Standard Total Knee Arthroplasty Research Articles

Finite element analysis of the effect of tibial osteotomy on the stress of polyethylene liner in total knee arthroplasty.

To explore the effects of tibial osteotomy varus angle combined with posterior tibial slope (PTS) on the stress of polyethylene liner in total knee arthroplasty (TKA) by building finite element model (FEM). Established the FEM of standard TKA with tibial osteotomy varus angle 0° to 9° were established and divided into 10 groups. Next, each group was created 10 FEMs with 0° to 9° PTS separately. Calculated the stress on polyethylene liner in each group in Abaqus. Finally, the relevancy between tibial osteotomy angle and polyethylene liner stress was statistically analyzed using multiple regression analysis. As the varus angle increased, the area of maximum stress gradually shifted medially on the polyethylene liner. As the PTS increases, the percentage of surface contact forces on the medial and lateral compartmental of the polyethylene liner gradually converge to the same. When the varus angle is between 0° and 3°, the maximum stress of the medial compartmental surfaces of polyethylene liner rises smoothly with the increase of the PTS. When the varus angle is between 4° and 9°, as the increase of the PTS, the maximum stress of polyethylene liner rises first and then falls, forming a trough at PTS 5° and then rises again. Compared to the PTS, the varus angle has a large effect on the maximum stress of the polyethylene liner (p < .001). When the varus angle is 0° to 3°, PTS 0° is recommended, which will result in a more equalized stress distribution of the polyethylene liner in TKA.

Appraisal of Clinical Improvement With Total Knee Arthroplasty in Valgus Knee Deformities: A Case Series.

Introduction This case series explores the efficacy of unassisted total knee arthroplasty (TKA) in addressing valgus knee deformity secondary to osteoarthritis. The study aims to evaluate functional outcomes pre- and post-surgery using the Knee Society Score (KSS) and radiological assessments in short-term follow-up. Six patients underwent TKA and were evaluated retrospectively. Statistical analysis revealed significant improvements in the angle of deformity, KSS, and range of motion postoperatively. The study underscores the success of TKA in correcting valgus deformity, improving knee function, and enhancing patient satisfaction. TKAis a highly successful treatment for osteoarthritis, providing functional recovery and improved quality of life. However, valgus knee deformity presents a challenge in TKA, affecting approximately 10% of patients. This study aims to assess the functional outcomes of TKA for valgus deformity using KSSand radiological evaluation in short-term follow-up. Materials and methods A retrospective observational study was conducted from November 2022 to December 2023, involving six patients with valgus knee deformity secondary to osteoarthritis. TKA was performed with no technological assistance, and patients were assessed pre- and post-surgery using KSS and radiological measurements. Statistical analysis was performed using paired t-tests. Case description Six patients with grade two valgus deformity underwent technology-unassisted TKA. The postoperative assessment revealed significant improvements in the tibiofemoral angle, KSS, and range of motion. The medial parapatellar approach for TKA was utilized with a standard unconstrained primary TKA prosthesis, resulting in successful correction of deformity and improved knee alignment. Discussion TKA is a widely performed and reliable surgical intervention, with valgus knee deformity posing specific challenges. This study demonstrates the effectiveness of conventional TKA in correcting valgus deformity, improving knee function, and enhancing patient satisfaction in a very small case series. Comparison with previous studies supports the findings of the pre-existing literature, highlighting the importance of appropriate surgical approach and patient selection. Conclusion TKAutilizing a medial parapatellar approach proved effective in our small case series in correcting valgus deformity, improving knee function, and enhancing patient satisfaction. Short-term follow-up reveals significant improvements in stability, posture, and KSS scores. Further assessments and longer-term follow-up are warranted to confirm the long-term effectiveness of this approach.

A Retrospective Study to Compare Patient Outcomes from Standard Total Knee Arthroplasty (TKA) versus Navigation-Guided Arthroplasty Using the Brainlab Software-Guided Surgical System at a Center in Hebei Province January 2021 to July 2023.

