Total Knee Arthroplasty Bellemans, Johan; Ries, Michael D; Victor, Jan M. K
2005, 2004-12-31
eBook
"Take away my knee pain and give me better motion". This is what the arthritic patient expects from a Total Knee Arthroplasty (TKA). By virtue of standardization of the TKA procedure, surgeons can ...nowadays solve the pain issue for the majority of the patients.
Restoration of function is a goal of a different order and forms the scope of this book. The editors confronted today's leading knee surgeons with the limitations of current surgical techniques and technology. They challenged them to define new thresholds of functional capacity after Total Knee Arthroplasty. "A Guide to Get Better Performance in TKA" describes the cutting edge in surgical techniques, prosthetic design and achievement of excellent function for these patients.
Background
The role of unicompartmental arthroplasty in managing osteoarthritis of the knee remains controversial. The Oxford medial unicompartmental arthroplasty employs a fully congruent mobile ...bearing intended to reduce wear and increase the lifespan of the implant. Long-term second decade results are required to establish if the design aim can be met.
Questions/purposes
We report the (1) 20-year survivorship for the Oxford mobile bearing medial unicompartmental knee arthroplasty; (2) reasons for the revisions; and (3) time to revision.
Methods
We reviewed a series of 543 patients who underwent 682 medial Oxford meniscal bearing unicompartmental knee arthroplasties performed between 1983 and January 2005. The mean age at implantation was 69.7 years (range, 48–94 years). The median followup was 5.9 years (range, 0.5 to 22 years). One hundred and forty-one patients (172 knees) died. None were lost to followup. The primary outcome was 20-year survival, a key variable in assessing the longevity of arthroplasty.
Results
The 16-year all cause revision cumulative survival rate was 91.0% (CI 6.4, 71 at risk) and survival was maintained to 20 years (91.0%, CI 36.2, 14 at risk). There had been 29 revision procedures: 10 for lateral arthrosis, nine for component loosening, five for infection, two bearing dislocations, and three for unexplained pain. In addition, five patients had undergone bearing exchange, four for dislocation and one for bearing fracture. The mean time to revision was 3.3 years (range, 0.3–8.9 years).
Conclusions
Mobile bearing unicompartmental knee arthroplasty is durable during the second decade after implantation.
Level of Evidence
Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.
Purpose
Kinematic alignment in TKA is supposed to restore function by aligning the components to the premorbid flexion–extension axis instead of altering the joint line and natural kinematic axes of ...the knee. The purpose of this study was to compare mechanically aligned TKA to kinematic alignment.
Methods
In this study, 200 patients underwent TKA and were randomly assigned to 2 groups: 100 TKAs were performed using kinematic alignment with custom-made cutting guides in order to complete cruciate-retaining TKA; the other 100 patients underwent TKA that was manually performed using mechanical alignment. The WOMAC and combined Knee Society Score (KSS), as well as radiological alignment, were determined as outcome parameters at the 12-month endpoint.
Results
WOMAC and KSS significantly improved in both groups. There was a significant difference in both scores between groups in favour of kinematic alignment. Although the kinematic alignment group demonstrated significantly better overall results, more outliers with poor outcomes were also seen in this group. A correlation between post-operative alignment deviation from the initial plan and poor outcomes was also noted. The most important finding of this study is that applying kinematic alignment in TKA achieves comparable results to mechanical alignment in TKA. This study also shows that restoring the premorbid flexion–extension axis of the knee joint leads to better overall functional results.
Conclusion
Kinematic alignment is a favourable technique for TKA.
Clinical relevance
The kinematic alignment idea might be a considerable alternative to mechanical alignment in the future.
Level of evidence
II.
Designed as a concise guide to the essentials of total knee arthroplasty, as well as revision total knee arthroplasty, the text is ideal for orthopedic residents and surgeons. World-renowned experts ...cover basic principles and instrumentation, ligament releases, and bone defects. Fixation in total knee arthroplasty, both with cement and cementless, is considered. Complex topicsregarding revision arthroplasty are detailed as well, including three-step technique, constrained total knee designs, and two-stage reimplantation for infected total knee arthroplasty. Revision of periprosthetic femur fractures and tibial periprosthetic fractures is also addressed. By highlighting key topics in total knee arthroplasty, this practical book is an invaluable reference to have on hand.
This work aims to summarize clearly the current concepts in the surgical treatment of Osteoarthritis of the knee, including High Tibial or Femoral Osteotomy, Unicompartmental Knee Arthroplasty and ...Total Knee Arthroplasty. This book can be read at different levels: basic chapters are particularly dedicated to non-specialized or junior surgeons, rheumatologists, radio logists and physiotherapists. More specialized aspects dealing with difficult cases and controversial topics are dedicated to highly specialized surgeons. Numerous chapters focus on difficult cases in primary TKA, such as TKA on stiff knees, TKA in case of severe deformity or TKA following HTO or failed UKA. Strategy and options in revision TKA are also discussed in the second part of the book. Thanks to its didactic approach, the reader will find quick answers to technical or conceptual difficulties. The use of numerous figures, X-rays and algorithms clarifies the statements and guides the reader throughout this book.
