Key Takeaways & Executive Findings
- •• The correction leverage technique significantly reduced distal locking screw placement time compared to the free-hand technique (t=-4.136, P < 0.001). • The correction leverage technique significantly reduced the number of X-ray exposures (t=-19.696, P < 0.001). • The first-attempt accuracy was 100% in the correction leverage group versus 71% in the free-hand group (χ2=5.253, P < 0.05). • The correction leverage technique offers faster locking, higher accuracy, and lower radiation exposure without requiring additional equipment, making it a promising alternative for distal locking screw placement.
Abstract
BACKGROUND: Interlocking intramedullary nail fixation is the "gold standard" for the treatment of femoral shaft fractures, and the difficulty of distal locking nail implantation has always been a difficult problem to solve. OBJECTIVE: By comparing the clinical effects of correction leverage technique and free-hand locking nail technique, it is further explained whether the correction leverage technique can be fast and accurate. The distal locking screw of femoral intramedullary nail was placed without direct X-ray radiation exposure, thereby solving the problem of difficult distal locking screw placement. METHODS: A total of 52 patients with femoral shaft fractures who had difficulty in distal locking screw placement during interlocking intramedullary nail fixation were enrolled from the Department of Orthopedics and Traumatology, Affiliated Traditional Chinese Medicine Hospital of Southwest Medical University from July 2022 to September 2024. They were divided into two groups according to the placement protocol: correction leverage group (26 cases) used the correction leverage technique for distal locking screw placement, and free-hand group (26 cases) used the traditional free-hand technique. The distal locking screw placement time, number of X-ray exposures, and first-attempt accuracy were compared between the two groups. RESULTS AND CONCLUSION: (1) The distal locking screw placement time in the correction leverage group was significantly shorter than that in the free-hand group (t=-4.136, P < 0.001). (2) The number of X-ray exposures in the correction leverage group was less than that in the free-hand group (t=-19.696, P < 0.001). (3) The first-attempt accuracy in the correction leverage group (100%) was higher than that in the free-hand group (71%), with a significant difference (χ2=5.253, P < 0.05). (4) These results indicate that compared with simple free-hand screw placement, the correction leverage technique has the advantages of faster locking, higher accuracy, and lower X-ray radiation. This technique does not require auxiliary equipment and has strong operability, and is worthy of further clinical validation and promotion for interlocking intramedullary nail fixation of femoral shaft fractures.
1. Introduction
Femoral shaft fractures, commonly resulting from high-energy trauma such as traffic accidents in young males and low-energy falls in osteoporotic elderly patients, represent a significant clinical challenge. Interlocking intramedullary nailing has become the gold standard for treating these fractures due to its mechanical stability from central fixation and its minimally invasive insertion that preserves periosteal blood supply, thereby reducing nonunion rates and facilitating early weight-bearing rehabilitation. However, distal locking screw placement remains a critical technical hurdle, with reported first-attempt success rates as low as 76.92%.
Existing solutions have notable limitations. The free-hand technique, while avoiding alignment guide errors, relies heavily on C-arm fluoroscopy, increasing radiation exposure for both patients and surgical staff and prolonging operative time by approximately 30%. Alternatively, the open-window method with an enlarged incision allows direct visualization of the locking hole but at the cost of increased soft tissue damage, elevating infection and secondary trauma risks. These drawbacks not only extend anesthesia time and increase blood loss but may also compromise screw purchase due to repeated drilling, ultimately affecting functional outcomes.
To address these issues, we introduce the correction leverage technique. When fluoroscopy reveals that the compression rod has deviated, indicating impending failure of distal locking, the rod is temporarily retained in the medullary canal to maintain its position. A new drill hole is then created adjacent to the original rod hole, and the rod is reinserted to guide the locking screw accurately. This innovative approach eliminates the need for complete rod removal and allows precise screw placement. Preliminary model bone experiments have demonstrated that this technique reduces X-ray exposure by over 50% and shortens locking time by 40%, with 100% accuracy. This study aims to compare the clinical outcomes of the correction leverage technique versus the free-hand technique, further validating its efficacy in achieving rapid, accurate, and radiation-free distal locking screw placement.
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HE Zhiyu, WAN Zhihong, HUANG Yu, LIU Anming, WU Jiaqi, WANG Guoyou, ZHANG Lei, CHEN Xiaojun (2026). Application of correction leverage technique in primary failure of distal locking screw during antegrade femoral intramedullary nailing. Chinese Journal of Tissue Engineering Research. https://doi.org/10.12307/2026.21408
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Frequently Asked Questions
What is the correction leverage technique for distal locking screw placement?
The correction leverage technique is a novel method used when the initial distal locking screw placement fails during femoral intramedullary nailing. It involves retaining the compression rod in the medullary canal to maintain its position, drilling a new hole adjacent to the original rod hole, and then reinserting the rod to guide the screw accurately, thereby avoiding complete removal and reducing radiation exposure.
How does the correction leverage technique compare to the free-hand technique in terms of operative time?
In a comparative study, the correction leverage technique significantly reduced distal locking screw placement time compared to the free-hand technique (t=-4.136, P < 0.001), indicating faster screw placement.
Does the correction leverage technique reduce radiation exposure?
Yes, the correction leverage technique significantly reduced the number of X-ray exposures compared to the free-hand technique (t=-19.696, P < 0.001), thereby lowering radiation exposure for both patients and surgical staff.
What is the first-attempt accuracy of the correction leverage technique?
The first-attempt accuracy of the correction leverage technique was 100% in the study, compared to 71% for the free-hand technique, with a statistically significant difference (χ2=5.253, P < 0.05).
Is the correction leverage technique easy to adopt in clinical practice?
Yes, the correction leverage technique does not require additional equipment and is highly operable, making it a promising technique for clinical adoption after further validation.
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