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Alternative alignment concepts have garnered great interest in an effort to improve patient satisfaction following primary total knee arthroplasty (TKA). The purpose of this study is to determine variation or deviation from an individual's native joint line in primary TKA using neutral mechanical versus a restricted kinematic technique.An institutional review board-approved prospective cohort study was performed evaluating the effect of neutral mechanical alignment (nMA) versus a restricted kinematic alignment (rKA) on the native joint line in 100 consecutive patients undergoing primary TKA. Using preoperative computed tomography and intraoperative 3-dimensional software, 2 virtual preoperative plans were created: nMA and rKA. Templated bone resections were recorded. Change in joint line was calculated using known implant planar thickness and planned bone resection.nMA yielded significantly greater deviation from the patient's native joint line along the lateral compartment of the knee (lateral distal femoral condyle, lateral posterior femoral condyle, lateral tibial resection). With nMA, the lateral distal femoral joint line was distalized by a mean 4.3 versus 2.6 mm using rKA technique (P.001). In rKA,60% of knees had3 mm of deviation from the native lateral posterior femoral offset, whereas in nMA,95% of knees had ≥3 mm change in the lateral posterior femoral condylar offset.nMA-TKA resulted in statistically larger joint line deviations compared to rKA-TKA, most notably along the lateral distal femoral condyle joint line. Further analysis is needed to determine the clinical consequences of joint line deviation from the native anatomy using nMA as the target for primary TKA.

Initial design cementless metal-backed patellar implants failed due to multiple reasons including implant design, use of first-generation polyethylene, and surgical technique. This study evaluates clinical outcomes and survivorship of total knee arthroplasty (TKA) using a current generation highly porous metal-backed patellar component. One-hundred twenty-five consecutive primary cementless TKAs with a compression molded highly porous metal-backed patella were reviewed. One-hundred three TKAs (82.4%) with 5-year clinical and radiographic follow-up were available for review. These were matched with 103 consecutive TKAs using a cemented patella of the same implant design. The cementless cohort had a mean age of 65.5 years, body mass index (BMI) of 33.0, and follow-up of 64.4 months. Indications for cementless TKA were based on multiple factors including age, BMI, and bone quality. There were no revisions for loosening or mechanical failure of the cementless patella compared with two cemented patellae revised for aseptic loosening. Eight patients required revisions in the cementless cohort: three for prosthetic joint infection (PJI), two for instability, one periprosthetic femur fracture, one for patella instability, and one for extensor mechanism rupture. Five patients required revisions in the cemented cohort: two for aseptic patellar loosening, one for aseptic femoral loosening, one for PJI, and one for instability. All-cause survivorship at 5 years was 92.2 and 95.1% for the cementless metal-backed implant and cemented implant cohorts, respectively. Use of a compression molded highly porous metal-backed patella component demonstrated excellent clinical and radiographic results at 5-year follow-up. Longer follow-up is required to evaluate the ability of highly porous cementless patella implants to provide durable long-term fixation.

Highly cross-linked polyethylene (HXLPE) has become the preferred bearing surface in total hip arthroplasty. However, its acceptance in total knee arthroplasty (TKA) has not been as robust because of concerns pertaining to wear and its impact on implant failure. Therefore, this multicenter study was purposed to evaluate the 10-year (1) radiographic outcomes; (2) complications; and (3) implant survivorship in patients with TKA receiving a sequentially irradiated and annealed HXLPE. A retrospective, multi-center study was performed on 139 patients (171 TKAs) who underwent primary TKA with HXLPE and possessed a minimum of 10-year follow-up. Radiographs were analyzed for radiolucencies along the implant-fixation interface using the Modern Knee Society Radiographic Evaluation System. Kaplan-Meier analysis determined implant survivorship when the end points were revision for polyethylene wear and polyethylene revision for any reason. Sixteen TKAs (9.9%) demonstrated periprosthetic linear radio-lucencies. Seventeen TKAs (9.9%) required additional surgeries, 9 (5.3%) of which were revisions, with 1 (0.6%) TKA requiring revision because of polyethylene wear. Other causes of revision included instability (1.8%), infection (1.6%), and arthrofibrosis (1.6%). The mean time to revision was 5.9 years (range, 0.1–11.1 years). Survivorship pertaining to polyethylene revision for wear was 99.4%, whereas all-cause polyethylene revision was 94.7%. This study in patients undergoing primary TKA using a second-generation HXLPE demonstrated excellent results with respect to polyethylene wear characteristics and strength with a 99.4% survivorship at 10 years. [ Orthopedics . 2023;46(2):e111–e117.]

