Complications in endoscopic spine surgery: a systematic review.

PURPOSE: This systematic review aims to investigate the complication rate of endoscopic spine surgeries, stratifying them by technique, district and kind of procedure performed. METHODS: This study was conducted according to the PRISMA statement. The literature search was conducted in MEDLINE, CINAHL, EMBASE, Cochrane Register, OTseeker and ScienceDirect database. Types of studies included were observational studies (cohort studies, case-control studies and case series) and randomised or quasi-randomised clinical with human subjects. No restrictions on publication year were applied. Repeated articles, reviews, expert's comments, congress abstracts, technical notes and articles not in English were excluded. Several data were extracted from the articles. In particular, data of perioperative (≤ 3 months) and late (> 3 months) complications were collected and grouped according to: (1) surgical technique [uniportal full-endoscopic spine surgery (UESS) or unilateral biportal endoscopic spine surgery (UBESS)]; (2) spinal district treated [cervical, thoracic or lumbar] and (3) type of procedure [discectomy/decompression or fusion]. Complication analysis was performed in subgroups with at least 100 patients to have clinically meaningful statistical validity. RESULTS: A total of 117 full-text articles were assessed for eligibility. Of the 117 records included, 95 focused their research on UESS (14 LOE V, 33 LOE IV, 43 LOE III and five LOE II) and 23 on UBESS (three LOE V, eight LOE IV, 10 LOE III and two LOE II). A total of 20,020 patients were extracted to investigate the incidence of different perioperative and late complications, 10,405 for UESS and 9615 for UBESS. CONCLUSION: The present study summarises the complications reported in the literature for spinal endoscopic procedures. On the one hand, the most relevant described were perioperative complications (transient neurological deficit, dural tear and dysesthesia) that are especially meaningful for endoscopic discectomy and decompression. On the other hand, late complications, such as mechanical implant failure, are more common in endoscopic interbody fusion. LEVEL OF EVIDENCE: I.

Men and women undergoing total hip arthroplasty have different clinical presentations before surgery and different outcomes at 1-year follow-up.

PURPOSE: The purpose of this study was to investigate the influence of sex on patients undergoing total hip arthroplasty (THA) for hip osteoarthritis (HOA), aiming to assess the clinical and functional outcomes using patient-reported outcome measures (PROMs). METHODS: A retrospective analysis of patients undergoing THA at Ospedale Galeazzi-Sant'Ambrogio between 2016 and 2022 was conducted. Inclusion criteria encompassed Kellgren-Lawrence grade III or IV HOA, with preoperative and 12-month postoperative PROMs. Enroled patients have been selected from a larger cohort without matching design for confounders. The analyses were performed using R software v4.0.3 (R Core Team) and data distributions were assessed using the Shapiro-Wilk normality test. RESULTS: One hundred ninety patients (72 male and 118 female) who had both preoperative and postoperative PROMs have been analysed from our institutional prosthesis registry (Datareg). Baseline and 12-month post-THA PROMs showed significant improvements overall. VAS score dropped notably from baseline to 3 months postsurgery (7.1 ± 2.1 vs. 0.9 ± 1.7). Functional and mental PROMs, including Harris Hip Score-functional (HHS-F), Harris Hip Score-total (HHS-t), SF-12PS and SF-12MS, exhibited substantial improvements post-THA. Stratifying by sex, males had lower baseline VAS, higher HHS-F, SF-12MS and hip disability and osteoarthritis outcome score-physical function short form (HOOS-PS). At 12 months, males displayed significantly better VAS, HHS-F, SF-12PS and HOOS-PS scores. Complication rates were minimal (1.5%), with stable rates across genders, mostly involving dislocation and periprosthetic fractures. Implant survival at 12 months reached an impressive 99%. CONCLUSION: THA remains an effective treatment for severe HOA. However, females presented with worse baseline conditions and showed relatively less improvement at 1-year postsurgery compared to males. This difference could be attributed to physiological and psychosocial factors associated with sex, including hormonal changes, muscle mass decline and perception of pain. Longer follow-ups and prospective studies are necessary to validate these findings and facilitate personalised approaches in HOA treatment, emphasising the need for careful consideration of sex-related variables in clinical decision-making for THA patients. LEVEL OF EVIDENCE: Level III.

