Subchondral insufficiency fracture of the knee: review of current concepts and radiological differential diagnoses

Diagnostic imaging findings in lame Warmblood horses with bone injuries of the medial proximal phalanx glenoid cavity

This retrospective study aims to describe baseline and follow-up imaging findings in subchondral and trabecular bone damage occurring outside of the sagittal groove in the proximal phalanx (P1) glenoid in a case series of lame Warmblood horses. Thirteen lame horses (16 forelimbs) with standing magnetic resonance imaging (sMRI) evidence of nonsagittal groove glenoid subchondral and trabecular bone injury of P1 as the main lesion were included. All injuries were located at the medial aspect of the P1 glenoid. At sMRI, changes included subchondral bone plate thickening and trabecular sclerosis, bone marrow edema-like signal, subchondral bone resorption (11/16), and new bone production (8/16). Subchondral bone resorption in the transverse plane was linear (8/11), round (2/11), or ill-defined (1/11). Sclerosis, bone resorption, and new bone production were seen radiographically in 10, 4, and 5 limbs, respectively. All limbs had concurrent metacarpal condyle sMRI imaging abnormalities, osteophytosis, and joint effusion. Follow-up sMRIs were obtained in 8 of 16 limbs, five of which showing progression of the resorptive lesion. One horse encountered a comminuted fracture of the affected P1 18 months after the follow-up sMRI examination. The imaging appearance of the medial glenoid bone injuries of P1 in this case series is consistent with chronic bone overload. The linear configuration of bone resorption seen in eight lesions suggests short, incomplete stress fractures, which is supported by the ultimate catastrophic fracture occurring in one case.

Association of Spontaneous Osteonecrosis of the Knee with Ipsilateral Meniscus and Posterior Root Tear: Systematic Review and Meta-analysis

Objective

The relationship between spontaneous osteonecrosis of the knee (SONK) and ipsilateral meniscus tear remains to be established, and the possible causes are clarified and summarized.

Methods

We conducted a search in Pubmed, Web of Science, Embase, and the Cochrane Library to include all English articles published from the establishment of the database until April 2023. The odds ratio (OR) and 95% confidence interval (CI) were calculated to evaluate the relationship between SONK and ipsilateral meniscus lesions.

Results

A total of 405 patients were included in eight articles, including 157 males and 248 females, with an average age of 63.94 years and an average BMI of 26.36 kg/m2. In patients with medial SONK, the prevalence of ipsilateral meniscus tear was 0.8982, 95% CI (0.7389, 0.9648), and the prevalence of ipsilateral posterior root tear was 0.6198, 95% CI (0.5169, 0.7118). The prevalence of ipsilateral meniscus tears in patients with lateral SONK was 0.2188, 95% CI (0.1150, 0.3711), and the prevalence of ipsilateral posterior root tears was 0.1667, 95% CI (0.1071, 0.2424).

Conclusions

SONK is significantly associated with meniscus or root tears, which limit meniscus function and lead to changes in the stress environment between the knee and the tibiofemur, increasing the chance of incomplete fracture. We suggest that the expression of SONK can be replaced with subchondral insufficiency fracture of the knee.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43465-024-01140-4.

Subchondral insufficiency fractures: overview of MRI findings from hip to ankle joint

Subchondral insufficiency fracture (SIF) represents a potentially severe condition that can advance to osteoarthritis, with collapse of the articular surface. SIF manifests as a fracture in bone weakened by non-tumorous disease, precipitated by repetitive physiological stress, without a clear history of major trauma. It is observed along the central weight-bearing region of the femoral condyle, with a higher incidence in the medial femoral condyle, but also in other large weight-bearing synovial joints, such as the femoral head, tibial plateau, or talus.A review of the literature from the past six years was performed by searching PubMed and ScienceDirect databases, using the keywords "subchondral insufficiency fracture" and "spontaneous osteonecrosis of the knee". The inclusion criteria were scientific papers presented in the English language that reported on the magnetic resonance imaging (MRI) aspects of SIF of the lower limb.Detecting SIF at the level of the hip, knee, and ankle may present challenges both clinically and radiologically. The MRI appearance is dominated by a bone marrow edema-like signal and subchondral bone changes that can sometimes be subtle. Subchondral abnormalities are more specific than the pattern of bone marrow edema-like signal and are best shown on T2-weighted and proton-density-weighted MR images. MRI plays an important role in accurately depicting even subtle subchondral fractures at the onset of the disease and proves valuable in follow-up, prognosis, and the differentiation of SIF from other conditions. · Subchondral insufficiency fractures may affect the hip, knee, and ankle.. · Subchondral insufficiency fractures may heal spontaneously or progress to collapse.. · MRI is important for the detection, follow-up, and prognosis of subchondral insufficiency fractures.. · Differential diagnosis may include transient osteoporosis and osteonecrosis of systemic origin.. · Buturoiu MM, Ghiea S, Weber M. Subchondral insufficiency fractures: overview of MRI findings from hip to ankle joint. Fortschr Röntgenstr 2024; DOI 10.1055/a-2344-5337.

