Andrea Manunta

Sheep embryonic stem-like cells transplanted in full-thickness cartilage defects.

Articular cartilage regeneration is limited. Embryonic stem (ES) cell lines provide a source of totipotent cells for regenerating cartilage. Anatomical, biomechanical, physiological and immunological similarities between humans and sheep make this animal an optimal experimental model. This study examines the repair process of articular cartilage in sheep after transplantation of ES‐like cells isolated from inner cell masses (ICMs) derived from in vitro‐produced (IVP) vitrified embryos. Thirty‐five ES‐like colonies from 40 IVP embryos, positive for stage‐specific embryonic antigens (SSEAs), were pooled in groups of two or three, embedded in fibrin glue and transplanted into osteochondral defects in the medial femoral condyles of 14 ewes. Empty defect (ED) and cell‐free glue (G) in the controlateral stifle joint served as controls. The Y gene sequence was used to detect ES‐like cells in the repair tissue by in situ hybridization (ISH). Two ewes were euthanized at 1 month post‐operatively, three each at 2 and 6 months and four at 12 months. Repairing tissue was examined by biomechanical, macroscopic, histological, immunohistochemical (collagen type II) and ISH assays. Scores of all treatments showed no statistical significant differences among treatment groups at a given time period, although ES‐like grafts showed a tendency toward a better healing process. ISH was positive in all ES‐like specimens. This study demonstrates that ES‐like cells transplanted into cartilage defects stimulate the repair process to promote better organization and tissue bulk. However, the small number of cells applied and the short interval between surgery and euthanasia might have negatively affected the results. Copyright

Subchondral bone remodeling: comparing nanofracture with microfracture. An ovine in vivo study.

PURPOSE microfracture, providing direct stimulation of chondrogenic mesenchymal stem cells (MSCs) in the subchondral bone, remains the most frequently used primary cartilage repair technique. However, the newly formed type I collagen-rich fibrocartilaginous tissue has poor biomechanical properties and a tendency to degenerate. To overcome these limitations the nanofracture technique was introduced. Our purpose was to compare subchondral bone remodeling 6 months after microfracture versus nanofracture (subchondral needling) treatment in an ovine model. METHODS full-thickness chondral lesions were created in the load-bearing area of the medial femoral condyles in four adult sheep. Each animal was then treated on one side with microfracture and on the contralateral side with nanofracture. Subchondral bone remodeling was assessed by micro-CT using a Bruker(®) SKYSCAN and CTVOX 2.7 software (Bruker Corp., Billerica, MA, USA) for image reconstruction; trabecular bone density measurements were performed through a color-representation structure thickness analysis. RESULTS at the six-month endpoint, the microfracture-treated samples showed limited perforation depth and cone-shaped channels with large diameters at the joint surface. The channel walls displayed a high degree of regularity with significant trabecular bone compaction leading to a sealing effect with limited communication with the surrounding trabecular canals. Condyles treated with nanofracture showed channels characterized by greater depth and smaller diameters and natural irregularities of the channel walls, absence of trabecular compaction around the perforation, remarkable communication with trabecular canals, and neo-trabecular remodeling inside the channels. CONCLUSIONS nanofracture is an effective and innovative repair technique allowing deeper perforation into subchondral bone with less trabecular fragmentation and compaction when compared to microfracture; it results in better restoration of the normal subchondral bone architecture at six months. CLINICAL RELEVANCE our data support the use of smaller-diameter and deeper subchondral bone perforation for MSC stimulation; this technique may prove to be an attractive alternative to standard microfracture procedures.

The use of embryonic cells in the treatment of osteochondral defects of the knee: an ovine in vivo study.

