Patient reported outcomes and implant survivorship after Total knee arthroplasty with the persona knee implant system: two year follow up

Radiological and clinical outcomes after Attune primary total knee arthroplasty using Stemmable Tibia: A two-year follow-up prospective bi-center study

This prospective bi-center study aimed to analyze the outcomes of primary total knee arthroplasty using the Stemmable Tibia Attune system. A total of 100 patients who underwent primary total knee arthroplasty with Stemmable Tibia from January 2019 to December 2021 were enrolled in the study. Radiological outcomes (hip-knee-ankle axis and medial proximal tibial angle) were assessed preoperatively and postoperatively. Clinical outcomes (visual analog scale score, Hospital for Special Surgery score, Knee Society function score, Knee Society knee score, flexion contracture, further flexion, and range of motion) were analyzed preoperatively and at 6 weeks, 3 months, 6 months, 1 year, and 2 years postoperatively. Complications (periprosthetic joint infection and aseptic loosening) were examined. The hip-knee-ankle axis decreased (preoperative: 9.5° ± 6.3°, postoperative: 1.1° ± 2.7°), whereas the medial proximal tibial angle increased (preoperative: 84.6° ± 4.1°, postoperative: 89.8° ± 1.9°). The visual analog scale score, Hospital for Special Surgery score, Knee Society knee score, and Knee Society function score increased postoperatively. The Knee Society knee score indicated above good outcomes (100.0% and 99.0% at 1 and 2 years postoperatively, respectively). The Knee Society function score also showed above good results (98.0% and 93.0% at 1 and 2 years postoperatively, respectively). The range of motion significantly improved (p < 0.001): flexion contracture decreased from 9.10° ± 7.23° to 2.15° ± 2.87°, whereas further flexion increased from 136.05° ± 14.78° to 139.80° ± 10.02°. One patient developed periprosthetic joint infection; no early loosening was observed. In conclusion, Attune primary total knee arthroplasty with Stemmable Tibia not only is safe and effective but also leads to radiological and clinical improvements.

Mid-term results of an anatomic total knee replacement design

INTRODUCTION

A significant proportion of patients remain dissatisfied following total knee arthroplasty (TKA) surgery. Reasons for this are unclear. Contemporary implants seek to mirror innate anatomy. Such innovations are necessarily subject to scrutiny to validate their use. The Zimmer-Biomet Persona® Personalized Knee system is such an anatomic TKA. This work seeks to establish medium term survival data and patient reported outcomes for this implant.

METHODS

This was a cohort study of prospectively collected data on all patients undergoing Persona TKA at our institution. Patients were managed using a standardised protocol for intra- and post-operative care. Survivorship data were collected using our National Joint Registry and corroborated with local data. Range of motion, Oxford Knee Score (OKS) and patient satisfaction were recorded at six weeks and one year post-operatively. Hip-knee-ankle radiographs were used to record pre- and post-operative alignment.

RESULTS

Data were collected for 749 knees in 679 patients. Overall survivorship was 99.0% at a mean 5.35 years, with seven patients undergoing revision surgery during the study period. Significant improvements in the OKS (mean 20.7 points) and range of motion were observed (mean 104.6° at one year). 94.9% of patients were satisfied at one year. Mean correction was to a mechanical femoro-tibial angle of 0.8° varus.

CONCLUSIONS

We demonstrate excellent medium term survival of the Persona TKA in this large cohort, coupled with improvements in patient reported outcomes, range of motion and patient satisfaction at one year which compare favourably to other implants.

The Effect of Prosthetic Joint Infection on Work Status and Quality of Life: A Multicenter, International Study

BACKGROUND

Periprosthetic joint infection (PJI) and subsequent revision surgeries may affect patients' social and physical health, ability to complete daily activities, and disability status. This study sought to determine how PJI affects patients' quality of life through patient-reported outcome measures with minimum 1-year follow-up.

METHODS

Patients who suffered PJI following primary total joint arthroplasty (TJA) from 2012 to 2021 were retrospectively reviewed. Patients met Musculoskeletal Infection Society criteria for acute or chronic PJI, underwent revision TJA surgery, and had at least 1 year of follow-up. Patients were surveyed regarding how PJI affected their work and disability status, as well as their mental and physical health. Outcome measures were compared between acute and chronic PJIs. In total, 318 patients (48.4% total knee arthroplasty and 51.6% total hip arthroplasty) met inclusion criteria.

RESULTS

Following surgical treatment for knee and hip PJI, a substantial proportion of patients reported that they were unable to negotiate stairs (20.5%), had worse physical health (39.6%), and suffered worse mental health (25.2%). A high proportion of patients reported worse quality of life (38.5%) and social satisfaction (35.3%) following PJI. Worse reported patient-reported outcome measures including patients' ability to complete daily physical activities were found among patients undergoing treatment for chronic PJI, and also, 23% of patients regretted their initial decision to pursue primary TJA.