A high level of scientific evidence is available to guide treatment of primary shoulder stiffness: The SIAGASCOT consensus.

PURPOSE: Shoulder stiffness (SS) is a condition characterised by active and passive restricted glenohumeral range of motion, which can occur spontaneously in an idiopathic manner or be associated with a known underlying aetiology. Several treatment options are available and currently no consensus has been obtained on which treatment algorithm represents the best choice for the patient. Herein we present the results of a national consensus on the treatment of primary SS. METHODS: The project followed the modified Delphi consensus process, involving a steering, a rating and a peer-review group. Sixteen questions were generated and subsequently answered by the steering group after a thorough literature search. A rating group composed by professionals specialised in the diagnosis and treatment of shoulder pathologies rated the question-answer sets according to the scientific evidence and their clinical experience. RESULTS: Recommendations were rated with an average of 8.4 points out of maximum 9 points. None of the 16 answers received a rating of less than 8 and all the answers were considered as appropriate. The majority of responses were assessed as Grade A, signifying a substantial availability of scientific evidence to guide treatment and support recommendations encompassing diagnostics, physiotherapy, electrophysical agents, oral and injective medical therapies, as well as surgical interventions for primary SS. CONCLUSIONS: A consensus regarding the conservative and surgical treatment of primary SS could be achieved at a national level. This consensus sets basis for evidence-based clinical practice in the management of primary SS and can serve as a model for similar initiatives and adaptable guidelines in other European countries and potentially on a global scale. LEVEL OF EVIDENCE: Level I.

One-stage vs two-stage bilateral THA in Lombardy: a cost-effectiveness analysis.

BACKGROUND: Total hip arthroplasty (THA) is the most common treatment for primary and secondary end-stage hip osteoarthritis (OA). Almost 20% of all patients undergoing primary THA suffer from bilateral hip OA and, consequently, will need a contralateral procedure to be performed in the following years. The aim of this study is to evaluate the cost-effectiveness and the reliability of one-stage bilateral THA (1-BTHA) compared to two-stage bilateral THA (2-BTHA), in low-risk patients, performed with anterior minimally invasive surgery (AMIS). METHODS: Single patient's costs were obtained by dividing the annual costs report by the number of hospitalizations, considering the diagnosis related group (DRG) of the two procedures. Then, 16 patients undergoing 1-BTHA and 8 undergoing 2-BTHA were examined. Hemoglobin (Hb) values before surgery and before discharge, transfusion rate and the occurrence of post-operative complications were observed. RESULTS: Procedural costs were divided in different subgroups: pre-hospitalization, operating room, hospital stay, post-operative follow-up and other costs. 1-BTHA total costs amount to 5.754,82€, while performing 2-BTHA costs 7.624,32€. However, considering DRG reimbursement, the hospital's profit margin following 1-BTHA is lower than that following 2-BTHA (6.346,18€ versus 9.261,68€). Surgical time was found not to be significantly different between 1-BTHA and 2-BTHA (141,13 ± 26,1 min vs 164,8 ± 44,3 min; p = 0,111). The two groups showed a statistically significant difference in Hb decrease (4,8 ± 1,3 g/dl vs 3,3 ± 0,9; p = 0,001), despite no variances in transfusion rate. No further complications were observed in either group. CONCLUSIONS: This study demonstrates how, in carefully selected patients, 1-BTHA performed with AMIS is a cost-effective and safe technique compared to 2-BTHA, resulting in a shorter OR time, LOS and lower overall costs. LEVEL OF EVIDENCE: III.

A novel less invasive endoscopic-assisted procedure for complete reduction of low-and high-grade isthmic spondylolisthesis performed by anterior and posterior combined approach.

