Functional and Radiologic Outcomes of Degenerative Versus Traumatic Full-Thickness Rotator Cuff Tears Involving the Supraspinatus Tendon.

BACKGROUND: Arthroscopic rotator cuff repair (ARCR) is among the most commonly performed orthopaedic procedures. Several factors-including age, sex, and tear severity-have been identified as predictors for outcome after repair. The influence of the tear etiology on functional and structural outcome remains controversial. PURPOSE: To investigate the influence of tear etiology (degenerative vs traumatic) on functional and structural outcomes in patients with supraspinatus tendon tears. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: Patients undergoing ARCR from 19 centers were prospectively enrolled between June 2020 and November 2021. Full-thickness, nonmassive tears involving the supraspinatus tendon were included. Tears were classified as degenerative (chronic shoulder pain, no history of trauma) or traumatic (acute, traumatic onset, no previous shoulder pain). Range of motion, strength, the Subjective Shoulder Value, the Oxford Shoulder Score (OSS), and the Constant-Murley Score (CMS) were assessed before (baseline) and 6 and 12 months after ARCR. The Subjective Shoulder Value and the OSS were also determined at the 24-month follow-up. Repair integrity after 12 months was documented, as well as additional surgeries up to the 24-month follow-up. Tear groups were compared using mixed models adjusted for potential confounding effects. RESULTS: From a cohort of 973 consecutive patients, 421 patients (degenerative tear, n = 230; traumatic tear, n = 191) met the inclusion criteria. The traumatic tear group had lower mean baseline OSS and CMS scores but significantly greater score changes 12 months after ARCR (OSS, 18 [SD, 8]; CMS, 34 [SD,18] vs degenerative: OSS, 15 [SD, 8]; CMS, 22 [SD, 15]) (P < .001) and significantly higher 12-month overall scores (OSS, 44 [SD, 5]; CMS, 79 [SD, 9] vs degenerative: OSS, 42 [SD, 7]; CMS, 76 [SD, 12]) (P≤ .006). At the 24-month follow-up, neither the OSS (degenerative, 44 [SD, 6]; traumatic, 45 [SD, 6]; P = .346) nor the rates of repair failure (degenerative, 14 [6.1%]; traumatic 12 [6.3%]; P = .934) and additional surgeries (7 [3%]; 7 [3.7%]; P = .723) differed between groups. CONCLUSION: Patients with degenerative and traumatic full-thickness supraspinatus tendon tears who had ARCR show satisfactory short-term functional results. Although patients with traumatic tears have lower baseline functional scores, they rehabilitate over time and show comparable clinical results 1 year after ARCR. Similarly, degenerative and traumatic rotator cuff tears show comparable structural outcomes, which suggests that degenerated tendons retain healing potential.

A case for ongoing structural support to maximise infectious disease modelling efficiency for future public health emergencies: A modelling perspective.

This short communication reflects upon the challenges and recommendations of multiple COVID-19 modelling and data analytic groups that provided quantitative evidence to support health policy discussions in Switzerland and Germany during the SARS-CoV-2 pandemic. Capacity strengthening outside infectious disease emergencies will be required to enable an environment for a timely, efficient, and data-driven response to support decisions during any future infectious disease emergency. This will require 1) a critical mass of trained experts who continuously advance state-of-the-art methodological tools, 2) the establishment of structural liaisons amongst scientists and decision-makers, and 3) the foundation and management of data-sharing frameworks.

Explicit modeling of antibody levels for infectious disease simulations in the context of SARS-CoV-2.

Measurable levels of immunoglobulin G antibodies develop after infections with and vaccinations against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). These antibody levels are dynamic: due to waning, antibody levels will drop over time. During the COVID-19 pandemic, multiple models predicting infection dynamics were used by policymakers to support the planning of public health policies. Explicitly integrating antibody and waning effects into the models is crucial for reliable calculations of individual infection risk. However, only few approaches have been suggested that explicitly treat these effects. This paper presents a methodology that explicitly models antibody levels and the resulting protection against infection for individuals within an agent-based model. The model was developed in response to the complexity of different immunization sequences and types and is based on neutralization titer studies. This approach allows complex population studies with explicit antibody and waning effects. We demonstrate the usefulness of our model in two use cases.

