The proximal humeral locking plate positioning to the pectoralis major tendon in achieving the proper calcar screw location: a cadaveric study

Background Proximal humeral fracture is the third most common of osteoporotic fracture. Most surgical cases were treated by fixation with anatomical locking plate system. The calcar screw plays a role in medial support and improving varus stability. Proximal humerus fracture in elderly patients are commonly seen with greater tuberosity (GT) fracture. The GT fragment is sometimes difficult to use as an anatomic landmark for proper plate and screw position. Therefore, the insertion of pectoralis major tendon (PMT) may be used as an alternative landmark for appropriate plate and calcar screw position. The purpose of study is going to identify the vertical distance from PMT to a definite point on the position of locking plate. Methods 30 cadaveric shoulders at the department of clinical anatomy were performed. Shoulders with osteoarthritic change (n = 5) were excluded. Finally, 25 soft cadaveric shoulders were recruited in this study. The PHILOS™ plate was placed 2 mm posterior to the bicipital groove. A humeral head (HH) was cut in the coronal plane at the level of the anterior border of the PHILOS plate with a saw. A calcar screw was inserted close to the inferior cortex of HH. Distance from the upper border of elongated combi-hole (UB-ECH) to the upper border of pectoralis major tendon (UB-PMT) was measured. The plate was then moved superiorly until the calcar screw was 12 mm superior to the inferior border of HH and the distance was repeatedly measured. Results The range of distance from UB-PMT to the UB-ECH was from − 4.50 ± 7.95 mm to 6.62 ± 7.53 mm, when calcar screw was close to inferior border of HH and when the calcar screw was 12 mm superior to the inferior border of HH, respectively. The highest probability of calcar screw in proper location was 72% when UB-ECH was 3 mm above UB-PMT. Discussion and conclusion The GT fragment is sometimes difficult to use as an anatomic landmark for proper plate and screw position. PMT can be used as an alternative anatomic reference. UB-PMT can serve as a guide for proper calcar screw insertion. UB-ECH should be 3 mm above UB-PMT and three-fourths of cases achieved proper calcar screw location.

Biomechanical Evaluation of Oblique Lateral Locking Plate System for Oblique Lumbar Interbody Fusion: A Finite Element Analysis

Objective: Oblique lateral locking plate system (OLLPS) with the locking and reverse pedicle track screw configuration is a novel internal fixation designed for oblique lumbar interbody fusion(OLIF). It is placed in a single-position through the oblique lateral surgical corridor to reduce operative time and subsequent complications of prolonged anesthesia and prone positioning. The purpose of this study was to verify the biomechanical effect of OLLPS.Methods: The intact finite element model of L1–S1（Intact） was established based on CT images of a healthy male volunteer. The L4-L5 intervertebral space was selected as the surgical segment. The surgical models were established separately according to the OLIF surgical procedures and the different internal fixations: (1) stand-alone OLIF (SA); (2) OLIF with 2-screw lateral plate (LP-2); (3) OLIF with 4-screw lateral plate (LP-4); (4) OLIF with OLLPS (OLLPS); and (5) OLIF with bilateral pedicle screw fixation (BPS). After validating the intact model, the physiological loading was applied to the superior surface of L1 to simulate flexion, extension, left bending, right bending, left rotation, and right rotation motions. The evaluation indexes included the L4/5 range of motion (ROM), the L4 maximum displacement, and the maximum stress of the superior and inferior endplate, cage, and supplemental fixation.Results: In OLIF surgery, OLLPS provided multiplanar stability which was similar to that of BPS. Compared with LP-2 and LP-4, OLLPS had the better biomechanical properties in enhancing the instant stability of the surgical segment, reducing the stress of the superior and inferior endplates of the surgical segment, and reducing the risk of cage subsidence.Conclsions: With the minimally invasive background, OLLPS can be an alternative to BPS in OLIF and has a better prospect of clinical promotion and application.

A prospective study to evaluate functional results of PHILOS locking plate system in management of proximal humerus fractures in adults

<p class="abstract"><strong>Background:</strong> Various management options are available for management of proximal humerus fractures where PHILOS plating is one of them. But data available in literature on its use and efficacy in management of all types of proximal humerus fractures is still dicey. So, we through our study attempted to grow our knowledge regarding its functional results, complication rates, etc. for use in coming future.</p><p class="abstract"><strong>Methods:</strong> 30 patients with proximal humerus fractures classified on the basis of Neer’s classification were included in study who were operated from 2018 to 2020 at our institute. These patients were operated by PHILOS locking plate system with either delto-pectoral or trans-deltoid approach and they are followed up at regular intervals to assess them clinicoradiologicallly and functionally by Neer’s criteria.<strong></strong></p><p class="abstract"><strong>Results:</strong> In our study we found maximum incidence of these fracture between age group of 40-80 years (66.66%) with male to female ratio of 2:1 with 19 patients having left sided and 11 patients having right sided proximal humerus fracture. Complications were found in 11 patients (36.67%). Functional evaluation was carried out using Neer’s criteria at final follow up which came to excellent results in 3, satisfactory in 18, unsatisfactory in 7 and failure in 2 patients. Average time of fracture union was 12.62 weeks.</p><p class="abstract"><strong>Conclusions:</strong> PHILOS locking plate system serves good purpose in management of fractures of proximal humerus but requires trained faculty to do this operation who has detailed knowledge about shoulder anatomy and mechanism of injury to reduce complications associated with this type of modality.</p>

