Graeme P. Whyte

One-Stage Cartilage Repair Using a Hyaluronic Acid–Based Scaffold With Activated Bone Marrow–Derived Mesenchymal Stem Cells Compared With Microfracture: Five-Year Follow-up

Background: Articular cartilage injury is frequently encountered, yet treatment options capable of providing durable cartilage repair are limited. Purpose: To investigate the medium-term clinical outcomes of cartilage repair using a 1-stage technique of a hyaluronic acid–based scaffold with activated bone marrow aspirate concentrate (HA-BMAC) and compare results with those of microfracture. A secondary aim of this study was to identify specific patient demographic factors and cartilage lesion characteristics that are associated with superior outcomes. Study Design: Cohort study; Level of evidence, 2. Methods: Fifty physically active patients (mean age, 45 years) with grade IV cartilage injury of the knee (lesion size, 1.5-24 cm2) were treated with HA-BMAC or microfracture and were observed prospectively for 5 years. Patients were placed into the HA-BMAC group if the health insurance policy of the treating institution supported this option; otherwise, they were placed into the microfracture group. Objective and subjective clinical assessment tools were used preoperatively and at 2 and 5 years postoperatively to compare treatment outcomes. Results: Significant improvements in outcome scores were achieved in both treatment groups at 2 years (P < .001). In the microfracture group, 64% were classified as normal or nearly normal according to the International Knee Documentation Committee (IKDC) objective score at 2 years, compared with 100% of those treated with HA-BMAC (P < .001). Normal or nearly normal objective assessments in the microfracture group declined significantly after 5 years to 28% of patients (P = .004). All patients treated with HA-BMAC maintained improvement at 5 years according to Lysholm, Tegner, IKDC objective, and IKDC subjective scores. Tegner, IKDC objective, and Knee injury and Osteoarthritis Outcome Score (KOOS) assessments demonstrated higher scores in the HA-BMAC treatment group compared with microfracture at 5 years. Lysholm and IKDC subjective scores were similar between treatment groups at 5 years. Poorer outcomes in the microfracture group were demonstrated in cases of lesions larger than 4 cm2 and nonsolitary lesions. Age greater than 45 years, large size of lesion, and treatment of multiple lesions were not associated with poorer outcome in patients treated with HA-BMAC. Conclusion: Repair of chondral injury using a hyaluronic acid–based scaffold with activated bone marrow aspirate concentrate provides better clinical outcomes and more durable cartilage repair at medium-term follow-up compared with microfracture. Positive short-term clinical outcomes can be achieved with either microfracture or HA-BMAC. Cartilage repair using HA-BMAC leads to successful medium-term outcomes independent of age or lesion size.

Biologic Inlay Osteochondral Reconstruction: Arthroscopic One-Step Osteochondral Lesion Repair in the Knee Using Morselized Bone Grafting and Hyaluronic Acid-Based Scaffold Embedded With Bone Marrow Aspirate Concentrate

Cartilage injury of the knee that is associated with significant subchondral bone loss can result in great morbidity, and treatment options that provide durable repair are limited. Osteochondral autograft and allograft reconstruction of these lesions has been used extensively; however, these techniques often require a more invasive surgical exposure, and restoring the natural articular surface radius of curvature can be challenging, particularly in larger lesions. Cell-based repair of these lesions, using autologous chondrocytes in conjunction with bone grafting, has been used with success, although this procedure requires the patient to undergo 2 operations, and access is often restricted due to the high associated costs. Comparable medium-term clinical outcomes have been shown with scaffold-associated mesenchymal stem cell grafting, and this cell-based procedure may also be performed arthroscopically to minimize patient morbidity. In cases of cartilage injury associated with bone loss, this procedure has great potential to repair osteochondral injury when used in conjunction with bone grafting. We present the one-step arthroscopic technique of biologic inlay osteochondral reconstruction in the knee, using an autologous bone graft and a hyaluronic acid-based scaffold embedded with bone marrow aspirate concentrate, to treat full-thickness cartilage lesions associated with significant subchondral bone loss.

