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1.
A Randomized Controlled Trial of PEEK Versus Titanium Interference Screws for Anterior Cruciate Ligament Reconstruction With 2-Year Follow-up.
Shumborski, S, Heath, E, Salmon, LJ, Roe, JP, Linklater, JP, Facek, M, Pinczewski, LA
The American journal of sports medicine. 2019;(10):2386-2393
Abstract
BACKGROUND Graft fixation with interference screws for anterior cruciate ligament (ACL) reconstruction is a highly successful technique. Polyether ether ketone (PEEK) is a novel thermoplastic polymer with high biocompatibility and mechanical properties that mimic native bone, and it can be imaged on computed tomography or magnetic resonance imaging (MRI) without signal flare. PURPOSE To compare the clinical performance of ACL reconstruction with PEEK and titanium interference screws at 2 years and to evaluate a novel method of measuring tunnel volume. STUDY DESIGN Randomized controlled trial; Level of evidence, 1. METHODS A total of 133 patients underwent arthroscopic ACL reconstruction with 4-strand hamstring autografts and were randomized to have titanium or PEEK interference screws for femoral and tibial tunnel fixation. At 2 years, subjective Lysholm and International Knee Documentation Committee scores were assessed and clinical examination performed. At 12 months, MRI was performed to assess graft incorporation and cyst formation, and a novel technique was employed to measure tunnel volumes. RESULTS There were no significant differences in graft rerupture rate, contralateral ACL rupture rate, subjective outcomes, or objective outcomes. In the titanium and PEEK groups, MRI demonstrated high overall rates of graft integration (96%-100% and 90%-93%, respectively) and ligamentization (89% and 84%) and low rates of synovitis (22% and 10%) and cyst formation (0%-18% and 13%-15%). There was a higher proportion of patients with incomplete graft integration within the femoral tunnel in the PEEK group as compared with the titanium group (10% vs 0%, P = .03); however, the authors suggest that metal artifact precluded proper assessment of the graft in the titanium group by MRI. Tunnel volumes also appeared to be equivalent in the 2 groups and were measured with a novel technique that was highly reproducible in the PEEK group secondary to the absence of flare. CONCLUSION Two-year clinical analysis of PEEK interference screws for femoral and tibial fixation of ACL reconstructions showed equivalent clinical performance to titanium interference screws. Given the excellent mechanical characteristics, biological compatibility, and absence of metal artifact on MRI, PEEK has become our material of choice for interference screw fixation in ACL reconstruction.
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Minimizing Injury and Maximizing Return to Play: Lessons from Engineered Ligaments.
Baar, K
Sports medicine (Auckland, N.Z.). 2017;(Suppl 1):5-11
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Abstract
Musculoskeletal injuries account for more than 70% of time away from sports. One of the reasons for the high number of injuries and long return to play is that we have only a very basic understanding of how our training alters tendon and ligament (sinew) structure and function. Sinews are highly dense tissues that are difficult to characterize both in vivo and in vitro. Recently, engineered ligaments have been developed in vitro using cells from human anterior cruciate ligaments or hamstring tendons. These three-dimensional tissues can be grown in a laboratory, treated with agents thought to affect sinew physiology, and then mechanically tested to determine their function. Using these tissues, we have learned that sinews, like bone, quickly become refractory to an exercise stimulus, suggesting that short (<10 min) periods of activity with relatively long (6 h) periods of rest are best to train these tissues. The engineered sinews have also shown how estrogen decreases sinew function and that a factor released following intense exercise increases sinew collagen synthesis and function. Last, engineered sinews are being used to screen possible nutritional interventions that may benefit tendon or ligament function. Using the data derived from these tissue-engineered sinews, new nutritional and training regimes are being designed and tested with the goal of minimizing injury and accelerating return to play.
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Osteoarthritis-related biomarkers following anterior cruciate ligament injury and reconstruction: a systematic review.