BACKGROUND This retrospective study aimed to compare patient outcomes from standard total knee arthroplasty (TKA) vs navigation-guided arthroplasty using the Brainlab software-guided surgical system at Cangzhou Hospital of Integrated TCM-WM, Hebei, Hebei Province, China from January 2021 to July 2023. MATERIAL AND METHODS A total of 239 patients who underwent total knee arthroplasty in Cangzhou Hospital of Integrated TCM-WM, Hebei from January 2021 to July 2023 were retrospectively analyzed. According to the inclusion criteria, 212 eligible patients were selected for analysis and divided into a Navigation Group (NG) (n=105) and a Traditional Group (TG) (n=107) according to surgical method used. Outcomes measured included duration of disease, operative time, intraoperative blood loss volume, postoperative length of hospital stay, and pain measured by the hospital for special surgery knee score (HSS), Western Ontario and McMaster University Osteoarthritis Index (WOMAC), and forgotten joint score (FJS). RESULTS The comparison of perioperative results between the 2 groups showed that the incision length in the NG was significantly longer than that in the TG (P<0.001, 95% Cl 2.59-3.35). At 3 months after surgery, the HSS score of the NG was statistically higher than that of the TG (P=0.002, 95% Cl 3.42-4.46); the WOMAC score of the NG was lower than that of the TG (P<0.001, 95% Cl -4.41-2.87); and the FJS score of the NG was significantly higher than that of the TG (P=0.003, 95% Cl 2.39-3.67). CONCLUSIONS Compared with conventional TKA, use of the Brainlab navigation system is associated with a longer incision, more accurate implantation position of the prosthesis, faster recovery of knee joint function, and helps patients to "forget" about their knee prosthesis in the short term.

Total knee arthroplasty in patients with a proximal tibial stress fracture associated with bilateral severe knee osteoarthritis

Introduction/Objective. Proximal tibial stress fractures associated with bilateral severe knee osteoarthritis are rare and, due to possible consequences, are considered a treatment challenge. This paper aims to present the applied treatment method of these patients and its results. Methods. A prospective study followed 14 patients with an average age of 74.1 years and with unilateral proximal tibial stress fracture associated with bilateral severe knee osteoarthritis. Surgical treatment involved modular total knee arthroplasty (TKA) on the fracture side, in the first act, and contralateral standard TKA, in the second act, based on the severe osteoarthritis. Rehabilitation was performed for 21 days after both operations and included the following: kinesiotherapy, electrotherapy, magnetotherapy, hydrotherapy, and thermotherapy. Monitoring parameters were as follows: X-ray, range of motion, and WOMAC index. Monitoring periods were preoperative and three, six, and nine months after the first TKA surgery. Results. The radiological findings in all patients during these follow-up periods were normal. All tibial stress fractures healed within six months after surgery. Knee function was significantly improved nine months after the first TKA surgery compared to the preoperative finding. A statistically significant improvement in the physical functioning was found in all postoperative periods, especially nine months after the first TKA surgery (p &lt; 0.05). Conclusion. Modular total knee arthroplasty on the tibial stress fracture side and delayed standard total knee arthroplasty of contralateral osteoarthritic knee combined by postoperative inpatient rehabilitation give optimal final functional outcome.

No difference in patient reported outcome and inflammatory response after coated and uncoated total knee arthroplasty – a randomized controlled study

BackgroundAllergies against implant materials are still not fully understood. Despite controversies about its relevance, some patients need treatment with hypoallergenic implants. This study compared coated and standard total knee arthroplasty (TKA) regarding inflammatory response and patient-reported outcome measures (PROMs).Methods76 patients without self-reported allergies against implant materials were included in a RCT and received a coated or standard TKA of the same cemented posterior-stabilized knee system. 73 patients completed the 3-year follow-up. Two patients died and there was one revision surgery. Serum levels of cytokines with a possible role in implant allergy were measured in patient`s serum (IL-1beta, IL-5, IL-6, IL-8, IL-10, IFN γ, TNF α) prior to, one and three years after surgery. Furthermore, PROMs including knee function (Oxford Knee Score, Knee Society Score) and health-related quality of life (QoL, EuroQuol questionnaire) were assessed. Additionally, 8 patients with patch-test proven skin allergy against implant materials who received the coated implant were assessed similarly and compared to a matched-pair group receiving the same implant.ResultsThere were no differences in function and QoL between the assessed groups at any follow-up. The majority of patients demonstrated no elevation of the measured blood cytokines. Cytokine patterns showed no differences between study groups at any follow-up. The allergy patients demonstrated slower functional improvement and minor differences in cytokine pattern. Yet these results were not significant. There were no differences in the matched-pair analysis.ConclusionWe observed no relevant increase in serum cytokine levels in any group. The inflammatory response measured seems limited, even in allergy patients. Furthermore, there were no differences between coated and standard TKA in non-allergy patients in the 3-year Follow-Up period.Trial registrationThe study protocol was registered in the US National Institutes of Health’s database (http://www.clinicaltrials.gov) registry under NCT03424174 on 03/17/2016.

