Biologic Augmentation of Isolated Meniscal Repair.

PURPOSE OF REVIEW: The limited blood supply and intrinsic healing capacity of the meniscus contributes to suboptimal tissue regeneration following injury and surgical repair. Biologic augmentation techniques have been utilized in combination with isolated meniscal repair to improve tissue regeneration. Several innovative strategies such as Platelet-Rich Plasma (PRP), fibrin clots, mesenchymal stem cells (MSCs), bone marrow stimulation, meniscal scaffolds, and meniscal wrapping, are being explored to enhance repair outcomes. This article provides a comprehensive review of recent findings and conclusions regarding biologic augmentation techniques. RECENT FINDINGS: Studies on PRP reveal mixed outcomes, with some suggesting benefits in reducing failure rates of isolated meniscal repair, while others question its efficacy. Fibrin clots and PRF (Platelet-rich fibrin), although promising, show inconsistent results and lack sufficient evidence for definitive conclusions. MSCs demonstrate potential in preclinical studies, but clinical trials have been limited and inconclusive. Bone marrow stimulation appears effective in certain contexts, but its broader applicability remains uncertain. Meniscal scaffolds, including CMI (Collagen Meniscal Implants) and Actifit (polyurethane scaffolds), show encouraging short- and mid-term outcomes but have not consistently surpassed traditional methods in the long term. Meniscal wrapping is infrequently studied but demonstrates positive short-term results with certain applications. The review reveals a diverse range of outcomes for biologic augmentation in meniscal repair. While certain techniques show promise, particularly in specific scenarios, the overall efficacy of these methods has yet to reach a consensus. The review underscores the necessity for standardized, high-quality research to establish the definitive effectiveness of these biologic augmentation methods.

The Psychology of ACL Injury, Treatment, and Recovery: Current Concepts and Future Directions.

CONTEXT: Interest in the relationship between psychology and the outcomes of anterior cruciate ligament (ACL) reconstruction (ACLR) continues to grow as variable rates of return to preinjury level of activity continue to be observed. EVIDENCE ACQUISITION: Articles were collected from peer-reviewed sources available on PubMed using a combination of search terms, including psychology, resilience, mental health, recovery, and anterior cruciate ligament reconstruction. Further evaluation of the included bibliographies were used to expand the evidence. STUDY DESIGN: Clinical review. LEVEL OF EVIDENCE: Level 4. RESULTS: General mental health and wellbeing, in addition to a host of unique psychological traits (self-efficacy, resilience, psychological readiness and distress, pain catastrophizing, locus of control, and kinesiophobia) have been demonstrated convincingly to affect treatment outcomes. Moreover, compelling evidence suggests that a number of these traits may be modifiable. Although the effect of resilience on outcomes of orthopaedic surgical procedures has been studied extensively, there is very limited information linking this unique psychological trait to the outcomes of ACLR. Similarly, the available information related to other parameters, such as pain catastrophizing, is limited with respect to the existence of adequately sized cohorts capable of accommodating more rigorous and compelling analyses. A better understanding of the specific mechanisms through which psychological traits influence outcomes can inform future interventions intended to improve rates of return to preinjury level of activity after ACLR. CONCLUSION: The impact of psychology on patients' responses to ACL injury and treatment represents a promising avenue for improving low rates of return to preinjury activity levels among certain cohorts. Future research into these areas should focus on specific effects of targeted interventions on known, modifiable risk factors that commonly contribute to suboptimal clinical outcomes. STRENGTH-OF-RECOMMENDATION TAXONOMY (SORT): B.

Analysis of abduction moment arms after rotator cuff tear and acellular dermal matrix allograft reconstruction.

