Lithium Chloride Effects Field-Induced Protein Unfolding and the Transport Energetics Inside a Nanopipette.

The tapered geometry of nanopipettes offers a unique perspective on protein transport through nanopores since both a gradual and fast confinement are possible depending on the translocation direction. The protein capture rate, unfolding, speed of translocation, and clogging probability are studied by toggling the LiCl concentration between 2 and 4 M. Interestingly, the proteins in this study could be transported with or against electrophoresis and offer vastly different attributes of sensing. Herein, a ruleset for studying proteins is developed that prevents irreversible pore clogging and yields upward of >100,000 events/nanopore. The extended duration of experiments further revealed that the capture rate takes ∼2 h to reach a steady state, emphasizing the importance of reaching equilibrated transport for studying the energetics and kinetics of protein transport (i.e., diffusion vs barrier-limited). Even in the equilibrated transport state, improper lowpass filtering was shown to distort the classification of diffusion-limited vs barrier-limited transport. Finally, electric-field-induced protein unfolding was found to be most prominent in electroosmotic-dominant transport, whereas electrophoretic-dominant events show no evidence of unfolding. Thus, our findings showcase the optimal conditions for protein translocations and the impact on studying protein unfolding, transporting energetics, and acquiring high bandwidth data.

Prior Meniscectomy in Patients Undergoing Primary Total Knee Arthroplasty is Associated With Worse Short-Term Outcomes.

BACKGROUND: Patients undergoing total knee arthroplasty (TKA) who have prior meniscectomy may have increased rates of postoperative infection, arthrofibrosis, and revision. However, aside from an increased risk of complications, it is unclear whether prior meniscectomy impacts functional outcomes after TKA. This study was conducted to compare functional outcomes following TKA in patients who did and did not have a prior meniscectomy. We hypothesized that patients who had a prior ipsilateral meniscectomy would have worse functional outcomes after undergoing TKA. METHODS: A retrospective matched case-control study was conducted at a tertiary academic center. Patients who underwent both meniscectomy and TKA (cases) or TKA alone (controls) from 2013 to 2020 were identified from our institutional database using current procedural terminology codes. Cases were matched in a 1:3 ratio to controls using age, sex, race, body mass index, and a comorbidity index. Inclusion criteria comprised a minimum of 1-year follow-up for the Knee Injury and Osteoarthritis Outcome Score Junior (KOOS-JR). Exclusion criteria included patients undergoing revision TKA and patients who had a history of ligamentous knee surgery or fracture. T- and Chi-squared analyses were conducted, with significance threshold being P < .05. A total of 589 cases and 1,767 controls were included after matching. There were no significant differences in demographic variables. Cases underwent TKA after their meniscectomy at a mean of 2.9 years (range: 42 days to 16 years). RESULTS: While no significant difference existed for preoperative KOOS-JR scores (46.4 versus 46.4; P = .984), postoperative KOOS-JR scores were significantly lower in the case group (71.9 versus 75.3; P = .001). The case group also achieved the KOOS-JR minimal clinically important difference (MCID) and patient acceptable symptom state (PASS) at significantly lower rates than the control group [(MCID: 71.0 versus 77.3%; P = .011) (PASS: 69.4 versus 76.7%; P = .001);]. CONCLUSION: Patients who had a prior meniscectomy may experience lower postoperative functional outcome scores after TKA and had a lower rate of achieving the MCID and PASS for KOOS-JR. Patient expectations should be adjusted accordingly.

Nanopore Current Enhancements Lack Protein Charge Dependence and Elucidate Maximum Unfolding at Protein's Isoelectric Point.

Protein sequencing, as well as protein fingerprinting, has gained tremendous attention in the electrical sensing realm of solid-state nanopores and is challenging due to fast translocations and the use of high molar electrolytes. Despite providing an appreciable signal-to-noise ratio, high electrolyte concentrations can have adverse effects on the native protein structure. Herein, we present a thorough investigation of low electrolyte sensing conditions across a broad pH and voltage range generating conductive pulses (CPs) irrespective of protein net charge. We used Cas9 as the model protein and demonstrated that unfolding is noncooperative, represented by the gradual elongation or stretching of the protein, and sensitive to both the applied voltage and pH (i.e., charge state). The magnitude of unfolding and the isoelectric point (pI) of Cas9 was found to be correlated and a critical factor in our experiments. Electroosmotic flow (EOF) was always aligned with the transit direction, whereas electrophoretic force (EPF) was either reinforcing (pH < pI) or opposing (pH > pI) the protein's movement, which led to slower translocations at higher pH values. Further exploration of higher pH values led to slowing down of protein with > 30% of the population being slower than 0.5 ms. Our results would be critical for protein sensing at very low electrolytes and to retard their translocation speed without resorting to high-bandwidth equipment.

