Snap Crackle And Pop: Diagnosing And Treating The Challenging Snapping Popliteus Tendon Syndrome

Title: Snap Crackle and Pop: Diagnosing and Treating the Challenging Snapping Popliteus Tendon Syndrome HISTORY: A 17-year-old female presented with persistent right knee pain, popping, and swelling that progressed over two years following a marching band injury. She was previously seen by an outside orthopedic surgeon and underwent two knee arthroscopic procedures including an IT band lengthening, followed by extensive physical therapy, but her symptoms continued without any improvement. Despite these interventions, reported ongoing discomfort and popping sensation in her lateral knee that impacted her daily activities. She was referred by her new orthopedic surgeon to the primary care sports medicine team to get a dynamic ultrasound assessment to assess for snapping popliteus tendon syndrome. PHYSICAL EXAMINATION: non-antalgic gait. No effusion. On passive flexion and extension of the right knee, a visible popping was observed in the posterolateral corner. Tenderness over posterior lateral joint line, with increased pain on varus stress. She had no pain, apprehension, or instability with lateral patellar translation. Mild lateral patellar tracking was noted without evidence of instability. Sensation was intact and strength 5/5 throughout right lower extremity. DIFFERENTIAL DIAGNOSIS: #1: Torn Lateral Meniscus #2: Snapping Popliteus Tendon Syndrome #3: Popliteomeniscal Fascicle Tear #4: Snapping Biceps Femoris Tendon #5: Lateral Collateral Ligament Sprain TEST AND RESULTS: X-rays of the right knee AP/Lateral/Sunrise views: no obvious fractures, dislocations, joint space narrowing, or misalignments. MRI of the right knee: did not reveal any findings specific to patient’s complaint. Dynamic Bedside Ultrasound: snapping popliteal tendon with flexion and extension. FINAL/WORKING DIAGNOSIS:Snapping Popliteus Tendon Syndrome TREATMENT AND OUTCOMES: 1.A steroid injection in the popliteus tendon sheath2. Right knee arthroscopic synovectomy with lateral femoral condyle tubercle debridement. After tubercle resection, visualized the knee in flexion and extension confirming resolution of the snapping popliteus tendon.3.Started post-operative physical therapy.4.At the six-week postoperative follow-up, patient was recovering well with no complaints.