Publications by authors named "Theodore B Shybut"

13 Publications

  • Page 1 of 1

Higher Incidence of Complete Lateral Meniscal Root Tears in Revision Compared With Primary Anterior Cruciate Ligament Reconstruction.

Arthrosc Sports Med Rehabil 2021 Apr 31;3(2):e367-e372. Epub 2021 Jan 31.

Joseph Barnhart Department of Orthopedic Surgery, Baylor College of Medicine, Houston, Texas, U.S.A.

Purpose: To evaluate the incidence of complete lateral meniscal posterior root tears (LMPRTs) repaired at revision as compared with primary anterior cruciate ligament (ACL) reconstruction (PACLR) and to determine whether other demographic or surgical characteristics were associated with LMPRTs needing repair.

Methods: A chart review was performed to identify the PACLR and revision ACL reconstruction (RACLR) cohorts. Demographic and surgical characteristics were recorded. Cases with concurrent lateral meniscal posterior root repair were identified. Cases were classified as acute (<5 months) or chronic (>5 months) based on the time from reported injury to surgery. Tunnel malposition in revision cases was recorded if either tunnel or both tunnels were malpositioned on radiographs and magnetic resonance imaging.

Results: Data from 167 cases, 140 PACLR and 27 RACLR cases, were included. The cohorts had similar demographic characteristics including age, sex, and lateral meniscal injury. The overall incidence of lateral meniscal root repair in ACL reconstruction patients was 12.6% (21 of 167 patients). The incidence of LMPRT repair was 7.1% (10 of 140 patients) in the PACLR cohort versus 40.7% (11 of 27 patients) in the RACLR cohort. The revision cohort was significantly more likely to have a chronic injury (66.7% [18 of 27 patients] vs 31.4% [44 of 140 patients]). The most significant predictor of concurrent lateral meniscal posterior root repair was RACLR versus PACLR for both univariate and multivariate logistic regression analyses (χ = 20.603; < .0001; odds ratio, 13.887; 95% confidence interval, 1.531-125.993). Analysis of tunnel positions for the revision group revealed that PACLR tunnel malposition was a significant predictor of LMPRTs (χ = 4.91,  = .027).

Conclusions: Complete LMPRTs warranting repair are encountered with a significantly greater frequency at RACLR as compared with PACLR. The overall incidence of LMPRT repair at RACLR is high. In this cohort, LMPRT repair in RACLR cases was associated with tunnel malposition of the PACLR.

Level Of Evidence: Level III, retrospective cohort study.
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April 2021

Editorial Commentary: This Is the Way: Extra-Articular Augmentation Is an Essential Consideration in Contemporary Anterior Cruciate Ligament Surgery.

Arthroscopy 2021 05;37(5):1667-1669

Since the rediscovery of the anterolateral ligament, extra-articular augmentation (EA) has evolved from controversial to an essential consideration in contemporary anterior cruciate ligament reconstruction surgery. Anterolateral ligament (ALL) reconstruction and lateral extra-articular tenodesis are 2 common methods. Indications among early adopters pioneering anterolateral ligament reconstruction at anterior cruciate ligament surgery included revision anterior cruciate ligament (ACL) case, chronic ACL tear, high-grade pivot shift, and patients with hyperlax, hypermobile knees. Newer indications include young patient age, pivoting sport/high-demand/high-risk athlete, and concurrent medial meniscus repair. Questions remain regarding best practices as indications continue to evolve regarding technique, graft choice, angle/position of reconstruction fixation, and whether EA should be reconstructed routinely. This fast-moving surgical evolution serves as a reminder of 2 key concepts; first, that anterior cruciate ligament tears occur more fundamentally in the setting of anterolateral rotatory instability, in which concurrent soft tissue injuries are common, and, second, that even our best "anatomic" reconstructions do not fully recapitulate the native ACL, both of which give impetus to reconstructing the ALL.
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May 2021

Fellowship Training Is a Significant Predictor of Sports Medicine Physician Social Media Presence.

Arthrosc Sports Med Rehabil 2021 Feb 30;3(1):e199-e204. Epub 2021 Jan 30.

Baylor College of Medicine, Houston, Texas, U.S.A.

Purpose: To quantify social media use of professional sports team physicians on popular platforms and analyze differences between users and nonusers.

Methods: Team physicians for professional sports teams in the National Football League, National Hockey League, Major League Baseball, and National Basketball Association were identified and characterized based on training background, practice setting, and geographic location. Rates of social media presence on Facebook, Twitter, LinkedIn, Instagram, and ResearchGate were determined. Differences between social media users and nonusers were analyzed.

