Low early complication rates after arthroscopic meniscus repair and meniscectomy.

PURPOSE: To evaluate the 30-day complication rates after arthroscopic meniscus repair and meniscectomy using the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database, with subgroup analysis of patients aged > 40 years. METHODS: NSQIP registries between 2006 and 2019 were queried using Current Procedural Terminology codes to identify patients undergoing arthroscopic meniscus repair (CPT 29882, 29883) and meniscectomy (29880, 29881). The following 30-day complications were assessed: pulmonary embolism (PE), venous thromboembolism (VTE), surgical site infection (SSI), reoperation, and readmission. Complications rates between treatment groups were compared using multivariate logistic regression analyses adjusted for sex, age, steroid use, and smoking/dyspnoea/COPD. A subgroup analysis was performed for patients aged > 40 years. RESULTS: A total 6354 meniscus repairs and 99,372 meniscectomies were identified. Complication rates were < 1% for both meniscus repair and meniscectomy. Meniscus repair was associated with significantly higher rates of PE, VTE, and readmission compared to meniscectomy: PE (0.2% vs 0.1%, p < 0.001), VTE (0.8% vs 0.4%, p < 0.001), superficial SSI (0.1% vs 0.2%, n.s), deep SSI (0.07% vs 0.1%, n.s), reoperation (0.5% vs 0.4%, n.s), and readmission (0.9% vs 0.8%, p = 0.003). Among patients aged > 40 years, complication rates were < 1.3% for both meniscus repair and meniscectomy. Similar trends and rates were found in patients aged > 40 years undergoing meniscus repair versus meniscectomy: PE (0.38% vs 0.12%, p < 0.001), VTE (1.07% vs 0.46%, p < 0.001), superficial SSI (0.03% vs 0.19%, n.s), deep SSI (0.1% vs 0.06%, n.s), reoperation (0.48% vs 0.43%, n.s), and readmission (1.2% vs 0.85%, p = 0.01). CONCLUSION: Arthroscopic meniscus repair and meniscectomy are both low-risk procedures with 30-day complication rates < 1% overall and < 1.3% among patients aged > 40 years. These findings support meniscus repair whenever feasible in the setting of preserved articular cartilage. Understanding of the short-term complication rates after arthroscopic meniscus repair and meniscectomy can aid surgeons in providing comprehensive preoperative counselling to patients considering such treatments, specifically when discussing the risks and benefits of meniscus repair. LEVEL OF EVIDENCE: III.

Trends and complications of distal biceps tendon repair among American Board of Orthopaedic Surgery part II oral examination candidates.

BACKGROUND: Surgical fixation of distal biceps tendon ruptures can restore supination strength and minimize biceps fatigue, resulting in high patient satisfaction rates. Surgical approaches can vary (single incision vs. double incision), and the number of fixation techniques has increased in recent years. The reported rate of postoperative complications after surgical repair of distal biceps tendon injuries is high, ranging from 15% to 35%. The purpose of this study was to assess the trends and postoperative complication profile among newly trained surgeons who performed distal biceps tendon repairs utilizing the American Board of Orthopaedic Surgery database. METHODS: The American Board of Orthopaedic Surgery database was retrospectively queried for patients treated with distal biceps tendon repair by part II examination candidates between 2017 and 2020. Distal biceps tendon repairs were isolated using the Current Procedural Terminology code 24,342. Distal triceps tendon injuries were excluded with International Classification of Diseases code S46.3∗∗. Patient demographics, intraoperative data, and surgeon fellowship training were collected. Surgeon-reported postoperative 90-day complications, including general anesthetic, medical, and surgical complications, rates of readmission, and rates of reoperation were recorded. Comparisons of rates among patient groups organized by surgeon fellowship training were performed using the chi-squared test. RESULTS: A total of 2089 distal biceps tendon repairs were included in the analysis. The average patient age was 47.5 yr, and 97.3% of patients were men. The majority of cases was performed by surgeons with fellowship training in sports medicine, hand/upper extremity, and shoulder and elbow, with 867 (41.5%) cases performed by sports medicine-trained surgeons, 740 (35.4%) by hand/upper extremity-trained surgeons, and 313 (15.0%) by shoulder and elbow-trained surgeons. In total, 608 (29.1%) patients experienced an anesthetic (0.2%), medical (1.1%), or surgical (28.2%) complication. The most common surgical complications were nerve injury (20.6%), failure of tendon repair or fixation (2.4%), and infection (1.7%). The overall reoperation rate was 2.4%. There were no significant differences in complication or reoperation rates among subspecialty training received. DISCUSSION AND CONCLUSION: Among newly trained surgeons, those with fellowship training in sports medicine, hand/upper extremity, and shoulder and elbow performed the most distal biceps tendon repairs, and there was no difference in complication rates among subspecialty training received. Complication rates after distal biceps tendon repair performed by newly trained surgeons were similar to those previously reported in large cohort studies, with nerve injury as the most common complication.

