Does operative time affect infection rate in primary total knee arthroplasty?

Coronal plane deformity in total knee arthroplasty is associated with increased operative time and disposition to skilled nursing facility

PURPOSE

Studies demonstrate similar long-term Total Knee Arthroplasty (TKA) outcomes in patients with significant versus minimal preoperative coronal plane deformity. Limited short-term outcomes data, which determine costs of care, exist.

METHODS

We retrospectively explored the impact of preoperative coronal plane deformity on operative time, length of stay (LOS), and discharge to skilled nursing facility (SNF) in TKA. A total of 3,964 patients undergoing unilateral primary TKA at our institution from 2014 to 2019 were included (1,158 > 10˚ deformity: mean age 67.2 years, 47% male; 2,806 < 10˚ deformity: mean age 67 years, 37.4% male). The degree of coronal plane deformity (mechanical axis deviation on preoperative radiographs) was recorded. Patients with no knee radiographs ≤ 3 years preoperatively were excluded. Statistical analysis included Chi-Square tests, Student's t-tests, Mann-Whitney U tests, and uni- and multivariable linear and logistic regression analyses.

RESULTS

The > 10˚ deformity cohort had a longer time from procedure start to finish (113.56 vs. 110.68 min; p = 0.020), greater deviation from surgeon mean operative time (+ 6.19 vs. + 0.69 min; p < 0.001), and higher proportion of cases requiring > 15 (26.8% vs. 22%;p = 0.001) and > 30 (12.3% vs. 7.8%;p < 0.001) additional minutes over their scheduled times. LOS was similar between cohorts (median 2 days, IQR 1-3). The deformity cohort more likely discharged to SNF (19.9% vs. 15.8%;p = 0.002). For every 1˚ increase in coronal plane deformity, operative time increased by 0.566 min (p = 0.000). The odds of SNF discharge increased with increasing coronal plane deformity (OR 1.029 [1.009,1.050]; p = 0.004).

CONCLUSION

Greater preoperative coronal deformity is associated with increased operative time and odds of discharge to SNF in TKA.

Intermittent tourniquet compared to throughout tourniquet use during Total Knee Arthroplasty in patients with Body Mass Index of 30 or more: A retrospective cohort study

Background

Tourniquet use during total knee arthroplasty (TKA) reduces bleeding which optimises bone-cement interface for prosthesis stability and improves surgical field visualisation. However, prolonged usage can lead to complications and poorer outcomes. Some surgeons advocate for intermittent tourniquet application. Limited literature exists for patients with high body mass index (BMI). This study aims to compare the outcomes of intermittent tourniquet (IT) to throughout tourniquet (TT) use among obese patients undergoing primary TKA for knee osteoarthritis.

Methods

This was a retrospective cohort study. In the TT group, tourniquet was inflated from the beginning and released once the bone cement has hardened. In the IT group, tourniquet was inflated at the beginning, released after initial incision and haemostasis, then inflated again during cementation. Tourniquet was released once the bone cement had set. Categorical outcome measures were analysed using Chi-squared or Fisher's exact test. T-test or Kruskal-Wallis test were used for continuous data.

Results

When comparing IT to TT among patients with BMI≥30 (IT n = 48, TT n = 47), the mean duration of surgery was shorter in the TT group (p < 0.05). The difference in haemoglobin drop between the two groups was not statistically significant from post-operative day three onwards. There was no difference in transfusion rate (p > 0.05). ROM was greater in the IT group up to three weeks post-operatively (p < 0.05). When comparing patients with BMI <30 (n = 71) and BMI≥30 (n = 48) with IT use, there was no statistically significant difference in ROM and LOS.

Conclusion

Patients with BMI≥30 in the IT group had greater ROM in the initial post-operative period. Although operative time and blood loss were greater among the IT group, there was no difference in transfusion rate. Outcomes of TKA performed with IT were similar for patients with BMI≥30 and BMI <30. The authors recommend intermittent tourniquet use during TKA for patients with BMI≥30.

Level of evidence

3.

Comparison of robotic-assisted total knee arthroplasty: an updated systematic review and meta-analysis

This study was conducted to compare the changes in different clinical scores and imaging indexes of patients who underwent robot-assisted total knee arthroplasty (RA-TKA) and manual total knee arthroplasty (M-TKA). PubMed, Web of Science, Cochrane Library and Embase were searched according to PRISMA guidelines in June 2024. Search terms included "robot-assisted", "manual" and "total knee arthroplasty". Outcome indicators included American Knee Society Score (KSS), Western Ontario McMaster Universities Osteoarthritis Index (WOMAC), Oxford Knee Score (OKS), range of motion (ROM), Hospital for Special Surgery (HSS) score, Forgotten Joint Score (FJS), 36-Item Short Form Health Survey (SF-36), operation duration (min), intraoperative blood loss (ml), pain score, patient's satisfaction scores, hip-knee-ankle (HKA) angle, frontal femoral component angle, frontal tibia component angle, lateral femoral component angle and lateral tibia component angle. A total of 1,033 articles were obtained after removing duplicates, and 12 studies involving 2,863 patients (1,449 RA-TKAs and 1,414 M-TKAs) were finally meta-analyzed (22-32). The baseline data of both groups were similar in all results. Meta-analysis suggested a better performance of the RA-TKA group than the M-TKA group regarding the HKA angle. The manual TKA reduced the operation time and significantly improved the range of motion. The results of > 6 months follow-up showed that M-TKA was better than RA-TKA in terms of KSS score and WOMAC. Compared with M-TKA, RA-TKA can produce more accurate prosthetic alignment, but it does not lead to better clinical results. Orthopedic surgeons should choose between two surgical procedures according to their own experience and patients' characteristics.

Greater Risk of Periprosthetic Joint Infection Associated with Prolonged Operative Time in Primary Total Knee Arthroplasty: Meta-Analysis of 427,361 Patients

Background/Objectives: Periprosthetic joint infection (PJI) is a severe complication in total knee arthroplasty (TKA) with catastrophic outcomes. The relationship between prolonged operative times and PJI remains debated. This meta-analysis investigated the link between prolonged operative times and the risk of PJI in primary TKA. Methods: A comprehensive search of the MEDLINE/PubMed, Cochrane Library, and EMBASE databases was conducted to identify studies comparing the incidence of PJI in TKAs with prolonged versus short operative times, as well as those comparing operative times in TKAs with and without PJI. Pooled standardized mean differences (SMD) in operative times between groups with and without PJI or surgical site infections (SSI), including superficial SSIs and PJIs, were analyzed. Additionally, the pooled odds ratios (OR) for PJI in TKAs with operative times exceeding 90 or 120 min were examined. Results: Seventeen studies involving 427,361 patients were included. Significant differences in pooled mean operative times between the infected and non-infected TKA groups were observed (PJI, pooled SMD = 0.38, p < 0.01; SSI, pooled SMD = 0.72, p < 0.01). A higher risk of PJI was noted in surgeries lasting over 90 or 120 min compared to those of shorter duration (90 min, pooled OR = 1.50, p < 0.01; 120 min, pooled OR = 1.56, p < 0.01). Conclusions: An association between prolonged operative time and increased risk of PJI in primary TKA has been established. Strategies for infection prevention should encompass thorough preoperative planning aimed at minimizing factors that contribute to prolonged operative times.

Is Operative Time Associated With Obesity-related Outcomes in TKA?

BACKGROUND

Obesity-based cutoffs in TKA are premised on higher rates of postoperative complications. However, operative time may be associated with postoperative complications, leading to an unnecessary restriction of TKA in patients with obesity. If operative time is associated with these obesity-related outcomes, it should be accounted for in order to ensure all measurable factors associated with negative outcomes are examined for patients with obesity after TKA.

QUESTIONS/PURPOSES

We asked: (1) Is operative time, controlling for BMI class, associated with readmission, reoperation, and postoperative major and minor complications? (2) Is operative time associated with a difference in the direction or strength of obesity-related adverse outcomes?

METHODS

In this comparative study, we extracted all records on elective, unilateral TKA between January 2014 and December 2020 in the American College of Surgeons National Surgical Quality Improvement Program database, resulting in an initial sample of 394,381 TKAs. Patients with emergency procedures (0.1% [270]) and simultaneous bilateral TKAs (2% [8736]), missing or null data (1% [4834]), and those with operative times less than 25 minutes (0.1% [548]) were excluded, leaving 96% (379,993) of our original sample size. The National Surgical Quality Improvement Program database was selected because of its inclusion of operative time, which is not found in any other national database. BMI was subdivided into underweight (BMI < 18.5 kg/m 2 , < 1% [719]), normal weight (BMI 18.5 to 24.9 kg/m 2 , 9% [34,513]), overweight (BMI 25.0 to 29.9 kg/m 2 , 27% [101,538]), Class I obesity (BMI 30.0 to 34.9 kg/m 2 , 29% [111,712]), Class II obesity (BMI 35.0 to 39.9 kg/m 2 , 20% [76,605]), and Class III obesity (BMI ≥ 40.0 kg/m 2 , 14% [54,906]). The mean operative time was 91 ± 36 minutes, 61% of patients were women (233,062 of 379,993), and the mean age was 67 ± 9 years. Patients with obesity tended to be younger and more likely to have preoperative comorbidities and longer operative times than patients with normal weight. Multivariable logistic regression models examined the main effects of operative time with respect to 30-day readmission, reoperation, and major and minor medical complications, while adjusting for BMI class and other covariates including age, sex, race, smoking status, and number of preoperative comorbidities. We then evaluated the potential interaction effect of BMI class and operative time. This interaction term helps determine whether the association of BMI with postoperative outcomes changes based on the duration of the surgery, and vice versa. If the interaction term is statistically significant, it implies the association of BMI with adverse postoperative outcomes is inconsistent across all patients. Instead, it varies with the operative time. Adjusted odds ratios and 95% confidence intervals were calculated, and interaction effects were plotted.

RESULTS

After controlling for obesity, longer procedure duration was independently associated with higher odds of all outcomes (30-minute estimates; adjusted ORs are per minute), including readmission (9% per half-hour of surgical duration; adjusted OR 1.003 [95% CI 1.003 to 1.004]; p < 0.001), reoperation (15% per half-hour of surgical duration; adjusted OR 1.005 [95% CI 1.004 to 1.005]; p < 0.001), postoperative major complications (9% per half-hour of surgical duration; adjusted OR 1.003 [95% CI 1.003 to 1.004]; p < 0.001), and postoperative minor complications (18% per half-hour of surgical duration; adjusted OR 1.006 [95% CI 1.006 to 1.007]; p < 0.001). The interaction effect indicates that patients with obesity had lower odds of reoperation than patients with normal weight when operative times were shorter, but higher odds of reoperation with a longer operative duration.

