Influence of different position modal parameters on milling chatter stability of orthopedic surgery robots.

This research is dedicated to exploring the dynamics of milling chatter stability in orthopedic surgery robots, focusing on the impact of position modal parameters on chatter stability. Initially, we develop a dynamic milling force model for the robotic milling process that integrates both modal coupling and regenerative effects. We then employ the zero-order frequency domain method to derive a chatter stability domain model, visually represented through stability lobe diagrams (SLDs). Through conducting hammer test experiments, we ascertain the robot's modal parameters at varying positions, enabling the precise generation of SLDs. This study also includes experimental validation of the chatter SLD analysis method, laying the groundwork for further examination of chatter stability across different positional modal parameters. Finally, our analysis of the variations in modal parameters on the stability of robot milling chatter yields a theoretical framework for optimizing cutting parameters and developing control strategies within the context of orthopedic surgery robots.

Development and validation of a new drug-focused predictive risk score for postoperative delirium in orthopaedic and trauma surgery patients.

BACKGROUND: Postoperative delirium (POD) is the most common complication following surgery in elderly patients. During pharmacist-led medication reconciliation (PhMR), a predictive risk score considering delirium risk-increasing drugs and other available risk factors could help to identify risk patients. METHODS: Orthopaedic and trauma surgery patients aged ≥ 18 years with PhMR were included in a retrospective observational single-centre study 03/2022-10/2022. The study cohort was randomly split into a development and a validation cohort (6:4 ratio). POD was assessed through the 4 A's test (4AT), delirium diagnosis, and chart review. Potential risk factors available at PhMR were tested via univariable analysis. Significant variables were added to a multivariable logistic regression model. Based on the regression coefficients, a risk score for POD including delirium risk-increasing drugs (DRD score) was established. RESULTS: POD occurred in 42/328 (12.8%) and 30/218 (13.8%) patients in the development and validation cohorts, respectively. Of the seven evaluated risk factors, four were ultimately tested in a multivariable logistic regression model. The final DRD score included age (66-75 years, 2 points; > 75 years, 3 points), renal impairment (eGFR < 60 ml/min/1.73m2, 1 point), anticholinergic burden (ACB-score ≥ 3, 1 point), and delirium risk-increasing drugs (n ≥ 2; 2 points). Patients with ≥ 4 points were classified as having a high risk for POD. The areas under the receiver operating characteristic curve of the risk score model were 0.89 and 0.81 for the development and the validation cohorts, respectively. CONCLUSION: The DRD score is a predictive risk score assessable during PhMR and can identify patients at risk for POD. Specific preventive measures concerning drug therapy safety and non-pharmacological actions should be implemented for identified risk patients.

A Look Forward and a Look Back: The Growing Role of ERAS Protocols in Orthopedic Surgery.

The success of enhanced recovery after surgery (ERAS) protocols in improving patient outcomes and reducing costs in general surgery are widely recognized. ERAS guidelines have now been developed in orthopedics with the following recommendations. Preoperatively, patients should be medically optimized with a focus on smoking cessation, education, and anxiety reduction. Intraoperatively, using multimodal and regional therapies like neuraxial anesthesia and peripheral nerve blocks facilitates same-day discharge. Postoperatively, early nutrition with appropriate thromboprophylaxis and early mobilization are essential. As the evidence of their improvement in patient outcomes and satisfaction continues, these pathways will prove invaluable in optimizing patient care in orthopedics.

Anesthesia for the Patient Undergoing Foot and Ankle Surgery.

Modern anesthetic management for foot and ankle surgery includes a variety of anesthesia techniques including general anesthesia, neuraxial anesthesia, or MAC in combination with peripheral nerve blocks and/or multimodal analgesic agents. The choice of techniques should be tailored to the nature of the procedure, patient comorbidities, anesthesiologist skill level, intensity of anticipated postoperative pain, and surgeon preference.

