Lower limb muscle power is thought to influence outcome following
total knee replacement (TKR). Post-operative deficits in muscle
strength are commonly reported, although not explained. We hypothesised
that post-operative recovery of lower limb muscle power would be
influenced by the number of satellite cells in the quadriceps muscle at
time of surgery. Biopsies were obtained from 29 patients undergoing TKR. Power
output was assessed pre-operatively and at six and 26 weeks post-operatively
with a Leg Extensor Power Rig and data were scaled for body weight.
Satellite cell content was assessed in two separate analyses, the
first cohort (n = 18) using immunohistochemistry and the second
(n = 11) by a new quantitative polymerase chain reaction (q-PCR)
protocol for Pax-7 (generic satellite cell marker) and Neural Cell
Adhesion Molecule (NCAM; marker of activated cells).Objectives
Methods
We assessed the effect of mental disability on
the outcome of total knee replacement (TKR) and investigated whether
mental health improves post-operatively. Outcome data were prospectively
recorded over a three-year period for 962 patients undergoing primary
TKR for osteoarthritis. Pre-operative and one year Short-Form (SF)-12 scores
and Oxford knee scores (OKS) were obtained. The mental component
of the SF-12 was stratified into four groups according to level
of mental disability (none ≥ 50, mild 40 to 49, moderate 30 to 39,
severe <
30). Patients with any degree of mental disability had
a significantly greater subjective physical disability according
to the SF-12 (p = 0.06) and OKS (p <
0.001). The improvement
in the disease-specific score (OKS) was not affected by a patient’s
mental health (p = 0.33). In contrast, patients with mental disability
had less of an improvement in their global physical health (SF-12)
(p <
0.001). However, patients with any degree of mental disability
had a significant improvement in their mental health post-operatively
(p <
0.001). Despite a similar improvement in their disease-specific scores
and improvement in their mental health, patients with mental disability
were significantly more likely to be dissatisfied with their TKR
at one year (p = 0.001). Patients with poor mental health do benefit
from improvements in their mental health and knee function after
TKR, but also have a higher rate of dissatisfaction. Cite this article:
In Norway total joint replacement after hip dysplasia
is reported more commonly than in neighbouring countries, implying
a higher prevalence of the condition. We report on the prevalence
of radiological features associated with hip dysplasia in a population
of
2081 19-year-old Norwegians. The radiological measurements used
to define hip dysplasia were Wiberg’s centre-edge (CE) angle at
thresholds of <
20° and <
25°, femoral head extrusion index
<
75%, Sharp’s angle >
45°, an acetabular depth to width ratio
<
250 and the sourcil shape assessed subjectively. The whole
cohort underwent clinical examination of their range of hip movement,
body mass index (BMI), and Beighton hypermobility score, and were
asked to complete the EuroQol (EQ-5D) and Western Ontario and McMaster
Universities Osteoarthritis Index (WOMAC). The prevalence of hip
dysplasia in the cohort varied from 1.7% to 20% depending on the
radiological marker used. A Wiberg’s CE angle <
20° was seen
in 3.3% of the cohort: 4.3% in women and 2.4% in men. We found no
association between subjects with multiple radiological signs indicative
of dysplasia and BMI, Beighton score, EQ-5D or WOMAC. Although there
appears to be a high prevalence of hip dysplasia among 19-year-old
Norwegians, this is dependent on the radiological parameters applied. Cite this article:
Radiostereometric analysis (RSA) can detect early
micromovement in unstable implant designs which are likely subsequently
to have a high failure rate. In 2010, the Articular Surface Replacement
(ASR) was withdrawn because of a high failure rate. In 19 ASR femoral
components, the mean micromovement over the first two years after implantation
was 0.107 mm ( We conclude that the ASR femoral component achieves initial stability
and that early migration is not the mode of failure for this resurfacing
arthroplasty.
