Meniscus treatment: biological augmentation strategies: a narrative review

Objective

An up-to-date description on the biological augmentation strategies for meniscal repair procedures was performed to highlight the main preclinical and clinical evidence available in the literature.

Background

Meniscal repair is a key surgical procedure to preserve as much meniscal tissue as possible to limit the development of knee osteoarthritis (OA). Unfortunately, the results of meniscal repair procedures are not always satisfactory, reporting an overall risk of failure of 25%, likely conditioned due to the poor vascularization of the meniscal tissue. For this reason, several biologic augmentation techniques have been developed to improve the meniscal healing process, ranging from mechanical stimulations to biological products.

Methods

A literature review was conducted on the main biological augmentation procedures combined to the meniscal repair process. A description of the rationale, surgical technique, and preclinical and clinical evidence was performed.

Conclusions

Mechanical stimulations and fibrin clot were the first techniques applied showing several limitations and not exciting results. Recently, platelet-rich plasma (PRP) augmentation to meniscal repair is slowly spreading in the clinical practice. Early evidence from comparative studies showed a significantly lower failure rate in patients treated with PRP augmentation compared with controls. Conversely, the current few and low-level data on mesenchymal stem/stromal cells (MSCs) for meniscal augmentation repair make this a promising but anecdotal topic. Further high-quality clinical studies are needed to support and guide the use of biological strategies for the augmentation of meniscus repair, PRP.

The 50 most-cited clinical articles in cartilage surgery research: a bibliometric analysis

PURPOSE

Articular cartilage lesions remain a challenge for orthopedic surgeons. The identification of the most important articles can help identifying the most influential techniques of the past, the current prevalent focus, and emerging strategies. The aim of this study was to identify milestones and trends in cartilage research.

METHODS

This study is a bibliometric analysis based on published articles. All citation count data included in the "Scopus database" were used to identify eligible studies up to December 2020. The 50 most-cited articles on cartilage surgery were ranked based on the citation count and analyzed regarding citation density and quality (Coleman score and RoB 2.0 tool). A further search was performed to identify the most promising clinical studies among the latest publications on cartilage surgery.

RESULTS

Different kinds of cartilage treatments were investigated in the 50 most-cited clinical articles. Regenerative techniques with chondrocytes were the most reported with a total of 23 articles, followed by microfracture technique in 17 articles and mosaicplasty or osteochondral autograft transplantation (OAT) in 11. Forty-five articles focused on the knee. A higher citation density was found in the most recent articles (p = 0.004). The study of the most promising landmarks of the most recent articles showed new cell-free or tissue engineering-based procedures and an overall increasing quality of the published studies.

CONCLUSION

This bibliometric analysis documented an increasing interest in cartilage surgery, with efforts toward high-quality studies. Over the years, the focus switched from reconstructive toward regenerative techniques, with emerging options including cell-free and tissue-engineering strategies to restore the cartilage surface.

LEVEL OF EVIDENCE

IV.

Leukocyte-Rich versus Leukocyte-Poor Platelet-Rich Plasma for the Treatment of Knee Osteoarthritis: A Double-Blind Randomized Trial

BACKGROUND

Platelet-rich plasma (PRP) is gaining large interest in clinical practice as a minimally invasive injective treatment for knee osteoarthritis (OA). Different preparation methods are available, and the presence of leukocytes, deemed detrimental in some preclinical studies, is one of the most debated aspects regarding PRP efficacy.

PURPOSE

To compare the safety and effectiveness of leukocyte-rich PRP (LR-PRP) and leukocyte-poor PRP (LP-PRP) for the treatment of knee OA.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A total of 192 patients with symptomatic knee OA (Kellgren-Lawrence grade 1-3) were randomly allocated to 3 weekly injections of LR-PRP or LP-PRP. LP-PRP was obtained with a filter for leukodepletion. LR-PRP and LP-PRP were divided into aliquots of 5 mL, with a mean platelet concentration of 1146.8 × 10⁹/L and 1074.9 × 10⁹/L and a mean leukocyte concentration of 7991.4 × 10⁶/L and 0.1 × 10⁶/L, respectively. Patients were evaluated at baseline and thereafter at 2, 6, and 12 months for the primary outcome, the International Knee Documentation Committee (IKDC) subjective score; and for secondary outcomes, the Knee injury and Osteoarthritis Outcome Score (KOOS) subscales, EuroQol-visual analog scale (EQ-VAS), and Tegner score.

RESULTS

No differences between groups were observed in terms of absolute values or improvement of the clinical scores across all follow-up intervals. The mean IKDC subjective score at baseline and 12 months improved from 45.6 to 60.7 in the LR-PRP group as compared with 46.8 to 62.9 in the LP-PRP group (P = .626). No severe adverse events were described in either group, although 15 mild adverse events (knee pain or swelling) were reported: 12.2% for LR-PRP and 4.7% for LP-PRP (P = .101). No statistically significant difference was also found between LR-PRP and LP-PRP in terms of failures (7.8% vs 3.5%, P = .331).

CONCLUSION

This double-blind randomized trial showed that 3 intra-articular LR-PRP or LP-PRP injections produced similar clinical improvement in the 12 months of follow-up in patients with symptomatic knee OA. Both treatment groups reported a low number of adverse events, without intergroup differences. The presence of leukocytes did not significantly affect the clinical results of PRP injections.

REGISTRATION

NCT02923700 (ClinicalTrials.gov identifier).

