This prospective study compares the outcome of
157 hydroxyapatite (HA)-coated tibial components with 164 cemented
components in the ROCC Rotating Platform total knee replacement
in 291 patients. The mean follow-up was 7.6 years (5.2 to 11). There
were two revisions for loosening: one for an HA-coated and one for
a cemented tibial component. Radiological evaluation demonstrated
no radiolucent lines with the HA-coated femoral components. A total
of three HA-coated tibial components exhibited radiolucent lines
at three months post-operatively and these disappeared after three
further months of protected weight-bearing. With HA-coated components
the operating time was shorter (p <
0.006) and the radiological
assessment of the tibial interface was more stable (p <
0.01).
Using revision for aseptic loosening of the tibial component as
the end point, the survival rates at nine years was identical for
both groups at 99.1%. Our results suggest that HA-coated components perform at least
as well as the same design with cemented components and compare
favourably with those of series describing cemented or porous-coated
knee replacements, suggesting that fixation of both components with
hydroxyapatite is a reliable option in primary total knee replacement.
Graft-tunnel mismatch of the bone-patellar tendon-bone
(BPTB) graft is a major concern during anatomical anterior cruciate
ligament (ACL) reconstruction if the femoral tunnel is positioned
using a far medial portal technique, as the femoral tunnel tends
to be shorter compared with that positioned using a transtibial
portal technique. This study describes an accurate method of calculating
the ideal length of bone plugs of a BPTB graft required to avoid
graft–tunnel mismatch during anatomical ACL reconstruction using
a far medial portal technique of femoral tunnel positioning. Based on data obtained intra-operatively from 60 anatomical ACL
reconstruction procedures, we calculated the length of bone plugs
required in the BPTB graft to avoid graft–tunnel mismatch. When
this was prevented in all the 60 cases, we found that the mean length
of femoral bone plug that remained in contact with the interference
screw within the femoral tunnel was 14 mm (12 to 22) and the mean
length of tibial bone plug that remained in contact with the interference
screw within the tibial tunnel was 23 mm (18 to 28). These results
were used to validate theoretical formulae developed to predict
the required length of bone plugs in BPTB graft during anatomical
ACL reconstruction using a far medial portal technique. Cite this article:
The purpose of this study was to investigate whether the femoral
head–neck contour, characterised by the alpha angle, varies with
the stage of physeal maturation using MRI evaluation of an asymptomatic
paediatric population. Paediatric volunteers with asymptomatic hips were recruited to
undergo MRI of both hips. Femoral head physes were graded from 1
(completely open) to 6 (completely fused). The femoral head–neck
contour was evaluated using the alpha angle, measured at the 3:00
(anterior) and 1:30 (anterosuperior) positions and correlated with
physeal grade, with gender sub-analysis performed.Objectives
Methods
We previously compared the component alignment in total knee replacement using a computer-navigated technique with a conventional jig-based method. We randomly allocated 71 patients to undergo either computer-navigated or conventional replacement. An improved alignment was seen in the computer-navigated group. The patients were then followed up post-operatively for two years, using the Knee Society score, the Short Form-36 health survey, the Western Ontario and McMaster Universities osteoarthritis index, the Bartlett Patellar pain questionnaire and the Oxford knee score, to assess functional outcome. At two years post-operatively 60 patients were available for assessment, 30 in each group and 62 patients completed a postal survey. No patient in either group had undergone revision. All variables were analysed for differences between the groups either by Student’s The clinical outcome of the patients with a computer-navigated knee replacement appears to be no different to that of a more conventional jig-based technique at two years post-operatively, despite the better alignment achieved with computer-navigated surgery.
Whether to use total or unicompartmental knee
replacement (TKA/UKA) for end-stage knee osteoarthritis remains controversial.
