Patient-specific instrumentation does not improve radiographic alignment or clinical outcomes after total knee arthroplasty.

Background and purpose - Patient-specific instrumentation (PSI) for total knee arthroplasty (TKA) has been introduced to improve alignment and reduce outliers, increase efficiency, and reduce operation time. In order to improve our understanding of the outcomes of patient-specific instrumentation, we conducted a meta-analysis. Patients and methods - We identified randomized and quasi-randomized controlled trials (RCTs) comparing patient-specific and conventional instrumentation in TKA. Weighted mean differences and risk ratios were determined for radiographic accuracy, operation time, hospital stay, blood loss, number of surgical trays required, and patient-reported outcome measures. Results - 21 RCTs involving 1,587 TKAs were included. Patient-specific instrumentation resulted in slightly more accurate hip-knee-ankle axis (0.3°), coronal femoral alignment (0.3°, femoral flexion (0.9°), tibial slope (0.7°), and femoral component rotation (0.5°). The risk ratio of a coronal plane outlier (> 3° deviation of chosen target) for the tibial component was statistically significantly increased in the PSI group (RR =1.64). No significance was found for other radiographic measures. Operation time, blood loss, and transfusion rate were similar. Hospital stay was significantly shortened, by approximately 8 h, and the number of surgical trays used decreased by 4 in the PSI group. Knee Society scores and Oxford knee scores were similar. Interpretation - Patient-specific instrumentation does not result in clinically meaningful improvement in alignment, fewer outliers, or better early patient-reported outcome measures. Efficiency is improved by reducing the number of trays used, but PSI does not reduce operation time.

Prosthetic alignment after total knee replacement is not associated with dissatisfaction or change in Oxford Knee Score: A multivariable regression analysis.

BACKGROUND: Approximately 18% of the patients are dissatisfied with the result of total knee replacement. However, the relation between dissatisfaction and prosthetic alignment has not been investigated before. METHODS: We retrospectively analysed prospectively gathered data of all patients who had a primary TKR, preoperative and one-year postoperative Oxford Knee Scores (OKS) and postoperative computed tomography (CT). The CT protocol measures hip-knee-ankle (HKA) angle, and coronal, sagittal and axial component alignment. Satisfaction was defined using a five-item Likert scale. We dichotomised dissatisfaction by combining '(very) dissatisfied' and 'neutral/not sure'. Associations with dissatisfaction and change in OKS were calculated using multivariable logistic and linear regression models. RESULTS: 230 TKRs were implanted in 105 men and 106 women. At one year, 12% were (very) dissatisfied and 10% neutral. Coronal alignment of the femoral component was 0.5 degrees more accurate in patients who were satisfied at one year. The other alignment measurements were not different between satisfied and dissatisfied patients. All radiographic measurements had a P-value>0.10 on univariate analyses. At one year, dissatisfaction was associated with the three-months OKS. Change in OKS was associated with three-months OKS, preoperative physical SF-12, preoperative pain and cruciate retaining design. DISCUSSION: Neither mechanical axis, nor component alignment, is associated with dissatisfaction at one year following TKR. Patients get the best outcome when pain reduction and function improvement are optimal during the first three months and when the indication to embark on surgery is based on physical limitations rather than on a high pain score. LEVEL OF EVIDENCE: 2.

Access blood flow and the risk of complications in mature forearm and upper arm arteriovenous fistulas.

BACKGROUND/AIMS: Optimization of vascular access use in the 'fistula first' era requires comprehension of its clinical behavior. Little is known about mature arteriovenous fistula (AVF) performance and the role of fistula location. Widely used access flow (Qa) was used to analyze complication risks and functionality after first hemodialysis use. METHODS: 178 Mature AVFs were analyzed. Complication was defined as permanent failure or >or=1 intervention. Factors associated with complications and mean Qa were determined using Cox proportional-hazards and linear regression models. RESULTS: Baseline Qa was significantly lower in complicated versus uncomplicated forearm and upper arm AVFs. In complicated forearm AVFs, preoperative arterial diameter was smaller while the risk of complications was graded per 100 ml/min baseline Qa increase. Diabetics had an increased risk of upper arm AVF complications. In uncomplicated forearm AVFs, diabetes was related to lower mean Qa, and BMI to higher Qa. CONCLUSIONS: In mature AVFs, baseline Qa depends on fistula location and is related to the risk of complications in a graded manner.

