Radiographic assessment of knee–ankle alignment after total knee arthroplasty for varus and valgus knee osteoarthritis
Introduction
Total knee arthroplasty (TKA) is a very successful surgical procedure used to treat end-stage osteoarthritis (OA) of the knee so that pain can be relieved and joint function can be restored due to the correction of lower extremity malalignment [1], [2]. It is also known that TKA surgery can achieve normal Saxial alignment of the lower extremity in the coronal, sagittal and rotational planes by implanting the prosthesis precisely, contributing to improve long-term survival of the prosthesis [3]. Postoperative lower extremity alignment, measured on anteroposterior radiographs, is an important determinant of long-term outcomes following TKA [4], [5]. Several factors such as soft tissue laxity, tibial bone loss, inappropriate bone resection, improper cementation, pre-operative varus deformity of > 20°, and femoral bowing of > 5° could contribute to malalignment after TKA [6]. Malalignment after TKA could cause overloading of the implant bearing and the bone itself, leading to osteolysis, instability and early loosening [7], [8], which is one of the major mechanisms leading to early clinical failure and may result in revision surgery [4], [9], [10], [11], [12]. Moreland pointed out that prosthetic alignment is the most crucial factor affecting the survival of the implant [9]. Other studies have also thought that prosthesis survival following TKA depends on restoration of the mechanical alignment of the operated leg [11], [13], [14].
Patients with OA knee and requiring TKA commonly present with ankle OA and abnormal ankle alignment; [15] however, whether ankle malalignment is affected after TKA, and/or correlates with knee malalignment pre-operatively and postoperatively, remains uncertain. Few reports are available that assess the association of the abnormal alignment and degenerative changes in the ankle joint with the varus or valgus deformity in the knee. Two studies from different institutions reported inconsistent findings regarding the relationship between ankle and knee malalignment in TKA [15], [16]. Indeed, Chandler and Moskal did not find a relationship between knee and hindfoot malalignment before or after TKA [16]. Meanwhile, Tallroth et al. demonstrated that the ankle tilt is pre-operatively associated with deviation in the tibiofemoral angle and mechanical axis [15]. However, few studies have actually used full-length standing anteroposterior radiographs of both lower extremities to assess this issue, and there is no consensus concerning the change of knee–ankle alignment after TKA for varus or valgus OA knee.
The aim of this study was to compare pre-operative and postoperative knee–ankle alignment and angles, using both hip-to-ankle radiographs in the standing position, and assess knee–ankle alignment after primary TKA.
Section snippets
Patient information
A retrospective study was conducted of patients with symptomatic varus or valgus OA knee who had undergone primary TKA between January and October 2013 in China–Japan Friendship Hospital. During this period, all patients were submitted to routine pre-operative and postoperative full-length standing anteroposterior radiographs of both lower extremities. Exclusion criteria were patients that: lacked full-length pre-operative or postoperative standing anteroposterior radiographs; had unclear
Correlation between the knee and ankle alignment
Abnormal knee alignment significantly correlated with ankle malalignment in unilateral varus or valgus gonarthrosis pre-operatively and postoperatively. The HKA had a significant positive correlation with the TAA angle on the unilateral operative side before (P < 0.001) (Figure 2A, Table 2) and after TKA (P = 0.032) (Figure 2B, Table 2). There was also a significant positive correlation between the HKA and the TAA angle on the unilateral non-operative side before (P < 0.001) (Figure 2C, Table 2) and
Discussion
The present findings indicated that ankle alignment correlates with knee alignment both pre-operatively and postoperatively. The pre-operative malalignment of the knee was corrected, and the ankle tilt angle was accordingly improved on the operative side after TKA. In addition, both pre-operative knee and ankle malalignment could be simultaneously corrected following TKA.
Osteoarthritis is the most common form of arthritis; it often occurs in the knee, and can induce pain and physical disability
Source of funding
No disclosures of funding were received for this work.
Conflict of interest
This study was supported by the National Natural Science Foundation of China (81372013) and the Research Fund of China–Japan Friendship Hospital (2013-MS-27, 2014-4-QN-29). China–Japan Friendship Hospital Youth Science and Technology Excellence Project (2014-QNYC-A-06). The authors declare that they have no conflict of interest.