Expedited gene delivery for osteochondral defect repair in a rabbit knee model: A one-year investigation.

Objective: To evaluate a single-step, gene-based procedure for repairing osteochondral lesions. Design: Osteochondral lesions were created in the patellar groove of skeletally mature rabbits. Autologous bone marrow aspirates were mixed with adenovirus vectors carrying cDNA encoding green fluorescent protein (Ad.GFP) or transforming growth factor-ß1 (Ad.TGF-ß1) and allowed to clot. The clotted marrow was press-fit into the defects. Animals receiving Ad.GFP were euthanized at 2 weeks and intra-articular expression of GFP examined by fluorescence microscopy. Animals receiving Ad.TGF-ß1 were euthanized at 3 months and 12 months; repair was compared to empty defects using histology and immunohistochemistry. Complementary in vitro experiments assessed transgene expression and chondrogenesis in marrow clots and fibrin gels. In a subsequent pilot study, repair at 3 months using a fibrin gel to encapsulate Ad.TGF-ß1 was evaluated. Results: At 2 weeks, GFP expression was seen at variable levels within the cartilaginous lesion. At 3 months, there was no statistically significant improvement (p > 0.05) in healing of lesions receiving Ad.TGF-ß1 and variability was high. At 12 months, there were still no significant difference (p > 0.05) between the empty defects and those receiving Ad.TGF-ß1 in the overall, cartilage, and bone scores. Variability was still high. In vitro experiments suggested that variability reflected variable transduction efficiency and chondrogenic activity of the marrow clots; using fibrin gels instead of marrow may address this issue but more research is needed. Conclusions: This approach to improving the repair of osteochondral lesions needs further refinement to reduce variability and provide a more robust outcome.

Advantages of CT Versus MRI for Preoperative Assessment of Osteochondritis Dissecans of the Capitellum.

BACKGROUND: Magnetic resonance imaging (MRI) is considered to be the gold standard for imaging of osteochondritis dissecans (OCD). PURPOSE/HYPOTHESIS: The purpose was to determine the additional value of a preoperative computed tomography (CT) scan in adolescent patients with capitellar OCD of the elbow. Consistent with the fact that OCD is a lesion involving the subchondral bone, the hypothesis was that CT would be superior to MRI for imaging OCD of the capitellum. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 3. METHODS: All patients being treated surgically for an OCD of the capitellum between 2006 and 2016 at one institution were reviewed for preoperative imaging. A total of 28 patients met the inclusion criteria. Corresponding MRI and CT scans were compared retrospectively. Multiple parameters were recorded, with special emphasis on OCD lesion size, fragmentation, and tilt as well as joint surface integrity, loose bodies, and osteophytes. RESULTS: The OCD lesions were best seen on CT scans, whereas MRI T1-weighted images overestimated and T2-weighted images underestimated the size of defects. A subchondral fracture nonunion was found on CT scans in 18 patients, whereas this was seen on MRI T1-weighted images in only 2 patients (P < .001) and MRI T2-weighted images in 4 patients (P < .001). Fragmentation of the OCD fragment was found on CT scans in 17 patients but on MRI scans in only 9 patients (P = .05). Osteophytes as a sign of secondary degenerative changes were seen on CT scans in 24 patients and were seen on MRI scans in 15 patients (P = .02). Altogether, only 51 of 89 secondary changes including loose bodies, effects on the radial head and ulnohumeral joint, and osteophytes that were seen on CT scans were also seen on MRI scans (P = .002). CONCLUSION: OCD fragmentation and secondary changes were more often diagnosed on CT. These factors indicate OCD instability or advanced OCD stages, which are indications for surgery. In an adolescent who is considered at risk for OCD (baseball, gymnastics, weightlifting, tennis) and who has lateral elbow joint pain with axial or valgus load bearing, CT is our imaging modality of choice for diagnosing and staging OCD of the capitellum.

[CME-Sonography 106: Subacromial Bursa - A Myth]. / CME Sonografie 106: Bursa subacromialis ­ ein Mythos CME-Fragen.

CME-Sonography 106: Subacromial Bursa - A Myth Abstract. In everyday clinical practice, we frequently encounter bursitis. It can occur in practically any joint region, for example in local mechanical overload situations, after a trauma or in the context of an inflammatory systemic disease. In this review we focus on the location of bursitis in the shoulder region and would like to contribute to get away from the "myth" called subacromial bursitis.

