Throughout the 20th Century, it has been postulated that the knee moves on the basis of a four-bar link mechanism composed of the cruciate ligaments, the femur and the tibia. As a consequence, the femur has been thought to roll back with flexion, and total knee arthroplasty (TKA) prostheses have been designed on this basis. Recent work, however, has proposed that at a position of between 0° and 120° the medial femoral condyle does not move anteroposteriorly whereas the lateral femoral condyle tends, but is not obliged, to roll back – a combination of movements which equates to tibial internal/ femoral external rotation with flexion. The aim of this paper was to assess if the articular geometry of the GMK Sphere TKA could recreate the natural knee movements The pattern of knee movement was studied in 15 patients (six male: nine female; one male with bilateral TKAs) with 16 GMK Sphere implants, at a mean age of 66 years (53 to 76) with a mean BMI of 30 kg/m2 (20 to 35). The motions of all 16 knees were observed using pulsed fluoroscopy during a number of weight-bearing and non-weight-bearing static and dynamic activities.Objectives
Methods
We undertook a retrospective cohort study to
determine clinical outcomes following the revision of metal-on-metal (MoM)
hip replacements for adverse reaction to metal debris (ARMD), and
to identify predictors of time to revision and outcomes following
revision. Between 1998 and 2012 a total of 64 MoM hips (mean age
at revision of 57.8 years; 46 (72%) female; 46 (72%) hip resurfacings
and 18 (28%) total hip replacements) were revised for ARMD at one specialist
centre. At a mean follow-up of 4.5 years (1.0 to 14.6) from revision
for ARMD there were 13 hips (20.3%) with post-operative complications
and eight (12.5%) requiring re-revision. The Kaplan–Meier five-year survival rate for ARMD revision was
87.9% (95% confidence interval 78.9 to 98.0; 19 hips at risk). Excluding
re-revisions, the median absolute Oxford hip score (OHS) following
ARMD revision using the percentage method (0% best outcome and 100%
worst outcome) was 18.8% (interquartile range (IQR) 7.8% to 48.3%),
which is equivalent to 39/48 (IQR 24.8/48 to 44.3/48) when using
the modified OHS. Histopathological response did not affect time
to revision for ARMD (p = 0.334) or the subsequent risk of re-revision
(p = 0.879). Similarly, the presence or absence of a contralateral
MoM hip bearing did not affect time to revision for ARMD (p = 0.066)
or the subsequent risk of re-revision (p = 0.178). Patients revised to MoM bearings had higher rates of re-revision
(five of 16 MoM hips re-revised; p = 0.046), but those not requiring
re-revision had good functional results (median absolute OHS 14.6%
or 41.0/48). Short-term morbidity following revision for ARMD was
comparable with previous reports. Caution should be exercised when choosing
bearing surfaces for ARMD revisions. Cite this article:
The December 2014 Knee Roundup360 looks at: national guidance on arthroplasty thromboprophylaxis is effective; unicompartmental knee replacement has the edge in terms of short-term complications; stiff knees, timing and manipulation; neuropathic pain and total knee replacement; synovial fluid α-defensin and CRP: a new gold standard in joint infection diagnosis?; how to assess anterior knee pain?; where is the evidence? Five new implants under the spotlight; and a fresh look at ACL reconstruction
We present an economic evaluation using data
from the Distal Radius Acute Fracture Fixation Trial (DRAFFT) to compare
the relative cost effectiveness of percutaneous Kirschner wire (K-wire)
fixation and volar locking-plate fixation for patients with dorsally-displaced
fractures of the distal radius. The cost effectiveness analysis (cost per quality-adjusted life
year; QALY) was derived from a multi-centre, two-arm, parallel group,
assessor-blind, randomised controlled trial which took place in
18 trauma centres in the United Kingdom. Data from 460 patients
were available for analysis, which includes both a National Health
Service cost perspective including costs of surgery, implants and
healthcare resource use over a 12-month period after surgery, and
a societal perspective, which includes the cost of time off work
and the need for additional private care. There was only a small difference in QALYs gained for patients
treated with locking-plate fixation over those treated with K-wires.
At a mean additional cost of £714 (95% confidence interval 588 to
865) per patient, locking-plate fixation presented an incremental
cost effectiveness ratio (ICER) of £89 322 per QALY within the first
12 months of treatment. Sensitivity analyses were undertaken to
assess the ICER of locking-plate fixation compared with K-wires.
These were greater than £30 000. Compared with locking-plate fixation, K-wire fixation is a ‘cost
saving’ intervention, with similar health benefits. Cite this article:
Our aim was to compare the one-year post-operative
outcomes following retention or removal of syndesmotic screws in
adult patients with a fracture of the ankle that was treated surgically.
