Risk factors of post-operative malalignment in fixed-bearing medial unicompartmental knee arthroplasty

Ahn, Ji Hyun; Kang, Ho Won; Yang, Tae Yeong; Lee, Jang Yun

doi:10.1007/s00264-015-3014-1

Cited by 15 publications

(6 citation statements)

References 26 publications

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“…Several authors examined the correlation between the BMI and UKA survival (10,11,(16)(17)(18)(19)(20)(21). As far as we know, this study is the first to examine which component's malalignment has an effect on medial UKA survival and long-term clinical outcome in obese patients.…”

Section: Discussionmentioning

confidence: 99%

“…Several authors' opinion is that the reason for failures is component malalignment such as varus-valgus component malalignment (3,10,11), more than 6 degrees of intraprosthetic divergence, more than 3 degrees of change in tibial component's obliquity and 2 degrees of cange of TS (4). Chatellard (4) reported that more than 2 mm of prosthetic joint space elevation or depression and more than 5 degrees of residual varus deformity both lead to mechanical failure.…”

Section: Discussionmentioning

confidence: 99%

“…Several articles have been published about the range of acceptable components' malalignment (3)(4)(5)(6)(8)(9)(10)(11).…”

Section: Introductionmentioning

confidence: 99%

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Medial Unicompartmental Knee Arthroplasty: Correlation Between Components’ Malalignment and Long-term Outcome in Obese Patients

Zsakai¹,

Nadianmehr²,

Oláh³

et al. 2017

Trauma Mon

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Background: The (UKA) is performed as an alternative to total knee arthroplasty (TKA) and high tibial osteotomy for unicompartmental osteoarthritis. Objectives: We examined whether the tolerable range of component malalignment is narrower in obese (BMI > 30) than in nonobese patients. Methods: We performed 163 consecutive all-poly medial UKA from 01/01/1995 to 31/10/2003. We examined 83 patients (88 knees) at a minimal follow-up period of 10 years. We examined the correlation between limb-and component malalignment and clinical outcome separately in the obese (67 knees) and nonobese (21 knees) group. Results: The 10-year prothesis survival was 92.8%, and 9 UKA were converted to total knee arthroplasty. The average time to revision was 84.44 (48 to 144) months. The 8 obese and 1 nonobese patients had slightly higher BMI (33.47) than the 83 long-term followed patients (31.72). In each of these 9 patients, knee score and functional score were poor. At every revision, we used stems and augments. In the obese group, the prosthetic joint space depression correlated with fair and poor knee and functional scores, the prosthetic joint space elevation is correlated with degenerative changes in lateral tibiofemoral joint. Conclusions:In the obese group, we noted at least 2 mm of prosthetic joint space depression in all of the 8 failured knees, and 4 mm or more than 4 mm in 6 cases. We hypothesize that the reason fot the subsidence of tibial component is the increased loading because of prosthetic joint space depression. The result of this study suggests that tibial component positioning which provides an optimal level of prosthetic joint space reduces the risk of failure in medial UKA, prevents degenerative changes in lateral tibiofemoral joint, and provides better long-term clinical outcome.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

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Medial Unicompartmental Knee Arthroplasty: Correlation Between Components’ Malalignment and Long-term Outcome in Obese Patients

Zsakai¹,

Nadianmehr²,

Oláh³

et al. 2017

Trauma Mon

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“…Ahn et al noted the likelihood of post-operative malalignment during medial UKA in patients with a greater varus angle in pre-operative distal femoral varus angle (DFVA), tibial bone varus angle (TBVA), and valgus stress angle, particularly with a greater varus DFVA, which was the strongest predictor for malalignment. 70 …”

