bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hip Arthroscopy in Athletes
Authors: Thomas Byrd J. W. , Jones Kay S. 
Published: August 2009

Background Arthroscopy is a well-accepted technique in the management of many athletic-related hip disorders, yet little quantitative outcomes data have been reported. Purpose To report the results of hip arthroscopy in a consecutive series of athletes with 10-year follow-up. Study Design Case series; Level of evidence, 4. Methods Since 1993, all patients undergoing hip arthroscopy at our institution have been prospectively assessed with a modified Harris hip score preoperatively and then postoperatively at 1, 3, 6, 12, 24, 60, and 120 months or until a subsequent procedure was performed. The variables studied included age, sex, type of sport, level of sport, diagnosis, duration of symptoms, onset of symptoms, and center edge angle. Fifty-two procedures were performed on 50 patients who had achieved 10-year follow-up. Fifteen patients developed symptoms in the course of athletic activities and their cases represent the substance of this study. Results Follow-up information was available for all 15 patients (11 men and 4 women). The average age was 31.7 years (range, 14–70 years). Type of sport involved included football (3), tennis (3), basketball (2), golf (2), and others (5); with 9 recreational, 4 high school, and 2 intercollegiate athletes. Diagnoses included chondral damage (8), labral tear (7), arthritis (5), avascular necrosis (1), loose body (1), and synovitis (1). The median improvement in the modified Harris hip score was 45 points (from 51 preoperatively to 96, on the 100-point scale), with 13 patients (87%) returning to their sport. All 5 athletes with arthritis eventually underwent total hip arthroplasty at an average of 6 years. There were no complications. Conclusion Arthroscopy to address hip injuries in athletes can result in substantial improvement with durable results. However, arthritis is a prognostic indicator of poor long-term outcomes.
Comparison of Arthroscopic Medial Meniscal Suture Repair Techniques
Authors: Choi Nam-Hong , Kim Tae-Hyung , Victoroff Brian N. 
Published: August 2009

Background There are no reports comparing meniscal healing between inside-out and all-inside repairs using sutures. Hypothesis No difference in healing rate exists between meniscal repairs with inside-out and all-inside suture repair in conjunction with anterior cruciate ligament reconstruction with hamstring tendon. Study Design Cohort study; Level of evidence, 2. Methods Forty-eight consecutive patients underwent meniscal repairs of longitudinal tears of the posterior horn of the medial meniscus combined with anterior cruciate ligament reconstructions. All-inside repair was attempted when the tears were located in the red-red zone or the ramp area of the meniscus. If a tear that was in the ramp area or red-red zone extended to the midbody of the meniscus, or if there was a tear in red-white zone, the inside-out repair technique was used. Fourteen patients had all-inside meniscal repairs, and 34 patients had inside-out meniscal repairs with absorbable sutures. Identical postoperative rehabilitation protocols were used. Postoperative evaluations included Lysholm knee scoring scale, Tegner activity levels, Lachman and pivot-shift tests, and KT-1000 arthrometer. Assessment of meniscal status was performed using joint line tenderness, McMurray test, and range of motion. Follow-up magnetic resonance imaging scans were obtained on all patients. Results Mean follow-up was 35.7 months. No patient had joint line tenderness or reported pain or clicking on McMurray test. There was no significant difference in range of motion between groups. Follow-up magnetic resonance imaging scans demonstrated that 10 (71.4%) menisci were healed and 4 (28.6%) partially healed in the all-inside group; 24 (70.6%) menisci were healed and 10 (29.4%) partially healed in the inside-out group. There was no significant difference in meniscal healing between groups. There were no differences in Lachman test, KT-1000 arthrometer side-to-side differences measurements, Lysholm scores, and Tegner activity scales. There was a significant difference in pivot-shift test between groups ( P = .023). There were 2 complications associated with surgery. In the inside-out group, 1 patient required manipulation, and 2 patients had limited motion at final follow-up. Two patients in the inside-out group experienced transient saphenous nerve injury. Conclusion There was no significant difference in meniscal healing between inside-out and all-inside repair techniques in combination with anterior cruciate ligament reconstructions.
Application of Bone Marrow-Derived Mesenchymal Stem Cells in a Rotator Cuff Repair Model
Authors: Gulotta Lawrence V. , Kovacevic David , Ehteshami John R. , Dagher Elias , Packer Jonathan D. , Rodeo Scott A. 
Published: August 2009