Bone injury imaging in knee and ankle joints using fast-field-echo resembling a CT using restricted echo-spacing MRI: a feasibility study

Purpose

To explore the consistency of FRACTURE (Fast-field-echo Resembling A CT Using Restricted Echo-spacing) MRI and X-Ray/computerized tomography (CT) in the evaluation of bone injuries in knee and ankle joints.

Methods

From Nov. 2020 to Jul. 2023, 42 patients with knee joint or ankle joint injuries who underwent FRACTURE MRI examinations were retrospectively collected. 11 patients were examined by both X-Ray and FRACTURE examinations. 31 patients were examined by both CT and FRACTURE examinations. The fracture, osteophyte, and bone destruction of the joints were evaluated by two radiologists using X-Ray/CT and FRACTURE images, respectively. Kappa test was used for consistency analysis.

Results

The evaluation consistency of fracture, osteophyte and bone destruction via X-Ray and FRACTURE images by radiologist 1 were 0.879, 0.867 and 0.847 respectively, and for radiologist 2 were 0.899, 0.930, and 0.879, respectively. The evaluation consistency of fracture, osteophyte and bone destruction via CT and FRACTURE images by radiologist 1 were 0.938, 0.937 and 0.868 respectively, and for radiologist 2 were 0.961, 0.930, and 0.818, respectively.

Conclusion

For fracture, osteophyte, and bone destruction of knee and ankle joints. FRACTURE MRI showed a high consistency with X-Ray/CT examinations.

Rates and predictors of reimplantation of matrix-induced autologous chondrocyte implantation following first stage cartilage harvest: A cohort study

PURPOSE

To assess the reimplantation rate and predictors of patients requiring second-staged matrix-induced autologous chondrocyte implantation (MACI) reimplantation after initial first stage cartilage biopsy.

METHODS

A retrospective review was performed from 2018 to 2022 among patients who underwent only phase I MACI biopsy procedure (biopsy group) or both phase I with transition to phase II implantation of chondrocytes (implantation group) at a single tertiary center. Demographic, qualitative, and quantitative measurements were recorded, and univariate and multivariate regression analysis was performed to assess predictors of ultimately requiring second stage MACI implantation.

RESULTS

A total of 71 patients (51% female, age 27.7 ± 10.6 years (range 12-50)) were included in this study. Eventually, 25 of 71 patients (35.2%) experienced persistence of symptoms after initial MACI biopsy and other concomitant procedures, requiring second-stage implantation. Univariate analysis showed the implantation group compared to the biopsy group had a greater lesion size (5.2 cm2 ± 3.3 vs. 3.3 cm2 ± 1.4, p = 0.024), a higher proportion patients ≥ 26 years of age (76% vs. 43%, p = 0.009), a medial femoral condyle lesion more commonly (33% vs 11%, p = 0.005), were more often female (72% vs. 39%, p = 0.008), and had less often soft tissue repair at time of biopsy (32% vs. 61%, p = 0.020). Backward multivariate logistic regression analysis revealed that size of the lesion (OR 1.43, p = 0.031) and age ≥ 26 years old at time of biopsy (OR 3.55, p = 0.042) were independent predictors of not responding to initial surgery and requiring implantation surgery.

