Revision ACL reconstruction in pediatric and adolescent patients yields low rates of graft failure and good functional scores, but low rates of return to sport: A systematic review.

PURPOSE: To evaluate outcomes following revision ACL reconstruction in pediatric and adolescent patients in terms of graft failure rate and functional patient outcomes. METHODS: A systematic review of Cochrane, Embase, Scopus, Ovid, and PubMed databases was performed for all original clinical studies that reported outcomes of pediatric and adolescent patients undergoing revision ACL reconstruction. Non-English studies and studies not reporting both graft failure rates and an additional outcome measure were excluded. We evaluated patient demographics, injury mechanisms, surgical technique characteristics, concomitant injuries, failure rates, patient-reported outcome measures (PROM), complications, and return to sports rates. Risk of bias (ROB) was assessed with the methodological index for non-randomized studies (MINORS). RESULTS: Five studies with a total of 239 knees in 234 patients were included. Failure of the revision ACLR ranged from 9% to 21%. Return to previous level of activity ranged between 27% and 68%. PROMs were variable, with good Lysholm score (range 84.5 to 93.7), moderate Tegner activity score (range 5.5 to 9), and good IKDC scores (range 79.9 to 80.0). Allograft was used in 48% of revisions, followed by bone patellar tendon bone (BPTB) autograft in 34%, and hamstrings (HS) autograft in 14%. Meniscus injury and cartilage injury was present in 53.1% to 92.5% and 5.5% to 59.4% of knees, respectively. Gwet's AC1 coefficient was 0.89, indicating a high degree of interrater reliability. The average MINOR score was 6 and heterogeneity was low (I2=9%). The included studies did not present with sufficient detail to disaggregate clinical outcomes by patient sex. CONCLUSIONS: Revision ACLR yields a graft failure ranging from 9 to 20%. Revision patients experience good PROMs but low rates of return to pre-injury level of sport. Further, revision ACLR was associated with high rates of intraarticular damage and relatively low rates of meniscal repair at the time of second surgery. LEVEL OF EVIDENCE: IV, systematic review of level IV evidence.

Arthroscopic Patella Realignment for Children And Adolescents: A Single Incision Technique.

Management of patellofemoral conditions in children and adolescents can be extremely challenging. Apart from the patellofemoral instability patients, there are several other disorders that can cause significant morbidity, patellofemoral maltracking, patellar tilt, and Hoffa's fat pad impingement syndrome are common problems that may not respond to nonoperative management. Understanding the exact pathology and apply the appropriate management is critical for successful outcome. Identification of novel surgical interventions that can provide symptom relief in a safe manner is important. This technical note describes a surgical technique for patella realignment in young patients that combines safety, simplicity, and reproducibility.

Editorial Commentary: Waiting at Least 1 Month After an Intra-articular Corticosteroid Injection for Performing a Knee, Shoulder, and Hip Arthroscopy Could Minimize the Risk for Postoperative Infection: Platelet-Rich Plasma Is an Alternative.

An intra-articular corticosteroid is associated with a higher risk of joint infection. Identifying the necessary time interval from the injection to the arthroscopic procedure that does not impose an additional risk of infection is critical for the safety of our patients. Increasing evidence suggests that there is a high risk of infection at the first 4 weeks after the injection, but it seems that this risk declines to normal levels after that period. Interestingly, this time interval of 4 weeks is comparable between knee, shoulder, and hip injection and subsequent arthroscopy. A delay of an arthroscopic intervention at any joint for at least 4 weeks is recommended. Finally, platelet-rich plasma (PRP) is equally effective as corticosteroids in terms of pain management and anti-inflammatory response, with the advantage of promoting healing. PRP may also be associated with a lower risk of postoperative infection in patients undergoing arthroscopy, representing a biologic alternative.

Plastic and elastic biomechanical properties of anterior cruciate ligament autografts.