BACKGROUND: Biomechanical testing of abduction moment arms presents a useful method to assess the contributions of individual rotator cuff muscles to glenohumeral function. This study aimed to investigate the changes in abduction moment arms after the treatment of supraspinatus tears with superior capsular reconstruction (SCR), bursal acromial reconstruction (BAR), and a combined SCR-BAR procedure, all with human dermal allograft. METHODS: We tested 7 fresh-frozen cadaveric specimens under 6 conditions: (1) intact, (2) 50% supraspinatus tear (partial tear), (3) 100% supraspinatus tear, (4) SCR, (5) SCR combined with BAR, and (6) BAR. In each condition, the moment arms for the individual muscles of the teres minor, subscapularis, and infraspinatus were calculated throughout 90° of abduction using a motion capture system. Analysis of variance and post hoc Tukey testing were performed to determine significance. RESULTS: In the teres minor, the moment arms in the SCR (11.9 mm), BAR (10.1 mm), and SCR-BAR (11.9 mm) conditions were greater than those in the intact (8.5 mm; P = .001, P = .001, and P = .001, respectively), partial tear (9.1 mm; P = .001, P = .128, and P = .001, respectively), and complete tear (8.8 mm; P = .001, P = .011, and P = .001, respectively) conditions. Similarly, in the subscapularis, the moment arms in the SCR (13.4 mm), BAR (13.8 mm), and SCR-BAR (13.5 mm) conditions were greater than those in the intact (10.6 mm; P = .006, P = .001, and P = .003, respectively) and partial tear (10.4 mm; P = .006, P = .001, and P = .003, respectively) conditions. In the teres minor, the SCR (11.9 mm) and SCR-BAR (11.9 mm) conditions were also found to have significantly increased moment arms compared with the BAR condition (10.1 mm; P = .001 and P = .001, respectively). In the infraspinatus, the BAR condition (13.8 mm) was found to have a significantly decreased moment arm compared with the partial tear condition (15.8 mm, P = .026), with no other significant findings between conditions. CONCLUSION: Our results suggest that the moment arm contributions of the individual muscles comprising the rotator cuff can change after reconstruction to compensate for tears. SCR and SCR-BAR increase the moment arms in the teres minor and subscapularis, potentially allowing for increased abduction ability.

Corrigendum to "Sox9 augments BMP2-induced chondrogenic differentiation by downregulating Smad7 in mesenchymal stem cells (MSCs)" [Genes & Diseases 4 (2017) 229-239].

[This corrects the article DOI: 10.1016/j.gendis.2017.10.004.].

Comparison between micro-anchor skin dressing and liquid bonding agent for elective knee arthroscopy portal closure.

OBJECTIVE: The objective of the current study was to evaluate outcomes of elective knee arthroscopy portal closure comparing two skin closure techniques. METHOD: This was a randomised controlled trial including healthy volunteers aged ≥18 years undergoing elective knee arthroscopy that used two portals. At the time of surgery, each patient's two arthroscopy portal closures were randomised to one of two closure techniques; the first technique used approximation of the skin with a micro-anchor skin dressing (BandGrip Inc., US), while the second closure technique used an absorbable suture (Biosyn Monofilament, Medtronic) and a liquid bonding agent skin closure (Dermabond, Ethicon Inc., US). Postoperative complications and patient-reported outcomes were evaluated at the first visit after knee arthroscopy and at six weeks postoperatively. RESULTS: A total of 38 patients (76 portals) were enrolled in this study. No patients reported wound complications of either portal; thus, there was no significant difference (p>0.05) in wound complication rates between the skin closure techniques. Survey questions regarding any difference in appearance and cosmesis between the closure techniques' portal sites were responded to by 15 patients, all of whom indicated no difference in appearance between the portal sites. There was also no statistically significant difference between the two closure techniques with regards to appearance. CONCLUSION: There was no significant difference in presence of wound complications or appearance between skin closure with the micro-anchor skin dressing and the absorbable suture/liquid bonding agent skin closure.

Multiligamentous Knee Injuries: Current Concepts Review.

Multiligamentous knee injuries (MLKI) are rare but devastating injuries that have a potential to cause long-term sequelae and significant morbidity. Frequently occurring concomitantly with knee dislocations (KD), MLKI have many risk factors that influence their incidence and treatment outcomes. Proper understanding of these risk factors can assist the surgeon with evaluation, surgical planning, and managing patient expectations both pre- and postoperatively. The purpose of this review is fourfold: (1) identify the risk factors and injuries associated with MLKI, (2) describe factors implicated in the treatment of MLKI, (3) report the effect of these risk factors on outcomes of MLKI, and (4) provide a brief insight into MLKI at our tertiary referral academic care center. This was a retrospective review of literature relevant to MLKI. Studies that described injuries, risk factors, treatment techniques, or outcomes associated with MLKI were included in our review. A total of 35 studies (consisting of level 3 and 4 evidence) published between 2009 and 2020 were found and included in our analysis. In addition, 25 patients who underwent treatment for MLKI at the University of Chicago Medical Center between December 2015 and December 2019 were included in our analysis. MLKI tend to occur in the younger male population. Increasing age, body mass index, and severity of the injury have been correlated with worse functional and patient-reported outcomes. Operative treatment is indicated for MLKI; however, timing and repair versus reconstruction is still debated, and is often decided on a patient by patient basis. Retrospective cohort studies have indicated that reconstruction may be favored; however, further more rigorous studies are needed to better characterize this finding. MLKIs are devastating injuries with significant variability in presentation, treatment, and outcome. Variations in these are largely attributable to the mechanism and severity of injury, timing, and surgeon preference. A holistic approach, and understanding of the present literature, is required to best optimize patient outcome.

