Aman Gupta

Rush University Medical Center, Chicago, IL, United States

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Publications (6)17.15 Total impact

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    ABSTRACT: BACKGROUND:Suture anchor fixation has become the preferred method for arthroscopic repairs of rotator cuff tears. Recently, newer arthroscopic repair techniques including transosseous-equivalent repairs with anchors or arthroscopic transosseous suture passage have been developed. PURPOSE:To compare the initial biomechanical performance including ultimate load to failure and localized cyclic elongation between transosseous-equivalent repair with anchors (TOE), traditional transosseous repair with a curved bone tunnel (TO), and an arthroscopic transosseous repair technique utilizing a simple (AT) or X-box suture configuration (ATX). STUDY DESIGN:Controlled laboratory study. METHODS:Twenty-eight human cadaveric shoulders were dissected to create an isolated supraspinatus tear and randomized into 1 of 4 repair groups (TOE, TO, AT, ATX). Tensile testing was conducted to simulate the anatomic position of the supraspinatus with the arm in 60° of abduction and involved an initial preload, cyclic loading, and pull to failure. Localized elongation during testing was measured using optical tracking. Data were statistically assessed using analysis of variance with a Tukey post hoc test for multiple comparisons. RESULTS:The TOE repair demonstrated a significantly higher mean ± SD failure load (558.4 ± 122.9 N) compared with the TO (325.3 ± 79.9 N), AT (291.7 ± 57.9 N), and ATX (388.5 ± 92.6 N) repairs (P < .05). There was also a significantly larger amount of first-cycle excursion in the AT group (8.19 ± 1.85 mm) compared with the TOE group (5.10 ± 0.89 mm). There was no significant difference between repair groups in stiffness during maximum load to failure or in normalized cyclic elongation. Failure modes were as follows: TOE, tendon (n = 4) and bone (n = 3); TO, suture (n = 6) and bone (n = 1); AT, tendon (n = 2) and bone (n = 3) and suture (n = 1); ATX, tendon (n = 7). CONCLUSION:This study demonstrates that anchorless repair techniques using transosseous sutures result in significantly lower failure loads than a repair model utilizing anchors in a TOE construct. CLINICAL RELEVANCE:Suture anchor repair appears to offer superior biomechanical properties to transosseous repairs regardless of tunnel or suture configuration.
    The American journal of sports medicine 12/2012; · 3.61 Impact Factor
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    ABSTRACT: This study determines the biomechanical advantage and the optimal configuration of a high tibial osteotomy (HTO) and meniscus transplantation performed concurrently. Six cadaver knees were placed in a spatial frame, and an HTO was completed. Loading points between a mechanical 6 degrees of varus and 8 degrees ofvalgus were loaded to 800 N for medial meniscal intact, meniscectomized, and transplanted states. Posterior slope was also increased by 3 degrees in these specimens. Contact data was recorded. Peak pressures significantly increased in the meniscectomized state in every degree of varus/valgus (p < 0.05). For both peak and total medial compartment pressures, there was a significant drop (p < 0.001) between neutral and 3 degrees of valgus. Lateral compartment pressures linearly increased from varus to valgus orientation. There was no significant change in the pressure profile of the knee with a 3-degree increase in posterior slope. This biomechanical study confirms the hypothesis that an HTO improves the peak pressures in the medial compartment at all degrees of varus/valgus alignment in the setting of meniscal transplantation. Furthermore, the largest decrease in medial pressures was between neutral and 3 degrees of valgus, suggesting that perhaps neutral aligned knees could benefit from an HTO.
    The journal of knee surgery 03/2011; 24(1):45-53.
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    ABSTRACT: Multiple bone-grafting procedures have been described for patients with glenoid bone loss and shoulder instability. The purpose of this study was to investigate the alterations in glenohumeral contact pressure associated with the placement and orientation of Latarjet or iliac crest bone graft augmentation and to compare the amount of glenoid bone reconstruction with two coracoid face orientations. Twelve fresh-frozen cadaver shoulders were tested in static positions of humeral abduction (30 degrees , 60 degrees , and 60 degrees with 90 degrees of external rotation) with a 440-N compressive load. Glenohumeral contact pressure and area were determined sequentially for (1) the intact glenoid; (2) a glenoid with an anterior bone defect involving 15% or 30% of the glenoid surface area; (3) a 30% glenoid defect treated with a Latarjet or iliac crest bone graft placed 2 mm proud, placed flush, or recessed 2 mm in relation to the level of the glenoid; and (4) a Latarjet bone block placed flush and oriented with either the lateral (Latarjet-LAT) or the inferior (Latarjet-INF) surface of the coracoid as the glenoid face. The amount of glenoid bone reconstructed was compared between the Latarjet-LAT and Latarjet-INF conditions. Bone grafts in the flush position restored the mean peak contact pressure to 116% of normal when the iliac crest bone graft was used (p < 0.03 compared with the pressure with the 30% defect), 120% when the Latarjet-INF bone block was used (p < 0.03), and 137% when the Latarjet-LAT bone block was used (p < 0.04). Use of the Latarjet-LAT bone block resulted in mean peak pressures that were significantly higher than those associated with the iliac crest bone graft (p < 0.02) or the Latarjet-INF bone block (p < 0.03) at 60 degrees of abduction and 90 degrees of external rotation. With the bone grafts placed