The Feasibility of Blinding Intraoperative Electro-Auricular Acupuncture Under Neuraxial Anesthesia.

Objective: Demand for complementary medicine, in particular, acupuncture, has increased over the past few years but widespread acceptance has been limited, in part, by the lack of high-quality studies, including lack of blinding. Acupuncture studies traditionally have difficulty with blinding as sham acupuncture can have up to a 40%-50% analgesic effect. This study randomized patients between Acupuncture and No Acupuncture (standard of care) without using sham needles. The primary outcome was adequate blinding of electro-auricular acupuncture in the intraoperative setting with secondary outcomes of pain/nausea control. Materials and Methods: Forty patients undergoing anterior cruciate ligament reconstruction were enrolled. Subjects were randomly assigned to receive acupuncture (Enhanced Electro-Auricular Trauma Protocol) or No Acupuncture during their surgeries. All patients received spinal anesthesia and intravenous midazolam, ketamine, and propofol for sedation. 1000 mg of intravenous (IV) acetaminophen and up to 30 mg of IV ketorolac were given at closure. No opioids or peripheral nerve blocks were administered intraoperatively. Results: Bang's Blinding indices were 0.2 (95% confidence interval [CI]: -0.02, 0.42) in the Acupuncture group, and 0.11 (95% CI: -0.10, 0.31) in the No Acupuncture group on postoperative day 1. Both groups had adequate blinding. There were no differences in pain scores, nausea/vomiting incidence, opioid consumption 0-24 hours, or patient satisfaction. Five patients in the No Acupuncture group received rescue blocks, while no patients in the Acupuncture group needed a rescue block (Fisher's exact test: p = 0.047). Conclusions: This study proved the primary hypothesis that adequate blinding of intraoperative acupuncture can be performed when patients are under sedation and neuraxial anesthesia. This research is registered at ClinicalTrials.gov as Clinical Trial Registration #: NCT03711734.

Synthetic PVA Osteochondral Implants for the Knee Joint: Mechanical Characteristics During Simulated Gait.

BACKGROUND: Although polyvinyl alcohol (PVA) implants have been developed and used for the treatment of femoral osteochondral defects, their effect on joint contact mechanics during gait has not been assessed. PURPOSE/HYPOTHESIS: The purpose was to quantify the contact mechanics during simulated gait of focal osteochondral femoral defects and synthetic PVA implants (10% and 20% by volume of PVA), with and without porous titanium (pTi) bases. It was hypothesized that PVA implants with a higher polymer content (and thus a higher modulus) combined with a pTi base would significantly improve defect-related knee joint contact mechanics. STUDY DESIGN: Controlled laboratory study. METHODS: Four cylindrical implants were manufactured: 10% PVA, 20% PVA, and 10% and 20% PVA disks mounted on a pTi base. Devices were implanted into 8 mm-diameter osteochondral defects created on the medial femoral condyles of 7 human cadaveric knees. Knees underwent simulated gait and contact stresses across the tibial plateau were recorded. Contact area, peak contact stress, the sum of stress in 3 regions of interest across the tibial plateau, and the distribution of stresses, as quantified by tracking the weighted center of contact stress throughout gait, were computed for all conditions. RESULTS: An osteochondral defect caused a redistribution of contact stress across the plateau during simulated gait. Solid PVA implants did not improve contact mechanics, while the addition of a porous metal base led to significantly improved joint contact mechanics. Implants consisting of a 20% PVA disk mounted on a pTi base significantly improved the majority of contact mechanics parameters relative to the empty defect condition. CONCLUSION: The information obtained using our cadaveric test system demonstrated the mechanical consequences of femoral focal osteochondral defects and provides biomechanical support to further pursue the efficacy of high-polymer-content PVA disks attached to a pTi base to improve contact mechanics. CLINICAL RELEVANCE: As a range of solutions are explored for the treatment of osteochondral defects, our preclinical cadaveric testing model provides unique biomechanical evidence for the continued investigation of novel solutions for osteochondral defects.