Harkey, MS, Luc, BA, Golightly, YM, Thomas, AC, Driban, JB, Hackney, AC, Pietrosimone, B
Osteoarthritis and cartilage. 2015;(1):1-12
Abstract
OBJECTIVE There is an increased risk of developing knee osteoarthritis (OA) following anterior cruciate ligament (ACL) injury. Biomarkers may provide diagnostic, prognostic, or burden of disease indicators of OA before radiographic changes become apparent. Unfortunately, there has been no systematic review to clarify which biomarkers may be most informative following injury. Therefore, this review critically investigated existing studies of OA-related biomarkers in ACL-deficient (ACL-D) and reconstructed (ACL-R) patients to summarize the current evidence and identify knowledge gaps. DESIGN A systematic review of the literature in Web of Science and PubMed databases (1960-June 2014) was performed. All English-language case-control and longitudinal studies assessing OA-related biomarkers in ACL-D and ACL-R patients were considered. Data regarding biomarker changes over time within ACL-D and ACL-R patients as well as differences in ACL-D/ACL-R patients compared with a control group were extracted from pertinent studies. RESULTS A descriptive summary of 20 included studies was produced. In ACL-D patients compared with controls, synovial fluid biomarkers indicated elevated collagen turnover, while the inflammatory cytokine response was inconclusive. In ACL-R patients, serum concentrations indicated decreased collagen breakdown, but urine concentrations were indicative of greater collagen breakdown when compared to controls. Compared to preoperative values, the overall inflammatory cytokine response measured with synovial fluid biomarkers increased while plasma biomarkers did not change following reconstruction. CONCLUSION Patients with ACL-D or ACL-R have altered biomarkers indicative of OA. More research with standardized reporting is needed to effectively determine which biomarkers are the most indicative for OA development and progression following ACL injury.
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Serum cytokines and muscle strength after anterior cruciate ligament surgery are not modulated by high-doses of vitamins E (α- and γ-tocopherol's) and C.
Barker, T, Henriksen, VT, Rogers, VE, Trawick, RH
Cytokine. 2015;(2):279-86
Abstract
The purpose of this investigation was to identify if supplemental vitamin E (consisting of α- and γ-tocopherol's) and C modulate serum cytokine and muscle strength following an ACL injury and surgery. Subjects were randomly assigned to one of two groups: (1) placebo (n=14) or (2) vitamins E (α-[600m g RRR-α-tocopherol, αT] and γ-[600 mg of RRR-γT]) and C (1000 mg ascorbic acid, AA) (EC; n=15). Supplements were taken daily starting ∼2-wk prior to and concluding 16-wk after surgery. Fasting blood samples were obtained and single-leg peak isometric force measurements were performed at baseline (prior to supplementation), before surgery (∼120-min - blood draw only), and 8-wk, 12-wk, and 16-wk after surgery. αT, γT, AA, and cytokines were measured in each blood sample, and peak isometric force was measured on the injured and non-injured legs separately at each testing session. An exercise protocol consisting of repetitive knee and hip extension and flexion contractions to exhaustion was performed on the injured limb at 16-wk. Vitamin E and C supplementation significantly (all p<0.05) increased plasma αT (∼40%), γT (∼160%), and AA (∼50%) concentrations. Serum cytokine concentrations, peak isometric force, and time to exhaustion during the exercise protocol were not significantly different between groups. Based on these findings, we conclude that vitamin E and C supplementation increases their endogenous levels without minimizing muscular weakness or modulating serum cytokine concentrations after ACL surgery.
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The effects of isometric and isotonic training on hamstring stiffness and anterior cruciate ligament loading mechanisms.