CONCLUSION

We found that operative time, a proxy for surgical complexity, had a moderate, differential association with obesity over a 30-minute period. Perioperative modification of surgical complexity such as surgical techniques, training, and team dynamics may make safe TKA possible for certain patients who might have otherwise been denied surgery. Decisions to refuse TKA to patients with obesity should be based on a holistic assessment of a patient's operative complexity, rather than strictly assessing a patient's weight or their ability to lose weight. Future studies should assess patient-specific characteristics that are associated with operative time, which can further push the development of techniques and strategies that reduce surgical complexity and improve TKA outcomes.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Clinical Outcomes of Offset Stem Couplers with or without Cone Augmentation in Revision Total Knee Arthroplasty

Intramedullary stems are often required in patients undergoing revision total knee arthroplasty (rTKA) to achieve stable fixation. Significant bone loss may require the addition of a metal cone to maximize fixation and osteointegration. The purpose of this study was to investigate clinical outcomes in rTKA using different fixation techniques. We conducted a single-institution retrospective review of all patients who received a tibial and femoral stem during rTKA between August 2011 and July 2021. Patients were separated into three cohorts based on fixation construct: press-fit stem with an offset coupler (OS), fully cemented straight (CS) stem, and press-fit straight (PFS) stem. A subanalysis of patients who received tibial cone augmentation was also conducted. A total of 358 patients who underwent rTKA were included in this study, of which 102 (28.5%) had a minimum 2-year follow-up and 25 (7.0%) had a minimum 5-year follow-up. In the primary analysis, 194 patients were included in the OS cohort, 72 in the CS cohort, and 92 in the PFS cohort. When stem type alone was considered, there was no significant difference in rerevision rate (p = 0.431) between cohorts. Subanalysis of patients who received augmentation with a tibial cone demonstrated that OS implants led to significantly higher rates of rerevision compared with the other two stem types (OS: 18.2% vs. CS: 2.1% vs. PFS: 11.1%; p = 0.037). The findings of the present analysis demonstrate that CS and cones in rTKA may provide more reliable long-term outcomes compared with press-fit stems with OS. LEVEL III EVIDENCE:  Retrospective Cohort Study.

Global mapping of institutional and hospital-based (Level II-IV) arthroplasty registries: a scoping review

PURPOSE

Four joint arthroplasty registries (JARs) levels exist based on the recorded data type. Level I JARs are national registries that record primary data. Hospital or institutional JARs (Level II-IV) document further data (patient-reported outcomes, demographic, radiographic). A worldwide list of Level II-IV JARs must be created to effectively assess and categorize these data.

METHODS

Our study is a systematic scoping review that followed the PRISMA guidelines and included 648 studies. Based on their publications, the study aimed to map the existing Level II-IV JARs worldwide. The secondary aim was to record their lifetime, publications' number and frequency and recognise differences with national JARs.

RESULTS

One hundred five Level II-IV JARs were identified. Forty-eight hospital-based, 45 institutional, and 12 regional JARs. Fifty JARs were found in America, 39 in Europe, nine in Asia, six in Oceania and one in Africa. They have published 485 cohorts, 91 case-series, 49 case-control, nine cross-sectional studies, eight registry protocols and six randomized trials. Most cohort studies were retrospective. Twenty-three per cent of papers studied patient-reported outcomes, 21.45% surgical complications, 13.73% postoperative clinical and 5.25% radiographic outcomes, and 11.88% were survival analyses. Forty-four JARs have published only one paper. Level I JARs primarily publish implant revision risk annual reports, while Level IV JARs collect comprehensive data to conduct retrospective cohort studies.

CONCLUSIONS

This is the first study mapping all Level II-IV JARs worldwide. Most JARs are found in Europe and America, reporting on retrospective cohorts, but only a few report on studies systematically.

Transillumination method in total knee arthroplasty: new approach with old tools

PURPOSE

In this study, we evaluated the possibility of precise intraoperative localization of the lateral genicular arteries by an orthopaedic surgeon using the transillumination method.

METHODS

Twelve patients underwent cemented TKA with patella-friendly Zimmer Biomet NexGen Legacy Posterior Stabilized prostheses (without patellar resurfacing), seven right knees and five left knees. The mean age of patients in the study group was 66.636 ± 7.003 years. The minimal follow-up period was 13 months (mean-16.363 ± 2.5 months). Functional outcomes were assessed using Knee Society and a specific patellar questionnaire-Kujala Score. Intraoperative detection of insufficient patellar stability and/or patellar maltracking was based on the no-thumb technique. In pre- and postoperative period X-ray investigation, standard standing X-ray and Merchant view were used to evaluate implant position and patellofemoral congruency.

RESULTS

In this study, ten out of twelve knee joints (83.3%) had at least one artery visible by the proposed method in the lateral parapatellar area. Five out of ten knee joints had more than one artery that could be visualized and identified as an arterial vessel. Postoperative Knee Society Score showed significant improvement from a mean 51.181 ± 3.868 to a mean 88.727 ± 3.663. Mean hospital length of stay is 8.545 ± 1.863 days. X-ray assessment using standard anteroposterior, lateral, and Merchant skyline views showed appropriate implant positioning and patellofemoral congruency. The mean Kujala Score in the postoperative period (3 and 6 months) was 67.3 ± 6.75 and 75.6 ± 6.42, respectively.

CONCLUSIONS

Using the proposed transillumination method can help preserve the lateral blood supply to the patella and to avoid devascularized patella-related complications.

TRIAL REGISTRATION

Retrospectively registered on 5 of May 2023, Registration number - 3/3-1757.

The Effect of American Society of Anesthesiologists Score and Operative Time on Surgical Site Infection Rates in Major Abdominal Surgeries

BACKGROUND

The objective of this study was to evaluate the influence of two crucial variables, the American Society of Anesthesiologists (ASA) score and operative time, on the occurrence of surgical site infections (SSIs) in the context of major abdominal surgical procedures.

METHODOLOGY

A cross-sectional research study involved patients undergoing various gastrointestinal surgical procedures. Surgical details, procedure duration, and ASA score were meticulously documented. Patients were observed for surgical site infections (SSIs) during their inpatient stay until discharge. Following their discharge, patients were monitored in the outpatient department for a minimum of 30 days post-surgery, and those who underwent mesh procedures were observed for one year.

RESULTS

In the overall study population, surgical site infections were identified in 42 cases, constituting 6.7%. There was a significant association between ASA grade and the incidence of surgical site infections (p=0.001), indicating a higher prevalence of infections in cases with elevated ASA grades. Furthermore, a statistically significant association exists between the average duration of surgery and the occurrence of surgical site infections (p=0.001). The mean surgery duration for cases with infections is reported as 206.33 min, with a standard deviation of 103.73, while for cases without infections, the mean duration is 99.72 min, with a standard deviation of 79.71. In the multivariate analysis, it was found that an ASA score of 3 or higher and operative time exceeding 90 min were identified as independent factors for predicting the likelihood of surgical site infections.

CONCLUSION

 The significant associations identified between the American Society of Anesthesiologists (ASA) grade, average surgery duration, and SSIs underscore the importance of comprehensive preoperative assessment and procedural management in infection prevention.

Does experience with total knee arthroplasty in morbidly obese patients effect surgical outcomes

INTRODUCTION

Literature examining the risks, benefits, and potential complications of TKA in morbidly obese patients is conflicting. Surgeons with more experience performing TKA on morbidly obese patients may generate superior outcomes. This study sought to assess whether complication rates and implant survivorship in morbidly obese TKA patients varies between high (HV) and low (LV) volume surgeons.

METHODS

A retrospective review was performed to include all morbidly obese (BMI ≥ 40) patients that underwent primary TKA between January 2016 and July 2021 at our high-volume center. Demographics and clinical outcomes were collected and compared between surgeons with a higher morbidly obese TKA volume (> 10 annual cases) and surgeons with a lower morbidly obese TKA volume.

RESULTS

A total of 964 patients (HV 91 [9.4%], LV 873 [90.6%]) were identified. The HV surgeon and LV surgeons had an average annual volume of 15.3 and 5.2 cases, respectively. The average BMI for the HV and LV cohorts were 44.5 ± 3.7 and 44.0 ± 3.6, respectively (p = 0.160). The HV surgeon had significantly lower operative times (105.7 ± 17.4 vs. 110.7 ± 29.6 min, p = 0.018), and a lower 90-day minor complication rate (0.0% vs. 4.7%, p = 0.035). For patients with at least 2-year follow-up, all-cause revision (3.4% vs. 12.5%, p = 0.149) and revision due to PJI (0.0% vs. 5.8%, 0.193) rates were numerically lower in the HV cohort. Improvements in KOOS, JR and VR-12 scores were similar at 3-month and 1-year follow-up. Freedom from all-cause revision (HV: 96.6% vs. LV: 80.4%, p = 0.175) and revision due to PJI (HV: 100.0% vs. LV: 93.6%, p = 0.190, p = 0.190) at latest follow-up did not statistically differ between groups.

CONCLUSION

The HV surgeon had significantly lower operative time and 90-day minor complication rates and numerically lower all-cause revision and revision due to PJI rates when performing TKA in morbidly obese patients. Surgeon's experience may affect surgical outcomes after TKA in morbidly obese patients.

LEVEL OF EVIDENCE

III.