DNA Coil Dynamics and Hydrodynamic Gating of Pressure-Biased Nanopores.

Nanopores are ideally suited for the analysis of long DNA fragments including chromosomal DNA and synthetic DNA with applications in genome sequencing and DNA data storage, respectively. Hydrodynamic fluid flow has been shown to slow down DNA transit time within the pore, however other influences of hydrodynamic forces have yet to be explored. In this report, a broad analysis of pressure-biased nanopores and the impact of hydrodynamics on DNA transit time, capture rate, current blockade depth, and DNA folding are conducted. Using a 10 nm pore, it is shown that hydrodynamic flow inhibits the early stages of linearization of DNA and produces predominately folded events which are initiated by folded DNA (2-strands) entering the pore. Furthermore, utilizing larger pores (30 nm) leads to unique DNA gating behavior in which DNA events can be switched on and off with the application of pressure. A computational model, based on combining electrophoretic drift velocities with fluid velocities, accurately predicts the pore size required to observe DNA gating. Hydrodynamic fluid flow generated by a pressure bias, or potentially more generally by other mechanisms like electroosmotic flow, is shown to have significant effects on DNA sensing and can be useful for DNA sensing technologies.

What Are the All-Cause Survivorship Rates and Functional Outcomes in Patients Younger Than 55 Years Undergoing Primary Knee Arthroplasty? A Systematic Review.

BACKGROUND: Approximately one-fourth of TKAs will be performed in patients 55 years or younger within the next decade. Postoperative outcomes for younger patients who had a knee arthroplasty were systematically reviewed in 2011; however, numerous studies evaluating young patients who had both a TKA and unicompartmental knee arthroplasty (UKA) have been reported in the past decade. Therefore, to better counsel this growing population of young patients undergoing knee arthroplasty, an updated understanding of their expected postoperative outcomes is warranted. QUESTIONS/PURPOSES: In this systematic review, we evaluated (1) all-cause survivorship, (2) reasons for revision, (3) patient-reported outcomes, and (4) return to physical activity and sport in patients 55 years or younger undergoing primary TKA or UKA. METHODS: A comprehensive search of PubMed, Medline, SportDiscus, and CINAHL was performed to identify all original studies evaluating outcomes after primary knee arthroplasty for young patients (55 years of age or younger) from inception until March 2021. The following keywords were used: knee, arthroplasty, replacement, pain, function, revision, survivorship, sport, physical activity, and return to play. Only original research studies that were related to knee arthroplasty and reported postoperative outcomes with a minimum 1-year follow-up for patients 55 years or younger were included. Unpublished materials, publications not available in English, and studies with a primary diagnosis of rheumatoid arthritis were excluded. The Methodological Index for Non-Randomized Studies (MINORS) score was used to evaluate the study quality of case series and comparative studies, while the Cochrane Risk of Bias tool and the Jadad scale were used for randomized studies. The primary outcomes of interest for this study were all-cause survivorship rate, reasons for all-cause revision, Knee Society and Knee Society Function scores (minimum clinically important difference [MCID] 7.2 and 9.7, respectively), WOMAC scores (MCID 10), Tegner scores (no reported MCID for knee arthroplasty), and return to physical activity or sport. Knee Society and Knee Society Function scores range from 0 to 100, with scores from 85 to 100 considered excellent and below 60 representing poor outcomes. All-cause survivorship rate and reasons for revision were both reported in 17 total studies. Knee Society scores were presented in 19 and Knee Society Function scores were reported in 18 included studies. WOMAC scores and Tegner scores were each found in four included studies, and return to physical activity and return to sport analyses were performed in seven studies. Overall, 21 TKA studies and five UKA studies were included in this analysis, featuring 3095 TKA knees and 482 UKA knees. RESULTS: Kaplan-Meier estimates of all-cause survivorship ranged from 90% to 98% at 5 to 10 years of follow-up after TKA and from 84% to 99% (95% CI 93% to 98%) at 10 years to 20 years post-TKA. All-cause UKA survivorship was 90% at 10 years and 75% at 19 years in the largest Kaplan-Meier estimate of survivorship for patients younger than 55 who underwent UKA. Common reasons for revision in TKA patients were polyethylene wear/loosening, aseptic tibial loosening, and infection, and in UKA patients the common reasons for revision were knee pain, aseptic loosening, progression of knee osteoarthritis, and polyethylene wear/loosening. Knee Society scores ranged from 85 to 98 for 5-year to 10-year follow-up and ranged from 86 to 97 at 10-year to 20-year follow-up in TKA patients. Knee Society Function scores ranged from 70 to 95 for 5-year to 10-year follow-up and ranged from 79 to 86 at 10-year to 20-year follow-up. Return to physical activity and sport was reported variably; however, most patients younger than 55 have improved physical activity levels after knee arthroplasty relative to preoperative levels. CONCLUSION: Although all-cause survivorship rates were frequently above 90% and patient-reported outcome scores were generally in the good to excellent range, several studies reported long-term survivorship rates from 70% to 85% and fair patient-reported outcome scores, which must be factored into any preoperative counseling with patients. We could not control for surgeon volume in this report, and prior research suggests that increasing volume is associated with less frequent complications; in addition, the studies we included were variably affected by selection bias, transfer bias, and assessment bias, which makes it likely that the findings of our review represent best-case estimates. To limit the frequency of revision in patients younger than 55 years undergoing TKA, clinicians should be cautious of polyethylene wear/loosening, aseptic tibial loosening, and infection, while knee pain and progression of knee osteoarthritis are also common reasons for revision in patients younger than 55 undergoing UKA. Further research should isolate younger knee arthroplasty patients and evaluate postoperative activity levels while accounting for preoperative physical activity and sport participation. LEVEL OF EVIDENCE: Level IV, therapeutic study.