A total of 51 patients (35 males, 16 females), with a mean age of
33.5 years (16 to 62), undergoing fibular osteosynthesis and syndesmotic
screw fixation, were randomly allocated to retention of the syndesmotic
screw or removal at three months post-operatively. The two groups
were comparable at baseline. One year post-operatively, there was no significant difference
in the mean Olerud–Molander ankle score (82.4 retention We conclude that removal of a syndesmotic screw produces no significant
functional, clinical or radiological benefit in adult patients who
are treated surgically for a fracture of the ankle. Cite this article:
Periprosthetic joint infection (PJI) complicates
between 0.5% and 1.2% primary total hip arthroplasties (THAs) and
may have devastating consequences. The traditional assessment of
patients suffering from PJI has involved the serological study of
inflammatory markers and microbiological analysis of samples obtained
from the joint space. Treatment has involved debridement and revision
arthroplasty performed in either one or two stages. We present an update on the burden of PJI, strategies for its
diagnosis and treatment, the challenge of resistant organisms and
the need for definitive evidence to guide the treatment of PJI after
THA. Cite this article:
The June 2015 Knee Roundup360 looks at: Cruciate substituting
Single-event multilevel surgery (SEMLS) has been used as an effective
intervention in children with bilateral spastic cerebral palsy (BSCP)
for 30 years. To date there is no evidence for SEMLS in adults with
BSCP and the intervention remains focus of debate. This study analysed the short-term outcome (mean 1.7 years, standard
deviation 0.9) of 97 ambulatory adults with BSCP who performed three-dimensional
gait analysis before and after SEMLS at one institution. Aims
Methods
Cemented femoral stems with force closed fixation
designs have shown good clinical results despite high early subsidence.
A new triple-tapered stem in this category (C-stem AMT) was introduced
in 2005. This study compares this new stem with an established stem
of similar design (Exeter) in terms of migration (as measured using radiostereometric
analysis), peri-prosthetic bone remodelling (measured using dual
energy x-ray densitometry, DXA), Oxford Hip Score, and plain radiographs. A total of 70 patients (70 hips) with a mean age of 66 years
(53 to 78) were followed for two years. Owing to missing data of
miscellaneous reasons, the final analysis represents data from 51
(RSA) and 65 (DXA) patients. Both stems showed a typical pattern
of migration: Subsidence and retroversion that primarily occurred
during the first three months. C-stem AMT subsided less during the
first three months (p = 0.01), before stabilising at a subsidence rate
similar to the Exeter stem from years one to two. The rate of migration
into retroversion was slightly higher for C-stem AMT during the
second year (p = 0.03). Whilst there were slight differences in
movement patterns between the stems, the C-stem AMT exhibits good
early clinical outcomes and displays a pattern of migration and
bone remodelling that predicts good clinical performance. Cite this article:
The October 2014 Oncology Roundup360 looks at: how best to reconstruct humeral tumours; not everything is better via the arthroscope; obesity and sarcoma; frozen autograft;
The October 2014 Knee Roundup360 looks at: microfracture equivalent to OATS; examination better than MRI in predicting hamstrings re-injury; a second view on return to play with hamstrings injuries; dislocation risks in the Oxford Unicompartmental Knee; what about the tibia?; getting on top of lateral facet pain post TKR; readmission in TKR; patient-specific instrumentation; treating infrapatellar saphenous neuralgia; and arthroscopy in the middle-aged.
Although the vast majority of patients that undergo
total knee replacement have satisfactory outcomes with a generally
low complication rate, occasionally a patient will be encountered
that has had multiple failed surgeries, and now reaches a crossroad
as to whether limb salvage will be acceptable or not. Cite this article:
The December 2015 Wrist &
Hand Roundup
Total knee arthroplasty (TKA) is an established
and successful procedure. However, the design of prostheses continues
to be modified in an attempt to optimise the functional outcome
of the patient. The aim of this study was to determine if patient outcome after
TKA was influenced by the design of the prosthesis used. A total of 212 patients (mean age 69; 43 to 92; 131 female (62%),
81 male (32%)) were enrolled in a single centre double-blind trial
and randomised to receive either a Kinemax (group 1) or a Triathlon
(group 2) TKA. Patients were assessed pre-operatively, at six weeks, six months,
one year and three years after surgery. The outcome assessments
used were the Oxford Knee Score; range of movement; pain numerical
rating scales; lower limb power output; timed functional assessment
battery and a satisfaction survey. Data were assessed incorporating
change over all assessment time points, using repeated measures
analysis of variance longitudinal mixed models. Implant group 2
showed a significantly greater range of movement (p = 0.009), greater
lower limb power output (p = 0.026) and reduced report of ‘worst
daily pain’ (p = 0.003) over the three years of follow-up. Differences
in Oxford Knee Score (p = 0.09), report of ‘average daily pain’
(p = 0.57) and timed functional performance tasks (p = 0.23) did
not reach statistical significance. Satisfaction with outcome was
significantly better in group 2 (p = 0.001). These results suggest that patient outcome after TKA can be influenced
by the prosthesis used. Cite this article:
The aims of this study were to report functional
outcomes of salvage procedures for patients with cerebral palsy (CP)
who have chronic dislocation of the hip using validated scoring
systems, and to compare the results of three surgical techniques. We reviewed 37 patients retrospectively. The mean age at the
time of surgery was 12.2 years (8 to 22) and the mean follow-up
was 56 months (24 to 114). Patients were divided into three groups:
14 who underwent proximal femoral resection arthroplasty (PFRA group
1), ten who underwent subtrochanteric valgus osteotomy (SVO group 2),
and 13 who underwent subtrochanteric valgus osteotomy with resection
of the femoral head (SVO with FHR group 3). All patients were evaluated
using the Caregiver Priorities and Child Health Index of Life with
Disabilities (CPCHILD) and the Pediatric Quality of Life Inventory
(PedsQL). Significant improvements occurred in most CPCHILD and PedsQL
subsection scores following surgery in all patients, without significant
differences between the groups. There were 12 post-operative complications.
