Editorial Commentary: For Single-Bundle Anterior Cruciate Ligament Reconstruction, Graft Fixation Should Be Performed at a Medium Tension in Full Extension: Multiple Bundle Reconstruction May Require a Different Strategy.

Successful anterior cruciate ligament reconstruction requires a multifaceted approach to replicate normal knee anatomy and biomechanics. Graft tensioning force and the angle at which this tension is applied intraoperatively are factors under the surgeon's control. The literature suggests the best tensioning strategy for single bundle reconstructions is at medium tension in full extension, while tensioning multiple bundles is best done at 20° at lower overall tension. Graft tensioning should be individualized with attention paid to graft choice and fixation. Generally, stiffer grafts are thought to require additional force to create the same amount of lengthening. For example, bone-patellar tendon-bone grafts tend to be stiffer than quadrupled hamstring grafts and the native anterior cruciate ligament. Hamstring grafts also are thought to exhibit greater stress relaxation over time, thus elongating and potentially causing increased laxity over time. Pretensioning may eliminate some postoperative graft creep, typically more of an issue with hamstring grafts.

The Majority of Patients Aged 40 and Older Having Allograft Anterior Cruciate Ligament Reconstruction Achieve a Patient Acceptable Symptomatic State.

PURPOSE: To evaluate patient satisfaction, retear rates, and patient-reported outcomes (PROs) in patients aged 40 and older undergoing allograft anterior cruciate ligament reconstruction (ACLR). The secondary goal was to compare these parameters between groups of patients with intact versus failed grafts, and to evaluate these in relation to a historically reported International Knee Documentation Committee (IKDC) patient-acceptable symptoms state (PASS) score. METHODS: Records of patients aged 40 and older who underwent ACLR between 2005 and 2016 at a single institution with a minimum 2-year follow-up were retrospectively reviewed. Patient-reported satisfaction, outcome scores, and failure rates were analyzed. The rate of achieving a previously defined IKDC PASS score based on younger cohorts was reported, and an updated PASS threshold for older patients was calculated. RESULTS: 201 patients were included with a mean age of 48.6 years (range: 40-68) and mean follow-up of 6.2 years (range: 2.8-11.2). 182 (90.5%) patients reported satisfaction following surgery. 16 (8.0%) patients experienced failure of their ACLR, 10 of which underwent revision ACLR. The median IKDC score in the intact ACLR group was 86.2, compared to 66.7 in the failure group (P < .001). In total, 134 (72.4%) patients in the intact group achieved the historical PASS score of 75.9 on IKDC compared to only 4 (25%) in the failure group (χ2 = 15.396, P < .001). An updated IKDC PASS threshold for older cohorts was calculated to be 66.7. CONCLUSION: Patients aged 40 and older who underwent allograft ACLR had an 8.0% failure rate at a mean follow-up of 6 years. Graft failure in patients aged 40 and older was associated with worse PROs. The majority of patients achieved the historically reported IKDC PASS threshold. Additionally, an updated age-appropriate IKDC PASS score of 66.7 was calculated to aid in future ACLR studies assessing older patients. STUDY DESIGN: Level IV.

Outcomes of Surgically Treated Fifth Metatarsal Fractures in Major League Soccer Athletes.

BACKGROUND: Sports-related fractures of the fifth metatarsal are common in professional athletes. Data regarding outcomes of surgical management including refracture, complications, and return-to-play statistics are available for other professional American sports with a notable exception of soccer. PURPOSE: To quantify the burden of operative fifth metatarsal fractures in Major League Soccer (MLS) athletes, to compare outcomes as well as refracture and complication rates with other professional sports, to analyze factors that may contribute to treatment failure, and to report on return-to-play characteristics for affected players. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: We searched all injuries in the prospectively collected HealtheAthlete database for MLS for operative fifth metatarsal fractures for seasons 2013 to 2017. Additional information regarding each fracture including demographics, treatment, postoperative course, and return-to-play statistics were compiled from HealtheAthlete and supplemented by teams' chief medical officers, coaches, trainers, and online sources. RESULTS: There were 21 fractures in 18 players during the study period. Mean time to radiographic healing was 8.5 weeks (n = 17). Mean time to return to play was 11.1 weeks (n = 19). Of 21 fractures, 20 (95%) players returned to sport. Of 18 players, 4 (22.2%) experienced refracture. Of 18 players, 5 (27.8%) and 2 (11.1%) reported previous stress injuries on the contralateral and ipsilateral limb, respectively. Player performance characteristics showed small declines in the first year of return that improved by the second year. CONCLUSION: MLS athletes who sustain a sports-related fifth metatarsal fracture can expect a high rate of return to sport with time to radiographic healing and return to play as well as risk of refracture similar to other professional cohorts.

