Unexplained proximal tibiofibular joint pain after high tibial osteotomy

Problems of the proximal tibiofibular joint (pTFj) after high tibial osteotomy (HTO) are rare. With this case report, we strive to highlight the importance of investigating the pTFj in patients with unexplained knee pain after HTO. A 44 year old male patient presented with diffuse pain on his left knee 3 years after medial opening wedge HTO due to medial compartment overloading in a varus knee. Patient described persistent anterior tibial and lateral knee pain. 2 years after HTO, patient underwent implant removal but the knee pain persisted. As the reason for the persistent pain was not identified, further radiological evaluation was done. Single photon emission computerized tomography/computerized tomography (SPECT/CT) revealed that there was no increased uptake within the tibiofemoral joint, indicating a biologically well performed correction of the varus deformity. However, markedly increased tracer uptake was found at the pTFj. On the inherent axial CT scans, it was seen that the proximal screws were too long and placed within the pTFj. Along with this a severe osteoarthritis of the pTFj was identified. The cause of the patient's pain was then confirmed by a CT guided infiltration of local anesthetic. An arthrodesis of the pTFj was performed and at 12 months followup after the arthrodesis the patient was pain free. This case highlights how important it is to evaluate the pTFj in patients with unexplained pain after HTO. SPECT/CT was helpful in identifying the patient's problem in this challenging case.