The Influence of Psychosocial Factors on Hip Surgical Disorders and Outcomes After Hip Arthroscopy: A Systematic Review.

PURPOSE: To systematically review the associations between mental health and preoperative or postoperative outcomes of hip arthroscopy for femoroacetabular impingement. METHODS: The literature search was conducted using the PubMed, EMBASE and PsychINFO databases following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines. RESULTS: Nine studies were identified that met the inclusion and exclusion criteria. All studies assessing patient-reported outcomes found significantly lower patient-reported outcomes (modified Harris Hip Score, Hip Outcome Score-Activities of Daily Living, Hip Outcome Score-Sports-Specific Subscale, and International Hip Outcome Tool scores) related to worse mental health functioning before surgery. Specifically, preoperative Hip Outcome Score-Activities of Daily Living and Hip Outcome Score-Sports-Specific Subscale were significantly greater in control patients than patients in the mental health group by 11.6 points (mean difference; 95% confidence interval 7.58-15.79, P < .001) and 10 points (95% confidence interval 5.14-14.87, P < .001), without significant heterogeneity between studies (I2 = 28.59, P = .25; I2 = 0, P = .93), respectively. Patients with lower mental health status also had lower rates of achieving a minimal clinically important difference in 5 studies included in this review. CONCLUSIONS: This systematic review finds consistent evidence supporting the association between negative psychological function and worse preoperative and postoperative outcomes for patients with hip disorders. Understanding both the effect of mental health on surgical outcomes and the potential benefits of psychological intervention may represent an opportunity to improve patient outcomes following hip arthroscopy. LEVEL OF EVIDENCE: IV, systematic review of Level II-IV studies.

Constricted Apertures for Dynamic Trapping and Micro-/Nanoscale Discrimination Based on Recapture Kinetics.

Sensing via analyte passage through a constricted aperture is a powerful and robust technology which is being utilized broadly, from DNA sequencing to single virus and cell characterization. Micro- and nanoscale structures typically translocate a constricted aperture, or pore, using electrophoretic force. In the present work, we explore the advances in metrology which can be achieved through rapid directional switching of hydrodynamic forces. Interestingly, multipass measurements of microscale and nanoscale structures achieve cell discrimination. We explore this cell-discrimination phenomenon as well as other features of hydrodynamic focusing such as dynamic trapping and discrete interval sensing.

