Purpose: The purpose of this study was to evaluate the effects of screw position and compaction of the bone tunnel on the strength of the flexor tendon graft after fixation using interference screws.

Methods: Forty fresh-frozen porcine tibias were used for this study. The digital flexor tendons were folded into a quadrupled graft measuring 9 mm in diameter. In the extraction-drilling group, tibial bone tunnels were drilled with a conventional cannulated 9-mm drill bit in a single step. In the compaction-drilling group, bone tunnels were drilled using a cannulated 7-mm drill bit and were expanded to a final diameter of 9 mm in 0.5-mm increments by placement of dilators with increasing diameter. The grafts were fixed using 9 × 30-mm titanium screws in central and eccentric positions. Specimens underwent a cyclic-loading test, and the surviving specimens were then loaded until failure.

Results: Graft displacement after 1,500 loading cycles occurred significantly more often in the extraction-drilling group with eccentric screw placement than in the groups of extraction-drilling (P < .05) and compaction-drilling (P < .01) with central screw placement. There were no statistically significant differences for the maximum screw insertion torque, maximum load at failure, or stiffness among the 4 groups. One strand of the quadrupled tendon grafts showed partial injury during screw insertion in 3 (30%) and 4 (40%) of 10 specimens of the extraction-drilling and compaction-drilling groups with central screw placement, respectively.

Conclusions: Central screw placement significantly decreased the displacement of the tendon graft in comparison with eccentric screw placement in the extraction-drilling condition. Compaction of the bone tunnel walls by serial dilation in a central screw position did not increase the strength of interference screw fixation of a soft tissue graft.

Clinical Relevance: When using the extraction method and fixing the graft in an eccentric position, it is advisable to provide additional fixation outside the tunnel to prevent slippage of the graft.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.arthro.2013.07.263DOI Listing

Publication Analysis

Top Keywords

screw placement
20
screw position
12
tendon graft
12
central screw
12
screw
11
interference screw
8
graft fixation
8
compaction bone
8
bone tunnel
8
extraction-drilling group
8

Similar Publications

Applying a three-dimensional curved lumbar spine model to simulate surgery for training residents in pedicle screw insertion.

Surg Radiol Anat

December 2024

Department of Anatomy, Digital Imaging and 3D Modelling Laboratory, Faculty of Medicine, Ege University, Bornova, 35100, Izmir, Turkey.

Purpose: The challenges of spinal surgery can be overcome by deeply understanding the anatomical and surgical complexities of the region through the use of model simulators. This study investigates the impact of digitally designed simulators, specifically lumbar spinal models with abnormal curvature, on preoperative planning and their effectiveness as training tools. The study addresses challenges in spine surgery, such as unique deformities, classification issues, and associated abdominal structure abnormalities.

View Article and Find Full Text PDF

Introduction Spinal fusion surgery with pedicle screws is commonly performed to stabilize the spine of osteoporotic patients. However, securing a strong screw fixation in osteoporotic bone presents significant challenges due to the reduced bone density. This study aimed to compare the biomechanical performance in an osteoporotic bone model of pedicle screws inserted using two different techniques, the Jamshidi needle technique and the pedicle probe technique, as well as the influence of tapping on both these techniques.

View Article and Find Full Text PDF

Study Design: This is a cross-sectional survey.

Objectives:  This study aimed to evaluate the availability and knowledge of navigation technologies for educational purposes and patient management in spine surgeons in Latin America.

Methods: A cross-sectional study was conducted among Latin American Spine Association members using a comprehensive 16-question survey to evaluate their knowledge and practices regarding navigation in spinal surgery.

View Article and Find Full Text PDF

Objective: To maximize local tumor control, stabilize affected bones, and preserve or replace joints with minimal interventional burden, thereby enhancing quality of life for empowered living.

Indications: Suitable for patients with bone metastases, particularly those with severe pain and/or fractures and appropriate life expectancy.

Contraindications: In primary bone tumors, refer to the sarcoma surgery team for evaluation of wide resection.

View Article and Find Full Text PDF

Immediate Implant Placement in a Hypothyroid Geriatric Patient: Aesthetic Excellence, Secondary Stability, and Successful Outcome-A Case Report.

Plast Aesthet Nurs (Phila)

December 2024

Sowmya Srinivas, BDS, MDS, PhD, is an Assistant Professor at the Department of Prosthodontics, JSS Dental College and Hospital, JSS Academy of Higher Education and Research, Mysore, Karnataka, India.

Placing an implant immediately into extraction sockets provides a distinct advantage over delayed placement, eliminating the need for a 4 to 6 months waiting period for bone formation. However, when patients present with hypothyroidism, the feasibility of immediate placement of dental implants becomes uncertain. This case involved a hypothyroid woman in her late 60s with loose lower anterior teeth.

View Article and Find Full Text PDF

Want 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!