Protective Sport Bracing for Athletes With Mid-Season Shoulder Instability.

CONTEXT: In-season glenohumeral instability is a common clinical dilemma faced by physicians who care for athletes. Both nonoperative and operative management of athletes with in-season glenohumeral instability have been well described. Functional bracing remains less understood as a treatment modality. This review aims to provide an update on the most recent literature regarding the use of functional bracing for shoulder instability. EVIDENCE ACQUISITION: MEDLINE (PubMed and Ovid platforms), Web of Science, Embase, and Cochrane Database of Systemic Reviews were searched for articles available in English through June 1, 2021. The search terms shoulder brace, shoulder instability, athlete, in-season, glenohumeral instability, anterior shoulder instability, posterior shoulder instability, and bracing were used. STUDY DESIGN: Clinical review. LEVEL OF EVIDENCE: Level 3. RESULTS: Research on the clinical outcomes of functional bracing remains mixed for patients with shoulder instability. Two studies have demonstrated improved return to play with functional bracing, while 1 study demonstrated no difference in return to play between braced athletes and nonbraced athletes with anterior instability. One previous study demonstrated that prophylactic use of bilateral shoulder stabilizing braces significantly decreased time lost due to injury in athletes with posterior instability. Previous biomechanical studies have demonstrated improved proprioception with brace wear as well as successful limitation of active shoulder range of motion. CONCLUSION: Bracing in athletes with shoulder instability remains an important nonoperative treatment modality. While clinical benefits are yet to be validated through high-quality studies, preliminary results suggest a potential benefit to recovery, with minimal downsides. Nevertheless, the use of bracing remains an individual choice but is especially recommended in settings of high-risk sports for shoulder instability, such as football.

Long Head of the Biceps Autograft Performs Biomechanically Similar to Human Dermal Allograft for Superior Capsule Reconstruction After Rotator Cuff Tear.

PURPOSE: To provide a biomechanical comparison between human dermal (HD) allograft and long head of biceps tendon (LHBT) autograft with and without posterior side-to-side suturing for superior capsule reconstruction. METHODS: Eight fresh-frozen cadaveric shoulder specimens were tested in 5 conditions: (1) intact, (2) complete supraspinatus tear, (3) LHBT, (4) LHBT with side-to-side suturing, and (5) HD allograft with side-to-side suturing. Functional abduction force, superior translation of humeral head, translational range of motion, and rotational range of motion were tested at 0°, 30°, 60°, and 90° of abduction within each condition. Data were analyzed using analysis of variance with post-hoc Tukey testing for pairwise comparison, with a significance value set at .05. RESULTS: Functional abduction force in the LHBT, LHBT + suture, and HD + suture conditions was significantly increased compared with the supraspinatus tear condition at abduction angles of 30° (P = .011, .001, and .017, respectively), 60° (P = .004, .001, and .002, respectively), and 90° (P = .013, .001, and .038, respectively). In addition, superior translation of the humeral head in the LHBT, LHBT + suture, and HD + suture conditions was significantly decreased compared with the tear condition at abduction angles of 30° (P = .03, .049, .03, respectively) and 60° (P = .02, .04, .03, respectively). All 3 reconstructive techniques were statistically identical to the intact rotator cuff condition in regard to translational and rotational range of motion. CONCLUSIONS: Superior capsule reconstruction with LHBT autograft without side-to-side suturing, LHBT with posterior side-to-side suturing, and HD allograft with posterior side-to-side suturing all equivalently restore functional abduction force and decrease superior translation of the humeral head after a complete supraspinatus tear. CLINICAL RELEVANCE: Superior capsule reconstruction with long head of the biceps tendon autograft and human dermal allograft both restore functional abduction force and decrease superior translation of the humeral head, while displaying no losses in the range of motion in a cadaveric model.