Blackburn, JT, Norcross, MF
Journal of electromyography and kinesiology : official journal of the International Society of Electrophysiological Kinesiology. 2014;(1):98-103
Abstract
Greater hamstring musculotendinous stiffness is associated with lesser ACL loading mechanisms. Stiffness is enhanced via training, but previous investigations evaluated tendon rather than musculotendinous stiffness, and none involved the hamstrings. We evaluated the effects of isometric and isotonic training on hamstring stiffness and ACL loading mechanisms. Thirty-six healthy volunteers were randomly assigned to isometric, isotonic, and control groups. Isometric and isotonic groups completed 6 weeks of training designed to enhance hamstring stiffness. Stiffness, anterior tibial translation, and landing biomechanics were measured prior to and following the interventions. Hamstring stiffness increased significantly with isometric training (15.7%; p=0.006), but not in the isotonic (13.5%; p=0.089) or control (0.4%; p=0.942) groups. ACL loading mechanisms changed in manners consistent with lesser loading, but these changes were not statistically significant. These findings suggest that isometric training may be an important addition to ACL injury prevention programs. The lack of significant changes in ACL loading mechanisms and effects of isotonic training were likely due to the small sample sizes per group and limited intervention duration. Future research using larger sample sizes and longer interventions is necessary to determine the effects of enhancing hamstring stiffness on ACL loading and injury risk.
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Operative and nonoperative treatment options for ACL tears in the adult patient: a conceptual review.
Bogunovic, L, Matava, MJ
The Physician and sportsmedicine. 2013;(4):33-40
Abstract
Injury to the anterior cruciate ligament (ACL) is common among athletic individuals. Both nonoperative and operative treatment options exist. The optimal treatment of an adult with an ACL tear depends on several patient-specific factors, including age, occupation, and desired activity level. In less active patients with sedentary jobs, nonoperative management, consisting of physical therapy, bracing, and activity modification can yield successful results. In active patients who want to resume participation in jumping, cutting, or pivoting sports, patients who have physically demanding occupations, or patients who fail a trial of nonoperative management, ACL reconstruction is recommended. Reconstruction utilizing autograft tissue is preferred over allograft, especially in the younger athlete, but allograft tissue is a reasonable option in the older (aged > 40 years) and less active adult, as well. Successful results have been achieved with both patellar tendon and hamstring grafts. The optimal treatment in adult patients with ACL tears should be based on careful consideration of the patient's goals for return to activity, knee-specific comorbidities, such as coexistent meniscal pathology or osteoarthritis, and his or her willingness to follow a detailed rehabilitation regimen. Our article provides an overview of current nonoperative and operative treatment options for adults with ACL tears, considers the outcomes of both nonoperative and operative strategies, and provides general recommendations as to the ideal management for a given patient.
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Effect of calcium phosphate-hybridized tendon graft in anterior cruciate ligament reconstruction: a randomized controlled trial.
Mutsuzaki, H, Kanamori, A, Ikeda, K, Hioki, S, Kinugasa, T, Sakane, M
The American journal of sports medicine. 2012;(8):1772-80
Abstract
BACKGROUND The authors developed a novel technique to improve tendon-bone healing by hybridizing calcium phosphate (CaP) with a tendon graft using an alternating soaking process. HYPOTHESIS Anterior cruciate ligament (ACL) reconstruction using the CaP-hybridized tendon graft would have a better clinical outcome and reduce the percentage of bone tunnel enlargement compared with a conventional method because of the enhanced anchoring between the tendon graft and the bone. STUDY DESIGN Randomized controlled trial; Level of evidence, 1. METHODS Patients (N = 64) with unilateral ACL rupture underwent arthroscopically assisted single-bundle ACL reconstruction using a 4-strand semitendinosus tendon or 4-strand