The treatment of patients with allergies to metal in total joint arthroplasty is an ongoing debate. Possibilities include the use of hypoallergenic prostheses, as well as the use of standard cobalt-chromium (CoCr) alloy. This non-designer study was performed to evaluate the clinical outcome and survival rates of unicondylar knee arthroplasty (UKA) using a standard CoCr alloy in patients reporting signs of a hypersensitivity to metal. A consecutive series of patients suitable for UKA were screened for symptoms of metal hypersensitivity by use of a questionnaire. A total of 82 patients out of 1737 patients suitable for medial UKA reporting cutaneous metal hypersensitivity to cobalt, chromium, or nickel were included into this study and prospectively evaluated to determine the functional outcome, possible signs of hypersensitivity, and short-term survivorship at a minimum follow-up of 1.5 years.Aims
Patients and Methods
The aim of this independent multicentre study was to assess the
mid-term results of mobile bearing unicondylar knee arthroplasty
(UKA) for isolated lateral osteoarthritis of the knee joint. We retrospectively evaluated 363 consecutive, lateral UKAs (346
patients) performed using the Oxford domed lateral prosthesis undertaken
in three high-volume knee arthroplasty centres between 2006 and
2014. Mean age of the patients at surgery was 65 years (36 to 88)
with a mean final follow-up of 37 months (12 to 93)Aims
Patients and Methods
The Oxford mobile-bearing unicompartmental knee
replacement (UKR) is an effective and safe treatment for osteoarthritis
of the medial compartment. The results in the lateral compartment
have been disappointing due to a high early rate of dislocation
of the bearing. A series using a newly designed domed tibial component
is reported. The first 50 consecutive domed lateral Oxford UKRs in 50 patients
with a mean follow-up of three years (2.0 to 4.3) were included.
Clinical scores were obtained prospectively and Kaplan-Meier survival
analysis was performed for different endpoints. Radiological variables
related to the position and alignment of the components were measured. One patient died and none was lost to follow-up. The cumulative
incidence of dislocation was 6.2% (95% confidence interval (CI)
2.0 to 17.9) at three years. Survival using revision for any reason
and aseptic revision was 94% (95% CI 82 to 98) and 96% (95% CI 85
to 99) at three years, respectively. Outcome scores, visual analogue
scale for pain and maximum knee flexion showed a significant improvement
(p <
0.001). The mean Oxford knee score was 43 ( Clinical results are excellent and short-term survival has improved
when compared with earlier series. The risk of dislocation remains
higher using a mobile-bearing UKR in the lateral compartment when
compared with the medial compartment. Patients should be informed
about this complication. To avoid dislocations, care must be taken
not to elevate the lateral joint line.
The aim of this retrospective cohort study was
to identify any difference in femoral offset as measured on pre-operative
anteroposterior (AP) radiographs of the pelvis, AP radiographs of
the hip and corresponding CT scans in a consecutive series of 100
patients with primary end-stage osteoarthritis of the hip (43 men
and 57 women with a mean age of 61 years (45 to 74) and a mean body
mass index of 28 kg/m2 (20 to 45)). Patients were positioned according to a standardised protocol
to achieve reproducible projection and all images were calibrated.
Inter- and intra-observer reliability was evaluated and agreement
between methods was assessed using Bland-Altman plots. In the entire cohort, the mean femoral offset was 39.0 mm (95%
confidence interval (CI) 37.4 to 40.6) on radiographs of the pelvis,
44.0 mm (95% CI 42.4 to 45.6) on radiographs of the hip and 44.7
mm (95% CI 43.5 to 45.9) on CT scans. AP radiographs of the pelvis
underestimated femoral offset by 13% when compared with CT (p <
0.001).
No difference in mean femoral offset was seen between AP radiographs
of the hip and CT (p = 0.191). Our results suggest that femoral offset is significantly underestimated
on AP radiographs of the pelvis but can be reliably and accurately
assessed on AP radiographs of the hip in patients with primary end-stage
hip osteoarthritis. We, therefore, recommend that additional AP radiographs of the
hip are obtained routinely for the pre-operative assessment of femoral
offset when templating before total hip replacement.
Peri-prosthetic femoral fracture after total hip replacement (THR) is associated with a poor outcome and high mortality. However, little is known about its long-term incidence after uncemented THR. We retrospectively reviewed a consecutive series of 326 patients (354 hips) who had received a CLS Spotorno replacement with an uncemented, straight, collarless tapered titanium stem between January 1985 and December 1989. The mean follow-up was 17 years (15 to 20). The occurrence of peri-prosthetic femoral fracture during follow-up was noted. Kaplan-Meier survival analysis was used to estimate the cumulative incidence of fracture. At the last follow-up, 86 patients (89 hips) had died and eight patients (eight hips) had been lost to follow-up. A total of 14 fractures in 14 patients had occurred. In ten hips, the femoral component had to be revised and in four the fracture was treated by open reduction and internal fixation. The cumulative incidence of peri-prosthetic femoral fracture was 1.6% (95% confidence interval 0.7 to 3.8) at ten years and 4.5% (95% confidence interval 2.6 to 8.0) at 17 years after the primary THR. There was no association between the occurrence of fracture and gender or age at the time of the primary replacement. Our findings indicate that peri-prosthetic femoral fracture is a significant mode of failure in the long term after the insertion of an uncemented CLS Spotorno stem. Revision rates for this fracture rise in the second decade. Further research is required to investigate the risk factors involved in the occurrence of late peri-prosthetic femoral fracture after the implantation of any uncemented stem, and to assess possible methods of prevention.
Our aim in this prospective study was to evaluate the outcome of total shoulder replacement in the treatment of young and middle-aged active patients with primary glenohumeral osteoarthritis. We reviewed 21 patients (21 shoulders) with a mean age of 55 years (37 to 60). The mean follow-up was seven years (5 to 9). The same anatomical, third-generation, cemented implant had been used in all patients. All the patients were evaluated radiologically and clinically using the Constant and Murley score. No patients required revision. In one a tear of the supraspinatus tendon occurred. Overall, 20 patients (95%) were either very satisfied (n = 18) or satisfied (n = 2) with the outcome. Significant differences (p <
0.0001) were found for all categories of the Constant and Murley score pre- and post-operatively. The mean Constant and Murley score increased from 24.1 points (10 to 45) to 64.5 points (39 to 93), and the relative score from 30.4% (11% to 50%) to 83% (54% to 116%). No clinical or radiological signs of loosening of the implant were seen. For young and middle-aged patients with osteoarthritis, third-generation total shoulder replacement is a viable method of treatment with a low rate of complications and excellent results in the mid-term.
We followed the first 354 consecutive implantations of a cementless, double-tapered straight femoral stem in 326 patients. Follow-up was at a mean of 12 years (10 to 15). The mean age of the patients was 57 years (13 to 81). At follow-up, 56 patients (59 hips) had died, and eight (eight hips) had been lost to follow-up. Twenty-five hips underwent femoral revision, eight for infection, three for periprosthetic fracture and 14 for aseptic loosening. The overall survival was 92% at 12 years (95% CI 88 to 95). Survival with femoral revision for aseptic loosening as an endpoint was 95% (95% CI 92 to 98). The median Harris hip score at follow-up was 84 points (23 to 100). Radiolucent lines (<
2 mm) in Gruen zones 1 and 7 were present in 38 (16%) and 34 hips (14%), respectively. Radiolucencies in zones 2 to 6 were found in five hips (2%). The results for mid- to long-term survival with this femoral component are encouraging and compare with those achieved in primary cemented total hip arthroplasty. The high rate of loosening of the cup and the high rate of pain are, however, a source of concern.