Acute kidney injury (AKI) is a complex disorder for which currently there is no accepted definition. Having a uniform standard for diagnosing and classifying AKI would enhance our ability to manage these patients. Future clinical and translational research in AKI will require collaborative networks of investigators drawn from various disciplines, dissemination of information via multidisciplinary joint conferences and publications, and improved translation of knowledge from pre-clinical research. We describe an initiative to develop uniform standards for defining and classifying AKI and to establish a forum for multidisciplinary interaction to improve care for patients with or at risk for AKI. Members representing key societies in critical care and nephrology along with additional experts in adult and pediatric AKI participated in a two day conference in Amsterdam, The Netherlands, in September 2005 and were assigned to one of three workgroups. Each group's discussions formed the basis for draft recommendations that were later refined and improved during discussion with the larger group. Dissenting opinions were also noted. The final draft recommendations were circulated to all participants and subsequently agreed upon as the consensus recommendations for this report. Participating societies endorsed the recommendations and agreed to help disseminate the results. The term AKI is proposed to represent the entire spectrum of acute renal failure. Diagnostic criteria for AKI are proposed based on acute alterations in serum creatinine or urine output. A staging system for AKI which reflects quantitative changes in serum creatinine and urine output has been developed. We describe the formation of a multidisciplinary collaborative network focused on AKI. We have proposed uniform standards for diagnosing and classifying AKI which will need to be validated in future studies. The Acute Kidney Injury Network offers a mechanism for proceeding with efforts to improve patient outcomes.

Acute Kidney Injury Network: report of an initiative to improve outcomes in acute kidney injury

![Graphic][1] Infection at the site of a total joint arthroplasty can be classified into four basic categories: Type I (early postoperative), Type II (late chronic), Type III (acute hematogenous), and Type IV (positive intraoperative cultures with clinically unapparent infection).

![Graphic][2] The current standard of care for late chronic infection is considered to be two-stage revision arthroplasty including removal of the prosthesis and cement, thorough debridement, placement of an antibiotic-impregnated cement spacer, a course of intravenous antibiotics, and a delayed second-stage revision arthroplasty.

![Graphic][3] The choice of the spacer, either articulating or nonarticulating, is based on many factors, including the amount of bone loss, the condition of the soft tissues, the need for joint motion, the availability of prefabricated spacers or molding methods, and antibiotic selection.

![Graphic][4] Current data have demonstrated that the use of antibiotic-impregnated cement spacers has improved the outcomes of the treatment of infection associated with total joint arthroplasty.

Total joint replacement is one of the most frequent and successful types of operations in orthopaedics. Infection is a rare yet devastating complication of the procedure, with a reported prevalence of 0.5% to 3% and with a higher reported prevalence after total knee arthroplasty than after total hip arthroplasty1-4. There is also a higher rate of infection after revision hip and knee arthroplasties than after primary hip and knee arthroplasties1-8.

Two-stage revision surgery was first described in 1983 by Insall et al., who demonstrated the necessity of removing the implants as well as the cement and of introducing antibiotic therapy for definitive treatment9. This procedure has emerged as the standard of care for a late chronic infection at the site of a total joint replacement4,5,10-17. Garvin and Hanssen reviewed twenty-nine studies and found that two-stage …

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Antibiotic-impregnated cement spacers for the treatment of infection associated with total hip or knee arthroplasty.

The subvastus or Southern approach to the knee had been described as early as 1929 but is not found in standard modern orthopedic textbooks. This approach for primary total knee arthroplasty (TKA) preserves the integrity of the extensor mechanism and maintains the vascular supply to the patella. To appreciate the potential benefits of this approach, a complete understanding of the surgical anatomy is essential. The benefits of the subvastus approach make it a valuable technique for primary TKA.

Subvastus (Southern) approach for primary total knee arthroplasty.

Background: Several studies have established a relationship between the preoperative hemoglobin level and the need for postoperative blood transfusion. We analyzed the relationship between preoperative hemoglobin levels, as well as other factors such as age, gender, weight, height, type and duration of the total joint replacement surgery, and the need for postoperative blood transfusion.

Methods: A retrospective study of 296 patients treated with 370 procedures (209 total hip arthroplasties [56.5%] and 161 total knee arthroplasties [43.5%]) from 1994 to 1998 was carried out. A univariate analysis was performed to establish the relationship between all independent variables and the need for postoperative transfusion. Variables that were determined to have a significant relationship were included in a multivariate analysis.

Results: The univariate analysis revealed a significant relationship between the need for postoperative blood transfusion and preoperative hemoglobin levels (p = 0.0001), duration of surgery (p = 0.0001), weight (p = 0.002), height (p = 0.019), and gender (p = 0.0056). However, the multivariate analysis identified a significant relationship only between the need for transfusion and the preoperative hemoglobin level (p = 0.0001) and weight (p = 0.011); height (p = 0.776) and gender (p = 0.122) were discounted as significant factors. Patients with a preoperative hemoglobin level of 150 g/L.

Conclusions: The preoperative hemoglobin level (p = 0.0001) and weight of the patient (p = 0.011) were shown to predict the need for blood transfusion after hip and knee replacement.

Preoperative hemoglobin levels and the need for transfusion after prosthetic hip and knee surgery: analysis of predictive factors.

Background: Patellar fracture can occur as a complication following total knee arthroplasty. The purpose of this study was to evaluate a large series of patellar fractures to determine the results of different forms of treatment of specific fracture types.