Background Rotator cuff tendons heal to bone with interposed scar tissue, which makes repairs prone to failure. The purpose of this study was to determine if the application of bone marrow-derived mesenchymal stem cells (MSCs) can improve rotator cuff healing after repair. Hypothesis Application of MSCs to the repair site will result in superior results compared with controls on histologic and biomechanical testing. Study Design Controlled laboratory study. Methods Ninety-eight Lewis rats underwent unilateral detachment and repair of the supraspinatus tendon; 10 rats were used for MSC harvest. Eight animals were used for cell tracking with Ad-LacZ. The remaining animals received either 10 6 MSCs in a fibrin carrier, the carrier alone, or nothing at the repair site. Animals were sacrificed at 2 and 4 weeks for histologic analysis to determine the amount of fibrocartilage formation and the collagen organization at the insertion. Biomechanical testing was also performed. Results Specimens treated with Ad-LacZ–transduced MSCs exhibited more β-galactosidase activity at the repair site compared with controls at both 2 and 4 weeks, although activity at 4 weeks was less than that at 2 weeks. There were no differences in the amount of new cartilage formation or collagen fiber organization between groups at either time point. There were also no differences in the biomechanical strength of the repairs, the cross-sectional area, peak stress to failure, or stiffness. Conclusion The addition of MSCs to the healing rotator cuff insertion site did not improve the structure, composition, or strength of the healing tendon attachment site despite evidence that they are present and metabolically active. Clinical Relevance A biologic solution to the problem of tendon-to-bone healing in the rotator cuff remains elusive. The repair site may lack the cellular and/or molecular signals necessary to induce appropriate differentiation of transplanted cells. Further studies are needed to determine if cell-based strategies need to be combined with growth and differentiation factors to be effective.
Activity Level and Graft Type as Risk Factors for Anterior Cruciate Ligament Graft Failure
Authors: Borchers James R. , Pedroza Angela , Kaeding Christopher 
Published: August 2009

Background Anterior cruciate ligament (ACL) graft failure is an uncommon but devastating event after reconstruction, and risk factors for graft failure are not well understood. Hypothesis Returning to a high activity level after ACL reconstruction and use of an allograft are risk factors for ACL graft failure. Study Design Case-control study; Level of evidence, 3. Methods Twenty-one patients with ACL graft failure were identified over a 2-year period. Forty-two age- and sex-matched controls were identified over the same period. A 1:2 matched case-control design was used to evaluate activity level after reconstruction and graft type as risk factors for ACL graft failure. Logistic regression analysis was used to determine odds ratios for activity level after reconstruction and for graft type among cases and controls. Association (interaction) between activity level after reconstruction and graft type was evaluated comparing stratum-specific odds ratios. Results Univariate logistic regression models showed an increased odds of ACL graft failure for those with high activity level compared with low activity level (odds ratio [OR], 5.53; 95% confidence interval [CI], 1.18–28.61; P = .03) and for allografts compared with autografts (OR, 5.56; 95% CI 1.55–19.98; P = .009). A bivariate logistic regression model showed a 35% change in the odds ratio for activity level (OR, 4.33; 95% CI, 0.89–21.16; P = .07) and a 13% change in the odds ratio for allograft compared with autograft (OR, 4.93; 95% CI, 1.34–18.20; P = .02). Stratum-specific odds ratios between activity level and graft type show a multiplicative interaction between higher activity level and allograft for much greater odds of ACL graft failure. Conclusion Higher activity level after reconstruction and allograft use for reconstruction are risk factors for ACL graft failure. Stratum-specific odds ratios show a multiplicative interaction between higher activity level after ACL reconstruction and allograft use, greatly increasing the odds for ACL graft failure.
Defining Safe Rehabilitation for Ulnar Collateral Ligament Reconstruction of the Elbow
Authors: Bernas Geoffrey A. , Ruberte Thiele Ramon A. , Kinnaman Karen A. , Hughes Richard E. , Miller Bruce S. , Carpenter James E. 
Published: August 2009