Banded Versus Non-banded Sleeve Gastrectomy: A Systematic Review and Meta-Analysis

Standard bariatric surgeries include biliopancreatic diversion (BPD), sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), and adjustable gastric banding (AGB). Laparoscopic sleeve gastrectomy (LSG) is currently favored due to safety, efficacy, and shorter operation time. However, previous literature shows 75.6% weight regain post LSG. Introducing Laparoscopic band sleeve gastrectomy (LBSG) to maintain pouch size is proposed to improve outcomes and reduce weight regain. This study aims to compare the safety and efficacy of LSG vs. LBSG in obese patients. A comprehensive search strategy was executed to identify pertinent literature comparing LBSG and LSG in obese patients. Eligible studies underwent independent screening, and pertinent data were systematically extracted. The analysis employed pooled risk ratios (RR) for dichotomous outcomes and mean differences (MD) for continuous variables, each accompanied by their respective 95% confidence intervals (CI). Our systematic review and meta-analysis included 15 studies encompassing 3929 patients. Regarding body mass index (BMI), at six, 12, and 24 months, no substantial differences were found between LBSG and LSG groups (p < 0.05). Still, at 36 months, LBSG exhibited significantly lower BMI than LSG (MD = -2.07 [-3.84, -0.29], p = 0.02). Excess Weight Loss (EWL) favored LBSG at 12, 24, and 36 months with MD of 3.30 [0.42, 6.18], 4.13 [1.44, 6.81], and 18.43 [9.44, 27.42], p = 0.02, 0.003, < 0.00001, respectively). Operative time did not significantly differ between the procedures (MD = 2.95, 95%CI [-0.06, 5.95], p = 0.05). Resolution of comorbidities, overall complications, post-operative bleeding, reflux, and early complications did not significantly differ between LBSG and LSG. However, LBSG showed higher post-operative regurgitation than LSG (RR = 2.38, 95%CI [1.25, 4.54], p = 0.008). LBSG showed a substantial decrease in BMI at three-year follow-up and higher EWL at one, two, and three years. However, LBSG procedures exhibited a higher incidence of post-operative regurgitation symptoms than LSG. No substantial differences were noted in BMI at six, 12, or 24 months, EWL at six months, operative time, bleeding, reflux, or overall complications.

Resident Impact on Primary Total Knee Arthroplasty: A Consecutive Series Under a Single Surgeon

Background

The literature has displayed conflicting evidence on resident involvement in surgical procedures. The goal of this study was to assess the impact of resident involvement on primary total knee arthroplasty (TKA) under a single fellowship-trained adult reconstruction surgeon.

Methods

Two hundred sequential patients were retrospectively reviewed by a single surgeon: the first cohort represented the final 100 TKAs performed by the surgeon without resident involvement (NRI), serving as the control group, and the second cohort represented the initial 100 TKAs performed by the same surgeon with resident involvement (RI), serving as the experimental group. Perioperative variables such as number of people in operating room (OR), surgical time, and tourniquet time, and postoperative variables such as infection, minor complications, medial distal femoral angle, medial proximal tibia angle, and total angulation were assessed.

Results

The rate of infection was significantly lower in the RI group (0%) compared to the NRI group (1%) (P = .043). The number of staff in the OR (P < .001), the tourniquet time (P < .001), and OR time (P < .001) were significantly higher in the RI group compared to the NRI group. There was no difference in coronal plane radiographic measurements: medial distal femoral angle (P = .10), medial proximal tibia angle (P = .19), or total angulation (P = .27).

Conclusions

Resident involvement in primary TKA neither demonstrated any significant difference in coronal plane radiographic alignment of the prosthesis nor an increased risk of infection despite increased operative time, tourniquet time, and number of people in OR.

Level of evidence

Level 3 - Therapeutic retrospective cohort study.

Increased complications rates and inferior patient reported outcomes following total knee arthroplasty due to post-traumatic osteoarthritis with previous fracture treatment: a systematic review

PURPOSE

This study aims to present the existing literature relating to patient-reported outcome measures (PROMs) and complications in patients undergoing total knee arthroplasty (TKA) due to posttraumatic osteoarthritis (PTOA) with prior fracture treatment around the knee compared with patients who underwent TKA because of primary osteoarthritis (OA).

METHODS

A systematic review was undertaken and synthesised in accordance with the PRISMA guidelines by searching existing literature in the following databases: PubMed, Scopus, Cochrane Library and EMBASE. A search string according to the PECO was used. After analysing 2781 studies, 18 studies (5729 PTOA patients/149,843 OA patients) were included for a final review. An analysis revealed that 12 (67%) were retrospective cohort studies, four (22%) were register studies and the remaining two (11%) were prospective cohort studies. The mean Critical Appraisal Skills Programme (CASP) score was 23.6 out of 28, signifying studies of moderate quality.

RESULTS

The most frequently reported outcome measure were postoperative complications, reported in all eighteen studies. Intraoperative complications were reported in ten (4165 PTOA/124.511 OA) and patient-reported outcome measures (PROMs) in six studies (210 PTOA/2768 OA). A total of nine different PROMs were evaluated. As far as PROMs were concerned, the scores were inferior for PTOA but did not differ statistically from OA, except for one study, which favoured the OA group. Across all studies, postoperative complications were higher in the PTOA group, reporting infections as the most common complication. Furthermore, a higher revision rate was reported in the PTOA group.

CONCLUSION

PROM analysis suggests that both patient groups benefit from a TKA in terms of functional outcome and pain relief, however, patient-reported outcomes could be inferior for PTOA patients. There is consistent evidence for increased complication rates following PTOA TKA. Patients undergoing TKA due to PTOA after fracture treatment should be informed about the risk for inferior results and refrain from comparing their knee function to patients with TKA after OA. Surgeons should be aware of the challenges that PTOA TKA poses.

LEVEL OF EVIDENCE

Level III.

A Systematic Review of Data Collection by National Joint Replacement Registries: What Opportunities Exist for Enhanced Data Collection and Analysis?

BACKGROUND

National joint replacement registries assist surgeons and hospitals with guiding decision making and quality of care. The data points collected are essential to interpret and analyze data and to understand confounding variables and other sources of bias, which can impair retrospective observational research. The aim of this study was to review all national joint replacement registries to assess what data points are recorded, and in what manner, for primary and revision total hip arthroplasty (THA) and total knee arthroplasty (TKA) so that improvements can be made to enhance data collection, interpretation, and analysis.

METHODS

All national registries were identified through Internet and publication search and contacted to invite participation. Data collection forms for both primary and revision THA and TKA were requested. Data collected were entered into an Excel spreadsheet.

RESULTS

The study group for primary and revision THA consisted of 28 national registries, with 26 agreeing to participate. The study group for primary TKA consisted of 27 national registries, with 24 agreeing to participate. Patient identification details were recorded uniformly. Only a minority recorded patient details beyond American Society of Anesthesiologists and body mass index. Most registries did not record surgeon variables: who actually performed or assisted the procedure and their level of training. There was variation in the degree of detail recorded for diagnosis, mostly regarding secondary causes of osteoarthritis and fracture. The details regarding case complexity were limited. Half recorded previous operations, and fewer recorded bone defects. The location of knee arthritis, preoperative limb alignment, and deformities were rarely recorded. Surgical approach and technological adjuncts were routinely collected, but few other details on the surgical technique were recorded. Implant details and fixation were uniformly collected, although a minority recorded specific details, including cement antibiotic or cementing technique. It was uncommon to record whether additional or adjunctive procedures were concurrently performed. Approximately half the registries lacked a revision specific form. The majority recorded reoperations in addition to revision procedures. Patient, surgeon, case, and postoperative details were recorded similar to primary procedures. There was variation in the degree of details recorded for the reasons underlying the revision +/- reoperation, with most recording greater detail for infection and fracture. Many included details on case complexity and bone defects, including the severity, classification, and how the defect was managed. The majority recorded the specific revision procedure that was performed (total or partial), the fixation used, and the components removed or revised. Other specific aspects of fixation including acetabular screws, cone or sleeve use, stems, and augments were less commonly recorded.

CONCLUSION

Substantial data are recorded by all registries, although each one is different. Data solicited lack many patient factors, surgeon variables, case complexity, and surgical techniques. Separate revision forms are not universal, and many registries do not record reoperation procedures, specific causes of revision, and the revision construct.

LEVEL OF EVIDENCE

Level II, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Increased operative time has a negative impact on clinical outcome in arthroscopic rotator cuff repair

BACKGROUND

Few data are available about the impact of operative time on outcome of rotator cuff repair.

AIM

The aim of this study was to evaluate the impact of operative time on clinical outcome and tendon healing after arthroscopic rotator cuff repair.

METHODS

Patients operated on for distal supraspinatus tear in our institution between 2012 and 2018 were included retrospectively. Operative time, from skin incision until skin closure, was extracted from medical files. For statistical analysis, operative time was treated as a quantitative variable. Endpoints were clinical outcome (Constant score, range of motion), tendon healing (on CT or MRI) and complications at 1 year. The significance threshold was set at p = 0.05.

RESULTS

A total of 219 Patients, with a mean age of 54.6 years (range 40-70 years), were included. Mean operative time 44.9 min (range 14-140 min). Significant correlations (p < 0.05) were found for Constant score and external rotation at 1 year: increasing operative time by 1 min led to a decrease in Constant score of 0.115 points, or 6.9 points for a 60-min increase (p = 0.0167) and a decrease in external rotation of 0.134°, or 8.04° for a 60-min increase (p = 0.0214). No significant correlations were found for anterior elevation at 1 year (p = 0.2577), tendon healing at 1 year (p = 0.295) or onset of complications during follow-up (p = 0.193).

DISCUSSION

The minimal clinically important difference in Constant score in patients undergoing rotator cuff surgery is between 6 and 10 points. An increase of more than 60 min in operative time significantly impacted clinical outcome of arthroscopic distal supraspinatus repair, but not tendon healing.

LEVEL OF EVIDENCE

Level III: Retrospective Cohort Design. Therapeutic Study.

The Frequency and Severity of Complications in Surgical Treatment of Osteochondral Lesions of the Talus: A Systematic Review and Meta-Analysis of 6,962 Lesions

OBJECTIVE

The primary aim was to determine and compare the complication rate of different surgical treatment options for osteochondral lesions of the talus (OLTs). The secondary aim was to analyze and compare the severity and types of complications.

DESIGN

A literature search was performed in MEDLINE (PubMed), EMBASE (Ovid), and the Cochrane Library. Methodological quality was assessed using the Methodological Index for Non-Randomized Studies (MINORS). Primary outcome was the complication rate per surgical treatment option. Secondary outcomes included the severity (using the Modified Clavien-Dindo-Sink Complication Classification System for Orthopedic Surgery) and types of complications. The primary outcome, the severity, and the sub-analyses were analyzed using a random effects model. A moderator test for subgroup-analysis was used to determine differences. The types of complications were presented as rates.

RESULTS

In all, 178 articles from the literature search were included for analysis, comprising 6,962 OLTs with a pooled mean age of 35.5 years and follow-up of 46.3 months. Methodological quality was fair. The overall complication rate was 5% (4%-6%; treatment group effect, P = 0.0015). Analysis resulted in rates from 3% (2%-4%) for matrix-assisted bone marrow stimulation to 15% (5%-35%) for metal implants. Nerve injury was the most observed complication.

