Accelerometer-based navigation improves early patient-reported outcomes after gap-balanced total knee arthroplasty

Dorian S. Wood; Tara M. Eckel; Kurt J. Kitziger; Paul C. Peters; Brian P. Gladnick

doi:10.1016/j.jor.2020.12.011

View/Download PDF

Buy Reprints

PDF

Translate this page into:

23 (); 37-40

doi:

10.1016/j.jor.2020.12.011

Accelerometer-based navigation improves early patient-reported outcomes after gap-balanced total knee arthroplasty

Dorian S. Wood^a, Tara M. Eckel^b, Kurt J. Kitziger^b,c, Paul C. Peters^b,c, Brian P. Gladnick^b,c,

a Baylor Univeristy Medical Center, Department of Orthopaedic Surgery, 3500 Gaston Ave, Dallas, TX, 75246, USA

b W.B. Carrell Memorial Clinic, Adult Hip and Knee Reconstruction, 9301 N. Central Expressway, Suite 500, Dallas, TX, 75231, USA

c Texas Health Presbyterian Hospital Dallas, Department of Orthopaedic Surgery, 8200 Walnut Hill Lane, Dallas, TX, 75231, USA

∗Corresponding author: Brian P. Gladnick. bgladnick@carrellclinic.com

Received: 2020-10-21, Accepted: 2020-12-20, Published: 2020-12-24

Professor P K Surendran Memorial Education Foundation

Disclaimer:
This article was originally published by Reed Elsevier India Pvt. Ltd. and was migrated to Scientific Scholar after the change of Publisher.

Abstract

To investigate the effect of accelerometry-based navigation (ABN) on early clinical outcomes after TKA.

71 TKAs were performed via ABN and 37 TKAs via standard instrumentation (STD). Patients were assessed at the second post-operative visit to determine early KOOS, JR scores.

At average 2.7 months, mean KOOS, JR in the ABN group was 68.5 (range 34.2–100) compared to 62.5 (range 20.9–84.6) in the STD group (p = 0.045). Tourniquet time averaged 65.2min (range 51–79min) in STD group, compared with 70.7min (range 53–108min) in ABN group (p = 0.029).

Early KOOS, JR scores are improved with ABN for TKA.

Keywords

Accelerometer-based navigation

Total knee arthroplasty

Patient reported outcomes

Tourniquet time

Show Related Articles from PubMed

1 Introduction

Total knee arthroplasty (TKA) continues to be a highly successful procedure in the modern era.¹ However, malpositioned implants may lead to increased rates of polyethylene wear, increased risk of aseptic loosening, and decreased implant survival, and thus techniques that improve precision and accuracy of component placement continue to be of interest to arthroplasty surgeons.^1–3 To this end, several computer-assisted surgery (CAS) navigation platforms have been developed, and multiple authors have demonstrated that CAS reduces radiographic outliers and improves component position for TKA.^4–8

Early CAS platforms often required large consoles and placement of extramedullary pins, and have been associated with high capital costs, longer operative times, and increased risk of extramedullary pin site associated complications.⁹^,¹⁰ More recently, an accelerometry-based navigation (ABN) platform has been developed that uses low-profile handheld accelerometer components and does not require insertion of extramedullary pins. Several studies have demonstrated ABN to be comparable to early CAS platforms for achieving accuracy of component alignment.^11–14 However, there remains debate as to whether this improved radiographic accuracy translates into better clinical outcomes. In fact, several studies have suggested there may be no difference in patient reported outcomes (PROs) when comparing ABN and other CAS platforms with standard instrumentation,^15–19 and in fact may increase the complexity or duration of the operation.

Thus, we designed the present study in order to investigate the following research questions: 1) does accelerometry-based navigation improve early patient reported outcomes after TKA using a standardized, gap-balancing technique? And 2) is ABN comparable to standard instrumentation for gap-balanced TKA in regards to operative time?

