The August 2024 Knee Roundup. 360. looks at: Calcification’s role in knee osteoarthritis: implications for surgical decision-making; Lower complication rates and shorter lengths of hospital stay with technology-assisted
Abstract. Robotic-assisted
We reviewed the long-term clinical and radiological
results of 63 uncemented Low Contact Stress (LCS) total knee replacements
(TKRs) in 47 patients with rheumatoid arthritis. The mean age of
the patients at the time of surgery was 69 years (53 to 81). At
a mean follow-up of 22 years (20 to 25), 12 patients were alive
(17 TKRs), 27 had died (36 TKRs), and eight (ten TKRs) were lost
to follow-up. Revision was necessary in seven patients (seven TKRs, 11.1%)
at a mean of 12.1 years (0 to 19) after surgery. In the surviving
ten patients who had not undergone revision (15 TKRs), the mean
Oxford knee score was 30.2 (16 to 41) at a mean follow-up of 19.5
years (15 to 24.7) and mean active flexion was 105° (90° to 150°).
The survival rate was 88.9% at 20 years (56 of 63) and the Kaplan–Meier
survival estimate, without revision, was 80.2% (95% confidence interval
37 to 100) at 25 years. Cite this article:
The August 2023 Knee Roundup. 360. looks at: Curettage and cementation of giant cell tumour of bone: is arthritis a given?; Anterior knee pain following
The February 2023 Knee Roundup. 360. looks at: Machine-learning models: are all complications predictable?; Positive cultures can be safely ignored in revision arthroplasty patients that do not meet the 2018 International Consensus Meeting Criteria; Spinal versus general anaesthesia in contemporary primary total knee arthroplasty; Preoperative pain and early arthritis are associated with poor outcomes in
In the absence of patellar resurfacing, we have
previously shown that the use of electrocautery around the margin of
the patella improved the one-year clinical outcome of total knee
replacement (TKR). In this prospective randomised study we compared
the mean 3.7 year (1.1 to 4.2) clinical outcomes of 300 TKRs performed
with and without electrocautery of the patellar rim: this is an
update of a previous report. The overall prevalence of anterior knee
pain was 32% (95% confidence intervals [CI] 26 to 39), and 26% (95%
CI 18 to 35) in the intervention group compared with 38% (95% CI
29 to 48) in the control group (chi-squared test; p = 0.06). The
overall prevalence of anterior knee pain remained unchanged between
the one-year and 3.7 year follow-up (chi-squared test; p = 0.12). The
mean total Western Ontario McMasters Universities Osteoarthritis
Indices and the American Knee Society knee and function scores at
3.7 years’ follow-up were similar in the intervention and control
groups (repeated measures analysis of variance p = 0.43, p = 0.09
and p = 0.59, respectively). There were no complications. A total
of ten patients (intervention group three, control group seven)
required secondary patellar resurfacing after the first year. Our study suggests that the improved clinical outcome with electrocautery
denervation compared with no electrocautery is not maintained at
a mean of 3.7 years’ follow-up. Cite this article:
Antibiotic impregnated articulating spacers are
used in two-stage revision total knee arthroplasty to deliver local antibiotic
therapy while preserving function. We have observed infection control
in greater than 95% of cases with functional outcomes approaching
those seen in revision for aseptic loosening. Higher failure has
been observed with methicillin resistant organisms.