CONCLUSION

This study found that 35% of patients undergoing MACI phase I biopsy harvest eventually required autologous implantation. Independent risk factors for progressing to implantation after failed initial surgery were larger defect size and older age.

LEVEL OF EVIDENCE

III, Cohort Study.

High incidence of medial meniscus root/radial tears and extrusion in 253 patients with subchondral insufficiency fractures of the knee

PURPOSE

The demographic and radiological risk factors of subchondral insufficiency fractures of the knee (SIFK) continue to be a subject of debate. The purpose of this study was to associate patient-specific factors with SIFK in a large cohort of patients.

METHODS

Inclusion criteria consisted of patients with SIFK as verified on magnetic resonance imaging (MRI). All radiographs and MRIs were reviewed to assess characteristics such as meniscus tear presence and type, subchondral oedema presence and location, location of SIFK, mechanical limb alignment, osteoarthritis as assessed by Kellgren-Lawrence grade and ligamentous injury. A total of 253 patients (253 knees) were included, with 171 being female. The average body mass index (BMI) was 32.1 ± 7.0 kg/m2.

RESULTS

SIFK was more common in patients with medial meniscus tears (77.1%, 195/253) rather than tears of the lateral meniscus (14.6%, 37/253) (p < 0.001). Medial meniscus root and radial tears of the posterior horn were present in 71.1% (180/253) of patients. Ninety-one percent (164/180) of medial meniscus posterior root and radial tears had an extrusion ≥3.0 mm. Eighty-one percent (119/147) of patients with SIFK on the medial femoral condyle and 86.8% (105/121) of patients with SIFK on the medial tibial plateau had a medial meniscus tear. Varus knees had a significantly increased rate of SIFK on the medial femoral condyle in comparison to valgus knees (p = 0.016).

CONCLUSION

In this large cohort of patients with SIFK, there was a high association with medial meniscus root and radial tears of the posterior horn, meniscus extrusion ≥3.0 mm as well as higher age, female gender and higher BMI. Additionally, there was a particularly strong association of medial compartment SIFK with medial meniscus tears. As SIFK is frequently undiagnosed, identifying patient-specific demographic and radiological risk factors will help achieve a prompt diagnosis.

LEVEL OF EVIDENCE

Level IV.

Bone marrow edema of the knee: a narrative review

Bone marrow edema (BME) is a frequent MRI finding in patients with knee pain. According to the etiology, BME of the knee can be classified into three main categories: ischemic, mechanic, and reactive. The diagnosis may be difficult, because of the specificity of symptoms and the poor radiographic findings. MRI is the gold standard, showing an area of altered signal of the bone with an high signal intensity on fat-suppressed, T2 weighted images, usually in combination with an intermediate or low signal intensity on T1 weighted images. Bone marrow edema tends to be self-limiting and, in most cases, resolves without any consequences in a varying amount of time. However, since it may evolve to complete joint destruction, early diagnosis and correct treatment are crucial to prevent the articular degeneration. Conservative therapy is the first step, with no weight-bearing for 3 to 6 weeks on the affected side, in combination with the administration of anti-inflammatory drugs or painkillers to manage symptoms. In non-responding forms and more advanced stages, minimally invasive preservative surgery can provide significant results, with subchondroplasty and core decompression being the two main procedures available. Knee arthroplasty, both total (TKA) or unicompartmental (UKA), is the only effective option when the degradation of cartilage is diffuse and in patients with subchondral bone collapse.

Presence of subchondral fracture in cases diagnosed as transient osteoporosis of the hip: a retrospective independent reader-based study

OBJECTIVE

Transient osteoporosis of the hip (TOH) is an uncommon, typically self-limited diagnosis of uncertain etiology. We hypothesize that TOH represents an underlying subchondral fracture, and a discrete fracture line can often be detected on high-resolution MRI.

MATERIALS AND METHODS

A retrospective PACS query identified patients meeting imaging criteria for TOH with intense bone marrow edema (BME) in the femoral head on MRI. Those with poor quality studies, other underlying pathologies, or antecedent trauma were excluded. Three musculoskeletal radiologists independently reviewed each case for presence of a definite subchondral fracture line on small field of view (FOV) MR images of the affected hip. Extent of BME, reciprocal acetabular BME, and joint effusion size were also recorded. Binomial logistic regression was performed to determine statistically significant predictors of subchondral fracture.

