A study to evaluate the safety of platelet-derived growth factor for treatment of osteochondral defects of the talus

The Frequency and Severity of Complications in Surgical Treatment of Osteochondral Lesions of the Talus: A Systematic Review and Meta-Analysis of 6,962 Lesions

OBJECTIVE

The primary aim was to determine and compare the complication rate of different surgical treatment options for osteochondral lesions of the talus (OLTs). The secondary aim was to analyze and compare the severity and types of complications.

DESIGN

A literature search was performed in MEDLINE (PubMed), EMBASE (Ovid), and the Cochrane Library. Methodological quality was assessed using the Methodological Index for Non-Randomized Studies (MINORS). Primary outcome was the complication rate per surgical treatment option. Secondary outcomes included the severity (using the Modified Clavien-Dindo-Sink Complication Classification System for Orthopedic Surgery) and types of complications. The primary outcome, the severity, and the sub-analyses were analyzed using a random effects model. A moderator test for subgroup-analysis was used to determine differences. The types of complications were presented as rates.

RESULTS

In all, 178 articles from the literature search were included for analysis, comprising 6,962 OLTs with a pooled mean age of 35.5 years and follow-up of 46.3 months. Methodological quality was fair. The overall complication rate was 5% (4%-6%; treatment group effect, P = 0.0015). Analysis resulted in rates from 3% (2%-4%) for matrix-assisted bone marrow stimulation to 15% (5%-35%) for metal implants. Nerve injury was the most observed complication.

CONCLUSIONS

In 1 out of 20 patients treated surgically for an OLT, a complication occurs. Metal implants have a significantly higher complication rate compared with other treatment modalities. No life-threatening complications were reported.

Preparation and Characterization of Biomimetic Functional Scaffold with Gradient Structure for Osteochondral Defect Repair

Osteochondral (OC) defects cannot adequately repair themselves due to their sophisticated layered structure and lack of blood supply in cartilage. Although therapeutic interventions are reaching an advanced stage, current clinical therapies to repair defects are in their infancy. Among the possible therapies, OC tissue engineering has shown considerable promise, and multiple approaches utilizing scaffolds, cells, and bioactive factors have been pursued. The most recent trend in OC tissue engineering has been to design gradient scaffolds using different materials and construction strategies (such as bi-layered, multi-layered, and continuous gradient structures) to mimic the physiological and mechanical properties of OC tissues while further enabling OC repair. This review focuses specifically on design and construction strategies for gradient scaffolds and their role in the successful engineering of OC tissues. The current dilemmas in the field of OC defect repair and the efforts of tissue engineering to address these challenges were reviewed. In addition, the advantages and limitations of the typical fabrication techniques for gradient scaffolds were discussed, with examples of recent studies summarizing the future prospects for integrated gradient scaffold construction. This updated and enlightening review could provide insights into our current understanding of gradient scaffolds in OC tissue engineering.

Arthroscopic debridement of osteochondral lesions of the talus: A systematic review

BACKGROUND

Arthroscopic debridement (AD) for the osteochondral lesions of the talar dome (OLT) was widely documented in the nineties with satisfactory results. However, in modern treatment algorithms, its role is not described. The present systematic review aims to evaluate the current evidence on the clinical outcomes of AD in the management of OLT.

METHODS

Two independent reviewers searched PubMed, EMBASE, Scopus, and Virtual Health Library databases evaluating the clinical outcomes of AD of OLT with a minimum 6-month follow-up. The following terms "talus", "chondral", "cartilage", "injury", "lesion", "delamination", "damage", "excision", "curettage", "debridement", "chondrectomy", "chondroplasty", were used alone and in combination with Boolean operators AND and OR. Studies in which surgical technique was not described, an additional procedure was performed after debridement, and/or outcomes were not reported separately when more than one technique was implemented were excluded. The modified Coleman methodology score (mCMS) was used to evaluate the methodological quality of the included studies. A narrative analysis was conducted. Publication bias was assessed using the ROBIS tool.

RESULTS

AD showed satisfactory short and medium-term outcomes for the primary treatment of OLT irrespectively of size and depth. However, the heterogeneity of the included studies and the level of available evidence hinders its recommendation.

CONCLUSIONS

There is a paucity of evidence evaluating AD alone for OLT treatment in the last two decades. Bone-marrow stimulation techniques remain the first-line surgical strategy for OLT treatment without proven superiority. Adopting AD for OLT treatment instead of MF could represent a paradigm breakthrough in clinical practice given its many potential advantages while preserving the subchondral plate.

