bluuebunny/crossref_metadata_2025 huggingface dataset:
‘Ask not what your community can do for you’: obligations, New Labour and welfare reform
Authors: Lund Brian
Published: July 2017

The governing principle of New Labour's approach to social policy is the fastening of duties to rights. New Labour asserts that the bond between the taxpayer and the welfare recipient can be restored only by reconstructing welfare as a mechanism that reconnects the ‘socially excluded’ to the mainstream via ‘character’ improvement. This rights/obligations connection has been reflected in the attachment of new requirements to the receipt of cash benefits and in a preference for the provision of services in kind rather than payments in cash. In this article it is argued that New Labour's ‘one-sided’ account of the affinity between ‘givers’ and ‘receivers’—stripped of the ‘New’ Liberal notion of entitlement to a share in the ‘collective social surplus’—undermines social rights. The transfer to services ‘in kind’ restricts individual freedom and, as its neoconservative genealogy indicates, the rights/ obligations discourse opens the door to the use of stigma to enforce obligations.
Property Relations and Landlordism—a Realist Approach
Authors: Allen J
Published: July 2017

Analysis of the role of concepts in urban social research is largely an undeveloped area. Justification of the adoption of particular forms of classification in studies are rarely offered and are often passed over in favour of a discussion of the more tractable areas of empirical research. In this paper the practice of conceptual analysis adopted in one sphere of urban research, landlordism and property relations, is evaluated and criticised for its unreflective mechanistic approach. Invariably, the object (landlordism) is subjected to a form of analysis which treats it as if it were analogous to an onion, from which layers may be peeled off, one after another. It is argued that this mode of analysis does not reveal the economic and social properties that constitute different types of landlordism, which, in turn, may provide the basis for an understanding of the spatial variation in the structure of the market for privately rented housing in Britain. An alternative mode of conceptual analysis, based upon the principles of a realist philosophy of science, is proposed, which has the potential to explain the structural unevenness of the rental market and the roles adopted by different groups of landlords in this market.
A state of flux: Histories of social media research
Authors: Lomborg Stine
Published: July 2017

This article sets out to map the broad contours of social media research, teasing out in particular the ways in which the scholarly literature in the fields of media and communication research has addressed social media as a phenomenon since the emergence of the term ‘social media’ in the early 2000s. As a communicative phenomenon and research object, social media would appear to be in flux. Changes to existing services, the emergence of new services, and the disappearance of previously popular services testify to the sense of social media as a moving target. Researchers of social media seem to accept change, rather than continuity, as a condition for the study of social media. This is evident in our choice of research topics and data sources, but also in our discourses on social media. By examining the sense of flux of social media research in a historical perspective, this article aims to provide useful directions for future media and communication research on social media. Specifically, it suggests ways to stabilise social media as an object of study and to install a greater historical awareness in social media research.
Global Impact of Danish Headache Research
Authors: Lance JW
Published: July 2017

Over the past 40 years, Denmark has established a world reputation for the comprehensive nature and excellence of its headache research. Advances have been made in epidemiology, genetics, pathophysiology and treatment across the whole spectrum of headache entities. Moreover, the IHS classification of headache, the guidelines for clinical trials and text books on the basic mechanisms and management of headaches were initiated from Denmark. These achievements are a tribute to all those who have participated and to the continuing leadership of Jes Olesen.
Biomechanical Analysis of a Posterior Cruciate Ligament Reconstruction
Authors: Harner Christopher D. , Vogrin Tracy M. , Höher Jürgen , Ma C. Benjamin , Woo Savio L-Y.
Published: July 2017

We hypothesized that posterior cruciate ligament reconstructions are often compromised by associated injuries to the posterolateral structures. Therefore, we evaluated a posterior cruciate ligament reconstruction in isolated and combined injury models using a robotic/ universal force-moment sensor testing system. The resulting knee kinematics and the in situ forces in the native and reconstructed posterior cruciate ligament were determined under four external loading conditions. In the isolated injury model, reconstruction reduced posterior tibial translation to within 1.5 1.3 to 2.4 1.4 mm of the intact knee at 30° and 90° under a 134-N posterior tibial load. In the combined injury model, deficiency of the posterolateral structures increased posterior tibial translation of the reconstructed knee by 6.0 2.7 mm at 30° and 4.6 1.5 mm at 90° of flexion. External rotation increased up to 14° while varus rotation increased up to 7°. In situ forces in the posterior cruciate ligament graft also increased significantly (by 22% to 150%) for all loading conditions. Our results demonstrate that a graft that restores knee kinematics for an isolated posterior cruciate ligament deficiency is rendered ineffective and may be overloaded if the posterolateral structures are deficient. Therefore, surgical reconstruction of both structures is recommended in the setting of a combined injury.
The Effect of Nonphysiologically High Initial Tension on the Mechanical Properties of in Situ Frozen Anterior Cruciate Ligament in a Canine Model
Authors: Katsuragi Ryosei , Yasuda Kazunori , Tsujino Jun , Keira Motoharu , Kaneda Kiyoshi
Published: July 2017

