There is an increasing demand worldwide for total hip arthroplasty in patients over 80 years old. This study is the largest of its kind reporting long term outcomes and clinical survivorship of patients over 80 years old undergoing THR.

13171 patients 80 years or older who underwent THR between 2000 and 2019 were included. Demographic and operative data was collected including age, sex, laterality, date of surgery and operative technique. Presence and date of complications were collected. Data was also collected for the same time period on 80910 patients aged 51–79 years undergoing THR for comparison.

4103 (31.2%) male and 9068 female (68.8%) patients were included in the 80year old cohort. Median age was 83 (IQR 81–83, range 80–98). 32682 (40.4%) male and 48227 (59.6%) females were included in the 50–79year old cohort. Median age was 68 (IQR 62–73, range 50–79).

The 80 cohort was more likely to sustain post operative complications in the 6 months following surgery including DVT (81/13171 vs 364/80910, P<0.05), myocardial infarction (177/13171 vs 341/80910, P<0.05), acute renal failure (371/12800 vs 812/80910 P<0.05).

The 50–79year old cohort was over twice as likely to undergo revision surgery than the 80 year old cohort (HR 2.55, 95% CI 2.216–2.932, p<0.001). Of those requiring revision surgery, the elderly cohort were more likely to undergo earlier revision surgery (378days, 95%CI 236–519d vs 1586days, 95%CI 1471–1700d, p<0.001). In those undergoing revision surgery, a higher proportion were done for infection in the 80 year old cohort (39/219 (17.8%) vs 215/2809 (7.7%), p<0.05.

This study demonstrates good outcomes in terms of medical complications and a low overall risk of requiring revision surgery in patients 80years old undergoing THR. Patients over the age of 80 should be counselled on the relatively increased risk of medical complications post operatively.

Subtrochanteric femoral fractures are a subset of hip fractures generally treated with cephalomedullary nail fixation\[1\]. Single lag screw devices are most commonly-used, but integrated dual screw constructs have become increasingly popular\[2,3\]. The aim of this study was to compare outcomes of fixation of subtrochanteric femoral fractures using a single lag screw (Gamma3 nail, GN) with a dual screw device (InterTAN nail, IN). The primary outcome was mechanical failure, defined as lag screw cut-out, back-out, nail breakage or peri-implant fracture.

Consecutive adult patients (18yrs) with subtrochanteric femoral fracture treated in a single centre were retrospectively identified using electronic records. Patients that underwent surgical fixation using either a long GN (2010–2017) or IN (2017–2022) were included. Medical records and radiographs were reviewed to identify complications of fixation. Cox regression analysis was used to determine the risk of mechanical failure and secondary outcomes by implant design. Multivariable regression models were used to identify predictors of mechanical failure.

The study included 622 patients, 354 in the GN group (median age 82yrs, 72% female) and 268 in the IN group (median age 82yrs, 69% female). The risk of any mechanical failure was increased two-fold in the GN group (HR 2.44 \[95%CI 1.13 to 5.26\]; _p=0.024_). Mechanical failure comprising screw cut-out (_p=0.032_), back-out (_p=0.032_) and nail breakage (_p=0.26_) was only observed in the GN group. Technical predictors of failure included varus >5° for cut-out (OR 19.98 \[2.06 to 193.88\]; _p=0.01_), TAD;25mm for back-out (8.96 \[1.36 to 58.86\]; p=0.022) and shortening 1cm for peri-implant fracture (7.81 \[2.92 to 20.91\]; _p=<0.001_).

Our results demonstrate that an intercalated screw construct is associated with a lower risk of mechanical failure compared with the a single lag screw device. Intercalated screw designs may reduce the risk of mechanical complications for patients with subtrochanteric femoral fractures.