Editorial Commentary: Two-Year Follow-Up Is Too Short to Determine the Effectiveness of Anterior Cruciate Ligament Primary Repair

Although recent studies have shown good results of anterior cruciate ligament primary repair at 2-year follow-up, one must be careful in adopting this technique. Historically, the classic study from West Point showed repair fails at 5 years. Perhaps future results will be improved with scaffolds, augmentation, or biologics. Only time will tell. For now, what's the (West) Point?

How to Recognize, Correct, and Avoid Intraoperative Complications During Anterior Cruciate Ligament Reconstructions

Technical complications are a leading cause of graft failure following anterior cruciate ligament reconstructions. Complications can occur during any phase of the procedure, from graft harvesting to tunnel preparation to graft fixation. Predicting potential causes of technical difficulty and developing strategies to avoid potential pitfalls can limit the number of intraoperative complications. If adverse events do occur intraoperatively, prompt recognition and treatment can lead to favorable outcomes. It is important to discuss strategies to understand potential complications and develop tactics to avoid and correct adverse events that can occur during anterior cruciate ligament reconstruction.

No Deficits in Functional Outcomes of the Contralateral Limb Are Seen When the Hamstring Is Harvested for Augmentation of Small Diameter Ipsilateral Hamstring Autograft

Purpose

To evaluate clinical outcomes of the contralateral, nonoperative limb in patients undergoing contralateral hamstring (HS) autograft harvest compared with patients undergoing ipsilateral HS autograft harvest alone.

Methods

This study included 96 patients who underwent isolated anterior cruciate ligament reconstruction (ACLR) using 4-stranded HS autograft (n = 85) or 4-stranded HS autograft augmented with contralateral HS (n = 13) due to inclusion of ipsilateral graft diameter <8 mm. Isokinetic flexion and extension strength and dynamic performance of the ipsilateral and contralateral limbs and limb symmetry index (LSI) were evaluated at 6 months' postoperatively. Rates of contralateral native ACL tear at minimum 2 years also were compared. For all comparisons, P < .05 was considered statistically significant.

Results

Normalized isokinetic knee flexion and extension strength of the contralateral limb did not differ between cohorts (P = .34; P = .21, respectively). LSI for knee extension peak torque and knee flexion peak torque did not differ between cohorts (P = .44; P = .67, respectively). No difference in LSI was seen for any dynamic performance testing (single leg hop, P = .97; triple leg hop, P = .14; 6-m timed hop, P = .99). No difference was observed in International Knee Documentation Committee (P = .99) or Knee Injury and Osteoarthritis Outcome Score subscale measures (P = .39-.86). No difference in rates of contralateral knee native ACL tears were seen between cohorts (HS autograft + contralateral HS augmentation, n = 2, 15.4%; HS autograft, n = 7, 8.4%; P = .26).

Conclusions

In this study, at the time of return to sport, we found no differences in contralateral limb functional performance or limb symmetry measurements between patients undergoing contralateral HS autograft harvest for augmentation of smaller (<8 mm) diameter HS autografts harvested from the injured extremity.

Level of Evidence

Level III, retrospective cohort study.

Exposures to FD&C synthetic color additives from over-the-counter medications and vitamins in United States children and pregnant women

BACKGROUND

Food and Drug Administration (FDA) Food Drug and Cosmetic (FD&C) synthetic color additives (SCAs) have been associated with attentional and behavioral problems in children. Efforts to quantify exposure have focused on foods, while the contribution of medications and supplements remains unknown.

OBJECTIVE

To estimate exposures to SCAs in children (2-16 years) and pregnant women from intake of common over-the-counter (OTC) medications and vitamins.

METHODS

We estimated single-day exposure (mg/kg/day) to FD&C SCAs based on measurements of 25 different products and recommended dosages on product labels. Exposures were compared to SCA exposure estimates from food we previously developed and acceptable daily intakes (ADIs) established by FDA and the World Health Organization.

RESULTS

The highest exposure was found for FD&C Red No. 40 in a children's cold/cough/allergy syrup. A child aged 12-16 years consuming the maximum daily dosage would have an exposure of 0.221 mg/kg/day, which is twice this age group's typical exposure to this additive from food. No estimated exposures exceeded the ADIs.

SIGNIFICANCE

Some children's OTC medications and vitamins may cause daily SCA exposures comparable to those from foods. OTC medications and vitamins should be considered in efforts to quantify population exposure to FD&C SCAs.

IMPACT

Exposure to synthetic color additives (SCAs) from foods has been associated with behavioral problems in children. Exposures from over-the-counter (OTC) medications and vitamins remain unquantified despite widespread use. We estimated exposures in children and pregnant women for 25 different OTC medication and vitamin products sold in the United States. While exposures were below acceptable daily intakes (ADIs) established by the US Food and Drug Administration and the World Health Organization, some were comparable to typical daily exposures from foods. This work critically informs future SCA exposure assessments and provides valuable information for parents concerned about the health effects of SCAs.

Establishing a Consensus Definition of a Knee Fracture-Dislocation (Schenck Knee Dislocation V) Using a Global Modified Delphi Method

BACKGROUND

Knee fracture-dislocations are complex injuries; however, there is no universally accepted definition of what constitutes a fracture-dislocation within the Schenck Knee Dislocation (KD) V subcategory. The purpose of this study was to establish a more precise definition for fracture patterns included within the Schenck KD V subcategory.

METHODS

A series of clinical scenarios encompassing various fracture patterns in association with a bicruciate knee ligament injury was created by a working group of 8 surgeons. Utilizing a modified Delphi technique, 46 surgeons from 18 countries and 6 continents with clinical and academic expertise in multiligamentous knee injuries undertook 3 rounds of online surveys to establish consensus. Consensus was defined as ≥70% agreement with responses of either "strongly agree" or "agree" for a positive consensus or "strongly disagree" or "disagree" for a negative consensus.

RESULTS

There was a 100% response rate for Rounds 1 and 2 and a 96% response rate for Round 3. A total of 11 fracture patterns reached consensus for inclusion: (1) nondisplaced articular fracture of the femur; (2) displaced articular fracture of the femur; (3) tibial plateau fracture involving the weight-bearing surface (with or without tibial spine involvement); (4) tibial plateau peripheral rim compression fracture; (5) posterolateral tibial plateau compression fracture, Bernholt type IIB; (6) posterolateral tibial plateau compression fracture, Bernholt type IIIA; (7) posterolateral tibial plateau compression fracture, Bernholt type IIIB; (8) Gerdy's tubercle avulsion fracture with weight-bearing surface involvement; (9) displaced tibial tubercle fracture; (10) displaced patellar body fracture; and (11) displaced patellar inferior pole fracture. Fourteen fracture patterns reached consensus for exclusion from the definition. Two fracture patterns failed to reach consensus for either inclusion or exclusion from the definition.

CONCLUSIONS

Using a modified Delphi technique, this study established consensus for specific fracture patterns to include within or exclude from the Schenck KD V subcategory.

LEVEL OF EVIDENCE

Prognostic Level V . See Instructions for Authors for a complete description of levels of evidence.

