Subchondral Fracture Research Articles

Case of Successful Treatment of a Patient with Subchondral Fracture of the Knee Joint using Subchondral Platelet-Rich Plasma Injection

We report the treatment of a patient with a pronounced knee pain syndrome related to a subchondral knee joint fracture in the context of osteoarthritis. Traditional treatment methods for this pathology have demonstrated limited efficacy. In our approach, we utilized subchondral Platelet-Rich Plasma (PRP) injections to alleviate the pain syndrome and stimulate reparative regeneration. Notably, we achieved a stable and rapid reduction in knee pain, with observed regression of pathological changes on MRI scans after a two-month follow-up. We report the treatment of a patient with a pronounced knee pain syndrome related to a subchondral knee joint fracture in the context of osteoarthritis. Traditional treatment methods for this pathology have demonstrated limited efficacy. In our approach, we utilized subchondral Platelet-Rich Plasma (PRP) injections to alleviate the pain syndrome and stimulate reparative regeneration. Notably, we achieved a stable and rapid reduction in knee pain, with observed regression of pathological changes on MRI scans after a two-month follow-up.

Functional improvement of unicompartmental knee arthroplasty compared with total knee arthroplasty for subchondral insufficiency fracture of the knee

Subchondral insufficiency fracture of the knee (SIFK) causes acute knee pain in adults and often requires surgical management. Unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA) are the two most common surgical treatments for SIFK. While both UKA and TKA have their advantages, there is no consensus for SIFK localized on the medial compartment. We hypothesized that patients with SIFK treated with UKA would show superior patient-reported outcomes compared to those who underwent TKA. A total of 90 patients with SIFK located medially were included in the TKA (n = 45) and UKA (n = 45) groups. Size of SIFK lesions were measured on MR images. Patient reported outcomes in the form of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Hospital Special Surgery (HSS) scores, and Knee Society Scores (KSS) were assessed preoperatively, postoperative 6, 12 months, and at the final follow-up. There were no differences in the size of the SIFK lesion between two groups. At 6 months, WOMAC score was better in the UKA group than the TKA group (p < .01). Both groups had a significant improvement in WOMAC, HSS, and KSS scores at the final follow-up compared to preoperative scores. The UKA group had better range of motion of the knee preoperatively and postoperatively than the TKA group (p < .01 and p < .01). UKA group showed a higher relative risk than the TKA group in terms of complications (RR = 3.0) but with no statistical significance (P = 0.31). Unicompartmental arthroplasty and total joint arthroplasty can produce successful outcomes in patients with SIFK with proper patient selection, regardless of the size of SIFK lesion.

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

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

Subchondral fatigue fracture of the femoral head in young military recruits: Potential risk factors.

Subchondral fatigue fracture of the femoral head (SFFFH) mainly occurs in young military recruits and might be confused with osteonecrosis of the femoral head. However, less research focuses on the risk factor for SFFFH. To evaluate the intrinsic risk factors for SFFFH in young military recruits. X-ray and magnetic resonance imaging data were used for analysis. Acetabular anteversion of the superior acetabulum, acetabular anteversion of the center of the acetabulum (AVcen), anterior acetabular sector angle (AASA), posterior acetabular sector angle, superior acetabular sector angle, neck-shaft angle (NSA), inferior iliac angle (IIA), and ischiopubic angle were calculated. Then, logistic regression, receiver operating characteristic curve analysis, and independent samples t-test were performed to identify the risk factors for SFFFH. Based on the results of logistic regression, age [odds ratio (OR): 1.33; 95% confidence interval (95%CI): 1.12-1.65; P = 0.0031] and treatment timing (OR: 0.86; 95%CI: 0.75-0.96; P = 0.015) could be considered as the indicators for SFFFH. AVcen (P = 0.0334), AASA (P = 0.0002), NSA (P = 0.0007), and IIA (P = 0.0316) were considered to have statistical significance. Further, AVcen (OR: 1.41; 95%CI: 1.04-1.95) and AASA (OR: 1.44; 95%CI: 1.21-1.77), especially AASA (area under curve: 66.6%), should be paid much more attention due to the higher OR than other indicators. We have for the first time unveiled that AASA and age could be key risk factors for SFFFH, which further verifies that deficient anterior coverage of the acetabulum might be the main cause of SFFFH.