Low-Intensity Pulsed Ultrasound Augments Tendon, Ligament, and Bone-Soft Tissue Healing in Preclinical Animal Models: A Systematic Review.

PURPOSE: To appraise the available animal and human studies investigating low-intensity pulsed ultrasound stimulation (LIPUS) on tendon, ligament, and bone-soft tissue (B-ST) junction healing. METHODS: A systematic review of PUBMED, EMBASE, and the Cochrane Library was performed for animal and human studies investigating the effects of LIPUS on tendon, ligament, and B-ST junction healing. The systematic search was performed using the key term "low intensity pulsed ultrasound" and any of the following: "tendon," "ligament," "tendon-bone," and "bone-tendon." Inclusion criteria consisted of (1) randomized controlled trials assessing the effect of LIPUS on bone, tendon, and soft tissue in animals or humans and (2) English-language articles. RESULTS: A total of 28 animal and 2 human studies met inclusion criteria. Animal studies utilized various models, including Achilles and patellar tendon transections, medial collateral ligament transections, and surgical repair of patellar tendon, rotator cuff tendon, and anterior cruciate ligament, to evaluate the effects of LIPUS. Animal studies demonstrated significantly improved collagen content and organization, bone formation, fibrocartilage remodeling, and mechanical strength with LIPUS treatment compared with controls. In human trials, LIPUS treatment of chronic tendinopathies did not improve clinical outcomes. CONCLUSIONS: In acute injury animal models, LIPUS augmented healing of acute tendon, ligament, and B-ST junction injuries through increased collagen content and organization; increased anti-inflammatory cellular signaling; and increased angiogenesis. However, in 2 human studies investigating chronic tendinopathy, LIPUS did not lead to superior outcomes compared with controls. CLINICAL RELEVANCE: Animal models suggest that LIPUS may be a promising noninvasive treatment modality for accelerating patient recovery after acute tendon and ligament injuries, as well as after surgical repair of B-ST junction injuries, but this has not been demonstrated in human studies. Randomized clinical trials evaluating LIPUS for acute tendon and ligament injuries are warranted.

Effects of Prenatal Phthalate Exposure and Childhood Exercise on Maternal Behaviors in Female Rats at Postpartum: A Role of Oxtr Methylation in the Hypothalamus.

Both the detrimental effect of prenatal exposure to di-(2-ethylhexyl)-phthalate (DEHP) and the beneficial effects of physical exercise on brain functions have been reported. The oxytocin pathway has been implicated in the onset of maternal behaviors. Epigenetic modification of the oxytocin receptor gene (OXTR) through DNA methylation has been associated with the pathogenesis of neuropsychiatric disorders. The purpose of this study was to investigate the effects of prenatal DEHP exposure on oxytocin-regulated maternal behaviors and to examine the protective effect of exercise. Pregnant rats (F0) were fed with vehicle or DEHP during gestation and the offspring females (F1) were assessed for their maternal behaviors by pup retrieval test at postpartum. The results showed that reduced pup retrieval activities without significant alteration of stress responses were observed in the prenatally DEHP-exposed females. Prenatal DEHP exposure decreased the expressions of oxytocin, Oxtr mRNA, and oxytocin receptor, and increased Oxtr methylation in the hypothalamus of postpartum female rats. There were no significant effects of exercise on behavioral, biochemical, and epigenetic measurements. These results suggest that prenatal DEHP exposure has a long-term adverse effect on maternal behaviors; Oxtr hyper-methylation may be a potential epigenetic mechanism for this alteration, which cannot be prevented by physical exercise during childhood.

High-fat diet reduces novelty-induced expression of activity-regulated cytoskeleton-associated protein.

Chronic high-fat-diet (HFD) consumption can lead to the development of brain insulin resistance, which then exerts deleterious effects on learning and memory. Activity-regulated cytoskeleton-associated protein (Arc) is a memory-related protein, and its expression can be induced by insulin stimulation. In HFD-fed animals, their basal Arc protein levels in cerebral cortex and hippocampus are reduced. However, the effects of HFD on novelty-induced Arc protein expression that is important for cognitive function is still unknown. In the present study, after feeding HFD (60% kcal from fat) for 5 weeks, mice developed brain insulin resistance and had a significant reduction in the novelty-induced but not the basal Arc protein levels in their hippocampi. Further experiments were performed in primary rat hippocampal neurons. The results show that, under the condition of neuronal insulin resistance, acute insulin stimulation induced less activation of the phosphatidylinositol 3-kinase/protein kinase B/p70 ribosomal S6 kinase (PI3K/Akt/p70S6K) pathway, resulting in reduced induction of Arc protein expression. Accordingly, it is suggested that following HFD feeding, the reduction in novelty-induced Arc protein expression in animal's hippocampus is probably related to a suppressed activation of the PI3K/Akt/p70S6K pathway due to the existence of brain insulin resistance.