Surgical Treatment of Iatrogenic Nerve Injury Following Arthroscopic Capsulolabral Repair.

PURPOSE: Case reports of nerve injuries following arthroscopic capsulolabral repair emphasize the proximity of major nerves to the glenoid. This study describes preoperative localization using nerve-sensitive magnetic resonance imaging in a small cohort of patients with iatrogenic nerve injuries following arthroscopic capsulolabral repair and the outcomes of nerve repair in these patients. METHODS: Cases of iatrogenic nerve injury following arthroscopic capsulolabral repair referred to 2 surgeons from January 2017 to December 2019 were identified. Clinical charts, electrodiagnostic testing, magnetic resonance imaging studies, and operative reports were reviewed. RESULTS: Four cases of iatrogenic nerve injury were identified. The time to presentation to our institution ranged from 2 weeks to 8 years. The axillary nerves in 3 cases were tethered by a suture at the inferior glenoid, whereas 1 case had a suture tied around the radial and median nerves inferior to the glenohumeral joint capsule. One case underwent excision and nerve transfer, 1 underwent excision and nerve repair, and 2 underwent suture removal and neurolysis. Open and arthroscopic approaches, including a recently described approach to the axillary nerve in the "blind zone," were used. Three cases demonstrated good recovery of all affected motor and sensory functions after surgery. At the 10-month follow-up, 1 case had persistent weakness, but there was evidence of axonal regeneration on electrodiagnostic testing. CONCLUSIONS: Arthroscopic capsulolabral repair places regional nerves, particularly the axillary nerve, at risk owing to their proximity to the joint capsule and inferior glenoid. Patients with neuropathic pain in the distribution of affected nerves with corresponding sensorimotor loss following arthroscopic capsulolabral surgery should undergo focused magnetic resonance imaging with nerve-sensitive sequences and electrodiagnostic testing to localize the injury. The use of multiple surgical windows to the axillary nerve in the "blind zone" enables full visualization for neurolysis, suture removal, and nerve repair or transfer. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic V.

Surgical Games: A Simulation-Based Structured Assessment of Orthopedic Surgery Resident Technical Skill.

BACKGROUND: Simulation-based education and objective evaluation of surgical skill have been incorporated into many surgical training programs. We describe the development and implementation of a timed, multitask, station-based Surgical Games to evaluate orthopedic resident surgical skills. METHODS: Participants in the study were postgraduate-year 2 to 5 orthopedic surgery residents from a single institution. Residents completed 4-timed simulated tasks: cadaveric carpal tunnel release (CTR), Sawbones model of total knee arthroplasty (TKA), Sawbones model of ankle fracture open reduction internal fixation (ORIF), and knee arthroscopy simulator (KAS) of removal of loose body. Evaluations were performed using standardized score sheets by attending surgeons. Resident performance was analyzed by postgraduate-year and number of weeks of prior task-related residency training. RESULTS: A total of 32 residents were assessed at the 4 stations. Total scores were significantly different for CTR (p = 0.006), TKA (p = 0.05), and the KAS (p = 0.004) by year of training, but not for the ankle ORIF task. Residents with more task-specific experience performed significantly better on the KAS (p < 0.001), TKA (p = 0.002), and CTR (p = 0.02) tasks but not on the ankle ORIF task (p = 0.1). Overall, residents rated the exercise valuable to their education with mean scores of 3.9 ± 0.54 on a 5-point Likert Scale. CONCLUSIONS: This Surgical Games exercise provided an objective evaluation of surgical skill that correlated with year-in-training and prior experience in skill-specific rotations for the KAS, TKA, and CTR tasks. This surgical skills assessment provided an opportunity for effective structured feedback and identification of areas for improvement.

Opioid Consumption After Arthroscopic Meniscal Procedures and Anterior Cruciate Ligament Reconstruction.