THU439 Baby's Coming, Break A Leg! A Case Of Transient Osteoporosis Of The Hip

Abstract Disclosure: A. Khan: None. A. Syeda: None. H.B. Aftab: None. Introduction: Pregnancy-associated osteoporosis (PAO) is a rare condition presenting as fragility fractures usually in the latter part of pregnancy or immediate postpartum period. Vertebral fractures are more commonly reported but femoral fractures have also been described in the literature as a distinct entity: transient osteoporosis of the hip (TOH). We present a case of bilateral (B/L) femoral fractures in a woman during pregnancy and in the postpartum period. Case: A 31-year-old, gravida 1 female developed left leg pain at 26 weeks of gestation. The pain radiated from her left lower back to her left knee. It was severe in intensity resulting in her walking with crutches. Subsequent MRI of the left hip showed subchondral insufficiency fracture of the femoral head with prominent bone marrow edema extending from the head into the femoral neck. She was managed conservatively with non-weight bearing status and oral analgesics. She had an uncomplicated vaginal delivery at 39 weeks of gestation. During the first postpartum week she developed right hip pain. MRI of right hip revealed nondisplaced right femoral head subchondral insufficiency fracture with associated effusion and synovitis. She recovered within the next 3 months with resolution of her pain with conservative management. Other than limited calcium intake in childhood, there were no other identifiable risk factors for osteoporosis. Bone density scan revealed normal Z-scores at the lumbar spine and non-dominant wrist. The hips were not evaluated. Workup for secondary causes of osteoporosis was unremarkable including normal serum calcium, PTH, phosphorus, magnesium, SPEP, tissue transglutaminase antibodies, estradiol, LH, FSH, prolactin levels. However, 24-hour urine calcium level was low at 11 (35-250) mg/24hr. Elevated levels of bone specific alkaline phosphatase and urine N-telopeptide (NTX) were noted at 19.9 (5.3-19.5) mcg/L and 110 (4-64) nM BCE/mM creatinine, respectively. Patient was continued on vitamin D and calcium supplements. She breastfed for the initial 2 months but was advised to stop. At her most recent follow up visit 4 months postpartum patient was doing well. Discussion: TOH is a rare entity, and presentation as B/L femoral fractures is exceedingly rare. During pregnancy and lactation, the skeletal system undergoes bone loss to compensate for the calcium demand of the fetal skeletal system. In TOH, venous stasis from the gravid uterus resulting in bone marrow edema is the proposed mechanism in addition to pregnancy associated bone loss. In our patient, a low 24-hr urine calcium could suggest low calcium intake which could have contributed to the fracture as well. While recurrence of PAO has been described, no recurrence of TOH has been reported in subsequent pregnancies. Our case highlights the importance of keeping this rare entity on the differential in pregnant women presenting with back or hip pain. Presentation: Thursday, June 15, 2023

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.

Intertrochanteric curved varus osteotomy for subchondral fracture of the femoral head: a case series