Treatment of Juvenile Knee Osteochondritis Dissecans with a Cell-Free Biomimetic Osteochondral Scaffold: Clinical and MRI Results at Mid-Term Follow-up

OBJECTIVE

Osteochondral surgical procedures have been described for the treatment of unfixable osteochondritis dissecans (OCD), but only few of them have been studied for juvenile OCD (JOCD) lesions. A cell-free biomimetic osteochondral scaffold showed positive results in adult patients. The aim of this study was to evaluate the results of this scaffold for the treatment of knee JOCD at mid-term follow-up.

DESIGN

Twenty patients (14 males, 6 females) were included in this study. Mean age was 16.2 ± 1.4 years, average defect size was 3.2 ± 1.8 cm², and mean symptoms duration was 20.2 ± 17.9 months. After the implantation of the osteochondral collagen-hydroxyapatite scaffold (Maioregen, Fin-Ceramica, Faenza, Italy), patients were evaluated preoperatively and prospectively at 1, 2, and at final mean follow-up of 6 years (range 5-7 years) with International Knee Documentation Committee (IKDC) subjective and objective, Tegner, and EuroQol visual analogue scale (VAS) scores. MRI evaluation was performed with the MOCART 2.0 score.

RESULTS

All scores showed a significant improvement. IKDC subjective score went from 50.3 ± 17.4 preoperative score to 75.3 ± 14.6 at 1 year (P = 0.002), 80.8 ± 14.6 at 2 years and 85.0 ± 9.3 at 6 years. The Tegner score improved from the preoperative evaluation of 2.6 ± 1.4 to 5.5 ± 2.0 at 6 years (P < 0.0005), although without reaching the level registered before the onset of symptoms. A longer symptoms duration influenced negatively IKDC subjective and Tegner scores up to 2 years (P = 0.003 and P = 0.002, respectively) but did not affect the final outcome. Lesion size did not affect the final result. The MOCART 2.0 score showed a significant improvement between 1-year and final follow-up, but with persisting subchondral alterations.

CONCLUSIONS

This study demonstrated a clinical improvement stable over time with a high survival rate, although with persisting abnormal MRI findings, especially at subchondral bone level. This procedure can be considered a suitable option for the treatment of young patients affected by knee OCD. Level of evidence. Case series, level IV.

Scaffolds for Knee Chondral and Osteochondral Defects: Indications for Different Clinical Scenarios. A Consensus Statement

OBJECTIVE

To develop patient-focused consensus guidelines on the indications for the use of scaffolds to address chondral and osteochondral femoral condyle lesions.

DESIGN

The RAND/UCLA Appropriateness Method (RAM) was used to develop patient-specific recommendations by combining the best available scientific evidence with the collective judgement of a panel of experts guided by a core panel and multidisciplinary discussers. A list of specific clinical scenarios was produced regarding adult patients with symptomatic lesions without instability, malalignment, or meniscal deficiency. Each scenario underwent discussion and a 2-round vote on a 9-point Likert-type scale (range 1-3 "inappropriate," 4-6 "uncertain," 7-9 "appropriate"). Scores were pooled to generate expert recommendations.

RESULTS

Scaffold (chondral vs. osteochondral), patient characteristics (age and sport activity level), and lesion characteristics (etiology, size, and the presence of osteoarthritis [OA]) were considered to define 144 scenarios. The use of scaffold-based procedures was considered appropriate in all cases of chondral or osteochondral lesions when joints are not affected by OA, while OA joints presented more controversial results. The analysis of the evaluated factors showed a different weight in influencing treatment appropriateness: the presence of OA influenced 58.3% of the indications, while etiology, size, and age were discriminating factors in 54.2%, 29.2%, and 16.7% of recommendations, respectively.

CONCLUSIONS

The consensus identified indications still requiring investigation, but also the convergence of the experts in several scenarios defined appropriate or inappropriate, which could support decision making in the daily clinical practice, guiding the use of scaffold-based procedures for the treatment of chondral and osteochondral knee defects.

Synovial Fluid Biomarkers in Knee Osteoarthritis: A Systematic Review and Quantitative Evaluation Using BIPEDs Criteria

OBJECTIVE

The aim of this systematic review was to analyze the evidence about the efficacy of the several synovial fluid (SF) biomarkers proposed for knee osteoarthritis (OA), categorizing them by both molecular characteristics and clinical use according to the BIPEDs criteria, to provide a comprehensive and structured overview of the current literature.

DESIGN

A systematic review was performed in May 2020 on PubMed, Cochrane Library, and Embase databases about SF biomarkers in patients with knee OA. The search was limited to articles in the last 20 years on human studies, involving patients with knee OA, reporting SF biomarkers. The evidence for each selected SF biomarker was quantified according to the 6 categories of BIPEDs classification.

RESULTS

A total of 159 articles were included in the qualitative data synthesis and 201 different SF biomarkers were identified. Among these, several were investigated multiple times in different articles, for a total of 373 analyses. The studies included 13,557 patients with knee OA. The most promising SF biomarkers were C4S, IL-6, IL-8, Leptin, MMP-1/3, TIMP-1, TNF-α, and VEGF. The "burden of disease" and "diagnostic" categories were the most represented with 132 and 106 different biomarkers, respectively.

