Correlation between shape-closed femoral stem design and bone cement implantation syndrome in osteoporotic elderly femoral neck fracture undergoing cemented hip arthroplasty: A retrospective case-control study in 128 patients.

BACKGROUND:Bone cement implantation syndrome (BCIS) is a serious and potentially fatal complication especially in patients with osteoporotic femoral neck fracture (OFNF) undergoing cemented hip arthroplasty (CHA). Recent studies showed that the shape-closed femoral stem profile could lead to a significant increase of the intramedullary pressure during cementation and prosthesis insertion. This study aimed to (1) correlate the use of shaped-closed femoral stem and other perioperative risk factors with severe grade of BCIS grade 2 or 3: BCIS gr2/3, and (2) identify the prevalence of BCIS in the elderly patients with OFNF and treated with CHA. HYPOTHESIS:Large wedge-shaped (or "shape-closed") femoral stem design would significantly associate with BCIS gr2/3 in the elderly patients who sustained OFNF and underwent CHA. PATIENTS AND METHODS:A total of 128 OFNF patients, who aged over 75years and underwent CHA were retrospectively reviewed and then allocated into 2 groups: SC Group (use shape-closed femoral stem, n=40) and FC Group (use force-closed femoral stem, n=88). BCIS was grading in all patients according to Donaldson classification. Perioperative data between the patients with BCIS-gr2/3 and those with BCIS grade 0 or 1 (BCIS-gr0/1) were compared. Multiple logistic regression analysis was used to identify predictive factors for BCIS-gr2/3. RESULTS:The prevalence of overall BCIS and BCIS-gr2/3 was 32.8% (n=42) and 6.2% (n=8), respectively. The total in-hospital and 1-year mortality rates were 2.3% and 4.7%, respectively. The major perioperative complication in patients with BCIS-gr2/3 was significantly higher compared to those in patients with BCIS-gr0/1 (62.5% vs. 10.0%, p=0.001). Multivariate analysis showed that age>90years (OR=9.4, 95% CI: 1.4-62.9, p=0.02), preinjury Parker mobility score<4 (OR=48.8; 95% CI: 2.7-897.2, p=0.008) and shape-closed femoral stem used (OR=19.1; 95% CI: 1.8-204.5, p=0.01) were the significant independent predictors for BCIS-gr2/3 in these patients. CONCLUSION:BCIS in OFNF patients undergoing CHA is common and associates with a high major perioperative complication rate. Our initial hypothesis is validated as the patients at risk for BCIS-gr2/3 are those whose CHA procedures use a shape-closed femoral stem design and with extreme age, and having poor preinjury ambulatory status. Therefore, we recommended using cementless stem as the first option in OFNF. However, if CHA is needed, strict guideline for cement insertion should be followed with force-closed stem application to avoid the risk of BCIS-gr2/3. LEVEL OF EVIDENCE:III; retrospective case-control study.