An experimental study was performed in 32 adult beagle dogs to clarify the effect of nonphysiologically high initial tension on the mechanical and histologic properties of in situ frozen anterior cruciate ligaments. Both anterior cruciate ligaments in each dog underwent the in situ freeze-thaw treatment. The tibial insertion of the ligament was then made free from the tibia along with a cylindrical bone block. In the right knee, an initial tension of 20 N was applied on the anterior cruciate ligament by translocating the bone block in the distal direction. In the left knee, this bone block was anatomically reduced. Each bone block was firmly fixed with an interference screw. Ten animals were sacrificed at 6 weeks and 10 at 12 weeks. The tensile strength and the tangent modulus in the highly tensioned knee were significantly less than those in the physiologically tensioned knee at 12 weeks. Histologically, cell nuclei appeared to be spindle-shaped in the physiologically tensioned knee, while oval nuclei and focal degenerative changes with a number of vacuoles were occasionally found in the matrix in the highly tensioned knee. This study demonstrated that a nonphysiologically high tension significantly deteriorates the mechanical properties of the in situ frozen anterior cruciate ligament compared with physiologic tension.
Osteochondritis Dissecans of the Patellofemoral Joint
Authors: Peters Tracy A. , McLean Iain D.
Published: July 2017

Osteochondritis dissecans of the patellofemoral joint is an uncommon condition that may be the cause of anterior knee pain or crepitus. We present the clinical features of 37 patients with osteochondritis dissecans lesions of the patellofemoral joint (24 on the patella, 13 on the trochlear groove), including two patients with medial trochlear groove lesions, which have not, to our knowledge, been previously reported. The osteochondral lesions involved the convex articular surfaces. The median age of patients when first examined was 15 years, and 54% of patients had open epiphyses. These lesions were more common in male patients than in female patients (four-to-one ratio). Osteochondritis dissecans of the patellofemoral joint can be overlooked unless quality radiographs are viewed with care and, at arthroscopy, both the patella and trochlear groove are assessed. Treatment depends on the symptoms, site, and nature of the lesion and the patient's age. Nonoperative management includes patellar taping and vastus medialis obliquus muscle exercises. Operative intervention is indicated for patients with mechanical symptoms and includes arthroscopy, consisting of chondroplasty and removal of loose bodies, and lateral retinacular release. In this study treatment generally improved the symptoms, but patients with articular cartilage loss had persistent patellofemoral crepitus and discomfort.
Chronic Achilles Tendon Overuse Injury: Complications after Surgical Treatment
Authors: Paavola Mika , Orava Sakari , Leppilahti Juhana , Kannus Pekka , Järvinen Markku
Published: July 2017

We analyzed the complications after surgical treatment of Achilles tendon overuse injuries in 432 consecutive patients. The patients underwent a clinical examination 2 weeks, and 1, 2, and 5 months after the surgery. If a complication appeared, the patient was followed up clinically for at least 1 year. There were 46 (11%) complications in the 432 patients: 14 skin edge necroses, 11 superficial wound infections, 5 seroma formations, 5 hematomas, 5 fibrotic reactions or scar formations, 4 sural nerve irritations, 1 new partial rupture, and 1 deep vein thrombosis. Fourteen patients with a complication had reoperations: four patients for skin edge necrosis, two for superficial wound infection, two for seroma formation, one for hematoma formation, two for fibrotic reaction or scar formation, two for sural nerve irritation, and one for a new partial rupture. About every 10th patient treated surgically for chronic Achilles tendon overuse injury suffered from a postoperative complication that clearly delayed recovery. However, the majority of patients with a complication healed and returned to their preinjury levels of activity. To reduce this morbidity, it is essential that the surgeon be continuously aware of the possibility of postoperative complications and use proper surgical techniques.
The Relative Incidence of Anterior Cruciate Ligament Injury in Men and Women at the United States Naval Academy
Authors: Gwinn David E. , Wilckens John H. , McDevitt Edward R. , Ross Glen , Kao Tzu-Cheg
Published: July 2017

The purpose of this study was to evaluate the relative risk of anterior cruciate ligament injury in female versus male midshipmen at the United States Naval Academy. From 1991 to 1997, we recorded the incidence of anterior cruciate ligament injury during intercollegiate athletics, intramural athletics, and military training. The subjects were male and female varsity athletes, coed intramural athletes, and participants in military training consisting of the obstacle course and instructional wrestling. All patient data were collected at the time of injury. Records filed at the intramural sports office, along with a questionnaire completed by coaches and trainers, were used to estimate midshipmen exposures. Results showed that in intercollegiate soccer, basketball, and rugby, women had a relative injury risk of 3.96 compared with men. In coed soccer, basketball, softball, and volleyball, the women's relative injury risk was 1.40 compared with men. In military training, women had a relative injury risk of 9.74 compared with men. In comparing overall annual anterior cruciate ligament injury rates among midshipmen, we found that women had a relative injury risk of 2.44 compared with men. We concluded that female midshipmen have an increased relative risk of anterior cruciate ligament injury as compared with men in intercollegiate athletics, basic military training, and throughout their service academy career. This increase was not statistically significant at the intramural level of athletics.
The Effect of Reconstruction of the Medial Patellofemoral Ligament on Patellar Tracking
Authors: Sandmeier Robert H. , Burks Robert T. , Bachus Kent N. , Billings Annette
Published: July 2017

