Cortical Desmoid of the Distal Femur—Incidentaloma or Insertional Tendinopathy?

Abstract

Background: The cortical desmoid (DFCI) of the posteromedial femoral condyle is considered an asymptomatic incidental finding in adolescents without clinical relevance. The aim of this study was to evaluate the clinical relevance of DFCI from both a tumor orthopedic and sports medicine point of view. Methods: n = 23 patients (13.74 ± 2.74 years; nineteen female, four male) with DFCI of the posteromedial femoral condyle were included. A localized posteromedial knee pain on exertion was differentiated from non-specific knee pain. Symptom duration, additional pathologies, number of MRIs, sports activity and training intensity, downtime, therapeutic modalities, and relief/remission of symptoms were documented. The Tegner activity scale (TAS) and Lysholm score (LS) were collected. The influence of specific posteromedial pain, MRI presence of paratendinous cysts, sports level as well as physiotherapy on downtime and LS/TAS was statistically analyzed. Results: 100% reported knee symptoms at initial presentation. A localized posteromedial pain was documented in 52%. In 16/23 (70%) additional functional pathologies were diagnosed. Patients were physically highly active with high training intensities (6.52 ± 5.87 h/week) and performance level (65% competitive vs. 35% recreational). Patients underwent 1.91 ± 0.97 MRIs (max four). Symptom duration was 10.48 ± 11.02 weeks. A follow-up examination was performed after 12.62 ± 10.41 months (n = two lost to follow-up). 17/21 had physiotherapy, on average 17.06 ± 13.33 units. Overall downtime was 13.39 ± 12.50 weeks, the return-to-sports (RTS) rate 81%. 100%/38% reported a relief/remission of complaints. LS was 93.29 ± 7.95, median TAS before onset of knee complaints/at follow-up 7 (6–7)/7 (5–7). Specific posteromedial pain, presence of paratendinous cysts, sports level and physiotherapy had no significant influence on downtime and outcome parameters (n.s.). Conclusions: DFCI as a pathognomonic finding is recurrently encountered in the MRIs of children and adolescents. This knowledge is essential to spare patients from overtreatment. Contrary to the literature, the present results implicate a clinical relevance of DFCI particularly in those who are physically highly active with localized pain on exertion. Structured physiotherapy as basic treatment is recommended.

Tumor-Like Distal Femoral Cortical Irregularities of the Knee in Adolescent Competitive Alpine Skiers: Longitudinal Assessment Over 48 Months

“…No longitudinal assessment of the DFCI morphology on MRI was performed, but the results of Mester et al 12 support the assumption that DFCIs are not solely self-limiting and that some might benefit from structured physical therapy. In our study, DFCIs were persistent, and it is important to note that invasive diagnostic procedures such as biopsies should generally be avoided.…”

“…In previous studies, DFCIs have often been described as self-limiting lesions that disappear throughout adolescence. 4 , 8 , 11 - 13 In a case report by Tscholl et al, 20 the DFCIs of a female gymnast and a female judoka resolved over 2 years. However, there was no information on their level of physical activity during the follow-up period.…”

“…Contrary to previous studies, the results of this study suggest that DFCIs are a reaction to excessive shear stress that persists throughout skeletal maturation, especially in competitive athletes with high physical demands over a long period. Mester et al 12 recently assessed DFCIs in a cohort of 21 children and found an association with localized posteromedial knee pain in 53%. The patients were treated nonoperatively with structured physical therapy and rest from physically demanding sportive activities.…”

“…The American Journal of Sports Medicine 2024;52 (7):1820-1825 DOI: 10.1177/03635465241239868 Ó 2024 The Author(s) cohorts. 4,8,[11][12][13] No established therapeutic guidelines have been published to date. 13 Although often asymptomatic, DFCIs may be associated with knee pain or instability; especially in athletes and those with high physical demands, the reported prevalence ranges between 3.6% in the general population and 58% in competitive athletes.…”

“… 1 , 17 In recent case reports, nonoperative management—including rest, physical therapy, and anti-inflammatory medications—has been proposed. 20 Mester et al 12 recently observed that DFCIs are clinically relevant and may cause activity-limiting knee pain, predominantly in patients with high physical activity. They further noted that structured physical therapy led to significant pain relief, but the rate of complete remission after 12 months was low.…”