Although UKA results in a faster recovery, lower rates of morbidity
and mortality and fewer complications, the long-term revision rate
is substantially higher than that for TKA. The effect of each intervention on
patient-reported outcome remains unclear. The aim of this study
was to determine whether six-month patient-reported outcome measures
(PROMs) are better in patients after TKA or UKA, using data from
a large national joint registry (NJR). We carried out a propensity score-matched cohort study which
compared six-month PROMs after TKA and UKA in patients enrolled
in the NJR for England and Wales, and the English national PROM
collection programme. A total of 3519 UKA patients were matched
to 10 557 TKAs. The mean six-month PROMs favoured UKA: the Oxford Knee Score
was 37.7 (95% confidence interval (CI) 37.4 to 38.0) for UKA and
36.1 (95% CI 35.9 to 36.3) for TKA; the mean EuroQol EQ-5D index
was 0.772 (95% CI 0.764 to 0.780) for UKA and 0.751 (95% CI 0.747
to 0.756) for TKA. UKA patients were more likely to achieve excellent
results (odds ratio (OR) 1.59, 95% CI 1.47 to 1.72, p <
0.001)
and to be highly satisfied (OR 1.27, 95% CI 1.17 to 1.39, p <
0.001), and
were less likely to report complications than those who had undergone
TKA. UKA gives better early patient-reported outcomes than TKA; these
differences are most marked for the very best outcomes. Complications
and readmission are more likely after TKA. Although the data presented
reflect the short-term outcome, they suggest that the high revision
rate for UKA may not be because of poorer clinical outcomes. These
factors should inform decision-making in patients eligible for either
procedure. Cite this article:
In 11 paediatric patients (seven girls and four
boys, from 12 to 15 years old) with unilateral obligatory patellar dislocation
and ligamentous laxity vastus medialis advancement, lateral release,
partial patellar ligament transposition and Galeazzi semitendinosus
tenodesis was undertaken to stabilise the patella. The diagnostic criterion
for ligamentous laxity was based on the Beighton scale. Outcomes
were evaluated radiologically and functionally by measurement of
the range of knee movement and isokinetic testing. The evaluation
also included the Lysholm knee scale. Follow-up studies took place
at a mean of 8.1 years (5 to 15) post-operatively. Normal patellar tracking without any recurrence of dislocation
was obtained in ten out of 11 patients. Pain related to vigorous
activity was reported by nine patients. Compared with the opposite
normal side, the isokinetic tests revealed a statistically significant
decrease in the maximal torque values for the affected quadriceps
muscle (p = 0.003 and p = 0.004), but no difference between the
knee flexors (for angular velocities of 60°/s and 180°/s) (p = 0.858
and p = 0.79). The applied surgical technique generally prevents the recurrence
of the disorder in children with habitual patellar dislocation and
ligamentous laxity. Quadriceps muscle weakness can be expected to
occur post-operatively, Cite this article:
Instability in flexion after total knee replacement
(TKR) typically occurs as a result of mismatched flexion and extension
gaps. The goals of this study were to identify factors leading to
instability in flexion, the degree of correction, determined radiologically,
required at revision surgery, and the subsequent clinical outcomes.
Between 2000 and 2010, 60 TKRs in 60 patients underwent revision
for instability in flexion associated with well-fixed components.
There were 33 women (55%) and 27 men (45%); their mean age was 65
years (43 to 82). Radiological measurements and the Knee Society
score (KSS) were used to assess outcome after revision surgery.
The mean follow-up was 3.6 years (2 to 9.8). Decreased condylar
offset (p <
0.001), distalisation of the joint line (p <
0.001)
and increased posterior tibial slope (p <
0.001) contributed
to instability in flexion and required correction at revision to regain
stability. The combined mean correction of posterior condylar offset
and joint line resection was 9.5 mm, and a mean of 5° of posterior
tibial slope was removed. At the most recent follow-up, there was
a significant improvement in the mean KSS for the knee and function
(both p <
0.001), no patient reported instability and no patient
underwent further surgery for instability. The following step-wise approach is recommended: reduction of
tibial slope, correction of malalignment, and improvement of condylar
offset. Additional joint line elevation is needed if the above steps
do not equalise the flexion and extension gaps. Cite this article:
The role of arthroscopy in the treatment of soft-tissue
injuries associated with proximal tibial fractures remains debatable.
