We have performed a form of lunate replacement arthroplasty, which included excision of the lunate and insertion of a vascularised radial bone flap wrapped in pronator quadratus, for stage IIIB or stage IV Kienböck’s disease, in 41 patients who have been followed up for more than three years. All patients reported an improvement in their symptoms, and 20 of the 41 became free of pain after the operation. Extension and flexion of the wrist were increased by a mean of 9° and 6°, respectively (p <
0.05). The radioscaphoid angle and the carpal height ratio were not significantly changed and only minimal deterioration was observed due to degenerative change. The size, density or location of the inserted bone did not change with time. A vascularised radial bone flap wrapped in pronator quadratus can be a reliable treatment option for advanced Kienböck’s disease, when the pedicled bone and muscle envelope acts as a stable spacer for the excised lunate.
We present the prevalence of multiple fractures
in the elderly in a single catchment population of 780 000 treated over
a 12-month period and describe the mechanisms of injury, common
patterns of occurrence, management, and the associated mortality
rate. A total of 2335 patients, aged ≥ 65 years of age, were prospectively
assessed and of these 119 patients (5.1%) presented with multiple
fractures. Distal radial (odds ratio (OR) 5.1, p <
0.0001), proximal humeral
(OR 2.2, p <
0.0001) and pelvic (OR 4.9, p <
0.0001) fractures
were associated with an increased risk of sustaining associated
fractures. Only 4.5% of patients sustained multiple fractures after
a simple fall, but due to the frequency of falls in the elderly
this mechanism resulted in 80.7% of all multiple fractures. Most
patients required admission (>
80%), of whom 42% did not need an
operation but more than half needed an increased level of care before
discharge (54%). The standardised mortality rate at one year was
significantly greater after sustaining multiple fractures that included
fractures of the pelvis, proximal humerus or proximal femur (p <
0.001). This mortality risk increased further if patients were <
80 years of age, indicating that the existence of multiple fractures after
low-energy trauma is a marker of mortality.
Disruption of the interosseous membrane is easily
missed in patients with Essex-Lopresti syndrome. None of the imaging
techniques available for diagnosing disruption of the interosseous
membrane are completely dependable. We undertook an investigation to identify whether a simple intra-operative
test could be used to diagnose disruption of the interosseous membrane
during surgery for fracture of the radial head and to see if the
test was reproducible. We studied 20 cadaveric forearms after excision of the radial
head, ten with and ten without disruption of the interosseous membrane.
On each forearm, we performed the radius joystick test: moderate
lateral traction was applied to the radial neck with the forearm
in maximal pronation, to look for lateral displacement of the proximal radius
indicating that the interosseous membrane had been disrupted. Each
of six surgeons (three junior and three senior) performed the test
on two consecutive days. Intra-observer agreement was 77% (95% confidence interval (CI)
67 to 85) and interobserver agreement was 97% (95% CI 92 to 100).
Sensitivity was 100% (95% CI 97 to 100), specificity 88% (95% CI
81 to 93), positive predictive value 90% (95% CI 83 to 94), and
negative predictive value 100%). This cadaveric study suggests that the radius joystick test may
be useful for detecting disruption of the interosseous membrane
in patients undergoing open surgery for fracture of the radial head
and is reproducible. A confirmatory study
We carried out a prospective randomised study to evaluate the blood loss in 60 patients having a total knee arthroplasty and divided randomly into two equal groups, one having a computer-assisted procedure and the other a standard operation. The surgery was carried out by a single surgeon at one institution using a uniform approach. The only variable in the groups was the use of intramedullary femoral and tibial alignment jigs in the standard group and single tracker pins of the imageless navigation system in the tibia and femur in the navigated group. The mean drainage of blood was 1351 ml (715 to 2890; 95% confidence interval (CI) 1183 to 1518) in the computer-aided group and 1747 ml (1100 to 3030; CI 1581 to 1912) in the conventional group. This difference was statistically significant (p = 0.001). The mean calculated loss of haemoglobin was 36 g/dl in the navigated group There was a highly significant reduction in blood drainage and the calculated Hb loss between the computer-assisted and the conventional techniques. This allows the ordering of less blood before the operation, reduces risks at transfusion and gives financial saving. Computer-assisted surgery may also be useful for patients in whom blood products are not acceptable.