2 Methods

2.1

2.1 Study design

The present study is a retrospective review of a prospectively collected series of TKA patients undergoing total knee arthroplasty at a high-volume specialty orthopaedic hospital. Approval for the study was obtained by the Institutional Review Board (IRB) prior to its commencement. We queried our institutional arthroplasty database and included all patients undergoing primary unilateral total knee arthroplasty by a single fellowship-trained arthroplasty surgeon, using the same posterior-stabilized implant system (Triathlon® Total Knee System, Stryker, Mahwah, NJ, USA) and a standard gap-balancing technique, between November 2018 and March 2020. We excluded patients undergoing revision surgery, unicompartmental knee arthroplasty, or conversion of previous knee surgery to TKA. Application of our inclusion and exclusion criteria yielded a total of 108 TKAs for final enrollment in the study population. The senior author initially used only standard instrumentation for the first 37 patients (STD group), and then fully converted to accelerometry-based navigation for the next 71 patients (ABN group), yielding two consecutive series of patients for study. Baseline demographic variables were recorded for the study patients and are included in Table 1. In addition, for each patient we collected pre-operative and short-term postoperative (second post-operative visit) Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS, JR.). For ABN patients, we determined the postoperative mechanical axis using long limb hip-knee-ankle films; however these data were not collected prior to using the ABN navigation.

Table 1 Patient demographic variables.

	ABN Group (n = 71)	STD Group (n = 37)	p Value
Age (mean, in years)	65.7 (range 41–85)	68.0 (range 48–89)	0.256
Gender			0.156
*Male*	38 (53.5%)	14 (37.8%)
*Female*	33 (46.5%)	23 (62.2%)
Body Mass Index (mean BMI, kg/m²)	30.0 (range 19.7–39.2)	30.8 (range 21.2–39.5)	0.410
Side			1.000
*Left*	37	20
*Right*	34	17
Preoperative Diagnosis			0.547
*Osteoarthritis*	70 (97.2%)	37 (100.0%)
*Avascular Necrosis*	1 (1.4%)	0 (0.0%)
*Post-traumatic*	1 (1.4%)	0 (0.0%
Early Follow-Up (Second postoperative visit)	2.7 months (range 1–4 months)	2.7 months (range 1–5 months)	0.702

2.2

2.2 Description of surgical technique

In all patients, unilateral TKA was performed through a medial parapatellar arthrotomy using a gap-balancing technique. The extension gap was cut initially and balanced into a rectangular gap using spacer blocks and targeted releases where necessary. In the STD group, the distal femoral cut was performed using a flexible intramedullary guide, set at 5° of anatomic valgus and slight flexion as allowed by the intramedullary guide to accommodate the femoral bow. The tibia in the STD group was cut using an extramedullary guide placed perpendicular to the anatomic axis of the tibia. For the ABN group, both extension gap cuts were navigated with an accelerometry-based platform (KneeAlign®, OrthAlign, Aliso Viejo, CA, USA) using a previously described technique,¹³ and were planned perpendicular to the mechanical axis of the femur with three degrees of flexion, and perpendicular to the mechanical axis of the tibia with three degrees of posterior slope.

The remainder of the procedure was identical for both groups. Following rectangular balancing of the extension gap, the flexion gap was tensed at 90° with a tensiometer and the femoral cutting block was pinned in a configuration to create a rectangular flexion gap of equal width to the extension gap. After final preparation of the femur and tibia, the patella was resurfaced with an anatomic component. All implants were cemented simultaneously under tourniquet control. A periarticular injection of liposomal bupivacaine was performed using a previously described technique.²⁰

2.3

2.3 Study outcomes and statistical analysis

The primary outcome under study was the short-term KOOS, JR score at the second post-operative visit, which at our institution is scheduled at three months post-operatively. Obtaining the second follow-up visit at three months allows capture of PROs and assessment of the patient at the conclusion of the 90-day global period for early detection of complications or other clinical issues, while not being so early that the initial inflammation and swelling from surgery may render subtle clinical differences between groups undetectable. For patient convenience, this visit may vary between 1 and 5 months post-operatively, and we included data from the second post-operative visit provided that the encounter was conducted during this timeframe. As a secondary outcome we evaluated tourniquet time in minutes (min), as recorded intraoperatively. All data were entered, stored, and analyzed using Microsoft Excel (Microsoft Corporation, Redmond, WA, USA), StatTools (CUHK, Hong Kong, China), and GraphPad QuickCalcs (GraphPad Software, San Diego, CA, USA). Continuous variables were analyzed using the Student's t-test, while categorical variables were analyzed using Fisher's exact test. In all cases, statistical significance was set at p = 0.05.