Aims. Micromotion of the polyethylene (PE) inlay may contribute to backside PE wear in addition to articulate wear of
We undertook a study in which 138 female patients with a mean age of 71.2 years (51 to 82) received a standard NexGen CR-flex prosthesis in one knee and a gender-specific NexGen CR-flex prosthesis in the other. The mean follow-up period was 3.25 years (3.1 to 3.5). The aspect ratios of the standard and gender-specific prostheses were compared with that of the distal femur. The mean post-operative Knee Society knee scores were 94 (70 to 100) and 93 (70 to 100) points and the function scores were 83 (60 to 100) and 84 (60 to 100) points for the standard implants and the gender-specific designs, respectively. The mean post-operative Western Ontario and McMaster Universities score was 26.4 points (0 to 76). Patient satisfaction, the radiological results and the complication rates were similar in the two groups. In those with a standard prosthesis, the femoral component was closely matched in 80 knees (58.0%), overhung in 14 (10.1%) and undercovered the bone in 44 (31.9%). In those with a gender-specific prosthesis, it was closely matched in 15 knees (10.9%) and undercovered the bone in 123 (89.1%). Since we found no significant differences between the two groups with regard to the clinical and radiological results, patient satisfaction or complication rate, the goal of the design of the gender-specific CR-flex prosthesis to improve the outcome was not achieved in our patients.
We aimed to obtain anthropometric data on Korean
knees and to compare these with data on commonly available total
knee arthroplasties (TKAs). The dimensions of the femora and tibiae
of 1168 knees were measured intra-operatively. The femoral components
were found to show a tendency toward mediolateral (ML) under-coverage
in small femurs and ML overhang in the large femurs. The ML under-coverage
was most prominent for the small prostheses. The ML/anteroposterior
(ML/AP) ratio of Korean tibiae was greater than that of tibial components. This study shows that, for different reasons, current TKAs do
not provide a reasonable fit for small or large Korean knees, and
that the ‘gender-specific’ and ‘stature-specific’ components help
for large Korean femurs but offer less satisfactory fits for small
femurs. Specific modifications of prostheses are needed for Asian
knees.
Between April 2004 and July 2007, we performed 241 primary total knee replacements in 204 patients using the e.motion posterior cruciate-retaining, multidirectional mobile-bearing prosthesis. Of these, 100 were carried out using an image-free navigation system, and the remaining 141 with the conventional technique. We conducted a retrospective study from the prospectively collected data of these patients to assess the early results of this new mobile-bearing design. At a mean follow-up of 49 months (32 to 71), 18 knees (7.5%) had mechanical complications of which 13 required revision. Three of these had a peri-prosthetic fracture, and were removed from the study. The indication for revision in the remaining ten was loosening of the femoral component in two, tibiofemoral dislocation in three, disassociation of the polyethylene liner in four, and a broken polyethyene liner in one. There were eight further mechanically unstable knees which presented with recurrent disassociation of the polyethylene liner. There was no significant difference in the incidence of mechanical instability between the navigation-assisted procedures (8 of 99, 8.1%) and the conventionally implanted knees (10 of 139, 7.2%). In our view, the relatively high rate of mechanical complications and revision within 30 months precludes the further use of new design of knee replacement.
Aims. Distal femoral resection in conventional
We carried out a prospective, continuous study on 529 patients who underwent primary total knee replacement between January 2006 and December 2007 at a major teaching hospital. The aim was to investigate weight change and the functional and clinical outcome in non-obese and obese groups at 12 months post-operatively. The patients were grouped according to their pre-operative body mass index (BMI) as follows: non-obese (BMI <
30 kg/m2), obese (BMI At 12 months, a clinically significant weight loss of ≥ 5% had occurred in 40 (12.6%) of the obese patients, but 107 (21%) gained weight. The change in the International Knee Society score was less in obese and morbidly obese compared with non-obese patients (p = 0.016). Adverse events occurred in 30 (14.2%) of the non-obese, 59 (22.6%) of the obese and 20 (35.1%) of the morbidly obese patients (p = 0.001).
