We report on the radiological findings in a series of 871 consecutive primary condylar knee replacements followed up for an average of four years. A new radiological sign has been identified, consisting of a smoothly tapering wedge of cement visible beneath the horizontal portion of the tibial component on the anteroposterior radiograph. This was found in 25.4% of our cases and appears to indicate a persistent soft-tissue imbalance following condylar arthroplasty of the knee. The cement-wedge sign was associated with a highly significant increase in radiolucent lines at the tibial cement-bone interface.
We report the use of long curved Kuntscher nails to maintain stability during arthrodesis of nine infected and five uninfected failures of total knee replacement. The curvature of the nail helps positioning and avoids the need for cortical perforation. A single-stage operation was possible in most cases. Union rates are comparable with those of other series and even patients with delayed union have satisfactory function.
We hypothesised there was no clinical value in
using an autologous blood transfusion (ABT) drain in either primary total
hip (THR) or total knee replacement (TKR) in terms of limiting allogeneic
blood transfusions when a modern restrictive blood management regime
was followed. A total of 575 patients (65.2% men), with a mean age
of 68.9 years (36 to 94) were randomised in this three-arm study
to no drainage (group A), or to wound drainage with an ABT drain
for either six hours (group B) or 24 hours (group C). The primary
outcome was the number of patients receiving allogeneic blood transfusion.
Secondary outcomes were post-operative haemoglobin (Hb) levels,
length of hospital stay and adverse events. This study identified only 41 transfused patients, with no significant
difference in distribution between the three groups (p = 0.857).
The mean pre-operative haemoglobin (Hb) value in the transfused
group was 12.8 g/dL (9.8 to 15.5) 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.
This prospective randomised clinical trial evaluated the effect of alternatives for allogeneic blood transfusions after total hip replacement and total knee replacement in patients with pre-operative haemoglobin levels between 10.0 g/dl and 13.0 g/dl. A total of 100 patients were randomly allocated to the Eprex (pre-operative injections of epoetin) or Bellovac groups (post-operative retransfusion of shed blood). Allogeneic blood transfusions were administered according to hospital policy. In the Eprex group, 4% of the patients (two patients) received at least one allogeneic blood transfusion. In the Bellovac group, where a mean 216 ml (0 to 700) shed blood was retransfused, 28% (14 patients) required the allogeneic transfusion (p = 0.002). When comparing Eprex with Bellovac in total hip replacement, the percentages were 7% (two of 30 patients) and 30% (nine of 30 patients) (p = 0.047) respectively, whereas in total knee replacement, the percentages were 0% (0 of 20 patients) and 25% (five of 20 patients) respectively (p = 0.042). Pre-operative epoetin injections are more effective but more costly in reducing the need for allogeneic blood transfusions in mildly anaemic patients than post-operative retransfusion of autologous blood.
The June 2023 Hip & Pelvis Roundup. 360. looks at: Machine learning to identify surgical candidates for hip and
Primary arthroplasty may be denied to very elderly patients based upon the perceived outcome and risks associated with surgery. This prospective study compared the outcome, complications, and mortality of total hip (TKR) and total knee replacement (TKR) in a prospectively selected group of patients aged ≥ 80 years with that of a control group aged between 65 and 74 years. There were 171 and 495 THRs and 185 and 492 TKRs performed in the older and control groups, respectively. No significant difference was observed in the mean improvement of Oxford hip and knee scores between the groups at 12 months (0.98, (95% confidence interval (CI) −0.66 to 2.95), p = 0.34 and 1.15 (95% CI −0.65 to 2.94), p = 0.16, respectively). The control group had a significantly (p = 0.02 and p = 0.04, respectively) greater improvement in the physical well being component of their SF-12 score, but the older group was more satisfied with their THR (p = 0.047). The older group had a longer hospital stay for both THR (5.9
The purpose of this study was to measure the
radiological parameters of femoral component alignment of the Oxford
Phase 3 unicompartmental knee replacement (UKR), and evaluate their
effect on clinical outcome. Multiple regression analysis was used
to examine the relative contributions of the radiological assessment
of femoral component alignment in 189 consecutive UKRs performed
by a single surgeon. The American Knee Society scores were compared
between groups, defined as being within or outside recommended tolerances
of the position of the femoral component. For the flexion/extension
position 21 UKRs (11.1%) lay outside the recommended limits, and for
posterior overhang of the femoral component nine (4.8%) lay outside
the range. The pre-operative hip/knee/ankle (HKA) angle, narrowest
canal distance from the distal femoral entry point of the alignment
jig and coronal entry-point position had significant effects on
the flexion/extension position. Pre-operative HKA angle had a significant
influence on posterior overhang of the femoral component. However,
there was no significant difference in American Knee Society scores
relative to the position of the femoral component.