Less severe complications were seen in group 1 than in groups 2
and 3. Salvage surgery appears to provide pain relief in patients with
CP who have painful chronic dislocation of the hip. The three salvage
procedures produced similar results, however, we recommend the use
of PFRA as the complications are less severe. Take home message: Salvage surgery can be of benefit to patients
with CP with chronic painful hip dislocation, but should be limited
to selected patients considering complications. Cite this article:
Metal-on-metal resurfacing of the hip (MoMHR)
has enjoyed a resurgence in the last decade, but is now again in question
as a routine option for osteoarthritis of the hip. Proponents of
hip resurfacing suggest that its survival is superior to that of
conventional hip replacement (THR), and that hip resurfacing is
less invasive, is easier to revise than THR, and provides superior
functional outcomes. Our argument serves to illustrate that none
of these proposed advantages have been realised and new and unanticipated
serious complications, such as pseudotumors, have been associated
with the procedure. As such, we feel that the routine use of MoMHR
is not justified. Cite this article:
A small proportion of children with Gartland
type III supracondylar humeral fracture (SCHF) experience troubling limited
or delayed recovery after operative treatment. We hypothesised that
the fracture level relative to the isthmus of the humerus would
affect the outcome. We retrospectively reviewed 230 children who underwent closed
reduction and percutaneous pinning (CRPP) for their Gartland type
III SCHFs between March 2003 and December 2012. There were 144 boys
and 86 girls, with the mean age of six years (1.1 to 15.2). The
clinico-radiological characteristics and surgical outcomes (recovery
of the elbow range of movement, post-operative angulation, and the
final Flynn grade) were recorded. Multivariate analysis was employed
to identify prognostic factors that influenced outcome, including
fracture level. Multivariate analysis revealed that a fracture below
the humeral isthmus was significantly associated with poor prognosis
in terms of the range of elbow movement (p <
0.001), angulation
(p = 0.001) and Flynn grade (p = 0.003). Age over ten years was also
a poor prognostic factor for recovery of the range of elbow movement (p
= 0.027). This is the first study demonstrating a subclassification system
of Gartland III fractures with prognostic significance. This will
guide surgeons in peri-operative planning and counselling as well
as directing future research aimed at improving outcomes. Cite this article:
Excision of the proximal femur for tumour with
prosthetic reconstruction using a bipolar femoral head places a considerable
load on the unreplaced acetabulum. We retrospectively reviewed the changes which occur around the
affected hip joint by evaluating the post-operative radiographs
of 65 consecutive patients who underwent proximal prosthetic arthroplasty
of the femur, and in whom an acetabular component had not been used.
There were 37 men and 28 women with a mean age of 57.3 years (17
to 93). Radiological assessment included the extent of degenerative
change in the acetabulum, heterotopic ossification, and protrusio
acetabuli. The mean follow-up was 9.1 years (2 to 11.8). Degenerative changes
in the acetabulum were seen in three patients (4.6%), Brooker grade
1 or 2 heterotopic ossification in 17 (26%) and protrusion of the
prosthetic head in nine (13.8%). A total of eight patients (12.3%) needed a revision. Five were
revised to the same type of prosthesis and three (4.6%) were converted
to a total hip arthroplasty. We conclude that radiological evidence of degenerative change,
heterotopic ossification and protrusion occur in a few patients
who undergo prosthetic arthroplasty of the proximal femur for tumour.
The limited extent of these changes and the lack of associated symptoms
do not justify the routine arthroplasty of the acetabulum in these patients. Cite this article: