Hemorrhagic Ligamentum Flavum Cyst in the Adjacent Level of Lytic Spondylolisthesis - A Case of Diagnostic and Therapeutic Dilemma.

INTRODUCTION

Arthrofibrosis of the knee is an adverse outcome after anterior cruciate ligament (ACL) reconstruction. Definitions and classifications vary widely based on extension and flexion losses, patellar mobility, and location. In general, it is understood as a restricted range of motion (ROM) due to scar tissue, and it is often defined as symptomatic limitation in knee ROM compared to the opposite knee. The frequency of ACL injuries, and consequently arthrofibrosis, is rising among children and adolescents, with an incidence rate ranging from 2 to 14% in the pediatric population. Treatment options for arthrofibrosis include oral corticosteroids, physical therapy, casting, manipulation under anesthesia, and arthroscopic lysis of adhesions, with early recognition being a crucial intervention. To our knowledge, this is the first report in the literature to describe the development of chondromalacia after the resolution of arthrofibrosis with conservative measures in a pediatric patient.

CASE REPORT: A 17-year-old male developed arthrofibrosis after combined ACL reconstruction and autologous osteochondral graft transfer. Knee flexion was restored with a high-frequency, intensive physical therapy and home exercise program but at a cost of developing anterior knee and patellofemoral chondromalacia.

CONCLUSION

Because complications can arise from the greater patellofemoral contact forces observed in arthrofibrosis, orthopaedic surgeons should consider early lysis of adhesions for the management of post-operative arthrofibrosis, particularly involving the parapatellar retinaculum, in adolescents who are non-responsive to conservative measures. In addition, restrictions on high levels of loading should be considered during the initial post-operative period in scenarios in which ROM has not been achieved.