Editorial Commentary: Second-Generation Microfracture-We Are Only As Strong As Our Weakest Link.

Injuries to the articular cartilage of the knee are increasingly common, especially in athletes. The operative management of these focal chondral lesions continues to be a regenerative challenge. The microfracture (MFx) procedure has become a first-line arthroscopic treatment method for small, symptomatic chondral lesions, and it frequently serves as the standard technique against which other cartilage repair procedures are compared. Over time, outcome studies have defined the weaknesses and limitations of first-generation MFx. The second iteration of MFx seeks to optimize regeneration using the trilogy of cells, scaffolds, and growth factors. As surgeons, we are only as strong as our weakest link.

Delayed ACL Reconstruction in Patients ≥40 Years of Age Is Associated With Increased Risk of Medial Meniscal Injury at 1 Year.

BACKGROUND: Anterior cruciate ligament (ACL) tears in the pediatric and young adult ACL-deficient knee are often associated with meniscal or chondral injury with delayed time to surgery. The incidence of ACL reconstruction performed in patients aged ≥40 years is rising, and it is unclear if delayed surgery in this cohort similarly affects the health of the meniscus and cartilage. PURPOSE: To evaluate whether delayed reconstruction in a cohort of patients aged ≥40 years is associated with an increased risk of meniscal or chondral injury. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Records of patients aged ≥40 years who underwent primary arthroscopic ACL reconstruction between 2012 and 2016 at an academic hospital were retrospectively reviewed. Patient characteristic data and time to surgery were recorded. Operative reports were analyzed for meniscal and chondral injuries as well as treatment. Patients were grouped according to time to surgery, defined as early (<90 days) or delayed (≥90 days). Logistic regression modeling was used to form associations between elapsed time to surgery and patient characteristics to meniscal and chondral damage. Additionally, risks for meniscal and chondral injury were analyzed at time points of 180 days and 1 year from injury to surgery. RESULTS: A total of 227 patients met the study criteria: 106 patients underwent early surgery, and 121 underwent delayed surgery. The authors identified 127 medial meniscal tears and 106 lateral meniscal tears. Medial, lateral, and patellofemoral compartment chondral injury was reported in 127, 82, and 130 patients, respectively. Delayed surgery (≥90 days) was not associated with increased risk of medial or lateral meniscal tears or any chondral injury at 90 days. Each year of increased age was associated with an increased odds ratio: 1.09 ( P = .001) for medial meniscal tears, 1.06 ( P = .014) for lateral meniscal tears, 1.10 ( P = .001) for medial compartment chondral injuries, and 1.07 ( P = .007) for patellofemoral compartment chondral injuries. Additionally, each unit of increased body mass index was associated with an increased odds ratio: 1.09 ( P = .039) for medial meniscal tears and 1.14 ( P = .003) for medial compartment cartilage injury. Analysis of 180-day and 1-year time points revealed an increased risk (odds ratio, 3.47; 95% CI, 1.55-7.77; P = .002) for medial meniscal injury when surgery was delayed for >1 year. CONCLUSION: Delayed ACL reconstruction (≥90 days) among patients aged ≥40 years was not associated with an increased risk of meniscal or chondral injury. Increasing age and body mass index were associated with higher risks of meniscal and chondral injuries in this cohort. Delay in surgery for >1 year was associated with increased risk of medial meniscal tear.

Molecular population genetics of SLC4A1 and Southeast Asian ovalocytosis.

Southeast Asian ovalocytosis (SAO) is an erythrocyte abnormality that protects affected individuals from cerebral malaria. This trait is caused by a 27-bp deletion in the SLC4A1 gene, which is lethal when homozygous. We reseqeunced approximately 5 kb of SLC4A1 in an Indonesian population where SAO is prevalent to better understand the evolution of this clinically important trait. The four SAO chromosomes we resequenced share a single haplotype that differs from a sampled non-SAO haplotype only by the 27-bp deletion. Comparison of Indonesian sequence data to that from two other Asian populations (aboriginal Taiwanese and Japanese) shows Indonesian SLC4A1 to be strongly differentiated from the Taiwanese, but not the Japanese. Indeed, the Taiwanese sample contains only chromosomes that are highly divergent from all sampled SAO chromosomes. Because earlier studies have found an association between Austronesian-speakers (who most likely originated in Taiwan) and SAO, our failure to find SAO-like chromosomes in Taiwan is unexpected. Finally, our data find a strong excess of high-frequency derived alleles in all three populations. These alleles include the non-synonymous 'Memphis' variant, which is known to affect anion transport across the erythrocyte membrane. Our data suggest a role for recent natural selection acting on Memphis or a linked variant.