BACKGROUND: Anterior cruciate ligament (ACL) rupture is a common orthopedic injury, occurring in roughly 68.6 per 100,000 persons annually, with the primary treatment option being ACL reconstruction. However, debate remains about the appropriate graft type for restoring the native biomechanical properties of the knee. Furthermore, plastic graft elongation may promote increased knee laxity and instability without rupture. This study aims to investigate the plastic properties of common ACL-R graft options. METHODS: Patellar tendon (PT), hamstring tendon (HT), and quadriceps tendon (QT) grafts were harvested from 11 cadaveric knees (6 male and 5 female) with a mean age of 71(range 55-81). All grafts were mechanically tested under uniaxial tension until failure to determine each graft's elastic and plastic biomechanical properties. RESULTS: Mechanically, the QT graft was the weakest, exhibiting the lowest failure force and the lowest failure stress (QT < HT, p = 0.032). The PT was the stiffest of the grafts, having a significantly higher stiffness (PT > QT, p = 0.0002) and Young's modulus (PT > QT, p = 0.001; PT > HT, p = 0.041). The HT graft had the highest plastic elongation at 4.01 ± 1.32 mm (HT > PT, p = 0.002). The post-yield behavior of the HT tendon shows increased energy storage capabilities with the highest plastic energy storage (HT > QT, p = 0.012) and the highest toughness (HT > QT, p = 0.032). CONCLUSION: Our study agrees with prior studies indicating that the failure load of all grafts is above the requirements for everyday activities. However, grafts may be susceptible to yielding before failure during daily activities. This may result in the eventual loss of functionality for the neo-ACL, resulting in increased knee laxity and instability.

Editorial Commentary: Personalized Anterior Cruciate Ligament Reconstruction and Rehabilitation Mitigate Postoperative Arthrofibrosis: Prevention Is the Best Approach.

Arthrofibrosis after anterior cruciate ligament reconstruction can become a major complication requiring surgical intervention. The reported incidence approximates 8% but varies widely (2%-35%) and, as not all patients require surgery, may be underreported. Several risk factors are involved. Female sex, older age, surgery within the first month after injury, and meniscus repair are consistently associated with increased risk. Other factors include graft size and type, concomitant procedures, use of anticoagulants, and genetic factors. By identifying risk factors, we can modify our surgical technique and rehabilitation to meet each patient's needs with fewer complications.

Conservative Treatment of Isolated Dorsal Dislocations of Fourth and Fifth Carpometacarpal Joints: A Report of a Rare Case.

Carpometacarpal (CMC) dislocations without associated fractures of the adjacent bones are extremely infrequent injuries. Dorsal or volar dislocations occur after high-energy injuries and may lead to early post-traumatic arthritis and carpal instability. The purpose of this study was to present a case of dorsal dislocation of both the fourth and fifth CMC joints that were treated with closed reduction and casting. A 31-year-old man developed severe acute pain, functional limitation, and deformity of the wrist after falling from a height. The clinical examination revealed intense localized tenderness, swelling, and palpable prominence over the fourth and fifth metacarpals. Standard anteroposterior and lateral views demonstrated dislocations of the examined CMC joints without any accompanied fracture. The injury was treated with anatomic closed reduction and cast immobilization for overall five weeks followed by early mobilization. Twelve weeks after injury, the patient had regained grip strength, and six months post-traumatically he satisfactorily returned to his previous hard labor-intensive activities without any functional deficits or chronic pain. Conclusively, CMC dislocations can be treated conservatively in case of early diagnosis and stable anatomic closed reduction.

Editorial Commentary: Patellofemoral Instability Results in Osteoarthritis, and Nonanatomic Surgery and Surgical Over-constraint May Also Cause Osteoarthritis.

When we are looking at the stars, we are in fact looking back in time. This is because it takes years for the light from the stars to reach us. In similar fashion, when we are evaluating data on osteoarthritis after patellofemoral surgery, we need to consider what kind of procedure was performed. Furthermore, it is extremely important to answer the question of whether the patellofemoral instability itself or the surgical procedure is causing the arthritis. Recent evidence suggests that recurrent patellofemoral instability is causing cartilage degeneration and stopping this process via surgical restoration of the anatomy and biomechanics of the patellofemoral joint may significantly reduce the risk of osteoarthritis. Shear loading of the cartilage can be detrimental. An instability event elicits inflammatory markers that are shown to induce arthritis. On the other hand, there is the argument that over-constraint may lead to arthritis owing to an increase in cartilage loading. Another argument is that surgery may not fully restore the patellofemoral anatomy. Appropriate patient selection and continuous evolution of our surgical procedures are key elements toward successful management of patellofemoral instability.

Editorial Commentary: Major Technical Advances in Knee Anterior Cruciate Ligament Reconstruction Address Anatomy, Biomechanics, and Healing.