We reviewed the seven- to ten-year results of our previously reported prospective randomised controlled trial comparing total hip replacement and hemiarthroplasty for the treatment of displaced intracapsular fracture of the femoral neck. Of our original study group of 81 patients, 47 were still alive. After a mean follow up of nine years (7 to 10) overall mortality was 32.5% and 51.2% after total hip replacement and hemiarthroplasty, respectively (p = 0.09). At 100 months postoperatively a significantly greater proportion of hemiarthroplasty patients had died (p = 0.026). Three hips dislocated following total hip replacement and none after hemiarthroplasty. In both the total hip replacement and hemiarthroplasty groups a deterioration had occurred in walking distance (p = 0.02 and p <
0.001, respectively). One total hip replacement required revision compared with four hemiarthroplasties which were revised to total hip replacements. All surviving patients with a total hip replacement demonstrated wear of the cemented polyethylene component and all hemiarthroplasties had produced acetabular erosion. There was lower mortality (p = 0.013) and a trend towards superior function in patients with a total hip replacement in the medium term.
We have investigated the accuracy of placement of the femoral component using imageless navigation in 100 consecutive Birmingham Hip Resurfacings. Pre-operative templating determined the native neck-shaft angle and planned stem-shaft angle of the implant. The latter were verified post-operatively using digital anteroposterior unilateral radiographs of the hip. The mean neck-shaft angle determined before operation was 132.7° (118° to 160°). The mean planned stem-shaft angle was a relative valgus alignment of 9.7° ( Navigation in hip resurfacing may afford the surgeon a reliable and accurate method of placement of the femoral component.
Complications involving the patellofemoral joint,
caused by malrotation of the femoral component during total knee replacement,
are an important cause of persistent pain and failure leading to
revision surgery. The aim of this study was to determine and quantify
the influence of femoral component malrotation on patellofemoral
wear, and to determine whether or not there is a difference in the
rate of wear of the patellar component when articulated against
oxidised zirconium (OxZr) and cobalt-chrome (CoCr) components. An The results suggest that patellar maltracking due to an internally
rotated femoral component leads to an increased mean patellar wear.
Although not statistically significant, the mean wear production
may be lower for OxZr than for CoCr components.
A complete cement mantle is important for the longevity of a total hip replacement. In the minimally-invasive direct anterior approach used at the Innsbruck University hospital, the femoral component has to be inserted into the femoral canal by an angulated movement. In a cadaver study, the quality and the extent of the cement mantle surrounding 13 Exeter femoral components implanted straight through a standard anterolateral transgluteal approach were compared with those of 13 similar femoral components implanted in an angulated fashion through a direct anterior approach. A third-generation cementing technique was used. The inner and outer contours of the cement mantles was traced from CT scans and the thickness and cross-sectional area determined. In no case was the cement mantle incomplete. The total mean thickness of the cement mantle was 3.62 mm (95% confidence interval 3.59 to 3.65). The mean thickness in the group using the minimally-invasive approach was 0.16 mm less than that in the anterolateral group. The distribution of the thickness was similar in the two groups. The mean thickness was less on the anteromedial and anterolateral aspect than on the posterior aspect of the femur. There is no evidence that the angulated introduction of Exeter femoral components in the direct anterior approach in cadavers compromises the quality, extent or thickness of the cement mantle.
In navigated total hip arthroplasty, the pelvis and the femur are tracked by means of rigid bodies fixed directly to the bones. Exact tracking throughout the procedure requires that the connection between the marker and bone remains stable in terms of translation and rotation. We carried out a cadaver study to compare the intra-operative stability of markers consisting of an anchoring screw with a rotational stabiliser and of pairs of pins and wires of different diameters connected with clamps. These devices were tested at different locations in the femur. Three human cadavers were placed supine on an operating table, with a reference marker positioned in the area of the greater trochanter. K-wires (3.2 mm), Steinman pins (3 and 4 mm), Apex pins (3 and 4 mm), and a standard screw were used as fixation devices. They were positioned medially in the proximal third of the femur, ventrally in the middle third and laterally in the distal portion. In six different positions of the leg, the spatial positions were recorded with a navigation system. Compared with the standard single screw, with the exception of the 3 mm Apex pins, the two-pin systems were associated with less movement of the marker and could be inserted less invasively. With the knee flexed to 90° and the dislocated hip rotated externally until the lower leg was parallel to the table (figure-four position), all the anchoring devices showed substantial deflection of 1.5° to 2.5°. The most secure area for anchoring markers was the lateral aspect of the femur.
