Complications associated with open reduction and internal fixation for adult distal humerus fractures: a multicenter retrospective study

Enhanced Long-Term Antibacterial and Osteogenic Properties of Silver-Loaded Titanium Dioxide Nanotube Arrays for Implant Applications

Objective

This study explored constructing silver-loaded titanium dioxide nanotube (TiO2 NT) arrays on titanium surfaces using anodic oxidation combined with ion implantation. We assessed the cytocompatibility, antibacterial properties, and osteogenic potential of these silver-loaded TiO2 NT arrays, along with the underlying mechanisms.

Methods

We utilized anodization to create TiO2 NT arrays and employed ion implantation to load silver ions, categorizing samples into groups NT-Ag-II-L, NT-Ag-II-M, and NT-Ag-II-H based on different Ag ion dosages. Characterization was performed via scanning electron microscopy (SEM). We evaluated cell compatibility and assessed the antimicrobial performance and Ag ion release profiles. The osteogenic ability of the samples was measured, and the effects on ERK5 and osteogenesis-related factors were analyzed. To clarify the role of ERK5 in osteogenesis, we inhibited the ERK5 pathway using BIX02188 and subsequently re-evaluated osteogenic capacity in co-cultured cells.

Results

SEM analysis showed that in the NT-Ag-II-M group, Ag ions exhibited a flake-like distribution atop the TiO2 NTs, while NT-Ag-II-L and NT-Ag-II-H groups presented clustered grid structures. Energy-filtered transmission electron microscopy (EFTEM) confirmed orderly Ag ion arrangements within the lumens of the nanotubes. Notably, the silver-loaded TiO2 NT arrays did not inhibit MC3T3-E1 cell proliferation and enhanced early cellular adhesion. All samples displayed significant antimicrobial activity initially, which decreased after seven days; however, Ag ion release decreased gradually over the first 14 days before stabilizing. Additionally, the samples increased alkaline phosphatase activity, collagen secretion, and extracellular matrix mineralization, up-regulating ERK5 and other osteogenic factors. Inhibition of the ERK5 pathway suppressed the osteogenic capabilities of the samples.

Conclusion

Anodization and ion implantation successfully produced silver-loaded TiO2 NT arrays on titanium surfaces, demonstrating no cytotoxicity, sustained antimicrobial properties, and enhanced osteogenic potential. The antimicrobial effect relates to silver ion release, whereas osteogenesis is promoted by ERK5 signaling triggered by silver ions.

Intraoperative Subperiosteal Elevation of the Ulnar Nerve Is a Safe and Effective Way to Minimize Postoperative Ulnar Neuritis in Distal Humerus Fractures

OBJECTIVES

To describe subperiosteal elevation of the ulnar nerve and compare to anterior transposition and in situ decompression techniques.

METHODS

DESIGN

Retrospective comparative study.

SETTING

Urban Level 1 trauma center.

PATIENT SELECTION CRITERIA

Distal humerus fractures (Orthopaedic Trauma Association/AO 13) treated with open reduction internal fixation between 2014 and 2022.

OUTCOME MEASURES AND COMPARISONS

Rate of preoperative and postoperative neuritis grouped by the management of the ulnar nerve. During subperiosteal elevation, the ulnar nerve was identified and raised off the ulna subperiosteally and mobilized submuscularly anterior to the medial epicondyle to protect the nerve. The nerve was released only laterally off the triceps, and the medial soft tissue attachment is maintained. The main outcome measurements was rate of neuritis documented within physical examination.

RESULTS

Within the 125 patients, 35 underwent subperiosteal elevation (mean age of 56 ± 21 years, 57% female), 63 in situ decompression (mean age of 60 ± 18 years, 46% female), and 27 anterior transposition (mean age of 55 ± 20 years, 59% female). Preoperative ulnar neuritis was present in 34%, 21%, and 33% of patients treated with subperiosteal elevation, in situ decompression, and anterior transposition, respectively ( P = 0.26). At postoperative evaluation, symptom resolution occurred in 100%, 69%, and 33% of patients treated with subperiosteal elevation, in situ decompression, and anterior transposition, respectively ( P = 0.003). New cases of postoperative ulnar neuritis occurred in 6%, 8%, and 26% of patients treated with subperiosteal elevation, in situ decompression, and anterior transposition, respectively ( P = 0.054). Subperiosteal elevation outperformed anterior transposition regarding postoperative ulnar neuritis ( P = 0.019) and symptom resolution ( P = 0.002) and performed similarly to in situ decompression ( P > 0.05). On multiple regression analysis, anterior transposition was an independent risk factor for postoperative neuritis (OR = 5.2, P = 0.023).