CONCLUSIONS

The systematic review identified numerous SF biomarkers. However, despite the high number of studies on the plethora of identified molecules, the evidence about the efficacy of each biomarker is supported by limited and often conflicting findings. Further research efforts are needed to improve the understanding of SF biomarkers for a better management of patients with knee OA.

Subchondral and intra-articular injections of bone marrow concentrate are a safe and effective treatment for knee osteoarthritis: a prospective, multi-center pilot study

PURPOSE

Subchondral bone is becoming a treatment target for knee OA patients, with promising early findings on the use of bone marrow aspirate concentrate (BMAC). The aim of this prospective, multi-centric pilot study was to evaluate safety as well as clinical and MRI outcomes of a combined approach of intra-articular and subchondral BMAC injections.

METHODS

Thirty patients (19 men, 11 women, 56.4 ± 8.1 years) with symptomatic knee OA were treated with a combination of an intra-articular and two subchondral BMAC injections (femoral condyle and tibial plateau). Patients were evaluated at baseline and at 1-3-6-12 months of follow-up with the IKDC subjective, VAS, KOOS, and EQ-VAS scores. The MRI evaluation was performed with the WORMS score.

RESULTS

No major complications were reported and only two patients were considered treatment failures, requiring a new injective or surgical treatment. The IKDC subjective score improved significantly from 40.5 ± 12.5 to 59.9 ± 16.1 at 3 months, 59.1 ± 12.2 at 6 months, and 62.6 ± 19.4 at 12 months (p < 0.0005). A similar improvement was reported for VAS pain and all KOOS subscales at all follow-ups, while EQ-VAS did not show any significant improvement. The MRI analysis showed a significant bone marrow edema reduction (p = 0.003), while the remaining WORMS parameters did not show any significant changes.

CONCLUSION

The pilot evaluation of this combined BMAC injective treatment showed safety and positive outcome up to 12 months of follow-up in patients with symptomatic knee OA associated with subchondral bone alterations. These findings suggest that targeting both subchondral bone and joint environment can provide promising results, and that BMAC can be a valid option for this combined approach to treat knee OA.

Minimal Clinically Important Difference and Patient Acceptable Symptom State in Patients With Knee Osteoarthritis Treated With PRP Injection

Background:

Although several injection-based treatments have been proposed to address knee osteoarthritis (OA), it is often difficult to understand the clinical relevance of the obtained results. The psychometric measures of minimal clinically important difference (MCID) and Patient Acceptable Symptom State (PASS) were developed to better interpret study findings.

Purpose:

To establish the MCID and the PASS for the International Knee Documentation Committee (IKDC) Subjective score and the Knee injury and Osteoarthritis Outcome Score (KOOS) in patients treated with intra-articular platelet-rich plasma (PRP) injections for knee OA.

Study Design:

Case series; Level of evidence, 4.

Methods:

This study included 215 patients with knee OA (68% men, 32% women; age, 53.2 ± 11.3 years; body mass index, 26.8 ± 4.3 kg/m²) who underwent intra-articular PRP injections. Patients were assessed through the IKDC Subjective score and KOOS subscales, and the MCID and the PASS for both measures were independently calculated at 6 and 12 months post-injection. The MCID was calculated using the value equal to half of the standard deviation of the overall cohort improvement. The PASS was assessed using a 2-point scale (satisfied or not satisfied), with threshold values being detected through a receiver operating characteristic curve analysis and the Youden index to maximize the sensitivity and the specificity of the threshold values.

Results:

All scores improved significantly from baseline to 6 months and baseline to 12 months (P < .001 for all scores). All scores were stable from 6 to 12 months except for the KOOS Quality of Life subscale, which improved further (P = .033). For the IKDC, the MCID values were 8.6 and 8.5 points and the PASS scores were 59.7 and 62.1 at 6 and 12 months, respectively. Overall, the MCID and the PASS for all KOOS subscales remained constant at the 2 follow-up points. The percentage of patients who achieved the MCID and the PASS was higher than 85% at both 6 and 12 months post-injection.

Conclusion:

This study provided the MCID and PASS thresholds for the IKDC and KOOS scores in patients with knee OA treated with PRP injections. These psychometric measures may allow a better interpretation of the clinical relevance of injection-based treatment outcomes for knee OA.

Multi-layer cell-free scaffolds for osteochondral defects of the knee: a systematic review and meta-analysis of clinical evidence

Purpose

The aim of this study was to analyze the clinical results provided by multi-layer cell-free scaffolds for the treatment of knee osteochondral defects.

Methods

A systematic review was performed on PubMed, Web of Science, and Cochrane to identify studies evaluating the clinical efficacy of cell-free osteochondral scaffolds for knee lesions. A meta-analysis was performed on articles reporting results of the International Knee Documentation Committee (IKDC) and Tegner scores. The scores were analyzed as improvement from baseline to 1, 2, and ≥ 3 years of follow-up. The modified Coleman Methodology Score was used to assess the study methodology.

Results

A total of 34 studies (1022 patients) with a mean follow-up of 35 months was included. Only three osteochondral scaffolds have been investigated in clinical trials: while TruFit® has been withdrawn from the market for the questionable results, the analysis of MaioRegen and Agili-C™ provided clinical improvements at 1, 2, and ≥ 3 years of follow-up (all significantly higher than the baseline, p < 0.05), although with a limited recovery of the sport-activity level. A low rate of adverse events and an overall failure rate of 7.0% were observed, but the overall evidence level of the available studies is limited.