Are Oblique Views Necessary? A Review of the Clinical Value of Oblique Knee Radiographs in the Acute Setting.

INTRODUCTION: The purpose of this study was to assess the added clinical value of oblique knee radiographs four-view (4V) compared to orthogonal anteroposterior (AP) and lateral radiographs in a two-view (2V) series. METHODS: We obtained 200 adult, 4V knee radiographs in 200 patients in the ED and randomly divided them into two groups with 100 series in each group. Ten reviewers - three musculoskeletal radiologists and seven orthopedic surgeons - performed radiograph analyses. These reviewers were randomly divided evenly into group one and group two. Reviewers were blinded to patient data and first reviewed 2V radiographs (AP/lateral) only, and then reviewed 4V radiographs, including AP/lateral, and two additional oblique views for the same patients at least four weeks later. Acute pathology identification and the need for further imaging was assessed for all reviewers, and clinical decision-making (operative vs nonoperative treatment, need for admission, need for additional imaging) was assessed only by the seven orthopaedic surgeon reviewers. RESULTS: Mean sensitivity for pathology identification was 79% with 2V and 81% with 4V (P =0.25). Intra-observer kappa value was 0.81 (range 0.54-1.00). Additional oblique radiographs led orthopaedic reviewers to change their treatment recommendations in 62/329 patients (18.84%) (P <0.001). Eight of 329 radiographic series were identified as "critical misses." (2.43%) (P =0.004), when pathology was reported as normal or reviewers recommended nonoperative treatment on 2V radiographs but changed their recommendation to operative management after the addition of oblique radiographs. The number needed to treat (NNT) for any treatment change and for "critical misses" was 83 and 643, respectively. CONCLUSION: Although the addition of oblique radiographs may improve a clinician's ability to identify subtle pathologic findings not identified on 2V, it rarely leads to significant changes in treatment recommendations. Given the high NNT, limiting the usage of these oblique radiographs in the general patient population may reduce costs without significantly affecting patient care.

Lower Extremity Stress Fractures in the National Basketball Association, 2013-2014 Through 2018-2019.

Background: Players in the National Basketball Association (NBA) are at risk for lower extremity stress fractures, partly because of the sport's high-intensity demand on the lower body. Purpose: To provide insight on the identification and management of potential risk factors associated with lower extremity stress fractures in NBA athletes. Study Design: Case series; Level of evidence, 4. Methods: A retrospective study was conducted using the NBA electronic medical record database for all players who were on an NBA roster for ≥1 game from the 2013-2014 through 2018-2019 seasons. Player characteristics, games missed, and treatment methodology were independently analyzed. Results were presented as incidence per 1000 player-games. Results: There were 22 stress fractures identified in 20 NBA players over the course of 6 years, with an average of 3.67 stress fractures per year and an incidence of 0.12 stress fractures per 1000 player-games. Most stress fractures occurred in the foot (17/22), and 45% (10/22) of stress fractures were treated surgically, with the most common site of operation being the navicular. On average, approximately 37 games and 243 days were missed per stress fracture injury. There was no significant difference in time to return to play between high-risk stress fractures treated operatively versus nonoperatively (269.2 vs 243.8 days; P = .82). Conclusion: The overall incidence of stress fractures in NBA players was 0.12 per 1000 player-games, and a high percentage of players returned to NBA activity after the injury. There was a relatively even distribution between high-risk stress fractures treated operatively and nonoperatively. When comparing high-risk stress fractures treated operatively to ones treated nonoperatively, no significant difference in average time to return to play in the NBA was found.

Concussions Increase the Odds of Lower-Extremity Injuries in National Football League Players: Four-Year Review of Publicly Available Data.