BACKGROUND: Procedure-specific opioid-prescribing guidelines have the potential to decrease the number of unused pills in the home without compromising patient satisfaction. However, there is a paucity of data on the minimum necessary quantity to prescribe for outpatient orthopaedic surgeries. PURPOSE: To prospectively record daily opioid use and pain levels after arthroscopic meniscal procedures and anterior cruciate ligament reconstruction (ACLR) at a single institution. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A total of 95 adult patients who underwent primary arthroscopic knee surgery (meniscectomy, repair, or ACLR) were enrolled. Patients with a history of opioid dependence were ineligible. Daily opioid consumption and Numeric Rating Scale pain scores were collected through an automated text-messaging platform starting on postoperative day 1 (POD1). At 6 weeks or at patient-reported cessation of opioid use, final survey questions were asked. Patients who failed to complete data collection were excluded. Opioid use was converted into "pills" (oxycodone 5-mg equivalents) to facilitate comparisons and clinical applications. Factors associated with high and low opioid use were compared. RESULTS: Of the 95 patients enrolled, 71 (74.7%) were included in the final analysis. Of these, 40 (56.3%) underwent meniscal surgery and 31 (43.7%) underwent ACLR. After outpatient arthroscopic meniscectomy or repair, the total median postdischarge opioid use was 0.3 pills (oxycodone 5-mg equivalents), with 75% of patients consuming 3.3 or fewer pills (range, 0-19 pills). For ACLR, the median postdischarge consumption was 7 pills (75th percentile, 23.3 pills; range, 0-41 pills). Almost one-third of patients (32.3%) took no opioids after surgery (3 ACLR, 20 meniscus). All meniscus patients and 71% of ACLR patients ceased opioid consumption by postoperative day 7. CONCLUSION: Opioids may not be necessary in all patients, particularly after meniscal surgery and in comparison with ACLR. For patients requesting opioids for pain relief, reasonable prescription quantities are 5 oxycodone 5-mg pills after arthroscopic meniscal procedures and 20 5-mg pills after ACLR. Slowing the current opioid epidemic and preventing future crises is dependent on refining prescribing habits. Clinicians should strongly consider patient education regarding expected pain as well as pain management strategies.

Lateral Meniscal Graft Transplantation: Effect of Fixation Method on Joint Contact Mechanics During Simulated Gait.

BACKGROUND: Controversy exists regarding the optimal bony fixation technique for lateral meniscal allografts. PURPOSE/HYPOTHESIS: The objective was to quantify knee joint contact mechanics across the lateral plateau for keyhole and bone plug meniscal allograft transplant fixation techniques throughout simulated gait. It was hypothesized that both methods of fixation would improve contact mechanics relative to the meniscectomized condition, while keyhole fixation would restore the distribution of contact stress closer to that of the intact knee. STUDY DESIGN: Controlled laboratory study. METHODS: Six human cadaveric knees were mounted on a multidirectional dynamic simulator and subjected to the following conditions: (1) native intact meniscus, (2) keyhole fixation of the native meniscus, (3) bone plug fixation of the native meniscus, and (4) meniscectomy. Contact area, peak contact stress, and the distribution of stress across the tibial plateau were computed at 14% and 45% of the gait cycle, at which axial forces are at their highest. Translation of the weighted center of contact stress throughout simulated gait was computed. RESULTS: Both bony fixation techniques improved contact mechanics relative to the meniscectomized condition. The keyhole technique was not significantly different from the intact condition for the following metrics: contact area, peak contact stress, distribution of force between the meniscal footprint and cartilage-to-cartilage contact, and the position of the weighted center of contact. In contrast, bone plug fixation resulted in a significant decrease of 21% to 28% in contact area at 14% and 45% of the simulated gait cycle, a significant increase in peak contact stresses of 34% at 45% of the gait cycle, and a shift in the weighted center of contact, which increased forces in the cartilage-to-cartilage contact area at 45% of the gait cycle. CONCLUSION: While both keyhole and bone plug fixation methods improved lateral compartment contact mechanics relative to the meniscectomized knee, keyhole fixation restored contact mechanics closer to that of the intact knee. CLINICAL RELEVANCE: Method of meniscal fixation is under the direct control of the surgeon. From a biomechanics perspective, keyhole fixation is advocated for its ability to mimic intact knee joint contact mechanics.

