Radiographic Comparison of the Mechanical Axis Including Calcaneus to the Conventional Mechanical Axis in Medial Unicompartmental Knee Arthroplasty

Author(s):  
Yuichi Kuroda ◽  
Koji Takayama ◽  
Kazunari Ishida ◽  
Shinya Hayashi ◽  
Shingo Hashimoto ◽  
...  

AbstractSince a hindfoot alignment is not included in the conventional mechanical axis (hip–ankle [HA] line), a mechanical axis including the calcaneus (hip–calcaneus [HC] line) has recently attracted attention as an alternative weight-bearing line. However, there are few reports on unicompartmental knee arthroplasty (UKA) regarding the HC line. Therefore, this study aimed to compare postoperative alignments after UKA between the HA line and the HC line. Postoperatively, HC radiographs were taken in 88 consecutive patients who underwent medial UKA. The hip–knee–ankle (HKA) and hip–knee–calcaneus (HKC) angles were compared in the same patient. Regarding tibial inclination, the conventional tibial component–ankle (TCA) angle was compared with reference to the HC line (tibial component–calcaneus [TCC] angle). The mean postoperative HKA and HKC angles were 2.8 ± 2.7 and 2.0 ± 2.5 degree, respectively. The mean postoperative TCA and TCC angles were 87.7 ± 2.1 and 88.5 ± 2.1 degree, respectively. There were significant differences between the two groups in both lower limb alignment and tibial component angle. The present study indicated that the HKC and the TCC angles significantly decreased the varus alignment by approximately 1 degree compared with the HKA and TCA angles. Neutral in the HA line corresponds to valgus in reference to the HC line, which may result in overcorrection. Surgeons should consider evaluating the HC line in place of the HA line, which may affect preoperative planning and postoperative outcome during UKA. This is a Level II, diagnostic study.

2020 ◽  
Vol 48 (5) ◽  
pp. 030006052092242
Author(s):  
Guanghan Gao ◽  
Zheng Li ◽  
Yannong Wang ◽  
Guangzhong Yang ◽  
Jiang Huang ◽  
...  

Objective This study was performed to investigate the influence of a standard Oxford vertical cut on the coronal coverage and rotation of the tibial component and determine whether a relationship exists between coverage and rotation. Methods We retrospectively analyzed 71 patients with anteromedial osteoarthritis of the knee treated by Oxford unicompartmental knee arthroplasty in one center from October 2016 to October 2017. The distance of coronal coverage was measured on a postoperative anteroposterior view of the tibial component. Two different reference lines between the lateral wall of the tibial component were defined as rotation angle α and β, respectively, on a computed tomography scan. Results The mean distance was 0.3 ± 1.1 mm. The mean angle α and β were 5.7° ± 4.6° and 8.4° ± 4.6°, respectively. There were no significant differences in the distance according to the tibial component rotation or in the α and β angles according to the coronal coverage. No significant correlation was found between the α and β angles and the distance. Conclusion A standard tibial vertical cut caused various changes in coronal coverage and rotation of the tibial component. The rotation of the tibial component did not affect coverage within a certain range.


2019 ◽  
Vol 33 (02) ◽  
pp. 180-189 ◽  
Author(s):  
Giuseppe Gianluca Costa ◽  
Mirco Lo Presti ◽  
Alberto Grassi ◽  
Giuseppe Agrò ◽  
Sergio Cialdella ◽  
...  