Objective: To investigate the effect of multiple concussions on the risk of lower-extremity injuries in National Football League (NFL) players. Methods: All active NFL players from September 2016 to January 2017 through September 2019 to January 2020 regular seasons were eligible for inclusion. All players who sustained multiple concussions during the study period were identified using publicly available data and included in the multiple concussion (MC) cohort. Players who sustained a single concussion (SC) as well as controls were age and position matched to the MC cohort using MEDCALC case-control. Lower-extremity injuries were then documented for the players included in all 3 cohorts. Results: The odds of sustaining a lower-extremity injury were significantly greater in the MC as well as the SC cohort when compared with the no concussion (NC)-matched cohort (odds ratio 2.92, standard deviation [SD] 1.7-4.9) and 2.28 (SD 1.5-3.6), respectively. However, we found no significant difference in the odds of sustaining a lower-extremity injury when comparing the SC with the MC cohort (odds ratio 1.00, SD 0.7-1.3). The time to lower-extremity injury after return to play from a concussion was significantly shorter in the SC group when compared with the MC group, within 1 year following a concussion injury (P = .01). Conclusions: There was a significant increase in the odds of suffering a lower-extremity injury after return to play in NFL players exposed to SC or MC when compared with age- and position-matched controls who did not sustain a concussion within the study period. There was no significant difference in the odds of suffering a lower-extremity injury after return to play for NFL players exposed to MC when compared with players exposed to a SC during our study period. Our findings suggest a potential need for injury-prevention protocols following concussion injuries. Level of Evidence: Level III, retrospective comparative prognostic trial.

Postoperative Anterior Cruciate Ligament Reconstruction Quadricep and Patella Tendon Rupture, Infection, and Lysis of Adhesions Decreased Despite Changing Graft Trends Over the Past Decade.

Purpose: To investigate recent trends in postoperative complications following anterior cruciate ligament (ACL) reconstruction. Methods: Patients who underwent ACL reconstruction surgery were identified in a national insurance database and separated into 2 cohorts based on the date of their initial surgery comprising the years 2010 to 2012 and 2016 to 2018, respectively. Patients were matched 1:1 based on comorbidities and Elixhauser Comorbidity Index. All patients were assessed for postoperative complications within 18 months of surgery. Rate of complication was compared between cohorts. Results: Overall, the all-cause complication rate was 2%. There were significantly more quadriceps tendon rupture, patella tendon rupture, lysis of adhesion, and infection in the early cohort. There were significantly more instances of deep vein thrombosis in the late cohort. We found no significant difference in manipulations under anesthesia between the 2 cohorts. Conclusions: Patients who underwent surgery in the late cohort had lower rates of postoperative complications, except for deep vein thrombosis. The rate of postoperative quadriceps tendon rupture decreased despite considerable increase in the use of quadriceps tendon autograft. Clinical Relevance: As there has been an increased use of quadriceps tendon autografts, but little is known about the postoperative complications after ACL reconstruction with these grafts. This information has the potential to improve patient outcomes.

The Relationship Between Preoperative Opioid Use and Adverse Events Following Total Knee Arthroplasty.

This study aims to compare perioperative events following total knee arthroplasty (TKA) amongst various degrees of preoperative opioid use. In total, 84,569 patients undergoing TKA were identified from a Humana Claims Dataset, and stratified by their preoperative opioid use based on number of prescriptions filled within 6 months of surgery (naïve 0 [50,561]; sporadic 1 [12,411]; chronic 2 or greater [21,687]). Outcomes of interest included Center for Medicare and Medicaid Services (CMS)-reportable complications, need for postoperative supplemental oxygen, 90-day readmission, and hospital length of stay. Complication rates (9.8% vs 8.9% vs 12.6%; p < 0.01), need for supplemental oxygen (3.0% vs 3.1% vs 5.3%; p = 0.03), mean length of stay (2.1 vs 2.8 vs 3.5; p < 0.01), and 90-day readmission (9.7% vs 10.8% vs 16.4%; p < 0.01) significantly differed amongst groups. On logistic regression, only the chronic opioid use group was associated with significantly increased likelihood of complications, need for supplemental oxygen, and readmission. (Journal of Surgical Orthopaedic Advances 31(2):100-103, 2022).

The Injury Rate in NBA Players Did Not Increase Following Return to Play After the COVID-19 Stay-at-Home Order.