CONCLUSIONS

In 1 out of 20 patients treated surgically for an OLT, a complication occurs. Metal implants have a significantly higher complication rate compared with other treatment modalities. No life-threatening complications were reported.

Impact of time to revision total knee arthroplasty on outcomes following aseptic failure

INTRODUCTION

Prior studies have demonstrated an association between time to revision total knee arthroplasty (rTKA) and indication; however, the impact of early versus late revision on post-operative outcomes has not been reported.

MATERIALS AND METHODS

A retrospective, observational study examined patients who underwent unilateral, aseptic rTKA at an academic orthopedic hospital between 6/2011 and 4/2020 with > 1-year of follow-up. Patients were early revisions if they were revised within 2 years of primary TKA (pTKA) or late revisions if revised after greater than 2 years. Patient demographics, surgical factors, and post-operative outcomes were compared.

RESULTS

470 rTKA were included (199 early, 271 late). Early rTKA patients were younger by 2.5 years (p = 0.002). The predominant indications for early rTKA were instability (28.6%) and arthrofibrosis/stiffness (26.6%), and the predominant indications for late rTKA were aseptic loosening (45.8%) and instability (26.2%; p < 0.001). Late rTKA had longer operative times (119.20 ± 51.94 vs. 103.93 ± 44.66 min; p < 0.001). There were no differences in rTKA type, disposition, hospital length of stay, all-cause 90-day emergency department visits and readmissions, reoperations, and number of re-revisions.

CONCLUSIONS

Aseptic rTKA performed before 2 years had different indications but demonstrated similar outcomes to those performed later. Early revisions had shorter surgical times, which could be attributed to differences in rTKA indication.

LEVEL OF EVIDENCE

III, retrospective observational analysis.

Intraoperative technology increases operating room times in primary total knee arthroplasty

INTRODUCTION

Optimization of patient outcomes and identification of factors to improve the surgical workflow are increasingly important. Operating room time is one modifiable factor that leads to greater hospital efficiency as well as improved outcomes such as shorter length of stay and fewer infections and readmissions. The aim of this study was to identify factors associated with operative time disparities in total knee arthroplasty (TKA).

METHODS

A retrospective review of 7659 consecutive primary TKA cases was conducted. Patient demographic data, discrete operating room (OR) times, use of technology (i.e. robotic-assisted surgery, computer navigation), surgeon experience and the level of training of the first assistant were collected. Multivariate regression analysis was used to determine the effect of hospital characteristics on operative times. Operative times of five minutes or greater were considered to be clinically significant.

RESULTS

While the use of technology (182.64 ± 39.85 vs 158.70 ± 37.45 min; B = 26.09; p < 0.0001) and greater surgeon experience (162.14 ± 39.87 vs 158.69 ± 33.18 min, B = 3.15, p = 0.002) were found to increase OR times, level of training of the first assist (161.65 vs 156.4 min; Β = - 0.264; p = 0.487) did not. Of the discrete OR times examined, incision time and total time under anesthesia were negatively impacted by the use of technology.

CONCLUSION

Use of technology was the only study variable found to significantly increase OR times. With increased operative times and limited evidence that technology improves long-term patient outcomes, surgeons should carefully consider the benefits and cost of technology in TKA.

Tranexamic acid is not associated with decreased infection risk after primary shoulder arthroplasty: a cohort study of 9276 patients

BACKGROUND

The use of tranexamic acid (TXA) is associated with less blood loss and reduced transfusion risk after shoulder arthroplasty surgery. Recent studies have shown lower odds of postoperative infection after hip or knee arthroplasty with its use. The purpose of this study was to determine whether TXA use reduces the risk of infection after primary elective shoulder arthroplasty.

METHODS

A retrospective cohort study was conducted using data from a US integrated health care system's shoulder arthroplasty registry. Patients aged 18 years who underwent primary elective anatomic total shoulder arthroplasty for osteoarthritis or primary reverse shoulder arthroplasty for rotator cuff arthropathy were included (2013-2020). We compared patients who received preoperative intravenous TXA to those who did not receive TXA by assessing the risk for revision due to deep infection within 5 years' follow-up using multivariable Cox proportional hazard regression. Interaction between TXA and diabetes status was analyzed separately.

RESULTS

The study sample included 9276 shoulder arthroplasties performed by 153 surgeons at 43 hospitals. The mean age was 70.0 years and 48% were male. The 5-year probability of revision for deep infection was 0.8% and 0.7% for patients with and without TXA, respectively. We failed to observe a difference in infection risk after adjustment for confounders and surgeon differences (hazard ratio [HR] 1.00, 95% confidence interval [CI] 0.56-1.80, P = .998). Further, no differences were observed in patients with (HR 1.64, 95% CI 0.42-6.44, P = .481) or without diabetes (HR 0.79, 95% CI 0.40-1.55, P = .488).

CONCLUSION

In a multicenter cohort of more than 9000 primary shoulder arthroplasty procedures, the use of preoperative TXA was not associated with a decrease in the 5-year probability of revision for deep infection.

Is sequential bilateral robotic total knee arthroplasty a safe procedure? A matched comparative pilot study

INTRODUCTION

To our knowledge, no papers have reported the results of robotic-assisted surgery for sequential bilateral Total Knee Arthroplasty (TKA). Indeed, sequential bilateral TKA present several benefits, as one single anesthesia, surgical episode, hospitalization, and rehabilitation. The purpose of our study was to evaluate peri-operative outcomes and compare the complication rates, clinical outcomes, and implant positioning of sequential bilateral TKA performed with a robotic-assisted system versus a conventional technique.

MATERIALS AND METHODS

All patients who underwent a sequential bilateral robotic-assisted primary TKA (raTKA) in our institution between November 2019 and February 2021 were included. Twenty patients met the inclusion criteria and were matched with 20 sequential bilateral TKA performed with a conventional technique. The two groups were comparable for the demographic data and the preoperative parameters, including preoperative anticoagulation and ASA score. The minimum follow-up was 6 months.

RESULTS

The operative time was significantly longer in the robotic group (< 0.0001), with a mean additional time of 29 min. There was no significant difference between both groups for postoperative blood loss, rate of blood transfusion, or postoperative pain. The average length of stay was 5 days. There was one early complication in the robotic group due to the tibial trackers. The functional outcomes were similar between both groups, except for the functional KSS score, which was better at 6 months in the robotic group (p < 0.0001). The restoration of the knee alignment and the distal femoral anatomy were significantly better in the robotic group than in the conventional group.

CONCLUSIONS

Despite a longer operative time, the peri-operative parameters of sequential bilateral TKA were similar between robotic and conventional techniques. Further, sequential bilateral raTKA was at least as safe as a conventional technique, without additional risk of medical complications.

Fat tissue is a poor predictor of 1 year outcomes after total knee arthroplasty: A secondary analysis of a randomized clinical trial

BACKGROUND AND OBJECTIVE

Obesity may increase the risk of adverse events after total knee arthroplasty (TKA). Although body mass index (BMI) is commonly used in categorizing obesity, its accuracy is limited. Body fat percentage (BFP) might indicate adiposity status and predict arthroplasty-related outcomes better than BMI. We investigated whether BFP is predictive of TKA-related outcomes.

METHODS

In this secondary analysis, BFP was measured preoperatively from 294 participants of a randomized trial that investigated the effects of tourniquet and anesthesia methods on TKA. Data concerning in-hospital assessments and events were collected. Knee range of motion (ROM) was measured, the Brief Pain Inventory-short form and Oxford Knee Score questionnaires were used to collect data on patient-reported pain and function, and the 15-dimensional health-related questionnaire was used to assess quality of life preoperatively and 3 and 12 months postoperatively. The patients reported satisfaction to TKA 3 and 12 months postoperatively. Data concerning infectious and thromboembolic events within 90 postoperative days and revision surgery, manipulation under anesthesia, and mortality within 1 year were collected. A separate post hoc analysis was performed for 399 participants to assess the effects of BMI on the respective outcomes.

RESULTS

A 1-unit increase in BFP affected the ROM by -0.37° (95% confidence interval (CI) = -0.60 to -0.13) 12 months after surgery. BFP was not significantly associated with the operation time or adverse events. However, the number of most adverse events remained too low for adjusted analysis. A 1-unit increase in BMI increased the operation time by 0.57 min (95% CI = 0.10 to 1.04) and affected the ROM by -0.47° (95% CI = -0.74 to -0.20) 12 months postoperatively. Neither BFP nor BMI was significantly associated with acute pain, pain management, length of stay, or with pain, function, quality of life, or satisfaction to TKA at 12 months after surgery.

CONCLUSIONS

BFP seems to be a poor predictor of in-hospital results and of patient-reported outcomes 1 year after TKA.

TWITTER HANDLE

In this secondary analysis of a randomized trial, body fat percentage was poorly predictive of clinical outcomes during hospital stay and of patient-reported outcomes 1 year after TKA.

Infections of Tumor Prostheses: An Updated Review on Risk Factors, Microbiology, Diagnosis, and Treatment Strategies

Several causes contribute to the high infection rate in tumor prostheses, including extensive tissue dissection and patients' immunosuppression due to the neoplastic disease. Most of these infections develop within the first 2 years following surgery with 70% of them occurring during the first year, while they are often associated with a low pathogen burden. The pathogenesis of infections in tumor prostheses is linked to bacteria developing in biofilms. Approximately half of them are caused by Staphylococcus spp., followed by Streptococcus spp., Enterococcus spp., and Enterobacteriaceae spp., while multiple pathogens may be isolated in up to 25% of the cases, with coagulase-negative Staphylococci (CoNS) and Enterococccus spp. being the most frequent pair. Although early detection and timely management are essential for complete resolution of these challenging infections, prompt diagnosis is problematic due to the highly varying clinical symptoms and the lack of specific preoperative and intraoperative diagnostic tests. Surgical management with one- or two-stage revision surgery is the mainstay for successful eradication of these infections. The recent advances in laboratory diagnostics and the development of biofilm-resistant prostheses over the past years have been areas of great interest, as research is now focused on prevention strategies. The aim of this study is to review and consolidate the current knowledge regarding the epidemiology, risk factors, microbiology, and diagnosis of infections of tumor prostheses, and to review the current concepts for their treatment and outcomes.