Nanodiagnostics: A review of the medical capabilities of nanopores.

Modern diagnostics strive to be accurate, fast, and inexpensive in addition to properly identifying the presence of a disease, infection, or illness. Early diagnosis is key; catching a disease in its early stages can be the difference between fatality and treatment. The challenge with many diseases is that detectability of the disease scales with disease progression. Since single molecule sensors, e.g., nanopores, can sense biomolecules at low concentrations, they have the potential to become clinically relevant in many of today's medical settings. With nanopore-based sensing, lower volumes and concentrations are required for detection, enabling it to be clinically beneficial. Other advantages to using nanopores include that they are tunable to an enormous variety of molecules and boast low costs, and fabrication is scalable for manufacturing. We discuss previous reports and the potential for incorporating nanopores into the medical field for early diagnostics, therapeutic monitoring, and identifying relapse/recurrence.

Do Relaxation Exercises Decrease Pain After Arthroscopic Rotator Cuff Repair? A Randomized Controlled Trial.

BACKGROUND: Pain after rotator cuff repair is commonly managed with opioid medications; however, these medications are associated with serious adverse effects. Relaxation exercises represent a potential nonpharmacologic method of pain management that can be easily implemented without substantial adverse effects; however, the effects of relaxation exercises have not been studied in a practical, reproducible protocol after arthroscopic rotator cuff repair. QUESTIONS/PURPOSES: (1) Does performing relaxation exercises after arthroscopic rotator cuff repair (ARCR) decrease pain compared with standard pain management medication? (2) Does performing relaxation exercises after ARCR decrease opioid consumption? (3) What proportion of patients who used the relaxation techniques believed they decreased their pain level, and what proportion continued using these techniques at 2 weeks? (4) Does performing relaxation exercises after ARCR affect shoulder function? METHODS: During the study period, 563 patients were eligible for inclusion; however, only 146 were enrolled, randomized, and postoperatively followed (relaxation group: 74, control group: 72); 68% (384 of 563) of patients were not contacted due to patient and research staff availability. Thirty-three patients were unenrolled preoperatively or immediately postoperatively due to change in operative procedure (such as, only debridement) or patient request; no postoperative data were collected from these patients. Follow-up proportions were similar between the relaxation and control groups (relaxation: 80%, control: 81%; p = 0.90). The relaxation group received and reviewed educational materials consisting of a 5-minute video and an educational pamphlet explaining relaxation breathing techniques, while the control group did not receive relaxation education materials. Patients recorded their pain levels and opioid consumption during the 5 days after ARCR. Patients also completed the American Shoulder and Elbow Surgeons shoulder score preoperatively and 2, 6, 13, 18, and 26 weeks postoperatively. Linear mixed models were created to analyze postoperative pain, opioid consumption measured in morphine milligram equivalents (MMEs), and shoulder function outcomes. A per-protocol approach was used to correct for patients who were enrolled but subsequently underwent other procedures. RESULTS: There was no difference in pain scores between the relaxation and control groups during the first 5 days postoperatively. There was no difference in pain scores at 2 weeks postoperatively between the relaxation and control groups (3.3 ± 3 versus 3.5 ± 2, mean difference -0.22 [95% CI -1.06 to 0.62]; p = 0.60). There was no difference in opioid consumption during the first 5 days postoperatively between the relaxation and control groups. The use of relaxation exercises resulted in lower 2-week narcotics consumption in the relaxation group than in the control group (309 ± 241 MMEs versus 442 ± 307 MMEs, mean difference -133 [95% CI -225 to -42]; p < 0.01). Sixty-two percent (41 of 66) of patients in the relaxation group believed the relaxation exercises decreased their pain levels. Fifty-two percent (34 of 66) were still performing the exercises at 2 weeks postoperatively. During the 6-month follow-up period, there was no difference in shoulder function between the relaxation and control groups. CONCLUSION: The preoperative administration of quick, basic relaxation exercises allowed patients to use appreciably lower opioid analgesic doses over the first 2 weeks after ARCR, without any worsening of pain scores. We consider this result promising but preliminary; it is possible that a more intense mindfulness intervention-the one we studied here was disseminated using only a 5-minute video-would deliver reductions in pain and further reductions in opioid usage. LEVEL OF EVIDENCE: Level II, therapeutic study.

