Subchondral Calcium Phosphate is Ineffective for Bone Marrow Edema Lesions in Adults With Advanced Osteoarthritis

The Combined Intraosseous Administration of Orthobiologics Outperformed Isolated Intra-articular Injections in Alleviating Pain and Cartilage Degeneration in a Rat Model of MIA-Induced Knee Osteoarthritis

BACKGROUND

Intra-articular (IA) platelet-rich plasma (PRP) and bone marrow aspirate concentrate (BMAC) injections have shown efficacy and safety in treating osteoarthritis (OA). However, the effectiveness and mechanisms of combined intraosseous (IO) administration of these orthobiologics have yet to be explored.

PURPOSE/HYPOTHESIS

The purpose of this study was to evaluate the effect on pain, cartilage, synovium/infrapatellar fat pad (IFP), and subchondral bone in rat knee OA, comparing isolated IA with combined IA and IO (IA+IO) injections of PRP or BMAC. It was hypothesized that combined injections would be superior to sole IA injections.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 48 rats were divided into 6 groups: sham (only joint puncture during OA induction with IA+IO saline injection treatment) and 5 groups with OA induction, control (IA+IO saline injection), PRP (IA PRP+IO saline injection), BMAC IA (IA BMAC+IO saline injection), PRP IA+IO (IA+IO PRP injection), and BMAC IA+IO (IA+IO BMAC injection). OA was induced by IA injection of monosodium iodoacetate (MIA). Rats were administered different orthobiologics according to their grouping 3 weeks after the MIA injection. Pain changes were evaluated using the weightbearing ratio assay at weeks 3, 4, 5, 7, and 9 after OA induction. Rats were euthanized at week 9 for gross, radiological, histological, immunohistochemical, and immunofluorescence assessments of cartilage, synovium, and subchondral bone.

RESULTS

Compared with the control group, all orthobiologics injection groups had reduced joint pain. Compared with IA injection, IA+IO injections provided superior pain relief by suppressing calcitonin gene-related peptide and substance P in both the synovium/IFP and subchondral bone. IA+IO injections slowed the progression of subchondral bone lesions by inhibiting CD31hiEmcnhi vessel formation and excessive osteoclast and osteoblast turnover while preserving subchondral bone microarchitecture, slowing cartilage degeneration. However, IA+IO injections did not outperform isolated IA injections in reducing synovitis and synovium/IFP fibrosis. Compared with PRP, BMAC exhibited superior inhibition of pain-related mediators, but no significant differences were observed in synovitis suppression, infrapatellar fat pad fibrosis, and subchondral bone protection.

CONCLUSION

IA+IO injections of orthobiologics were more effective in relieving pain, slowing cartilage degeneration, and inhibiting abnormal vascularization and remodeling compared with isolated IA injections. BMAC showed superior pain relief in the synovium/IFP and subchondral bone compared with PRP. Further research is needed to optimize PRP and BMAC components for enhanced efficacy in OA management.

CLINICAL RELEVANCE

Our findings contribute to advancing the understanding of pain relief mechanisms and support the endorsement of IO injection of orthobiologics for the treatment of OA and joint pain.

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.

Core Decompression Combined with Intraosseous Autologous Conditioned Plasma Injections Decreases Pain and Improves Function in Patients with Symptomatic Knee Bone Marrow Lesions

The purpose of this prospective case series was to determine the effectiveness of using a combination of the core decompression and injection of autologous conditioned plasma (ACP) for the treatment of symptomatic knee bone marrow lesions (BML), as well as to report on the preliminary clinical results based on magnetic resonance imaging (MRI) and patient-reported outcomes (PROMs). Patients with OA-related BML who failed to improve on conservative treatment for three months underwent an identical procedure consisting of arthroscopy, core decompression, and the intraosseous injection of ACP and were followed up for 12 months. A statistically significant reduction in pain and an improvement in function, as measured by the Numeric Pain Rating Scale (NPRS) and Knee Injury and Osteoarthritis Outcome Score (KOOS), was observed at one-week follow-up (8.3 ± 0.8 to 1.5 ± 1.0; p ≤ 0.001 and 33.4 ± 10.6 to 53.9 ± 13.6; p ≤ 0.001 respectively). After six weeks, weight-bearing was allowed, but the trend did not change-the NPRS continued to be low (average 1.4 on 12-month follow-up) and the total KOOS increased 44.6 points from the baseline (average 78.0 on 12-month follow-up). The Whole-Organ Magnetic Resonance Imaging Score improved from 66.1 ± 19.4 prior to surgery to 58.0 ± 15.9 (p < 0.001) after 3 months. In our study, there was no control group, randomisation was not performed, and the sample size was relatively small. A combination of core decompression and the intraosseous injection of ACP into the affected subchondral area proved to be a safe and effective procedure that provides rapid pain relief and a significant increase in joint function up to one year postoperatively.

Efficacy of Subchondroplasty in the Treatment of Pain Associated With Bone Marrow Lesions in the Osteoarthritic Knee

Background

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.

Purpose/Hypothesis

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.

Study Design

Case series; Level of evidence, 4.

Methods

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.

Results

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.

Conclusion

About half of the study patients achieved a reduction in the NRS of 4 points at the 6-month follow-up after SCP.

Registration

NCT04905394 (ClinicalTrials.gov identifier).