Risk of complications with prolonged operative time in morbidly obese patients undergoing elective total knee arthroplasty

BACKGROUND

Patients with a high body-mass index (BMI) are at increased risk for significant complications after total knee arthroplasty (TKA). We explored whether operative time is a modifiable risk factor for infectious and thromboembolic complications.

METHODS

A retrospective observational cohort study of the ACS-NSQIP registry, including all patients who underwent primary TKA (2015-2018), and were morbidly obese (BMI 40 kg/m² or greater) was performed. We created four categories of operative time in minutes: less than 60, 60-90, 91-120, and greater than 120. The association of prolonged operative time with superficial/deep surgical site infection (SSI), DVT and PE within 30 days postoperatively was evaluated using multivariate logistic regression.

RESULTS

34,190 patients were included (median age 63 [IQR 57-68], mean BMI of 44.6 kg/m² [SD 4.4]). The majority of patients had an operative time between 60-90 mins (n = 13,640, 39.9%) or 91-120 mins (n = 9908, 29.0%). There was no significant association between longer operative time and superficial/deep/organ-space SSI or PE. DVT risk was significantly increased. Patients with time exceeding 120 mins had nearly 2.5 greater odds of DVT compared to less than 60 minutes (OR 2.47, 95% CI: 1.39-4.39, P = 0.002). Odds of DVT were 1.73 times greater in those with time of 91-120 mins (OR 1.73, 95%CI: 0.98-3.05, P = 0.06).

CONCLUSION

Early infection and thromboembolic complications with prolonged operative time in morbidly obese patients remain low. We did not identify a significant association with increased operative time and superficial/deep SSI, or PE. There was a significantly increased risk for deep vein thrombosis with prolonged operative time.

Fast-Track for Total Ankle Replacement: A Novel Enhanced Recovery Protocol for Select Patients

BACKGROUND

Enhanced recovery after surgery programs, also called fast-track protocols, were developed and successfully applied in the last decade for hip and knee reconstruction. Specific fast-track protocols have not yet been applied to ankle prostheses. The aim of the study was to develop and validate an enhanced recovery protocol for total ankle replacement (TAR) evaluating the clinical and radiographic results. We hypothesize that on the basis of well-defined pre- and postoperative characteristics, the current knowledge on ankle replacement, and referring to hip and knee reconstruction, it is possible to identify a "patient type" to be safely eligible to a Fast-Track Protocol with at least comparable results and without increasing the complications risk.

METHODS

We identified 8 predictive variables that might affect the outcome of TAR. Those variables were the body mass index, the state of anxiety or depression, the functional preoperative status, ankle equinus, the coronal malalignment, the surgical time, the surgical accessory procedures, and the bone quality. These characteristics were evaluated for each patient with almost validated outcome tools attributing a specific score. Based on the score obtained, the patients were divided into 2 groups: the Standard Protocol group (Control Group) and the Fast-Track Protocol group (Study Group). The main difference between treatment of the 2 groups relates to the use of postoperative plaster casts: in the Fast-Track group the cast was removed the first day after surgery and walking was allowed in sports shoes assisted with crutches, whereas in the Standard Protocol group, the cast was removed after 3 weeks. Clinical and radiographic evaluation was performed for all patients preoperatively and postoperatively every 6 months.

RESULTS

A total of 163 patients received a score between 1 and 5 and were included in the control group (Standard Protocol); 47 patients received a score of 0 and were allocated to the study group (Fast-Track Protocol). Clinically, except for the preoperative American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot scale score, no statistically significant differences were recorded in the multiple comparisons between the 2 groups. No significant differences were found regarding complications.

CONCLUSION

In selected patients, it is possible to apply an enhanced recovery protocol of rehabilitation, focused on immediate weightbearing and mobilization without any plaster or boot.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

Simultaneous bilateral total knee arthroplasty is safe and effective for patients in different ages

BACKGROUND

Simultaneous bilateral total knee arthroplasty is considered beneficial for patients with bilateral end-stage knee osteoarthritis, even though there could be potential postoperative complications. Presently, there is a paucity of evidence of the efficacy and safety of SB-TKA for elderly patients. This study aimed to compare the clinical outcomes of simultaneous bilateral total knee arthroplasty by different age groups.

METHODS

A total of 216 knees of 108 patients, who underwent simultaneous bilateral total knee arthroplasty for osteoarthritis at our hospital between April 2015 and September 2018, were divided into three groups based on age: 60s (44 knees), 70s (106 knees), and 80s (66 knees). Perioperative data and postoperative clinical outcomes 1 year after surgery were compared between the age groups.

RESULTS

The patients in the Group 60s were characterized by a higher body mass index (BMI) (P < 0.01), a lower pre-operative knee function score (P < 0.01), longer operation time (P < 0.01), greater intra-operative (P < 0.01), and postoperative bleeding (P = 0.026). No significant difference was found in terms of occurrence of various postoperative complications, although deep vein thrombosis and delirium occurred slightly more frequently in the Group 70s and the Group 80s than in the Group 60s group. The Knee Society Knee Score, a function score, and patient satisfaction scores were significantly improved in all groups 1 year after surgery. Moreover, these indexes of clinical outcomes were similar among the three groups.

CONCLUSION

Performing simultaneous bilateral total knee arthroplasty in 80s patients was found to be as safe and effective as in the 60s and 70s patients.

LEVEL OF EVIDENCE

3 (A retrospective cohort study).

Complications and downsides of the robotic total knee arthroplasty: a systematic review

PURPOSE

The purpose of this systematic review is to describe the complications and downsides of robotic systems in total knee arthroplasty (TKA).

METHODS

A comprehensive search according to the PRISMA guidelines was performed across PubMed, MEDLINE, Cochrane Central Register of Controlled Trials, Scopus, and Google Scholar from inception until December 2021. All articles of any study design directly reporting on complications and downsides of the robotic system in TKA were considered for inclusion. Risk of bias assessment was performed for all included studies using the Cochrane risk of bias and MINORS score.

RESULTS

A total of 21 studies were included, consisting of 4 randomized controlled trials, 7 prospective studies and 10 retrospective studies. Complications of the robotic system were pin-hole fracture, pin-related infection, iatrogenic soft tissue and bony injury, and excessive blood loss. While, downsides were longer operative duration, higher intraoperative cost, learning curve and aborting a robotic TKA due to different reasons. Iatrogenic injuries were more common in the active robotic system and abortion of the robotic TKA was reported only with active robotic TKA.

CONCLUSION

Robotic TKA is associated with certain advantages and disadvantages. Therefore, surgeons need to be familiar with the system to use it effectively. Widespread adoption of the robotic system should always be evidence-based.

LEVEL OF EVIDENCE

IV.

EFFICACY AND SAFETY OF KNOTLESS BARBED SUTURES IN CAPSULAR CLOSURE FOLLOWING DISTAL FEMUR FRACTURE FIXATION

Introduction

Good wound closure is an important step in management of distal femur fracture to prevent infection and faster rehabilitation. Knotless barbed sutures can save time and distribute wound tension evenly. However, its role in terms of functional outcome, closure time, and postoperative complications has not been studied in a distal femur fracture.

Material and methods

A total of 47 patients aged more than 18 years of distal femur fracture treated with distal femur locking plate were randomized either into either barbed or traditional suture groups. in the barbed group, capsular wound closure was carried out with 2-0 bidirectional barbed knotless sutures (Quill SRS^® PDO, Angiotech, Vancouver, BC, Canada). In patients assigned to group B, capsular closure was done with 1-0 Vicryl^® (Ethicon inc. Somerville, NJ) and 5-0 Ethibond^® alternatively.

Results

The mean flexion at the knee joint was 105.7±15.6 degrees in the study group while it was 110.4±13.7 in the control group (p= 0.2133). Mean estimated closure time was significantly shorter in the study group as compared to the control group (p<0.05). Cases of needle prick injury were higher in traditional suture group. Patients developed stitch abscess and superficial infection in both groups. However, the difference in incidence between the two was not statistically significant.

Conclusion

Barbed suture is an efficient method of wound closure. It reduces wound closure time with similar complication rate as with use of conventional sutures. Evidence Level II; Randomized Clinical Trial.

Where are We Now and What are We Hoping to Achieve with Robotic Total Knee Arthroplasty? A Critical Analysis of the Current Knowledge and Future Perspectives

Robotic-assisted total knee arthroplasty (rTKA) has been developed to improve knee kinematics and functional outcomes, expedite recovery, and improve implants long-term survivorship. Robotic devices are classified into active, semi-active, and passive, based on their degree of freedom. Their capacity to provide increased accuracy in implants positioning with reduced radiographic outliers has been widely proved. However, these early advantages are yet to be associated with long-term survivorship. Moreover, multiple drawbacks are still encountered including a variable learning curve, increased setup and maintenance costs, and potential complications related to the surgical technique. Despite recent technologies applied to TKA have failed to prove substantial improvements, robotic-assisted surgery seems to be here to stay and revolutionize the field of TKA. To support its consistent usage on a daily basis, long-term results are still awaited, and further improvements are necessary to reduce the expenses related to it.

Red cell distribution width, eosinophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio can predict the development of infection and the number of antibiotics used in elderly patients undergoing revision total knee arthroplasty

Introduction: We aimed to evaluate the relationship between complete blood parameters reported to be associated with inflammation and development of complications, length of hospital stays and the number of antibiotics used in elderly patients undergoing revision total knee arthroplasty (rTKA). Material and Method: Our retrospective study was conducted in a single center and included 72 older patients who underwent rTKA operations. We recorded patients’ firs day preoperative, first day postoperative and 45th day postoperative whole blood parameters. Results: It was found that the development of postoperative infection and the number of antibiotics used were higher in patients with low preoperative Hb values and high platelet-to-lymphocyte ratio (PLR) rates. In patients with high RDW value and high eosinophil-lymphocyte ratio (ELR) one day after surgery, both the development of infection (P=0.002, P=0.002) and the number of antibiotics used during follow-up were found to be significantly higher ​(P

Comparison of Operative Times in Primary Bilateral Total Knee Arthroplasty Performed by a Single Surgeon

Purpose: Prolonged operative time (OT) is associated with adverse complications after total knee arthroplasty (TKA). The purpose of this study was to determine whether preoperative factors, such as sex, age, body mass index, body weight (BW), body height, American Society of Anesthesiologists grade, tibiofemoral angle, hospital for special surgery scores, surgical side, surgical order, and calendar year of surgery, affect OT. Methods: One hundred and nineteen patients (238 knees) with osteoarthritis who underwent staged bilateral primary TKA performed by a single surgeon were evaluated. The medical records of 15 males and 104 females were retrospectively reviewed. All variables were expressed as median (interquartile range). Results: The OT for all TKAs was 57 min (51, 65). The OT on the left side (59 min (52−67)) was longer than that on the right side (55 min (50−62)) (p = 0.015). Multiple regression analysis revealed that longer OT was related to BW (β = 0.488, p < 0.001), calendar year of surgery (β = −0.218, p< 0.001), and operative side (β = −0.151, p = 0.007). The Jonckheere−Terpstra test showed a trend toward decreasing OT with calendar year on the left side (p = 0.037) (surgeon’s non-dominant side), but not on the right (p = 0.795). Body height, BW, and body mass index showed weak correlations (r = 0.212, p = 0.001; r = 0.352, p < 0.001; r = 0.290, p < 0.001, respectively) with OT. Conclusion: Patients with a large physique, and especially obesity, with an affected knee on the surgeon’s non-dominant side may require a longer OT; OT decreased over time.

