Total knee arthroplasty (TKA) may provoke ankle symptoms. The aim of this study was to validate the impact of the preoperative mechanical tibiofemoral angle (mTFA), the talar tilt (TT) on ankle symptoms after TKA, and assess changes in the range of motion (ROM) of the subtalar joint, foot posture, and ankle laxity. Patients who underwent TKA from September 2020 to September 2021 were prospectively included. Inclusion criteria were primary end-stage osteoarthritis (Kellgren-Lawrence stage IV) of the knee. Exclusion criteria were missed follow-up visit, post-traumatic pathologies of the foot, and neurological disorders. Radiological angles measured included the mTFA, hindfoot alignment view angle, and TT. The Foot Function Index (FFI) score was assessed. Gait analyses were conducted to measure mediolateral changes of the gait line and ankle laxity was tested using an ankle arthrometer. All parameters were acquired one week pre- and three months postoperatively.Aims
Methods
This study compared the cobalt and chromium serum ion concentration of patients treated with two different metal-on-metal (MoM) hinged total knee arthroplasty (TKA) systems, as well as a titanium nitride (TiN)-coated variant. A total of 63 patients (65 implants) were treated using either a MoM-coated (n = 29) or TiN-coated (n = 7) hinged TKA (GenuX mobile bearing, MUTARS; Implantcast, Germany) versus the BPKS (Brehm, Germany) hinged TKA (n = 27), in which the weight placed on the MoM hinge is diffused through a polyethylene (PE) inlay, reducing the direct load on the MoM hinge. Serum cobalt and chromium ion concentrations were assessed after minimum follow-up of 12 months, as well as functional outcome and quality of life.Aims
Methods
We have studied 27 tibial prostheses retrieved from knee replacements after 1 to 9 years. In 22 the femoral components were of cobalt-chrome, in five polyacetal. The design of the components gave a nominal contact area of 320 mm2 on each condyle. The tibial component was of high-density polyethylene (HDP) at least 6 mm thick, and not heat-treated. In the metal/HDP prostheses the average wear rate was 0.025 mm/year. The relative wear on the medial and lateral sides was related to the
Eight-plates are used to correct varus-valgus deformity (VVD) or limb-length discrepancy (LLD) in children and adolescents. It was reported that these implants might create a bony deformity within the knee joint by change of the roof angle (RA) after epiphysiodesis of the proximal tibia following a radiological assessment limited to anteroposterior (AP) radiographs. The aim of this study was to analyze the RA, complemented with lateral knee radiographs, with focus on the tibial slope (TS) and the degree of deformity correction. A retrospective, single-centre study was conducted. The treatment group (n = 64 knees in 44 patients) was subclassified according to the implant location in two groups: 1) medial hemiepiphysiodesis; and 2) lateral hemiepiphysiodesis. A third control group consisted of 25 untreated knees. The limb axes and RA were measured on long standing AP leg radiographs. Lateral radiographs of 40 knees were available for TS analysis. The mean age of the patients was 10.6 years (4 to 15) in the treatment group and 8.4 years (4 to 14) in the control group. Implants were removed after a mean 1.2 years (0.5 to 3).Aims
Methods
The axis of the talo-crural joint was analysed by roentgen stereophotogrammetry in eight healthy volunteers. Examinations were performed at 10 degrees increments of flexion and pronation/supination of the foot as well as medial and lateral rotation of the leg. Results indicate that the talo-crural joint axis changes continuously throughout the range of movement. In dorsiflexion it tended to be oblique downward and laterally. In rotation of the
Robotic-assisted unicompartmental knee arthroplasty (UKA) promises accurate implant placement with the potential of improved survival and functional outcomes. The aim of this study was to present the current evidence for robotic-assisted UKA and describe the outcome in terms of implant positioning, range of movement (ROM), function and survival, and the types of robot and implants that are currently used. A search of PubMed and Medline was performed in October 2018 in line with the Preferred Reporting Items for Systematic Review and Meta-Analysis statement. Search terms included “robotic”, “knee”, and “surgery”. The criteria for inclusion was any study describing the use of robotic UKA and reporting implant positioning, ROM, function, and survival for clinical, cadaveric, or dry bone studies.Aims
Materials and Methods
We conducted a retrospective study to investigate the effect of femoral bowing on the placement of components in total knee replacement (TKR), with regard to its effect on reestablishing the correct mechanical axis, as we hypothesised that computer-assisted total knee replacement (CAS-TKR) would produce more accurate alignment than conventional TKR. Between January 2006 and December 2009, 212 patients (306 knees) underwent TKR. The conventional TKR was compared with CAS-TKR for accuracy of placement of the components and post-operative alignment, as determined by five radiological measurements. There were significant differences in the reconstructed mechanical axes between the bowed and the non-bowed group after conventional TKR (176.2° ( For patients with significant femoral bowing, the reconstructed mechanical axes were significantly closer to normal in the CAS group than in the conventional group (179.2° (
New developments in osteotomy techniques and methods of fixation have caused a revival of interest of osteotomies around the knee. The current consensus on the indications, patient selection and the factors influencing the outcome after high tibial osteotomy is presented. This paper highlights recent research aimed at joint pressure redistribution, fixation stability and bone healing that has led to improved surgical techniques and a decrease of post-operative time to full weight-bearing.
Correct positioning and alignment of components during primary total knee replacement (TKR) is widely accepted to be an important predictor of patient satisfaction and implant durability. This retrospective study reports the effect of the post-operative mechanical axis of the lower limb in the coronal plane on implant survival following primary TKR. A total of 501 TKRs in 396 patients were divided into an aligned group with a neutral mechanical axis (± 3°) and a malaligned group where the mechanical axis deviated from neutral by >
3°. At 15 years’ follow-up, 33 of 458 (7.2%) TKRs were revised for aseptic loosening. Kaplan-Meier survival analysis showed a weak tendency towards improved survival with restoration of a neutral mechanical axis, but this did not reach statistical significance (p = 0.47). We found that the relationship between survival of a primary TKR and mechanical axis alignment is weaker than that described in a number of previous reports.