Conclusions

Multi-layer scaffolds may provide clinical benefits for the treatment of knee osteochondral lesions at short- and mid-term follow-up and with a low number of failures, although the sport-activity level obtained seems to be limited. Further research with high-level studies is needed to confirm the role of multi-layer scaffold for the treatment of knee osteochondral lesions.

Cell-Free Scaffolds in Cartilage Knee Surgery: A Systematic Review and Meta-Analysis of Clinical Evidence

OBJECTIVE

To evaluate current evidence and results of cell-free scaffold techniques for knee chondral lesions.

DESIGN

A systematic review was conducted on 3 medical electronic databases according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines, and the methodological quality was assessed with a modified Coleman Methodology Score. A meta-analysis was performed on the articles reporting results for visual analogue scale (VAS), Lysholm, and International Knee Documentation Committee (IKDC) scores. In order to investigate the clinical results improvement over time of cell-free cartilage scaffold implantation, all scores were reported and analyzed as improvement from basal scores at 1, 2, and ≥3 years' follow-up.

RESULTS

A total of 23 studies involving 521 patients were included in the qualitative data synthesis. The Coleman score showed an overall poor study quality with the majority of studies reporting results at short-/mid-term follow-up. Sixteen studies were included in the meta-analysis, showing a significant improvement from basal score at 1, 2, and ≥3 years' follow-up. The improvement reached at 1 year remained stable up to the last follow-up for all scores.

CONCLUSIONS

The current literature suggests that cell-free scaffolds may provide good clinical short-/mid-term results; however, the low evidence of the published studies and their short mean follow-up demand further evidence before more definitive conclusions can be drawn on their real potential over time and on their advantages and disadvantages compared to the cell-based strategies for the treatment of cartilage lesions.

Matrix-assisted chondrocyte transplantation with bone grafting for knee osteochondritis dissecans: stable results at 12 years

PURPOSE

To document clinical and radiological results of arthroscopic matrix-assisted autologous chondrocyte transplantation (MACT) combined with bone grafting for the treatment of knee osteochondritis dissecans (OCD) at long-term follow-up.

METHODS

Thirty-one knees in 29 patients (20.4 ± 5.7 years) were treated for symptomatic unfixable OCD lesions (2.6 ± 1.1 cm²) and prospectively evaluated at 2, 5, and 12 years (average, minimum 10 years). Patients were evaluated over time with IKDC subjective score, EQ-VAS, and Tegner scores. Failures were also documented. At the final follow-up, MRI evaluation was performed in 14 knees with the MOCART 2.0 score.

RESULTS

Beside 4 early failures, an overall clinical improvement was documented: the IKDC subjective score improved from 39.9 ± 16.8 to 82.1 ± 17.0 and 84.8 ± 17.2 at 2 and 5 years, respectively (p < 0.0005), and remained stable for up to 12 years (85.0 ± 20.2). EQ-VAS and Tegner scores presented similar trends, but patients did not reach their original activity level. Worse results were obtained for lesions bigger than 4 cm². At MRI evaluation, subchondral bone abnormalities were detected in over 85% of knees at long-term follow-up.

CONCLUSIONS

Arthroscopic bone grafting followed by MACT for unfixable knee OCD can offer a promising and stable clinical outcome over time in lesions smaller than 4 cm², with a low failure rate of 13%. Persistent subchondral alterations were documented at long-term MRI evaluation, suggesting the limits of this approach to regenerate the osteochondral unit in patients affected by knee OCD.

LEVEL OF EVIDENCE

IV.

Higher 90-Day Mortality after Surgery for Hip Fractures in Patients with COVID-19: A Case-Control Study from a Single Center in Italy

The mortality of hip fracture (HF) patients is increased by concomitant COVID-19; however, evidence is limited to only short follow-up. A retrospective matched case-control study was designed with the aim to report the 90-day mortality and determine the hazard ratio (HR) of concomitant HF and COVID-19 infection. Cases were patients hospitalized for HF and diagnosed with COVID-19. Controls were patients hospitalized for HF not meeting the criteria for COVID-19 diagnosis and were individually matched with each case through a case-control (1:3) matching algorithm. A total of 89 HF patients were treated during the study period, and 14 of them were diagnosed as COVID-19 positive (overall 15.7%). Patients' demographic, clinical, and surgical characteristics were similar between case and control groups. At 90 days after surgery, 5 deaths were registered among the 14 COVID-19 cases (35.7%) and 4 among the 42 HF controls (9.5%). COVID-19-positive cases had a higher risk of mortality at 30 days (HR = 4.51; p = 0.0490) and 90 days (HR = 4.50; p = 0.025) with respect to controls. Patients with concomitant HF and COVID-19 exhibit high perioperative mortality, which reaches a plateau of nearly 30-35% after 30 to 45 days and is stable up to 90 days. The mortality risk is more than four-fold higher in patients with COVID-19.

Biologic Augmentation Reduces the Failure Rate of Meniscal Repair: A Systematic Review and Meta-analysis

Background

Clinical results after isolated meniscal repair are not always satisfactory, with an overall failure rate of around 25%. To improve the success rate of meniscal repair, different biologic augmentation techniques have been introduced in clinical practice, but their real efficacy is still controversial.

Purpose/Hypothesis

To evaluate the safety, clinical results, and failure rate of biologic augmentation techniques for meniscal repair. The hypothesis was that biologic augmentation would improve the results of meniscal repair.