CONCLUSIONS

A PJI negatively affects patients' ability to carry out everyday activities. This patient population is prone to report challenges overcoming disability and returning to work. Patients should be adequately educated regarding the risk of PJI to decrease later potential regrets.

LEVEL OF EVIDENCE

Case series (IV).

Novel morphogenic knee implant delivers comparable mid-term outcomes as compared to conventional non-morphogenic implants

INTRODUCTION

Conventional total knee arthroplasty (C-TKA) implants have well-established mid- and long-term outcomes. The novel TKA (N-TKA) implants provide morphogenic implant components with smaller size increments to facilitate anatomical replication. The aim of the study is to evaluate if these advantages provides better clinical outcomes.

MATERIALS AND METHODS

Registry data prospectively collected within a single institution from 2014 to 2018 was reviewed and propensity score matching was performed to match C-TKA to N-TKA. 70 pairs of cruciate retaining (CR) TKA and 116 pairs of posterior stabilized (PS) TKA were identified. Range of motion, SF-36, Knee Society Knee Score (KSKS), Knee Society Function Score (KSFS) and Oxford Knee Score (OKS) were assessed preoperatively, 6 and 24 months postoperatively. Satisfaction was assessed 6 and 24 months postoperatively. Independent T test was performed for parametric data, whereas Wilcoxon rank-sum analysis was performed for non-parametric data.

RESULTS

Both C-TKA and N-TKA cohorts demonstrated statistically significant improvement for KSKS, KSFS, OKS and SF-36 at 6 and 24 months postoperatively. C-TKA CR patients had better flexion at 6 months as compared to N-TKA CR (108.7° versus 98.3°, respectively, p = 0.046). At 24 months, there was no difference between C-TKA and N-TKA for range of motion, KSKS, KSFS, OKS and SF-36 PCS, regardless of insert type (p > 0.05).

CONCLUSIONS

Both models showed great postoperative improvements in KSFS, KSKS, OKS and SF-36 and have comparable early and mid-term outcomes, suggesting that N-TKAs are suitable substitutes for C-TKA. Longer follow-up studies are required to evaluate the long-term outcomes of N-TKAs.

LEVEL OF EVIDENCE

lll.

Long-term outcomes of the Nexgen© posterior stabilized knee: minimum 15 year follow-safe and effective

PURPOSE

Studying long-term survivorship and functional outcomes for specific prostheses is critical for elucidating areas in need of design improvement. This study reports the long-term of the NexGen Posterior Stabilized (PS) Total Knee implant (TKA) (Zimmer Biomet, Warsaw IN) Performed by a single surgeon.

METHODS

Data from patients treated with the NexGen PS TKA between January 2003 and December 2005 with a minimal follow-up of 15 years was collected from a prospectively collected database. Survivorship rates and Oxford Knee Scores (OKS) were obtained for those patients available for follow-up.

RESULTS

Ninety-five patients met the inclusion criteria during the study period. OKS was available for 44 (46%) patients. Ten patients required revision surgery (10.52%). Implant-specific survivorship of all cases that were reviewed was 98%. Survivorship of implants in patients that we were able to reach, or deceased patients was 93%. The average Oxford Knee Score was 39.1 (14-48. SD ± 7.70) with 48 being the maximal score.

CONCLUSION

Despite some concerns about durability of this implant, good longevity and function was demonstrated. At a minimum of 15 years follow-up in this cohort. Given these results design features of this system should be considered for future generations of implants.

Favorable outcomes of posterior cruciate-stabilized inserts over ultracongruent inserts in total knee arthroplasty

OBJECTIVE

Posterior cruciate-stabilized (PS) and ultracongruent (UC) inserts are used during total knee arthroplasty (TKA), but superiority in gaining postoperative knee flexion and functionality remains contested. Therefore, this study compared postoperative outcomes between PS and UC inserts.

METHODS

A retrospective review evaluated unilateral or bilateral TKAs with PS or UC inserts from August 2011 to March 2020. Nonparametric statistics were performed to evaluate differences in patient demographics, pre- and postknee flexion and Knee Society Knee (KSS-K) and Function Score (KSS-F). Univariate and multivariable regressions were performed to evaluate the influence on postoperative knee flexion ≥ 120°, presented as odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

Patient demographics were not significantly different between the 577 PS and 399 UC knees evaluated. Postoperatively, a larger proportion of UC knees demonstrated knee flexion < 120° (36.0% vs. 18.6%, p < 0.001) and lower KSS-K (91.0 ± 8.7 vs. 91.6 ± 10.3, p < 0.001) and KSS-F (76.8 ± 21.6 vs. 79.9 ± 21.6, p = 0.007) than the PS group. The PS group had greater improvement in flexion angle (4.9° ± 14.9° vs. 1.0° ± 15.6°, p < 0.001) and KSS-F (27.3 ± 23.3 vs. 23.1 ± 25.3, p = 0.007) as compared to that of UC patients. Patients with preoperative flexion < 120° (OR 2.787, CI 2.066-3.761; p < 0.001), higher body mass index (OR 1.033, CI 1.006-1.061; p = 0.017) and UC insert (OR 2.461, CI 1.832-3.307; p < 0.001) were less likely to achieve flexion ≥ 120°.