Pentosan Polysulfate Affords Pleotropic Protection to Multiple Cells and Tissues

Pentosan polysulfate (PPS), a small semi-synthetic highly sulfated heparan sulfate (HS)-like molecule, shares many of the interactive properties of HS. The aim of this review was to outline the potential of PPS as an interventional therapeutic protective agent in physiological processes affecting pathological tissues. PPS is a multifunctional molecule with diverse therapeutic actions against many disease processes. PPS has been used for decades in the treatment of interstitial cystitis and painful bowel disease, it has tissue-protective properties as a protease inhibitor in cartilage, tendon and IVD, and it has been used as a cell-directive component in bioscaffolds in tissue engineering applications. PPS regulates complement activation, coagulation, fibrinolysis and thrombocytopenia, and it promotes the synthesis of hyaluronan. Nerve growth factor production in osteocytes is inhibited by PPS, reducing bone pain in osteoarthritis and rheumatoid arthritis (OA/RA). PPS also removes fatty compounds from lipid-engorged subchondral blood vessels in OA/RA cartilage, reducing joint pain. PPS regulates cytokine and inflammatory mediator production and is also an anti-tumor agent that promotes the proliferation and differentiation of mesenchymal stem cells and the development of progenitor cell lineages that have proven to be useful in strategies designed to effect repair of the degenerate intervertebral disc (IVD) and OA cartilage. PPS stimulates proteoglycan synthesis by chondrocytes in the presence or absence of interleukin (IL)-1, and stimulates hyaluronan production by synoviocytes. PPS is thus a multifunctional tissue-protective molecule of potential therapeutic application for a diverse range of disease processes.

What Factors are Associated With Conversion to Knee Arthroplasty After Subchondroplasty?

BACKGROUND

Subchondral bone marrow lesions identified on knee MRI are believed to play a role in osteoarthritis-associated pain. The subchondroplasty procedure is an arthroscopically assisted procedure for treating such lesions to avoid larger procedures such as knee arthroplasty. However, the survivorship free of conversion to arthroplasty and the factors associated with an increased likelihood of conversion of subchondroplasty to arthroplasty have not been well defined.

QUESTIONS/PURPOSES

We performed this study to (1) determine the 5-year survivorship of subchondroplasty free from conversion to knee arthroplasty (unicompartmental or total) and (2) identify variables that were associated with progression to knee arthroplasty after a subchondroplasty procedure.

METHODS

In all, 216 patients who underwent a subchondroplasty procedure performed by one surgeon with subchondroplasty experience at a single-center, multilocation facility between September 2014 and August 2017 were retrospectively evaluated to estimate survivorship free from conversion to knee arthroplasty at 5 years. The mean ± SD age and BMI at the time of subchondroplasty procedure were 59 ± 11 years and 33 ± 8 kg/m2, respectively; 60% (129 of 216) of the patients were women. Other variables collected were smoking status and grade and location of chondral lesions. The electronic medical record was reviewed to determine whether the patient had a knee arthroplasty after subchondroplasty. Survivorship free from conversion to knee arthroplasty at 5 years was calculated from a Kaplan-Meier survivorship estimator. Factors associated with progression to knee arthroplasty were examined using t-tests and chi-square analyses. Variables showing evidence of an association with knee arthroplasty were explored further using a Kaplan-Meier survivorship estimator (n = 190).

RESULTS

Kaplan-Meier survivorship free from conversion to knee arthroplasty was 73% (95% CI 67% to 79%) at 5 years after subchondroplasty. We found that age older than 50 years and Grade 4 chondral lesions were associated with conversion to knee arthroplasty. Patients with a Grade 4 chondral lesion had 5-year survivorship of 62% (95% CI 54% to 71%) and 59% (95% CI 50% to 69%) for those older than 50 years with a Grade 4 chondral lesion.

CONCLUSION

Currently, we recommend a detailed, informed discussion of the risks versus benefits with patients who are considering a subchondroplasty procedure, particularly patients aged 50 years and older and those with Grade 4 chondral lesions. Future randomized trials, including those that compare the subchondroplasty procedure with arthroscopy alone or nonoperative management options, are still needed to confirm the efficacy and role of the subchondroplasty procedure in patients with knee osteoarthritis, because only such prospective studies can determine the success of the procedure.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Tissue Integration of Calcium Phosphate Compound after Subchondroplasty: 4-Year Follow-Up in a 76-Year-Old Female Patient

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.

Carboplasty, a Simple Tibial Marrow Technique for Knee Osteoarthritis: A Placebo-Controlled Randomized Trial

Background

Carboplasty is a new minimally invasive technique for knee osteoarthritis (OA) that consists of injecting tibial marrow aspirate into the bone-cartilage interface as well as intra-articularly.

Purpose

To compare the clinical and imaging outcomes, as well as the safety, of carboplasty for symptomatic knee OA in a placebo-controlled trial.

Study Design

Randomized controlled trial; Level of evidence, 1.

Methods

The authors conducted a randomized controlled trial to compare carboplasty with placebo for the treatment of symptomatic knee OA. Patients who had failed medical treatment and had bone edema on magnetic resonance imaging (MRI) were randomized in a 1:1 ratio to carboplasty or placebo. The primary outcome of the study was the Numeric Pain Rating Scale (NPRS) for the knee at 1 year (scores range from 0 to 10, with a higher score indicating worse pain). Secondary outcomes were the Knee injury and Osteoarthritis Outcome Score (KOOS), treatment responder rate (based on achieving the minimal clinically important difference of the NPRS), MRI bone edema reduction, and treatment safety.