Do Patients With Hypoallergenic Total Knee Arthroplasty Implants for Metal Allergy Do Worse? An Analysis of Health Care Utilizations and Patient-Reported Outcome Measures

BackgroundMetal allergy is a rare and controversial cause of implant failure and poor outcomes following total knee arthroplasty (TKA). Few studies have investigated clinical and patient-reported outcome measures (PROMs) in patients treated with hypoallergenic implants. This investigation aimed to compare: (1) health care utilizations (eg, hospital length of stay, 90-day readmission rate, and incidence of nonhome discharge) and (2) 1-year PROMs between patients who received hypoallergenic and standard TKA implants. MethodsThis was a retrospective review of prospectively collected data from patients who underwent primary TKA between 2018 and 2019. Propensity score matching (3:1) was used to compare standard TKA patients with those who received hypoallergenic TKA implants, respectively. Knee injury and Osteoarthritis Outcome Score (KOOS) pain, KOOS Physical function Shortform (PS), and Veterans RAND 12-Item Health Survey Mental Component Score were collected preoperatively and at 1-year. After matching, 190 hypoallergenic and 570 standard TKAs were analyzed. ResultsNo differences were observed in length of stay (P = .98), 90-day readmission (P = .89), and nonhome discharge (P = .82). Additionally, there was no significant difference in change from preoperative to 1-year PROMs (KOOS pain, P = .97; KOOS PS, P = .88; Veterans RAND 12-Item Health Survey Mental Component Score, P = .28). Patient-reported satisfaction was similar at 1-year (P = .23). Patients achieved similar rates of Patient Acceptable Symptom State (PASS) and minimal clinically important difference (MCID) for KOOS pain (PASS, P = .77; MCID, P = .33) and KOOS PS (PASS, P = .44; MCID, P = .65). ConclusionPatients treated with hypoallergenic TKA implants for suspected metal allergy had similar outcomes compared to patients who had standard implants and no metal allergy.

Do High-Flexion Total Knee Arthroplasty Have More Adverse Events™

Introduction: High-flexion knee prosthesis was proposed to result in better outcomes after knee arthroplasty. However, latest meta-analysis revealed that this implant indeed only produced better range of motion (ROM) and no benefits in other functional outcomes, including weight-bearing flexion. Moreover, recent studies suggested that more complications occurred in high-flexion total knee arthroplasty (TKA) instead. Objectives: This study focuses on the adverse events of high-flexion TKA compared to standard TKA in mid to long term of follow-up. Methods: Systematic search was done in online databases, i.e. Pubmed, ScienceDirect, ClinicalKey. We only included studies with a minimum follow-up duration of 5 years, expecting that this mid to long term follow-up could provide a better picture of the outcomes. Results: Seven studies were included in the final quantitative analyses, involving a total of 2,693 knees in high-flexion TKA and 3,892 knees in standard TKA. High-flexion TKA significantly had higher revision surgery compared to standard TKA (p = 0.03), 41(1.52%) and 53 (1,36%) knees, respectively. Loosening was not statistically different between those groups. Generally, radiolucent line was also more frequently observed in high-flex TKA (p = 0.01), 7.43% V 3.83% at femoral side and 5.69% V 4.41% at tibial side. Although infection and instability were higher in high-flexion knee, only a few studies found the occurrence of these parameters. Four studies evaluated the incidence of osteolysis and none was found in both groups. Conclusion: Considering that high-flexion TKA may only yield on better ROM but carry a bigger risk of adverse events, one has to cautiously weighing up the benefits and risks when planning of delivering a high-flexion TKA.

