Four stem fractures in a 12-year follow-up study of 9,135 patients with Exeter hip stems at seven teaching facilities in Japan.

BACKGROUND: Although excellent long-term results have been reported for the Exeter stem, stem fracture is recognized as a rare complication. However, there have been no reports on the incidence and risk factors for stem fractures based on detailed population information. This study aimed to clarify the incidence of Exeter hip stem fracture based on detailed population information from seven Exeter stem teaching centers in Japan and to examine the risk factors for stem fracture. METHODS: A total of 8,499 primary total hip arthroplasties (THA) and 636 revision hip arthroplasties (revisions) performed at seven Exeter teaching hospitals between 1999 and 2021 were included and retrospectively investigated based on medical records. RESULTS: Stem fractures were identified in two primary THA (fracture rate: 0.02%) and two revision THA (fracture rate: 0.21%) cases. The stem length was ≤125 mm in three out of these four cases. Revision and 30 stem were the risk factors for stem fractures. Weight and body mass index (BMI) were not significantly associated with the occurrence of stem fractures. CONCLUSIONS: In Western countries, the incidence of Exeter stem fractures is reportedly 0.017-0.15% for primary THA and 0.99-1.21% for revision THA. In this study, the incidence of primary THA was 0.02%, which is similar to the lowest reported rate, whereas the incidence of revision THA was 0.21%, which is lower than that reported in previous studies. Revision surgery had the same risk factors as those reported in the West-namely, stem length ≤125 mm (except for the 30 stem) and BMI, which were not risk factors in Japanese patients.

Multi-center study of use of the Exeter stem in Japan: a 10-year follow-up report.

PURPOSE: Since the introduction of the Exeter stem for clinical use in Japan in 1996, the number of stems used has continued to rise owing to its favorable results. We investigated the outcomes of patients who had previously undergone total hip arthroplasty with the Exeter stem in Japan with a 10-year + follow-up period. METHODS: This retrospective cohort study used clinical and radiographic data of 682 cases of primary total hip arthroplasty performed using the Exeter stem. RESULTS: The mean postoperative follow-up period was 13.3 years. Femoral-side revision was required in 14 hips, with no cases of aseptic stem loosening-associated revision observed. Kaplan-Meier survival analysis predicted 97.3% 15-year survival when revision for any reason was used as the endpoint. CONCLUSION: The obtained findings suggested the excellent long-term stability of the Exeter stem for primary total hip arthroplasty in Japan.

Ligamentum flavum haematoma: a report of two cases.

We present 2 cases of ligamentum flavum haematoma causing root compression. Magnetic resonance imaging showed an epidural mass linked to the ligamentum flavum. The mass was isointense in T1-weighted images, and was centrally hyperintense and peripherally hypointense in T2-weighted images. Surgical removal of the ligamentum flavum achieved resolution of the symptoms. The definitive diagnosis could only be confirmed by histopathological examinations. The differential diagnoses include lumbar disc herniation and lumbar spinal canal stenosis caused by neoplasm, infection, epidural haematoma, or facet cyst.