A new fixation device called DePuy Synthes Femoral Neck System (FNS) offers a safe substitute to cannulated compression screw (CCS), with similar rates of complications for femoral neck fractures that are more stable and less displaced, according to a Singapore study.
Likewise, FNS appears to be a safer option compared with dynamic hip screw (DHS) in the fixation of femoral neck fractures for the few patients with high-energy conditions. However, “this observation warrants further studies with a larger sample size for a meaningful conclusion to be drawn,” said lead study author Dr Zhe Zheng Lim, Department of Orthopaedic Surgery, Tan Tock Seng Hospital, Singapore.
Lim and colleagues conducted this dual-centre retrospective cohort study on femoral neck fractures (AO type 31-B) treated with closed reduction and internal fixation using FNS, DHS, or CCS between April 2016 and April 2020. Eighty-five patients were included in the analysis (FNS: n=28, DHS: n=29, and CCS: n=28).
Those aged <16 years, with chronic fractures beyond 7 days, pathological fractures, fracture extending to the intertrochanteric region or ipsilateral neck and shaft fractures, and neck fractures were excluded.
Both the FNS and CCS groups had a lower Garden and Pauwels classification than the DHS group (p<0.001 for both). [Singapore Med J 2026;67:620-627]
The median duration of operation was significantly shorter with FNS than with DHS and CCS (60 vs 115 and 70 min, respectively; p<0.001). Post hoc analysis revealed a significant difference between the FNS and DHS groups (adjusted p<0.001).
Furthermore, the FNS group had lower intraoperative blood loss than the DHS and CCS groups (proportion of patients losing <50 mL of blood: 75 percent vs 13.8 percent and 39.3 percent, respectively; p<0.001).
“This was likely due to the smaller footprint and a streamlined surgical procedure with the use of a single central guide wire,” Lim said. “However, there is a lack of consensus on the operation characteristics.”
Postoperative complications
Three (10.7 percent) patients in the FNS group had postoperative orthopaedic complications compared with just one (3.6 percent) in the CCS group (adjusted p=0.321). Moreover, such complications occurred more frequently in the DHS vs FNS group, but this did not reach statistical significance (27.6 percent vs 10.7 percent; adjusted p=0.321).
Two patients who received FNS had avascular necrosis (AVN), of whom one was complicated by implant migration and underwent implant removal and left hip hemiarthroplasty. The other one was still awaiting follow-up for further management at the time of writing, according to Lim and colleagues.
Notably, no significant differences were observed in median time to radiological union or median femoral neck shortening at union (p>0.05 for both) across the three groups.
“The choice of FNS or CCS did not have any effect on time to radiological union, as fracture healing should be independent of the fixation device,” Lim said.
“The simple instrumentation process of FNS reduced surgical time and blood loss compared to CCS,” according to Lim and colleagues. “Therefore, we recommend that FNS be considered for fixation of femoral neck fractures.”
According to DePuy Synthes, FNS had up to two times stronger construct than CCS and 40-percent more rotational stability than DHS, while maintaining the benefits of a smaller incision, lower blood loss, and greater ease of insertion due to a smaller footprint and an efficient surgical procedure. [https://www.jnjmedtech.com/libraries/pdf.js/web/viewer.html?file=/system/files/pdf/100509-220913%20FNS%20Value%20Brief%20Final.pdf#pagemode=none]