalous PCB within the sheath of the FCR tendon, we documented the specific finding and location where the PCB entered the sheath of the FCR tendon.Results: There were nine patients (10.8%) who had an anomalous course of PCB penetrating the sheath of the FCR tendon. The average entering point of PCB into the sheath of the FCR tendon was 3.07 cm from the distal wrist crease (range, 2.5–3.6 cm).Conclusion: An anomalous course of the PCB entering the sheath of the FCR tendon was observed at a high frequency (10.8%). Care must be taken not to injure the PCB during a dissecting of the FCR sheath during a modified Henry approach for a distal radius fracture.

Comparison between external locking plate fixation and conventional external fixation for extraarticular proximal tibial fractures: a finite element analysis

Background Good clinical outcomes for locking plates as an external fixator to treat tibial fractures have been reported. However, external locking plate fixation is still generally rarely performed. This study aimed to compare the stability of an external locking plate fixator with that of a conventional external fixator for extraarticular proximal tibial fractures using finite element analysis. Methods Three models were constructed: (1) external locking plate fixation of proximal tibial fracture with lateral proximal tibial locking plate and 5-mm screws (ELP), (2) conventional external fixation of proximal tibial fracture with an 11-mm rod and 5-mm Schanz screws (EF-11), and (3) conventional external fixation of a proximal tibial fracture with a 7-mm rod and 5-mm Schanz screws (EF-7). The stress distribution, displacement at the fracture gap, and stiffness of the three finite element models at 30-, 40-, 50-, and 60-mm plate–rod offsets from the lateral surface of the lateral condyle of the tibia were determined. Results The conventional external fixator showed higher stiffness than the external locking plate fixator. In all models, the stiffness decreased as the distance of the plate–rod from the bone surface increased. The maximum stiffness was 121.06 N/mm in the EF-11 model with 30-mm tibia–rod offset. In the EF-7 model group, the maximum stiffness was 40.00 N/mm in the model with 30-mm tibia–rod offset. In the ELP model group, the maximum stiffness was 35.79 N/mm in the model with 30-mm tibia–plate offset. Conclusions Finite element analysis indicated that external locking plate fixation is more flexible than conventional external fixation and can influence secondary bone healing. External locking plate fixation requires the placement of the plate as close as possible to the skin, which allows for a low-profile design because the increased distance from the plate to the bone can be too flexible for bone healing. Further experimental mechanical model tests are necessary to validate these finite element models, and further biological analysis is necessary to evaluate the effect of external locking plate fixation on fracture healing.

Effect of subacromial erosion shape on rotator cuff and clinical outcomes after hook plate fixation in type 5 acromioclavicular joint dislocations: a retrospective cohort study

Background Surgical fixation using hook plates is widely used in the treatment of acromioclavicular (AC) joint dislocations. The purpose of this study was to evaluate the incidence and shape of subacromial erosions after removal of the hook plate in type 5 AC joint dislocations. Further, we evaluated the effect of the shape of the subacromial erosion on the rotator cuff. Methods We retrospectively reviewed 30 patients who underwent hook plate fixation for type 5 AC joint dislocations at our hospital between December 2010 and December 2018. Patients with a follow-up of at least 1 year were included. Clinical outcomes were assessed using the final follow-up Constant-Murley, Korean Shoulder, and visual analog scores. To ensure that the appropriate reduction was well maintained, the coracoclavicular distances of the injured and contralateral sides were evaluated at the last follow-up. Computed tomography was performed to investigate the presence and shape of the subacromial erosion after hook plate removal at 4 months after surgery. Ultrasonography was performed to investigate the presence of rotator cuff lesions at the last follow-up. Clinical and radiological outcomes were compared between groups divided according to the presence and types of subacromial erosions. Results Subacromial erosion was observed in 60% of patients (18/30): 13, 2, and 3 simple groove, cave, and marginal protrusion types, respectively. Four patients showed reduction loss at the final follow-up. There were no significant differences in clinical and radiological outcomes between the groups with and without subacromial erosion. Moreover, there were no significant differences between groups according to the types of subacromial erosion. There were no rotator cuff lesions, such as partial tears, in the injured shoulders. Conclusions Hook plate fixation may induce subacromial erosions. However, the subacromial erosions caused by the hook plate did not affect the clinical outcomes of type 5 AC joint dislocations. Moreover, regardless of its shape, the subacromial erosion did not affect the clinical outcomes nor cause rotator cuff lesions after plate removal.

Effects of plate contouring quality on the biomechanical performance of high tibial osteotomy fixation: A parametric finite element study

Locking plates have threaded holes, in which threaded-head screws are affixed. Hence, they do not need to be in intimate contact with underlying bone to provide fixation. There are, however, reports that a large distance between the plate and the bone might cause clinical complications such as delayed union or nonunion, screw pull out, and screw and plate breakage. Considering the diversity in the capabilities and costs of different plate customization techniques, the purpose of this study was to investigate the effect of the plate contouring quality on the biomechanical performance of high tibial osteotomy (HTO) fixation. A finite element model of proximal tibia was developed in Abaqus, using the QCT data of a cadaver. The model was then subjected to open-wedge HTO (correction angle 12°) with TomoFix plate fixation. The sagittal curvature of the plate was changed parametrically to provide certain levels of geometrical fit, and the biomechanical performance parameters of fixation were assessed. Results indicated 5%, 9% and 38% increase in the stiffness of the construct, and the von Mises stress in the plate and locking screw just above the osteotomy site, respectively, when the level of fit of plate changed from 0% (initial non-contoured initial shape) to 100% (fully adapted shape). The same change decreased the pressure at the lateral hinge of the osteotomy by 61%, and the mean of the tensile stress on the screw shaft by 12%. It was concluded that the level of fit has conflicting effects on the biomechanical parameters of the HTO fixation system, that is, the structural stiffness, the pressure at the lateral hinge, the stresses in the plate and screws, and the pull out resistance of the screws. In particular, for HTO patients with high quality bone, the optimal level of fit should provide a tradeoff between these parameters.