Stem cells in degenerative orthopaedic pathologies: effects of aging on therapeutic potential.

PURPOSE: The purpose of this study was to summarize the current evidence on the use of stem cells in the elderly population with degenerative orthopaedic pathologies and to highlight the pathophysiologic mechanisms behind today's therapeutic challenges in stem cell-based regeneration of destructed tissues in the elderly patients with osteoarthritis (OA), degenerative disc disease (DDD), and tendinopathies. METHODS: Clinical and basic science studies that report the use of stem cells in the elderly patients with OA, DDD, and tendinopathies were identified using a PubMed search. The studies published in English have been assessed, and the best and most recent evidence was included in the current study. RESULTS: Evidence suggests that, although short-term results regarding the effects of stem cell therapy in degenerative orthopaedic pathologies can be promising, stem cell therapies do not appear to reverse age-related tissue degeneration. Causes of suboptimal outcomes can be attributed to the decrease in the therapeutic potential of aged stem cell populations and the regenerative capacity of these cells, which might be negatively influenced in an aged microenvironment within the degenerated tissues of elderly patients with OA, DDD, and tendinopathies. CONCLUSIONS: Clinical protocols guiding the use of stem cells in the elderly patient population are still under development, and high-level randomized controlled trials with long-term outcomes are lacking. Understanding the consequences of age-related changes in stem cell function and responsiveness of the in vivo microenvironment to stem cells is critical when designing cell-based therapies for elderly patients with degenerative orthopaedic pathologies.

Multilayer scaffolds in orthopaedic tissue engineering.

PURPOSE: The purpose of this study was to summarize the recent developments in the field of tissue engineering as they relate to multilayer scaffold designs in musculoskeletal regeneration. METHODS: Clinical and basic research studies that highlight the current knowledge and potential future applications of the multilayer scaffolds in orthopaedic tissue engineering were evaluated and the best evidence collected. Studies were divided into three main categories based on tissue types and interfaces for which multilayer scaffolds were used to regenerate: bone, osteochondral junction and tendon-to-bone interfaces. RESULTS: In vitro and in vivo studies indicate that the use of stratified scaffolds composed of multiple layers with distinct compositions for regeneration of distinct tissue types within the same scaffold and anatomic location is feasible. This emerging tissue engineering approach has potential applications in regeneration of bone defects, osteochondral lesions and tendon-to-bone interfaces with successful basic research findings that encourage clinical applications. CONCLUSIONS: Present data supporting the advantages of the use of multilayer scaffolds as an emerging strategy in musculoskeletal tissue engineering are promising, however, still limited. Positive impacts of the use of next generation scaffolds in orthopaedic tissue engineering can be expected in terms of decreasing the invasiveness of current grafting techniques used for reconstruction of bone and osteochondral defects, and tendon-to-bone interfaces in near future.

Diagnosis and Management of Periprosthetic Joint Infections After Total Ankle Arthroplasty.

Periprosthetic joint infection (PJI) after total ankle arthroplasty (TAA) is a dreaded complication that may lead to catastrophic outcomes. Risk factors include a history of surgery on the operated ankle, low preoperative function scores, diabetes, extended surgical time, and postoperative wound-healing problems. Clinical presentation varies and may include increasing ankle pain and swelling, high temperature, local erythema, wound drainage, and dehiscence. The initial diagnostic evaluation should include plain radiographs, erythrocyte sedimentation rate, C-reactive protein levels, and leukocyte count. In suspected cases with elevated erythrocyte sedimentation rate and C-reactive protein, aspiration of the ankle joint for synovial fluid analysis, Gram staining, and culture should be performed. Antibiotic therapy should be based on the pathogen identified, and the surgical strategy should be determined based on the time lines of PJI. Early PJI can be treated with irrigation and débridement with polyethylene exchange. The surgical treatment of choice for late PJI is two-stage revision arthroplasty, which includes removal of the implant, insertion of an antibiotic spacer, and reimplantation of a TAA. In certain chronic PJI cases, permanent articulating antibiotic spacers can be left in place or an ankle arthrodesis can be performed. Below-knee amputation is considered as the final option after limb-sparing procedures have failed.

Development of the femoral trochlear groove in rabbits with patellar malposition.