in a proud position, peak contact pressure increased to 250% of normal (p < 0.01) in the anteroinferior quadrant and there was a concomitant increase in the posterosuperior glenoid pressure to 200% of normal (p < 0.02), indicating a shift posteriorly. Peak contact pressures of bone grafts placed in a recessed position revealed high edge-loading. Augmentation with the Latarjet-LAT bone block led to restoration of the glenoid articular contact surface from the 30% defect state to a 5% defect state. Augmentation of the 30% glenoid defect with the Latarjet-INF bone block resulted in complete restoration to the intact glenoid articular surface area. Glenohumeral contact pressure is optimally restored with a flush iliac crest bone graft or with a flush Latarjet bone block with the inferior aspect of the coracoid becoming the glenoid surface. Bone grafts placed in a proud position not only increase the peak pressure anteroinferiorly, but also shift the articular contact pressure to the posterosuperior quadrant. Glenoid bone augmentation with a Latarjet bone block with the inferior aspect of the coracoid as the glenoid surface resulted in complete restoration of the 30% anterior glenoid defect to the intact state. These findings indicate the clinical utility of a flush iliac crest bone graft and utilization of the inferior surface of the coracoid as the glenoid face for glenoid bone augmentation with a Latarjet graft.
    The Journal of Bone and Joint Surgery 06/2010; 92(6):1478-89. · 3.23 Impact Factor
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    ABSTRACT: In sum, 1-, 2-, and 4-stranded allografts are used for soft tissue anterior cruciate ligament reconstruction; however, the fixation properties of fixation devices are not well assessed. There are no differences in the biomechanical characteristics of 1 (Achilles)-, 2 (posterior tibialis)-, and 4 (semitendinosus)-stranded allograft tibial fixation. Controlled laboratory study. Sixty-three fresh-frozen porcine tibiae were used to evaluate the fixation of 1-, 2-, and 4-stranded human tendon allografts (Achilles, posterior tibialis, and semitendinosus) with 3 fixation devices (Delta, Intrafix, and Calaxo screws). With use of a materials testing system, each graft was subjected to 500 cycles of loading (50-250 N, 0.75 mm/sec) to determine displacement and cyclic stiffness, followed by a monotonic failure test (20 mm/min) to determine maximum load and pullout stiffness. For each graft type, there were no significant biomechanical differences between fixation devices. However, the 1-stranded graft (Achilles) construct demonstrated significantly higher mean displacement (3.17 +/- 1.62 mm), lower cyclical stiffness (156 +/- 25 N/mm), lower load to failure (479 +/- 87 N), and lower pullout stiffness (140 +/- 28 N/mm). In comparison with the 2-stranded graft (posterior tibialis), the 4-stranded graft (semitendinosus) exhibited lower displacement (0.86 +/- 0.44 to 1.12 +/- 0.51 mm) and higher ultimate failure load (832 +/- 255 to 656 +/- 168 N). Numerous differences in fixation properties were noted when comparing a device to each of the 3 grafts. The 1-stranded allograft demonstrated inferior biomechanical tibial fixation properties when compared with 2 (posterior tibialis)- and 4 (semitendinosus)-stranded allograft constructs for all fixation devices tested. This study demonstrated that not all tibial fixation devices are designed to adequately accommodate different types of anterior cruciate ligament allografts. Biomechanical evidence suggests that caution is warranted when using an Achilles allograft fixated solely with an interference device.
    The American journal of sports medicine 06/2009; 37(8):1531-8. · 3.61 Impact Factor
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    ABSTRACT: Although a tibial inlay technique for posterior cruciate ligament reconstruction is advantageous, metallic screw fixation of the bone block is required. This may pose problems for future surgery (eg, osteotomies, total knee replacement). There is no significant difference in the biomechanical integrity of bone block fixation using stainless steel versus bioabsorbable screw fixation of the tibial inlay graft in posterior cruciate ligament reconstruction. Controlled laboratory study. Fourteen human cadaveric knees were randomized to receive either stainless steel or bioabsorbable screw fixation of a bone-patellar tendon-bone graft. Cyclic tensile testing of each construct was performed, followed by a load-to-failure test. Digital video digitization was used to optically determine tendon graft deformation. Cyclic creep deformation showed no significant difference between the 2 groups (P = .8). The failure load (stainless steel, 461 +/- 231 N; bioabsorbable, 638 +/- 492 N; P = .7) and linear stiffness (stainless steel, 116 +/- 22 N/mm, bioabsorbable, 106 +/- 44 N/mm; P = .6) also showed no significant difference between the 2 groups. Optically measured graft deformation was not significant for distal (P = .7) and midsubstance (P = .8) regions, while proximal deformation was significantly higher for bioabsorbable fixation (P = .02). All samples failed at the tibial insertion site with the tibial bone block fracturing at the screws. Bioabsorbable screw fixation using a tibial inlay technique does not compromise the strength and stiffness characteristics afforded by metallic fixation. From a biomechanical perspective, bioabsorbable screws are a viable alternative to metal in the context of tibial inlay reconstruction. Use of bioabsorbable fixation can potentially eliminate future hardware problems after posterior cruciate ligament reconstruction using a tibial inlay technique.
    The American journal of sports medicine 02/2009; 37(4):748-53. · 3.61 Impact Factor
  • Arthroscopy The Journal of Arthroscopic and Related Surgery 01/2009; 25(6):e7. · 3.10 Impact Factor