semitendinosus and gracilis tendons with EndoButton femoral fixation and screw washer tibial fixation. These patients were equally randomized to undergo the CaP (n = 32) or conventional (n = 32) method using a transtibial tunnel approach according to the closed envelope method. In the CaP group, the tendon graft was hybridized with the CaP at both ends of the graft. One surgeon performed all reconstructions without knowing which graft was prepared. Patients' backgrounds regarding age at surgery, gender, period before surgery, and associated meniscal injuries were similar in the 2 groups. All patients followed the same postoperative protocol. At 1 and 2 years after surgery, they were evaluated with the manual knee laxity test, KT-1000 arthrometry, International Knee Documentation Committee (IKDC) examination form, Tegner scale, and Lysholm scale. Also, 1 year postoperatively, bone tunnel enlargement was analyzed using computed tomography, intensity of the tendon graft by magnetic resonance imaging (MRI), and tendon graft appearance by arthroscopic examination. All the examinations were performed blindly. RESULTS All patients underwent a minimum 2-year follow-up. KT-1000 arthrometry data indicated statistically significant decreased average anterior tibial translation in the CaP group compared with the conventional method group: 1.0 ± 2.0 mm versus 1.9 ± 1.6 mm (P < .05), respectively, at 1 year; 1.6 ± 2.1 mm versus 2.6 ± 2.4 mm (P < .05), respectively, at 2 years. The Lysholm score was higher in the CaP group than in the conventional method group at 2 years (96.9 ± 4.3 vs 91.7 ± 13.3, P < .05). The CaP-hybridized tendon graft reduced the percentage of bone tunnel enlargement of the anteroposterior diameter at the main joint aperture site 1 year postoperatively (femoral side: 15.5% ± 13.4% vs 22.1% ± 16.4%, P < .05; tibial side: 19.3% ± 17.1% vs 26.1% ± 13.7%, P < .05). The results of the pivot-shift test, IKDC grade, and Tegner score; the intensity of the tendon graft (MRI); and arthroscopic appearance were not significantly different at both follow-up periods in the 2 groups. CONCLUSION The CaP-hybridized tendon graft improved anterior knee stability and Lysholm scores at the 2-year follow-up and improved anterior knee stability and reduced the percentage of bone tunnel enlargement in both tunnels at the 1-year follow-up compared with the conventional method for single-bundle ACL reconstruction. However, longer follow-up is needed to investigate the appearance of any increased instability.
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Vitamins E and C modulate the association between reciprocally regulated cytokines after an anterior cruciate ligament injury and surgery.
Barker, T, Martins, TB, Hill, HR, Kjeldsberg, CR, Trawick, RH, Leonard, SW, Walker, JA, Traber, MG
American journal of physical medicine & rehabilitation. 2011;(8):638-47
Abstract
OBJECTIVE : The purpose of this study was to identify the influence of vitamin E and C supplementation on inflammatory cytokines and the association between reciprocally regulated cytokines after anterior cruciate ligament surgery. DESIGN : A double-blind, placebo-controlled study was conducted in men undergoing anterior cruciate ligament surgery who were randomly assigned to one of two groups (n = 10/group): (1) antioxidant (vitamins E and C) or (2) matching placebos starting ∼2 wks before (baseline) and concluding 3 mos after surgery. Plasma inflammatory cytokines were measured in fasting blood draw samples before and after anterior cruciate ligament surgery. RESULTS : Plasma interleukin (IL) 1β concentrations were double at 3 mos after surgery compared with baseline. Plasma IL-1β increased to a greater (P < 0.05) extent relative to IL-4 in the placebo group (mean ± SE slope, 18.87 ± 0.68; r = 0.97) than in the antioxidant group (mean ± SE slope, 4.84 ± 0.42; r = 0.89). Similarly, the relative increase in IL-1β to IL-2 was greater (P < 0.05) in the placebo (mean ± SE slope, 2.70 ± 0.21) than in the antioxidant (mean ± SE slope, 1.08 ± 0.23) group. CONCLUSIONS : Vitamins E and C were ineffective in ameliorating the increases in IL-1β but altered associations between reciprocally regulated cytokines after anterior cruciate ligament surgery.
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Antioxidant supplementation lowers circulating IGF-1 but not F(2)-isoprostanes immediately following anterior cruciate ligament surgery.