Enthesis Healing Is Dependent on Scaffold Interphase Morphology-Results from a Rodent Patellar Model.

The use of multiphasic scaffolds to treat injured tendon-to-bone entheses has shown promising results in vitro. Here, we used two versions of a biphasic silk fibroin scaffold to treat an enthesis defect created in a rat patellar model in vivo. One version presented a mixed transition between the bony and the tendon end of the construct (S-MT) while this transition was abrupt in the second version (S-AT). At 12 weeks after surgery, the S-MT scaffold promoted better healing of the injured enthesis, with minimal undesired ossification of the insertion area. The expression of tenogenic and chondrogenic markers was sustained for longer in the S-MT-treated group and the tangent modulus of the S-MT-treated samples was similar to the native tissue at 12 weeks while that of the S-AT-treated enthesis was lower. Our study highlights the important role of the transition zone of multiphasic scaffolds in the treatment of complex interphase tissues such as the tendon-to-bone enthesis.

Predicting the effects of COVID-19 related interventions in urban settings by combining activity-based modelling, agent-based simulation, and mobile phone data.

Epidemiological simulations as a method are used to better understand and predict the spreading of infectious diseases, for example of COVID-19. This paper presents an approach that combines a well-established approach from transportation modelling that uses person-centric data-driven human mobility modelling with a mechanistic infection model and a person-centric disease progression model. The model includes the consequences of different room sizes, air exchange rates, disease import, changed activity participation rates over time (coming from mobility data), masks, indoors vs. outdoors leisure activities, and of contact tracing. It is validated against the infection dynamics in Berlin (Germany). The model can be used to understand the contributions of different activity types to the infection dynamics over time. It predicts the effects of contact reductions, school closures/vacations, masks, or the effect of moving leisure activities from outdoors to indoors in fall, and is thus able to quantitatively predict the consequences of interventions. It is shown that these effects are best given as additive changes of the reproduction number R. The model also explains why contact reductions have decreasing marginal returns, i.e. the first 50% of contact reductions have considerably more effect than the second 50%. Our work shows that is is possible to build detailed epidemiological simulations from microscopic mobility models relatively quickly. They can be used to investigate mechanical aspects of the dynamics, such as the transmission from political decisions via human behavior to infections, consequences of different lockdown measures, or consequences of wearing masks in certain situations. The results can be used to inform political decisions.

Picrosirius Red Staining: Revisiting Its Application to the Qualitative and Quantitative Assessment of Collagen Type I and Type III in Tendon.

Collagen has a major role in the structural organization of tendons. Picrosirius red (PSR) staining viewed under polarized light microscopy is the standard method to evaluate the organization of collagen fibers in tissues. It is also used to distinguish between type I and type III collagen in tissue sections. However, accurate analysis and interpretation of PSR images are challenging because of technical factors and historical misconceptions. The aim of this study was to clarify whether collagen types I and III can be distinguished by PSR staining in rat Achilles tendons, using double immunohistochemistry as the positive control. Our findings showed that PSR staining viewed with polarized light microscopy was suitable for qualitative and quantitative assessment of total collagen but was not able to distinguish collagen types. We found it critical to use a polarizing microscope equipped with a rotating stage; tendon section orientation at 45° with respect to crossed polarizers was optimal for the qualitative and quantitative assessment of collagen organization. Immunohistochemistry was superior to PSR staining for detection of collagen type III. We also compared formalin and Bouin solution as fixatives. Both produced similar birefringence, but formalin-fixed tendons provided higher quality histological detail with both hematoxylin-eosin and immunostaining.

Fluoroscopy of the Elbow: A Cadaveric Study Defining New Standard Projections to Visualize Important Anatomical Landmarks.

