Clinical evaluation of micro-fragmented adipose tissue as a treatment option for patients with meniscus tears with osteoarthritis: a prospective pilot study.

PURPOSE: The management of knee pain secondary to meniscal tears with osteoarthritis is limited by the poor inherent healing potential of the meniscus. Previous studies have reported on the benefit of autologous micro-fragmented fat as a therapeutic for various knee pathologies. The goal of this prospective pilot study was to determine the safety and potential treatment effect of micro-fragmented adipose tissue injection for patients with knee pain secondary to osteoarthritis and meniscal tears who have failed conservative management. METHODS: Twenty subjects with knee pain secondary to osteoarthritis with associated meniscal tear after failed conservative management were enrolled in the study. Numeric Pain Scale (NPS) and Knee Injury and Osteoarthritis Outcome Scale (KOOS) following ultrasound-guided intra-meniscal and intra-articular micro-fragmented adipose tissue injections were examined at three, six and 12 months. RESULTS: The mean NPS revealed a significant decrease in patient pain at the 1-year time point compared with baseline (5.45 to 2.21, p < .001). Similarly, overall, mean KOOS symptoms significantly improved from 57.7 to 78.2 (p < .001), with all 4 KOOS subscales demonstrating significant improvement at the final one year follow-up. One subject developed uncomplicated cellulitis at the harvest site which was treated with oral antibiotics. Other complications were minor and mostly limited to adipose harvest. CONCLUSION: This study demonstrated that micro-fragmented adipose tissue injected directly into a torn meniscus and knee joint using ultrasound guidance represents a safe and potentially efficacious treatment option for patients with knee pain suffering from degenerative arthritis and degenerative meniscal tears. A larger, randomized, controlled trial is warranted to determine efficacy. TRIAL REGISTRATION: Clinicaltrials.org Identifier: NCT03714659.

Treatment of Knee Meniscus Pathology: Rehabilitation, Surgery, and Orthobiologics.

The meniscal tear treatment paradigm traditionally begins with conservative measures such as physical therapy and referral for operative management for persistent or mechanical symptoms. As a result, the partial meniscectomy is performed more than any other orthopedic procedure in the United States. This treatment paradigm has shifted because recent literature has supported the attempt to preserve or repair the meniscus whenever possible given its importance for the structural integrity of the knee joint and the risk of early osteoarthritis associated after meniscus excision. Choosing an appropriate management strategy depends on multiple factors such as patient demographics and location of the tear. Physical therapy remains a first-line treatment for knee pain secondary to meniscus tear and should be pursued in the setting of acute and chronic knee pain. Furthermore, there is a growing amount of evidence showing that elderly patients with complex meniscus tears in the setting of degenerative arthritis should not undergo arthroscopic surgery. Direct meniscus repair remains an option in ideal patients who are young, healthy, and have tears near the more vascular periphery of the meniscus but it is not suitable for all patients. Use of orthobiologics such as platelet-rich plasma and mesenchymal stem cells have shown promise in augmenting surgical repairs or as standalone treatments, although research for their use in meniscal tear management is limited.

Zinc has insulin-mimetic properties which enhance spinal fusion in a rat model.

BACKGROUND CONTEXT: Previous studies have found that insulin or insulin-like growth factor treatment can stimulate fracture healing in diabetic and normal animal models, and increase fusion rates in a rat spinal fusion model. Insulin-mimetic agents, such as zinc, have demonstrated antidiabetic effects in animal and human studies, and these agents that mimic the effects of insulin could produce the same beneficial effects on bone regeneration and spinal fusion. PURPOSE: The purpose of this study was to analyze the effects of locally applied zinc on spinal fusion in a rat model. STUDY DESIGN/SETTING: Institutional Animal Care and Use Committee-approved animal study using Sprague-Dawley rats was used as the study design. METHODS: Thirty Sprague-Dawley rats (450-500 g) underwent L4-L5 posterolateral lumbar fusion (PLF). After decortication and application of approximately 0.3 g of autograft per side, one of three pellets were added to each site: high-dose zinc calcium sulfate (ZnCaSO4), low-dose ZnCaSO4 (half of the high dose), or a control palmitic acid pellet (no Zn dose). Systemic blood glucose levels were measured 24 hours postoperatively. Rats were sacrificed after 8weeks and the PLFs analyzed qualitatively by manual palpation and radiograph review, and quantitatively by micro-computed tomography (CT) analysis of bone volume and trabecular thickness. Statistical analyses with p-values set at .05 were accomplished with analysis of variance, followed by posthoc tests for quantitative data, or Mann-Whitney rank tests for qualitative assessments. RESULTS: Compared with controls, the low-dose zinc group demonstrated a significantly higher manual palpation grade (p=.011), radiographic score (p=.045), and bone formation on micro-CT (172.9 mm(3) vs. 126.7 mm(3) for controls) (p<.01). The high-dose zinc also demonstrated a significantly higher radiographic score (p=.017) and bone formation on micro-CT (172.7 mm(3) vs. 126.7 mm(3)) (p<.01) versus controls, and was trending toward higher manual palpation scores (p=.058). CONCLUSIONS: This study demonstrates the potential benefit of a locally applied insulin-mimetic agent, such as zinc, in a rat lumbar fusion model. Previous studies have demonstrated the benefits of local insulin application in the same model, and it appears that zinc has similar effects.