Acknowledgments
We are grateful to all the participating patients of this study. We thank the staff members of this trial, our colleagues, and all the study staff for their enormous efforts in collecting and ensuring the accuracy and completeness of all the data.
References (26)
- et al.
Computer assisted navigation in total knee arthroplasty: improved coronal alignment
J Arthroplasty
(2005) - et al.
Coronal alignment in total knee arthroplasty: just how important is it?
J Arthroplasty
(2009) - et al.
Evaluation of knee and hindfoot alignment before and after total knee arthroplasty: a prospective analysis
J Arthroplasty
(2004) - et al.
Does measurement of the anatomic axis consistently predict hip–knee–ankle angle (HKA) for knee alignment studies in osteoarthritis? Analysis of long limb radiographs from the multicenter osteoarthritis (MOST) study
Osteoarthritis Cartilage
(2011) - et al.
Effect of body mass index on limb alignment after total knee arthroplasty
J Arthroplasty
(2013) - et al.
Cartilage lesions and ankle osteoarthrosis: review of the literature and treatment algorithm
Rev Bras Ortop
(2014) - et al.
Tibiofemoral alignment and the results of knee replacement
J Bone Joint Surg Am
(1985) - et al.
Limb alignment in computer-assisted minimally-invasive unicompartmental knee replacement
J Bone Joint Surg Br
(2006) - et al.
Improved accuracy of component alignment with the implementation of image-free navigation in total knee arthroplasty
Knee Surg Sports Traumatol Arthrosc
(2008) - et al.
Which factors increase risk of malalignment of the hip–knee–ankle axis in TKA?
Clin Orthop Relat Res
(2013)
Alignment in total knee arthroplasty: correlated biomechanical and clinical observations
Clin Orthop Relat Res
Coronal alignment after total knee replacement
J Bone Joint Surg Br
Mechanisms of failure in total knee arthroplasty
Clin Orthop Relat Res
Cited by (23)
Effect of Total Knee Arthroplasty on Coronal Alignment of the Ankle Joint
2022, Journal of ArthroplastyCitation Excerpt :In a more recent cohort by the same group, including 24 patients which underwent <10° valgus correction with TKA, they found a correlation to improved ankle tilt and tibiotalar angles after knee deformity correction. The authors concluded that both preoperative knee and ankle malalignment can be both corrected simultaneously following TKA [4]. Interestingly, our study results showed significant changes in ankle alignment only when correcting >10° of knee valgus deformity.
Amelioration in Ankle Pain and Improvement in Function After Total Knee Arthroplasty for Ipsilateral Knee and Ankle Osteoarthritis: A Report of Two Cases
2020, Arthroplasty TodayCitation Excerpt :The ankle alignment correlates with the knee alignment both preoperatively and postoperatively. Hence, preoperative malalignment of both the knee and ankle could be simultaneously corrected after TKA [9]. We report 2 cases of ankle OA ipsilateral to varus knee OA in 2 female patients who had chronic ankle and knee pain and were treated with TKA.
Aggravation of Ankle Varus Incongruency Following Total Knee Replacement Correcting ≥10° of Genu Varum Deformity: A Radiographic Assessment
2020, Journal of ArthroplastyCitation Excerpt :The cause of ankle pain following TKR has not been clearly explained, especially for varus ankle incongruencies. Previous studies have reported that correction of knee alignment during TKR or high tibial osteotomy (HTO) could improve the radiographical alignment of the ankle joint and possibly be helpful in restoring the biomechanics of the ankle [11,12]. Another study reported significant clinical improvement of knee and ipsilateral ankle osteoarthritis following HTO [10], and a case report showed excellent outcome of treating ankle pain by HTO in a patient with an asymptomatic varus knee [16].
Mechanical and anatomical axis of the lower limb in total ankle arthroplasty
2020, FootCitation Excerpt :The management of patients with concomitant knee and ankle osteoarthritis can be very challenging. Ankle alignment is affected by varus and valgus knee osteoarthritis and improves with total knee replacement surgery [13]. It is also recommended that correction of any proximal deformity prior to TAR surgery takes place and in cases of symptomatic knee osteoarthritis this is easily explained to the patient.
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Joint first authors.