Creating a Legion of Diabetes Patient Advocates: DPAC Policy Training Meeting and Hill Day.

The Diabetes Patient Advocacy Coalition (DPAC) held a Policy Training Meeting and Hill Day September 29-October 1, 2018, in Washington, DC. Attendees were members of DPAC's Board of Directors and Staff, Patient Advisory Board, and individuals identified through a competitive call for applicants on DPAC's website and social media. We were joined by advocates from the Association of Black Cardiologists and the Endocrine Society. The Policy Training Meeting focused on teaching citizen advocates how to share their stories with legislators while integrating facts and statistics to reinforce their experiences. After two days of training, we met with our legislators on Capitol Hill to discuss two closely related issues: access to affordable insulin and diabetes self-management training. The partnership of patient advocates and health care providers was a powerful tool to get our message across. Meetings like this encourage open discussion and networking as well as education regarding individual advocacy. They are an effective way to bring people together as allies for the diabetes community. DPAC plans to hold additional Policy Training Meetings to develop leaders in each state who represent the voice of people living with diabetes.

The Scaffold-Articular Cartilage Interface: A Combined In Vitro and In Silico Analysis Under Controlled Loading Conditions.

The optimal method to integrate scaffolds with articular cartilage has not yet been identified, in part because of our lack of understanding about the mechanobiological conditions at the interface. Our objective was to quantify the effect of mechanical loading on integration between a scaffold and articular cartilage. We hypothesized that increased number of loading cycles would have a detrimental effect on interface integrity. The following models were developed: (i) an in vitro scaffold-cartilage explant system in which compressive sinusoidal loading cycles were applied for 14 days at 1 Hz, 5 days per week, for either 900, 1800, 3600, or 7200 cycles per day and (ii) an in silico inhomogeneous, biphasic finite element model (bFEM) of the scaffold-cartilage construct that was used to characterize interface micromotion, stress, and fluid flow under the prescribed loading conditions. In accordance with our hypothesis, mechanical loading significantly decreased scaffold-cartilage interface strength compared to unloaded controls regardless of the number of loading cycles. The decrease in interfacial strength can be attributed to abrupt changes in vertical displacement, fluid pressure, and compressive stresses along the interface, which reach steady-state after only 150 cycles of loading. The interfacial mechanical conditions are further complicated by the mismatch between the homogeneous properties of the scaffold and the depth-dependent properties of the articular cartilage. Finally, we suggest that mechanical conditions at the interface can be more readily modulated by increasing pre-incubation time before the load is applied, as opposed to varying the number of loading cycles.

Tracking Cumulative Radiation Exposure in Orthopaedic Surgeons and Residents: What Dose Are We Getting?