Knee extensor torque-velocity relationships following anterior cruciate ligament reconstruction

BACKGROUND

The inherent nature of the torque-velocity relationship is the inverse nature between the velocity of muscle contraction and torque production and is an indication of muscle function. The purpose of this study was to characterize the torque-velocity relationship in the quadriceps following anterior cruciate ligament reconstruction compared to healthy limbs.

METHODS

681 participants were included, 493 of which were patients at least four months following anterior cruciate ligament reconstruction (23.2 ± 10.08 yr, 6.6 ± 5.37 months post-surgery) and 188 were healthy participants (21.6 ± 3.77 yr). A subset of 175 post-surgical participants completed a repeated visit (8.1 ± 1.71 months post-surgery). Participants completed isokinetic knee extension at 90°/s and 180°/s. A one-way ANOVA was used to compare torque velocity relationships by limb type (surgical, contralateral, healthy). Paired samples t-tests were conducted to analyze the torque-velocity relationship across limbs and across time.

FINDINGS

There was a large effect for limb type on torque-velocity (F(2, 1173) = 146.08, p < 0.001, η2 = 0.20). Surgical limbs demonstrated significantly lower torque-velocity relationships compared to the contralateral limbs (ACLR: 0.26 Nm/kg, contralateral:0.55 Nm/kg, p < 0.001, d = 1.18). Healthy limbs had similar torque-velocity relationships bilaterally (dominant limb: 0.48 Nm/kg, non-dominant limb: 0.49 Nm/kg, p = 0.45). The torque velocity relationship for the involved limb significantly increased in magnitude over time (+0.11 Nm/kg, p < 0.001, d = -0.61) while the contralateral limb torque-velocity relationship remained stable over time (0.0 Nm/kg difference, p = 0.60).

INTERPRETATION

Following surgery, the knee extensors appear to have altered torque-velocity relationships compared to contralateral and healthy limbs. This may indicate a specific target for assessment and rehabilitation following surgery.

Comparison of Patient-Reported Outcomes, Strength, and Functional Performance in Primary Versus Revision Anterior Cruciate Ligament Reconstruction

BACKGROUND

Clinical outcomes after revision anterior cruciate ligament reconstruction (ACLR) are not well understood.

HYPOTHESIS

Patients undergoing revision ACLR would demonstrate worse patient-reported outcomes and worse limb symmetry compared with a cohort undergoing primary ACLR.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

672 participants (373 with primary ACLR, 111 with revision ACLR, and 188 uninjured) completed functional testing at a single academic medical center. Descriptive information, operative variables, and patient-reported outcomes (International Knee Documentation Committee score, Knee injury and Osteoarthritis Outcome Score, and Tegner Activity Scale score) were assessed for each patient. Quadriceps and hamstring strength tests were conducted using a Biodex System 3 Dynamometer. Single-leg hop for distance, triple hop test, and the 6-m timed hop test were also assessed. Limb symmetry index (LSI) between the ACLR limb and contralateral limb was calculated for strength and hop testing. Normalized peak torque (N·m/kg) was calculated for strength testing.

RESULTS

No differences were found in group characteristics, excluding body mass (P < .001), or in patient-reported outcomes. There were no interactions between revision status, graft type, and sex. Knee extension LSI was inferior (P < .001) in participants who had undergone primary (73.0% ± 15.0%) and revision (77.2% ± 19.1%) ACLR compared with healthy, uninjured participants (98.8% ± 10.4%). Knee flexion LSI was inferior (P = .04) in the primary group (97.4% ± 18.4%) compared with the revision group (101.9% ± 18.5%). Difference in knee flexion LSI between the uninjured and primary groups, as well as between the uninjured and revision groups, did not reach statistical significance. Hop LSI outcomes were significantly different across all groups (P < .001). Between-group differences in extension in the involved limb (P < .001) were noted, as the uninjured group exhibited stronger knee extension (2.16 ± 0.46 N·m/kg) than the primary group (1.67 ± 0.47 N·m/kg) and the revision group (1.78 ± 0.48 N·m/kg). As well, differences in flexion in the involved limb (P = .01) were found, as the revision group exhibited stronger knee flexion (1.06 ± 0.25 N·m/kg) than the primary group (0.97 ± 0.29 N·m/kg) and the uninjured group (0.98 ± 0.24 N·m/kg).

CONCLUSION

At 7 months postoperatively, patients who had undergone revision ACLR did not demonstrate inferior patient-reported outcomes, limb symmetry, strength, or functional performance compared with patients who had undergone primary ACLR. Patients who had undergone revision ACLR exhibited greater strength and LSI than their counterparts with primary ACLR, but these parameters were still inferior to those of uninjured controls.

Hip Strength Recovery After Anterior Cruciate Ligament Reconstruction

Background

Return-to-play (RTP) assessment after anterior cruciate ligament reconstruction (ACLR) rarely includes hip strength.

Hypothesis

It was hypothesized that (1) patients after ACLR will have weaker hip abduction (AB) and adduction (AD) strength compared with the contralateral limb, with larger deficits in women, (2) there will be a correlation between hip and thigh strength ratios and patient-reported outcomes (PROs), and (3) hip AB and AD strength will improve over time.

Study Design

Descriptive laboratory study.

Methods

Included were 140 patients (74 male, 66 female; mean age, 24.16 ± 10.82 years) who underwent RTP assessment at 6.1 ± 1.6 months after ACLR; 86 patients underwent a second assessment at 8.2 ± 2.2 months. Hip AB/AD and knee extension/flexion isometric strength were measured and normalized to body mass, and PRO scores were collected. Strength ratios (hip vs thigh), limb differences (injured vs uninjured), sex-based differences, and relationships between strength ratios and PROs were determined.

Results

Hip AB strength was weaker on the ACLR limb (ACLR vs contralateral: 1.85 ± 0.49 vs 1.89 ± 0.48 N·m/kg; P < .001) and hip AD torque was stronger (ACLR vs contralateral: 1.80 ± 0.51 vs 1.76 ± 0.52 N·m/kg; P = .004), with no sex-by-limb interaction found. Lower hip-to-thigh strength ratios of the ACLR limb were correlated with higher PRO scores (r = -0.17 to -0.25). Over time, hip AB strength increased in the ACLR limb more than in the contralateral limb (P = .01); however, the ACLR limb remained weaker in hip AB at visit 2 (ACLR vs contralateral: 1.88 ± 0.46 vs 1.91 ± 0.45 N·m/kg; P = .04). In both limbs, hip AD strength was greater at visit 2 than visit 1 (ACLR: 1.82 ± 0.48 vs 1.70 ± 0.48 N·m/kg; contralateral: 1.76 ± 0.47 vs 1.67 ± 0.47 N·m/kg; P < .01 for both).

Conclusion

The ACLR limb had weaker hip AB and stronger AD compared with the contralateral limb at initial assessment. Hip muscle strength recovery was not influenced by sex. Hip strength and symmetry improved over the course of rehabilitation. Although strength differences across limbs were minor, the clinical importance of these differences is still unknown.

Clinical Relevance

The evidence provided highlights the need to integrate hip strength into RTP assessments to identify hip strength deficits that may increase reinjury or lead to poor long-term outcomes.