Study Design

Systematic review and meta-analysis of comparative studies.

Methods

A systematic review of the literature was performed in March 2020 of 3 electronic databases (PubMed, Scopus, and the Cochrane Library) regarding meniscal repair combined with biologic augmentation techniques. Articles combining biologic augmentation with other surgical procedures besides meniscal suture were excluded. The quality of the included studies was assessed using a modified Coleman Methodology Score, and the risk of bias was evaluated using the ROBINS-I (Risk of Bias in Non-randomized Studies of Interventions) and the RoB 2.0 (Revised Tool for Risk of Bias in Randomized Trials) for nonrandomized and randomized controlled trials, respectively.

Results

A total of 11 studies were included in the qualitative analysis: platelet-rich plasma (PRP) augmentation in 6 comparatives studies, fibrin clot augmentation in 2 case series, and mesenchymal stem cells augmentation in 2 case series and 1 case report. One severe adverse event of septic arthritis was reported for PRP 1 month after surgery. The quality of evidence evaluated with the modified Coleman Methodology Score was low overall. Five studies reporting on 286 patients (111 PRP augmentation, 175 control) were included in the quantitative synthesis. A significantly lower risk of failure was documented in the PRP augmentation group as compared with the control group: 9.9% (4.5%-19.1%) versus 25.7% (12.7%-38.7%) (P < .0005).

Conclusion

The literature on biologic meniscal augmentation is recent and scarce. Only a few comparative trials are available, all focusing on the potential of PRP. The meta-analysis documented that PRP is safe and useful in improving the survival rate, with a 9.9% rate of failure versus 25.7% for the control group. Further high-level studies are needed to confirm these findings and identify the most effective biologic augmentation strategy to improve the outcome of meniscal repair.

Complications of Tranexamic Acid in Orthopedic Lower Limb Surgery: A Meta-Analysis of Randomized Controlled Trials

OBJECTIVE

Tranexamic acid (TXA) is increasingly used in orthopedic surgery to reduce blood loss; however, there are concerns about the risk of venous thromboembolic (VTE) complications. The aim of this study was to evaluate TXA safety in patients undergoing lower limb orthopedic surgical procedures.

DESIGN

A meta-analysis was performed on the PubMed, Web of Science, and Cochrane Library databases in January 2020 using the following string (Tranexamic acid) AND ((knee) OR (hip) OR (ankle) OR (lower limb)) to identify RCTs about TXA use in patients undergoing every kind of lower limb surgical orthopedic procedures, with IV, IA, or oral administration, and compared with a control arm to quantify the VTE complication rates.

RESULTS

A total of 140 articles documenting 9,067 patients receiving TXA were identified. Specifically, 82 studies focused on TKA, 41 on THA, and 17 on other surgeries, including anterior cruciate ligament reconstruction, intertrochanteric fractures, and meniscectomies. The intravenous TXA administration protocol was studied in 111 articles, the intra-articular in 45, and the oral one in 7 articles. No differences in terms of thromboembolic complications were detected between the TXA and control groups neither in the overall population (2.4% and 2.8%, respectively) nor in any subgroup based on the surgical procedure and TXA administration route.

CONCLUSIONS

There is an increasing interest in TXA use, which has been recently broadened from the most common joint replacement procedures to the other types of surgeries. Overall, TXA did not increase the risk of VTE complications, regardless of the administration route, thus supporting the safety of using TXA for lower limb orthopedic surgical procedures.

Long-term Results of Arthroscopic Matrix-Assisted Autologous Chondrocyte Transplantation: A Prospective Follow-up at 15 Years

BACKGROUND

Matrix-assisted autologous chondrocyte transplantation (MACT) procedures have been developed to overcome some of the limits of first-generation autologous chondrocyte implantation. However, while good autologous chondrocyte implantation results have been documented over time, data are scarce on the long-term MACT results.

PURPOSE

To evaluate long-term clinical results of a large cohort of patients treated with hyaluronic acid-based MACT for articular cartilage defects of the knee.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A long-term evaluation of 113 patients was performed (91 men, 22 women; mean ± SD age, 29.0 ± 10.6 years) for 115 knees affected by chondral and osteochondral lesions of the femoral condyles and trochlea. Of these, 61 knees had undergone previous surgery, while other procedures were combined during the same operation in 48 knees. These patients were prospectively evaluated before surgery and at 2, 5, and 10 years after surgery, as well as at a final mean follow-up of 15 years (range, 12-18 years), with various clinical scores: International Knee Documentation Committee (IKDC), EuroQol visual analog scale (EQ-VAS), and Tegner. Both surgical and clinical failures were documented.

RESULTS

The IKDC subjective score increased from the basal level of 39.9 ± 14.6 (mean ± SD) to 77.3 ± 20.5 (P < .0005) at 2 years; results remained stable up to the 15-year follow-up (76.9 ± 20.5). EQ-VAS and Tegner scores showed a statistically significant improvement up to 10 years, with a further significant improvement at the final follow-up. A failure rate of 15.0% was documented, which increased to 21.7% when clinical failures were also considered. A worse outcome was found for older age (P < .0005), female sex (P = .002), degenerative lesions (P < .0005), longer duration of symptoms (P = .005), and previous surgery (P < .0005).