Allograft reconstruction of the medial patellofemoral complex in skeletally immature patients: a technical note.

Patellofemoral instability (PFI) is a common disorder in children and adolescents. Surgical stabilization of the patella poses challenges in skeletally immature patients due to anatomical peculiarities at this stage, leading to the absence of an established standard reconstruction technique. Recently, there has been a notable interest in the medial patellofemoral complex (MPFC), encompassing the medial patellofemoral ligament (MPFL) and the medial quadriceps tendon femoral ligament (MQTFL), owing to their role in restricting lateral patellar displacement. This paper aims to describe the surgical technique employed by the author for reconstructing the medial patellofemoral complex with allograft in skeletally immature patients with patellofemoral instability. Study design: surgical technique.

La inestabilidad patelofemoral (PFI) es un trastorno común en niños y adolescentes. La estabilización quirúrgica de la rótula plantea desafíos en pacientes esqueléticamente inmaduros debido a peculiaridades anatómicas en esta etapa, lo que lleva a la ausencia de una técnica de reconstrucción estándar establecida. Recientemente, ha habido un interés notable en el complejo femororrotuliano medial (MPFC), que abarca el ligamento femororrotuliano medial (MPFL) y el ligamento femoral del tendón del cuádriceps medial (MQTFL), debido a su papel en la restricción del desplazamiento rotuliano lateral. Este artículo tiene como objetivo describir la técnica quirúrgica empleada por el autor para reconstruir el complejo femororrotuliano medial con aloinjerto en pacientes esqueléticamente inmaduros con inestabilidad femororrotuliana. Diseño del estudio: técnica quirúrgica.

Outcomes of surgical treatment of patellar instability in children with Down syndrome.

BACKGROUND: patellar instability is a relatively frequent musculoskeletal disorder in children with Down syndrome (DS). However, such a condition has seldom been studied in the literature, even less its surgical treatment. Different techniques have been offered for this condition; the evidence for surgical options is scarce and primarily based on case reports or case series with few patients and heterogeneous techniques. Given this background, we aimed to evaluate the outcomes of a uniform kind of surgical procedure for such a condition that combined lateral soft tissue release, medial patellofemoral ligament (MPFL) reconstruction (using a partial-thickness quadriceps tendon autograft), the Roux-Goldthwait procedure, and V-Y quadricepsplasty (if needed). MATERIALS AND METHODS: This retrospective study involved 11 skeletally immature patients (12 knees; 9 males and 2 females), 5.5 to 14.1 years of age, with DS who had patellofemoral instability (PFI) and were managed by this technique between October 2018 and March 2020. Preoperative radiography, CT scan, and MRI were performed to evaluate the physis status, lower limb alignment, patellar height, trochlear morphology, and any associated knee pathology. A functional knee assessment was done by using the Kujala score and the modified Lysholm score. RESULTS: The mean time of follow-up (± SD) was 47.7 ± 5.8 months (range: 39-56). Pre-operatively, the Kujala score (± SD) was 52.6 ± 14.3 (range: (31-74), and at final follow-up, it was 92.2 ± 4.4 (range: (88-98), showing a significant improvement (P < 0.001). The preoperative modified Lysholm score (± SD) was 54.3 ± 8.1 (range: 39-62), and at final follow-up it was 92.4 ± 5.3 (range: 82-96), showing a significant improvement (P < 0.001). All patients had a stable patella without a recurrence of instability and regained full ROM. There was no incidence of a patellar fracture or femoral physis injury. CONCLUSIONS: Our proposed technique of combined soft tissue procedures, including lateral soft tissue release, MPFL reconstruction (using a partial-thickness quadriceps tendon autograft), the Roux-Goldthwait procedure, and V-Y quadricepsplasty, was an effective method for treating patellar instability in children with DS while avoiding physeal injury and patellar fracture. Functional scores and radiological outcomes were improved. LEVEL OF EVIDENCE: IV; retrospective case series.