A total of 179 adult patients with displaced intra-articular fractures of the distal radius was randomised to receive indirect percutaneous reduction and external fixation (n = 88) or open reduction and internal fixation (n = 91). Patients were followed up for two years. During the first year the upper limb musculoskeletal function assessment score, the SF-36 bodily pain sub-scale score, the overall Jebsen score, pinch strength and grip strength improved significantly in all patients. There was no statistically significant difference in the radiological restoration of anatomical features or the range of movement between the groups. During the period of two years, patients who underwent indirect reduction and percutaneous fixation had a more rapid return of function and a better functional outcome than those who underwent open reduction and internal fixation, provided that the intra-articular step and gap deformity were minimised.
Ununited fractures of the scaphoid with extensive bone resorption are usually treated by bone grafting and internal fixation, using either an open or a minimally invasive technique. We studied the feasibility of percutaneous fixation without bone grafting in a consecutive series of 27 patients with established nonunion of an undisplaced fracture of the scaphoid and extensive local resorption of bone. They were treated by a single surgeon with rigid fixation alone, using a headless cannulated screw inserted through a volar percutaneous technique. Clinical examination, standard radiographs and CT confirmed that the fracture had united in all patients at a mean of 11.6 weeks (8 to 16), and that their functional scores had improved. We concluded that extensive resorption at the fracture site is not an absolute indication for bone grafting, and that percutaneous fixation alone will eventually produce healing of ununited undisplaced fractures of the scaphoid regardless of the size of the gap.
We analysed the incidence of slipped capital
femoral epiphysis (SCFE) in South Australia, investigating possible associations
between an increased incidence of SCFE, the local indigenous population
and the Australian obesity epidemic during the last 20 years. Data
including race, age and gender were collected to obtain a profile
of the South Australian SCFE patient, and were then compared with
epidemiological data for South Australian adolescents. We concluded
that the incidence of both obesity and SCFE is increasing. We also
noted that the median weight of SCFE patients has increased and
the mean age at diagnosis has decreased. Despite weight profiles
comparable with those of the general population, we noted that an
indigenous child was three times more likely to develop SCFE than
a non-indigenous child. As far as we know there is no published
literature on the predisposition of Aboriginal Australians to SCFE.
We evaluated the concentrations of chromium and cobalt ions in blood after metal-on-metal surface replacement arthroplasty using a wrought-forged, high carbon content chromium-cobalt alloy implant in 64 patients. At one year, mean whole blood ion levels were 1.61 μg/L (0.4 to 5.5) for chromium and 0.67 μg/L (0.23 to 2.09) for cobalt. The pre-operative ion levels, component size, female gender and the inclination of the acetabular component were inversely proportional to the values of chromium and/or cobalt ions at one year postoperatively. Other factors, such as age and level of activity, did not correlate with the levels of metal ions. We found that the levels of the ions in the serum were 1.39 and 1.37 times higher for chromium and cobalt respectively than those in the whole blood. The levels of metal ions obtained may be specific to the hip resurfacing implant and reflect its manufacturing process.
In order to compare the effect of oral apixaban
(a factor Xa inhibitor) with subcutaneous enoxaparin on major venous
thromboembolism and major and non-major clinically relevant bleeding
after total knee and hip replacement, we conducted a pooled analysis
of two previously reported double-blind randomised studies involving 8464
patients. One group received apixaban 2.5 mg twice daily (plus placebo
injection) starting 12 to 24 hours after operation, and the other
received enoxaparin subcutaneously once daily (and placebo tablets)
starting 12 hours (± 3) pre-operatively. Each regimen was continued
for 12 days ( Apixaban 2.5 mg twice daily is more effective than enoxaparin
40 mg once daily without increased bleeding.
Carbonate-substituted hydroxyapatite (CHA) is more osteoconductive and more resorbable than hydroxyapatite (HA), but the underlying mode of its action is unclear. We hypothesised that increased resorption of the ceramic by osteoclasts might subsequently upregulate osteoblasts by a coupling mechanism, and sought to test this in a large animal model. Defects were created in both the lateral femoral condyles of 12 adult sheep. Six were implanted with CHA granules bilaterally, and six with HA. Six of the animals in each group received the bisphosphonate zoledronate (0.05 mg/kg), which inhibits the function of osteoclasts, intra-operatively. After six weeks bony ingrowth was greater in the CHA implants than in HA, but not in the animals given zoledronate. Functional osteoclasts are necessary for the enhanced osteoconduction seen in CHA compared with HA.