Aims. The use of cementless total knee arthroplasty (TKA) components has increased during the past decade. The initial design of cementless metal-backed patellar components had shown high failure rates due to many factors. The aim of this study was to evaluate the clinical results of a second-generation cementless, metal-backed patellar component of a modern design. Methods. This was a retrospective review of 707 primary TKAs in 590 patients from a single institution, using a cementless, metal-backed patellar component with a mean follow-up of 6.9 years (2 to 12). A total of 409 TKAs were performed in 338 females and 298 TKAs in 252 males. The mean age of the patients was 63 years (34 to 87) and their mean BMI was 34.3 kg/m. 2. (18.8 to 64.5). The patients were chosen to undergo a cementless procedure based on age and preoperative radiological and intraoperative bone quality. Outcome was assessed using the Knee Society knee and function scores and range of motion (ROM), complications, and revisions. Results. A total of 24 TKAs (3.4%) in 24 patients failed and required revision surgery, of which five were due to patellar complications (0.71%): one for aseptic patellar loosening (0.14%) and four for polyethylene dissociation (0.57%). A total of 19 revisions (2.7%) were undertaken in 19 patients for indications which did not relate to the patella: four for aseptic tibial loosening (0.57%), one for aseptic femoral loosening (0.14%), nine for periprosthetic infection (1.3%), one for popliteus impingement (0.14%), and four for instability (0.57%). Knee Society knee and function scores, and ROM, improved significantly when comparing pre- and postoperative values. Survival of the metal-backed patellar component for all-cause failure was 97.5% (95% confidence interval 94.9% to 100%) at 12 years. Conclusion. The second-generation cementless
Aims. The diagnosis of periprosthetic joint infection (PJI) continues to present a significant clinical challenge. New biomarkers have been proposed to support clinical decision-making; among them, synovial fluid alpha-defensin has gained interest. Current research methodology suggests reference methods are needed to establish solid evidence for use of the test. This prospective study aims to evaluate the diagnostic accuracy of high-performance liquid chromatography coupled with the mass spectrometry (LC-MS) method to detect alpha-defensin in synovial fluid. Methods. Between October 2017 and September 2019, we collected synovial fluid samples from patients scheduled to undergo revision surgery for painful
Aims. Periprosthetic joint infection (PJI) occurs in approximately 1% to 2% of
Aims. The aim of this study was to report health-related quality of life (HRQoL) and joint-specific function in patients waiting for total hip or knee arthroplasty surgery (THA or TKA) in Northern Ireland, compared to published literature and a matched normal population. Secondary aims were to report emergency department (ED) and out-of-hours general practitioner (OOH GP) visits, new prescriptions of strong opioids, and new prescriptions of antidepressants while waiting. Methods. This was a cohort study of 991 patients on the waiting list for arthroplasty in a single Northern Ireland NHS trust: 497 on the waiting list for ≤ three months; and 494 waiting ≥ three years. Postal surveys included the EuroQol five-dimension five-level questionnaire (EQ-5D-5L), visual analogue scores (EQ-VAS), and Oxford Hip and Knee scores to assess HRQoL and joint-specific function. Electronic records determined prescriptions since addition to the waiting list and patient attendances at OOH GP/EDs. Results. Overall, 712/991 (71.8%) responded at ≤ three months for THA (n = 164) and
We performed a randomised, prospective study of 80 mobile-bearing total knee arthroplasties (80 knees) in order to measure the effects of varus-valgus laxity and balance on the range of movement (ROM) one year after operation. Forty knees had a posterior-cruciate-ligament (PCL)-retaining prosthesis and the other 40 a PCL-sacrificing prosthesis. In the balanced group (69 knees) in which the difference between varus and valgus was less than 2°, the mean ROM improved significantly from 107.6° to 117.7° (p <
0.0001). By contrast, in the 11 knees which were unbalanced and in which the difference between varus and valgus laxity exceeded 2°, the ROM decreased from a mean of 121.0° to 112.7° (p = 0.0061). We conclude that coronal laxity, especially balanced laxity, is important for achieving an improved ROM in mobile-bearing total knee arthroplasty.
Aims. The aims of this study were to assess mapping models to predict the three-level version of EuroQoL five-dimension utility index (EQ-5D-3L) from the Oxford Knee Score (OKS) and validate these before and after