Source of the study: University of Auckland, Auckland, New Zealand and University of Otago, Christchurch, New Zealand

Outcomes following knee arthroplasty are typically defined as implant survivorship at defined timepoints, or revision incidence over time. These estimates are difficult to conceptualise, and lack context for younger patients with more remaining years of life. We therefore aimed to determine a ‘lifetime’ risk of revision as a more useful metric for total (TKA) and unicompartmental knee arthroplasty (UKA).

The New Zealand Joint Registry was used to identify 96,497 primary TKAs and 13,481 primary UKAs performed between 1999 and 2019. Patient mortality and revision incidence were also extracted. Estimates of lifetime risk were calculated using an actuarial lifetable method. The estimates were stratified by age and gender. Reasons for revision were categorised using previously published standardised definitions.

The lifetime risk of UKA revision was two-fold higher than TKA across all age groups (range 3.7-40.4% UKA, 1.6-22.4% TKA). Revision risk was higher for males with TKA (range 3.4%-25.2% males, 1.1%-20% females), but higher for females with UKA (range 4.3%-43.4% vs. 2.9%-37.4% for males). Revision due to infections were higher for TKA (1.5% males, 0.7% females) compared with UKA (0.4% males, 0.1% females). The increased risk in younger UKA patients was associated with higher incidence of aseptic loosening (UKA 2%, TKA 1%) and ‘unexplained pain’ (UKA 2%, TKA 0.2%).

The risk for UKA was two-fold higher than TKA, and this was partially explained by a higher proportion of revisions due to ‘unexplained pain’. For TKA, males had higher risk of revision, in contrast to UKA where females had higher risk; this gender difference was associated with higher incidence of infections with TKA. Younger age, gender and higher ASA status were also associated with increased lifetime risk of UKA revision. Lifetime risk of revision can provide a meaningful measure of arthroplasty outcomes to aid patient counselling.

Aims

The success of total knee arthroplasty (TKA) is usually measured using functional outcome scores and revision-free survivorship. However, reporting the lifetime risk of revision may be more meaningful to patients when gauging risks, especially in younger patients. We aimed to assess the lifetime risk of revision for patients in different age categories at the time of undergoing primary TKA.

Aims

Joint registries typically use revision of an implant as an endpoint and report survival rates after a defined number of years. However, reporting lifetime risk of revision may be more meaningful, especially in younger patients. We aimed to assess lifetime risk of revision for patients in defined age groups at the time of primary surgery.

Weber A fractures are a sub-group of ankle fractures parallel or distal to the joint line, below the level of the syndesmosis. Most stable Weber A fractures are managed conservatively with no significant difference in outcome vs. surgical intervention.^1,2In an effort to ensure staff time was being used as efficiently as possible, a consultant-led virtual fracture clinic (VFC) was introduced to manage Weber A fractures. Patients not requiring immediate surgery were reviewed remotely and, wherever possible, were ‘virtually discharged’ to a nurse-led telephone line. Those with diagnostic uncertainty, unusual features or delayed recovery received a face to face review from a nurse or surgeon.

To examine how patients were allocated under this protocol, along with overall patient satisfaction and functional outcome.

An audit of satisfaction and outcome was performed of all patients who presented with a Weber A fracture to the ED between October 2011 and October 2012. The minimum follow-up period was two years. A satisfaction and patient reported outcome (5-level-likert-scale, EQ-5D, MOXFQ) measure was conducted via telephone.^3,4After exclusions, 79 patients were left, of which 63 were successfully contacted (80%).

Of the 79 patients included, 33 (42%) required early face-to-face review while 46 (58%) were discharged with advice following discussion at the VFC. Of the 63 successfully contacted, receipt of the information leaflet was recalled by 61 (97%) and 54 (86%) were satisfied with the information they had received. There was no difference in patient satisfaction regarding recovery (p=0.079) or treatment information (p=0.236) provided between avulsion and transverse fractures or in functional outcome according to MOXFQ (p=0.626) or EQ-Vas (p=0.915) scores.

Patient satisfaction can remain high without face-to-face consultations following injury. This was demonstrated by the high satisfaction with recovery (83%) and with information provided (86%) and is consistent with current published literature and similar to what would have been achieved with traditional fracture clinic review.⁵The new protocol reduces unnecessary hospital attendances for patients and reduces the burden of unnecessary review in orthopaedic departments. Only 15% of patients required review at a traditional fracture clinic and 27% at a nurse-led clinic, freeing resources for more complex cases.