Introduction. Bone marrow lesions (BMLs) are MRI-visible subchondral bone alterations, highly correlated with symptoms in the knee. Subchondroplasty (SCP) is able to fill the subchondral defects associated with BMLs using an injectable bone substitute material. The aim of the present study is to evaluate the 12-month outcomes of the SCP in the treatment of symptoms of mild-to-moderate knee osteoarthritis (OA) patients with persistent BMLs of the knee. Materials and Methods. Subjects affected by BMLs of the femoral condyle or tibial plateau that were present for >3 months and not responsive to conservative treatments were enrolled in this prospective multicenter trial. All the patients underwent SCP. Follow-up was conducted at 1, 3, 6 and 12 months. All subjects completed Numerical Rating Scale (NRS) for pain, Knee Injury and Osteoarthritis Outcome (KOOS) score, Euro Quality of life-5 dimensions (EQ-5D) score, and a subject global satisfaction scale. Demographic information of the patients was also collected. Results. A total of 79 patients completed the 12-month follow-up. Statistically significant improvements on all clinical scales were registered from baseline to the 12-month follow-up. No severe adverse events were reported. Four patients were considered failed. A 12-month subgroup analysis was performed to evaluate the possible correlation between all the KOOS subscales and age, gender, number of BMLs, location of BMLs, and Kellgren-Lawrence grade: no statistically significant associations were observed. Conclusion. SCP is a safe and effective procedure for the treatment of symptoms related to persisting BMLs in mild-to-moderate osteoarthritic knees, with a low failure rate up to 12 months\' evaluation.

Introduction Hallux rigidus (HR) refers to osteoarthritis of the first metatarsal phalangeal joint, resulting in stiffness, pain, and limitation in daily function. Surgery of HR is indicated in those who have failed a trial of non-operative management and is typically divided into joint-preserving (JP) and joint-sacrificing procedures. Cheilectomy is the most commonly practiced JP procedure, often done in conjunction with associated procedures for HR. Our paper aims to report the clinical outcomes after cheilectomy and cheilectomy done with subchondroplasty (SCP) performed for HR. Methods All patients who underwent cheilectomy for HR between 2017 and 2022 were identified and had their outcomes evaluated at the time of this review. The patients had their pre-operative radiographs and clinical and operative notes analyzed for the grading of HR. Functional outcomes were assessed with the use of the visual analog scale (VAS) and American Orthopaedic Foot and Ankle Society (AOFAS) scores, as well as comparing the pre-operative and post-operative degree of dorsiflexion of the affected first metatarsophalangeal joint. This study was approved by the SingHealth Institutional Review Board (IRB) Institution with approval number 2021/2629. Results A total of 19 patients and 20 feet were included in our study at a mean follow-up of 29.8 months. There was an increase in dorsiflexion of the first MTP joint by 27.2 degrees (p-value = <0.0001). Patients who underwent cheilectomy alone (Group 1) had a mean improvement in VAS scores of 5.46 (p-value = <0.0001). Patients who underwent SCP of the first metatarsal head along with cheilectomy (Group 2) had an improvement in VAS scores by 5.78 (p-value = 0.0007). There was a mean improvement in AOFAS scores of 25.6 (p-value = <0.0001) for patients in Group 1. Patients in Group 2 had a mean improvement in AOFAS scores of 31.0 (p-value = 0.0003). Conclusion Both cheilectomy and cheilectomy performed with SCP for HR show good outcomes at short-term follow-up (mean 29.8 months). Cheilectomy is a viable alternative to arthrodesis for the surgical treatment of HR even in patients with higher grades. The use of SCP should be further explored as an adjunct in the surgical treatment of HR.

UNASSIGNED: Bone marrow lesions (BMLs) are common subchondral defects revealed by magnetic resonance imaging (MRI) in patients with osteoarthritis, often associated with pain and functional limitation. Subchondroplasty (SCP) is a relatively new technique in which bone substitute material (BSM) is injected inside BML areas to provide structural support to the subchondral bone, preventing its collapse and reducing pain.
UNASSIGNED: The purpose of this study was to characterize changes in pain, functional and radiological outcomes, conversion to knee replacement, and complications after SCP. We hypothesized that ≥70% of patients would achieve a reduction in pain of ≥4 points on a numeric rating scale (NRS) at a 6-month follow-up after SCP.
UNASSIGNED: Case series; Level of evidence, 4.
UNASSIGNED: Patients with symptomatic knee BMLs who underwent SCP were prospectively evaluated preoperatively and at 1, 6, 12, and 24 months postoperatively. Functional outcomes were measured with the NRS for pain, Knee Society Score (KSS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and International Knee Documentation Committee (IKDC) scores. Radiographs and MRI were performed preoperatively and at 6- and 12-month follow-ups to verify edema healing and changes in bone structure.
UNASSIGNED: A total of 50 patients were included in the study. The mean follow-up was 26 months (24-30 months). Compared with preoperative values, the mean NRS score decreased at every follow-up point (P < .0001 for all) and the IKDC, WOMAC, and KSS scores improved significantly at 6- and 12-month follow-ups. At 6 months postoperatively, 27 patients (54%) registered a reduction on the NRS of ≥4 points. Postoperative MRI revealed a hypointense zone surrounded by a hyperintense signal at the injection site. Standard radiography showed osteoarthritis grade worsening in 4 (8%) patients. Knee replacement was performed in 11 patients -in 7 patients due to the worsening or persistence of disabling symptoms and in 4 patients due to the progression of osteoarthritis. The leakage of BSM occurred in 6 patients without any clinical consequences during the study period.
UNASSIGNED: About half of the study patients achieved a reduction in the NRS of 4 points at the 6-month follow-up after SCP.
UNASSIGNED: NCT04905394 (ClinicalTrials.gov identifier).

