Multiligament knee injury (MLKI): an expert consensus statement on nomenclature, diagnosis, treatment and rehabilitation.

Multiligament knee injuries (MLKIs) represent a broad spectrum of pathology with potentially devastating consequences. Currently, disagreement in the terminology, diagnosis and treatment of these injuries limits clinical care and research. This study aimed to develop consensus on the nomenclature, diagnosis, treatment and rehabilitation strategies for patients with MLKI, while identifying important research priorities for further study.

Return to Sports in Patients Aged 50 Years or Younger After Robotic-Assisted Patellofemoral Arthroplasty: A 10-Year Experience Reporting High Clinical Benefits and High Patient Satisfaction With Return to an Active Lifestyle.

Background: Limited data are available on return to sports and patient psychometric ratings of success after patellofemoral arthroplasty (PFA) in younger patients with high expectations to return to an active lifestyle.

Purpose/hypothesis: The purpose of this article was to determine the role of PFA and its success in meeting patient expectations regarding the return to low-impact recreational sports and an active lifestyle in younger, active patients. It was hypothesized that PFA would allow younger patients to return to low-impact sports and an active lifestyle and achieve high patient psychometric ratings.

Functional Interaction of the Cruciate Ligaments, Posteromedial and Posterolateral Capsule, Oblique Popliteal Ligament, and Other Structures in Preventing Abnormal Knee Hyperextension.

Background: The ligaments and soft tissue capsular structures of the knee joint that provide a resisting force to prevent abnormal knee hyperextension have not been determined. This knowledge is required for the diagnosis and treatment of knee hyperextension abnormalities.

Purpose: To determine the resisting moment of knee ligament and capsular structures that resist knee hyperextension.

Blood Flow Restriction Training Can Improve Peak Torque Strength in Chronic Atrophic Postoperative Quadriceps and Hamstrings Muscles.

Purpose: To report a prospective study of patients who underwent blood flow restriction training (BFRT) for marked quadriceps or hamstring muscle deficits after failure to respond to traditional rehabilitation after knee surgery.

Methods: The BFRT protocol consisted of 4 low resistance exercises (30% of 1 repetition maximum): leg press, knee extension, mini-squats, and hamstring curls with 60% to 80% limb arterial occlusion pressure. Knee peak isometric muscle torque (60° flexion) was measured on an isokinetic dynamometer.

Generalized Joint Laxity Is Associated With Increased Failure Rates of Primary Anterior Cruciate Ligament Reconstructions: A Systematic Review.

Purpose: To investigate patients with generalized joint laxity (GJL) after primary anterior cruciate ligament reconstruction (ACLR) as to the risk of ACLR failure, graft selection success rates, and overall clinical outcomes.

Methods: A systematic review of the PubMed and EMBASE databases was performed to identify studies published from the inception of the databases through February 4, 2020. The inclusion criteria were original studies written in English involving outcomes of patients with GJL who had undergone primary ACLR.

A Biomechanical Study of Pivot-Shift and Lachman Translations in Anterior Cruciate Ligament-Sectioned Knees, Anterior Cruciate Ligament-Reconstructed Knees, and Knees With Partial Anterior Cruciate Ligament Graft Slackening: Instrumented Lachman Tests Statistically Correlate and Supplement Subjective Pivot-Shift Tests.

Purpose: To determine the statistical and predictive correlation between instrumented Lachman and pivot-shift tests with progressive loss of anterior cruciate ligament (ACL) function.

Methods: The kinematic correlations between pivot-shift and Lachman anterior tibial translations (ATTs) in ACL-deficient and ACL-reconstructed states and in partially lax ACL grafts were determined with precise robotic testing in cadaveric knees. The Lachman test (100-N anteroposterior) and 2 pivot-shift loadings were conducted: anterior tibial loading (100 N), valgus rotation (7 Nm), and internal rotation (5 Nm and 1 Nm).

Editorial Commentary: Long-Term Survivorship of Knee Meniscal Transplant Surgery-The Importance of Patient-Reported Outcomes With Magnetic Resonance Imaging Demonstration of Retained Meniscal Transplant Function.

The altered knee joint function and symptomatic state in younger patients after meniscectomy and progressive tibiofemoral arthritis remain an important unsolved treatment dilemma. Meniscal allograft transplantation has evolved as an acceptable treatment because there are few (if any) other options. The procedure is effective in most patients, who experience a decrease in tibiofemoral pain and improved knee function, even allowing a return to light recreational activities.

