Arthroplasty Today最新文献

Background

Polyurethane tibial and acetabular inserts that release high concentrations of antibiotics were used with debridement and implant retention to treat prosthetic joint infections. The hypothesis was that a low-friction, antibiotic-releasing bearing could provide a simpler, safer, and more patient-accepted treatment for infection using antibiotic cement and intravenous antibiotics.

Methods

Patients (n = 106) with culture-positive infections received antibiotic inserts. Vancomycin and tobramycin were mixed into the polyurethane polymer at 7% by weight. Contraindications to debridement antibiotics and implant retention were a sinus tract, loose prostheses, and/or the wound could not be closed. Measurable outcomes were success in controlling infection, complications, patient acceptable symptomatic state, and need for revision surgery. Antibiotic levels were measured in joint fluid and blood; laboratory mechanical wear tests were performed; and results were compared to bone cement and polyethylene containing antibiotics.

Results

Antibiotic-infused spacers sustained joint fluid antibiotic levels 8-12 times the therapeutic level and produced low serum levels with no toxicities. Mechanical testing showed low wear and retained mechanical integrity. All patients achieved complication-free remission of infection at a follow-up of 5-26 years. All patients had Harris hip and Knee Society scores above 85, and 68% achieved patient acceptable symptomatic state.

Conclusions

All patients achieved remission of infection, fewer complications compared to revision using antibiotic bone cement, no antibiotic toxicity or adverse drug reactions, and 68% achieved patient acceptance. The antibiotic polyurethane inserts provided antibacterial efficacy comparable with currently used bone cement spacers, and their wear rate was approximately 20 times lower than bone cement as an articulation.

Background

There is a paucity of data regarding compensation for early-career adult reconstruction surgeons. This study aims to quantify the time throughout the full episode of care for a Medicare primary total hip/knee arthroplasty and convert to per-hour pay for early-career arthroplasty surgeons at various geographic locations and practice settings. Using Center for Medicare and Medicaid Services data, this study also compares the compensation of early-career vs established total joint arthroplasty (TJA) surgeons.

Methods

Between January 2022 and January 2023, 3 early-career surgeons in 3 different locations collected prospective data on time spent in patient care during the global period following primary TJAs (pTJAs). A weighted average time spent per pTJA during global period was calculated with the 2024 work relative value unit and conversion factor to establish a per-hour rate. This rate was compared to the compensation rates of other healthcare-related fields and established TJA surgeons using Relative Value Scale Update Committee (RUC) values.

Results

A total of 334 pTJAs (148 hips and 186 knees) were performed among 3 surgeons, and per-hour rates of $87.62 and $87.70 were found, respectively. These are less than hospital/healthcare system/health insurance/med tech CEOs, lawyers, dentists, and travel nurses. Early-career TJA surgeons were found to take 7.98%-8.68% longer than RUC standard times for a TJA episode of care.

Conclusions

This study quantifies the per-hour compensation of early-career arthroplasty surgeons, who earn lower compensation rates to travel nurses and take longer than Center for Medicare and Medicaid Services RUC times for pTJAs. Given the increasing demand for pTJAs, decreasing reimbursement rates, and concern over burnout, access to quality pTJA care for patients is concerning.

Background

Every degree of change in pelvic tilt (PT) leads to a 0.7° change in anteversion and a 0.3° change in inclination. This study aimed to determine the significance of contralateral hip arthritis on changes in PT using preoperative and postoperative anteroposterior radiographs.

Methods

There were 193 primary total hip arthroplasties done by 2 surgeons at a single academic tertiary referral center reviewed between September 2021 and January 2023. PT was calculated as Tilt = −(ln[(B/A) × (1/0.483)]) / 0.051. Value A is the distance from the base of the SI joint to the superior margin of the obturator foramen; value B is the height of the obturator foramen. After exclusions, contralateral hips were identified as being normal (n = 75), arthritic (n = 39) (Tönnis grade 3/4), replaced (n = 34), or having undergone simultaneous bilateral total hip arthroplasty (n = 5) on postoperative films. Difference in PT was measured between preoperative and postoperative films taken 1-3 months after surgery. Analyses for statistical significance were calculated using t-tests and one-way analysis of variance.

Results

Average change in PT in patients with normal contralateral hips was −5.2° with an absolute mean difference of 7.6°, −1.5° for arthritic contralateral hips with an absolute mean difference of 5.0°, −1.6° for replaced contralateral hips with a mean absolute difference of 4.3°, and 2.2° for bilateral hips with a mean absolute difference of 2.6° (P < .01).

Conclusions

Differences in postoperative PT changes between healthy, arthritic, and replaced contralateral hip study groups were significant. Changes in preoperative to postoperative tilt may have implications for optimal cup placement.

Background

The primary objective of this study was to determine the accuracy and precision of component positioning of the ROSA Robotic System for total knee arthroplasty (TKA).

Methods

A Preferred Reporting Items for Systematic Reviews and Meta-Analysis systematic review was conducted using 4 electronic databases (MEDLINE, EMBASE, Pubmed, and Cochrane Library) to identify all clinical and radiological studies reporting information about the use and results of the ROSA system. The criteria for inclusion were published research articles evaluating the accuracy of component positioning, learning curve, component alignment, complications, and functional outcomes in adults who underwent robotic-assisted TKA. The National Institutes of Health Quality Assessment Tool was used to evaluate the quality of all the included studies.

Results

A total of 26 studies were assessed for eligibility, and 17 met the inclusion criteria. Nine studies reported on the accuracy and precision of component positioning. The ROSA platform for TKA had a cutting error of less than 0.6^° for all coronal and sagittal parameters. Pooled analysis demonstrated accuracy within 0.61-1.87^° and precision within 0.97-1.34^° when the final intraoperative plan was compared to postoperative radiographs with fewer outliers. Four studies reported improved functional scores with ROSA-assisted TKA than conventional TKA within 1 year of surgery. There was no difference in overall complication rates when compared to conventional TKA.