UNASSIGNED: Transient bone marrow edema (TBME) is a condition that typically presents in middle-aged adults with a male to female ratio of 3:1. Cases have also been noted in females during the third trimester of pregnancy. Vitamin D deficiency has been linked to this condition as the pathophysiology demonstrates poorly mineralized osteoid in presenting lesions. It is rare for a healthy child or adolescent to present with TBME introducing the purpose of this case study. This case report aims to provide medical and surgical education on TBME in a young and healthy adolescent. To our best knowledge, this is the first report on the use of subchondroplasty to treat transient bone marrow of the navicular in an adolescent male.
UNASSIGNED: A 16-year-old adolescent male with foot and ankle pain is treated from September of 2017 to September of 2019. The patient failed initial conservative treatments. His treatment concluded with subchondroplasty of the navicular bone, typically contraindicated due to the risk of avascular necrosis (AVN). The patient received follow-up in March of 2020, which included additional magnetic resonance imaging (MRI) for long-term treatment outcome data.
UNASSIGNED: The patient was successfully treated with subchondroplasty after conservative therapy failed. In patients with TBME, subchondroplasty may not be the best option due to risk of AVN. At 1-year follow-up, our patient was asymptomatic and MRI showed reduction in edema.

Subchondroplasty is a new minimally invasive surgical technique developed to treat bone marrow lesions (BML) and early osteoarthritis (OA). During the procedure, engineered calcium phosphate compound (CPC) is injected. It is claimed by the manufacturer that during the healing process, the CPC is replaced with new bone. The purpose of this study was to verify the replacement of CPC with new bone after subchondroplasty for the first time in humans. A 76-year old woman was referred for resistant medial knee pain. Standing radiographs showed varus knee OA and magnetic resonance imaging (MRI) revealed BML. She was treated with subchondroplasty of medial femoral condyle. Excellent relief of pain was achieved after procedure. Afterwards, the pain worsened, the radiographs confirmed the OA progression and the patient was treated with a total knee arthroplasty (TKA) 4 years after primary procedure. The resected bone was examined histologically and with micro-computed tomography (CT). Histologically, bone trabeculae of subcortical bone were embedded in the amorphous mass. However, no signs of CPC resorption and/or bone replacement have been found with micro-CT. In short term, excellent pain relief could be expected after the subchondroplasty procedure. However, there was no replacement of CPC with bone and the technique probably did not influence the natural process of knee OA.

BACKGROUND: Knee osteoarthritis (KOA) is increasingly prevalent in North American society. The significant societal burden it represents makes it essential to promote and target new treatments in earlier phases of the disease. Among others, subchondroplasty is a newly documented technique using calcium phosphate injection targeting the osteochondral lesions preceding KOA, also known as Bone Marrow Lesions (BMLs). This article aimed to review the existing literature on clinical and radiological outcomes of subchondroplasty in the treatment of BMLs in KOA.
METHODS: A systematic review was performed using PubMed, Embase, Medline and Cochrane Database of Systematic Reviews. Studies on calcium phosphate injections into BMLs for KOA and its clinical and radiological outcomes were screened and reviewed by independent evaluators.
RESULTS: After screening, ten articles were included, totaling 540 patients. Follow-up ranged from 6 months to 7 years. Overall, the procedure showed significant functional and quality of life improvement, as well as pain relief, as shown by Patients-Reported Outcomes Measures (PROMs). There were very few complications reported, the most important being leakage of calcium phosphate outside the targeted site. Conversion rate to total knee arthroplasty (TKA) ranged from 14 % to 30 % at 2 years post-procedure. Long term radiological outcomes have been poorly documented.
CONCLUSIONS: Subchondroplasty is a promising avenue for the treatment of KOA. However, quality evidence is still required before any real conclusions and practical management guidelines can be drawn. Prospective, randomized studies with a control group and a rigorous assessment of long-term clinical and radiological outcomes are recommended.