The June 2024 Knee Roundup. 360. looks at: The estimated lifetime risk of revision after primary knee arthroplasty influenced by age, sex, and indication; Should high-risk patients seek out care from high-volume surgeons?; Stability and fracture rates in medial unicondylar
Using a new, non-invasive method, we measured the patellofemoral force (PFF) in cadaver knees mounted in a rig to simulate weight-bearing. The PFF was measured from 20° to 120° of flexion before and after implanting three designs of knee prosthesis. Medial unicompartmental arthroplasty with a meniscal-bearing prosthesis and with retention of both cruciate ligaments caused no significant change in the PFF. After arthroplasty with a posterior-cruciate-retaining prosthesis and division of the anterior cruciate ligament, the PFF decreased in extension and increased by 20% in flexion. Implantation of a posterior stabilised prosthesis and division of both cruciate ligaments produced a decrease in the PFF in extension but maintained normal load in flexion. There was a direct relationship between the PFF and the angle made with the patellar tendon and the long axis of the tibia. The abnormalities of the patellar tendon angle which resulted from implantation of the two total prostheses explain the observed changes in the PFF and show how the mechanics of the patellofemoral joint depend upon the kinematics of the tibiofemoral articulation.
We performed routine venography after operation in a consecutive series of 252 patients with total joint arthroplasties in whom no form of routine chemical or mechanical prophylaxis had been used. The prevalence of deep-vein thrombosis (DVT) was 32% (16% distal, 16% proximal) after total hip replacement and 66% (50% distal, 16% proximal) after total knee replacement (p <
0.001). We did not treat distal DVT. There were only two readmissions within three months of surgery because of thromboembolic disease. There were two deaths within this period, neither of which was due to pulmonary embolism.
We report the results of 75 consecutive primary press-fit Kinemax arthroplasties with an average follow-up of 14 months (three to 28). We reviewed 26 cemented and 49 non-cemented tibial components implanted into 72 patients (30 men and 42 women, median age 70 years). At the latest follow-up the overall evaluation (Hospital for Special Surgery knee rating scale) for cemented cases was excellent in 54%, good in 42% and poor in 4%. No cemented prosthesis loosened. Of the non-cemented cases 55% were excellent, 23% good, and 2% fair. Ten tibial implants (20%) loosened and required revision. Residual pain marred the result in 24% of the non-cemented prostheses and in 4% of the cemented group. We do not recommend the press-fit, smooth-surfaced Kinemax prosthesis for non-cemented use.
The incidence of deep vein thrombosis in 244 patients who had total knee replacement has been studied. In 120 the prosthesis was cemented and in 124 it was cementless. In all cases the replacement was primary and a porous-coated prosthesis with a porous-coated central tibial stem was used. Deep vein thrombosis was diagnosed by venography, and pulmonary embolism by perfusion scanning. The incidence of deep vein thrombosis in the cementless knees (23.8%) and in the cemented (25%) was approximately the same. The only significant predisposing factors for deep vein thrombosis in both groups were obesity, prolonged postoperative immobilisation, previous venous disease and hyperlipidaemia.
