scholarly journals The effect of postoperative mechanical axis alignment on the revision rate of primary total knee arthroplasty after a follow up of 10 years

10.29007/3c7w ◽  
2018 ◽  
Author(s):  
Eun-Kyoo Song ◽  
Jongkeun Seon ◽  
Dong-Hyun Lee ◽  
Je-Hyoung Yeo

The purpose of this study is to evaluate the effect of postoperative mechanical alignment on clinical outcomes and revision rate by comparing acceptable mechanical axis group from neutral and an outlier mechanical axis.Between 2000 and 2006, clinical and radiographic data of 334 primary TKAs were retrospectively reviewed. Post-operative mechanical axis was investigated within 1 month after TKA. The first group was an acceptable group of 286 knees (85.6%, with mechanical axis of 0°±3°). The second group was an outlier group of 48 knees (14.4%, with mechanical axis of beyond 0°±3°). Clinical outcomes before surgery and at the final follow up were analyzed using scoring method such as Hospital for Special Surgery, Knee Society Score, and Western Ontario & McMaster Universities Osteoarthritis Index (WOMAC) score. Radiologic outcomes including changes of mechanical axis between immediate postop and last follow-up were evaluated. Postoperative complications and revision rates were also evaluated.The mean degrees in change of mechanical axis between immediate postop and last follow-up were greater in the outlier group (1.6°±2.7) than acceptable group (0.8°±2.4). No significance difference in clinical outcome was found between the two groups. The incidence of aseptic loosening, instability, polyethylene wear, polyethylene breakage, and periprosthetic fracture was 2/4/2/2/2 each in the acceptable group and 1/1/2/0/0 each in the outlier group. Six (2.1%) of 286 in the acceptable group and 4 (8.3%) of 48 in the outlier group were revised (p=0.04). The Kaplan-Meier survival analysis showed a tendency towards improved survival with restoration of neutral mechanical axis. However, such improvement was not statistically significant (p=0.25).Restoration of neutral limb alignment is a factor of total knee arthroplasty that can result in less revision rate and higher longevity. However, there are no significant differences in clinical outcomes between the two groups.

2021 ◽  
Vol 10 (1) ◽  
pp. 142
Author(s):  
Meagan E. Tibbo ◽  
Afton K. Limberg ◽  
Kevin I. Perry ◽  
Mark W. Pagnano ◽  
Michael J. Stuart ◽  
...  

Debate remains regarding the utility of mechanical axis alignment as a predictor of durability after total knee arthroplasty (TKA). Our study aimed to assess the effects of coronal alignment on implant durability, clinical outcomes, and radiographic results with a single fixed-bearing TKA design. All patients undergoing primary cemented TKA of a single design (Stryker Triathlon) from 2005–2007 with >10 years of follow-up and available pre-operative and post-operative hip–knee–ankle radiographs were included (n = 89). Radiographs were measured to determine coronal alignment and assessed for loosening. Mean preoperative mechanical axis alignment was −6° ± 6.7° (varus, range, −16°–23°), while mean post-operative alignment was −1° ± 2.7° (varus, range, −3°–15°). The aligned group was defined as knees with a post-operative mechanical axis of 0° ± 3° (n = 73) and the outlier group as those outside this range (n = 16). No patients underwent revision. Ten-year survivorship free from any reoperation was 99% and 100% in the aligned and outlier groups, respectively (p = 0.64). Knee Society scores improved significantly in both groups (p < 0.001) and did not differ at final follow-up (p = 0.15). No knees demonstrated radiographic evidence of loosening. Post-operative mechanical axis alignment within 3° of neutral was not associated with improved implant durability, clinical outcomes, or radiographic results at 10 years following primary TKA.


2019 ◽  
Vol 101-B (11) ◽  
pp. 1356-1361 ◽  
Author(s):  
Brian P. Chalmers ◽  
Kapil G. Mehrotra ◽  
Rafael J. Sierra ◽  
Mark W. Pagnano ◽  
Michael J. Taunton ◽  
...  