Talar osteonecrosis is a well-described phenomenon following talar neck fracture, but is a rarely described complication after procedures about the foot and ankle. Here we describe the clinical course of 5 cases of talar osteonecrosis following injection of calcium phosphate into the talus (subchondroplasty) with or without acute lateral ligament repair after acute lateral ankle ligament injuries performed at an outside institution. Practitioners should be aware of this potentially devastating complication. Future research is indicated to determine the safety and efficacy of subchondroplasty for the talus.
METHODS: Level V, case series.

Knee subchondroplasty (SCP) is one of the most novel minimally invasive methods for treating bone marrow lesions. The literature suggests that it is safe, with few complications and good outcomes. However, no studies have documented its usage for managing large subchondral bone cysts. This article outlines a case report and details the pearls and pitfalls of SCP in treating large subchondral bone cysts. Our patient underwent arthroscopic debridement with medial femoral condyle SCP. Mild posterior extravasation of synthetic bone substitute was observed on Postoperative Day 1, which was immediately rectified on revision arthroscopy. Gradual escalation of weight bearing and good pain relief were subsequently achieved, and the patient has remained complication-free after two years. No further extravasation were observed on repeat radiography. SCP is a feasible temporising measure that may help to delay the need for bone allograft or immediate knee arthroplasty in younger patients while retaining function and delaying loss of productivity.

OBJECTIVE: To evaluate clinical outcomes after intraosseous injection for knee osteoarthritis systematically with available clinical evidence.
METHODS: A systematic search methodology of the PUBMED, EMBASE, and CINAHL databases was conducted in November 2020. The search workflow was in adherence to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The following inclusion criteria were adopted: clinical trials of any level of evidence, reporting clinical outcomes following intraosseous injections of bone substitutes or biologic agents, and mesenchymal stem cells or platelet-rich plasma into the knee as treatment modalities for osteoarthritis. Duplicate data and articles not written in English were excluded from this review.
RESULTS: Six studies were identified and included in this review, with a total of 167 patients. Two studies used subchondroplasty CaP injections, while 4 studies used intraosseous injections of platelet-rich plasma. Two studies provided Level II evidence, 2 studies provided Level III evidence, and a further 2 provided Level IV evidence. Five out of 6 studies reported data using the visual analog scale, 4 studies used the Knee Injury and Osteoarthritis Outcome Score, while 3 studies used the Western Ontario and McMaster Universities Osteoarthritis Index. Clinical improvements in pain and functionality were documented in all trials, with only a few patients experiencing adverse events.
CONCLUSIONS: Intraosseous injections for knee osteoarthritis are safe and effective. However, multiple pertinent variables such as safety, cost of treatment, and performance against placebos and other treatment modalities require further evaluation before intraosseous injections can be considered as standard treatment for patients presenting with osteoarthritis of the knee.

Purpose  The aim of this prospective study was to assess the effectiveness in terms of pain relief and functional improvement of the Subchondroplasty procedure in the treatment of osteoarthritis-related bone marrow lesions (BMLs) of the knee. Methods  The study included first 15 consecutive patients undergone to Subchondroplasty procedure for the treatment of chronic degenerative BMLs in which previous conservative treatment have failed. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores, Knee Injury and Osteoarthritis Outcome Scores (KOOS), and visual analog scale (VAS) pain scores were obtained preoperatively and at 1, 6, and 12 months of follow-up. Results  WOMAC scores significantly improved from 39.7 ± 20.2 before surgery to 26.8 ± 16.1 at the 1-month follow-up ( p  = 0.045). A further significant improvement to 15.5 ± 12.7 ( p  = 0.02) and to 8.6 ± 3.1 ( p  < 0.01) was obtained both at 6-month and at 1-year follow-up. KOOS scores improved significantly from 47.5 ± 16.6 before surgery to 65.4 ± 14.9 at 1 month ( p  = 0.013) and to 80.4 ± 15.1 at 6-month follow-up ( p  = 0.01). A further improvement to 85.6 ± 15.1 was recorded 1 year postoperatively, although nonsignificant. VAS score showed a significant improvement from 55.8 ± 20.5 preoperatively to 36.2 ± 16.9 at 1 month ( p  = 0.008) and to 18.2 ± 17.3 at 6-month follow-up ( p  = 0.005). This further improved to 12.8 ± 17.9 at 1-year follow-up, although not significantly. Conclusion  Subchondroplasty procedure represents a safe and valid surgical option in the treatment of osteoarthritis-related BMLs of the knee, providing an improvement in terms of pain relief and functional recovery. Longer studies are required to evaluate how long these improvements may last. Level of Evidence  Therapeutic case-series, Level IV study.