Mini-invasive nail versus DHS to fix pertrochanteric fractures: a case-control study

Abstract

Background: Fixation devices to treat trochanteric fractures belong to two general categories: dynamic hip screw (DHS) type and intramedullary type implants. In spite of possible pitfalls, both are considered valid options. Comparing a sliding screw-plate system (DHS) along a mini-invasive nailing device (BCM nail) with primary insertion of the cephalic screw, sheds light on the debated management of trochanteric fractures.

Hypothesis: Due to its design, the BCM nailing system allows a stable internal fixation and promotes enhanced postoperative functional recovery.

Objectives: To test this hypothesis in a comparative prospective case-control study using the DHS screw-plate as a reference.

Materials and methods: Two groups of 30 patients, older than 60 years old, with trochanteric fractures were included in this study. The screw-plates were placed according to the standard method. Regarding the nailing system, the cephalic screw was positioned first, then the nail was inserted through the screw via a mini-invasive approach and locked distally using a bicortical screw. Comparison between the two groups was based on (1) operative data: operating time, intra- and postoperative blood loss; (2) immediate postoperative course: complications, length of hospital stay, delay to sitting in a wheelchair; (3) the postdischarge evolution: weightbearing, readmission to hospital; (4) functional outcomes: recovery and mobility; (5) anatomical outcomes: restitution and bone healing.

Results: The operating time (54+/-8.8 min vs 59+/-13.8 min) and intraoperative (1.37+/-0.98 vs 1.90+/-1.43) and at Day 3 (1.25+/-1.05 vs 1.82+/-1.5) blood loss (haemoglobin loss), were favourable to the screw-plate subgroup (p<0.05). The delay to sitting in a wheelchair (4.76+/-1.53 d vs 4+/-1.44 d) was favourable to the nail subgroup (p<0.05). There was a higher incidence of secondary displacements in the screw-plate subgroup (3/26 [11.5%] vs 0/25 [0%]) (p<0.05). The screw-plate subgroup demonstrated a poorer healing rate at 3 months (88% vs 100%) (p<0.05). Regarding functional recovery, a lesser decrease in the Parker score was observed in the nail subgroup at 3 postoperative months (2.42+/-2.3 vs 1.52+/-1.44) (p<0.05).

Conclusion: This study has shown the benefits of the BCM nail in terms of stability. But the potential advantages of this mini-invasive technique were limited by ancillary-related difficulties which need to be rectified. These preliminary results are in favour of a further development of this innovating device.