CONCLUSION

Arthroscopic MACT offered good and long-lasting results that were stable over time and resulted in a limited number of failures and reinterventions for up to 15 years of follow-up. Several factors were identified as having a prognostic value: a worse outcome could be expected in older patients, female patients, those affected by lesions with a degenerative cause, those having a longer duration of symptoms, and patients who underwent previous surgery.

Osteochondritis Dissecans of the Knee: Etiology and Pathogenetic Mechanisms. A Systematic Review

OBJECTIVE

The purpose of this manuscript is to analyze the evidence regarding etiopathogenesis of knee osteochondritis dissecans (OCD) lesions through a systematic review, so to summate the current understanding of the origin and progression of this pathologic articular processes.

DESIGN

A systematic review of the literature was performed on the PubMed and Cochrane databases on October 2017 by 2 independent authors and included all levels of evidence. This included all English language literature, pertaining specifically to etiopathology of knee OCD with exclusions for review articles and expert opinion. Of 965 identified records, 154 full-text articles were assessed for eligibility and 86 studies met the inclusion criteria.

RESULTS

According to these studies, the etiology of OCD can be of a biological or mechanical origin: 40 articles proposed a biological hypothesis, including genetic causes (27), ossification center deficit (12), and endocrine disorders (9); conversely, 52 articles supported a mechanical hypothesis, including injury/overuse (18), tibial spine impingement (5), discoid meniscus (16), and biomechanical alterations (20) as the cause of the onset of OCD. The pathogenic processes were investigated by 36 of these articles, with a focus on subchondral bone fracture and ischemia as the ultimate events leading to OCD.

CONCLUSIONS

Biological and mechanical factors are found to result in subchondral bone remodeling alterations, acting independently or more likely synergically in the progression of knee OCD. The former includes genetic causes, deficit of ossification centers and endocrine disorders; the latter, tibial spine impingement, discoid meniscus, and biomechanical alterations, together with injuries and overuse. The resultant subchondral bone ischemia and/or fracturing appears to determine the onset and progression of OCD.

LEVEL OF EVIDENCE

Systematic review of level II-IV studies, level IV.

Compliance in post-operative rehabilitation is a key factor for return to sport after revision anterior cruciate ligament reconstruction

PURPOSE

To assess the rate of return to sport (RTS) following revision Anterior Cruciate Ligament Reconstruction (ACLR) in a rehabilitation-based cohort of patients. A secondary goal of the study was to evaluate the association between compliance in post-operative rehabilitation and RTS rate.

METHODS

The study cohort included 79 sport-active patients (62 males, 17 females, 30.0 ± 10.2 years old) who underwent revision ACLR surgery and followed the same functional-oriented rehabilitation protocol. Patients were evaluated using a RTS survey: return to any kind of sport participation, return to the same pre-injury sport, return to the same sport at the same pre-injury level. With regards to compliance in post-operative rehabilitation, patients were then grouped in (1) Fully Compliant (FC), (2) Moderately Compliant (MC), (3) Scarcely Compliant (SC), and (4) Non-Compliant (NC).

RESULTS

At an average follow-up of 29 ± 12 months, 86% of the patients returned to some kind of sport activity, 62% returned to the same pre-injury sport activity and 59% returned to the same pre-injury level of sport activity. While no surgical aspects were correlated with RTS, higher BMI was found to have a negative influence (p = 0.033). Regardless of the type of sport, compliance significantly affected RTS at the same pre-injury level (p = 0.006): 86% in FC, 67% in MC, 50% in SC, and 45% in NC. For each compliance goal achieved, the probability of RTS increased by 68% (OR = 1.68; p = 0.027).

CONCLUSION

RTS at the same pre-injury level after revision ACLR is challenging. A higher compliance in rehabilitation significantly increases the chances of RTS.

LEVEL OF EVIDENCE

IV.

Low rate of return to pre-injury sport level in athletes after cartilage surgery: a 10-year follow-up study

PURPOSE

Although articular surface is frequently damaged in athletes, results in terms of return to sport and level of activity after cartilage surgery remain rather unpredictable and poorly documented. The aim of this study is to evaluate the clinical outcome in terms of rate and level of return to sport in a group of competitive athletes who underwent matrix-assisted autologous chondrocyte transplantation (MACT), as well as the impact on their athletic career.

METHODS

Thirty-one male patients (mean age 22.6 ± 6.3 years) p racticing sport at competitive level, affected by focal chondral/osteochondral lesions of the distal femur, were enrolled and treated with arthroscopic hyaluronan-based MACT. Patients were evaluated prospectively at 1-year intervals with the IKDC subjective, Tegner, and EuroQol VAS scores during their pre-operative visit and subsequent follow-ups for up to 10 years. Return to sport in terms of level, time and maintenance of the activity level was documented, together with surgical or clinical failures.

RESULTS

A marked improvement in all scores was found: IKDC increased from 40.3 ± 13.4 to 81.7 ± 14.4 (p < 0.0005) at 12 months; a further improvement was observed at 2 years (89.5 ± 11.3; p = 0.008), then results were stable for up to 10 years (87.3 ± 13.6). The analysis of return to sport documented that 64.5% of patients were able to return at a competitive level, and 58.1% performed at the same pre-injury level, with activity rates decreasing over time. The rate of patients returning to competitive level was 84% in those without previous surgery (vs. 33% who had undergone previous surgery), 87% for those with traumatic lesions (vs. 33% and 50% for degenerative and OCD lesions, respectively), and 92.3% in younger patients (age < 20 years). Among these factors, multivariate analysis demonstrated that previous surgery was the single most influencing factor for returning to the same sport level (p = 0.010).

