Objectives: This study developed a new 6 degree-of-freedom, unconstrained biomechanical model that replicated the in vivo loading environment of femoral fractures. The objective of this study was to determine whether various distal fixation strategies alter failure mechanisms and/or offer mechanical advantages when performing retrograde intramedullary nail (IMN) stabilization of supracondylar femur fractures in osteoporotic bone.
Methods: Forty fresh-frozen human femora were allocated into 2 groups of matched pairs: "locked" (fixed angle locking construct with both distal locking screws rigidly attached to the IMN) versus "unlocked" (conventional locking technique with 2 distal locking screws targeted through the distal locking screw holes of the IMN) and "locked" versus "washer" (fixed angle locking with the most distal screw exchanged for a bolt with condyle washers) distal fixation of a retrograde IM nails. A comminuted fracture (OTA 33-A3) was simulated with a wedge osteotomy. Bone density measurements were completed on all specimens before instrumentation. Instrumented femurs were loaded axially to failure, whereas 6 degree-of-freedom translations and angulations were measured using Roentgen stereophotogrammetric analysis.
Results: Mean (± SD) load born by "locked" specimens (1609 ± 667 N) at clinical failure was 38.1% greater (P = 0.09) than the corresponding mean load born by "unlocked" specimens (1165 ± 772 N). Clinical failure for the "washer" group (1738 ± 772 N) was 29.9% greater (P = 0.07) than the corresponding mean of the "locked" counterparts (1338 ± 822 N). Failure load was most clearly related to bone density in the "unlocked" fixation group.
Conclusions: Predicting failure load based on bone density using a least squares estimate suggests that the washer construct provides superior fixation to other treatment techniques. The failure mechanism for a comminuted, supracondylar fracture cannot be analyzed accurately with a 1-dimensional measurement. The most common failure mechanism in this model was medial translation and varus angulation.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1097/BOT.0b013e31825199c9 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Enteric neuronal substrates underlying spontaneous and evoked neurogenic contractions in mouse colon.
Cell Mol Gastroenterol Hepatol
January 2025
Dept of Physiology & Cell Biology, University of Nevada Reno School of Medicine, Reno, NV. Electronic address:
Background And Aims: Gastrointestinal motility persists when peripheral cholinergic signaling is blocked genetically or pharmacologically, and a recent study suggests nitric oxide drives propagating neurogenic contractions.
Methods: To determine the neuronal substrates that underlie these contractions, we measured contractile-associated movements together with calcium responses of cholinergic or nitrergic myenteric neurons in un-paralyzed ex vivo preparations of whole mouse colon. We chose to look at these two subpopulations because they encompass nearly all myenteric neurons.
Outcome of a Nail-plate Fixation Combination for a Distal Femur Fracture in a 99-year-old Patient.
J Orthop Case Rep
January 2025
Department of Orthopedic Surgery, NYU Langone Health, NYU Langone Orthopedic Hospital, New York, NY.
Introduction: This report describes the use of a combination of a retrograde femoral nail and distal femur locking plate for the treatment of an open intra-articular distal femur fracture in a 99-year-old female. The purpose of this report is to highlight that nail-plate fixation constructs can be performed percutaneously and expeditiously even in extremely old patients; therefore, patient age should not be a limiting factor in choosing this construct to allow for immediate weight-bearing.
Case Report: The patient was a 99-year-old female who presented to the emergency room after a fall.
Minimally Invasive Plate Osteosynthesis Using Locking Plates for Distal Femur Fractures: A Retrospective Analysis of 40 Cases.
J Orthop Case Rep
January 2025
Department of Orthopedics, Sree Balaji Medical College and Hospital, BIHER, Chromepet, Chennai, Tamil Nadu, India.
Introduction: Distal femur fractures present significant surgical challenges due to their complex anatomy and limited soft tissue coverage. Minimally invasive plate osteosynthesis (MIPO) has emerged as a promising alternative to traditional open techniques, aiming to reduce soft-tissue damage while maintaining stable fixation, particularly when used with locking plates.
Materials And Methods: This retrospective study analyzed 40 consecutive patients with distal femur fractures treated with MIPO and locking plates.
Flexor Carpi Ulnaris Surgical Approach to the Volar Ulnar Corner of the Distal Radius.
Tech Hand Up Extrem Surg
January 2025
Department of Orthopaedics, University of Miami, Miller School of Medicine, Miami, FL.
There are many approaches to the wrist both volar and dorsal, depending on the injury at hand. The design of the volar locking plate has created a rise in distal radius fractures being treated using a volar FCR approach and its modifications. It does, however, have limitations in visualization of the volar ulnar corner of the radius.
View Article and Find Full Text PDFFirst metatarsal osteotomy with an intramedullary locking plate is a good alternative for the reintervention of recurrent hallux valgus.
J Foot Ankle Surg
January 2025
Orthopedic Surgery and Traumatology Department, Bellvitge University Hospital, L'Hospitalet de Llobregat, Barcelona, Spain.
This study describes the results of first metatarsal (M1) distal osteotomy with an intramedullary locking plate in persistent/recurrent painful hallux valgus (HV) deformity (without advanced degenerative changes) after primary surgery. Outcomes included postoperative incidences of HV angle (HVA)<16°, intermetatarsal angle (IMA)<9°, proximal articular set angle (PASA)<10°, and the American Orthopedic Foot and Ankle Society (AOFAS) score. Data normality was assessed with the Shapiro-Wilk test, and preoperative vs.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!