1007 - From medical student to patient: Case Report on a Postero-lateral Corner injury with Sciatic Nerve Palsy while playing basketball.

Case Diagnosis: Grade III Posterolateral Corner Injury with Sciatic Nerve Palsy

Case Description: 24 y/o male presents 3-days after GLF resulting in left knee trauma while playing basketball. Mechanism described as tripping and falling on the left leg causing varus with an audible pop. Patient presents with foot drop, instability, numbness, 3/10 pain, and using crutches. X-rays were negative for fractures in the knee or ankle.

PE of the knee: Anterior Drawer test (-), Posterior Drawer test (-), Lachman test (-), Valgus stress test (-), Varus Stress test (+), McMurray test (-). X-Ray of the knee was negative for fractures. Treatment plan involves MRI, pain management, physical therapy, nerve conduction study and surgery.

MRI confirmed grade III PLC injury with associated biceps femoris tendon tear & sprain of the ACL. EMG/NCV was compatible with severe axonotmesis of the common peroneal nerve. PLC reconstruction with arthroscopic exploration was achieved 6 weeks post-lesion. Post- up rehabilitation was successful.

Discussions: Grade III injuries usually involve rupture of the PCL. PLC rehabilitation went according to plan, but no meaningful advances were made in nerve recovery evidenced by EMG/NCV. F/U ultrasound revealed suspected distal sciatic nerve damage with resulting neuroma, confirmed via surgical exploration 1 year s/p PLC reconstruction. . Outcomes to peripheral nerve injury have not been favorable. Possible treatment options include peripheral nerve transfer, posterior tibialis tendon transfer or continued use of AFO.

Conclusions: PLC injuries are uncommon for which high clinical suspicion is required to identify and treat promptly, even when the history doesn’t align to the expected mechanism.The proposed question following this case is: when does a more proximal exploration is warranted ?Distal sciatic nerve damage associated to isolated PLC injury has not not been documented, to our knowledge, until now.