The Posterior Trans-Septal Portal in Knee Arthroscopy Review of the Technique Evolution, Indications, and Technical Pearls

Complete arthroscopic visualization of the posterior com-partment of the knee is limited when using the traditional anterior portals. The trans-septal portal technique, created in 1997, has allowed surgeons to view the complete posterior compartment of the knee in a less-invasive way compared to open surgery. Since the description of the posterior trans-septal portal, several authors have modified the technique. However, the paucity of literature describing the trans-septal portal technique hints that widespread arthroscopic adop-tion has not yet been achieved. While still in its infancy, the literature has cumulatively reported over 700 successful knee surgeries using the posterior trans-septal portal technique with no reports of neurovascular injury. However, creation of the trans-septal portal carries risks due to its close prox-imity to the popliteal and middle geniculate artery, giving surgeons little room for technical error when developing this portal. Knowledge of the posterior anatomy, the evolution of the trans-septal portal, and current recommendations and safety options for using the technique will benefit orthopedic surgeons looking to incorporate this technique into their surgical arsenal. Furthermore, utilization of the trans-septal portal technique offers a significant benefit to the surgical treatment of conditions that involve the need for posterior knee access or visualization.

Extensor Mechanism Disruption Impacts Treatment of Dislocated and Multiligament Injured Knees: Treatment and Schenck Classification Recommendations Based on a Global Delphi Method

BACKGROUND

Multiligament knee injury (MLKI) with associated extensor mechanism (EM) involvement is a rare injury, with limited evidence to guide optimal treatment. The purpose of this study was to identify areas of consensus among a group of international experts regarding the treatment of patients with MLKI and concomitant EM injury.

METHODS

Utilizing a classic Delphi technique, an international group of 46 surgeons from 6 continents with expertise in MLKI undertook 3 rounds of online surveys. Participants were presented with clinical scenarios involving EM disruption in association with MLKI, classified using the Schenck Knee-Dislocation (KD) Classification. Positive consensus was defined as ≥70% agreement with responses of either "strongly agree" or "agree," and negative consensus was defined as ≥70% agreement with "strongly disagree" or "disagree."

RESULTS

There was a 100% response rate for rounds 1 and 2 and a 96% response rate for round 3. There was strong positive consensus (87%) that an EM injury in combination with MLKI significantly alters the treatment algorithm. For an EM injury in conjunction with a KD2, KD3M, or KD3L injury, there was positive consensus to repair the EM injury only and negative consensus regarding performing concurrent ligamentous reconstruction at the time of initial surgery.

CONCLUSIONS

In the setting of bicruciate MLKI, there was overall agreement on the significant impact of EM injury on the treatment algorithm. We therefore recommend that the Schenck KD Classification be updated with the addition of the modifier suffix "-EM" to highlight this impact. Treatment of the EM injury was judged to have the highest priority, and there was consensus to treat the EM injury only. However, given the lack of clinical outcome data, treatment decisions need to be made on a case-by-case basis with consideration of the numerous clinical factors that are encountered.

CLINICAL RELEVANCE

Little clinical evidence exists to guide the surgeon on the management of EM injury in the setting of a multiligament injured or dislocated knee. This survey highlights the impact that EM injury has on the treatment algorithm and provides some guidance for management until a further large case series or prospective studies are undertaken.

The "N+10 Rule" to Avoid Graft-Tunnel Mismatch in Bone-Patellar Tendon-Bone ACL Reconstruction Using Independent Femoral Tunnel Drilling

Background

Graft-tunnel mismatch (GTM) is a common problem in anterior cruciate ligament (ACL) reconstruction (ACLR) using bone-patellar tendon-bone (BPTB) grafts.

Hypothesis

Application of the "N+10 rule" in endoscopic ACLR with BPTB grafts will result in acceptable tibial tunnel length (TTL), minimizing GTM.

Study Design

Controlled laboratory study.

Methods

Endoscopic BPTB ACLR was conducted on the paired knees of 10 cadaveric specimens using 2 independent femoral tunnel drilling techniques-accessory anteromedial portal and flexible reamer. The graft bone blocks were trimmed to 10 × 20 mm, and the intertendinous distance (represented by "N") between the bone blocks was measured. The N+10 rule was used to set the angle of the ACL tibial tunnel guide to the appropriate number of degrees for drilling. The amount of excursion or recession of the tibial bone plug in relation to the anterior tibial cortical aperture was measured in both flexion and extension. A GTM threshold of ±7.5 mm was set based on prior studies.

Results

The mean BPTB ACL intertendinous distance was 47.5 ± 5.5 mm. The mean measured intra-articular distance was 27.2 ± 3 mm. Using the N+10 rule, the mean total (flexion plus extension) GTM was 4.3 ± 3.2 mm (GTM in flexion, 4.9 ± 3.6 mm; GTM in extension, 3.8 ± 3.5 mm). In 18 of 20 (90%) cadaveric knees, the mean total GTM fell within the ±7.5-mm threshold. When comparing the actual measured TTL to the calculated TTL, there was a mean difference of 5.4 ± 3.9 mm. When comparing femoral tunnel drilling techniques, the total GTM for the accessory anteromedial portal technique was 2.1 ± 3.7 mm, while the total GTM for the flexible reamer technique was 3.6 ± 5.4 mm (P = .5).

Conclusion

The N+10 rule resulted in an acceptable mean GTM in both flexion and extension. The mean difference between the measured versus calculated TTL using the N+10 rule was also acceptable.

Clinical Relevance

The N+10 rule is a simple and effective intraoperative strategy for achieving desired TTL regardless of patient-specific factors to avoid excessive GTM in endoscopic BPTB ACLR using independent femoral tunnel drilling.

Influence of interim functional assessments on patient outcomes at the time of return to activity following ACL-reconstruction

OBJECTIVE

To compare patient outcomes at the time of the return to activity (RTA) progression between those with a prior interim assessment and those without.

DESIGN

Retrospective, Cohort Study.

SETTING

Controlled Laboratory.

PARTICIPANTS

Patients following Anterior Cruciate Ligament Reconstruction (ACLR) were recruited through an ongoing RTA assessment program. Patients were stratified into two testing groups = "Single RTA test": only assessment between 6 and 9 months post-ACLR and "Repeat RTA test": prior assessment performed >2-months before their RTA assessment. Patients were matched based on time post-surgery, age, activity level, and graft type.

MAIN OUTCOME MEASURE

Self-reported knee function and isokinetic knee flexor and extensor strength/symmetry were compared between groups.

RESULTS

392 patients were identified. Once matched, 138 patients (21.1 ± 7.0 years, 7.3 ±0 .9 mo post-ACLR) were analyzed. Repeat RTA test patients demonstrated higher measures of self-reported knee function (P = .04) and greater knee flexion strength (P = .006) and symmetry (P = .05).

CONCLUSION

Patients with interim functional assessments reported greater self-reported knee function and higher hamstring strength at the time of RTA compared to patients that completed their only assessment within this time point. Early functional assessments may identify individualized deficits that can be addressed while patients are under supervision of rehabilitation specialists.

