Articular cartilage solutions for the knee: present challenges and future direction

Fixation Methods, Complications, and Outcomes After Primary Fixation of Isolated Chondral Fragments in the Knee: A Systematic Review

BACKGROUND

Knee injuries resulting in purely cartilaginous defects are rare, and controversy remains regarding the reliability of chondral-only fixation.

PURPOSE

To systematically review the literature for fixation methods and outcomes after primary fixation of chondral-only defects within the knee.

STUDY DESIGN

Systematic review; Level of evidence, 5.

METHODS

A literature search was conducted following the 2020 PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines using keywords and Boolean phrases in PubMed, Embase, Cochrane, and Scopus on October 10, 2023. Human studies reporting fixation methods and outcomes after primary fixation of chondral-only defects within the knee were included in this systematic review. Studies reporting subchondral bone involvement were excluded. Study quality was assessed using the Joanna Briggs Institute critical appraisal tool. Postoperative outcomes, reoperations, and return to sport/activity were evaluated. Failure was defined as chondral fragment dislodgement or failure of healing postoperatively.

RESULTS

A total of 18 studies (N = 93 patients) were identified. The mean patient age was 16 years (mean range, 11-32 years), with a mean final follow-up of 42.4 months (mean range, 5-61.2 months). Men comprised 81% (n = 59/73) of patients. Bioabsorbable implants (n = 13 studies) were the most commonly reported fixation method. Complications related to fixation of the chondral fragment occurred in 10.8% of patients (n = 10/93), with all other complications occurring in 9.8% (n = 9/93) of patients. Revision surgery directly associated with the chondral fragment was reported in 10.8% (n = 10/93) of patients. Successful return to sport/activity was observed in 90% (n = 60/67) of patients. Intact fixation was reported in 85% (n = 75/88) of patients undergoing postoperative magnetic resonance imaging, computed tomography, or second-look arthroscopy.

CONCLUSION

Primary fixation of chondral-only defects can lead to low rates of failure and revision surgery with a high return to sport/activity in young patients, even with relatively large lesions. Bioabsorbable implants and absorbable sutures were the most common fixation methods, primarily performed via open arthrotomy after diagnostic arthroscopy. Failure of fixation and implant irritation were the most commonly reported complications related to fixation, with reoperations directly related to fragment fixation performed in 10.8% of patients. Healing of the chondral fragment as evaluated using postoperative magnetic resonance imaging, computed tomography, or second-look arthroscopy was reported in 85% of patients.

Rehabilitation of Soccer Players' Knee Injuries: Cartilage Reconstruction, Anterior Cruciate Ligament Surgery, and Intensive Recovery-A Pilot Study

Knee injuries, particularly anterior cruciate ligament (ACL) damage and cartilage defects, are highly prevalent among athletes and affect their sports performance and long-term joint function. The purpose of this research was to evaluate the effectiveness of a comprehensive combination therapy approach for individuals with ACL and cartilage injuries. Twelve professional soccer players aged 18 to 30 years underwent bone-tendon-bone ACL reconstruction, microfracture cartilage repair surgery, and hyaluronic acid scaffold treatment. Early postoperative rehabilitation included immediate supervised physiotherapy and complete weight bearing. Follow-up assessments involved clinical evaluations, functional joint assessments, and magnetic resonance imaging (MRI) scans to measure cartilage defect repair and symptom alleviation. The results showed that patients resumed pain-free activities within 3-4 weeks and returned to their pre-injury level within 4.5 months. MRI demonstrated the absence of inflammatory reactions, repair of marrow edema, and the emergence of new cartilage. Six months and one year after surgery, the Knee Injury and Osteoarthritis Outcome Score (KOOS) and the Short Form (36) Health Survey (SF-36) questionnaire results demonstrated considerable improvement in patients' health condition and quality of life. Overall, the study suggests that the combination of Hyalofast membranes, microfracture surgery, tissue adhesive, and intensive postoperative physical therapy may be a potential alternative to commonly used treatments for patients with ACL rupture, allowing them to recover efficiently and return to sports activities.

Differences in the Demographics and Preferred Management of Knee Cartilage Injuries in Soccer Players Across FIFA Centers of Excellence

OBJECTIVE

We sought to report on the demographics and epidemiology of knee cartilage injuries and preferred management in soccer players, across FIFA Medical Centers of Excellence (FMCE).

DESIGN

A descriptive questionnaire focusing on characteristics of knee cartilage injuries and their management in soccer players during the 10-year period prior to the distribution of the questionnaire was sent to all FMCE around the world in September 2019 via an online platform. Voluntary responses from centers were processed and analyzed. Descriptive characteristics were reported using median and interquartile ranges (IQR) for continuous variables and frequencies and percentages (%) for discrete variables.