3 Results

No differences were noted between patient groups for any of the perioperative demographic variables or pre-operative KOOS, JR scores (Tables 1 and 2). At early follow-up (average 2.7 months), the mean post-operative KOOS, JR score in the ABN group was 68.5 (range 34.2–100), compared with a mean score of 62.5 (range 20.9–84.6) in the STD group (p = 0.045). The mean difference in KOOS, JR (ΔKOOS, JR) score between the pre-operative and post-operative visit was +28.3 in the ABN group, compared with +20.8 in the STD group (p = 0.06). Tourniquet time averaged 65.2 min (range 51–79 min) in the STD group, compared with 70.7 min (range 53–108 min) in the ABN group (p = 0.029).

Table 2 Patient reported outcome scores.

	ABN Group (n = 71)	STD Group (n = 37)	p Value
Preoperative KOOS, JR (mean)	40.5 (range 0–68.3)	44.0 (range 0–68.3)	0.224
Post-Operative KOOS, JR (mean)	68.5 (range 34.2–100)	62.5 (range 20.9–84.6)	0.045*
ΔKOOS, JR (mean)	28.3 (range −13.3–65.8)	20.8 (range −19.2–84.6)	0.060

Post-operative hip-knee-ankle radiographs were available for review in 66 of the 71 ABN TKAs (92.9%). The average post-operative mechanical axis for ABN TKA was 0.0° (range: 5.4° varus to 3.6° valgus), with 60/66 ABN TKAs (90.9%) found to have a post-operative mechanical axis within three degrees of neutral (0.0°).

4 Discussion

In the present study, we determine that early post-operative PROs (KOOS, JR) were significantly improved using accelerometer-based navigation (ABN) compared with conventional standard (STD) instrumentation during gap-balanced TKA. On average, ABN TKA patients scored approximately six points higher on the KOOS, JR than STD patients at 2.7 months, a statistically significant result. ABN TKA operations were significantly longer, with an average increase of 5.5 min of tourniquet time per TKA. Post-operative radiographic analysis demonstrated that ABN TKAs were aligned within three degrees of the neutral mechanical axis in greater than 90% of knees.

Our study has several limitations. As a retrospective review of prospectively collected data, this investigation is nonetheless susceptible to the selection bias inherent of all retrospective studies. We attempted to mitigate this potential bias by enrolling a consecutive series of patients from a prospectively collected database using pre-determined inclusion and exclusion criteria. Additionally, we report baseline demographic variables including PROs, demonstrating no pre-operative differences between the ABN and STD groups. A second limitation is that we did not collect full length hip-knee-ankle films on our patients until after converting to navigated TKA, thus we are unable to compare radiographic outcomes between ABN and STD groups. However, multiple previous studies have already demonstrated improved radiographic outcomes using navigation,^5–7^,¹³ and these studies are consistent with the radiographic data in our ABN group. The purpose of the present study was not to investigate radiographic outcomes, but rather early patient-reported clinical outcomes, after TKA. We believe a strength of this study is that we collected data from a consecutive series of patients using a standardized, gap-balanced technique by a single fellowship-trained arthoplasty surgeon using the same posterior-stabilized implant system, thereby reducing error that might be introduced through variability in operative setting, surgical technique, or implant choice.