PURPOSE: The optimal surgical management of low- and high-grade isthmic spondylolisthesis (LGS and HGS -IS) is debated as well as whether reduction is needed especially for high-grade spondylolisthesis. Both anterior and posterior techniques can be associated with mechanical disadvantages as hardware failure with loss of reduction and L5 injury. We purpose a novel endoscopic-assisted technique (Sled technique, ST) to achieve a complete reduction in two surgical steps: first anteriorly through a retroperitoneal approach to obtain the greatest part of correction and then posteriorly to complete reduction in the same operation. METHODS: ST efficacy and complications rate were evaluated through a retrospective functional and radiological analysis. RESULTS: Thirty-one patients, 12 male (38.7%) and 19 female (61.3%), average age: 45.4 years with single level IS underwent olisthesis reduction by ST. Twenty-three IS involved L5 (74.2%), 7 L4 (22.5%) and 1 L3 (3.3%). No intraoperative complications were recorded. One patient required repositioning of a pedicle screw. A significant improvement of functional and radiological parameters (L4-S1 and L5-S1 lordosis) outcomes was recorded (p < 0.001). CONCLUSION: ST provides a complete reduction in the slippage in LGS and HGS. The huge anterior release as well as the partial reduction in the slippage by the endoscopic-assisted anterior procedure, because of the cage is acting as a "guide rail", facilitate the final posterior reduction, always complete in our series, minimizing mechanical stresses and neurological risks. CLINICALTRIALS: gov Identifier: NCT03644407.

Micro-fragmented adipose tissue (mFAT) associated with arthroscopic debridement provides functional improvement in knee osteoarthritis: a randomized controlled trial.

PURPOSE: Current conservative treatments for knee OA provide limited benefits, with symptoms relief for a short amount of time. Regenerative medicine approaches such as the use of microfragmented adipose tissue (mFAT) showed promising results in terms of durable effects and the possibility to enhance tissue healing and counteract the progression of the pathology. Nevertheless, up to today, the large part of clinical data about mFAT use refers to uncontrolled studies, especially in the surgical setting. The purpose of this study was to evaluate the effectiveness of mFAT applied in association with arthroscopic debridement (AD) for the treatment of knee OA, in terms of symptoms relief and tissue healing. METHODS: This study is a prospective, randomized controlled clinical trial. 78 patients affected by knee OA grade 3-4 according to KL classification were randomly assigned to AD or AD + mFAT treatment groups. Clinical, radiological and serological assessments were performed at 6 months after treatment. Additional clinical evaluation was performed at the end of the study with an average follow-up of 26.1 ± 9.5 months. VAS, KOOS, WOMAC and SF-12 were also collected at both timepoints, KSS only at 6 months. RESULTS: Treatment with AD + mFAT improved functional scores at both 6 months (KOOS-PS: + 11.7 ± 20.2 vs + 24.4 ± 22.5, in AD and AD + mFAT, respectively, p = 0.024; KSS: + 14.9 ± 15.9 vs + 24.8 ± 23.5, in AD and AD + mFAT, respectively, p = 0.046) and 24-month follow-ups (KOOS-PS Functional subscale: - 2.0 ± 3.5 vs - 4.7 ± 4.2, in AD and AD + mFAT, respectively, p = 0.012). Lower T2-mapping scores were obtained in AD + mFAT-treated group in medial and lateral condyle compartments (p < 0.001). Slight increase was observed in the levels of a serum biomarker of cartilage deposition (PIIINP) in both groups at 6-month follow-up (p = 0.037). CONCLUSION: mFAT improves functional outcome and MRI appearance when used in association with AD, therefore supporting its use in the treatment of knee OA in an arthroscopic setting.

Knee Osteoarthritis: Epidemiology, Pathogenesis, and Mesenchymal Stem Cells: What Else Is New? An Update.

Osteoarthritis (OA) is a chronic disease and the most common orthopedic disorder. A vast majority of the social OA burden is related to hips and knees. The prevalence of knee OA varied across studies and such differences are reflected by the heterogeneity of data reported by studies conducted worldwide. A complete understanding of the pathogenetic mechanisms underlying this pathology is essential. The OA inflammatory process starts in the synovial membrane with the activation of the immune system, involving both humoral and cellular mediators. A crucial role in this process is played by the so-called "damage-associated molecular patterns" (DAMPs). Mesenchymal stem cells (MSCs) may be a promising option among all possible therapeutic options. However, many issues are still debated, such as the best cell source, their nature, and the right amount. Further studies are needed to clarify the remaining doubts. This review provides an overview of the most recent and relevant data on the molecular mechanism of cartilage damage in knee OA, including current therapeutic approaches in regenerative medicine.

