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 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.
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.
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/
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.
The properties of impacted morsellised bone graft (MBG) in revision total knee arthroplasty (TKA) were studied in 12 horses. The left hind metatarsophalangeal joint was replaced by a human TKA. The horses were then randomly divided into graft and control groups. In the graft group, a unicondylar, lateral uncontained defect was created in the third metatarsal bone and reconstructed using autologous MBG before cementing the TKA. In the control group, a cemented TKA was implanted without the bone resection and grafting procedure. After four to eight months, the animals were killed and a biomechanical loading test was performed with a cyclic load equivalent to the horse’s body-weight to study mechanical stability. After removal of the prosthesis, the distal third metatarsal bone was studied radiologically, histologically and by quantitative and micro CT. Biomechanical testing showed that the differences in deformation between the graft and the control condyles were not significant for either elastic or time-dependent deformations. The differences in bone mineral density (BMD) between the graft and the control condyles were not significant. The BMD of the MBG was significantly lower than that in the other regions in the same limb. Micro CT showed a significant difference in the degree of anisotropy between the graft and host bone, even although the structure of the area of the MBG had trabecular orientation in the direction of the axial load. Histological analysis revealed that all the grafts were revascularised and completely incorporated into a new trabecular structure with few or no remnants of graft. Our study provides a basis for the clinical application of this technique with MBG in revision TKA.
We studied the effect of a layer of cement placed under the tibial component of Freeman-Samuelson total knee prostheses with a metal back and an 80 mm intramedullary stem, using roentgen stereophotogrammetry to measure the migration of the tibial component during one year in 13 uncemented and 16 cemented knees. The addition of cement produced a significant reduction in migration at one year, from a mean of 1.5 mm to one of 0.5 mm (p less than 0.01), including a significant reduction in pure subsidence. One year postoperatively the clinical results were similar between the groups, but, at three years, one uncemented knee had required revision.
Recent publications have drawn attention to the fact that some brands of joint replacement may contain variants which perform significantly worse (or better) than their ‘siblings’. As a result, the National Joint Registry has performed much more detailed analysis on the larger families of
Aims. This study aimed to investigate the estimated change in primary and revision arthroplasty rate in the Netherlands and Denmark for hips, knees, and shoulders during the COVID-19 pandemic in 2020 (COVID-period). Additional points of focus included the comparison of patient characteristics and hospital type (2019 vs COVID-period), and the estimated loss of quality-adjusted life years (QALYs) and impact on waiting lists. Methods. All hip, knee, and shoulder arthroplasties (2014 to 2020) from the Dutch Arthroplasty Register, and hip and
We determined the cumulative survival rates, in arthroplasty of the knee, of three designs of tibial component, using a change of position on standard radiographs or revision for aseptic loosening as criteria of failure. The average migration of each of the three designs in the first postoperative year is known from roentgen stereophotogrammetric analysis reported by other authors. The ranking order of the components as judged by cumulative survival is the same as that determined by early migration. This finding supports the view that the measurement of early migration can predict late aseptic loosening and therefore that such measurements are clinically of value.