We evaluated patellar tracking in six cadaveric knees with the medial restraints intact and then sectioned to determine their contribution to lateral translation of the patella with and without a lateral force on the patella. The medial patellofemoral ligament was then reconstructed with a gracilis tendon graft and patellar tracking was again evaluated. The knees were extended using a materials testing machine, and patellar tracking was measured with a position sensing system. With no lateral force applied to the patella, patellar tracking was unaffected by the presence or absence of the medial restraints or by reconstruction of the medial patellofemoral ligament. With a lateral force applied to the patella, patellar tracking was changed significantly by the loss of the medial restraints. Normal patellar tracking was substantially restored by reconstruction of the medial patellofemoral ligament.
The Influence of Screw Geometry on Hamstring Tendon Interference Fit Fixation
Authors: Weiler Andreas , Hoffmann Reinhard F. G. , Siepe Christoph J. , Kolbeck Stefan F. , Südkamp Norbert P.
Published: July 2017

We used a standardized model of calf tibial bone to investigate the influence of screw diameter and length on interference fit fixation of a three-stranded semitendinosus tendon graft for anterior cruciate ligament reconstruction. Biodegradable poly-(L-lactide) interference screws with a diameter of 7, 8, and 9 mm and a length of 23 and 28 mm were used. We examined results in three groups of 10 specimens each: group 1, screw diameter equaled graft diameter and screw length was 23 mm; group 2, screw diameter equaled graft diameter plus 1 mm and screw length was 23 mm; group 3, screw diameter equaled graft diameter and screw length was 28 mm. The mean pull-out forces in groups 1, 2, and 3 were 367.2 78 N, 479.1 111.1 N, and 537.4 139.1 N, respectively. The force data from groups 2 and 3 were significantly higher than those from group 1. These results indicate that screw geometry has a significant influence on hamstring tendon interference fit fixation. Increasing screw length improves fixation strength more than oversizing the screw diameter. This is important, especially for increasing tibial fixation strength because the tibial graft fixation site has been considered to be the weak link of such a reconstruction.
The Effect of Ciprofloxacin on Tendon, Paratenon, and Capsular Fibroblast Metabolism
Authors: Williams Riley J. , Attia Erik , Wickiewicz Thomas L. , Hannafin Jo A.
Published: July 2017

The pathologic mechanisms underlying fluoroquinolone-induced tendinopathy are poorly understood. The observed incidence of tendinitis and tendon rupture in patients treated with ciprofloxacin hydrochloride suggests that the fluoroquinolone antibiotics alter tendon fibroblast metabolism. The purpose of this study was to examine the effect of ciprofloxacin on fibroblast metabolism in vitro. Canine Achilles tendon, paratenon, and shoulder capsule specimens were maintained in culture with ciprofloxacin (5, 10, or 50 g/ml). Fibroblast proliferation, collagen synthesis, proteoglycan synthesis, and matrix-degrading activity were analyzed. Incubation of Achilles tendon, Achilles paratenon, and shoulder capsule fibroblasts with ciprofloxacin resulted in a statistically significant 66% to 68% decrease in cell proliferation compared with control cells at day 3 in culture. Ciprofloxacin caused a statistically significant 36% to 48% decrease in collagen synthesis compared with controls in all fibroblast cultures. Ciprofloxacin caused a statistically significant 14% to 60% decrease in proteoglycan synthesis in all fibroblast cell lines. Compared with unstimulated control fibroblasts, culture media from Achilles tendon, paratenon, and shoulder capsule cells that were exposed to ciprofloxacin demonstrated statistically significant increases in matrix-degrading proteolytic activity after 72 hours in culture. This study demonstrates that ciprofloxacin stimulates matrix-degrading protease activity from fibroblasts and that it exerts an inhibitory effect on fibroblast metabolism. The increase in protease activity and the inhibition of both cell proliferation and the synthesis of matrix ground substance may contribute to the clinically described tendinopathies associated with ciprofloxacin therapy.
Imaging Techniques for the Evaluation of Glenohumeral Instability
Authors: Sanders Timothy G. , Morrison William B. , Miller Mark D.
Published: July 2017

The ability to image lesions associated with glenohumeral instability has evolved significantly over the past 2 decades. In the past, several imaging techniques ranging from conventional radiography to computerized axial arthrography and, most recently, to magnetic resonance imaging have been used to depict various labral abnormalities. In most instances, conventional radiography remains the initial imaging study for evaluating the patient with persistent shoulder pain and instability. Recently, however, magnetic resonance arthrography has been firmly established as the imaging modality of choice for demonstrating specific soft tissue abnormalities associated with glenohumeral instability. This article will review the role of various imaging modalities including conventional radiography, conventional arthrography, computerized axial arthrography, magnetic resonance imaging, and magnetic resonance arthrography. Emphasis will be placed on the role of magnetic resonance arthrography as it pertains to the lesions associated with glenohumeral instability. A thorough discussion of the appearance of normal anatomic structures, anatomic variations that mimic abnormality, and the various lesions associated with glenohumeral instability will be provided.
Low-Risk Stress Fractures
Authors: Boden Barry P. , Osbahr Daryl C. , Jimenez Carlos
Published: July 2017

Stress fractures can occur in almost any bone in the body, with the lower extremity weightbearing bones, especially the tibia, tarsals, and metatarsals, being affected most frequently. Although the cause of these fractures is multifactoral, repetitive physical forces without adequate rest are the primary culprits. Stress fractures may be broadly classified as low-risk or high-risk injuries. Low-risk stress fractures, the topic of this review article, can be diagnosed through a thorough history, physical examination, and radiographs. Nuclear scintigraphy is occasionally necessary for confirmation, especially for fractures of the spine and pelvis. When diagnosed early and treated with restriction of activity, low-risk stress fractures have a favorable prognosis.
The Effects of Patellar Taping on Patellofemoral Incongruence
Authors: Gigante Antonio , Pasquinelli Fabiana Magrini , Paladini Paolo , Ulisse Serena , Greco Francesco
Published: July 2017