RESULTS

A total of 15 centers from 5 continents responded to the questionnaire and reported on a total of 4526 soccer players. Among centers, the median age was 27 years (IQR: 23-38), the median rate of male players was 75% (IQR: 68-90), and the median rate of professional players was 10% (IQR: 5-23). The most common reported etiology for cartilage injury was traumatic (median 40%, IQR: 13-73). The most common nonoperative treatment utilized was physical therapy (median 90%, IQR: 51%-100%) and the most common operative treatment utilized was bone marrow stimulation/micro-fracture (median 40%, IQR: 19-54%). The utilization of other cartilage restoration procedures varied across centers.

CONCLUSIONS

Our findings highlight different tendencies in the management of these injuries across FMCE and emphasize the need for collaborative efforts focusing on establishing consensus guidelines for the optimal management of these challenging injuries in soccer players.

Surgical Fixation of Chondral-Only Fragments of the Knee: A Case Series With a Mean 4-Year Follow-up

Background:

Chondral-only fragments of the knee have traditionally been treated with excision, with or without cartilage restoration procedures. This is because of the historical assumption that cartilage has limited ability to heal to cancellous or subchondral bone. There is now a growing body of evidence supporting surgical fixation of these fragments.

Hypothesis:

We hypothesized that surgical fixation of chondral fragments would result in acceptable rates of healing with improvement in clinical outcome scores.

Study Design:

Case series; Level of evidence, 4.

Methods:

Data were collected on 15 surgically fixed chondral-only fragments in 14 patients. We retrospectively collected participant demographic information, lesion characteristics, primary mechanism (osteochondritis dissecans vs traumatic shear injury), fixation methods, reoperation information, second-look arthroscopic information, and clinical outcome scores. The mean clinical follow-up was 3.96 years, with a minimum of 1-year follow-up. All patients underwent follow-up magnetic resonance imaging at a mean of 2 years after the index procedure.

Results:

The mean age of our cohort was 17.7 years. We found an 80% survival rate for fixation of the fragments at a mean 4-year follow-up. There were statistically significant improvements in postoperative Knee injury and Osteoarthritis Outcome Score and Tegner scores compared with preoperative scores. Follow-up magnetic resonance imaging scans showed complete healing in 10 knees, partial healing in 2 knees, and loss of fixation in 3 knees. Second-look arthroscopic surgery of 3 knees for reasons other than fragment symptoms showed healing of the fragment, while arthroscopic surgery of 3 symptomatic knees showed loss of fixation.

Conclusion:

Surgical fixation of chondral-only lesions showed an 80% success rate with improvements in the KOOS and Tegner scores.

Enhancement of chondrogenic differentiation supplemented by a novel small compound for chondrocyte-based tissue engineering

Purpose

Chondrocyte -based tissue engineering has been a promising option for the treatment of cartilage lesions. In previous literature, TD198946 has been shown to promote chondrogenic differentiation which could prove useful in cartilage regeneration therapies. Our study aimed to investigate the effects of TD198946 in generating engineered cartilage using dedifferentiated chondrocyte-seeded collagen scaffolds treated with TD198946.

Methods

Articular chondrocytes were isolated from mini pig knees and expanded in 2-dimensional cell culture and subsequently used in the experiments. 3-D pellets were then cultured for two weeks. Cells were also cultured in a type I collagen scaffolds for four weeks. Specimens were cultured with TD198946, BMP-2, or both in combination. Outcomes were determined by gene expression levels of RUNX1, SOX9, ACAN, COL1A1, COL2A1 and COL10A1, the glycosaminoglycan content, and characteristics of histology and immunohistochemistry. Furthermore, the maturity of the engineered cartilage cultured for two weeks was evaluated through subcutaneous implantation in nude mice for four weeks.

Results

Addition of TD198946 demonstrated the upregulation of gene expression level except for ACAN, type II collagen and glycosaminoglycan synthesis in both pellet and 3D scaffold cultures. TD198946 and BMP-2 combination cultures showed higher chondrogenic differentiation than TD198946 or BMP-2 alone. The engineered cartilage maintained its extracellular matrices for four weeks post implantation. In contrast, engineered cartilage treated with either TD198946 or BMP-2 alone was mostly absorbed.

Conclusions

Our results indicate that TD198946 could improve quality of engineered cartilage by redifferentiation of dedifferentiated chondrocytes pre-implantation and promoting collagen and glycosaminoglycan synthesis.

A Case Series of Successful Repair of Articular Cartilage Fragments in the Knee

BACKGROUND

It is unclear whether chondral fragments without bone have the potential to heal after fixation. Controversy exists and opinions differ regarding the optimal treatment of chondral defects after pure chondral fracture.

PURPOSE

To determine clinical and radiographic outcomes after internal fixation of traumatic chondral fragments repaired to bone in the knee.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A retrospective clinical and radiographic evaluation of 10 male patients with a mean age of 14.6 years (range, 10-25 years) at the time of surgery was performed. Eight of 10 patients were skeletally immature. Patients were selected by operating surgeons per the presence of a large displaced pure chondral fragment on magnetic resonance imaging and confirmed on intraoperative inspection. All patients had a diagnosed traumatic displaced pure chondral fracture of the knee (without bone) and underwent internal fixation with minimum 1-year follow-up. Validated patient-reported and surgeon-measured outcomes were collected pre- and postoperatively. All patients were evaluated at a mean 56 months postoperatively.