Background There is a paucity of data on the long-term performance of highly cross-linked polyethylene (HXLPE). Therefore, this study evaluated 10-year 1) functional, 2) radiographic, and 3) surgical outcomes in patients who underwent total hip arthroplasty with sequentially irradiated and annealed HXLPE. Methods A retrospective, multicenter study was conducted on patients who underwent primary total hip arthroplasty and received HXLPE polymer (n = 151). Two-dimensional radiographic linear and volumetric wear analyses were quantified using the Martell Hip Analysis software, while functional outcomes were assessed by analyzing postoperative Short-Form-12 (SF-12) Physical and Mental Health Surveys and Harris Hip Scores. Radiographic outcomes included yearly linear (mm/y) and volumetric (mm3/y) wear rates. Surgical outcomes included additional operations and survivorship. Results SF-12 scores were within 1 standard deviation (SD) of the normal population (SF-12 Physical: 47.0; SF-12 Mental: 52.0), while the Harris Hip Scores of 89.5 was borderline between “good” and “excellent.” Total and annual linear wear rates were 0.164 mm (SD: 0.199 mm) and 0.015 mm/y (SD: 0.018 mm/y), respectively. The mean total volumetric wear rate was 141.4 mm3 (SD: 165.0) and 12.6 mm3/y (SD: 14.9 mm3/y) when broken down into a yearly rate. Eleven patients required revisions, resulting in an all-cause polyethylene survivorship of 92.7%, with a polyethylene wear survivorship of 100.0%. Conclusions Our results demonstrate clinically undetectable linear and volumetric wear rates after 10 years in those who received the unique sequentially irradiated and annealed HXLPE. Furthermore, high rates of survivorship coupled with low all-cause revision rates illustrate the polymers' capability to potentially increase implant longevity.

AimsAlternative alignment concepts, including kinematic and restricted kinematic, have been introduced to help improve clinical outcomes following total knee arthroplasty (TKA). The purpose of this study was to evaluate the clinical results, along with patient satisfaction, following TKA using the concept of restricted kinematic alignment.MethodsA total of 121 consecutive TKAs performed between 11 February 2018 to 11 June 2019 with preoperative varus deformity were reviewed at minimum one-year follow-up. Three knees were excluded due to severe preoperative varus deformity greater than 15°, and a further three due to requiring revision surgery, leaving 109 patients and 115 knees to undergo primary TKA using the concept of restricted kinematic alignment with advanced technology. Patients were stratified into three groups based on the preoperative limb varus deformity: Group A with 1° to 5° varus (43 knees); Group B between 6° and 10° varus (56 knees); and Group C with varus greater than 10° (16 knees). This study group was compared with a matched cohort of 115 TKAs and 115 patients using a neutral mechanical alignment target with manual instruments performed from 24 October 2016 to 14 January 2019.ResultsMean overall patient satisfaction for the entire cohort was 4.7 (SE 0.1) on a 5-point Likert scale, with 93% being either very satisfied or satisfied compared with a Likert of 4.3 and patient satisfaction of 81% in the mechanical alignment group (p < 0.001 and p < 0.006 respectively). At mean follow-up of 17 months (11 to 27), the mean overall Likert, Knee Injury and Osteoarthritis Outcome Score for Joint Replacement, Western Ontario and McMaster Universities Osteoarthritis Index, Forgotten Joint Score, and Knee Society Knee and Function Scores were significantly better in the kinematic group than in the neutral mechanical alignment group. The most common complication in both groups was contracture requiring manipulation under anaesthesia, involving seven knees (6.1%) in the kinematic group and nine knees (7.8%) in the mechanical alignment group.ConclusionWith the advent of advanced technology, and the ability to obtain accurate bone cuts, the target limb alignment, and soft-tissue balance within millimetres, using a restricted kinematic alignment concept demonstrated excellent patient satisfaction following primary TKA. Longer-term analysis is required as to the durability of this method. Cite this article: Bone Joint J 2021;103-B(6 Supple A):59–66.

Stiffness following total knee arthroplasty (TKA) is a disabling complication and manipulation under anesthesia (MUA) is often performed as an early intervention. Few studies have focused on the revision risk, infection risk, demographics, and clinical outcomes in Medicare patients undergoing MUA following primary TKA.We reviewed 142,440 patients who had primary TKA from a national database and identified 3,652 patients (2.6%) who underwent MUA. Patient demographics and comorbid conditions were evaluated to identify risk factors. Incidence of revision and periprosthetic joint infection (PJI) at 1-, 2-, and 5-year time points in a cohort of MUA patients was compared to patients who did not undergo MUA. Multivariate Cox regressions were used for statistical analyses.The incidence of MUA was higher in Black versus White individuals (4.1 versus 2.5%, P.001). Revision risk was significantly greater in the MUA group at 1-, 2-, and 5-year time points with a hazard ratio (HR) of, 3.81, 3.90, and 3.22 respectively, P.001. One- and 2-year revision risk was significantly greater when MUA occurred at 6 to 12 months post-TKA when compared to3 months, P.05. Risk of PJI was significantly greater in the MUA group with a HR of 2.2, 2.2, and 2.1 at 1, 2, and 5 years, respectively P.001.The incidence of MUA was 2.6%. There was an increased incidence of revision surgery and PJI in patients undergoing MUA. Patients at increased risk for stiffness following TKA should be closely monitored and treated with early intervention to minimize risk of poor outcomes.

