Twenty-Five-Years and Greater, Results After Nonmodular Cemented Total Knee Arthroplasty

Unraveling the gait dynamics - A comparative study of iASSIST and conventional total knee replacement techniques in osteoarthritic elderly patients

Background

Osteoarthritis (OA) stands as the most prevalent disability among the elderly population. Assessing functional outcomes after Total Knee Replacement (TKR) typically involves Gait analysis along with other evaluation methods. The objective of this study was to compare Gait results, including temporospatial parameters, joint angles, gait profile score (GPS), and movement analysis profiles (MAP), between conventional and iASSIST TKR techniques.

Method

The study involved 21 participants (mean age 68.4 ± 4.2 years), with 16 females and 5 males. Among them, 11 patients had traditional surgery (15 TKR), and 10 patients had iASSIST surgery (13 TKR), totaling 28 knees (7 bilateral). The pre-operative Gait analysis was conducted one day before the surgical procedure, whereas the postoperative Gait analysis was performed, on average, 210 ± 20 days after surgery. Gait analysis was conducted using the Qualisys Motion capture system, operating at a rate of 120 Hz. The data were thoroughly analyzed using Visual 3D C-Motion Software.

Results

An analysis of gait biomechanics metrics, encompassing temporospatial parameters, joint angles, GPS, and MAP, was undertaken. Significant differences were observed in sagittal plane joint angles of the pelvis and hip, transverse plane joint angles of the knee, cadence, and MAP of foot internal/external rotation. However, there were no statistically significant differences between the two TKR techniques in the remaining temporospatial variables, joint angles, GPS, or MAP.

Conclusion

This study revealed a significant difference between iASSIST-guided TKR and conventional TKR, demonstrating that the iASSIST procedure led to improvements in walking biomechanics. Findings hold potential utility for orthopedic surgeons in their decision-making processes, ultimately contributing to the improvement of functional outcomes following TKR.

Cementless Total Knee Arthroplasty: A State-of-the-Art Review

» The demographic profile of candidates for total knee arthroplasty (TKA) is shifting toward younger and more active individuals.» While cemented fixation remains the gold standard in TKA, the interest is growing in exploring cementless fixation as a potentially more durable alternative.» Advances in manufacturing technologies are enhancing the prospects for superior long-term biological fixation.» Current research indicates that intermediate to long-term outcomes of modern cementless TKA designs are comparable with traditional cemented designs.» The selection of appropriate patients is critical to the success of cementless fixation techniques in TKA.» There is a need for high-quality research to better understand the potential differences and relative benefits of cemented vs. cementless TKA systems.

Weight-bearing line at the ankle joint level shifted laterally after total knee arthroplasty for varus knee osteoarthritis: Evaluation of the hip-to-calcaneus line

BACKGROUND

Few studies have comprehensively examined how alignment beyond the ankle joint changes after Total knee arthroplasty (TKA). This retrospective study aimed to answer the questions: (1) do the radiological parameters beyond the ankle joint, including the weight-bearing line at the ankle joint level, change after TKA in varus knee osteoarthritis? (2) Does the lower extremity alignment correlate with alignment beyond the ankle joint?

HYPOTHESIS

Our hypothesis was that TKA altered the radiological parameters beyond the ankle, which correlated with the lower extremity alignment.

PATIENTS AND METHODS

This retrospective study included 67 patients who underwent mechanically aligned TKA for varus knee osteoarthritis. The hip-knee-ankle angle (HKA), tibial plafond inclination angle (TPIA), hindfoot alignment angle (HA), talar tilt (TT), and weight-bearing line at the ankle joint level (mechanical ankle joint axis point [MAJAP]) were measured using radiographs taken before and 6 months after TKA; each parameter was compared between the two time points. The correlations between HKA and other parameters were examined preoperatively and postoperatively.

RESULTS

The mean HKA, TPIA, HA, TT, and MAJAP changed significantly after TKA from 15.0±6.1̊ to 2.6̊±3.5̊, from 10.8̊±5.7̊ to 4.7̊±3.9̊, from 2.3̊±5.5̊ to -2.5̊±4.5̊, from 0.2̊±1.3̊ to -0.5̊±1.4̊, and from 29.3±23.3 to 54.3±20.6, respectively. Correlations were noted between the preoperative HKA and the preoperative TPIA (r=0.58), HA (r=0.36), and MAJAP (r=-0.59), and between the postoperative HKA and the postoperative TPIA (r=0.54) and MAJAP (r=-0.38).

DISCUSSION

TKA for varus knee osteoarthritis altered radiological parameters beyond the ankle, with the weight-bearing line at the ankle joint level passing more laterally. The weight-bearing line at the ankle joint level was correlated with lower extremity alignment both preoperatively and postoperatively.

LEVEL OF EVIDENCE

IV; single-centre retrospective observational study.

Interaction between functional capability and sleep quality at midterm after total knee arthroplasty: a Japanese retrospective cohort study

No report has clarified the frequency and interacting factors affecting sleep disturbance among Asian patients at midterm after total knee arthroplasty (TKA). This study aimed to evaluate the frequency of sleep disturbance at midterm after TKA in a Japanese cohort and to identify intervening factors for sleep. We hypothesized that residual knee pain and decreased functional capability negatively interact with sleep quality after TKA. A total of 209 Japanese participants (average age: 77.1 ± 8.3 years; postoperative follow-up period: 4.5 ± 1.9 years) who underwent primary TKA for knee osteoarthritis were included in this study. Sleep quality, satisfaction, pain, functional capability, joint awareness, and mental condition were evaluated using the Pittsburgh Sleep Quality Index (PSQI), Knee Society Score (KSS) 2011, Forgotten Joint Score (FJS)-12, and 12-Item Short-Form Health Survey (SF-12) Mental Component Summary (MCS). Multivariable analysis was performed to determine the influencing factors on PSQI. The scores for the PSQI, satisfaction with pain level while lying in bed, pain during level walking, functional activity category in the KSS 2011, awareness of the artificial joint in bed at night in the FJS-12, and SF-12 MCS were 6.7 ± 3.0, 5.8 ± 1.8, 1.6 ± 2.3, 62 ± 22, 1.5 ± 1.4, and 56 ± 9.3 on average, respectively. Sleep disturbance (PSQI ≥ 5.5) occurred in 54% of the Japanese participants. Multivariable analysis revealed that high functional capability was a significant factor associated with sleep quality improvement (p < 0.05). Decreased functional capability, not residual knee pain, negatively interacted with sleep quality. The sleep disturbance rate was high during the middle postoperative period after TKA in the Japanese cohort.

