Handedness-related outcome following arthroscopic shoulder stabilization.

INTRODUCTION: Bankart's repair technique represents a standard procedure for arthroscopic shoulder stabilization with excellent functional outcomes. Information concerning handedness-related outcome is missing. Here, we compare the postoperative outcome following arthroscopic shoulder stabilization in relation to handedness, taking sex and age as covariates into account. PATIENTS AND METHODS: Our retrospective dual-cohort study included 36 patients with dominant side shoulder instability (mean follow-up 33 months) and 31 patients with non-dominant side shoulder instability (mean follow-up 41 months), who underwent arthroscopic shoulder stabilization due to traumatic anterior-inferior shoulder instability. All had experienced recurrent dislocations preoperatively. The impact of handedness, and of age and sex as covariates on postoperative outcome was evaluated by the Rowe score, the apprehension test and self-reported VAS. RESULTS: Postoperatively, the Rowe score of the dominant side (mean 81.8, median 97.5) and the non-dominant side (mean 84.8, median 100) was not different (P = 0.718). Likewise, the univariate analysis for handedness (P = 0.806), sex (P = 0.627) and age (P = 0.929) as well as multivariate analysis for handedness (P = 0.721), sex (P = 0.583) and age (P = 0.898) showed no difference. The apprehension test for dominant versus non-dominant side operated patients was not different (P = 0.194). The univariate and multivariate analysis for handedness (P = 0.202 and P = 0.387, respectively) and age (P = 0.322 and P = 0.310, respectively) revealed no difference. However, the univariate and multivariate analysis for sex (P = 0.007 and P = 0.013, respectively) showed a difference. In relation to handedness, the results for the validated self-reported pain (rest pain P = 0.696, load-dependent pain P = 0.332) and surgery outcome satisfaction (P = 0.912) VAS were not different. CONCLUSIONS: Patients with shoulder instability, who underwent arthroscopic Bankart repair for stabilization of their dominant or non-dominant shoulder showed no handedness-related difference in postoperative outcome based on Rowe score, apprehension test and self-reported VAS. For the orthopedic practice, this suggests that handedness is not a risk factor for patients outcome. LEVEL OF EVIDENCE: Level IV, cohort study.

Injection with autologous conditioned serum has better clinical results than eccentric training for chronic Achilles tendinopathy.

PURPOSE: Chronic Achilles tendinopathy is one of the most common causes of malfunction and pain, which can lead to a significant reduction of the quality of life. The hypothesis of this study argues that autologous conditioned serum (i.e. Orthokine) injections in chronic midportion Achilles tendinopathy have a better outcome than eccentric training. METHODS: This study investigates, retrospectively, the effects of peritendinous autologous conditioned serum injections as compared to standard eccentric training in 50 patients with chronic Achilles tendinopathy between 2012 and 2015. Before injection or eccentric training and 6 weeks, 12 weeks and 6 months thereafter, the patients were assessed by means of the VISA-A-G score (Victorian Institute of Sport Assessment-Achilles questionnaire-German). An MRI was also performed before and 6 months after injection and eccentric training. RESULTS: Both patient groups had statistically significant better VISA-A-G scores after injection or eccentric training compared to the baseline before injection (90 vs 40, respectively, P < 0.001) or eccentric training (81 vs 47, respectively, P < 0.001). Comparing the baseline corrected VISA-A-G scores, patients in the autologous-conditioned-serum-group had significantly higher changes in VISA-A-G scores than the eccentric-training-group after 12 weeks (40 vs 36, P = 0.018) and 6 months (50 vs 34, P = 0.034). Both patient groups had statistically significant (P < 0.001) reduction of tendon thickness (autologous conditioned serum: 0.32; eccentric training: 0.24) and length of bursa (autologous conditioned serum: 0.24; eccentric training: 0.21) as well as significant (P < 0.001) improvement of tendon quality in MRI (autologous conditioned serum: 14 vs 1; eccentric training: 14 vs 2). There were no statistical differences in MRI-findings between the two groups. CONCLUSION: Both therapies led to improvement of MRI-findings, including reduction of tendon thickness and tendon quality. Autologous-conditioned-serum-injections show greater clinical long-term benefit as compared to eccentric training and, therefore, offers a good alternative to eccentric training. LEVEL OF EVIDENCE: Therapeutic studies, Level III.