Although favorable results have been reported with total hip arthroplasty, joint-preserving treatment should be the first choice for subchondral fracture of the femoral head (SFF) in young patients. This study reviewed four young male patients with SFF who underwent intertrochanteric curved varus osteotomy (CVO). The patients had a mean age of 32.3 years (range: 18–49 years). Conservative treatment was initially attempted in all cases, but failed to alleviate the pain, leading to surgical intervention at an average time of 6 months (range: 4–10 months) after symptom onset. As the fracture sites were located medial to the lateral edge of the acetabulum in all cases, CVO was performed to achieve a postoperative intact ratio of ≥ 34% in the weight-bearing region of the femoral head. The average follow-up period after surgery lasted 4.3 years (range: 2–7 years). Clinical and radiographic assessments were performed pre- and postoperatively. At the latest follow-up, the mean Harris hip score improved from 67.3 preoperatively to 99.5 postoperatively. The average preoperative intact ratio of the weight-bearing region of the femoral head was 12.3%, which increased to 44.3% postoperatively. No progression to femoral head collapse or joint space narrowing was observed on the plain radiographs. CVO is a simple, less-invasive, and beneficial approach for treating SFF in young patients whose fractures occur medial to the lateral edge of the acetabulum.

Characterization of adverse joint outcomes in patients with osteoarthritis treated with subcutaneous tanezumab

Due to the risk of rapidly progressive osteoarthritis (RPOA), the phase III studies of subcutaneous (SC) tanezumab in patients with moderate to severe hip or knee osteoarthritis (OA) included comprehensive joint safety surveillance. This pooled analysis summarizes these findings. Joint safety events in the phase III studies of SC tanezumab (2 placebo- and 1- nonsteroidal anti-inflammatory drug [NSAID]-controlled) were adjudicated by a blinded external committee. Outcomes of RPOA1 and RPOA2, primary osteonecrosis, subchondral insufficiency fracture, and pathological fracture comprised the composite joint safety endpoint (CJSE). Potential patient- and joint-level risk factors for CJSE, RPOA, and total joint replacement (TJR) were explored. Overall, 145/4541 patients (3.2%) had an adjudicated CJSE (0% placebo; 3.2% tanezumab 2.5 mg; 6.2% tanezumab 5 mg; 1.5% NSAID). There was a dose-dependent risk of adjudicated CJSE, RPOA1, and TJR with tanezumab vs NSAID. Patient-level cross-tabulation found associations between adjudicated RPOA with more severe radiographic/symptomatic (joint pain, swelling, and physical limitation) OA. Risk of adjudicated RPOA1 was highest in patients with Kellgren-Lawrence (KL) grade 2 or 3 OA at baseline. Risk of adjudicated RPOA2 or TJR was highest in patients with KL grade 4 joints at baseline. A higher proportion of joints with adjudicated RPOA2 had a TJR (14/26) than those with adjudicated RPOA1 (16/106). In placebo- and NSAID controlled studies of SC tanezumab for OA, adjudicated CJSE, RPOA, and TJR most commonly occurred in patients treated with tanezumab and with more severe radiographic or symptomatic OA. NCT02697773; NCT02709486; NCT02528188.

A novel animal model of osteonecrosis of the femoral head based on 3D printing technology

BackgroundOsteonecrosis of the femoral head (ONFH) is a prevalent orthopedic condition characterized by the disruption of blood supply to the femoral head, leading to ischemia of internal tissues, subchondral bone fractures, necrosis, and eventual collapse of the weight-bearing portion of the femoral head. This condition results in severe functional impairment, pain, and even disability of the hip joint. Existing animal models of ONFH have limitations in replicating the natural disease progression accurately. Thus, there is a critical need to develop a novel animal model capable of better simulating localized pressure on the human femoral head to facilitate ONFH-related research.MethodsIn this study, we present a novel approach for modeling ONFH, which involves integrating stress factors into the modeling process through the utilization of 3D printing technology and principles of biomechanics. A total of 36 animals were randomly assigned to six groups, where they received either the novel modeling technique or the traditional hormone induction method. Subsequently, an 8-week treatment period was implemented, followed by conducting micro-CT scans and histological evaluations to assess tissue outcomes.ResultsThe study evaluated the cytotoxicity of the material used in the new model, and it was observed that the material did not exhibit any cytotoxic effects on cells. Additionally, the novel model successfully replicated the pathological features of ONFH, including femoral head collapse, along with a substantial presence of empty bone lacunae, cartilage defects, and subchondral bone fractures in the subchondral bone region.ConclusionIn conclusion, our study provides evidence that the new model shows the ability to simulate the progression of the disease, making it a valuable tool for research in this field and can contribute to the development of better treatment strategies for this debilitating condition. It holds great promise for advancing our understanding of the pathogenesis of ONFH and the potential therapeutic interventions for this challenging clinical problem.