IMPACT OF TOTAL KNEE ARTHROPLASTY ON PHYSICAL ACTIVITY

Abstract Knee osteoarthritis (OA) pain often challenges the physical activity necessary for managing life-threatening chronic diseases. Standard severe knee OA treatment of total knee arthroplasty (TKA) and physical therapy (PT) is effective at improving pain and function but whether such benefits translate to physical activity is unclear. We enrolled 22 participants with severe knee OA scheduled for a TKA (Age,mean±SD=69.0±5.8y, female=63.6%) and assessed pain (i.e.,Numeric Pain Rating), physical function (i.e.,Knee Osteoarthritis Outcome Score), and physical activity (i.e.,activity monitors and journals for 7-days) before and 1-month, 3-month, and 6-month after TKA. Using paired-wise ANOVA, pre-to-postTKA pain and function improved but not physical activity. Using regression analyses, outpatient PT sessions during first two months post-TKA were positively related to 3- and 6-month physical activity (r=0.51-070, P=0.003-0.029). Standard TKA and PT for severe OA improved pain and function but not physical activity. However, early post-TKA PT and physical activity relationships are promising, warranting exploration.

Effects of Surgical Approach and Tourniquet Use on Patient-Reported Outcomes Following Total Knee Arthroplasty: A Pilot Randomized Clinical Trial.

Total knee arthroplasty (TKA) is one of the most successful procedures for the treatment of severe knee osteoarthritis. Various surgical approaches have been investigated in the hopes of improving postoperative outcomes. Two include the medial parapatellar (standard) and midvastus. As the midvastus approach does not disrupt the extensor mechanism, it may be advantageous for functional recovery, however length of stay and long-term function are similar between approaches. Tourniquet use during TKA has conflicting results in the literature. We hypothesized that a future trial comparing outpatient versus standard TKA could appropriately use either surgical approach with or without a tourniquet. Therefore, the objective of this pilot randomized trial was to compare postoperative pain, function, quality of life, and satisfaction between patients who underwent a medial parapatellar or midvastus approach for TKA ± tourniquet use. We conducted a randomized trial with a two-by-two factorial design to compare the medial parapatellar to the midvastus surgical approach for TKA ± tourniquet use. The Short Form-12 (SF-12), Western Ontario McMaster Osteoarthritis Index (WOMAC), and Knee Society Score (KSS) were collected at baseline, postoperatively at two, six, 12 weeks, and one year. Eighty-three patients were included. Postoperative WOMAC scores were statistically but not clinically higher at six weeks and three months in favour of no tourniquet use. There were no differences in postoperative WOMAC scores between approaches. Short Form-12 and KSS scores increased in both groups with no significant differences postoperatively (p > 0.05). There were no clinically significant differences in postoperative pain, function, quality of life, or satisfaction between surgical approaches or whether a tourniquet was used. As such, both surgical approaches ± tourniquet use are safe and reliable. We believe a future larger randomized trial could likely incorporate either surgical approach or tourniquet preferences without significant impact on patient reported outcomes.

Continuous glycemia monitoring in perioperative period in patients undergoing total knee or hip arthroplasty: A protocol for a prospective observational study.

In every surgical subspecialty surgical site infection (SSI) or implant infections, although occur seldom, pose a threat to patients' health. Risk factors of such states is diabetes mellitus (DM), considered one of the most widespread health-related problems of the 21st century. Orthopedists perform big joint replacements that usually concern older adults and therefore often deal with patients suffering from comorbidities. DM is frequently one of them and can furthermore often remain underdiagnosed. The other risk for complication is a rapid beginning of the rehabilitation which starts on the day following the surgery. To eliminate the debilitating impact of DM and hypoglycemia on surgical patients, we aim to investigate the relationship between the glycemia values and the postoperative outcomes in certain periods of time in patients undergoing orthopedic surgeries. Participants meeting inclusion criteria will have inserted a glycemia measuring device (Dexcom G5, Inc., San Diego, CA) in the periods of time. First time it will take place 14 days prior to the surgery and right after the surgery for the second time for the period of another 14 days. All patients will undergo standard total knee arthroplasty or total hip arthroplasty procedures. Patients will be assessed preoperatively and 14 days, 1, 3, 6, 12, and 24 months postoperatively. The assessment of the joint condition will consist of: patient-reported outcomes (The Knee injury and Osteoarthritis Outcome Score, Harris Hip Score, the Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC]); assessment of potential SSI and cardiovascular complications (the Finnish Diabetes Risk Score [FINDRISC], the Systematic Coronary Risk Evaluation [SCORE]) and the clinical examination. To investigate the influence of orthopedic surgery (anesthesia) on glycemia and the significance and safety of early patients mobilization after the big joints surgeries. To investigate changes of glycemia in patients with normal glycemia metabolism, potentially protecting them from hypoglycemia during hospital stay and increasing their awareness of potential development of DM in the future. Additionally, this study will correlate perioperative glycemic levels with risk of cardiovascular events in one year follow-up, and its influence on SSI and implant complications.

