Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT05218954 |
| Other study ID # |
WarsawMU/HO |
| Secondary ID |
|
| Status |
Completed |
| Phase |
|
| First received |
|
| Last updated |
|
| Start date |
January 1, 2020 |
| Est. completion date |
June 1, 2021 |
Study information
| Verified date |
January 2022 |
| Source |
Medical University of Warsaw |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Observational
|
Clinical Trial Summary
One of the typical complications which occurs after total hip replacement (THR) procedure is
heterotopic ossification (HO). According to current studies abnormal formation of bone after
trauma or replacement of the hip could reach even 90% of cases. Heterotopic ossifications are
causing the following symptoms, such as: pain, swelling, erythema and warmth along with joint
immobility. Those factors could have an impact on maintaining the posture, especially in
patients after THR.
It is well known since the 90s that the risk of fall among the population older than 65 is
high. Data shows that over 30% of those people have such an incident at least once in a year.
Majority of them do not have further consequences, however about 10% result in serious trauma
to the head and musculoskeletal system. Falls of people who underwent THR are sometimes
connected with periprosthetic fractures, which treatment is much more complicated and is
associated with a higher risk of failure than treatment of ordinary fractures of the lower
limb. What may even worsen the situation is that elderly people very often suffer from many
diseases including osteoporosis or neoplasm which increase the risk of fracture. The rate of
falls is even higher among patients hospitalised from hip fractures. In the first month after
returning home about 14% of patients fall. During the 6 month period after hospitalisation it
reaches 53%. So far, the influence of heterotopic ossifications on the risk of falls is
unknown in the literature.
Description:
This study was conducted according to the STROBE (Strengthening the Reporting of
Observational studies in Epidemiology) and an appropriate checklist was presented to the
editors of the Journal. Study protocol was designed as a retrospective matched-cohort
observational study. This study was approved by Institutional Bioethics Committee (Number:
KB/102/2007) Between January 2020 and December 2020 312 patients undergoing total hip
replacement were observed. During the standard 6-weeks, 3-months and 6-months follow-up visit
every patient had an AP pelvic weight-bearing x-ray. All patients were qualified and operated
by a fellowship-trained single surgeon. For the present analysis, the following demographic
patient data were queried: sex, age at surgery (years), and BMI. 49 patients, who developed
ectopic bone formation were observed. For these patients, a propensity score based on age,
sex and BMI was generated. Patients with HO were matched to patients without HO patients
using a 0.1 propensity score threshold with priority given to exact matches.
All patients were operated through an anterolateral approach with the patient lying on the
healthy side with one-third medium gluteal muscle dissection. Uncemented Taperloc/Allofit
total hip implants (Zimmer Biomet, Warsaw, IN, USA) were used in every single case. Femoral
neck dissection was performed after full joint dislocation, between the tip of the greater
trochanter to the point 10 mm proximal to the lesser trochanter. Acetabular cup was placed
aiming 30-40 degrees of acetabular cup inclination and 10 degrees of anteversion. Femoral
stem was aimed to be placed in the anatomical axis of the femur. The postoperative protocol
included chemical and mechanical thromboprophylaxis unless specifically contraindicated. All
patients received one dose of parenteral antibiotics at the induction of anaesthesia and two
further doses post-operatively. No pre- or postoperative ectopic bone formation prophylaxis
was performed. Flexion and extension exercises of the hip, knee and ankle and isometric
quadriceps contraction exercises were started on the first postoperative day, with full
weight-bearing as tolerated. The aim of mobilisation with a physiotherapist was to obtain
flexion of the hip of 90° mobilising and safely walking with crutches by the third
postoperative day.
At 6-months follow-up visit, radiographs analysis in terms of any ectopic bone formation was
performed using Brooker's classification.
All patients fulfilled WOMAC (The Western Ontario and McMaster Universities Arthritis Index)
and Oxford questionnaires preoperatively and during follow-up visits.
Both cohorts underwent biomechanical assessment, performed by two independent blinded
researchers (PC, KŻ) who were not aware whether patients developed ectopic bone following
total hip replacement. Every analysis was performed using the Biodex Balance System (Biodex,
Inc, Shirley, NY) with participants both feet standing steadily on the platform. Every
participant was protected from falling with the use of support. Device screen was installed
at the level of the patient's sight to avoid taking an uncomfortable position that might have
influenced the results.
Postural stability test was performed, containing the results from three measurements. Every
measurement has been performed on the 12th level of the platform stability for 20 seconds
with 10 seconds break between every test. Results obtained from the participants were
recorded as stability index (SI) values which represent deviations of platform position from
the vertical in degrees. The higher SI values are, the more difficult it was for participants
to maintain stability during the test.
Risk of fall test - a single test consisted of the results obtained from three measurements.
Each measurement was performed at level 6 of the platform stability for 20 seconds with a
10-second rest time between attempts. The person conducting the test informed the patient in
advance of how the test would proceed and then gave verbal instructions during each test. The
patients were positioned in the centre of the platform, both feet set with their feet
shoulder-width apart. The final result of each test was a computerised risk of fall
assessment report with patient scores related to normative data.