Background Morbidly obese patients undergoing cemented primary total knee arthroplasty (TKA) can pose a challenging problem with implant survivorship due to greater stress at the cement-bone interface. With the advent of additive manufacturing (three-dimensional printing), highly porous implants are now readily available. The purpose of this study was to review the results of primary TKA in the morbidly obese (body mass index [BMI] ≥ 40) patient using a highly porous cementless tibial baseplate. Methods This is a retrospective study of 167 TKAs in patients with morbid obesity undergoing primary cementless TKA with a minimum 5-year follow-up. A total of 6 patients died and 14 were lost to follow-up, leaving 147 TKAs in 136 patients with a mean follow-up of 66 months (range 60–79 months). The average age was 59 years (range 36–84 years) and average BMI was 45 kg/m2 (range 39.5–63.9). Clinical results, patient-reported outcome measures, radiographs, and complications were reviewed. Results There were 9 failures requiring revision, including 3 for aseptic tibial loosening (2.0%), 2 for deep infection (1.4%), 2 for patellar resurfacing (1.4%), 1 for patella instability (0.7%), and 1 for extensor mechanism rupture (0.7%). Knee Society Score (KSS) improved from 48 to 90 at 2- and 5-year follow-up. KSS function score improved from 49 to 68 and 79 at 2- and 5-year follow-up, respectively. Survivorship with aseptic loosening as the endpoint was 98.0% at 5 years. Conclusion Cementless TKA using a highly porous tibial baseplate in morbidly obese patients demonstrated excellent clinical results with 98% survivorship at 5 years and appears to offer durable long-term biologic fixation as an alternative to mechanical cement fixation in this challenging group of patients.

Large femoral head sizes are commonly used in total hip arthroplasty (THA) to minimize the risk of instability. With small acetabular cup-size, large femoral head diameter often results in the use of thin polyethylene liners. The purpose of this study was to evaluate clinical and radiographic results of large femoral heads against thin polyethylene liners with minimum 5-year follow-up.This was a retrospective review identifying 58 primary THAs utilizing thin polyethylene inserts from one manufacturer (X3 polyethylene, Stryker, Mahwah, NJ) and large femoral heads (36 mm or greater) with minimum 5-year follow-up. A total of 3 patients were deceased and 11 lost to follow-up, leaving 44 patients for review. All patients were female with mean age 65.7 (range 26-85) and mean body mass index (BMI) 29.9 (range 19.6-45.4). Average length of follow-up was 8.5 years (range 5.1-11.3). Outcome measures included survivorship, complications, PROMs and radiographic analysis.There were four revisions: two aseptic loosening, one prosthetic joint infection, and one recurrent dislocation. Average HOOS-Jr, FJS-12, and patient satisfaction using Likert score was 94.3/100, 92.9/100, and 4.69/5.00, respectively, with 94% of patients reporting being satisfied or very satisfied. Radiographic analysis at average of 8.5 years demonstrated well-fixed implants without evidence of progressive radiolucent lines, osteolysis, or failure of the polyethylene liner. Survivorship using failure of the thin polyethylene liner as the endpoint was 100% at an average of 8.5 years.Thin polyethylene liners used with large femoral head sizes in small acetabular cups demonstrated excellent results at average 8.5-year follow-up with no cases of liner fracture or osteolysis.

Aims Robotic-assisted total knee arthroplasty (RA-TKA) has been introduced to provide accurate bone cuts and help achieve the target knee alignment, along with symmetric gap balancing. The purpose of this study was to determine if any early clinical benefits could be realized following TKA using robotic-assisted technology. Methods In all, 140 consecutive patients undergoing RA-TKA and 127 consecutive patients undergoing conventional TKA with minimum six-week follow-up were reviewed. Differences in visual analogue scores (VAS) for pain at rest and with activity, postoperative opiate usage, and length of stay (LOS) between the RA-TKA and conventional TKA groups were compared. Results Patients undergoing RA-TKA had lower average VAS pain scores at rest (p = 0.001) and with activity (p = 0.03) at two weeks following the index procedure. At the six-week interval, the RA-TKA group had lower VAS pain scores with rest (p = 0.03) and with activity (p = 0.02), and required 3.2 mg less morphine equivalents per day relative to the conventional group (p < 0.001). At six weeks, a significantly greater number of patients in the RA-TKA group were free of opioid use compared to the conventional TKA group; 70.7% vs 57.0% (p = 0.02). Patients in the RA-TKA group had a shorter LOS; 1.9 days versus 2.3 days (p < 0.001), and also had a greater percentage of patient discharged on postoperative day one; 41.3% vs 20.5% (p < 0.001). Conclusion Patients undergoing RA-TKA had lower pain levels at both rest and with activity, required less opioid medication, and had a shorter LOS.

