Epidemiology of Existing Extensor Mechanism Pathology in Primary Anterior Cruciate Ligament Ruptures in an Active-Duty Population

RESULTS

A total of 197 active-duty patients, including 27 females (13.7%) and 170 males (86.3%), underwent primary ACL reconstruction during the study time period. A total of 93 right knees and 104 left knees were evaluated. The average age at presentation was 29 years (range, 19-45 years).

Of the 197 patients, only 1 was found to have a multipartite patella (prevalence, 0.5%). This 37-year-old male patient showed a right bipartite patella located in the superior-lateral aspect (Figure 1).

Four patients had free ossicles within the inferior patellar tendon consistent with unresolved Osgood-Schlatter’s disease (prevalence, 2.0%) (Figure 2). All 4 patients were male, which is consistent with the higher incidence of Osgood-Schlatter’s disease in males than in females. The average age of these patients was 27.5 years (range, 22-33 years).

The most common extensor mechanism pathology present on preoperative imaging was proximal patella tendon thickening suggestive of patella tendinopathy. Thickening of the proximal portion of the patellar tendon was present in 15 of the 197 MRIs (prevalence, 7.6%) (Figure 3). The average width of this thickening was 8.49 mm (7.17-10.17 mm), and the average age of patients with radiographic evidence of patellar tendinopathy was 29.9 years (range, 20-43 years). Gender distribution was predominantly male (14 males, 1 female). Details of all extensor mechanism pathologies found are provided in the Table.

Table. Identified Extensor Mechanism Pathology