Abstract
Objectives:
Discoid lateral meniscus (DLM) in pediatric patients presents across a broad age range. It is unknown whether clinical presentation and DLM morphology differ between age groups. This study investigates age-based differences in DLM characteristics from a multi-center retrospective database of DLM. We hypothesize that there are predictable differences in presentation and DLM morphology between age groups.
Methods:
This retrospective study included surgically treated DLM patients between January 2000 and March 2020 from 9 centers in North America. Patients’ demographic and clinical characteristics were collected. Statistical analysis was performed to compare characteristics of DLM between age groups: < 7, 7-10, 11-13, 14-16, and ≥ 17 years. Kruskal-Wallis test and Chi-square or Fisher Exact test were used to compare age groups for continuous and categorical variables, respectively. Statistical significance was defined as p-value < 0.05.
Results:
868 patients with mean age 12 years (range: 1-22 years) were included for analysis. More patients were female (57%) than male, especially in the younger age groups. The proportion of patients in each age group: <7 years (7.6%), 7-10 years (25.8%), 11-13 years (28.2%), 14-16 years (25.2%), ≥17 years (13.1%). Patients <7 years had significantly longer duration from initial presentation to surgery (median 214 days vs ≥17 years 28.5 days; p<0.05). Among patients <7 years, over 40% presented with a complaint of either “snapping” or “clunking.” Meanwhile, patients aged ≥17 years more commonly presented with complaints of swelling (33%) and locking (44%) [Figure1]. Incidence of discoid meniscus tear was highest among patients ≥17 years (80.7%), and lowest among <7 years (56.1%). Among patients with tear (N=648), patients ≥17 years were significantly more likely to have radial and parrot beak tears compared to other age groups (radial 18.5%, parrot beak 7.6%; Table 1). Patients 13 and under were more likely to have stiffness on exam (18%-25%) compared to patients 14 years and older (10%-13%; p<0.05). During surgery, patients 13 years and younger were more likely than older patients to have instability of the meniscus (41%-48% vs 26%-30%; p<0.05) and meniscus repair (46%-48% vs 32%-33%; p<0.05).
Conclusions:
Younger patients tend to present with “clunking” DLM and do not typically proceed acutely to surgery. They are more likely to have preoperative stiffness and instability, and more likely to undergo meniscus repair. Older patients are more likely to have a tear, and receive more acute treatment, though repair Is less frequent. These age-based differences in presentation and characteristics of DLM are important in counseling these patients and treatment decision-making.