CONCLUSION

Favorable clinical and functional outcomes were noted in the PS group as compared to UC inserts in TKA. The greater improvement in overall knee flexion may suggest the PS insert may be especially appropriate for patients with lower preoperative range of motion.

LEVEL OF EVIDENCE

III, retrospective comparative study.

Total knee arthroplasty: do newer CR implants yield better results? A single center prospective study

The aim of this study was to compare whether the newest TKA prosthesis (Persona) gives improved clinical outcomes due its more anatomical design in comparison to older prostheses (balanSys). This study included a total of 89 patients planned for TKA from June 2018 to September 2019. Outcomes such as Knee Injury and Osteoarthritis Outcome Score (KOOS), range of motion (ROM), numeric pain rating scale (NRS), analgesics and alignment were recorded next to patient characteristics and complications. Our results showed a significant improvement in NRS, ROM and functional scores postoperatively compared to preoperatively for both the Persona and the balanSys implants. Although the flexion ROM for the Persona group was higher at 6 and 12 months postoperative compared to the balanSys, this was mainly a regaining of the preoperative ROM. Throughout all timepoints, there were no statistically significant differences observed in NSAID and opioid usage between the balanSys and Persona groups. Both implants are safe and efficient to use in the treatment of knee osteoarthritis. Although Persona had an improved postoperative flexion, this did not have an impact on any of the patient-reported outcomes.

Experiences with and perception of patient-reported outcome measurement in patients undergoing knee and hip replacement in Germany

BACKGROUND

Patient-reported outcome measures - PROMs - have been developed to provide an assessment of patients' physical function, symptoms, and health-related quality of life. With patient-centered care becoming increasingly important, several national strategies have been initiated for PROM measurement. However, Germany is only at the beginning of this process. The objective of this study is to assess patients' experience with and perception of completing PROMs in patients undergoing knee and hip replacement in Germany.

METHODS

This study used survey data from patients undergoing hip or knee replacement surgery in a hospital in Germany. Before surgery, patients completed a PROMs survey. After at least 6 months, patients were re-contacted to fill in a questionnaire about their experiences with and perception of the PROMs data collection.

RESULTS

Most patients either agreed or totally agreed that the time to fill in the questionnaire was appropriate (89%), that the purpose of the PROMs collection was clear (85%), that the questionnaire's content applied to their appointment (73%), and that this systematic assessment was beneficial (81%). The corresponding proportions were 54% for feeling productive while waiting and 50% for feeling that the information in the questionnaire affected the patient-doctor interaction positively. Only few significant associations were found between patient characteristics and the favorability of patients' ratings. There were no significant differences between hip and knee replacement surgery patients regarding the favorability rating on any survey question.

CONCLUSIONS

The results of this study suggest that PROMs collection in the context of hip and knee replacement surgery is practicable and partly also perceived beneficial by patients. Orthopedic procedures could serve as a starting point for broader use and routine PROMs collection in Germany.

Early migration in unicompartmental knee arthroplasty: a radiostereometric study of 26 patients with 24 months of follow-up

BACKGROUND AND PURPOSE

Aseptic loosening, mainly caused by migration, is one of the most common indications for revisions in unicompartmental knee arthroplasty (UKA). In this study, we investigated the early migration of the Persona Partial Knee (PPK, Zimmer Biomet, Warsaw, IN), a cemented medial fixed-bearing unicompartmental knee prosthesis, and evaluated the clinical results.

PATIENTS AND METHODS

26 primary PPKs were implanted. Radiographs were obtained direct postoperatively, at 6 weeks, 6, 12 and 24 months postoperatively. Migration of the femoral and tibial component was calculated using model-based radiostereophotogrammetric analysis (mRSA) in terms of translations and rotations. Patient-reported outcome measures (PROMs) were also registered.

RESULTS

At 24 months postoperatively, we found low migration of both the femoral and tibial component in the first 6 months, after which both components stabilized. Only the rotation of the tibial component about the z-axis did not stabilize. All PROMs improved after 24 months compared with preoperative PROMs.

CONCLUSION

The Persona Partial Knee shows low migration of both the femoral and tibial component and PROMs were improved at 24 months follow-up. Long-term follow-up is needed to investigate the performance of the prosthesis compared with other prostheses.

Early outcomes using a 'kinematic retaining' total knee replacement - A multicentre prospective study at two years follow-up

BACKGROUND

Although predictable implant longevity in total knee replacement (TKR) is now established, work continues to satisfy the demands of patients who seek full restoration of the painless function of the native knee following TKR. This prospective study examines the early clinical outcomes of 156 patients implanted with a novel 'kinematic-retaining' (KR) implant.

METHODS

156 Physica KR TKRs were implanted for primary osteoarthritis at three European centres. Patients were reviewed up to two years using radiographic, clinical and functional evaluations.