PURPOSE the aim of this study was to determine whether local delivery of embryonic stem-like (ESL) cells into osteochondral defects in the femoral condyles of sheep would enhance regeneration of hyaline articular cartilage. METHODS male ESL cells embedded in fibrin glue were engrafted into osteochondral defects in the medial condyles (ESL-M) of the left femur in 22 ewes. An identical defect was created in the medial condyle of the contralateral stifle joint and left untreated as a control (empty defect, ED). The ewes were divided into 5 groups. Four sheep each were euthanized at 1, 2, 6, and 12 months from surgery, and 6 ewes were euthanized 24 months post-implantation. To study the effect of varying loads on the long-term regeneration process, an identical defect was also created and ESL cell engraftment performed in the lateral condyle (ESL-L) of the left stifle joint of the animals in the 12- and 24-month groups. The evaluation of regenerated tissue was performed by biomechanical, macroscopic, histological, immunohistochemical (collagen type II) and fluorescent in situ hybridization (FISH) assays. RESULTS no significant differences were found between treated and control sites in the biomechanical assays at any time point. ESL cell grafts showed significantly greater macroscopic evidence of regeneration as compared to controls at 24 months after surgery; significantly better histological evidence of repair in ESL-M samples versus controls was found throughout the considered period. At 24 months from surgery there was significantly improved integration of graft edges with the host tissue in the ESL-M as compared to the ESL-L samples, demonstrating that load bearing positively affects the long-term regeneration process. CONCLUSIONS ESL cells enhanced the regeneration of hyaline cartilage. FISH confirmed that the regenerative tissue originated from ESL cells. CLINICAL RELEVANCE ESL cells are able to self-renew for prolonged periods without differentiation and, most importantly, to differentiate into a large variety of tissues.

Use of an Elastomeric Knee Brace in Patellofemoral Pain Syndrome: Short-Term Results

Purpose  This article verifies the effectiveness of a new brace on patellofemoral pain syndrome (PFPS) in adjunct to a specifically developed rehabilitation program. Methods  Two groups of 30 patients with PFPS were prospectively and randomly allocated to a rehabilitation protocol, with (group A) or without (group B) the use of a specific brace. All the patients were assessed at 3, 6, and 12 months using the disease-specific Kujala scale and a visual analog scale (VAS) for pain; time to return to sport and patient satisfaction with the brace were also recorded. Results  Kujala scales values showed constant and progressive improvement. The mean score at 6 months was 79.8 ± 6.8 points in group A and 76.8 ± 8.6 in group B, rising at 12 months to 80.9 ± 7.5 in group A and 78.4 ± 8.3 in group B. VAS scores significantly differed ( p  < 0.05) between the two groups at both 6 and 12 months; the score recorded at 12 months was 0.9 ± 1.3 in the brace-treated group and 1.8 ± 1.6 in the controls. The patients who used a brace showed a quicker return to sports and 75% of the patients in this group were satisfied. Conclusion  All the scores improved progressively in both groups. The most significant improvement concerned pain, showing that the brace used in this study may allow a better subjective outcome and a quicker return to sport. Level of Evidence  Level II, prospective randomized controlled trial.

Early joint degeneration and antagonism between growth factors and reactive oxygen species. Is non-surgical management possible?

PURPOSE in pathological conditions such as osteo-arthritis (OA), overproduction of reactive oxygen species (ROS) may overwhelm the antioxidant defenses of chondrocytes, thus promoting oxidative stress and cell death. It can be hypothesized that increasing the antioxidant machinery of chondrocytes may prevent the age-associated progression of this disease. Growth factors (GFs) play an important role in promoting both the resolution of inflammatory processes and tissue repair. In view of these considerations, we set out to investigate the protective effect, against H2O2-induced oxidative cell death, potentially exerted by fluid drained from the joint postoperatively. METHODS the present study was conducted in 20 patients diagnosed with bilateral knee osteoarthritis and treated, between January 2013 and June 2014, with prosthetic knee implantation on the side more affected by the arthritic process, together with intraoperative placement of a closed-circuit drainage aspiration system. As a result, 20 different serum samples were collected from the drained articular fluid, prepared using two different methodologies. In addition, forty blood serum samples were obtained and prepared: 20 from the surgically treated patients and 20 from healthy controls. The present work was undertaken to investigate the potential protective effect of sera obtained from articular fluid drainage against hydrogen peroxide-induced oxidative stress in cultured human chondrocytes. RESULTS exposure of chondrocytes to hydrogen peroxide elicited a dose-dependent increase in oxidative stress and chondrocyte cell death, phenomena that were significantly counteracted by the pre-treatment of cell cultures with sera from articular fluid drainage. CONCLUSIONS oxidatively stressed chondrocytes treated with sera obtained from articular fluid drainage lived longer than those treated with blood serum samples and longer than untreated ones. CLINICAL RELEVANCE synovial fluids are usually discarded once the drainage reservoir is full; instead they could benefit the patients from whom they are collected, as they are rich in growth factors and they may act as antagonists of ROS effects. Accordingly, they could be used to treat chondropathies, early OA, and mild OA located in other sites.

Italian consensus statement for the use of allografts in ACL reconstructive surgery

PurposeGraft choice for primary anterior cruciate ligament reconstruction (ACL-R) is debated, with considerable controversy and variability among surgeons. Autograft tendons are actually the most used grafts for primary surgery; however, allografts have been used in greater frequency for both primary and revision ACL surgery over the past decade. Given the great debate on the use of allografts in ACL-R, the “Allografts for Anterior Cruciate Ligament Reconstruction” consensus statement was developed among orthopedic surgeons and members of SIGASCOT (Società Italiana del Ginocchio, Artroscopia, Sport, Cartilagine, Tecnologie Ortopediche), with extensive experience in ACL-R, to investigate their habits in the use of allograft in different clinical situations. The results of this consensus statement will serve as benchmark information for future research and will help surgeons to facilitate the clinical decision making.MethodsIn March 2017, a formal consensus process was developed using a modified Delphi technique method, involving a steering group (9 participants), a rating group (28 participants) and a peer-review group (31 participants). Nine statements were generated and then debated during a SIGASCOT consensus meeting. A manuscript has been then developed to report methodology and results of the consensus process and finally approved by all steering group members.ResultsA different level of consensus has been reached among the topics selected. Strong agreement has been reported in considering harvesting, treatment and conservation methods relevant for clinical results, and in considering biological integration longer in allograft compared to autograft. Relative agreement has been reported in using allograft as the first-line graft for revision ACL-R, in considering biological integration a crucial aspect for rehabilitation protocol set-up, and in recommending a delayed return to sport when using allograft. Relative disagreement has been reported in using allograft as the first-line graft for primary ACL-R in patients over 50, and in not considering clinical results of allograft superior to autograft. Strong disagreement has been reported in using allograft as the first-line graft for primary ACL-R and for skeletally immature patients.ConclusionsResults of this consensus do not represent a guideline for surgeons, but could be used as starting point for an international discussion on use of allografts in ACL-R.Level of evidenceIV, consensus of experts.

Development of a Device-Assisted Nerve-Regeneration Procedure in Disruptive Lesions of the Brachial Plexus

Background We describe the development of a new surgical procedure to be used in the treatment of disruptive brachial plexus (BP) lesions. It is centered on an artificial device designed to assist nerve regeneration by providing a confined and protected environment. Nerve fibers can repair inside the device, while the adverse massive scar‐tissue formation is limited to the outside of the device. Methods Steps in the development of the procedure were (1) definition of the rationale, (2) design of the device, (3) choice of an in vivo translational model, (4)refinement of the surgical procedure, and (5) performance of an in vivo pilot study as a proof of concept. An interdisciplinary team from several laboratories was involved in this work over a period of 6 years. Results Results showed the absence of significant scar tissue in the regenerate and the presence of myelinated fibers aligned proximodistally between the stumps. This surgical approach can be seen not only as a definitive treatment but also as an early examination and stabilization before some different surgery will be later performed. It may also be used as additional protection for traditional surgery like end‐to‐end coaptation. Conclusions We conclude that the availability of a suitable device‐assisted early treatment, even if not to be considered definitive, could help in addressing the BP lesions at an earlier stage and this may improve the final outcome. Our evidence justifies further experimentation on this approach.

Surgical Treatment of Objective Patellar Instability: Long-Term Results

Purpose  To evaluate the long-term results of classical “à la carte” surgical treatment of objective patellar instability as proposed by Dejour in 1987. Methods  A multicentric retrospective study was conducted evaluating patients that underwent surgical procedure with a 10-year minimum follow-up (mean 12.7; range, 10–15). Surgical procedures were medial transfer of the tibial tubercle transfer according to Elmslie and Trillat et al in 38 cases, plasty of the vastus medialis obliquus according to Insall in 15 cases, open lateral retinacular release in 13 cases, capsuloplasty in 3 cases, and trochleoplasty in 1 case. Different combinations of surgical procedures were adopted according to the pathological features. Subjective outcome was assessed with the visual analog scale (VAS), Kujala score, subjective International Knee Documentation Committee (IKDC) score, Tegner score, and Crosby and Insall scale. Radiographic exams were used to assess the patellar tilt by the Laurins angle and patellofemoral osteoarthritis (OA) according to the Iwano radiological OA scale. Results  Forty patients were evaluated. Subjectively, 60% of patients achieved a result judged good, 34% sufficient, and 6% poor. There were only two cases of recurrence of instability. Mean score results were Kujala score 73.4 ± 9.9 (range, 55–95), VAS 4.5 ± 1.2 (range, 1–6), IKDC 64.8 ± 7.9 (range, 51–88), and Tegner score 4. Only nine patients returned to sports activities). Ten patients developed a grade I patellofemoral OA, 8 patients a grade II, and 22 patients a grade III. Average patellar tilt was 10° ±  3.9°. Conclusion  This retrospective study showed that the traditional surgical procedure was successful for the treatment of patellar instability, but it did not prevent symptomatic patellofemoral OA. Level of Evidence  Level IV, retrospective case series.

Tuberculosis of the Knee: A Case Report and Literature Review

Tuberculosis (TB) is currently in resurgence due to immigration from endemic areas. Skeletal TB frequently mimics more common etiologies and can be difficult to diagnose. A case of TB knee arthritis in a young woman with painful and swelling knee is reported here. Arthrotomy was performed and inflamed synovial tissue was found, with multiple rice bodies in the eroded lateral femoral condyle. The patient was treated with an antituberculosis polytherapy and at 1-year follow-up, she reported relief from pain and swelling. We believe that all surgeons assessing patients from TB endemic regions have to adopt an updated approach to TB treatment. Thus, a literature review is also reported here on the current strategies used in different knee TB cases.

Second Generation Needling Techniques for the Treatment of Chondral Defects in Animal Model

Purpose  To compare the macroscopic, histological, and immunohistochemical characteristics of the repair tissue of chondral defects treated with microfracture and nanofracture in an ovine model. Methods  Full-thickness chondral lesions were created in the medial femoral condyle of both knees in four adult sheep and were treated with microfracture on one side and with nanofracture on the contralateral side. Chondral repair was assessed after 12 months by macroscopic, histological, and immunohistochemical analyses. Results  Histological cartilage repair significantly improved in the samples treated with nanofracture for cellular morphological characteristics and cartilage architecture. The immunohistochemical analysis showed a significantly higher immunoreactivity to type II collagen in the defects treated with nanofracture. Conclusion  Nanofracture provided better repair tissue than microfracture, with a more satisfactory cartilage architecture renovation and tissue having greater type II collagen content. Clinical Relevance  Mesenchymal stem cell stimulation is the most frequently used primary cartilage repair procedure. Nanofracture represents a novel technique to stimulate bone marrow that results into a successful repair of chondral defects.