PURPOSE: The geometry of the trochlear groove is considered to be an important determinant in the pathogenesis of the patellofemoral joint disorders. However, the effect of patellar position during the development of the femoral trochlear groove is unclear. This animal study aimed to investigate the relationship between the position of the patella and development of the femoral trochlear groove in growing rabbits. METHODS: Thirty-two knees from 16 rabbits were included in this study and were divided into two groups. First group consisted of the left knees and was used as a control group with no surgical interventions. The second group involved the right knees on which patellar tendon Z-plasty lengthening was performed to cause patellar malposition (patella alta) before 1 month of age. Computed tomographic (CT) evaluations of both knees were obtained when the animals were 1 month age before the surgical intervention and also at 6 months after the surgical intervention. Angle and depth measurements were acquired from the proximal, middle, and distal reference points along the femoral trochlear groove. After the CT scan acquisition at 6 months following the surgical procedures, rabbits were killed and additional measurements of the trochlear groove angles were performed manually. RESULTS: The mean middle and distal trochlear groove angles for the experiment group with patella alta were significantly higher compared to that of control group (p < 0.017). The increase in mean trochlear depth for the animals in the control group was found to be significantly higher compared to experiment group at the distal zone (p < 0.017). CONCLUSION: Distal femoral groove with an inadequately positioned patella becomes more flattened and this may be a predisposing factor for patellar instability. LEVEL OF EVIDENCE: Controlled laboratory study, Level II.

Arthroscopy-assisted reduction versus open reduction in the fixation of medial malleolar fractures.

PURPOSE: Purpose of this case-control study was to evaluate the feasibility and advantages of arthroscopically assisted reduction and internal fixation of isolated medial malleolar fractures and compare the outcomes with conventional open reduction and internal fixation. METHODS: Forty-seven patients with medial malleolar fractures were grouped into two: arthroscopy-assisted group, and conventional open reduction and internal fixation group. Arthroscopic treatment group consisted of 21 patients. The mean age was 34 years (range: 22-49 years). Conventional open reduction and internal fixation group included 26 patients. The mean age was 42 years (range: 22-58 years). According to Herscovici system, 6 fractures in the arthroscopy group were classified as type-B, 13 fractures as type-C, and 2 fractures were classified as type-D. In both groups, fractures were classified according to Herscovici system. Radiological and clinical outcomes were evaluated according to van Dijk classification and Olerud-Molander scoring system, respectively. RESULTS: The mean follow-up period was 26 months (18-52 months) for arthroscopically assisted group and 38 months (24-58 months) for the conventional group. According to van Dijk classification, there was only one patient with Grade 1 osteoarthritic changes in arthroscopically assisted group compared with the conventional group where two patients had Grade 2 and one patient had Grade 1 osteoarthritic changes. Median Olerud Scores were 92.3 (75-100) and 86.3 (70-100) for the arthroscopically assisted group and for the conventional group, respectively. The difference was statistically significant (p = 0.015). CONCLUSIONS: With the use of arthroscopically assisted techniques in fixation of isolated medial malleolar fractures, surgeon can evaluate intra-articular surface and reduction that may be of value in the improvement in clinical outcomes over conventional surgical treatment. LEVEL OF EVIDENCE: Case-control study, Level III.

Surgical simulation in orthopaedic skills training.

Mastering rapidly evolving orthopaedic surgical techniques requires a lengthy period of training. Current work-hour restrictions and cost pressures force trainees to face the challenge of acquiring more complex surgical skills in a shorter amount of time. As a result, alternative methods to improve the surgical skills of orthopaedic trainees outside the operating room have been developed. These methods include hands-on training in a laboratory setting using synthetic bones or cadaver models as well as software tools and computerized simulators that enable trainees to plan and simulate orthopaedic operations in a three-dimensional virtual environment. Laboratory-based training offers potential benefits in the development of basic surgical skills, such as using surgical tools and implants appropriately, achieving competency in procedures that have a steep learning curve, and assessing already acquired skills while minimizing concerns for patient safety, operating room time, and financial constraints. Current evidence supporting the educational advantages of surgical simulation in orthopaedic skills training is limited. Despite this, positive effects on the overall education of orthopaedic residents, and on maintaining the proficiency of practicing orthopaedic surgeons, are anticipated.

Development of femoral trochlear groove in growing rabbit after patellar instability.