RESULTS

Of the 137 patients retained at two years' follow up, none had been revised. Within 6 post-operative months, 51.7% and 79.9% had excellent clinical and functional KSS values respectively, increasing to 81.8% and 88.3% beyond two years. Mean KSS improvement was 34.8 (from 48.6 to 83.4). All KOOS sub-scores improved significantly with total KOOS improving from a mean of 35.5 (SD ±13.0) to 86.5 (±13.7) at two years post-operatively. Pain and sports KOOS sub-scores improved rapidly during the early post-operative periods, with sustained improvements beyond this. Mean OKS improved by 44.1 (±5.1) at two years. VAS satisfaction scores improved significantly at all time points beyond six weeks. Mean FJS-12 was 75.7 at two years, with no significant effects of age or gender. No progressive adverse radiographic features were noted.

CONCLUSIONS

Early clinical and radiographic outcomes of this kinematic-retaining knee prosthesis are promising, with improvements in clinical parameters similar to, or exceeding those published in other contemporary TKR designs.

LEVEL OF EVIDENCE

II, Multicentre Prospective cohort study.

The AAHKS Clinical Research Award: Are Minimum Two-Year Patient-Reported Outcome Measures Necessary for Accurate Assessment of Patient Outcomes After Primary Total Knee Arthroplasty?

BACKGROUND

The two-year minimum follow-up after total knee arthroplasty (TKA) required by most academic journals is based on implant survivorship studies rather than patient-reported outcome measures (PROMs). Additionally, the COVID-19 pandemic placed an unprecedented burden on patients and staff and halted asymptomatic surveillance clinic visits to minimize exposure. The purpose of this study was to determine if clinically meaningful differences were observed in PROMs beyond one year after TKA.

METHODS

A retrospective review was performed on prospectively collected PROMs after 1093 primary TKAs at a suburban academic center. PROMs related to pain, function, activity level, and satisfaction were compared by subsequent follow-up intervals preoperatively, at 4 months, 1 year, and minimum 2 years using paired data analysis techniques.

RESULTS

Pain with level walking and while climbing stairs improved from preoperative levels to 4-month, 1-year, and minimum 2-year follow-up. The University of California Los Angeles activity level and Knee Injury and Osteoarthritis Outcome Score for Joint Replacement improved over the same intervals. Patient satisfaction improved over postoperative follow-up intervals (84.0%, 87.3%, and 90.9%). While PROMs improved with statistical and clinical significance preoperatively to 4-month to 1-year follow-up, improvements from 1-year to minimum 2-year follow-up were small and did not reach minimum clinically important differences for nearly all PROMs, demonstrating significant overlap of the 95% confidence intervals.

CONCLUSION

While long-term follow-up after TKA remains important for implant survivorship, it appears that one-year PROMs are as clinically reliable and meaningful as two-year PROMs. Therefore, it is reasonable to question the currently accepted 2-year minimum follow-up requirement used in peer-reviewed research involving PROMs.

LEVEL OF EVIDENCE

Level III.

An anatomo-functional implant positioning technique with robotic assistance for primary TKA allows the restoration of the native knee alignment and a natural functional ligament pattern, with a faster recovery at 6 months compared to an adjusted mechanical technique

PURPOSE

An anatomo-functional implant positioning (AFIP) technique in total knee arthroplasty (TKA) could restore physiological ligament balance (symmetric gap in extension, asymmetric gap in flexion). The purposes were to compare (1) ligament balancing in extension and flexion after TKA in the AFIP group, (2) TKA alignment, implant positioning and patellar tracking between AFIP and adjusted mechanical alignment (aMA) techniques, (3) clinical outcomes between both groups at 12 months.

METHODS

All robotic-assisted TKA with an AFIP technique were included (n = 40). Exclusion criteria were genu valgum (HKA angle > 183°), extra-articular deformity more than 10°, and patellar maltracking (high-grade J-sign). One control patient with a TKA implanted by an aMA technique was matched for each case, based on age, body mass index, sex, and knee alignment. Ligament balancing (medial and lateral gaps in millimeters) in full extension and at 90° of flexion after TKA in the AFIP group was assessed with the robotic system. TKA alignment (HKA angle), implants positioning (femoral and tibial coronal axis, tibial slope, joint-line orientation), patellar tracking (patellar tilt and translation) and the Knee Society Score (KSS) at 6 and 12 months were compared between both groups. The ligament balancing was compared using a t test for paired samples in the AFIP group. The radiographic measurements and KSS scores were compared between groups using a t test for independent samples.

RESULTS

In the AFIP group, there was no significant difference between the medial and lateral gap laxity in extension (NS). A significant opening of the lateral gap was observed in flexion compared to extension (mean: + 2.9 mm; p < 0.0001). The mean postoperative HKA angle was comparable between both groups (177.3° ± 2.1 in the AFIP group vs 176.8° ± 3.2; NS). In the AFIP group, the femoral anatomy was restored (90.9° ± 1.6) and the tibial varus was partially corrected (87.4° ± 1.8). The improvement of Knee and Function KSS at 6 months was better in the AFIP group (59.3 ± 11.9 and 51.7 ± 20, respectively, versus 49.3 ± 9.7 and 20.8 ± 13; p < 0.001).

CONCLUSION

The AFIP concept allowed the restoration of the native knee alignment and a natural functional ligament pattern. With a more physiological target for ligament balancing, the AFIP technique had equivalent clinical outcomes at 12 months compared to aMA, with a faster recovery.

LEVEL OF EVIDENCE

III retrospective therapeutic case control series.

Similar migration for medial congruent and cruciate-retaining tibial components in an anatomic TKA system: a randomized controlled trial of 60 patients followed with RSA for 2 years

Background and purpose - There is an ongoing debate regarding the appropriate level of constraint in primary TKA. To provide increased stability and better kinematics, more resembling a natural knee, a medial congruent (MC) tibial insert has been introduced. To investigate potential impact on implant migration, we evaluated the cemented Persona TKA, randomizing between MC and cruciate-retaining (CR) tibial designs. Patients and methods - 60 patients with primary osteoarthritis were randomized to either the CR or MC tibial component. Radiostereometric analysis (RSA) examinations, evaluating translational and rotational migration as well as maximal total point motion (MTPM), were performed on the first postoperative day, at 3 months, and 1 and 2 years after surgery. Preoperative, and 1- and 2-year patientreported outcome measures (PROMs) data (KOOS and FJS) were collected. Results - The mean tibial MTPM at 3 months were 0.48 mm (95% CI 0.37-0.58) and 0.56 mm (0.45-0.67) for the CR and MC respectively. 2 years postoperatively the respective values were 0.62 mm (0.50-0.73) and 0.73 mm (0.49-0.96). There was no statistically significant difference in migration between groups, for either the femoral or the tibial component, regarding x-, y-, and z-translations or rotations. Both CR and MC groups improved as expected in PROM scores pre- to postoperatively, but without a statistically significant difference between groups. There were no revisions or other serious adverse events related to surgery. Interpretation - The results are promising, indicating good fixation for both designs, and this is in line with other well-performing TKAs on the market. The increased medial congruity of the MC inlay does not seem to affect the migration or the PROMs up to 2 years.

Prevention of deep venous thrombosis in patients undergoing knee arthroplasty by intermittent pneumatic compression apparatus

OBJECTIVE

This study discussed and analyzed the preventive value of intermittent pneumatic compression combined with early rehabilitation training for deep vein thrombosis (DVT) in patients undergoing total knee arthroplasty (TKA).

METHODS

During January 2019 to April 2020, 85 patients who underwent TKA in our hospital were selected as subjects, and were randomly divided into an observation group (n=44) and control group (n=41) by table of random numbers. The control group patients received conventional nursing care after TKA surgery, while the observation group received combinative treatment of intermittent pneumatic compression therapy and early rehabilitation training like the conventional treatment in the control group. Subsequently, the circumference and mobility of knee joint, hemorrheologic indexes and the incidence of DVT between the two groups of patients before and after surgery were compared.

RESULTS

The knee circumferences of the two groups on 3 d and 7 d preoperatively were higher than 1 d before surgery (P<0.05), and the indexes of the observation group on 3 d and 7 d preoperatively were lower than that of the control group (P<0.05). The range of motion (ROM) of the two groups 3 d postoperatively were higher than that before surgery (P<0.05), the ROM in observation group 7 d postoperatively was increased than 3 d postoperatively (P<0.05), and the observation group had higher ROM on 3 d and 7 d postoperatively than that of control group (P<0.05). The two groups of patients had insignificant difference in knee function before treatment (P>0.05); the knee function of the two groups after treatment was better than pretreatment (P<0.05), and the observation group was better than the control group (P<0.05). The observation group had lower DVT incidence than the control group (P<0.05).

CONCLUSION

Combinative treatment of intermittent pneumatic compression and early rehabilitation training can effectively improve the postoperative knee function of patients undergoing TKA, promote recovery, and effectively prevent DVT. In conclusion, the combinative treatment is worthy of clinical application.

Component gap control during posterior-stabilised total knee arthroplasty using the posterior condylar pre-cut technique

Purpose

Adjusting the gap lengths to ensure equal lengths in both extension and flexion during total knee arthroplasty (TKA) is important for achieving successful outcomes. We designed a new pre-cut trial component (PCT) for posterior-stabilised (PS) TKA and aimed to determine whether the pre-cut technique is useful for component gap (CG) control in PS TKA.

Methods

A total of 70 knees were included. The PS PCT for PS TKA is composed of a 9-mm-thick distal part and 5-mm-thick posterior part with a cam structure. First, the distal femur and proximal tibia were cut to create an extension gap. Next, a 4-mm pre-cut was made from the posterior femoral condylar line; then, the PS PCT was attached, and the CGs were checked and compared at 0° and 90° knee flexion. Final CGs with the trial femoral components were compared with gaps in PS PCT at 0° and 90° knee flexion.