BACKGROUND: Despite new 3-dimensional imaging modalities, 2-dimensional fluoroscopy remains the standard intraoperative imaging modality. The elbow has complex anatomy, and defined standard fluoroscopic projections are lacking. Therefore, the aim of this study was to define standard projections of the elbow for intraoperative fluoroscopy. METHODS: This study consisted of 2 parts. In part I, dissected cadaveric elbows were examined under fluoroscopy, and their radiographic anatomical features were assessed, with focus on projections showing defined anatomical landmarks. In part II, projections from part I were verified on entire cadavers to simulate intraoperative imaging. Standard projections for anteroposterior (AP) and lateral views as well as oblique and axial views were recorded. RESULTS: Eight standardized projections could be defined and included 3 AP, 1 lateral, 2 oblique, and 2 axial views. By applying these specific projections, we could visualize the epicondyles, the trochlea with its medial and lateral borders, the capitellum, the olecranon, the greater sigmoid notch, the coronoid process including its anteromedial facet, the proximal radioulnar joint with the radial tuberosity, and the anterior and posterior joint lines of the distal part of the humerus. These standard projections were reliably obtained using a specific sequence. CONCLUSIONS: Knowledge about radiographic anatomy and standard projections is essential for visualizing important landmarks. With the presented standard projections of the elbow, important anatomical landmarks can be clearly examined. Thus, fluoroscopic visualization of anatomical fracture reduction and correct implant placement should be facilitated. CLINICAL RELEVANCE: This basic science cadaveric study defines fluoroscopic standard projections of the elbow essential for visualization of anatomical landmarks during surgery.

Prediction of Covid-19 spreading and optimal coordination of counter-measures: From microscopic to macroscopic models to Pareto fronts.

The Covid-19 disease has caused a world-wide pandemic with more than 60 million positive cases and more than 1.4 million deaths by the end of November 2020. As long as effective medical treatment and vaccination are not available, non-pharmaceutical interventions such as social distancing, self-isolation and quarantine as well as far-reaching shutdowns of economic activity and public life are the only available strategies to prevent the virus from spreading. These interventions must meet conflicting requirements where some objectives, like the minimization of disease-related deaths or the impact on health systems, demand for stronger counter-measures, while others, such as social and economic costs, call for weaker counter-measures. Therefore, finding the optimal compromise of counter-measures requires the solution of a multi-objective optimization problem that is based on accurate prediction of future infection spreading for all combinations of counter-measures under consideration. We present a strategy for construction and solution of such a multi-objective optimization problem with real-world applicability. The strategy is based on a micro-model allowing for accurate prediction via a realistic combination of person-centric data-driven human mobility and behavior, stochastic infection models and disease progression models including micro-level inclusion of governmental intervention strategies. For this micro-model, a surrogate macro-model is constructed and validated that is much less computationally expensive and can therefore be used in the core of a numerical solver for the multi-objective optimization problem. The resulting set of optimal compromises between counter-measures (Pareto front) is discussed and its meaning for policy decisions is outlined.

[Update on Shoulder Arthroplasty]. / Aktueller Stand der Schulterendoprothetik.

Update on Shoulder Arthroplasty Abstract. Shoulder arthroplasty is indicated for treatment of primary osteoarthritis, cuff tear athropathy, complex proximal humerus fractures, and posttraumatic situations. The rotator cuff plays an important role. In case of an intact rotator cuff, anatomical shoulder arthroplasty is preferred. Over the past decades, the number of hemi prostheses has declined in favor of total shoulder arthroplasties. Reverse shoulder arthroplasty is used for severe and irreparable rotator cuff tears, advanced cuff tear athropathy, and increasingly for complex proximal humerus fractures. Reverse shoulder arthroplasties account for almost 80 % of all shoulder prostheses. Modern implants allow conversion from an anatomic to a reverse situation if needed. Improved understanding of the pathology, new implant designs, and preoperative 3D planning have improved the overall outcome.

An Improved, Chemically Modified RNA Encoding BMP-2 Enhances Osteogenesis In Vitro and In Vivo.

IMPACT STATEMENT: The use of chemically modified RNA (cmRNA) with increased stability using translation initiator of short untranslated regions (TISU) offers the prospect of finally allowing us to unlock the potent osteogenic properties of BMP-2 in a clinically expedient manner. As noted, delivery of recombinant BMP-2 protein has had modest clinical efficacy, whereas gene delivery is effective but very difficult to translate into human clinical use. This study shows the great potential of cmRNA encoding BMP-2 with TISU in a long-bone critical-sized rat model.