Coaching in Sports Medicine

Similar to elite athletes, surgeons use their skills on a daily basis but coaching for skillset refinement is not common among surgeons. Surgeon coaching has been proposed a method by which surgeons can gain insight into their performance and optimize their practice. However, many barriers exist to surgeon coaching such as logistics, time, cost, and pride. Ultimately, the tangible improvement in surgeon performance, the elevation of surgeon well-being, the optimization of the practice, and better patient outcomes support a wider implementation of surgeon coaching for surgeons at all stages of their career.

Lateral Extra-Articular Tenodesis Staple Risks Penetration of Anterior Cruciate Ligament Reconstruction Tunnel

Purpose

To identify the risk of anterior cruciate ligament (ACL) femoral tunnel penetration with the use of a staple for lateral extra-articular tenodesis (LET) graft fixation and to determine whether this varied between 2 different techniques for ACL femoral tunnel drilling.

Methods

Twenty paired, fresh-frozen, cadaver knees underwent ACL reconstruction with a LET. Left and right knees were randomized to ACL reconstruction with femoral tunnel creation by use of either a rigid guide pin and reamer through the accessory anteromedial portal or by the use of a flexible guide pin and reamer through the anteromedial portal. Immediately after tunnel creation, the LET was performed and fixated with a small Richard's staple. Fluoroscopy was used to obtain a lateral view of the knee to determine staple position, and visualization of the ACL femoral tunnel was performed with the arthroscope to investigate penetration of the staple into the femoral tunnel. The Fisher exact test was conducted to determine whether there was any difference in tunnel penetration between tunnel creation techniques.

Results

The staple was noted to penetrate the ACL femoral tunnel in 8 of 20 (40%) extremities. When stratified by tunnel creation technique, the Richards staple violated 5 of 10 (50%) of the tunnels made via the rigid reaming technique compared with 3 of 10 (30%) of those created with a flexible guide pin and reamer (P = .65).

Conclusions

A high incidence of femoral tunnel violation is seen with lateral extra-articular tenodesis staple fixation.

Level of Evidence

Level IV, controlled laboratory study.

Clinical Relevance

The risk of penetrating the ACL femoral tunnel with a staple for LET graft fixation is not well understood. Yet, the integrity of the femoral tunnel is important for the success of ACL reconstruction. Surgeons can use the information in this study to consider adjustments to operative technique, sequence, or fixation devices used when performing ACL reconstruction with concomitant LET to avoid the potential for disruption of ACL graft fixation.

Dataset of FD&C Certified Food Dyes in Foods Commonly Consumed by Children

This is dataset describing the levels of Food, Drug, & Cosmetic (FD&C) dye in juice drinks, breakfast cereals, frozen desserts, ice cream cones, fruit flavored soft drinks, frostings & icings, fruit snacks/candy, decoration chips for baking, water enhancers, and flavored fruit drink powder. Data values are organized by absolute values, averages, SDs and % RSD. High performance liquid chromatography with a photometric diode array detector (HPLC-PDA) was used to measure dye levels and generate the data. These values can be used to calculate levels of dyes consumed within various populations, such as children, and compare them to accepted daily intake (ADIs) values established by the United States Food & Drug Administration (US FDA). The data are interpreted in "Survey of Certified Food Dye Levels in Food Samples Consumed by Children for Updated Exposure Levels" in the Journal of Food Additives and Contaminants: Part B.¹.

Risk Factors for Infection and Revision Surgery following Patellar Tendon and Quadriceps Tendon Repairs: An Analysis of 3,442 Patients

Disruption of the extensor mechanism is debilitating with surgical repair being the accepted treatment. The incidence of infection and reoperation after extensor mechanism repair are not well reported in the literature. Thus, the objective of the current study was to (1) determine the incidence of surgical site infection and reoperation within 1 year of primary extensor mechanism repair and (2) identify independent risk factors for infection and reoperation following patellar and quadriceps tendon repair. A retrospective review of the 100% Medicare Standard Analytic files from 2005 to 2014 was performed to identify patients undergoing isolated patellar tendon repair and quadriceps tendon repair. Diagnosis of infection within 1 year of operative intervention and revision repair were assessed. Extensor mechanism injuries in the setting of total knee arthroplasty and polytrauma were excluded. Multivariate logistic regression analysis was performed to evaluate risk factors for postoperative infection and reoperation within 1 year. Infection occurred in 6.3% of patients undergoing patellar tendon repair and 2.6% of patients undergoing quadriceps tendon repair. Diabetes mellitus (odds ratio [OR] = 1.89, p = 0.005) was found to be an independent risk factor for infection following patellar tendon repair. Reoperation within 1 year occurred in 1.3 and 3.9% following patellar tendon and quadriceps tendon repair, respectively. Age less than 65 years (OR = 2.77, p = 0.024) and obesity (OR = 3.66, p = 0.046) were significant risk factors for reoperation after patellar tendon repair. Hypertension (OR = 2.13, p = 0.034), hypothyroidism (OR = 2.01, p = 0.010), and depression (OR = 2.41, p = 0.005) were significant risk factors for reoperation after quadriceps tendon repair. Diabetes mellitus was identified as a risk factor for infection after patellar tendon repair. Age less than 65 years, peripheral vascular disease, and congestive heart failure were risk factors for infection after quadriceps tendon repair. The current findings can be utilized to counsel patients regarding preoperative risk factors for postoperative complications prior to surgical intervention for extensor mechanism injuries.

All-Inside Meniscal Repair: A Historical View

Background:

All-inside meniscal repair first became popularized in the early 2000s. Since that time, there has been a wide variety of all-inside implants on the market with rapid changes and developments in recent years.

Indications:

Small, peripheral, longitudinal tears are best suited for all-inside repair, but this technique may even be used for large bucket handle tears especially when hybridized with an inside-out repair.

Technique Description:

A percutaneous release of the medial collateral ligament (MCL) with an 18-g spinal needle is frequently performed when working in the medial compartment to improve visualization and decrease risk of iatrogenic chondral injury. Close familiarity with the characteristics of the chosen all-inside device including device angle, modifiability of device angle, modifiability of needle depth, deployment method, and tensioning technique is important for obtaining reproducible results. Typically, obtaining a vertical mattress stitch configuration is optimal as it captures more circumferential collagen fibers in the repair.

Results:

Factors to consider when selecting an all-inside meniscal repair device include the ergonomics of the device, implant cost, availability, rigid versus suture-based anchor, core needle diameter, device flexibility, and percent of misfires.

Discussion:

Complications from use of all-inside meniscus repair devices include device failure, soft tissue entrapment, cyst formation, and injury to the popliteal artery. Outcomes, however, with current devices are good and comparable to inside-out meniscus repair with about a 90% return to sports rate at 12 months postoperatively. The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Varus collapse following anterior closing wedge proximal tibial osteotomy for ACL revision reconstruction: a case series

A slope-correcting anterior closing wedge proximal tibial osteotomy is a powerful tool for correcting increased posterior tibial slope in the setting of a failed anterior cruciate ligament reconstruction. This case series documents three cases in which patients collapsed into varus following an anterior closing wedge proximal tibia osteotomy. Two patients had osteotomies fixated with a “suture-staple” construct, and all had medical comorbidities or reported noncompliance post-operatively. Therefore, meticulous care during the planning, execution, and rehabilitation phases is critical as multiple factors throughout the arc of care may contribute towards anterior closing wedge proximal tibial osteotomy varus collapse. Careful optimization of medical comorbidities and rigid fixation with either a plate and screws or compression staples should be used rather than a “suture-staple” to mitigate this risk.

