A 75-year-old man underwent tension band wiring with cerclage wiring for treatment of a transverse patellar fracture of the right knee (). At 10 weeks postoperatively, radiographs demonstrated breakage of the superior portion of the cerclage wire (). Although he was advised to have all fixation devices removed after fracture healing and continuous follow-up, the patient was lost to follow-up after a clinical examination and plain radiography at 16 weeks postoperatively because he had no symptoms such as irritation due to the wire or limitation of range of motion. At 16 weeks, the wire was still radiographically at the superior part of the right patella.\nThe patient returned to our outpatient clinic 2 years after the surgery because the wire had perforated the skin anteriorly. He did not recall any trauma to the knee since the last follow-up. Radiographs of the right knee demonstrated that the cerclage wire was broken into pieces, and a fragment had migrated into the posterior compartment (). We could not decide from plain radiographs or three-dimensional computed tomography (3D CT) whether the wire fragment was in the posterior compartment of the knee joint or the popliteal fossa (). Because there was a risk of chondral damage if it was inside the joint or neurovascular damage if it was in the popliteal fossa, the patient agreed to surgery to remove the hardware.\nA skin incision was made anteriorly over the previous incision and all the wires were removed. An arthroscopic examination was then performed; before scoping the posterior compartment, we performed the routine arthroscopic assessment through the standard anteromedial portal. Any structural damage including chondral lesion due to the wire migration was not found. Then, we examined the posterior compartment through the posteromedial or posterolateral portal. However, we could not find the wire fragment by palpating with a probe. However, we could not find the wire fragment by palpating the posterior structures with a probe introduced through the posteromedial or posterolateral portal. Before finishing the arthroscopic examination and approaching the popliteal fossa from the posterior aspect of the knee, we used intraoperative fluoroscopy, which demonstrated that the wire fragment had moved when we palpated the upper part of the posterior septum with the arthroscopic probe. This suggested that the wire was embedded in the posterior septum. We therefore made a posterior transseptal portal according to the procedure of Ahn and Ha and enlarged the portal upwards with a radiofrequency probe []. We eventually found the fragment embedded in the septum and were able to remove it safely through the posteromedial portal (Figures and ).\nAfter surgery, the patient could walk without pain and showed full range of motion at final follow-up.
A 51-year-old man reported with complaints of recent onset of left knee pain. He had sustained a displaced comminuted fracture of his left patella following a fall 15 months ago. Modified tension band wiring with cerclage wiring was successfully performed, and the patient was recovering well. He was well for the last 14 months and returned to his job without any pain or functional disability. However, he started experiencing deep-seated pain within the left knee with restriction of movements for the last 4 weeks. There was no recent history of any fall or trauma to the left knee. Clinical examination of the left knee revealed no patella or joint line tenderness but pieces of wires were palpable percutaneously. There was no effusion and the cruciate and collateral ligaments were intact; there was no neurovascular deficit. There was no extensor lag and knee extension power was normal. The range of motion of the knee was painfully restricted.\nRadiographs of the left knee revealed a united fracture patella with broken cerclage wire (). The inferio-medial segment of the broken cerclage wire was found to have migrated into the posterior compartment of the knee joint and hooked anteriorly at the base of anterior cruciate ligament.\nThe patient underwent surgery for removal of the patella wires. Fluoroscopic examination before surgery revealed the posterior part of wire had shifted its position with anterior part of it still hooked with anterior cruciate ligament. An arthroscopic examination of the knee was done through the standard anteromedial and anterolateral portal. Any structural damage including chondral lesion due to wire migration was not found, a migrated piece of wire was found embedded at the base of anterior cruciate ligament, going toward posterior compartment of knee through medial side of notch, which was removed (). We used intraoperative fluoroscopy (), before finishing the arthroscopic examination of knee, which demonstrated that, there was no remaining piece of wire in posterior compartment of knee. The rest of the broken wires were removed via a midline anterior knee incision along the old scar. The patella was stable after complete removal of the wires, indicating union of the rest of the fragments.\nThe patient was discharged the next morning and his wounds healed at 2 weeks. Complaints of knee pain resolved completely following the surgery, and the patient was able to resume work at 2 weeks.