In Vitro and In Vivo Biocompatibility Assessment of a Thermosensitive Injectable Chitosan-Based Hydrogel for Musculoskeletal Tissue Engineering.

Musculoskeletal impairments, especially cartilage and meniscus lesions, are some of the major contributors to disabilities. Thus, novel tissue engineering strategies are being developed to overcome these issues. In this study, the aim was to investigate the biocompatibility, in vitro and in vivo, of a thermosensitive, injectable chitosan-based hydrogel loaded with three different primary mesenchymal stromal cells. The cell types were human adipose-derived mesenchymal stromal cells (hASCs), human bone marrow stem cells (hBMSCs), and neonatal porcine infrapatellar fat-derived cells (IFPCs). For the in vitro study, the cells were encapsulated in sol-phase hydrogel, and then, analyzed via live/dead assay at 1, 4, 7, and 14 days to compare their capacity to survive in the hydrogel. To assess biocompatibility in vivo, cellularized scaffolds were subcutaneously implanted in the dorsal pouches of nude mice and analyzed at 4 and 12 weeks. Our data showed that all the different cell types survived (the live cell percentages were between 60 and 80 at all time points in vitro) and proliferated in the hydrogel (from very few at 4 weeks to up to 30% at 12 weeks in vivo); moreover, the cell-laden hydrogels did not trigger an immune response in vivo. Hence, our hydrogel formulation showed a favorable profile in terms of safety and biocompatibility, and it may be applied in tissue engineering strategies for cartilage and meniscus repair.

Human Sarcopenic Myoblasts Can Be Rescued by Pharmacological Reactivation of HIF-1α.

Sarcopenia, an age-related decline in muscle mass and strength, is associated with metabolic disease and increased risk of cardiovascular morbidity and mortality. It is associated with decreased tissue vascularization and muscle atrophy. In this work, we investigated the role of the hypoxia inducible factor HIF-1α in sarcopenia. To this end, we obtained skeletal muscle biopsies from elderly sarcopenic patients and compared them with those from young individuals. We found a decrease in the expression of HIF-1α and its target genes in sarcopenia, as well as of PAX7, the major stem cell marker of satellite cells, whereas the atrophy marker MURF1 was increased. We also isolated satellite cells from muscle biopsies and cultured them in vitro. We found that a pharmacological activation of HIF-1α and its target genes caused a reduction in skeletal muscle atrophy and activation of PAX7 gene expression. In conclusion, in this work we found that HIF-1α plays a role in sarcopenia and is involved in satellite cell homeostasis. These results support further studies to test whether pharmacological reactivation of HIF-1α could prevent and counteract sarcopenia.

Quadriceps muscle group function and after total knee arthroplasty-asystematic narrative update.

BACKGROUND: This article systematically summarizes the present evidences, published in the last 20 years, regarding the pre- and post-operative factors, which may influence recovery of the function of the quadriceps muscle group following total knee arthroplasty (TKA). We following the PRISMA methodology, including meta-analyses and high-level evidence studies (prospective trials, and, when unavailable, retrospective studies). SOURCES OF DATA: Pubmed and Cochrane databases: 582 articles were identified and 54 of them were selected. AREAS OF AGREEMENT: Tourniquets inflated at high pressure exert a detrimental effect on the quadriceps muscle group. Faster quadriceps recovery takes place using mini-invasive approaches, an eight-week rehabilitation period including balance training and the use of nutraceuticals. AREAS OF DISAGREEMENT: Pre-habilitation and pre-operative factors, analgesic methods and different TKA implants. GROWING POINTS AND AREAS TIMELY FOR DEVELOPING RESEARCH: Telerehabilitation seems a cost-effective tool for rehabilitation after TKA. Patients' optimization protocols before TKA should include standardized nutraceuticals intake.

The use of electronic PROMs provides same outcomes as paper version in a spine surgery registry. Results from a prospective cohort study.

