Scottish Arthroplasty Project
Figures from January 2001 to December 2025

About this release

The Scottish Arthroplasty Project (SAP) was set up to improve care for patients who have joint replacement surgery (arthroplasty). This annual release by Public Health Scotland (PHS) presents data on the number of arthroplasty operations in Scotland that took place between 2001 and 2025 and on the frequency of complications, such as infection or revision surgery.

Main points

• The number of arthroplasty operations remain significantly above pre-pandemic levels. 18,707 first (primary) hip or knee replacements performed in NHS Scotland hospitals in 2025 compared to 15,911 in 2019.

This chart show both primary hip and primary knee procedure from 2001 to 2025. Both follow a similar increasing trend from 2001 with a sharp decrease during 2020 which slowly increasing to 2025 above pre-pandemic levels.

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Primary hip and knee arthroplasty procedures performed by NHS Boards per year (2001-2025)

• Primary hip and knee replacement procedures performed in Scottish independent hospitals still represent a substantial proportion of overall activity but the levels have not significantly increased compared with 2024 data. These procedures are carried out independently of NHS hospitals and not included in NHS Scotland figures.
• Over the last 10 years, the mean length of stay has decreased from 5.1 to 2.4 days for primary hip procedures, and from 5.2 to 2.6 days for primary knee procedures.

Background

The Scottish Arthroplasty Project remains one of the oldest arthroplasty registries in the world. It is a member of the International Society of Arthroplasty Registries and, in comparison to many other countries, can produce good quality data for a very modest outlay, with the principal aim of providing quality assurance and adverse outcome monitoring of major joint replacement surgery in Scotland.

The Scottish Arthroplasty Project analyses hospital inpatient information to monitor the number of complications following hip and knee replacements in Scotland, and to ensure that surgeons performing these operations do not have a higher-than-expected complication rate. Where there is a higher-than-expected number of complications following operations performed by a particular surgeon, the surgeon is notified and asked to investigate the reasons for the increased rate in complications and to develop an action plan to reduce their recurrence.

Further information

The next update of this publication will be 2 August 2027.