Non-treatment of stable ramp lesions does not degrade clinical outcomes in the setting of primary ACL reconstruction.

PURPOSE: The purpose of this study was to evaluate the clinical outcomes of various methods of treatment of stable and unstable ramp lesions compared to patients with no meniscal pathology at the time of primary ACL reconstruction. METHODS: All patients with a preoperative MRI performed at our facility who were enrolled in an institutional ACL registry and 1-year clinical follow-up were identified. A musculoskeletal radiologist reviewed preoperative MRI scans for evidence of a ramp lesion. Ramp lesions were classified as stable if a peripheral tear of the posterior horn of the medial meniscus was identified by MRI, but did not displace into the medial compartment with anteriorly directed probing at the time of surgery. Ramp lesions were classified as unstable if a tear was identified by preoperative MRI at the meniscocapsular junction and the meniscus was displaceable into the medial compartment with probing. Reoperation rates for ACL graft failure or recurrent medial meniscus pathology were collected. Patient-reported outcome scores (IKDC, SF12 PCS, SF12 MCS, and Marx Activity scale) were recorded at baseline and final follow-up. RESULTS: A total of 162 patients were included in the analysis with median 2-year (range 1-5 years) clinical follow-up. Patients with a repaired unstable ramp lesion had a significantly higher likelihood of reoperation for recurrent medial meniscus pathology than patients without meniscal pathology at the time of index surgery. Patients with an untreated stable ramp lesion had a similar rate of reoperation when compared to patients without meniscal pathology. At final follow-up, there was no difference between groups in IKDC score, SF12 PCS/MCS, or Marx activity score or change in any score. CONCLUSIONS: Patients with untreated stable ramp lesions have similar clinical outcomes at median 2-year (range 1-5 years) follow-up when compared to patients without a ramp lesion. Treatment of stable ramp lesions at the time of ACL reconstruction does not have clinical benefit. LEVEL OF EVIDENCE: III.

Therapeutic postoperative anticoagulation is a risk factor for wound complications, infection, and revision after shoulder arthroplasty.

BACKGROUND: The purpose of the present study was to examine the relationship between postoperative therapeutic anticoagulation, wound complications, infection, and revision. METHODS: Using a national insurance database from 2007 to 2016, patients who underwent shoulder arthroplasty with an indication for postoperative therapeutic anticoagulation in the case of atrial fibrillation or acute postoperative venous thromboembolism were identified. Those with a prescription for a therapeutic anticoagulant within 2 weeks of surgery were identified and compared with controls without postoperative therapeutic anticoagulant prescriptions. Wound complications and postoperative infection at 3 and 6 months, and revision shoulder arthroplasty at 6 months and all time points were then compared in the database using a multivariable logistic regression analysis. RESULTS: A total of 17,272 patients were included, including 684 patients who received therapeutic anticoagulation and 16,588 controls. Patients receiving therapeutic anticoagulation experienced increased wound complications at 3 months (odds ratio [OR] 3.0, 95% confidence interval [CI] 2.0-4.6, P < .0001) and 6 months (OR 2.5, 95% CI 1.7-3.8, P < .0001). Patients receiving therapeutic anticoagulation also experienced increased rates of wound infection at 3 months (OR 1.5, 95% CI 1.1-2.0, P = .007) and 6 months (OR 1.8, 95% CI 1.4-2.3, P < .0001). Finally, patients receiving therapeutic anticoagulation experienced increased rates of revision surgery at 6 months (OR 1.8, 95% CI 1.3-2.5, P = .0003) and within 9 years (OR 1.5, 95% CI 1.1-2.0, P = .007). CONCLUSIONS: Wound complications and revision rates in patients undergoing shoulder arthroplasty who require postoperative therapeutic anticoagulation are significantly elevated compared with controls.

Recovery of BDNF and CB1R in the Prefrontal Cortex Underlying Improvement of Working Memory in Prenatal DEHP-Exposed Male Rats after Aerobic Exercise.