Results: In total, 505 professional team physicians were identified across 4 major professional sports; 64.6% of physicians were orthopaedic surgeons. Of 505 physicians, 65.7% had a social media presence. More specifically, 21.8% had a professional Facebook page, 22.6% a professional Twitter page, 52.1% a LinkedIn profile, 21.4% a ResearchGate profile, and 9.1% an Instagram account. Fellowship-trained physicians ( = .008) had greater odds of having a social media presence.

Conclusions: Nearly two-thirds of professional team physicians have a social media presence, most commonly LinkedIn. Fellowship training is a significant predictor of sports medicine physician social media presence. Sports league affiliation, training background, practice setting, and geographic location are unrelated to social media presence.

Level Of Evidence: IV, cross-sectional study.
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February 2021

Osteochondral Autograft Transfer for Capitellar Chondral and Osteochondral Defects.

Arthrosc Tech 2020 Nov 20;9(11):e1727-e1730. Epub 2020 Nov 20.

Department of Orthopaedic Surgery, Baylor College of Medicine, Houston, Texas, U.S.A.

Chondral and osteochondral lesions of the humeral capitellum, most notably osteochondritis dissecans, most commonly present in adolescent baseball players and gymnasts. A variety of surgical techniques can be used to address these lesions. Osteochondral autograft transfer has recently shown superior rates of return to sport. We describe osteochondral autograft transfer from the contralateral knee to treat a large full-thickness chondral lesion of the humeral capitellum. Osteochondral allograft backfill of the donor site is shown as well. This surgical procedure is technically demanding but very reproducible and maximizes return to play in patients while minimizing donor-site morbidity.
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November 2020

Risk factors for hardware removal following operative treatment of middle- and distal-third clavicular fractures.

J Shoulder Elbow Surg 2021 Mar 11;30(3):e103-e113. Epub 2020 Jul 11.

Kelsey-Seybold Clinic, Houston, TX, USA.

Background: The incidence of hardware removal (HWR) after operative fixation of clavicular fractures varies widely. Risk factors related to HWR remain incompletely understood. The aim of this study was to evaluate the incidence of and risk factors for HWR after plate fixation of middle- and distal-third clavicular fractures. We hypothesized that (1) the total HWR incidence would be <20%, (2) the HWR incidence of operatively treated distal- and middle-third clavicular fractures would not be statistically different, and (3) symptomatic implants would be the most common HWR indication.

Methods: We performed a multi-hospital retrospective study of skeletally mature patients who underwent plate fixation of middle- and distal-third clavicular fractures from November 2008 to November 2018. Data included patient demographic characteristics, mechanism of injury, operative records, hardware-related symptoms, subsequent HWR, and complications.

Results: A total of 103 patients (aged 16-75 years, 76.7% male patients) were included. Of the patients, 87 (84.5%) underwent plate fixation for midshaft clavicular fractures and 16 (15.5%) underwent plate fixation for distal-third clavicular fractures. HWR was performed in 13 patients (12.6%). A significantly higher percentage of HWR procedures were performed for distal clavicular fractures (50%) than for middle-third clavicular fractures (4.9%, P < .0001). An initial high-energy mechanism of injury was associated with HWR (P = .0025). The most common indication for HWR was symptomatic hardware (69.2%). The overall complication rate was 14.5%.

Conclusion: The overall incidence of clavicular HWR was 12.6%. A distal fracture location was associated with a significantly higher incidence of HWR. An initial high-energy mechanism of injury was a significant risk factor for HWR. The primary indication for HWR was symptomatic hardware.
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March 2021

Effects of Aspirin on Growth Factor Release From Freshly Isolated Leukocyte-Rich Platelet-Rich Plasma in Healthy Men: A Prospective Fixed-Sequence Controlled Laboratory Study.

Am J Sports Med 2019 04 19;47(5):1223-1229. Epub 2019 Mar 19.

Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.

Background: The benefits of platelet-rich plasma (PRP) are believed to be in part dependent on growth factor release after platelet activation. Platelet activation is complex and involves multiple mechanisms. One important mechanism is driven by cyclooxygenase 1 (COX-1)-mediated conversion of arachidonic acid (AA) to precursor prostaglandins that then mediate proinflammatory responses that trigger growth factor release. Acetylsalicylic acid (ASA; also known as aspirin) is known to irreversibly inhibit COX-1, thereby blocking AA-mediated signaling; however, it is unclear whether ASA use alters growth factor release from freshly isolated PRP.

