Seventeen studies (n=2,099) met the inclusion criteria: 14 RCTs and three non-randomised studies.
Patients who underwent minimally invasive surgery were significantly more likely to be transfused compared to those who received sliding hip screws hip fracture surgery (RR 0.63, 95% CI 0.41 to 0.96; seven RCTs). This was also the case for studies that used extramedullary plates (RR 0.29, 95% CI 0.13 to 0.62; one RCT) and external fixator devices (RR 0.05, 95% CI 0.01 to 0.25; two RCTs). The relative risk ratio for intramedullary devices was not statistically significant (four RCTs). There was no statistically significant difference in the 12-month mortality with minimally invasive surgery compared to standard sliding hip screw fracture surgery (RR 0.99, 95% CI 0.82 to 1.2; 11 RCTs) or failure of fracture fixation. Studies were not pooled for the remaining outcomes.
The drop in haemoglobin was significantly less in the minimally invasive surgery group than in sliding hip screws (in four of six studies). The six studies that reported average intraoperative blood loss found a significantly decreased blood loss with minimally invasive surgery compared with sliding hip screws. In three of five studies there was significantly less pain in the minimally invasive group. In eight of nine studies there was no between group difference in length of hospital stay. The results for surgery time were mixed across studies: eight of sixteen studies reported a significantly shorter surgery time with minimally invasive surgery, four shorter surgery time with sliding hip screws, and four reported no statistical significant difference.
The most severe intraoperative complications involved fractures on the greater trochanter or femoral shaft with insertion of the nail which were reported in the intramedullary device studies.