The purpose of this study was to investigate the effects of right leg restriction at the knee, ankle or both, on a driver’s braking times. Previous studies have not investigated the effects of knee restriction on braking performance. A total of 23 healthy drivers performed a series of emergency braking tests in a driving simulator in either an above-knee plaster cast, a below-knee cast, or in a knee brace with an increasing range of restriction. The study showed that total braking reaction time was significantly longer when wearing an above-knee plaster cast, a below-knee plaster cast or a knee brace fixed at 0°, compared with braking normally (p <
0.001). Increases in the time taken to move the foot from the accelerator to the brake accounted for some of the increase in the total braking reaction time. Unexpectedly, thinking time also increased with the level of restriction (p <
0.001). The increase in braking time with an above-knee plaster cast in this study would increase the stopping distance at 30 miles per hour by almost 3 m. These results suggest that all patients wearing any lower-limb plaster cast or knee brace are significantly impaired in their ability to perform an emergency stop. We suggest changes to the legislation to prevent patients from driving with lower-limb plaster casts or knee braces.
We reviewed 111 hemispherical Duraloc series-500 acetabular components with a minimum follow-up of 12 years. The mean clinical and radiological follow-up was 13.4 years (12 to 15). A Profile hydroxyapatite-coated anatomical femoral component was used in each case. Six patients had a late dislocation, for whom the polyethylene liner was exchanged. Each acetabular component was well fixed and all femoral components showed signs of bone ingrowth. The mean rate of femoral head penetration was 0.10 mm/year (0.021 to 0.481). The probability of not developing femoral cortical hypertrophy and proximal osteopenia by 12 years was 80.2% (95% confidence interval, 72.7 to 87.6) and 77.5% (95% confidence interval, 69.7 to 85.2), respectively. Despite these good clinical results, further follow-up is needed to determine whether these prostheses will loosen with time.
In this cross-over study, we evaluated two types of knee brace commonly used in the conservative treatment of osteoarthritis of the medial compartment. Twelve patients confirmed radiologically as having unilateral osteoarthritis of the medial compartment (Larsen grade 2 to grade 4) were studied. Treatment with a simple hinged brace was compared with that using a valgus corrective brace. Knee kinematics, ground reaction forces, pain and function were assessed during walking and the Hospital for Special Surgery scores were also determined. Significant improvements in pain, function, and loading and propulsive forces were seen with the valgus brace. Treatment with a simple brace showed only significant improvements in loading forces. Our findings suggest that although both braces improved confidence and function during gait, the valgus brace showed greater benefit.
The aims of this study were to examine the repeatability of measurements of bone mineral density (BMD) around a cemented polyethylene Charnley acetabular component using dual-energy x-ray absorptiometry and to determine the longitudinal pattern of change in BMD during the first 24 months after surgery. The precision of measurements of BMD in 19 subjects ranged from 7.7% to 10.8% between regions, using a four-region-of-interest model. A longitudinal study of 27 patients demonstrated a transient decrease in net pelvic BMD during the first 12 months, which recovered to baseline at 24 months. The BMD in the region medial to the dome of the component reduced by between 7% and 10% during the first three months, but recovered to approximately baseline values by two years. Changes in BMD in the pelvis around cemented acetabular components may be measured using dual-energy x-ray absorptiometry. Bone loss after insertion of a cemented Charnley acetabular component is small, transient and occurs mainly at the medial wall of the acetabulum. After two years, bone mass returns to baseline values, with a pattern suggesting a uniform transmission of load to the acetabulum.
Labral tears are commonly associated with femoroacetabular impingement. We reviewed 151 patients (156 hips) with femoroacetabular impingement and labral tears who had been treated arthroscopically. These were subdivided into those who had undergone a labral repair (group 1) and those who had undergone resection of the labrum (group 2). In order to ensure the groups were suitably matched for comparison of treatment effects, patients with advanced degenerative changes (Tönnis grade >
2, lateral sourcil height <
2 mm and Outerbridge grade 4 changes in the weight-bearing area of the femoral head) were excluded, leaving 96 patients (101 hips) in the study. At a mean follow-up of 2.44 years (2 to 4), the mean modified Harris hip score in the labral repair group (group 1, 69 hips) improved from 60.2 (24 to 85) pre-operatively to 93.6 (55 to 100), and in the labral resection group (group 2, 32 hips) from 62.8 (29 to 96) pre-operatively to 88.8 (35 to 100). The mean modified Harris hip score in the labral repair group was 7.3 points greater than in the resection group (p = 0.036, 95% confidence interval 0.51 to 14.09). Labral detachments were found more frequently in the labral repair group and labral flap tears in the resection group. No patient in our study group required a subsequent hip replacement during the period of follow-up. This study shows that patients without advanced degenerative changes in the hip can achieve significant improvement in their symptoms after arthroscopic treatment of femoroacetabular impingement. Where appropriate, labral repair provides a superior result to labral resection.