A prospective randomised controlled trial of cemented and uncemented tibial baseplates: functional and radiological outcomes

INTRODUCTION

With the success of uncemented fixation in younger patients undergoing total hip arthroplasty and the growing demand for total knee arthroplasty (TKA) in a younger cohort of patients, there has been an increasing interest in cementless tibial baseplate fixation. We sought to determine whether there was a clear advantage to the use of three different forms of tibial baseplate fixation. The primary outcome of this study was survivorship and secondary outcomes were functional and radiological outcomes, up until 10 years.

MATERIALS AND METHODS

We conducted a randomised controlled trial and recruited 224 patients with 274 knees. Patients underwent TKA by a single surgeon utilising a standard surgical technique. All patients received a cruciate retaining TKA with a cementless femoral component, and were randomised to receive either a cemented tibial component, a pegged porous coated cementless tibial component with screws or a cementless tantalum monoblock tibial component with pegs. Patient reported outcome measures (PROMS), radiological data and survivorship were assessed until 10 years post-operatively.

RESULTS

Pre-operative range of motion, alignment and PROMS were similar between the three groups. The use of cemented, cementless with screws or cementless with pegs fixation options, lead to differences in functional outcomes. There was greater improvement in the Oxford score and Knee Society Score in patients who received a cemented baseplate compared to tantalum and the pegged porous groups. However, radiological and survival outcomes were similar in all three groups. Overall survivorship was 99.6%, with one knee with cementless tibial fixation and screws revised for subsidence at 3 years. There were no cases of venous thromboembolism, periprosthetic fracture or infection.

CONCLUSIONS

Irrespective of tibial fixation method, functional and radiological outcomes remain similar at follow-up at 10 years, with no clear difference in outcome between each group. Each method of fixation also had excellent survivorship over this period and should reassure surgeons that whichever method of fixation they choose, long-term outcomes are likely to be satisfactory.

Evaluation of the balance function before and after total knee arthroplasty using Berg balance scale

INTRODUCTION

The purpose of this study was to evaluate balance function before and after total knee arthroplasty (TKA) using Berg balance scale (BBS). The study also aimed to identify factors associated with balance impairment.

MATERIALS AND METHODS

Ninety-three knees in 90 patients were prospectively evaluated using their BBS scores, passive knee extension/flexion angles, Visual analogue scale for pain scores, hip-knee-ankle angles, and knee extensor/flexor muscle strengths before and after TKA. A total BBS score of less than 45 indicates an enhanced risk of multiple falls. Multivariate logistic regression models were performed to elucidate factors associated with post-operative BBS score.

RESULTS

A significant difference in mean pre- and post-operative BBS scores were noted (49.3 ± 6.4 vs. 52.2 ± 4.7) (p < 0.05). The percentage of pre- and post-operative BBS scores less than 45 were 20% and 10% (p < 0.05). Rheumatoid Arthritis (RA), lower pre-operative BBS score, and larger post-operative knee flexion contracture were significantly associated with lower post-operative BBS score (p < 0.01). The post-operative knee flexion contracture greater than 10° was significantly associated with substantially high odds of post-operative BBS scores less than 45 (Odds ratio 7.6; 95% confidential interval 1.69-34.17).

CONCLUSIONS

While TKA significantly improved BBS scores, 10% of the patients remained at a risk for multiple falls. RA, lower pre-operative BBS score, and post-operative knee flexion contracture greater than 10° retained balance impairment even after TKA.

Modern cementless posterior stabilized mobile-bearing total knee arthroplasty shows comparable clinical and radiographical results to its cemented predecessor at 1-year follow-up

PURPOSE

The purpose of this study was to evaluate perioperative and short-term clinical and radiographical results of a modern PS mobile-bearing cementless TKA system.

METHODS

A retrospective review of a consecutive series of TKAs was performed by a single surgeon using a cementless or cemented TKA of the same design (Attune, DePuy Synthes, Massachusetts, USA). The 2011 Knee Society Score, Forgotten Joint Score-12, Hip-Knee-Ankle angle, and the presence of radiolucent lines (RLLs) were reviewed 1-year postoperatively with 1:1 matching performed for age, gender, body mass index, and preoperative UCLA score. Fisher's exact test or independent Student's t-test were used for statistical analyses.

RESULTS

Forty-five cementless and 45 cemented TKAs were reviewed after 1:1 matching. The mean operative time was 8.8 min shorter (P < .01), and the mean amount of drainage was 40.0 ml greater (P = .04) in the cementless cohort. At 1-year postoperatively, there were no significant differences in both cohorts in 2011 Knee Scores and Forgotten Joint Scores-12, with no patients requiring revision surgery (NS). The incidence of RLLs was significantly higher in cementless TKAs (51%) than that in cemented TKAs (22%, P < .01). However, the mean width of RLLs in the cementless TKAs (0.2 mm) was significantly smaller (P < .01) than that in the cemented TKAs (0.8 mm) at 1-year postoperatively with no progression.

CONCLUSION

A recently introduced cementless PS mobile-bearing TKA design demonstrated comparable postoperative and radiographical results to its cemented predecessor at 1-year follow-up.

LEVEL OF EVIDENCE

Retrospective cohort study, Level III.

Latex Allergy as an Independent Risk Factor for Prosthetic Joint Infection

In response to increasing rates of self-reported latex allergies, changes have been made to prevent anaphylaxis in the operating room, including the use of latex-free gloves. However, the impact of these changes on the risk of prosthetic joint infection (PJI) after arthroplasty is unclear. This study evaluated whether documented latex allergy is an independent risk factor for PJI and aseptic revision surgery after total hip arthroplasty (THA) and total knee arthroplasty (TKA). A retrospective matched cohort study was conducted with an administrative claims database. A total of 17,501 patients who underwent TKA and had documented latex allergy were matched 1:4 with 70,004 control subjects, and 8221 patients who underwent THA and had documented latex allergy were matched 1:4 with 32,884 control subjects. Multivariable logistic regression showed that patients who had TKA and had a latex allergy showed significantly higher risk of PJI at both 90 days (odds ratio [OR], 1.26) and 1 year (OR, 1.22) and significantly higher risk of aseptic revision TKA at 1 year (OR, 1.21) after surgery compared with control subjects. Patients who had THA and had a latex allergy had significantly higher risk of PJI at 1 year (OR, 1.19) compared with control subjects. Rates of aseptic revision THA were higher in the latex allergy cohort but statistically comparable (P>.05). Latex allergy was associated with significantly increased risk of PJI and aseptic revision after TKA and significantly increased risk of PJI after THA. More work is needed to determine whether these risks can be mitigated or if latex allergy is an inherent, nonmodifiable risk factor requiring modification to typical arthroplasty pathways. [Orthopedics. 2022;45(4):244-250.].