Follistatin-like protein 1 modulates IL-17 signaling via IL-17RC regulation in stromal cells.

Follistatin-like protein 1 (FSTL-1) possesses several newly identified roles in mammalian biology, including interleukin (IL)-17-driven inflammation, though the mechanism underlying FSTL-1 influence on IL-17-mediated cytokine production is unknown. Using parallel in vitro bone marrow stromal cell models of FSTL-1 suppression, we employed unbiased microarray analysis to identify FSTL-1-regulated genes and pathways that could influence IL-17-dependent production of IL-6 and granulocyte colony-stimulating factor. We discovered that FSTL-1 modulates Il17rc gene expression. Specifically, FSTL-1 was necessary for Il17rc gene transcription, IL-17RC surface protein expression and IL-17-dependent cytokine production. This work identifies a mechanism by which FSTL-1 influences IL-17-driven inflammatory signaling in vitro and reveals a novel function for FSTL-1, as a modulator of gene expression. Thus enhanced understanding of the interplay between FSTL-1 and IL-17-mediated inflammation may provide insight into potential therapeutic targets of IL-17-mediated diseases and warrants ongoing study of in vivo models and clinical scenarios of FSTL-1-influenced diseases.

Operative Techniques For Treatment Of Chronic Massive Rotator Cuff Lesions : Deltoid Flap Transfer Versus Arthroscopic Debridement.

The treatment of chronic massive rotator cuff lesions remains challenging. Extensive reconstruction techniques as deltoid flap transfer as well as low invasive arthroscopic debridement techniques were established and showed good results. In present study 106 patients with massive rotator cuff lesions were treated by deltoid muscle flap transfer (n = 47 group I) and by arthroscopic debridement (n = 59 group II). Postoperative outcome was determined by amount of pain, range of motion, shoulder functionality according to Constant-Murley Shoulder Score and radiological assessment of acromiohumeral distance (AHD). Statistically analysis was done by the T-Test and Mann-Whitney-U-Test. Both groups showed significant improvement of range of motion compared to preoperative situation, but statistical analysis revealed no significant difference between both groups either in flexion or abduction. Overall shoulder functionality increased significantly in group I (30,2 points) and group II (20,6 points) postoperative, however group I improved significantly more in overall functionality compared to group II (p < 0,01). Therefore, present study showed that surgical treatment with arthroscopic debridement or deltoid muscle flap transfer can improve shoulder function in patients with chronic massive rotator cuff lesions. Deltoid muscle flap showed significantly better results in overall shoulder function and seems superior regarding clinical outcome. However, in regard to the good outcome a detailed risk-benefit analysis should be done before a deltoid-flap transfer is performed.

The effect of subacromial injections of autologous conditioned plasma versus cortisone for the treatment of symptomatic partial rotator cuff tears.

PURPOSE: Rotator cuff tears are one of the most common causes of shoulder malfunction and pain, which lead to a significant reduction in the quality of life. This present study investigated the effects of subacromial platelet-rich plasma injections [i.e. autologous conditioned plasma (ACP) injections] as compared to standard subacromial cortisone injection therapy in 50 patients with partial rotator cuff tears. METHODS: Before injection, and 6 weeks, 12 weeks and 6 months thereafter, the patients were assessed by the Constant-Murley score (CMS), the American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES), the simple shoulder test (SST) and a pain visual analogue scale (VAS). An MRI was also performed before and 6 months after injection. RESULTS: Both patient groups had statistically significant better shoulder score outcomes over time. ASES, SST and CMS outcomes after 12 versus 6 weeks were better in the ACP group as compared to the cortisone group. VAS, ASES and CMS outcomes after 12 weeks versus baseline in the ACP group were better as compared to the cortisone group. There was a statistically significant difference between ACP group and cortisone group 12 weeks after injection regarding VAS, ASES, SST and CMS in favour of the ACP group. The MRI showed an improvement in grade of tendinopathy in both groups, however, without statistically significant differences between the two groups. CONCLUSION: Compared with cortisone injections, ACP injections show earlier benefit as compared to cortisone injections although a statistically significant difference after 6 months could not be found. Therefore, subacromial ACP injections are a good alternative to subacromial cortisone injections, especially in patients with contraindication to cortisone. LEVEL OF EVIDENCE: Therapeutic study, Level III.