Patellar taping for the purpose of patellar medialization is a nonoperative rehabilitation technique used in the treatment of patellofemoral pain. Despite early reports of excellent success rates, the indications for this treatment and its efficacy on patellofemoral pain are unclear. The present computed tomography study was undertaken to evaluate the effect of patellar taping on patellofemoral incongruence. Sixteen female patients (age range, 16 to 25 years) with anterior knee pain related to patellofemoral incongruence underwent computed tomography examination with their quadriceps muscles relaxed and contracted both before and after patellar taping. Patellar lateralization was measured as lateral patellar displacement, and patellar tilt was measured as lateral patellar angle. Patellar taping did not significantly affect patellofemoral lateralization or tilt. The results of this study do not support the use of this method for passive correction of patellofemoral incongruence. Although patellar taping may well be effective in controlling anterior knee pain during physical therapy, it does not do so by medializing the patella.
The Elongation Behavior of the Anterior Cruciate Ligament Graft in Vivo
Authors: Beynnon Bruce D. , Uh Benjamin S. , Johnson Robert J. , Fleming Braden C. , Renström Per A. , Nichols Claude E.
Published: July 2017

The relationship between the elongation values of an autogenous bone-patellar tendon-bone graft immediately after fixation and the anterior-posterior laxity of the knee 5 years later was studied in vivo. Immediately after fixation, the change in the graft midsubstance length during passive knee flexion-extension was measured using a Hall-effect transducer, and anterior-posterior knee laxity was measured with the KT-1000 arthrometer. Subjects were divided into group 1 (N=6), with graft elongation values bounded by the 95% confidence intervals of the normal anterior cruciate ligament elongation values, and group 2 (N=7), subjects with values outside these intervals. Immediately after reconstruction, the side-to-side difference in anterior-posterior laxity between the reconstructed and uninjured knees was not different between group 1 (2.6±0.7 mm, mean SEM) and group 2 (1.7±1.0 mm) (P 0.49). At 5-year follow-up, the difference was 1.2±0.7 mm for group 1, while for group 2 it was significantly greater at 4.7±0.6 mm (P<0.004). At surgery, graft elongation values produced by flexion of the knee that are outside the limits of the anterior cruciate ligament result in significant increases in anterior knee laxity at long-term follow-up, while grafts with elongation values similar to the normal anterior cruciate ligament do not. Not only is restoration of anterior-posterior laxity values to within normal limits important, but the biomechanical behavior of the graft produced by flexion-extension of the knee should be appreciated.
Graft Incorporation within the Tibial Bone Tunnel after Anterior Cruciate Ligament Reconstruction with Bone-Patellar Tendon-Bone Autograft
Authors: Ishibashi Yasuyuki , Toh Satoshi , Okamura Yoshihisa , Sasaki Tomoyuki , Kusumi Tomomi
Published: July 2017

We described histologic changes in patellar tendon autografts that occur over time within the tibial tunnel in specimens harvested from patients undergoing revision anterior cruciate ligament reconstruction. Ten patients, averaging 21.2 years of age, were divided into two groups based on the time period between their original and revision surgery: early revision (less than 1 year, four patients) and late revision (more than 1 year, six patients). Among the early revision group, the tendon within the tunnel showed increased cellularity and random collagen bundles. A specimen from the shortest early revision case revealed a normal original bone-tendon junction, whereas others showed an obscured structure. Between the tendon and the tunnel wall, granulation tissue was seen and the bone-tendon junction was still immature. In the late revision group, the tendon appeared similar to normal ligament. The original bone-tendon junction was not seen, and the tendon continued completely to the tunnel wall with Sharpey-like fibers. Observations in the early revision group suggest that tendon remodeling and bone-tendon integration continue for at least several months after transplantation. The original bone-tendon junction appears to have shifted to the proximal patellar tendon-tunnel wall junction with time. These findings are in agreement with prior animal studies.
The Relationship between the Angle of the Tibial Tunnel in the Coronal Plane and Loss of Flexion and Anterior Laxity after Anterior Cruciate Ligament Reconstruction
Authors: Howell Stephen M. , Gittins Mark E. , Gottlieb John E. , Traina Steven M. , Zoellner Timothy M.
Published: July 2017

Tension in an anterior cruciate ligament graft is greater with the knee in flexion when the angle of the tibial tunnel in the coronal plane is vertical or more perpendicular to the medial joint line of the tibia; however, the relationship of the angle of the tibial tunnel to knee function has not been studied. Greater graft tension may limit knee flexion or stretch the graft and increase anterior laxity. Five surgeons treated 119 subjects by reconstructing a torn anterior cruciate ligament using a double-looped semitendinosus and gracilis graft and a standardized technique. The femoral tunnel was drilled through the tibial tunnel. Radiographs were analyzed for tibial tunnel placement and a clinical evaluation was made 4 months postoperatively. Knees were assigned to subgroups according to the angle of the tibial tunnel in the coronal plane (65° to 69°, 70° to 74°, 75° to 79°, 80° to 84°, and 85° to 89°), with the angle of the latter subgroup being most vertical. Loss of flexion increased significantly from 0.5° to 6.5° and anterior laxity increased significantly from 0.5 to 2.2 mm as the tunnel angle was increased. The average angle of the tibial tunnel varied significantly, 11° between surgeons (range, 69° to 80°). We found a tibial tunnel angle of 75° or more is associated with greater loss of flexion and anterior laxity. Surgeons do not drill the angle of the tibial tunnel in the coronal plane accurately. We now routinely drill the tibial tunnel at an angle of 65° to 70° in the coronal plane because it may reduce loss of flexion and anterior laxity.
Popliteal Cysts in Adults
Authors: Rupp Stefan , Seil Romain , Jochum Petra , Kohn Dieter
Published: July 2017