Investigating Risk Factors and Magnetic Resonance Imaging (MRI)-Based Grading of Subchondral Incomplete Fracture (SIF) of Medial Femoral Condyle.

Subchondral insufficiency fractures (SIF) of the knee joint are prevalent in osteoporosis patients over the age of 55. Early diagnosis of SIF fracture of the medial femoral condyle is crucial for delaying disease progression, early therapy, and potential disease reversal. Magnetic resonance imaging (MRI) is useful in detecting SIF, which is often undetectable on initial radiographs. This study aimed at developing a grading system for subchondral insufficiency fractures (SIF) based on MRI to predict outcomes and evaluate risk factors. In this study, MRI was used to examine SIF risk variables in the medial condyle of the femur to help clinicians diagnose, treat, and delay the condition. A total of 386 patients with SIF from 2019 to 2021 were retrospectively analyzed and divided into 106 patients in the disease group and 280 patients in the control group according to whether they had SIF. The lesion site, meniscus, ligament, and other parameters were evaluated and compared. At the same time, a grading system was introduced to stratify and statistically analyze the size of the lesion area, the degree of bone marrow edema (BME), meniscus tears, and other parameters in the patients. Most SIF were low-grade (LG) fractures, and the predictors of LG and high-grade (HG) fractures included heel tear (P =0.031), degree of medial malleolus degeneration (P < 0.001), advanced age (P < 0.001), and lesion size (P < 0.001). The prognostic factors that showed significant differences between the two groups included age (P =0.027), gender (P =0.005), side (P =0.005), medial tibial plateau injury (P < 0.0001), femoral medullary bone marrow edema (P < 0.0001), medial tibial plateau bone marrow edema (P < 0.0001), meniscus body partial injury (P =0.016), heel tear (P =0.001), anterior cruciate ligament injury (P =0.002), and medial collateral ligament injury (P < 0.0001). This current study proposed an MRI-based grading system for inferior condylar fractures of the femur, in which HG inferior condylar fractures are associated with severe medial malleolus degeneration, advanced age, lesion size (correlation), and meniscus heel tears.

Case Report: 3 Tesla magnetic resonance imaging of Rapidly Progressive Osteoarthritis of the Hip

Rapidly progressive osteoarthritis of the hip (RPOH) is a rare disease with few mentions in the literature. Recent studies have suggested a female predisposition. The nature of disease progression and some specific radiological features like lesion patterns, location within the hip joint and the presence of subchondral fractures help differentiate rapidly progressive osteoarthritis from classical osteoarthritis. Awareness of RPOH as a differential in arthropathies among clinicians would save crucial time, reduce unnecessary investigations and help better manage patients. The treatment in earlier stages is often conservative, managed only by painkillers, physiotherapy, and traction however, most of the cases need surgical intervention, i.e., total hip replacement. The following case study is a classic case of RPOH in a male with trauma as one of its etiological factors and has progressed to the final grade, i.e., grade III according to grading by Ancut a Zazgyva displaying all the imaging features of RPOH as described in the literature.

