Liquid Phase 3D Printing: How This New Technology Can Help Bring 3D Printing to the Operating Room.

PURPOSE OF REVIEW: The purpose of this review is to discuss the state of technology in liquid phase three-dimensional (3D) metal printing, how this has affected the field of orthopedic surgery, and changes that we can expect in the future with the rise of this printing technology. We will also discuss how liquid phase metal printing can possibly bring three-dimensional printing to the operating room. RECENT FINDINGS: The use of liquid phase 3D metal printing may become commonplace for manufacturing orthopedic implants and devices. Traditional metal printing involved powder-based metals and high-energy beam technologies that are expensive, time-consuming, and potentially wasteful. This unfortunately leaves them out of reach for most end consumers such as orthopedic surgeons. Liquid phase metal printing is less expensive and faster. However, there is still major work required to bring this technology to the operating room and benefit patients. While major strides have been made in the field of liquid phase metal three-dimensional printing, there are still significant developments in the pipeline. These could lead to future production of personalized orthopedic implants and devices with optimal material properties for patients.

Free Flap Coverage for Complex Primary and Revision Total Knee Arthroplasty.

BACKGROUND: Free flap coverage in the setting of a total knee arthroplasty is rare. The purpose of the current study was to evaluate the outcome of patients who underwent a free flap to assist with soft-tissue coverage following a complex total knee arthroplasty. METHODS: The authors used their institutional total joint registry to retrospectively review patients undergoing a free soft-tissue flap in the setting of complex primary and revision total knee arthroplasty. Among 29,069 primary and 6433 revision total knee arthroplasties from 1994 to 2017, eight (0.02 percent) required a free flap for wound coverage. This included three primary total knee arthroplasties (0.01 percent) for posttraumatic arthritis and five revision total knee arthroplasties (0.07 percent) in the setting of infection. Median follow-up was 4 years. RESULTS: Free flaps included vertical rectus abdominis (n = 3), anterior lateral thigh (n = 2), latissimus (n = 2), and transverse rectus abdominis (n = 1). There were no total flap losses; however, one patient required additional skin grafting. Reoperation occurred in six patients, of which four were revisions of the total knee arthroplasty for infection (n = 2) and tibial component loosening (n = 2). One patient ultimately underwent transfemoral amputation for persistent infection. Following reconstruction, there was improvement in the median Knee Society Score (49 versus 82; p = 0.03) and total range of motion between preoperative and postoperative assessments (70 degrees versus 85 degrees; p = 0.14). CONCLUSION: Free flap coverage in the setting of total knee arthroplasty was associated with a high rate of reoperation; however, the limb was able to be preserved in the majority of patients, with a reasonable functional outcome. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Outcomes of Open and Endoscopic Repairs of Chronic Partial- and Full-Thickness Proximal Hamstring Tendon Tears: A Multicenter Study With Minimum 2-Year Follow-up.

BACKGROUND: The preponderance of literature on the repair of proximal hamstring tendon tears focuses on the acute phase (<4 weeks). As such, there is a paucity of data reporting on the outcomes of chronic proximal hamstring tears. PURPOSE: To report minimum 2-year postoperative patient-reported outcome (PRO) scores, visual analog scale (VAS) for pain, and patient satisfaction from patients who underwent open or endoscopic repair of partial- and full-thickness chronic proximal hamstring tendon tears. STUDY DESIGN: Case series study; Level of evidence, 4. METHODS: Between April 2002 and May 2017, prospectively collected data from 3 tertiary care institutions were retrospectively reviewed for patients who underwent open and endoscopic repair of partial- and full-thickness chronic proximal hamstring tendon tears. Patients were included only if they had a chronic proximal hamstring tear (defined as ≥4 weeks from symptom onset to surgery). Patients were excluded if they had a tear treated <4 weeks after injury, underwent hamstring reconstruction, or claimed workers' compensation. Patients who reported minimum 2-year follow-up for VAS, patient satisfaction, and the following PROs had their outcomes analyzed: the modified Hip Harris Score, Non-arthritic Hip Score, iHOT-12 (International Hip Outcome Tool), and Hip Outcome Score-Sports Specific Subscale. RESULTS: Fifty patients (34 females and 16 males) were included in this study. There were 19 endoscopic repairs and 31 open repairs. Within the cohort, 52.0% had a full-thickness tendon tear on magnetic resonance imaging, and 48.0% had a partial tear. Average follow-up time was 58.07 ± 37.27 months (mean ± SD; range, 24-220 months). The mean age and body mass index of the group were 46.13 ± 13 years and 25.43 ± 5.14. The average time from injury to surgery was 66.73 weeks (range, 5.14-215.14 weeks). Average postoperative PROs were as follows: modified Hip Harris Score, 91.94 ± 9.96; Non-arthritic Hip Score, 91.33 ± 9.99; iHOT-12, 87.17 ± 17.54; Hip Outcome Score-Sports Specific Subscale, 87.15 ± 18.10; and VAS, 1.16 ± 1.92. Patient satisfaction was 8.22 ± 1.20. CONCLUSION: Patients who underwent open and endoscopic repairs for chronic partial- and full-thickness proximal hamstring tendon tears reported high PROs and satisfaction at a minimum 2-year follow-up with low rates of complications.

