A novel large animal model of posttraumatic osteoarthritis induced by inflammation with mechanical stability.

OBJECTIVES: Animal models are needed to reliably separate the effects of mechanical joint instability and inflammation on posttraumatic osteoarthritis (PTOA) pathogenesis. We hypothesized that our modified intra-articular drilling (mIAD) procedure induces cartilage damage and synovial changes through increased inflammation without causing changes in gait. METHODS: Twenty-four Yucatan minipigs were randomized into the mIAD (n=12) or sham control group (n=12). mIAD animals had two osseous tunnels drilled into each of the tibia and femur adjacent to the anterior cruciate ligament (ACL) attachment sites on the left hind knee. Surgical and contralateral limbs were harvested 15 weeks post-surgery. Cartilage degeneration was evaluated macroscopically and histologically. Synovial changes were evaluated histologically. Interleukin-1 beta (IL-1ß), nuclear factor kappa B (NF-κB), and tumor necrosis factor alpha (TNF-α) mRNA expression levels in the synovial membrane were measured using quantitative real-time polymerase chain reaction. IL-1ß and NF-κB levels in chondrocytes were assessed using immunohistochemistry. Load asymmetry during gait was recorded by a pressure-sensing walkway system before and after surgery. RESULTS: The mIAD surgical knees demonstrated greater gross and histological cartilage damage than contralateral (P<.01) and sham knees (P<.05). Synovitis was present only in the mIAD surgical knee. Synovial inflammatory marker (IL-1ß, NF-κB, and TNF-α) expression was three times higher in the mIAD surgical knee than the contralateral (P<.05). Chondrocyte IL-1ß and NF-κB levels were highest in the mIAD surgical knee. In general, there were no significant changes in gait. CONCLUSIONS: The mIAD model induced PTOA through inflammation without affecting gait mechanics. This large animal model has significant applications for evaluating the role of inflammation in PTOA and for developing therapies aimed at reducing inflammation following joint injury.

Psychological and Social Components of Recovery Following Anterior Cruciate Ligament Reconstruction in Young Athletes: A Narrative Review.

Anterior cruciate ligament (ACL) rupture is a common injury in young athletes. To restore knee stability and function, patients often undergo ACL reconstruction (ACLR). Historically, there has been a focus in this population on the epidemiology of ACL injury, the technical aspects of ACL reconstruction, and post-operative functional outcomes. Although increasingly recognized as an important aspect in recovery, there remains limited literature examining the psychological aspects of post-operative rehabilitation and return to play following youth ACL reconstruction. Despite technical surgical successes and well-designed rehabilitation programs, many athletes never reach their preinjury athletic performance level and some may never return to their primary sport. This suggests that other factors may influence recovery, and indeed this has been documented in the adult literature. In addition to restoration of functional strength and stability, psychological and social factors play an important role in the recovery and overall outcome of ACL injuries in the pediatric population. Factors such as psychological readiness to return-to-play (RTP), motivation, mood disturbance, locus of control, recovery expectations, fear of reinjury, and self-esteem are correlated to the RTP potential of the young athlete. A better understanding of these concepts may help to maximize young patients' outcomes after ACL reconstruction. The purpose of this article is to perform a narrative review of the current literature addressing psychosocial factors associated with recovery after ACL injury and subsequent reconstruction in young athletes. Our goal is to provide a resource for clinicians treating youth ACL injuries to help identify patients with maladaptive psychological responses after injury and encourage a multidisciplinary approach when treating young athletes with an ACL rupture.

COVID-19 and Review of Current Recommendations for Return to Athletic Play.

In December 2019 a respiratory illness known as Coronavirus 2 (SARS-CoV-2, COVID-19) broke out in a region in China and rapidly spread to become a pandemic affecting all sporting events worldwide. The Summer Olympics scheduled to be held in Tokyo were postponed until 2021, and all professional leagues in the United States postponed or canceled events. As the United States has begun to open up, there remains uncertainty of when sporting events can safely be held. Many professional leagues and the National Collegiate Athletic Association have established guidelines and recommendations for their athletes to compete safely. In this article, we review the protocols that have been established to allow athletes to return to play, and we review briefly the effects COVID-19 infection may have on athletes.

Factors Associated With a Delay in Achieving Full Knee Extension Before Anterior Cruciate Ligament Reconstruction.