Synergistic effects of robotic surgery and IPACK nerve block on reduction of opioid consumption in total knee arthroplasty

BackgroundThere are numerous strategies to combat postoperative analgesia and expedite recovery after total knee arthroplasty (TKA). The purpose of this study was to determine opioid consumption, length of stay, and functional outcomes after robotic versus standard TKA in the setting of various regional pain modalities. MethodsA consecutive series of patients treated with unilateral primary robotic or standard TKA from January 2018–February 2021 were retrospectively identified. Regional pain modalities included peri-articular injection (PAI), adductor canal block (ACB), and infiltration between popliteal artery and capsule of knee (IPACK). Patient demographics, operative/perioperative variables, and postoperative function were recorded. Daily opiate consumption was calculated as morphine milligram equivalents (MME). Multivariate regression was performed to control for age, sex, and race. ResultsAfter review, 283 patients (177 Females; 106 Males) were included. Robotic TKA patients received IPACK + ACB (36), while standard TKA patients received either ACB (45), IPACK + ACB (167), or PAI (35). Daily inpatient opioid consumption in the standard IPACK + ACB (p = 0.02) and robotic IPACK + ACB groups (p = 0.0001) was significantly lower compared to standard ACB. When combined with IPACK block, robotic procedures synergistically lowered opiate consumption (p = 0.004) compared to standard procedures and led to earlier discharge (p = 0.003). The robotic IPACK + ACB cohort also demonstrated improved early ambulation compared to standard ACB, (p = 0.05), whereas the same benefit was not seen for patients who received IPACK during standard TKA. ConclusionsThe utilization of IPACK block decreases inpatient postoperative opioid requirements following TKA. Robotic TKA and IPACK block appeared to have a synergistic effect on opioid consumption and postoperative recovery.

A Novel Multilayer-Coating for Total Knee Arthroplasty Implants is Safe – 10-Year Results From a Randomized-Controlled Trial

BackgroundThis randomized-controlled trial was initiated to compare a new multilayer hypoallergenic coating system with the standard implant in total knee arthroplasty (TKA) in terms of serum metal ion levels, patient-reported outcomes (PROs), and implant survival. MethodsA total of 120 patients were randomized to receive a coated or standard TKA of the same knee system. Serum metal ion levels (ie, cobalt, chromium, molybdenum, and nickel) as well as knee function (Oxford Knee Score, OKS), quality of life (SF-36), and physical activity (UCLA activity scale) were assessed before surgery and until the 10 year follow-up. A total of 24 patients died and there was one revision in each group. This resulted in 85 patients who completed follow-up. ResultsBoth groups demonstrated equally good improvement in PROs after surgery and constant score values thereafter. The majority of patients had metal ion serum levels below detection limit. Only cobalt levels demonstrated a slight increase in the standard group at 5- and 10-year follow-up. However, all patients displayed values below 3 μg/L. The cumulative 10-year survival was 98% in both groups. ConclusionThere were no problems with the new coating system. No relevant increase in metal ion serum levels were measured. A slight increase in cobalt serum levels in the standard TKA was noted, thus not reaching critical values. The new coating system demonstrated equally good PROs as the standard TKA. Excellent implant survival was observed in both groups. Level of evidenceI.

A New Reference Axis for Tibial Component Rotation in Total Knee Arthroplasty: A Three-dimensional Computed Tomography Analysis.