Editorial Commentary: Risks of Biologic Therapies in Sports Medicine: Landmines on the Road to the Holy Grail.

Biologic therapies hold great promise in the treatment of a variety of sports medicine conditions, including cartilage injuries, osteoarthritis, and tendon or ligament tears. Cell-based therapies currently under investigation include autologous products such as platelet-rich plasma, bone marrow aspirate concentrate, other adipose and mesenchymal stem cell products, and allogeneic products such as umbilical cord and placenta-derived products. However, their use does not come without risk, and the complications of these treatments can be underreported. Risks include infection, sterile inflammatory response, or a combination. Many times, when offering injection therapy, we consider the greatest risk a lack of efficacy. A "no harm, no foul" attitude is taken. Many of us think that the biggest risk of such injections, due to out-of-pocket expense, would be damage to someone's checkbook more than damage to their health. However, there are real medical risks to our treatments. Regulatory efforts around the use of biologics are needed to track both efficacy and side effects, as we advance this technology and expand its use in the future.

Cartilage Disease of the Patellofemoral Joint: Realignment, Restoration, Replacement.

Chondral lesions of the patellofemoral joint are common, and when symptomatic they can be difficult to manage. Not only are there various degrees of injury with multiple etiologies, but patellofemoral anatomy is complex and the patient's lower extremity alignment may contribute to the pathology. Treatment depends on the location, size, and depth of the lesion and may require realignment or concomitant stabilizing procedures. Tibial tubercle osteotomy can be performed in isolation or combined with various cartilage-based treatments, including marrow stimulation techniques, autologous chondrocyte implantation, osteochondral autograft, and osteochondral allograft. End-stage lesions, failed primary patellofemoral cartilage restoration with diffuse involvement, or isolated primary patellofemoral arthritis may be amenable to treatment with patellofemoral arthroplasty. Recent investigations in properly indicated patients using advanced techniques have shown that management of patellofemoral cartilage disease is now more effective and predictable than in the past.

Prospective Randomized Study Evaluating the Effects of Preoperative Opioid Counseling on Postoperative Opioid Use after Outpatient Lower Extremity Orthopaedic Surgery.

The objective of this study was to investigate the effect of standardized preoperative opioid counseling on postoperative opioid consumption for patients undergoing outpatient lower extremity orthopaedic surgery. Participating patients undergoing elective outpatient lower extremity orthopaedic surgery were randomized to either receive preoperative opioid counseling or not receive counseling (control group). Counseling was delivered via a five-minute pre-recorded standardized video preoperatively. Postoperatively, patients in both groups were queried for their postoperative pain experience, opioid consumption, non-opioid medication consumption, and any adverse effects related to their pain management experience. A total of 107 patients were studied, with 45 in the counseling group and 62 in the control group. Patients that received preoperative opioid counseling consumed on average 6.5 opioid pills postoperatively; the control group consumed 12.4 opioid pills (p = 0.008). Preoperative opioid counseling resulted in a statistically significant reduction in postoperative opioid consumption after outpatient lower extremity orthopaedic surgery. (Journal of Surgical Orthopaedic Advances 30(1):002-006, 2021).

Are Patient and Surgeon Expectations after ACL Reconstruction Realistic?

