Our study revealed that in comparison with cemented hemiarthroplasty, cementless hemiarthroplasty using a long modular stem without reconstruction of femoral calcar can provide satisfactory clinical outcomes and function scores. Besides, the duration of surgery and estimated blood loss were less in cementless group.
For unstable intertrochanteric fractures, the representative treatment is internal fixation including intramedullary fixation (Gamma nail, proximal femoral nail anti-rotation) and plate fixation (dynamic hip screw, dynamic condylar screw). Intertrochanteric fractures mainly occur in the elderly, who often have osteoporosis, comorbidities, poor bone healing and postoperative complications, and these patients have high mortality[23, 24]. Internal fixation is difficult to maintain stable reduction for unstable intertrochanteric fractures in the elderly due to osteoporosis, varus deformity, cut-out, malunion, and metal failure, and patients are recommended to restrict early weight wearing and prolong bed rest, thus resulting in related complications[18]. So bipolar hemiarthroplasty is preferred in elderly intertrochanteric fractures and has advantages of early ambulation due to the immediate stability[8], however, cementation of acrylic cement can cause cardiopulmonary complications[11, 25]. Cementless bipolar hemiarthroplasties can avoid the side effect caused by cement. Several studies have reported the use of cementless stems in elderly intertrochanteric fractures; to gain the initial stability and early ambulation, the long stems have been applicated[9, 10, 13, 17]. To reconstruct the femoral calcar, it will need a surgeon with a wealth of surgical skills, extra expose and cerclage wires for reduction and fixation of the fragment, which will cause more time cost and blood loss, thus increasing the risk for octogenarians. Abdelkhalek et al. reported that the mean operative time was 140 min (range 110–170 min) for unstable intertrochanteric fractures with the femoral calcar reconstruction[26]. Park et al. reported that the mean operative time was 75.3 min (range 50–185 min) for unstable intertrochanteric fractures treated with a rectangular cross-section stem[27]. Kim et al. reported that the mean operative time of cementless calcar-replacement hemiarthroplasty for unstable intertrochanteric fractures is 96 ± 26 min[13]. In our study, the mean operative time without femoral calcar reconstruction was 37.9 ± 4.5 min, which is more less than previous reports. And compared with the cemented group, the mean operative time was less (p < 0.01).
Due to the distal rigid fixation through MPII, patients with cementless stems can achieve initial stability and walk with a crutch at a mean 3.0 ± 0.7 days. Porous-coated stem can induce bone ingrowth and reduce the risk of loosening. Besides, the femur was hand-reamed so no intraoperative femur fractures occurred in our patients. With the proximal components and spacers, the stem can fit the leg length and femoral anteversion better. Given all this, even the femoral calcar was not reestablished, patients with MPII prostheses still achieved enough initial stabilities and satisfactory clinical functions as well as patients with cemented prostheses.
Studies on the bone cement implantation syndrome have been reported. Olsen et al. conducted a retrospective cohort study on 1095 patients with femoral neck fractures treated with cemented hemiarthroplasty (n = 986) and uncemented hemiarthroplasty (n = 109), the incidence of hypoxia and/or hypotension was higher in the cemented group (p = 0.003), the incidence of severe hypotension/hypoxia was 6.9% in the cemented group while no severe hypotension/hypoxia was observed in the uncemented group[28]. Tan et al. retrospectively investigated the on-table, day zero, day one, day seven, and day 30 mortality of 751 femoral neck fracture patients with cemented stems, 7-day and 30-day mortality rates were 2.7% and 6.8%, respectively. Compared with total hip arthroplasty, patients with hemiarthroplasty have a higher 30-day mortality associated with increasing ASA grade (p < 0.01) when adjusted for age, gender, and type of surgery[29]. Duijnisveld et al. reported that 9-year mortality rates did not differ between patients with femoral neck fractures undergoing cemented or uncemented hemiarthroplasties, 9-year revision rates were 3.1% (cemented group) and 5.1% (uncemented group), respectively (p < 0.05)[30]. Fenelon et al. conducted a meta-analysis on the perioperative mortality after cemented or uncemented hemiarthroplasties for displaced femoral neck fractures, 22 studies with a total of 183167 hemiarthroplasties were reviewed, the cemented hemiarthroplasty is associated with an increased mortality rate for the first 48 hours (p < 0.01), and no difference was observed for day seven, day 30 and one-year mortality[31]. To avoid the bone cement implantation syndrome for very elderly patients with intertrochanteric fractures, a long cementless stem is a good choice. Kim et al. have proved the satisfactory mid-term outcomes with 97.3% survival rate for any reason and 99.1% survival rate for femoral stem revision[32]. In our study, compared with cemented group, patients in cementless group showed no significant differences in postoperative ambulatory status, overall mortality and HHS. However, within postoperative 30 days, three patients in cemented group died while no patient died in cementless group. Periprosthetic fractures occurred in two patients within one year after surgery in cementless group, in consistent with the study by Yoon, B. et al., we should pay attention to prevent periprosthetic fractures especially during one-year postoperatively for cementless stems[33]. In our study, the one-year mortality of cemented and uncemented group was 12.9% and 6.1%, respectively (p = 0.048). Our one-year mortality in uncemented group was less than previously reported one-year mortality[13, 18].
This study has several limitations. First, it did not include a large number of patients. However, in this study we only focused on patients aged 80 years or more treated with cemented or uncemented hemiarthroplasty without calcar reconstruction for unstable intertrochanteric fractures, which makes eligible patients less. Second, the follow-up period was relatively short. In fact, a long-term follow-up is barely possible in octogenarians with the mean age of 84.9 years and the overall mortality of 21.5% in our study. And it has limited clinical relevance considering the remaining life expectancy.