Effect of severity and cause of preoperative anemia on the transfusion rate after total knee arthroplasty

This study aimed to (1) evaluate the preoperative Hb cut-off value for transfusion after unilateral and bilateral staged (1 week apart) TKAs, respectively, and (2) determine whether cause of preoperative anemia can affect transfusion rate after TKA. A total of 951 patients who underwent TKA (unilateral: 605, bilateral staged: 346) from 2016 to 2019 were reviewed retrospectively. Patient demographics, comorbidities, preoperative Hb level, surgery types, and cause of anemia were evaluated as possible risk factors. The cut-off values for preoperative Hb level to reduce transfusion after TKA were evaluated in each surgery type. Preoperative Hb level, surgery type, and cardiac disease were identified as the risk factors for transfusion after TKA, and preoperative Hb levels of 11.8 (AUC 0.88) and 12.8 (AUC 0.76) were the cut-off values for transfusion after unilateral and staged bilateral TKAs, respectively. Although transfusion rate was higher in anemia with iron deficiency (ID) group than anemia without ID group, preoperative Hb level was also lower in anemia with ID group than anemia without ID group. Single use of preoperative Hb level with different cut-offs depending on the surgery types can be useful indicator for preoperative optimization regardless of cause of anemia.

Central Sensitization and Postoperative Improvement of Quality of Life in Total Knee and Total Hip Arthroplasty: A Prospective Observational Study

Background:

While total knee arthroplasty (TKA) and total hip arthroplasty (THA) lead to excellent clinical outcomes, some patients experience residual surgical site pain and reduced satisfaction. This prospective observational study investigated the prevalence of preoperative and postoperative residual central sensitization (CS) after TKA and THA. The influence of residual CS on the improvement in quality of life (QOL) was also investigated.

Methods:

The participants were 40 patients who underwent TKA and 47 patients who underwent THA. CS was measured using the central sensitization inventory (CSI) questionnaire. Knee symptoms were evaluated using the Knee Injury and Osteoarthritis Outcome Scales (KOOS), and hip symptoms were evaluated using the Japanese Orthopedic Association Hip-disease Evaluation Questionnaires (JHEQ). General QOL was evaluated using EuroQOL (EQ-5D-5l). Regression analysis was performed to estimate factors related to low QOL after surgery.

Results:

Preoperatively, 47.5% of TKA patients and 66.0% of THA patients were CS positive (P=0.083), which reduced to 10.0% (P=0.042) and 25.5% (P=0.202), respectively, 3 months after surgery. Although the improvements in KOOS subscales and EQ-5D-5l scores in TKA patients with residual CS were significantly lower than in those without residual CS, residual CS status had no effect on JHEQ subscales and EQ-5D-5l scores in THA patients. Regression analysis indicated that EQ-5D-5l was negatively correlated with CSI in the TKA group (P=0.017). In contrast, CSI was not correlated with EQ-5D-5l in the THA group (P=0.206).

Conclusion:

Postoperative QOL improvement was achieved 3 months after THA regardless of residual CS status. In contrast, preoperative CS was negatively associated with the improvement in QOL after TKA.

Pulsatile Lavage Systems with High Impact Pressure and High Flow Produce Cleaner Cancellous Bone Prior to Cementation in Cemented Arthroplasty

In cemented joint arthroplasty, state-of-the-art cementing techniques include high-pressure pulsatile saline lavage prior to cementation. Even with its outstanding importance in cementation, there are surprisingly few studies regarding the physical parameters that define pulsatile lavage systems. To investigate the parameters of impact pressure, flow rate, frequency and the cleaning effect in cancellous bone, we established a standardized laboratory model. Standardized fat-filled carbon foam specimens representing human cancellous bone were cleaned with three different high-pressure pulsatile lavage systems. Via CT scans before and after cleaning, the cleaning effect was evaluated. All systems showed a cleaning depth of at least 3.0 mm and therefore can be generally recommended to clean cancellous bone in cemented joint arthroplasty. When comparing the three lavage systems, the study showed significant differences regarding cleaning depths and volume, with one system being superior to its peer systems. Regarding the physical parameters, high impact pressure in combination with high flow rate and longer distance to the flushed object seems to be the best combination to improve the cleaning of cancellous bone and therefore increase the chances of a deeper cement penetration that is required in cemented joint arthroplasty. In summary, this study provides the first standardized comparison of different lavage systems and thus gives initial guidance on how to optimally prepare cancellous bone for cemented joint arthroplasty.

Clinical Course of Pain and Function Following Total Knee Arthroplasty: A Systematic Review and Meta-Regression

BACKGROUND

Total knee arthroplasty (TKA) is widely considered a successful intervention for osteoarthritis and other degenerative knee diseases. This study addresses the need for a high-quality meta-analysis that outlines the clinical course of pain and function post-TKA.

METHODS

The review included prospective cohort studies assessing pain or function of patients undergoing primary TKA at baseline (preoperatively) and at least 2 additional time points including one at least 12 months postoperatively. Two reviewers independently screened references, extracted data, and assessed risk of bias using the Quality in Prognosis Studies tool. The time course of recovery of pain and function was modeled using fractional polynomial meta-regression.

RESULTS

In total, 191 studies with 59,667 patients were included, most with low risk of bias. The variance-weighted mean pain score (/100, 0 = no pain) was 64.0 (95% confidence interval [CI] 60.2-67.7) preoperatively, 24.1 (95% CI 20.3-27.9) at 3 months, 20.4 (95% CI 16.7-24.0) at 6 months, and 16.9 (95%CI 13.6-20.3) at 12 months, and remained low (10.1; 95% CI 4.8-15.4) at 10 years postoperatively. The variance-weighted mean function score (/100, 0 = worst function) was 47.1 (95% CI 45.7-48.4) preoperatively, 72.8 (95% CI 71.3-74.4) at 3 months, 76.3 (95% CI 74.7-77.8) at 6 months, and 78.1 (95%CI 76.4-79.7) at 12 months. Function scores were good (79.7; 95% CI 77.9-81.5) at 10 years postoperatively.