We compared lower limb coronal alignment measurements
obtained pre- and post-operatively with long-leg radiographs and
computer navigation in patients undergoing primary total knee replacement
(TKR). A series of 185 patients had their pre- and post-implant
radiological and computer-navigation system measurements of coronal alignment
compared using the Bland-Altman method. The study included 81 men
and 104 women with a mean age of 68.5 years (32 to 87) and a mean
body mass index of 31.7 kg/m2 (19 to 49). Pre-implant
Bland–Altman limits of agreement were -9.4° to 8.6° with a repeatability
coefficient of 9.0°. The Bland–Altman plot showed a tendency for the
radiological measurement to indicate a higher level of pre-operative
deformity than the corresponding navigation measurement. Post-implant
limits of agreement were -5.0° to 5.4° with a repeatability coefficient
of 5.2°. The tendency for valgus knees to have greater deformity
on the radiograph was still seen, but was weaker for varus knees. The alignment seen or measured intra-operatively during TKR is
not necessarily the same as the deformity seen on a standing long-leg
radiograph either pre- or post-operatively. Further investigation
into the effect of weight-bearing and surgical exposure of the joint
on the mechanical femorotibial angle is required to enable the most appropriate
intra-operative alignment to be selected.
Diabetes mellitus is recognised as a risk factor
for carpal tunnel syndrome. The response to treatment is unclear,
and may be poorer than in non-diabetic patients. Previous randomised
studies of interventions for carpal tunnel syndrome have specifically
excluded diabetic patients. The aim of this study was to investigate
the epidemiology of carpal tunnel syndrome in diabetic patients,
and compare the outcome of carpal tunnel decompression with non-diabetic
patients. The primary endpoint was improvement in the QuickDASH
score. The prevalence of diabetes mellitus was 11.3% (176 of 1564).
Diabetic patients were more likely to have severe neurophysiological
findings at presentation. Patients with diabetes had poorer QuickDASH
scores at one year post-operatively (p = 0.028), although the mean
difference was lower than the minimal clinically important difference
for this score. After controlling for underlying differences in
age and gender, there was no difference between groups in the magnitude of
improvement after decompression (p = 0.481). Patients with diabetes
mellitus can therefore be expected to enjoy a similar improvement
in function.
Recent studies have shown that modulating inflammation-related
lipid signalling after a bone fracture can accelerate healing in
animal models. Specifically, decreasing 5-lipoxygenase (5-LO) activity
during fracture healing increases cyclooxygenase-2 (COX-2) expression
in the fracture callus, accelerates chondrogenesis and decreases
healing time. In this study, we test the hypothesis that 5-LO inhibition
will increase direct osteogenesis. Bilateral, unicortical femoral defects were used in rats to measure
the effects of local 5-LO inhibition on direct osteogenesis. The
defect sites were filled with a polycaprolactone (PCL) scaffold
containing 5-LO inhibitor (A-79175) at three dose levels, scaffold
with drug carrier, or scaffold only. Drug release was assessed Objectives
Methods
Incomplete avulsion of the proximal hamstrings
can be a severely debilitating injury that causes weakness, pain
while sitting and inability to run. The results of the surgical treatment
of 23 consecutive patients with such injuries at least two years
after surgery are described. The surgery consisted of the repair
of the hamstrings directly onto the ischial tuberosity. At review,
using a visual analogue scale (VAS, 0 to 100), pain while sitting improved
from a mean of 40 (0 to 100) to 64 (0 to 100) (p = 0.024), weakness
from a mean of 39 (0 to 90) to 76 (7 to 100) (p = 0.0001) and the
ability to run from a mean of 24 (0 to 88) to 64 (0 to 95) (p =
0.0001). According to a VAS, satisfaction was rated at a mean of
81 (0 to 100) and 20 patients (87%) would have the same procedure
again. Hamstring strength measured pre- and post-operatively had
improved significantly from a mean of 64% (0% to 95%) to 88% (50%
to 114%) compared with the normal side. Most of these patients with symptomatic incomplete hamstring
avulsions unresponsive to conservative treatment had an improved
outcome after surgical repair.
In a double-blinded randomised controlled trial,
83 patients with primary osteoarthritis of the hip received either
a ceramic-on-metal (CoM) or metal-on-metal (MoM) total hip replacement
(THR). The implants differed only in the bearing surfaces used.