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.

Surgical technique for treatment of concomitant grade II MCL lesion in patients with ACL rupture.

Combined lesions of anterior cruciate ligament (ACL) and medial collateral ligament (MCL) are frequent in athletes. While surgical treatment of ACL injury is mandatory treatment regime of concomitant grade II MCL lesions remains unclear with tendency to surgical intervention. Standardized surgical technique is lacking. Present study wants to introduce surgical technique for treatment of concomitant grade II MCL lesion and report short term outcome results. 5 Patients with acute ACL rupture and grade II MCL-lesion were included. All patients received surgical treatment of concomitant MCL lesion by distinct surgical technique and ACL reconstruction. We evaluated valgus instability, anterior instability and range of motion (ROM) according to international knee documentation commitee (IKDC) and Lysholm­Score both preoperative and after 6, 16 weeks and 9 months postoperative. All Patients showed excellent clinical results at final follow-up. Valgus and anterior stability could be restored in all patients. 1 patient (20%) lost 15° in flexion of ROM at final follow up. However in all 5 patients (100%) the findings were graded as normal or nearly nor-mal according to IKDC knee examination form. Lysholm-Score averaged 94,6. Therefore presented surgical technique improved both, valgus and anterior stability, and led to excellent short term results at final follow up.

Frozen shoulder--comparison of different surgical treatment options.

In this study data from 54 patients with persisting primary frozen shoulder were collected and evaluated retrospectively. All included patients underwent a specific kind of surgical treatment of the shoulder. Three different surgical techniques were compared to each other. A group of 21 patients received a combination of arthroscopic capsular release and subacromial decompression. 18 patients were treated by subacromial decompression combined with mobilization under anesthesia and 15 patients underwent selective arthroscopic capsular release. We evaluated glenohumeral range of motion in every patient pre-and postoperatively. The investigated directions of motion were abduction, flexion and external rotation. The collected results were compared statistically. The mean follow-up of the treated patients was 37 weeks (range 11-52 weeks). All three surgical treatments improved the range of movement in every glenohumeral direction significantly. They achieved equal improvements in abduction and flexion. Regarding external rotation selective arthroscopic capsular release revealed not significantly better results than the other two surgical treatments, but there was a trend towards significance (p-value 0.0694). This study showed that all performed surgical techniques improved ranges of movement in the glenohumeral joint in patients with persistent frozen shoulder. Arthroscopic capsular release, alone or with subacromial decompression, is a safe procedure and showed the best results postoperatively. In our opinion arthroscopic capsular release should be recommended as the first choice treatment in persistent frozen shoulder.

Improvement of tendon repair using muscle grafts transduced with TGF-ß1 cDNA.

Tendon rupture is a common injury. Inadequate endogenous repair often leaves patients symptomatic, with tendons susceptible to re-rupture. Administration of certain growth factors improves tendon healing in animal models, but their delivery remains a challenge. Here we evaluated the delivery of TGF-ß1 to tendon defects by the implantation of genetically modified muscle grafts. Rat muscle biopsies were transduced with recombinant adenovirus encoding TGF-ß1 and grafted onto surgically transected Achilles tendons in recipient animals. Tissue regenerates were compared to those of controls by biomechanical testing as well as histochemical and immunohistochemical analyses. Healing was greatly accelerated when genetically modified grafts were implanted into tendon defects, with the resulting repair tissue gaining nearly normal histological appearance as early as 2 weeks postoperatively. This was associated with decreased deposition of type III collagen in favour of large fibre bundles indicative of type I collagen. These differences in tendon composition coincided with accelerated restoration of mechanical strength. Tendon thickness increased in gene-treated animals at weeks 1 and 2, but by week 8 became significantly lower than that of controls suggesting accelerated remodelling. Thus localised TGF-ß1 delivery via adenovirus-modified muscle grafts improved tendon healing in this rat model and holds promise for clinical application.

Effect of BMP-12, TGF-ß1 and autologous conditioned serum on growth factor expression in Achilles tendon healing.

