Modular junctions are ubiquitous in contemporary hip arthroplasty. The head-trunnion junction is implicated in the failure of large diameter metal-on-metal (MoM) hips which are the currently the topic of one the largest legal actions in the history of orthopaedics (estimated costs are stated to exceed $4 billion). Several factors are known to influence the strength of these press-fit modular connections. However, the influence of different head sizes has not previously been investigated. The aim of the study was to establish whether the choice of head size influences the initial strength of the trunnion-head connection. Ti-6Al-4V trunnions (n = 60) and two different sizes of cobalt-chromium (Co-Cr) heads (28 mm and 36 mm; 30 of each size) were used in the study. Three different levels of assembly force were considered: 4 kN; 5 kN; and 6 kN (n = 10 each). The strength of the press-fit connection was subsequently evaluated by measuring the pull-off force required to break the connection. The statistical differences in pull-off force were examined using a Kruskal–Wallis test and two-sample Mann–Whitney U test. Finite element and analytical models were developed to understand the reasons for the experimentally observed differences.Objectives
Materials and Methods
Hip resurfacing arthroplasty (HRA) is an alternative to conventional
total hip arthroplasty for patients with osteonecrosis (ON) of the
femoral head. Our aim was to report the long-term outcome of HRA,
which is not currently known. Long-term survivorship, clinical scores and radiographic results
for 82 patients (99 hips) treated with HRA for ON over a period
of 18 years were reviewed retrospectively. The mean age of the 67
men and 15 women at the time of surgery was 40.8 years (14 to 64).
Patients were resurfaced regardless of the size of the osteonecrotic
lesion.Aims
Patients and Methods
The PROximal Fracture of the Humerus: Evaluation by Randomisation (PROFHER) trial has recently demonstrated that surgery is non-superior to non-operative treatment in the management of displaced proximal humeral fractures. The objective of this study was to assess current surgical practice in the context of the PROFHER trial in terms of patient demographics, injury characteristics and the nature of the surgical treatment. A total of ten consecutive patients undergoing surgery for the treatment of a proximal humeral fracture from each of 11 United Kingdom hospitals were retrospectively identified over a 15 month period between January 2014 and March 2015. Data gathered for the 110 patients included patient demographics, injury characteristics, mode of surgical fixation, the grade of operating surgeon and the cost of the surgical implants.Objectives
Methods
The December 2012 Hip &
Pelvis Roundup360 looks at: swimming against the tide with resurfacing; hip impingement surgery; the relationship between obesity and co-morbidities and joint replacement infection; cemented hips; cross-linked polyethylene notching; whether cement is necessary in oncological arthroplasty; and how total hip replacement may result in weight gain.
The August 2014 Oncology Roundup360 looks at: Anaesthesic modality does not affect outcomes in tumour surgery; infection predictors in orthopaedic oncology; sarcoma depth unimportant in survival; photon/proton radiotherapy surprisingly effective in chondrosarcoma control; total humerus replacement a success!; LDH simple predictor of survival in sarcoma; Denosumab again! and Oops procedures in triplicate.
The June 2013 Hip &
Pelvis Roundup360 looks at: failure in metal-on-metal arthroplasty; minimal hip approaches; whether bisphosphonates improve femoral bone stock following arthroplasty; whether more fat means more operative time; surgical infection; vascularised fibular graft for osteonecrosis; subclinical SUFE; and dentists, hips and antibiotics.
The aim of this study was to evaluate the prognostic
and therapeutic factors which influence the oncological outcome
of parosteal osteosarcoma. A total of 80 patients with a primary parosteal osteosarcoma
were included in this retrospective study. There were 51 females
and 29 males with a mean age of 29.9 years (11 to 78). The mean follow-up was 11.2 years (1 to 40). Overall survival
was 91.8% at five years and 87.8% at ten years. Local recurrence
occurred in 14 (17.5%) patients and was associated with intralesional
surgery and a large volume of tumour. On histological examination,
80% of the local recurrences were dedifferentiated high-grade tumours.
A total of 12 (14.8%) patients developed pulmonary metastases, of
whom half had either a dedifferentiated tumour or a local recurrence.
Female gender and young age were good prognostic factors. Local
recurrence was a poor prognostic factor for survival. Medullary
involvement or the use of chemotherapy had no impact on survival. The main goal in treating a parosteal osteosarcoma must be to
achieve a wide surgical margin, as inadequate margins are associated
with local recurrence. Local recurrence has a significant negative
effect on survival, as 80% of the local recurrences are high-grade
dedifferentiated tumours, and half of these patients develop metastases. The role of chemotherapy in the treatment of parosteal osteosarcoma
is not as obvious as it is in the treatment of conventional osteosarcoma.
The mainstay of treatment is wide local excision. Cite this article:
The February 2014 Oncology Roundup360 looks at: suspicious lesions; limb salvage in pelvic sarcomas; does infection affect oncological survival?; cancer patient pathways; radiological arthritis with cement augmentation in GCT; and post-chemotherapy increase in tumour volume as a predictor of poor prognosis.