Response of the Injured Tendon to Growth Factors in the Presence or Absence of the Paratenon.

BACKGROUND: The paratenon is important for Achilles tendon healing. There is much interest in the use of exogenous growth factors (GFs) as potential agents for accelerating the healing of damaged Achilles tendons. PURPOSE/HYPOTHESIS: The present study used a rat model to study the responses of the injured Achilles tendon to GFs in the presence or absence of the paratenon. The hypothesis was that responses of the injured tendon to GFs would be lower in the absence of a paratenon. STUDY DESIGN: Controlled laboratory study. METHODS: A 4-mm defect was created in the right Achilles tendon of 60 skeletally mature rats, which were treated with a validated combination of GFs (bFGF, BMP-12, and TGF-ß1). Animals were randomly assigned to the intact paratenon (IP) group or resected paratenon (RP) group. Healing was studied anatomically, mechanically, and histologically after 1, 2, and 4 weeks. RESULTS: IP tendons showed improved healing compared with RP tendons. IP tendons were significantly stronger (32.2 N and 48.9 N, respectively) than RP tendons (20.1 N and 31.1 N, respectively) after 1 and 2 weeks. IP tendons did not elongate as much as RP tendons and had greater cross-sectional areas (18.0 mm2, 14.4 mm2, and 16.4 mm2, respectively) after 1, 2, and 4 weeks compared with RP tendons (10.5 mm2, 8.4 mm2, and 11.9 mm2, respectively). On histology, earlier collagen deposition and parallel orientation of fibrils were found for IP tendons. CONCLUSION: The paratenon is essential for efficient Achilles tendon healing. Healing with GFs in this Achilles tendon defect model was superior in the presence of the paratenon. CLINICAL RELEVANCE: Biological approaches to tendon engineering using GFs are in vogue and have been shown to improve healing of the rat Achilles tendon, most likely by inducing progenitor cells located within the paratenon. Clinically, resection or incision of the paratenon has been proposed for wound closure. Our data demonstrate the fundamental importance of the paratenon, which therefore should be preserved during Achilles tendon repair, especially if augmented with products such as platelet-rich plasma or autologous conditioned serum that are rich in GFs.

The Role of the Paratenon in Achilles Tendon Healing: A Study in Rats.

BACKGROUND: The role of the paratenon in tendon healing is unknown. The present study compares healing in the presence or absence of the paratenon in an Achilles tendon defect model in rats. HYPOTHESIS: Resection of the paratenon impairs tendon healing. STUDY DESIGN: Controlled laboratory study. METHODS: Sixty skeletally mature Sprague Dawley rats were randomly assigned to either a resected paratenon (RP) group or an intact paratenon (IP) group. In all animals, a 4-mm portion of the Achilles tendon was resected in the midsubstance. In the RP group, the paratenon was resected completely. In the IP group, the paratenon was opened longitudinally and closed again after the tendon defect had been created. One, 2, and 4 weeks after surgery, 7 animals per group were tested biomechanically and 3 animals per group examined histologically. RESULTS: The recovery of mechanical strength was much more rapid in IP tendons. Tear resistance was significantly increased for IP tendons (41.3 ± 8.8 N and 47.3 ± 14.1 N, respectively) compared with RP tendons (19.3 ± 9.1 N and 33.2 ± 6.4 N, respectively) after 1 and 2 weeks. The cross-sectional area was larger in the IP group after 1 and 2 weeks (8.2 ± 2.3 mm2 and 11.3 ± 3.1 mm2 vs 5.0 ± 2.4 mm2 and 5.9 ± 2.0 mm2, respectively) compared with the RP group. Tendon stiffness was greater in the IP group after 1 week (10.4 ± 1.9 N/mm vs 4.5 ± 1.6 N/mm, respectively) compared with the RP group. In comparison, normal contralateral tendons had a maximal tear resistance of 56.6 ± 7.2 N, a cross-sectional area of 3.6 ± 0.7 mm2, and stiffness of 17.3 ± 3.8 N/mm. Hematoxylin and eosin staining revealed slightly delayed healing of RP tendons. Early collagen formation was seen in the IP group already after 1 week, whereas in the RP group, this only occurred after 2 weeks. After 4 weeks, the IP tendons showed more collagen crimp formation than the RP tendons. CONCLUSION: An intact paratenon promotes healing of the Achilles tendon. CLINICAL RELEVANCE: Although incision or resection of the paratenon has been advocated when repairing injured or degenerative tendons, our data suggest that the integrity of the paratenon should be preserved.