PURPOSE: Achilles tendon ruptures are devastating and recover slowly and incompletely. There is a great demand for biomolecular therapies to improve recovery, yet little is understood about growth factors in a healing tendon. Here, the role of growth factors during tendon healing in a rat model and their reaction to single and multiple growth factor treatment are explored. METHODS: Rat tendons were transected surgically and resutured. The expression of bFGF, BMP-12, VEGF and TGF-ß1 was assessed by immunohistochemical analysis one to 8 weeks after surgery. Paracrine effects of TGF-ß1 or BMP-12 added by adenoviral transfer, as well as the effect of autologous conditioned serum (ACS) on growth factor expression, were evaluated. RESULTS: bFGF, BMP-12 and VEGF expression was highest 1 week after transection. bFGF and BMP-12 declined during the remaining period whereas VEGF expression persisted. TGF-ß1 expression dramatically increased after 8 weeks. ACS treatment increased bFGF (P = 0.007) and BMP-12 (P = 0.004) expression significantly after 8 weeks. Also overall expression of bFGF, BMP-12 and TGF-ß1 regardless of time point was significantly greater than controls with ACS treatment (P < 0.05). Both BMP-12 and TGF-ß1 treatments had no significant effect. No effect was observed in VEGF with any treatment. CONCLUSION: bFGF, BMP-12, VEGF and TGF-ß1 are differentially expressed during tendon healing. Additional BMP-12 or TGF-ß1 has no significant influence, whereas ACS generally increases expression of all factors except VEGF. Staged application of multiple growth factors may be the most promising biomolecular treatment.

Development of a force-determining tensor to measure "physiologic knee ligament gaps" without bone resection using a total knee arthroplasty approach.

BACKGROUND: Ligament balancing is a challenging but essential part of successful total knee arthroplasty. There is general agreement that flexion and extension gaps should be equal and symmetrical. However, to date there are no available comparisons to physiologically normal knee joints that have not undergone bone resection. There are also no standards specifying which instruments (e.g., spacers, distractors, trial components, navigation systems) and particularly what degree of force should be used for gap distraction. METHODS: To measure the physiological extension and flexion gaps, a prototypical force-determining tensor (Aesculap, Tuttlingen, Germany) was constructed and adapted so that force could be applied directly through Schanz screws inserted medially and laterally on the tibia and femur, independent of each other and without the need for bony resection. Ten normal cadaveric knees were assessed using a standard medial parapatellar total knee arthroplasty approach with patellar subluxation. Gap measurements were carried out twice, alternating distraction forces of 100 and 200 N each time. RESULTS: The prototype was implemented successfully. Repeat measurements showed only slight deviation from the original, resulting in minimal standard error. Precision did not vary with the application of greater force (200 N), but gap size increased significantly (p < 0.001). CONCLUSIONS: The success of this assessment with cadaveric knees indicates that this prototype can be applied to measure flexion and extension gaps without the need for bony resection. Increasing the distraction force to 200 N does not improve results, so 100 N per compartment appears adequate. Most likely, the extension and flexion gaps are physiologically asymmetric and unequal, and the kinematics are markedly altered after resection of the PCL and/or ACL. This new force-determining tensor can be used for further analyses, e.g., to explore the effects of selective ligament resection.

Double-plate fixation in lateral clavicle fractures-a new strategy.

BACKGROUND: Lateral clavicle fractures Neer type II often lead to the dislocation of the medial fragment and an increased rate of nonunion after conservative treatment. Therefore, most authors recommend an open reduction and internal fixation. Double-plate fixation is a common technique in the treatment of complex radius fractures. The authors use it as a routine procedure in the treatment of lateral clavicle fractures Neer type II. In this article, we present our experiences. METHODS: From January 2006 to June 2008, 11 patients with lateral clavicle fractures of Neer type II were treated with an open reduction and internal fixation using the double-plate technique. RESULTS: All patients showed osseous union on radiographs after 10 weeks to 16 weeks. In eight of nine cases, the operated shoulder regained full range of motion. In all patients, we observed immediate postoperative recovery without severe complications. One female patient complained about slight pain and restricted motion in abduction of > 90°. In two patients, we observed the migration of one screw. It was removed under local anesthesia 9 weeks and 26 weeks after surgery. CONCLUSIONS: This study, for the first time, describes the technique of double-plate fixation for the treatment of lateral clavicle fractures. This technique provides a stable fixation even in small and comminuted distal fragments.