BACKGROUND: The purpose of this study was to determine the amount of cumulative radiation exposure received by orthopaedic surgeons and residents in various subspecialties. We obtained dosimeter measures over 12 months on 24 residents and 16 attending surgeons. METHODS: Monthly radiation exposure was measured over a 12-month period for 24 orthopaedic residents and 16 orthopaedic attending surgeons. The participants wore a Landauer Luxel dosimeter on the breast pocket of their lead apron. The dosimeters were exchanged every rotation (5 to 7 weeks) for the resident participants and every month for the attending surgeon participants. Radiation exposure was compared by orthopaedic subspecialty, level of training, and type of fluoroscopy used (regular C-arm compared with mini C-arm). RESULTS: Orthopaedic residents participating in this study received monthly mean radiation exposures of 0.2 to 79 mrem/month, lower than the dose limits of 5,000 mrem/year recommended by the United States Nuclear Regulatory Commission (U.S. NRC). Senior residents rotating on trauma were exposed to the highest monthly radiation (79 mrem/month [range, 15 to 243 mrem/month]) compared with all other specialty rotations (p < 0.001). Similarly, attending orthopaedic surgeons who specialize in trauma or deformity surgery received the highest radiation exposure of their peers, and the mean exposure was 53 mrem/month (range, 0 to 355 mrem/month). CONCLUSIONS: Residents and attending surgeons performing trauma or deformity surgical procedures are exposed to significantly higher doses of radiation compared with all other subspecialties within orthopaedic surgery, but the doses are still within the recommended limits. CLINICAL RELEVANCE: The use of ionizing radiation in the operating room has become an indispensable part of orthopaedic surgery. Although all surgeons in our study received lower than the yearly recommended dose limit, it is important to be aware of how much radiation we are exposed to as surgeons and to take measures to further limit that exposure.

Hospital for Special Surgery ACL Registry: 2-Year Outcomes Suggest Low Revision and Return to OR Rates.

BACKGROUND: Anterior cruciate ligament (ACL) injuries are among the most common knee injuries. Patient outcomes, rate of subsequent operations, and rate of subsequent ACL reconstruction following primary ACL reconstruction need to be evaluated. QUESTIONS/PURPOSES: This study was designed to answer the following questions: (1) What is the return to surgery (OR) rate following primary ACL reconstruction and (2) what is the revision ACL reconstruction rate? METHODS: Data was drawn from the Hospital for Special Surgery (HSS) ACL Registry. International Knee Documentation Committee (IKDC) Subjective Knee Evaluation, Lysholm-Tegner Scales, Marx Activity Scale, and SF12 were completed by patients at baseline, 1-, and 2-year follow-up. Clinical data and intraoperative data were registered by surgeons on an intraoperative form. Subsequent surgery rates were determined by evaluating the medical records for subsequent surgery, laterality, surgeon, procedure description, and type of anesthesia. RESULTS: The majority of the ACL reconstructions performed were autograft (76.6%) with the most common graft being bone-patellar tendon-bone (BTB) autograft (47.2%), hamstring autograft (21.9%), and Achilles allograft (18.2%). Average IKDC score improved from 51.9 (SD 16.1) at baseline to 83.5 (SD 14.2) at 2-year follow-up. Females had a 2.5-point lower IKDC and 1.4-point Marx scores compared to males. Of the enrolled patients, 7.3% had revision ACL surgery with 70.4% being ipsilateral ACL surgery. Of the enrolled patients, 10.3% had subsequent knee surgery with 72.3% being ipsilateral knee surgery. Multivariable logistic regression analysis showed that patients less than 18 years of age at the time of their index surgery were over three times more likely to undergo a revision ACL reconstruction compared to older patients and were at four times higher risk than older patients for any subsequent knee surgery. CONCLUSION: Understanding ACL surgery, patient outcomes, and risk factors for revision ACL surgery and subsequent knee surgery after primary ACL reconstruction is essential. Patients less than 18 years of age have a higher risk of subsequent knee surgery and subsequent ACL surgery than older patients.

Risk Factors for Revision Surgery After Superior Labral Anterior-Posterior Repair: A National Perspective.