Results

In total, 50 patients (25 carboplasty vs 25 placebo) were enrolled and followed up with for an average of 18 months (range, 14-24 months). The average NPRS at baseline decreased from 7.1 ± 0.9 to 2.9 ± 2.1 (P < .001) at 1 year in the carboplasty group and from 7.7 ± 0.9 to 4.9 ± 2.2 (P < .001) in the placebo group. On average, patients after carboplasty improved 60% from their initial NPRS, and patients after placebo improved 37% (P = .003). Patients had a statistically significantly greater improvement from baseline in all KOOS subscales in the carboplasty group compared with the placebo group (P < .001). The responder rates were 96% for carboplasty and 76% for placebo (P = .098). Bone edema was reduced in 72% of patients in the carboplasty group and 44% of patients in the placebo group (P = .045). Neither group had adverse events related to treatment.

Conclusion

Carboplasty resulted in greater pain reduction, a significantly greater improvement in all KOOS subscales, and a similar safety profile compared with placebo in patients with symptomatic knee OA and bone edema.

Registration

ISRCTN69838191 (ISRCT Registry).

Subchondroplasty in the treatment of bone Marrow lesion in early Knee Osteoarthritis: A systematic review of clinical and radiological outcomes

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.

METHOD

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.

Effects of physical exercise and body weight on disease-specific outcomes of people with rheumatic and musculoskeletal diseases (RMDs): systematic reviews and meta-analyses informing the 2021 EULAR recommendations for lifestyle improvements in people with RMDs

BACKGROUND

A European League Against Rheumatism (EULAR) taskforce was convened to develop recommendations for lifestyle behaviours in rheumatic and musculoskeletal diseases (RMDs). This paper reviews the literature on the effects of physical exercise and body weight on disease-specific outcomes of people with RMDs.

METHODS

Three systematic reviews were conducted to summarise evidence related to exercise and weight in seven RMDs: osteoarthritis, rheumatoid arthritis, systemic lupus erythematosus, axial spondyloarthritis (axSpA), psoriatic arthritis, systemic sclerosis and gout. Systematic reviews and original studies were included if they assessed exercise or weight in one of the above RMDs, and reported results regarding disease-specific outcomes (eg, pain, function, joint damage). Systematic reviews were only included if published between 2013-2018. Search strategies were implemented in the Medline, Embase, Cochrane Library of systematic reviews and CENTRAL databases.

RESULTS

236 articles on exercise and 181 articles on weight were included. Exercise interventions resulted in improvements in outcomes such as pain and function across all the RMDs, although the size of the effect varied by RMD and intervention. Disease activity was not influenced by exercise, other than in axSpA. Increased body weight was associated with worse outcomes for the majority of RMDs and outcomes assessed. In general, study quality was moderate for the literature on exercise and body weight in RMDs, although there was large heterogeneity between studies.

CONCLUSION

The current literature supports recommending exercise and the maintenance of a healthy body weight for people with RMDs.

Knee Intraosseous Injections: A Systematic Review of Clinical Evidence of Different Treatment Alternatives

OBJECTIVE

To systematically review the available clinical evidence regarding the safety and efficacy of knee intraosseous injections for the treatment of bone marrow lesions in patients affected by knee osteoarthritis.

DESIGN

A literature search was carried out on PubMed, Embase, and Google Scholar databases in January 2020. The following inclusion criteria were adopted: (1) studies of any level of evidence, dealing with subchondral injection of bone substitute materials and/or biologic agents; (2) studies with minimum 5 patients treated; and (3) studies with at least 6 months' follow-up evaluation. All relevant data concerning clinical outcomes, adverse events, and rate of conversion to arthroplasty were extracted.

RESULTS

A total of 12 studies were identified: 7 dealt with calcium phosphate administration, 3 with platelet-rich plasma, and 2 with bone marrow concentrate injection. Only 2 studies were randomized controlled trials, whereas 6 studies were prospective and the remaining 4 were retrospective. Studies included a total of 459 patients treated with intraosseous injections. Overall, only a few patients experienced adverse events and clinical improvement was documented in the majority of trial. The lack of any comparative evaluation versus subchondral drilling alone is the main limitation of the available evidence.

CONCLUSIONS

Knee intraosseous injections are a minimally invasive and safe procedure to address subchondral bone damage in osteoarthritic patients. They are able to provide beneficial effects at short-term evaluation. More high-quality evidence is needed to confirm their potential and to identify the best product to adopt in clinical practice.

Intraosseous Injections Are Safe And Effective in Knee Osteoarthritis: A Systematic Review

Purpose

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.

Conclusion

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.

Knee subchondroplasty for management of subchondral bone cysts: a novel treatment method

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.

Subchondroplasty in the Treatment of Bone Marrow Lesions of the Knee: Preliminary Experience on First 15 Patients

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.

Subchondroplasty for Bone Marrow Lesions in the Arthritic Knee Results in Pain Relief and Improvement in Function

Subchondroplasty is a relatively new joint preserving procedure, which involves the localized injection of calcium pyrophosphate bone substitute into the bone marrow lesion. The advent of magnetic resonance imaging (MRI) has greatly facilitated the identification of these bone marrow lesions. We investigated the clinical efficacy of subchondroplasty in the treatment of symptomatic bone marrow lesions in the knee, including knees with preexisting osteoarthritis. This study comprised of 12 patients whose knees were evaluated with standard radiographs and MRI to identify and localize the bone marrow lesions. They then underwent subchondroplasty under intraoperative radiographic guidance. Preoperative and postoperative visual analog scale (VAS) pain scores, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores, and Knee Injury and Arthritis Outcome Scores (KOOS) were obtained. VAS scores improved significantly from 7.5 ± 1.8 before surgery to 5.2 ± 2.7 after surgery. This further improved to 2.1 ± 2.4 at the one-year follow-up. KOOS scores improved significantly from 38.5 ± 17.0 before surgery to 73.2 ± 19.0 at the one-year follow-up. WOMAC scores improved significantly from 47.8 ± 20.5 before surgery to 14.3 ± 13.2 at the one-year follow-up. Subchondroplasty offers an effective way to treat subchondral bone marrow lesions in the arthritic knee, resulting in improvement in symptoms and early return to activity. Long-term studies are required to evaluate if these benefits can last. This is a Level II study.