Early-life exposure to di-(2-ethylhexyl)-phthalate (DEHP) has been suggested to relate to hyperactivity, lack of attention, and working memory deficits in school-age children. Brain-derived neurotrophic factor (BDNF) and endocannabinoids are induced by aerobic exercises to provide beneficial effects on brain functions. This study investigated the mechanisms underlying working memory impairment and the protective role of exercise in prenatal DEHP-exposed male rats. Sprague Dawley dams were fed with vehicle or DEHP during gestation. The male offspring were trained to exercise on a treadmill for 5 weeks, which was followed by an assessment of their working memory with a T-maze delayed non-match-to-sample task. The expressions of BDNF, dopamine D1 receptor (D1R), cannabinoid receptor 1 (CB1R), and fatty acid amide hydrolase (FAAH) in the prefrontal cortex were detected by Western blot. The results showed that DEHP-exposed rats exhibited working memory impairments without significant alterations in locomotor activities. The reduced expressions of prefrontal BDNF and CB1R were obtained in the DEHP-exposed rats, while D1R and FAAH were barely affected. Importantly, aerobic exercise during childhood-adolescence prevented the impairment of working memory in the DEHP-exposed rats by recovering the BDNF and CB1R expressions in the prefrontal cortex. These findings suggest that exercise may provide beneficial effects in ameliorating the impairment of working memory in the prenatal DEHP-exposed male rats at late adolescence.

The impact of prior upper-extremity surgery on orthopedic injury and surgery in collegiate athletes.

BACKGROUND: The influence of prior upper-extremity (UE) surgery on a collegiate athletic career is poorly understood. This study aimed to investigate the impact of prior UE surgery on participation, injury, and surgery rates in collegiate athletes. METHODS: Division I athletes who commenced collegiate athletics from 2003-2009 were retrospectively identified. Pre-participation evaluation forms were queried for the history of pre-collegiate UE surgery. Data on sport played, seasons played, injuries, days missed, and orthopedic imaging and surgical procedures were collected through athletic and medical records and compared with those of athletes without prior UE surgery. Subgroup analysis was performed for shoulder surgery, elbow surgery, and wrist and/or hand surgery. RESULTS: Between 2003 and 2009, 1145 athletes completed pre-participation evaluations. Of these athletes, 77 (6.7%) underwent at least 1 pre-collegiate UE surgical procedure. Prior UE surgery was most common in men's water polo (15.0%), baseball (14.9%), and football (12.6%). The UE surgery group had a higher rate of collegiate UE injury (hazard ratio, 4.127; P < .01) and missed more days per season because of UE injury (16.5 days vs. 6.7 days, P = .03) than controls. Athletes with prior shoulder surgery (n = 20) also experienced more UE injuries compared with controls (hazard ratio, 15,083; P = .02). They missed more days per season (77.5 days vs. 29.8 days, P < .01), underwent more magnetic resonance imaging scans (0.96 vs. 0.40, P < .01), and underwent more orthopedic surgical procedures per season (0.23 vs. 0.08, P < .01). The elbow subgroup and wrist and/or hand subgroup were comparable with controls on all measures. CONCLUSIONS: Collegiate athletes with prior shoulder surgery missed more days and underwent more magnetic resonance imaging scans and surgical procedures in college, whereas those with prior elbow surgical procedures and wrist and/or hand surgical procedures were comparable with controls.

Efficacy of intraarticular corticosteroid hip injections for osteoarthritis and subsequent surgery.

OBJECTIVE: Our study aimed to determine the duration of pain relief from intraarticular hip corticosteroid injections and identify patient predictive factors on injection response. We also sought to determine the subsequent rate of hip surgery and whether severity of hip osteoarthritis or injection response correlated with the decision to undergo surgery. MATERIALS AND METHODS: All intraarticular hip steroid injections performed for osteoarthritis under fluoroscopic guidance at a single institution between January 2010 to December 2012 were retrospectively reviewed. Response was divided into three groups: no relief, immediate (≤ 2 weeks of pain relief), and continued (> 2 weeks of pain relief). Presence of hip surgery for osteoarthritis performed within 2 years following injection was obtained. Correlation between patient characteristics with injection outcome and hip surgery was analyzed. RESULTS: Of 78 patients, a total of 82 injections were analyzed. For injections, 19.5% (16/82) showed no response, 47.6% (39/82) showed immediate response, and 32.9% (27/82) showed continued response. There was no significant correlation between injection outcome with age, Tönnis grade, BMI, or duration of symptoms. In total, 48.7% had hip surgery within 2 years after initial injection. There was a significant association between Tönnis grade and surgery, with higher Tönnis grades correlating with decision to undergo surgery (p = 0.002). CONCLUSIONS: Gender, age, BMI, duration of symptoms, and radiographic severity of disease do not predict injection response. Due to high surgical rates and poor response, intraarticular hip steroid injections may be less effective in the long term, and surgical management may be considered earlier.

