Efficacy of Intrawound Vancomycin in Prevention of Periprosthetic Joint Infection After Primary Total Knee Arthroplasty: A Prospective Double-Blinded Randomized Control Trial.

BACKGROUND: Periprosthetic joint infection (PJI) after total knee arthroplasty (TKA) is a devastating complication. Intrawound vancomycin powder has been shown to reduce infection rates in spine surgery, but its role in arthroplasty remains controversial. This prospective randomized control trial aimed to evaluate the efficacy of intrawound vancomycin in preventing PJI after primary TKA. METHODS: A total of 1,022 patients were randomized to the study group (n = 507, who received 2 grams intrawound vancomycin powder before arthrotomy closure) or to the control group (n = 515, no local vancomycin) with a minimum follow-up of 12-months. The primary outcome was the incidence of PJI or surgical site infection (SSI). Secondary outcomes included associated minor complications such as stitch abscess, persistent wound drainage, and delayed stitch removal. Other parameters evaluated include reoperation rates and incidences of nephrotoxicity. RESULTS: The overall infection rate in 1,022 patients was 0.66%. There was no significant difference in PJI rate in the study group (N = 1; 0.2%) versus the control group (N = 3; 0.58%), P = .264. Reoperation rates in the study group (N = 4; 0.78%) and control (N = 5; 0.97%), and SSI rates in the study (N = 1; 0.2%) and control groups (N = 2; 0.38%) were comparable. The Vancomycin cohort, however, demonstrated a significantly higher number of minor wound complications (n = 67; 13.2%) compared to the control group (n = 39; 7.56%, P < .05). Subgroup analysis showed diabetics in the study group to also have a higher incidence of minor wound complications (24 [14.1%] versus 10 [6.2%]; P < 05]. Multivariate analyses found that vancomycin use (odds ratio = 1.64) and smoking (odds ratio = 1.85) were associated with an increased risk of developing minor wound complications. No cases of nephrotoxicity were reported. CONCLUSIONS: Intrawound vancomycin powder does not appear to reduce PJI/SSI rate in primary total knee arthroplasties, including high-risk groups. Although safe from a renal perspective, intrawound vancomycin was associated with an increase in postoperative aseptic wound complications. Intrawound vancomycin may not be effective in reducing the rate of PJI in primary TKA.

Operating room efficiency for a high-volume surgeon in simultaneous bilateral robotic-assisted total knee arthroplasty: a prospective cohort study.

Robotic-assisted total knee arthroplasty (RATKA) has been shown to achieve more accurate component positioning and target alignment than conventional jig-based instrumentation; however, concerns remain regarding its adoption since it is associated with steep learning curves, higher operational costs, and increased surgical time. This study aims to compare the operating times of three cohorts of patients undergoing simultaneous bilateral TKA, i.e., first 50 RATKA, last 50 RATKA (at the end of 1 year), and 50 conventional TKA. This prospective cohort study was conducted at a single high-volume tertiary care center by a single experienced surgeon on 150 patients (300 knees), who were allotted into three equal cohorts of 50, between February 2020 and December 2021. Simultaneous bilateral TKAs were done in all three groups and operative times recorded. We describe the technique for optimizing the surgical time of SB-RATKA for efficient operative room logistics. The operating times of the two robotic-assisted TKA cohorts were compared with the operating times of the conventional SB-TKA cohort. The mean age of the study population was 59(±6.2) years with the majority of females (82%). The mean coronal deformity was comparable between the cohorts. The mean operating time in the conventional CTKA, initial 50 RATKA, and final 50 RATKA cohorts were 115.56 (±10.7), 127.8 (±26), and 91.66 (±13.5) min, respectively, all of which showed a statistically significant difference (p < 0.001). The mean operating times of the final 50 RATKA at the end of 1 year improved by about 36 min with all the SB-RATKA cases being completed in under 120 min. The efficiency of SB-RATKA improved significantly with time and experience, resulting in shorter operational times within a year, revealing the potential of robotic-assisted surgery to surpass conventional approaches in TKA in terms of operating room efficiency.