The objective of this prospective study was to determine the prevalence of popliteal cysts and the associated intraarticular lesions in a group of 100 patients scheduled for arthroscopic surgery of the knee and to evaluate the results of arthroscopic treatment for these intraarticular lesions without removal of the cyst. One hundred patients without any knee complaints served as a control group. The diagnosis of a popliteal cyst was made on the basis of ultrasonography. The prevalence of popliteal cysts was 20% in the study group and 0% in the control group. Patients with a popliteal cyst had a significantly higher prevalence of medial meniscal tears (70% versus 19%) and of chondral lesions (85% versus 28%). Tears of the lateral meniscus, however, were more evenly distributed (20% versus 36%). Sixteen of 20 patients with a popliteal cyst were available for a follow-up examination 1 to 3 years after the arthroscopic procedure. Eleven popliteal cysts had persisted. Chondral lesions were the most relevant prognostic factor; all patients with persisting cysts had grade III or grade IV lesions. We conclude that the popliteal cyst is a secondary phenomenon and that treatment should address the underlying intraarticular lesions. In cases of osteoarthritis it may be impossible to treat the chondral lesion successfully in terms of eliminating the effusion.
Fixed Posterior Subluxation in Posterior Cruciate Ligament-Deficient Knees
Authors: Strobel Michael J. , Weiler Andreas , Schulz Martin S. , Russe Kai , Eichhorn H.-Jürgen
Published: July 2017

Among 248 patients seen for posterior cruciate ligament insufficiency, 109 (44%) had fixed posterior subluxation of the tibia, defined as a condition in which posterior sag could not be reduced to a neutral position, as evidenced by posterior tibial displacement of 3 mm or more on anterior stress radiographs at 200 N. The mean fixed posterior displacement was 6.23 mm (range, 3 to 20). The fixed posterior subluxation was divided into three grades: I, 3 to 5 mm (57.8%); II, 6 to 10 mm (33.9%); and III, more than 10 mm (8.3%). Comparison of the 109 study patients with the 139 control patients revealed a history of a failed posterior cruciate ligament operation or of a patellar tendon harvest, male sex, and a long history of posterior cruciate ligament insufficiency as significant risk factors for the development of a fixed posterior subluxation. After patients were treated with a posterior tibial support brace, the fixed posterior subluxation could be reduced to a mean of 2.58 ± 5.22 mm within an average treatment period of 180 days. Fixed posterior subluxation can be detected in patients with posterior cruciate ligament deficiency by anterior and posterior stress radiographs and should be addressed before posterior cruciate ligament reconstruction to prevent early overloading of the graft.
Painful Conditions in the Achilles Tendon Region in Elite Badminton Players
Authors: Fahlström Martin , Lorentzon Ronny , Alfredson Håkan
Published: July 2017

The purpose of this study was to investigate the prevalence and characteristics of painful conditions in the Achilles tendon region in elite badminton players. The study group consisted of 66 players in the Swedish elite division (highest level) in badminton, 41 men (mean age, 24.4 years) and 25 women (mean age, 21.9 years). Twenty-one players (32%) reported the occurrence of a disabling painful condition in the Achilles tendon region during the previous 5 years, and 11 players (17%) had an ongoing painful condition. A majority of the painful conditions (12 of 21, or 57%) were described as involving the midportion of the Achilles tendon. The players who had a painful condition reported a significantly higher weekly training load as measured by the number of hours spent in total training, badminton training, and endurance and strength training. There were no differences in age, sex, and body mass index between the players with and without painful conditions in the Achilles tendon region.
Thermal Chondroplasty of Chondromalacic Human Cartilage
Authors: Edwards Ryland B. , Lu Yan , Nho Shane , Cole Brian J. , Markel Mark D.
Published: July 2017

We compared the effects of treatment with bipolar and monopolar radiofrequency energy on 30 osteochondral sections harvested from 22 patients with spontaneously occurring chondromalacia who were undergoing knee arthroplasty. Specimens with chondromalacia grades 2 or 3 were randomly assigned to one of two bipolar or one monopolar treatment groups. All samples were marked and mounted on a jig to allow simulation of an arthroscopic surgical procedure with a flow rate of 100 ml/min of a balanced electrolyte solution at 22°C. Under arthroscopic visualization, the designated area was treated until smooth, and the total treatment time was recorded. There was no difference in patients’ ages, chondromalacia grade, or cartilage thickness among groups. Significant chondrocyte death, as determined by cell viability staining with confocal laser microscopy, was observed with each group. The bipolar devices produced significantly greater depths of chondrocyte death (2228 ± 1003 μm and 2810 ± 517 μm) than did the monopolar device (737 ± 391 μm). The bipolar devices caused cell death to subchondral bone significantly more often (13 of 20 specimens) than did the monopolar device (0 of 10 specimens). Caution should be used in treating fibrillated cartilage with radiofrequency energy, particularly with the bipolar devices tested.
Creep Behavior of a Rabbit Model of Ligament Laxity after Electrothermal Shrinkage in Vivo
Authors: Wallace Andrew L. , Hollinshead Robert M. , Frank Cyril B.
Published: July 2017