PURPOSE: The geometry of an articular surface is an important determinant of joint function. Although the geometry of the trochlear groove is considered to be important in the pathogenesis of patellofemoral joint disorders, the effects of the patella during the development of the femoral trochlear groove are unclear. This animal study aimed to investigate the relationship between the position of the patella and development of femoral trochlear groove in growing rabbits. METHODS: Twenty-four knees of 12 rabbits were included in this study and were divided into two groups. First group consisted of the left knees and was used as the control group to which no surgical procedures were applied. Second group involved the right knees to which medial soft tissue restraints release was applied before 1 month of age. Computed tomographic (CT) evaluation of both knees of each rabbit was made in their first month of age before medial retinacular release and also during post-op 1-year follow-up. CT measurements included both the angle and depth of the femoral trochlear groove from 3 different parts (proximal, middle and distal) of the distal femur, and then these measurements were averaged. RESULTS: Measurements revealed that while in the control group the groove angle decreased 27.4 degrees and the depth increased 0.11 mm, in the operated counterparts groove angle decreased 16.8 degrees and groove depth increased 0.03 mm, which indicated the flattening of the femoral groove in the operated group. These differences were found to be statistically significant (P < 0.05). CONCLUSION: The results indicated that distal femoral groove with inadequate patellar position becomes more flattened and causes predisposition for patellar instability. Consequently, the clinical relevance of this study was that early reconstruction of the patellofemoral joint should be performed in the childhood to prevent the patellofemoral problems that are likely to be encountered in the following years.

An emerging cell-based strategy in orthopaedics: endothelial progenitor cells.

PURPOSE: The purpose of this article was to analyze the results of studies in the literature, which evaluated the use of endothelial progenitor cells (EPCs) as a cell-based tissue engineering strategy. METHODS: EPCs have been successfully used in regenerative medicine to augment neovascularization in patients after myocardial infarction and limb ischemia. EPCs' important role as vasculogenic progenitors presents them as a potential source for cell-based therapies to promote bone healing. RESULTS: EPCs have been shown to have prominent effects in promoting bone regeneration in several animal models. Evidence indicates that EPCs promote bone regeneration by stimulating both angiogenesis and osteogenesis through a differentiation process toward endothelial cell lineage and formation of osteoblasts. Moreover, EPCs increase vascularization and osteogenesis by increased secretion of growth factors and cytokines through paracrine mechanisms. CONCLUSION: EPCs offer the potential to emerge as a new strategy among other cell-based therapies to promote bone regeneration. Further investigations and human trials are required to address current questions with regard to biology and mechanisms of action of EPCs in bone tissue engineering.

The Course of Tarsal Tunnel Syndrome after Ultrasound-Guided Injections.

BACKGROUND: Local ultrasound (US)-guided injections of anesthetics with corticosteroids are commonly performed for the conservative treatment of tarsal tunnel syndrome (TTS). OBJECTIVE: This retrospective study aimed to investigate the outcomes of TTS after US-guided injections. METHODS: The study included patients who were diagnosed with TTS and received US-guided injections as part of their initial treatment. The pain levels were noted on a scale between zero and ten before and after each injection. The patients were divided into non-surgical and surgical groups. The nonsurgical group included patients who had received US-guided injections and did not proceed to surgical treatment, and the surgical group included those who received US-guided injections and ultimately underwent tarsal tunnel release (TTR). The two groups were compared in terms of age, post-injection follow-up time, and the amount of pain reduction immediately after injection (ΔPN). In the surgical group, outcomes of surgical treatment were also assessed. RESULTS: A total of 218 patients were diagnosed with TTS and received US-guided injections. After the injections, 169 patients (77.5%) did not go on to TTR (nonsurgical group) and 49 patients (22.5%) underwent TTR (surgical group). The average ages for the nonsurgical and surgical groups were 53.8 and 48.9 years (P = 0.03). The average time between the injection and final follow-up for the nonsurgical group was 339 days. The average time between the injection and TTR for the surgical group was 145 days. There were no differences in pain relief after the injections between the nonsurgical and surgical groups (mean ΔPN: 3.6 and 3.8, respectively). The average post-surgical follow-up time was 117 days. At final follow-up, 41 patients (84%) in the surgical group had complete resolution of pain and neurological symptoms. CONCLUSION: US-guided injection can be an effective conservative treatment option for patients with TTS. Younger patients may be more likely to proceed to TTR. Level of Evidence: Level III.

Galeazzi fracture.