Morphologic Properties of Cartilage Lesions in the Knee Arthroscopically Prepared by the Standard Curette Technique Are Inferior to Lesions Prepared by Specialized Chondrectomy Instruments

Background: Cartilage lesion preparation is an important component to cartilage repair procedures, given the effect of prepared lesion morphology on the formation of durable and well-integrated repair tissue. Purpose: To compare the quality of arthroscopic cartilage lesion debridement performed by (1) the standard curette (SC) technique and (2) specialized chondrectomy (CM) instruments, to provide technical guidance for optimization of cartilage lesion preparation in the setting of arthroscopic cartilage repair. Study Design: Controlled laboratory study. Methods: Articular cartilage lesions of standardized size (8 × 15 mm) were demarcated within the trochlea and femoral condyles of 20 human cadaver knee specimens. Orthopaedic surgeons performed arthroscopic lesion preparation using 2 techniques that consisted of SC preparation and preparation by CM instruments. A histologic comparative analysis was performed within each treatment group and between treatment groups to evaluate the morphology of prepared cartilage defects. Results: The mean angle deviation from perpendicular of the cartilage wall at the front of the prepared cartilage lesions was significantly greater in the SC group versus the CM group (29.8° ± 21.4° vs 7.7° ± 7.6°, P < .001). In lesions prepared via the SC technique, the cartilage walls at the front of the prepared lesions were significantly less perpendicular than the cartilage walls at the rear of the lesions (29.8° ± 21.4° vs 11.0° ± 10.3°, P < .001), whereas lesions prepared by the CM technique demonstrated comparable verticality of surrounding cartilage walls at the front and rear aspects of the lesions (7.7° ± 7.6° vs 9.4° ± 12.3°, P = .827). Depth of lesion debridement was accomplished to the target level by the CM technique in 86% of prepared lesions, compared with 34% of lesions in the SC group. The prepared cartilage wall profile was characterized as the most ideal morphology in 55% of prepared lesions in the CM group, as opposed to 10% in the SC group. Conclusion: Arthroscopic cartilage lesion preparation with SC instruments results in superior perpendicularity of surrounding cartilage walls to subchondral bone and greater consistency of debrided lesion depth, as compared with the standard debridement technique with curettes. Clinical Relevance: Arthroscopic preparation using standard curette technique leads to suboptimal morphologic characteristics of prepared lesions that likely affect the quality of repair tissue, compared to preparation using specialized chondrectomy instruments.

Emerging Orthobiologic Approaches to Ligament Injury

Ligament injuries about the knee occur frequently during recreational and competitive sporting activities, and there is a wide array of treatment options to restore function and enable return-to-play. Interventions that utilize biologic therapy, or surgical augmentation with these biologic factors, may provide valuable additional therapeutic options to current methods typically used for treatment of these conditions. Cellular therapies have the potential to address deficiencies in the healing of injured ligaments by treating damaged tissue at a molecular level and by providing an environment that enhances reparative processes.

Cartilage Repair in the Knee Using Umbilical Cord Wharton's Jelly–Derived Mesenchymal Stem Cells Embedded Onto Collagen Scaffolding and Implanted Under Dry Arthroscopy

Cell-based cartilage repair procedures are becoming more widely available and have shown promising potential to treat a wide range of cartilage lesion types and sizes, particularly in the knee joint. More recently, techniques have evolved from 2-step techniques that use autologous chondrocyte expansion to 1-step techniques that make use of mesenchymal stem cells (MSCs) embedded onto biocompatible scaffolding. Our 1-step technique has been further developed to provide cell-based cartilage repair using MSCs that have the potential to be used in an off-the-shelf manner, without the need for autologous tissue harvest. Precursor MSCs can be isolated in abundance from the Whartons jelly of umbilical cord tissue. These cells have been shown to have the desired capacity for proliferation, differentiation, and release of trophic factors that make them an excellent candidate for use in the clinical setting to provide cell-based restoration of hyaline-like cartilage. Although allogeneic in nature, these cells stimulate little or no host immune response and can be stored for long periods while maintaining viability. We present a technique of cartilage repair in the knee using Whartons jelly–derived MSCs embedded onto scaffolding and implanted in a minimally invasive fashion using dry arthroscopy.

The Role of Orthobiologics in Return to Play

Bioactive proteins and growth factors are an integral component of healing processes and have the potential to affect metabolic cascades that impact tissue regeneration at all stages. These factors can be used in athletes for a wide variety of musculoskeletal injuries in the form of such biologics as platelet-rich plasma, or in conjunction with cellular therapies, to facilitate return to play. Cellular therapies, most often used in the form of mesenchymal stem cell isolates, are increasingly being used to treat athletic injury. In addition to tendinous or ligamentous injury, mesenchymal stem cell therapies are used to treat articular cartilage lesions. In combination with biologic scaffolding, mesenchymal stem cell isolates can be used to treat cartilage lesions of wide ranging sizes and severity. Orthobiologic therapies are advancing rapidly and are used to treat a large spectrum of injuries, helping to facilitate return to play at all levels of football competition.