Editorial Commentary: Measurements for Successful High Tibial Osteotomy: Understanding Supine Versus Standing and Intraoperative Fluoroscopic Alignment Is Required.

A high tibial osteotomy (HTO) that is used to correct varus malalignment, such as with medial arthrosis or before cartilage restoration or posterolateral reconstructions, represents an important and required surgery for clinical success. A major problem that occurs with HTO planning is that the preoperative measurements, with either lower limb supine or standing weight-bearing radiographs, will invariably show abnormal medial or lateral tibiofemoral compartment opening resulting from soft-tissue laxity or injury. It is imperative that this tibiofemoral joint opening be accounted for in the osteotomy correction calculations.

One in 5 Athletes Sustain Reinjury Upon Return to High-Risk Sports After ACL Reconstruction: A Systematic Review in 1239 Athletes Younger Than 20 Years.

Context: Anterior cruciate ligament (ACL) reconstruction (ACLR) is frequently performed in patients younger than 20 years whose goal is to return to sport (RTS). Varying reinjury rates have been reported, and the factors responsible are unclear. Studies differ with regard to age, graft type, surgical techniques, postoperative rehabilitation, RTS guidelines, and methods used to determine ACL failures.

Degenerative Meniscus Lesions: An Expert Consensus Statement Using the Modified Delphi Technique.

Purpose: The purpose of this study was to perform an evidence-based, expert consensus survey using the Delphi panel methodology to develop recommendations for the treatment of degenerative meniscus tears.

Methods: Twenty panel members were asked to respond to 10 open-ended questions in rounds 1 and 2. The results of the first 2 rounds served to develop a Likert-style questionnaire for round 3.

Anterior Cruciate Ligament Graft Conditioning Required to Prevent an Abnormal Lachman and Pivot Shift After ACL Reconstruction: A Robotic Study of 3 ACL Graft Constructs.

Background: Anterior cruciate ligament (ACL) graft conditioning protocols to decrease postoperative increases in anterior tibial translation and pivot-shift instability have not been established.

Purpose: To determine what ACL graft conditioning protocols should be performed at surgery to decrease postoperative graft elongation after ACL reconstruction.

Study Design: Controlled laboratory study.

Blood Flow-Restricted Training for Lower Extremity Muscle Weakness due to Knee Pathology: A Systematic Review.

Context:: Blood flow-restricted training (BFRT) has been suggested to treat lower extremity muscle weakness. The efficacy of BFRT for muscle problems related to knee pathology is unclear.

Objective:: To determine whether BFRT (1) improves muscle strength and cross-sectional area (CSA) for chronic knee-related lower extremity atrophy and (2) prevents muscle atrophy after knee surgery.

Two Different Knee Rotational Instabilities Occur With Anterior Cruciate Ligament and Anterolateral Ligament Injuries: A Robotic Study on Anterior Cruciate Ligament and Extra-articular Reconstructions in Restoring Rotational Stability.

Purpose: To determine the effect of 2 extra-articular reconstructions on pivot-shift rotational stability and tibial internal rotation as a basis for clinical recommendations.

Methods: A robotic simulator tested 15 cadaver knees. Group 1 (anterior cruciate ligament [ACL] cut) underwent ACL bone-patellar tendon-bone reconstruction followed by sectioning the anterolateral structures and an extra-articular, manual-tension iliotibial band (ITB) tenodesis.

The Effect of an ACL Reconstruction in Controlling Rotational Knee Stability in Knees with Intact and Physiologic Laxity of Secondary Restraints as Defined by Tibiofemoral Compartment Translations and Graft Forces.

Background: The effect of an anterior cruciate ligament (ACL) reconstruction on restoring normal knee kinematics in unstable knees with physiologic laxity of secondary ligamentous restraints remains unknown. The purpose of this study was to determine the stabilizing function of an ACL reconstruction and the resulting ACL graft forces in knees with severely abnormal anterior subluxation due to associated laxity of secondary restraints.

Methods: A 6-degree-of-freedom robotic simulator was used to test 21 cadaveric knees studied as a whole and in subgroups of lax secondary restraints (Lax-SR) and intact secondary restraints (Intact-SR), based on abnormal translations and tibial rotations.

Low-impact sports activities are feasible after meniscus transplantation: a systematic review.

Purpose: To determine sports activities achieved after meniscus transplantation and if associations exist between sports activity levels and transplant failure or progression of tibiofemoral osteoarthritis (OA).