Galeazzi fracture is a fracture of the radial diaphysis with disruption at the distal radioulnar joint (DRUJ). Typically, the mechanism of injury is forceful axial loading and torsion of the forearm. Diagnosis is established on radiographic evaluation. Underdiagnosis is common because disruption of the ligamentous restraints of the DRUJ may be overlooked. Nonsurgical management with anatomic reduction and immobilization in a long-arm cast has been successful in children. In adults, nonsurgical treatment typically fails because of deforming forces acting on the distal radius and DRUJ. Open reduction and internal fixation is the preferred surgical option. Anatomic reduction and rigid fixation should be followed by intraoperative assessment of the DRUJ. Further intraoperative interventions are based on the reducibility and postreduction stability of the DRUJ. Misdiagnosis or inadequate management of Galeazzi fracture may result in disabling complications, such as DRUJ instability, malunion, limited forearm range of motion, chronic wrist pain, and osteoarthritis.

Osteoid osteoma and osteoblastoma.

Osteoid osteoma and osteoblastoma are commonly seen benign osteogenic bone neoplasms. Both tumors are typically seen in the second decade of life, with a notable predilection in males. Histologically, these tumors resemble each other, with characteristically increased osteoid tissue formation surrounded by vascular fibrous stroma and perilesional sclerosis. However, osteoblastomas are larger than osteoid osteomas, and they exhibit greater osteoid production and vascularity. Clinically, osteoid osteoma most commonly occurs in the long bones (eg, femur, tibia). The lesions cause night pain that is relieved with nonsteroidal anti-inflammatory drugs (NSAIDs). Osteoblastoma is most frequently located in the axial skeleton, and the pain is usually not worse at night and is less likely to be relieved with NSAIDs. Osteoblastoma can be locally aggressive; osteoid osteoma lacks growth potential. Osteoid osteoma may be managed nonsurgically with NSAIDs. When surgery is required, minimally invasive methods (eg, CT-guided excision, radiofrequency ablation) are preferred. Osteoblastoma has a higher rate of recurrence than does osteoid osteoma, and patients must be treated surgically with intralesional curettage or en bloc resection.

The effects of the synovium on chondrocyte growth: an experimental study.

PURPOSE: The objective of this study was to evaluate the effects of synovium on the proliferation of the cartilage tissue and chondrocytes using a rabbit knee model as an in vivo synovial culture medium. METHODS: Twelve New Zealand rabbits were used as the animal model in this investigation. Standard size chondral and osteochondral cartilage grafts were taken from, respectively, the left and right knees of all the animals. Two groups of 6 animals were formed: in Group I (synovium group), grafts were placed into the synovial tissue and in group II (patellar tendon group) behind the patellar tendon of the corresponding knees. After 4 months, samples were collected and evaluated macroscopically by measuring their dimensions (vertical = D1, horizontal = D2, and depth = D3) and volumes, and histologically by counting the chondrocyte number using camera lucida method. RESULTS: Macroscopically, the increase in average D1, D2, and D3 measurements and volume in the osteochondral specimens were significantly higher compared to the chondral specimens in both groups (P < 0.05). However, no significant difference was observed between the two groups in terms of macroscopic values. Histologically, the mean chondrocyte counts in osteochondral and chondral specimens for Group I (synovium) were 20.2 and 18.1, and for Group II (patellar tendon) were 18.7 and 15.6, respectively. The mean number of chondrocytes was found to be significantly higher in osteochondral specimens than that of chondral specimens in either group (P < 0.05). Overall average chondrocyte count was significantly higher for Group I compared to Group II (P < 0.05). CONCLUSION: Transplantation of the cartilage grafts into the synovial tissue in rabbit knees significantly enhanced the chondrocyte production compared with the group where the grafts were transplanted into intra-articular patellar tendon. The results of this study indicate that native synovial tissue may have the potential to be used as an in vivo culture medium for osteochondral tissue growth.

Arthroscopy-assisted fracture fixation.