BACKGROUND: Arthrofibrosis commonly occurs after an acute anterior cruciate ligament (ACL) injury and following ACL reconstruction and can lead to poor outcomes. Preoperative stiffness has been shown to be associated with postoperative stiffness; however, few studies have examined predictors of preoperative delay in obtaining full knee extension. PURPOSE: To examine demographic and injury factors as predictors of time required to achieve full knee extension preoperatively in patients with an acute ACL injury. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: A total of 172 patients with an acute ACL tear at presentation (defined as ≤3 weeks from injury) who underwent magnetic resonance imaging (MRI) within 6 weeks of the injury were included in this analysis. Preoperative data included date of injury, age at injury, sex, body mass index, mechanism of injury (noncontact/contact), time from injury to surgery (days), time to achieve full extension prior to surgery (weeks), and bone bruising on MRI. Time to achieve full extension was categorized as <3 or ≥3 weeks. Unadjusted and adjusted logistic regression was used to examine predictors of delayed time to achieve full extension (≥3 vs <3 weeks). Odds ratios and 95% CIs were reported. RESULTS: Time to achieve full extension was early (<3 weeks) in 98 patients and delayed (≥3 weeks) in 74 patients. The average time to achieve full extension was 7 days in the early group and 32.5 days in the delayed group. Delayed time to achieve full extension was associated with increased lateral femoral condyle (LFC) bruising compared with early time to achieve extension (82.8% vs 66.7%, respectively; P = .03). No other statistically significant predictors were found after adjustment for age, sex, body mass index, and mechanism of injury. CONCLUSION: Acute ACL injuries associated with LFC bone bruising seen on MRI are more likely to result in reduced extension prior to ACL reconstruction. These injuries should be identified and addressed by an appropriate preoperative rehabilitation program, and surgery should be delayed to avoid risking arthrofibrosis postoperatively by reconstructing a knee with less than full extension.

A review of specialist palliative care provision and access across London - mapping the capital.

Palliative care provision varies by diagnosis, geography, and setting. The Minimum Data-set provides high-level data on provision, but comprehensive comparative information about specialist palliative care (SPC) provision is lacking. The London Cancer Alliance - now RM Partners' Accountable Cancer Network - palliative care group (West/South London) and PallE8 (North/East London), with Marie Curie, sought to address this gap. The aim was to provide comparative data on SPC provision across London to support commissioners and providers to assess provision, identify gaps, and reduce inequity. A data-collection template was developed through expert consensus. Demographic, diagnostic, and service data was collected, plus models of care, staffing levels, and use of clinical outcome/experience measures. Results were collated by organisation and CCG. Cleaned data was provided back to each organisation for verification before final analyses. RESULTS: All 50 adult SPC providers in London participated, representing hospitals, hospices and community services. •Patients in all 32 CCGs have access to hospice beds, with 322 beds from 15 providers (4 NHS) for a population of 9,323,570 (with 47,583 deaths annually).•SPC in London sees more non-cancer patients than is reported nationally; 79% of hospital advisory, 74% of community, and 88% of hospice in-patient services have higher proportions of non-cancer patients.•Considerable variation in out-of-hours availability of both hospital SPC and community SPC services across London; only 9 of 30 hospital and 17 of 26 community services provide seven-day visiting.•Wide variation in the models of community-based SPC; proportions of community patients attending day services vary from 1 in 4, to 1 in 17, just 13 CCGs have H@H-type provision, with few Rapid Response or Care Coordination services. CONCLUSIONS: This detailed survey demonstrates important gaps in availability and provision of SPC services. Recommendations are made for commissioners and providers to join together to address these. It also gives a comprehensive view of rapidly changing models of community-based care, to inform innovation and service development.

Vitamin D(3) cryosensitization increases prostate cancer susceptibility to cryoablation via mitochondrial-mediated apoptosis and necrosis.