Background Isolated patellofemoral joint arthritis has been identified in 10% of the population presenting with symptomatic knee osteoarthritis. Patient selection is important in order to improve survivorship following PF arthroplasty. The purpose of this study is to compare the use of a preoperative bone scan vs a magnetic resonance imaging (MRI) to identify the patient with isolated PF arthritis. Methods This is a retrospective review of 32 patients undergoing isolated PF arthroplasty for PF arthritis using the same implant design. Sixteen consecutive patients received a preoperative bone scan to confirm isolated PF arthritis. These patients were matched by age and gender to patients where an MRI was used to determine isolated PF arthritis. The bone scan cohort contained 13 females and three males with an average age of 48 years and average follow-up of 52 months. There was no significant difference in age, body mass index, follow-up, or preoperative range of motion between the groups. The MRI and bone scan results were reported by a radiologist specializing in orthopedic radiology. Results Survivorship was 100% in the PF arthroplasty group selected using a preoperative bone scan. Revision surgery with conversion to TKA was required in 5 of 16 patients (31%) when an MRI was used to identify isolated PF arthritis. Revision in all patients in the MRI group was due to progression of knee arthritis in the tibial-femoral joint. There were no cases of implant-related failures. Conclusion Patellofemoral arthroplasty using a modern design implant demonstrated 100% survivorship when a preoperative bone scan was used for patient selection to confirm isolated PF arthritis. In the group where only an MRI was used, there was a 31% failure due to progression of the disease. Based on this study, we would recommend the use of a bone scan as a tool in the selection criteria for patients undergoing PF arthroplasty.

Peripheral nerve blocks such as a femoral + sciatic block have demonstrated significant pain relief following TKA. However, these nerve blocks have residual motor deficits which prevent immediate postoperative ambulation. The purpose of this study was to compare outcomes in patients undergoing primary TKA with femoral and sciatic (Fem + Sci) motor nerve blocks versus an adductor canal and the interspace between the popliteal artery and the capsule of the posterior knee and adductor canal block (IPACK + ACB) sensory nerve blocks. A total of 100 consecutive patients were reviewed, 50 received Fem + Sci nerve blocks and 50 received IPACK + ACB blocks preoperatively. There were no differences in the two groups with respect to surgical technique, implant type, postoperative pain, and physical therapy protocols. Differences in opioid requirements, length of stay (LOS), distance walked, and common knee scoring systems were analyzed. Among them, 62% IPACK + ACB patients were discharged on postoperative day 1 compared with 14% in the Fem + Sci group (p

Acetabular component malpositioning is a frequent cause of complications in total hip arthroplasty including instability, increased wear, osteolysis, impingement, and revision surgery. Recently, robotics and navigation have been introduced to improve cup positioning in total hip arthroplasty. The purpose of this study was to compare the accuracy of postoperative acetabular component positioning using MAKO robotic-assisted versus manual acetabular component placement. A consecutive series of 100 total hip replacements were performed in 100 patients. The first 50 were performed using manual techniques, while the second 50 were performed using MAKO-guided acetabular component placement. Postoperative anteroposterior pelvis radiographs were used to determine the postoperative anteversion and inclination of the cup relative to the goal of 15 and 45°, respectively. In the manual group, the average anteversion and inclination was 14.3 and 44.2°, respectively, with 28% within 5° and 82% within 10° of the goal alignment, respectively. In the robotic group, the average anteversion and inclination was 15.1 and 45.6°, respectively, with 54 and 88% within 5 and 10° of the goal alignment, respectively. This equated to a statistically significant improvement in the number of acetabular components placed within 5° of the target alignment with the use of robotic guidance (p = 0.0142). From the authors' study, they were able to demonstrate a significant improvement in acetabular component alignment with the use of robotic techniques. Additional studies are needed to demonstrate improvement in clinical outcomes as a result of improved accuracy and precision of acetabular component placement.

The purpose of this study was to determine if significant clinical differences exist in patient-reported outcome measures (PROMs) between PS and CR TKAs implanted using robotic-assisted technology. This was an IRB-approved retrospective study from an institutional database evaluating 214 knees in 190 patients. Inclusion criteria included: primary RA-TKA, age 22-89 at the time of surgery, preoperative coronal limb deformity within 15º of neutral alignment, and minimum 1-year follow-up. The PS cohort consisted of 103 patients with 107 RA-TKAs, whereas the CR cohort consisted of 87 patients with 107 RA-TKAs. Cohorts were compared on the basis of demographics and PROMs (KSS knee, KSS function, FJS-12, KOOS-JR, WOMAC, and 5-point satisfaction Likert scale) collected preoperatively and at 1-year follow-up. Statistical analyses comparing measures were conducted via Student's t tests for continuous data and Chi-squared analyses for categorical data. There were no significant differences identified in short-term PROMs at 1-year follow-up between cohorts (all p values 0.05). 93.1% of patients with CR knees and 94.7% of patients with PS knees reported a satisfaction level of "very satisfied" or "satisfied". Revision arthroplasty occurred in six knees (2.8%, 3 knees in CR cohort, 3 knees in PS cohort) with no differences in overall complications between groups. The use of RA-TKA technology promoted high patient satisfaction scores within this study, independent of CR or PS implant type with no significant differences in PROMs, satisfaction, revisions, or complications between the two groups.