Clostridial Infection After Open Fractures of the Lower Extremity - Report of Two Cases and Discussion of Pathomechanism and Treatment.

BACKGROUND: Management of post-traumatic open fractures resulting from severe injuries of the lower extremity continues to challenge orthopedic and reconstructive surgeons. Moreover, post-traumatic osteoarticular infections due to Clostridium species are rare, with few reports in the literature. We describe possible pathomechanisms and propose treatment options for cases of delayed diagnosis of osteoarticular infections with Clostridium spp. CASE REPORTS: Two patients sustained severe osteoarticular infection due to Clostridium spp. after open epi- and metaphyseal fractures of the lower extremity. In combination with radical debridement, ankle arthrodesis and long-term antibiotic treatment, satisfactory results were achieved after a follow-up of 18 months and 24 years. CONCLUSION: Clostridium species are difficult to identify, treatment is usually delayed and most patients have unfavourable outcomes.

Rotatory stability of the knee after arthroscopic meniscus suture repair: a 5-to-17-year follow-up study of isolated medial and lateral meniscus tears.

The long-term rotatory stability of meniscus suture repair has not been firmly established clinically. Up to now there are only experimental studies done. This retrospective study aimed to compare the long-term rotatory stability of a knee with a meniscus suture repair with the stability of the uninjured knee in each of a cohort of patients. We evaluated both knees of 64 patients at an average follow-up of 11 years (range : 5 to 17) after successful arthroscopic meniscus suture repair. Each patient's injury was an isolated longitudinal-vertical meniscus tear and each patient's opposite knee was uninjured. All repairs were performed with the same outside in meniscus suture repair technique. Evaluation included standardised clinical examination, anterior stability testing with a ligament testing device, and rotational testing with a rotational laxiometer. In the stability assessments, the mean anteroposterior translation was the same for repaired and uninjured knees: 3 mm at 67 N and 5 mm at 89 N. The mean external rotation was the same in repaired knees and uninjured knees at 20 degrees of flexion (22 degrees) and similar in repaired knees (22 degrees) and uninjured knees (23 degrees) at 90 degrees flexion. The mean internal rotation was similar in repaired knees (12 degrees) and uninjured knees (13 degrees) at 20 degrees and 90 degrees of flexion. Our findings indicate that a knee with arthroscopic meniscus suture repair displays a rotational stability that is equal to or nearly equal to the stability of an uninjured knee. However, whether rotational stability will only be preserved due to meniscus repair and how much of the meniscus needs to be preserved in order to maintain the biomechanical stability of the knee remains unclear.

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.

A biomechanical comparison of two plating techniques in lateral clavicle fractures.

BACKGROUND: Neer Type IIb lateral clavicle fractures typically lead to dislocation of the medial fragment. Therefore, most surgeons recommend surgical treatment for such a fracture pattern. The use of a locking compression plate with a lateral extension has produced satisfactory results in various studies over recent years. Double-plate fixation is a common technique in the treatment of complex distal radius fractures. The authors use this technique as a routine procedure in the treatment of Neer type IIb fractures. In this biomechanical testing study, the mechanical properties of the two techniques were compared. METHODS: On 20 clavicles from fresh frozen cadavers a Neer Type IIb fracture-like osteotomy was performed. A cyclic loading test followed by a load-to-failure test was carried out. Parameters for statistical evaluation were the stiffness at cycles 1, 100 and 17,500 as well as the ultimate tensile load and the deformation at the point of failure. FINDINGS: All specimens withstood the cyclic loading test without any noticeable damage. At cycles 100 and 17,500, the double-plate technique was less stiff. Failure loads were not significantly different from each other, but deformation at the point of failure was significantly greater for the double-plate technique. INTERPRETATION: Both techniques provided sufficient fixation to the fracture site to endure the cyclic loading test, which is supposed to simulate an incident-free week postoperatively. In summary, the double-plate technique offers biomechanically a feasible alternative to the single-plate technique in lateral clavicle fractures of Neer Type IIb.

Quercetin transiently increases energy expenditure but persistently decreases circulating markers of inflammation in C57BL/6J mice fed a high-fat diet.