The surgical techniques in knee anterior cruciate ligament (ACL) reconstruction continue to evolve significantly. Improved understanding of the anatomy, biomechanics, and healing of the ACL has offered the foundation for several advances. The goal of these innovations is to successfully restore the native anatomy and biomechanical function of the native ligament, provide a stable and pain-free knee joint, allow return to prior level of activity, prevent rerupture, and prevent osteoarthritis. Taken in sum, these are lofty goals. The shift toward anatomic ACL reconstruction, development of diverse graft options and configurations, and the addition of reinforcement techniques, such as the anterolateral ligament reconstruction and lateral tenodesis techniques, are major advancements in ACL reconstruction.

Editorial Commentary: Addition of the Sartorius Tendon to Small-Diameter Hamstring Anterior Cruciate Ligament Autografts May Improve Outcomes in Pediatric and Revision Cases.

Graft selection in anterior cruciate ligament reconstruction can have a pivotal role in a successful outcome. One of the major concerns with hamstring autograft is the variability of the diameter of each tendon, and grafts with a diameter of less than 8 mm may result in an increased failure rate. The addition of the sartorius tendon as a fifth strand in small-diameter hamstring autografts increases graft strength and diameter. This may improve outcomes in pediatric and revision cases.

Editorial Commentary: Biologic Augmentation of Meniscus Repair Is Complex.

In the setting of biological augmentation for meniscus repair, it is extremely important to evaluate all aspects, including effectiveness, costs, potential risks, benefits, and limitations. It seems that everything matters in healing: the aspirate source of the bioactive agents, cell content, presence of stem cells and their type, growth factors, cytokines, biomechanical scaffold, and the quality of the tissue. There are several differences among mesenchymal, adipose, and peripheral blood stem cells, with the cell origin affecting the differentiation potential towards bone, cartilage and ligament. Moreover, different aspirate sources and fibrin clots have different content in cells, growth factors, and cytokines. In this equation, it is not as simple as the more the better. Different doses of growth factors may have different effects in the different cell types. And as this was not complicated enough, synergistic phenomena between cells and between growth factors can play a huge role. Add to that the role of the biomechanical environment, the proper timing of the healing phases and the inherent patient characteristics. There is very, very much to learn, and finally, we acknowledge that not all menisci repairs can always heal.

Assessment of Skeletal Maturity and Postoperative Growth Disturbance After Anterior Cruciate Ligament Reconstruction in Skeletally Immature Patients: A Systematic Review.

BACKGROUND: Growth disturbance is an uncommon but potentially serious complication after anterior cruciate ligament (ACL) reconstruction in skeletally immature patients. PURPOSE: To describe how the pediatric ACL literature has assessed preoperative skeletal maturity and the amount of growth remaining and to comprehensively review the incidence, reporting, and monitoring of postoperative growth disturbance. STUDY DESIGN: Systematic review; Level of evidence, 4. METHODS: This review included studies reporting original research of clinical outcomes of skeletally immature patients after ACL reconstruction. Patient characteristics, surgical techniques, preoperative assessments of skeletal maturity or growth remaining, and postoperative assessments of growth disturbances were extracted. RESULTS: A total of 100 studies met inclusion criteria. All studies reported chronological age, and 28 studies (28%) assessed skeletal age. A total of 44 studies (44%) used Tanner staging, and 12 studies (12%) obtained standing hip-to-ankle radiographs preoperatively. In total, 42 patients (2.1%) demonstrated a leg length discrepancy (LLD) >10 mm postoperatively, including 9 patients (0.5%) with LLD >20 mm; furthermore, 11 patients (0.6%) with LLD underwent growth modulation. Shortening was the most common deformity overall, but overgrowth was reported more frequently in patients who had undergone all-epiphyseal techniques. Most LLDs involved the femur (83%). A total of 26 patients (1.3%) demonstrated a postoperative angular deformity ≥5°, and 9 of these patients underwent growth modulation. The most common deformities were femoral valgus (41%), tibial recurvatum (33%), and tibial varus (22%). Although standing hip-to-ankle radiographs were the most common radiographic assessment of growth disturbance, most studies inadequately reported the clinical and radiographic methods of assessment for growth disturbance. Additionally, only 35% of studies explicitly followed patients to skeletal maturity. CONCLUSION: This systematic review described significant variability in the reporting and monitoring of growth-related complications after ACL reconstruction in skeletally immature patients. The incidence of LLD and angular deformity appeared to be low, but the quality of research was not comprehensive enough for accurate assessment. REGISTRATION: CRD42019136059 (PROSPERO).

Knee orthopedics as a template for the temporomandibular joint.