AbstractLong-term results of unicompartmental knee arthroplasty (UKA) have shown a slightly higher revision rate than total knee arthroplasty (TKA), and implant fixation geometry seems to affect prosthetic survivorship. Whether metal-backed tibial component leads to superior performance over the all-polyethylene design is unclear, and a lack of evidence exists in literature. Our purpose was to demonstrate which implant design of UKA (all-polyethylene or metal-backed tibial component) is clinically superior regarding revision rates and clinical functioning, and investigate the role of potential factors that could affect the revision rate. A systematic review was conducted for clinical studies comparing all-polyethylene and metal-backed tibial components used in primary UKAs in terms of revision rates and clinical scores. Meta-regression techniques were used to explore factors modifying the observed effect. All causes of revision were extracted and analyzed, to find statistically significant differences between the two groups. Our research strategy generated a systematic review of nine studies comprising 1,101 UKAs in 1,088 patients with 87 revisions for any reason. Meta-analysis showed a higher, but not statistically significant, risk of aseptic revision in the all-polyethylene group. Studies with a smaller sample size and higher percentage of female patients were correlated to a higher relative risk of revision in favor of all-polyethylene UKAs. Differently, patients' age and duration of follow-up did not influence the risk ratio. The main cause for revision was aseptic loosening in both implants' component, with no statistically differences in the two groups examined. Our results do not show a superiority of the metal-backed tibial component in UKAs in terms of survivorship, although extreme care must be given for patients with high risk of early failure, such as female patients. However, surgical experience, in combination with careful patient selection, remains paramount and may lead to better long-term outcomes in patients requiring UKA. This is a Level III, therapeutic study.


2002 ◽  
Vol 35 (7) ◽  
pp. 969-974 ◽  
Author(s):  
K. Iesaka ◽  
H. Tsumura ◽  
H. Sonoda ◽  
T. Sawatari ◽  
M. Takasita ◽  
...  

2013 ◽  
Vol 3 (1) ◽  
pp. 61-66 ◽  
Author(s):  
Robert A Magnussen ◽  
Evrard Gancel ◽  
Elvire Servien ◽  
Matthias Jacobi ◽  
Guillaume Demey ◽  
...  

ABSTRACT Introduction Unicompartmental knee arthroplasty (UKA) is a treatment option in patients with unicompartmental degenerative disease. Compared to total knee arthroplasty (TKA), the advantages of UKA include accelerated recovery and cruciate ligament retention. These advantages, along with emerging evidence that mild patellofemoral joint osteoarthritis does not compromise results of UKA have encouraged expansion of the indications for UKA. Symptomatic lateral patellofemoral joint degenerative disease is a common cause of UKA revision. Partial lateral patellar facetectomy can provide relief from symptoms of lateral patellofemoral degenerative disease. We hypothesize that simultaneous UKA and lateral patellar facetectomy provides durable pain relief and functional improvement in a patient population with degenerative disease of one tibiofemoral compartment and the lateral patellofemoral joint. Materials and methods: Between 2004 and 2008, 11 lateral UKA's were performed in association with partial lateral patellar facetectomy in 11 female patients (mean age: 66.7 years) with degenerative changes in one tibiofemoral compartment and the lateral patellofemoral joint. Patients were followed clinically and radiographically for a mean of 5 years. Results No patient underwent revision surgery in the followup period. The mean international Knee Society (IKS) knee score improved from 64.9 ± 11.2 points preoperatively to 87.5 ± 12.6 points at final follow-up (p = 0.01). The mean IKS functional score improved from 65.9 ± 23.5 points preoperatively to 83.2 ± 23.3 points at final follow-up (p = 0.012). The mean Kujala score was 84.3 ± 13.5 points postoperatively. Progression of patellofemoral OA was observed in one patient. Conclusion Simultaneous UKA and partial lateral patellar facetectomy is a viable treatment option for symptomatic degenerative disease involving one tibiofemoral compartment and the lateral patellofemoral joint. This treatment approach may be a useful alternative to TKA or bicompartmental arthroplasty in a carefully selected patient population. Level of evidence Case series—Level IV. Magnussen RA, Gancel E, Servien E, Jacobi M, Demey G, Neyret P, Lustig S. Simultaneous Unicompartmental Knee Arthroplasty and Lateral Patellar Facetectomy for Bicompartmental Degenerative Disease. The Duke Orthop J 2013;3(1):61-66.


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