Knee Osteoarthritis in the Region of Norrbotten

1. The study population consists of patients from the Swedish region of Norrbotten (northern part of Sweden) who had undergone TPF between the years of 2001 and 2015.
2. All patients are evaluated radiographically.
3. Condition-specific scores are assessed using the Knee injury and Osteoarthritis Outcome Score (KOOS). General health related quality of life are assessed by the EuroQol 5-Dimension 5-level (EQ-5D-5L) tool.
4. All patients are examined clinically.
5. The relationship between the development of radiographic OA in patients who had undergone TPF and such potential factors as gender, age, body mass index (BMI), fracture pattern or method of fracture treatment is being assessed.
6. The data from the Swedish Fracture Register and the Swedish Arthroplasty Register are used in order to follow the long-term results.

Primary outcomes

• Number of participants with radiographic osteoarthritis (OA) [At least 5 years]: Number of participants with radiographic OA at follow-up at least five years after the tibial plateau fracture was considered the primary endpoint of this study.

Secondary outcomes

• Score values in the condition-specific measure for assessment of symptoms and function related to the knee joint [At least 5 years]: The Knee injury and Osteoarthrtis Outcome Scale (KOOS) is used. KOOS is a self-administered knee-specific questionnaire consisting of 42 items in five subscales. A normalized score from 0 (extreme problems) to 100 (no problems at all) are calculated separately for each of the five subscales. Knee-related symptoms and function are evaluated with use of four out of five KOOS subscales: Pain, other Symptoms, Function in daily living (ADL) and Function in sport and recreation (Sport/Rec).
• Score values in assessment of condition-specific health-related quality of life [At least 5 years]: The condition-specific measure, Knee injury and Osteoarthrtis Outcome Scale (KOOS) is used. The score values in the KOOS subscale knee-related Quality of Life (QOL) are evaluated.
• Score values in assessment of general health-related qualilty of life [At least 5 years]: Assessment is performed with the EuroQol 5-Dimension 5-level (EQ-5D-5L). The questionnaire consists of five questions exploring five dimensions: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. Each dimension has five response levels, ranging from "no problems" to "extreme problems". An EQ-5D-5L index of 1.0 indicates the best possible health state and 0.0 denotes death.

Other outcomes

• Number of participants who had a surgical intervention due to OA secondary to the tibial plateau fracture [At least 5 years]: Number of participants who developed an end-stage OA and underwent either knee arthroplasty (either partial or total) or knee osteotomy.

Sex: All, ages: 18 Years to any

Inclusion Criteria:

* Patients from the region of Norrbotten (northern part of Sweden) who underwent tibial plateau fracture between the years of 2001 and 2015

Exclusion Criteria:

* Death without bilateral weighted X-ray minimum 5 years post injury
* Open growth plate in distal femur and/or proximal tibia
* Extraarticular or isolated eminentia fracture
* OA prior to injury
* Having a rheumatic disorder involving joints
* Earlier and/or later severe injury to the index knee
* Having cognitive disorders disqualifying from the study

• Results publication: Klaser J, Kotake L, Lindberg M, Wigge S, Lundqvist R, Szczesny G, Paradowski PT. Prevalence of osteoarthritis and clinical outcomes in patients with fractures of the tibial plateau - medium- and long-term analysis. BMC Musculoskelet Disord. 2025 May 27;26(1):522. doi: 10.1186/s12891-025-08786-7. PMID 40426131