Deformation of capsular tissue under constant load (creep) may lead to recurrent laxity after thermal shrinkage for shoulder instability. We investigated the effects of thermal shrinkage in a rabbit model in which the tibial insertion of the medial collateral ligament was elevated and shifted toward the joint line to create abnormal laxity. On the right side, radiofrequency electrothermal energy was applied to the shifted ligament, while the left side served as a control. Length, laxity, mass, cross-sectional area, water content, and creep behavior of the ligament were assessed at 0 (N = 8), 3 (N = 7), and 12 (N = 6) weeks postoperatively. Laxity was reduced with thermal treatment (0.65 ± 0.31 compared with 3.33 ± 0.25 mm). After 3 weeks, ligament mass, area, and water content were significantly increased in the thermally treated group compared with the untreated controls. At 12 weeks, cyclic creep strain remained greater than that in controls (1.25% ± 0.65% compared with 0.93% ± 0.22%). Although thermal shrinkage reduced laxity, there was increased potential to creep and failure at low physiologic stresses. These findings suggest that loading of thermally treated tissues should be carefully controlled during the early phase of rehabilitation after surgery.
The Clinical Significance of Anterior Horn Meniscal Tears Diagnosed on Magnetic Resonance Images
Authors: Shepard Michael F. , Hunter David M. , Davies Mark R. , Shapiro Matthew S. , Seeger Leanne L.
Published: July 2017

We assessed the accuracy of magnetic resonance imaging in detecting clinically significant lesions of the anterior horn of the meniscus by reviewing 947 consecutive knee magnetic resonance imaging reports. Of these, 76 (8%) indicated a tear of the anterior horn of the medial or lateral meniscus. Thirty-one of these 76 patients underwent a subsequent arthroscopic examination, and their operative reports were reviewed. The 45 patients who were not examined arthroscopically were contacted and interviewed for clinical follow-up. Among the 31 patients who underwent arthroscopic examination, 8 anterior horn tears were noted in the predicted area (26% true-positive results), 23 patients had intact anterior horns (74% false-positive results), and 18 had normal intact menisci in all zones. Of the 45 patients who did not undergo arthroscopic surgery, 6 had isolated anterior horn tears reported on magnetic resonance imaging, and 5 of the 6 were asymptomatic at follow-up. The other 39 patients had multiple pathologic conditions noted on the magnetic resonance imaging report and continued to report knee pain at the follow-up interview. Increased signal intensity at the anterior horn of the meniscus seen on magnetic resonance imaging commonly does not represent a clinically significant lesion. We recommend correlation with the physical examination when interpreting this “positive” finding on knee magnetic resonance imaging examinations.
Surgical Repair of Complete Proximal Hamstring Tendon Rupture
Authors: Klingele Kevin E. , Sallay Peter I.
Published: July 2017

Background:

Complete proximal hamstring tendon rupture is a rare injury associated with significant functional loss. Nonoperative treatment has proven inadequate in returning patients to their previous activity level.

Purpose:

We wanted to describe the outcome of primary surgical repair of the proximal hamstring tendon avulsion.

Study Design:

Retrospective cohort study.

Methods:

Between 1994 and 1999, 11 patients (4 women and 7 men) with an average age of 41.5 years (range, 21 to 51) had a diagnosis of complete proximal hamstring tendon rupture based on mechanism of injury, physical examination, and radiographic assessment. All underwent a single operation followed by standard postoperative physical therapy. At the latest follow-up (average, 34 months), patients completed a questionnaire regarding such outcome parameters as pain, function, leg control, stiffness, return to activity, and overall satisfaction.

Results:

Isokinetic muscle testing revealed an overall average of 91% return of hamstring muscle strength. Ten of 11 patients were satisfied with the result, and 7 of 9 athletically active patients were able to return to sport an average of 6 months (range, 3 to 10) after surgery. No difference between early and late repairs was identified in regard to functional outcome or return to sport.

Conclusions:

Satisfactory results can be achieved with both early and late hamstring tendon repairs in a majority of cases with surgical repair.
Clinical Association of Acute Lateral Ankle Sprain with Syndesmotic Involvement
Authors: Uys Hendrik D. , Rijke Arie M.
Published: July 2017

Background

Information concerning the clinical association between syndesmosis injury and grade of lateral ankle ligament damage would aid in the diagnosis and treatment of ankle sprains.

Hypothesis

Evaluation of lateral ligament injury in terms of percentage tear of both the anterior talofibular and calcaneofibular ligaments can provide information on the extent of syndesmotic involvement.

Study Design

Prospective cohort study.

Methods

Twenty-five patients volunteered to have magnetic resonance imaging examinations performed and 21 volunteered to undergo graded stress radiographs. Talar tilt angles were measured from radiographs taken with 0, 6, 9, 12, and 15 daN of force applied medially just above the ankle joint, and the percentage of ligament tear and grade of injury were determined. Scans were obtained with the foot in neutral and plantar flexion to image the anterior talofibular and calcaneofibular ligaments.

