Extension-Block Pinning for Unstable Dorsal Proximal Interphalangeal Joint Fracture-Dislocations: A Simple, Percutaneous Technique With Reproducible Outcomes

Background: Proximal interphalangeal (PIP) joint fracture-dislocations can be technically challenging injuries to treat, and no technique has proven to be superior nor lead to predictably good outcomes. We describe our experience of treating unstable dorsal fracture-dislocations of the PIP joint with extension-block pinning (EBP) at our institution over a 22-year period. Methods: In all, 23 patients with 24 unstable dorsal fracture-dislocations of the PIP joint treated with EBP between January 1998 and October 2020 were identified. All patients underwent closed reduction of the PIP joint and insertion of a Kirschner wire into the proximal phalanx, creating a mechanical block. Range of motion and joint congruity were assessed at final clinic follow-up. Long-term function was assessed via completion of a Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) questionnaire. Spearman’s correlation coefficient was utilized to assess if any association existed between treatment delay, pin-in-body days, or amount of articular surface involved and QuickDASH score. Results: Mean range of motion at final follow-up was 83.3° and 22 of 24 PIP joints demonstrated a congruent reduction. In all, 15 of the 23 patients completed the QuickDASH questionnaire at a median long-term follow-up of 57.5 months (range: 3-157 months). Average QuickDASH score was 18.8, indicating minimal long-term disability. No statistically significant associations were found between treatment delay, pin-in-body days, or amount of articular surface involved and QuickDASH score. Conclusions: EBP offers a simple and innovative method to treat a complex injury of the PIP joint. It is technically straightforward and cheap, and produces excellent functional outcomes with minimal long-term disability.

A biomechanical analysis of anterior cervical discectomy and fusion alone or combined cervical fixations in treating compression-extension injury with unilateral facet joint fracture: a finite element study

Background Compression-extension injury with unilateral facet joint fracture is one of the most devastating injuries of subaxial cervical spine. However, it is not yet clear which fixation technique represents the optimal choice in surgical management. This study aims to assess the construct stability at the operative level (C4/C5 cervical spine) following anterior cervical discectomy and fusion (ACDF) alone and combined fixation techniques (posterior-anterior fixations). Methods A previously validated three-dimensional C2-T1 finite element model were modified to simulate surgical procedures via the anterior-only approach (ACDF) and combined cervical approach [(transarticular screw, lateral mass screw, unilateral pedicle screw, bilateral pedicle screw) + ACDF, respectively] for treating compression-extension injury with unilateral facet joint fracture at C4/C5 level. Construct stability (range of rotation, axial compression displacement and anterior shear displacement) at the operative level was comparatively analyzed. Results In comparison with combined fixation techniques, a wider range of motion and a higher maximum von Mises stress was found in single ACDF. There was no obvious difference in range of motion among transarticular screw and other posterior fixations in the presence of anterior fixation. In addition, the screws inserted by transarticular screw technique had high stress concentration at the middle part of the screw but much less than 500 MPa under different conditions. Furthermore, the variability of von Mises stress in the transarticular screw fixation device was significantly lower than ACDF but no obvious difference compared with other posterior fixations. Conclusions Of the five fixation techniques, ACDF has proven poor stability and high structural stress. Compared with lateral and pedicle screw, transarticular screw technique was not worse biomechanically and less technically demanding to acquire in clinical practice. Therefore, our study suggested that combined fixation technique (transarticular screw + ACDF) would be a reasonable treatment option to acquire an immediate stabilization in the management of compression-extension injury with unilateral facet joint fracture. However, clinical aspects must also be regarded when choosing a reconstruction method for a specific patient.

Investigation of ultrasonically welded thermoplastic composite joints using netlike energy directors

This paper proposes a netlike energy director (ED) made of carbon fiber-reinforced thermoplastic (CFRP) composites to improve the ultrasonic welding energy efficiency. To explore the benefits of using netlike EDs, the joint qualities with flat EDs and without EDs are included for references. Also, the influence of the netlike ED geometry (i.e., hexagonal nets with different side lengths and thicknesses) on weld attributes and joint quality are investigated in terms of joint cross-sectional microstructure, fracture morphology, and maximum shear load. It is found that for both the netlike and flat EDs, the welding process can be accelerated compared to the one without EDs, which is caused by the concentration of welding energy into the expected welding region and the avoidance of welding edges introduced by surface curvature. Meanwhile, compared with flat EDs, the maximum shear loads of the joints with netlike EDs are improved, introduced by the decrease of the contact area and consequent higher cyclic strain, resulting in more melted materials during the ultrasonic welding process. However, with the increasing of the netlike ED thickness, more porosities are generated in the welding layer leading to reduced bonded region and decrease of the maximum shear load. From the joint fracture morphology analysis, it is found that the netlike EDs introduces carbon fibers in the welding layer, and the fracture modes include fiber-matrix debonding and fiber pull-out in addition to polymer fracture, confirming the feasibility of improving joint quality by introducing CFRP netlike EDs.

An Uncommon Presentation of Fracture-dislocation of the 4th and 5th Carpometacarpal Joints with Volar Displacement and its Management

Introduction: Carpo-metacarpal joint fracture-dislocations are rare injuries. They constitute less than 1% of all hand injuries [1]. They often go unnoticed [2]. Of these, dorsal fracture-dislocations on the ulnar side are more commonly seen [3] because of the greater stabilizing dorsal structures. Volar fracture-dislocations are very rare and difficult to diagnose for which, one should have a keen eye on. Case Report: This is a case of a 51-year-old female with a closed injury to her wrist. With clinical suspicion and appropriate radiographs fracture-dislocation of the 4th and 5th carpometacarpal joints with volar displacement was diagnosed. She underwent closed reduction and percutaneous Kirschner wire fixation, followed by 6 weeks of immobilization. At the final follow-up in 4 months, the patient was noted to have a satisfactory outcome following intense physiotherapy. Conclusion: Fourth and fifth carpometacarpal joint fracture-dislocations of the fingers are unique; their diagnosis can be challenging and often overlooked [4], which if missed can have very poor outcomes. The functional prognosis depends on the precocity of diagnosis and appropriate reduction and vigorous rehabilitation. Keywords: Carpometacarpal joint, fracture-dislocation, volar displacement, wrist injury.

New Technique for Custom-Made Spacers in Septic Two-Stage Revision of Total Hip Arthroplasties

The choice of spacer in the interim phase of two-stage revision hip arthroplasty is crucial. Conventional concepts like a Girdlestone situation, handformed or preformed bone cement spacers show complications like soft-tissue contractions, abrasion of bone cement particles, dislocation, breakage and a low level of mobility in the interim phase. To address these disadvantages, the senior author developed a new technique for custom-made spacers in septic two-stage revision of total hip arthroplasties using prosthetic implants with individualized antibiotic mixture in the cement applying a mechanical inferior cementation method. The aim of this study was to evaluate the results of these spacers with respect to their non-inferiority in terms of reinfection and survival-rate of the new implant and to describe the complications associated with this procedure. Our collective consisted of 130 patients with a median follow-up of nearly five years. With a reinfect-free rate of 92% and a spacer-related complication rate of 10% (8% articular dislocation, 1% periprosthetic joint fracture, 1% breakage), this procedure seems to be safe and superior regarding complications compared to conventional concepts. Further studies are necessary to show the clinical benefit of this procedure.