Medial pantarsal arthrodesis with Compact UniLock 2.0 locking plate system in a cat

Background: Pantarsal arthrodesis is a salvage procedure carried out for the treatment of tarsal joint disease, including severe osteoarthritis with intractable pain in the tarsocrural joint, tarsal fractures, shearing injuries, tarsocrural joint instability, and failure of the common calcaneal tendon. Although medial plating is preferable, the high incidence of post-surgery complications is possible. Using thin, pre-contouring or easy contouring, locking plates might reduce the incidence of such complications. However, to date, there are no pre-contouring and dedicated locking plates forpantarsal arthrodesis with medial placement.Case Description: The case of an 18-month-old female stray European cat has been referred because of a severe tibiotarsal injury improperly treated with an intramedullary pin. The patient was submitted for medial pantarsal arthrodesis, performed with the Compact UniLock 2.0™ locking plate systema (DePuy Synthes, Oberdorf, Switzerland). The authors hypothesized that this particularly innovative osteosynthesis system could present advantages compared to the systems already in use for medial pantarsal arthrodesis and therefore reduce the risk of complications.Conclusion: This innovative titanium locking system, because of its versatile contour function and thinness, allowed the good functional recovery of the limb and showed numerous advantages over traditional systems.

Fixation Stability and Stiffness of Two Implant Systems for Proximal Femoral Varization Osteotomy

Proximal femoral varization osteotomy is a well-established surgical procedure in children with severe hip problems. This study aimed to evaluate the fixation stability and stiffness of two new implant systems. A biomechanical testing model was created with a total of 12 synthetic femora. Proximal femoral varization osteotomy was performed in every femur, and the synthetic femora were fixed with two different implant systems (PediLoc Locking Proximal Femur Plate System versus PediLoc Locking Cannulated Blade Plate System; OrthoPediatrics, Warsaw, IN, USA). The average torsional stiffness of the locking plate group was higher than for the cannulated blade plate group. Differences in internal and external rotations were seen between the two groups, but they were not significant. Using the tested implants in severe osteoporotic bones might show other results. Therefore, it might be helpful to use the locking plate system in osteoporotic bones and in cases of revision operations where stability is of critical focus.

The outcome of first metatarsophalangeal joint arthrodesis using a locking compression plate

ABSTRACT BACKGROUND: Arthrodesis of the first metatarsophalangeal joint (MTPJ) is a common and frequently performed procedure in the practice of orthopaedic foot and ankle surgery. Fusion techniques and preferred surgical implants have significantly evolved during recent years. It is however still under debate which surgical device provides the best outcome. One of the modern techniques described includes the use of a dorsal anatomical locking plate. These plates are usually used in combination with an additional compression cross screw across the arthrodesis site. The aim of this study was to assess the outcome of arthrodesis of the first MTPJ using a dorsal locking plate without making use of additional compression cross screw fixation. METHODS: We retrospectively assessed data at an orthopaedic practice specialising in foot and ankle surgery. All patients who had a first MTPJ arthrodesis with an anatomical locking plate system between 2010 and 2016 were identified. No additional compression cross screw fixation was done in any of these cases. Standard standing dorsoplantar and lateral X-rays of the foot were taken six weeks after surgery. As a primary objective, these radiographs were assessed to determine the rate of radiological union. As a secondary objective, any other complications that occurred in the post-operative period were recorded. RESULTS: We included 115 patients in the study. Fifteen of these patients underwent bilateral first MTPJ arthrodesis surgery, making the total number of feet included in the study 130. Of these, 86% (n=99) were female and 14% (n=16) were male. The mean age at the time of surgery was 54.7 years (range 37-74). An observed radiological union rate of 97% at three months after surgery was recorded. A total of four cases (3%) presented with symptomatic non-union. Two of these were successfully revised and progressed to union before the nine-month follow-up. One patient had bilateral surgery for severe rheumatoid arthritis with poor bone quality. No union was achieved even after a revision procedure with bone grafting. A Keller-type resection arthroplasty was eventually performed in this patient. Another secondary complication that was recorded is an overall infection rate of 2%. CONCLUSION: The results of this retrospective study suggest that high union rates and a low incidence of complications can be expected when fusing the first MTPJ with the use of a locking plate system without the need for an additional compression cross screw Level of evidence: Level 4 Keywords: first metatarsophalangeal joint, fusion, arthrodesis, locking plate, union