BACKGROUND AND PURPOSE: Patient-Reported Measured Outcomes (PROMs) are essential to gain a full understanding of a patient's condition, and in spine surgery, these questionnaires are of help when tailoring a surgical strategy. Electronic registries allow for a systematic collection and storage of PROMs, making them readily available for clinical and research purposes. This study aimed to investigate the reliability between the electronic and paper form of ODI (Oswestry Disability Index), SF-36 (Short Form Health Survey 36) and COMI-back (Core Outcome Measures Index for the back) questionnaires. METHODS: A prospective analysis was performed of ODI, SF-36 and COMI-back questionnaires collected in paper and electronic format in two patients' groups: Pre-Operatively (PO) or at follow-up (FU). All patients, in both groups, completed the three questionnaires in paper and electronic form. The correlation between both methods was assessed with the Intraclass Correlation Coefficients (ICC). RESULTS: The data from 100 non-consecutive, volunteer patients with a mean age of 55.6 ± 15.0 years were analysed. For all of the three PROMs, the reliability between paper and electronic questionnaires results was excellent (ICC: ODI = 0.96; COMI = 0.98; SF36-MCS = 0.98; SF36-PCS = 0.98. For all p < 0.001). CONCLUSIONS: This study proved an excellent reliability between the electronic and paper versions of ODI, SF-36 and COMI-back questionnaires collected using a spine registry. This validation paves the way for stronger widespread use of electronic PROMs. They offer numerous advantages in terms of accessibility, storage, and data analysis compared to paper questionnaires.

Hypoxia as a Stimulus for the Maturation of Meniscal Cells: Highway to Novel Tissue Engineering Strategies?

The meniscus possesses low self-healing properties. A perfect regenerative technique for this tissue has not yet been developed. This work aims to evaluate the role of hypoxia in meniscal development in vitro. Menisci from neonatal pigs (day 0) were harvested and cultured under two different atmospheric conditions: hypoxia (1% O2) and normoxia (21% O2) for up to 14 days. Samples were analysed at 0, 7 and 14 days by histochemical (Safranin-O staining), immunofluorescence and RT-PCR (in both methods for SOX-9, HIF-1α, collagen I and II), and biochemical (DNA, GAGs, DNA/GAGs ratio) techniques to record any possible differences in the maturation of meniscal cells. Safranin-O staining showed increments in matrix deposition and round-shape "fibro-chondrocytic" cells in hypoxia-cultured menisci compared with controls under normal atmospheric conditions. The same maturation shifting was observed by immunofluorescence and RT-PCR analysis: SOX-9 and collagen II increased from day zero up to 14 days under a hypoxic environment. An increment of DNA/GAGs ratio typical of mature meniscal tissue (characterized by fewer cells and more GAGs) was observed by biochemical analysis. This study shows that hypoxia can be considered as a booster to achieve meniscal cell maturation, and opens new opportunities in the field of meniscus tissue engineering.

Testing Hypoxia in Pig Meniscal Culture: Biological Role of the Vascular-Related Factors in the Differentiation and Viability of Neonatal Meniscus.

Menisci play an essential role in shock absorption, joint stability, load resistance and its transmission thanks to their conformation. Adult menisci can be divided in three zones based on the vascularization: an avascular inner zone with no blood supply, a fully vascularized outer zone, and an intermediate zone. This organization, in addition to the incomplete knowledge about meniscal biology, composition, and gene expression, makes meniscal regeneration still one of the major challenges both in orthopedics and in tissue engineering. To overcome this issue, we aimed to investigate the role of hypoxia in the differentiation of the three anatomical areas of newborn piglet menisci (anterior horn (A), central body (C), and posterior horn (P)) and its effects on vascular factors. After sample collection, menisci were divided in A, C, P, and they were cultured in vitro under hypoxic (1% O2) and normoxic (21% O2) conditions at four different experimental time points (T0 = day of explant; T7 = day 7; T10 = day 10; T14 = day 14); samples were then evaluated through immune, histological, and molecular analyses, cell morpho-functional characteristics; with particular focus on matrix composition and expression of vascular factors. It was observed that hypoxia retained the initial phenotype of cells and induced extracellular matrix production resembling a mature tissue. Hypoxia also modulated the expression of angiogenic factors, especially in the early phase of the study. Thus, we observed that hypoxia contributes to the fibro-chondrogenic differentiation with the involvement of angiogenic factors, especially in the posterior horn, which corresponds to the predominant weight-bearing portion.