Robot-assisted retractor in spine surgery: Preliminary evaluation of its feasibility and two operation mode in beagles.

OBJECTIVE: To assess the feasibility of the robot-assisted retractor. To compare the muscle injury of the two operation modes, intermittent retraction mode and continuous retraction mode in the robot-assisted retractor to find a better robot operation mode. METHODS: A new robot-assisted retractor experimental platform was developed. Three incisions were made on the backs of three beagles. The robot-assisted retractor was used to retract the muscle on both sides of the incisions in intermittent retraction mode and continuous retraction mode, and the operation of the robot system was observed. The muscle samples were stained with hematoxylin-eosin (HE) to observe the muscle injury. The difference between the muscle injuries of the two groups was statistically compared using paired t test. RESULTS: The robot-assisted retractor can precisely retract to the specified position without malfunction or dangerous actions. Histologic evaluation showed that fewer muscle injury was found in the intermittent retraction mode group of the robot-assisted retractor compared to the continuous retraction mode group. CONCLUSION: The robot-assisted retractor offers a certain degree of feasibility and safety. The robot-assisted retractor is able to effectively reduce muscle injury with the intermittent retraction mode.

A discrete-event simulation model for assessing operating room efficiency of thoracic, gastrointestinal, and orthopedic surgeries.

BACKGROUND: In hospital management, pinpointing steps that most enhance operating room (OR) throughput is challenging. While prior literature has utilized discrete event simulation (DES) to study specific strategies such as scheduling and resource allocation, our study examines an earlier planning phase, assessing all workflow stages to determine the most impactful steps for subsequent strategy development. METHODS: DES models real-world systems by simulating sequential events. We constructed a DES model for thoracic, gastrointestinal, and orthopedic surgeries summarized from a tertiary Chinese hospital. The model covers preoperative preparations, OR occupation, and OR preparation. Parameters were sourced from patient data and staff experience. Model outcome is OR throughput. Post-validation, scenario analyses were conducted for each department, including: (1) improving preoperative patient preparation time; (2) increasing PACU beds; (3) improving OR preparation time; (4) use of new equipment to reduce the operative time of a selected surgery type; three levels of improvement (slight, moderate, large) were investigated. RESULTS: The first three improvement scenarios resulted in a 1%-5% increase in OR throughput across the three departments. Large reductions in operative time of the selected surgery types led to approximately 12%, 33%, and 38% increases in gastrointestinal, thoracic, and orthopedic surgery throughput, respectively. Moderate reductions resulted in 6%-17% increases in throughput and slight reductions of 1%-7%. CONCLUSIONS: The model could reliably reflect OR workflows of the three departments. Among the options investigated, model simulations suggest that improving OR preparation time and operative time are the most effective.

Bupivacaine-fentanyl isobaric spinal anesthesia reduces the risk of ICU admission in elderly patients undergoing lower limb orthopedic surgery.

BACKGROUND: To evaluate if bupivacaine-fentanyl isobaric spinal anesthesia could reduce the risk of ICU admission compared with general anesthesia in elderly patients undergoing lower limb orthopedic surgery. METHODS: This study comprised a retrospective review of all lower limb orthopedic surgeries performed at our hospital between January 2013 and December 2019. According to anesthesia methods, patients were divided into the spinal anesthesia group (n = 1,728) and the general anesthesia group (n = 188). The primary outcome evaluated was the occurrence of ICU admission. Secondary outcomes included hemodynamic changes, postoperative complications, and mortality. RESULTS: Repeated measure analysis of variance indicated that the difference between the two groups in the systolic blood pressure (SBP) was not significant before anesthesia (T0), immediately after anesthesia (T1), and before leaving the operation room (T8) (P > 0.05), but significant (P < 0.01) from 5 min after anesthesia (T2) to after operation (T7). The proportions of ICU admission (6.4% vs. 23.8%, P < 0.01) and unplanned intubation (0.1% vs. 3.8%, P < 0.01) were significantly lower in the spinal anesthesia group compared with those in the general anesthesia group. Multivariate logistic regression revealed that after controlling for potential confounding factors, the odds of ICU admission for patients in the spinal anesthesia group was 0.240 times (95% CI 0.115-0.498; P < 0.01) than those in the general anesthesia group. CONCLUSIONS: Bupivacaine-fentanyl isobaric spinal anesthesia significantly reduced the risk of ICU admission and unplanned intubation, and provided better intraoperative hemodynamics in elderly patients undergoing lower limb orthopedic surgery. TRIAL REGISTRATION: This study has been registered in the Chinese Clinical Trial Registry (ChiCTR2000033411).