The compartmental distribution of knee osteoarthritis - a systematic review and meta-analysis

OBJECTIVES

For a population with knee osteoarthritis (OA), determine: 1) the prevalence of single compartmental, bicompartmental and tricompartmental OA, 2) the prevalence of isolated medial tibiofemoral, lateral tibiofemoral, or patellofemoral OA, and combinations thereof.

METHODS

PubMed and Web of Science databases, and reference lists of identified studies, were searched to find studies which reported on the compartmental distribution and prevalence of knee OA. Two independent reviewers assessed studies against pre-defined inclusion criteria and prevalence data were extracted along with subject characteristics. The methodological quality of each included study was assessed. A random-effects model meta-analysis was performed for each OA category to estimate the relative prevalence of OA in the knee compartments amongst people with knee OA.

RESULTS

16 studies (3,786 knees) met the inclusion criteria. High heterogeneity was measured. Normalised for knees with OA, estimated prevalence rates (95% CI) were: single compartmental 50% (31.5-58.3%), bicompartmental 33% (23.1-37.2%) and tricompartmental only 17% (8.8-24.8%). Isolated medial tibiofemoral OA, isolated patellofemoral OA, and combined medial tibiofemoral and patellofemoral OA were more common than tricompartmental disease, occurring in 27% (15.2-31.1%), 18% (9.9-22.7%) and 23% (14.1-27.3%) of people respectively. Single/bicompartmental patterns of disease involving the lateral tibiofemoral compartment were less common, summing to 15% (8.5-18.7%).

CONCLUSION

Three-quarters of people with knee OA do not have tricompartmental disease. This is not reflected in the frequency with which partial and combined partial knee arthroplasties are currently used.

TRIAL REGISTRATION NUMBER

PROSPERO systematic review protocol (CRD42019140345).

Ten-Year Survivorship, Patient-Reported Outcome Measures, and Patient Acceptable Symptom State After Over-the-Top Hamstring Anterior Cruciate Ligament Reconstruction With a Lateral Extra-articular Reconstruction: Analysis of 267 Consecutive Cases

BACKGROUND

Long-term patient-reported outcome measures (PROMs) and predictors of success or failure after anterior cruciate ligament (ACL) reconstruction are not fully understood, especially when combined with a lateral extra-articular reconstruction.

PURPOSE

To assess the long-term PROMs, revision rate, and predictors of success or failure after ACL reconstructions using an over-the-top surgical technique with single-bundle hamstring tendon autografts and a lateral extra-articular reconstruction.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

The study cohort consisted of 267 consecutive patients (mean age, 30.7 years) who underwent ACL reconstruction with an over-the-top surgical technique with single-bundle hamstring tendon autografts and a lateral extra-articular augmentation between November 2007 and May 2009. The number of subsequent ACL revisions and reoperations were recorded. Subjective clinical status was assessed with PROMs-specifically, the Knee injury and Osteoarthritis Outcome Score (KOOS), Lysholm, Tegner, and visual analog scale for pain-at a minimum follow-up of 10 years.

RESULTS

Overall, 3% of patients underwent ACL revision, with a 10-year survival rate of 96.3%. High sport activity (hazard ratio, 6.9; P = .285) and concomitant meniscal lesion (hazard ratio, 2.6; P = .0487) were predictors of ACL revision or new meniscectomy. The mean ± SD Lysholm score was 94.1 ± 10.8, while that for the visual analog scale for pain was 0.2 ± 0.9 at rest and 2.1 ± 2.6 during activity. KOOS subscale scores were as follows: 95.7 ± 8.1 for Pain, 92.5 ± 10.5 for Symptoms, 98.4 ± 7.4 for Activities of Daily Living, 90.7 ± 17.2 for Sport, and 91.2 ± 17.1 for Quality of Life; respectively, 88%, 99%, 81%, 89%, and 91% of patients achieved the Patient Acceptable Symptom State. Female sex and chondropathy with Outerbridge grade ≥2 were predictors of worse KOOS subscales. Overall, 82% of patients returned to sport, and 57% were still participating at the 10-year evaluation.

CONCLUSION

ACL reconstruction with an over-the-top surgical technique with single-bundle hamstring autografts and a lateral extra-articular reconstruction provided satisfactory results in terms of function, symptoms, sports, and quality of life in 80% to 90% of patients after 10 years. Long-term survivorship was 96%. Sport participation declined from 82% postoperatively to 57% at long-term follow-up. A concomitant medial meniscal lesion was a predictor of higher risk of ACL failure or new meniscal lesion, while advanced chondropathy and female sex were predictors of higher pain, lower function, and poor quality of life scores.

