Arthroscopic Visualization Is a Reliable Method of Confirming Femoral Button Placement During Anterior Cruciate Ligament Reconstruction.

Purpose: To compare arthroscopic visualization with intraoperative fluoroscopy for confirming proper femoral button placement during ACLR.

Methods: Fifty consecutive patients undergoing soft-tissue ACLR between March 2021 and February 2022 were evaluated for inclusion in this study. Both primary and revision ACLR cases using suspensory fixation were included.

Return to Sport in Middle-aged and Older Athletes After Unicompartmental Knee Arthroplasty at a Mean 10-Year Follow-up: Radiographic and Clinical Outcomes.

Background: Return to sport is essential information when an athlete contemplates surgical intervention. Young athletes, <30 years of age, may undergo complex cartilage procedures or femoral/tibial osteotomies to successfully treat single-compartment knee osteoarthritis. Unicompartmental knee arthroplasty (UKA) may offer an attractive alternative option to middle-aged/older athletes with timely return to the same sport without a lengthy rehabilitation.

The Effects of Tensioning of the Anterior Cruciate Ligament Graft on Healing after Soft Tissue Reconstruction.

The purpose of this study is to determine the effect of the magnitude of static mechanical tension on the anterior cruciate ligament (ACL) graft at the time of surgery on healing within the graft tunnels. Ninety male rats underwent unilateral ACL resection followed by reconstruction with a soft tissue tendon autograft. The ACL graft mechanical environment was modulated by different ACL graft pretension levels at the time of surgery (no pretension: 0N; moderate tension: 5N; over tension: 10N).

No Difference in Outcomes Detected Between Decellular Nerve Allograft and Cable Autograft in Rat Sciatic Nerve Defects.

Background: Nerve injuries with a gap/defect represent a clinical challenge without a clear solution. Reconstruction with cable autografts is a common treatment technique, and repair with decellular nerve allograft is a newer option. The purpose of this study was to compare the functional outcomes of reconstruction with cable autografts with those of matched-diameter decellular nerve allografts to evaluate the relative importance of diameter as well as the autograft-versus-allograft nature of the reconstruction.

Effect of Dynamic Changes in Anterior Cruciate Ligament In Situ Graft Force on the Biological Healing Response of the Graft-Tunnel Interface.

Background: Anterior cruciate ligament (ACL) grafts that are placed for reconstruction are subject to complex forces. Current "anatomic" ACL reconstruction techniques may result in greater in situ graft forces. The biological effect of changing magnitudes of ACL graft force on graft-tunnel osseointegration is not well understood.

Notch Signaling Mediates Skeletal Muscle Atrophy in Cancer Cachexia Caused by Osteosarcoma.

Skeletal muscle atrophy in cancer cachexia is mediated by the interaction between muscle stem cells and various tumor factors. Although Notch signaling has been known as a key regulator of both cancer development and muscle stem cell activity, the potential involvement of Notch signaling in cancer cachexia and concomitant muscle atrophy has yet to be elucidated. The murine K7M2 osteosarcoma cell line was used to generate an orthotopic model of sarcoma-associated cachexia, and the role of Notch signaling was evaluated.

Use of a new model allowing controlled uniaxial loading to evaluate tendon healing in a bone tunnel.

The optimal mechanical loading regimen for the healing of a tendon graft in a bone tunnel is unknown. We developed a rat model that directly tensions a healing tendon graft, without the use of confounding joint motion. Fifty cycles of either 0, 3, or 6 N of tension were applied to groups daily for 3 or 6 weeks.

ALDH Activity Correlates with Metastatic Potential in Primary Sarcomas of Bone.

Osteosarcoma (OS), chondrosarcoma (CSA), and Ewings sarcoma (ES) are the most common primary malignancies of bone, and are rare diseases. As with all sarcomas, the prognosis of these diseases ultimately depends on the presence of metastatic disease. Survival is therefore closely linked with the biology and metastatic potential of a particular bone tumor's cells.

Cadaveric investigation on radial nerve strain using different posterior surgical exposures for extraarticular distal humeral ORIF: merits of nerve decompression through a lateral paratricipital exposure.

Objective: To determine whether the type of posterior surgical approach for distal humeral fracture open reduction and internal fixation influenced radial nerve strain during simulated operative retraction in a cadaveric model.

Methods: Three different posterior surgical exposures: triceps splitting, lateral paratricipital, and paratricipital with release of the lateral intermuscular septum were used. Radial nerve strain was measured using a microDVRT, while traction was applied with a digital force gauge at forces 0.

Dynamic contact mechanics on the tibial plateau of the human knee during activities of daily living.

Despite significant advances in scaffold design, manufacture, and development, it remains unclear what forces these scaffolds must withstand when implanted into the heavily loaded environment of the knee joint. The objective of this study was to fully quantify the dynamic contact mechanics across the tibial plateau of the human knee joint during gait and stair climbing. Our model consisted of a modified Stanmore knee simulator (to apply multi-directional dynamic forces), a two-camera motion capture system (to record joint kinematics), an electronic sensor (to record contact stresses on the tibial plateau), and a suite of post-processing algorithms.

Effect of diet-induced vitamin D deficiency on rotator cuff healing in a rat model.

Background: Few studies have considered hormonal influences, particularly vitamin D, on healing.

Hypothesis: Vitamin D deficiency would have a negative effect on the structure of the healing tendon-bone interface in a rat model and would result in decreased tendon attachment strength.

Study Design: Controlled laboratory study.

A novel device to apply controlled flexion and extension to the rat knee following anterior cruciate ligament reconstruction.

We designed and validated a novel device for applying flexion-extension cycles to a rat knee in an in vivo model of anterior cruciate ligament reconstruction (ACL-R). Our device is intended to simulate rehabilitation motion and exercise post ACL-R to optimize physical rehabilitation treatments for the improved healing of tendon graft ligament reconstructions. The device was validated for repeatability of the knee kinematic motion by measuring the force versus angular rotation response from repeated trials using cadaver rats.

Recombinant human platelet-derived growth factor-BB augmentation of new-bone formation in a rat model of distraction osteogenesis.

Background: Distraction osteogenesis creates a challenging bone-healing environment with protracted demand for cells of the osteoblast lineage. Platelet-derived growth factor-BB (PDGF-BB) is an osteoblast mitogen and chemotaxin that has been shown to accelerate and/or enhance bone-healing in several preclinical studies. The purpose of the present study was to determine whether recombinant human platelet-derived growth factor-BB (rhPDGF-BB) would have a similar effect on regenerate healing after distraction osteogenesis.