Purpose: To assess the effects of low-dose ASA use on activation of growth factor release from freshly isolated human PRP via AA and thrombin (TBN).

Study Design: Controlled laboratory study.

Methods: Twelve healthy men underwent blood collection and leukocyte-rich PRP (LR-PRP) preparation through a double-spin protocol to obtain baseline whole blood and PRP counts the same day. PRP was aliquoted into 3 groups: nonactivated, AA activated, and TBN activated. Immediately after activation, the concentrations of transforming growth factor β1 (TGF-β1), vascular endothelial growth factor (VEGF), and platelet-derived growth factor AB (PDGF-AB) were measured using enzyme-linked immunosorbent assays (ELISAs). The same 12 participants were then placed on an 81-mg daily dose of oral ASA for 14 days. Repeat characterization of whole blood and PRP analyses was done on day 14, followed by repeat ELISAs of growth factors under the same nonactivated and activated settings as previously stated.

Results: Fourteen days of daily ASA had no effect on the number of platelets and leukocytes measured in whole blood and LR-PRP. Compared with nonactivated LR-PRP, AA- and TBN-mediated activation led to significant release of VEGF and PDGF-AB. In contrast, release of TGF-β1 from LR-PRP was observed only with activation by AA, not with TBN. Consistent with its inhibitory role in AA signaling, ASA significantly inhibited AA-mediated release of all 3 growth factors measured in this study. Although ASA had no effect on TBN-mediated release of VEGF and TGF-β1 from LR-PRP, ASA did partially block TBN-mediated release of PDGF-AB, although the mechanism remains unclear.

Conclusion: Daily use of low-dose ASA reduces VEGF, PDGF-AB, and TGF-β1 expression in freshly isolated human LR-PRP when activated with AA.

Clinical Relevance: Reduction in growth factor release attributed to daily use of low-dose ASA or other COX inhibitors can be mitigated when PRP samples are activated with TBN. Clinical studies are needed to determine whether activation before PRP injection is needed in all applications where ASA is in use and to what extent ASA may inhibit growth factor release in vivo at the site of injury.
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April 2019

Efficacy of a Virtual Arthroscopic Simulator for Orthopaedic Surgery Residents by Year in Training.

Orthop J Sports Med 2018 Nov 21;6(11):2325967118810176. Epub 2018 Nov 21.

Department of Orthopedic Surgery, Baylor College of Medicine, Houston, Texas, USA.

Background: Virtual reality arthroscopic simulators are an attractive option for resident training and are increasingly used across training programs. However, no study has analyzed the utility of simulators for trainees based on their level of training/postgraduate year (PGY).

Purpose/hypothesis: The primary aim of this study was to determine the utility of the ArthroS arthroscopic simulator for orthopaedic trainees based on their level of training. We hypothesized that residents at all levels would show similar improvements in performance after completion of the training modules.

Study Design: Descriptive laboratory study.

Methods: Eighteen orthopaedic surgery residents performed diagnostic knee and shoulder tasks on the ArthroS simulator. Participants completed a series of training modules and then repeated the diagnostic tasks. Correlation coefficients () were calculated for improvements in the mean composite score (based on the Imperial Global Arthroscopy Rating Scale [IGARS]) as a function of PGY.

Results: The mean improvement in the composite score for participants as a whole was 11.2 ± 10.0 points ( = .0003) for the knee simulator and 14.9 ± 10.9 points ( = .0352) for the shoulder simulator. When broken down by PGY, all groups showed improvement, with greater improvements seen for junior-level residents in the knee simulator and greater improvements seen for senior-level residents in the shoulder simulator. Analysis of variance for the score improvement variable among the different PGY groups yielded an value of 1.640 ( = .2258) for the knee simulator data and an value of 0.2292 ( = .917) for the shoulder simulator data. The correlation coefficient () was -0.866 for the knee score improvement and 0.887 for the shoulder score improvement.

Conclusion: Residents training on a virtual arthroscopic simulator made significant improvements in both knee and shoulder arthroscopic surgery skills.

Clinical Relevance: The current study adds to mounting evidence supporting virtual arthroscopic simulator-based training for orthopaedic residents. Most significantly, this study also provides a baseline for evidence-based targeted use of arthroscopic simulators based on resident training level.
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November 2018

Triceps Ruptures After Fluoroquinolone Antibiotics: A Report of 2 Cases.

Sports Health 2017 Sep/Oct;9(5):474-476. Epub 2017 Jun 13.

Baylor College of Medicine, Houston, TX.