BACKGROUND: Data regarding risk factors for revision surgery after superior labral anterior-posterior (SLAP) repair are limited to institutional series. PURPOSE: To define risk factors for revision surgery after SLAP repair among patients in a large national database. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: A national insurance database was queried for patients undergoing arthroscopic SLAP repair (Current Procedural Terminology [CPT] code 29807) for the diagnosis of a SLAP tear. Patients without a CPT modifier for laterality were excluded. Revision surgery was defined as (1) subsequent ipsilateral SLAP repair (CPT 29807), (2) ipsilateral arthroscopic debridement for the diagnosis of a SLAP tear (CPT 29822 or 29823, with diagnosis code 840.7), (3) subsequent ipsilateral arthroscopic biceps tenodesis (CPT 29828), (4) subsequent ipsilateral open biceps tenodesis (CPT 23430), and (5) subsequent biceps tenotomy (CPT 23405). Multivariable binomial logistic regression analysis was performed to identify risk factors for revision surgery after SLAP repair, including patient demographics/comorbidities, concomitant diagnoses, and concomitant procedures performed. Odds ratios (ORs), 95% CIs, and P values were calculated. The estimated financial impact of revision surgery was also calculated. RESULTS: There were 4751 patients who met inclusion and exclusion criteria. Overall, 121 patients (2.5%) required revision surgery after SLAP repair. Regression analysis identified numerous risk factors for revision surgery, including age >40 years (OR, 1.5; 95% CI, 1.2-1.8; P = .045), female sex (OR, 1.5; 95% CI, 1.3-1.8; P = .010), obesity (OR, 1.8; 95% CI, 1.5-2.2; P = .001), smoking (OR, 2.0; 95% CI, 1.6-2.4; P < .0001), and diagnosis of biceps tendinitis (OR, 3.5; 95% CI, 3.0-4.2; P < .0001) or long head of the biceps tearing (OR, 5.1; 95% CI, 4.1-6.3; P < .0001) at or before the time of surgery. Concomitant rotator cuff repair and distal clavicle excision were not significant risk factors for revision surgery. The cost of revision surgery averaged almost $9000. CONCLUSION: Risk factors for revision surgery after SLAP repair include age >40 years, female sex, obesity, smoking, and diagnosis of biceps tendinitis or long head of the biceps tearing. The diagnosis of biceps tendinitis (OR, 3.5) or long head of the biceps tearing (OR, 5.1) at or before the time of surgery was an especially significant risk factor for revision surgery. The high cost of revision surgery highlights the importance of appropriate indications to avoid the need for subsequent procedures.

Subscapularis tendon loading during activities of daily living.

BACKGROUND: The purpose of this study was to determine the relative amount of load that is transmitted through the superior portion of the subscapularis during activities of daily living as compared with the load that is transmitted through the middle and inferior portions in a normal shoulder and in a shoulder with a supraspinatus tear. METHODS: By use of the Newcastle shoulder model, the subscapularis was modeled with 3 lines of action encircling the humeral head. The load was measured in the entire subscapularis, and the percentage of this load in each of the 3 tendinous bands was calculated. Subsequently, a supraspinatus tear was simulated, and the forces generated by the subscapularis and glenohumeral joint contact forces were measured. RESULTS: The maximum force produced by the entire subscapularis muscle for the various activities ranged from 3 to 43 N. Load sharing between the 3 subscapularis bands showed that the superior band bore the largest percentage of the total load of the muscle (95% ± 2%). The load in the subscapularis, particularly in the superior band, increased significantly when a supraspinatus tear was simulated (P < .0001). CONCLUSION: The superior band of the subscapularis tendon bears the highest percentage of load compared with the middle or inferior band. The load in the subscapularis increased significantly in the presence of a simulated supraspinatus tear. Because a disproportionate amount of force is transmitted through the superior subscapularis, more clinical research is warranted to determine whether tears in this region should be routinely repaired.

Assessment of emerging biotoxins (pinnatoxin G and spirolides) at Europe's first marine reserve: Lough Hyne.