Poster 121: Association Between MRI Findings in ACL Injury and Subacute Synovial Fluid Inflammatory Biomarker Levels at the Time Of Surgery

Objectives: To Investigate the association between MRI findings following anterior cruciate ligament (ACL) injury and synovial fluid biomarker profile at the time of surgery Methods: Patients undergoing surgery for ACL injury from October 2011 to December 2021 were included in a database of subjects who had synovial fluid samples collected at the time of surgery. From this cohort, 82 subjects with acute ACL injury were retrospectively selected who met the following inclusion criteria: no history of prior knee trauma to suggest chronic ACL injury, history of acute non- contact knee injury, MRI examination of the knee performed within 3 weeks of knee injury, subsequent knee surgery performed between 4 and 12 weeks of knee injury, and no additional ligament tear requiring surgical treatment. All subjects underwent a preoperative MRI examination of the knee using multi-planar, multi-contrast fast spin-echo sequences. Synovial fluid was aspirated from the operative knee prior to surgical incision. Concentrations of inflammatory biomarkers including regulation on activation normal T cell expressed and secreted (RANTES), interleukin 6 (IL-6), vascular endothelial growth factor (VEGF), tissue inhibitor matrix metalloproteinase 1 (TIMP1), interleukin 1 receptor agonist (IL1-RA) and matrix metalloproteinase 3 (MMP-3) were measured. The MRI examinations of all subjects were reviewed by a fellowship trained musculoskeletal radiologist to assess the presence and severity of various MRI features of acute and chronic knee injury using the validated Anterior Cruciate Ligament Osteoarthritis Score (ACLOAS) system. Nonparametric Wilcoxon tests and Fisher’s exact test were used to compare demographic factors, MRI findings, clinical symptoms, and synovial fluid inflammatory biomarkers between clusters. K-means cluster analysis was used to identify 2 distinct clusters of subjects with acute ACL injury based on biomarkers concentrations in synovial fluid. Results: The mean age of the cohort was 31.6 ± 8 years, average body mass index (BMI) was 25.5 ± 4.4 kg/m2. There 42.7% (n=35) of the cohort was female and 85.4% (n=70) were non-smokers. Two distinct clusters were identified: cluster 1 included 45 subjects and was marked by older subjects (33.2 ± 9.1 years, p=.038) with lower levels of all inflammatory synovial fluid biomarkers. Cluster 2 included 37 subjects and was marked by younger patients (29.7 ± 6.1 years, p=.038) with a more pro-inflammatory synovial fluid biomarker profile, higher ACLOAS Hoffa’s synovitis score (p=.001), and a higher incidence of subchondral bone fractures (54%, p=.002). There were no differences between clusters in time from injury to surgery (p=), BMI (p=.141), or ACLOAS meniscus (p=.086), cartilage (p=.730), or effusion scores (p=.202) Conclusions: Given the variable outcomes seen following ACL reconstruction (ACLR) surgery, a better understanding of the pathophysiology following ACL injury is needed. This study found distinct cluster of patients who exhibited a higher inflammatory reaction at the time of surgery as well as more severe findings on preoperative MRI. These findings could be used to identified clinical parameters associated with more inflammation at the time of surgery and their effect on clinical outcomes of ACLR.

Bone marrow edema of the hip: a narrative review.

Bone marrow edema (BME) of the hip is a radiological-clinical condition with symptoms ranging from asymptomatic to severe, and it is characterized by increased interstitial fluid within the bone marrow, usually at the femur. Depending on the etiology it can be classified as primary or secondary. The primary cause of BME is unknown, while the secondary forms include traumatic, degenerative, inflammatory, vascular, infectious, metabolic, iatrogenic, and neoplastic etiologies. BME could be classified as reversible or progressive. Reversible forms include transient BME syndrome and regional migratory BME syndrome. Progressive forms include avascular necrosis of the femoral head (AVNH), subchondral insufficiency fracture, and hip degenerative arthritis. The diagnosis can be difficult, because at the beginning, the outbreak of hip pain, typically acute and disabling without any prior trauma or exceptional physical activity, is poorly supported by radiographic findings. MRI is the gold standard, and it shows an area of intermediate signal on T1-weighted MRI scans and a high signal on T2-weighted scans, usually lacking sharps margins. In the reversible form, BME is typically self-limiting, and it can be managed conservatively by means of pharmacological and physical therapy. Surgery is generally required for progressive forms in patients who failed non-operative treatment, and it ranges from femoral head and neck core decompression to total hip arthroplasty.