Results

CGs using PS PCTs were 10.2 mm at 0° and 13.6 mm at 90° knee flexion. According to the release of the posterior capsule at intercondylar notch and the adjustment of the cutting level of posterior femoral condyle, the final CG on knee extension was 11.3 mm; it did not significantly differ from CGs with PS PCT. The final CG at 90° knee flexion was 12.7 mm; it did not significantly differ from the estimated gap (12.4 mm) in PS PCT after flexion gap control.

Conclusion

CG control using PS PCT is a useful technique during PS TKA.

Level of evidence

Level IV: Case series.

Minimum Five Years Follow-Up of Total Knee Arthroplasty Using Morphometric Implants in Patients With Osteoarthritis

BACKGROUND

The use of morphometric implants in total knee arthroplasty (TKA) has shown better early clinical outcomes compared to conventional implants. The primary objective of this study is to evaluate the functional outcome and the implant survivorship of a morphometric TKA at a minimum of 5 years of follow-up.

METHODS

From May 2012 to June 2015, all patients undergoing primary TKA with a single design of morphometric posterior-stabilized prosthesis (Persona; Zimmer) in a prospective observational single-center study were evaluated. The Knee Society Scoring System (KSS) and the Knee Injury and Osteoarthritis Outcome Score (KOOS) were completed preoperatively, 1, 3, and 5 years postoperatively. Kaplan-Meier was used to calculate survivorship of the implants. The average follow-up was 75 months.

RESULTS

In total, 237 TKAs were performed in 235 patients with a mean age of 73 years (49-90). The KSS Knee Score increased from 44.7 (13-64) preoperatively to 93.6 (71-100), the KSS Function Score from 45.8 (17-69) to 92.2 (51-98), and the KSS Satisfaction Score from 26.6 (16-51) to 41 (35-55) at 5 years of follow-up. Similarly, for the KOOS score, a significant improvement of all the subscales was observed at 5 years of follow-up. Implant survival without reoperation at 5 years of follow up was 98.72% (95% confidence interval 0.95-1.00).

CONCLUSION

This is the first study demonstrating that significant improvements of the functional scores with good survivorship can be achieved at a minimum of 5 years of follow-up with TKA using morphometric implants.

Early outcomes of a modern cemented total knee arthroplasty : is tibial loosening a concern?

AIMS

Recent total knee arthroplasty (TKA) designs have featured more anatomical morphologies and shorter tibial keels. However, several reports have raised concerns about the impact of these modifications on implant longevity. The aim of this study was to report the early performance of a modern, cemented TKA design.

METHODS

All patients who received a primary, cemented TKA between 2012 and 2017 with a minimum two-year follow-up were included. The implant investigated features an asymmetrical tibial baseplate and shortened keel. Patient demographic details, Knee Society Scores (KSS), component alignment, and the presence of radiolucent lines at final follow-up were recorded. Kaplan-Meier analyses were performed to estimate survivorship.

RESULTS

A total of 720 of 754 primary TKAs (95.5%) were included with a mean follow-up of 3.9 years (SD 1.3); 562 (78.1%) were cruciate-retaining and 158 (21.9%) were posterior-stabilized. A total of 11 (1.5%) required reoperation for periprosthetic joint infection and seven (1.0%) for aseptic tibial loosening (five cruciate-retaining, two posterior-stabilized). Loosening occurred at a mean of 3.3 years (0.9 to 6.5). There were no cases of loosening in the 33 patients who received a 14 mm × 30 mm tibial stem extension. All-cause survivorship was 96.6% at three years (95% confidence interval (CI) 95.3% to 98.0%) and 96.2% at five years (95% CI 94.8% to 97.7%). Survivorship with revision for aseptic loosening was 99.6% at three years (95% CI 99.1% to 100.0%) and 99.1% at five years (95% CI 98.4% to 99.9%). Tibial components were in significantly more varus in those with aseptic loosening (mean 3.4° (SD 3.7°) vs 1.3° (SD 2.0°); p = 0.015). There were no other differences in demographic, radiological, or surgical characteristics between revised and non-revised TKAs for aseptic loosening (p = 0.293 to 1.00). Mean KSS improved significantly from 57.3 (SD 9.5) preoperatively to 92.6 (SD 8.9) at the final follow-up (p < 0.001).

CONCLUSION

This is the largest series to date of this design of implant. At short-term follow-up, the rate of aseptic tibial loosening is not overly concerning. Further observation is required to determine if there will be an abnormal rate of loosening at mid- to long-term follow-up. Cite this article: Bone Joint J 2021;103-B(6 Supple A):51-58.

Two-year RSA migration results of symmetrical and asymmetrical tibial components in total knee arthroplasty: a randomized controlled trial

AIMS

The objective of this study was to compare the two-year migration pattern and clinical outcomes of a total knee arthroplasty (TKA) with an asymmetrical tibial design (Persona PS) and a well-proven TKA with a symmetrical tibial design (NexGen LPS).