Arthroscopic-Assisted Intraosseous Bioplasty of the Acetabulum

Intraosseous bioplasty (IOBP), has been previously described for arthroscopic-assisted treatment of subchondral bone cysts in the proximal tibia associated with early stages of knee osteoarthritis (OA). This technique entails combining bone marrow aspirate concentrate or concentrated platelet-rich plasma with demineralized bone matrix as a bone substitute before injecting into a subchondral bone defect under fluoroscopic guidance. The principles of IOBP as a procedure that combines core decompression with biologic bone substitute augmentation can be extended to treat subchondral bone marrow lesions such as acetabular and femoral cysts in degenerative hip OA. Intraosseous bioplasty of the hip, in particular the acetabulum, when done using this technique, is a useful alternative that can be beneficial in treating young patients with early hip arthritis to achieve successful outcomes while delaying more invasive procedures. The Technical Note described here presents a step-by-step approach, including tips and pearls for arthroscopic-assisted IOBP with decompression of the subchondral cyst in the acetabulum followed by bone substitute injection under fluoroscopic guidance. We believe this method is a safe and reproducible way to treat subchondral defects in young patients with signs of early osteoarthritis of the hip joint.

Bone Marrow Edema, Clinical Significance, and Treatment Options: A Review

Bone marrow edema (BME) is a descriptive term used to describe high-signal intensity changes detected on magnetic resonance fluid-sensitive sequences that could be attributed to a number of underlying pathologies. Regardless of the cause, physiologic remodeling of the subchondral bone can be limited because of ongoing joint forces, increased focalization of stress, and reduced healing capacity of the subchondral bone. BME is a known prognostic factor associated with pain, dysfunction, and progressive cartilage damage. This review summarizes the current known causes of BMEs, theories related to histopathological changes, and current treatment options including novel biologic surgical options.

Subchondroplasty of the Ankle and Hindfoot for Treatment of Osteochondral Lesions and Stress Fractures: Initial Imaging Experience

Objective:To describe the imaging findings of patients treated with subchondroplasty (SCP) of the ankle and hindfoot. Materials and Methods: Eighteen patients (10 men, 8 women; age mean 43.1 years [range 20.1-67.7 years]) underwent ankle and hindfoot SCP at a single center over a 14-month period. Imaging data were reviewed retrospectively by 2 radiologists by consensus interpretation, including preoperative radiography (18), computed tomography (CT) (11), and magnetic resonance imaging (MRI) (13) and postoperative radiography (10), CT (4), and MRI (6). Follow-up imaging was acquired 1 month to 1.6 years following SCP. Results: Indications for SCP included symptomatic bone marrow lesions (BMLs) secondary to an osteochondral lesion (OCL) (16/18) or stress fracture (2/18). While focal radiodensity related to the SCP procedure was retrospectively identifiable on postoperative radiography in all except 1 case (10/11), postprocedural findings were not described by the interpreting radiologist in 6/11 cases. On CT, the average injected synthetic calcium phosphate (CaP) volume was 1.15 cm³ (SD = 0.33 cm³); mean CT attenuation of the injectate was 1220 HU (range 1058-1465 HU). In all patients who had pre- and postoperative MRI (5/18), BML size decreased on follow-up MRI. Extra-osseous extrusion of CaP was not seen on postoperative radiography, CT, or MRI. Conclusion: Physicians should be aware of the expanding preoperative indications and postoperative imaging findings of SCP, which is being performed with increasing frequency in the ankle and hindfoot.Levels of Evidence: Diagnostic, Level III: Retrospective cohort study.

Talar Avascular Necrosis After Calcium Phosphate Injection Treatment of Talar Bone Marrow Lesions: A Report of 2 Cases

CASE

We report on 2 patients who developed avascular necrosis (AVN) of the talus and poor patient outcomes after undergoing calcium phosphate injection into talar dome bone marrow lesions.

CONCLUSION

Subchondroplasty, defined as calcium phosphate injection for the treatment of articular bone marrow edema, is a recently described procedure for use in the ankle joint. In our opinion, the limited available research is of poor quality and describes equivocal improvement in patient symptoms after this procedure. Given the debilitating outcomes and extensive AVN we observed in 2 patients, we strongly advise caution in the use of this procedure in the talus.

Management of Bone Marrow Lesions of the Hip With Subchondral Calcium Phosphate Injection: Surgical Technique and Tips

Bone marrow lesions (BMLs) are localized areas of edema within subchondral bone, which are often due to early chondromalacia changes, subchondral insufficiency stress or microfractures, and/or avascular necrosis. The presence of BMLs worsen outcomes after arthroscopy and arthroplasty, thus making their management important in the preservation of hip function. In recent years, the advent of Subchondroplasty (SCP; Zimmer Knee Creations Incorporated, Exton, PA)-a minimally invasive surgical technique that involves injecting an isothermic calcium phosphate solution to stabilize BMLs-has shown promising results in managing pain from osteoarthritis (OA). The SCP material (AccuFill Bone Substitute Material, Zimmer Knee Creations Incorporated) has a similar physical and chemical structure to native bone mineral. In this Technical Note, we discuss a surgical approach for managing acetabular and femoral head BMLs with SCP. We also review the prior clinical trials reporting on SCP for knee OA. SCP may be a promising technique as part of the treatment algorithm for managing hip OA, and clinical trial enrollment has begun for hip SCP. On the basis of these results, further investigations into this procedure may be warranted.