Level of evidence: IV.

Dietary Exposure to United States Food and Drug Administration-Approved Synthetic Food Colors in Children, Pregnant Women, and Women of Childbearing Age Living in the United States

The Food and Drug Administration (FDA) regulates artificial food colors (AFCs) in the United States. Exposure to AFCs has raised concerns about adverse behavioral effects in children. We quantified AFC exposure in women of childbearing age, pregnant women, and children and compared them to FDA and World Health Organization acceptable daily intakes (ADIs). We estimated the “typical” and “high” single-day and two-day average dietary exposure to each AFC (mg/kg/day) based on laboratory measurements and food consumption data from the 2015−2016 National Health and Nutrition Examination Survey (NHANES). We also examined whether AFC intake differed by income, education, and ethnicity. Exposure tended to be higher in children and the highest AFC exposure was found for Red No. 40. Children’s mean and 95th percentile FD&C Red No. 3 estimated intakes exceeded the ADIs in some instances. Juice drinks, soft drinks, icings, and ice cream cones were major foods contributing to children’s (<16 years old) AFC exposure. AFC intake was higher in participants with lower incomes and education and of African American ethnicity. The findings indicate widespread AFC exposure including in very young children. Research is needed on the sociodemographic determinants of exposure and AFC toxicokinetics to better describe the absorption and organ-specific exposure.

A novel meniscofemoral ligament variant intra-substance to the PCL

While much detail is known about each anatomic structure of the knee and its contributory effect on biomechanics, our understanding is still evolving. In particular, the function of the meniscofemoral ligaments and their anatomical variants have yet to be fully described. In this report, a never-before-described anatomical meniscofemoral ligament variant intra-substance to the PCL is presented. Arthroscopists should be aware of the novel variant as a growing number of studies have demonstrated the biomechanical importance of the meniscofemoral ligaments in protecting the lateral meniscus and supporting the function of the PCL.Level of Evidence: IV.

Disagreement in Pass Rates Between Strength and Performance Tests in Patients Recovering From Anterior Cruciate Ligament Reconstruction

BACKGROUND

Performance on strength and functional tests is often used to guide postoperative rehabilitation progress and return to activity decisions after anterior cruciate ligament reconstruction (ACLR). Clinicians may have difficulty in determining which criteria to follow if there is disagreement in performance outcomes among the tests.

PURPOSE/HYPOTHESIS

The purpose of this study was to compare pass rates between strength tests and single-leg hop (SLHOP) tests among men and women and between patients with lower and higher preinjury activity levels recovering from ACLR. We hypothesized that pass rates would be nonuniformly distributed among test types, sex, and activity level and that more participants would pass hop tests than strength tests.

DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A total of 299 participants (146 men; 153 women)-at a mean of 6.8 ± 1.4 months after primary, unilateral, and uncomplicated ACLR (mean age, 23 ± 9.7 years; mean height, 172 ± 10.5 cm; mean mass, 75.8 ± 18.4 kg)-completed testing. Quadri.tif strength was evaluated using peak torque during isokinetic knee extension at 90 deg/s and 180 deg/s. Jump distance during the SLHOP and triple hop tests was measured (in cm). Strength and hop test measures were evaluated based on the limb symmetry index ((LSI) = (ACLR / contralateral side) × 100). We operationally defined "pass" as >90% on the LSI.

RESULTS

Pass rates were nonuniformly distributed between isokinetic knee extension at 90 deg/s and the SLHOP test (χ² = 18.64; P < .001). Disagreements between isokinetic testing at 90 deg/s and the SLHOP test occurred in 36.5% (109/299) of the participants. Among those who failed strength testing and passed hop testing, a greater portion reported higher activity levels before their injury (χ² = 6.90; P = .01); however, there was no difference in pass rates between men and women. Similar patterns of disagreement were observed between all strength test and hop test outcomes.

CONCLUSION

ACLR patients with higher activity levels may be more likely to pass hop testing despite failing quadri.tif strength testing. This may be an indicator of movement compensations to achieve jump symmetry in the presence of quadri.tif weakness.

Case Report Demonstrating Multifactorial Risks of Anterior Cruciate Ligament Re-tear Injuries and Appropriate Response Among Those With High Chance of Recurrence

We present the case of a collegiate football player with an extensive bilateral ligamentous knee injury history to elucidate the mechanisms and possible explanations behind why some athletes sustain recurrent injuries. We hope to initiate thought on altering rehabilitation schedules for athletes who are at an increased risk of re-injury. A 21-year-old collegiate American football player presented with a re-tear of his left anterior cruciate ligament (ACL) and medial meniscus following reconstructive surgery. The initial injury occurred to the patient when he was 15 and suffered a right ACL, lateral collateral ligament, and lateral meniscus tear in a non-contact injury. At the age of 19, he suffered his second injury, a contact-associated left ACL tear. Upon return to play six months following the left ACL tear, the patient sustained a non-contact bucket handle tear of the right medial meniscus. One year later, he presented with a re-tear of his left ACL. His initial left and right ACLs were repaired with hamstring autografts, and his current left ACL was repaired with a bone-patellar tendon-bone graft. This case illustrates an all too common situation plaguing the modern orthopedic sports medicine surgeon. At what point should a surgeon diverge from the standard rehabilitation schedule of ACL surgery due to a patient being at too high of a risk for a re-tear? We propose further investigations into risk factors as well as rehabilitation protocols to help surgeons identify and optimize treatment for these patients.

Potential impacts of synthetic food dyes on activity and attention in children: a review of the human and animal evidence

Concern that synthetic food dyes may impact behavior in children prompted a review by the California Office of Environmental Health Hazard Assessment (OEHHA). OEHHA conducted a systematic review of the epidemiologic research on synthetic food dyes and neurobehavioral outcomes in children with or without identified behavioral disorders (particularly attention and activity). We also conducted a search of the animal toxicology literature to identify studies of neurobehavioral effects in laboratory animals exposed to synthetic food dyes. Finally, we conducted a hazard characterization of the potential neurobehavioral impacts of food dye consumption. We identified 27 clinical trials of children exposed to synthetic food dyes in this review, of which 25 were challenge studies. All studies used a cross-over design and most were double blinded and the cross-over design was randomized. Sixteen (64%) out of 25 challenge studies identified some evidence of a positive association, and in 13 (52%) the association was statistically significant. These studies support a relationship between food dye exposure and adverse behavioral outcomes in children. Animal toxicology literature provides additional support for effects on behavior. Together, the human clinical trials and animal toxicology literature support an association between synthetic food dyes and behavioral impacts in children. The current Food and Drug Administration (FDA) acceptable daily intakes are based on older studies that were not designed to assess the types of behavioral effects observed in children. For four dyes where adequate dose-response data from animal and human studies were available, comparisons of the effective doses in studies that measured behavioral or brain effects following exposure to synthetic food dyes indicate that the basis of the ADIs may not be adequate to protect neurobehavior in susceptible children. There is a need to re-evaluate exposure in children and for additional research to provide a more complete database for establishing ADIs protective of neurobehavioral effects.

