Detection of Intra-Articular Screw Penetration of Proximal Humerus Fractures: Is Postoperative Computed Tomography the Necessary Imaging Modality?

Detection of intra-articular implant penetration of the canine stifle with radiography: A cadaveric study

OBJECTIVE

To determine if intra-articular implant penetration (IAIP) could be detected with radiography when implants were placed at predetermined positions within the canine stifle.

STUDY DESIGN

Experimental cadaveric study.

SAMPLE POPULATION

Five skeletally mature canine cadavers.

METHODS

Periarticular implants (3.5 mm stainless steel cortical screws) were placed in the proximomedial tibia and directed toward either the medial or lateral tibial condyle to a predetermined distance from the joint surface: -2 mm (below the joint surface), 0 mm (at the level of the subchondral bone), and 2 mm (above the joint surface). Joint examination was performed to confirm IAIP. Standard orthogonal radiographic views of the stifle were obtained. Radiographs were reviewed by registered small animal surgery and radiology specialists, residents, and board-eligible residents via an online survey.

RESULTS

Overall, 32.4% of radiographs were incorrectly classified as penetrating the joint surface. Implants directed toward the lateral tibial condyle were misclassified more frequently than those directed toward the medial tibial condyle (23.8% vs. 8.3%, respectively). The overall accuracy of detecting IAIP of the stifle with radiography was 77.9% with a sensitivity and specificity of 97.2% and 67.6%, respectively.

CONCLUSION

Approximately 32% of non-penetrating implants were incorrectly identified as penetrating the joint, particularly those directed laterally. The overall accuracy of radiography for the detection of IAIP of the stifle was 78%.

CLINICAL SIGNIFICANCE

While radiography can be effective in detecting IAIP, there is a significant rate of misclassification, especially for non-penetrating implants, which may lead to unnecessary interventions.

The Clinical and Radiological Outcomes and Complications of Bilboquet Implant for Proximal Humerus Fractures: A Systematic Review

Background/Objectives: There is no consensus in the literature regarding the optimal treatment for complex proximal humerus fractures (PHFs). The aim of this study is to evaluate the clinical, functional, and radiological outcomes, and complications, associated with the Bilboquet implant in the treatment of PHFs. Methods: The search was conducted from the first description of the Bilboquet device in 1994 to June 2024, across PubMed, Web of Science, and Google Scholar, using specific keywords such as ("Bilboquet" OR "Bilboquet prosthesis" OR "Bilboquet device") AND ("proximal humerus fracture" OR "shoulder fracture"), along with Boolean operators. The inclusion criteria comprised studies published in English or French that focused on the use of the Bilboquet implant for PHFs. Eligible study designs included case series, cohort studies, randomized controlled trials (RCTs), and non-RCTs evaluating clinical, functional, and radiological outcomes, and complications. Studies that do not contain relevant results to this systematic review, pediatric populations, or the use of alternative implants were excluded. Results: A total of eight studies (235 patients) published between 1996 and 2021 were included. The mean age was 68.6 years (56 to 76.8) in all the studies. The majority of patients, 76.2%, were females, with male patients accounting for only 23.8%. A total of 10 (4.3%) patients had 2-part fractures, 40% of patients had 3-part fractures, and 55.7% of patients had 4-part fractures. The mean follow-up was 36.4 months (25.8-88.7), with a mean constant score of 69.7 (62-78.6). Complications included non-union in 2.65% of cases, avascular necrosis in 19.7%, revision surgery in 5.1%, and protrusion of the staple in 4.3%. Conclusions: Despite limited knowledge of the Bilboquet implant, it shows promise in managing complex PHFs in both young and older adults, with favorable clinical and radiological outcomes. It offers advantages over traditional fixation methods and allows easy conversion to arthroplasty if osteonecrosis occurs. However, the long-term outcomes require further study. While early results are promising, larger randomized studies are needed to confirm its broader clinical utility.

Pre-operative virtual three-dimensional planning for proximal humerus fractures: A proof-of-concept study

Purpose

To (1) evaluate surgeon agreement on plating features (position and screw length) in virtual 3D planning software, (2) describe outcomes (fracture reduction, plate position, malpositioning of calcar screws and screw lengths) of plate fixations planned with routine pre-operative assessment (2D- and 3D CT imaging) and those planned with dedicated virtual 3D software of the same proximal humerus fracture.

Methods

Fourteen proximal humerus fractures were retrospectively reduced and fixed with virtual planning software by eight attending orthopaedic surgeons and compared to the true surgical fixation with post-operative computed tomography (CT) scans. Reduction differences were quantified using CT micromotion analysis.