The purpose of this study was to introduce a new reference axis for tibial rotation in total knee arthroplasty (TKA) and verify its reliability. A consecutive series of 80 knees that underwent TKA from 2018 to 2020 as well as 80 healthy knees were analyzed using a three-dimensional tibial model. A coordinate system was established based on the standard TKA tibial cut. The line connecting the lateral-tibial eminence and the medial 1/3rd of the tibial tubercle or the medial border of the tibial tubercle was identified as the lateral eminence line (LE line) and the medial lateral eminence line (MLE line), respectively. To evaluate the reliability of the new reference axis, Akagi's line, the medial third of the tibial tubercle (1/3 line) was compared with the LE and MLE lines by measuring the angle between the lines and the Z-axis. In the coronal view, the intersection angle (TPA), which is composed of the line connecting the center of the medial and lateral tibial plateau with the Z-axis, was measured. The mean angle between Akagi's line and the Z-axis in the healthy group and the osteoarthritis (OA) group was 87.57 ± 3.48° and 87.61 ± 3.47°, respectively. The mean angle between the LE line and Z-axis in the healthy and OA groups was 87.15 ± 4.13° and 86.78 ± 3.95°, respectively. A weak correlation was found between the TPA and Akagi's line and the 1/3 line. A moderate correlation was observed between the TPA and LE lines. There were no significant differences between the healthy and OA groups (P > 0.05) in any of the four reference axes. The LE line showed excellent intra- and inter-observer reliability and reproducibility. The novel and easily drawn LE line is a preferable option for tibial component rotational alignment in TKA.

Primary total knee arthroplasty assisted by computed tomography-free navigation for secondary knee osteoarthritis following massive calcium phosphate cement packing for distal femoral giant-cell bone tumor treatment: a case report

BackgroundGiant cell tumor of bone (GCTB) is an intermediate tumor commonly arising from the epiphysis of the distal femur and proximal tibia. Standard GCTB treatment is joint-preserving surgery performed using thorough curettage and the filling of the cavity with allo-, auto-, polymethyl methacrylate (PMMA), or synthetic bone graft. Calcium phosphate cement (CPC) is an artificial bone substitute, which has the benefit of being able to adjust defects, consequently inducing immediate mechanical strength, and promoting biological healing. Secondary osteoarthritis may occur following GCTB treatment and may need additional surgery if severe. However, details regarding surgery for secondary osteoarthritis have not been fully elucidated. There are no reports on the use of total knee arthroplasty (TKA) for the treatment of secondary osteoarthritis following CPC packing. The insertion of an alignment rod is a standard procedure in TKA; however, it was difficult to perform in this case due to CPC. Therefore, we used a computed tomography (CT)-free navigation system to assist the distal femur cut. This study presents a knee joint secondary osteoarthritis case following CPC packing for GCTB curettage that was treated with standard TKA.Case presentationA 67-year-old Japanese woman, who was previously diagnosed with left distal femur GCTB and was treated by curettage and CPC packing 7 years ago, complained of severe knee pain. Left knee joint plain radiography revealed Kellgren and Lawrence (K-L) grade 4 osteoarthritis without evidence of tumor recurrence. Therefore, she was scheduled for TKA. There are no reports on the cutting of a femoral condyle surface with massive CPC with accurate alignment. Because it is difficult to insert the alignment rod intramedullary and cut the femoral condyle with CPC, we planned CT-free navigation-guided surgery for accurate bone cutting using an oscillating tip saw system to prevent CPC cracks. We performed standard TKA without complications, as planned. Postoperative X-ray showed normal alignment. Knee Society Knee Score (KSKS) and Knee Society Function Score (KSFS) ameliorated from 27 and 29 to 64 and 68, respectively The patient can walk without a cane postoperatively.ConclusionThere was no report about the surface TKA guided by CT-free navigation after primary GCT surgery with CPC. We believe that this case report will help in planning salvage surgery for secondary osteoarthritis after CPC packing.

Intraoperative Load Sensing in Total Knee Arthroplasty Leads to a Functional but Not Clinical Difference: A Comparative, Gait Analysis Evaluation.

Introduction: Although Total Knee Arthroplasty (TKA) is a successful procedure, a significant number of patients are still unsatisfied, reporting instability at the mid-flexion range (Mid-Flexion Instability-MFI). To avoid this complication, many innovations, including load sensors (LS), have been introduced. The intraoperative use of LS may facilitate the balance of the knee during the entire range of motion to avoid MFI postoperatively. The objective of this study was to perform a Gait Analysis (GA) evaluation of a series of patients who underwent primary TKA using a single LS technology. Methods: The authors matched and compared two groups of patients treated with the same posterior stabilized TKA design. In Group A, 10 knees were intraoperatively balanced with LS technology, while 10 knees (Group B) underwent standard TKA. The correct TKA alignment was preoperatively determined aiming for a mechanical alignment. Clinical evaluation was performed according to the WOMAC, Knee Society Score (KSS) and Forgotten Joint Score, while functional evaluation was performed using a state-of-the-art GA platform. Results: We reported excellent clinical results in both groups without any statistical difference in patient reported outcome measurements (PROMs); from a functional standpoint, several GA space–time parameters were closer to normal in the sensor group when compared to the standard group, but a statistically significant difference was not reached. Conclusions: Gait Analysis represents a valid method to evaluate TKA kinematics. This study, with its limitations, showed that pressure sensitive technology represents a valid aid for surgeons aiming to improve the postoperative stability of TKA; however, other factors (i.e., level of intra-articular constraint and alignment) may play a major role in reproducing the normal knee biomechanics.