Impact of Hepatitis B on Complications and Functional Outcomes in Patients Undergoing TKR.

Background: In India, infected patients with hepatitis B virus (HBV) undergoing total knee replacement (TKA) are increasing. It is recognized that patients with HBV infection are more susceptible to complications after surgery. To evaluate the effect of HBV infection on complications and functional outcome after TKA was the aim of this study. Methods: This is the retrospective observation analysis of patients who underwent primary total knee replacement in our hospital from 2017 to 2019. A total of 92 patients were included in the study, of which 46 patients were asymptomatic HBV-positive, and these 46 patients were compared with a matched cohort of another 46 patients who were non-HBV. Results: A total of 92 patients were analyzed (asymptomatic HBV n = 46, non-HBV n = 46). The incidence rate of total complications in patients undergoing TKA with asymptomatic HBV was 19.57% compared to 4.3% in non-HBV (p < 0.001). Applied with regression models, patients with HBV had an 8.6% increased risk of surgical complication which included one peri-prosthetic joint infection, three wound dehiscence compared with the non-HBV group which had 2.17% surgical complications (one wound dehiscence). Medical complications were higher in asymptomatic HBV group with 10.87% (which includes one pulmonary embolism, two DVT, and two strokes). In comparison with the non-HBV group which had 2.17% medical complications (one DVT), asymptomatic HBV group had 5.35-fold (95% CI 1.09-26.33; p < 0.01) increase in overall complications. Post-TKA surgical complications are 4.29-fold (95% CI 0.46-39.91; p < 0.01) higher compared to non-HBV group. Conclusion: Our study showed asymptomatic hepatitis B patients are at an increased risk of complications (peri-prosthetic joint infections and wound dehiscence) compared to normal patients. In hepatitis B and non-hepatitis B patients, functional outcomes in terms of OKS are comparable.

Functional alignment is associated with increased incidence of pre-balance, reduced soft-tissue release, and post-operative pain compared to mechanical alignment in patients undergoing simultaneous bilateral robotic-assisted TKA.

This study aimed to compare two alignment strategies in the same patient undergoing simultaneous bilateral robotic-assisted TKA (SB-RATKA): mechanical alignment (MA), the gold-standard, and functional alignment (FA), a balance-driven, personalized alignment strategy. The outcome measures included quantitative assessment of soft-tissue release, incidence of knee balance, and post-operative pain. This was a prospective, self-controlled, randomized-controlled trial involving 72 patients who underwent SB-RATKA using the MAKO® robotic system with comparable grades of deformity and pain in both knees. 65 patients were finally included with one alignment strategy done per knee, with the patients blinded to the strategy used. The study recorded the additional soft-tissue releases required, incidence of pre-balance, and daily post-operative VAS pain scores. The mean age of the study population was 57.95 years, with a female preponderance (N = 53, 81.6%). MA group had significantly more medial compartment tightness in both flexion (MA-15.6 ± 1.8; FA-17 ± 1.3) and extension (MA-14.9 ± 1.9; FA-17 ± 1.1) (p < 0.0001) compared to the FA group after dynamic balancing. 66% of knees in the FA group (N = 43) achieved pre-balance compared to 32.3% in the MA group (N = 21) (p < 0.0001). VAS scores showed a significant reduction in pain in the FA group up to 72 h post-surgery (p < 0.0001). The requirement for posteromedial release (PM), posterior capsular (PC) release, tibial reduction osteotomy (TRO), and superficial MCL pie crusting (sMCL) were significantly lower in FA (PM-22, PC-13, TRO-8, sMCL-2) compared to MA (PM-44, PC-29, TRO-18, sMCL-8). Functional alignment strategy consistently resulted in a higher incidence of knee balance with a significant reduction in soft-tissue releases and immediate post-operative pain when compared to MA in the same patient undergoing SB-RATKA. Therapeutic Level 1.