The Assessment of Quality, Accuracy, and Readability of Online Educational Resources for Platelet-Rich Plasma.

PURPOSE: To critically evaluate the quality, accuracy, and readability of readily available Internet patient resources for platelet-rich plasma (PRP) as a treatment modality for musculoskeletal injuries. METHODS: Using the 3 most commonly used Internet search engines (Google, Bing, Yahoo), the search term "platelet rich plasma" was entered, and the first 50 websites from each search were reviewed. The website's affiliation was identified. Quality was evaluated using 25-point criteria based on guidelines published by the American Academy of Orthopaedic Surgeons, and accuracy was assessed with a previously described 12-point grading system by 3 reviewers independently. Readability was evaluated using the Flesch-Kincaid (FK) grade score. RESULTS: A total of 46 unique websites were identified and evaluated. The average quality and accuracy was 9.4 ± 3.4 (maximum 25) and 7.9 ± 2.3 (maximum 12), respectively. The average FK grade level was 12.6 ± 2.4, which is several grades higher than the recommended eighth-grade level for patient education material. Ninety-one percent (42/46) of websites were authored by physicians, and 9% (4/46) contained commercial bias. Mean quality was significantly greater in websites authored by health care providers (9.8 ± 3.1 vs 5.9 ± 4.7, P = .029) and in websites without commercial bias (9.9 ± 3.1 vs 4.5 ± 3.2, P = .002). Mean accuracy was significantly lower in websites authored by health care providers (7.6 ± 2.2 vs 11.0 ± 1.2, P = .004). Only 24% (11/46) reported that PRP remains an investigational treatment. CONCLUSIONS: The accuracy and quality of online patient resources for PRP are poor, and the information overestimates the reading ability of the general population. Websites authored by health care providers had higher quality but lower accuracy. Additionally, the majority of websites do not identify PRP as an experimental treatment, which may fail to provide appropriate patient understanding and expectations. CLINICAL RELEVANCE: Physicians should educate patients that many online patient resources have poor quality and accuracy and can be difficult to read.

Trends in the Surgical Management of Acromioclavicular Joint Arthritis Among Board-Eligible US Orthopaedic Surgeons.

PURPOSE: (1) Define the epidemiologic trend of distal clavicle excision (DCE) for acromioclavicular (AC) joint arthritis among board-eligible orthopaedic surgeons in the United States, (2) describe the rates and types of reported complications of open and arthroscopic DCE, and (3) evaluate the effect of fellowship training on preferred technique and reported complication rates. METHODS: The American Board of Orthopaedic Surgery (ABOS) database was used to identify DCE cases submitted by ABOS Part II Board Certification examination candidates. Inclusion criteria were predetermined using a combination of ICD-9 and CPT codes. Cases were dichotomized into 2 groups: open or arthroscopic DCE. The 2 groups were then analyzed to determine trends in annual incidence, complication rates, and surgeon fellowship training. RESULTS: From April 2004 to September 2013, there were 3,229 open and 12,782 arthroscopic DCE procedures performed and submitted by ABOS Part II Board Eligible candidates. Overall, the annual incidence of open DCE decreased (78-37 cases per 10,000 submitted cases, P = .023). Although the annual number of arthroscopic DCE remained steady (1160-1125, P = .622), the percentage of DCE cases performed arthroscopically increased (65%-79%, P = .033). Surgeons without fellowship training were most likely to perform a DCE via an open approach (31%) whereas surgeons with sports medicine training were more likely to perform DCE arthroscopically compared with other fellowship groups (88%, P < .001). Open DCE was associated with a higher surgical complication rate overall when compared with arthroscopic DCE (9.4% vs 7.6%, respectively; P < .001). When compared with other fellowship-trained surgeons, sports medicine surgeons maintained a lower reported surgical complication rate whether performing open or arthroscopic DCE (5.5%, P = .027). CONCLUSIONS: In recent years, open management of AC joint arthritis has declined among newly trained, board-eligible orthopaedic surgeons, possibly because of an increased complication rate associated with open treatment. Fellowship training was significantly associated with the type of treatment (open vs arthroscopic) rendered and complication rates. LEVEL OF EVIDENCE: Level IV, case series.

Kartogenin Enhances Collagen Organization and Mechanical Strength of the Repaired Enthesis in a Murine Model of Rotator Cuff Repair.