Increased inflammatory response is associated with less favorable functional results 5 years after total knee arthroplasty

PurposeAllergy against implant materials is discussed controversially and still not fully understood. Despite these controversies, a relevant number of patients receive hypoallergenic knee implants. The aim of this study was to compare a new coating system with the standard implant in total knee arthroplasty (TKA). Additionally, the influence of proinflammatory cytokines on patient-reported outcome measures (PROMs) was investigated.Methods120 patients without known metal allergy and without previous metal implants were included. The patients were randomized to receive a coated or standard TKA of the same knee system. 105 patients completed the 5 year follow-up. Patient-reported outcome measures (PROMs) including knee function (Oxford Knee Score, OKS), quality of life (SF36) and UCLA activity scale were assessed. Additionally, several cytokines with a possible role in implant allergy were measured in patient`s serum (IL-1beta, IL-5, IL-6, IL-8, IL-10, IP-10, IFN γ, TNF α). Group comparison was performed using Mann–Whitney U test for continuous values and chi-square test for categorical values.ResultsThere were no differences in PROMs between both groups at any follow-up. The majority of patients demonstrated no elevation of the measured blood cytokines. The blood cytokine pattern after 5 years demonstrated no differences between study groups. There was a significant association between elevated IL-8 values and worse results in the overall OKS (p = 0.041), the OKS function component (p = 0.004), the UCLA activity scale (p = 0.007) and the physical component of SF36 (p = 0.001).ConclusionThere were no problems with the new coating during mid-term follow-up and no differences in PROMs between coated and standard TKA. Patients with an increased inflammatory response demonstrated worse functional results, regardless of the implant.Level of evidenceI.Clinical trial registrationThe study protocol was registered in the US National Institutes of Health’s database (http://www.clinicaltrials.gov) registry under NCT00862511.

Risk of Revision Surgery and Manipulation Under Anesthesia in Patients With Cannabis Use Disorder Undergoing Total Knee Arthroplasty.

Background: Total knee arthroplasty (TKA) is a very common orthopedic procedure and with legalization of cannabis in many states, orthopedic surgeons are frequently encountering patients undergoing TKA with preoperative cannabis use disorder. There is conflicting and limited evidence on the impact of preoperative cannabis use and postoperative outcome.Methods and materials: In this study we retrospectively reviewed PearlDiver insurance database and analyzed the characteristics of the cannabis use in TKA patients and the impact of preoperative diagnosis of cannabis use disorder on postoperative risk of manipulation under anesthesia (MUA) within one year and revision risk within two years. We compared our results to a matched sample of opioid use patients and standard TKA patients.Result: Our study shows that cannabis use disorder was found in less than 1% of the patients undergoing total knee replacement. We identified 278 patients with cannabis use disorder undergoing TKA. More than 90% of the patients are between 40 to 69 years. There was no statistically significant gender difference noted with 130 males and 148 females. Matching sample analysis showed that the risk of MUA and risk of revision in these cannabis use patients are comparable to standard knee replacement patients and in TKA patients taking preoperative opioids.Conclusion: Retrospective database review failed to identify any increased risk of MUA or two-year revision in cannabis use TKA patients.

Is standard total knee arthroplasty with lateral femoral overhanging a cause of anterior knee pain? A randomized controlled trial.