Results

Grades of lateral ligament injury determined by magnetic resonance imaging and graded stress radiography were the same. The extent of syndesmotic injury could be assessed for all patients.

Conclusions

Intact tibiofibular ligaments were found equally frequently among patients with normal or any grade of lateral ligament damage, but the more severe injuries to the syndesmotic ligaments were associated with normal or minimally traumatized lateral ligaments. The inverse correlation can be explained on the basis of the difference between the mechanisms that precipitate these injuries.
Effects of Meniscal and Articular Surface Status on Knee Stability, Function, and Symptoms after Anterior Cruciate Ligament Reconstruction
Authors: Wu W. Howard , Hackett Thomas , Richmond John C.
Published: July 2017

Background

Concomitant injuries to secondary structures have been proposed as a major cause of failure of anterior cruciate ligament reconstruction.

Purpose

Our purpose was to determine the relationship between meniscal status at the time of anterior cruciate ligament reconstruction and ultimate long-term function and stability.

Study Design

Prospective cohort study.

Methods

We prospectively studied 63 patients for an average of 10.4 years after arthroscopically assisted bone-patellar tendon-bone anterior cruciate reconstruction. All surgeries were performed between 1988 and 1991; concomitant meniscal surgery was performed if necessary. Subjects were divided into subgroups relative to the integrity of their menisci at the end of the reconstruction procedure (intact meniscus, partial meniscectomy, complete meniscectomy).

Results

Patients who had undergone any degree of meniscal resection reported significantly more subjective complaints and activity limitations than those with intact menisci. Subjective International Knee Documentation Committee and Lysholm scores were lower in the meniscectomy subgroups than in the meniscus-intact group. Objective testing revealed a significantly lower ability to perform the single-legged hop in the meniscectomy subgroups. Ligament stability based on instrumented laxity measurements was not significantly different between the subgroups. Radiographic abnormalities were also more common in the subgroups that had undergone meniscectomy.

Conclusions

The menisci should be repaired if at all possible, especially in the setting of anterior cruciate ligament reconstruction, for optimal functional outcome and patient satisfaction.
Wrist Pain, Distal Radial Physeal Injury, and Ulnar Variance in Young Gymnasts: Does a Relationship Exist?
Authors: DiFiori John P. , Puffer James C. , Aish Bassil , Dorey Frederick
Published: July 2017

Background

Chronic wrist pain affects up to 79% of young gymnasts. Distal radial growth plate injury and positive ulnar variance have also been reported in this population.

Hypothesis

There is a relationship between wrist pain, radiographic findings of distal radial growth plate injury, and ulnar variance in skeletally immature young gymnasts.

Study Design

Cross-sectional study.

Methods

Fifty-nine gymnasts (28 girls and 31 boys; average age, 9.3 years) completed a questionnaire detailing training and wrist pain symptoms. Each received a wrist examination, grip strength measurement, and bilateral wrist radiographs.

Results

Wrist pain was reported by 56% of the gymnasts (33 of 59), with 45% (15 of 33) describing pain of at least 6 months’ duration. Factors significantly associated with wrist pain included higher skill level, older age, and more years of training. For those between 10 and 14 years of age, 83% had wrist pain, compared with 44% for those outside of that age range. Fifty-one percent of the gymnasts (30 of 59) had findings of stress injury to the distal radial physis of at least a grade 2; 7% (4) had frank widening of the growth plate. Wrist pain prevalence was significantly related to the grade of radiographic injury. Mean ulnar variance was significantly more positive than established norms. Ulnar variance was not associated with wrist pain or radiographic injury of the distal radial physis.

Conclusions

Radiographic findings of distal radial physeal injury are associated with wrist pain among young nonelite gymnasts.
Biomechanical Evaluation of a New Ulnar Collateral Ligament Reconstruction Technique with Interference Screw Fixation
Authors: Ahmad Christopher S. , Lee Thay Q. , ElAttrache Neal S.
Published: July 2017

Background

Techniques for ulnar collateral ligament reconstruction have evolved.

Hypothesis

Ulnar collateral ligament reconstruction with interference screw fixation restores elbow kinematics and failure strength to that of the native ligament.

Study Design

Controlled laboratory study.

Methods

Of 10 matched pairs of cadaveric elbows, one underwent kinematic testing under conditions of an intact, released, and reconstructed ligament. Single 5-mm diameter bone tunnels were created at the isometric anatomic insertion sites on the medial epicondyle and sublime tubercle. Graft fixation was achieved with 5 × 15 mm soft tissue interference screws. The reconstructed and contralateral intact elbows were then tested to failure.

Results

Average stiffness for intact elbows (42.81 ± 11.6 N/mm) was significantly greater than for reconstructed elbows (20.28 ± 12.5 N/mm). Ultimate moment for intact elbows (34.0 ± 6.9 N·m) was not significantly different from reconstructed elbows (30.6 ± 19.2 N·m). Release of the ulnar collateral ligament caused a significant increase in valgus instability. Reconstruction restored valgus stability to near that of the intact elbow.

Conclusions

With this reconstruction method, failure strength was comparable with that of the native ligament and physiologic elbow kinematics were reliably restored.