We have investigated whether the use of laminar-flow theatres and space suits reduced the rate of revision for early deep infection after total hip (THR) and knee (TKR) replacement by reviewing the results of the New Zealand Joint Registry at ten years. Of the 51 485 primary THRs and 36 826 primary TKRs analysed, laminar-flow theatres were used in 35.5% and space suits in 23.5%. For THR there was a significant increase in early infection in those procedures performed with the use of a space suit compared with those without (p <
0.0001), in those carried out in a laminar-flow theatre compared with a conventional theatre (p <
0.003) and in those undertaken in a laminar-flow theatre with a space suit (p <
0.001) when compared with conventional theatres without such a suit. The results were similar for TKR with the use of a space suit (p <
0.001), in laminar-flow theatres (p <
0.019) and when space suits were used in those theatres (p <
0.001). These findings were independent of age, disease and operating time and were unchanged when the surgeons and hospital were analysed individually. The rate of revision for early deep infection has not been reduced by using laminar flow and space suits. Our results question the rationale for their increasing use in routine joint replacement, where the added cost to the health system seems to be unjustified.
Although the Western Ontario and McMaster Universities
(WOMAC) osteoarthritis index was originally developed for the assessment
of non-operative treatment, it is commonly used to evaluate patients
undergoing either total hip (THR) or total knee replacement (TKR).
We assessed the importance of the 17 WOMAC function items from the perspective
of 1198 patients who underwent either THR (n = 704) or TKR (n =
494) in order to develop joint-specific short forms. After these
patients were administered the WOMAC pre-operatively and at three,
six, 12 and 24 months’ follow-up, they were asked to nominate an
item of the function scale that was most important to them. The
items chosen were significantly different between patients undergoing
THR and those undergoing TKR (p <
0.001), and there was a shift
in the priorities after surgery in both groups. Setting a threshold
for prioritised items of ≥ 5% across all follow-up, eight items
were selected for THR and seven for TKR, of which six items were
common to both. The items comprising specific WOMAC-THR and TKR
function short forms were found to be equally responsive compared
with the original WOMAC function form. Cite this article:
Aims. This study aimed to investigate the risk of postoperative complications in COVID-19-positive patients undergoing common orthopaedic procedures. Methods. Using the National Surgical Quality Improvement Programme (NSQIP) database, patients who underwent common orthopaedic surgery procedures from 1 January to 31 December 2021 were extracted. Patient preoperative COVID-19 status, demographics, comorbidities, type of surgery, and postoperative complications were analyzed. Propensity score matching was conducted between COVID-19-positive and -negative patients. Multivariable regression was then performed to identify both patient and provider risk factors independently associated with the occurrence of 30-day postoperative adverse events. Results. Of 194,121 included patients, 740 (0.38%) were identified to be COVID-19-positive. Comparison of comorbidities demonstrated that COVID-19-positive patients had higher rates of diabetes, heart failure, and pulmonary disease. After propensity matching and controlling for all preoperative variables, multivariable analysis found that COVID-19-positive patients were at increased risk of several postoperative complications, including: any adverse event, major adverse event, minor adverse event, death, venous thromboembolism, and pneumonia. COVID-19-positive patients undergoing hip/
Aims. The preventive effects of bisphosphonates on articular cartilage in non-arthritic joints are unclear. This study aimed to investigate the effects of oral bisphosphonates on the rate of joint space narrowing in the non-arthritic hip. Methods. We retrospectively reviewed standing whole-leg radiographs from patients who underwent
We have compared the survival of 67 revision arthroplasties of the knee undertaken for aseptic loosening with and without the retention of a secure, cemented femoral component. All the patients had undergone a single primary procedure at a mean of nine years previously. In group I (25 knees) the original femoral component was secure and was retained. There were no abrasions or osteolysis. The knees were stable, normally aligned, with minimal bone loss. In group II 42 knees did not fulfil these criteria and underwent revision of both components. The mean follow-up was four years. Re-revision for loosening was required in seven knees (28%) in group I and three (7%) in group II (p <
0.01). The remaining knees function well with Knee Society scores averaging 84/69 and no radiological evidence of osteolysis. When revising cemented implants, retention of a secure femoral component cannot be recommended even when conditions appear to be suitable.