Application of a self-designed pre-positioned 3D honeycomb guide device in internal fixation with percutaneous cannulated screws for treatment of femoral neck fractures

Feng GAO; Feng XU; Zifei YIN; Pingkang QIAN; Chen KUANG; Quan YANG; Xiaofeng WU

ABSTRACT

Objective:

To evaluate our self-designed pre-positioned 3D honeycomb guide device in the internal fixation with percutaneous cannulated screws for femoral neck fractures.

Methods:

A retrospective study was conducted to analyze the data of 60 patients with femoral neck fracture who had been treated with cannulated screw fixation at Department of Orthopaedics, Kunshan Hospital of Traditional Chinese Medicine Affiliated to Nanjing University of Traditional Chinese Medicine from June 2019 to June 2022. According to the difference in intraoperative positioning for placement of cannulated screws, the patients were divided into a study group of 30 cases whose placement of cannulated screws was assisted by our self-designed pre-positioned 3D honeycomb guide device, and a control group of 30 cases whose cannulated screws were positioned freehand. In the study group, there were 17 males and 13 females with an age of (44.9±9.2) years, and 2 cases of type Ⅱ, 18 cases of type Ⅲ, and 10 cases of type Ⅳ by the Garden classification. In the control group, there were 11 males and 19 females with an age of (43.5±7.9) years), and 1 case of type Ⅱ, 16 cases of type Ⅲ, and 13 cases of type Ⅳ by the Garden classification. Closed reduction and inverted triangle internal fixation with 3 cannulated screws were conducted for all fractures. The Garden crossline index, operation time, fluoroscopy frequency, needle drillings, fracture healing time, and Harris hip functional score at the last follow-up were compared between the 2 groups. The postoperative imaging indicators in the 2 groups were measured, including screw spacing, distance from screw to neck cortex, screw coverage area, parallel deviation between screws, and deviation from screw to neck axis.

Results:

There were no statistically significant differences in the baseline characteristics between the 2 groups, indicating comparability ( P>0.05). All patients were followed up for (14.4±1.9) months after surgery. In the study group, operation time [(33.1±5.5) min], fluoroscopy frequency [(13.7±2.2) times], needle drillings [(3.7±0.6) times], distance from screw to neck cortex [(12.4±2.8) mm], parallel deviation between screws in the anteroposterior view (2.2°±1.1°), parallel deviation between screws in the lateral view (2.4°±1.0°), deviation from screw to neck axis in the anteroposterior view (4.0°±0.9°) and deviation from screw to neck axis in the lateral view (3.2°±0.8°) were all significantly smaller than those in the control group [(46.5±8.6) min, (23.1±5.2) times, (11.0±2.2) times, (19.0±3.3) mm, 6.5°±2.6°, 7.1°±2.9°, 7.7°±2.6°, and 9.2°±3.1°] (all P<0.05). The screw spacing [(45.7±5.8) mm] and screw coverage area [(74.1±10.9) mm 2] in the study group were both significantly larger than those in the control group [(31.3±7.7) mm and (55.5±9.0) mm 2] ( P<0.05). There was no statistically significant difference between the 2 groups in Garden crossline index, fracture healing time, follow-up time, or Harris hip functional score at the last follow-up ( P>0.05). Follow-ups revealed 1 case of bone non-union in the study group and 2 cases of bone non-union and screw withdrawal in the control group, but no such complications as infection, deep vein thrombosis, screw penetration or rupture, or femoral head necrosis in either group.

Conclusion:

In the internal fixation with percutaneous cannulated screws for the treatment of femoral neck fractures, our self-designed pre-positioned 3D honeycomb guide device can shorten surgical time, significantly reduce fluoroscopy frequency and needle drillings, and effectively improve accuracy of screw placement.