Standing on shoulder of giants: the incredible legacy of the Judet family in orthopaedic surgery.

In orthopaedic surgery, as well as other areas in medicine, it is common for a surgical technique to carry the original authors' name describing the procedure. The Judet family represents a unique history, since several orthopaedic procedures are known as "Judet's technique". The aim of this historic review is to outline the genealogy of the orthopaedic arm of the Judet family, while crediting each surgical procedure to the specific family member that described the technique.

Thermal Damage in Orthopaedics.

There are numerous potential sources of thermal damage encountered in orthopaedic surgery. An understanding of the preclinical mechanisms of thermal damage in tissues is necessary to minimize iatrogenic injuries and use these mechanisms therapeutically. Heat generation is a phenomenon that can be used to a surgeon's benefit, most commonly for hemostasis and local control of tumors. It is simultaneously one of the most dangerous by-products of orthopaedic techniques as a result of burring, drilling, cementation, and electrocautery and can severely damage tissues if used improperly. Similarly, cooling can be used to a surgeon's advantage in some orthopaedic subspecialties, but the potential for harm to tissues is also great. Understanding the potential of a given technique to rapidly alter local temperature-and the range of temperatures tolerated by a given tissue-is imperative to harness the power of heat and cold. In all subspecialties of orthopaedic surgery, thermal damage is a relevant topic that represents a direct connection between preclinical and clinical practice.

Surgical management of chronic Achilles tendon rupture: evidence-based guidelines.

BACKGROUND: Chronic Achilles tendon ruptures (CATR) often require surgical intervention to restore function. Despite numerous treatment modalities available, the optimal management strategy remains controversial given the limited high-quality evidence available. This article aims to provide evidence-based guidelines for the surgical management of CATR through a comprehensive systematic review of the available data. The consensus reached by synthesizing the findings will assist clinicians in making informed decisions and improving patient outcomes. METHODS: A group of 9 foot surgeons in three continents was consulted to gather their expertise on guidelines regarding the surgical management of CATR. Following the proposal of 9 clinical topics, a thorough and comprehensive search of relevant literature published since 1980 was conducted for each topic using electronic databases, including PubMed, MEDLINE, and Cochrane Library, to identify relevant studies published until 1 October 2023. All authors collaborated in drafting, discussing, and finalizing the recommendations and statements. The recommendations were then categorized into two grades: grade a (strong) and grade b (weak), following the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) concept. Additionally, feedback from 21 external specialists, who were independent from the authors, was taken into account to further refine and finalize the clinical guidelines. RESULTS: Nine statements and guidelines were completed regarding surgical indications, surgical strategies, and postoperative rehabilitation protocol. CONCLUSION: Based on the findings of the systematic review, this guideline provides recommendations for the surgical management of CATR. We are confident that this guideline will serve as a valuable resource for physicians when making decisions regarding the surgical treatment of patients with CATR.

Return to Play and Functional Outcomes Following Treatment of Acute Achilles Tendon Ruptures: A Systematic Review and Meta-Analysis.