CONCLUSIONS

These long-term results showed that chondrocyte-based regenerative approach has some limitations in terms of sport-related outcomes. The level of high functional knee restoration needed for such high-demanding activity level can be challenging to achieve, especially in patients with a more compromised joint homeostasis. Return to sport rate varies significantly according to specific patient and lesion characteristics and best results are obtained in young patients with traumatic lesions without previous surgery, which should be considered when treating athletes affected by cartilage lesions.

LEVEL OF EVIDENCE

IV.

High Rate of Failure After Matrix-Assisted Autologous Chondrocyte Transplantation in Osteoarthritic Knees at 15 Years of Follow-up

BACKGROUND

Chondral and osteochondral lesions in osteoarthritic knees of young patients remain challenging for orthopaedic surgeons, due to a combination of high functional demands and limited indications for joint replacement in this population. The possibility of extending the indication of cartilage regenerative procedures to these patients may allow the delay of metal resurfacing.

PURPOSE

To analyze the potential of a cartilage regenerative approach to provide clinical benefits in young patients with osteoarthritic knees, documenting outcomes in terms of clinical improvement as well as failures, in particular regarding knee replacement, at long-term follow-up.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A total of 41 patients (mean ± SD age, 43 ± 9 years) who had cartilage lesions (4 ± 2 cm²) in osteoarthritic knees (Kellgren-Lawrence grade 2 or 3) underwent matrix-assisted autologous chondrocyte transplantation (MACT) as a salvage procedure. Patients were evaluated with International Knee Documentation Committee (IKDC), EuroQol visual analog scale (EQ-VAS), and Tegner scores before surgery; at 1, 2, 5, and 9 years after surgery; and at a final follow-up at a mean of 15 years after surgery (range, 14-18 years). Failures were also recorded.

RESULTS

An improvement was observed in all scores after surgery, but a progressive worsening over time was noted. The mean ± SD IKDC score improved from 38.6 ± 16.2 to a maximum of 66.0 ± 18.6 at 2 years (P < .0005), with a subsequent deterioration until the final evaluation at 56.2 ± 21.7 (P = .024). A similar trend was confirmed by EQ-VAS scores. Tegner scores improved at all follow-up points but did not reach the preinjury level. Patients who underwent combined surgery obtained significantly lower results. Only 13 patients (32%) had an IKDC score higher than 70. During the follow-up period, 21 patients underwent reoperation (18 with knee replacement) and 3 more patients experienced clinical failure, for a total surgical and clinical failure rate of 59% at 15 years.

CONCLUSION

The use of cartilage regenerative surgical procedures, such as MACT, as salvage procedures for young, active patients affected by chondral and osteochondral lesions in osteoarthritic knees led to a limited improvement, with the majority of patients experiencing failure at long-term follow-up. Although a minor subpopulation experienced favorable and stable improvement, the use of MACT for such a challenging indication remains questionable until responding patients can be profiled.

Osteochondritis Dissecans of the Knee - Conservative Treatment Strategies: A Systematic Review

OBJECTIVE

Osteochondritis dissecans (OCD) lesions are a relevant problem that affects the long-term prognosis of young patients. The purpose of this study was to analyze the evidence on potential and indications of nonsurgical treatment strategies for knee OCD.

DESIGN

The search was conducted on 3 medical electronic databases according to PRISMA guidelines, including reports of any level of evidence dealing with the conservative management of knee OCD. Of 1688 identified records, 55 full-text articles were screened: 27 studies met the inclusion criteria, for a total of 908 knees, and were used for the analysis.

RESULTS

No high-level studies were found: 24 articles were case series and 3 case reports, reporting on different treatments summarized in (1) restriction of physical activity, (2) physiokinesitherapy and muscle-strengthening exercises, (3) physical instrumental therapies, (4) limitation of weightbearing, and (5) immobilization. The analysis showed an overall healing rate of 61.4%, with large variability (10.4%-95.8%). A conservative treatment based on restriction of sport and strenuous activities seems a favorable approach, possibly combined with physiokinesitherapy. Negative prognostic factors were also identified: larger lesion size, more severe lesion stages, older age and skeletal maturity, discoid meniscus, and clinical presentation with swelling or locking.

CONCLUSIONS

The literature on conservative treatments for knee OCD is scarce. Among different non-surgical treatment options, strenuous activity restriction seems a favorable approach, whereas there is no evidence that physical instrumental therapy, immobilization, or weightbearing limitation could be beneficial. However, further studies are needed to improve treatment potential and indications for the conservative management of knee OCD.