Direct superior approach versus posterolateral approach in total hip arthroplasty: a randomized controlled trial on early outcomes on gait, risk of fall, clinical and self-reported measurements.

Background and purpose - Several surgical approaches are used in primary total hip arthroplasty (THA). In this randomized controlled trial we compared gait, risk of fall, self-reported and clinical measurements between subjects after direct superior approach (DSA) versus posterolateral approach (PL) for THA.Patients and methods - Participants with DSA (n = 22; age 74 [SD 8.9]) and PL (n = 23; age 72 [7.7]) underwent gait analysis, risk of fall assessment and Timed Up and Go Test (TUG) before (PRE), 1 month (T1) and 3 months after (T3) surgery. Data on bleeding and surgical time was collected.Results - DSA resulted in longer surgical times (90 [14] vs. 77 [20] min) but lower blood loss (149 [66] vs. 225 [125] mL) than PL. DSA had lower risk of fall at T3 compared with T1 and higher TUG scores at T3 compared with T1 and PRE. PL improved balance at T3 compared with T1 and PRE. Spatiotemporal gait parameters improved over time for both DSA and PL with no inter-group differences, whereas DSA, regarding hip rotation range of motion, showed lower values at T3 and T1 compared with PRE and, furthermore, this group had lower values at T1 and T3 compared with PL. All foregoing comparisons are statistically signficant (p < 0.05)Interpretation - DSA showed longer surgical time and lower blood loss compared with PL and early improvements in TUG, spatiotemporal, and kinematic gait parameters, highlighting rapid muscle strength recovery.

Fragility Fractures: Risk Factors and Management in the Elderly.

Given the progressive ageing of Western populations, the fragility fractures market has a growing socioeconomic impact. Fragility fractures are common in the elderly, negatively impacting their quality of life, limiting autonomy, increasing disability, and decreasing life expectancy. Different causes contribute to the development of a fractures in frail individuals. Among all, targeting fragile patients before the development of a fracture may represent the greatest challenge, and current diagnostic tools suffer from limitations. This study summarizes the current evidence on the management of fragility fractures, discussing risk factors, prevention, diagnosis, and actual limitations of the clinical therapeutic options, putting forward new ideas for further scientific investigation.

Outcome of total hip and total knee arthroplasty and vitamin D homeostasis.

BACKGROUND: Low levels of vitamin D are common in patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA), but it is still unclear whether the outcome of such surgery is related to vitamin D levels. SOURCES OF DATA: Publicly available electronic databases were systematically reviewed to update knowledge about the role of vitamin D in THA and TKA patients, and to appraise the correlation between vitamin D levels before surgery and post-surgical outcomes. Eight studies were included in our review: six employed prospective observational designs, two reported retrospective database interrogations. Six prospective observational studies and two retrospective database interrogations matched inclusion and exclusion criteria. AREAS OF AGREEMENT: Patients undergoing THA and TKA have a high prevalence of hypovitaminosis D. Five of eight studies (62.5%) report a statistically significant association between low vitamin D status and worse outcomes after THA and TKA. AREAS OF CONTROVERSY: Different explanations have been proposed for vitamin D insufficiency, but some authors have questioned the correctness of the methods used to measure the vitamin D levels. GROWING POINTS: A trial focusing on the role of vitamin D supplementation on safety and outcomes of patients undergoing THA and TKA with low vitamin D status is ongoing. AREAS TIMELY FOR DEVELOPING RESEARCH: Further studies should explore the possible causal relationship between vitamin D status and outcomes of THA and TKA and verify the laboratory methods to analyse it.

Therapeutic potential of microRNA in tendon injuries.