METHODS

A randomized controlled radiostereometric analysis (RSA) trial was conducted including 75 cemented posterior-stabilized TKAs. Implant migration was measured with RSA. Maximum total point motion (MTPM), translations, rotations, clinical outcomes, and patient-reported outcome measures (PROMs) were assessed at one week postoperatively and at three, six, 12, and 24 months postoperatively.

RESULTS

A linear mixed-effect model using RSA data of 31 asymmetrical and 38 symmetrical TKAs did not show a difference in mean MTPM migration pattern of the tibial or femoral components. Mean tibial component MTPM at two years postoperative of the asymmetrical TKA design was 0.93 mm and 1.00 mm for the symmetrical design. For the femoral component these values were 1.04 mm and 1.14 mm, respectively. No significant differences were observed in other migration parameters or in clinical and PROM measurements.

CONCLUSION

The TKA design with an asymmetrical tibial component has comparable component migration with the proven TKA with a symmetrical tibial component. This suggests the risk of long-term aseptic loosening of the two designs is comparable. Cite this article: Bone Joint J 2021;103-B(5):855-863.

Early outcomes and predictors of patient satisfaction after TKA: a prospective study of 200 cases with a contemporary cemented rotating platform implant design

Purpose

The purpose of the study was to identify the earliest time point where subjects realized the greatest clinical improvement after TKA, and the time when post-operative scores became superior to pre-operative scores. Post-hoc exploratory analyses were conducted to investigate predictors of early post-operative outcomes and patient satisfaction.

Methods

Six investigators across 4 sites in the Netherlands prospectively implanted 200 subjects with a contemporary cemented rotating platform device. Patient Reported Outcome Measurements (PROMs) KOOS-PS, PKIP, and EQ-5D were collected pre-operatively and post-operatively through 2-years. PROMs change from pre-operative baseline were summarized, along with radiographic outcomes and adverse events (AEs). Pre-operative patient characteristics were explored for correlation with patient outcomes, and patient satisfaction for correlation with KOOS-PS.

Results

Follow-up compliance was 99% at 6-months, and 95.5% at 2-years. The percentage with higher KOOS-PS compared to baseline was 81.3% at 6-months. KOOS-PS, PKIP, and PKIP subscore means were all better at 6-weeks versus baseline. Gender, BMI, hypertension, and pre-operative KOOS-PS were weakly correlated with 6-week KOOS-PS (multivariate R-squared = 14.1%), but only pre-operative KOOS-PS demonstrated correlation with post-operative KOOS-PS at 6-months or later (R-squared < 5% at 6-months and 2 years). Satisfaction was moderately correlated with concurrent KOOS-PS at each post-operative time point, with (R-squared = 35.3% at 6-months, and 37.5% at 2 years).

Conclusion

The greatest mean clinical improvement occurred within the first 6-weeks. Although some pre-operative factors were correlated with higher early post-operative KOOS-PS outcomes, these advantages disappeared by 6-months aside from weak correlation with pre-operative KOOS-PS. Post-operative KOOS-PS was moderately correlated with concurrent post-operative satisfaction. These results may be used for pre-operative counseling and management of patient’s postoperative expectations.

Trial registration

Clinicaltrials.gov, NCT02339610. Registered 15 January 2015.

Midterm results of a new personalized knee implant for total knee arthroplasty: implant survivorship and patient-reported outcome after five years' follow-up

PURPOSE

The Persona® system is a newly launched implant designed for total knee arthroplasty (TKA) with technical innovations intended for a better functional outcome and higher flexion range. The aim of this study is to evaluate midterm outcomes and survivorship of a cohort of patients with a minimum of 5-year follow-up and to confirm previous results described in the literature.

METHODS

A cohort of 91 knees (85 patients) that underwent a patella-preserving TKA with the Persona® implant and who were followed for a mean of 5.9 years' period was included in the study. Functional values were measured: Oxford Knee Score (OKS), Knee Society Knee score (KSKS) and Knee Society Function score (KSFS). Range of movement (ROM), lower limb axis correction, mobilization and complications were also registered at the last follow-up and underwent statistical analysis.

RESULTS

We found a low rate of complications or radiological changes with an implant-related revision rate of 2.19%. Mean results for PROMS were 44.21 ± 4 in OKS, 90.94 ± 2.4 in KSS and 97.88 ± 9.6 in KSFS. Mean postoperative ROM was 120.8º ± 12.37º. There was no change in implant positions at the final follow-up. We found radiolucent lines in 3 knees (3.29%).

CONCLUSION

At a mean follow-up of 5.9 years, the implant-related cumulative percentage revision rate was 3.3% (2 of 91) at a mean follow-up of 5.9 years, with good clinical and functional results.

The influence of previous arthroscopic treatment on subsequent primary total knee arthroplasty: the comparison between bilateral knees of the same patient

BACKGROUND

To explore whether previous arthroscopic knee surgery affects future total knee arthroplasty (TKA) results or not.