RESULTS

Fifty patients met inclusion criteria (29 females, 0 pregnant). Mean age was 62±12 years (range 35-84). Average duration of symptoms before MRI was 102±135 days. Ten patients had bone densitometry within 2 years of MRI, six demonstrating osteopenia or osteoporosis. Subchondral fractures were unanimously identified in 44/50 (88%). Interclass correlation coefficient with absolute agreement was 0.73, 95% CI (0.57-0.84), indicating near-excellent agreement. Most cases demonstrated a large joint effusion (23/50, 46%) and acetabular BME (31/50, 62%). Increasing size of joint effusion was a statistically significant predictor of subchondral fracture (p=0.05), with 6.9 higher odds. There was a strong correlation with osteopenia/osteoporosis and fracture (p<0.001).

CONCLUSION

Discrete subchondral fractures were identified unanimously on small FOV imaging in the majority of TOH cases.

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.

Comparison of the efficacy of Oxford unicondylar replacement for the treatment of spontaneous osteonecrosis of the knee versus medial knee osteoarthritis: a meta-analysis

OBJECTIVE

Meta-analysis of the comparative efficacy of Oxford unicompartmental knee arthroplasty (OUKA) for the treatment of spontaneous osteonecrosis of the knee (SONK) and medial knee osteoarthritis (MKOA).

METHODS

A computerized search was conducted for literature related to OUKA treatments of SONK and MKOA across various databases, including the China National Knowledge Infrastructure, WAN FANG, VIP, SinoMed, Cochrane Library, PubMed, Embase, and Web of Science, covering the period from each database's inception to September 2023. Literature screening, quality assessment and data extraction were performed according to the inclusion and exclusion criteria. After extracting the literature data, RevMan 5.4 software was applied to analyse the postoperative knee function score, postoperative knee mobility, postoperative pain, bearing dislocation rate, aseptic loosening, postoperative progression of posterolateral arthritis, and revision rate.

RESULT

A total of 9 studies were included, including 6 cohort studies and 3 matched case‒control studies. A total of 1544 knees were included, including 183 in the SONK group and 1361 in the MKOA group. The meta-analysis results showed that the SONK and MKOA groups showed a significant difference in postoperative knee function scores [MD = 0.16, 95% CI (- 1.20, 1.51), P = 0.82], postoperative knee mobility [MD = - 0.05, 95% CI (- 1.99. 1.89), P = 0.96], postoperative pain [OR = 0.89, 95% CI (0.23, 3.45), P = 0.87], rate of bearing dislocation [OR = 1.28, 95% CI (0.34, 4.81), P = 0.71], aseptic loosening [OR = 2.22, 95% CI (0.56, 8.82), P = 0.26], postoperative posterolateral arthritis progression [OR = 2.14, 95% CI (0.47, 9.86), P = 0.33], and revision rate [OR = 1.28, 95% CI (0.53, 3.04), P = 0.58] were not statistically significant.

CONCLUSION

OUKA treatment with SONK and MKOA can achieve similar satisfactory clinical results.

The CT knee arthrogram revisited

The CT arthrogram is an underrated diagnostic study of the joint. Although MRI is considered superior to CT in joint imaging due to its higher resolution, CT arthrograms provide unique insights into the knee joint, with simultaneous dynamic assessment and an option for management in some conditions. In this pictorial essay, I will discuss the standard techniques and various pathologies affecting the knee joint and their CT arthrography appearance.

Top 15 musculoskeletal lesions in the aging recreational sporter: a pictorial review

Because of the increased life expectancy, the aging population can participate in recreational sports activities. The fact that activity is promoted as having a positive effect on mental and physical health is another factor that may contribute to a trend of increased participation in sports activities by middle-aged and older patients. Due to age-related degeneration of tendons, muscles, joints and decreasing Bone Mineral Density, the musculoskeletal (MSK) system in the aging patient is more vulnerable to trauma. Therefore, sports-related lesions are commonly encountered in the daily routine of most imaging departments. In our radiological practice, we have seen a trend for an increase in sport-related injury referrals particularly in a population aged 40 years and over. Currently, 10% of referrals for imaging studies for sport injuries are in patients older than 40-year-old. This article consists of a pictorial review of the imaging appearance of the most encountered MSK lesions in aging recreational sporters in a radiological practice according to their anatomical location. We have chosen the 15 most encountered acute and overuse sports-related lesions involving the lower and upper extremity that are referred to our department of medical imaging. We especially focus on the most characteristic imaging findings on ultrasound and magnetic resonance imaging (MRI). Because of the high prevalence of MSK lesions in older asymptomatic patients, imaging findings must be interpreted in conjunction with the clinical presentation.