Bilateral bone marrow edema syndrome of the humeral head mimicking avascular necrosis: a case report

BackgroundBone marrow edema syndrome (BMES), previously referred to as transient osteoporosis, is an uncommon and underdiagnosed self-limiting condition typically affecting the weight-bearing joints of the hip and lower limb. Its occurrence in upper limb or non-weight bearing joints is particularly rare.Case presentationWe report the case of an otherwise healthy 42-year-old man who gradually developed severe and disabling left shoulder pain over the course of 6 months. Nine months after onset, he presented clinically with bilateral involvement and radiologically (magnetic resonance imaging, MRI) with diffuse BME associated with a subchondral insufficiency fracture, suggestive of proximal humeral avascular necrosis. Clinical evidence of subacromial shoulder impingement and MRI findings of bilateral subchondral bursitis and tenosynovitis with effusion of the biceps tendons likely resulted from primary BME, as musculoskeletal sonography confirmed the absence of rotator cuff tears. Repeated MRI findings at 2, 12, and 18 months documented near complete resolution of both edema and fracture, consistent with BMES of the proximal humerus. During this time, the patient reported a gradual improvement in both pain symptoms and range of motion. The clinical picture of insidious shoulder pain, exacerbated by activity and improved by load relief, in the absence of predisposing factors for osteonecrosis or antecedent trauma in patients of middle age, should indicate the possibility of the diagnosis of BMES.ConclusionsThis unprecedented report documents a rare case of bilateral BMES of the humeral head mimicking avascular necrosis. The correct diagnosis of BMES within an atypical anatomical location avoids invasive measures in the affected bone. The misdiagnosis of secondary BME and idiopathic osteonecrosis can be avoided by recognizing the characteristics of BME and subchondral fractures of the humeral head in the absence of rotator cuff tears, as well as their evolution on serial MRI.

What Is New in Stage 3 of the 2019 Revised Association Research Circulation Osseous Staging System of Osteonecrosis of the Femoral Head: A Relationship to Bone Resorption.

The aim of the study is to evaluate the stage 3 findings of the 2019 revision of the Association Research Circulation Osseous (ARCO) staging system for osteonecrosis of the femoral head between 3A and 3B and the relationship with bone resorption area. We retrospectively enrolled 87 patients with ARCO stage 3 osteonecrosis of the femoral head, divided into stage 3A (n = 73) and 3B (n = 14). The revised stage 3 findings included subchondral fracture, fracture in necrotic portion, and flattening of the femoral head and were compared between stage 3A and 3B. The association between these findings and the causative features of bone resorption area was also evaluated. All stage 3 cases had subchondral fractures. In stage 3A, these fractures were generated by crescent sign (41.1%) and by fibrovascular reparative zone in 58.9%; however, in stage 3B, fibrovascular reparative zone generated 92.9% of these fractures and crescent sign only 7.1% with statistical significance (P = 0.034). Necrotic portion fracture was noted in 36.7% and femoral head flattening was observed in 14.9% of all stage 3. Necrotic portion fracture (92.9% vs 26.0%) and femoral head flattening (71.4% vs 4.1%) were observed more frequently in stage 3B than 3A (P < 0.001). Almost all subchondral fractures by fibrovascular reparative zone (96.4%) and necrotic portion fracture (96.9%), and all femoral head flattening was presented with bone resorption area with expanding areas. The ARCO stage 3 descriptions reflect severity in this order: subchondral fracture, necrotic portion fracture, and femoral head flattening. More severe findings are usually associated with expanding bone resorption areas.

Subchondral insufficiency fracture is a predictive factor of osteoarthritis progression and conversion to arthroplasty in non-surgically treated medial meniscus root tear.