Background Ulnar collateral ligament reconstruction of the elbow using a variety of techniques has been successful in enabling overhead athletes with ulnar collateral ligament insufficiency to return to competition. Most current postoperative rehabilitation programs begin with a period of motion restriction, including limiting elbow extension, that is followed by a transition from elbow strengthening to an interval throwing program, to competition. Motion restrictions early in the postoperative period may increase the risk for contractures. There is limited information to support current motion restrictions. Purpose (1) To determine strain on the reconstructed ulnar collateral ligament during a rehabilitation protocol that includes passive range of motion, isometric muscle contraction, and varus and valgus torques. (2) To develop guidelines for a safe initial rehabilitation protocol. Study Design Controlled laboratory study. Methods Eight cadaveric elbows underwent ulnar collateral ligament reconstruction with the docking technique using a gracilis tendon graft. Differential variable reluctance transducers on the anterior and posterior bands of the reconstructed anterior bundle of the ulnar collateral ligament were used to measure strain, while an optical motion tracking system monitored elbow motion. Strain was measured in the following 3 settings: passive range of motion, 22.2 N isometric flexion and extension contractions, and 3.34 N·m varus and valgus torques with the arm at 90° of flexion. Results Range of motion from maximum extension to 50° of flexion produced 3% or less strain in both bands of the reconstructed ligament. Forearm rotation did not significantly affect strain in the anterior or posterior bands ( P = .336 and P = .357). Strain at 90° approached 7% in the posterior band (upper 95% confidence interval). Isometric muscle contractions had no measurable effect on strain. Varus torques decreased and valgus torques increased strain significantly ( P < .05). Conclusion In the immediate postoperative period, full extension is safe, while flexion beyond 50° may place deleterious strain on the reconstruction. Isometric flexion and extension exercises do not increase ligament strain but may be unsafe at 90° of flexion, while valgus exercises (internal rotation at the shoulder) can increase strain in the reconstructed ligament. Clinical Relevance The results have implications for the development of appropriate rehabilitation protocols after ulnar collateral ligament reconstructive surgery.
Electromechanical Delay of the Knee Flexor Muscles Is Impaired After Harvesting Hamstring Tendons for Anterior Cruciate Ligament Reconstruction
Authors: Ristanis Stavros , Tsepis Elias , Giotis Dimitrios , Stergiou Nicholas , Cerulli Guiliano , Georgoulis Anastasios D. 
Published: August 2009

Background Changes in electromechanical delay during muscle activation are expected when there are substantial alterations in the structural properties of the musculotendinous tissue. In anterior cruciate ligament reconstruction, specific tendons are being harvested for grafts. Thus, there is an associated scar tissue development at the tendon that may affect the corresponding electromechanical delay. Purpose This study was conducted to investigate whether harvesting of semitendinosus and gracilis tendons for anterior cruciate ligament reconstruction will affect the electromechanical delay of the knee flexors. Study Design Case-control study; Level of evidence, 3. Methods The authors evaluated 12 patients with anterior cruciate ligament reconstruction with a semitendinosus and gracilis autograft, 2 years after the reconstruction, and 12 healthy controls. Each participant performed 4 maximally explosive isometric contractions with a 1-minute break between contractions. The surface electromyographic activity of the biceps femoris and the semitendinosus was recorded from both legs during the contractions. Results The statistical comparisons revealed significant increases of the electromechanical delay of the anterior cruciate ligament–reconstructed knee for both investigated muscles. Specifically, the electromechanical delay values were increased for both the biceps femoris ( P = .029) and the semitendinosus ( P = .005) of the reconstructed knee when compared with the intact knee. Comparing the anterior cruciate ligament–reconstructed knee against healthy controls revealed similar significant differences for both muscles (semitendinosus, P = .011; biceps femoris, P = .024). Conclusion The results showed that harvesting the semitendinosus and gracilis tendons for anterior cruciate ligament reconstruction significantly increased the electromechanical delay of the knee flexors. Increased hamstring electromechanical delay might impair knee safety and performance by modifying the transfer time of muscle tension to the tibia and therefore affecting muscle response during sudden movements in athletic activities. However, further investigation is required to identify whether the increased electromechanical delay of the hamstrings can actually influence optimal sports performance and increase the risk for knee injury in athletes with anterior cruciate ligament reconstructions.
Medial Open Wedge High Tibial Osteotomy
Authors: Wang Joon Ho , Bae Ji Hoon , Lim Hong Chul , Shon Won Yong , Kim Cheol Woong , Cho Jae Woo 
Published: August 2009

Background High tibial osteotomy can affect the posterior tibial slope in the sagittal plane because of the triangular configuration of the proximal tibia. However, the effect of the location of cortical hinge on posterior tibial slope has not been previously described. Hypothesis Posterolateral location of the cortical hinge will increase posterior tibial slope after medial open wedge osteotomy, and lateral location of the cortical hinge will not affect the change of the posterior tibial slope. Study Design Controlled laboratory study. Methods We performed incomplete valgus open wedge osteotomy on 12 paired knees of 6 fresh-frozen human cadavers (age, 63.4 ± 7.5 years) using an OrthoPilot navigation system. The left and right legs of each specimen were randomly assigned to a posterolateral (group A) or a lateral (group B) cortical hinge group. Changes in mean medial proximal tibial angle, posterior tibial slope, and opening wedge angle were measured and compared after surgery. Results In group A, mean medial proximal tibial angle changed from 84.37° ± 2.8° to 93.48° ± 3.06° ( P = .028); mean posterior tibial slope increased significantly from 8.71° ± 0.81° to 12.16° ± 0.84° ( P = .031); and mean wedge angle was 1.92° ± 0.46°. In group B, mean medial proximal tibial angle changed from 82.98° ± 2.53° to 90.89° ± 3.25° ( P = .027); mean posterior tibial slope changed from 9.19° ± 1.11° to 9.78° ± 1.27° ( P = .029); and mean wedge angle was 7.25° ± 0.72°. Conclusion The location of the intact cortical hinge affects the posterior tibia slope. During medial open wedge osteotomy, the change of posterior tibial slope was larger in the posterolateral than in the lateral cortical hinge group. Clinical Relevance To prevent the unintentional increase of the posterior tibial slope, special attention should be paid to locate the intact cortical hinge on the lateral, not the posterolateral, side of the tibia.
Effects of cigarette smoke on endothelial function of pulmonary arteries in the guinea pig
Authors: Ferrer Elisabet , Peinado Víctor Ivo , Díez Marta , Carrasco Josep Lluís , Musri Melina Mara , Martínez Anna , Rodríguez-Roisin Robert , Albert Barberà Joan 
Published: August 2009

