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 34-year-old Taiwanese man presented to our emergency department with a 3-day history of coughing and chest tightness. He had a history of essential hypertension and congestive heart failure followed up at our cardiovascular department and under medication control. He was an express delivery worker with right hand dominance.\nA chest radiograph on November 16, 2018, revealed metallic internal fixation pins and wire over his right clavicle, and an unidentified object of metallic density at the left side of his upper neck. A further cervical spine radiograph was arranged, which revealed a foreign body of metallic density crossing over the C2–C4 level on the left side of his neck (Fig. ) that indicated a loosened K-wire. He recalled that he had suffered from a right clavicle fracture which was operated on for wire fixation approximately 15 years ago, but had lost follow-up since then. Palpation of his neck revealed no palpable foreign body. His oral cavity was clear, and findings on nasopharyngoscopy were also normal. A series of chest radiographs from 3 years ago showed that the wire had migrated from the right AC joint to the left side of his neck (Fig. ). Computed tomography angiography was performed to evaluate the position of the K-wire regarding the major vessels. The wire was removed by exploratory neck dissection under C-arm fluoroscopy assistance. The wire was found beneath the carotid sheath and removed by gentle traction along its axis (Fig. ). His postoperation recovery was uneventful, and he was discharged 4 days later.