PURPOSE: To investigate the use of kartogenin (KGN) in augmenting healing of the repaired enthesis after rotator cuff repair in a murine model. METHODS: Seventy-two C57BL/6 wild-type mice underwent unilateral detachment and transosseous repair of the supraspinatus tendon augmented with either fibrin sealant (control group; n = 36) or fibrin sealant containing 100 µmol/L of KGN (experimental group; n = 36) applied at the repair site. Postoperatively, mice were allowed free cage activity without immobilization. Mice were humanely killed at 2 and 4 weeks postoperatively. Repair site integrity was evaluated histologically through fibrocartilage formation and collagen fiber organization and biomechanically through load-to-failure testing of the supraspinatus tendon-bone construct. RESULTS: At 2 weeks, no differences were noted in percent area of fibrocartilage, collagen organization, or ultimate strength between groups. At 4 weeks, superior collagen fiber organization (based on collagen birefringence [17.3 ± 2.0 vs 7.0 ± 6.5 integrated density/µm2; P < .01]) and higher ultimate failure loads (3.5 ± 0.6 N vs 2.3 ± 1.1 N; P = .04) were seen in the KGN group. The percent area of fibrocartilage (13.2 ± 8.4% vs 4.4 ± 5.4%; P = .04) was higher in the control group compared with the KGN group. CONCLUSIONS: Rotator cuff repair augmentation with KGN improved the collagen fiber organization and biomechanical strength of the tendon-bone interface at 4 weeks in a murine model. CLINICAL RELEVANCE: These findings have implications for improving the structural integrity of the repaired enthesis and potentially reducing the retear rate after rotator cuff repair, which can ultimately lead to improvements in clinical outcomes.

The Timing of Hip Arthroscopy After Intra-articular Hip Injection Affects Postoperative Infection Risk.

PURPOSE: To evaluate the association of preoperative intra-articular hip injection with surgical site infection after hip arthroscopy. METHODS: A large administrative database was used to identify all patients undergoing hip arthroscopy from 2007 to 2015 within a single private insurer and from 2005 to 2012 within Medicare in the United States. Those that received an ipsilateral preoperative intra-articular hip injection were identified. The patients were then divided into the following groups based on the interval between preoperative injection and ipsilateral hip arthroscopy: (1) <3 months, (2) 3 to 6 months, and (3) 6 to 12 months. These groups were compared to a control group composed of patients with no history or a remote history (>12 months) of preoperative hip injection. Patients developing a surgical site infection within 6 months following hip arthroscopy were identified using International Classification of Diseases, Ninth Revision, and Current Procedural Terminology codes associated with infection. Groups were compared using a multivariate logistic regression analysis to control for age, gender, body mass index, smoking status, alcohol usage, and multiple medical comorbidities including diabetes mellitus, hemodialysis use, inflammatory arthritis, and peripheral vascular disease. RESULTS: In total, 19% of privately insured and 6% of Medicare patients received a hip injection within 12 months of hip arthroscopy. The overall infection rate in privately insured and Medicare patients was 1.19% and 1.10%, respectively. Preoperative hip injection within 3 months of surgery was associated with a significantly higher risk of postoperative infection versus controls (2.16%, odds ratio [OR] 6.1, P < .001, for privately insured group; 2.80%, OR 1.99, P = .037, for Medicare group). In contrast, preoperative hip injection given after more than 3 months of surgery was not associated with an increased risk of postoperative infection versus controls. CONCLUSIONS: Risk of infection after hip arthroscopy increased when preoperative intra-articular hip injections were given within 3 months of surgery. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Similar Outcomes After Osteochondral Allograft Transplantation in Anterior Cruciate Ligament-Intact and -Reconstructed Knees: A Comparative Matched-Group Analysis With Minimum 2-Year Follow-Up.

PURPOSE: To compare failure rates and clinical outcomes of osteochondral allograft transplantation (OCA) in anterior cruciate ligament (ACL)-intact versus ACL-reconstructed knees at midterm follow-up. METHODS: After a priori power analysis, a prospective registry of patients treated with OCA for focal chondral lesions ≥2 cm2 in size with minimum 2-year follow-up was used to match ACL-reconstructed knees with ACL-intact knees by age, sex, and primary chondral defect location. Exclusion criteria included meniscus transplantation, realignment osteotomy, or other ligamentous injury. Complications, reoperations, and patient responses to validated outcome measures were reviewed. Failure was defined by any procedure involving allograft removal/revision or conversion to arthroplasty. Kaplan-Meier analysis and multivariate Cox regression were performed to evaluate the association of ACL reconstruction (ACLR) with failure. RESULTS: A total of 50 ACL-intact and 25 ACL-reconstructed (18 prior, 7 concomitant) OCA patients were analyzed. The mean age was 36.2 years (range, 14-62 years). Mean follow-up was 3.9 years (range, 2-14 years). Patient demographics and chondral lesion characteristics were similar between groups. ACL-reconstructed patients averaged 2.2 ± 1.9 prior surgeries on the ipsilateral knee compared with 1.4 ± 1.4 surgeries for ACL-intact patients (P = .014). Grafts used for the last ACLR included bone-patellar tendon-bone autograft, hamstring autograft, Achilles tendon allograft, and tibialis allograft (data available for only 11 of 25 patients). At final follow-up, 22% of ACL-intact and 32% of ACL-reconstructed patients had undergone reoperation. OCA survivorship was 90% and 96% at 2 years and 79% and 85% at 5 years in ACL-intact and ACL-reconstructed patients, respectively (P = .774). ACLR was not independently associated with failure. Both groups demonstrated clinically significant improvements in the Short Form-36 pain and physical functioning, International Knee Documentation Committee subjective, and Knee Outcome Survey-Activities of Daily Living scores at final follow-up (P < .001), with no significant differences in preoperative, postoperative, and change scores between groups. CONCLUSIONS: OCA in the setting of prior or concomitant ACLR does not portend higher failure rates or compromise clinical outcomes. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