AbstractBackgroundCigarette smoking may contribute to pulmonary hypertension in chronic obstructive pulmonary disease by altering the structure and function of pulmonary vessels at early disease stages. The objectives of this study were to evaluate the effects of long-term exposure to cigarette smoke on endothelial function and smooth muscle-cell proliferation in pulmonary arteries of guinea pigs.Methods19 male Hartley guinea pigs were exposed to the smoke of 7 cigarettes/day, 5 days/week, for 3 and 6 months. 17 control guinea pigs were sham-exposed for the same periods. Endothelial function was evaluated in rings of pulmonary artery and aorta as the relaxation induced by ADP. The proliferation of smooth muscle cells and their phenotype in small pulmonary vessels were evaluated by immunohistochemical expression of α-actin and desmin. Vessel wall thickness, arteriolar muscularization and emphysema were assessed morphometrically. The expression of endothelial nitric oxide synthase (eNOS) was evaluated by Real Time-PCR.ResultsExposure to cigarette smoke reduced endothelium-dependent vasodilatation in pulmonary arteries (ANOVA p < 0.05) but not in the aorta. Endothelial dysfunction was apparent at 3 months of exposure and did not increase further after 6 months of exposure. Smoke-exposed animals showed proliferation of poorly differentiated smooth muscle cells in small vessels (p < 0.05) after 3 months of exposure. Prolonged exposure resulted in full muscularization of small pulmonary vessels (p < 0.05), wall thickening (p < 0.01) and increased contractility of the main pulmonary artery (p < 0.05), and enlargement of the alveolar spaces. Lung expression of eNOS was decreased in animals exposed to cigarette smoke.ConclusionIn the guinea pig, exposure to cigarette smoke induces selective endothelial dysfunction in pulmonary arteries, smooth muscle cell proliferation in small pulmonary vessels and reduced lung expression of eNOS. These changes appear after 3 months of exposure and precede the development of pulmonary emphysema.
Long-range regulation is a major driving force in maintaining genome integrity
Authors: Mongin Emmanuel , Dewar Ken , Blanchette Mathieu 
Published: August 2009

Abstract

Background
The availability of newly sequenced vertebrate genomes, along with more efficient and accurate alignment algorithms, have enabled the expansion of the field of comparative genomics. Large-scale genome rearrangement events modify the order of genes and non-coding conserved regions on chromosomes. While certain large genomic regions have remained intact over much of vertebrate evolution, others appear to be hotspots for genomic breakpoints. The cause of the non-uniformity of breakpoints that occurred during vertebrate evolution is poorly understood.

Results
We describe a machine learning method to distinguish genomic regions where breakpoints would be expected to have deleterious effects (called breakpoint-refractory regions) from those where they are expected to be neutral (called breakpoint-susceptible regions). Our predictor is trained using breakpoints that took place along the human lineage since amniote divergence. Based on our predictions, refractory and susceptible regions have very distinctive features. Refractory regions are significantly enriched for conserved non-coding elements as well as for genes involved in development, whereas susceptible regions are enriched for housekeeping genes, likely to have simpler transcriptional regulation.

Conclusion
We postulate that long-range transcriptional regulation strongly influences chromosome break fixation. In many regions, the fitness cost of altering the spatial association between long-range regulatory regions and their target genes may be so high that rearrangements are not allowed. Consequently, only a limited, identifiable fraction of the genome is susceptible to genome rearrangements.
Disparities in allele frequencies and population differentiation for 101 disease-associated single nucleotide polymorphisms between Puerto Ricans and non-Hispanic whites
Authors: Mattei Josiemer , Parnell Laurence D , Lai Chao-Qiang , Garcia-Bailo Bibiana , Adiconis Xian , Shen Jian , Arnett Donna , Demissie Serkalem , Tucker Katherine L , Ordovas Jose M 
Published: August 2009

Abstract

Background
Variations in gene allele frequencies can contribute to differences in the prevalence of some common complex diseases among populations. Natural selection modulates the balance in allele frequencies across populations. Population differentiation (FST) can evidence environmental selection pressures. Such genetic information is limited in Puerto Ricans, the second largest Hispanic ethnic group in the US, and a group with high prevalence of chronic disease. We determined allele frequencies and population differentiation for 101 single nucleotide polymorphisms (SNPs) in 30 genes involved in major metabolic and disease-relevant pathways in Puerto Ricans (n = 969, ages 45–75 years) and compared them to similarly aged non-Hispanic whites (NHW) (n = 597).

Results
Minor allele frequency (MAF) distributions for 45.5% of the SNPs assessed in Puerto Ricans were significantly different from those of NHW. Puerto Ricans carried risk alleles in higher frequency and protective alleles in lower frequency than NHW. Patterns of population differentiation showed that Puerto Ricans had SNPs with exceptional FST values in intronic, non-synonymous and promoter regions. NHW had exceptional FST values in intronic and promoter region SNPs only.

Conclusion
These observations may serve to explain and broaden studies on the impact of gene polymorphisms on chronic diseases affecting Puerto Ricans.