Although the knee joint and temporomandibular joint (TMJ) experience similar incidence of cartilage ailments, the knee orthopedics field has greater funding and more effective end-stage treatment options. Translational research has resulted in the development of tissue-engineered products for knee cartilage repair, but the same is not true for TMJ cartilages. Here, we examine the anatomy and pathology of the joints, compare current treatments and products for cartilage afflictions, and explore ways to accelerate the TMJ field. We examine disparities, such as a 6-fold higher article count and 2,000-fold higher total joint replacement frequency in the knee compared to the TMJ, despite similarities in osteoarthritis incidence. Using knee orthopedics as a template, basic and translational research will drive the development and implementation of clinical products for the TMJ. With more funding opportunities, training programs, and federal guidance, millions of people afflicted with TMJ disorders could benefit from novel, life-changing therapeutics.

Comparison between partial and full coverage repair in massive rotator cuff tears. A minimum five year follow-up.

BACKGROUND: Massive rotator cuff surgical management can be challenging. Controversy exists in the literature regarding the potential benefit of full head coverage for arthroscopic rotator cuff repair. The purpose of this study was to compare re-tear rate and clinical outcome of arthroscopic repair of massive rotator cuff tears in relation to the achievement of full humeral head footprint coverage or not. Hypothesis We hypothesized that there will be no difference in re-tear rate and clinical outcomes between full and partial coverage rotator cuff repairs. PATIENTS AND METHODS: A retrospective analysis of all adult patients with a massive rotator cuff tear who underwent arthroscopic repair with a minimum five years follow-up was performed. Outcomes analyzed included re-tear rate, the American Shoulder and Elbow Surgeons (ASES) Shoulder Score, and the Penn Shoulder Score. Correlation and subgroup analyses were performed in order to evaluate whether age, symptom duration, tear size, coverage percentage, and fatty infiltration had any effect in outcome. RESULTS: The average ASES score was 76.3±25.2, and average Penn Shoulder Score was 75.8±23.1 at 7.9 years mean follow-up in 27 patients analyzed. Re-tear rate was similar between full and partial footprint coverage repair with 2 versus 4 failures, respectively (p=0.64). ASES and Penn Shoulder scores were 84.2 and 83.7 for full rotator cuff repair versus 70.6 and 71.1, for partial coverage repair (p=0.20 and p=0.22, respectively). The percentage of head coverage and the tear size were both found to be significantly correlated with outcome, with coefficient of determination R2 of 0.40 and 0.217, respectively, while a global fatty degeneration index GFDI <1.5 was associated with improved functional outcome. DISCUSSION: No difference in failure rate and functional outcome was detected between full and partial coverage rotator cuff repair. The size of the tear and fatty infiltration were inversely correlated with functional score while the percentage of coverage achieved was positively correlated with favorable outcome. LEVEL OF EVIDENCE: III; retrospective comparative study.

A Thoracoscopic Technique Used in Anterior Vertebral Tethering for Adolescent Idiopathic Scoliosis.

Anterior vertebral tethering (AVT) is a relatively recent alternative to posterior spinal fusion for progressive curves in growing patients with idiopathic scoliosis. AVT uses a thoracoscopic approach to minimize trauma to the thoracic wall and chest cavity. There are limited technical descriptions of this method. Patients benefit from proficiency and reproducibility to allow for appropriate spinal curve correction over time. This Technical Note outlines the steps of the thoracoscopic approach to AVT and reviews the current indications for AVT over posterior spinal fusion, as well as the most recently published clinical outcomes of this procedure.

Editorial Commentary: Artificial Intelligence in Sports Medicine Diagnosis Needs to Improve.

From imaging interpretation and health monitoring to drug development, the role of artificial intelligence (AI) in medicine has increased. But AI is not ready to replace humans when it comes to the diagnosis of sports medicine conditions. Rather, in highly specialized fields such as sports medicine, when it comes to interpretation of diagnostic studies such as magnetic resonance imaging scans (that are more sophisticated than simple radiographs), experts outperform AI systems at present. Key features of clinical practice, such as the physical examination, in-person consultation, and ultimately, decision making, cannot be easily replaced. As every novel "smart" tool is incorporated into our lives, we need to be ready to embrace its use, but we also ought to be critical of its implementation and seek transparency at every step of the process. We cannot afford to see AI as an antagonistic element in our practices but rather as a valuable assistant that could someday improve diagnostic accuracy.