Comparison of reconstructive techniques following oncologic intraarticular resection of proximal humerus.

INTRODUCTION: The proximal humerus is a common site of primary and metastatic disease in the upper extremity. Historically, the goal of a hemiarthroplasty reconstruction was to provide a stable platform for hand and elbow function, with limited shoulder function. Techniques utilizing a reverse endoprosthesis (endoprosthetic replacement [EPR]) and allograft-prosthetic composite (APC) have been developed; however, there is a paucity of comparative studies. METHODS: A total of 83 (42 females, 41 males) patients undergoing an intraarticular resection of the humerus were reviewed. Reconstructions included 30 reverse and 53 hemiarthroplasty; including hemiarthroplasty EPR (n = 36) and APC (n = 17), and reverse EPR (n = 20) and APC (n = 10). RESULTS: Reverse reconstructions had improved forward elevation (85° vs. 44°, p < .001) and external rotation (30° vs. 21°; p < .001) versus a hemiarthroplasty. Reverse reconstructions had improved American Shoulder and Elbow Surgeons scores (65 vs. 57; p = .01) and Musculoskeletal Tumor Society 93 scores (72 vs. 63; p < .001) versus hemiarthroplasty. Subluxation of the reconstruction was a common (n = 23, 27%), only occurring in hemiarthroplasty patients (EPR [n = 13, 36%] and APC [n = 10, 59%]). CONCLUSION: The current series highlights the improved functional outcome in patients undergoing reconstruction with a reverse arthroplasty compared to the traditional hemiarthroplasty. Currently reverse shoulder arthroplasty (APC or EPR) is our preferred methods of reconstruction in this patient population.

Survey of AAHKS International Members on the Impact of COVID-19 on Hip and Knee Arthroplasty Practices.

BACKGROUND: Coronavirus disease 2019 (COVID-19) pandemic poses an important risk to global health. METHODS: This study surveyed 370 international orthopedic surgeons affiliated with the American Association of Hip and Knee Surgeons to help identify the global impact of the COVID-19 pandemic on patient care. RESULTS: A total of 99 surgeons (27% of those surveyed) completed the questionnaire representing 32 different countries. Except for surgeons in Japan, all respondents noted that their practice had been affected to some degree and 70% of the surgeons have canceled elective procedures. More than a third of the surgeons have had to close their practices altogether and the remaining open practices were estimated to be sustainable for 7 weeks on average given their current situation. CONCLUSION: The COVID-19 pandemic has resulted in marked changes to the majority of international arthroplasty practices.

Validation and Modification of a Severity of Illness Score for Children With Acute Hematogenous Osteomyelitis.

BACKGROUND: Children with osteomyelitis demonstrate a wide spectrum of illness. Objective measurement of severity is important to guide resource allocation and treatment decisions, particularly for children with advanced illness. The purpose of this study is to validate and improve a previously published severity of illness scoring system for children with acute hematogenous osteomyelitis (AHO). METHODS: Children with AHO were prospectively studied during evaluation and treatment by a multidisciplinary team who provided care according to evidence-based guidelines to reduce variation. A severity of illness score was calculated for each child and correlated with surrogate measures of severity. Univariate analysis was used to assess the significance of each parameter within the scoring model along with new parameters, which were evaluated to improve the model. The scoring system was then modified by the addition of band count to replace respiratory rate. The modified score was calculated and applied to the prospective cohort followed by correlation with the surrogate measures of severity. RESULTS: One hundred forty-eight children with AHO were consecutively studied. The original severity of illness score correlated well with length of stay and other established measures of severity. Band percent of the white blood cell differential ≥1.5% was found to be significantly associated with severity and chosen to replace respiratory rate in the model. The modified calculated severity scores correlated well with the chosen surrogate measures and significantly differentiated children with osteomyelitis on the basis of causative organism, length of stay, intensive care, surgeries, bacteremia, and disseminated or multifocal disease. CONCLUSIONS: The findings of this study validate the previously published severity of illness scoring tool in large cohort of children who were prospectively evaluated. The replacement of respiratory rate with band count improved the scoring system.