CONCLUSION

Patients undergoing primary TKA can expect a large and rapid but incomplete recovery of pain and function in the first postoperative year. At 10 years, the gains in pain scores may still remain while there is an improvement in function.

Does Additive Pressurized Carbon Dioxide Lavage Improve Cement Penetration and Bond Strength in Cemented Arthroplasty?

The modern cementing technique in cemented arthroplasty is a highly standardized and, therefore, safe procedure. Nevertheless, aseptic loosening is still the main reason for revision after cemented total knee or cemented total hip arthroplasty. To investigate whether an additional carbon dioxide lavage after a high-pressure pulsatile saline lavage has a positive effect on the bone-cement interface or cement penetration, we set up a standardized laboratory experiment with 28 human femoral heads. After a standardized cleaning procedure, the test implants were cemented onto the cancellous bone. Subsequently, the maximum failure load of the bone-cement interface was determined using a material testing machine to pull off the implant, and the cement penetration was determined using computed tomography. Neither the maximum failure load nor cement penetration into the cancellous bone revealed significant differences between the groups. In conclusion, according to our experiments, the additive use of the carbon dioxide lavage after the high-pressure pulsatile lavage has no additional benefit for the cleaning of the cancellous bone and, therefore, cannot be recommended without restrictions.

Comparison of in vivo knee kinematics before and after bicruciate-stabilized total knee arthroplasty during squatting

Background

No studies have directly evaluated kinematic changes during squatting before and after bicruciate-stabilized total knee arthroplasty (BCS-TKA) with the dual cam-post mechanism and asymmetric surfaces. This study investigated the effect of BCS-TKA on changes to pre- and postoperative skeletal knee kinematics, to identify factors associated with postoperative skeletal kinematic parameters.

Methods

Seventeen knees in 17 patients were prospectively recruited before primary TKA for advanced medial knee osteoarthritis. Subjects underwent BCS-TKA and were evaluated more than 1 year postoperatively. In vivo dynamic skeletal knee kinematics were evaluated using periodic radiographic images collected during squatting to quantify the tibiofemoral functional extension/flexion angle, anteroposterior (AP) translation, and axial rotation angle using image-matching techniques. Rotational alignments of femoral and tibial components were measured postoperatively using computed tomography images.

Results

The pre- and postoperative tibiofemoral functional extension/flexion angles during squatting were 12.2° ± 6.7°/100.1° ± 16.8° and 9.6° ± 8.6°/109.4° ± 16.8°, respectively, with a significant difference in flexion angle (p < .05). Total AP translation was significantly larger postoperatively than preoperatively (10.8 mm ± 3.7 mm vs. 14.4 mm ± 4.2 mm, respectively; p < .05). The pre- and postoperative total rotation angles were 6.6° ± 3.0° and 6.4° ± 3.7°, respectively, indicating no significant difference. The pre- and postoperative tibiofemoral functional flexion angles were significantly associated with each other (p = .0434, r = .49). The postoperative total rotation angle was significantly smaller when the total component rotational mismatch angle between the femoral and tibial components was above 5° vs. below 5° (4.6° ± 2.7° vs. 8.3° ± 3.9°, respectively; p < .05).

Conclusions

BCS-TKA significantly increased the tibiofemoral functional flexion angles, with larger AP translation postoperatively. Both preoperative skeletal kinematics and surgical techniques affected the skeletal kinematics of the replaced knee. A total component rotational mismatch angle greater than 5° significantly decreased postoperative total knee rotation during squatting.

Effect of tourniquet application on cement penetration in primary total knee arthroplasty: a meta-analysis

Background

Tourniquet application is expected to improve surgery exposure and cementation process in total knee arthroplasty (TKA) but its effectiveness remains controversial and needs to be further explored. The aim of this meta-analysis was to assess the effect of tourniquet in primary TKA. The hypothesis is that the tourniquet application affects the cement penetration in TKA.

Methods

A search was conducted in PubMed, Embase, and the Cochrane Library for the potentially eligible articles. Two independent researchers reviewed the articles retrieved against the pre-designed inclusion and exclusion criteria. In primary TKA, cement penetration was assessed, and the data between the tourniquet-assisted and non-tourniquet-assisted TKAs were compared. Statistical significance was set at P < 0.05.

Results

A total of 4 randomized controlled trials and 3 non-randomized controlled trials (involving 675 patients) were included. There was no significant difference between the tourniquet-assisted and non-tourniquet-assisted TKAs in terms of cement penetration (P > 0.05). There were no significant differences in the total surgical time, blood loss, blood transfusion, the Knee Society Score, and the visual analogue scale (VAS) between the two kinds of procedures (P > 0.05).

Conclusions

Tourniquet application may not affect cement penetration in primary TKA and may not help reduce blood loss, ease knee pain or improve the knee function. A surgeon may choose to use a tourniquet or not according to his or her own preference.

Level of Evidence

Level Ib, meta-analysis.

Cement use in total knee arthroplasty: 40 versus 80 grams

BACKGROUND

Studies of cement use in total knee arthroplasty (TKA) have historically addressed mechanical properties and application strategies. Recently, cement technique has been studied as a means to reduce cost. We transitioned from opening two bags (80 grams) of cement to one bag (40 grams) of cement for primary TKA to improve cost efficacy. This study investigates the radiographic outcome and cost of TKAs performed with 40 versus 80 grams of cement.

METHODS

TKAs from January 2017 to January 2019 were evaluated. Cement mantle and implant alignment were assessed per the Modern Knee Society Radiographic Evaluation System at four months by three blinded reviewers. Data was analyzed according to quantity of cement used. Cement mantle quality at 16 implant zones was compared. Cost was evaluated.

RESULTS

163 patients (age 66.8 yrs. +/- 8.9, 51.5% female) underwent TKA with 80 grams of cement, while 142 patients (age 67.1 yrs. +/- 9.3, 56.3% female) underwent TKA utilizing 40 grams of cement. There was no significant difference in cement mantle quality. The most common zone of cement deficiency was the femoral posterior flange (9% in 40 gram group versus 4% in 80 gram group, p value = 0.08). There was no difference in implant size. Cost saving was calculated at $7,810 for the 40 gram group.