Introduction: Anterior knee pain (AKP) may persist after total knee arthroplasty (TKA), even if well aligned and stable, and is reported in up to 30% of patients, leading to patient dissatisfaction. The gender-specific knee prostheses have been designed to reduce femoral component overhanging in females and improve patient satisfaction. The purpose of this study was to determine AKP between gender-specific knee prosthesis and unisex knee prosthesis following minimally invasive surgery (MIS) TKA with patellar resurfacing. Methods: This study was a randomized trial comparing a gender-specific vs. unisex knee prosthesis in females with knee osteoarthritis. Follow-up occurred at 6 weeks, 3 months, 6 months, 1 year, and 2 years. Pre- and postoperative AKP were measured at each follow-up. Intraoperative lateral overhanging of the femoral component and patellar tracking were also measured and compared between the two groups. Results: Sixty females were recruited; 30 underwent gender-specific knee prosthesis (Gp1) and 30 underwent unisex knee prosthesis (Gp2). No patients were lost to follow-up. The incidence rates of AKP and visual analog scale AKP pain scores at 2 years were 7 vs. 7% (p = 1.00) and 0.95 ± 0.31 (0–1) points vs. 1.10 ± 0.28 (0–1) points (p = 0.68) for gender and unisex prostheses, respectively. Patellar tilt and patellar shift were similar between the two groups. Patellar tilt and patellar shift were 2.56° ± 2.03 (0–8) vs. 2.67° ± 2.35 (0–9) (p = 0.46) and 1.25 ± 1.09 (0–3.2) mm vs. 1.15 ± 0.97 (0–2.9) mm (p = 0.34) for Gp1 and Gp2, respectively. Mean lateral femoral overhanging was 0.23 ± 0.63 mm (range: 1–2 mm, Gp1) vs. 1.57 ± 1.36 mm (range: 1–3 mm, Gp2) (p ≤ 0.001). Conclusion: Both types of prostheses had similar incidence rates of AKP, VAS scores for AKP. Lateral femoral overhanging of ≤ 3 mm was not the cause of AKP.

Metal wear debris generation in primary total knee arthroplasty: is it an issue?

More durable total knee arthroplasties (TKAs) are needed, due to the rising life expectancy, the higher activity levels of patients and the growing concerns about aseptic loosening being caused by metal hypersensitivity. In response, different hypoallergenic metal coatings have been developed for TKAs. However, possible adverse effects of these different metals (cobalt-chromium-molybdenum, zirconium, titanium and tantalum) have been neglected. The aim was to summarize the local and systemic adverse effects (including metal hypersensitivity), survival ratios, patient-reported outcome measures (PROMs) and the plasma metal ion concentrations of the different TKA coatings. A literature search on PubMed and EMBASE was performed. In total, 15 studies were found eligible. Common adverse effects of TKA were infection, loosening, pain, instability and hyper- coagulation disorders. Serious adverse effects related to TKA implants were not reported. The survival ratios and patient-reported outcome measures seem to confirm these good results. In contrast with chromium and cobalt, no significant differences were reported in the nickel, molybdenum and titanium concentrations. No significant differences between the hypoallergenic and standard TKA implants were found in terms of adverse effects, survival ratios and PROMs. A causal relationship between the common adverse effects and the different metals is unlikely. Due to the heterogeneity of the TKA implants used, no firm conclusions could be made. Further research with longer follow-up studies are needed to find possible adverse effects and differences. Thus far, the hypoallergenic implants seem to perform equal to the standard implants.

Effectiveness of Perineural Injections Combined with Standard Postoperative Total Knee Arthroplasty Protocols in the Management of Chronic Postsurgical Pain After Total Knee Arthroplasty.

BackgroundDespite increased experience and technical developments in total knee arthroplasty (TKA), chronic postsurgical pain (CPSP) remains one of physicians’ biggest challenges. The aim of the present study was to evaluate the effectiveness of perineural injection therapy (PIT) in the management of CPSP after TKA.Material/MethodsA total of 60 patients who had been surgically treated with TKA because of advanced knee osteoarthritis was included in the present study. The study included 2 groups. Group A consisted of patients who received 3 rounds of PIT combined with standard postoperative TKA protocol during the same period. Group B received standard postoperative TKA protocols (rehabilitation programs, oral and intravenous analgesics). Clinical effectiveness was evaluated via Western Ontario and McMaster Universities Arthritis Index (WOMAC) and Visual Analog Scale (VAS) at baseline and 1-, 3-, and 6-month follow-ups.ResultsAll repeated measures showed significant improvements (P<0.001) in both groups for VAS and WOMAC scores. These scores were significantly better in group A in all follow-up periods compared with group B (P<0.001). Twenty-nine patients (93.5%) in group A reported excellent or good outcomes compared with 26 patients (89.6%) in group B.ConclusionsPIT is a promising approach in CPSP with minimal cost, simple and secure injection procedures, minimal side effects, and higher clinical efficacy.