BACKGROUND: Patient expectations may affect their satisfaction and functional outcomes after treatment of musculoskeletal injuries. Although there is evidence that patient expectations of ACL reconstruction (ACLR) are inflated, there is limited knowledge about the relationship between physician and patient expectations and patient outcomes after they completely recover from ACLR. Furthermore, it is unclear if specific patient factors influence these expectations. QUESTIONS/PURPOSES: (1) Are patient and surgeon expectations of knee function 18 months after ACLR similar? (2) Are patients' and surgeons' expectations of outcomes similar to patients' actual 2-year outcomes? (3) Is there a relationship between preoperative or intraoperative parameters and expectations? (4) Is there a relationship between preoperative or intraoperative parameters and 2-year ACLR outcomes? METHODS: One-hundred twenty-nine patients undergoing primary ACLR were prospectively enrolled in this study, with 98 (76%) completing 2-year follow-up. Patients completed the IKDC Subjective Knee Evaluation preoperatively and at 3, 6, 12, and 24 months postoperatively. Patients also completed the same questionnaires preoperatively to evaluate expected knee function 18 months after surgery. Immediately postoperatively, surgeons completed the same questionnaires regarding the expected postoperative outcome at 18 months postoperative. Preoperative and intraoperative data were collected to determine an association between expectations and outcomes. Nonparametric analysis was performed using the Mann-Whitney U test, the paired Wilcoxon signed ranks tests and Spearman's correlations, as applicable. RESULTS: There was no difference between patient and surgeon expectations (patient, 94.8 [range 47.4-100] versus surgeon, 94.3 [range 46-100]; p = 0.283), and there was no correlation between higher patient expectations and higher surgeon expectations (r = 0.168, p = 0.078). Patient and surgeon expectations were greater than the actual postoperative outcomes (2-year postoperative: 89.7 [range 32.2 to 100]; p < 0.0001); however, the differences are unlikely to be perceived. There was no correlation between higher 2-year postoperative outcomes and higher patient expectations (r = 0.14, p = 0.186) or higher surgeon expectations (r = 0.019, p = 0.86). Arthroscopic evidence of cartilage damage was independently associated with the worst patient and surgeon expectations. The surgeons themselves were also independently associated with surgeon expectation (p < 0.001). No parameters were associated with postoperative outcomes. CONCLUSIONS: There are no clinically significant differences between surgeon expectations, patient expectations, and 2-year actual outcomes. However, there is also no correlation between the patient expectations, surgeon expectations, and actual outcomes. Although expectations are similar to actual outcomes for most patients, surgeons are unable to accurately predict outcomes for specific patients; thus, preventing adequate patient counseling. Surgeons should be cautious when evaluating and counseling patients preoperatively and avoid assuming high expectations. LEVEL OF EVIDENCE: Level II, therapeutic study.

Editorial Commentary: Graft Choice for Anterior Cruciate Ligament Reconstruction: Will There Ever Be a Correct Answer? Probably Not.

Graft choice for anterior cruciate ligament reconstruction has been a great controversy in the sports medicine literature for the last 25 years. It has been well studied in the orthopaedic literature, with numerous randomized control trials and large database studies. There remain advantages and disadvantages to each autograft choice, primarily bone-patellar tendon-bone, quadrupled hamstring, as well as allograft. More recently, quadriceps autograft has also been studied as a suitable alternative. Most studies show nearly equivalent functional outcomes for autograft anterior cruciate ligament using bone-patellar tendon-bone and hamstring autografts in athletes younger than the age of 25 years, whereas allograft may be preferred for older athletes.

Development of a return to play checklist following patellar instability surgery: a Delphi-based consensus.

PURPOSE: To date, there is no consensus for the appropriate timing or functional evaluation for safe return to play following patellar instability surgery. The purpose of this study is to develop a consensus-based return to play checklist following patellar stabilization surgery using the Delphi method. METHODS: A 3-part survey series was conducted following the systematic guidelines of the Delphi technique for gathering consensus from experts in the management of patellofemoral instability. All surveys were completed between July and November of 2017. A literature search was performed in SCOPUS and PubMed to identify existing sources on return to play following patellar instability surgery and determining patellofemoral joint strength in athletes, which served as the basis for the surveys. RESULTS: 12 of the 19 selected participants (63%) completed the first-round survey, 11 of those 12 participants (92%) completed the second-round survey, and 10 of these 11 participants (91%) completed the final survey. Of the final ten participants, there was representation from seven different states in the USA. Nine of the ten (90%) respondents endorsed the final checklist. The final checklist included eight overarching domains with defined and reproducible objective criteria. CONCLUSION: The standardized list of objective and reproducible criteria for rehabilitation outlined below should help practitioners focus more on patient-centred factors and less on arbitrary timelines. No prior study has gathered consensus from experts on this topic; therefore, this study should serve as a benchmark to help guide patients back to sport safely. LEVEL OF EVIDENCE: V.

The Clinical Evidence Behind Biologic Therapies Promoted at Annual Orthopaedic Meetings: A Systematic Review.

