Subchondral insufficiency fractures of the medial tibial condyle are associated with medial meniscus extrusion: A retrospective observational study.

BACKGROUND: To the best of our knowledge, no prior studies have identified any risk factors for subchondral insufficiency fractures of the medial tibial condyle. This study aimed to explain relationships between subchondral insufficiency fractures of the medial tibial condyle and the meniscus status, lower extremity alignment, or osteoporosis. METHODS: This retrospective study included 325 consecutive patients whose chief complaint is knee joint pain and who had visited one institution between April 2016 and March 2021, of which 70 patients (8 men and 62 women) who had suspected subchondral insufficiency fractures of the medial tibial condyle had undergone magnetic resonance imaging and radiographic examination. These patients were divided into two groups based on the results of their magnetic resonance imaging: the insufficiency fracture group included 46 patients who had subchondral insufficiency fractures of the medial tibial condyle and the nonfracture group included 24 patients without fractures. The meniscus injury and medial meniscus extrusion (MME) were evaluated by using magnetic resonance imaging. The Kellgren-Lawrence grade, the femorotibial angle, and the percent mechanical axis (%MA) were evaluated with the use of knee radiographs. T-scores were also measured by using dual-energy X-ray absorptiometry with a bone densitometer. RESULTS: MME were significantly larger and the %MA was significantly smaller in the insufficiency fracture group than that in the nonfracture group. The prevalence of medial meniscus injuries and pathological MME were higher in the insufficiency fracture group than those in the nonfracture group. The prevalence of varus knee and osteoporosis did not vary remarkably different between the two groups. CONCLUSION: The patients who had insufficiency fractures of the medial tibial condyle tended to have medial meniscus extrusion.

Recurrent Subchondral Insufficiency Fracture of the Femoral Head: A Case Report.

Introduction: Subchondral insufficiency fracture (SIF) of the femoral head has been reported to occur in older women with osteoporosis. No cases with recurrence of SIF at another site in the ipsilateral femoral head have been described. Case Report: We report a case of a 75-year-old woman with recurrent SIF at another site in the ipsilateral femoral head. SIF was first observed at an anterolateral site on the femoral head and treated non-operatively. The hip pain disappeared after 3 months but recurred 5 months later when another SIF was newly observed at a posterolateral-to-medial site on the femoral head. This SIF was also treated non-operatively. Five months later, the pain was alleviated, but progression of osteoarthritis was seen on X-rays. Conclusion: After an initial SIF, the possibility of recurrence should be considered if pain recurs, even on the ipsilateral side.

Outcomes of Hybrid Total Hip Arthroplasty for Subchondral Insufficiency Fracture of the Femoral Head.

Background: The purpose of this study was to evaluate functional outcomes, radiologic results, and complications after hybrid total hip arthroplasty (THA) in patients with subchondral insufficiency fractures (SIFs) of the femoral head. Methods: From June 2009 to December 2020, among 985 patients who underwent hybrid THA at our hospital, 19 patients diagnosed with SIF through a retrospective chart review were included. Those under 50 years of age, with radiographic findings of osteonecrosis on the contralateral side of surgery, a history of organ transplantation, and alcohol abuse, were excluded. Functional evaluation was performed using a modified Harris Hip Score (HHS). After surgery, inclination and anteversion of the acetabular cup and version of the femoral system were measured using postoperative x-ray. The outpatient follow-up was performed at 6 weeks, 3 months, 9 months, and 12 months after surgery and every year thereafter. Complications including dislocation, implant loosening, stem subsidence, and periprosthetic infection were observed on follow-up radiographs. Results: The average follow-up time was 29.3 ± 9.1 months (range, 24-64 months) with no loss to follow-up. The mean modified HHS was 83.4 ± 9.6 (range, 65-100) at the last outpatient clinic follow-up. The average inclination of the acetabular cup was 41.9° ± 3.4° (range, 37°-48°), and the anteversion was 27.5° ± 6.7° (range, 18°-39°). The version of the femoral stem was 19° ± 5.7° (range, 12°-29°). There was no case of intraoperative fracture. There were no cases of dislocation, loosening of the cup, subsidence of the femoral stem, intraoperative or periprosthetic fracture, or periprosthetic infection on the follow-up radiographs. Conclusions: In our study, hybrid THA showed favorable outcomes in patients diagnosed with SIF, and there were no further special considerations as for THA performed due to other diseases or fractures.

Osteoporosis, Osteoarthritis, and Subchondral Insufficiency Fracture: Recent Insights.