Active and passive sampling methods were employed over a four-month period, at a site off the South-West coast of Ireland, to characterise the occurrence of cyclic imines in the water column. The marine toxins 13-desmethyl-SPXC, 20-methyl SPXG toxins and pinnatoxin G were detected using active sampling from Diaion HP-20 resin. Seven water depths were sampled to determine stratification of the toxins in the water column using Solid Phase Adsorption and Toxin Tracking (SPATT). Both 13-desmethyl-SPXC and pinnatoxin G were detected using two different resin types; Diaion HP-20 and Amberlite XAD761. HP-20 proved more effective at accumulating the toxins, with a higher percentage of positive samples and a higher ratio of toxin adsorbed relative to XAD761. No temporal variation in toxin-quantities was detected, indicating that there was no change in density of causative algal species in the water column. Pinnatoxin G was detected more frequently from surface to 30 m depth, with a similar pattern observed for 13-desmethyl-SPXC occurrence using XAD761. No difference in the occurrence of 13-desmethyl-SPXC was observed between depths using HP-20 resin. This is the first reported incidence of pinnatoxin G in Irish waters and highlights cyclic imines as emerging toxins in European waters.

Increased Lateral Tibial Slope Is a Risk Factor for Pediatric Anterior Cruciate Ligament Injury: An MRI-Based Case-Control Study of 152 Patients.

BACKGROUND: Increased posterior tibial slope is associated with increased risk of anterior cruciate ligament (ACL) injury in adults. A similar association has not been rigorously examined in children and adolescents. PURPOSE: To determine whether alterations in posterior tibial slope are associated with ACL tears in pediatric and adolescent patients and to quantify changes in tibial slope by age. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: Magnetic resonance imaging (MRI) studies of the knee were reviewed by 3 raters blinded to each other in a 1:1 sample of cases and age- and sex-matched controls. A total of 76 skeletally immature ACL-injured knees were compared with 76 knees without ACL injury; the mean age of the study population was 14.8 ± 1.3 years. The posterior slope of the articular surface of the medial tibial plateau and lateral tibial plateau was measured by use of a method similar to that used in previous studies in adult populations. The current study technique differed in that the slope was measured on the cartilage surface, not the subchondral bone. Comparisons between knees were made with t tests, and Spearman correlation analysis was used to assess changes in tibial slope with advancing age. RESULTS: Increased slope of the lateral tibial plateau (LTS) was significantly increased in ACL-injured patients compared with controls (5.7° ± 2.4° vs 3.4° ± 1.7°; P < .001). There was no statistically significant difference in the slope of the medial tibial plateau (MTS) in the ACL-injured and control knees (5.4° ± 2.2° vs 5.1° ± 2.3°; P = .42). There was no difference in LTS between male and female patients (4.46° vs 4.58°; P = .75). Receiver operating characteristic (ROC) analysis of the LTS revealed that a posterior tibial slope cutoff of >4° resulted in a sensitivity of 76% and a specificity of 75% for predicting ACL tears in this cohort. Spearman correlation analysis revealed that MTS and LTS decreased, or flattened, by 0.31° (P = .028, correlation coefficient r = -0.18) and 0.37° (P = .009, correlation coefficient r = -0.21) per year, respectively, as adolescents age. CONCLUSION: The LTS was significantly associated with an increased risk of ACL injury in pediatric and adolescent patients. The MTS was not associated with risk of injury. Posterior slope was found to decrease, or flatten, with age. A cutoff of >4° for the posterior slope of the lateral compartment is 76% sensitive and 75% specific for predicting ACL injury in this cohort. The LTS did not influence the incidence of ACL injury differently between sexes.

Outcomes for surgical treatment of posterolateral instability of the knee.

Injuries to the posterolateral corner (PLC) of the knee can be associated with a variety of additional ligamentous and soft-tissue injuries. The clinical outcome of a PLC injury is dependent on associated injuries, the chronicity of injury, and the method of reconstruction. This chapter discusses the current literature regarding outcomes of surgical treatment of acute and chronic injuries. The majority of the current literature includes level IV case series evidence. Anatomic reconstruction of the PLC with concomitant treatment of associated knee ligament injuries in acute and chronic cases is the preferred treatment. There are mixed outcomes with acute repair of injured tissues as well as advancement procedures. The surgical treatment must be tailored to the specific needs of the patient and the ligament injury pattern.