Hospital specific aspects predominantly determine primary failure of hemodialysis arteriovenous fistulas.

BACKGROUND: Primary failure of the arteriovenous fistula (AVF) is a major problem affecting native hemodialysis access use. A multicenter guideline implementation program, Care Improvement by Multidisciplinary approach for Increase of Native vascular access Obtainment (CIMINO), was designed to identify modifiable and nonmodifiable factors involved in the early functionality of the AVF. METHODS: Physicians and dialysis staff in 11 centers in the Netherlands (N = 1092 prevalent vascular accesses) were strongly and repeatedly advised to adhere to current guidelines. It was advised to always perform a standard preoperative duplex examination and physicians were encouraged to attempt salvaging procedures for failing and failed fistulae. Specially appointed access nurses prospectively registered all created vascular accesses in an internet-linked database. Primary failure (PF) was defined as a complication of the AVF before the first successful cannulation for hemodialysis treatment. Modifiable and nonmodifiable factors were related to risk of primary failure using logistic regression models. We restricted the analyses to the first AVF of each patient that was placed during the observation period. RESULTS: Between May 2004 and May 2006, an AVF was created in 395 patients. Primary failure occurred in one third (131 cases). Factors related to an increased risk of primary failure were female gender (odds ratio (OR): 1.73, 95% confidence interval (CI): 1.01-2.94), renal replacement therapy prior to AVF placement (OR: 1.19 per year on RRT, CI: 1.05-1.34), diabetes mellitus (OR: 3.08, CI: 1.53-6.20), and AVF placement at the wrist (compared with elbow) (OR: 1.86, CI: 1.03-3.36). Primary failure rate among the participating centers varied from 8% to 50%. Compared to the two centers with the lowest primary failure rates, six centers had a significantly higher primary failure rate. Adjustment for risk factors and surgery-related factors did not materially change the center-related findings. CONCLUSION: In conclusion, we have identified location of AVF placement as a modifiable factor influencing primary failure risk. More importantly, this study shows that the probability of primary failure is strongly related to the center of access creation, suggesting an important role for the vascular surgeon's skills and decisions.

Accelerated increase of arteriovenous fistula use in haemodialysis centres: results of the multicentre CIMINO initiative.

BACKGROUND: In the Netherlands, arteriovenous fistulas (AVFs) are used in 60-65% of the haemodialysis patients and this compares poorly with the European average. A multicentre guidelines implementation programme, CIMINO, was initiated aiming at increasing the use of AVFs. METHODS: Physicians and dialysis staff in 11 participating centres (N=1092 vascular accesses) were strongly and repeatedly advised to adhere to current guidelines with extra attention for pre-operative duplex examination and salvaging of failing and failed fistulae. Specially appointed access nurses prospectively registered all created vascular accesses using an internet-linked database. In 22 other centres (N=1566 accesses), the CIMINO programme was not offered and they were considered the control group. RESULTS: On 1 January 2006, average follow-up time of the CIMINO group and the control group were 13.3 months and 34.1 months, respectively. A total of 598 new vascular accesses (77% AVFs) were created in the CIMINO group. Prevalent AVF use increased from 58.5% (range: 31-79%) to 62.7% (range: 45-83%) in the CIMINO group and from 65.5% (range: 31-91%) to 67.3% (range: 42-91%) in the control group. The increase in AVF use per year was significantly quicker than in the control group (P<0.05). Use of untunnelled catheters decreased whereas that of tunnelled catheters increased. CONCLUSIONS: This initiative shows that a multicentre guidelines implementation programme results in an accelerated increase of AVF use in comparison with a time control group. These data suggest that the choice of access placement depends predominantly on centre-specific factors.