Rupture of the triceps brachii tendon is exceedingly rare, and surgical repair is generally indicated. Fluoroquinolone antibiotics have been implicated in tendon pathology, including tendon ruptures. Triceps rupture has not been previously reported in the setting of fluoroquinolone antibiotic therapy. We present 2 cases of triceps tendon rupture after treatment with fluoroquinolones. In both cases, triceps repair was performed with good outcomes. These cases highlight a risk of fluoroquinolone-induced tendinopathy to athletes. The sports medicine team should be aware of this risk and consider it when choosing antibiotics to treat athletes.
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September 2017

Posterior Root Meniscal Tears: Preoperative, Intraoperative, and Postoperative Imaging for Transtibial Pullout Repair.

Radiographics 2016 Oct;36(6):1792-1806

From the Departments of Radiology (A.R.P., R.R.W., M.H.W., C.D.B.) and Orthopedic Surgery (T.B.S.), Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030.

The menisci play an important biomechanical role in axial load distribution of the knees by means of hoop strength, which is contingent on intact circumferentially oriented collagen fibers and meniscal root attachments. Disruption of the meniscal root attachments leads to altered biomechanics, resulting in progressive cartilage loss, osteoarthritis, and subchondral edema, with the potential for development of a subchondral insufficiency fracture. Identification of meniscal root tears at magnetic resonance (MR) imaging is crucial because new arthroscopic surgical techniques (transtibial pullout repair) have been developed to repair meniscal root tears and preserve the tibiofemoral cartilage of the knee. An MR imaging classification of posterior medial meniscal root ligament lesions has been recently described that is dedicated to the posterior root of the medial meniscus. An arthroscopic classification of meniscal root tears has been described that can be applied to the anterior and posterior roots of both the medial meniscus and the lateral meniscus. This arthroscopic classification includes type 1, partial stable root tears; type 2, complete radial root tears; type 3, vertical longitudinal bucket-handle tears; type 4, complex oblique tears; and type 5, bone avulsion fractures of the root attachments. Knowledge of these classifications and the potential contraindications to meniscal root repair can aid the radiologist in the preoperative reporting of meniscal root tear types and the evaluation of the tibiofemoral cartilage. As more patients undergo arthroscopic repair of meniscal root tears, familiarity with the surgical technique and the postoperative radiographic and MR imaging appearance is important to adequately report the imaging findings. RSNA, 2016.
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October 2016

Effect of lateral meniscal root tear on the stability of the anterior cruciate ligament-deficient knee.

Am J Sports Med 2015 Apr 14;43(4):905-11. Epub 2015 Jan 14.

University of Texas Health Science Center at Houston, Houston, Texas, USA.

Background: Meniscal root tears are an increasingly recognized subset of meniscal injury. The menisci are critical secondary stabilizers of the anterior cruciate ligament (ACL). The kinematic effect of lateral meniscus posterior root tear in the setting of ACL injury is not known.

Purpose/hypothesis: The purpose of this study was to determine the effect of tear of the lateral meniscal root on stability of the ACL-deficient knee. The hypothesis was that disruption of the lateral meniscal root will further destabilize the ACL-deficient knee during a simulated pivot shift.

Study Design: Controlled laboratory study.

Methods: Pivot-shift testing of 8 fresh-frozen cadaveric knees was performed after attachment of photoreflective flags and preparation of CT scans. Each knee was mounted in a custom activity simulator and dynamically loaded from 15° to 90° of flexion with all the permutations of the following: iliotibial band force (50, 75, 100, 125, 150, and 175 N), internal rotation moments (1, 2, and 3 N·m), and valgus moments (5 and 7 N·m). In addition, anterior stability tests were performed by applying a 90-N anterior force to the tibia at flexion angles of 15°, 30°, 45°, 60°, and 90°. During each test, the anterior tibial translation and rotation of the tibia were measured with a high-resolution multiple infrared camera motion analysis system for the following 3 conditions: ACL-intact (ACL-I), ACL-deficient (ACL-D), and ACL-deficient/lateral meniscal posterior root avulsion (ACL-D/LMR-A).

Results: A pivot-shift phenomenon was observed in the ACL-D and ACL-D/LMR-A conditions. The mean tibial translation of the lateral tibial condyle during the pivot-shift maneuver was 2.62 ± 0.53 mm for the ACL-I knees, 6.01 ± 0.51 mm for the ACL-D knees (P value vs. intact: .0005), and 8.13 ± 0.75 mm for the ACL-D/LMR-A knees (P value vs intact: <.0001). During the pivot-shift maneuver, translation was significantly increased in the ACL-D/LMR-A condition compared with the ACL-D condition (P = .0146). Compared with the intact group, anterior tibial translation during the Lachman maneuver also increased at 30° and 90° of flexion in the ACL-D group (P < .0001) and the ACL-D/LM group (P < .0001). No statistically significant difference was found between the ACL-D and ACL-D/LMR-A groups during the Lachman maneuver at 30° and 90° (P = .16 and .72, respectively).