Effect of Hypothyroidism on Complications in Patients Undergoing TKA in Indian Population.

Background: The number of hypothyroidism patients undergoing total knee replacement (TKA) in India is increasing. It is assumed that patients with hypothyroidism are more prone to complications following surgery. The aim of this study is to evaluate the impact of hypothyroidism on the complications following TKA. Methods: This is a case-control analysis of patients who underwent primary total knee replacement in our hospital from 2017 to 2019. A total of 600 patients were included in the study, of which 300 patients were with hypothyroidism. We compared with a matched cohort of another 300 patients without hypothyroidism as control group. Results: A total of 600 patients were analyzed (Hypothyroid group n = 300, Control group n = 300). The medical complications were found to be 6.2% in the hypothyroid group compared to 4% in control group (p = 1.66, odds ratio 0.61). Surgical complications in the hypothyroid group were 3% compared to 0.6% in control group (p = 4.53, odds ratio = 0.21), overall complication rates were not significant statistically when compared between hypothyroid and control group (p = 5.01, odds ratio 0.47). Subgroup analysis of complications of hypothyroid patients with euthyroid status versus uncontrolled hypothyroidism was done and we found no statistical difference in complications. Conclusion: The conclusion can be that the rate of hospital stay, surgical site infections and complications were higher in hypothyroid group when compared with control group though statistically not significant.

Radiological Evaluation of the Phenotype of Indian Osteoarthritic Knees based on the Coronal Plane Alignment of the Knee Classification (CPAK).

Background: Understanding constitutional alignment of the lower limb is essential to optimize alignment strategies during total knee arthroplasty. The coronal plane alignment of knee (CPAK) classification system was proposed as a comprehensive assessment tool based on coronal alignment and variations in joint line obliquity (JLO). This prospective observational cross-sectional study aimed to evaluate the phenotype of knees in the Indian population based on the CPAK system. Methods: Two cohorts of individuals (250 young healthy volunteers and 250 elderly patients with knee osteoarthritis) underwent radiological assessment with long-leg radiographs and were classified based on the CPAK system. Measurements included the mechanical and arithmetic hip-knee-ankle angles (mHKA, aHKA), joint line obliquity (JLO), lateral distal femoral angle (mLDFA) and medial proximal tibial angle (mMPTA). Knees were grouped into 9 CPAK phenotypes based on aHKA and JLO. Results: A total of 1000 knees were evaluated. In cohort-1 of healthy young adults, most knees were distributed in the CPAK class II phenotype (128 knees, 25.6%) followed by CPAK Type I (106 knees, 21.2%). In cohort-2 of elderly arthritic adults, most knees were distributed in Type I (294 knees, 58.8%) with constitutional varus and apex-distal joint line orientation. Conclusion: The majority of the study population was found to have constitutional varus alignment. In addition, a high proportion of patients in both categories, especially arthritic patients undergoing TKA, were found to have varus alignment with an apex-distal oblique joint line. This classification may help optimize component positioning to restore constitutional alignment and joint line orientation during TKA.

Comparison of patient reported outcomes after robotic versus manual total knee arthroplasty in the same patient undergoing staged bilateral knee arthroplasty.