Operative Time and Risk of Surgical Site Infection and Periprosthetic Joint Infection: A Systematic Review and Meta-Analysis

BACKGROUND

The purpose of this study was to perform a systematic review and meta-analysis on the association between operative time and peri-prosthetic joint infection (PJI) after primary total hip arthroplasty (THA) and total knee arthroplasty (TKA).

METHODS

PubMed, Embase, and Cochrane CENTRAL databases were searched for relevant articles dating 2000-2020. Relationship of operative time and PJI rate in primary total joint arthroplasty (TJA) was evaluated by pooled odds ratios (OR) and 95% confidence intervals.

RESULTS

Six studies were identified for meta-analysis. TJA lasting greater than 120 minutes had greater odds of PJI (OR, 1.63 [1.00-2.66], p=0.048). Similarly, there were greater odds of PJI for TJA procedures lasting greater than 90 minutes (OR, 1.65 [1.27-2.14]; p<0.001). Separate analyses of TKA (OR, 2.01 [0.76-5.30]) and THA (OR, 1.06 [0.80-1.39]) demonstrated no difference in rates of PJI in cases of operative time ≥ 120 minutes versus cases < 120 minutes (p>0.05 for all). Using any surgical site infection (SSI) as an endpoint, both TJA (OR, 1.47 [1.181.83], p<0.001) and TKA (OR, 1.50 [1.08-2.08]; p=0.016) procedures lasting more versus less than 120 minutes demonstrated significantly higher odds of SSI.

CONCLUSION

Following TJA, rates of SSI and PJI are significantly greater in procedures ≥120 minutes in duration relative to those < 120 minutes. When analyzing TKA separately, higher rates of SSI were observed in procedures ≥ 120 minutes in duration relative to those <120 minutes. Rates of PJI in TKA or THA procedures alone were not significantly impacted by operative time. Level of Evidence: V.

Variation on a technique for the intra-muscular insertion of nerve endings to minimise neuropathic and residual pain in lower limb amputees: a retrospective cohort study

INTRODUCTION

A major cause of morbidity in lower limb amputees is phantom limb pain (PLP) and residual limb pain (RLP). This study aimed to determine whether a variation of the surgical technique of inserting nerve endings into adjacent muscle bellies at the time of lower limb amputation can decrease the incidence and severity of PLP and RLP.

METHODS

Data were retrospectively collected from January 2015 to January 2021, including eight patients that underwent nerve insertion (NI) and 36 that received standard treatment. Primary outcomes included the 11-point Numerical Rating Scale (NRS) for pain severity, and Patient-Reported Outcomes Measurement Information System (PROMIS) pain intensity, behaviour, and interference. Secondary outcome included Neuro-QoL Lower Extremity Function assessing mobility. Cumulative scores were transformed to standardised t scores.

RESULTS

Across all primary and secondary outcomes, NI patients had lower PLP and RLP. Mean 'worst pain' score was 3.5 out of 10 for PLP in the NI cohort, compared to 4.89 in the control cohort (p = 0.298), and 2.6 out of 10 for RLP in the NI cohort, compared to 4.44 in the control cohort (p = 0.035). Mean 'best pain' and 'current pain' scores were also superior in the NI cohort for PLP (p = 0.003, p = 0.022), and RLP (p = 0.018, p = 0.134). Mean PROMIS t scores were lower for the NI cohort for RLP (40.1 vs 49.4 for pain intensity; p = 0.014, 44.4 vs 48.2 for pain interference; p = 0.085, 42.5 vs 49.9 for pain behaviour; p = 0.025). Mean PROMIS t scores were also lower for the NI cohort for PLP (42.5 vs 52.7 for pain intensity; p = 0.018); 45.0 vs 51.5 for pain interference; p = 0.015, 46.3 vs 51.1 for pain behaviour; p = 0.569). Mean Neuro-QoL t score was lower in NI cohort (45.4 vs 41.9; p = 0.03).

CONCLUSION

Surgical insertion of nerve endings into adjacent muscle bellies during lower limb amputation is a simple yet effective way of minimising PLP and RLP, improving patients' subsequent quality of life. Additional comparisons with targeted muscle reinnervation should be performed to determine the optimal treatment option.

5-Year Survivorship and Outcomes of Robotic-Arm-Assisted Medial Unicompartmental Knee Arthroplasty

Purpose

While unicompartmental knee arthroplasty (UKA) has demonstrated benefits over total knee arthroplasty (TKA) in selected populations, component placement continues to be challenging with conventional surgical instruments, resulting in higher early failure rates. Robotic-arm-assisted UKA (RA-UKA) has shown to be successful in component positioning through preop planning and intraop adjustability. The purpose of this study is to assess the 5-year clinical outcomes of medial RA-UKA.

Methods

This study was a retrospective review of a single-center prospectively maintained cohort of 133 patients (146 knees) indicated for medial UKA from 2009 to 2013. Perioperative data and 2- and 5-year Knee injury Osteoarthritis Outcome Score (KOOS), Western Ontario and McMaster Universities Osteoarthritis Score (WOMAC), and Forgotten Joint Score (FJS) outcome measures were collected. Five-year follow-up was recorded in 119 patients (131 knees).

Results

Mean follow-up was 5.1 ± 0.2 years. Mean age and BMI were 68.0 ± 8.1 years and 29.3 ± 4.7 kg/m², respectively. At 2-year follow-up, mean KOOS, WOMAC, and FJS were 71.5 ± 15.3, 14.3 ± 7.9, and 79.1 ± 25.8, respectively. At 5-year follow-up, mean KOOS, WOMAC, and FJS were 71.6 ± 15.2, 14.2 ± 7.9, and 80.9 ± 25.1, respectively. Mean change in KOOS and WOMAC was 34.6 ± 21.4 and 11.0 ± 13.6, respectively (p < 0.001 and p < 0.001). For patient satisfaction at last follow-up, 89% of patients were very satisfied/satisfied and 5% were dissatisfied. For patient activity expectations at last follow-up, 85% met activity expectations, 52% were more active than before, 25% have the same level of activity, 23% were less active than before, and 89% were walking without support. All patients returned to driving after surgery at a mean 15.2 ± 9.4 days. Survivorship was 95% (95% CI 0.91-0.98) at 5 years. One knee (1%) had a patellofemoral revision, two knees (1.3%) were revised to different partial knee replacements, and five knees (3.4%) were converted to TKA.

Conclusion

Overall, medial RA-UKA demonstrated improved patient-recorded outcomes, high patient satisfaction, met expectations, and excellent functional recovery. Midterm survivorship was excellent. Longitudinal follow-up is needed to evaluate long-term outcomes of robotic-arm-assisted UKA procedures.

Predicting robotic-assisted total knee arthroplasty operating time

Aims

No predictive model has been published to forecast operating time for total knee arthroplasty (TKA). The aims of this study were to design and validate a predictive model to estimate operating time for robotic-assisted TKA based on demographic data, and evaluate the added predictive power of CT scan-based predictors and their impact on the accuracy of the predictive model.

Methods

A retrospective study was conducted on 1,061 TKAs performed from January 2016 to December 2019 with an image-based robotic-assisted system. Demographic data included age, sex, height, and weight. The femoral and tibial mechanical axis and the osteophyte volume were calculated from CT scans. These inputs were used to develop a predictive model aimed to predict operating time based on demographic data only, and demographic and 3D patient anatomy data.

Results

The key factors for predicting operating time were the surgeon and patient weight, followed by 12 anatomical parameters derived from CT scans. The predictive model based only on demographic data showed that 90% of predictions were within 15 minutes of actual operating time, with 73% within ten minutes. The predictive model including demographic data and CT scans showed that 94% of predictions were within 15 minutes of actual operating time and 88% within ten minutes.

Conclusion

The primary factors for predicting robotic-assisted TKA operating time were surgeon, patient weight, and osteophyte volume. This study demonstrates that incorporating 3D patient-specific data can improve operating time predictions models, which may lead to improved operating room planning and efficiency.

Cite this article: Bone Jt Open 2022;3(5):383–389.

Clinical and radiological outcomes of robotic-assisted unicompartmental knee arthroplasty: Early lessons from the first 100 consecutive knees in 85 patients

INTRODUCTION

Robotic-assisted unicompartmental knee arthroplasty (UKA) is associated with improved component positioning and comparable short- and mid-term implant survivorship with manual UKA. This study aims to evaluate clinical and radiological outcomes following robotic-assisted UKA as well as any potential learning-curves associated with the introduction of such new technology.

METHODS

Prospective study of patients undergoing robotic-assisted UKA. Outcome measures were patient-reported outcome measures (PROMs) including Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Knee Society Score (KSS) and Oxford Knee Score (OKS), complications, implant survivorship, component positioning and learning curve.

RESULTS

Eighty-five patients comprising 100 knees were recruited and followed up for 21.0 ± 4.3 months. At two years, there were significant and sustained improvements in PROMs and 100% implant survivorship rate. A high degree of implant accuracy was achieved with the robotic system. A cumulative learning curve of 20 cases was noted.

CONCLUSION

Robotic-assisted UKA achieves excellent implant accuracy and clinical outcomes in the short-term. Long-term follow up is needed to evaluate this relationship.

Fellow Involvement in Primary Total Knee Arthroplasty: Is There an "August Effect?"