PURPOSE: the purpose of this article was to systematically analyze the results of published studies in the literature which evaluated the use of arthroscopically assisted techniques in intra-articular fracture fixation. METHODS: published investigations to date were analyzed by classifying them according to joints that were involved with intra-articular fractures including: knee, ankle, hip, shoulder, elbow, and wrist joints. The results were studied to assess the feasibility, efficiency, and outcomes of arthroscopy-assisted fracture fixation. RESULTS: arthroscopy-assisted techniques have been used successfully for the treatment of fractures of the tibial plateau, tibial eminence, malleoli, pilon, calcaneus, femoral head, glenoid, greater tuberosity, distal clavicle, radial head, coronoid, distal radius, and scaphoid. The major advantages of arthroscopic fracture fixation over open methods are direct visualization of the intra-articular space, decreased invasiveness, and the possibility for multitask interventions through which fixation of the fracture, and repair of the soft tissues and the cartilage can be performed simultaneously. The time-consuming and technically demanding nature of the procedures with a prolonged learning curve and limited fixation alternatives are the main disadvantages of this technique. CONCLUSION: arthroscopic fixation is increasingly utilized for certain intra-articular fracture types due to the minimally invasive nature of the procedures and high accuracy. Randomized controlled trials are needed to justify wider use of arthroscopy-assisted techniques for treatment of intra-articular fractures.

Computer-assisted trauma surgery.

Computer-assisted orthopaedic surgery (CAOS) is performed by digitizing the patient's anatomy, combining the images in a computerized system, and integrating the surgical instruments into the digitized image background. This allows the surgeon to navigate the surgical instruments and the bone in an improved, virtual visual environment. CAOS in traumatology is performed with images obtained by fluoroscopy, CT, or three-dimensional fluoroscopy. CAOS is used in basic trauma procedures for preoperative planning, fracture reduction, intramedullary nailing, percutaneous screw or plate fixation, and hardware or shrapnel removal. Potential benefits of CAOS include minimal invasiveness, increased accuracy, and decreased radiation exposure. Limitations include a significant learning curve, increased surgical time, requirements for special setup and equipment handling in the operating room, specialized technical support, and cost. Current evidence shows no advantage with CAOS in trauma cases compared with conventional methods. Prospective randomized trials and clinical outcomes are lacking.

Prognostic Factors for Adjacent Segment Disease After L4-L5 Lumbar Fusion.

BACKGROUND: Adjacent segment disease (ASD) is an important consideration during decision making for lumbar spinal fusion. OBJECTIVE: To identify risk factors for development of ASD after L4-L5 fusion and differences in incidence between rostral and caudal ASD. METHODS: We retrospectively reviewed all consecutive patients at a single institution who underwent first-time spinal fusion at the L4-L5 level for degenerative spinal disease over a 10-yr period, using posterolateral pedicular screw fixation with or without posterior interbody fusion. ASD was defined as clinical and radiographic evidence of degenerative spinal disease requiring reoperation at the level rostral (L3-L4) or caudal (L5-S1) to the index fusion. RESULTS: Among 131 identified patients, the incidence of ASD requiring reoperation was 25.2% (n = 33). Twenty-four cases (18.3% of the entire cohort) developed rostral ASD (segment L3-L4), 3 cases (2.3%) developed caudal (L5-S1), and 6 cases (4.6%) developed bilateral ASD (both rostral and caudal). Cumulatively, the incidence of caudal ASD was significantly lower than rostral ASD (P < .001). Following multivariate logistic regression for factors associated with ASD reoperation, decompression of segments outside the fusion construct was associated with higher ASD rates (odds ratio [OR] = 2.68, P = .039), as was female gender (OR = 3.55, P = .011), whereas older age was associated with lower ASD incidence (OR = 0.95, P = .011). CONCLUSION: When considering posterior L4-L5 fusion, surgeons should refrain from prophylactic procedures in the L5-S1 level, without clinical indications, because ASD incidence on that segment is reassuringly low.

Fate of Hardware in Spinal Infections.

Background: Removal of hardware with irrigation and debridement in patients with surgical site infections (SSIs) is performed commonly. However, the removal of hardware from patients with SSIs after spinal procedures is controversial. Moreover, primary spinal infections such as spondylodiscitis may require instrumentation along with surgical debridement. The purpose of this article was to evaluate critically and summarize the available evidence related to retention of hardware in patients with deep SSIs, and the use of instrumentation in surgical treatment of primary spinal infections. Methods: A literature search utilizing PubMed database was performed. Studies reporting the management of deep SSIs after instrumented spinal procedures, and of primary spinal infections using instrumentation published in peer-reviewed journals were included. Identified publications were evaluated for relevance, and data were extracted from the studies deemed relevant. Results: Because SSIs occur typically during the early post-operative period before stable bony fusion has been achieved, the removal of instrumentation may be associated with instability of the spinal column, pseudarthrosis, progressive deformity, pain, loss of function, and deterioration in the activities of daily living (ADL). Hence, early SSIs after spinal instrumentation are usually treated without removal of hardware. Moreover, primary spinal infections such as spondylodiscitis may require surgical debridement and instrumentation in cases with associated instability. Conclusions: Retaining or using instrumentation in patients with SSIs after spinal procedures or in patients with primary spinal infections, respectively, are commonly practiced in the field of spine surgery. Further evidence is required for the development of definitive algorithms to guide spine surgeons in decision making regarding the fate of instrumentation in the treatment of spinal infections.