Editorial Commentary: Prevention of Complications During Multiple Ligament Knee Injury Reconstruction: It's Complicated!

Treatment of multiple-ligament knee injuries is complex and complicated. Surgeons should strive to keep their operative times under 5 hours, limit inside-out meniscal repair, consider fibular-based only posterolateral corner reconstructions (except in cases with associated proximal tibia-fibular joint injuries or massive posterolateral corner injuries), avoid acute surgery when possible, and proceed cautiously with ultra-low-velocity dislocations. Multiple-ligament knee injury reconstruction is challenging and complicated but a sincere thank you is extended to those surgeons who take on complex knee surgery.

Prevalence, Biomechanics, and Pathologies of the Meniscofemoral Ligaments: A Systematic Review

Purpose

To systematically review the literature to examine current understanding of the meniscofemoral ligaments (MFLs), their function, their importance in clinical management, and known anatomical variants.

Methods

A systematic review was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines using PubMed, EMBASE, and Cochrane databases. Studies were included if they reported on the biomechanical, radiographic, or arthroscopic evaluation of human MFLs, or if they reported on an anatomical variant. These were then categorized as cadaveric, radiographic, or clinical. Biomechanical, radiographic, patient-reported, and functional outcomes data were recorded.

Results

Forty-seven studies were included in the qualitative analysis, and 26 of them were included in the quantitative analysis. Of these, there were 15 cadaveric, 3 arthroscopic, and 9 radiographic studies that reported on the prevalence of MFLs. Overall, when looking at all modalities, the presence of either the anterior or posterior MFL (aMFL, pMFL) has been noted to be 70.8%, with it being the aMFL 17.4% and the pMFL 40.6%. The presence of both ligaments occurs in approximately 17.6% of individuals. Eleven reported on mean MFL length and thickness. When evaluating mean length in both men and women, the aMFL has been reported between 21.6 and 28.3 mm and the pMFL length in this population is between 23.4 and 31.2 mm. Five reported on cross-sectional area. Nine additional papers report anatomical variants.

Conclusions

This review shows that there continues to be a variable incidence of MFLs reported in the literature, but our understanding of their function continues to broaden. A growing number of anatomic and biomechanical studies have demonstrated the importance of the MFLs in supporting knee stability. Specifically, the MFLs serve an important role in protecting the lateral meniscus and augmenting the function of the posterior cruciate ligament.

Clinical Relevance

Our findings will aid the clinician in both identifying and treating pathologies of the meniscofemoral ligaments.

Using High-Throughput Screening to Evaluate Perturbations Potentially Linked to Neurobehavioral Outcomes: A Case Study Using Publicly Available Tools on FDA Batch-Certified Synthetic Food Dyes

There is growing evidence from human and animal studies indicating an association between exposure to synthetic food dyes and adverse neurobehavioral outcomes in children. However, data gaps persist for potential mechanisms by which the synthetic food dyes could elicit neurobehavioral impacts. We developed an approach to evaluate seven US FDA-batch-certified food dyes using publicly available high-throughput screening (HTS) data from the US EPA's Toxicity Forecaster to assess potential underlying molecular mechanisms that may be linked to neurological pathway perturbations. The dyes were screened through 270 assays identified based on whether they had a neurological-related gene target and/or were mapped to neurodevelopmental processes or neurobehavioral outcomes, and were conducted in brain tissue, targeted specific hormone receptors, or targeted oxidative stress and inflammation. Some results provided support for neurological impacts found in human and animal studies, while other results showed a lack of correlation with in vivo findings. The azo dyes had a range of activity in assays mapped to G-protein-coupled receptors and were active in assays targeting dopaminergic, serotonergic, and opioid receptors. Assays mapped to nuclear receptors (androgen, estrogen, and thyroid hormone) also exhibited activity with the food dyes. Other molecular targets included the aryl hydrocarbon receptor, acetylcholinesterase, and monoamine oxidase. The Toxicological Prioritization Index tool was used to visualize the results of the Novascreen assays. Our results highlight certain limitations of HTS assays but provide insight into potential underlying mechanisms of neurobehavioral effects observed in in vivo animal toxicology studies and human clinical studies.

Determining the Ratio of Wedge Height to Degree of Correction for Anterior Tibial Closing Wedge Osteotomies for Excessive Posterior Tibial Slope

BACKGROUND

Anterior closing wedge osteotomy of the proximal tibia may be considered in revision anterior cruciate ligament (ACL) reconstruction surgery for patients with excessive posterior tibial slope (PTS).

PURPOSE

(1) To determine the ratio of wedge thickness to degrees of correction for supratubercle (ST) versus transtubercle (TT) osteotomies for anterior closing wedge osteotomies and (2) to evaluate the accuracy of ST and TT osteotomies in achieving slope correction.

STUDY DESIGN

Controlled laboratory study.

METHODS

The computed tomography (CT) scans of 38 knees in 37 patients undergoing revision ACL reconstruction were used to simulate both ST and TT osteotomies. A 10° wedge was simulated in all CT models. The height of the wedge along the anterior tibia was recorded for each of the 2 techniques. The ratio of wedge height to achieved degree of correction was calculated. ST and TT osteotomies were performed on 3-dimensional (3D)-printed tibias of the 12 patients from the study group with the greatest PTS, after the desired degree of correction was determined. Pre- and postosteotomy slopes were measured for each tibia, and the actual change in slope was compared with the intended slope correction.

RESULTS

According to CT measurements, the ratio of wedge height to degree of correction was 0.99 ± 0.07 mm/deg for the ST osteotomy and 0.83 ± 0.06 mm/deg for the TT osteotomy (P < .001). When these ratios were used to perform simulated osteotomies on the twelve 3D-printed tibias, the mean slope correction was within 1° to 2° of the intended slope correction, regardless of osteotomy location (ST or TT) or whether slope was measured on the medial or lateral plateau. The ST technique tended to undercorrect and the TT technique tended to overcorrect.

CONCLUSION

When anterior tibial closing wedge osteotomies were removed to correct excessive PTS, removing a wedge with a ratio of 1 mm of wedge height for every 1° of intended correction for an ST technique and a ratio of 0.8 mm to 1° for a TT technique resulted in overall average slope correction within 1° to 2° of the target.

CLINICAL RELEVANCE

The calculated ratios will allow clinicians to more accurately correct PTS when performing anterior closing wedge tibial osteotomy.

Effect of Meniscal Treatment on Functional Outcomes 6 Months After Anterior Cruciate Ligament Reconstruction

Background

Meniscal injuries are commonly associated with anterior cruciate ligament (ACL) tears. Treatment of meniscal injuries can impart delayed weightbearing and range of motion restrictions, which can affect the rehabilitation protocol. The effect of meniscal treatment and subsequent restrictions on strength recovery after ACL reconstruction is unclear.

Purpose/Hypothesis

The purpose of this study was to compare strength, jumping performance, and patient-reported outcomes between patients who underwent isolated ACL reconstruction (ACLR) and those who underwent surgical intervention for meniscal pathology at the time of ACLR. Our hypothesis was that patients who underwent concurrent meniscal repair (MR) would have lower strength recovery owing to postoperative restrictions.