Enhanced Subchondroplasty Treatment for Post-Traumatic Cartilage and Subchondral Bone Marrow Lesions in a Canine Model

This study characterizes outcomes associated with subchondroplasty (SCP) versus SCP enhanced with platelet-rich plasma (PRP) or bone marrow aspirate concentrate (BMC) treatment of impact-induced subchondral bone marrow lesions (BML) using a validated preclinical canine model. With IACUC approval, purpose-bred research hounds (n = 24) underwent arthroscopic impact injury (40 N) to both medial femoral condyles. At 3 months, functional assessments, arthroscopy, and magnetic resonance imaging (MRI) were performed. One knee in each dog (n = 24; n = 12 per endpoint) was randomly assigned to SCP with the other knee randomly assigned to SCP + PRP, SCP + BMC or sham injection (control) (n = 8 per group; n = 4 per endpoint). Dogs were evaluated at 6 and 12 months after treatment using functional assessments, radiography, arthroscopy, and MRI and humanely euthanatized at 6 or 12 months after treatment for histologic assessments. At 6 months post-treatment, comfortable range-of-motion (CROM) was higher (p < 0.04) in SCP + PRP and SCP + BMC knees compared with controls. At 1 year post-treatment, %Total Pressure Index was higher (p = 0.036) in SCP + BMC compared with controls, pain was lower (p < 0.05) in SCP + BMC and SCP + PRP compared with SCP and controls, and CROM was higher (p < 0.05) in SCP + BMC and SCP + PRP compared with SCP and controls. Knees treated with SCP + PRP and SCP + BMC had better (p < 0.05) MRI grades than SCP and controls. No statistically significant differences in arthroscopic or histologic pathology were noted. Clinical significance: Biologics added to SCP treatment may further enhance its beneficial effects by improving range-of-motion, pain severity, and limb loading through 1 year after treatment. However, these benefits must be considered alongside cost, logistics, and treatment availability. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:740-746, 2020.

The Efficacy of Subchondroplasty for the Treatment of Knee Pain Associated with Bone Marrow Lesions

CONTEXT

Symptomatic bone marrow lesions on MRI in patients with knee osteoarthritis are strongly associated with progressive deterioration of the joint and an increased risk of progression requiring joint replacement surgery. This study evaluates the efficacy of knee arthroscopy with adjunctive subchondroplasty (i.e. cartilage stabilization) to improve self-rated visual analog scale (VAS) pain scores, rate of conversion to arthroplasty, and patient satisfaction levels.

METHODS

A retrospective chart review and phone survey was performed on 12 patients who had undergone knee arthroscopy with adjunctive subchondroplasty for knee pain associated with chronic subchondral bone marrow lesions on MRI. Follow-up for the 12 patients was 36 months on average (range of 12 to 51 months), self-reported paired preoperative and postoperative VAS scores were analyzed in addition to rate of conversion to arthroplasty and patient satisfaction.

RESULTS

The results demonstrated statistically significant reductions in mean preoperative VAS scores versus six-week postoperative VAS scores from 7.58 to 1.83 (p < 0.001) in addition to significant reductions in mean preoperative VAS scores to final postoperative VAS scores from 7.58 to 1.60 (p < 0.001). There was no statistically significant association (p > 0.05) with patients' demographic and clinical data (e.g., age, height, weight, BMI, length of symptoms) and rate of revision to total arthroplasty after receiving the arthroscopic subchondroplasty procedure. Out of the 12 patients, two (16.7%) patients went on to conversion to total knee arthroplasty.

CONCLUSIONS

In this series, knee arthroscopy with adjunctive subchondroplasty for the treatment of osteoarthritis with symptomatic bone marrow lesions was associated with clinically significant improvements in VAS pain scores. Furthermore, patients who underwent subchondroplasty had a low rate (16.7%) of conversion to total knee arthroplasty at 36-month follow-up.

Calcium phosphate injection of symptomatic bone marrow lesions of the knee: what is the current clinical evidence?

BACKGROUND

Chronic bone marrow lesions (BML) in the weight-bearing portions of the knee are often associated with symptomatic degenerative arthritis resulting in pain and dysfunction. Injection of bone substitute material like calcium phosphate has been described. Whilst some studies have reported encouraging results others have shown limited benefit of this technique.

AIM

The aim was to collate the available evidence on the injection of calcium phosphate and systematically evaluate the results to answer the questions encountered in clinical decision making: (1) does it provide effective long-lasting pain relief to avoid further surgical intervention? (2) which factors (patient/surgical) significantly influence the outcome? and (3) does it adversely affect the outcomes of subsequent arthroplasty?

METHODS

A literature search was performed to identify the studies describing the clinical outcomes of calcium phosphate injection for treatment of BML. We evaluated the reported clinical outcomes with respect to pain, function and complications. Isolated case reports and studies with no objective assessment of clinical outcomes were excluded.

RESULTS

We noted 46 articles in the current literature of which 8 described clinical outcomes of calcium phosphate injection. Mean (plus/minus SD) score on the visual analog scale (VAS) has been reported to improve from 7.90 (± 0.38) to 2.76 (± 0.90), whereas the International Knee Documentation Committee (IKDC) score improved from 30.5 (SD not reported (NR)) to 53.0 (SD NR). Pre and post procedure Short form survey (SF-12) scores were 29.8 (SD NR) and 36.7 (SD NR), respectively. In one study, scores on the Tegner Lysholm knee scoring scale improved in 12 out of 22 patients, whereas the remainder had no change in symptoms. Extravasation of calcium phosphate into the joint was the most common complication, whereas no adverse effect has been reported on subsequent arthroplasty.

CONCLUSION

Limited data from the published studies would suggest that calcium phosphate injection of BML may potentially improve pain and function. However, no evidence is currently available to clearly identify patient/surgical factors that may influence the long-term outcomes of this procedure. Hence pragmatic, prospective studies with stratified patient cohorts and robust reporting of outcome measures are essential to improve the understanding of the indications and clinical effectiveness of this novel procedure.