The purpose of this study is to determine if a fellow's involvement, as well as duration of a fellow's training, impacts complications, outcomes, and survivorship in primary total knee arthroplasty (TKA). A retrospective review identified 2,790 consecutive patients (3,530 knees) who underwent primary TKA between 2003 and 2008. A 2-year minimum follow-up was available on 2,785 knees (2,195 patients). Operative data, clinical outcomes, complications, and survivorship were compared between cases with and without a fellow involved as well as comparing cases in the first quarter (Q1) of the academic year to the last three quarters (Q2-4). Mean follow-up was 9.7 years. Fellows were involved in 1,434 (41%) surgeries. Fellow cases had significantly longer tourniquet times (59.5 vs. 49 minutes, p < 0.001) and operative times (82.4 vs. 70.8 minutes, p < 0.001). Overall, there was no difference in clinical, functional, or pain outcomes between attending and fellow cases. Fellow cases during Q1 had significantly worse pain scores (p = 0.009) and clinical scores (p < 0.001). Revision rate, infection rates, and survivorship were not significantly different between fellow and attendings or during Q1 of fellowship compared with attendings. Primary TKA survivorship and complications were not affected by fellow involvement or academic quarter. An "August Effect" may be suggested for clinical and pain outcomes in the first 3 months of fellowship.

Electromagnetic Navigated Versus Conventional Total Knee Arthroplasty-A Five-Year Follow-Up of a Single-Blind Randomized Control Trial

BACKGROUND

The objective of this study is to provide the 5-year follow-up results of a randomized study comparing conventional versus electromagnetic computer navigated total knee arthroplasty.

METHODS

Analysis of 127 patients (66 navigated and 61 conventional surgeries) was performed from a prospective, single-blinded, randomized controlled trial. Patient-reported outcome measures were collected at 5 years after surgery and compared with previously published 1-year clinical outcomes. Five-year surgical revision rates were collated and compared between intervention groups.

RESULTS

Overall, there have been continued improvements in the clinical scores of patients in both groups when compared with clinical data at 1 year; however, at 5 years, there is no statistical difference in any of the patient-reported outcome measures between conventional and navigated surgery. Interestingly, improved implant survivorship was observed in the navigated (0% revision rate) compared with the conventional group (4.9% all-cause revision rate).

CONCLUSION

Electromagnetic computer navigated technology produces similar clinical outcomes compared with traditional surgery. Further work is required to monitor implant survivorship, and clinical outcomes with long-term follow-up, to determine the cost effectiveness of this technology.

Risk factors, bacteriological profile and outcome of surgical site infections following orthopaedic surgery

Background and Objectives:

Surgical site infection (SSI) is a challenge for the surgeon. Incidence of SSI reported in literature varies from 0.5% to 15%. Severity of SSI ranges from superficial skin infection to life-threatening condition like septicaemia. It is responsible for increased morbidity, mortality, and economic burden to the hospital in general, and the patient in particular. The aim of this study was to assess the risk factors, bacteriological profile, length of hospitalization, and cost due to orthopaedic SSI in patients admitted to a tertiary care hospital.

Materials and Methods:

This was a prospective case control study. Cases were diagnosed based on CDC definition of nosocomial SSI. All cases were assessed preoperatively, intraoperatively and postoperatively, according to type of surgery, wound class, duration of operation, antimicrobial prophylaxis, use of drain, preoperative hospital stay, causative micro organism, total hospital stay, readmission rates and cost incurred. Age, sex and surgical procedure matched controls without SSI, were also assessed. Chi-square test and Fisher’s exact test were used for analysis. P= <0.05 was considered significant.

Results:

Out of 1023 patients, 47 cases had SSI, with a rate of 4.6%. Cigarette smoking was a risk factor for SSI (P = 0.0035). The most common etiologic agents were Acinetobacter baumannii and Staphylococcus aureus. Incidence of readmission among SSI cases was more compared to controls (P= 0.0001). Costs attributable to SSI (Indian Rupees) was Rs 32,542 (17,054 to 87,514) which was significantly more than those without SSI (P= <0.001).

Conclusion:

Despite latest surgical amenities, meticulous sterilization protocols and pre-operative antibiotic prophylaxis, SSI continues to be present in healthcare settings. The increase in duration of hospital stay due to SSI adds to additional burden to an already resource-constrained healthcare system.

Tranexamic acid in a periarticular multimodal cocktail injection for blood management in total knee arthroplasty: a prospective randomized study

Background

This study aimed to assess the efficacy of tranexamic acid (TXA) mixed in a periarticular multimodal cocktail (PAMC) as a topical administration and to determine whether combined use of intravenous and topical administration is more effective than a single administration of TXA.

Methods

A total of 240 patients who underwent primary total knee arthroplasty (TKA) was enrolled for this prospective randomized controlled study. Patients were divided into three groups of 80 patients each. Baseline data were comparable for all groups. Average follow-up was 18.7 months. Group 1 consisted of patients who received intravenous (IV) TXA, Group 2 patients were those who received TXA in a PAMC injection for topical administration, and Group 3 consisted of patients who received a combination of both intravenous and topical administration of TXA. Primary outcomes were postoperative hemoglobin drop and amount of suction drainage. Secondary outcomes were estimated blood loss (EBL), postoperative transfusion rate, and complications.

Results

The mean postoperative hemoglobin drop was significantly lower in Group 3 (2.13 ± 0.77 g/dL, p=0.004), and there was no difference between Group 1 and Group 2 (2.56 ± 1.07 g/dL vs 2.55 ± 0.86 g/dL, p=0.999). The mean drainage amount was significantly lower in Group 3 (326.58 ± 57.55 ml, p<0.001), and there was no difference between Group 1 and Group 2 (367.93 ± 87.26 ml vs 397.66 ± 104.10 ml, p=0.072). Similarly, the mean EBL was significantly lower in Group 3 (p=0.003), and there was no significant difference between Group 1 and Group 2 (p=0.992). There were no significant differences in requirement for postoperative transfusion rate or incidence of complications among the three groups.

Conclusion

TXA mixed in a PAMC injection showed a similar effect to IV administration of TXA following TKA. Furthermore, combined use of both IV and PAMC injection provided better perioperative bleeding control with similar safety in patients without relevant comorbidities.

Trial registration

WHO ICTRP identifier KCT0005703. Retrospectively registered: 12/24/2020

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04551-8.

Explanatory Factors for Periprosthetic Infection in Total Knee Arthroplasty

There are many studies whose results reveal possible risk factors for developing an infection after a total knee arthroplasty (TKA). The objective of this study is to analyse the risk factors that depend on the hospital and, especially, if the patellar replacement influences the appearance of periprosthetic infection. A retrospective study was performed, where data from the electronic registry of patients of people over 18 and who had undergone TKA, between the years 2015 and 2018, were reviewed. Dependent variables on the patients and the health care system were collected. The possible associations between the factors and the appearance of infection after TKA were studied using univariate and multivariate regression analyses. A total of 907 primary knee arthroplasties were included in the study. Those patients who had their patella replaced had a significantly higher risk of developing an infection (OR 2.07; 95% confidence interval 1.01–6.31). Likewise, patients who underwent surgery by surgeons with more than 10 years of experience were more than twice as likely to become infected than those operated on by younger surgeons (OR 2.64; 95%CI 1.01–6.97). Male patients were also found to be three times more likely to be infected than women (OR 2.99; 95%CI 1.32–5.74). Those interventions that were longer had a higher risk of infection. The same happened with patients who stayed in the hospital for a longer period of time. The rest of the variables did not show statistically significant results. In this study, it was found that the replacement of the patella may be a factor of infection, but it should be corroborated with randomized clinical trials. Furthermore, patients who underwent longer surgeries or those with prolonged hospital stays should be closely monitored to detect infection as soon as possible and establish the most appropriate treatment.

Comparison of the clinical and radiological outcomes between an isolated tibial component revision and total revision knee arthroplasty in aseptic loosening of an isolated tibial component

BACKGROUND

An isolated tibial component revision could be a treatment option for isolated tibial side loosening; however, few studies have proved its efficacy. This study aimed to compare the clinical and radiological outcomes between isolated (tibial component) and total (femoral and tibial component) revision total knee arthroplasty (TKA).

METHODS

Between January 2008 and February 2017, 31 patients underwent revision TKA for isolated tibial side loosening; 14 underwent an isolated tibial component revision (isolated group) and 17 underwent total (both femoral and tibial components) revision surgery (total group). The postoperative range of motion (ROM), Western Ontario and McMaster Universities osteoarthritis (WOMAC) index, Knee Society knee score (KSKS), Knee Society function score (KSFS), and mechanical axis (MA) were compared between the two groups. The intraoperative tourniquet time and amount of blood drainage were also compared.

RESULTS

The mean follow-up durations in the isolated and total groups were 40.7 and 56.1 months, respectively. Both groups had similar postoperative ROM, WOMAC index, KSKS, KSFS, and MA; however, significantly shorter tourniquet time (105.2 vs. 154.6 min, P < 0.001) and less blood drainage (417.2 vs. 968.1 ml, P < 0.001) were noted in the isolated group than in the total group.

CONCLUSION

Isolated tibial component revision TKA for tibial component loosening showed comparable clinical and radiological outcomes to those of total revision TKA. The advantages of the isolated tibial component revision surgery were short operation time and small blood loss.

STUDY DESIGN

Level III, Retrospective comparative study.

Low post-arthroplasty infection rate is possible in developing countries: long-term experience of local vancomycin use in Iran

Background

Utilizing intrawound vancomycin powder in TKA surgery has yielded rather contrasting results in the current literature. Furthermore, CDC criteria, although effective in general, are not specifically designed for post-TKA infections. Here, we present a 7-year experience of vancomycin use in primary TKA in a high-volume tertiary knee center in Iran. Also, new criteria are proposed to detect suspected superficial post-TKA infections.

Methods

This is a retrospective analysis of primary total knee arthroplasties performed in a tertiary knee center, from March 2007 to December 2018, by a single senior knee surgeon. All patients with follow-up periods of less than 1 year were excluded from the study. Since March 2011, all patients received vancomycin (powder, 1 g) before water-tight closure of the joint capsule. A comparison was made between this group and historical control subjects (operated from March 2007 to March 2011).

Results

Altogether, 2024 patients were included in the study. The vancomycin and the control groups included 1710 and 314 cases respectively. Patients were mostly women (male to female ratio, 1 to 4), with a mean age of 65.20 (SD = 10.83) years. In the vancomycin group, the rate of suspected SII (1.87%) and PJI (0.41%) was significantly lower than the control group (P = 0.002).

