Uncemented mobile bearing designs in medial unicompartmental knee arthroplasty (UKA) have seen an increase over the last decade. However, there are a lack of large-scale studies comparing survivorship of these specific designs to commonly used cemented mobile and fixed bearing designs. The aim of this study was to evaluate the survivorship of these designs. A total of 21,610 medial UKAs from 2007 to 2018 were selected from the Dutch Arthroplasty Register. Multivariate Cox regression analyses were used to compare uncemented mobile bearings with cemented mobile and fixed bearings. Adjustments were made for patient and surgical factors, with their interactions being considered. Reasons and type of revision in the first two years after surgery were assessed.Aims
Methods
This single-blinded randomised controlled trial
investigated whether one design of mobile-bearing (MB) total knee replacement
(TKR) has any advantage over a fixed-bearing (FB) design on long-term
fixation as measured by radiostereometry. The amount of wear underneath
the mobile bearing was also evaluated. A series of 42 knees was randomised
to MB or FB tibial components with appropriate polyethylene inserts
and followed for between ten and 12 years, or until the death of
the patient. The polyethylene in the MB group was superior in that
it was gamma-irradiated in inert gas and was calcium-stearate free;
the polyethylene in the FB group was gamma-irradiated in air and
contained calcium stearate. In theory this should be advantageous
to the wear rate of the MB group. At final follow-up the overall
mean migration was 0.75 mm (. sd. 0.76) in the MB group and
0.66 mm (. sd. 0.4) in the FB group, with the FB group demonstrating
more posterior tilt and the MB group more internal rotation. In
the FB group there was one revision for aseptic loosening, but none
in the MB group. There were no significant differences in clinical
or radiological scores. . For the MB group, the mean linear wear rate on the under-surface
was 0.026 mm/year (. sd. 0.014). This was significantly smaller
than the wear rate of 0.11 mm/year (. sd. 0.06) in the MB
between femur and polyethylene (p <
0.001). Nevertheless, even
in a best-case setting the mobile bearings of this TKR design had
no apparent advantage in terms of
Aims. Obtaining solid implant
Aims. The purpose of this study was to compare reoperation and revision rates of double plating (DP), single plating using a lateral locking plate (SP), or distal femoral arthroplasty (DFA) for the treatment of periprosthetic distal femur fractures (PDFFs). Methods. All patients with PDFF primarily treated with DP, SP, or DFA between 2008 and 2022 at a university teaching hospital were included in this retrospective cohort study. The primary outcome was revision surgery for failure following DP, SP, or DFA. Secondary outcome measures included any reoperation, length of hospital stay, and mortality. All basic demographic and relevant implant and injury details were collected. Radiological analysis included fracture classification and evaluation of metaphyseal and medial comminution. Results. A total of 111 PDFFs (111 patients, median age 82 years (interquartile range (IQR) 75 to 88), 86% female) with 32 (29%) Su classification 1, 37 (34%) Su 2, and 40 (37%) Su 3 fractures were included. The median follow-up was 2.5 years (IQR 1.2 to 5.0). DP, SP, and DFA were used in 15, 66, and 30 patients, respectively. Compared to SP, patients treated with DP were more likely to have metaphyseal comminution (47% vs 14%; p = 0.009), to be low fractures (47% vs 11%; p = 0.009), and to be anatomically reduced (100% vs 71%; p = 0.030). Patients selected for DFA displayed comparable amounts of medial/metaphyseal comminution as those who underwent DP. At a minimum follow-up of two years, revision surgery for failure was performed in 11 (9.9%) cases at a median of five months (IQR 2 to 9): 0 DP patients (0%), 9 SP (14%), and 2 DFA (6.7%) (p = 0.249). Conclusion. Using a strategy of DP
Aims. Both the femoral and tibial component are usually cemented at revision total knee arthroplasty (rTKA), while stems can be added with either cemented or press-fit (hybrid)
Aims. For many designs of total knee arthroplasty (TKA) it remains unclear whether cemented or uncemented
Aims. Early implant migration measured with radiostereometric analysis (RSA) has been proposed as a useful predictor of long-term
There has been a recent increase in interest
for non-cemented
Micromotion of the polyethylene (PE) inlay may contribute to backside PE wear in addition to articulate wear of total knee arthroplasty (TKA). Using radiostereometric analysis (RSA) with tantalum beads in the PE inlay, we evaluated PE micromotion and its relationship to PE wear. A total of 23 patients with a mean age of 83 years (77 to 91), were available from a RSA study on cemented TKA with Maxim tibial components (Zimmer Biomet). PE inlay migration, PE wear, tibial component migration, and the anatomical knee axis were evaluated on weightbearing stereoradiographs. PE inlay wear was measured as the deepest penetration of the femoral component into the PE inlay.Aims
Methods
Aims. The optimal method of tibial component
The Cementless Oxford Unicompartmental Knee Replacement
(OUKR) was developed to address problems related to cementation,
and has been demonstrated in a randomised study to have similar
clinical outcomes with fewer radiolucencies than observed with the
cemented device. However, before its widespread use it is necessary
to clarify contraindications and assess the complications. This
requires a larger study than any previously published. We present a prospective multicentre series of 1000 cementless
OUKRs in 881 patients at a minimum follow-up of one year. All patients
had radiological assessment aligned to the bone–implant interfaces
and clinical scores. Analysis was performed at a mean of 38.2 months
(19 to 88) following surgery. A total of 17 patients died (comprising
19 knees (1.9%)), none as a result of surgery; there were no tibial
or femoral loosenings. A total of 19 knees (1.9%) had significant
implant-related complications or required revision. Implant survival
at six years was 97.2%, and there was a partial radiolucency at
the bone–implant interface in 72 knees (8.9%), with no complete radiolucencies.