PURPOSE: The purpose of this study is to systematically evaluate the available clinical data for biologic therapies promoted for articular cartilage defects and osteoarthritis of the knee at the 2016 American Orthopaedic Society for Sports Medicine Meeting (AOSSM) and the 2017 Arthroscopy Association of North America meeting (AANA). METHODS: Our sample included all exhibitors at the 2016 AOSSM meeting and 2017 AANA meeting. All biologic products marketed at each conference were identified by reviewing exhibition booths and company websites. A systematic review of the clinical data on each product was then completed using PubMed, EMBASE, and the product's own webpage. All clinical peer-reviewed studies with level I-IV evidence were included in the study. Basic science or preclinical studies were excluded. RESULTS: There were 16 products promoted for biologic therapy for articular cartilage defects or osteoarthritis of the knee at the AOSSM meeting and 11 products promoted at the AANA meeting. A total of 280 articles detailed clinical findings for the articular cartilage products displayed at AOSSM and AANA. Of the 280, there were 36 level I evidence studies, 37 level II evidence studies, 18 level III evidence studies, and 189 level IV evidence studies. Of these articles, 91% were for 4 products. Of all biologic products promoted at the 2 meetings, 65% did not have any peer-reviewed clinical data supporting their use. CONCLUSION: Overall, many biologic therapies promoted at leading arthroscopy and sports medicine conferences did not have clinical evidence evaluating their use in the peer-reviewed literature. Although scientific advancement requires new technology, orthopaedic surgeons should be cautious about using biologic therapies in their practice with no proven efficacy. There are likely promising new interventions that, with additional scientific research, will be proven efficacious for our patients. CLINICAL RELEVANCE: This article gives orthopaedic surgeons a detailed example of some of the biologic treatments being offered on the market for the treatment of knee articular cartilage disease. When patients request these treatments, physicians must be able to explain the data supporting their use.

Intraoperative Ketamine in Total Knee Arthroplasty Does Not Decrease Pain and Narcotic Consumption: A Prospective Randomized Controlled Trial.

BACKGROUND: Multiple studies have demonstrated that ketamine, a glutamate receptor blocker, may decrease postoperative pain in abdominal and orthopedic surgeries. However, its role with spinal anesthesia and total knee arthroplasty (TKA) remains unknown. The purpose of this study is to determine the efficacy of subanesthetic dosing of ketamine during TKA on postoperative pain and narcotic consumption. METHODS: In this prospective, randomized, double-blinded clinical trial, we enrolled 91 patients undergoing primary TKA with spinal anesthesia in a single institution from 2017 to 2018. Patients were randomized to receive intraoperative ketamine infusion at a rate of 6 mcg/kg/min for 75 minutes or a saline placebo. All patients received spinal anesthesia and otherwise identical surgical approaches, pain management, and rehabilitation protocols. Patient-reported visual analog pain scores were calculated preoperatively, postoperative days (POD) 0-7, and 2 weeks. Narcotic consumption was evaluated on POD 0 and 1. RESULTS: There was no difference in average pain between ketamine and placebo at all time points except for at PODs 1 (45 vs 56, P = .041) and 4 (39 vs 49, P = .040). For least pain experienced, patients administered with ketamine experienced a reduction in pain only at POD 4 (22 vs 35, P = .011). There was no difference in maximum pain cohorts at all time points of the study or in-hospital morphine equivalents between the 2 cohorts. CONCLUSION: As part of multimodal pain management protocol, intraoperative ketamine does not result in a clinically significant improvement in pain and narcotic consumption following TKA.

Return to Play Criteria Following Surgical Stabilization for Traumatic Anterior Shoulder Instability: A Systematic Review.

PURPOSE: To identify and describe in the existing literature any criteria used for return to play following surgical stabilization for traumatic, anterior shoulder instability. METHODS: We performed a systematic review evaluating surgical stabilization for primary traumatic anterior shoulder instability in skeletally mature patients with a minimum of 1-year follow-up using Level I to IV studies in PubMed and EMBASE from January 1994 to January 2017. RESULTS: Fifty-eight studies with at least 1 explicitly stated criterion for return to play were identified from a review of more than 5,100 published articles. Seven different categories of return to play criteria were identified, the most common of which were time from surgery (89.6%), strength (18.9%), and range of motion (13.8%). Pain, stability, proprioception, and postoperative radiographic evaluation were also used. As hypothesized, in 75.8% of the included studies (44/58), time was the only criterion explicitly used. The most commonly used time for return to play was 6 months. CONCLUSIONS: This systematic review identifies 7 criteria that have been used in the available literature to determine when patients are ready to return to play; however, consistent with our hypothesis, 75% of studies used time from surgery as the sole listed criterion, with the most commonly used time point of 6 months postoperative. All of these criteria can be used in future research to develop a comprehensive checklist of functional criteria in hopes of reducing recurrent injury. LEVEL OF EVIDENCE: Level IV, systematic review.

