Isolated Patellofemoral Joint Arthroplasty: Can Preoperative Bone Scans Predict Survivorship?

Background: Isolated patellofemoral joint arthritis has been identified in 10% of the population presenting with symptomatic knee osteoarthritis. Patient selection is important in order to improve survivorship following PF arthroplasty. The purpose of this study is to compare the use of a preoperative bone scan vs a magnetic resonance imaging (MRI) to identify the patient with isolated PF arthritis.

Anterior cruciate ligament reconstruction, rehabilitation, and return to play: 2015 update.

Anatomical discoveries and a growing appreciation of the knee as a complex organ are driving innovations in patient care decision-making following anterior cruciate ligament (ACL) injury. Surgeons are increasing their efforts to restore combined mechanical-neurosensory ACL function and placing more consideration on when to reconstruct versus repair native anatomical structures. Surgical options now include primary repair with or without reinforcing the injured ACL with suture-based internal bracing, and growing evidence supports biological augmentation using platelet-rich plasma and mesenchymal stem cells to enhance tissue healing.

In situ comparison of varying composite tibial tunnel interference screws used for ACL soft tissue graft fixation.

Purpose: This mechanical study using an in vitro porcine model compared composite interference screw fixation of soft tissue ACL grafts in tibial tunnels.

Methods: Forty-eight porcine profundus tendons and tibiae were divided into four groups of 12 closely matched specimens. Equivalent diameter grafts were assigned to each group.

Lower extremity neuromuscular compensations during instrumented single leg hop testing 2-10 years following ACL reconstruction.

Background: This study compared lower extremity EMG activation and sagittal plane kinematics of subjects at a minimum of 2 years post-successful ACL reconstruction and rehabilitation during instrumented single leg hop testing.

Methods: Comparisons were made based on subject responses to the following question, "compared to prior to your knee injury how capable are you now in performing sports activities"? Group 1=very capable, Group 2=capable, and Group 3=not capable. In addition to EMG (1000 Hz) and kinematic (60 Hz) data, subjective knee function, internal health locus of control, sports activity characteristics (intensity, frequency) pre-knee injury, and at follow-up were also compared.

ACL double bundle linked cortical-aperture tibial fixation: a technical note.

Introduction: The purpose of this technical note is to describe the tibial fixation characteristics for an all-inside anatomic anterior cruciate ligament (ACL) reconstruction method that links extra-cortical button suspensory and aperture fixation replicating double bundle soft tissue graft function in single femoral and tibial sockets.

Materials And Methods: A 55° drill guide aligned guidewires in the ACL footprint center of 8 porcine tibiae (mean apparent bone mineral density = 1.15 g/cm(2)).

Progressive resistance, whole body long-axis rotational training improves kicking motion motor performance.

Objectives: To evaluate lower extremity muscle activation, peak resultant ground reaction force (GRF) production and quickness during performance of a kicking motion following progressive resistance, whole body long-axis rotational training.

Design: Randomized, controlled study.

Setting: Kinesiological research laboratory.

Repair of peripheral vertical meniscus lesions in porcine menisci: in vitro biomechanical testing of 3 different meniscus repair devices.

Background: All-inside meniscus repair eliminates the need for an extra incision and decreases neurovascular injury risk. Biomechanical testing can help delineate the efficacy of all-inside device use.

Hypothesis: There would be no group differences between 4 peripheral meniscus repair techniques and 3 different devices tested.

"Figure 8" single socket double bundle ACL technique.

Using single femoral and tibial tunnels, we describe a technique of anatomically recreating the anteromedial and posterolateral anterior cruciate ligament (ACL) bundles. Transtibial, flexible reamers are utilized to create a "Figure 8" notched tunnel thereby recreating the anatomic footprint of the femoral insertion of the ACL. Rotational control of the individual bundles is created via the notched tunnel and each bundle is tensioned to 80 N individually.

Cyclic test comparison of all-inside device and inside-out sutures for radial meniscus lesion repair: an in vitro porcine model study.

Purpose: To compare biomechanical fixation and gapping characteristics of a new all-inside meniscus repair method for radial meniscus lesion repair versus conventional inside-out suture repair under submaximal cyclic loading and load-to-failure test conditions.

Methods: Fresh-frozen porcine tibiae with attached lateral menisci and joint capsules were harvested and stored for 48 hours at -20°C. After thawing for 12 hours, equivalent-size healthy specimens were randomly assigned to 2 groups of 8 specimens each.

Mesenchymal stem cell therapy in the sports knee: where are we in 2011?

Background: The relationship between biological tissue healing following knee injury or surgery and long-term clinical outcome has come to the forefront of sports medicine practice. This has led many knee surgeons to incorporate biologically mediated healing factors into the management of knee injuries. In particular, the clinical use of mesenchymal stem cells has opened new horizons.

Knee flexion angle is more important than guidewire type in preventing posterior femoral cortex blowout: a cadaveric study.

Purpose: This study compared femoral intraosseous "tunnel" length and distance from the posterior femoral cortex (PFC) when straight and flexible guidewires were drilled through an accessory anteromedial portal at 90° and 120° knee flexion. We had 2 study hypotheses: (1) 120° knee flexion would create longer femoral intraosseous tunnels than 90° knee flexion regardless of guidewire type and (2) 120° knee flexion would display a more consistent PFC blowout safety margin than 90° knee flexion regardless of guidewire type.

Methods: Straight and flexible guidewires were drilled at 90° and 120° flexion in 8 cadaveric knees.

Intratunnel versus extratunnel fixation of hamstring autograft for anterior cruciate ligament reconstruction.