Methods: A systematic search was performed using PubMed and Cochrane online databases. Inclusionary criteria were English language, clinical trials published from 1996 through May 2017, minimum 2 years of follow-up, and sports activity data reported.

Effect of Fatigue Protocols on Lower Limb Neuromuscular Function and Implications for Anterior Cruciate Ligament Injury Prevention Training: A Systematic Review.

Background: Approximately two-thirds of anterior cruciate ligament (ACL) tears are sustained during noncontact situations when an athlete is cutting, pivoting, decelerating, or landing from a jump. Some investigators have postulated that fatigue may result in deleterious alterations in lower limb biomechanics during these activities that could increase the risk of noncontact ACL injuries. However, prior studies have noted a wide variation in fatigue protocols, athletic tasks studied, and effects of fatigue on lower limb kinetics and kinematics.

Rotational Knee Instability in ACL-Deficient Knees: Role of the Anterolateral Ligament and Iliotibial Band as Defined by Tibiofemoral Compartment Translations and Rotations.

Background: The anterolateral ligament (ALL) has been proposed as a primary restraint for knee rotational stability. However, the data remain inconclusive. The purpose of this study was to determine the effect of the ALL and the iliotibial band (ITB) on knee rotational stability.

Is an Anterolateral Ligament Reconstruction Required in ACL-Reconstructed Knees With Associated Injury to the Anterolateral Structures? A Robotic Analysis of Rotational Knee Stability.

Background: The effect of an anterolateral ligament (ALL) reconstruction on rotational knee stability and corresponding anterior cruciate ligament (ACL) graft forces using multiple knee loading conditions including the pivot-shift phenomenon has not been determined.

Purpose: First, to determine the rotational stability and ACL graft forces provided by an anatomic bone-patellar tendon-bone ACL reconstruction in the ACL-deficient knee alone and with an associated ALL/iliotibial band (ITB) injury. Second, to determine the added rotational stabilizing effect and reduction in ACL graft forces provided by an ALL reconstruction.

Anterolateral Ligament and Iliotibial Band Control of Rotational Stability in the Anterior Cruciate Ligament-Intact Knee: Defined by Tibiofemoral Compartment Translations and Rotations.

Purpose: To determine the stabilizing effect of the anterolateral ligament (ALL) and iliotibial band (ITB) in resisting internal tibial rotation limits and anterior subluxations of the tibiofemoral compartments in anterior cruciate ligament (ACL)-intact knees during anterior drawer, internal rotation, and under 2 different 4-degree-of-freedom pivot-shift conditions.

Methods: A 6-degree-of-freedom robotic simulator tested 19 fresh-frozen cadaver specimens with 3 testing conditions: intact, ALL- or ITB-sectioned (random), and both ALL and ITB sectioned. Anterior translation of the medial and lateral compartments and internal tibial rotation were measured under 100 N anterior drawer, 5 Nm internal rotation, and 2 pivot-shift conditions.

Editorial Commentary: Lateral Extra-articular Reconstructions With Anterior Cruciate Ligament Surgery: Are These Operative Procedures Supported by In Vitro Biomechanical Studies?

There remains controversy on the role of a concurrent lateral extra-articular procedure with anterior cruciate ligament (ACL) reconstruction. Previous biomechanical studies often are historical and inconclusive. Studies show the anterolateral ligament and iliotibial band are secondary restraints and, when injured in conjunction with the ACL, produce gross (Grade 3) pivot-shift subluxations.

Aerobic Physical Fitness and Recreational Sports Participation After Total Knee Arthroplasty.

Context: Total knee arthroplasty (TKA) is routinely performed in younger patients who desire to be active in fitness and recreational sports. The activities patients can participate in without symptoms and the level of aerobic fitness routinely maintained are important to investigate.

Objective: To determine physical activity (PA) and recreational sports resumed after primary TKA, symptoms or limitations with these activities, and the effect of postoperative rehabilitation on achieving fitness and sports goals.

Long-term Survivorship and Function of Meniscus Transplantation.

Background: Clinical outcomes and survivorship of meniscus transplants remain unclear, especially when magnetic resonance imaging (MRI) and weightbearing radiographic findings are included as endpoints. Many studies calculate survivorship based only on subsequent operative procedures.

Purpose: We prospectively determined long-term survivorship and functional outcomes of 72 consecutive meniscus transplants.