Bilateral trochlear subchondral insufficieny fracture of the knee in a professional cyclist

This case report presents a rare case of subsequent ipsilateral and contralateral subchondral insufficiency fracture of the knee (SIFK) in the trochlea of the femur within months, manifested in a professional cyclist. SIFKs in the trochlea have not yet been reported in the literature; however, their appearance in a professional cyclist might be explained by the amount of repetitive pressure on the patellofemoral joint when cycling. In both instances, atraumatic anterior knee pain occurred, resolving after conservative treatment for 6-9 weeks. The patient reached their previous activity level. The authors believe SIFK in the younger population may be more common than currently perceived due to its self-limiting behaviour and a lack of performing immediate MRIs in this younger group whenever an overload injury is suspected.

Subchondral insufficiency fractures, subchondral insufficiency fractures with osteonecrosis, and other apparently spontaneous subchondral bone lesions of the knee-pathogenesis and diagnosis at imaging

Subchondral insufficiency fractures (SIFs) and SIFs with osteonecrosis (SIF-ONs) of the knee (previously misnamed spontaneous osteonecrosis of the knee (SONK)) are bone lesions that appear without prior traumatic, tumoral, or inflammatory event.Both conditions are characterized in the early stages by epiphyseal bone marrow edema (BME)-like signal at MRI. However, while SIFs usually heal spontaneously, they can also evolve to osteonecrosis (i.e., SIF-ON), which may progress to an irreversible collapse of the articular surface. Careful analysis of other MRI signs may help differentiate the two conditions in the early phase. In SIFs, the BME edema-like signal extends to the area immediately adjacent to the subchondral plate, while in SIF-ONs, this subchondral area shows low signal intensity on fluid-sensitive MR images due to altered bone marrow. The thickness and length of subchondral areas with low fluid-sensitive signal intensity are important factors that determine the prognosis of SIF-ONs. If they are thicker than 4 mm or longer than 14 mm, the prognosis is poor. The differential diagnosis of SIFs and SIF-ONs include bone lesions associated with the "complex regional pain syndrome" (CRPS), epiphyseal osteonecrosis of systemic origin, and those related to cartilage pathology.Clinical relevance statement Imaging plays an essential role in diagnosing subchondral insufficiency fractures (SIFs) from subchondral insufficiency fractures with osteonecrosis (SIF-ONs) and collapse, as well as in distinguishing them from other spontaneous knee subchondral bone lesions presenting with bone marrow edema-like signal.Key points• Subchondral insufficiency fractures may affect the knee, especially in older adults.• Subchondral insufficiency fractures usually heal spontaneously.• Sometimes, subchondral osteonecrosis and collapse may complicate subchondral insufficiency fractures.• Bone marrow-like edema is an aspecific sign seen in all these lesions.• Degraded marrow in osteonecrosis complicating fractures is hypointense on fluid-sensitive sequences.

Subchondral Insufficiency Fractures of the Knee: A Clinical Narrative Review

» Subchondral insufficiency fractures of the knee (SIFKs) are subchondral plate fractures with a prevalence of 2% to 4% of all knee injuries.» Magnetic resonance imaging is the gold standard for evaluating SIFK, while plain radiographs have limited the use in the diagnosis of SIFK.» Among patients with SIFK, 50% to 100% have meniscal pathology.» Medical therapies and standard treatments traditionally used in the management of knee osteoarthritis differ from recommended management of SIFK patients.» Randomized controlled trials and cohort studies with long-term follow-up are needed to determine the optimal rehabilitation protocol, interventional therapy, and prognosis of SIFK patients.