Background Tourniquet use is common in total knee arthroplasty (TKA), but debate exists regarding its use and effect on patient outcomes. The study purpose was to compare the effect of short tourniquet (ST) time vs long tourniquet (LT) time on pain, opioid consumption, and patient outcomes. Methods Patients were prospectively randomized to an ST time of 10 min vs LT time. A total of 100 consecutive patients undergoing primary cementless robotic-assisted TKA underwent randomization, with 5 patients unable to complete follow-up, leaving 49 in the ST group and 46 in the LT cohort. Visual analog scale pain scores, morphine equivalent, serum creatine kinase, distance walked, range of motion, length of stay (LOS), surgical time, hemoglobin (Hgb), and Knee Society Scores (KSS) were prospectively collected. Results Visual analog scale pain was statistically equivalent at 24, 48, and 72 hours and at 2 and 6 weeks postoperatively. Morphine equivalent consumption was 36 vs 44 (P = .03), 48 vs 50 (P = .72), 31 vs 28 (P = .57), and 4.7 vs 5.5 (P = .75) in the LT vs ST cohorts at 24 hours, 48 hours, 2weeks, and 6weeks postoperatively. Change in Hgb postoperative day 1 was 2.7 in both groups (P = .975). Postoperative day 1 creatine kinase-MB was 3.7 and 3.0 (P = .30) in LT and ST cohorts. Six-week postoperative KSS Knee and Function scores were 82.4 and 70.5 in LT group vs 80.8 and 72.3 in ST group (P = .61 and P = .63). Postoperative range of motion, LOS, and surgical time were equivalent. Conclusion This study demonstrates no significant advantage of ST use in primary TKA with respect to opioid consumption, patient-reported pain, KSS scores, LOS, or postoperative Hgb level.

Proximally coated, morphometric wedge femoral stems illustrated excellent survivorship and clinical outcomes at a minimum five-year postoperative follow up.We completed a retrospective review of 186 THA patients from three high-volume surgeons to assess clinical- and patient-reported outcomes five years after implantation with a cementless, proximally coated morphometric wedge femoral stem. We reviewed Gruen zones on early postoperative and mid-term radiographs for signs of osteolysis, loosening, and wear. Clinical- and patient-reported outcomes were compared with previously published two-year outcomes for these femoral stems.No progression of radiolucencies or loosening was observed radiographically when comparing minimum one-year and five-year follow up. Reactive radiodense lines were observed in 23 cases (12.64%), and 13 cases (7.14%) exhibited true radiolucencies of 1-3mm, and all remained unchanged between follow ups or were no longer present on the five-year film. Cortical hypertrophy was noted in Gruen zones 3 and/or 5 in 11 cases (6.04%). No stems were revised for mechanical loosening or for periprosthetic fracture. Nine (9) patients (4.87%) underwent revisions during the follow-up period for periprosthetic infection, femoral head and/or acetabular component revisions, and impingement requiring release and femoral head change. Average Harris Hip Scores were excellent at five years and improved slightly when compared to a two-year follow up; however, this change was not statistically significant. Health-related quality of life mental component and physical component scores were a mean of 48.45 and 43.10 at 5 years, respectively. All cause Kaplan-Meier survivorship of the femoral stem was calculated at 98.4% at an average 65.7 months post implantation. Additionally, this cohort exhibited 100% aseptic survivorship during the follow-up period.Newer-generation morphometric wedge femoral stems for THA exhibit excellent radiographic stability, patient satisfaction, and clinical outcomes five years post implantation.

Alignment after total knee arthroplasty (TKA) plays an important role with respect to patient satisfaction and implant survivorship. In patients undergoing ipsilateral TKA with prior total hip arthroplasty (THA), the femoral intramedullary (IM) guide cannot be fully inserted into the femoral canal because of the prior THA. The purpose of this study was to determine the effect of femoral component alignment using a shorter IM guide during TKA in patients with an ipsilateral THA. We identified 42 patients undergoing ipsilateral TKA with the use of a short IM guide in the setting of a prior THA. A matched cohort group was identified from our total joint registry that included 42 patients who underwent primary TKA. The surgical goal was to achieve 5 degrees of valgus on the femoral side and 0 degree on the tibial side with an overall postoperative tibial–femoral angle of 5 degrees of valgus. Patients were evaluated clinically using Knee Society pain scores (KSSs), function scores, and with radiography. Both the tibial–femoral limb alignment and the femoral component alignment were compared using Student's t-test. There were no significant differences between the two groups with respect to sex, age, body mass index (BMI), pre- and postoperative KSSs. There was a statistically significant difference between the two groups with respect to radiographic tibial–femoral limb alignment, 4.33 degrees of valgus in the short stem THA–TKA group versus 5.4 degrees of valgus in the TKA group (p

