The aim of this study was to examine the results of revision
total knee arthroplasty (TKA) undertaken for stiffness in the absence
of sepsis or loosening. We present the results of revision surgery for stiff TKA in 48
cases (35 (72.9%) women and 13 (27.1%) men). The mean age at revision
surgery was 65.5 years (42 to 83). All surgeries were performed
by a single surgeon. Stiffness was defined as an arc of flexion
of <
70° or a flexion contracture of >
15°. The changes in the
range of movement (ROM) and the Western Ontario and McMasters Osteoarthritis
index scores (WOMAC) were recorded.Aims
Patients and 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.
The purpose of this study was to compare clinical
outcomes of total knee arthroplasty (TKA) after manipulation under
anaesthesia (MUA) for post-operative stiffness with a matched cohort
of TKA patients who did not requre MUA. In total 72 patients (mean age 59.8 years, 42 to 83) who underwent
MUA following TKA were identified from our prospective database
and compared with a matched cohort of patients who had undergone
TKA without subsequent MUA. Patients were evaluated for range of
movement (ROM) and clinical outcome scores (Western Ontario and
McMaster Universities Arthritis Index, Short-Form Health Survey,
and Knee Society Clinical Rating System) at a mean follow-up of
36.4 months (12 to 120). MUA took place at a mean of nine weeks
(5 to 18) after TKA. In patients who required MUA, mean flexion
deformity improved from 10° (0° to 25°) to 4.4° (0° to 15°) (p <
0.001),
and mean range of flexion improved from 79.8° (65° to 95°) to 116°
(80° to 130°) (p <
0.001). There were no statistically significant
differences in ROM or functional outcome scores at three months,
one year, or two years between those who required MUA and those
who did not. There were no complications associated with manipulation At most recent follow-up, patients requiring MUA achieved equivalent
ROM and clinical outcome scores when compared with a matched control
group. While other studies have focused on ROM after manipulation,
the current study adds to current literature by supplementing this
with functional outcome scores. Cite this article:
The August 2015 Research Roundup360 looks at: Lightbulbs, bleeding and procedure durations; Infection and rheumatoid agents; Infection rates and ‘bundles of care’ revisited; ACI: new application for a proven technology?; Hydrogel coating given the thumbs up; Hydroxyapatite as a smart coating?
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.
We carried out a prospective study to assess the clinical outcome, complications and survival of the NexGen Legacy posterior-stabilised-Flex total knee replacement (TKR) in a consecutive series of 278 knees between May 2003 and February 2005. Mean follow-up for 259 TKRs (98.2%) was 3.8 years (3.0 to 4.8). Annual follow-up showed improvement in the Knee Society scores (paired This relatively large study indicates that the legacy posterior stabilised-Flex design provides excellent short-term outcome but warrants ongoing evaluation to confirm the long-term durability and functioning of the implant.
Component malalignment can be associated with
pain following total knee replacement (TKR). Using MRI, we reviewed
50 patients with painful TKRs and compared them with a group of
16 asymptomatic controls to determine the feasibility of using MRI
in evaluating the rotational alignment of the components. Using
the additional soft-tissue detail provided by this modality, we
also evaluated the extent of synovitis within these two groups.
Angular measurements were based on the femoral transepicondylar
axis and tibial tubercle. Between two observers, there was very
high interobserver agreement in the measurements of all values.
Patients with painful TKRs demonstrated statistically significant
relative internal rotation of the femoral component (p = 0.030).
There was relative internal rotation of the tibial to femoral component
and combined excessive internal rotation of the components in symptomatic
knees, although these results were significant only with one of
the observers (p = 0.031). There was a statistically significant
association between the presence and severity of synovitis and painful
TKR (p <
0.001). MRI is an effective modality in evaluating component rotational
alignment.
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 use of autograft bone is the best option
when undertaking a procedure that requires bone graft because it
is osteogenic, osteoconductive and osseo-inductive. Pain, morbidity
and complications associated with harvesting iliac or non-iliac
sites occur in between 6% and 30% of cases. An alternative source
of graft with possibly a lower morbidity is the intramedullary canal.
In this study, 28 patients undergoing 30 arthrodesis procedures
on the hindfoot had a mean of 48 cm3 (43 to 50) of bone
harvested locally from the hindfoot or the tibial shaft by antegrade or
retrograde reaming. No patient sustained a fracture of the calcaneum,
talus or tibia. There was no morbidity except for one complication
when the reamer breached the medial tibial cortex. This healed uneventfully. This method of using the reamer–irrigator–aspirator system is
an extension of the standard technique of intramedullary reaming
of the lower limb: it produces good-quality bone graft with viable
growth factors consistent with that of the iliac crest, and donor
site morbidity is low. This is an efficient method of obtaining
autologous bone for use in arthrodesis of the ankle or hindfoot.
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.
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:
We analysed at a mean follow-up of 7.25 years the clinical and radiological outcome of 117 patients (125 knees) who had undergone a primary, cemented, modular Freeman-Samuelson total knee replacement. While the tibial and femoral components were cemented, the patellar component was uncemented. A surface-cementing technique was used to secure the tibial components. A total of 82 knees was available for radiological assessment. Radiolucent lines were seen in 41 knees (50%) and osteolytic lesions were seen in 13 knees (16%). Asymptomatic, rotational loosening of the patellar implant was seen in four patients and osteolysis was more common in patients with a patellar resurfacing. Functional outcome scores were available for 41 patients (41 knees, 35%) and the mean Western Ontario McMasters Universities score was 77.5 (
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:
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:
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.
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.
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:
We report the long-term survival of a prospective randomised consecutive series of 501 primary knee replacements using the press-fit condylar posterior cruciate ligament-retaining prosthesis. Patients received either cemented (219 patients, 277 implants) or cementless (177 patients, 224 implants) fixation. Altogether, 44 of 501 knees (8.8%) underwent revision surgery (24 cemented This single-surgeon series, with no loss to follow-up, provides reliable data of the revision rates of one of the most commonly-used total knee replacements. The survival of the press-fit condylar total knee replacement remained good at 15 years, irrespective of the method of fixation.