Study Design

Cohort study; Level of evidence, 3.

Methods

Patients with ACLR were stratified into isolated ACLR, ACLR and meniscectomy (ACLR-MS), or ACLR-MR groups and were compared with healthy controls. The ACLR-MR group was restricted to partial weightbearing and to 90° of knee flexion for the first 6 weeks postoperatively. All participants completed patient-reported outcomes (International Knee Documentation Committee [IKDC] and Knee injury and Osteoarthritis Outcome Score [KOOS]) and underwent bilateral isokinetic and isometric strength tests of the knee extensor and flexor groups as part of a return-to-sports test battery at 5 to 7 months postoperatively.

Results

A total of 165 patients with ACLR (50 with isolated ACLR, 44 with ACLR-MS, and 71 with ACLR-MR) and 140 healthy controls were included in the study. Follow-up occurred at a mean of 5.96 ± 0.47 months postoperatively. The control group demonstrated higher subjective knee function, unilateral peak extensor torque, and limb symmetry than did the ACLR-MS and ACLR-MR groups combined (P < .001 for all). There were no differences in IKDC, KOOS subscales, or unilateral or limb symmetry measures of peak knee extensor or flexor torque among the isolated ACLR, ACLR-MS, and ACLR-MR groups.

Conclusion

Persistent weakness, asymmetry, and reduced subjective outcome scores at 6-month follow-up after ACLR were not influenced by meniscal treatment. These findings suggested that the weightbearing and range of motion restrictions associated with meniscal repair recovery do not result in loss of early strength or worse patient-reported outcomes.

Developing and implementing core competencies in children's environmental health for students, trainees and healthcare providers: a narrative review

Knowledge of the health impacts of environmental exposures (such as pollution disasters, poor air quality, water contamination, climate change) on children's health has dramatically increased in the past 40 years. The World Health Organization (WHO) estimated that 23% of all deaths worldwide were attributable to the environment, and 26% of deaths in children less than 5 years old could be prevented with removal of environmental risks factors. Yet, little has permeated medical education, leaving pediatric providers ill equipped to address these issues. To address this gap, members from the Pediatric Environmental Health Specialty Units, a United States nationwide network of academically affiliated experts who have created numerous environmental health educational materials and programs, have identified fifteen core environmental health (EH) competencies needed by health care providers to enable them to effectively address environmental health concerns. These competencies can serve as the foundation for the development and implementation of relevant educational programs. The core EH competencies are based upon these foundational elements: 1) Definition of "children's environmental health" that describes how environmental exposures (positive and negative) in early life influence the health and development in childhood and across the entire human life span 2) Children are not "little adults" and so have unique vulnerabilities to environmental hazards; 3) Environmental health inequities exist, causing some children to have a disproportionate amount of unhealthy exposures and consequently a greater risk of adverse effects; 4) Climate change will translate to numerous adverse health effects that will particularly affect children worldwide. In this article, the authors describe the core environmental health competencies and provide resources, online tools, strategies, and examples targeted to all levels of training and practice to better enable leaders and educators to bring this important content to the forefront.

Predicting ACL Reinjury from Return to Activity Assessments at 6-months Post-Surgery: A Prospective Cohort Study

CONTEXT

Return to activity(RTA) assessments are commonly administered following ACL-Reconstruction(ACLR) to manage post-operative progressions back to activity. To date, there is little knowledge on the clinical utility of these assessments to predict patient outcomes such as secondary ACL injury once returned to activity.

OBJECTIVE

To identify what measures of patient function at 6-months post-ACLR best predict return to activity and second ACL injury at a minimum of 2-years following ACLR.

DESIGN

Prospective-cohort Setting: Laboratory Patients: A total of 234 patients with primary, unilateral ACLR completed functional assessments at approximately 6-months post-ACLR. A total of 192(82%) completed follow-up ≥ 2-years post ACLR.

MAIN OUTCOME MEASURES

Six-month functional assessments consisted of patient reported outcomes, isokinetic knee flexor and extensor strength, and single-leg hopping. The ability to return to activity and secondary ACL injury were collected at a minimum of two-years following ACLR.

RESULTS

In patients who did RTA(n=155), a total of 44(28%) individuals had a subsequent ACL injury; graft n=24(15.5%), contralateral ACL n=20(13%). A greater proportion of females had a secondary injury to the contralateral ACL(15/24, 63%) whereas a greater proportion of males reinjured the ipsilateral ACL graft(15/20, 75%, P=.017) Greater knee extension symmetry at 6-months increased the probability of reinjury(B=.016, P=.048). In patients who RTA before 8-months, every 1% increase in quadriceps strength symmetry at 6-months increased the risk of reinjury by 2.1%(B=.021, P=.05). In patients who RTA after 8-months, every month that RTA was delayed reduced the risk of reinjury by 28.4%(B=-284, P=.042).

CONCLUSIONS

Patients with more symmetric quadriceps strength at 6-months post ACLR were more likely to experience another ACL rupture, especially in those who returned to sport earlier than 8-months after the index surgery. Clinicians should be cognizant that returning high functioning patients to activity earlier than 8-months post-ACLR may place them at an increased risk for reinjury.

An Imaging Overview of the Posterior Septum of the Knee and Trans-Septal Portal Procedure: Normal Anatomy, Indications, and Unique Imaging Considerations

The posterior trans-septal portal technique is an arthroscopic surgery of the knee providing surgeons with the ability to fully visualize the posterior compartment. With this procedure, portals are placed at the posteromedial and posterolateral aspect of the knee. Visualization of the medial and lateral posterior compartments then allows working space for the creation of the intra-articular portal that is made by dividing the posterior septum. We provide an imaging overview of the posterior septum, the trans-septal portal technique, possible indications, and introduce how surrounding anatomy may warrant unique imaging considerations.

Allograft Bone Dowels Show Better Incorporation in Femoral Versus Tibial Tunnels in 2-Stage Revision Anterior Cruciate Ligament Reconstruction: A Computed Tomography-Based Analysis

PURPOSE

The purpose of this study was to quantitatively evaluate the radiographic outcomes of allograft dowels used in 2-stage revision anterior cruciate ligament reconstruction (ACLR) and to compare the incorporation rates of dowels placed in tibial and femoral tunnels.

METHODS

Prospective review of patients who underwent 2-stage revision ACLR with allograft bone dowels. Inclusion criteria were tibial/femoral tunnel diameter of ≥14 mm on preoperative computed tomography (CT) or overlapping of prior tunnels with planned tunnels. Second-stage timing was determined based on qualitative dowel integration on CT obtained at ∼3 months after the first stage. Quantitative analysis of incorporation rates was performed with the union ratio (UR) and occupying ratio (OR) on postoperative CT scans.

RESULTS

Twenty-one patients, with a mean (SD) age of 32.1 (11.4; range, 18-50) years, were included. Second-stage procedures were performed at a mean (SD) of 6.5 (2.1; range, 2.4-11.5) months after first-stage revision. All dowels showed no signs of degradation at the host bone/graft junction at the second-stage procedure. The mean (SD) diameter of the dowels placed in tibial tunnels was greater than those placed in femoral tunnels (16.1 [2.3] mm vs 12.4 [1.6] mm; P < .05). CT was obtained at a mean (SD) of 121 (28; range, 59-192) days after the first-stage surgery. There was no difference between the OR of femoral and tibial tunnels (mean [SD], 87.6% [4.8%] vs 85.7% [10.1%]; P = .484), but the UR was significantly higher in femoral tunnels (mean [SD], 83% [6.2%] vs 74% [10.5%], P = .005). The intraclass correlation coefficients of OR and UR measurements indicated good reliability.