Treatment of unstable knee osteochondritis dissecans in the young adult: results and limitations of surgical strategies-The advantages of allografts to address an osteochondral challenge

Joint surface incongruence resulting from osteochondritis dissecans (OCD) alters the articular physiologic congruence, increasing the contact stress on adjacent joint surfaces and accelerating wear and the cascade of joint degeneration. Accordingly, the restoration of articular surface integrity is of major importance, especially in young adults where, in lesions left untreated or following simple fragment excision, early osteoarthritis can be anticipated. Therefore, the treatment algorithm in unstable knee OCD of the young adult foresees surgical options to restore the articular surface. Several procedures have been proposed, including refixation of the detached fragment bone marrow stimulation, osteochondral autograft implantation, fresh osteochondral allograft transplantation, and cell-based or cell-free regenerative techniques. The aim of this review was to summarize the evidence for these surgical strategies, reporting their results and limitations. The overall evidence documents positive results for each of the assorted surgical procedures applied to treat unstable OCD, thus indicating support for their selected use to treat osteochondral defects paying particular attention to their specific indications for the lesion characteristics. The fixation of a good quality fragment should be pursued as a first option, while unfixable small lesions may benefit from autografts. For large lesions, available cell-based or cell-free osteochondral scaffold are a feasible solution but with limitation in terms of regenerated tissue quality. In this light, fresh allografts may offer articular surface restoration with viable physiologic osteochondral tissue providing a predictably successful outcome, and therefore they may currently represent the most suitable option to treat unstable irreparable OCD lesion in young adults. LEVEL OF EVIDENCE: V.

Nonsurgical Treatments of Patellar Tendinopathy: Multiple Injections of Platelet-Rich Plasma Are a Suitable Option: A Systematic Review and Meta-analysis

BACKGROUND

Patellar tendinopathy is a condition characterized by anterior knee activity-related pain. It has a high incidence among athletes engaged in jumping sports and may become a chronic condition. Nonoperative management is the first choice in these patients, and several nonsurgical treatment options have been proposed. Nonetheless, clear indications on the most effective approach to address patellar tendinopathy are still lacking.

PURPOSE

To analyze the evidence on nonoperative options to treat chronic patellar tendinopathy through a systematic review of the literature and to perform a meta-analysis to identify the most effective nonsurgical option.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

The search was conducted with the PubMed and Cochrane databases on January 4, 2017. All clinical English-language reports of any level of evidence on nonsurgical treatment of patellar tendinopathy were included. The quality of each article was assessed by use of the Coleman score. A meta-analysis was performed on all articles reporting the Victorian Institute of Sport Assessment scale for patellar tendinopathy to evaluate the results of the most described treatments.

RESULTS

A total of 70 studies involving 2530 patients were included in the qualitative data synthesis. The Coleman score showed an overall poor study quality. The most described treatment groups that could be included in the meta-analysis were reported in 22 studies on eccentric exercise, extracorporeal shockwave therapy (ESWT), and platelet-rich plasma (PRP). Single and multiple PRP injections were evaluated separately. Eccentric exercise therapies obtained the best results ( P < .05) at short-term (<6 months, mean 2.7 ± 0.7 months). However, multiple injections of PRP obtained the best results ( P < .05), followed by ESWT and eccentric exercise, at long-term follow-up (≥6 months, mean 15.1 ± 11.3 months).

CONCLUSION

The literature documents several nonsurgical approaches for the treatment of chronic patellar tendinopathy with important limitations in terms of study quality. The available evidence showed an overall positive outcome, but some differences have been highlighted. Eccentric exercises may seem the strategy of choice in the short-term, but multiple PRP injections may offer more satisfactory results at long-term follow-up and can be therefore considered a suitable option for the treatment of patellar tendinopathy.

Treatment of Knee Osteochondritis Dissecans With a Cell-Free Biomimetic Osteochondral Scaffold: Clinical and Imaging Findings at Midterm Follow-up

BACKGROUND

Osteochondritis dissecans (OCD) is a developmental condition of subchondral bone that may result in secondary separation and instability of the overlying articular cartilage, which in turn may lead to degeneration of the overall joint and early osteoarthritis. Biphasic scaffolds have been developed to address defects of the entire osteochondral unit by reproducing the different biological and functional requirements and guiding the growth of both bone and cartilage.

PURPOSE

To evaluate midterm clinical and imaging results after cell-free osteochondral scaffold implantation for the treatment of knee OCD.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Twenty-seven patients (8 women, 19 men; mean age, 25.5 ± 7.7 years) were treated for knee OCD, with International Cartilage Repair Society (ICRS) grade 3 to 4 lesions with a mean size of 3.4 ± 2.2 cm² (range, 1.5-12 cm²), and prospectively evaluated for up to 5 years using the ICRS classification system and the Tegner score. Eighteen patients underwent magnetic resonance imaging (MRI) at 24 and 60 months of follow-up, and the graft was evaluated using the magnetic resonance observation of cartilage repair tissue (MOCART) score for the cartilage layer, while a specific score was used for subchondral bone.

RESULTS

All patients significantly improved their clinical scores at each follow-up until their final evaluation. The mean International Knee Documentation Committee (IKDC) subjective score improved from 48.4 ± 17.8 to 82.2 ± 12.2 at 2 years ( P < .0005), and it then remained stable for up to 5 years postoperatively (90.1 ± 12.0). The mean Tegner score increased from 2.4 ± 1.7 preoperatively to 4.4 ± 1.6 at 2 years ( P = .001), with a further increase up to 5.0 ± 1.7 at 5 years of follow-up ( P < .0005 vs preoperatively), reaching almost the preinjury level (5.7 ± 2.2). The MOCART score showed stable results between 24 and 60 months, whereas the subchondral bone status significantly improved over time. No correlation was found between MRI findings and clinical outcomes.

CONCLUSION

This 1-step cell-free scaffold implantation procedure showed good and stable results for up to 60 months of follow-up for the treatment of knee OCD. MRI showed abnormalities, in particular at the subchondral bone level, but there was an overall improvement of features over time. No correlation was found between imaging and clinical findings.