High Short-Term Failure Rate Associated With Decellularized Osteochondral Allograft for Treatment of Knee Cartilage Lesions.

PURPOSE: To report the short-term clinical and radiographic outcomes following the use of decellularized osteochondral (OC) allograft plugs in the treatment of distal femoral OC lesions. METHODS: An Institutional Review Board-approved database with prospectively collected data was used to identify patients treated with the decellularized OC allograft plugs implant. Demographic information, patient-reported outcomes, magnetic resonance imaging (MRI), and the number and type of reoperations were assessed. Failure was defined as revision surgery with removal of the implant. Patients were evaluated pre- and postoperatively using the Short Form-36, Activity of Daily Living Score, International Knee Documentation Committee Subjective Evaluation, Cincinnati Knee Rating System, and Marx Activity Scale. MRIs were evaluated using the OsteoChondral Allograft MRI Scoring System. RESULTS: Thirty-four patients were identified, with a mean age of 45 (±11.9) years; 71% were male. Fifteen (44%) patients had undergone prior ipsilateral surgical intervention. Mean defect size was 4 (±1.5) cm2, and median number of allografts per knee was 2 (range, 1-5). Mean follow-up duration was 15.5 months (range, 6-24). Ten patients (29%) required revision surgery with removal of the implant. Implant survivorship was 61% at 2 years. Female gender was independently predictive of failure, with a hazard ratio of 9.4 (95% confidence interval [CI], 2.0-58.9; P = .005). Defect size was also independently predictive of failure, with a hazard ratio of 1.9 per 1 cm2 increase (95% CI, 1.2-3.1; P = .005). MRIs obtained at 1 year postoperatively demonstrated significantly improved osseous integration (P = .0086) and opposing cartilage (P = .019) in the nonfailure group as compared with the failure group. CONCLUSIONS: Based on the high short-term failure rate observed in this study, the authors advise that a decellularized OC allograft plugs implant should be used with caution in the treatment of OC lesions of the knee, as similar outcomes have not been noted with other cartilage restoration techniques. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Early complications of acromioclavicular joint reconstruction requiring reoperation.

PURPOSE: Prior studies have reported high complication rates with acromioclavicular joint reconstruction (ACJR). However, many of these reports have suffered from small sample sizes and inclusion of older surgical techniques. The purpose of this study was to determine the rates of early complications requiring reoperation in patients treated with ACJR. METHODS: From 2007 to 2011, patients who were treated with ACJR were identified using the PearlDiver database, a large insurance database in the USA. The following reoperations were then queried from this patient cohort: irrigation and debridement within 30 days of index surgery, manipulation under anaesthesia (MUA) of the shoulder joint within 3 months of index surgery, and revision ACJR, distal clavicle excision, and removal of hardware within 6 months of index surgery. RESULTS: In total, 2106 patients treated with ACJR were identified. The reoperation rates for irrigation and debridement, MUA, revision ACJR, distal clavicle excision, and removal of hardware were 2.6, 1.3, 4.2, 2.8, and 6.2 %, respectively. Patients ≥35 years of age and females more likely to undergo a reoperation after ACJR. Specifically, patients ≥35 years of age were more likely to undergo MUA and revision ACJR, while patients ≥50 years of age were more likely to undergo an irrigation and debridement. Females were more likely than males to undergo revision ACJR and distal clavicle excision. CONCLUSIONS: Older patients and females were more likely to experience postoperative complications requiring reoperations, including revision ACJR, distal clavicle excision, and irrigation and debridement. By analysing a large cohort of patients across multiple centres and providers, this study provides valuable insight into the recent complication profiles of ACJR, allowing surgeons to appropriately counsel patients on the risks of these procedures. LEVEL OF EVIDENCE: IV.