Our hypothesis was that MRI over-diagnoses clinically relevant associated
soft-tissue injuries. This prospective study involved 50 consecutive
patients who underwent surgical treatment for a split-depression fracture
of the lateral tibial condyle (AO/OTA type B3.1). The mean age of
patients was 50 years (23 to 86) and 27 (54%) were female. All patients
had MRI and arthroscopy. Arthroscopy identified 12 tears of the
lateral meniscus, including eight bucket-handle tears that were
sutured and four that were resected, as well as six tears of the
medial meniscus, of which five were resected. Lateral meniscal injuries
were diagnosed on MRI in four of 12 patients, yielding an overall
sensitivity of 33% (95% confidence interval (CI) 11 to 65). Specificity
was 76% (95% CI 59 to 88), with nine tears diagnosed among 38 menisci
that did not contain a tear. MRI identified medial meniscal injuries
in four of six patients, yielding an overall sensitivity of 67%
(95% CI 24 to 94). Specificity was 66% (95% CI 50 to 79), with 15
tears diagnosed in 44 menisci that did not contain tears. MRI appears to offer only a marginal benefit as the specificity
and sensitivity for diagnosing meniscal injuries are poor in patients
with a fracture. There were fewer arthroscopically-confirmed associated
lesions than reported previously in MRI studies. Cite this article:
Instability is the reason for revision of a primary
total knee replacement (TKR) in 20% of patients. To date, the diagnosis
of instability has been based on the patient’s symptoms and a subjective
clinical assessment. We assessed whether a measured standardised
forced leg extension could be used to quantify instability. A total of 25 patients (11 male/14 female, mean age 70 years;
49 to 85) who were to undergo a revision TKR for instability of
a primary implant were assessed with a Nottingham rig pre-operatively
and then at six and 26 weeks post-operatively. Output was quantified
(in revolutions per minute (rpm)) by accelerating a stationary flywheel.
A control group of 183 patients (71 male/112 female, mean age 69
years) who had undergone primary TKR were evaluated for comparison. Pre-operatively, all 25 patients with instability exhibited a
distinctive pattern of reduction in ‘mid-push’ speed. The mean reduction
was 55 rpm ( Cite this article:
The biomechanics of the patellofemoral joint can become disturbed during total knee replacement by alterations induced by the position and shape of the different prosthetic components. The role of the patella and femoral trochlea has been well studied. We have examined the effect of anterior or posterior positioning of the tibial component on the mechanisms of patellofemoral contact in total knee replacement. The hypothesis was that placing the tibial component more posteriorly would reduce patellofemoral contact stress while providing a more efficient lever arm during extension of the knee. We studied five different positions of the tibial component using a six degrees of freedom dynamic knee simulator system based on the Oxford rig, while simulating an active knee squat under physiological loading conditions. The patellofemoral contact force decreased at a mean of 2.2% for every millimetre of posterior translation of the tibial component. Anterior positions of the tibial component were associated with elevation of the patellofemoral joint pressure, which was particularly marked in flexion >
90°. From our results we believe that more posterior positioning of the tibial component in total knee replacement would be beneficial to the patellofemoral joint.
There are many reasons why a total knee replacement
(TKR) may fail and qualify for revision. Successful revision surgery
depends as much on accurate assessment of the problem TKR as it
does on revision implant design and surgical technique. Specific
modes of failure require specific surgical solutions. Causes of
failure are often presented as a list or catalogue, without a system
or process for making a decision. In addition, strict definitions
and consensus on modes of failure are lacking in published series
and registry data. How we approach the problem TKR is an essential
but neglected aspect of understanding knee replacement surgery.
It must be carried out systematically, comprehensively and efficiently.
Eight modes of failure are described: 1) sepsis; 2) extensor discontinuity;
3) stiffness; 4) tibial- femoral instability; 5) patellar tracking;
6) aseptic loosening and osteolysis; 7) periprosthetic fracture
and 8) component breakage. A ninth ‘category’, unexplained pain
is an indication for further investigation but not surgery. Cite this article:
Seven stiff total knee arthroplasties are presented
to illustrate the roles of: 1) manipulation under general anesthesia;
2) multiple concurrent diagnoses in addition to stiffness; 3) extra-articular
pathology; 4) pain as part of the stiffness triad (pain and limits
to flexion or extension); 5) component internal rotation; 6) multifactorial
etiology; and 7) surgical exposure in this challenging clinical
problem.