Purpose
Knee adduction moment (KAM) has been recognized as a good clinical surrogate for medial tibiofemoral joint loading and is associated with implant durability after total knee arthroplasty ...(TKA). This study aimed to examine the effects of joint line obliquity in kinematically aligned TKA (KA-TKA) on KAM during gait.
Methods
The study enrolled 21 knees from 18 patients who underwent cylindrical axis reference KA-TKA and a matched group of 21 knees from 18 patients who underwent mechanically aligned (MA)-TKA as controls. Gait analyses were performed the day before TKA and at an overall mean of 2.6 years postoperatively. First peak KAM and variables associated with frontal knee kinetics were determined and compared between groups.
Results
In KA-TKA, the proximal tibia was resected with 3.4° ± 1.5° of varus in relation to the mechanical axis, and the final femorotibial shaft axis was 176.7° ± 3.8° with KA-TKA and 174.4° ± 3.0° with MA-TKA. KAM was significantly smaller with KA-TKA than with MA-TKA (
p
< 0.032). Regarding variables affecting KAM, significant differences were evident between the two TKAs for knee adduction angle (
p
= 0.0021), lever arm (
p
= 0.028), and Δlever arm (
p
= 0.0001).
Conclusions
In KA-TKA, joint line obliquity reduced peak KAM during gait, despite slight varus limb alignment, and this reduced KAM in KA-TKA can tolerate constitutional varus alignment. In clinical settings, KA-TKA thus represents a promising technical option for patients with large coronal bowing of the shaft carrying a risk of increased KAM after TKA.
Level of evidence
III.
Purpose
Surgeons performing total knee arthroplasty (TKA) on the osteoarthritic valgus deformity often use a posterior stabilized (PS) and semi-constrained implants to substitute for the release of a ...contracted posterior cruciate ligament (PCL) instead of a cruciate retaining (CR) implant. Calipered kinematic alignment (KA) strives to retain the PCL and use a CR implant. The aim of this study of the windswept deformity was to determine whether the level of implant constraint, outcome scores, and alignment after bilateral calipered KA TKA are different between a pair of knees with a varus and valgus deformity in the same patient.
Methods
A review of a prospectively collected database identified all patients with a windswept deformity treated with bilateral TKA (
n
= 19) out of 2430 consecutive primary TKAs performed between 2014 and 2019. Operative reports determined the level of implant constraint. Patient response to the Forgotten Joint Score (FJS) and Oxford Knee Score (OKS) assessed outcomes at a mean follow-up of 2.3 years. Postoperative alignment was measured on an A-P computer tomographic scanogram of the limb.
Results
CR implants were used in 15 of 19 (79%) valgus deformities and 17 of 19 (89%) of varus deformities (n.s.). No knees required a semi-constrained implant. There was no difference in the median postoperative FJS and OKS (n.s.), and a 1° or less difference in the mean postoperative distal lateral femoral angle (
p
= 0.005) and proximal medial tibial angle (n.s.) between the paired varus and valgus knee deformity.
Conclusion
Based on this small series, surgeons that use calipered KA TKA can expect to use CR implants in most patients with windswept deformity and achieve comparable outcome scores and alignment between the paired varus and valgus deformity.
Level of evidence
IV
Purpose
Manufacturers of total knee arthroplasty (TKA) have introduced narrower femurs to improve bone-implant fit. However, few studies have reported the clinical consequences of mediolateral ...oversizing. Our hypothesis was that component oversizing negatively influences the results after TKA.
Methods
One hundred and twelve prospectively followed patients with 114 consecutive TKA (64 females and 50 males) were retrospectively assessed. The mean age of the patients was 72 years (range, 56 to 85 years). The dimensions of the femur and tibia were measured on a preoperative CT-scan and were compared with those of the implanted TKA. The influence of size variation on the clinical outcomes 1 year after surgery was assessed.
Results
Mediolateral overhang was observed in at least one area in 66 % of the femurs (84 % in females and 54 % in males) and 61 % of the tibia (81 % in females and 40 % in males). Twenty-two patients presented no overhang in any area and 16 had overhang in all studied zones. The increase in the Pain and KOOS scores were 43 ± 21 and 36 ± 18 in the patients without overhang and 31 ± 19 and 25 ± 13 in patients with overhang (
p
= 0.033;
p
= 0.032). Knee flexion was 127° ± 7 and 121° ± 11, respectively. Regression and latent class analysis showed a significant negative correlation between overall oversizing and overall outcome.
Conclusions
This study confirms that oversizing may lead to worse clinical results in TKA. The clinical consequences are that surgeons should pay attention not to oversize implants during implantation nd that oversizing should be ruled out in case of so called unexplained pain.
Level of evidence
IV.
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