Quercetin, a polyphenolic compound and a major bioflavonoid in the human diet, has anti-inflammatory properties and has been postulated to enhance energy expenditure (EE). We sought to determine whether quercetin alters body weight, body composition, EE, and circulating markers of inflammation. At 6 weeks (W) of age, 2 cohorts of C57BL/6J mice (N = 80) were placed on one of 2 diets for 3W or 8W: (1) high fat (HF) (45% kcal fat) or (2) high fat + quercetin (HF + Q) (45% kcal fat + 0.8% quercetin). Quercetin concentrations in the diet and plasma were evaluated using mass spectrometry. Body weight, composition (nuclear magnetic resonance), and food consumption were measured weekly. Energy expenditure was measured by indirect calorimetry at 3 and 8W, and inflammatory markers were measured in plasma obtained at 8W. The presence of quercetin in the HF diet did not alter food consumption over time in the HF + Q group and did not differ from the HF group at any time point. However, circulating plasma quercetin concentrations declined between 3 and 8W. At 3W, EE was higher during both day and night phases (P < .0001) in the HF + Q group compared with the HF group; but this difference was not detected at 8W and did not translate into significant differences between the HF + Q and HF groups with respect to body weight or body composition. During the night phase, concentrations of the inflammatory markers (interferon-gamma, interleukin-1alpha, and interleukin-4) were significantly lower when compared with HF treatment group (P < .05). Dietary supplementation with quercetin produces transient (3W) increases in EE that are not detected after 8W on the diet. A corresponding decrease in circulating quercetin between 3 and 8W suggests that metabolic adaptation may have diminished the impact of quercetin's early effect on EE and diminished its overall effect on nutrient partitioning and adiposity. However, quercetin at the levels provided was effective in reducing circulating markers of inflammation observed in animals on an HF diet at 8W.

Comparison of 2 plating techniques for lateral clavicle fractures, using a new standardized biomechanical testing setup.

BACKGROUND: Conservative treatment of lateral clavicle fractures (Neer type II) often ends with unsatisfactory results for patients. Operative treatment is thus gaining acceptance. A retrospective study found success using a double plate technique for these injuries. For the current study, a standardized testing setup was developed to compare the mechanical properties of single versus double plate technique for lateral clavicle fractures. METHODS: Six synthetic bones were tested for each technique. Neer type IIB fractures were created using computer-aided design (CAD). Fatigue testing was carried out with a cantilever bending test. Parameters measured were cycles undergone, failure load and stiffness at the point of failure. RESULTS: The standardized testing setup was able to provide reproducible failures. The double plate technique lasted about 16,000 more cycles and withstood an additional 22.4 N on average. CONCLUSIONS: The new modified standardized testing setup produced reproducible fixation failures for both clavicle fracture fixation techniques. The double plate technique seems to be mechanically superior to the single plate technique.

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.

Results of a New Treatment Concept for Concomitant Lesion of Medial Collateral Ligament in Patients with Rupture of Anterior Cruciate Ligament.

Anteromedial knee injury with rupture of anterior cruciate ligament (ACL) and concomitant lesion of medial collateral ligament (MCL) is common in athletes. No standardized treatment concept can be found within the literature. This study presents results of a new treatment concept for concomitant MCL lesions in patients with ACL rupture. In this study, 67 recreational athletes with ACL injury and concomitant MCL lesion were treated according to a distinct treatment concept. Patients were classified in six different types of concomitant MCL lesion depending on grade of MCL lesion and presence of anteromedial rotatory instability (AMRI). Final classification and surgical indication were determined 6 weeks posttraumatic. All patients received ACL reconstruction. MCL was treated by surgical or conservative regime due to type of concomitant MCL lesion. International Knee Documentation Committee (IKDC), AMRI, and Lysholm scores were evaluated both preoperatively and after 6 weeks, 16 weeks, 12 months, and 18 months postoperatively. All patients could be uniquely classified and treated according to the introduced treatment concept. AMRI was verifiable in patients with grade II and III MCL lesions. All patients showed good to excellent clinical results at the follow-up examinations. In all 67 patients (100%), the findings were graded as normal or nearly normal according to the IKDC knee examination form. Lysholm score averaged 93.9 at final follow-up. The introduced treatment concept showed good results on short-term outcome and provides a sufficient treatment strategy for concomitant MCL lesions in athletes with ACL rupture.