Short-Term Effects of Genicular Artery Embolization on Symptoms and Bone Marrow Abnormalities in Patients with Refractory Knee Osteoarthritis

PURPOSE

To evaluate the short-term outcomes of genicular artery embolization (GAE) for knee osteoarthritis (OA) with and without bone marrow lesion (BML) and/or subchondral insufficiency fracture of the knee (SIFK).

MATERIALS AND METHODS

This single-institution prospective observational pilot study analyzed 24 knees in 22 patients with mild to moderate knee OA, including 8 knees without BML, 13 knees with BML, and 3 knees with both BML and SIFK. The area and volume of BMLs on magnetic resonance images were measured before and after GAE. Baseline and postoperative pain and physical function were assessed using the visual analog scale (VAS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC).

RESULTS

GAE significantly reduced the BML area and volume 3 months after embolization in the knees with BML (both P < .0005). GAE significantly decreased the VAS scores at 3 and 6 months after embolization in patients without BML (both P = .04) and those with BML (both P = .01). GAE also lowered the WOMAC scores 3 months after embolization in patients without and with BML (P = .02 and P = .0002, respectively). However, GAE did not significantly alter the BML area and volume (both P = .25), VAS scores (P = 1.00), and WOMAC scores (P = .08) in patients with BML and SIFK at 3 months after GAE.

CONCLUSIONS

This observational pilot study suggested that GAE effectively reduces the BML area and volume and improves pain and physical function in patients with knee OA accompanied by BML but is inefficacious in those with both BML and SIFK.

Improved 2-Year Freedom from Arthroplasty in Patients with High-Risk SIFK Scores and Medial Knee Osteoarthritis Treated with an Implantable Shock Absorber versus Non-Operative Care

OBJECTIVE

Subchondral insufficiency fracture of the knee (SIFK) is associated with high rates of osteoarthritis (OA) and arthroplasty. The implantable shock absorber (ISA) is an extra-capsular implant that unloads the medial knee compartment. This study compared the 2-year freedom from arthroplasty rates in subjects with medial knee OA and SIFK when treated with an ISA versus a matched cohort of patients treated non-surgically.

DESIGN

This retrospective case-control study compared 2-year conversion rates to arthroplasty in SIFK score-, age-, and body mass index (BMI)-matched control subjects without prior surgical history with ISA-implanted subjects from an ongoing prospective study. Baseline and final radiographs, and MRIs were reviewed for evaluation of meniscus or ligament injuries, insufficiency fractures, and subchondral edema. Kaplan-Meier analysis assessed survival.

RESULTS

Forty-two patients (21 Control: 21 ISA), mean age = 52.3 ± 8.7 years, BMI = 29.5 ± 3.9 kg/m2, 40% female were evaluated. Both ISA and Control arms had the same numbers of low (n = 4), medium (n = 11), and high-risk (n = 6) SIFK scores. One- and 2-year freedom-from-arthroplasty rates were both 100% for ISA subjects, and 76% and 55%, respectively, for Controls (P = 0.001 for cross-group comparison). Control knees with low, medium, and high-risk SIFK scores had respective 1- and 2-year survival rates of 100% and 100%, 90% and 68% (P = 0.07 vs. ISA), and 33% and 0% (P = 0.002 vs. ISA).

CONCLUSIONS

ISA intervention was strongly associated with avoidance of arthroplasty at a minimum 2 years, especially in patients with high-risk SIFK scores. SIFK severity scoring predicted relative risk of conversion to arthroplasty through at least 2 years in non-surgically treated subjects.

Patterns of symptoms and insufficiency fractures in patients with tumour-induced osteomalacia