CONCLUSION

There was no difference in radiographic cement mantle appearance between primary knees performed with 40 or 80 grams of cement. Cement usage represents a target for cost saving and opportunity to increase the value of primary TKA. Based on the current incidence of TKA in the United States, cost savings could exceed 33 million dollars annually.

Total Knee Arthroplasty Improved Locomotive Syndrome in Knee Osteoarthritis Patients: A Prospective Cohort Study Focused on Total Clinical Decision Limits Stage 3

Purpose

The purpose of this study is to investigate the treatment efficacy of total knee arthroplasty (TKA) on locomotive syndrome (LS) focusing on total clinical decision limit (CDL) stage 3 leading to revealing the motor function indicators that can predict LS improvement in knee osteoarthritis patients who had received TKA.

Methods

This prospective cohort study was conducted in 47 patients evaluated as total CDL stage 3 before TKA who received primary TKA on the operated side and were diagnosed with Kellgren-Lawrence grade 2, 3, or 4 knee osteoarthritis on the nonoperated side. LS was evaluated using stand-up test, two-step test, and 25-Question Geriatric Locomotive Function Scale. In addition, the motor function indicators which could predict the LS improvement were examined. All assessments were conducted before TKA and three months after TKA.

Results

Of the 47 subjects who were evaluated to be in total CDL stage 3 before TKA, 13 patients (27.7%) were determined to show improvements in total CDL. From the result of the decision tree analysis, when the CDL of the two-step test before TKA was 1 or less, the improvement rate was 83.3%. Even if the CDL of the two-step test before TKA was higher than 1 and if the 3 m-Timed Up and Go test (3m-TUG) before TKA was 9.6 or less, the improvement rate was 50%.

Conclusions

As of three months after surgery, TKA can improve LS in about 30% of knee osteoarthritis patients. A two-step test before TKA and 3m-TUG before TKA can be used as motor function indicators to predict LS improvement. This study provides useful information for setting the goal for rehabilitation prior to surgery.

The Association Between Cement Viscosity and Revision Risk After Primary Total Knee Arthroplasty

BACKGROUND

Recent case series have reported early failure with the use of high-viscosity cement (HVC) in total knee arthroplasty (TKA). We evaluated revision risk after TKA with HVC compared with medium-viscosity cement (MVC) in a large cohort.

METHODS

We conducted a cohort study using data from Kaiser Permanente's Total Joint Replacement Registry. Patients who underwent fully cemented primary TKA for osteoarthritis were identified (2001-2018). Only posterior-stabilized, fixed-mobility designs of the 3 highest-volume implant systems (DePuy PFC, Zimmer NexGen, and Zimmer Persona) were included to mitigate confounding from implant characteristics. Palacos (Zimmer/Heraeus) and Simplex (Stryker) cements comprised the HVC and MVC exposure groups, respectively. Propensity score-weighted Cox proportional hazards regression was used to evaluate risk for any revision during follow-up and risk for revision from aseptic loosening specifically.

RESULTS

The final cohort comprised 76,052 TKAs, 41.1% using MVC. The crude 14-year cumulative revision probability was 4.55% and 5.12% for TKA with MVC and HVC, respectively. In propensity score-weighted Cox models, MVC compared with HVC had a lower risk of any revision (hazard ratio = 0.82, 95% confidence interval = 0.70-0.95) while no difference was observed for revision from aseptic loosening (hazard ratio = 0.80, 95% confidence interval = 0.56-1.13).

CONCLUSION

While we observed a lower risk for any revision with the use of Simplex MVC compared with Palacos HVC, we did not observe a difference in revision for aseptic loosening specifically. Given the widespread use of HVC, additional research to investigate other HVC and potential mechanisms for failure outside of loosening is warranted.

LEVEL OF EVIDENCE

Level III.

Primary Stability in Cementless Rotating Platform Total Knee Arthroplasty

Highly porous ingrowth surfaces have been introduced into tibial tray fixation to improve long-term survivorship in cementless total knee arthroplasty. This study was designed to evaluate the effect of porous ingrowth surface on primary stability in the implanted cementless tibial component. Three tibial tray designs possessing sintered bead or roughened porous coating ingrowth surfaces were implanted into a foam tibia model with primary stability assessed via digital image correlation during stair descent and condylar liftoff loading. Follow-up testing was conducted by implanting matched-pair cadaveric tibias with otherwise identical trays with two iterations of ingrowth surface design. Trays were loaded and micromotion evaluated in a condylar liftoff model. The sintered bead tibial tray exhibited slightly lower micromotion than the roughened porous coating in stair descent loading. However, no significant difference in primary stability was observed in condylar liftoff loading in either foam or cadaveric specimens. Cementless tibial trays featuring two different iterations of porous ingrowth surfaces demonstrated both good stability in cadaveric specimens with less than 80 microns of micromotion and 1 mm of subsidence under cyclic loading. While improved ingrowth surfaces may lead to improved biological fixation and long-term osteointegration, this study was unable to identify a difference in primary stability associated with subsequent ingrown surface design iteration.

Survival rate of cemented versus cementless tibial component in primary total knee arthroplasty over 5 years of follow-up: comparative study of 109 prostheses

INTRODUCTION

Knee osteoarthritis is the main indication for primary total knee arthroplasty (TKA). It is now accepted that cementless implantation of the femoral component provides equivalent results to cemented one, however, the optimal fixation method of the tibial component remains controversial. The purpose of this study was to compare the survivorship of cemented versus cementless tibial baseplate in primary total knee arthroplasty.

MATERIALS AND METHODS

We carried out a retrospective, monocentric study, including 109 TKA (Zimmer^® Natural Knee II ultra-congruent mobile-bearing) implanted between 2004 and 2010 for primary osteoarthritis, comparing 2 groups depending on tibial component fixation method, one cemented (n = 68) and one cementless (n = 41). Clinical (Knee Society Rating System (KSS), Hospital for Special Surgery (HSS) scores, range of motion) and radiodiological outcomes were assessed at last follow-up with a minimal follow-up of 5 years.

RESULTS

Mean follow-up were 8.14 [5.31-12.7] and 8.06 [5.22-12.02] years, respectively, in cemented and cementless groups. The tibial component survival rate was 100% [95CI: 91.4-100] in the cementless group and 97.1% [95CI: 89.78-99.42] in the cemented group (2 aseptic loosenings) (p = 0.27). Radiolucent lines were present in 31.7% (n = 13) of the cementless and 44.1% (n = 30) of the cemented baseplates (p = 0.2). The postoperative KSS knee score was higher in the cementless group (99 ± 3 vs. 97 ± 7.5; p = 0.02), but there was no significant difference in KSS function, global KSS and HSS scores. Mean range of flexion was 120 ± 10° in the cementless group and 122.5 ± 15° in the cemented group (p = 0.37). No significant differences were found on the radiographic data or on complications.