To investigate the radiographic and clinical outcomes of non-surgical treatment for medial meniscus posterior root tear (MMPRT), and prognostic factors for osteoarthritis (OA) progression and clinical failure. A prospectively collected database was retrospectively reviewed for patients who were diagnosed with acute medial meniscus posterior root tear (MMPRT) between 2013 and 2021 and treated non-surgically for more than 2years. Patient demographic characteristics and clinical outcomes including pain numeric rating scale (NRS), International Knee Documentation Committee (IKDC) subjective score, Lysholm score, and Tegner activity scale were evaluated. For radiographic evaluation, knee radiographs were obtained to assess the angle of knee alignment and Kellgren-Lawrence (K-L) grade during the first and annually follow-up visits. Baseline magnetic resonance (MR) images were reviewed for the presence of medial meniscus extrusion, bone marrow edema, subchondral insufficiency fracture of medial femoral condyle, and cartilage lesion. The OA progression group was defined as patients who experienced a worsening of one or more grades in the K-L classification system. Prognostic factors were evaluated for OA progression and conversion to total knee arthroplasty (TKA). Ninety-four patients (90 female and 4 male) with a mean age of 67.0 ± 7.3years (range, 53-83years) were followed for a mean of 46.1 ± 22.1months (range, 24.1-170.5). During the follow-up period, no significant differences in clinical scores were observed, and there were also no significant differences between the groups with and without OA progression. Overall, 12 patients (13%) underwent TKA at a mean of 20.7 ± 16.5months (range, 8-69months) and 34 patients (36%) demonstrated OA progression at a mean time of 24 ± 15months (range, 12-62). The subchondral insufficiency fracture was a prognostic factor for OA progression (p = 0.045 for knee radiograph and p = 0.019 for MR) and conversion to TKA (RR, 4.08 [95% CI 1.23-13.57]; p = 0.022). Non-surgical treatment for acute medial meniscus posterior root tear did not result in any significant change in clinical outcomes from the initial to the final follow-up. The rate of conversion to arthroplasty was 13%, and the rate of osteoarthritis progression was 36%. Furthermore, subchondral insufficiency fracture was found to be a concomitant prognostic factor correlated with OA progression and conversion to arthroplasty. This information can provide insights for physicians when discussing treatment options with patients, particularly regarding the use of non-surgical treatment and may contribute as a source for future studies of medial meniscus posterior root tear. IV.

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.

Time to reconsider post arthroscopic osteonecrosis of the knee: a systematic review.

The etiology of post-arthroscopic osteonecrosis of the knee (PAONK) is still unknown. The aims of this systematic review were to analyze the main characteristics of patients who developed osteonecrosis after arthroscopy. We considered for inclusion in the review case reports, case series, retrospective and prospective clinical trial, that involved patients who developed osteonecrosis of the knee within 1year of arthroscopy for meniscal lesion or anterior cruciate ligament rupture with or without chondropathy. In all cases, there was a pre-operative magnetic resonance imaging that excluded the presence of osteonecrosis. We used the MINORS criteria to estimate the risk of bias. A total of 13 studies that involved 125 patients were included in the review. Only 14 out of 55 patients performed the pre-operative MRI after the "window period", which we considered 6weeks between the onset of symptoms and positive MRI findings. A diagnosis of PAONK was made for 55 patients within 1year of surgery. Of these, 29% was treated conservatively, while 71% repeated surgery. Osteonecrosis after knee arthroscopy is a reality and surgeon shouldn't underestimate the persistence or re-emergence of symptoms after arthroscopy. It may be due to subchondral insufficiency fractures in osteopenic bone, without evidence of necrosis. However, there are not elements enough to differentiate clinical and radiological characteristics of PAONK from SPONK. Terminology should be simplified, distinguishing subchondral insufficiency fractures of the knee as a precursor of primary osteonecrosis of the knee.

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.

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. 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. 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). 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.

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

PurposeTo 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 MethodsThis 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). ResultsGAE 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. ConclusionsThis 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.