Section: Complications Of Ukamentioning

confidence: 99%

Unicompartmental knee arthroplasty

Rodríguez-Merchán¹,

Gómez-Cardero²

2018

EFORT Open Reviews

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An age younger than 60 years, a body weight of 180 lb (82 kg) or more, performing heavy work, having chondrocalcinosis and having exposed bone in the patellofemoral (PF) joint are not contraindications for unicompartmental knee arthroplasty (UKA).Severe wear of the lateral facet of the PF joint with bone loss and grooving is a contraindication for UKA.Medial UKA should only be performed in cases of severe osteoarthritis (OA) as shown in pre-operative X-rays, with medial bone-on-bone contact and a medial/lateral ratio of < 20%.The post-operative results of UKA are generally good. Medium-term and long-term studies have reported acceptable results at 10 years, with implant survival greater than 95% for UKAs performed for medial OA or osteonecrosis and for lateral UKA, especially when fixed-bearing implants are used.When all implant-related re-operations are considered, the 10-year survival rate is 94%, and the 15-year survival rate is 91%.Aseptic loosening is the principal failure mechanism in the first few years in mobile-bearing implants, whereas OA progression causes most failures in later years in fixed-bearing implants.The overall complication rate and the comprehensive re-operation rate are comparable in both mobile bearings and fixed bearings.The survival likelihood of the all-polyethylene UKA implant is similar to that of metal-backed modular designs for UKA.Notable cost savings of approximately 50% can be achieved with an outpatient UKA surgery protocol. Outpatient surgery for UKA is efficacious and safe, with satisfactory clinical results thus far.Cite this article: EFORT Open Rev 2018;3:363-373. DOI: 10.1302/2058-5241.3.170048

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“…Therefore, a reproducible method of predicting postoperative coronal alignment is desired to assume the risk of postoperative coronal malalignment. However, only a few studies have reported the risk factors of postoperative coronal malalignment in UKA [ 20 , 21 ].…”

Section: Introductionmentioning

confidence: 99%

Predicting postoperative coronal alignment after fixed-bearing unicompartmental knee arthroplasty using a new morphological assessment method: the arithmetic hip-knee-ankle angle

Nakano,

Tsubosaka,

Kamenaga

et al. 2023

International Orthopaedics (SICOT)

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Purpose Only a few reports have been published so far on factors that predict postoperative coronal alignment after unicompartmental knee arthroplasty (UKA). The purpose of this study is to clarify the relationship between the arithmetic hip-knee-ankle angle (aHKA) and postoperative coronal alignment after medial fixed-bearing UKA. Methods One hundred and one consecutive patients (125 knees) who underwent medial fixed-bearing UKA were assessed. Pre- and postoperative coronal HKA angles, lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), and the thickness of the tibial and femoral bone cut were measured. aHKA was calculated as 180° − LDFA + MPTA. Correlations between postoperative HKA angle and aHKA, LDFA, and MPTA were investigated by single regression analysis. After the patients were divided into three groups according to the postoperative HKA angle, i.e., HKA angle > 180°, 175° < HKA angle ≤ 180°, and HKA angle ≤ 175°, aHKA, LDFA, MPTA, preoperative HKA angle, and the thickness of the distal femoral as well as tibial bone cut were compared among the three groups. Results aHKA and MPTA were positively correlated with postoperative HKA angle, while no correlation was found between postoperative HKA angle and LDFA. Among the three groups classified by postoperative HKA angle, significant differences were found in aHKA, MPTA, and preoperative HKA angle, while no significant difference was found in LDFA and the amount of distal femoral and tibial osteotomies. Conclusions aHKA was correlated with postoperative HKA angle after medial fixed-bearing UKA, which was probably due to the influence of MPTA.

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Risk factors of post-operative malalignment in fixed-bearing medial unicompartmental knee arthroplasty

Abstract: Attention should be given to the possibility of post-operative malalignment during medial UKA in patients with a greater varus angle in pre-operative DFVA, TBVA and valgus stress angle, especially with a greater varus DFVA, which was the strongest predictor for malalignment.

Cited by 15 publications

References 26 publications

Medial Unicompartmental Knee Arthroplasty: Correlation Between Components’ Malalignment and Long-term Outcome in Obese Patients

Medial Unicompartmental Knee Arthroplasty: Correlation Between Components’ Malalignment and Long-term Outcome in Obese Patients

Unicompartmental knee arthroplasty

Predicting postoperative coronal alignment after fixed-bearing unicompartmental knee arthroplasty using a new morphological assessment method: the arithmetic hip-knee-ankle angle

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