The June 2014 Knee Roundup360 looks at: acute repair preferable in hamstring ruptures; osteoarthritis a given in ACL injury, even with reconstruction?; chicken and egg: patellofemoral dysfunction and hip weakness; meniscal root tears as bad as we thought; outcomes in the meniscus; topical NSAIDs have a measurable effect on synovitis; nailing for tibial peri-prosthetic fracture.
We have reviewed 22 patients at a mean of 30 years (28 to 31) after a whiplash injury. A complete recovery had been made in ten (45.5%) while one continued to describe severe symptoms. Persistent disability was associated with psychological distress but both improved in the period between 15 and 30 years after injury. After 30 years, ten patients (45.5%) were more disabled by knee than by neck pain.
In this systematic review, our aim was to explore
whether or not patients are able to return to athletic activity
following lower limb joint replacement. We also investigated any evidence
as to whether participation in athletic activity post-joint replacement
increases complications and reduces implant survival. A PubMed, Embase and Sports Discus search was performed using
the MeSH terms ‘Sport’, ‘Athletic’, ‘Athlete’, ‘Physical’, ‘Activity’,
‘Arthroplasty’, ‘Total Hip Replacement’, ‘Hip Resurfacing’, ‘Total
Knee Replacement’, ‘Unicompartmental Knee Replacement’ and ‘Unicondylar
Knee Replacement’. From this search, duplications were excluded,
the remaining abstracts were reviewed and any unrelated to the search
terms were excluded. The remaining abstracts had their full papers
reviewed. Following joint replacement, participation in sporting activity
is common principally determined by pre-operative patient activity
levels, BMI and patient age. The type of joint replaced is of less
significance. Total time spent performing activity does not change
but tends to be at a lower intensity. There is little evidence in
the literature of an association between high activity levels and
early implant failure. Cite this article:
The October 2014 Trauma Roundup360 looks at: proximal humeral fractures in children; quadrilateral surface plates in transverse acetabular fractures; sleep deprivation and poor outcomes in trauma; bipolar hemiarthroplasty; skeletal traction; forefoot fractures; telemedicine in trauma; ketamine infusion for orthopaedic injuries; and improved functional outcomes seen with trauma networks.
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.
Isolated patellofemoral osteoarthritis can be a disabling disease. When conservative treatment fails, surgical options can be unpredictable and may be considered too aggressive for middle-aged and active people. We analysed the clinical and radiological results of a new coronal osteotomy involving thinning of the patella in a selected group of patients with isolated patellofemoral osteoarthritis. Since 1991, 31 patients (35 knees) have been treated, of whom 34 were available for follow-up at a mean of 9.1 years. The Knee Society Score, the Patellar score and the Short-form-36 questionnaire were used for clinical evaluation. We also examined the radiological features to confirm bone consolidation and assess the progression of osteoarthritis. A significant improvement in the functional scores and radiological parameters was noted. All patients except one were satisfied with the operation. Radiological progression of the patellofemoral osteoarthritis was slowed but radiological femorotibial osteoarthritis progressed in 23 (65%) cases, with a total knee replacement becoming necessary in four cases without technical problems in resurfacing the patella. We compared the results with other forms of surgical treatment reported in the literature. This treatment offers good clinical and radiological results, presenting an alternative method of managing patellofemoral osteoarthritis.
The first Cochrane Corner of 2014 reports on a bumper number of new and updated reviews from the Cochrane Collaboration. Since November the Cochrane collaboration have turned their beady eye to scrutinise several topical (and sometimes controversial) orthopaedic issues such as pin site care, the use of Continuous Passive Motion (CPM) in the rehabilitation of total knee replacement (TKR) and the efficacy of nerve blocks.