Conclusion: A tear of the lateral meniscal posterior root further reduces the stability of the ACL-deficient knee during rotational loading.

Clinical Relevance: This study shows that lateral meniscal root injury further destabilizes the ACL-deficient knee and thus advances the concept that the lateral meniscus is a secondary stabilizer of the knee under pivot-shift loading. In the absence of stronger evidence, the study data suggest a rationale for surgical repair of lateral meniscal root tears encountered in the setting of ACL tears.
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April 2015

Functional outcomes of anterior cruciate ligament reconstruction with tibialis anterior allograft.

Bull Hosp Jt Dis (2013) 2013 ;71(2):138-43

Background: Allografts offer potential advantages over autografts in anterior cruciate ligament reconstruction (ACLR), including the absence of donor site morbidity, shorter operative times, improved cosmesis, and easier rehabilitation. There is limited and conflicting outcome data for ACLR with tibialis anterior allograft. The purpose of this study was to evaluate the functional outcomes of ACLR with tibialis anterior allograft.

Methods: We retrospectively evaluated primary ACL reconstructions using tibialis anterior allograft between January 2004 and December 2006. Clinical outcomes were measured by KT-1000 arthrometry, and International Knee Documentation Committee (IKDC), Lysholm, and Tegner scores.

Results: 19 patients were available for follow-up at a mean of 2.7 years (range: 2.0 to 3.2). One patient experienced a traumatic re-rupture that required revision and another patient was advised to undergo revision reconstruction for a failed graft. Based on IKDC and Lysholm scoring, 12 patients (63%) had good or excellent results, 4 (21%) patients had fair results, and 3 (16%) patients had poor results. The mean side-to-side difference was 2.7 mm (0 to 8.2) and the mean decrease in Tegner activity level was 1.4 (0 to 6).

Conclusion: An alarming number of patients demonstrated residual laxity after ACL reconstruction with tibialis anterior allograft. We recommend against using tibialis anterior allograft as a first choice graft for high demand patients.
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May 2014

The effect of progressive degrees of medial meniscal loss on stability after anterior cruciate ligament reconstruction.

J Knee Surg 2013 Oct 19;26(5):363-9. Epub 2013 Mar 19.

Methodist Center for Sports Medicine, The Methodist Hospital, Houston, Texas.

Previous studies report conflicting results on whether loss of the medial meniscus compromises knee stability after reconstruction of the anterior cruciate ligament (ACL). The purpose of this study was to determine whether the degree of medial meniscus deficiency affects the stability of the ACL-reconstructed knee. Six cadaveric knees were arthroscopically reconstructed with bone-patellar tendon-bone autografts using an anatomic "footprint" technique. Knees tested were ACL-deficient and after reconstruction under three different meniscal states: with partial medial meniscectomy, subtotal meniscectomy, and meniscal root transection. Biomechanical testing was performed at 30 and 60 degrees of flexion under two loading conditions: (1) 134-N anterior tibial load termed anterior tibial translation (ATT) and (2) 10-Nm valgus load combined with 5 Nm of internal tibial torque termed provocative pivot maneuver (PPM). Knee kinematics was measured using a custom activity simulator, motion analysis system, and three-dimensional CT reconstructions. During both ATT and PPM loading, ACL deficiency resulted in a significant increase in anterior translation compared with knees with an intact ACL or those that had undergone ACL reconstruction (p < 0.05). Neither the addition of a partial nor subtotal medial meniscectomy led to increased instability. Only after medial meniscal root transection was increased instability of the ACL-deficient knee detected compared with intact, partial, or subtotal meniscectomy states (p < 0.01). In all states of meniscal deficiency, ACL reconstruction restored internal tibial rotation and anterior translation at 30 degrees to that of the intact knee (p > 0.05). Anatomic single bundle ACL reconstruction was able to restore knee stability in all conditions of medial meniscal deficiency.
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October 2013

Second metatarsal physeal arrest in an adolescent flamenco dancer: a case report.

Foot Ankle Int 2008 Aug;29(8):859-62

Department of Orthopaedic Surgery, New York University Hospital for Joint Diseases, New York, NY 10128, USA.

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August 2008