METHODS

A total of 56 patients with the previous arthroscopic treatment on one knee underwent subsequent bilateral total knee arthroplasty in our hospital from September 2012 to July 2018. Data on each patient were collected in regards to changes in postoperative clinical and functional scores, various other scores, as well as postoperative functional recovery and complications. We defined the knees with a previous arthroscopic history as group A, and the counter side as group B. The Knee Society clinical score, functional scores, range of motion (ROM), finger joint size (FJS), visual analogue scale (VAS) scores were assessed before and after surgery. Using the Kolmogorov-Smirnov Test to test the normality of continuous variables, and the chi-square test to compare the rate of reoperation and complications between two groups. For all statistical comparisons, P < 0.05 was considered significant.

RESULTS

There were no statistically significance differences found in postoperative Knee Society clinical scores and functional scores between group A and group B, as well as in ROM, FJS, VAS scores and local complications.

CONCLUSION

There were no statistically significant differences found in postoperative functional recovery and complications in patients, who underwent total knee arthroplasty with previous knee arthroscopy.

Do the increment of femoral condyle curvature and the change of tibia shape improve clinical outcome in total knee arthroplasty? A propensity score matching analysis

PURPOSE

Recently, the Persona total knee arthroplasty (TKA) system with more anatomical features and a similarly high flexion to the previous version, LPS-Flex, was introduced and is widely used. This study aimed to compare the early outcomes obtained using Persona versus an LPS-Flex fixed PS implant.

METHODS

A total of 784 knees that underwent primary TKAs (162: Persona group and 622: LPS-Flex group) were included. After 1:2 propensity score matching, there were 143 and 286 knees in Persona and LPS-Flex groups, respectively. Range of motion at the 2-year follow-up was the primary variable. Secondary variables were functional score, ability to perform activities requiring deep knee flexion, patient satisfaction, and radiographic measurements, including radiolucent line (RLL).

RESULTS

The average postoperative maximal flexion measured by goniometer at 2 years after TKA was 126.1° ± 10.8° (range 95°-140°) for the Persona group and 132.7° ± 11.7° (range 103°-145°) for the LPS-Flex group (P < 0.05). This significant difference was observed from 1 year postoperatively (P < 0.05). The two groups did not show a significant difference in functional score, postoperative ability in high flexion activities, and satisfaction at the 2-year follow-up. The rate of RLL was significantly lower in the Persona group (P < 0.05).

CONCLUSION

At the 2-year follow-up, the Persona group had less maximal flexion; however, the difference in flexion did not seem to affect clinical outcomes. According to the radiological results, the Persona system shows less RLL than does the LPS-Flex system.

LEVEL OF EVIDENCE

III.

A Five-Year Comparative Functional and Clinical Evaluation of Two Contemporary Cruciate-Retaining Knee Implants

Background

The purpose of our study was to compare 2 commonly used highly successful cruciate-retaining knee designs on the basis of patient-reported outcome measures (PROMs), range of motion (ROM), and anterior knee pain (AKP) at a minimum follow-up of 5 years.

Methods

A cohort of 65 patients underwent unilateral total knee arthroplasty, from January 2013 to December 2013, using NexGen Cruciate Retaining (Zimmer Biomet, Warsaw, IN), a nonmorphogenic knee (NMK) system. They were subsequently operated upon for the contralateral knee using Persona Cruciate Retaining (Zimmer Biomet, Warsaw, IN), a morphogenic knee (MK) system between January 2014 and June 2014. Of the 65 patients, 63 participated in this study. All the patients were compared preoperatively and postoperatively on the basis of PROMs, ROM, and AKP.

Results

On the basis of PROMs, ROM, and AKP, there was a statistically significant difference between the 2 groups favoring the MK group, with an ROM of 126.14° in the MK group as compared with 120.76° in the NMK group and P value of <.01.

Conclusions

PROMs, ROM, and AKP improved significantly over time after total knee arthroplasty using both MK and NMK implants; however, the outcomes of the former were better than those of the latter, although this difference was not clinically significant.

Early Experience and Results Using Patient-Reported Outcomes Measurement Information System Scores in Primary Total Hip and Knee Arthroplasty

BACKGROUND

Our study determined if preoperative Patient-Reported Outcomes Measurement Information System (PROMIS) scores could predict achieving minimum clinically important differences (MCIDs) in postoperative PROMIS scores after primary total hip and knee arthroplasty.

METHODS

Ninety-three patients were administered the PROMIS Depression, Pain Interference, and Physical Function domains at their preoperative appointment and 6-week follow-up visit. MCIDs were drawn from existing literature for the PROMIS domains.

RESULTS

The MCID was achieved in 74% of patients for Pain Interference, 34% for Physical Function, and 24% for Depression. Our model could predict with 90% specificity which patients would meet MCID if their preop PROMIS Pain score was above 38, Physical Function score less than 19, or Depression score above 22.

CONCLUSION

Preoperative PROMIS Pain Interference, Physical Function, and Depression scores can predict achieving MCID in postoperative PROMIS scores.