Our finding that accelerometry-based navigation for TKA results in improved early PROs compared with standard, non-navigated TKA contradicts results from previous studies. Stulberg et al. performed a case-controlled study comparing CAS with standard instrumentation; and found no difference in PROs at one year.¹⁷ Liow and colleagues performed a retrospective case-matched study comparing CAS with conventional TKA, and also found no difference in Knee Society Score (KSS), Oxford Knee Score, or Short-Form 36 at six months of follow-up.¹⁸ Specifically in regard to accelerometry-based navigation, multiple retrospective studies have demonstrated reduction in radiographic outliers, but found no difference in six-week or 12-month PROs when comparing ABN to standard instrumentation.⁷^,¹¹^,¹⁵ Goh and colleagues prospectively matched ABN to CAS and non-navigated TKA, and similarly found no difference in KSS, Oxford Knee Score, or SF-36 scores between the three groups at two years follow-up.¹⁶ The present study would contradict these previous authors’ findings, in that we report a small but statistically significant improvement in post-operative KOOS, JR scores with ABN TKA compared to standard instrumentation at early (average 2.7 months) follow-up. One potential explanation for the differences between our findings and those of previous authors may be the choice of PRO (KOOS, JR) or the duration of follow-up; our endpoint of early (mean 2.7 months) follow-up may allow for detection of subtle differences between groups. Very early follow-up (less than six weeks) may be too early in the recovery curve to detect such differences, while waiting for later follow-up greater than one year may be too late to detect such differences after the patient is already fully recovered. Future prospective studies may elect to evaluate PROs at this particular time-point in order to determine if these observed differences persist.

Previous authors have investigated the relationship between navigation and duration of operative time. Kawaguchi et al. and Ueyama et al. have reported no significant difference between ABN and standard instrumentation regarding operative time.⁷^,¹¹ Conversely, when comparing surgical duration between ABN, CAS, and standard instrumentation, Goh and colleagues found that ABN had a significantly longer operative time compared with standard instrumentation by more than 7 min.¹⁶ Our findings were consistent with that of Goh and colleagues, in that patients undergoing ABN TKA has approximately 5 more minutes of tourniquet time when compared to non-navigated TKA.

5 Conclusion

In conclusion, the present study contradicts the findings of previous authors, in that our data would suggest a small but significant improvement in early patient-reported outcomes (KOOS, JR) using accelerometry-based navigation for TKA, compared to non-navigated TKA. In our series, this improvement came at an average cost of five additional minutes of tourniquet time per TKA. The authors feel that ABN for TKA is an easy, reliable platform for reducing radiographic outliers, and contrary to previous reports may also improve patient-reported outcomes.

Ethical approval

The study was approved by the Institutional Review Board at our medical center.