INTRODUCTION: The regulatory role of microRNA (miRNA) in several conditions has been studied, but their function in tendon healing remains elusive. This review summarizes how miRNAs are related to the pathogenesis of tendon injuries and highlights their clinical potential, focusing on the issues related to their delivery for clinical purposes. SOURCES OF DATA: We searched multiple databases to perform a systematic review on miRNA in relation to tendon injuries. We included in the present work a total of 15 articles. AREAS OF AGREEMENT: The mechanism of repair of tendon injuries is probably mediated by resident tenocytes. These maintain a fine equilibrium between anabolic and catabolic events of the extracellular matrix. Specific miRNAs regulate cytokine expression and orchestrate proliferation and differentiation of stromal cell lines involved in the composition of the extracellular matrix. AREAS OF CONTROVERSY: The lack of effective delivery systems poses serious obstacles to the clinical translation of these basic science findings. GROWING POINT: In vivo studies should be planned to better explore the relationship between miRNA and tendon injuries and evaluate the most suitable delivery system for these molecules. AREAS TIMELY FOR DEVELOPING RESEARCH: Investigations ex vivo suggest therapeutic opportunities of miRNA for the management of tendon injuries. Given the poor pharmacokinetic properties of miRNAs, these must be delivered by an adequate adjuvant transport system.

Useful and innovative methods for the treatment of postoperative coronal malalignment in adult scoliosis: the "kickstand rod" and "tie rod" procedures.

STUDY DESIGN: Surgical technique description and case series. OBJECTIVE: To describe the use of two techniques for the correction of postoperative coronal imbalance after surgical treatment for adult spine deformity (ASD). Sagittal and coronal spinal malalignments are often present in patients with ASD or in patients who have undergone spine surgery. Surgical correction of coronal imbalance is insufficiently investigated, and the literature provides a limited spectrum of surgical options when compared to sagittal imbalance. Nevertheless, this deformity can compromise the surgical outcome and can increase the risk of hardware failure. METHODS: The kickstand (KR) and tie rod (TR) techniques utilize an accessory rod, linking the previous instrumentation to an independent iliac screw. After a proper release of the lumbar spine with anterior release or posterior osteotomies, the KR technique pushes with distraction on the concave side, whereas the TR technique pulls with compression on the convex side. Four patients (mean age, 64 years; SD 5.7) affected by severe postoperative coronal imbalance were treated. C7-PL ranges from 39 to 76 mm. The mean preoperative ODI was 70/100 (range from 55 to 82). All patients had previous spinopelvic fixation as a consequence of corrective surgery for adult spine deformity. The patients were surgically treated with the addition of supplementary rods connected to the ilium. The rods were used in the concavity or convexity of the deformity functioning as "kickstand" or "tie" or a combination of both. RESULTS: The mean surgical correction of C7-PL was 35 mm (range from 20 to 52 mm). In particular, the mean correction for kickstand rod technique was 26 mm and for tie rod technique was 43 mm. All of the patients improved their preoperative disability, and mean ODI was 30/100 (range from 10 to 60) at median 19-month follow-up. All postoperative imaging showed implants were in proper position without hardware failure. All of the patients treated demonstrated an immediate postoperative improvement in terms of coronal displacement of the spine. No complications were observed. At 1-year follow-up, all of the patients remained satisfactory in terms of clinical outcomes. CONCLUSION: The kickstand and tie rod techniques are effective in the treatment of postoperative coronal malalignment. Further studies are needed to confirm these findings. LEVEL OF EVIDENCE: V: Case report. These slides can be retrieved under Electronic Supplementary Material.

Functional and radiological outcome of anterior retroperitoneal versus posterior transforaminal interbody fusion in the management of single-level lumbar degenerative disease.

OBJECTIVE: In this study the authors compared the anterior lumbar interbody fusion (ALIF) and posterior transforaminal lumbar interbody fusion (TLIF) techniques in a homogeneous group of patients affected by single-level L5-S1 degenerative disc disease (DDD) and postdiscectomy syndrome (PDS). The purpose of the study was to analyze perioperative, functional, and radiological data between the two techniques. METHODS: A retrospective analysis of patient data was performed between 2015 and 2018. Patients were clustered into two homogeneous groups (group 1 = ALIF, group 2 = TLIF) according to surgical procedure. A statistical analysis of clinical perioperative and radiological findings was performed to compare the two groups. A senior musculoskeletal radiologist retrospectively revised all radiological images. RESULTS: Seventy-two patients were comparable in terms of demographic features and surgical diagnosis and included in the study, involving 32 (44.4%) male and 40 (55.6%) female patients with an average age of 47.7 years. The mean follow-up duration was 49.7 months. Thirty-six patients (50%) were clustered in group 1, including 31 (86%) with DDD and 5 (14%) with PDS. Thirty-six patients (50%) were clustered in group 2, including 28 (78%) with DDD and 8 (22%) with PDS. A significant reduction in surgical time (107.4 vs 181.1 minutes) and blood loss (188.9 vs 387.1 ml) in group 1 (p < 0.0001) was observed. No significant differences in complications and reoperation rates between the two groups (p = 0.561) was observed. A significant improvement in functional outcome was observed in both groups (p < 0.001), but no significant difference between the two groups was found at the last follow-up. In group 1, a faster median time of return to work (2.4 vs 3.2 months) was recorded. A significant improvement in L5-S1 postoperative lordosis restoration was registered in the ALIF group (9.0 vs 5.0, p = 0.023). CONCLUSIONS: According to these results, interbody fusion is effective in the surgical management of discogenic pain. Even if clinical benefits were achieved earlier in the ALIF group (better scores and faster return to work), both procedures improved functional outcomes at last follow-up. The ALIF group showed significant reduction of blood loss, shorter surgical time, and better segmental lordosis restoration when compared to the TLIF group. No significant differences in postoperative complications were observed between the groups. Based on these results, the ALIF technique enhances radiological outcome improvement in spinopelvic parameters when compared to TLIF in the management of adult patients with L5-S1 DDD.

Effects of sagittal tibial osteotomy on frontal alignment of the knee and patellar height.

AIM OF THE STUDY: The aim of this study was to evaluate the radiographic effect of sagittal tibial osteotomy (STO), flexion tibial osteotomy (FTO) and deflexion tibial osteotomy (DTO) around the knee. It has been hypothesized that proximal STO modifies patellar height and could cause varus/valgus changes of the anatomical tibial axis: The purpose of the study was to verify this and to analyse these modifications. METHOD: Patients underwent proximal STO in our department between 2007 and 2018: overall 28 consecutive patients (19 males, 9 females; 28 knees). Twelve patients underwent DTO, and 16 patients underwent FTO. Two independent observers measured the pre-operative and post-operative radiological indexes: posterior tibial slope, Caton-Deschamps Index (CDI) and Modified Insall-Salvati Index (MISI) in the lateral views; medial Tibial Plateau-Tibial Shaft (mTPTS) and medial Femoral Shaft-Tibial Shaft (mFTA) anatomical angles were measured in the frontal plane. RESULTS: No complications were reported at the average follow-up of 1.6 ± 1.1 years. The mean mTPTS significantly increased from 0.6° ± 2.4° pre-operatively to 2.9° ± 2.6° of varus post-operatively (DTO (pre-operative 0.3 ± 3.1°, post-operative 2.4 ± 2.1°, ns); FTO (pre-operative 0.9 ± 1.9°, post-operative 3.2 ± 3.0°, P < 0.05)). The mean mFTA significantly reduced from 186.2° ± 4.9° pre-operatively to 182.7° ± 3.9° post-operatively (DTO (pre-operative 183.4 ± 3.3°, post-operative 180.6 ± 3.5°, ns); FTO (pre-operative 188.5 ± 4.9°, post-operative 184.4 ± 3.4°, P < 0.05)). The overall analysis reported no differences statistically significant in patellar height indexes. DISCUSSION: The main finding of this study is that STO slightly modifies tibial anatomical axes. This finding is more evident in FTOs. This surgical technique, due to its design, does not influence the patellar height. The tibial tuberosity osteotomy, performed in most of the cases to better expose tibial metaphysis and to avoid patellar tendon damages, provides another benefit that is the possibility to easily preserve the native patellar height. CONCLUSION: Sagittal tibial osteotomies slightly modify tibial anatomical axes in frontal plan without influencing the patellar height. This surgical procedure resulted to be effective and reliable in correcting the sagittal knee alignment but reporting, particularly of FTO, varus changes of anatomical tibial axis.