Surgical Treatment of Insufficiency Fractures of the Knee

Bone marrow lesions (BMLs) in the knee represent focal edema caused by subchondral bone attrition and microfractures to the trabecular bone. These lesions are poor prognostic indicators for several orthopaedic procedures but also have been associated with the progression of osteoarthritis. Current research is aimed at treating BMLs with the intent to improve the overall structural integrity of the subchondral bone and delay the need for arthroplasty. The injection of calcium phosphate bone substitute has been proposed to treat BMLs because animal models have shown its potential to stimulate bone repair. This technical note describes the key steps involved in performing percutaneous fixation of BMLs with a hard-setting bone substitute, as well as associated pearls and pitfalls. Although continued research with prospective comparative cohorts and long-term follow-up is needed to determine the efficacy of this procedure, this intervention holds promise in delaying the need for total knee replacement in the arthritic patient with a focal lesion.

Evaluation and Management of Subchondral Calcium Phosphate Injection Technique to Treat Bone Marrow Lesion

PURPOSE

This study aimed to compile available data in medical literature about subchondral calcium phosphate injection, comparing results obtained with this technique, as well as indications, complications, and other important factors in treatment of bone marrow lesions.

DESIGNS

A literature review using PubMed and Medline database in order to identify works with terms "subchondral calcium phosphate injection," " subchondroplasty®," "bone marrow lesion," and "knee." Eight relevant articles were found.

RESULTS

A total of 164 patients with bone marrow lesion mainly on femoral condyle and tibial plateau recovered with significant functional improvement of knee after subchondral calcium phosphate treatment. Although 25% of them still had some type of pain complaint, they also showed improvement. There were few complications reported and return to activities occurred after 3 months on average.

CONCLUSIONS

Few studies evaluate the result of using subchondral calcium phosphate injection technique. However, all presented favorable results regarding pain and improvement of knee function. In addition, within 2 years, there was a 70% reduction in conversion to total knee arthroplasty in patients with previous surgical indication who choose calcium phosphate treatment.

Subchondroplasty of the Foot: Two Case Reports

Early avascular necrosis of metatarsal heads and cuboid injuries are uncommon conditions encountered by foot and ankle specialists. Treatment options are limited and typically include long periods of offloading or non-weightbearing. There is limited published information on alternative treatment approaches for such pathologies when conservative therapies fail. Presented are 2 patient cases treated with a percutaneous calcium phosphate injection after failure of standard therapy, persistent pain, and bone marrow edema in the foot.

Short-Term Outcomes for the Biologic Treatment of Bone Marrow Edema of the Knee Using Bone Marrow Aspirate Concentrate and Injectable Demineralized Bone Matrix

Purpose

To evaluate short-term outcomes for the biologic treatment of bone marrow edema (BME) of the knee using bone marrow aspirate concentrate (BMAC) and injectable demineralized bone matrix (iDBM).

Methods

We performed a review of prospectively collected data from patients who underwent treatment for bone marrow lesions (BMLs) of the knee using BMAC and iDBM (IntraOsseous BioPlasty; Arthrex, Naples, FL) between May 2017 and December 2018. Inclusion criteria included patients aged 18 to 65 years with the presence of BME on T2-weighted magnetic resonance imaging in the subchondral weightbearing region of the tibia or femoral condyle, with pain corresponding to the same compartment. The International Knee Documentation Committee (IKDC), pain visual analog scale (VAS), and 12-Item Short Form Health Survey (SF-12) scores were used to evaluate clinical outcomes.

Results

We evaluated 20 patients who were treated at a single academic medical institution over a mean 14.5-month follow-up (median, 14 months; range, 6-25 months). The average patient age was 51.7 years (range 38-62 years). Compared with preoperative values, the visual analog scale decreased from 7.0 to 1.3 (P = .008). The mean International Knee Documentation Committee scores improved from 29.2 to 66.1 (P = .063). Both the Physical and Mental Component Scores of the 12-Item Short Form Health Survey also showed improvement (Physical Component Score, P = .438; Mental Component Score, P = .563). Based on postoperative magnetic resonance imaging, 75% (3 of 4) of the BMLs demonstrated complete healing. The survival rate was 93% at 1-year follow-up.

Conclusion

Biologic treatment of BME of the knee using BMAC and iDBM is an effective adjunct to arthroscopy that provides short-term pain relief for BMLs associated with degenerative conditions of the knee. This procedure is associated with clinically significant improvements in knee pain and function at a short-term follow-up.

Level of Evidence

Level IV, therapeutic case series.

Surgical modalities for the management of bone marrow edema of the knee joint

Background

Bone marrow edema (BME) is a radiological term which can be found in many conditions with varied pathogenesis and histopathological images. It usually presents with pain in the affected joint and is diagnosed with MRI. Subchondroplasty (SCP) and core decompression (CD) are the surgical methods that are available to achieve pain relief and functional improvement. Both surgical methods have their own indications and are used depending on the patient's history. The aim of this literature review article is to discuss the surgical modalities for the management of bone marrow edema focusing on the knee joint. Such topic which analyzes both surgical methods for treatment of bone marrow edema of the knee joint has never been described in a review article before.

Materials and methods

For the purpose of our manuscript we thoroughly searched electronic databases such as Pubmed and Medline to acquire the appropriate material for our review paper. Only English articles were used in this review. In our study we included every article that had described the surgical management of BME of the knee by CD and SCP. In the discussion we included 18 studies (9 CD and 9 SCP) with a total number of patients equal to 397, while 206/397 had undergone surgical intervention (169 underwent SCP and 37 CD).