Background: Robotic-assisted total knee arthroplasty (RATKA) has been proven to improve accuracy of component positioning and reducing alignment target outliers. However, the clinical benefit of robotics is often debated. Recent studies have shown reduced pain and faster recovery in the immediate post-operative period and may be associated with improved PROMs and satisfaction. The aim of this study was to assess PROMs and satisfaction in a unique patient population undergoing bilateral staged TKA to compare manual (MTKA) and RATKA in the same patient. Methods: 55 patients underwent bilateral staged TKA, performed by a single surgeon at a single institute. Patients who underwent TKA for the first knee with manual technique and RATKA for the second side, were eligible for inclusion in the study. Primary outcome assessed was the Oxford Knee Score and secondary outcomes included the Forgotten Joint Score (FJS), patient satisfaction, mean duration for independent ambulation after TKA, and patient perspectives on recovery evaluated with a questionnaire. Results: Both RATKA and MTKA were associated with comparable PROMs. Though RATKA was associated with improved joint perception (Mean FJS after MTKA surgery was 70.3 (SD = 10.66) and significantly lower than the mean FJS after RATKA (73, SD = 10.95, p-value < 0.01), but the difference was not clinically relevant. A higher proportion of patients were more likely to be very satisfied or satisfied after RATKA. A significant proportion of patients felt the knee operated with RATKA was less painful and felt more natural compared to MTKA at final follow-up (p < 0.01). Majority of patients would undergo RATKA again and recommend robotic-TKA to others. Conclusion: Robotic-assisted surgery was associated with improved patient satisfaction, faster independent ambulation compared to manual techniques. PROMs however, were comparable without clinically significant differences. Patients preferred robotic-assisted surgery, with a significantly higher proportion perceiving knee operated by RATKA felt more natural.

Avoiding Lateral Laxity in Robotic Arm-Assisted Total Knee Arthroplasty-A Surgical Technique Describing a New Method of Gap Capture and Balancing Strategy.

INTRODUCTION: Optimal flexion-extension gap balancing is an important factor in outcomes after total knee arthroplasty. Knees with varus deformities are commonly associated with a greater degree of lateral laxity both in extension and flexion. Residual lateral laxity could be encountered by surgeons during component trialling after robotic-assisted total knee arthroplasty (RATKA), necessitating additional medial soft tissue release for a thicker insert. This study describes a new technique of gap assessment during RATKA and we propose a functional alignment based balancing strategy to avoid residual lateral laxity. MATERIALS AND METHODS: This surgical technique was prospectively employed in 105 patients undergoing primary MAKO® (Stryker, Kalamazoo, Michigan) RATKA for osteoarthritis of the knee with varus deformity, between January 2021 and July 2021. Patients included had an initial lateral extension laxity of more than 24mm. Surgical data points collected consisted of characterization of the laxity profile of the knee using the medial and lateral extension and flexion initial gap captures, final gap captures after dynamic balancing with a functional alignment strategy, and residual lateral extension gap laxity in millimeters at the end of implantation. RESULTS: The mean initial lateral extension gap was 25.76mm (standard deviation [SD]=1.47) and the mean lateral flexion gap was 24.4mm (SD=1.94). Balance was achieved in all the patients with a 9 or 11mm insert, with a mean residual lateral laxity of 0.51mm (SD=0.73, range 0-2mm). The majority of patients (n=66, 62.85%) had zero lateral laxity at the end of final implantation while 24 patients (22.8%) had 1mm of residual lateral laxity. CONCLUSION: Residual lateral joint laxity can be avoided consistently and predictably in RATKA cases with initial gap capture of up to 30mm in lateral extension and flexion with this new technique of gap capture and employing various steps of balancing strategy described.

Unusual Failure of Modular TKA Prosthesis and Screw Migration following Revision Total Knee Arthroplasty.

Introduction: The use of modular implants for revision TKA are ever increasing in number due to their definitive advantage over their monoblock counterparts by providing the surgeon with the versatility needed to achieve equal gaps and manage bone defects. This superiority comes at the cost of certain unique complications attributable to its modular design such as loosening and fractures at the areas of component coupling that are prone to fatigue failure with suboptimal fixation. Case Report: We present a case of modular femoral component failure in a 59-year man of Asian decent after revision TKA secondary to disengagement and migration of the extension stem locking bolt of a Total Condylar-III prosthesis. Patient presented with pain, effusion, and instability 2.5 years after stage-2 revision TKA. Radiographs revealed migration of the femur-stem locking bolt into the joint cavity. The femoral component and stem were loose. The locking bolt was extracted, and he underwent re-revision surgery with revised femoral components. Conclusion: Stem-condylar junction of modern modular TKA implants are prone to early loosening and failure. This diagnosis should be anticipated on serial follow-up radiographs and in patients who complain of sudden onset of instability following revision surgery.