To compare time dependent functional improvement for patients with medial, respectively lateral knee osteoarthritis (OA) after treatment with opening wedge osteotomy relieving the pressure on the osteoarthritic part of the knee. In all, 49 patients (52 knees) with a mean age of 47 years (31 to 64) underwent high tibial osteotomies (HTO), and 24 patients with a mean age of 48 years (31 to 62) low femoral osteotomies (LFO) with opening wedge technique due to medial, respectively lateral knee OA with malalignment. All osteotomies were stabilized with a Puddu plate and bone grafting performed in the same time period (2000 to 2008). The patients were evaluated by the Knee Injury and Osteoarthritis Outcome Score (KOOS) pre-operatively and at six months, and at one, two, five, and ten years postoperatively. The knee OA was graded according to the Ahlbäck and Kellgren-Lawrence radiological scoring systems.Aims
Methods
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
The aim of this study was to report the outcome of femoral condylar fresh osteochondral allografts (FOCA) with concomitant realignment osteotomy with a focus on graft survivorship, complications, reoperation, and function. We identified 60 patients (16 women, 44 men) who underwent unipolar femoral condylar FOCA with concomitant realignment between 1972 and 2012. The mean age of the patients was 28.9 years (10 to 62) and the mean follow-up was 11.4 years (2 to 35). Failure was defined as conversion to total knee arthroplasty, revision allograft, or graft removal. Clinical outcome was evaluated using the modified Hospital for Special Surgery (mHSS) score.Aims
Patients and Methods
The aim of this prospective randomised study was to compare the
time course of clinical improvement during the first two years following
a closing or opening wedge high tibial osteotomy (HTO). It was hypothesised
that there would be no differences in clinical outcome between the
two techniques. Between 2007 and 2013, 70 consecutive patients were randomly
allocated to undergo either a closing or opening wedge HTO. All
patients had medial compartment osteoarthritis (OA), and were aged
between 30 years and 60 years. They were evaluated by independent
investigators pre-operatively and at three and six months, and one
and two years post-operatively using the Knee Injury and Osteoarthritis
Outcome Score (KOOS), the Oxford Knee Score (OKS), the Lysholm score,
the Tegner activity score, the University of California, Los Angeles
(UCLA) activity scale and range of movement (ROM).Aims
Patients and Methods
The aim of this study was to compare the post-operative radiographic
and clinical outcomes between kinematically and mechanically aligned
total knee arthroplasties (TKAs). A total of 60 TKAs (30 kinematically and 30 mechanically aligned)
were performed in 60 patients with varus osteoarthritis of the knee
using a navigation system. The angles of orientation of the joint
line in relation to the floor, the conventional and true mechanical
axis (tMA) (the line from the centre of the hip to the lowest point
of the calcaneus) were compared, one year post-operatively, on single-leg
and double-leg standing long leg radiographs between the groups.
The range of movement and 2011 Knee Society Scores were also compared
between the groups at that time.Aims
Patients and Methods
In patients undergoing medial opening wedge high tibial osteotomy
(MOWHTO), soft tissue opening on the medial side of the knee is
difficult to predict. When the load bearing axis is corrected beyond
a certain point, the knee joint tilts open on the medial side. We
therefore hypothesised that there is a tipping point and defined
this as the coronal hypomochlion. In this prospective study of 150 navigated MOWHTOs (144 consecutive
patients), data were collected before surgery and at three months
post-operatively. In order to calculate the hypomochlion, we compared
the respective changes to the joint line convergence angle (JLCA)
with the post-operative axis of the leg. The change to the medial proximal
tibial angle accounts for only about 80% of the change to the femorotibial
angle; 20% of the correction can therefore be attributed to non-osseous,
soft-tissue changes.Aims
Patients and Methods
In arthritis of the varus knee, a high tibial
osteotomy (HTO) redistributes load from the diseased medial compartment
to the unaffected lateral compartment. We report the outcome of 36 patients (33 men and three women)
with 42 varus, arthritic knees who underwent HTO and dynamic correction
using a Garches external fixator until they felt that normal alignment
had been restored. The mean age of the patients was 54.11 years
(34 to 68). Normal alignment was achieved at a mean 5.5 weeks (3
to 10) post-operatively. Radiographs, gait analysis and visual analogue
scores for pain were measured pre- and post-operatively, at one
year and at medium-term follow-up (mean six years; 2 to 10). Failure
was defined as conversion to knee arthroplasty. Pre-operative gait analysis divided the 42 knees into two equal
groups with high (17 patients) or low (19 patients) adductor moments.