CONCLUSION

In this study, the survival rate of the tibial component is not influenced by its fixation method at a mean follow-up of 8 years in osteoarthritis, which confirms the reliability of cementless fixation in primary TKA.

Posterior clearance increases the knee extension angle in cruciate retaining type total knee arthroplasty: Intraoperative evaluation using a navigation system

BACKGROUND

Posterior osteophyte of the femur can impinge on the tibia insert in total knee arthroplasty (TKA). Although osteophyte removal [posterior clearance (PC)] improves the flexion angle, its influence on the gaps and extension angle are unclear. This study investigated the effect of PC on the gaps and range of motion (ROM) using a navigation system, as well as PC's relationship with osteophyte size.

METHODS

Twenty-seven knees that underwent cruciate-retaining (CR)-type TKA were examined. Before and after PC, the ROM, hip-knee-ankle (HKA) angle, and flexion and extension gaps were recorded using a navigation system. Osteophyte size was measured in the lateral view in radiographs, and in the sagittal and axial planes of computed tomography (CT) images. The effects of PC on the gaps and ROM were analysed statistically.

RESULTS

PC caused the extension gap to increase by 0.7 ± 0.9 mm in the medial (p < 0.001), and 0.9 ± 1.5 mm in the lateral compartment (p = 0.006). The extension angle increased by 4.9 ± 1.6°, flexion angle increased by 6.5 ± 5.0°, and HKA decreased by 0.3°. The increase in extension angle by PC was significantly correlated with the preoperative HKA angle (r = 0.594) and with the osteophyte area in radiographs and CT (r = 0.626 to 0.681).

CONCLUSIONS

The extension and flexion gaps increased less than 1 mm in the medial and lateral compartments. PC achieving an additional 5° extension angle could promote full extension in severely deformed knees with a large posterior osteophyte. The extension angle increase by PC was correlated with the preoperative HKA angle and osteophyte size.

The Effect of Tranexamic Acid and Tourniquet Use on Tibial Cement Penetration in Primary Total Knee Arthroplasties

Background

In this study, our aim was to compare the effects of tourniquet and tranexamic acid (TXA) use on tibial cement penetration in primary total knee arthroplasty (TKA) using radiograph images. In addition, we also aimed at investigating the effects of age, gender, body mass index (BMI), and bone mineral density on cement penetration.

Methods

One hundred seventy patients who underwent TKA for primary osteoarthritis were retrospectively evaluated. TXA was administered to patients in group 1 (n = 96), and tourniquet application was used in patients in group 2 (n = 74). Tibial cement penetration was evaluated radiologically on a total of 4 zones: 2 anteroposterior and 2 lateral zones. In addition, age, gender, BMI, and bone mineral density were recorded in each group.

Results

The mean cement penetration in the total study population was 2.34 ± 0.24 mm, with a mean of 2.33 ± 0.25 mm in the TXA group and a mean of 2.35 ± 0.24 mm in the tourniquet group (P = .453). A negative correlation was detected between BMI and anteroposterior 1 values in the total and TXA groups (P = .022 and P = .029). In the evaluation of the differences between genders, significantly higher penetration values were observed only in the females in the tourniquet group (P = .024).

Conclusions

The use of TXA instead of a tourniquet does not reduce the depth of cement penetration in TKA. The clinical implications of individual-induced penetration differences may be significant for future implant survival.

Gait Analysis Comparing Kinematic, Kinetic, and Muscle Activation Data of Modern and Conventional Total Knee Arthroplasty

Background

To provide normal knee function, a total knee arthroplasty (TKA) implant with an anatomic surface shape and an adequate sagittal position has been developed. However, it is unclear how this modern implant influences knee joint kinetics and muscle activation during a gait. Therefore, we evaluated this modern TKA prosthesis and compared it with a conventional TKA prosthesis for gait analysis in terms of kinetics and muscle activation.

Methods

Subjects were patients (>60 years of age) with knee osteoarthritis who had undergone unilateral TKA. Twelve patients received the modern TKA prosthesis (group modern), and the other 12 patients received a conventional TKA prosthesis (group conventional). The subjects underwent motion capture analyses with a force plate, and kinematic and kinetic data were acquired from a 10-m gait test. Electromyography data of 6 lower limb muscles were simultaneously collected during the gait test. The 2 groups were compared using unpaired t-tests.

Results

In group modern, gait speed was faster, step length was longer, and the knee flexion angle during the initial stance phase was larger. Furthermore, in group modern, the maximum knee extension moment was higher; however, the quadriceps muscle activity tended to be lower than that in group conventional.

Conclusions

Gait characteristics of group modern were more like a normal gait, and knee joint extension moments were greater. This finding indicates that the quadriceps muscles can be more effectively activated, and the anterior stability function of the anterior cruciate ligament may be reproduced with the shape of the modern implant.

The patient results and satisfaction of knee arthroplasty in a validated grading system

INTRODUCTION

The validated Knee Osteoarthritis Grading System (KOGS) was implemented and clinical results were compared with patient satisfaction data and implant survivorship in a multi-centre study with surgeons familiar with unicompartmental knee arthroplasty (UKA), patellofemoral arthroplasty (PFA) and total knee arthroplasty (TKA). This is also the first study to evaluate the prevalence of UKA and TKA in consecutive osteoarthritis (OA) knee arthroplasties assessed by this system..

METHOD

A consecutive cohort of knees was gathered at three different institutions as categorized by KOGS and surgically treated with the recommended implant unless clinical reasons or patient preference precluded such an option. One thousand one hundred seventy-seven consecutive knees were evaluated including 311 TKA (26%), 695 medial UKA (59%), 154 lateral UKA (13%) and 17 PFA (2%) and the results of the categories evaluated with the Oxford Knee Score (OKS) and the complications reflected in the different categories.

RESULTS

The failure rate of the UKA (3.5%) or TKA (1.6%) is not higher than accepted results in the literature and the difference in complications is negligible between the UKA (72%) and TKA (26%) cohorts. Revision of a UKA to a TKA as an endpoint was 0.58% with ipsilateral progression at 0.8% over a period of five to 84 months (mean follow-up of 36 months) despite the 'excessive' proportion of UKA in this cohort. The Oxford Score improvement is significant in TKA and UKA and contributes to the acceptable outcomes (The OKS for TKA improved from 20 pre-operatively to 36 post-operatively and the UKA improved from 22 pre-operatively to 39 post-operatively).