Background Obese and morbidly obese patients undergoing primary total knee arthroplasty (TKA) place significant stress at the bone-cement-implant interface over the life of the patient. The purpose of this study is to evaluate results of cemented, posterior-stabilized TKA in obese and morbidly obese patients at an average follow-up of 10 years. Methods Retrospective study of 181 patients who had a cemented, posterior-stabilized TKA between 2000 and 2013 with body mass index >35 at the time of surgery was conducted. Clinical data and radiographs were evaluated along with survivorship, complications, and revisions. Minimum follow-up was 5 years with an average follow-up of 10 years. Results There were 135 women and 46 men in the study, with mean age of 60.2 years (range 43-80), mean body mass index of 42.0 (range 35.1-66.1), and an average follow-up of 10 years (range 5-18). There were a total of 39 failures (22%) that underwent revision TKA surgery with mean time to revision of 8 years. Failures included 25 (14%) cases of aseptic loosening; 9 (5%) polyethylene wear; 2 (1%) prosthetic joint infection; and 3 additional revisions for instability, pain, and stiffness. There were a total of 11 cases of isolated tibial component loosening and 13 for both tibial and femoral loosening. Survivorship at 15 years with aseptic loosening as the endpoint was 86.7%, and for all causes 79.6% at 15 years. Conclusion Aseptic loosening is the leading cause of failure following TKA in obese and morbidly obese patients with decreasing survivorship from 96.1% to 91.2% and 86.7% at 5, 10, and 15 years, respectively.

Aims:Approximately 20% of patients are dissatisfied with their total knee arthroplasty (TKA). Purpose of this study was to determine if patient satisfaction could be improved following TKA using computer technology to obtain the target alignment and precisely balanced gaps.Patients & Methods:75 consecutive patients undergoing primary robotic-arm assisted TKA (RA-TKA) with real-time intraoperative alignment and gap balancing information were compared with a prospective cohort of 75 consecutive patients undergoing primary TKA with manual jig-based instruments during the same time period. There were no differences between groups with age, gender, BMI, and ASA scores. TKA’s were performed by a single surgeon using same implant design, anesthesia and surgical protocols. Patient satisfaction survey using Knee Society (KSS) and Likert scoring system was obtained at 1-year follow-up.Results:Likert scoring system demonstrated 95% of patients in the computer technology group were either very satisfied or satisfied versus 75% in the manual instruments TKA group (p=0.005) at 1-year follow-up. Second question of the KSS which deals with pain at rest was significantly better in RA-TKA group (p=0.04). Fifth question which deals with recreational activities was also significantly improved in the RA-TKA group, p=0.02. RA-TKA group had a better average overall satisfaction score of 7.1 versus 6.4 in the manual instrument group, p=0.03.Conclusion:Using intraoperative computer technology to achieve the target alignment with flexion/extension gap balancing to within 1mm, a significant improvement in patient satisfaction was demonstrated compared to TKA using conventional manual jig-based instruments.

Background: Decreasing length of stay (LOS) following primary total knee arthroplasty (TKA) has been an important focus by all the stakeholders involved in the delivery of care. LOS is dictated by both the patient and hospital-related factors. The purpose of this study was to determine if early mobilization on post-operative day 0 (POD 0) following primary TKA has an effect on hospital LOS and discharge to home vs. rehabilitation facilities. Methods: An analysis was performed of consecutive primary TKAs performed at a single institution over one year. Patients were assigned to two groups: POD 0 or POD 1, based on their day of mobilization. Patients were mobilized following surgery based on time of arrival to the orthopaedic floor and availability of physical therapy (PT) resources. The two groups were compared for LOS and discharge disposition using univariate analysis. A total of 408 consecutive TKAs were evaluated and from this group, a total of 143 patients who were mobilized on POD 0 were then matched to 143 patients mobilized on POD 1. There were no significant differences in age, sex, American Society of Anesthesiologists score, or body mass index (BMI) between POD 0 and POD 1 groups. Results: There was a significant difference in LOS between POD 0 and POD 1 groups, 2.44 vs. 2.80 days (P=0.002). There were also differences in discharge to home vs. rehabilitation, 70.63% of the POD 0 cohort were discharged home compared to 58.74% in POD 1 (P=0.035). Conclusions: There was a significant reduction in LOS and there were differences in discharge disposition between patients who mobilized on POD 0 vs. POD 1, with more patients mobilized on POD 0 discharged home. Hospitals should work with their total joint arthroplasty programs to mobilize close to 100% of the patients undergoing primary TKA on POD 0 in order to decrease LOS and healthcare expenditure.

The purpose of this study was to determine the risk factors associated with reinfection in patients treated with irrigation and debridement (I&D) with liner exchange for an acute (less than 3 months) prosthetic joint infection following the index primary total knee arthroplasty (TKA). Medicare claims database was queried to identify patients with periprosthetic joint infection within 3 months of their index TKA who underwent I&D with tibial polyethylene liner exchange. Exclusion criteria included age 85 years old (p 6 weeks after index procedure compared with those performed within 2 weeks. Patients older than 85 years, diabetics, or treated with I&D with liner exchange > 14 days following the primary TKA had a significantly higher risk of reinfection within 1 year. Patients should be cautioned on the risk of reinfection prior to proceeding with I&D with liner exchange > 2 weeks following the index procedure.