Purpose: To determine which is more effective: intratunnel or extratunnel anterior cruciate ligament soft-tissue graft fixation. A secondary purpose was to determine whether groups displayed differing relations between objective International Knee Documentation Committee (IKDC) grade and the timing of full weight bearing (FWB), jogging/running, and return to sports. The study hypotheses were that intratunnel fixation would display a greater percentage of normal or nearly normal objective IKDC grades and enable earlier FWB, return to jogging/running, and return to sports.

Outside-in meniscus repair: the last 25 years.

Recent advances in our understanding of knee biomechanics and load transmission have emphasized the need for meniscus preservation. However, the literature suggests that more needs to be done. The outside-in arthroscopic meniscus repair was first described by Warren in 1985.

A new technique for arthroscopic meniscus transplant using soft tissue fixation and anatomical meniscal root reinsertion.

Unlabelled: Allograft meniscus transplant is considered as a treatment option for meniscus-deficient patients to provide pain relief and decrease contact stress. This procedure is now considered as safe and reliable for the treatment for knee pain after total menisectomy. This is a new technique that has been developed for arthroscopic meniscus transplant with no bone blocks.

Consideration of growth factors and bio-scaffolds for treatment of combined grade II MCL and ACL injury.

The literature suggests that a Grade II medial collateral ligament (MCL) injury in combination with anterior cruciate ligament (ACL) injury will heal naturally and not compromise patient outcome following ACL reconstruction. Evidence based on bone-patella tendon-bone autograft use is stronger than evidence supporting anatomically placed soft tissue graft use. Current ACL reconstruction practices make greater use of soft tissue grafts, differing fixation methods, and anatomically lower placement on the inner wall of the lateral femoral condyle.

Collagen meniscus implantation: a systematic review including rehabilitation and return to sports activity.

Purpose: To determine collagen meniscus implant (CMI) efficacy for improving patient function, symptoms, and activity level. Study methodologies, rehabilitation, and return to sports guidelines were also reviewed.

Methods: MedLine, EMBASE, CINAHL, Life Science Citations, and Cochrane Central Register of Controlled Trials databases were searched from January 1995-May 2011 using the term collagen meniscal or meniscus implant.

The posteromedial knee arthroscopy portal: a cadaveric study defining a safety zone for portal placement.

Purpose: To define a neurovascular safety zone for proper placement of at least 2 posteromedial (PM) portals and to describe a safe intra-articular entrance point based on the location of the PM capsular folds.

Methods: Arthroscopy was performed on 10 fresh-frozen cadaveric knees. With the knee flexed 90°, PM portals were created under direct visualization with a 70° arthroscope.

Whole body, long-axis rotational training improves lower extremity neuromuscular control during single leg lateral drop landing and stabilization.

Background: Poor neuromuscular control during sports activities is associated with non-contact lower extremity injuries. This study evaluated the efficacy of progressive resistance, whole body, long-axis rotational training to improve lower extremity neuromuscular control during a single leg lateral drop landing and stabilization.

Methods: Thirty-six healthy subjects were randomly assigned to either Training or Control groups.

Single leg jumping neuromuscular control is improved following whole body, long-axis rotational training.

Improved lower extremity neuromuscular control during sports may decrease injury risk. This prospective study evaluated progressive resistance, whole body, long-axis rotational training on the Ground Force 360 device. Our hypothesis was that device training would improve lower extremity neuromuscular control based on previous reports of kinematic, ground reaction force (GRF) or electromyographic (EMG) evidence of safer or more efficient dynamic knee stability during jumping.

Osseous deficits after anterior cruciate ligament injury and reconstruction: a systematic literature review with suggestions to improve osseous homeostasis.

Purpose: This systematic review was performed to improve our understanding of the current evidence regarding the influence of anterior cruciate ligament (ACL) injury and reconstruction on involved lower extremity apparent bone mineral density, bone content, or bone area mass (bone integrity).

Methods: Two independent reviewers performed a Medline search from 1966 to January 2010 using the terms "anterior cruciate ligament" or "ACL" combined with "wound" or "injury" and "bone density" or "osteoporosis." Study inclusion criteria were English-language human studies.

Lower extremity compensatory neuromuscular and biomechanical adaptations 2 to 11 years after anterior cruciate ligament reconstruction.

Purpose: To determine whether compensatory neuromuscular and biomechanical adaptations exist after successful anterior cruciate ligament reconstruction and rehabilitation.

Methods: Seventy subjects, 5.3 +/- 3 years after surgery, participated in this study.

Biomechanical comparison of screw-in suture anchor-suture combinations used for Bankart repair.

Introduction: Bankart repair laxity may contribute to pathologic joint instability. This biomechanical study compared two screw-in suture anchor-suture combinations under tensile loads.

Methods: Twelve pairs of scapulae were implanted with either a 3 mm diameter, 14 mm long poly-L/D-lactide suture anchor with a suture eyelet (Group 1) or a 3.

Effect of cryoprotectant incubation time on handling properties of allogeneic tendons prepared for knee ligament reconstruction.

Soft tissue tendon allografts prepared for anterior cruciate ligament reconstruction are becoming increasingly popular; although concerns exist regarding increased long-term laxity and traumatic rupture rates. This qualitative study evaluated the tissue handling properties of human tibialis posterior tendons prepared using a patented process to improve allograft remodeling and ligamentization under differing cryoprotectant incubation times over 60-min rehydration. Tendons that had been incubated for 8 h had smaller diameters than those that were incubated for 2 h (8.