Surgical repair of osteochondral lesions of the talus using biologic inlay osteochondral reconstruction: Clinical outcomes after treatment using a medial malleolar osteotomy approach compared to an arthroscopically-assisted approach

BACKGROUND Surgical treatment of osteochondral lesions of the talus affecting the medial aspect of the talar dome is typically performed using medial malleolar osteotomy to optimize access. This study compares clinical outcomes of lesions repaired using biologic inlay osteochondral reconstruction in patients who did or did not undergo medial malleolar osteotomy, depending on defect dimensions. METHODS Patients treated for osteochonral lesions of the talus through a medial mallolar approach or arthroscopically-assisted approach were prospectively followed. Assessment tools consisted of the visual analogue scale (VAS) and the American Orthopaedic Foot and Ankle Society Ankle-Hindfoot score (AOFAS). The magnetic resonance observation of cartilage repair tissue (MOCART) score was used postoperatively. RESULTS Data for 24 patients (mean age 34years, mean follow-up 22 months) was analyzed. Mean preoperative/final AOFAS and VAS in those who underwent osteotomy were 57.7/81.2 and 5.7/1.9 (p<0.001), respectively. In those who underwent arthroscopically-assisted reconstruction, mean preoperative/final AOFAS and VAS were 54.4/84.0 and 7.6/2.0 (p<0.001), respectively. There was no difference in mean MOCART score (p=0.662) for those treated with osteotomy (67.3) compared to those without (70.8). CONCLUSIONS Osteochondral lesions of the talar dome can be treated successfully by biological inlay osteochondral reconstruction technique without medial malleolar osteotomy, with good to excellent clinical outcomes expected. MRI demonstrates good integration of the graft into surrounding tissue.

Osteochondritis Dissecans of the Knee in Football Players

Osteochondritis dissecans (OCD) of the knee is a frequent cause of pain and functional limitation among skeletally immature and young athletes. Chronic overuse of the lower extremity in young soccer players can cause OCD at the knee and ankle joints; furthermore, with increased competitiveness of amateur sports, more injuries may cause OCD. Increased joint stress, such as an increased pressure at the medial femoral condyle in young patients with genu varum, might cause decreased blood flow and trigger the development of OCD. Symptoms are usually preceded by trauma in 40–60% of the cases. Juveniles and adolescents will complain of vague, nonspecific poorly localized anterior knee pain with variable intermittent amount of swelling, locking of the knee grinding, or catching; pain is aggravated by activity and relieved by rest. If not recognized and appropriately treated, it can create further limitation and lead to early osteoarthritis. OCD is a disorder of one or more ossification centers, characterized by sequential degeneration or aseptic necrosis and recalcification. OCD lesions involve both bone and cartilage but appear to affect the subchondral bone primarily and secondarily affect the articular cartilage.

Osteochondritis Dissecans: Pathoanatomy, Classification, and Advances in Biologic Surgical Treatment

Osteochondritis dissecans (OCD) is an articular disorder that results from a pathologic process involving subchondral bone that frequently leads to injury of the overlying articular cartilage. This condition may lead to significant pain and functional impairment, particularly among young athletes. In cases where surgical treatment is considered, a variety of therapeutic options may be used for repair of the injured tissue, including grafting of the osteochondral unit with allograft or autograft, or cell-based cartilage repair. Recent developments that make use of biomaterials and cell-based cartilage repair have demonstrated encouraging results and are an important treatment advancement in this rapidly evolving field of tissue repair.

Biologic Knee Arthroplasty for Cartilage Injury and Early Osteoarthritis

Injury to knee articular cartilage is a prominent cause of functional limitation that affects both genders over a wide range of ages. Retaining the native knee joint is often a priority for younger individuals who wish to maintain their active lifestyle. Due to improvements in surgical techniques and technology, a greater number of treatment options are becoming increasingly available to treat extensive areas of cartilage injury, including cases of early degenerative change. Cartilage restoration procedures, when combined with bony realignment surgery as indicated, have provided successful clinical outcomes in knees affected by multiple compartment cartilage injury. The technique of biologic arthroplasty of the knee joint, using cell-based cartilage repair technology with concurrent bony realignment, has been demonstrated to provide successful clinical outcomes in a wide range of cartilage lesion types, including cases that would typically be considered early osteoarthritis.