CONCLUSIONS

Subperiosteal elevation is an effective way to minimize postoperative neuritis and similar to an in situ decompression during distal humerus fracture fixation. Based on the results of this cohort, authors recommended that anterior transposition of the ulnar nerve be used with caution due to its association with postoperative ulnar neuritis.

LEVEL OF EVIDENCE

Therapeutic, Level III. See Instructions for Authors for a complete description of levels of evidence.

Ulnar Nerve Management in Complex Elbow Dislocations: A Retrospective Monocentric Study

BACKGROUND/OBJECTIVES

The ulnar nerve's unique anatomy makes it vulnerable to complex elbow dislocations. Depending on the nature of the injury, the clinical treatment and outcomes related to the nerve may vary. Unfortunately, the current literature provides limited and fragmented information on managing the ulnar nerve and the incidence of neuropathy in complex elbow dislocations. This study aimed to determine the occurrence of ulnar nerve pain and its relationship with transposition.

METHODS

A retrospective evaluation was conducted on a consecutive series of 44 patients who underwent surgery for complex elbow dislocations. The average follow-up period was 29 months. Patients were categorized based on their condition (trans-olecranon fracture-dislocation, Terrible Triad, Monteggia-like lesions, and injuries not falling into the previous categories). The study assessed whether the ulnar nerve was released from the cubital tunnel and underwent transposition. Additionally, the study examined the number of patients experiencing ulnar pain in the postoperative period and its duration over time. All patients were also evaluated using the Mayo Elbow Performance Score (MEPS), Disabilities of Arm, Shoulder, and Hand (DASH) score, and Oxford Elbow Score (OES).

RESULTS

Patients who underwent simultaneous ulnar nerve transposition surgery with complex elbow dislocation showed a higher incidence of neuropathy. In these patients, the symptoms were less severe but lasted longer. MEPS, DASH, and OES did not show statistically significant differences between the two groups; however, they were slightly better for the group without ulnar nerve transposition.

CONCLUSIONS

Surgeons should refrain from routinely transposing the ulnar nerve in complex elbow dislocations. However, further studies involving larger populations are necessary.

Weak Points of Double-Plate Stabilization Used in the Treatment of Distal Humerus Fracture through Finite Element Analysis

BACKGROUND

Multi-comminuted, intra-articular fractures of the distal humerus still pose a challenge to modern orthopedics due to unsatisfactory treatment results and a high percentage (over 50%) of postoperative complications. When surgical treatment is chosen, such fractures are fixed using two plates with locking screws, which can be used in three spatial configurations: either parallel or one of two perpendicular variants (posterolateral and posteromedial). The evaluation of the fracture healing conditions for these plate configurations is unambiguous. The contradictions between the conclusions of biomechanical studies and clinical observations were the motivation to undertake a more in-depth biomechanical analysis aiming to indicate the weak points of two-plate fracture stabilization.

METHODS

Research was conducted using the finite element method based on an experimentally validated model. Three variants of distal humerus fracture (Y, λ, and H) were fixed using three different plate configurations (parallel, posterolateral, and posteromedial), and they were analyzed under six loading conditions, covering the whole range of flexion in the elbow joint (0-145°). A joint reaction force equal to 150 N was assumed, which corresponds with holding a weight of 1 kg in the hand. The biomechanical conditions of bone union were assessed based on the interfragmentary movement (IFM) and using criteria formulated by Steiner et al. Results: The IFMs were established for particular regions of all of the analyzed types of fracture, with distinction to the normal and tangential components. In general, the tangential component of IFM was greater than normal. A strong influence of the elbow joint's angular position on the IFM was observed, with excessive values occurring for flexion angles greater than 90°. In most cases, the smallest IFM values were obtained for the parallel plaiting, while the greatest values were obtained for the posteromedial plating. Based on IFM values, fracture healing conditions in particular cases (fracture type, plate configuration, loading condition, and fracture gap localization) were classified into one of four groups: optimal bone union (OPT), probable union (PU), probable non-union (PNU), and non-union (NU).

CONCLUSIONS

No plating configuration is able to ensure distal humerus fracture union when the full elbow flexion is allowed while holding a weight of 1 kg in the hand. However, flexion in the range of 0-90° with such loadings is acceptable when using parallel plating, which is a positive finding in the context of the early rehabilitation process. In general, parallel plating ensures better conditions for fracture healing than perpendicular plate configurations, especially the posteromedial version.