Diagnostic Value of MRI and Radiographs of the Knee to Identify Osteochondral Lesions in Acute Patellar Instability.
Hayden P BakerJason DickherberManoj ReddyAndrew RizziAdam KahnAravind AthivirahamPublished in: The journal of knee surgery (2021)
The purpose of this study was to define the diagnostic value of magnetic resonance imaging (MRI) and plain radiographs (X-ray [XR]) in identifying an osteochondral defect or loose body in patients undergoing operative treatment for patellar instability. A total of 87 patients treated operatively for patellar instability with medial patellofemoral ligament (MPFL) reconstruction between 2015 and 2019 were identified. Inclusion criteria were evidence of clinical patellar instability, preoperative XR and MRI studies, and concomitant diagnostic knee arthroscopy and MPFL reconstruction performed to address patellar instability. Patients were excluded if they had a history of prior procedure for patellar instability on the surgical knee, underwent MPFL reconstruction without concomitant diagnostic knee arthroscopy, or had an anterior cruciate ligament or posterior cruciate ligament deficient knee. Operative notes and arthroscopic images were reviewed to identify osteochondral or chondral injuries and loose bodies noted during diagnostic arthroscopy. The primary outcome was the identification of intra-articular loose bodies, chondral injury, or osteochondral defect on preoperative plain radiographs and MRI in patients with patellar instability. All MRIs were performed on a 3T MRI. The sensitivity and specificity of identifying loose bodies on MRI were 0.52 and 0.92 and on XR were 0.23 and 0.98, respectively. The sensitivity and specificity of identifying osteochondral lesions on MRI were 0.43 and 0.81 and on XR were 0.08 and 0.97, respectively. Of the 87 available reports, 45 (51%) described performing chondroplasty for Outerbridge grade II/III chondral lesions on diagnostic arthroscopy. In conclusion, MRI and XR are poorly sensitive at identifying loose bodies or osteochondral defects after patellar dislocations. The poor sensitivity of imaging studies must be considered when determining whether or not to recommend operative management to a patient with patellar instability. This is a Level IV, diagnostic study.
Keyphrases
- anterior cruciate ligament
- total knee arthroplasty
- magnetic resonance imaging
- contrast enhanced
- anterior cruciate ligament reconstruction
- patients undergoing
- diffusion weighted imaging
- computed tomography
- magnetic resonance
- emergency department
- high resolution
- chronic kidney disease
- end stage renal disease
- intensive care unit
- minimally invasive
- knee osteoarthritis
- prognostic factors
- newly diagnosed
- mass spectrometry
- machine learning
- photodynamic therapy