Results

Intraclass correlation for screw lengths was 0.97 (95% CI: 0.96-0.98) and 0.90 (95% CI: 0.79-0.96) for plate position. Mean difference in total fracture rotation of the head between the virtual and conventional group was 22.0°. Plate position in the virtual planning group was 3.2 mm more proximal. There were no differences in inferomedial quadrant calcar screw positioning and, apart from the superior posterior converging screw, no significant differences in screw lengths.

Conclusion

Reproducibility on plate position and screw length with virtual planning software is adequate. Apart from fracture reduction, virtual planning yielded similar plate positions, screw malpositioning rates and lengths compared to routine pre-operative assessment.

Accuracy of detecting burst of the lateral wall in intertrochanteric hip fractures with plain radiographs: Is postoperative CT necessary?

Background

Postoperative burst of the lateral femoral wall is thought to be the main predictor of reoperation for intertrochanteric fractures, which is routinely evaluated using plain radiographs. We retrospectively compared computed tomography (CT) scans and radiographs regarding the ability to detect burst of the lateral wall. We also investigated whether intramedullary nails may cause iatrogenic burst of the lateral wall.

Methods

From January 2010 to December 2021, patients aged 65 years and older who undergone intertrochanteric fractures treated with the proximal femoral nail antirotation 2 (PFNA-Ⅱ) were included. The incidence of burst of the lateral wall was evaluated with two different imaging modalities by two observers. Two rounds of evaluation were performed: (1) with plain radiographs alone; and (2) with CT scans combined with radiographs. Interobserver and intraobserver agreement (κ value) for evaluation of the lateral wall burst was assessed.

Results

A total of 1507 patients were included (362 males and 1145 females). Compared with radiographs alone (12.0 %, 181/1507 patients), a higher rate of lateral wall burst was found by CT scans combined with radiographs (72.9 %, 1098/1507 patients) for observer 1 at first reading (P < 0.001). Similar results were seen in other evaluations. Interobserver and intraobserver agreement was substantial for radiographs alone (κ, 0.659-0.727) and almost perfect for CT scans combined with radiographs (κ, 0.847-0.926).

Conclusions

Computed tomography combined with radiographs is superior to radiographs alone for detecting burst of the lateral wall after intertrochanteric fracture fixation. Additionally, PFNA-Ⅱ could cause iatrogenic burst of the lateral wall for intertrochanteric fractures in the elderly.

Periarticular screws: what's in and what's out of the joint?

Periarticular hardware placement can be challenging and a source of angst for orthopaedic surgeons due to fear of penetrating the articular surface and causing undue harm to the joint. In recent years, many surgeons have turned to computed tomography (CT) and other intraoperative or postoperative modalities to determine whether hardware is truly extraarticular in areas of complex anatomy. Yet, these adjuncts are expensive, time consuming, and often unnecessary given the advancement in understanding of intraoperative fluoroscopy. We present a review article with the goal of empowering surgeons to leave the operating room, with fluoroscopy alone, assured that all hardware is beneath the articular surface that is being worked on. By understanding a simple concept, surgeons can extrapolate the information in this article to any joint and bony surface in the body. While targeted at both residents and surgeons who may not have completed a trauma fellowship, this review can benefit all orthopaedic surgeons alike.

[Research progress on intra-articular screw penetration in proximal humeral fracture treated with locking plate]

Objective

To review the research progress on intra-articular screw penetration in proximal humeral fracture treated with locking plate.

Methods

The domestic and foreign literature about the proximal humeral fracture treated with locking plate was extensively reviewed. The incidence of screw penetration and risk factors were summarized from both primary and secondary screw penetrations, and the reasons of the intra-articular screw penetration and the technical solutions to avoid the penetration were analyzed.

Results

The incidence of intra-articular screw penetration is about 11%-30%, which includes primary and secondary screw penetrations. The primary screw penetration is related to improper operation, inaccurate measurement, and "Steinmetz solid" effect, which results in inadequate fluoroscopy and blind zone. The secondary screw penetration is related to the loss of reduction and varus, collapse, and necrosis of the humeral head. The risk factors for intra-articular screw penetration include the bone mass density, the fracture type, the quality of fracture reduction, the applied location, number, and length of the plate and screws, and whether medial column buttress is restored. Improved fracture reduction, understanding the geometric distribution of screws, good intraoperative fluoroscopy, and reconstruction of medial column buttress stability are the key points for success.

Conclusion

The risk of the intra-articular screw penetration in the proximal humeral fractures treated with locking plates is still high. Follow-up studies need to further clarify the cause and mechanism of screw penetration, and the risk factors that lead to screw penetration, in order to effectively prevent the occurrence of this complication.