The increased incidence of osteoarthritis (OA), particularly knee and hip OA, and osteoporosis (OP), owing to population aging, have escalated the medical expense burden. Osteoarthritis is more prevalent in older women, and the involvement of subchondral bone fragility spotlights its association with OP. Notably, subchondral insufficiency fracture (SIF) may represent a more pronounced condition of OA pathophysiology. This review summarizes the relationship between OA and OP, incorporating recent insights into SIF. Progressive SIF leads to joint collapse and secondary OA and is associated with OP. Furthermore, the thinning and fragility of subchondral bone in early-stage OA suggest that SIF may be a subtype of OA (osteoporosis-related OA, OPOA) characterized by significant subchondral bone damage. The high bone mineral density observed in OA may be overestimated due to osteophytes and sclerosis and can potentially contribute to OPOA. The incidence of OPOA is expected to increase along with population aging. Therefore, prioritizing OP screening, early interventions for patients with early-stage OA, and fracture prevention measures such as rehabilitation, fracture liaison services, nutritional management, and medication guidance are essential.

[Bone marrow edema syndromes of the knee]. / Knochenmarködem-Syndrome am Kniegelenk.

Bone marrow edema represents a common finding on magnetic resonance imaging (MRI) of the knee and other joints, which can occur as a primary pathology or as a secondary phenomenon of various bone and joint pathologies. This article reviews the terminology, definition, pathology and differential diagnosis of bone marrow edema of the knee taking into consideration current concepts.

A case of osteogenesis imperfecta diagnosed after subchondral insufficiency fracture of bilateral femoral heads.

Osteogenesis imperfecta (OI) is a heterogeneous disorder characterised by bone fragility. Herein, we report a case of OI diagnosed after subchondral insufficiency fracture (SIF) of bilateral femoral heads. A 37-year-old woman was referred to Saitama Medical University Hospital due to left hip pain without any trauma that lasted for 2 months. She was subsequently diagnosed with SIF of the left femoral head. After 3 months, she further developed SIF of the right hip without any trauma. Magnetic resonance imaging of the bilateral hips showed linear low-signal changes of the subchondral bone and bone marrow oedema of the femoral head on T2-weighted coronal and sagittal images, diagnosing of both SIFs. The bone mineral density was 0.851 g/cm2 (T-score, -1.3) at the lumbar spine, 0.578 g/cm2 (T-score, -1.9) at the right femoral neck, and 0.582 g/cm2 (T-score, -1.9) at the left femoral neck. Considering that the patient had multiple histories of fracture, blue sclera, and mild bilateral sensorineural hearing loss, she satisfied the diagnostic criteria for OI. Genetic testing revealed a mutation in COL1A1 (NM_000088.3, c.3806G>A: p. Trp1269*). After 7 months of conservative therapy, her symptoms improved. After 4 years, both hips were pain-free with no evidence of osteoarthritis progression. OI can result in insufficiency fractures due to bone fragility in adolescence and adulthood or later, and none of the cases of OI, except for the current case, were diagnosed as a result of bilateral SIF.

Staged Bi-compartmental Knee Arthroplasty for Contralateral Compartment Failure After Medial Unicompartmental Knee Arthroplasty in Dialysis Patients: Two Case Reports.

Unicompartmental knee arthroplasty (UKA) is a minimally invasive surgical technique with good clinical outcomes; however, its outcomes in patients undergoing hemodialysis are unknown. Herein, we report two cases of patients undergoing hemodialysis who underwent staged bi-compartmental UKA (Bi-UKA) for early contralateral compartment failure after medial UKA. We describe the case of early contralateral compartment failure after medial UKA in two women patients aged 71 and 72 years with a dialysis history of seven and 22 years, respectively. Three months after right medial UKA, she had persistent joint edema and arthralgia after minor trauma, with recurrent gait disturbance in the first case. An MRI showed a bone marrow lesion in the contralateral compartment, and a lateral UKA was added. In the second case, the knee pain worsened without any trigger three years after leaving the medial UKA. A subchondral insufficiency fracture (SIF) was diagnosed by a plain radiograph showing a radiolucent area on the lateral femoral condyle. Gait disturbance did not improve, and a lateral UKA was performed. In our hospital, medial UKA was performed on seven knees of dialysis patients in 10 years since 2011, and contralateral compartment failure was observed in two knees at an early stage. In both cases, lumbar bone density was normal and there was no postoperative overcorrection in leg alignment, but a SIF of the contralateral side occurred, suggesting that bone fragility of the contralateral compartment due to long-term dialysis was the underlying cause. Staged Bi-UKA was minimally invasive and useful as a revision surgery.