Current Strategies in Prevention of Postoperative Infections in Spine Surgery.

STUDY DESIGN: Narrative review. OBJECTIVES: Postoperative surgical site infections (SSIs) are among the most common acute complications in spine surgery and have a devastating impact on outcomes. They can lead to increased morbidity and mortality as well as greater economic burden. Hence, preventive strategies to reduce the rate of SSIs after spine surgery have become vitally important. The purpose of this article was to summarize and critically analyze the available evidence related to current strategies in the prevention of SSIs after spine surgery. METHODS: A literature search utilizing Medline database was performed. Relevant studies from all the evidence levels have been included. Recommendations to decrease the risk of SSIs have been provided based on the results from studies with the highest level of evidence. RESULTS: SSI prevention occurs at each phase of care including the preoperative, intraoperative, and postoperative periods. Meticulous patient selection, tight glycemic control in diabetics, smoking cessation, and screening/eradication of Staphylococcus aureus are some of the main preoperative patient-related preventive strategies. Currently used intraoperative measures include alcohol-based skin preparation, topical vancomycin powder, and betadine irrigation of the surgical site before closure. Postoperative infection prophylaxis can be performed by administration of silver-impregnated or vacuum dressings, extended intravenous antibiotics, and supplemental oxygen therapy. CONCLUSIONS: Although preventive strategies are already in use alone or in combination, further high-level research is required to prove their efficacy in reducing the rate of SSIs in spine surgery before evidence-based standard infection prophylaxis guidelines can be built.

Bisphosphonates and parathyroid hormone analogs for improving bone quality in spinal fusion: State of evidence.

Spinal fusion is among the most commonly performed surgical procedures for elderly patients with spinal disorders - including degenerative disc disease with spondylolisthesis, deformities, and trauma. With the large increase in the aging population and the prevalence of osteoporosis, the number of elderly osteoporotic patients needing spinal fusion has risen dramatically. Due to reduced bone quality, postoperative complications such as implant failures, fractures, post-junctional kyphosis, and pseudarthrosis are more commonly seen after spinal fusion in osteoporotic patients. Therefore, pharmacologic treatment strategies to improve bone quality are commonly pursued in osteoporotic cases before conducting spinal fusions. The two most commonly used pharmacotherapeutics are bisphosphonates and parathyroid hormone (PTH) analogs. Evidence indicates that using bisphosphonates and PTH analogs, alone or in combination, in osteoporotic patients undergoing spinal fusion, decreases complication rates and improves clinical outcomes. Further studies are needed to develop guidelines for the administration of bisphosphonates and PTH analogs in osteoporotic spinal fusion patients in terms of treatment duration, potential benefits of sequential use, and the selection of either therapeutic agents based on patient characteristics.

Advancing Simulation-Based Orthopaedic Surgical Skills Training: An Analysis of the Challenges to Implementation.

Simulation-based surgical skills training is recognized as a valuable method to improve trainees' performance and broadly perceived as essential for the establishment of a comprehensive curriculum in surgical education. However, there needs to be improvement in several areas for meaningful integration of simulation into surgical education. The purpose of this focused review is to summarize the obstacles to a comprehensive integration of simulation-based surgical skills training into surgical education and board certification and suggest potential solutions for those obstacles. First and foremost, validated simulators need to be rigorously assessed to ensure their feasibility and cost-effectiveness. All simulation-based courses should include clear objectives and outcome measures (with metrics) for the skills to be practiced by trainees. Furthermore, these courses should address a wide range of issues, including assessment of trainees' problem-solving and decision-making abilities and remediation of poor performance. Finally, which simulation-based surgical skills courses will become a standard part of the curriculum across training programs and which will be of value in board certification should be precisely defined. Sufficient progress in these areas will prevent excessive development of training and assessment tools with duplicative effort and large variability in quality.