The Cholinergic Signaling Responsible for the Expression of a Memory-Related Protein in Primary Rat Cortical Neurons.

Cholinergic dysfunction in the brain is closely related to cognitive impairment including memory loss. In addition to the degeneration of basal forebrain cholinergic neurons, deficits in the cholinergic receptor signaling may also play an important role. In the present study, to examine the cholinergic signaling pathways responsible for the induction of a memory-related postsynaptic protein, a cholinergic agonist carbachol was used to induce the expression of activity-regulated cytoskeleton associated protein (Arc) in primary rat cortical neurons. After pretreating neurons with various antagonists or inhibitors, the levels of carbachol-induced Arc protein expression were detected by Western blot analysis. The results show that carbachol induces Arc protein expression mainly through activating M1 acetylcholine receptors and the downstream phospholipase C pathway, which may lead to the activation of the MAPK/ERK signaling pathway. Importantly, carbachol-mediated M2 receptor activation exerts negative effects on Arc protein expression and thus counteracts the enhanced effects of M1 activation. Furthermore, it is suggested for the first time that M1-mediated enhancement of N-methyl-D-aspartate receptor (NMDAR) responses, leading to Ca(2+) entry through NMDARs, contributes to carbachol-induced Arc protein expression. These findings reveal a more complete cholinergic signaling that is responsible for carbachol-induced Arc protein expression, and thus provide more information for developing treatments that can modulate cholinergic signaling and consequently alleviate cognitive impairment. J. Cell. Physiol. 231: 2428-2438, 2016. © 2016 Wiley Periodicals, Inc.

Magnetic resonance arthrography and the prevalence of acetabular labral tears in patients 50 years of age and older.

OBJECTIVE: Arthroscopy for acetabular labral tears has minimal impact on pain and function in older patients, especially in the setting of concomitant osteoarthritis. Still, many physicians seek this diagnosis with MR arthrography. Our purpose is to assess the frequency of acetabular labral tears in older patients with hip pain and correlate likelihood of labral pathology with severity of osteoarthritis as visualized on conventional radiograph. MATERIALS AND METHODS: From 2004 to 2013, 208 hip MRI arthrograms and corresponding radiographs on patients aged 50 years and older were identified. Age, gender, grade and location of labral tear, alpha angle, Tönnis grade, and joint space width were documented. Labral tears and alpha angle were identified and measured on MR arthrogram. Tönnis grade and joint space width were measured on radiographs. RESULTS AND CONCLUSIONS: On MR arthrography, true labral tearing was identified in 73 % of patients. There was some degree of labral pathology in 93.3 % of patients, and this increased to 100 % in patients with moderate to severe osteoarthritis, as defined by Tönnis grade 2-3 or joint space width ≤ 2 mm. There were no statistically significant correlations between labral tear grade and Tönnis grade or joint space width. Given the high frequency of labral pathology and the questionable efficacy of arthroscopic surgical intervention in older patients, MR arthrography should be primarily for those with minimal arthritis on radiograph and potential to benefit from surgery. If further imaging beyond radiographs is necessary in these patients, standard MRI may be a more appropriate imaging tool.

Trends associated with distal biceps tendon repair in the United States, 2007 to 2011.

BACKGROUND: Current studies investigating surgical treatment of distal biceps tendon tears largely consist of small, retrospective case series. The purpose of this study was to investigate the current patient demographics, surgical trends, and postoperative complication rates associated with operative treatment of distal biceps tendon tears using a large database of privately insured, non-Medicare patients. METHODS: Patients who underwent surgical intervention for distal biceps tendon tears from 2007 to 2011 were identified using the PearlDiver database. Demographic and surgical data as well as postoperative complications were reviewed. Statistical analysis was performed using linear regression analysis and χ(2) tests, with statistical significance set at P < .05. RESULTS: A total of 1443 patients underwent surgical treatment for distal biceps tendon tears. Men and patients aged 40 to 59 years accounted for 98% and 72% of the cohort, respectively. Regarding surgical technique, reinsertion to the radial tuberosity was preferred (95%) over tenodesis to the brachialis (5%) (P < .01). In total, revision surgery for tendon rerupture occurred in 5.4% of treated patients. The incidence of revision surgery for rerupture in acute and chronic distal biceps tears was 5.1% and 7.0%, respectively (P = .36). Postoperative infection and peripheral nerve injury rates were 1.1% and 0.6%, respectively. CONCLUSION: Surgeons strongly preferred anatomic reinsertion to the radial tuberosity for treatment, regardless of the chronicity of the injury. Postoperative complication rates were similar to those found in prior studies, although the true rate of rerupture may be higher than previously thought.