Conclusions

Our experience shows that application of local vancomycin during TKA surgery could be a reasonable infection prevention measure, although prospective randomized studies are required to evaluate its efficacy.

Surgical Site Infections and Perioperative Optimization of Host Immunity by Selection of Anesthetics

Surgical site infections are significant health care issues, and efforts to mitigate their occurrence have been ongoing worldwide, mainly focusing to reduce the spillage of microbes to the otherwise sterile tissues. Optimization of host immunity has been also recognized including temperature regulation (normothermia), adequate oxygenation, and glucose management. A number of papers have described the role of anesthetics in host immunity. The role of anesthetics in postoperative outcomes including surgical site infections has been also studied. We will review the current literature and propose the importance of anesthetic selection to potentially mitigate surgical site infections.

Operative Duration and Short-Term Postoperative Complications after Unicompartmental Knee Arthroplasty

BACKGROUND

Prolonged operative duration is an independent risk factor for postoperative complications in many orthopedic procedures ranging from shoulder arthroscopy to total hip and knee arthroplasties. It has not been well studied in unicompartmental knee arthroplasty (UKA). The purpose of this study is to assess the effect of operative duration on complications after UKA.

METHODS

Using the American College of Surgeons National Surgical Quality Improvement Program registry, we identified all primary unilateral UKAs from 2005 to 18. Patients were divided into three cohorts based on the operative duration: < 90 minutes, between 90 and 120 minutes, and >120 minutes. Baseline patient and operative demographics (age, gender, etc.) and thirty-day complications were compared using bivariate analysis. Multivariate analysis was used to assess the independent effect of operative duration on postoperative outcomes after adjusting for differences in baseline characteristics.

RESULTS

We identified 11,806 patients who underwent primary UKA from 2005 to 18. There was no difference in the "any complication" rate between cohorts. However, operative duration >120 minutes was associated with a significantly higher likelihood of reoperation (odds ratio [OR] 2.02, 95% confidence interval [CI]: 1.15-3.57, P = .015), non-home discharge (OR: 2.14, CI: 1.65-2.77, P < .001), surgical site infection (OR: 1.76, CI: 1.03-3.01, P = .038), and blood transfusions (OR: 3.23, CI: 1.44-7.22, P = .004) when compared with operative duration <90 minutes. There was no difference in mortality rates.

CONCLUSION

Increased operative duration greater than 2 hours in primary UKA is associated with an increased risk of non-home discharge, surgical site infection, reoperation, and blood transfusion.

Increase in Operative Time Is Associated With Postoperative Complications in Revision Total Knee Arthroplasty

Given the growing rate of revision total knee arthroplasties (TKAs), it is important to understand the potential risk factors associated with postoperative complications. The aim of this study was to determine the role of operative time in postoperative complications in revision TKA. A retrospective cohort study was performed using data from the American College of Surgeons National Surgical Quality Improvement Program database. Patients who had undergone revision TKA between 2007 and 2016 were identified and analyzed based on operative time. The effect of operative time on postoperative complications was examined using multinomial multivariate analysis. A total of 14,769 revision TKA patients were included. On adjusted multivariate analysis, each additional 15 minutes of operative time increased the likelihood of wound complications (odds ratio, 1.023; P=.020), postoperative blood transfusion (odds ratio, 1.169; P<.001), and extended hospital stay (odds ratio, 1.060; P<.001). An increase of 15 minutes of operative time was associated with several postoperative complications. Although operative time is often an uncontrollable factor, surgeons should consider the effect of prolonged operative time on potential complications in the acute postoperative period. [Orthopedics. 2021;44(1):18-22.].

Antibiotic-Laden Bone Cement Use and Revision Risk After Primary Total Knee Arthroplasty in U.S. Veterans

BACKGROUND

It is controversial whether the use of antibiotic-laden bone cement (ALBC) in primary total knee arthroplasty (TKA) affects periprosthetic joint infection (PJI) or revision rates. The impact of ALBC on outcomes of primary TKA have not been previously investigated in U.S. veterans, to our knowledge. The purposes of this study were to quantify utilization of ALBC among U.S. veterans undergoing primary TKA and to determine if ALBC usage is associated with differences in revision TKA rates.

METHODS

Patients who had TKA with cement from 2007 to 2015 at U.S. Veterans Health Administration (VHA) hospitals with at least 2 years of follow-up were retrospectively identified. Patients who received high-viscosity Palacos bone cement with or without gentamicin were selected as the final study cohort. Patient demographic and comorbidity data were collected. Revision TKA was the primary outcome. All-cause revisions and revisions for PJI were identified from both VHA and non-VHA hospitals. Unadjusted and adjusted regression analyses were performed to identify variables that were associated with increased revision rates.

RESULTS

The study included 15,972 patients who had primary TKA with Palacos bone cement at VHA hospitals from 2007 to 2015. Plain bone cement was used for 4,741 patients and ALBC was used for 11,231 patients. Utilization of ALBC increased from 50.6% in 2007 to 69.4% in 2015. At a mean follow-up of 5 years, TKAs with ALBC had a lower all-cause revision rate than those with plain bone cement (5.3% versus 6.7%; p = 0.0009) and a lower rate of revision for PJI (1.9% versus 2.6%; p = 0.005). On multivariable regression, ALBC use was associated with a lower risk of all-cause revision compared with plain bone cement (hazard ratio [HR]: 0.79, 95% confidence interval [CI]: 0.68 to 0.92; p = 0.0019). Seventy-one primary TKAs needed to be implanted with ALBC to avoid 1 revision TKA.

CONCLUSIONS

The utilization of ALBC for primary TKAs performed at VHA hospitals has increased over time and was associated with a lower all-cause revision rate and a lower rate of revision for PJI.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Postoperative Complications Causing Readmission in 30 Days after Total Knee Arthroplasty: A Retrospective Nested Case-Control Study of Risk Factors Based on Propensity Score Matching

We performed this study to identify independent risk factors for life-threatening postoperative complications causing 30-day readmissions after total knee arthroplasty (TKA). Improved understanding of these risks may improve efficiency and safety of treatment. We performed a retrospective, nested case-control study using an open-access database of 2,622 patients who underwent primary TKA at a tertiary academic medical center in Singapore between January 2013 and June 2014. Patients were grouped according to the incidence of complications. Multivariate logistic analysis was performed to identify predictive factors for TKA complications. The incidence of postoperative complications was 1.72%. Compared with cases performed with an operative time < 70 minutes, increased operative time was associated with a higher risk of complications. Case duration > 90 minutes was associated with an increased risk (adjusted odds ratio [aOR] = 4.57, p = 0.001; case duration ≥ 111 minutes, aOR = 4.64, p = 0.04; and case duration between 91 and 110 minutes, aOR = 3.20, p = 0.03). The correlation between operative time and complications was nonlinear. Cerebrovascular accident (CVA) or transient ischemic attack (TIA) was an independent risk factor for increased complication rate (aOR = 11.59, p = 0.02). Operative duration has been identified as an independent risk factor for complications after TKA. As it remains a modifiable factor to which doctors are interested in bringing quality improvement, the risk of postoperative complications will be reduced by minimizing the operative duration.

Surgical Duration Implicated in Major Postoperative Complications in Total Hip and Total Knee Arthroplasty: A Retrospective Cohort Study

Total hip and knee arthroplasties are two of the most commonly performed orthopaedic surgeries and are expected to increase in incidence in the coming decades. We sought to examine whether the duration of these procedures is related to various postoperative complications using data from 2010 to 2017 from the American College of Surgeons National Surgical Quality Improvement Program database.

Revision Rates and Functional Outcomes Among Severely, Morbidly, and Super-Obese Patients Following Primary Total Knee Arthroplasty: A Systematic Review and Meta-Analysis

BACKGROUND

Obesity has been associated with a greater burden of symptomatic knee osteoarthritis. There is some evidence that patients with a very high body mass index (BMI) may have a higher risk of complications and poor outcomes following total knee replacement compared with non-obese patients or obese patients with a lower BMI. We hypothesized that increasing degrees of obesity would be associated with deteriorating outcomes for patients following total knee replacement.

METHODS

We performed a comprehensive systematic review of 4 medical databases (MEDLINE, AMED, Ovid Healthstar, and Embase) from inception to August 2016. We extracted data to determine revision risk (all-cause, septic, and aseptic) and functional outcome scores (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC], Knee Society Score, Oxford Knee Score, EuroQol-5D, and Short Form [SF]-12 Physical Component Summary) in patients with severe obesity (BMI ≥35 kg/m), morbid obesity (BMI ≥40 kg/m), and super-obesity (BMI ≥50 kg/m) in comparison with patients with a normal BMI (<25 kg/m). Meta-analysis was performed using a random effects model.

RESULTS

We screened 3,142 titles and abstracts and 454 full-text articles to identify 40 eligible studies, of which 37 were included in the meta-analysis. Compared with patients with a normal BMI, the risk ratio for an all-cause revision surgical procedure was 1.19 (95% confidence interval [CI], 1.03 to 1.37; p = 0.02) in patients with severe obesity, 1.93 (95% CI, 1.27 to 2.95; p < 0.001) in patients with morbid obesity, and 4.75 (95% CI, 2.12 to 10.66; p < 0.001) in patients with super-obesity. The risk ratio for septic revision was 1.49 (95% CI, 1.28 to 1.72; p < 0.001) in patients with severe obesity, 3.69 (95% CI, 1.90 to 7.17; p < 0.001) in patients with morbid obesity, and 4.58 (95% CI, 1.11 to 18.91; p = 0.04) in patients with super-obesity. There were no significant differences (p > 0.05) in risk of aseptic revision. Based on the Knee Society Scores reported in a single study, patients with super-obesity had outcome scores, expressed as the standardized mean difference, that were 0.52 lower (95% CI, 0.80 lower to 0.24 lower; p < 0.001) than non-obese controls; however, no difference was observed for severe or morbidly obese patients.

CONCLUSIONS

The risk of septic revision is greater in patients with severe obesity, morbid obesity, and super-obesity, with progressively higher BMI categories associated with a higher risk. However, the risk of aseptic revision was similar between all obese and non-obese patients. Functional outcome improvements are also similar, except for super-obese patients, in whom data from a single study suggested slightly lower scores. These findings may serve to better inform evidence-based clinical, research, and policy decision-making.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.