There was no significant increase in complication rate compared
with cemented
Revision knee arthroplasty presents a number
of challenges, not least of which is obtaining solid primary fixation
of implants into host bone. Three anatomical zones exist within
both femur and tibia which can be used to support revision implants.
These consist of the joint surface or epiphysis, the metaphysis
and the diaphysis. The methods by which
We have carried out a radiostereometric study of 50 patients (54 knees) with osteoarthritis of the knee who were randomly allocated to receive a cemented or a hydroxyapatite-coated femoral component for total knee replacement. The patients were also stratified to receive one of three types of articulating surface (standard, rotating platform, Freeman-Samuelson (FS)1000) all based on the Freeman-Samuelson design. The tibial components were cemented in all cases. Radiostereometry was performed post-operatively and at 3, 12 and 24 months. The analysis was restricted to rotation of the femoral component over time. After two years, rotation of the femoral components in the transverse, longitudinal and sagittal planes did not differ between the cemented and the hydroxyapatite-coated implants (p = 0.2 to 0.9). In total knee replacements with a rotating platform, the femoral component tended to tilt more posteriorly than in the other two designs, regardless of the choice of
In a single-blind, randomised series of knee replacements in 116 patients, we used radiostereometric analysis (RSA) to measure micromotion in three types of tibial implant
Medial patellofemoral ligament (MPFL) reconstruction
is used to treat patellar instability and recurrent patellar dislocation.
Anatomical studies have found the MPFL to be a double-bundle structure.
We carried out a meta-analysis of studies reporting outcomes of
patellofemoral reconstruction using hamstring tendon autograft in
a double-bundle configuration and patellar
Objectives. Orthopaedic surgeons use stems in revision knee surgery to obtain
stability when metaphyseal bone is missing. No consensus exists
regarding stem size or method of
A total of 11 patients (12 knees) with stable lesions of osteochondritis dissecans of the knee underwent arthroscopic
Miller-Galante II total knee arthroplasty (MG II TKA) was performed on 32 knees in 30 patients. On both the femoral and tibial components, the fibre-metal area was plasma-sprayed with hydroxyapatite-tricalcium phosphate (HA-TCP). The clinical and radiographic outcome was evaluated. A mean pre-operative knee score of 26.0 ± 18.6 (SD) increased to 97.5 ± 3.5 and a mean pre-operative functional score of 21.7 ± 15.0 (SD) increased to 83.4 ± 12.4 at follow-up of seven years. Clear zones were common around the components at one month post-operatively but had completely disappeared after six months. An autopsy of a patient who underwent MG II TKA with HA-TCP two years previously, showed osteogenesis in all parts of the fibre-metal, and bone tissue comprised 77.7% of the interface. This coated prosthesis has good early
In this study we present our experience with
four generations of uncemented total knee arthroplasty (TKA) from Smith
&
Nephew: Tricon M, Tricon LS, Tricon II and Profix, focusing
on the failure rates correlating with each design change. Beginning
in 1984, 380 Tricon M, 435 Tricon LS, 305 Tricon 2 and 588 Profix
were implanted by the senior author. The rate of revision for loosening
was 1.1% for the Tricon M, 1.1% for the Tricon LS, 0.5% for the
Tricon 2 with a HA coated tibial component, and 1.3% for the Profix
TKA. No loosening of the femoral component was seen with the Tricon
M, Tricon LS or Tricon 2, with no loosening seen of the tibial component
with the Profix TKA. Regarding revision for wear, the incidence
was 13.1% for the Tricon M, 6.6% for the Tricon LS, 2.3% for the
Tricon 2, and 0% for the Profix. These results demonstrate that
improvements in the design of uncemented components, including increased
polyethylene thickness, improved polyethylene quality, and the introduction
of hydroxyapatite coating, has improved the outcomes of uncemented
TKA over time.
A total of 22 patients with a tibial avulsion
fracture involving the insertion of the posterior cruciate ligament
(PCL) with grade II or III posterior laxity were reduced and fixed
arthroscopically using routine anterior and double posteromedial
portals. A double-strand Ethibond suture was inserted into the joint
and wrapped around the PCL from anterior to posterior to secure
the ligament above the avulsed bony fragment. Two tibial bone tunnels
were created using the PCL reconstruction guide, aiming at the medial
and lateral borders of the tibial bed. The ends of the suture were
pulled out through the bone tunnels and tied over the tibial cortex
between the openings of the tunnels to reduce and secure the bony
fragment. Satisfactory reduction of the fracture was checked arthroscopically and
radiographically. The patients were followed-up for a mean of 24.5 months (19 to
28). Bone union occurred six weeks post-operatively. At final follow-up,
all patients had a negative posterior drawer test and a full range
of movement. KT-1000 arthrometer examination showed that the mean
post-operative side-to-side difference improved from 10.9 mm (standard
deviation ( We conclude that this technique is convenient, reliable and minimally
invasive and successfully restores the stability and function of
the knee. Cite this article: