Follow-up of collagen meniscus implant patients: Clinical, radiological, and magnetic resonance imaging results at 5years

This study investigated at medium term follow-up the clinical outcomes and any progression of knee osteoarthritis in a population of patients that underwent arthroscopic placement of a collagen meniscus implant. Thirty-four patients underwent arthroscopic placement of a collagen meniscus implant for a symptomatic deficiency of medial meniscal tissue. Follow-up evaluation included Lysholm II score and Tegner activity scores and MR arthrography of the knee at 2 and 5. years after surgery. Plain radiographs were also obtained at 5. years. Six patients were excluded. In eight cases arthroscopic second look evaluation was performed. Lysholm and Tegner activity scores at 2 and 5. years after surgery improved significantly compared to the preoperative score. These patients showed good to excellent clinical results after 5. years from a CMI placement. The chondral surfaces of the medial compartment had not degenerated further since placement of the CMI. MR signal had continued to mature between 2 and 5. years after implant, progressively decreasing signal intensity but in any case comparable to the low signal of a normal meniscus. In most of cases the CMI-new tissue complex had a slight reduction in size, compared to a normal medial meniscus, but the new tissue had no apparent negative effects.