Background: Tibial fracture after cementless Oxford unicompartmental knee arthroplasty (OUKA) is a rare but serious complication. It is reported more frequently in Asian countries. The aim of this retrospective study was to assess the morphological characteristics of the tibia by using a simple novel measurement method in patients with tibial fractures after OUKA. Methods: Six knees (all women) with tibial fractures after cementless OUKA (fracture group) and 150 knees without an obvious complication after cementless OUKA (control group) were examined retrospectively at our institution between January 2016 and April 2017. We drew a medial eminence line (ME line) defined as a line extending from the tip of the medial intercondylar eminence parallel to the tibial axis. The ME line was classified into two types (intramedullary type [type I] and extramedullary type [type E]), and the proportion of each type was compared between fracture patients and controls. Results: In the fracture group, there were four (66.7%) type E cases and two (33.3%) type I cases; in the control group, there were 18 (12%) type E cases and 132 (88%) type I cases. Fisher exact tests showed that the proportion of type E was higher in the fracture group than in the control group (p < 0.01). Conclusions Measurement of the ME line can be recommended as a useful method to assess the risk of postoperative fracture after cementless OUKA.

Gastric cancers that fulfill the Japanese criteria for curative endoscopic resection show a low risk of lymph node (LN) metastasis. Here, we report a case of LN metastasis from early gastric cancer that fulfilled the curative criteria. A 74-year-old Japanese woman was referred to our hospital for treatment of early gastric cancer identified at the site of a hyperplastic polyp that had been diagnosed 10 years prior to presentation. Contrast-enhanced computed tomography did not show any lymphadenopathy and laparoscopy-assisted distal gastrectomy was performed. Histopathological examination revealed a predominantly moderately differentiated adenocarcinoma that measured 15 mm in size and was confined to the mucosa. However, a single metastatic regional LN was observed. A few cancer cells showed positive staining for alpha-fetoprotein. It should be noted that early gastric cancer can be accompanied by LN metastasis even if it fulfills the criteria for curative endoscopic resection.
Adenocarcinoma ; Aged ; alpha-Fetoproteins ; Asian Continental Ancestry Group ; Female ; Gastrectomy ; Humans ; Lymph Nodes ; Lymphatic Diseases ; Mucous Membrane ; Neoplasm Metastasis ; Polyps ; Stomach Neoplasms