Accurate alignment and high function after kinematically aligned TKA performed with generic instruments

Howell, Stephen M.; Papadopoulos, Stelios; Kuznik, Kyle; Hull, Maury L.

doi:10.1007/s00167-013-2621-x

Cited by 292 publications

(319 citation statements)

References 33 publications

Supporting

Mentioning

302

Contrasting

Unclassified

Order By: Relevance

“…In particular we found no increase in the rate of patellofemoral complications in the KA group, similar to previous series using the KA technique [14,15,22,24,25]. The patellofemoral articulation is relevant because currently there is no implant specifically designed for use with KA; therefore, the relative internal rotation of the femoral component in KA versus the MA technique theoretically may adversely affect patellofemoral tracking [9,10].…”

Section: Discussionsupporting

confidence: 86%

“…First, the patientspecific instrumentation (PSI) guides used in the KA group were manufactured by a specific company using proprietary software analysis of the preoperative MRI scan. Other variants of KA such as using gap balancing or manual instrumentation to perform KA in TKA are described [25], and our results may not be generalizable to these techniques. However, the PSI guides were identical to those used in previous KA studies [14,15,22,24,34,36], and their accuracy has been validated in a clinical study [13].…”

Section: Discussionmentioning

confidence: 83%

“…In contrast, KA aims to position TKA components to recreate the patient's prearthritic articular surface anatomy, facilitating soft tissue balancing, which may, in turn, improve functional outcome [15,25,34]. Prospective data comparing MA with KA are limited to one previous trial [14], and given the excellent long-term results of MA, clear evidence of a functional advantage to KA is required before a change in technique can be recommended.…”

Section: Discussionmentioning

confidence: 99%

“…A study of 250 young adults without arthritis found only 66% of males and 80% of females had a hip-kneeankle angle within 3°of neutral with the majority of outliers demonstrating ''constitutional varus'' [7]. If such patients undergo TKA using MA principles, medial soft tissue releases are likely to be required [5,6,25]. In contrast, the kinematic alignment (KA) technique attempts to match implant position to recreate the anatomy of the prearthritic articular surface for the individual patient.…”

Section: Introductionmentioning

confidence: 99%

“…Advocates of KA suggest that this will offer advantages over the MA technique in terms of pain and function. Additionally, recent studies suggest early patientreported outcomes may be improved with KA [14,15,25,34], but comparative data are lacking.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

The Chitranjan S. Ranawat Award

Young

Walker

Bayan

et al. 2017

Clinical Orthopaedics &Amp; Related Research

198

View full text Add to dashboard Cite

Background Neutral mechanical alignment (MA) in total knee arthroplasty (TKA) aims to position femoral and tibial components perpendicular to the mechanical axis of the limb. In contrast, kinematic alignment (KA) attempts to match implant position to the prearthritic anatomy of the individual patient with the aim of improving functional outcome. However, comparative data between the two techniques are lacking.Questions/purposes In this randomized trial, we asked: (1) Are 2-year patient-reported outcome scores enhanced in patients with KA compared with an MA technique? (2) How does postoperative component alignment differ between the techniques? (3) Is the proportion of patients undergoing reoperation at 2 years different between the techniques? Methods Ninety-nine primary TKAs in 95 patients were randomized to either MA (n = 50) or KA (n = 49) groups. A pilot study of 20 TKAs was performed before this trial using the same patient-specific guides positioning in kinematic alignment. In the KA group, patient-specific cutting blocks were manufactured using individual preoperative MRI data. In the MA group, computer navigation was used to ensure neutral mechanical alignment accuracy. Postoperative alignment was assessed with CT scan, and functional scores (including the Oxford Knee Score, WOMAC, and the Forgotten Joint Score) were assessed preoperatively and at 6 weeks, 6 months, and 1 and 2 years postoperatively. No patients were lost to followup. We set sample size at a minimum of 45 patients per treatment arm based on a 5-point improvement in the mean Oxford Knee Score (OKS; the previously reported minimum clinically significant difference for the OKS in TKA), a pooled SD of 8.3, 80% power, and a two-sided significance level of 5%. Results We observed no difference in 2-year change scores (postoperative minus preoperative score) in KA versus MA The institution of one or more of the authors (SWY, MLW, AB, BF) has received, during the study period, funding from Stryker (Kalamazoo, MI, USA) One or more of the authors (AB, MLW, BF) or a member of his or her immediate family, has or may receive payments or benefits, during the study period, an amount of less than USD 10,000 from Stryker. All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research 1 editors and board members are on file with the publication and can be viewed on request. Clinical Orthopaedics and Related Research 1 neither advocates nor endorses the use of any treatment, drug, or device. Readers are encouraged to always seek additional information, including FDAapproval status, of any drug or device prior to clinical use. Each author certifies that his or her institution approved the human protocol for this investigation, that all investigations were conducted in conformity with ethical principles of research, and that informed consent for participation in the study was obtained. This work was performed at the Department of Orthopaedics, North Shore Hospital, Auckland, New Zealand. Postoperative hipknee-ankle a...

show abstract

Section: Discussionsupporting

confidence: 86%

Section: Discussionmentioning

confidence: 83%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

The Chitranjan S. Ranawat Award

Young

Walker

Bayan

et al. 2017

Clinical Orthopaedics &Amp; Related Research

198

View full text Add to dashboard Cite

show abstract

Conventionally instrumented inverse kinematic alignment for total knee arthroplasty: How is it done?

Russell,

Keyes,

Hirschmann

et al. 2024

J. exp. orthop.

View full text Add to dashboard Cite

PurposeFor primary total knee arthroplasty (TKA), there is an increasing trend towards patient‐specific alignment strategies such as kinematic alignment (KA) and inverse kinematic alignment (iKA), which by restoring native joint mechanics may yield higher patient satisfaction rates. Second, the most recent Australian joint registry report describes favourable revision rates for conventionally instrumented TKA compared to technology‐assisted techniques such as those using navigation, robotics or custom‐cutting blocks. The aim of this technique article is to describe in detail a surgical technique for TKA that: (1) utilises the principles of iKA and (2) uses conventionally instrumented guided resections thereby avoiding the use of navigation, robotics or custom blocks.MethodsA TKA technique is described, whereby inverse kinematic principles are utilised and patient‐specific alignment is achieved. Additionally, the patellofemoral compartment of the knee is restored to the native patellofemoral joint line. The sequenced technical note provided may be utilised for cemented or cementless components; cruciate retaining or sacrificing designs and for fixed or rotating platforms.ResultsAn uncomplicated, robust and reproducible technique for TKA is described.DiscussionKnee arthroplasty surgeons may wish to harness the emerging benefits of both a conventionally instrumented technique and a patient‐specific alignment strategy.Level of EvidenceLevel V.

show abstract

Changes in the rotational axes of the tibiofemoral joint caused by resection of the anterior cruciate ligament

Bonny

Howell

Hull

2016

Journal Orthopaedic Research

Self Cite

View full text Add to dashboard Cite

Kinematic alignment is a method of aligning implants in total knee arthroplasty (TKA) that strives to restore the native flexion-extension (F-E) and longitudinal rotation (LR) axes of the tibiofemoral joint. The anterior cruciate ligament (ACL) is typically resected at the time of TKA, which might change the position, and orientation of these axes from that of the native knee. Our objective was to determine whether resecting the ACL causes changes in the F-E and LR axes. A custom designed and validated instrumented spatial linkage (ISL) measured the F-E and LR axes in nine cadaveric knees before and after ACL resection. Changes in these axes were computed for knee flexion from 0° to 120°. For the F-E axis, the two statistically significant yet relatively small changes were internal rotation of 0.5° (p = 0.02) and posterior translation of 0.3 mm (p = 0.04). For the LR axis, the statistically significant and relatively large change was medial translation of 2.1 mm (p = 0.01). Changes to the LR axis in both medial-lateral position and varus-valgus orientation varied widely; 77% of a population of knees would have a medial-lateral position change greater than 1 mm, and 53% of a population of knees would have a varus-valgus orientation change greater than 1°. Knowledge of changes of the F-E and LR axes caused by resecting the ACL provides an important baseline for determining the changes in these axes caused by kinematic alignment and mechanical alignment of bi-cruciate retaining, posterior cruciate retaining, and posterior cruciate substituting implants. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:886-893, 2017.

show abstract

Accurate alignment and high function after kinematically aligned TKA performed with generic instruments

Abstract: IV.

Cited by 292 publications

References 33 publications

The Chitranjan S. Ranawat Award

The Chitranjan S. Ranawat Award

Conventionally instrumented inverse kinematic alignment for total knee arthroplasty: How is it done?

Changes in the rotational axes of the tibiofemoral joint caused by resection of the anterior cruciate ligament

Contact Info

Product

Resources

About