The primary purpose of this study of metal-on-metal
(MoM) hip resurfacing was to compare the effect of using a cementless
or cemented femoral component on the subsequent bone mineral density
(BMD) of the femoral neck. This was a single-centre, prospective, double-blinded control
trial which randomised 120 patients (105 men and 15 women) with
a mean age of 49.4 years (21 to 68) to receive either a cemented
or cementless femoral component. Follow-up was to two years. Outcome
measures included total and six-point region-of-interest BMD of
the femoral neck, radiological measurements of acetabular inclination,
neck-shaft and stem-shaft angles, and functional outcome scores
including the Harris hip score, the Western Ontario and McMaster
Universities Osteoarthritis Index and the University of California
at Los Angeles activity scale. In total, 17 patients were lost to follow-up leaving 103 patients
at two years. There were no revisions in the cementless group and
three revisions (5%) in the cemented group (two because of hip pain
and one for pseudotumour). The total BMD was significantly higher in the cementless group
at six months (p <
0.001) and one year (p = 0.01) than in the
cemented group, although there was a loss of statistical significance
in the difference at two years (p = 0.155). All patient outcomes improved significantly: there were no significant
differences between the two groups. The results show better preservation of femoral neck BMD with
a cementless femoral component after two years of follow-up. Further
investigation is needed to establish whether this translates into
improved survivorship. Cite this article:
The aims of this study were to compare the diagnostic test characteristics
of ultrasound alone, metal artefact reduction sequence MRI (MARS-MRI)
alone, and ultrasound combined with MARS-MRI for identifying intra-operative
pseudotumours in metal-on-metal hip resurfacing (MoMHR) patients
undergoing revision surgery. This retrospective diagnostic accuracy study involved 39 patients
(40 MoMHRs). The time between imaging modalities was a mean of 14.6
days (0 to 90), with imaging performed at a mean of 5.3 months (0.06
to 12) before revision. The prevalence of intra-operative pseudotumours
was 82.5% (n = 33).Aims
Methods
We assessed the age-related differences in the
use of total shoulder arthroplasty (TSA) and outcomes, and associated
time-trends using the United States Nationwide Inpatient Sample
(NIS) between 1998 and 2010. Age was categorised as <
50, 50
to 64, 65 to 79 and ≥ 80 years. Time-trends in the use of TSA were
compared using logistic regression or the Cochran Armitage test. The overall use of TSA increased from 2.96/100 000 in 1998 to
12.68/100 000 in 2010. Significantly lower rates were noted between
2009 and 2010, compared with between 1998 and 2000, for: mortality,
0.1% The rates of use of TSA/100 000 by age groups, <
50, 50 to
64, 65 to 79 and ≥ 80 years were: 0.32, 4.62, 17.82 and 12.56, respectively
in 1998 (p <
0.001); and 0.65, 17.49, 75.27 and 49.05, respectively
in 2010 (p <
0.001) with an increasing age-related difference
over time (p <
0.001). Across the age categories, there were
significant differences in the proportion: discharged to an inpatient
facility, 3.2% In a nationally representative sample, we noted a time-related
increase in the use of TSA and increasing age-related differences
in outcomes indicating a changing epidemiology of the use of TSA.
Age-related differences in outcomes suggest that attention should
focus on groups with the worst outcomes. Cite this article:
The purpose of this study was to compare the
amount of acetabular bone removed during hip resurfacing (HR) and cementless
total hip replacement (THR), after controlling for the diameter
of the patient’s native femoral head. Based on a power analysis,
64 consecutive patients (68 hips) undergoing HR or THR were prospectively
enrolled in the study. The following data were recorded intra-operatively:
the diameter of the native femoral head, the largest reamer used,
the final size of the acetabular component, the size of the prosthetic
femoral head and whether a decision was made to increase the size
of the acetabular component in order to accommodate a larger prosthetic femoral
head. Results were compared using two-sided, independent samples
Student’s
The December 2013 Oncology Roundup360 looks at: Peri-articular resection fraught with complications; Navigated margins; Skeletal tumours and thromboembolism; Conditional survival in Ewing’s sarcoma; Reverse shoulders and tumour; For how long should we follow up sarcoma patients?; and already metastasised?
The August 2012 Hip &
Pelvis Roundup360 looks at: whether cemented hip replacement might be bad for your health; highly cross-linked polyethylene; iHOT-33 - a new hip outcome measure; hamstring injuries; total hip replacement; stemmed metal-on-metal THR; bipolar hemiarthroplasty, neuromuscular disease and dislocation; the high risk of secondary hemiarthroplasty; and whether we have to repair the labrum after all?
Patients who have limb amputation for musculoskeletal
tumours are a rare group of cancer survivors. This was a prospective
cross-sectional survey of patients from five specialist centres
for sarcoma surgery in England. Physical function, pain and quality
of life (QOL) outcomes were collected after lower extremity amputation
for bone or soft-tissue tumours to evaluate the survivorship experience
and inform service provision. Of 250 patients, 105 (42%) responded between September 2012 and
June 2013. From these, completed questionnaires were received from
100 patients with a mean age of 53.6 years (19 to 91). In total
60 (62%) were male and 37 (38%) were female (three not specified).
The diagnosis was primary bone sarcoma in 63 and soft-tissue tumour
in 37. A total of 20 tumours were located in the hip or pelvis,
31 above the knee, 32 between the knee and ankle and 17 in the ankle
or foot. In total 22 had hemipelvectomy, nine hip disarticulation,
35 transfemoral amputation, one knee disarticulation, 30 transtibial
amputation, two toe amputations and one rotationplasty. The Toronto
Extremity Salvage Score (TESS) differed by amputation level, with
poorer scores at higher levels (p <
0.001). Many reported significant
pain. In addition, TESS was negatively associated with increasing
age, and pain interference scores. QOL for Cancer Survivors was
significantly correlated with TESS (p <
0.001). This relationship appeared
driven by pain interference scores. This unprecedented national survey confirms amputation level
is linked to physical function, but not QOL or pain measures. Pain
and physical function significantly impact on QOL. These results
are helpful in managing the expectations of patients about treatment
and addressing their complex needs. Cite this article: