[Post-treatment rehabilitation after autologous chondrocyte implantation: State of the art and recommendations of the Clinical Tissue Regeneration Study Group of the German Society for Accident Surgery and the German Society for Orthopedics and Orthopedic Surgery]. / Nachbehandlung bei der autologen Chondrozytentransplantation: Eine Bestandsaufnahme und Empfehlung der AG Klinische Geweberegeneration der DGU/DGOOC.

BACKGROUND: Over the course of the past two decades autologous chondrocyte implantation (ACI) has become an important surgical technique for treating large cartilage defects. The original method using a periostal flap has been improved by using cell-seeded scaffolds for implantation, the matrix-based autologous chondrocyte implantation (mb-ACI) procedure. MATERIAL AND METHODS: Uniform nationwide guidelines for post-ACI rehabilitation do not exist. A survey was conducted among the members of the clinical tissue regeneration study group concerning the current rehabilitation protocols and the members of the study group published recommendations for postoperative rehabilitation and treatment after ACI based on the results of this survey. RESULTS: There was agreement on fundamentals concerning a location-specific rehabilitation protocol (femoral condyle vs. patellofemoral joint). With regard to weight bearing and range of motion a variety of different protocols exist. Similar to this total agreement on the role of magnetic resonance imaging (MRI) for postsurgical care was found but again a great variety of different protocols exist. CONCLUSIONS: This manuscript summarizes the recommendations of the members of the German clinical tissue regeneration study group on postsurgical rehabilitation and MRI assessment after ACI (level IVb/EBM).

Postoperative Management for Articular Cartilage Surgery in the Knee.

The postoperative rehabilitation team plays a crucial role in optimizing outcomes after articular cartilage surgery. A comprehensive approach to postoperative physical therapy that considers the type of surgery, location in the knee, concurrent procedures, and patient-specific factors is imperative. While postoperative rehabilitation protocols should be specific to the patient and type of surgery performed and include phased rehabilitation goals and activities, the key principles for postoperative rehabilitation apply across the spectrum of articular cartilage surgeries and patients. These key principles consist of preoperative assessments that include physical, mental, and behavioral components critical to recovery; education and counseling with respect to expectations and compliance; and careful monitoring and adjustments throughout the rehabilitation period based on consistent communication among rehabilitation, surgical, and imaging teams to ensure strict patient compliance with restrictions, activities, and timelines to optimize functional outcomes after surgery.

Symptom Trajectories of Adolescents During Hematopoietic Stem Cell Recovery.

BACKGROUND: Adolescents undergoing allogeneic hematopoietic stem cell transplantation (HSCT) experience multiple symptoms during and after the transplant. These symptoms can increase the need for medical care and reduce the quality of their life. However, little is known about symptom experiences specific to adolescents undergoing HSCT. OBJECTIVE: The primary aim was to describe symptom incidence, severity, and distress trajectories among adolescents from pre-HSCT through 90 days post-HSCT. A secondary aim was to examine the relationship between symptom trajectories and demographic and treatment factors. METHODS: A repeated-measures design was used for this prospective study. Demographic and treatment information was collected from the medical record. Symptoms were assessed with the Memorial Symptom Assessment Scale 10-18. Symptom trajectories were identified by latent class growth analysis with growth mixture modeling; logistic regression evaluated relationships of demographic and treatment characteristics on the latent classes of symptom trajectories. RESULTS: Two distinct latent class trajectories were identified for symptom incidence, severity, and distress. Symptom incidence declined, but symptom severity and distress remained stable. No significant relationships were noted among any demographic or treatment characteristics to any of the symptom trajectories. CONCLUSIONS: Symptoms persist and remain severe and distressing throughout the first 90 days after HSCT, with pain and lack of energy among the highest in incidence, severity, and distress. IMPLICATIONS FOR PRACTICE: Awareness of symptom trajectories empowers nurses to assess for symptoms throughout the HSCT process and conduct meaningful symptom discussions with their patients.

Physical exercise as adjuvant therapy for patients undergoing hematopoietic stem cell transplantation.

Even when the procedures are successful, patients experience considerable physical, psychological and psychosocial stress before, during and after hematopoietic stem cell transplantation (HSCT). Physical exercise therapy constitutes a potentially promising intervention to reduce such stress within the framework of HSCT because of its multidimensional effectiveness. Up to May 2007, fifteen published studies have examined physical exercise interventions in the context of HSCT, with no study reporting any unexpected or negative effects. The most common intervention involved isolated aerobic exercise programs and occurred during or after the transplantation process; strength training programs and combined intervention strategies are being examined more rarely. Significant benefits from the exercise interventions have been predominantly reported for physical performance, quality of life and fatigue status of the patients. Several other benefits like a faster recurrence of immune cells or reduced severity of therapy-related side effects can be estimated. Future research is needed for the purpose of evidence-based medicine/therapy to provide more rigorous examinations of these interventions, to address existing methodological problems and to identify further effect levels of physical exercise therapy in the context of HSCT.

Rehabilitation after cell transplantation for cartilage defects.

Rehabilitation is a key element of successful treatment of cartilage defects with cell transplantation. The process of graft maturation takes approximately 18 months and cannot be accelerated, but requires carefully introduced steps leading to early recovery of joint function. Rehabilitation starts at 8 hours after surgery with the continuous passive motion (CPM) exercises and physiotherapy. For the first 6 weeks, patients continue with CPM in the range of 0 degrees to 45 degrees for femoral and tibial defects and 0 degrees to 30 degrees for patellofemoral joint reconstruction. Isometric muscle training and scar manual therapy are introduced. Patients are allowed to weight-bear as tolerated from the second week after surgery. After this initial phase, from 6 to 8 weeks after surgery, rehabilitation is accelerated with increased load-bearing and progressive range of motion to full flexion. Usually patients are able to walk without crutches in this time. Proprioceptive training is introduced with the advance of pain-free full range of motion and no discomfort with full weight-bearing. At 6 months after surgery, most patients recover joint function, making it possible for them to return to daily living activities. However, they need to continue with muscle, proprioceptive, and sports-specific rehabilitation exercises. The rehabilitation process is complicated, requiring close cooperation between the patient and surgeon-physiotherapist team to understand the symptoms and address them in a timely fashion.

Healing of chondral and osteochondral defects in a canine model: the role of cultured chondrocytes in regeneration of articular cartilage.

In this study a canine model was developed to investigate the nature of early healing responses to both chondral and osteochondral defects and to evaluate the tissue regenerative capacity of cultured autologous chondrocytes in chondral defects. The healing response to surgically created chondral defects was minor, with little cellular infiltration. In contrast, osteochondral defects exhibited a rapid cellular response, resulting ultimately in the formation of fibrous tissue. The lack of significant cellular activity in chondral defects suggests that an evaluation of the capacity of cultured autologous chondrocytes to regenerate articular cartilage is best studied in chondral defects using the canine model. When dedifferentiated cultured articular chondrocytes were implanted into chondral defects, islands of type II collagen staining were demonstrated in the regenerative tissue within 6 weeks. The relatively early expression of cartilage specific markers by the implanted chondrocytes, coupled with the inability of untreated chondral defects to repair or regenerate, demonstrates the utility of the canine model in evaluating novel materials for cartilage repair and regeneration.

Clinical rehabilitation guidelines for matrix-induced autologous chondrocyte implantation on the tibiofemoral joint.

SYNOPSIS: Autologous chondrocyte implantation (ACI) has become an established technique for the repair of full-thickness chondral defects in the knee. Matrix-induced ACI (MACI) is the third and current generation of this surgical technique, and, while postoperative rehabilitation following MACI aims to restore normal function in each patient as quickly as possible by facilitating a healing response without overloading the repair site, current published guidelines appear conservative, varied, potentially outdated, and often based on earlier ACI surgical techniques. This article reviews the existing evidence-based literature pertaining to cell loading and postoperative rehabilitation following generations of ACI. Based on this information, in combination with the technical benefits provided by third-generation MACI in comparison to its surgical predecessors, we present a rehabilitation protocol for patients undergoing MACI in the tibiofemoral joint that has now been implemented for several years by our institution in patients with MACI, with good clinical outcomes.

Autologous chondrocyte implantation: an overview of technique and outcomes.

Articular cartilage is susceptible to damage; however, it has limited capacity for repair. Damage can lead to persistent symptoms including pain, swelling, and loss of function and may ultimately progress to symptomatic degeneration of the joint. To restore function and minimize symptoms, many advocate surgical intervention in selected candidates, which can range from arthroscopic debridement to restorative procedures depending on patient and lesion characteristics. Autologous Chondrocyte Implantation (ACI) is a two-stage, typically second-line intervention where cultured autologous chondrocytes are used with the aim of resurfacing symptomatic chondral defects with hyaline or hyaline-like cartilage. Careful patient selection is important. We present an overview of this procedure including indications and contraindications, surgical technique, and post-operative management. A review of published ACI outcomes is then presented.

Rehabilitation after autologous chondrocyte implantation in athletes.

Over the years a variety of cartilage restorative procedures have been developed for athletes to address focal, full-thickness cartilaginous defects in the knee joint, including microfracture, osteochondral autografts, osteochondral allografts, autologous chondrocyte implantation (ACI), and most recently, next-generation ACI involving scaffolds or cell-seeded scaffolds. Since its introduction, ACI has yielded some very promising results in athletes and nonathletes alike. Rehabilitation following ACI requires an in-depth understanding of joint mechanics, and knowledge of the biologic and biomechanical properties of healing articular cartilage. A patient-, lesion-, and sports-specific approach is required on the part of the trainer or physical therapist to gradually restore knee joint function and strength so that the athlete may be able to return to competitive play. This article reviews the rehabilitation protocols for injured athletes following an ACI procedure.

High-resolution 1.5-Tesla magnetic resonance imaging for tissue-engineered constructs: a noninvasive tool to assess three-dimensional scaffold architecture and cell seeding.

Tissue-engineered scaffolds are made of biocompatible polymers with various structures, allowing cell seeding, growth, and differentiation. Noninvasive imaging methods are needed to study tissue-engineered constructs before and after implantation. Here, we show that high-resolution magnetic resonance imaging (MRI) performed on a clinical 1.5-T device is a reliable technique to assess three-dimensional structures of porous scaffolds and to validate cell-seeding procedures. A high-temperature superconducting detection coil was used to achieve a resolution of 30 x 30 x 30 microm(3) when imaging the scaffolds. Three types of structures with tuneable architectures were prepared from naturally derived polysaccharides and evaluated as scaffolds for mesenchymal stem cell (MSC) culture. To monitor cell seeding, MSCs were magnetically labeled using simple incubation with anionic citrate-coated iron-oxide nanoparticles for 30 min. Iron uptake was quantified using single-cell magnetophoresis, and cell proliferation was checked for 7 days after labeling. Three-dimensional (3D) microstructures of scaffolds were assessed using MRI, revealing lamellar or globular porous organization according to the scaffold preparation process. MSCs with different iron load (5, 12 and 31 pg of iron per cell) were seeded on scaffolds at low density (132 cells/mm(3)) and detected on 3D gradient-echo MR images according to phase distortions and areas of intensely low signal, whose size increased with cell iron load and echo time. Overall signal loss in the scaffold correlated with the number of seeded cells and their iron load. Different organizations of cells were observed depending on the scaffold architecture. After subcutaneous implantation in mice, scaffolds seeded with labeled cells could be distinguished in vivo from scaffold with nonlabeled cells by observation of signal and phase heterogeneities and by measuring the global signal loss. High-resolution 1.5-T MRI combined with efficient intracellular contrast agents shows promise for noninvasive 3D visualization of tissue-engineered constructs before and after in vivo implantation.

Mechanisms of granulocytosis in the absence of CD18.

Genetic deficiency in CD18 leads to disease characterized by myeloid hyperplasia, including profound granulocytosis and splenomegaly. Myeloid hyperplasia could directly result from the disruption of CD18 functions essential to granulopoiesis or basal leukocyte trafficking. Alternatively, myeloid hyperplasia could be reactive in nature, due to disruption of essential roles of CD18 in leukocyte responses to microbial challenge. To distinguish between these mechanisms, the hematopoietic systems of lethally irradiated wild-type (WT) mice were reconstituted with either WT fetal liver cells or CD18-deficient fetal liver cells, or an equal mixture of both types of cells. Granulocytosis and splenomegaly developed in mice that received CD18-deficient fetal liver cells. Splenomegaly was prevented and granulocytosis was inhibited by more than 95% in mice that had received both CD18-deficient and WT fetal liver cells, suggesting that myeloid hyperplasia was largely reactive in nature. Consistent with this postulate, the circulating life spans in the blood and the fraction of neutrophils that incorporated BrdU in the bone marrow were not increased for CD18-deficient neutrophils compared with the WT. However, these animals did develop mild granulocytosis compared with mice reconstituted with WT cells alone, and a higher percentage of CD18-deficient leukocytes were neutrophils compared with the WT leukocytes. These observations suggest that the granulocytosis observed in the absence of CD18 occurs through at least 2 mechanisms: one that is dramatically improved by the presence of WT cells, likely reactive in nature, and a second that is independent of the WT hematopoietic cells, involving an alteration in the lineage distribution of blood leukocytes.