CONCLUSION

KOGS achieves acceptable early survival and functional results when implemented and is a suitable tool for identifying the preferred implant as was validated.

Osteointegrative Sleeves for Metaphyseal Defect Augmentation in Revision Total Knee Arthroplasty: Clinical and Radiological 5-Year Follow-Up

BACKGROUND

Cementless metaphyseal implant fixation of revision total knee arthroplasty has encouraging early results. We analyzed midterm results and implant survival of osteointegrative augments in Anderson Orthopedic Research Institute (AORI) type 2a, 2b, and 3 defects. Reasons for implant failure were explored and the potential for anatomic joint line reconstruction evaluated.

METHODS

Sixty-seven consecutive patients (68 revision total knee arthroplasties) received cementless metaphyseal sleeves between 2011 and 2014. The mean follow-up was 5.0 years, mean age was 68.5 years, and mean body mass index was 31.4 kg/m². The clinical and radiographic results were determined using established scoring systems. Additionally, the survival rate was calculated and reasons for failure were analyzed.

RESULTS

In 2 patients (4.3%), sleeves had to be removed early postoperatively for deep infection after second-stage reimplantation. With continuously functioning remaining implants, the aseptic survival rate was 93.6%. Cleared up for initial technical issues due to poor bone quality, it is as high as 98%. The scores remained to be significantly improved by 64.8 points (Western Ontario and McMaster Universities Osteoarthritis Index) and 25.8 points (Knee Society score) (P < .001). In 10 patients (29.4%), diaphyseal radiolucencies were observed without suspicion of loosening. The mean joint line was noted to be 0.36 mm lower to the anatomic level.

CONCLUSION

At a mean follow-up of 5.0 years, cementless osteointegrative sleeves for metaphyseal fixation in AORI 2a, AORI 2b, and AORI 3 defects yielded continuous implant fixation even in cases with preceding revisions. The cleared up aseptic survival rate was 98% at 5 years. The modular sleeve design allowed joint line reconstruction near the anatomic level.

NaF PET assessment of bone metabolic changes around the femoral canal by intramedullary femoral alignment technique in total knee arthroplasty

We used the NaF PET scan to assess osteometabolic changes around the distal half of the femoral canal by intramedullary (IM) drill for femoral IM guiding rod insertion in total knee arthroplasty. Gentle IM rod insertion and focused attention can minimize surgical stress-induced biological reaction of the femoral IM canal.

The native coronal orientation of tibial plateaus may limit the indications to perform a kinematic aligned total knee arthroplasty

PURPOSE

To investigate the coronal alignment of tibial plateaus in normal and osteoarthritic knees and to simulate the effects of a tibial cut performed in total knee arthroplasty (TKA) using a kinematic alignment technique with standard instrumentation.

METHODS

The coronal alignment of tibial plateaus was measured in three groups including group 1 (reference group), 50 cadaveric tibiae showing no evidence of degenerative changes of tibial plateaus; group 2, 49 patients who underwent MR of the knee, showing no or mild degenerative changes of the knee joint and, group 3, 54 patients with knee osteoarthritis who underwent computer-assisted total knee arthroplasty.

RESULTS

The coronal alignment of tibial plateaus averaged 2.4° with no significant differences between groups. The mean coronal orientation of tibial plateaus was 3° ± 2° in men and 1.6° ± 2° in women (p = 0.03). A coronal alignment of tibial plateaus of 3° or more was found in 69 cases (45%) and 5° or more in 23 (14.7%). The simulation of a tibial cut performed with an error of 3° in varus in 15% of the subjects showing a native coronal orientation of tibial plateaus of 3° or more, led to a final tibial cut greater 6° in 13.7% of cases.

CONCLUSIONS

A coronal alignment of tibial plateaus of 3° or more in varus was found in near half of normal subjects and osteoarthritic patients. A preoperative measurement of the coronal alignment of tibial plateaus is advisable in any patients scheduled for kinematic aligned TKA. As errors in the alignment of the tibial component of 3° or more may occur using standard instrumentations, the results of this study raise questions on performing a kinematic aligned TKA with standard instrumentations.

LEVEL OF EVIDENCE

IV.

Underhang of the tibial component increases tibial bone resorption after total knee arthroplasty

PURPOSE

One of the causes of aseptic loosening is marked tibial bone resorption (TR) at the tibial bone-component interface after total knee arthroplasty (TKA). It was hypothesized that insufficient coverage of the tibial component and improper cementing technique would cause increased TR after cemented TKA.

METHODS

One hundred thirty-four primary TKAs in 107 patients with varus osteoarthritis were included in this study. The relationships between the TRs at 2 years after TKA and the tibial component underhang (TUH), the thickness of the cement mantle around the keel, and clinical parameters were evaluated.

RESULTS

The widths of TRs on anteroposterior radiographs were significantly larger on the medial side than on the lateral side (p = 0.001), whereas the difference between the anterior and posterior sides on lateral radiographs was relatively small. Multiple regression analyses showed that medial TR was positively related to medial TUH (p = 0.006), and lateral TR was positively related to a thicker distal cement mantle (p = 0.027). On the lateral view, stepwise selection indicated that postoperative knee flexion angle was the most significant risk factor (p = 0.005) for anterior TR, and posterior TUH was the strongest predictor (p = 0.001) of posterior TR.

CONCLUSIONS

To avert postoperative progressive TR, surgeons should perfectly fit a suitably sized tibial component to the medial edge of the tibia. Also, care should be taken to avoid an excessive cement mantle at the distal portion of the keel during TKA.

LEVEL OF EVIDENCE

IV.

Unacceptable failure rate of a ceramic-coated posterior cruciate-substituting total knee arthroplasty

Background

Aseptic loosening is one of the most elusive problems in total knee arthroplasty. We compared the failure rates of posterior cruciate-substituting total knee arthroplasty utilizing implants with hardened surface coating to a previous cohort of patients who underwent the procedure with traditional cruciate-retaining noncoated cobalt-chrome implants.

Methods

A retrospective study was conducted of 1099 total knee arthroplasties performed from 2009 to 2017. Two hundred forty-nine total knee arthroplasties performed from January 2015 to March 2017 under a single design were reviewed retrospectively and compared to the author’s previous 850 total knee arthroplasties performed from January 2009 to December 2014 under a different design.