OBJECTIVE: The purpose of this study was to investigate the injury rate in NBA players following return to play during the post-COVID-19 shutdown 2019-2020 NBA season. METHODS: This study was a retrospective review of all NBA players who were placed on the injury report during the preseason and first 4 weeks of the regular season as well as playoffs from the 2017-2018 through 2020-2021 NBA seasons. The data were compiled using publicly available injury reports. All injuries were recorded, and injury rates were calculated per 1000 athletic exposures. Risk ratio with 95% confidence intervals compared injury rates between the 2 cohorts. RESULTS: Over the course of the study period, 399 injuries were reported. The highest injury rate per athletic exposure was observed to have occurred during the first month of the regular season in the 2 seasons prior to the COVID-19 pandemic. There was no significant difference in the average number of games missed before and after the pandemic for the preseason (P = .95), first month of regular season (P = .62), and playoffs (P = .69). There was no significant difference in the rate of injury when comparing injury rates before and after the pandemic for the preseason (P = .25), first month of the regular season (P = .11), and playoffs (P = .3). CONCLUSION: The rate of injury in NBA players following the COVID-19 pandemic was not significantly higher than 2 recent past NBA seasons.

SATB2: A versatile transcriptional regulator of craniofacial and skeleton development, neurogenesis and tumorigenesis, and its applications in regenerative medicine.

SATB2 (special AT-rich sequence-binding protein 2) is a member of the special AT-rich binding protein family. As a transcription regulator, SATB2 mainly integrates higher-order chromatin organization. SATB2 expression appears to be tissue- and stage-specific, and is governed by several cellular signaling molecules and mediators. Expressed in branchial arches and osteoblast-lineage cells, SATB2 plays a significant role in craniofacial pattern and skeleton development. In addition to regulating osteogenic differentiation, SATB2 also displays versatile functions in neural development and cancer progression. As an osteoinductive factor, SATB2 holds great promise in improving bone regeneration toward bone defect repair. In this review, we have summarized our current understanding of the physiological and pathological functions of SATB2 in craniofacial and skeleton development, neurogenesis, tumorigenesis and regenerative medicine.

A Safe Interval between Preoperative Intra-articular Corticosteroid Injections and Subsequent Knee Arthroscopy.

The purpose of this study is to evaluate the influence of intra-articular corticosteroid injections prior to knee arthroscopy on the rate of postoperative infection and define a safe timing interval between intra-articular corticosteroid injections and subsequent knee arthroscopy. The PearlDiver Database was used to identify patients who underwent a knee arthroscopy from 2007 to 2017. Patients were sorted into an injection cohort if they received any intra-articular corticosteroid injections within 6 months before surgery and a control cohort if they received no such injections. The injection cohort was then stratified into subgroups based on the timing of the most recent injection. We identified two types of postoperative infection in the 6 months following surgery: a broad definition of infection using knee infection diagnoses, and a narrow definition of infection requiring surgical treatment. The effects of the timing of preoperative corticosteroid injections on the rates of postoperative infection were investigated. The rate of broadly defined postoperative infection was significantly higher in the 0 to 2 weeks injection group (6.90%, 20/290) than the control group (2.01%, 1,449/72,089, p < 0.001; odds ratio [OR]:3.61 [95% confidence interval [CI]: 2.29, 5.70]). We observed a significant difference regarding the rate of narrowly defined postoperative infection requiring surgical treatment between the 0 and 2 weeks injection group (1.38%, 4/290) and the control group (0.27%, 192/72,089, p < 0.001, OR:5.24 [95% CI: 1.94, 14.21]). No significant differences were observed between other subgroups and the control group in both types of postoperative infection. Intra-articular corticosteroid injections within 2 weeks of knee arthroscopy were statistically significantly associated with higher rates of postoperative infection. This is a Level III, retrospective comparative study.

Diagnostic Value of MRI and Radiographs of the Knee to Identify Osteochondral Lesions in Acute Patellar Instability.