Return to play (RTP) and functional outcomes are critical to treatment success for acute Achilles tendon rupture (AATR). This systematic review and meta-analysis explored treatment superiority essential in optimal treatment selection concerning individual patients and their expectations regarding RTP and functional outcomes. This study was in accordance with the preferred reporting items for systematic reviews and meta-analyses guidelines. The included studies were assessed regarding the level and quality of evidence. Fixed-effects models were employed for I2 < 25% and random-effects models for I2 ≥ 25%. The RTP rate meta-analysis of surgical vs conservative treatment revealed no significant difference. This was similar to the subgroup analysis of open repair and conservative treatment. The RTP rate and Achilles Tendon Total Rupture Score (ATRS) meta-analysis of open repair + earlier rehabilitation (ER) vs + later rehabilitation (LR) also revealed no significant differences. The mean time to RTP meta-analysis of open repair + ER vs + LR showed that open repair + ER was significantly favored (-4.19 weeks; p = .002). The ATRS meta-analysis of conservative treatment with ER vs with LR revealed no significant difference. This meta-analysis has revealed that the RTP rates following treatment of AATR are high. Therefore, the decision for surgical vs conservative treatment or open repair + ER vs + LR for AATR should not be selected based on the expectation of RTP. However, open repair + ER can be advocated over + LR for reduced mean time to RTP.

Vertebral body tethering for adolescent idiopathic scoliosis: a review.

PURPOSE: Adolescent Idiopathic Scoliosis (AIS) remains the most common type of pediatric scoliosis, mostly affecting children between ages 10 and 18. Vertebral body tethering (VBT) offers a non-fusion alternative to the gold standard spinal fusion that permits flexibility and some growth within instrumented segments. This article will serve as a comprehensive literature review of the current state-of-the-art of VBT in relation to radiographic and clinical outcomes, complications, and the learning curve associated with the procedure. METHODS: A systematic literature review was conducted on PubMed, Scopus, and Web of Science from April 2002 to December 2022. Studies were included if they discussed VBT and consisted of clinical studies in which a minimum 2-years follow-up was reported, and series that included anesthetic considerations, learning curve, and early operative morbidity. RESULTS: Forty-nine studies spanning the period from April 2002 to December 2022 were reviewed. CONCLUSION: This article illustrates the potential benefits and challenges of the surgical treatment of AIS with VBT and can serve as a basis for the further study and refinement of this technique ideally as a living document that will be updated regularly.

Anterior Vertebral Body Tethering: A Review of the Available Evidence.

Idiopathic scoliosis is a complex three-dimensional deformity of the spine with anterior overgrowth (hypokyphosis), coronal curvature, and axial rotation. Scoliosis treatment in the skeletally immature spine is therapeutically challenging because of growth and was commonly limited to observation, bracing treatment, or fusion. Fusion accomplishes powerful deformity correction at the expense of future growth and mobility of the involved segments, increasing the risk of adjacent segment degeneration and intervertebral disk disease later in life. Anterior vertebral body tethering is a motion-preserving technique that exploits the Hueter-Volkmann principle by applying compression at the anterior and convex aspects of the curve to stimulate differential vertebral growth for gradual deformity reduction without fusion. The appropriate timing, curve magnitude, tensioning, growth prediction, indications, and limitations of tethering are being refined as this technique becomes more prevalent. Early outcome studies show that growth modulation with vertebral body tethering is safe, can achieve good results, and preserve motion in select patients.

Damage-control orthopedics or early total care: What you need to know.

ABSTRACT: Patients with multisystem injuries are defined as multiply injured patients and may need multiple surgical procedures from more than one specialty. The importance of evaluating and understanding the resuscitation status of a multiple-injury patient is critical. Orthopedic strategies when caring for these patients include temporary stabilization or definitive early fixation of fractures while preventing further insult to other organ systems. This article will define multiple injuries and discuss specific markers used in assessing patients' hemodynamic and resuscitation status. The decision to use damage-control orthopedics or early total care for treatment of the patient are based on these factors, and an algorithm is presented to guide treatment. We will also discuss principles of external fixation and the management of pelvic trauma in a multiple-injury patient.