Osteoporotic Hip Fracture Incidence Rates in the Main Urban Area of Romania

Predictors of mortality for patients with hip fracture: a study of the nationwide 1-year records of 24,950 fractures in Romania

We conducted a study evaluating incidence rates and influencing factors in Romanian hip fracture patients. Our results showed that the type of fracture and its respective surgical procedure as well as hospital characteristics correlate with mortality. Updated incidences can result in updated treatment guidelines.

PURPOSE

The aim of our study was to assess incidence rates for a revision-calibration of the Romanian FRAX tool and to evaluate particularities of hip fracture cases to determine patient- and hospital-related variables affecting mortality.

METHODS

We conducted a retrospective study using hospital reports of hip fracture codes to the National School of Statistics (NSS) from January 1, 2019, until December 31, 2019. The study population included 24,950 patients presenting to Romanian public hospitals in all 41 counties: ≥ the age of 40 with diagnostic ICD 10 codes: S72.0 femoral neck fracture, S72.1 pertrochanteric femoral fracture, and S72.2 subtrochanteric femoral fracture and procedure codes: O11104 (trochanteric/sub capital internal fixation), O12101 (hemiarthroplasty), O11808 (closed femoral reduction with internal fixation), O12103 (partial arthroplasty), O12104 (total arthroplasty). Hospital length of stay (LoS) was classified as follows: < 6, 6-9, 10-14, and ≥ 15 days.

RESULTS

Incidence of hip fractures was 248/100,000 among those aged 50 + and 184/100,000 within the 40 + age category. Average age of the patients was 77 years (80 for females, 71 for males); 83.7% of the patients were 65 + with equivalent urban-rural distributions. Males had a 1.7 times higher mortality risk. Each year increase in age added a mortality risk of 6.9%. In-hospital mortality was 1.34 times higher among patients living in urban areas. Hemiarthroplasty and partial/total unilateral/bilateral arthroplasty had a lower risk of mortality than trochanteric/sub capital internal fixation (p < 0.02, p < 0.033).

CONCLUSION

Gender, age, residence, and procedure type had significant impact on mortality. Updated incidence rates will allow the revision of Romania's FRAX model.

Biomechanical comparison of the undercut thread design versus conventional buttress thread for the lag screw of the dynamic hip screw system

Objective: To compare the fixation stability of the lag screw with a undercut thread design for the dynamic hip screw (DHS) system versus the lag screw with the conventional buttress thread. Methods: The lag screws with the undercut thread (a flat crest feature, a tip-facing undercut feature) and buttress thread were both manufactured. Fixation stability was investigated using cyclic compressive biomechanical testing on custom osteoporotic femoral head sawbone. The forces required for the same vertical displacement in the two types of lag screw were collected to evaluate the resistance to migration. Varus angle was measured on X-ray images to assess the ability in preventing varus collapse. Finite element analysis (FEA) was performed to analyze the stress and strain distribution at the bone-screw interface of the two types of lag screws. Results: The biomechanical test demonstrated that the force required to achieve the same vertical displacement of the lag screw with the undercut thread was significantly larger than the lag screw with conventional buttress thread (p < 0.05). The average varus angles generated by the undercut and buttress threads were 3.38 ± 0.51° and 5.76 ± 0.38°, respectively (p < 0.05). The FEA revealed that the region of high-stress concentration in the bone surrounding the undercut thread was smaller than that surrounding the buttress thread. Conclusion: The proposed DHS system lag screw with the undercut thread had higher migration resistance and superior fixation stability than the lag screw with the conventional buttress thread.