The patient, a 38-year-old active-duty Marine, presented to our clinic with a history of persistent right knee pain that occurred while going up and down stairs and was most prominent along the anterior knee. His medical history was significant for a diagnostic arthroscopy done elsewhere for a "clean up" of the right knee, which provided minimal pain relief. The operative report and images demonstrated Outerbridge grade IV changes involving the lateral patellar facet, grade III and IV changes along the medial patellar facet, and grade IV changes along the entire trochlea down to the intercondylar notch. Magnetic resonance imaging (MRI) of his right knee was obtained, which demonstrated ongoing patellofemoral osteoarthritis with a kissing lesion involving the trochlea and lateral facet of the patella with subchondral cyst formation. No evidence of new pathology was present elsewhere in the knee. After exhausting all conservative treatment options, he underwent an uncomplicated patellofemoral arthroplasty for isolated right knee patellofemoral degenerative joint disease.
Four months after surgery, the patient had regained full range of motion (ROM) of his right knee and returned to his previous activity level, including running and playing basketball. Furthermore, he was able to pass the required endurance tests for military active-duty reinstatement.
Approximately ten months after surgery, he returned with moderate, sharp right knee pain, which he attributed to prolonged physical activity and playing sports. His knee pain was predominantly over the lateral joint line and was associated with catching and clicking. Clinical examination was significant for tenderness over the lateral joint line with positive Thessaly and McMurray tests. A mild effusion was present, and the ROM of the right knee was 0-125 . A stability examination revealed moderate (2B) laxity with Lachman and anterior drawer tests. No varus or valgus instability was present, and results of the dial and reverse pivot shift tests were normal. Based on his clinical examination and concern for lateral meniscus and anterior cruciate ligament (ACL) pathology, a metal reduction MRI was acquired. The images revealed an intact patellofemoral arthroplasty; however, evaluation of the ACL and menisci was nondiagnostic due to metallic susceptibility artifacts (Figures 1-3). The findings and treatment options were discussed with the patient, and due to his persistent pain and mechanical symptoms, he was scheduled for a diagnostic arthroscopy.
Prior to his surgery, we were afforded the opportunity to use a new diagnostic needle arthroscopy (mi-eye 2 ; Trice Medical, King of Prussia, PA) to evaluate his knee joint. After written consent was obtained, the patient's right knee was prepped in a standard sterile fashion, the subcutaneous tissue was infiltrated with 5 cc of 1% lidocaine, and mi-eye 2 was inserted into the lateral joint space. The mi-eye 2 quickly confirmed the presence of a complex, degenerative tear of the lateral meniscus. Upon further examination, we discovered an ACL tear, an intra-articular loose body, and a grade IV chondral lesion on the medial femoral condyle measuring approximately 20 mm x 20 mm (Figure 4). The mi-eye 2 provided direct visualization of the knee joint without requiring a formal operating room procedure and yielded an immediate diagnosis of the patient's intra-articular pathology, which was either equivocal or not evident on MRI.
As a result of the findings, the surgical plan was changed, and the patient subsequently underwent an arthroscopic partial lateral meniscectomy, allograft ACL reconstruction, and osteochondral allograft transplantation. The patient had an uncomplicated postoperative course and was discharged on the day of surgery. Knee ROM exercises were started immediately. He was managed with non-weight-bearing restrictions for 3 weeks, followed by progressive weight bearing from weeks 3 to 6, and then full weight bearing beginning 6 weeks after surgery.