Does the marine biotoxin okadaic acid cause DNA fragmentation in the blue mussel and the pacific oyster?

Two bivalve species of global economic importance: the blue mussel, Mytilus edulis and the pacific oyster, Crassostrea gigas were exposed in vivo, to the diarrhoetic shellfish toxin okadaic acid (OA), and impacts on DNA fragmentation were measured. Shellfish were exposed using two different regimes, the first was a single (24 h) exposure of 2.5 nM OA (∼0.1 µg/shellfish) and algal feed at the beginning of the trial (T0), after which shellfish were only fed algae. The second was daily exposure of shellfish to two different concentrations of OA mixed with the algal feed over 7 days; 1.2 nM OA (∼0.05 µg OA/shellfish/day) and 50 nM OA (∼2 µg OA/shellfish/day). Haemolymph and hepatopancreas cells were extracted following 1, 3 and 7 days exposure. Cell viability was measured using the trypan blue exclusion assay and remained above 85% for both cell types. DNA fragmentation was examined using the single-cell gel electrophoresis (comet) assay. A significant increase in DNA fragmentation was observed in the two cell types from both species relative to the controls. This increase was greater in the pacific oyster at the higher toxin concentration. However, there was no difference in the proportion of damage measured between the two cell types, and a classic dose response was not observed, increasing toxin concentration did not correspond to increased DNA fragmentation.

Application of passive (SPATT) and active sampling methods in the profiling and monitoring of marine biotoxins.

Solid phase adsorbent and toxin tracking (SPATT) enables temporally and spatially integrated monitoring of biotoxins in aquatic environments. Monitoring using two adsorbent resins was performed over a four-month period at Lough Hyne Marine Reserve, Ireland. A range of Diarhettic Shellfish Poisoning (DSP) toxins were detected from SPATT extracts throughout the study period. The majority of biotoxins were detected in the top 20-30 m of the water column and a spike in toxin accumulation was measured during August 2010. Phytoplankton analysis confirmed the presence of toxin-producing species Dinophysis acuta and Dinophysis acuminata during the bloom. SPATT has the potential to provide useful information on phycotoxin distribution in the water column; enabling evidence-based decisions regarding appropriate depths for obtaining phytoplankton and shellfish samples in marine biotoxin monitoring programmes. Active sampling was performed continuously over 7-days and high quantities of toxins were successfully accumulated in the HP-20 resin, okadaic acid (∼13 mg), dinophysis toxin-2 (∼29 mg), pectenotoxin-2 (∼20 mg) and pectenotoxin-2-seco acid (∼6 mg) proving this an effective method for accumulating DSP toxins from the marine environment. The method has potential application as a tool for assessing toxin profiles at proposed shellfish harvesting sites.

The mature athlete: aging tendon and ligament.

CONTEXT: Aging changes the biology, healing capacity, and biomechanical function of tendons and ligaments and results in common clinical pathologies that present to orthopedic surgeons, primary care physicians, physical therapists, and athletic trainers. A better understanding of the age-related changes in these connective tissues will allow better patient care. EVIDENCE ACQUISITION: The PubMed database was searched in December 2012 for English-language articles pertaining to age-related changes in tendons and ligaments. LEVEL OF EVIDENCE: Level 5. RESULTS: The mature athlete faces challenges associated with age-dependent changes in the rotator cuff, Achilles tendon, lateral humeral epicondylar tendons, quadriceps tendon, and patellar tendon. The anterior cruciate ligament and the medial collateral ligament are the most studied intra-articular and extra-articular ligaments, and both are associated with age-dependent changes. CONCLUSION: Tendons and ligaments are highly arranged connective tissue structures that maintain joint motion and joint stability. These structures are subject to vascular and compositional changes with increasing age that alter their mechanotransduction, biology, healing capacity, and biomechanical function. Emerging research into the etiology of age-dependent changes will provide further information to help combat the age-related clinical complications associated with the injuries that occur to tendons and ligaments.