Editorial Commentary: Meta-analysis Shows That Platelet-Rich Plasma Is Safe and Effective for Knee Osteoarthritis: Future Randomized Controlled Trials Must Be of High Quality-Not High Quantity.

The use of platelet-rich plasma in knee osteoarthritis is still controversial, and meta-analysis shows that platelet-rich plasma can be effective and safe for nonoperative management of knee osteoarthritis. Randomized controlled trials (RCTs) are essential tools for evaluating the effectiveness and safety of new therapeutic interventions. Meta-analysis of these RCTs is critical to try to approximate the truth but also reminds us that sometimes, "value does not necessarily derive from quantity but rather from quality." Given the fact that approximately 92.8% of published abstracts of RCTs report at least 1 significant outcome (indicated as at least P < .05), there is a notion that significant outcomes are most likely to become published, suggesting a potential publication bias. Therefore, additional studies repeating the significant outcomes are sometimes necessary.

Adult Dermal Stem Cells for Scaffold-Free Cartilage Tissue Engineering: Exploration of Strategies.

Dermis-isolated adult stem (DIAS) cells, abundantly available, are attractive for regenerative medicine. Strategies have been devised to isolate and to chondroinduce DIAS cells from various animals. This study aimed to characterize DIAS cells from human abdominal skin (human dermis-isolated adult stem [hDIAS] cells) and to compare and to refine various chondroinduction regimens to form functional neocartilage constructs. The stemness of hDIAS cells was verified (Phase I), three chondroinduction pretreatments were compared (Phase II), and, from these, one regimen was carried forward for refinement in Phase III for improving the mechanical properties of hDIAS cell-derived constructs. Multilineage differentiation and mesenchymal stem cell markers were observed. Among various chondroinduction pretreatments, the nodule formation pretreatment yielded constructs at least 72% larger in diameter, with higher glycosaminoglycan (GAG) content by 44%, compared with other pretreatments. Furthermore, it was found that culturing cells on nontissue culture-treated surfaces yielded constructs (1) on par with constructs derived from aggrecan-coated surfaces and (2) with superior mechanical properties than constructs derived from cells cultured on tissue culture-treated surfaces. After the nodule formation pretreatment, combined supplementation of TGF-ß1, IGF-I, and fetal bovine serum significantly enhanced aggregate modulus and shear modulus by 75% and 69%, respectively, over the supplementation by TGF-ß1 alone. In summary, human skin-derived DIAS cells are responsive to chondroinduction for forming neocartilage. Furthermore, the mechanical properties of the resultant human constructs can be improved by treatments shown to be efficacious in animal models. Advances made toward tissue-engineering cartilage using animal cells were shown to be applicable to hDIAS cells for cartilage repair and regeneration.

Editorial Commentary: The Posterior Cruciate Ligament Posteromedial Bundle Is Small but Vital to Posterior Cruciate Ligament Biomechanics: Don't Ignore the Underdog.

Posterior cruciate ligament (PCL) reconstruction leads to outcomes less favorable than those of anterior cruciate ligament reconstruction. In recent years, we have seen a surge of publications regarding PCL anatomy, isometry, and reconstruction techniques. PCL reconstruction has been revolutionized with lessons learned from analysis of PCL behavior, such as the distinct role of the posteromedial bundle (PMB) in the biomechanics of the knee at different flexion angles, as well as its co-dominant role with its counterpart, the anterolateral bundle. With the knee in extension, the PMB serves to restrict posterior translation, whereas in knee flexion, the PMB restricts internal rotation. It is rather too early to know whether the biomechanical advantage of double-bundle reconstruction will result in better clinical outcomes in the long term; however, the increased interest and the refinement of both single- and double-bundle reconstruction techniques will certainly advance our knowledge, ultimately translating into better patient outcomes.

Editorial Commentary: Tissue Engineering of the Meniscus: Are We at the Point That if Something Looks Like a Meniscus, We Can Call It a Meniscus?

It was thought that the meniscus together with articular cartilage would be among the first tissues to successfully engineer. However, despite extensive research in the field, this path was proven not to be easy. Tissue engineering of musculoskeletal tissues remains promising, and several advancements have further identified the role of biological treatments in meniscus repair and regeneration. To move forward, and advance from being promising to being forthcoming, an important step would be to improve the quality of presented studies. This editorial commentary proposes a checklist of necessary reported data for tissue engineering studies: macroscopic and histologic appearance, tissue composition, mechanical properties, and translational data.