OBJECTIVES: To investigate the effect and molecular mechanisms of action of Vitamin D(3) (VD(3) ) as a neo-adjunctive agent before cryosurgery in an effort to increase treatment efficacy for prostate cancer (CaP). To eliminate the potential for disease recurrence that exists at the periphery of the freeze lesion, where temperatures may be insufficient to destroy both androgen-sensitive (AS) and androgen-insensitive (AI) CaP. METHODS: Human CaP cells, LNCaP, were each genetically altered to express the AS and AI phenotypes and subjected to VD(3) treatment and freezing in an in vitro and tissue-engineered model. Cell viability, caspase inhibitor and western blot studies were used to determine the basis of the different responses of AI and AS cells to VD(3) cryosensitization. RESULTS: VD(3) was found to be a highly effective cryosensitizer, resulting in a >50% overall increase in cell death after -15 °C freezing. Fluorescence microscopy, western blot analysis and caspase protease assays confirmed that the increased activation of apoptosis was modulated through a mitochondrial-mediated pathway. Caspase inhibition studies showed that apoptosis played an integral role in cell death, with VD(3) cryosensitivation-induced apoptotic events responsible for >30% of the overall cell death after -15 °C freezing. CONCLUSIONS: The present study suggests that the use of VD(3) as a cryosensitizer increases cryoablation efficacy through the increased activity of apoptosis as well as through necrosis. The data show that through VD(3) treatment the overall level of AI CaP cell tolerance to freezing is reduced to a level similar to that of AS CaP. VD(3) pre-treatment in conjunction with cryoablation may increase treatment efficacy and reduce disease recurrence for CaP patients.

The pathophysiology of thermoablation: optimizing cryoablation.

PURPOSE OF REVIEW: To describe the response of prostate cancer to thermal therapies with an emphasis on cryoablative techniques. RECENT FINDINGS: Long-term follow-up studies demonstrate clearly the effectiveness of the use of modern cryoablative techniques in the management of prostate cancer. Recently published American Urology Association Best Practice Guidelines identify prostate cryoablation as both primary and salvage therapies. Recent findings demonstrate the effectiveness of -40 degrees C exposure as lethal to prostate cancer genotypes following a double freeze-thaw encounter. In addition, the use of adjunctive agents to sensitize the cancer to freezing is reported. SUMMARY: Thermal therapeutic options, especially cryoablation, are of growing interest for the treatment of prostatic and renal cancers. The methods of application of cryoablative therapy and the mechanisms of cell death that are attendant to the freezing-thaw encounter are clearly understood. Research focused on the development of freeze sensitizing agents that work adjunctively is of central interest in furthering the efficacy of this therapy.

Cryoablative response of prostate cancer cells is influenced by androgen receptor expression.

OBJECTIVE: To investigate in prostate cancer cells the consequences of androgen-insensitivity (AI) development on the cellular and molecular responses to freezing, as a challenge in prostate cancer treatment occurs when the androgen-sensitive (AS) phenotype switches to an AI phenotype, the latter of which is often refractory to many therapies. MATERIALS AND METHODS: PC-3 (AI) and LNCaP (AS) were each genetically altered to express the opposite phenotype and subjected to an in vitro freezing model. Viability, caspase inhibitor and Western blot studies were used to determine the basis of the differential responses of AI and AS cells. RESULTS: LNCaP high-passage cells, formed by repeated passage of LNCaP (AS) cells, were AI and showed a phenotypic shift to freeze resistance matching the freeze response of PC-3 cells (AI). While stably transfected androgen receptor (AR)-transfected cells (PC-3 AR) had a freezing sensitivity similar to that of the LNCaP (AS) cell line. Importantly, AI cell lines survived and recovered from freezing exposure to temperatures as low as -40 degrees C whereas AS cell lines did not. Caspase inhibition studies and related fluorescent probes showed an elevated level of apoptotic involvement in both AS cell lines after freezing compared with their AI counterparts. Western blot analysis showed that AR expression was modified after exposure to freezing. CONCLUSION: This study suggests that AS cancers may be far more sensitive to a freezing insult and this might be linked to elevated apoptosis and caspase activity. As such, cryoablation may prove most effective in cancer cells that have not yet progressed to a more resistant AI phenotype, but both generic variants can be fully ablated at sufficiently low temperatures.

Cryosurgical technique: assessment of the fundamental variables using human prostate cancer model systems.

