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.

Letter to the Editor concerning the article “Clinical outcomes of chondroblastoma treated using synthetic bone substitute: risk factors for developing radiographic joint degeneration”

The purpose of this letter to the Editor is to report some shortcomings in the statistical analysis and variable grouping in the recent publication of the article “Clinical outcomes of chondroblastoma treated using synthetic bone substitute: risk factors for developing radiographic joint degeneration,” and to further explore some of the factors that may affect the clinical prognosis of chondroblastoma patients. We also suggest future prospective controlled studies with large samples to improve the limitations encountered by Outani et al. (World J Surg Oncol. 18(1):47, 2020) due to insufficient statistical power of variables and lack of controls.

Regeneration of critical-sized defects, in a goat model, using a dextrin-based hydrogel associated with granular synthetic bone substitute

The development of injectable bone substitutes (IBS) have obtained great importance in the bone regeneration field, as a strategy to reach hardly accessible defects using minimally invasive techniques and able to fit to irregular topographies. In this scenario, the association of injectable hydrogels and bone graft granules is emerging as a well-established trend. Particularly, in situ forming hydrogels have arisen as a new IBS generation. An in situ forming and injectable dextrin-based hydrogel (HG) was developed, aiming to act as a carrier of granular bone substitutes and bioactive agents. In this work, the HG was associated to a granular bone substitute (Bonelike®) and implanted in goat critical-sized calvarial defects (14 mm) for 3, 6 and 12 weeks. The results showed that HG improved the handling properties of the Bonelike® granules and did not affect its osteoconductive features, neither impairing the bone regeneration process. Human multipotent mesenchymal stromal cells from the umbilical cord, extracellular matrix hydrolysates and the pro-angiogenic peptide LLKKK18 were also combined with the IBS. These bioactive agents did not enhance the new bone formation significantly under the conditions tested, according to micro-computed tomography and histological analysis.

Safety and Efficacy of a New Synthetic Material Based on Monetite, Silica Gel, PS-Wallastonite, and a Hydroxyapatite Calcium Deficient: A Randomized Comparative Clinic Trial

Background and Objectives: Maxillary bone defects related to post-extraction alveolar ridge resorption are usual. These defects may lead to failure in further surgical implant phases given the lack of bone volume to perform the dental implant. The objective of this clinical assay was to evaluate the safety and efficacy of an experimental synthetic bone substitute in the preservation of post-extraction maxillary alveoli. Materials and Methods: 33 voluntary patients who had at least one maxillary premolar tooth that was a candidate for exodontia (n = 39) and subsequent implant rehabilitation participated. The regenerated alveoli were monitored by means of periodic clinical examinations (days 9 ± 1, 21 ± 4, 42 ± 6, and 84 ± 6), measuring the height and width of the alveolar crest (days 0 and 180 ± 5), measurement of radiodensity using tomographic techniques (days 0–5 and 175 ± 5), and histological examination of biopsies collected at 180 ± 5 days. Results: No significant differences were observed during the entire follow-up period between the two groups with respect to the safety variables studied. A variation in width of −0.9 ± 1.3 mm and −0.6 ± 1.5 mm, and a variation in height of −0.1 ± 0.9 mm and −0.3 ± 0.7 mm was observed for experimental material Sil-Oss® and Bio-Oss®, respectively. The radiodensity of the alveoli regenerated with the experimental material was significantly lower than that corresponding to Bio-Oss®. However, the histological study showed greater osteoid matrix and replacement of the material with newformed bone in the implanted beds with the experimental material. Conclusions: Both materials can be used safely and proved equally effective in maintaining alveolar flange dimensions, they are also histologically biocompatible, bioactive and osteoconductive. The experimental material showed the advantage of being resorbable and replaced with newformed bone, in addition to promoting bone regeneration.