Clinical and Magnetic Resonance Imaging Outcomes of Microfracture Plus Chitosan/Blood Implant vs Microfracture for Osteochondral Lesions of the Talus

BACKGROUND

The aim of this study was to compare the clinical and magnetic resonance imaging (MRI) outcomes of arthroscopic microfracture (MF) plus chitosan-glycerol phosphate/blood implant and MF alone for the treatment of the osteochondral lesions of the talus (OCLTs).

METHODS

Patients who underwent either MF plus chitosan (group 1, n = 32) or MF alone (group 2, n = 31) between 2015 and 2019 in 2 separate time periods were retrospectively analyzed. Visual analog scale (VAS) score and American Orthopaedic Foot & Ankle Society (AOFAS) score were used for clinical evaluation. The magnetic resonance observation of cartilage repair tissue (MOCART) system was used for MRI evaluation. The mean follow-up time was 32 ± 13 months (range, 12-61 months).

RESULTS

Postoperatively, we detected significant improvements in both groups in terms of VAS and AOFAS scores. However, we observed no statistically significant difference between groups in terms of clinical scores, except the mean VAS function score, which was significantly higher in group 1 (P = .022). According to MOCART scale, complete repair with the filling of the chondral defect and intactness of the surface of the repair tissue were more common in group 1. However, these parameters did not significantly differ between groups (P = .257 and .242, respectively).

CONCLUSION

Arthroscopic MF plus chitosan glycerol phosphate/blood implant did not result in better clinical and MRI outcomes compared with MF alone in the treatment of OCLTs.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Scranton Type V Osteochondral Defects of Talus: Does one-stage Arthroscopic Debridement, Microfracture and Plasma Rich in Growth Factor cause the Healing of Cyst and Cessation of Progression to Osteoarthritis?

Introduction:

The study was conducted to evaluate the efficacy of arthroscopic debridement, microfracture and plasma rich in growth factor (PRGF) injection in the management of type V (Scranton) osteochondral lesions of talus and its role in healing the subchondral cyst and cessation of progression of ankle osteoarthritis.

Material and Methods:

This is a prospective case series conducted on patients who were diagnosed with type V osteochondral lesions of talus. All the cases were treated with arthroscopic debridement, microfracture, and PRGF injections. The patients were evaluated for the healing of subchondral cysts and progression of osteoarthritis with radiography (plain radiographs and computerised tomography Scan). Also, the patients’ outcome was evaluated with Quadruple Visual Analogue Scale, Ankle Range of Motion, Foot and Ankle Disability Index, Foot and Ankle Outcome Instrument and a Satisfaction Questionnaire.

Results:

Five male patients underwent arthroscopic debridement, microfracture and PRGF injection for type V osteochondral lesion of talus. The mean age of patients was 27.4 years (19-47 years). All the patients gave history of minor twisting injury. Subchondral cyst healing was achieved in all patients by six months post-surgery. However, four out of five patients had developed early osteoarthritic changes of the ankle by their last follow-up [mean follow-up 29 months (ranged 15-36 months)]. Despite arthritic changes, all the patients reported ‘Good’ to ‘Excellent’ results on satisfaction questionnaire and Foot and Ankle Disability Index and could perform their day to day activities including sports.

Conclusion:

Arthroscopic debridement, microfracture, and PRGF causes healing of the subchondral cyst but does not cause cessation of progression to osteoarthritis of ankle in type V osteochondral defects of talus. However, despite progress to osteoarthritis, patient satisfaction post-procedure is good to excellent at short-term follow-up.

Lesion Dynamics Under Varying Paracrine PDGF Signaling in Brain Tissue

Paracrine PDGF signaling is involved in many processes in the body, both normal and pathological, including embryonic development, angiogenesis, and wound healing as well as liver fibrosis, atherosclerosis, and cancers. We explored this seemingly dual (normal and pathological) role of PDGF mathematically by modeling the release of PDGF in brain tissue and then varying the dynamics of this release. Resulting simulations show that by varying the dynamics of a PDGF source, our model predicts three possible outcomes for PDGF-driven cellular recruitment and lesion growth: (1) localized, short duration of growth, (2) localized, chronic growth, and (3) widespread chronic growth. Further, our model predicts that the type of response is much more sensitive to the duration of PDGF exposure than the maximum level of that exposure. This suggests that extended duration of paracrine PDGF signal during otherwise normal processes could potentially lead to lesions having a phenotype consistent with pathologic conditions.