Autograft versus sterilized allograft for lateral calcaneal lengthening osteotomies: Comparison of 50 patients.

Sterilized allografts may be less resistant to collapse and prone to nonunion leading to loss of correction in open wedge osteotomies. These adverse events usually occur at early time points (i.e., < 9 months postoperatively). The goal of this study was to compare sterilized allografts to autologous grafts in respect to secondary loss of hindfoot alignment and graft incorporation after lateral calcaneal lengthening osteotomies.Fifty patients (22 F/ 28 M, age: 16-69 years) who had undergone 50 lateral calcaneal lengthening osteotomies for adult flatfoot deformity were included in this retrospective study. Cortical sterilized allografts were used in 25 patients, autologous grafts in the remaining 25. Patients' preoperative, 6 and 12 weeks, and 6 to 9 months follow-up weight-bearing radiographs of the affected foot were analyzed by 2 blinded radiologists: on each radiograph, graft incorporation, the talo-first metatarsal angle (TFMA), the talo-navicular coverage angle (TNCA), and the calcaneal pitch angle (CPA) were assessed. Loss of hindfoot alignment was defined as an increase of the TFMA or the TNCA or a decrease of the CPA, each by 5°.Inter- and intraclass correlation coefficients for TFMA, TNCA, and CPA measurements ranged from 0.93 to 0.99. At all follow-up visits, the ratio of patients with loss of hindfoot alignment and graft incorporation was not significantly different between the allograft and autograft group. However, loss of correction was associated with failure of graft incorporation.Compared with autografts, sterilized allografts do not increase the risk for loss of hindfoot alignment in lateral column lengthening of the calcaneus. With respect to mechanical resistance, allografts thus mean an equal and valid alternative without risk of donor site morbidities.

Effect of a Simple Collagen Type I Sponge for Achilles Tendon Repair in a Rat Model.

BACKGROUND: Several sophisticated approaches to tendon engineering have been investigated as ways to improve tendon healing with the early formation of repair tissue with possibly a high amount of type I collagen. Besides the new formation of collagen type I, there is evidence for the natural integration of surrounding collagen type I from healthy tendon parts into the healing defect. However, the simple application of a type I collagen sponge to the healing site to increase the amount of local collagen type I has not been investigated. HYPOTHESIS: Healing of the rat Achilles tendon can be accelerated by an additional supply of collagen type I, resulting in increased tear resistance. STUDY DESIGN: Controlled laboratory study. METHODS: The right Achilles tendons of 42 rats were transected. In half of the animals, a type I collagen sponge was placed into the gap. Animals were allowed to move freely in their cages to simulate early functional therapy. After 1, 2, and 4 weeks, tendon length, width, maximal load to failure, and stiffness were measured and the healing site studied histologically according to the Bonar score. Inflammation was evaluated by the appearance of macrophages and neutrophilic and eosinophilic granulocytes. RESULTS: Defects receiving collagen sponges showed improved healing, with significantly stronger (29.5 vs 5.0 N, respectively, at 1 week; P = .00003), shorter (11.6 vs 14.5 mm, respectively, at 4 weeks; P = .005), thicker (10.0 vs 1.8 mm(2), respectively, at 1 week; P = .00002), and less stiff (19.5 vs 30.5 N/mm, respectively, at 4 weeks; P = .02) tendons than control tendons. Overall, the biomechanical properties of the collagen-treated tendons appeared to be significantly closer to those of native, uninjured tendons compared with tendons in the control group. Histologically, no inflammatory reaction due to the collagen sponge was found. CONCLUSION: Tendon healing was accelerated by the type I collagen sponge. Moreover, the mechanical properties of collagen-treated tendons appeared to be significantly closer to those of normal, uninjured tendons compared with control tendons without collagen treatment. CLINICAL RELEVANCE: As a simple type I collagen sponge seems to increase the amount of local collagen type I, the careful use of such sponges might be an option for tendon augmentation during Achilles tendon surgery.

Simulated activity but real trauma: a systematic review on Nintendo Wii injuries based on a case report of an acute anterior cruciate ligament rupture.

Video gaming injuries are classically regarded as eccentric accidents and novelty diagnoses. A case of an anterior cruciate ligament (ACL) tear sustained during Wii boxing spurned us to review the literature for other Wii-related injuries and Wii-based posttraumatic rehabilitation. The English literature listed in PubMed was systematically reviewed by searching for "Wii (trauma or injury or fracture)." Full-text articles were included after duplicate, blinded review. The type and treatment of injury as well as the Wii-based rehabilitation programs found were analyzed. Additionally, a new case of an acute ACL tear-sustained playing, Wii boxing, is additionally presented. After exclusion of irrelevant articles, 13 articles describing Wii-related injuries were included reporting on 3 fractures, 6 nonosseous, 2 overuse injuries, and 2 rehabilitation programs using Wii for posttraumatic rehabilitation. Among the presented Wii-related injuries, only 12.5% were treated conservatively, whereas 87.5% underwent either surgical or interventional treatment. Because of the reported case, the literature search was limited to Wii-related injuries excluding other video games. Another limitation of this article lies in the fact that mainly case reports but no controlled trials exist on the topic. Assumingly, primarily the more severe injuries are reported in the literature with an unknown number of possibly minor injuries. Motion-controlled video games, such as Wii, are becoming increasingly popular as a recreational entertainment. Because of their wide acceptance and entertaining nature, they are also increasingly recognized as a tool in rehabilitation. However, although the activity is simulated, injuries are real. Our systematic review shows that Wii gaming can lead to severe injuries, sometimes with lasting limitations.

Biologics for tendon repair.

Tendon injuries are common and present a clinical challenge to orthopedic surgery mainly because these injuries often respond poorly to treatment and require prolonged rehabilitation. Therapeutic options used to repair ruptured tendons have consisted of suture, autografts, allografts, and synthetic prostheses. To date, none of these alternatives has provided a successful long-term solution, and often the restored tendons do not recover their complete strength and functionality. Unfortunately, our understanding of tendon biology lags far behind that of other musculoskeletal tissues, thus impeding the development of new treatment options for tendon conditions. Hence, in this review, after introducing the clinical significance of tendon diseases and the present understanding of tendon biology, we describe and critically assess the current strategies for enhancing tendon repair by biological means. These consist mainly of applying growth factors, stem cells, natural biomaterials and genes, alone or in combination, to the site of tendon damage. A deeper understanding of how tendon tissue and cells operate, combined with practical applications of modern molecular and cellular tools could provide the long awaited breakthrough in designing effective tendon-specific therapeutics and overall improvement of tendon disease management.

Tendon healing: an overview of physiology, biology, and pathology of tendon healing and systematic review of state of the art in tendon bioengineering.

PURPOSE: Tendon injuries vary from acute rupture to chronic tendinopathy. For an optimal treatment of either condition, a profound knowledge is essential. Therefore, this article shall give an overview of physiology, biology, and pathology of tendon healing and state of the art in tendon bioengineering. METHODS: For a preferably comprehensive survey, the current literature listed in PubMed and published in English peer-reviewed journals (March 2013) was systematically reviewed for tendon healing and tendon bioengineering including cytokine modulation, autologous sources of growth factors, biomaterials, gene therapy, and cell-based therapy. No differentiation was made between clinical and preclinical in vitro investigations. RESULTS: Tendon healing happens in certain stadiums of inflammation, formation, and remodelling. An additional process of "collagen recycling" close to the healing site has been described recently. With increasing comprehension of physiology and pathology of tendon healing, several promising approaches in tendon bioengineering using growth factors, biomaterials, gene therapy, or cell-based therapy are described. However, only some of these are already used routinely in clinics. CONCLUSION: Strong and resistant tendons are crucial for a healthy musculoskeletal system. The new approaches in tendon bioengineering are promising to aid physiological tendon healing and thus resulting in a stronger and more resistant tendon after injury. The growing knowledge in this field will need to be further taken into clinical studies so that especially those patients with prolonged courses, revision surgery, or chronic tendinopathy and high-demanding patients, i.e., professional athletes would benefit. LEVEL OF EVIDENCE: II.