Clinical Relevance

This technique returns elbow kinematics to near normal, with less soft tissue dissection and risk of ulnar nerve injury and ease of graft insertion, tensioning, and fixation.
Recovery of Chondrocyte Metabolic Activity after Thermal Exposure
Authors: Kaplan Lee D. , Chu Constance R. , Bradley James P. , Fu Freddie H. , Studer Rebecca K.
Published: July 2017

Background

The relationship between temperature elevation and thermal exposure time during thermal chondroplasty has implications for cell viability and subsequent articular cartilage function.

Purpose

To characterize cartilage metabolic changes after exposure to thermal stress and to determine whether changes seen acutely are reversible.

Study Design

Controlled laboratory study.

Methods

Human cartilage was exposed to a 45°, 50°, or 55°C bath for up to 3 minutes. Untreated control specimens were analyzed with each group. Viability and metabolic capability of treated and untreated specimens were evaluated immediately or 1 week after thermal stress by using methylthiotetrazole conversion, 3H-serine incorporation into protein, and 35S-sulfate incorporation into newly synthesized proteoglycan.

Results

Nonarthritic and arthritic articular cartilage metabolic activity declined with increasing thermal exposure. Articular cartilage displayed a recovery from thermal stress after exposure to the 50°C but not the 55°C bath. Arthritic cartilage displayed increased sensitivity with higher temperatures.

Conclusions

Understanding of the increased sensitivity to thermal stress of arthritic articular cartilage may be helpful in thermally based treatments.

Clinical Relevance

Further correlation with the temperatures attained during thermal chondroplasty will be necessary to confirm the clinical relevance of these in vitro observations to the use of radiofrequency energy devices to treat partial-thickness chondral lesions.
Imaging of the Elbow in the Overhead Throwing Athlete
Authors: Chen Andrew L. , Youm Thomas , Ong Bernard C. , Rafii Mahvash , Rokito Andrew S.
Published: July 2017

Elbow injuries in athletes who perform overhead throwing motions often present diagnostic challenges because of the undue stresses and often chronic, repetitive patterns of injury. Accurate and efficient assessment of the injured elbow is essential to maximize functional recovery and expedite return to play. Radiographic evaluation should be tailored to the specific injury suspected and requires a thorough understanding of normal anatomic relationships as well as familiarity with common injuries affecting these athletes.
Twisting and Braiding Reduces the Tensile Strength and Stiffness of Human Hamstring Tendon Grafts Used for Anterior Cruciate Ligament Reconstruction
Authors: Kim David H. , Wilson David R. , Hecker Aaron T. , Jung Tobias M. , Brown Charles H.
Published: July 2017

Background: Twisting and braiding of four-strand hamstring tendon grafts used for anterior cruciate ligament reconstruction has been proposed, but not proven, as a method of improving tensile properties.

Hypothesis: Twisting and braiding four-strand human hamstring tendon grafts will have no significant effect on initial graft strength or stiffness.

Study Design: Paired in vitro biomechanical study.

Methods: In 12 matched cadaveric pairs, a doubled gracilis and semitendinosus tendon graft from one knee was twisted 180° over a 30-mm length, while the doubled tendon graft from the contralateral knee was prepared for biomechanical testing with the graft strands in a parallel orientation. For an additional 12 matched pairs, a doubled graft was braided into a weave while the contralateral graft was prepared for testing in a parallel orientation. All four strands of each doubled tendon graft were equally tensioned with weights before being clamped in a tendon-freezing grip. Tensile testing was then performed.

Results: Twisting decreased graft strength by 26% (P < 0.01) and stiffness by 43% (P < 0.01), while braiding reduced strength by 46% (P < 0.01) and stiffness by 54% (P < 0.01), compared with parallel-oriented grafts.

Conclusions: Equally tensioned, parallel four-strand human hamstring tendon grafts were significantly stronger and stiffer than twisted or braided four-strand hamstring tendon grafts.

Clinical Relevance: We caution against the use of twisted or braided four-strand hamstring tendon grafts for anterior cruciate ligament reconstruction.
Results of Repeat Meniscal Repair
Authors: Voloshin Ilya , Schmitz Miguel A. , Adams Mark J. , DeHaven Kenneth E.
Published: July 2017

Background: The efficacy of repeat repair of retorn menisci has not been demonstrated.

Purpose: To document clinical and radiographic results of repeat repair of retorn menisci that had previously undergone primary repair.

Study Design: Uncontrolled retrospective review.

Methods: Eighteen consecutive repeat meniscal repairs were performed over an 11-year period.

Results: Fourteen of 18 patients (13 repeat meniscal repairs and 1 second repeat meniscal repair) had clinically intact menisci and were available for a mean follow-up of 7.33 years (range, 3.25 to 13.75). The average durability of the initial repair was 3.46 years (range, 0.17 to 14.67). Five patients sustained a tear at the site of rerepair; one underwent second repeat repair of the meniscus and the other four patients underwent partial meniscectomy. The mean Lysholm score for the remaining 14 patients was 82.1 (range, 38 to 100), and the mean Tegner score was 5.6 (range, 2 to 8). On the International Knee Documentation Committee rating scale, five knees received an overall rating of normal; six, nearly normal; and three, abnormal. Radiographs revealed grade 0 changes (normal) in five of the involved knee compartments and grade I changes (sclerosis or mild narrowing measuring 1 to 2 mm) in the remaining five.

Conclusions: Repeat repair of retorn menisci had a 72% survival rate with relief of symptoms and return to high levels of function.