Conclusions

The ROSA system is both highly accurate and precise, with fewer outliers when analyzed at various time points, including postoperative standing radiographs. Future studies with robust methodology and longer follow-up are required to demonstrate whether these findings have any clinical benefits in the long term.

This study presents a surgical technique for kinematically aligned medial unicompartmental knee arthroplasty with the MOTO (Medacta Corporate, Switzerland) partial knee implant. This technique aims to replicate the native medial femoral and tibial morphology by providing caliper-verified bone resections and kinematic alignment principles. The paper provides a comprehensive overview of the surgical steps and discusses the implications for implant longevity.

The use of metal-on-metal bearing couples in total hip arthroplasty can lead to an increased release of metal ions, particularly cobalt and chromium over time. This can lead to local and systemic metallosis, which has cytotoxic, genotoxic, and immunotoxic effects and can cause a host of secondary disorders. We describe the case of a 37-year-old female patient that was diagnosed with warm-antibody autoimmune hemolytic anemia (WAIHA) one and a half years after bilateral large-diameter head metal-on-metal total hip arthroplasty. For 11 years, it was refractory to all therapy, including splenectomy and rituximab, requiring long-term oral prednisone for disease control. Ultimately, systemic metallosis and periprosthetic joint infection were diagnosed, requiring explantation of the prostheses. By the sixth week postoperatively, she experienced complete spontaneous remission of her WAIHA. In conclusion, WAIHA can be associated with systemic metallosis in patients with metal-on-metal prosthetic joint replacements. Both hematologists and orthopedic surgeons should be aware of this.

Neurofibromatosis 1 (NF1) is a rare genetic syndrome that leads to the development of neurofibromas and increases the risk of malignancy, including malignant peripheral nerve sheath tumors. Patients with NF1 often have other orthopaedic manifestations, including short stature, osteopenia, and dysplasia. A 47-year-old patient with a history of NF1 and multiple neurofibromas of the right lower extremity presented with a severe valgus deformity, instability, and osteoarthritis of the right knee that was debilitating to daily life. Over time, the patient lost proprioception and potentially some sensation to the right knee with neurofibroma formation, leading to the development of Charcot arthropathy of the right knee with secondary osteoarthritis. The preoperative workup consisted of a magnetic resonance imaging of the knee to confirm no malignancy was present and templating to ensure the standard implant size was amenable for the patient. A primary total knee arthroplasty was performed with a cemented-stemmed hinged knee implant. At 6 months post-surgery, the patient had a dramatic improvement in her pain and quality of life.

Previous reports have described failures of modular fluted tapered femoral stems secondary to fatigue failure at the modular junction. However, the present study is the first reported case of modular fluted tapered femoral component failure involving atraumatic fracture of the proximal body following revision total hip arthroplasty. The failure occurred in a 52-year-old female with a history of postmenopausal osteoporosis on bisphosphonates who sustained an atraumatic fracture of the proximal body of a modular revision femoral stem. In the present case, revision THA utilizing a wider proximal body segment with proximal augmentation using strut allografts for biological and mechanical support provided the patient with a stable construct at 30-month follow-up.

Background

One of the most debated topics in modern total knee arthroplasty (TKA) is the impact of metal hypersensitivity (MH) as a potential cause of prosthesis failure. Implanting hypoallergenic prostheses to avoid potential problems in suspected cases of MH is one treatment option that can be used in such cases. However, their long-term clinical safety and efficacy are not well proven.

Methods

All literature relevant to modern hypoallergenic implants were reviewed and summarized to provide a comprehensive synopsis. In addition, a detailed literature search was performed on PUBMED, MEDLINE, and Google Scholar to identify all the clinical studies reporting outcomes for hypoallergenic knee implants. Our search was confined to those studies published as full manuscripts in the English language from July 2018 to July 2023.

Results

To minimize the risk of MH, new implant variants have been developed which are either under clinical evaluation or in routine clinical use. These include conventional metal implants with protective coatings (mono- or multilayer) and metal-free implants. However, there is insufficient clinical data to confirm the rationale and effectiveness of using these “hypoallergenic” TKA implants.

Conclusions

Published studies and arthroplasty registry data analyses indicate no significant differences between hypoallergenic and standard TKAs with overall good survival rates. In the future, further high-quality studies are needed to better understand the complexity of this subject.

Background

Institutional academic productivity varies on an individual level. This study aims to analyze the research output of adult reconstruction and arthroplasty fellowship programs in the United States.

Methods

The American Association of Hip and Knee Surgeons Fellowship Directory was used to evaluate 112 adult reconstruction and arthroplasty fellowships in the United States. Publication data and Hirsch index (h-index) were collected from the Scopus Database. All of each author’s total publications were analyzed with their current institution, regardless of their affiliation at the time of publication. Multivariate logistic regressions were performed to determine the effect of program size on research productivity.

Results

The total number of publications per institution ranged from 2 to 3743, with a mean of 289 and a median of 135. The h-index of individual faculty members ranged from 0 to 103, with a mean of 16 and a median of 11. The number of faculty (P < .001) and number of fellows (P = .003) per program had a significant effect on the total number of publications. The number of faculty did not have a significant effect on the median number of publications (P = .12) or the median h-index (P = .31). The number of fellows had a significant effect on the median number of publications (P < .001) and the median h-index (P < .001).

Conclusions

Academic productivity in adult reconstruction and arthroplasty fellowships within the United States varies widely, with the top few institutions responsible for a majority of the overall output.