Results

Follow-up of 180 patients out of 206 were available for our review. A total number of 166 patients (92.2%) were successfully treated. Specifically, 29 (100%) patients were treated by CD and 137 (90.7%) by SCP. In a study, 10 patients who underwent SCP for BME secondary to advanced osteoarthritis (OA) yielded poor results. In other studies, pain persistency was observed in 2 patients, 1 patient had postoperative infection and another patient eventually underwent total knee arthroplasty (TKA). 70% prevention of TKA was achieved by SCP in a study of 66 patients with BME secondary to advanced OA. Thus, a total number of 166 patients were considered as clinical success and 14 patients as clinical failure.

Conclusions

The included studies that have been published referred to the surgical methods of CD or SCP for the management of BME of the knee but none of that summarizes all current studies on both methods. Those studies seem that CD is a surgical technique that is proposed to perform in patients without findings of OA that usually fail to respond to conservative treatment. On the other hand, the option of SCP technique is carried out in patients with varied stage of OA associated with subchondral BME. Both methods aim to reduce the pain and to improve function in the setting of subchondral BME. Nevertheless it is not clear in literature which method is the best according to the criteria of the use. This literature review shows a lack of standardized guidelines with respect to diagnosis and surgical treatment.

Changing MRI after subchondroplasty with partial meniscectomy for knee osteoarthritis

A 54-year old woman with primary osteoarthritis and a tibial bone marrow lesion underwent subchondroplasty with injectable calcium phosphate. Post-operatively, the patient's symptoms worsened, and she lost the ability to bear weight. Follow-up MRI revealed previously absent, diffuse STIR hyperintensity in the tibia extending far beyond the surgical site. Twelve months post-operatively, symptoms spontaneously resolved. As the prevalence of subchondroplasty grows it will be important to recognize potential complications. To the authors' best knowledge this is the first report of significantly worsening pain and difficulty bearing weight corresponding with diffuse hyperintense T2 signal in the tibia after a calcium phosphate subchondroplasty.

Surgical Treatment of Bone Marrow Lesion Associated with Recurrent Plantar Fasciitis: A Case Report Describing an Innovative Technique Using Subchondroplasty®

Plantar fasciitis is one of the most common chief complaints seen in the foot and ankle clinic. With a relatively benign course, most cases are self-limiting or amendable to conservative therapy; ~90% of all plantar fasciitis cases will respond to these methods. When conservative treatment and time fail, surgical intervention can be necessary to improve outcomes. We present a novel method using Subchondroplasty^® (SCP^®; Zimmer Holdings, Inc.; Warsaw, IN) and revision fasciotomy in a case in which initial fasciotomy had failed. After the patient had failed to improve, a worsening underlying bone marrow lesion was identified at the origin of the plantar fascia; thus, SCP^® was used with repeat fasciotomy. SCP^® involves injecting calcium phosphate into bone marrow lesions to stimulate long-term bone repair. At 10 months after SCP^®, the patient remained pain free and had returned to running at the final follow-up examination. This surgical treatment should be considered as an adjunctive procedure for those patients with plantar fasciitis, identifiable bone marrow lesions on magnetic resonance imaging, and continued pain when other treatment modalities have failed.

Subchondroplasty for the treatment of post-traumatic bone marrow lesions of the medial femoral condyle in a pre-clinical canine model

This study characterizes long-term outcomes associated with subchondroplasty (SCP) treatment for impact-induced subchondral bone marrow lesions (BML) using a validated pre-clinical canine model. With IACUC approval, purpose-bred research hounds (n = 16) underwent arthroscopic impact injury (40N) to both medial femoral condyles. At 3 months, functional assessments, arthroscopy, and MRI were performed and knees (n = 32) were randomly assigned to SCP (3 ml fluoroscopically guided percutaneous injection of AccuFill BSM into BML bone defects) or sham injection (Control). Dogs were assessed at 3, 6, 12, and 24 months after treatment using functional assessments, radiographic evaluation, arthroscopy, and MRI. Dogs were humanely euthanatized at 3, 6, 12, or 24 months after treatment for gross, microCT, and histologic assessments. All knees had focal articular cartilage defects with associated subchondral BMLs, as well as clinical dysfunction, 3 months after injury. At the 3 and 6 months, SCP knees showed more functional impairment than Control knees, however, these differences were not statistically significant. At 1- and 2-year post-treatment, function in SCP knees was better than in Control knees with range of motion being significantly (p < 0.05) better for SCP. Radiographic, arthroscopic, MRI, gross, microCT, and histologic findings matched the functional assessments well with Control being associated with better results at the two early time points and SCP being associated with better results at 1 and 2 years. Clinical significance: SCP treatment using calcium phosphate bone void filler was associated with an initial increase in pain and dysfunction followed by symptomatic benefits for up to 2 years after treatment for post-traumatic femoral condyle BMLs in a preclinical canine model. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2709-2717, 2018.

Subchondroplasty: What the Radiologist Needs to Know

OBJECTIVE

Subchondroplasty is a novel minimally invasive procedure that is used to treat painful bone marrow lesions in patients with knee osteoarthritis or insufficiency fractures. The objective of this article is to describe the surgical technique and the pre- and postoperative imaging findings of a small case series acquired at a single center.

CONCLUSION

The radiologist should be familiar with the anticipated postoperative imaging appearances after subchondroplasty and the potential complications.

MRI findings of subchondroplasty of the knee: a two-case report

Bone marrow lesions observed in magnetic resonance imaging (MRI) have been recognized as a source of knee pain. Subchondroplasty was developed to treat these lesions with a percutaneous injection of calcium phosphate bone substitute into the bone. As subchondroplasty may potentially become a more common procedure in the treatment of knee osteoarthritis, it is important for radiologists to recognize the typical MRI findings and not to confuse them with other pathology. Here we report the MRI findings for two patients following subchondroplasty.