Barker, T, Leonard, SW, Trawick, RH, Walker, JA, Traber, MG
Redox report : communications in free radical research. 2009;(5):221-6
Abstract
Interleukin (IL)-10 is an anti-inflammatory cytokine that suppresses pro-inflammatory cytokines. We previously demonstrated that supplementation with vitamins E and C ameliorated the increase in IL-10 immediately following anterior cruciate ligament (ACL) surgery in the absence of other cytokine perturbations. Since both oxidative stress and insulin-like growth factor-1 (IGF-1) can modulate IL-10 concentrations, the mechanisms for these changes warranted further investigation. Our objective was to evaluate the mechanism for the IL-10 decrease following ACL surgery. This study consisted of randomized, double-blind, placebo-controlled experimental design. Subjects were randomly assigned to daily supplementation with either: (i) antioxidants (AO; vitamins E [alpha-tocopherol] and C [ascorbic acid]; n = 10); or (ii) matching placebos (PL; n = 10). Supplementation started approximately 2 weeks prior to surgery (baseline) and concluded 3 months after surgery. Subjects provided six fasting blood samples at: (i) baseline; (ii) immediately pre-surgery (Pre); (iii) 90 min; (iv) 72 h; (v) 7 days; and (vi) 3 months post-surgery. alpha-Tocopherol, ascorbic acid, F(2)-isoprostane and IGF-1 concentrations were measured in each blood sample. At 90 min relative to other times, plasma F(2)-isoprostane concentrations were significantly (P < 0.05) elevated in both groups, while at 90 min IGF-1 was significantly (P < 0.05) lower in the AO compared to the PL group. The changes in IGF-1 at 90 min relative to baseline were correlated (P < 0.0001) with the changes in IL-10. The decrease in IL-10 observed in the AO group is likely dependent on the decrease IGF-1 since lipid peroxidation was unchanged between the two groups.
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Efficacy of continuous femoral nerve block with stimulating catheters versus nonstimulating catheters for anterior cruciate ligament reconstruction.
Dauri, M, Sidiropoulou, T, Fabbi, E, Giannelli, M, Faria, S, Mariani, P, Sabato, AF
Regional anesthesia and pain medicine. 2007;(4):282-7
Abstract
BACKGROUND AND OBJECTIVES This prospective randomized controlled trial investigated the clinical efficacy of stimulating catheters for continuous femoral nerve block in patients who underwent anterior cruciate ligament reconstruction. METHODS Seventy patients were randomized to either a stimulating catheter (SC, n = 35) or a nonstimulating catheter (NSC, n = 35) for femoral nerve block using 25 mL ropivacaine 7.5 mg/mL and clonidine 50 microg injected through the catheter. A single-injection sciatic block was also given to ensure surgical anesthesia. The time to loss of sensation to cold and pinprick of the femoral nerve was registered as the onset time. Data were registered intra- and postoperatively regarding pain scores, adverse effects, and need for supplemental anesthesia and analgesia other than a continuous postoperative infusion of ropivacaine 2 mg/mL through the continuous femoral nerve catheter set at 7 mL/h. RESULTS Onset time was faster in the SC group (SC: 6.4 +/- 2.5, NSC: 8.3 +/- 2.9 min, P = .006). Visual analog scale pain scores were similar in both groups. The number of patient-controlled regional analgesia boluses (SC: 14.6 +/- 12.6, NSC: 23.2 +/- 13.6 mg ropivacaine 2 mg/mL, P = .008) as well as intravenous rescue ketorolac (SC: 34.3 +/- 35.7, NSC: 54 +/- 39.7 mg, P = .033) administered were higher in the NSC group. CONCLUSION Although the use of a stimulating catheter was associated with faster onset time for the femoral nerve block and lower additional analgesics postoperatively, the clinical superiority (analgesia; lateral femoral cutaneous, and obturator nerve block) of stimulating catheters was not evident in this clinical setting.