RESULTS

At surgery, the mean defect size that was primarily repaired with the displaced chondral fragment was 1.9 × 2.0 cm. With minimum 1-year follow-up, there were no clinical failures. All 8 patients who had subsequent magnetic resonance imaging follow-up had radiographic evidence of complete healing of the chondral fragment back to bone. At a mean follow-up of 56 months (range, 13-171 months; median, 36 months), patients had a mean International Knee Documentation Committee score of 94.74 (range, 87.4-100), a mean Marx Activity Scale score of 14.4 (range, 8-16), and a mean Tegner Activity Scale score of 7 (range, 5-9). At final follow-up, all patients except 1 returned to sports.

CONCLUSION

The treatment of large traumatic chondral fragments is controversial. In this select series of 10 young patients who underwent primary repair with internal fixation, there were no failures clinically. Patients demonstrated excellent short-term clinical and radiographic results after fixation of these relatively large chondral fragments in the knee.

Scaffold-free tissue engineering for injured joint surface restoration

Articular cartilage does not heal spontaneously due to its limited healing capacity, and thus effective treatments for cartilage injuries has remained challenging. Since the first report by Brittberg et al. in 1994, autologous chondrocyte implantation (ACI) has been introduced into the clinic. Recently, as an alternative for chondrocyte-based therapy, mesenchymal stem cell (MSC)-based therapy has received considerable research attention because of the relative ease in handling for tissue harvest, and subsequent cell expansion and differentiation. In this review, we discuss the latest developments regarding stem cell-based therapies for cartilage repair, with special focus on recent scaffold-free approaches.

Emerging Concepts in Treating Cartilage, Osteochondral Defects, and Osteoarthritis of the Knee and Ankle

The management and treatment of cartilage lesions, osteochondral defects, and osteoarthritis remain a challenge in orthopedics. Moreover, these entities have different behaviors in different joints, such as the knee and the ankle, which have inherent differences in function, biology, and biomechanics. There has been a huge development on the conservative treatment (new technologies including orthobiologics) as well as on the surgical approach. Some surgical development upraises from technical improvements including advanced arthroscopic techniques but also from increased knowledge arriving from basic science research and tissue engineering and regenerative medicine approaches. This work addresses the state of the art concerning basic science comparing the knee and ankle as well as current options for treatment. Furthermore, the most promising research developments promising new options for the future are discussed.

Knee donor-site morbidity after mosaicplasty - a systematic review

BACKGROUND

Mosaicplasty has been associated with good short- to long-term results. Nevertheless, the osteochondral harvesting is restricted to the donor-site area available and it may lead to significant donor-site morbidity.

PURPOSE

Provide an overview of donor-site morbidity associated with harvesting of osteochondral plugs from the knee joint in mosaicplasty procedure.

METHODS

Comprehensive search using Pubmed, Cochrane Library, SPORTDiscus and CINAHL databases was carried out through 10th October of 2016. As inclusion criteria, all English-language studies that assessed the knee donor-site morbidity after mosaicplasty were accepted. The outcomes were the description and rate of knee donor-site morbidity, sample's and cartilage defect's characterization and mosaicplasty-related features. Correlation between mosaicplasty features and rate of morbidity was performed. The methodological and reporting quality were assessed according to Coleman's methodology score.

RESULTS

Twenty-one studies were included, comprising a total of 1726 patients, with 1473 and 268 knee and ankle cartilage defects were included. The defect size ranged from 0.85 cm2 to 4.9 cm2 and most commonly 3 or less plugs (averaging 2.9 to 9.4 mm) were used. Donor-site for osteochondral harvesting included margins of the femoral trochlea (condyles), intercondylar notch, patellofemoral joint and upper tibio-fibular joint. Mean donor-site morbidity was 5.9 % and 19.6 % for knee and ankle mosaicplasty procedures, respectively. Concerning knee-to-knee mosaicplasty procedures, the most common donor-site morbidity complaints were patellofemoral disturbances (22 %) and crepitation (31 %), and in knee-to-ankle procedures there was a clear tendency for pain or instability during daily living or sports activities (44 %), followed by patellofemoral disturbances, knee stiffness and persistent pain (13 % each). There was no significant correlation between rate of donor-site morbidity and size of the defect, number and size of the plugs (p > 0.05).

CONCLUSIONS

Osteochondral harvesting in mosaicplasty often results in considerable donor-site morbidity. The donor-site morbidity for knee-to-ankle (16.9 %) was greater than knee-to-knee (5.9 %) mosaicplasty procedures, without any significant correlation between rate of donor-site morbidity and size of the defect, number and size of the plugs. Lack or imcomplete of donor-site morbidity reporting within the mosaicplasty studies is a concern that should be addressed in future studies.

LEVEL OF EVIDENCE

Level IV, systematic review of Level I-IV studies.