TY - JOUR
T1 - Neither lateral patellar facet nor patellar size are altered in patellofemoral unstable patients
T2 - a comparative magnetic resonance imaging analysis
AU - Otto, Alexander
AU - Tscholl, Philippe M.
AU - Pääsuke, Reedik
AU - Herbst, Elmar
AU - Willinger, Lukas
AU - Imhoff, Andreas B.
AU - Brucker, P. U.
N1 - Publisher Copyright:
© 2019, European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA).
PY - 2020/4/1
Y1 - 2020/4/1
N2 - Purpose: It remains unclear if morphologic patterns of the patella itself predispose to patellar instability. This study examined established patellar landmarks in relation to the femoral condyle width to clarify differences of patellar morphologies in patellofemoral stable and unstable patients. Methods: Magnetic Resonance Imaging of 50 subjects (20.7 ± 4.4 years; 17 males, 33 females) with patellofemoral instability (study group, SG) and 50 subjects (25.3 ± 5.8 years; 31 males, 19 females) with anterior cruciate ligament rupture (control group, CG) were analyzed. Corresponding patellar value indices (PW-I; LPF-I 1; LPF-I 2) in relation to the femoral condyle width (FCW) were evaluated after the measurement of absolute patellar dimension [patellar width (PW); direct length of the lateral patellar facet (LPF-1); projected length of the lateral patellar facet (LPF-2)]. The patellar shape according to Wiberg, trochlear dysplasia, patellar height, and tibial tubercle–trochlear groove (TT–TG) distance were determined. Results: The SG showed a significantly longer absolute (LPF 2) (P = 0.041) and relative (LPF-I 1, LPF-I 2) (P < 0.001) lateral facet of the patella. No significant differences were evaluable for the relative patellar width (PW-I) (ns). A patellar shape type 3 (P = 0.001) as well as a higher position of the patella and TT–TG-distance (P < 0.001) were significantly more often present in the SG. Conclusion: There are several bony alterations associated with patellofemoral instability, but our data did not show a significantly smaller lateral patellar facet or relative patellar width that could facilitate a patellar dislocation. This helps surgeons, that are considering to surgically address the patella in cases of patellofemoral instability, to better understand its morphologic pattern. Level of evidence: III.
AB - Purpose: It remains unclear if morphologic patterns of the patella itself predispose to patellar instability. This study examined established patellar landmarks in relation to the femoral condyle width to clarify differences of patellar morphologies in patellofemoral stable and unstable patients. Methods: Magnetic Resonance Imaging of 50 subjects (20.7 ± 4.4 years; 17 males, 33 females) with patellofemoral instability (study group, SG) and 50 subjects (25.3 ± 5.8 years; 31 males, 19 females) with anterior cruciate ligament rupture (control group, CG) were analyzed. Corresponding patellar value indices (PW-I; LPF-I 1; LPF-I 2) in relation to the femoral condyle width (FCW) were evaluated after the measurement of absolute patellar dimension [patellar width (PW); direct length of the lateral patellar facet (LPF-1); projected length of the lateral patellar facet (LPF-2)]. The patellar shape according to Wiberg, trochlear dysplasia, patellar height, and tibial tubercle–trochlear groove (TT–TG) distance were determined. Results: The SG showed a significantly longer absolute (LPF 2) (P = 0.041) and relative (LPF-I 1, LPF-I 2) (P < 0.001) lateral facet of the patella. No significant differences were evaluable for the relative patellar width (PW-I) (ns). A patellar shape type 3 (P = 0.001) as well as a higher position of the patella and TT–TG-distance (P < 0.001) were significantly more often present in the SG. Conclusion: There are several bony alterations associated with patellofemoral instability, but our data did not show a significantly smaller lateral patellar facet or relative patellar width that could facilitate a patellar dislocation. This helps surgeons, that are considering to surgically address the patella in cases of patellofemoral instability, to better understand its morphologic pattern. Level of evidence: III.
KW - Patella
KW - Patellar dysplasia
KW - Patellar facet
KW - Patellar morphology
KW - Patellar size
KW - Patellofemoral instability
KW - Trochlear dysplasia
UR - http://www.scopus.com/inward/record.url?scp=85071335026&partnerID=8YFLogxK
U2 - 10.1007/s00167-019-05660-7
DO - 10.1007/s00167-019-05660-7
M3 - Article
C2 - 31456062
AN - SCOPUS:85071335026
SN - 0942-2056
VL - 28
SP - 1064
EP - 1071
JO - Knee Surgery, Sports Traumatology, Arthroscopy
JF - Knee Surgery, Sports Traumatology, Arthroscopy
IS - 4
ER -