After correction, a statistically significant (p <
0.001, At final follow-up, after a mean of 15.9 years (12 to 20), there
was a survivorship of 59% (95% CI 59.6 to 68.9) irrespective of
adductor moment group, with a mean time to conversion to knee arthroplasty
of 9.5 years (3 to 18; 95% confidence interval ± 2.5). HTO remains a useful option in the medium-term for the treatment
of medial compartment osteoarthritis of the knee but does not last
in the long-term. Cite this article:
Because there have been no standard methods to determine pre-operatively
the thickness of resection of the proximal tibia in unicompartmental
knee arthroplasty (UKA), information about the relationship between
the change of limb alignment and the joint line elevation would
be useful for pre-operative planning. The purpose of this study
was to clarify the correlation between the change of limb alignment
and the change of joint line height at the medial compartment after
UKA. A consecutive series of 42 medial UKAs was reviewed retrospectively.
These patients were assessed radiographically both pre- and post-operatively
with standing anteroposterior radiographs. The thickness of bone
resection at the proximal tibia and the distal femur was measured
radiographically. The relationship between the change of femorotibial
angle (δFTA) and the change of joint line height, was analysed.Objectives
Methods
Progressive degenerative changes in the medial
compartment of the knee following lateral unicompartmental arthroplasty
(UKA) remains a leading indication for revision surgery. The purpose
of this study is to evaluate changes in the congruence and joint
space width (JSW) of the medial compartment following lateral UKA.
The congruence of the medial compartment of 53 knees (24 men, 23
women, mean age 13.1 years; Our data suggest that a well conducted lateral UKA may improve
the congruence and normalise the JSW of the medial compartment,
potentially preventing progression of degenerative change. Cite this article:
Radiological assessment of total and unicompartmental
knee replacement remains an essential part of routine care and follow-up.
Appreciation of the various measurements that can be identified
radiologically is important. It is likely that routine plain radiographs
will continue to be used, although there has been a trend towards
using newer technologies such as CT, especially in a failing knee,
where it provides more detailed information, albeit with a higher
radiation exposure. The purpose of this paper is to outline the radiological parameters
used to evaluate knee replacements, describe how these are measured
or classified, and review the current literature to determine their
efficacy where possible.
We systematically reviewed the published literature
on the complications of closing wedge high tibial osteotomy for
the treatment of unicompartmental osteoarthritis of the knee. Publications
were identified using the Cochrane Library, MEDLINE, EMBASE and
CINAHL databases up to February 2012. We assessed randomised (RCTs), controlled
group clinical (CCTs) trials, case series in publications associated
with closing wedge osteotomy of the tibia in patients with osteoarthritis
of the knee and finally a Cochrane review. Many of these trials
included comparative studies (opening wedge
Medium-term survivorship of the Oxford phase
3 unicompartmental knee replacement (UKR) has not yet been established
in an Asian population. We prospectively evaluated the outcome of
400 phase 3 Oxford UKRs in 320 Korean patients with a mean age at
the time of operation of 69 years (48 to 82). The mean follow-up
was 5.2 years (1 to 10). Clinical and radiological assessment was
carried out pre- and post-operatively. At five years, the mean Knee
Society knee and functional scores had increased significantly from
56.2 (30 to 91) pre-operatively to 87.2 (59 to 98) (p = 0.034) and
from 59.2 (30 to 93) to 88.3 (50 to 100) (p = 0.021), respectively.
The Oxford knee score increased from a mean of 25.8 (12 to 39) pre-operatively
to 39.8 (25 to 58) at five years (p = 0.038). The ten-year survival
rate was 94% (95% confidence interval 90.1 to 98.0). A total of
14 UKRs (3.5%) required revision. The most common reason for revision
was dislocation of the bearing in 12 (3%). Conversion to a total
knee replacement was required in two patients who developed osteoarthritis
of the lateral compartment. This is the largest published series of UKR in Korean patients.
It shows that the mid-term results after a minimally invasive Oxford
phase 3 UKR can yield satisfactory clinical and functional results
in this group of patients.
We report the outcome of 32 patients (37 knees) who underwent hemicallostasis with a dynamic external fixator for osteoarthritis of the medial compartment of the knee. There were 16 men (19 knees) and 16 women (18 knees) with a mean age at operation of 54.6 years (27 to 72). The aim was to achieve a valgus overcorrection of 2° to 8° or mechanical axis at 62.5% (± 12.5%). At a mean follow-up of 62.8 months (51 to 81) there was no change in the mean range of movement, and no statistically significant difference in the Insall-Salvati index or tibial slope (p = 0.11 and p = 0.15, respectively). The mean hip-knee-ankle angle changed from 190.6 (183° to 197°) to 176.0° (171° to 181°), with a mean final position of the mechanical axis of 58.5% (35.1% to 71.2%). The desired alignment was attained in 31 of 37 (84%) knees. There were 21 excellent, 13 good, two fair and one poor result according to the Oxford knee score with no correlation between age and final score. This score was at its best at one year with a statistically significant deterioration at two years (p = 0.001) followed by a small but not statistically significant deterioration until the final follow-up (p = 0.17). All the knees with Ahlback grade 1 osteoarthritis had excellent or good results. Complications included pin tract infections involving 16.4% of all pins used, delayed union in two, knee stiffness in four, fracture of the lateral cortex in one and ring sequestrum in one. In conclusion, hemicallostasis provides precision in attaining the desired alignment without interfering with tibial slope or patellar height, and is relatively free of serious complications.