Aims Knee osteonecrosis in advanced stages may lead to joint degeneration. Total knee arthroplasty (TKA) for osteonecrosis has traditionally been associated with suboptimal results. We analyzed outcomes of contemporary TKAs for osteonecrosis, with particular emphasis on: survivorship free from aseptic loosening, any revision, and any reoperation plus the clinical outcomes, complications, and radiological results. Patients and Methods In total, 156 patients undergoing 167 primary TKAs performed for osteonecrosis between 2004 and 2014 at a single institution were reviewed. The mean age at index TKA was 61 years (14 to 93) and the mean body mass index (BMI) was 30 kg/m2 (18 to 51) The mean follow-up was six years (2 to 12). A total of 110 TKAs (66%) were performed for primary osteonecrosis and 57 TKAs (34%) for secondary osteonecrosis. Overall, 15 TKAs (9%) had tibial stems, while 12 TKAs (7%) had femoral stems. Posterior-stabilized designs were used in 147 TKAs (88%) of TKAs. Bivariate Cox regression analysis was conducted to identify risk factors for revision and reoperation. Results Survivorship free from aseptic loosening, any revision, and any reoperation at ten years was 97% (95% confidence interval (CI) 93 to 100), 93% (95% CI 85 to 100), and 82% (95% CI 69 to 93), respectively. No factors, including age, sex, BMI, primary versus secondary osteonecrosis, stem utilization, and constraint, were identified as risk factors for reoperation. Four TKAs (2%) underwent revision, most commonly for tibial aseptic loosening (n = 2). Excluding revisions and reoperations, there was a total of 11 complications (7%), with the most common being a manipulation under anaesthesia (six TKAs, 4%). Mean Knee Society Scores (Knee component) significantly improved from 57 (32 to 87) preoperatively to 91 (49 to 100) postoperatively (p < 0.001). No unrevised TKAs had complete radiolucent lines or radiological evidence of loosening. Conclusion Contemporary cemented TKAs with selective stem utilization for osteonecrosis resulted in durable survivorship, a low complication rate, and reliable improvement in clinical outcomes. Cite this article: Bone Joint J 2019;101-B:1356–1361.


2019 ◽  
Vol 33 (07) ◽  
pp. 678-684 ◽  
Author(s):  
Fahad Hossain ◽  
Sujith Konan ◽  
Babar Kayani ◽  
Christina Kontoghiorghe ◽  
Toby Barrack ◽  
...  

AbstractThe use of valgus–varus constrained (VVC) implant designs in primary total knee arthroplasty (TKA) is considered in situations of severe deformities, bone loss, and inadequate soft tissue balance. It is not known whether the use of such prosthesis designs may predispose to reduced function owing to its constraining design. The components are usually implanted with diaphyseal stem extensions to dissipate the increased forces. The totally stabilized (TS) implant is a contemporary VVC design with metaphyseal fixation only. It has a conforming articulation with increased rotational freedom compared with conventional VVC designs. The aim of this study was to assess whether the use of the contemporary TS implant with its metaphyseally fixed components would be associated with inferior outcomes compared with conventional standard primary posterior stabilized (PS) implants. We reviewed 38 consecutive complex primary TKAs performed using the metaphyseally fixed TS implant and 76 matched patients receiving primary PS TKA, at a minimum follow-up of 24 months. The mean follow-up was 61.1 months (24–102). Only patients with osteoarthritis were included. Clinical outcome was assessed using range of motion (ROM) and Oxford knee score (OKS). Radiographic assessment was performed using the femorotibial angle (FTA) at 6 weeks followed by assessment of bone–implant interface lucencies at final follow-up. There were no major early postoperative complications. The mean postoperative ROM in the TS and PS groups were 114.1 and 112.0, respectively. There was no difference in the mean ROM and OKS between the two groups. The mean FTA for patients in both groups was within 3° of the expected. There was no evidence of progressive lucencies or implant migration at final follow-up. The metaphyseally fixed TS knee design achieves comparable short-term functional outcomes when compared with conventional PS designs in primary knee arthroplasty. Long-term follow-up studies are required to assess survivorship.


Author(s):  
Michael Brown ◽  
Rohan Ramasubbu ◽  
Mark Jenkinson ◽  
James Doonan ◽  
Mark Blyth ◽  
...  

Abstract Purpose The NexGen Legacy Posterior Stabilised (LPS) prosthesis (Zimmer Biomet, Warsaw, IN, USA) has augmentable and non-augmentable tibial baseplate options. We have noted an anecdotal increase in the number of cases requiring early revision for aseptic loosening since adopting the non-augmentable option. The purpose of this study was to ascertain our rates of aseptic tibial loosening for the two implant types within five years of implantation and to investigate the causes for any difference observed. Methods A database search was performed for all patients who underwent primary total knee arthroplasty (TKA) using the NexGen LPS between 2009 and 2015. Kaplan–Meier curves were plotted to assess for differences in revision rates between cohorts. We collected and compared data on gender, age, body mass index, component alignment and cement mantle quality as these were factors thought to affect the likelihood of aseptic loosening. Results Two thousand one hundred seventy-two TKAs were included with five year follow-up. There were 759 augmentable knees of which 14 were revised and 1413 non-augmentable knees of which 48 were revised. The overall revision rate at five years was 1.84% in the augmentable cohort and 3.4% in the non-augmentable cohort. The revision rate for aseptic loosening was 0.26% in the augmentable group and 1.42% in the non-augmentable group (p = 0.0241). Conclusions We have identified increased rates of aseptic loosening in non-augmentable components. This highlights the effect that minor implant changes can have on outcomes. We recommend that clinicians remain alert to implant changes and publish their own results when important trends are observed.


Author(s):  
Alejandro Lizaur-Utrilla ◽  
Fancisco A. Miralles-Muñoz ◽  
Matias Ruiz-Lozano ◽  
Santiago González-Parreño ◽  
Carolina Alonso-Montero ◽  
...  

Author(s):  
Jung-Won Lim ◽  
Yong-Beom Park ◽  
Dong-Hoon Lee ◽  
Han-Jun Lee

AbstractThis study aimed to evaluate whether manipulation under anesthesia (MUA) affect clinical outcome including range of motion (ROM) and patient satisfaction after total knee arthroplasty (TKA). It is hypothesized that MUA improves clinical outcomes and patient satisfaction after primary TKA. This retrospective study analyzed 97 patients who underwent staged bilateral primary TKA. MUA of knee flexion more than 120 degrees was performed a week after index surgery just before operation of the opposite site. The first knees with MUA were classified as the MUA group and the second knees without MUA as the control group. ROM, Knee Society Knee Score, Knee Society Functional Score, Western Ontario and McMaster Universities (WOMAC) score, and patient satisfaction were assessed. Postoperative flexion was significantly greater in the MUA group during 6 months follow-up (6 weeks: 111.6 vs. 99.8 degrees, p < 0.001; 3 months: 115.9 vs. 110.2 degrees, p = 0.001; 6 months: 120.2 vs. 117.0 degrees, p = 0.019). Clinical outcomes also showed similar results with knee flexion during 2 years follow-up. Patient satisfaction was significantly high in the MUA group during 12 months (3 months: 80.2 vs. 71.5, p < 0.001; 6 months: 85.8 vs. 79.8, p < 0.001; 12 months: 86.1 vs. 83.9, p < 0.001; 24 months: 86.6 vs. 85.5, p = 0.013). MUA yielded improvement of clinical outcomes including ROM, and patient satisfaction, especially in the early period after TKA. MUA in the first knee could be taken into account to obtain early recovery and to improve patient satisfaction in staged bilateral TKA.


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