The aim of this study was to report the patterns of symptoms and insufficiency fractures in patients with tumour-induced osteomalacia (TIO) to allow the early diagnosis of this rare condition. The study included 33 patients with TIO who were treated between January 2000 and June 2022. The causative tumour was detected in all patients. We investigated the symptoms and evaluated the radiological patterns of insufficiency fractures of the rib, spine, and limbs. The mean age of the patients was 57 years (24 to 87), and the mean duration of pain from onset to time of presentation was 3.9 years (0.75 to 23). The primary symptoms were low back pain (ten patients), chest wall pain (eight patients), and hip pain (eight patients). There were symptoms at more sites at the time of presentation compared with that at the time of the onset of symptoms. Bone scans showed the uptake of tracer in the rib (100%), thoracic and lumbar vertebrae (83%), proximal femur (62%), distal femur (66%), and proximal tibia (72%). Plain radiographs or MRI scans identified femoral neck fractures in 14 patients, subchondral insufficiency fractures of the femoral head and knee in ten and six patients, respectively, distal femoral fractures in nine patients, and proximal tibial fractures in 12 patients. Thoracic or lumbar vertebral fractures were identified in 23 of 29 patients (79.3%) when using any imaging study, and a biconcave deformity was the most common type of fracture. Insufficiency fractures in patients with TIO caused spinal pain, chest wall pain, and periarticular pain in the lower limbs. Vertebral fractures tended to be biconcave deformities, and periarticular fractures of the hips and knees included subchondral insufficiency fractures and epiphyseal or metaphyseal fractures. In patients with a tumour, the presence of one or more of these symptoms and an insufficiency fracture should suggest the diagnosis of TIO.

Talus bone: normal anatomy, anatomical variations and clinical correlations

Talus is a pivotal bone that assists in easy and correct locomotion and transfers body weight from the shin to the foot. Despite its small size, it is implicated in many clinical disorders. Familiarity with the anatomy of the talus and its anatomical variations is essential for the diagnosis of any disorder related to these variations. Furthermore, orthopedic surgeons must be fully aware by this anatomy during podiatry procedures. In this review, we attempt to present its anatomy in a simple, updated and comprehensive manner. We have also added the anatomical variations and some clinical points relevant to the unique and complex anatomy of talus. The talus has no muscle attachment. However, it does have many ligaments attached to it and others around it to keep it in place. Moreover, the bone plays a pig role in movements due to its involvement in many joints. Most of its surface is covered with articular cartilage. Therefore, its blood supply is relatively poor. This puts the talus at greater risk for poor healing as well as more complications in the event of injury than any other bone. We hope this review will make it easier for clinicians to pursue and understand the updated essential knowledge of one of the most complex bone anatomies that they need in their clinical practice.

Beyond Gonarthrosis in the Elderly: A Case Report of Subchondral Insufficiency Fracture of the Knee

Subchondral insufficiency fracture of the knee (SIFK) is a non-traumatic condition that has been, historically, associated with the elderly. Early diagnosis and management are essential to prevent evolution to subchondral collapse and secondary osteonecrosis, developing prolonged pain and functional losses. This article presents the case of an 83-year-old patient with severe right knee pain with 15 months of evolution, with sudden onset, and no history of trauma or sprain. Upon observation, the patient presented with a limping gait, antalgic posture with the knee in semi-flexion, pain on palpation of the joint medial line, severe pain on passive mobilization, limited joint range of motion, and a positive McMurray test. The X-ray only demonstrated a gonarthrosis grade 1 in the Kellgren and Lawrence classification with medial compartment affection. Due to the exuberant clinical picture with marked functional compromise, as well as clinical radiological dissociation, MRI was requested to rule out SIFK, which was later confirmed. The therapeutic orientation was then adjusted with an indication for non-weight bearing and analgesia, as well as orientation to an orthopedics consultation to request a surgical evaluation. SIFK is difficult to diagnose and may have an unpredictable outcome due to delayed treatment approaches. This clinical case encourages clinicians to consider subchondral fracture in the differential diagnosis of knee pain when an older patient, with subnormal radiographic findings, reports severe knee pain in the absence of overt traumatic injury.

Bone marrow lesions in the knee are associated with meniscal lesions and cartilage pathologies according to the six-letter system

PURPOSE

This study aims to find a correlation between bone marrow lesions (BMLs) in knee MRI and pathologies of joint structures. In addition, according to the six-letter system classification, the authors analyzed a potential association between the area affected by BMLs and the specific type of joint lesion.

METHODS

The authors screened all the knee MRIs performed in the investigation center between 2017 and 2018 to identify the presence of BMLs. The lesions were then categorized following the "six-letter system". The authors searched the presence of associated meniscal, chondral or ligamentous lesions. Finally, the authors researched a correlation between the lesion type described by the six-letter system classification and the associated lesions.

