MRI but not arthroscopy accurately diagnoses femoral MPFL injury in first-time patellar dislocations
Open Access
- 18 November 2011
- journal article
- knee
- Published by Wiley in Knee Surgery, Sports Traumatology, Arthroscopy
- Vol. 20 (8), 1575-1580
- https://doi.org/10.1007/s00167-011-1775-7
Abstract
Purpose The purpose of this study was to investigate whether the femoral part of the medial patellofemoral ligament (MPFL) and its injury can be accurately assessed by standard knee arthroscopy in first-time patellar dislocations or whether preoperative MRI is required to determine injury location in patients where primary MPFL repair is attempted. Methods Twelve patients with acute first-time dislocations and MRI-based injury of the femoral MPFL and ten patients with recurrent patellar dislocations underwent knee arthroscopy with the use of a 30-degree optic and standard antero-medial and antero-lateral portals. The femoral origin was marked with a cannula under lateral fluoroscopy. Arthroscopic findings of the location of the native femoral MPFL and its injury were compared to the results of MRI and mini-open exploration. Results In acute cases, the average time from primary patellar dislocation to MRI evaluation was 3 days (1–9 days), and the average time from MRI to surgery was 8 days (3–20 days). The native femoral origin of the MPFL was not visible in any of the chronic cases during arthroscopy. In addition, in all acute cases, arthroscopy failed to directly visualize injury of the femoral MPFL (0 of 12), but mini-open exploration confirmed injury in 11 of 12 patients. This means that arthroscopy was less accurate than MRI for the diagnosis of femoral MPFL injury (P < 0.05). Conclusion The results of this study indicate the limitations of knee arthroscopy in identifying the femoral disruption of the MPFL, a crucial injury that occurs in patellar dislocations. Thus, if a primary MPFL repair is planned, determination of the site of repair should be based on the preoperative MRI. Level of evidence Diagnostic study of non-consecutive patients, Level III.Keywords
This publication has 19 references indexed in Scilit:
- Patellar dislocations in children, adolescents and adults: A comparative MRI study of medial patellofemoral ligament injury patterns and trochlear groove anatomyEuropean Journal of Radiology, 2011
- In Vivo Positioning Analysis of Medial Patellofemoral Ligament ReconstructionThe American Journal of Sports Medicine, 2010
- Magnetic Resonance Imaging Characteristics of the Medial Patellofemoral Ligament Lesion in Acute Lateral Patellar Dislocations Considering Trochlear Dysplasia, Patella Alta, and Tibial Tuberosity–Trochlear Groove DistanceArthroscopy: The Journal of Arthroscopic & Related Surgery, 2010
- Conservative Versus Surgical Treatment for Repair of the Medial Patellofemoral Ligament in Acute Dislocations of the PatellaArthroscopy: The Journal of Arthroscopic & Related Surgery, 2009
- Femoral Avulsion of the Medial Patellofemoral Ligament after Primary Traumatic Patellar Dislocation Predicts Subsequent Instability in MenThe American Journal of Sports Medicine, 2009
- Isolated Repair of the Medial Patellofemoral Ligament in Primary Dislocation of the Patella: A Prospective Randomized StudyArthroscopy: The Journal of Arthroscopic & Related Surgery, 2008
- Radiographic Landmarks for Femoral Tunnel Placement in Medial Patellofemoral Ligament ReconstructionThe American Journal of Sports Medicine, 2007
- First-time Traumatic Patellar DislocationClinical Orthopaedics and Related Research, 2007
- Acute Dislocation of the PatellaThe American Journal of Sports Medicine, 1996
- Factors of patellar instability: An anatomic radiographic studyKnee Surgery, Sports Traumatology, Arthroscopy, 1994