The purpose of this study was to evaluate the efficacy and safety profiles of topical tranexamic acid (TXA) in patients undergoing elective total knee arthroplasty (TKA) with comorbid conditions precluding them from intravenous (IV) TXA use. A total of 104 patients were divided into two groups: 47 in the normal-risk group and 57 in the high-risk group, with the latter representing those with one or more risk factors for venous thromboembolism (VTE). Demographics were similar between groups, and there were no differences with regard to postoperative changes in hemoglobin (− 3.42 g/dL ± 1.07 and − 3.68 g/dL ± 1.07, p = 0.214), total drain output (630.2 mL ± 331.6 and 566.9 mL ± 343.9, p = 0.344), postoperative transfusion rate (2.1 and 3.5%, p = 0.675), or total number of complications 3 (6.5%) and 5 (8.8%) for the normal- and high-risk groups, respectively (p = 0.671). Topical TXA exhibited a similar safety and efficacy profile in reducing postoperative blood loss in a group of patients at increased thromboembolic risk, without a significant increase in complications or thromboembolic events. Topical TXA appears to represent a safe and efficacious alternative to IV TXA in patients at high risk for VTE undergoing TKA.

Background Primary total knee arthroplasty (TKA) in morbidly obese patients has been associated with greater postoperative complications. Cementless TKA has the potential for biologic fixation which may provide more durable long-term stability. Methods This was a multicenter review of 298 TKAs in 292 morbidly obese patients (body mass index, >40) undergoing TKA, with 154 TKAs (149 patients) in the cemented and 144 TKAs (143 patients) in the cementless group. Results There were significantly more revisions in the cemented group (n = 20) than in the cementless group (n = 1; 13.0% vs 0.7%). There was a significantly higher incidence of aseptic loosening in the cemented cohort vs the cementless cohort (9 vs 0 TKAs). All revisions in the cementless cohort were due to infection (0.7%). Conclusion Cementless fixation may be an alternative in the morbidly obese patient undergoing primary TKA.

Background Although cemented total knee arthroplasty (TKA) continues to be the gold standard, there are patient populations with higher failure rates with cemented TKAs such as the obese, morbidly obese, and younger active males. Cementless TKA usage continues to increase because of the potential benefits of long-term biologic fixation similar to the rise in cementless total hip arthroplasty. The purpose of this study was to evaluate the clinical and radiographic results of cementless TKA using a novel highly porous cementless tibial baseplate. Methods This was a retrospective matched case-control study of 400 primary TKAs comparing cementless vs cemented TKAs using the same implant design (Stryker Triathlon; Stryker Inc, Mahwah, NJ). Two-hundred patients with a mean age of 64 years (range 42-88 years) and body mass index (BMI) of 33.9 kg/m2 (range 19.7-57.1 kg/m2) were matched to 200 primary cemented TKA patients with a mean age of 64 years (range 43-87 years) and BMI of 33.1 kg/m2 (range 22.2-53.2 kg/m2). The mean follow-up in the cementless group was 2.4 years (range 2-3.5 years) and in the cemented group was 5.3 years (range 2-10.9 years). Clinical and radiographic analyses were evaluated. Statistical analysis was performed using the Microsoft Excel, version 15.21.1. Results There was no statistical difference in age, BMI, and preoperative Knee Society Scores between the 2 groups (P = .22, P = .82, and P = .43, respectively). Patients in both groups had a similar incidence of postoperative complications (P = .90). Cementless group had 7 revisions with one aseptic loosening of the tibial component (0.5%). Cementless tibial baseplates demonstrated areas of increased bone density at the pegs of the tibial baseplate. The cemented group had 8 total revisions with 5 cases of aseptic loosening (2.5%). Conclusion Early results of cementless TKA using a highly porous tibial baseplate designed with a keel and 4 pegs appear promising with one case of aseptic loosening at minimum 2-year follow-up. As the demographics of patients undergoing TKA change to include younger, obese, and more active patients, along with increased life expectancy, the use of a highly porous cementless tibial baseplate may be beneficial in providing long-term durable biologic fixation similar to the success of cementless total hip arthroplasty.

The purpose of this study was to compare the efficacy of topical Tranexamic Acid (TXA) versus Intravenous (IV) Tranexamic Acid for reduction of blood loss following primary total knee arthroplasty (TKA). This prospective randomized study involved 89 patients comparing topical administration of 2.0g TXA, versus IV administration of 10mg/kg. There were no differences between the two groups with regard to patient demographics or perioperative function. The primary outcome measure, perioperative change in hemoglobin level, showed a decrease of 3.06 ± 1.02 in the IV group and 3.42 ± 1.07 in the topical group (P = 0.108). There were no statistical differences between the groups in preoperative hemoglobin level, lowest postoperative hemoglobin level, or total drain output. One patient in the topical group required blood transfusion (P = 0.342). Based on our study, topical Tranexamic Acid has similar efficacy to IV Tranexamic Acid for TKA patients.

A major limiting factor in the longevity of total hip replacement is the wear rate of the hip bearing. As manufacturing technology has improved during the past several decades, much attention has been focused on developing newer generations of polyethylene that have lower rates of wear while minimizing free radical formation and subsequent osteolysis. The turning point for the manufacture of polyethylene was moving from gamma irradiation in air to irradiation in a low oxygen environment, which reduced free radical formation while increasing the wear resistance. New polyethylene manufacturing methods, including multiple cycles of irradiation and annealing, have resulted in greater wear resistance. Wear analysis studies are essential to determine if these new liners actually show a benefit from prior generations of polyethylene and, more importantly, if they are safe to use. This study involved a single center retrospective review of 60 patients with a mean follow-up of 5.5 years who underwent primary total hip arthroplasty with a second-generation highly cross-linked polyethylene manufactured by 3 cycles of sequential irradiation and annealing. Linear and volumetric wear rates were determined from digitized radiographs using contemporary wear analysis software. The mean linear wear rate for the entire group was 0.025 millimeters per year (mm/y). This value represents a linear wear rate 2.7 times less than that of a first-generation highly cross-linked polyethylene and 4.2 times less than that of a conventional polyethylene. At an average of 5 years, compared with a first-generation highly cross-linked polyethylene, a second-generation highly cross-linked polyethylene appears to show significant improvement regarding wear. [ Orthopedics. 2016; 39(6):e1178–e1182.]

Background The use of cementless femoral components has become the standard in younger patients due to increased implant survivorship and decreased loosening. However, it remains controversial whether these femoral stems can provide comparable results in elderly patients. Therefore, our purpose was to compare the (1) incidence of revisions; (2) clinical outcomes; (3) incidence of postoperative blood transfusions; and (4) differences in complications between the 2 cohorts. Methods Seventy-four consecutive patients (78 hips) aged 80 years or older, who underwent primary total hip arthroplasty using a cementless, tapered, femoral stem were retrospectively compared with a matched cohort of 76 patients (78 hips) who were less than 80 years. Mean age was 83 years (range, 80-91 years) vs 59 years (range, 17-79 years) for the matched group. Minimum follow-up was 2 years. Revision rates, clinical outcomes using the Harris Hip Score, incidences of complications, and postoperative transfusion rates were evaluated. Results In the octogenarian cohort, the aseptic survivorship was 99%, compared with 95% in the matched group. There were 2 aseptic loosenings (2.6%): 1 femoral implant loosening (1.3%) and 1 acetabular loosening, but only 1 revision was performed, as one of the patients declined revision surgery. In the matched cohort, there were 6 revisions (7.7%). There were no significant differences in revision rates between the 2 cohorts, and no significant differences in final Harris Hip Score scores. The incidence of blood transfusion in the study group was 42% vs 19% in control group ( P Conclusion The use of cementless, tapered, femoral stems yielded excellent results in the octogenarian group, although adequate patient preoperative optimization is necessary given the significantly higher transfusion incidence.

Tranexamic acid (TXA) has been used successfully in primary total knee arthroplasty (TKA) to minimize blood loss and transfusions. The purpose of this study is to determine its efficacy in patients undergoing revision TKA. In a retrospective review of 111 patients (68 control and 43 TXA), treatment patients receiving a single intravenous TXA dose of 10mg/kg required less transfusions ( P =0.03) and less total blood units consumed than controls ( P =0.03). When stratified by type of revision, treatment patients undergoing femoral and tibial component revision had lower transfusion rates than the controls ( P =0.03). Given the drawbacks of allogenic blood transfusion, we highly recommend the use of TXA in revision TKA, especially when both components are being revised.

Bicondylar tibial plateau fractures can be difficult to treat due to the extent of articular cartilage, metaphyseal bone, and soft tissue injury. The purpose of this study was to compare the outcomes of open reduction and locked plating vs fine-wire external fixation of 58 consecutive bicondylar tibial plateau fractures at a level I trauma center. All bicondylar tibial plateau fractures were classified as Schatzker V/VI or AO/OTA type 41C. Twenty-eight patients in one group were treated using a locked plating system, and 30 patients in another group were treated with a hybrid or circular external fixation frame. The 2 groups were similar demographically. When compared with external fixation, locked plating was associated with a decreased time to union (5.9 vs 7.4 months), decreased incidence of articular malunion (7% vs 40%; P=.003), decreased knee stiffness (4% vs 13%), and decreased overall complications (27% vs 48%). The Schatzker VI subgroup accounted for 25 of the 27 complications (93%) in the locked plating group and 40 of the 48 complications (83%) in the external fixation group. We reserve the use of external fixation devices in the treatment of tibial plateau fractures to span the fracture site until the patient is amenable to definitive fixation with locked plating.