Influence of femoral implant design modification on anterior knee pain and patellar crepitus in patients who underwent total knee arthroplasty without patella resurfacing

Improved postoperative kneeling ability in posterior stabilized total knee arthroplasty with medialized dome-patella resurfacing: A retrospective comparative outcome analysis

OBJECTIVES

This investigation aimed to evaluate if the modifications to prosthesis designs improve patients' clinical and functional outcomes after total knee arthroplasty (TKA), with a special focus on pain and kneeling ability.

METHODS

Retrospective and comparative analysis of consecutive patients who were treated with posterior stabilized TKA using two different prostheses designs (single surgeon, single vendor). Group 1 received a traditional design TKA (PFC Sigma; DePuy, Inc., Warsaw, IN) with conventional dome-patella resurfacing, and group 2 received a modern design implant (Attune; DePuy, Inc., Warsaw, IN) with medialized dome-patella resurfacing. Functional outcome (range of motion: ROM) and the Oxford Knee Score (OKS) were collected preoperatively, at 4-6 weeks and 12 months following surgery.

RESULTS

Ninety-nine participants were included. Of these, 30 received traditional-design implants and 69 received modern-design knee implants. The comparison between the two implants showed a statistically significant increase in total OKS and kneeling ability in the modern design cohort at 1-year follow-up compared to the traditional design cohort (p ​< ​0.01). In the modern design group, 53% (N ​= ​37) could kneel easily or with little difficulty, compared to 30% (N ​= ​9) in the traditional design group. No statistically significant differences in ROM or the OKS pain component were seen.

CONCLUSION

The incorporation of a medialized dome-patella in modern knee implant design may offer advantages over traditional designs, as seen in improved total OKS and kneeling ability at one-year follow-up. Further research with larger cohorts is needed to confirm these findings and explore the broader impact of implant design changes on patient outcomes.

LEVEL OF EVIDENCE

Clinical Study, Level III.

Modern implants in total knee arthroplasty are more patellofemoral joint friendly compared to their traditional design: a systematic review and meta-analysis

BACKGROUND

Implant designs for total knee arthroplasties (TKA) are continuously evolving to improve outcomes and satisfaction rates after TKA. The present systematic review and meta-analysis aimed to explore the evidence in the literature regarding the outcomes of the Attune knee system over the PFC Sigma knee design and investigate the advantage of one over the other.

METHODS

A systematic review and meta-analysis of published studies till August 2021 was performed using the defined eligibility criteria. This was a systematic review of the literature published in the Cochrane Central Register of Controlled Trials (CENTRAL) Library, PUBMED, and EMBASE. The analysis included prospective and retrospective comparative trials comparing TKA by PFC sigma or Attune posterior stabilized (PS) or cruciate-retaining (CR), fixed bearing, or rotating platform systems. Patient-reported outcome measures (PROM) and postoperative patellar complications were analysed in the studies utilizing attune knee system (modern implants) to its counterpart PFC sigma (traditional implants) for TKA. Quality assessment was conducted using NIH Quality Assessment Tool for controlled intervention studies (RCTs and case-control studies).

RESULTS

This review included 3 RCTs and the rest, 10 of which were non-RCT, including 5852 patients. ATTUNE designs suggested a statistically significant improvement in KSS over PFC Sigma designs. Other PROMs such as OKS and WOMAC scores yielded comparable results between the two groups. ATTUNE knee prosthesis did not result in better knee range of motion, patient satisfaction, or radiological outcomes than the PFC design. Regarding the complications, attune knee prosthesis demonstrated favourable results over PFC Sigma for anterior knee pain and patellofemoral (PF) crepitus.

CONCLUSIONS

The present systematic review highlights better KSS and lesser chances of PF complications favouring a modern implant design over its traditional counterpart. Other patient-reported outcome analyses at a short-term follow-up period were comparable among patients undergoing total knee replacements with two different implant designs. Radiological outcomes for component positioning also suggested similar results among the two groups.

Synovium removal from the articular side of the quadriceps tendon around the superior pole of patella reduces the crepitus after total knee arthroplasty

PURPOSE

The purpose of this study was to investigate whether synovium removal from the articular side of the quadriceps tendon around the superior pole of the patella after total knee arthroplasty (TKA) reduced the incidence of patellar crepitus (PC) or not.

METHODS

We retrospectively reviewed 134 consecutive patients who underwent primary posterior stabilized (PS)-TKA by one surgeon from 2010 to 2013. Sixty-seven patients performed without touching synovium at superior pole of patella and 67 patients performed with removing all synovium from superior pole of patella were compared; none had patellar resurfacing. Patients were followed up two and six weeks, three, six and 12 months and annually thereafter. The primary outcome was the incidence of PC, detected during follow-up, and was graded as absent (0), fine (1), or coarse (2).

RESULTS

At one year of follow-up, the synovial removal (SR) group had a significant lower rate of PC compared to the synovial preserved (SP) group: 15/67 (22%) vs 34/67 (51%), adjusted odds ratio = 0.29, 95% confidence interval (CI) = 0.14 to 0.64, P = 0.002. All PC in SR group were grade 1 while four knees in SP group were grade 2. Mean PC onset was eight months after surgery (range 1.5 to 12, P = 0.78) in both groups.

CONCLUSION

Removal of the synovium from the articular side of the quadriceps tendon around the superior pole of patellar reduced the incidence of PC after primary PS-TKA without patellar resurfacing. This is a promising technique and might enlighten surgeons to reduce the noise and improve patient satisfaction after total knee replacement.

The Role of Stability and Alignment in Improving Patient Outcomes After Total Knee Arthroplasty

»

Total knee arthroplasty (TKA) is an effective treatment option for many patients, but a small group of patients are dissatisfied following TKA.

»

Alignment, in combination with balance, stability, and knee kinematics, is an important modifiable surgical factor that can affect patient outcomes.

»

Driven by the subset of dissatisfied patients after TKA, new techniques have evolved in the search for a more anatomic reconstruction of individual knee morphology and a more accurate approximation of the individual lower-extremity alignment.

»

There is a need to optimize 3 aspects of TKA to improve patient outcomes-mechanical tooling processes, implants that resurface the epiphysis, and techniques that respect the variable anatomy of patients.

Notching is less, if femoral component sagittal positioning is planned perpendicular to distal femur anterior cortex axis, in navigated TKA

Purpose

In navigated TKA, the risk of notching is high if femoral component sagittal positioning is planned perpendicular to the sagittal mechanical axis of femur (SMX). We intended to determine if, by opting to place the femoral component perpendicular to distal femur anterior cortex axis (DCX), notching can be reduced in navigated TKA.

Methods

We studied 171 patients who underwent simultaneous bilateral computer-assisted TKA. Femoral component sagittal positioning was planned perpendicular to SMX in one knee (Femur Anterior Bowing Registration Disabled, i.e. FBRD group) and perpendicular to DCX in the opposite knee (Femur Anterior Bowing Registration Enabled, i.e. FBRE group). Incidence and depth of notching were recorded in both groups. For FBRE knees, distal anterior cortex angle (DCA), which is the angle between SMX and DCX, was calculated by the computer.

Results

Incidence and mean depth of notching was less (p = 0.0007 and 0.009) in FBRE versus FBRD group, i.e. 7% versus 19.9% and 0.98 mm versus 1.53 mm, respectively. Notching was very high (61.8%) in FBRD limbs when the anterior bowing was severe (DCA > 3°) in the contralateral (FBRE) limbs.

Conclusion

Notching was less when femoral component sagittal positioning was planned perpendicular to DCX, in navigated TKA.

Level of evidence

Therapeutic level II.

Influence of Patellar Morphology Classified by Wiberg Classification on Knee Joint Function and Patellofemoral Tracking After Total Knee Arthroplasty Without Patellar Resurfacing

BACKGROUND

To evaluate the influence of patellar morphology on knee joint function and patellofemoral tracking in patients with primary osteoarthritis after total knee arthroplasty (TKA) without patellar resurfacing.

METHODS

We performed a retrospective study of 156 patients with primary osteoarthritis who underwent TKA without patellar resurfacing from April 2018 to July 2019. As per Wiberg classification, patients were divided into Wiberg type I (group A, n = 38), II (group B, n = 88), and III (group C, n = 30) groups. The clinical data, postoperative follow-up data, and radiological data between three groups were compared.

RESULTS

There was no statistically significant difference in the HSS score and Feller score between the three groups before surgery and at each follow-up point after surgery (P > .05). At the last follow-up, there were no significant differences in the height and relative thickness of the patella between the three groups (P > .05). However, the incidence of anterior knee pain was significantly higher in group C than in the group B (P < .05). The patellar tilt angle was significantly larger in group C than in the groups A and B (both P < .05). The patellar facet angle was significantly larger in group A than in group B and C, which was also significantly larger in group B than in group C (both P < .05).

CONCLUSION

Patients with three different morphologic types of the patella both exhibited improved knee joint function after TKA, however, patients with Wiberg type Ⅲ patella were more prone to have poor patellofemoral tracking and anterior knee pain after surgery.