Arthroscopic Surgical Technique for an Acute Talar Dome Osteochondral Lesion in a Professional Rugby League Player

BACKGROUND

Talar osteochondral lesions represent challenging clinical entities, particularly in high-demand athletes. Surgical treatment of large lesions often requires a 2-step procedure, or the use of osteotomy in the case of autologous osteochondral transfer, which can delay return to sport.

METHODS

A professional rugby league player underwent surgery for a complex injury to the ankle. A talar osteochondral lesion with a maximal diameter of 15 mm was treated in an arthroscopic fashion using the cartilage taken from the completely displaced osteochondral fragment. Cartilage was cut into chips and combined with bone graft product containing platelet-derived growth factor and a porous collagen scaffold. Autologous cartilage was then reimplanted arthroscopically. The patient was allowed full ankle motion from 2 weeks postoperatively, and weightbearing was commenced at 6 weeks. Follow-up imaging and functional outcomes, including return to sport, were assessed at regular intervals.

RESULTS

The patient was able to return to professional rugby league by 23 weeks postoperatively. Magnetic resonance imaging at 16 months postoperatively showed restoration of the subchondral plate and osseous infill. At final follow-up, the patient remained pain free and was playing at preinjury level.

CONCLUSION

This report describes good outcomes using a novel, 1-step cartilage repair technique to treat a large talar osteochondral lesion in a professional athlete.

LEVELS OF EVIDENCE

Level V: Expert opinion.

Vancouver Experience of Recombinant Human Platelet-Derived Growth Factor

Joint arthrodesis utilizing autogenous bone graft remains the gold standard of treatment in fusion procedures of the foot and ankle. Graft harvest, however, has been associated with increased morbidity to patients as well as increased costs. With this in mind, multiple clinical studies have evaluated the efficacy of recombinant human platelet-derived growth factor (rh-PDGF-BB) with beta-tricalcium phosphate (B-TCP) to augment in foot and ankle arthrodesis with favorable results. These factors have led to the increased use of rh-PDGF-BB with B-TCP in Vancouver with good clinical results.

Non-unions treated with bone morphogenic protein 7: introducing the quantitative measurement of human serum cytokine levels as promising tool in evaluation of adjunct non-union therapy

BACKGROUND

In this study we sought to determine if application of bone morphogenic protein 7 (BMP-7) promotes physiological bone healing of non-unions and to investigate if serum cytokine analysis may serve as a promising tool in the analysis of adjunct non-union therapy. Therefore we analyzed the influence of BMP-7 application on the serum cytokine expression patterns on patients with impaired bone healing compared to patients that showed proper bone healing.

METHODS

Our study involved analyzing blood samples from 208 patients with long bone fractures together with patients that subsequently developed non-unions. From this large pool, 15 patients with atrophic non-union were matched to 15 patients with atrophic non-union treated with local application of BMP-7 as well as normal bone healing. Changes in the cytokine expression patterns were monitored during the 1st, 2nd, 4th, 8th, 12th and 52nd week. The patients were followed both clinically and radiologically for the entire duration of the study. Serum cytokine expression levels of transforming growth factor beta (TGF-β), platelet-derived growth factor (PDGF) and basic fibroblast growth factor (bFGF) were analyzed and compared.

RESULTS

Serum expression of TGF-β were nearly parallel in all three groups, however serum concentrations were significantly higher in patients with proper bone healing and those treated with BMP-7 than in patients with non-unions (p < 0.05). bFGF serum concentrations increased initially in patients with proper bone healing and in those treated with BMP-7. Afterwards, values decreased; bFGF serum concentrations in the BMP-7 group were significantly higher than in the other groups (p < 0.05). PDGF serum concentration levels were nearly parallel in all groups, serum concentrations were significantly higher in patients with proper bone healing and those treated with BMP-7 than in patients with non-unions (p < 0.05).

CONCLUSION

Treatment with BMP-7 in patients with former non-unions led to similar cytokine expression patterns after treatment as those found in patients with proper bone healing. Our results suggest that treatment with BMP-7 promote healing of non-unions. Furthermore, quantitative measurement of serum cytokine expression is a promising tool for evaluating the effectiveness of additional non-union therapies such as adjunct application of growth factors.