Long-Term Knee Health in Adults with a History of Adolescent Osgood-Schlatter: A National Cohort Study of Patients in Secondary Care in Denmark 1977-2020

Abstract

Background: Osgood-Schlatter has, until recently, been suggested to be a benign condition, affecting adolescents in terms of knee pain and decreased sports participation during growth, with no long-term consequences seen later in adulthood.

Objectives: The objectives of this study were to describe the long-term knee health in adults with a history of Osgood-Schlatter, compare these findings with healthy population estimates, and investigate if explanatory variables are associated with current knee health.

Methods: The Danish Patient Registry identified patients ≥ 18 years diagnosed with adolescent Osgood-Schlatter in hospitals during 1977-2020. All cases participated in a survey about knee-related health and comorbidities. Existing literature was sourced for the healthy population estimates for comparisons. Explanatory variables were recalled Osgood-Schlatter duration, pain levels, restrictions, and current tibial tubercle prominence.

Results: Of 1281 identified patients, 400 responded. Most reported having a current bony prominence of the tibial tubercle (85%) and sustained pain/problems from the same area (73%). Compared with healthy population estimates, Osgood-Schlatter cases scored lower on the Knee Injury and Osteoarthritis Outcome Score on all subscales (p < 0.05), particularly for "sport/rec" and "quality of life" (Cohen's d > 0.8). Similarly, cases exhibited a large risk of "jumper's knee" (odds ratio: 70.4 [95% confidence intervals, CI: 32.9; 155.0], p < 0.0001). Symptom duration and pain levels were negatively associated with several outcomes (p < 0.05).

Conclusions: Adults with a history of Osgood-Schlatter have significantly worse long-term knee health than what is observed from healthy population estimates. Recalled longer symptom duration and higher pain levels were associated with worse current knee health. This information should potentially guide management to maintain knee health over time, as the condition is not always as benign and self-limiting as previously thought.

Registration: NCT04313621.

Fig. 1

Self-reported knee health on KOOS subscales compared with healthy population estimates; OS Osgood–Schlatter, KOOS Knee Injury and Osteoarthritis Outcome Score, Rec recreation function, QoL quality of life

Fig. 2

Odds of having knee-related comorbidities compared with estimates from healthy populations; ACL anterior cruciate ligament

Fig. 3

Distribution of level of tibial bony prominence, by duration of Osgood–Schlatter. Figures in bars denotes the number of participants in for each subgroup

Fig. 4

Distribution of self-reported numerical outcomes by Osgood–Schlatter duration (a), pain during Osgood–Schlatter (b), and presence of current bony prominence at the tibial tubercle (c). Error bars denote 95% confidence intervals. KOOS subscales are scored from 0 to 100, with 0 representing extreme knee problems and 100 representing no knee problems. Knee pain is scored on a 0–100 numerical rating scale with zero representing no knee pain and 100 representing worst pain imaginable. KOOS Knee Injury and Osteoarthritis Outcome Score, Rec recreation function, QoL quality of life