Contact Versus Noncontact Anterior Cruciate Ligament Injuries: Is Mechanism of Injury Predictive of Concomitant Knee Pathology?

PURPOSE: To determine if mechanism of injury is predictive of concomitant knee pathology found at the time of anterior cruciate ligament (ACL) reconstruction. METHODS: All patients aged 16 to 35 who underwent ACL reconstruction at our institution between January 2009 and December 2015 were retrospectively reviewed. Mechanism of injury was determined from patient history. The presence of meniscal or chondral damage was determined from operative records, while collateral ligament injuries were determined by the treating surgeon's diagnosis after physical examination and their review of magnetic resonance imaging findings. Patients with inadequate documentation, history of a subsequent instability episode following the initial injury, or prior history of knee pathology were excluded. RESULTS: Six hundred eighty-seven patients (169 contact and 518 noncontact) were included. A 2-fold increase in the incidence of collateral ligament injury was identified between the 2 groups with 114 (67.5%) in the contact group and 175 (33.8%) in the noncontact group (P < .001). Twenty-six patients (15.4%) in the contact group compared with 9 (1.7%) in the noncontact group had a grade III collateral ligament injury (P < .001). Chondral injury was identified in 41 (24.3%) patients in the contact group and 87 (16.8%) in the noncontact group (P = .05) with 9 (5.3%) grade IV lesions in the contact group and 4 (0.8%) in the noncontact group (P < .001). Eleven patients in the contact group (6.5%) and 15 in the noncontact group (2.9%) had a chondral injury to the lateral femoral condyle (P = .04). CONCLUSIONS: Although we found no difference in the incidence or type of meniscal tears, we found a significant increase in the incidence of grade IV chondral injury, chondral injury to the lateral femoral condyle, and grade III collateral ligament damage in the setting of contact ACL injuries. This knowledge can aid surgeons in preoperative planning and patient counseling. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Anatomic Anterior Cruciate Ligament Reconstruction via Independent Tunnel Drilling: A Systematic Review of Randomized Controlled Trials Comparing Patellar Tendon and Hamstring Autografts.

PURPOSE: To collect the highest level of evidence comparing anatomic anterior cruciate ligament (ACL) reconstruction via independent tunnel drilling using bone-patellar tendon-bone (BTB) and hamstring tendon (HT) autografts in terms of clinical outcome and failure rate. METHODS: We performed a systematic review of clinical trials that randomized patients to ACL reconstruction with either BTB or HT autografts with a minimum 2-year follow-up. Only trials using independent tunnel drilling, including outside-in and anteromedial portal techniques, for both autografts were eligible for inclusion, whereas all transtibial studies were excluded. Study design, demographics, surgical technique, rehabilitation protocol, and clinical outcomes were compiled. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. Quality assessment was performed using the Coleman Methodological Scale (CMS). RESULTS: Six published studies reporting on 5 randomized controlled trials (RCTs) met the inclusion criteria. No study reported a difference in rerupture rate between BTB and HT. BTB-reconstructed knees experienced a greater incidence of anterior knee pain or crepitus in 2/7 trials and radiographic evidence of degenerative change in 3/7 trials. HT-reconstructed knees had increased instrumented laxity in 2/7 trials and less knee flexion strength postoperatively. CONCLUSIONS: This study collects all available Level I and II evidence for anatomic ACL reconstruction using BTB and HT grafts. According to the data presented in these studies, clinical outcome scores and failure rates showed no differences for anatomic reconstruction using either autograft. However, in some studies, BTB-reconstructed knees experienced a greater incidence of anterior knee pain and radiographic evidence of degenerative change, and in others, HT-reconstructed knees had increased laxity and less knee flexion strength. In our opinion, both BTB and HT autografts remain valid options for ACL reconstruction when using anatomic drilling techniques, providing a stable knee with reliable return to activity. LEVEL OF EVIDENCE: Level II, systematic review of Level I and II studies.