CONCLUSIONS

Allograft bone dowels are a viable graft choice to replenish bone stock in the setting of a staged revision ACL reconstruction. Allograft dowels placed in femoral tunnels had a higher healing union ratio than tibial tunnel allografts and no evidence of degradation at the bone/graft junction, with no difference seen in occupying ratio.

LEVEL OF EVIDENCE

Level IV, case series.

Effect of Tibial Tunnel Placement Using the Lateral Meniscus as a Landmark on Clinical Outcomes of Anatomic Single-Bundle Anterior Cruciate Ligament Reconstruction

BACKGROUND

It remains unclear if use of the lateral meniscus anterior horn (LMAH) as a landmark will produce consistent tunnel positions in the anteroposterior (AP) distance across the tibial plateau.

PURPOSE

To evaluate the AP location of anterior cruciate ligament (ACL) reconstruction tibial tunnels utilizing the LMAH as an intra-articular landmark and to examine how tunnel placement affects knee stability and clinical outcomes.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A retrospective review was conducted of 98 patients who underwent primary ACL reconstruction with quadrupled hamstring tendon autografts between March 2013 and June 2017. Patients with unilateral ACL injuries and a minimum follow-up of 2 years were included in the study. All guide pins for the tibial tunnel were placed using the posterior border of the LMAH as an intra-articular landmark. Guide pins were evaluated with the Bernard-Hertel grid in the femur and the Stäubli-Rauschning method in the tibia. Patients were divided by the radiographic location of the articular entry point of the guide pin with relation to the anterior 40% of the tibial plateau. Outcomes were evaluated by the Marx Activity Scale and International Knee Documentation Committee (IKDC) form. Anterior knee laxity was evaluated using a KT-1000 arthrometer and graded with the objective portion of the IKDC form. Rotational stability was evaluated using the pivot-shift test.

RESULTS

A total of 60 patients were available for follow-up at a mean 28.6 months. The overall percentage of AP placement of the tibial tunnel was 39.3% ± 3.8% (mean ± SD; range, 31%-47%). Side-to-side difference of anterior knee laxity was significantly lower in the anterior group than the posterior group (1.2 ± 1.1 mm vs 2.5 ± 1.3 mm; P < .001; r = 0.51). The percentage of AP placement of the tibial tunnel demonstrated a positive medium correlation with side-to-side difference of anterior knee laxity as measured by a KT-1000 arthrometer (r = 0.430; P < .001). The anterior group reported significantly better distribution of IKDC grading as compared with the posterior group (26 grade A and 6 grade B vs 15 grade A and 13 grade B; P = .043; V = 0.297). The pivot-shift test results and outcome scores showed no significant differences between the groups.

CONCLUSION

Using the posterior border of the LMAH as an intraoperative landmark yields a wide range of tibial tunnel locations along the tibial plateau, with anterior placement of the tibial tunnel leading toward improved anterior knee stability.

Editorial Commentary: Anterior Cruciate Ligament Tunnel Aperture Overlap Determines Need for 1- Versus 2-Stage Revision: Setting the Stage

Despite general agreement that tunnel widening ≥14 mm necessitates a 2-stage approach for revision anterior cruciate ligament (ACL) reconstruction, there is very little literature describing the effect of tunnel overlap between the previous tunnel and new tunnel with 1-stage ACL revisions. Tunnel overlap, particularly at the aperture, should be minimized without compromising anatomic tunnel location(s). This can often be accomplished with a 1-stage revision, but 2-stage revisions are sometimes required. Revision ACL reconstruction can be challenging and it is helpful for the surgeon to carefully plan preoperatively and have several options available to him/her intraoperatively, including the possibility of a 2-stage revision.

Health effects of wildfire smoke in children and public health tools: a narrative review

Wildfire smoke is an increasing environmental health threat to which children are particularly vulnerable, for both physiologic and behavioral reasons. To address the need for improved public health messaging this review summarizes current knowledge and knowledge gaps in the health effects of wildfire smoke in children, as well as tools for public health response aimed at children, including consideration of low-cost sensor data, respirators, and exposures in school environments. There is an established literature of health effects in children from components of ambient air pollution, which are also present in wildfire smoke, and an emerging literature on the effects of wildfire smoke, particularly for respiratory outcomes. Low-cost particulate sensors demonstrate the spatial variability of pollution, including wildfire smoke, where children live and play. Surgical masks and respirators can provide limited protection for children during wildfire events, with expected decreases of roughly 20%  and 80% for surgical masks and N95 respirators, respectively. Schools should improve filtration to reduce exposure of our nation's children to smoke during wildfire events. The evidence base described may help clinical and public health authorities provide accurate information to families to improve their decision making.

Percutaneous Medial Collateral Ligament Release Improves Medial Compartment Access During Knee Arthroscopy

Purpose

To quantify intraoperative joint space widening afforded by the outside-in, percutaneous release of the medial collateral ligament (MCL) and to evaluate its impact on medial compartment width and functional outcomes at 6-week follow-up for patients undergoing a partial medial meniscectomy without postoperative bracing.

Methods

Patients with posteromedial meniscus tears and no evidence of ipsilateral knee pathology, undergoing partial medial meniscectomy, were enrolled. Intraoperatively, medial compartment width was quantified with fluoroscopy before and after the percutaneous MCL release with an 18-gauge spinal needle proximal to the joint line. At 6-week follow-up, valgus stress radiographs re-evaluated medial compartment width. International Knee Documentation Committee (IKDC) and Patient-Reported Outcomes Measurement Information System (PROMIS) scores were completed preoperatively and at 6-week follow-up to evaluate functional outcomes. A paired sample t test performed at a 95% confidence interval (CI) was used to compare these variables.

Results

Forty-two patients, mean (± standard deviation) age 55.3 ± 10.7 years, were available for analysis of intraoperative medial compartment widening. Medial compartment width increased from 5.95 ± 1.32 to 11.09 ± 1.74 mm intraoperatively after MCL release. At 6-week follow-up, radiographic assessment demonstrated a mean medial compartment width of 5.85 ± .99 mm, which represented an insignificant change compared with the preoperative value (CI –0.68 to .33, P = .474). PROMIS and IKDC scores significantly improved from baseline, with increases of 6.9 ± 12.4 (CI 2.0 to 11.8, P = .008) and 11.7 ± 17.8 (CI 4.7 to 18.8, P = .002), respectively.

Conclusions

Percutaneous MCL release during knee arthroscopy improves visualization and facilitates instrumentation by providing an almost 2× wider working space within the medial tibiofemoral joint. In this study, the performance of percutaneous MCL release did not result in any complications. Radiographic and clinical resolution of iatrogenic laxity was demonstrated by 6-weeks postoperatively, without the use of postoperative bracing.

Level of Evidence

IV, therapeutic case series.