Valgus high tibial osteotomy for osteoarthritis of the medial compartment of the knee can be performed using medial opening- and lateral closing-wedge techniques. The latter have been thought to offer greater initial stability. We measured and compared the stability of opening- and closing-wedge osteotomies fixed by TomoFix plates using radiostereometry in a series of 42 patients in a prospective, randomised clinical trial. There were no differences between the opening- and closing-wedge groups in the time to regain knee function and full weight-bearing. Pain and knee function were significantly improved in both groups without any differences between them. All the osteotomies united within one year. Radiostereometry showed no clinically relevant movement of bone or differences between either group. Medial opening-wedge high tibial osteotomy secured by a TomoFix plate offers equal stability to a lateral closing-wedge technique. Both give excellent initial stability and provide significantly improved knee function and reduction in pain, although the opening-wedge technique was more likely to produce the intended correction.
Varus malalignment after total knee replacement is associated with a poor outcome. Our aim was to determine whether the same was true for medial unicompartmental knee replacement (UKR). The anatomical leg alignment was measured prospectively using a long-arm goniometer in 160 knees with an Oxford UKR. Patients were then grouped according to their mechanical leg alignment as neutral (5° to 10° of valgus), mild varus (0° to 4° of valgus) and marked varus (>
0° of varus). The groups were compared at five years in terms of absolute and change in the Oxford Knee score, American Knee Society score and the incidence of radiolucent lines. Post-operatively, 29 (18%) patients had mild varus and 13 (8%) had marked varus. The mean American Knee Society score worsened significantly (p <
0.001) with increasing varus. This difference disappeared if a three-point deduction for each degree of malalignment was removed. No other score deteriorated with increasing varus, and the frequency of occurrence of radiolucent lines was the same in each group. We therefore conclude that after Oxford UKR, about 25% of patients have varus alignment, but that this does not compromise their clinical or radiological outcome. Following UKR the deductions for malalignment in the American Knee Society score are not justified.
There have been several reports of good survivorship and excellent function at ten years with fixed-bearing unicompartmental knee replacement. However, little is known about survival beyond ten years. From the Bristol database of over 4000 knee replacements, we identified 203 St Georg Sled unicompartmental knee replacements (174 patients) which had already survived ten years. The mean age of the patients at surgery was 67.1 years (35.7 to 85) with 67 (38.5%) being under 65 years at the time of surgery. They were reviewed at a mean of 14.8 years (10 to 29.4) from surgery to determine survivorship and function. There were 99 knees followed up for 15 years, 21 for 20 years and four for 25 years. The remainder failed, were withdrawn, or the patient had died. In 58 patients (69 knees) the implant was The mean Bristol knee score of the surviving knees fell from 86 (34 to 100) to 79 (42 to 100) during the second decade. Survivorship to 20 years was 85.9% (95% CI 82.9% to 88.9%) and at 25 years was 80% (95% CI 70.2% to 89.8%). Satisfactory survival of a fixed-bearing unicompartmental knee replacement can be achieved into the second decade and beyond.
Twenty patients underwent simultaneous bilateral medial unicompartmental knee arthroplasty. Pre-operative hip-knee-ankle alignment and valgus stress radiographs were used to plan the desired post-operative alignment of the limb in accordance with established principles for unicompartmental arthroplasty. In each patient the planned alignment was the same for both knees. Overall, the mean planned post-operative alignment was to 2.3° of varus (0° to 5°). The side and starting order of surgery were randomised, using conventional instrumentation for one knee and computer-assisted surgery for the opposite side. The mean variation between the pre-operative plan and the achieved correction in the navigated and the non-navigated limb was 0.9° ( Assessment of lower limb alignment in the non-navigated group revealed that 12 (60%) were within ± 2° of the pre-operative plan, compared to 17 (87%) of the navigated cases. Computer-assisted surgery significantly improves the post-operative alignment of medial unicompartmental knee arthroplasty compared to conventional techniques in patients undergoing bilateral simultaneous arthroplasty. Improved alignment after arthroplasty is associated with better function and increased longevity.
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