Cryosurgery offers a promising therapeutic alternative for the treatment of prostate cancer. While often successful, complete cryoablation of cancerous tissues sometimes fails due to technical challenges. Factors such as the end temperature, cooling rate, duration of the freezing episode, and repetition of the freezing cycle have been reported to influence cryosurgical outcome. Accordingly, we investigated the effects of these variables in an in vitro prostate cancer model. Human prostate cancer PC-3 and LNCaP cultures were exposed to a range of sub-zero temperatures (-5 to -40 degrees C), and cells were thawed followed by return to 37 degrees C. Post-thaw viability was assessed using a variety of fluorescent probes including alamarBlue (metabolic activity), calceinAM (membrane integrity), and propidium iodide (necrosis). Freeze duration following ice nucleation was investigated using single and double freezing cycles (5, 10, and 20 min). The results demonstrated that lower freezing temperatures yielded greater cell death, and that LNCaP cells were more susceptible to freezing than PC-3 cells. At -15 degrees C, PC-3 yielded approximately 55% viability versus approximately 20% viability for LNCaP. Double freezing cycles were found to be more than twice as destructive versus a single freeze-thaw cycle. Both cell types experienced increased cell death when exposed to freezing temperatures for longer durations. When thawing rates were considered, passive (slower) thawing following freezing yielded greater cell death than active (faster) thawing. A 20% difference in viability between passive and active thawing was observed for PC-3 for a 10 min freeze. Finally, the results demonstrate that just reaching -40 degrees C in vitro may not be sufficient to obtain complete cell death. The data support the use of extended freeze times, multiple freeze-thaw cycles, and passive thawing to provide maximum cell destruction.

Time course of esophageal lesions after catheter ablation with cryothermal and radiofrequency ablation: implication for atrio-esophageal fistula formation after catheter ablation for atrial fibrillation.

BACKGROUND: Atrio-esophageal fistulas have been described as a consequence of radiofrequency (RF) ablation for the treatment of atrial fibrillation (AF). However, whether cryoablation can avoid this potential fatal complication remains unclear. METHODS AND RESULTS: We studied the effects of direct application of RF and cryoablation on the cervical esophagus in 16 calves. Cryoablation was performed with a 6.5-mm catheter probe using a single 5-minute freeze at <-80 degrees C, and RF ablation was delivered with an 8-mm catheter electrode at 50 W and 50 degrees C for 45-60 seconds. Histopathologic assessments were performed at 1, 4, 7, and 14 day(s) after completion of the ablation protocol: four animals were examined each day. A total of 85 direct esophageal ablations were performed: 41 with RF and 44 with cryoablation. There were no significant differences in lesion width, depth, or volume between cryoablation and RF ablation at Day 1, 4, and 14 after the procedure (P > 0.05). However, lesion width and volume were significantly larger with RF than with cryoablation at Day 7. Although acute (Day 1) and chronic (Day 14) RF and cryoablation lesions were of comparable size, histologic evidence of partial- to full-wall esophageal lesion ulceration was observed in 0 of 44 (0%) lesions with cryoablation, compared with 9 of 41 (22%) lesions with RF ablation (P = 0.0025). CONCLUSIONS: Direct application of cryoablation and RF ablation created similar acute and chronic lesion dimensions on the esophagus. However, cryoablation was associated with a significantly lower risk of esophageal ulceration, compared with RF ablation.

Cryoablation of renal cancer: variables involved in freezing-induced cell death.

The detection of renal tumors has increased significantly over recent years resulting in a greater demand for novel, minimally invasive techniques. Cryoablation has emerged as a valuable treatment modality for the management of renal cancer. In an effort to detail the effects of freezing in renal cancer, the human renal cancer (RCC) cell line, 786-O, was evaluated in vitro. 786-O cells were exposed to a range of freezing temperatures from -5 to -40 degrees C and compared to non-frozen controls. The data show that freezing to -5 degrees C did not affect 786-O cell viability, while -10 degrees C, -15 degrees C, and -20 degrees C results in a significant loss of viability (23, 70, and 91%, respectively). A complete loss of cell viability was evident at temperatures of -25 degrees C and colder. Following this analysis, variables involved in the success of cryoablation were investigated. For each of the temperatures tested, extended freeze hold times and passive thawing rates resulted in more extensive cell damage. Additionally, a double freeze-thaw cycle significantly increased cell death compared to a single cycle (62% vs. 22% at -10 degrees C; 89% vs. 63% at -15 degrees C, respectively). While these variables play an important part in the effective application of cryoablation, a molecular understanding of the cell death involved is critical to improving efficacy. Apoptotic inhibition afforded 12% (-10 degrees C), 25% (-15 degrees C), and 11% (-20 degrees C) protection following freezing. Using fluorescence microscopy analysis, the results demonstrated that apoptosis peaked at six hours post-thaw. Next, apoptotic initiating agents including 5-FU and resveratrol (RVT) applied prior to freezing exposure resulted in a significant increase in cell death compared to either application alone. Importantly, the combination of RVT and freezing was noticeably less effective when applied to normal renal cells. The results herein demonstrate the efficacy of freezing and describe a novel therapeutic model for the treatment of renal cancer that may distinguish between cancer and normal cells.

Development of a tissue engineered human prostate tumor equivalent for use in the evaluation of cryoablative techniques.

The study of the effectiveness of cryotherapy as a curative treatment for prostate cancer has often relied on the use of either in vitro cell culture monolayers or animal models. While the data gleaned from these studies have been valuable, each model has inherent limitations. In order to bridge the gap between in vitro studies and clinical applications, we developed a 3-dimensional, tissue engineered human prostate cancer model to simulate and assess the effects of cryotherapy and adjunctive treatments on cell viability and activation of cell death pathways throughout the thermally variable freeze zone. Human prostate cancer cells (PC3) were seeded into collagen based matrices and cryolesions were generated using an Oncura SeedNet Gold cryosurgical device with 17-gauge cryoprobes. Analyses revealed widespread necrosis diminishing towards the edge of the freeze zone, and a time-dependent wave of apoptosis starting as early as 1 hr post-thaw at low temperatures (< -40 degrees C) and moving toward the periphery (-20 degrees C) as recovery times reached 12 and 24 hr. Distal to the -10 degrees C isotherm, minimal cell death was apparent (< 20%) over controls. The adjunctive use of chemotherapeutic agents in conjunction with cryosurgery displayed a similar induction of cell death cascades, but with the zone of cryodestruction extending approximately 10 to 15 degrees C further into the freeze zone periphery. By providing an extracellular environment and a matrix to minimize innate variables, the tissue engineered model yielded a more in vivo-like, tumor-like environment supportive of a deeper understanding of the specific biological responses of cancer cells/tumors to cryotherapeutic intervention.

Cryosurgery for tumors - a clinical overview.

Cryosurgery, a method of treating disease by the production of freezing temperatures in the tissue, is a useful technique for the treatment of tumors. When the modern era of cryosurgery began in the mid 1960's, the technique was used only for tumors easily accessible by direct observation or via endoscopy, such as those of the skin, oral cavity, and prostate gland. In general, the technique had limited usefulness in the next two decades. However, with the advent of intraoperative ultrasound as a method of monitoring the process of freezing and with the development of more effective cryosurgical apparatus, the cryosurgical treatment of tumors of the viscera and other deep tissues became practical in the 1990's. This review assesses the present day status of cryosurgery in the management of diverse tumors.

Cryosurgery--a putative approach to molecular-based optimization.

Cryosurgery must be performed in a manner that produces a predictable response in an appropriate volume of tissue. In present-day clinical practice, that goal is not always achieved. Concerns with cryosurgical techniques in cancer therapy focus in part on the incidence of recurrent disease in the treated site, which is commonly approximately 20-40% in metastatic liver tumors, and prostate cancers. Whether the cause of this failure is disease-based or technique related, cryosurgery for cancer commonly needs the support of adjunctive therapy in the form of anti-cancer drugs or radiotherapy to increase the rate of cell death in the peripheral zone of the therapeutic lesion where cell survival is in balance for several days post-treatment. Recent evidence has identified a third mechanism of cell death associated with cryosurgery. This mechanism, apoptosis or gene regulated cell death, is additive with both the direct ice-related cell damage that occurs during the operative freeze-thaw intervals and coagulative necrosis that occurs over days post-treatment. In this manuscript we discuss, through a combination of literature review and new data, the combined roles of these distinct modes of cell death in a prostate and colorectal cancer. Data are presented suggesting that sub-freezing temperatures, when sequentially applied with low dose chemotherapy, may provide improved cancer cell death in the freeze zone periphery. Since the mechanism of action of most common chemotherapeutic agents is to initiate apoptosis in cancer cells, the observation that sub-freezing exposures yields a similar effect provides a possible route toward molecular-based procedural optimization to improve therapeutic outcome.

Cryosurgery - a review of recent advances and current issues.

Advances in cryosurgery since 1990 were initiated by the development of improved cryosurgical equipment and by the availability of intraoperative ultrasound to monitor the tissue-freezing process. Interest in research on the effects of freezing on tissue and on new clinical applications was then stimulated. The research led to a better understanding of the mechanisms of cryogenic injury, including cell death by apoptosis, which has emerged as a potential key to the use of adjunctive chemotherapy in the treatment of cancer. Optimization of cryosurgical technique will also improve clinical results.