We report the impact of implementing a new short-stay hip and knee arthroplasty pathway in a National Health Service (NHS) hospital. This was enacted due to existing concerns with a long length of stay (LOS) and reduced elective operating capacity each winter due to emergency bed pressures. The overnight introduction of this pathway was aimed to reduce LOS, alleviate bed pressures, minimise readmission rates and generate financial savings, all combining to facilitate full elective activity during the winter.

We conducted a prospective study at a regional tertiary arthroplasty centre. The new pathway was introduced across the service overnight. It includes rigorous preoperative optimisation, specific anaesthetic protocols and uniform changes in surgical practice to allow a focus on early mobilization and discharge on the day of surgery where possible.

Data collection spanned 17 months, including the initial six months post implementation of the short-stay pathway. LOS data was collected for the full period and data was compared pre- and post-implementation of the new pathway. Patient satisfaction and 30-day readmission data were also collected.

There was an immediate and significant decrease in median LOS from 4 days pre-implementation to 1 day post-implementation. Patient satisfaction was high, and the 30-day readmission rate was unchanged (5.95%), with no readmissions directly related to decreased inpatient stay. Financial analyses revealed substantial cost savings due to reduced LOS and the elimination of routine post-operative blood tests, estimated at over £1.6m per year. Elective activity over winter was significantly higher (79%) than in the same time period in the previous year.

An acute introduction of a carefully planned and coordinated short-stay hip and knee pathway is safe, cost-effective and popular with patients, but also contributes to increased efficiency in the delivery of elective healthcare in the context of increasing demand and financial constraints in the NHS.

We measured the orientation of the acetabular and femoral components in 45 patients (33 men, 12 women) with a mean age of 53.4 years (30 to 74) who had undergone revision of metal-on-metal hip resurfacings. Three-dimensional CT was used to measure the inclination and version of the acetabular component, femoral version and the horizontal femoral offset, and the linear wear of the removed acetabular components was measured using a roundness machine.

We found that acetabular version and combined version of the acetabular and femoral components were weakly positively correlated with the rate of wear. The acetabular inclination angle was strongly positively correlated with the rate of wear. Femoral version was weakly negatively correlated with the rate of wear. Application of a threshold of > 5 μm/year for the rate of wear in order to separate the revisions into low or high wearing groups showed that more high wearing components were implanted outside Lewinnek’s safe zone, but that this was mainly due to the inclination of the acetabular component, which was the only parameter that significantly differed between the groups.

We were unable to show that excess version of the acetabular component alone or combined with femoral version was associated with an increase in the rate of wear based on our assessment of version using CT.

This study compared component wear rates and pre-revision blood metal ions levels in two groups of failed metal-on-metal hip arthroplasties: hip resurfacing and modular total hip replacement (THR).

There was no significant difference in the median rate of linear wear between the groups for both acetabular (p = 0.4633) and femoral (p = 0.0872) components. There was also no significant difference in the median linear wear rates when failed hip resurfacing and modular THR hips of the same type (ASR and Birmingham hip resurfacing (BHR)) were compared.

Unlike other studies of well-functioning hips, there was no significant difference in pre-revision blood metal ion levels between hip resurfacing and modular THR.

Edge loading was common in both groups, but more common in the resurfacing group (67%) than in the modular group (57%). However, this was not significant (p = 0.3479). We attribute this difference to retention of the neck in resurfacing of the hip, leading to impingement-type edge loading. This was supported by visual evidence of impingement on the femur.

These findings show that failed metal-on-metal hip resurfacing and modular THRs have similar component wear rates and are both associated with raised pre-revision blood levels of metal ions.