# Incidence and treatment strategy for patellar instability in Norway

## TL;DR

This study examines how often patellar instability occurs in Norway and the surgical approaches used to treat it, highlighting the need for standardized care.

## Contribution

The study provides the first national overview of patellar instability incidence and surgical practices in Norway.

## Key findings

- The incidence rate of patellar instability in Norway is 9.6 per 100,000 people.
- Most hospitals perform between five and 20 patellar stabilization surgeries annually.
- Medial patellofemoral ligament reconstruction is the most common procedure, with gracilis as the preferred graft.

## Abstract

To determine the incidence and treatment strategy for patellar instability in the Norwegian healthcare system.

Clinicians from all regional health regions were invited to contribute to the development of a cross‐sectional survey of the current national clinical practices for managing this patient group. A tailored questionnaire was developed to determine how many hospitals in Norway performed patellar stabilization surgery and which surgical procedures and postoperative routines were used. Specifically, the following variables were included: number of procedures performed in 2023, types of procedures, treatment of children, choice of graft for primary MPFL reconstruction, routine use of orthoses and postoperative restrictions.

A survey was conducted among 68 hospitals, of which 35 reported performing patellar stabilisation procedures. The total number of procedures recorded was 532, yielding an incidence rate of 9.6 per 100,000 people. The number of procedures varied significantly among hospitals, with most performing between five and 20. All hospitals conducted medial patellofemoral ligament reconstruction, while 28 included bony procedures, and only seven performed derotational osteotomies. The preferred graft was gracilis (89%), and the most common fixation method on the femur was intrerference screw (60%). Postoperatively, only 20% of hospitals routinely recommended orthoses, primarily after tibial tuberosity osteotomy (86%). Restrictions on knee flexion were advised by 86% of respondents for up to eight weeks, and weight‐bearing restrictions were recommended by all after tibial tuberosity osteotomy.

This study offers an overview of patellar instability incidence and treatment in Norway, revealing significant variability in surgeries, procedures, restrictions, and follow‐up practices. This underscores the need for standardized guidelines and a national registry to improve patient outcomes and care quality. Future research should focus on evaluating long‐term outcomes of various surgical approaches and protocols to inform best practices.

Level III.