RESULTS

MRI exams of 4000 patients were studied, identifying 666 BMLs. The associated lesions were collected for all patients, resulting in an overall prevalence of related lesions in almost 90% of patients. The authors found a statistical significance for type TLD (Tibia-Lateral-Articular) and ACL rupture. The study suggests a strong positive correlation between type E (Edge) and meniscal fracture or extrusion.

CONCLUSION

BMLs in the knee are associated in 90% of cases with a radiological sign of related injury to the joint structures. The six-letter system of BMLs type TLD can be considered a sign of ACL rupture and type E as a high suspicious sign for meniscal extrusion. Those very typical BML patterns can help the clinician in the diagnosis of ACL tears and meniscal extrusion. Furthermore, the presence of a BML must be, for the clinician, a high suspicious sign of joint-related injuries.

LEVEL OF EVIDENCE

Level 1.

Magnetic resonance imaging of subchondral insufficiency fractures in the knee (literature review)

Stress fractures are an actual problem of modern medicine. A fracture associated with insufficiency of the bone tissue of the knee condyles is a new type of stress fracture that occurs in people aged 50–55 years in response to a normal daily activity, but with damage to the weakened subchondral bone tissue of the joint caused by various reasons. This literature review is mainly based on data from foreign medical sources, since there is very little information on this type of fracture in Russian sources. This is primarily due to the fact that initially the world and Russian medical communities designated this type of fracture as a spontaneous osteonecrosis of the knee (SONK). In recent years, this term has been revised abroad and replaced by a more suitable one – subchondral insufficiency fracture of the knee (SIF/SIFK). According to modern concepts, it is necessary to clearly distinguish among the concepts of osteonecrosis and subchondral insufficiency fracture of the knee. The reason for this is not only differences in the pathogenesis of these pathologies, but also fundamentally different approaches to managing these patients. Thus, taking into account the fundamental differences in the treatment of patients with stress fracture associated with bone insufficiency and patients with osteonecrosis, and also the relevance of stress fracture of the knee condyles, we state the following aim – to study the available literature on this problem.

Osteonecrosis of the Knee: Not all Bone Edema is the Same

Knee pain is among the most common complaints that an orthopedic surgeon may see in practice. It is often worked up with X-rays and MRI, leading to a myriad of potential diagnoses ranging from minimal edema patterns to various types of osteonecrosis. Similarities in certain causes can pose diagnostic challenges. The purpose of this review was to present the 3 types of osteonecrosis observed in the knee as well as additional causes to consider to help aid in the diagnosis and treatment..

A Case of Subchondral Insufficiency Fracture of the Knee at Lateral Femoral Condyle Treated With Unicompartmental Knee Arthroplasty

Spontaneous insufficiency fracture of the knee is a potentially devastating yet poorly understood disease entity that can lead to secondary osteoarthritis. Most cases involve the medial femoral condyle, and the lateral femoral condyle is rarely affected. The optimal treatment for spontaneous insufficiency fracture of the lateral femoral condyle remains undetermined, and there are no previous dedicated reports on treatment outcome with unicompartmental knee arthroplasty. A middle-aged lady presented with subacute left knee pain and a locked knee. Subsequent imaging studies revealed a spontaneous insufficiency fracture of the lateral femoral condyle. In view of the isolated compartment involvement, unicompartmental knee arthroplasty was performed with satisfactory outcome. At 1 year postoperatively, the patient had complete resolution of knee pain and was able to resume working.

Breast MRI during pregnancy and lactation: clinical challenges and technical advances

The breast experiences substantial changes in morphology and function during pregnancy and lactation which affects its imaging properties and may reduce the visibility of a concurrent pathological process. The high incidence of benign gestational-related entities may further add complexity to the clinical and radiological evaluation of the breast during the period. Consequently, pregnancy-associated breast cancer (PABC) is often a delayed diagnosis and carries a poor prognosis. This state-of-the-art pictorial review illustrates how despite currently being underutilized, technical advances and new clinical evidence support the use of unenhanced breast MRI during pregnancy and both unenhanced and dynamic-contrast enhanced (DCE) during lactation, to serve as effective supplementary modalities in the diagnostic work-up of PABC.