The serum levels of cobalt and chromium and functional outcome scores
were compared pre-operatively and at six and 12 months post-operatively. Data were available for 41 CoM and 36 MoM THRs (four patients
were lost to follow-up, two received incorrect implants). The baseline
characteristics of both cohorts were similar. Femoral head size
measured 36 mm in all but two patients who had 28 mm heads. The
mean serum cobalt and chromium levels increased in both groups,
with no difference noted between groups at six months (cobalt p
= 0.67, chromium p = 0.87) and 12 months (cobalt p = 0.76, chromium
p = 0.76) post-operatively. Similarly, the mean Oxford hip scores,
Western Ontario and McMaster Universities Osteoarthritis index and
University of California, Los Angeles activity scores showed comparable improvement
at 12 months. Our findings indicate that CoM and MoM couplings are associated
with an equivalent increase in serum cobalt and chromium levels,
and comparable functional outcome scores at six and 12-months follow-up.
Most patients (95%) with fibular hemimelia have
an absent anterior cruciate ligament (ACL). The purpose of this study
was to assess the long-term outcome of such patients with respect
to pain and knee function. We performed a retrospective review of
patients with fibular hemimelia and associated ACL deficiency previously
treated at our institution. Of a possible 66 patients, 23 were sent
the Musculoskeletal Outcomes Data Evaluation and Management System
(MODEMS) questionnaire and Lysholm knee score to complete. In all,
11 patients completed the MODEMS and nine completed the Lysholm
score questionnaire. Their mean age was 37 years (27 to 57) at review.
Five patients had undergone an ipsilateral Symes amputation. There
was no significant difference in any subsections of the Short-Form
36 scores of our patients compared with age-matched controls. The
mean Lysholm knee score was 90.2 (82 to 100). A slight limp was
reported in six patients. No patients had episodes of locking of the
knee or required a supportive device for walking. Four had occasional
instability with sporting activities. These results suggest that patients with fibular hemimelia and
ACL deficiency can live active lives with a similar health status
to age-matched controls.
We report a prospective analysis of clinical
outcome in patients treated with medial patellofemoral ligament
(MPFL) reconstruction using an autologous semitendinosus graft.
The technique includes superolateral portal arthroscopic assessment
before and after graft placement to ensure correct graft tension
and patellar tracking before fixation. Between October 2005 and
October 2010, a total of 201 consecutive patients underwent 219 procedures.
Follow-up is presented for 211 procedures in 193 patients with a
mean age of 26 years (16 to 49), and mean follow-up of 16 months
(6 to 42). Indications were atraumatic recurrent patellar dislocation
in 141 patients, traumatic recurrent dislocation in 50, pain with
subluxation in 14 and a single dislocation with persistent instability
in six. There have been no recurrent dislocations/subluxations.
There was a statistically significant improvement between available pre-
and post-operative outcome scores for 193 patients (all p <
0.001).
Female patients with a history of atraumatic recurrent dislocation
and all patients with history of previous surgery had a significantly
worse outcome (all p <
0.05). The indication for surgery, degree
of dysplasia, associated patella alta, time from primary dislocation
to surgery and evidence of associated cartilage damage at operation
did not result in any significant difference in outcome. This series adds considerably to existing evidence that MPFL
reconstruction is an effective surgical procedure for selected patients
with patellofemoral instability.
The use of two implants to manage concomitant ipsilateral femoral
shaft and proximal femoral fractures has been indicated, but no
studies address the relationship of dynamic hip screw (DHS) side
plate screws and the intramedullary nail where failure might occur
after union. This study compares different implant configurations
in order to investigate bridging the gap between the distal DHS
and tip of the intramedullary nail. A total of 29 left synthetic femora were tested in three groups:
1) gapped short nail (GSN); 2) unicortical short nail (USN), differing
from GSN by the use of two unicortical bridging screws; and 3) bicortical
long nail (BLN), with two angled bicortical and one unicortical bridging
screws. With these findings, five matched-pairs of cadaveric femora
were tested in two groups: 1) unicortical long nail (ULN), with
a longer nail than USN and three bridging unicortical screws; and
2) BLN. Specimens were axially loaded to 22.7 kg (50 lb), and internally
rotated 90°/sec until failure.Objectives
Methods
We carried out a prospective investigation into
the radiological outcomes of uncemented Oxford medial compartment
unicondylar replacement in 220 consecutive patients (231 knees)
performed in a single centre with a minimum two-year follow-up.
