Robotic arm-assisted versus conventional total knee arthroplasty: comparing complications, costs, and postoperative opioid use in propensity-matched cohorts.

PURPOSE: Limited literature exists substantiating benefits of robotic arm-assisted total knee arthroplasty (raTKA) over conventional total knee arthroplasty (cTKA). This study compared postoperative pain, complications, and costs between patients undergoing raTKA and cTKA using large, propensity score-matched cohorts. We hypothesize that the raTKA cohort will be associated with lower pain, lower anemia, and similar cost and other complications. METHODS: A commercially available patient database was used for this study. Patients with raTKA and cTKA were identified with current procedural terminology and international classification of diseases (ICD-9/ICD-10) codes. Exclusions and propensity score matching were applied to mitigate confounding bias. Complication rates, costs, and postoperative opioid uses were then compared between groups. RESULTS: Compared with patients with cTKAs (n = 31,105), patients with raTKAs (n = 6,221) had less postoperative opioid use (p < 0.01), lower rates of postoperative acute renal failure (OR 0.71; p < 0.01), anemia (OR 0.75; p < 0.01), and periprosthetic joint infection (OR 0.59; p = 0.04), and lower index costs ($875 vs. $1,169, p < 0.01). CONCLUSION: RaTKA was associated with less postoperative pain and complications compared with cTKA.

Three-dimensional-printed femoral diaphysis for biomechanical testing-Optimization and validation.

Polylactic acid (PLA) models of normal human femoral diaphyses were designed using three-dimensional (3D) printing technology to create inexpensive, accessible, and reproducible specimens for flexural biomechanical studies. These models were subjected to three-point bending and their response to loading was characterized. The anisotropic mechanical behavior of the 3D-printed femurs and the influence of printing orientations, infill density, wall layers, resolution, and other printing parameters were explored to develop a design space. The objective of the design space was set to emulate the flexural biomechanical response of the normal human femur bones. Results show the 3D-printed PLA diaphyseal femurs with 5% infill density, two-four wall layers, and a resolution of 200 µm resulted in a flexural strength of 184.8 ± 8.18 MPa. Models with 20% infill density and six wall layers resulted in a flexural modulus of 18.54 ± 0.543 GPa. These results emulate the biomechanical response of the normal human femur, as determined by historical target values derived from prior cadaveric and 3D printing data. With further research, inclusive of modeling the proximal and distal femur and more comprehensive biomechanical testing, 3D-printed femurs may ultimately serve as a cheap, accessible biomechanical resource for surgeons and researchers.

Clinical and radiological septic joint analysis of spontaneous sternoclavicular joint infections: achieving the best outcomes-a systems engineering approach.

OBJECTIVES: Spontaneous sternoclavicular joint infection (SSCJI) is a rare and poorly understood disease process. This study aims to identify factors guiding effective management strategies for SSCJI by using data mining. METHODS: An Institutional Review Board-approved retrospective review of patients from 2 large hospitals (2010-2022) was conducted. SSCJI is defined as a joint infection without direct trauma or radiation, direct instrumentation or contiguous spread. An interdisciplinary team consisting of thoracic surgeons, radiologists, infectious disease specialists, orthopaedic surgeons, hospital information experts and systems engineers selected relevant variables. Small set data mining algorithms, utilizing systems engineering, were employed to assess the impact of variables on patient outcomes. RESULTS: A total of 73 variables were chosen and 54 analysed against 11 different outcomes. Forty-seven patients [mean age 51 (22-82); 77% male] met criteria. Among them, 34 underwent early joint surgical resection (<14 days), 5 patients received delayed surgical intervention (>14 days) and 8 had antibiotic-only management. The antibiotic-only group had comparable outcomes. Indicators of poor outcomes were soft tissue fluid >4.5 cm, previous SSCJI, moderate/significant bony fragments, HgbA1c >13.9% and moderate/significant bony sclerosis. CONCLUSIONS: This study suggests that targeted antibiotic-only therapy should be considered initially for SSCJI cases while concurrently managing comorbidities. Patients displaying indicators of poor outcomes or no symptomatic improvement after antibiotic-only therapy should be considered for surgical joint resection.

Multiparametric Evaluation of Soft Tissue Sarcoma: Current Perspectives and Future Directions.

Imaging plays an essential role in diagnosing and managing musculoskeletal soft tissue masses. It provides anatomic details and aids in the characterization and prognostication of tumors. Advanced imaging is also essential for assessing treatment response and post-treatment surveillance. Several novel imaging techniques are now available that provide additional functional and metabolic information about these tumors. This additional information may be used to predict the biological behavior of the tumors and effectively assess the treatment response for optimizing their management. This article focuses on multiparametric imaging evaluation of soft tissue masses with a discussion of advancements in the domains of ultrasound, MRI, and CT imaging and how these may be helpful in pre- and post-treatment assessment of soft tissue tumors. Current perspectives on the role of diffusion imaging, perfusion imaging, and MR spectroscopy have been highlighted, and future directions of metabolic imaging are briefly outlined. As these advances hold a promising role in the multidisciplinary management of soft tissue sarcomas, it is important for the radiologist to be familiar with the latest advances and developments in imaging soft tissue tumors.

Computational evaluation of psoas muscle influence on walking function following internal hemipelvectomy with reconstruction.

An emerging option for internal hemipelvectomy surgery is custom prosthesis reconstruction. This option typically recapitulates the resected pelvic bony anatomy with the goal of maximizing post-surgery walking function while minimizing recovery time. However, the current custom prosthesis design process does not account for the patient's post-surgery prosthesis and bone loading patterns, nor can it predict how different surgical or rehabilitation decisions (e.g., retention or removal of the psoas muscle, strengthening the psoas) will affect prosthesis durability and post-surgery walking function. These factors may contribute to the high observed failure rate for custom pelvic prostheses, discouraging orthopedic oncologists from pursuing this valuable treatment option. One possibility for addressing this problem is to simulate the complex interaction between surgical and rehabilitation decisions, post-surgery walking function, and custom pelvic prosthesis design using patient-specific neuromusculoskeletal models. As a first step toward developing this capability, this study used a personalized neuromusculoskeletal model and direct collocation optimal control to predict the impact of ipsilateral psoas muscle strength on walking function following internal hemipelvectomy with custom prosthesis reconstruction. The influence of the psoas muscle was targeted since retention of this important muscle can be surgically demanding for certain tumors, requiring additional time in the operating room. The post-surgery walking predictions emulated the most common surgical scenario encountered at MD Anderson Cancer Center in Houston. Simulated post-surgery psoas strengths included 0% (removed), 50% (weakened), 100% (maintained), and 150% (strengthened) of the pre-surgery value. However, only the 100% and 150% cases successfully converged to a complete gait cycle. When post-surgery psoas strength was maintained, clinical gait features were predicted, including increased stance width, decreased stride length, and increased lumbar bending towards the operated side. Furthermore, when post-surgery psoas strength was increased, stance width and stride length returned to pre-surgery values. These results suggest that retention and strengthening of the psoas muscle on the operated side may be important for maximizing post-surgery walking function. If future studies can validate this computational approach using post-surgery experimental walking data, the approach may eventually influence surgical, rehabilitation, and custom prosthesis design decisions to meet the unique clinical needs of pelvic sarcoma patients.

Chondrosarcoma.

Chondrosarcoma is the second most common primary bone tumor, with >90% of cases representing the primary conventional subtype. In addition to arising de novo, conventional chondrosarcoma can arise secondary to a benign underlying lesion, such as enchondroma or osteochondroma. Symptoms are often characterized by focal, dull, aching pain to the affected region. Grade is a well-recognized prognostic factor in these tumors. Grade I lesions/atypical cartilaginous tumors rarely metastasize, rarely recur, and have a 10-year survival rate of >80%. By contrast, grade III lesions are associated with a poor prognosis with the highest local recurrence rates, a lung metastasis rate of >50%, and a 10-year survival rate of <30%. The standard treatment of high-grade conventional chondrosarcoma is complete surgical resection with wide margin. However, low-grade lesions may be amenable to curettage plus or minus adjuvant local treatment. Conventional chondrosarcoma does not respond to chemotherapy or standard radiation doses. Adjuvant treatment can be beneficial for some subtypes such as chemotherapy for dedifferentiated and mesenchymal chondrosarcoma and radiation additionally for mesenchymal chondrosarcoma. Emerging radiation technologies may also play a useful role in treating tumors in anatomically complex areas such as the spine or pelvis.

Comparison of cost and complications of primary total hip arthroplasty versus oncologic proximal femur replacement.

Aims and objective: Proximal femur replacement (PFR) is most commonly performed after a large resection of the proximal femur to remove tumor and is known to have high complication rates and worse function than a primary total hip replacement (THA). Many surgeons feel that current billing practices fail to adequately differentiate this procedure from a THA. This study aims to examine patients undergoing a primary THA or oncologic PFR and compare the relative economic impact and complication rates between cohorts. Materials & methods: Patient data was queried using a national database, identifying non-pediatric patients who underwent a primary THA or oncologic PFR. Exclusionary criteria were implemented, resulting in two cohorts, each with 380 patients matched in a 1:1 manner controlling for age, gender, and Charlson Comorbidity Index. Utilizing 2022 billing data, oncologic PFRs generated an average of 41.03 RVUs and primary THAs generated 19.60 RVUs. Total hospital cost was used to generate a cost:RVU ratio for each cohort. Key systemic and joint complication rates were additionally compared between cohorts. Results: The oncologic PFR cohort had significantly higher 90-day rates of anemia, deep vein thrombosis, and prosthetic dislocation compared to the primary THA cohort. The 90-day median hospital cost for oncologic PFR was $28,562.21 with a cost:RVU ratio of $696:1. The corresponding median hospital cost for primary THA was $9667.72, with a cost:RVU ratio of $493:1. Conclusion: Hospitals incur more cost per RVU for an oncologic PFR than a primary THA. Relative to primary THA, reimbursement for oncologic PFR is under-evaluated.