在骨模拟模型中，与全螺纹螺钉相比，部分螺纹螺钉在取出时需要更多操作。

Partially Threaded Screws Require More Work During Removal Compared to Fully Threaded Screws in a Bone Simulation Model.

作者信息

Mayers Alexander J, Hayes Daniel, Chaclas Nathan, Vogel Max, Grega Keith, Wheatley Benjamin B, Seeley Mark Alan

机构信息

Geisinger Health System, Danville, PA, USA.

Geisinger Commonwealth SOM, Scranton, PA, USA.

出版信息

J Pediatr Soc North Am. 2024 Jul 17;8:100099. doi: 10.1016/j.jposna.2024.100099. eCollection 2024 Aug.

DOI:10.1016/j.jposna.2024.100099

PMID:40433016

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC12088276/

Abstract

BACKGROUND

Routine slipped capital femoral epiphysis (SCFE) implant removal is controversial. Difficulty with hardware removal is well documented in SCFE patients, however, there is no biomechanical study demonstrating which specific aspect of screw morphology may be responsible for difficult removal. In this study, we compare the removal torques and work energy of fully and partially threaded cannulated SCFE screws from a bone simulation medium.

METHODS

70 mm × 6.5 mm partially (20 mm threads) and fully threaded stainless-steel screws were tested by reversing them from a cured liquid resin medium. Peak torque and total work energy were recorded from a load cell apparatus during each trial. The mean peak torque and total work energy were compared between the partially threaded and fully threaded screw groups using Student's t-test. < .05 was considered statistically significant.

RESULTS

The fully threaded screws ( = 20) had a mean peak torque of 10.59 Nm (standard deviation [SD] = 0.95 Nm), which was statistically significantly lower than the mean peak torque of the partially threaded screws ( = 23), 11.40 Nm (SD = 1.15 Nm) ( = .014). The fully threaded screws ( = 21) had a mean work of 598.7 J (SD = 208.3), which was statistically significantly lower than the mean work of the partially threaded screws ( = 23), 1,737.6 J (SD = 292.4 J) ( < .0001).

CONCLUSIONS

Although our study did not perfectly model the in vivo "stuck screw phenomenon," our data demonstrate that partially threaded screws require more work of removal. Surgeons should consider the use of fully threaded screws if anticipating future hardware removal when selecting implants in the treatment of SCFE.

KEY CONCEPTS

(1)Slipped capital femoral epiphysis hardware removal can be difficult, and construct selection can influence complication rates.(2)Removal torque differences exist between fully and partially threaded screws.(3)Partially threaded screws require greater work energy of removal in comparison to partially threaded screws.

LEVEL OF EVIDENCE

III.

摘要

背景

常规取出股骨头骨骺滑脱（SCFE）植入物存在争议。SCFE患者取出内固定装置存在困难，这已得到充分证明，然而，尚无生物力学研究表明螺钉形态的哪个具体方面可能导致取出困难。在本研究中，我们比较了模拟骨介质中全螺纹和部分螺纹空心SCFE螺钉的取出扭矩和功。

方法

通过将70 mm×6.5 mm的部分螺纹（20 mm螺纹）和全螺纹不锈钢螺钉从固化的液态树脂介质中反向取出进行测试。在每次试验中，通过测力传感器记录峰值扭矩和总功。使用学生t检验比较部分螺纹螺钉组和全螺纹螺钉组的平均峰值扭矩和总功。P < 0.05被认为具有统计学意义。

结果

全螺纹螺钉（n = 20）的平均峰值扭矩为10.59 Nm（标准差[SD] = 0.95 Nm），统计学上显著低于部分螺纹螺钉（n = 23）的平均峰值扭矩11.40 Nm（SD = 1.15 Nm）（P = 0.014）。全螺纹螺钉（n = 21）的平均功为598.7 J（SD = 208.3），统计学上显著低于部分螺纹螺钉（n = 23）的平均功1,737.6 J（SD = 292.4 J）（P < 0.0001）。