Failure of a Rotation Control Gamma 3 Lag Screw Used to Treat a Trochanteric Fracture

Additional use of anti-rotation U-blade (RC) decreases lag screw sliding and limb length inequality in the treatment of intertrochanteric fractures

The purpose of this study is to compare the cut-out rate and sliding distance associated with limb length inequality between operations using a standard non-sliding lag screw versus those using a non-sliding lag screw with U-blade (RC) in the Gamma3 nail. This is a retrospective review of two case series involving different lag screws for the Gamma3 nail. Propensity score matching analysis was used to adjust the confounding factors. A comparative analysis of 304 patients who treated with Gamma3 nail with either a standard non-sliding lag screw or a U-Blade (RC) lag screw was performed. Between 2014 and 2018, 152 patients were treated with U-blade (RC) lag screws, and these patients were matched with those treated with standard lag screws. There was no significant difference in cut-out rate between groups. However, additional use of anti-rotation U-blade (RC) could significantly decrease lag screw sliding, with the group treated with U-Blade (RC) lag screws exhibiting shorter sliding, especially in AO/OTA31 A2 and A3 fractures. Also, in A2 and A3 fractures, the mean lag screw sliding distance was greater than that seen in A1 fractures in both groups. These findings can help trauma surgeons choose the proper implant to reduce leg length inequality.

Gamma 3 U-Blade lag screws in patients with trochanteric femur fractures: are rotation control lag screws better than others?

Background

Intramedullary hip nails may be classified as blades or screws depending on the type of lag screw used. Recently, a combination of lag screw types with a U-clip insertion has also been used. The purpose of this study was to evaluate the clinical and radiological outcomes of these new screw types.

Methods

A total of 185 patients with trochanteric femoral fractures (age ≥ 65 years) who underwent surgery with intramedullary nails were selected. Surgeries with InterTrochanteric/SubTrochanteric (ITST), Proximal Femoral Nail Antirotation (PFNA), and Gamma 3 U-Blade lag screws were performed between January 2011 and June 2016. The AO/OTA classification, presence of a basicervical fracture type on 3D-CT, BMI, BMD, reduction quality, position of the lag screw, TAD (tip apex distance) of the lag screw, sliding distance of the lag screw, varus change (neck shaft angle), radiological union period, fixation failure and functional outcome as determined by walking ability were analyzed.

Results

There were 3/60 (5.0%) cases of fixation failure in the ITST group, all caused by cut-out; 4/57 (7.0%) in the PFNA II group: 3 caused by cut-through and 1 by metal fracture; 1/68 (1.5%) in the Gamma 3 U-Blade lag screw group (P = 0.301). In each group, the sliding distance of the lag screw showed a significant difference (P = 0.017), whereas significant sliding over 10 mm showed no statistically significant results.

Conclusion

There was only one (1.5%) case of fixation failure in the Gamma 3 U-Blade lag screw group. The sliding distance of the U-Blade was found to be in the middle, between the PFNA II (shorter) and ITST (longer) implants. The new rotational control lag screw seems to be comparable to other screw types.

Clinical Outcomes of U-blade Gamma3 Nails Used to Treat Patients with Trochanteric Fractures: Retrospective Multicenter Study

Purpose

This study was performed to assess the radiologic and clinical results of U-blade Gamma3 nail use for the treatment of trochanteric fractures.

Materials and Methods

Between September 2015 and May 2018, all patients aged 65 years and older who underwent surgery with U-blade Gamma3 nails were analyzed. A total of 129 patients were selected based on having at least six months of follow-up. Image evaluations included bone quality (T-score), fracture classification on plain radiograph (AO/OTA), computed tomography configuration, union period, position of lag screw, anatomical reduction, tip apex distance (TAD), sliding extent of lag screw, change of neck shaft angle, and complications leading to reoperations were analyzed. Functional outcome were assessed using the Koval grade (ambulatory ability) at the final follow-up.

Results

The mean time to union was 19.7 (range, 6-36) weeks. The screw position was centric (93 cases; 72.1%) and anatomical reduction was achieved in 74 cases (57.4%). The mean TAD was 20.3 (range, 12.3-38.1) mm. The mean sliding length of the lag screws was 3.8 (range, 0.1-12.6) mm. The mean change of neck shaft angle was 3.4° (range, 0-12.8°). Reoperations were required in two cases (1.6%) due to the cutting out of the lag screw (n=1) and metal failure with U-blade bending (n=1). Finally, Koval grades for 49.8% of patients reached preoperative status.

Conclusion

Overall, use of the U-blade Gamma3 nail led to favorable clinical results, suggesting that this system may be a good option for the treatment of trochanteric fractures.