Methods: A retrospective review identified eighty-five fractures (in seventy-seven patients) following 12,464 consecutive total knee arthroplasties performed between 1985 and 1998. Seventy-eight fractures occurred after primary total knee arthroplasty and seven, after revision total knee arthroplasty. Five fractures were treated elsewhere, and two others were lost to follow-up. The results of treatment of the remaining seventy-eight fractures were reviewed. Fractures were classified according to three main criteria: integrity of the extensor mechanism, fixation status of the patellar implant, and quality of the remaining bone stock. The mean duration of follow-up was 3.6 years.

Results: The prevalence of patellar fracture after total knee arthroplasty was 0.68%; fractures were significantly more prevalent among men (1.01%) than among women (0.40%) (p = 0.0004). Thirty-eight fractured patellae had a stable implant and an intact extensor mechanism (Type I). All but one were treated nonoperatively, and there was only one late failure of nonoperative treatment, which required operative intervention. Twelve fractures were associated with disruption of the extensor mechanism (Type II). Eleven were treated operatively; six knees had complications and five had a reoperation. Twenty-eight fractures occurred in association with a loose patellar component (Type III). Twenty were treated operatively; nine knees had complications, and four had a reoperation.

Conclusions: Patellar fractures after total knee arthroplasty are infrequent. Treatment can be guided by three main criteria: integrity of the extensor mechanism, fixation status of the patellar implant, and quality of the remaining bone. Fractures associated with a stable implant and an intact extensor mechanism were usually treated successfully with nonoperative means, with minimal complications. When operative treatment was required, it was associated with a high rate of complications and reoperations.

Patellar fracture after total knee arthroplasty.

Background
Studies have demonstrated sex differences in femoral shape and quadriceps angle raising a question of whether implant design should be sex-specific. Much of this research has addressed shape differences within the Caucasian population and little is known about differences among ethnic groups.

/pdf/three-dimensional-morphology-of-the-knee-reveals-ethnic-3sxkaj9awa.pdf

Three-dimensional Morphology of the Knee Reveals Ethnic Differences

A prospective clinical and radionuclide study was done to ascertain the effect of a lateral release on patella vascularity in total knee arthroplasty. Although the basic surgical procedure was the same in all 36 knees, postoperative technetium bone scans revealed a higher incidence (9 of 16, 56.4%) of vascular compromise in knees with a lateral release than in those without a lateral release (3 of 20, 15%). Although only one clinical complication (fractured patella not requiring secondary surgery) occurred, the lateral release itself appears to have a causal relationship with patella viability. It does not seem to be the sole determinant, however, because the development of a "cold" patella in three knees that did not have a lateral release implicates other factors, such as thermal necrosis and anatomic variation of the blood supply.

The relationship of lateral releases to patella viability in total knee arthroplasty

A prospective study ascertained the effect of lateral retinacular release and/or excision of the infrapatellar fat pad on patellar vascularity after total knee arthroplasty. Fifty patients (70 knees) had postoperative technetium bone scans, which revealed a higher incidence of vascular compromise of the patella after lateral release than without lateral release. Excision of the infrapatellar fat pad, commonly performed to enhance exposure and simplify access to the proximal tibia, did not compromise patellar vascularity.

Scintigraphic determination of patellar viability after excision of infrapatellar fat pad and/or lateral retinacular release in total knee arthroplasty.

Background Total knee arthroplasty is a treatment option for debilitating arthritis. In the postoperative period, patients experience moderate to severe pain affecting the rehabilitation, hospital stay, and patient satisfaction. This study aims at utilizing current best evidence to determine whether adductor canal block (ACB) or periarticular injection (PAI) is a better modality for managing short-term postoperative pain and opioid consumption. Methods Embase, MEDLINE, HealthStar, Emcare, and PubMed were searched for randomized controlled trials from 1946 to August 2018, for literature addressing the comparison of ACB and PAI for pain management in the setting of total knee arthroplasty. A systematic review and meta-analysis were performed. Results Six studies were included in our meta-analysis. When examining the combined visual analog scale (VAS) pain values for each group, analysis demonstrated greater reduction in scores for the PAI group, and the difference was statistically significant (P = .001). When comparing the VAS scores of subgroups analyzed at specific periods in time, there was a trend toward lower VAS scores in subgroups analyzed at 24 hours and 48 hours postoperatively (at rest and at movement) in the PAI group. Overall opioid consumption was lower in the PAI group, with demonstrated statistical significance (P = .03). When comparing the postoperative subgroups, there was a trend toward decreased opioid use in the PAI group, with 13.25% less opioid use at 48 hours and 9.5% less opioid use at 24 hours. Conclusion PAI could significantly improve postoperative pain and opioid consumption when compared with ACB. Additional, high-quality studies are required to further address this topic.

Adductor Canal Block or Local Infiltrate Analgesia for Pain Control After Total Knee Arthroplasty? A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

https://www.jscimedcentral.com/Orthopedics/orthopedics-sp-id-modern-anesthesia-1025.pdf

Giles R. Scuderi

Papers

Three-dimensional Morphology of the Knee Reveals Ethnic Differences

The relationship of lateral releases to patella viability in total knee arthroplasty

Scintigraphic determination of patellar viability after excision of infrapatellar fat pad and/or lateral retinacular release in total knee arthroplasty.

Adductor Canal Block or Local Infiltrate Analgesia for Pain Control After Total Knee Arthroplasty? A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Periarticular regional analgesia in total knee arthroplasty: a review of the neuroanatomy and injection technique.