The increased torque required to dislocate dual mobility (DM) components may increase peri-prosthetic femoral fracture (PPF) risk. Current literature often relies on revision as an endpoint and may underestimate PPF. This study aims to review PPF rate, risks and treatment following primary DM implantation.

Prospective cohort study of 549 patients following primary DM total hip arthroplasty (THA) between 2013 and 2021. Collected data included demographics, indication for surgery, cortical index and PPF.

549 patients were identified with primary DM THA. Mean age was 73 years (26–96). 446 (81.2%) patients had their index surgery following hip fracture. 18 patients (3.27%) sustained a PPF. Cumulative PPF rate was 1.5% at 1-year, 2.2% at 5-years and 3.27% overall. PPF was higher in patients undergoing surgery following hip fracture (4%) vs. other indications (1%). OR 4.04 (95% CI:0.53, 30.72), p=0.219. Mean cortical index was lower in patients with PPF 0.4 (95% CI:0.36, 0.45) compared to those without 0.46 (95% CI:0.45, 0.46) p=0.029. Treatment for PPF included 10 (55.6%) open reduction internal fixation (ORIF), 7 (38.9%) revision THA and 1 conservatively managed.

PPF rate following DM use is higher in our cohort than published rates. Our rates are comparable to some papers when subgroup analysis of older patients and cemented taper slip stems are considered. PPF risk with DM may be increased in patients undergoing surgery after hip fracture or with a lower cortical index preoperatively. Over half of PPF were managed with ORIF and may mask PPF risk studies that report using revision as an endpoint.

Aims

Dislocation remains a significant complication after total hip arthroplasty (THA), being the third leading indication for revision. We present a series of acetabular revision using a dual mobility cup (DMC) and compare this with our previous series using the posterior lip augmentation device (PLAD).

Fractured neck of femur is a significant health concern within the UK. NICE guidance on the management of displaced intracapsular fractures states that total hip arthroplasty should be offered when patients can; walk independently out of doors with no more than a stick, not cognitively impaired, medically fit for anaesthesia and the procedure. We previously managed this subgroup using THA with standard sockets. Following an audit of this practice a dislocation rate of 9% was identified and practice was changed to using dual mobility (THA-DM) with the theoretical advantage of reducing dislocation.

We reviewed all patients who underwent THA for fracture using Bluespier from 2013–2017. Operative notes and radiographs were reviewed to ensure the patients had undergone THA for displaced intracapsular fracture. Basic patient demographics were collected. Our primary outcome was dislocation rates at one year. Our secondary outcomes were length of time to surgery, length of stay, operative time, mortality, return to theatre rates and one year Oxford hip scores

We found a control group of 45 THA procedures and a dual mobility group of 143 procedures. The one year dislocation rate from the THA-SS group was 9% and the THA-DM group was 1.4%(CI±1.9%)(p=<0.05%). There were also non-significant reductions in time to surgery, length of stay, operative time, mortality, return to theatre rates. The one year Oxford hip score was comparable at 42.2 to 41.8.

This study demonstrates a significant reduction in one year dislocation rates with comparable oxford hip scores. Use of THA-DM should be considered in those patients who meet NICE criteria. Further research is needed into long term dislocation rates.

We undertook a retrospective cohort study to determine if body mass index (BMI) is an independent factor in determining patient outcome following total hip replacement (THR). Outcomes were determined using the Oxford Hip Score, a questionnaire designed to evaluate self-reported function and pain levels in people with hip pain. We looked at all THRs carried out on patients with a BMI of ≥30 over a 38 month period (220 operations) and compared these with 220 randomly selected THRs carried out on patients with a BMI of <30 within the same 38 month period. For each case we recorded patient BMI, P score and Oxford scores. We calculated the difference between pre-operative and one-year post-operative Oxford hip scores. We used Kendall's rank correlation to assess any potential correlation between BMI and functional change, and the Mann-Whitney U test to establish if functional change between the groups was statistically significant. Our study indicates that BMI is not an independent factor in determining relative subjective functional change following THR. Although it showed that patients with a BMI of ≥30 have worse function both before and after THR, there was no statistically significant difference between the two groups in terms of functional change. We therefore suggest that patients with a higher BMI be considered candidates for THR as they can expect the same degree of functional improvement. Given the trend for increasing numbers of obese patients in the population these findings could have a significant impact on the future of THR operations.

Study Design: A retrospective case note review.

Objective: To report on the accuracy of the Harlow-Wood bone biopsy trephine used via a percutaneous approach to obtain tissue from vertebral lesions.

Methods: 82 patients undergoing this procedure in either the University Hospital Nottingham or Leicester Royal Infirmary between 1995 and 2003 were included in the study. Data was collected regarding the provisional diagnosis, MRI diagnosis and final diagnosis based on micro-biological and histological reports.

Outcome Measures: Microbiological and histological reports were reviewed to determine the pathological nature of each biopsy. If the biopsy returned a positive diagnosis, or if the biopsy confirmed normal vertebral microbiology and histology in a patient who was subsequently disease-free, then the biopsy was deemed to have provided a diagnosis.

Results: The technique provided a diagnosis in 88% of cases, with a sensitivity of 87% and specificity of 100%. Where the provisional diagnosis was of a neoplastic lesion (n = 48), the diagnosis rate was 88%. Where the provisional diagnosis was of an infective lesion (n = 26), the diagnosis rate was 89%. Where the provisional diagnosis was uncertain (n = 8), the diagnosis rate was 88%.

Conclusions: Percutaneous biopsy of vertebral lesions using the Harlow-Wood bone trephine under fluoroscopic guidance can be performed safely and efficaciously. The high accuracy and sensitivity of this closed percutaneous technique, particularly in infective lesions, allows a timely diagnosis and subsequent early commencement of appropriate treatment.

The aim of our study was to demonstrate the safety of the use of a maximal allowable blood loss formula to reduce the transfusion requirements of elective primary arthroplasty patients.

In the UK, many arthroplasties are performed each year. Many patients will receive blood transfusion post operatively. Often these patients don’t predonate blood, and most units don’t use re-infusion drains. Blood is both costly, and potentially hazardous product to use; we felt it may be beneficial to patients to reduce the unnecessary use of allogenic blood.

We began with a prospective six-month audit, of transfusion requirements of our elective primary arthroplasty patients, establishing our blood use. Our results showed that 66% (58% knees, 73% hips) had at least one unit of blood post operatively, averaging 1.3 units per patient (1.1 knees, 1.5 hips).

Following this, we instituted a new protocol for postoperative blood transfusion. The protocol involved calculation of a maximum allowable blood loss (MABL) the patient could safely lose prior to the need for blood transfusion. This value is based on the patients weight and preoperative haematocrit. Blood loses up to this value would be made up with colloid replacement. When this MABL value is reached the patient has a bedside measurement of their haematocrit. If it has fallen below 0.3 for males and 0.27 for female patients then they are transfused blood, one unit at a time until it is at or above these reference values. As a ‘safety net’ all patients have a formal full blood count on days 1,2, and 3, and are transfused if their Hb is less than 8.5 g/dl.

This protocol was in place for one year (Feb. 2001-Feb. 2002). Our results show, on average a reduction of blood use from 1.3 units to 0.56 units per patient. The percentage transfused was reduced from 66% to 24% (11% knees, 34% hips).

Overall we had a significant reduction of 59% in units of blood transfused to patients following the new protocol. And feel that this method demonstrates a safe system to reduce transfusion requirements.