The functional outcomes using the mean Oxford knee score and the
mean high-activity arthroplasty score were significantly improved
over the pre-operative scores (p <
0.001). There were 196 patients
with a two-year radiological examination performed under fluoroscopic
guidance, aiming to provide images acceptable for analysis of the
bone–implant interface. Of the six tibial zones examined on each
knee on the anteroposterior radiograph, only three had a partial
radiolucent line. All were in the medial aspect of the tibial base plate
(zone 1) and all measured <
1 mm. All of these patients were
asymptomatic. There were no radiolucent lines seen around the femoral
component or on the lateral view. There was one revision for loosening
at one year due to initial inadequate seating of the tibial component.
These results confirm that the early uncemented Oxford medial unicompartmental
compartmental knee replacements were reliable and the incidence
of radiolucent lines was significantly decreased compared with the
reported results of cemented versions of this implant. These independent
results confirm those of the designing centre.
We examined patient and surgical factors associated
with deep surgical site infection (SSI) following total hip replacement
(THR) in a large integrated healthcare system. A retrospective review
of a cohort of primary THRs performed between 2001 and 2009 was
conducted. Patient characteristics, surgical details, surgeon and
hospital volumes, and SSIs were identified using the Kaiser Permanente
Total Joint Replacement Registry (TJRR). Proportional-hazard regression
models were used to assess risk factors for SSI. The study cohort
consisted of 30 491 THRs, of which 17 474 (57%) were performed on
women. The mean age of the patients in the whole series was 65.5
years (13 to 97; A comprehensive infection surveillance system, combined with
a TJRR, identified patient and surgical factors associated with
SSI. Obesity and chronic medical conditions should be addressed
prior to THR. The finding of increased SSI risk with bilateral THR
requires further investigation.
We compared the clinical and radiological outcomes
of two cementless femoral stems in the treatment of patients with
a Garden III or IV fracture of the femoral neck. A total of 70 patients At final follow-up there were no statistically significant differences
between the short anatomical and the conventional stems with regard
to the mean Harris hip score (85.7 (66 to 100) Our study demonstrated that despite the poor bone quality in
these elderly patients with a fracture of the femoral neck, osseo-integration
was obtained in all hips in both groups. However, the incidence
of thigh pain, pulmonary microemboli and peri-prosthetic fracture
was significantly higher in the conventional stem group than in
the short stem group.
Negative pressure wound therapy (NPWT) and vessel loop assisted
closure are two common methods used to assist with the closure of
fasciotomy wounds. This retrospective review compares these two
methods using a primary outcome measurement of skin graft requirement. A retrospective search was performed to identify patients who
underwent fasciotomy at our institution. Patient demographics, location
of the fasciotomy, type of assisted closure, injury characteristics,
need for skin graft, length of stay and evidence of infection within
90 days were recorded.Introduction
Methods
Symptomatic and asymptomatic deep-vein thrombosis
(DVT) is a common complication of knee replacement, with an incidence
of up to 85% in the absence of prophylaxis. National guidelines
for thromboprophylaxis in knee replacement are derived from total
knee replacement (TKR) data. No guidelines exist specific to unicompartmental knee
replacement (UKR). We investigated whether the type of knee arthroplasty
(TKR or UKR) was related to the incidence of DVT and discuss the
applicability of existing national guidelines for prophylaxis following
UKR. Data were collected prospectively on 3449 knee replacements,
including procedure type, tourniquet time, surgeon, patient age,
use of drains and gender. These variables were related to the incidence
of symptomatic DVT. The overall DVT rate was 1.6%. The only variable that had an
association with DVT was operation type, with TKR having a higher
incidence than UKR (2.2% TKR and UKR patients have different risk profiles for symptomatic
DVT. The risk-benefit ratio for TKR that has been used to produce
national guidelines may not be applicable to UKR. Further research
is required to establish the most appropriate form of prophylaxis
for UKR.