Results

This series demonstrated an alarming debonding of cement in the tibial implant. The resultant failure rate of 6% (P < .001) is higher than observed in 850 total knee arthroplasties in the previous 5 years and higher than those reported in the literature giving cause for concern regarding this implant.

Conclusions

Due to the observed excessive failure rate, the authors recommend exercising high levels of caution using this implant with hardened surface treatment until further testing can be ascertained as to the root cause of failure.

Early outcomes of patient-specific posterior stabilized total knee arthroplasty implants

Patient-specific implants have been linked to stiffness. The purpose of this study was to evaluate outcomes in patient-specific implants. We performed a retrospective review with a primary outcome of manipulation under anesthesia (MUA); secondary outcomes included Knee Society Scores (KSS), Knee Society Functional Scores (KSFS), range of motion (ROM), and Forgotten Joint Scores (FJS). Pre-operative measurements were similar in both groups. There was one MUA in the CPS and two in the OTS groups. There was no difference in postoperative scores. Our study suggests patient-specific implants have comparable rates of MUA and functional outcomes as conventional implants.

No improvement in reducing outliers in coronal axis alignment with patient-specific instrumentation

PURPOSE AND HYPOTHESIS

Patient-specific instrumentation (PSI) uses 3D preoperative imaging to produce individualized cutting blocks specific to patients' anatomy and according to the preoperative plan with the aim to reduce the number of mechanical leg alignment (MLA) outliers, to improve implant positioning and to decrease surgery time. The primary purpose of this study was to investigate the efficacy of a specific PSI in comparison with standard instrumentation (SI) in reducing the number of MLA outliers. It was hypothesized that the number of MLA outliers would be significantly lower in the PSI group.

METHODS

A multicenter randomized controlled trial was implemented. There were 59 patients in the PSI group and 66 in the SI group. The absolute number of outliers outside the ± 3° target neutral MLA was compared between the groups with a Chi-square test. As secondary outcomes, the Knee Society Score (KSS) and the Knee Injury and Osteoarthritis Outcome Score (KOOS) were compared between the groups preoperatively and at 90-day follow-up.

RESULTS

There were 15 (26.3%) MLA outliers in the PSI group and 8 (12.3%) in the SI group. The number of outliers was not independent from the group ( _X² (1) = 3.8, p = 0.04; Relative risk = 1.5). Preoperatively, there were no significant differences between the groups when comparing their KSS and KOOS sub-scores. At 90 days postoperatively, the patients in the SI group showed better KOOS-Quality of Life (KOSS-QOL) in comparison with the PSI group (p < 0.0001).

CONCLUSION

The use of PSI did not significantly reduce the number of MLA outliers in comparison with SI. There were no differences when comparing the achieved mean MLA of both groups.

LEVEL OF EVIDENCE

Level I, prospective randomized controlled trial.

Excellent Survival and Good Outcomes at 15 Years Using the Press-Fit Condylar Sigma Total Knee Arthroplasty

BACKGROUND

We report 15-year survival, clinical, and radiographic follow-up data for the Press-Fit Condylar Sigma total knee arthroplasty.

METHODS

Between October 1998 and October 1999, 235 consecutive TKAs were performed in 203 patients. Patients were reviewed at a specialist nurse-led clinic before surgery and at 5, 8-10, and 15 years postoperatively. Clinical outcomes, including Knee Society Score, were recorded prospectively at each clinic visit, and radiographs were obtained.

RESULTS

Of our initial cohort, 99 patients (118 knees) were alive at 15 years, and 31 patients (34 knees) were lost to follow-up. Thirteen knees (5.5%) were revised; 5 (2.1%) for infection, 7 (3%) for instability, and 1 (0.4%) for aseptic loosening. Cumulative survival with the end point of revision for any reason was 92.3% at 15 years and with revision for aseptic failure as the end point was 94.4%. The mean Knee Society Score knee score was 77.4 (33-99) at 15 years, compared with 31.7 (2-62) preoperatively. Of 71 surviving knees for which X-rays were available, 12 (16.9%) had radiolucent lines and 1 (1.4%) demonstrated clear radiographic evidence of loosening.

CONCLUSION

The Press-Fit Condylar Sigma total knee arthroplasty represents a durable, effective option for patients undergoing knee arthroplasty, with excellent survival and good clinical and radiographic outcomes at 15 years.

Uncemented Tantalum Monoblock Tibial Fixation for Total Knee Arthroplasty in Patients Less Than 60 Years of Age: Mean 10-Year Follow-up

BACKGROUND

Although tibial component loosening has been considered a concern after total knee arthroplasty without cement, such implants have been used in younger patients because of the potential for ingrowth and preservation of bone stock. However, mid-term and long-term studies of modern uncemented implants are lacking. We previously reported promising prospective 5-year outcomes after using an uncemented porous tantalum tibial component in patients who underwent surgery before the age of 60 years. The purpose of this study was to determine clinical and radiographic implant survivorship at 10 years in this large series of young patients.

METHODS

The original cohort included 79 patients (96 knees) who were <60 years old at the time of surgery. All procedures were performed with an uncemented, posterior-stabilized femoral component and a porous tantalum monoblock tibial component by 1 high-volume arthroplasty surgeon at a single institution. Patients were followed prospectively. The Knee Society Score (KSS), radiographic findings, and any complications or revisions were recorded.

RESULTS

At the latest follow-up, 76% (60) of the 79 patients (74% [71] of the 96 knees) were available for evaluation or had undergone revision (n = 6); 7 patients had died with the implants in place, and 12 patients were lost to follow-up. The average follow-up for the available implants was 10 years (range, 8 to 12 years). There were no progressive radiolucencies on radiographic review. The mean functional KSS was 68 points (range, 0 to 100 points). All revisions were for reasons unrelated to tibial fixation: femoral component loosening (1), stiffness (1), pain and swelling (2), and instability (2). The all-cause revision rate was 6% (6 of 96 knees).

CONCLUSIONS

Uncemented porous tantalum monoblock tibial components provided reliable fixation, excellent radiographic findings, and satisfactory functional outcomes at a mean of 10 years postoperatively. We identified no cases of tibial component loosening. These promising clinical and radiographic results support the use of uncemented tibial components. Such implants may produce well-integrated, durable long-term constructs in young patients.

LEVEL OF EVIDENCE

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