The purpose of this study was to define the diagnostic value of magnetic resonance imaging (MRI) and plain radiographs (X-ray [XR]) in identifying an osteochondral defect or loose body in patients undergoing operative treatment for patellar instability. A total of 87 patients treated operatively for patellar instability with medial patellofemoral ligament (MPFL) reconstruction between 2015 and 2019 were identified. Inclusion criteria were evidence of clinical patellar instability, preoperative XR and MRI studies, and concomitant diagnostic knee arthroscopy and MPFL reconstruction performed to address patellar instability. Patients were excluded if they had a history of prior procedure for patellar instability on the surgical knee, underwent MPFL reconstruction without concomitant diagnostic knee arthroscopy, or had an anterior cruciate ligament or posterior cruciate ligament deficient knee. Operative notes and arthroscopic images were reviewed to identify osteochondral or chondral injuries and loose bodies noted during diagnostic arthroscopy. The primary outcome was the identification of intra-articular loose bodies, chondral injury, or osteochondral defect on preoperative plain radiographs and MRI in patients with patellar instability. All MRIs were performed on a 3T MRI. The sensitivity and specificity of identifying loose bodies on MRI were 0.52 and 0.92 and on XR were 0.23 and 0.98, respectively. The sensitivity and specificity of identifying osteochondral lesions on MRI were 0.43 and 0.81 and on XR were 0.08 and 0.97, respectively. Of the 87 available reports, 45 (51%) described performing chondroplasty for Outerbridge grade II/III chondral lesions on diagnostic arthroscopy. In conclusion, MRI and XR are poorly sensitive at identifying loose bodies or osteochondral defects after patellar dislocations. The poor sensitivity of imaging studies must be considered when determining whether or not to recommend operative management to a patient with patellar instability. This is a Level IV, diagnostic study.

The targeting rule does not increase the rate of lower extremity injuries in NFL players over two seasons.

OBJECTIVES: In 2018 the NFL instituted playing rule article 8, which aimed to help decrease sport related concussion (SRC) by broadening the helmet-hit rule, making it a foul when a player lowers his head to make contact with his helmet against an opponent. Previous studies have demonstrated that the rate of lower extremity injuries increased following the institution of the targeting rule in NCAA football. The objective of this study was to determine if playing rule article 8 unintentionally led to a significant increase in the rate of lower extremity injuries sustained by NFL players during regular season games. METHODS: This study was a retrospective review of all NFL players who were placed on the publically available injury reports for a lower extremity injury from the 2016-2017 through 2019-2020 regular seasons. With article 8 taking effect starting with the 2018-2019 season, players were assigned to a pre- or post-rule cohort based on date of injury for purposes of injury rate comparison. Injury rates were calculated per 1000 athletic exposures (AE). Incidence rate ratio (RR) with 95% confidence intervals (CI) compared injury rates between the two cohorts. RESULTS: There was a 3% decrease in the lower extremity injury rate in 2018-2019 to 2019-2020 compared with 2016-2017 to 2017-2018, however this was not statistically significant (33.6 versus 34.3/1000 AEs, respectively; RR, 0.97; 95% CI 0.92-1.04). There was a 40% decrease in the SRC rate when comparing the post- to the pre-article-8 cohort (3.3 vs. 5.5/1000 AEs, respectively; RR 0.60; 95% CI 0.50-0.73). CONCLUSIONS: The rate of lower extremity injuries and players placed on the injury reserve over the past two NFL seasons following the enactment of playing rule article 8 has not significantly increased. However, the average games missed due to lower extremity injuries significantly increased under playing rule article 8, which suggests that the severity of lower extremity injuries possibly increased. LEVEL OF EVIDENCE: IV Diagnostic.

The Injury Rate in National Football League Players Increased Following Cancellation of Preseason Games Because of COVID-19.

PURPOSE: To investigate the injury rate in National Football League (NFL) athletes during the first 4 weeks of the 2020 NFL season. METHODS: This study was a retrospective review of all NFL players who were placed on the injury report during the preseason and the first 4 weeks of the regular season from the 2016-2017 through the 2020-2021 NFL regular seasons. Players' dates of injury were cross-referenced with an absence of statistics from the respective games for which they were ruled out so as to ensure accuracy. Injury rates were calculated per 1,000 athletic exposures. Relative risk with 95% confidence intervals compared injury rates between the 2 cohorts. RESULTS: Over the course of the study period of 4 NFL seasons, 3,025 injuries were reported. Of the 3,025 injuries reported, 582 (19%) occurred during weeks 1-4 of the 2020-2021 regular season, whereas 1,292 (53%) occurred during preseason weeks 1-4, and 1,151 (38%) occurred during regular-season weeks 1-4 of NFL seasons 2016-2017, 2018-2019, and 2019-2020. There was a significant increase in the injury rate during weeks 1-4 of the 2020-2021 regular season for all comparisons with the injury rate both during the preseasons and the regular seasons of 3 recent past NFL seasons. CONCLUSIONS: The rate of injury in NFL players during weeks 1-4 of the 2020-2021 regular seasons was significantly higher than during 3 recent past NFL preseasons and regular seasons. LEVEL OF EVIDENCE: Level IV, diagnostic case series.