Is There a Relationship between Patellofemoral Alignment and Osgood–Schlatter Disease? A Case-Control Study

Abstract

This study was aimed to investigate the role of anatomic variations in patellofemoral alignment in patients with or without Osgood-Schlatter disease (OSD) and to determine the potential anatomic risk factors that may play role in the etiology. This prospective observational case-control study was conducted on two groups of adolescent patients. Group 1 comprised patients who were diagnosed as having OSD and group 2 consisted of an equal number of age-matched patients who presented to the outpatient clinic with traumatic knee injury and underwent knee radiographic examination but without a diagnosis of OSD. Age, height, weight, body mass index (BMI), dominant side, and level of sporting activity were recorded. Quadriceps (Q) angles were measured using a long-arm goniometer with patients lying in the supine position with their knees in full extension and contracting the Q muscles. On anteroposterior, lateral knee, and tangential patella (Merchant and Laurin views) radiographs, the following measurements were performed: Insall–Salvati (IS), Caton–Deschamps (CD), and Blackburne–Peel (BP) indexes, congruence angles, lateral patellofemoral angles, sulcus angles, and patella type according to Grelsamer's morphology classification. Both groups were similar in respect of age (p = 0.160), sex (p = 0.311), height (p = 0.326), weight (p = 0.596), BMI (p = 0.153), and dominancy (p = 0.500). The rate of patients engaged in sports activities was significantly greater in the OSD group (p = 0.003). No significant difference was determined between the groups in respect to IS index, CD index, BP index, sulcus angle, lateral patellofemoral angle, and congruence angle (p–values: 0.358, 0.995, 0.912, 0.802, 1.000, and 0.907, respectively). The mean Q angle was measured as 15.6 ± 2.2 degrees in the OSD group and 14.3 ± 2.5 degrees in the control group (p = 0.014). Despite the difference being statistically significant, it was clinically insignificant because the difference was only 1.3 degrees. The principle etiologic factor seems to be increased physical activity rather than subtle variations is patellofemoral anatomy and alignment of extensor mechanism.

A systematic review of imaging findings in patients with Osgood‐Schlatter disease

“…Of the 40 studies included, 25 studies reported on OSD‐related imaging findings 4‐7,9,11‐30 . Most studies used radiography (n = 10) or US (n = 6), with the remaining studies using radiography and US (n = 4), radiography and MRI (n = 3), MRI only (n = 1) and one study using both CT, MRI, radiography, and bone scintigraphy (n = 1).…”

“…Eight cross‐sectional 4,15,20,24,27‐30 and two case‐control studies 6,7 reported on OSD imaging findings compared to controls. In the studies that included a control group, the imaging findings described above (Table 1) were not observed in the controls without OSD 4,7,15,27 .…”

“…Sixteen studies quantified anatomical and morphometric features proposed to be related to OSD 12‐15,20,24,30,32‐40 . Full details are outlined in Table 2 (patellofemoral characteristics) and Table 3 (tendon, attachment and tibial characteristics).…”

“…Interestingly, most of the identified differences were related to the tibial and not patellar characteristics (such as patellar height), which have traditionally been thought to be associated with OSD. Four studies showed the patellar height to be close to normal with findings of both patellar alta and baja in OSD and controls, although different standards were used to determine the patella's positioning 13,30,33,46 . Lee et al 13 and Demirag et al 34 found that the patellar tendon attaches more proximally and in a broader area onto the tibial tuberosity than controls.…”

A Prediction Modeling Based on the Hospital for Special Surgery (HSS) Knee Score for Poor Postoperative Functional Prognosis of Elderly Patients with Patellar Fractures

“…At six months postoperatively, radiological assessment was performed by two independent observers, who did not know the patient's clinical information. Insall-Salvati index [ 22 ], Blackburne-Peel index [ 23 ], congruence angle [ 24 ], and lateral patellofemoral angles [ 25 ] were measured using lateral and Laurin knee radiograph. The measurement was repeated three times, and the average of the measurements was used for the final analysis.…”