Funding

None declared

References

Moreland , . Mechanism of failure in total knee arthroplasty. Clin Orthop Relat Res (266):49-64.
[Google Scholar]
Ritter M.A., Davis K.E., Meding J.B., et al . The effect of alignment and BMI on failure of total knee replacement. J Bone Joint Surg Am. 2011;93(17):1588-1596.
[Google Scholar]
Ritter M.A., Faris P.M., Keating E.M., Meding J.B., . Postoperative alignment of total knee replacement. Its effect on survival. Clin Orthop Relat Res. 1994;299:153-156.
[Google Scholar]
Choong P., Dowsey M.M., Stoney J.D., . Does accurate anatomical alignment result in better function and quality of life? Comparing conventional and computer-assisted total knee arthroplasty. J Arthroplasty. 2009;24–4:560.
[Google Scholar]
Mason J. Bohannon, Fehring Thomas K., Estok Rhonda, et al . Meta-analysis of alignment outcomes in computer-assisted total knee arthroplasty surgery. J Arthroplasty. 2007;22(8):1097-1106.
[Google Scholar]
Matziolis G., Krocker D., Weiss U., Tohtz S., Perka C., . A prospective, randomized study of computer-assisted and conventional total knee arthroplasty. Three-dimensional evaluation of implant alignment and rotation. J Bone Joint Surg Am. 2007 Feb;89(2):236-243.
[Google Scholar]
Kawaguchi Kohei, Michishita Kazuhiko, Manabe Takeshi, Akasaka Yoshiyuki, Higuchi Junya, . Comparison of an accelerometer-based portable navigation system, patient-specific instrumentation, and conventional instrumentation for femoral alignment in total knee arthroplasty. Knee Surgery & Related Research. 2017;29(4):269-275.
[Google Scholar]
Bἂthis H., Perlick L., Tingart M., Luring C., Zurakowski D., Grifka J., . Alignment in total knee arthroplasty. A comparison of computer-assisted surgery with the conventional technique. J Bone Joint Surg Br. 2004 Jul;86(5):682-687.
[Google Scholar]
Khakha R.S., Chowdhry M., Norris M., Kheiran A., Chauhan S.K., . Low incidence of complications in computer assisted total knee arthroplasty--A retrospective review of 1596 cases. Knee. 2015 Oct;22(5):416-418.
[Google Scholar]
Brown M.J., Matthews J.R., Bayers-Thering M.T., Phillips M.J., Krackow K.A., . Low incidence of postoperative complications with navigated total knee arthroplasty. J Arthroplasty. 2017 Jul;32(7):2120-2126.
[Google Scholar]
Ueyama Hideki, Matsui Yoshio, Minoda Yukihide, Matsuura Masanori, Nakamura Hiroaki, . Using accelerometer-based portable navigation to perform accurate total knee arthroplasty bone resection in asian patients. Orthopedics. 2017;40(3):E465-e472.
[Google Scholar]
Scuderi G.R., Fallaha M., Masse V., Lavigne P., Amiot L.P., Berthiaume M.J., . Total knee arthroplasty with a novel navigation system within the surgical field. Orthop Clin N Am. 2014;45(2):167-173.
[Google Scholar]
Nam D., Weeks K., Reinhardt K., Nawabi D., Cross M., Mayman D., . Accelerometer-based, portable navigation vs imageless, large-console computer-assisted navigation in total knee arthroplasty. J Arthroplasty. 2013;28(2):255-261.
[Google Scholar]
Thiengwittayaporn Satit, Fusakul Yupadee, Kangkano Nunnapat, Jarupongprapa Chanintorn, Charoenphandhu Narattaphol, . Hand-held navigation may improve accuracy in minimally invasive total knee arthroplasty: a prospective randomized controlled trial. Int Orthop. 2016;40(1):51-57.
[Google Scholar]
Livermore Andrew T., Erickson Jill A., Blackburn Brenna, Peters Christopher L., . Does the sequential addition of accelerometer-based navigation and sensor-guided ligament balancing improve outcomes in TKA? The Bone & Joint Journal. 2020;102-B.6(Supple_A):24-30.
[Google Scholar]
Goh Graham Seow-Hng, Lincoln Liow Ming Han, Tay Darren Keng-Jin, Lo Ngai-Nung, Yeo Seng-Jin, Tan Mann-Hong, . Accelerometer-based and computer-assisted navigation in total knee arthroplasty: a reduction in mechanical Axis outliers does not lead to improvement in functional outcomes or quality of life when compared to conventional total knee arthroplasty. J Arthroplasty. 2018;33(2):379-385.
[Google Scholar]
Stulberg S.D., Yaffe M.A., Koo S.S., . Computer-assisted surgery versus manual total knee arthroplasty: a case-controlled study. J Bone Joint Surg. 2006;88(Suppl_4 Suppl 1):47-54.
[Google Scholar]
Liow Ming, Han Goh, Pang Lincoln, Tay Graham, Lo Seow-Hng, Yeo Hee-Nee, . Computer-assisted stereotaxic navigation improves the accuracy of mechanical alignment and component positioning in total knee arthroplasty. Arch Orthop Trauma Surg. 2016;136(8):1173-1180.
[Google Scholar]
Shoji Hiroaki, Teramoto Atsushi, Suzuki Tomoyuki, Okada Yohei, Watanabe Kota, Yamashita Toshihiko, . Radiographic assessment and clinical outcomes after total knee arthroplasty using an accelerometer-based portable navigation device. Arthroplasty Today. 2018;4(3):319-322.
[Google Scholar]
Mont M.A., Beaver W.B., Dysart S.H., Barrington J.W., Del Gaizo D.J., . Local infiltration analgesia with liposomal bupivacaine improves pain scores and reduces opioid use after total knee arthroplasty: results of a randomized controlled trial. J Arthroplasty. 2018 Jan;33(1):90-96.
[Google Scholar]