This study evaluated the effect of limb lengthening
on longitudinal growth in patients with achondroplasia. Growth of
the lower extremity was assessed retrospectively by serial radiographs
in 35 skeletally immature patients with achondroplasia who underwent
bilateral limb lengthening (Group 1), and in 12 skeletally immature
patients with achondroplasia who did not (Group 2). In Group 1,
23 patients underwent only tibial lengthening (Group 1a) and 12 patients
underwent tibial and femoral lengthening sequentially (Group 1b). The mean lengthening in the tibia was 9.2 cm (59.5%) in Group
1a, and 9.0 cm (58.2%) in the tibia and 10.2 cm (54.3%) in the femur
in Group 1b. The mean follow-up was 9.3 years (8.6 to 10.3). The
final mean total length of lower extremity in Group 1a was 526.6
mm (501.3 to 552.9) at the time of skeletal maturity and 610.1 mm
(577.6 to 638.6) in Group 1b, compared with 457.0 mm (411.7 to 502.3)
in Group 2. However, the mean actual length, representing the length
solely grown from the physis without the length of distraction,
showed that there was a significant disturbance of growth after
limb lengthening. In Group 1a, a mean decrease of 22.4 mm (21.3
to 23.1) (4.9%) was observed in the actual limb length when compared
with Group 2, and a greater mean decrease of 38.9 mm (37.2 to 40.8)
(8.5%) was observed in Group 1b when compared with Group 2 at skeletal
maturity. In Group 1, the mean actual limb length was 16.5 mm (15.8 to
17.2) (3.6%) shorter in Group 1b when compared with Group 1a at
the time of skeletal maturity. Premature physeal closure was seen
mostly in the proximal tibia and the distal femur with relative
preservation of proximal femur and distal tibia. We suggest that significant disturbance of growth can occur after
extensive limb lengthening in patients with achondroplasia, and
therefore, this should be included in pre-operative counselling
of these patients and their parents.
Wear of metal-on-metal bearings causes elevated levels of cobalt and chromium in blood and body fluids. Metal-on-metal bearings have two distinct wear phases. In the early phase, the wear rate is high. Later, it decreases and the bearing enters a steady-state phase. It is expected that as the wear rates decline, the level of cobalt detected in plasma will also decrease. We studied the baseline and exercise-related cobalt rise in 21 patients (13 men and eight women) with a mean age of 54 years (38 to 80) who had undergone successful hip resurfacing at a mean of 44 months (10 to 96) earlier. Our results showed that circulating baseline cobalt levels were not significantly correlated with the time since implantation (r = 0.08, p = 0.650). By contrast, the exercise-related cobalt rise was directly correlated with the inclination angle of the acetabular component (r = 0.47, p = 0.032) and inversely correlated with the time since implantation (r = −0.5, p = 0.020). Inclination of the acetabular component should be kept less than 40° to decrease the production of wear debris.
A consecutive series of 372 patients who underwent surgery for disorders of the rotator cuff involving arthroscopic subacromial decompression and open or arthroscopic repairs of the cuff were prospectively investigated as to the comparability of subjective and objective assessment scores of shoulder function. Assessments were made before operation and at 3, 6, 12, 18 and 24 months after surgery using the Disabilities of the Arm, Shoulder, and Hand score, the Oxford shoulder score and the Constant-Murley score, which was used as a reference. All scores were standardised to a scale of 0 to 100 for comparison. Statistical analysis compared the post-operative course and the mean score for the subjective Disabilities to the Arm, Shoulder and Hand score and Oxford shoulder score, with the objective Constant score at each interval. A strong correlation was evident between both subjective scores and the Constant score. We concluded that both the subjective scores would be useful substitutes for the Constant score, obviating the need for a trained investigator and the specialist equipment required to perform the Constant score.