4th International Medical Congress of Izmir Democracy University (IMCIDU) 2022, İzmir, Türkiye, 9 - 11 Aralık 2022, ss.144-147
Abstract
Introduction and Purpose: The knee joint is a complex joint consisting of the tibiofemoral and
patellofemoral joints. Morphological variations are common in the knee joint, due to the articulation of
anatomically incompatible bones. These variations may lead to various pathologies, mostly in the
patellofemoral joint. One of the most common pathologies and an important cause of knee pain is
chondromalacia. In this study, we aimed to investigate the relationship between lateral patellar tilt angle
(LPTA), lateral patellofemoral angle (LPFA), patella-patellar tendon angle (PPTA), and lateral trochlear
inclination angle (LTI), which are anatomical variations in the patellofemoral joint, and patellar
chondromalacia.
Materials and Methods: Cases who underwent knee magnetic resonance imaging (MRI) between June
and October 2022 were analyzed retrospectively. Fifty patients with and without patellar
chondromalacia were included randomly from these MRIs. Cases with a history of knee surgery,
arthroscopy and high-energy trauma were excluded. Two groups were formed with and without patellar
chondromalacia. LPTA, LPFA, PPTA and LTI were measured on knee MRIs. Demographic data and
anatomical measurements between the two groups were evaluated with Mann-Whitney U and continuity
corrected chi-square test.
Results: The median age of the patients included in the study was 45 (Interquartile Range [IQR]: 18.5).
There were 58 women and 42 men. In the patellar chondromalacia group, 17 (34%) patients had low-
grade chondromalacia and 33 (66%) patients had high-grade chondromalacia. The median age was 49
(IQR: 61) in the patellar chondromalacia group and 37.5 (IQR: 38) in the normal group (p<0.001). There
was no statistically significant difference in gender distribution between the two groups (p=0.156). The
median lateral patellar tilt angle was 6.76 (IQR: 15.15) in the patellar chondromalacia group and 6.92
(IQR: 19.25) in the normal group (p=0.610). The median lateral patellofemoral angle was 7.86 (IQR:
41.86) in the patellar chondromalacia group and 7.90 (IQR: 17.37) in the normal group (p=0.471).
Median patella – patellar tendon angle was 142.96 (IQR: 32.14) in the patellar chondromalacia group
and 145.87 (IQR: 27.77) in the normal group (p=0.006). The median lateral trochlear inclination angle
was 19.11 (IQR: 19.30) in the patellar chondromalacia group and 20.39 (IQR: 20.16) in the normal
group (p=0.127).
Discussion and Conclusion: The patellofemoral joint is an important component of the extensor
mechanism. It distributes the load on the knee joint more homogeneously during extension. It has been
described that anatomical differences in the patellofemoral joint can cause damage to the patellar
cartilage by affecting the load distribution. We found a statistically significant difference between the
groups in terms of median PPTA and median age. The median age of the patients in the chondromalacia
group was higher. This may have been due to degenerative cartilage changes. The lower detection of
median PPTA in the chondromalacia group indicates that the angular position of the patella may have
increased the load on the patellofemoral joint, leading to cartilage damage. In conclusion, it should be
kept in mind that demographic differences and anatomical variations may be a cause of patellar
chondromalacia.