Bone Malalignment Clinical Trial
Official title:
Computerized Tomography (CT) Scan Study of Bone Healing Following Open Wedge Proximal Tibial Osteotomy [CT Imaging Study for Knee Osteotomy (CISKO)]
Malalignment of the knee joint causes arthritis in later life. Currently there are three
surgical ways to treat knee arthritis: total knee replacement, partial knee replacement, and
high tibial osteotomy (HTO). The former two very much focus on treating the effect of
malalignment, i.e. removing the arthritic joint. However, HTO addresses the cause of the
arthritis, namely the joint malalignment. This preserves the patient's joint and it means
that a patient will start using the unaffected part of the knee joint more.
HTO involves cutting a wedge out the tibia to correct the alignment of that bone with the
knee joint, to redistribute load from the affected medial part to lateral part. To keep the
tibia in the new position, a medical nail device is attached to keep it in place and allow
new bone to regenerate within the wedge. Currently, the market leader for HTO is the TomoFix
(by DePuySynthes company) plate and nail device. As the name suggests, TomoFix is fixed at
surgery and therefore the change in bone angle cannot be changed afterwards. It does mean
that patients can be weight-bearing on the affected leg soon after the HTO procedure. A new
CE-marked device is being tested in an interventional trial; it is produced by Ellipse
Technologies. This device is an extendable nail and inserted intramedullary; following
surgery the nail is tend slowly extended over a period of time until the bone correction is
satisfactory.
The CISKO imaging study will assess whether there is a difference between the TomoFix and
Ellipse system in terms of bone regeneration in the tibial wedge by performing a CT-scan at
3 and 6 months post-operatively. This will be quantified by two independent radiological
reports. A secondary objective is to investigate patient satisfaction and also patient pain
levels at these time intervals. The degree of bone healing is usually the main factor
holding clinicians back when it comes to advising patients on what activities they can
return to post-operatively. A difference in bone healing between the two systems may impact
on the advice clinicians can give patients regarding recommencing more intense activities
such as recreational sports, which ultimately could positively impact patients' health and
well-being.
One treatment modality for medial osteoarthritis of the knee is open-wedge high tibial
osteotomy (HTO). The current most common way of performing HTO is to use fixation plates
with locking bolts implanted in the patient's tibia, to allow increased stability & joint
movement and the ability to be weight bearing on the affected leg sooner . However, despite
advances in high tibial osteotomy technology, it can still take most patients about six
months to fully recover from the procedure. Sedentary activities are usually picked up about
a month after surgery, before physical work is introduced 3 to 4 months after surgery,
followed by sports which can be reintroduced approximately 6-12 months after surgery. One
reservation for allowing patients to be fully weight bearing early on is the perceived risk
of loss of correction of the angle, although in practice this effect appears to be a rare
occurrence . For example, in a series of patients Takeuchi and colleagues showed that full
weight-bearing is possible two weeks after surgery without implications for the correction
made to the joint angle .
It is imperative that the open wedge is healed and repopulated by new bone, to strengthen
the tibia and allow full recovery following HTO. Regeneration will take place naturally,
although some surgeons apply aids to promote bone healing, such as the ChronOS β-tricalcium
phosphate wedge. However, research into this aspect of filling the wedge has shown that
there is no advantage to using the filler - both in terms of stability and bone healing time
of the wedge . Although fixed systems like Tomofix facilitate early weight-bearing of the
affected joint, the complete closure and consolidation of the wedge takes considerably
longer. In one study, 23 /27 (85%) osteotomies were fully healed twelve months after
procedure . Histologically, there is variability in the degree of healing and indeed
maturation of bone regeneration achieved in the tibial wedge. With current fixed plate
devices, even two years post-procedure, a minor subset of patients will not have significant
signs of regeneration in the surgical site. In the majority of patients, partial bone
regeneration with fibrocartilaginous tissue takes place and in some patients by new
regenerated fibrocartilage or hyaline-like cartilage will appear .
HTO could be improved upon to allow an earlier return to activities by patients and to
achieve better rates of healing - both in terms of time and maturity of the regenerated
bone. Ellipse Technologies have devised a new nail system for high tibial osteotomy that
differs from the established 'locked' plate and nail systems. Their system functions in a
more gradual fashion. The wedge is created in the tibia as per normal but then the Ellipse
nail is inserted and per day the nail is extended in small measures (appr 1.5 mm per day)
until the desired correction has been achieved. Currently the new Ellipse system is being
trialed in various countries in Europe, including the Netherlands and the UK. The main
Ellipse trial is seeking to establish whether the corrective power of this medical device is
more accurate than the plate/nail systems in use at present. The degree of bone regeneration
in the open wedge is reported on, but not in detail - e.g. by one reporting radiologist -
and by using standard X-ray imaging which is primarily used for angle measurements.
This present study seeks to explore in more detail how the Tomofix and Ellipse high-tibial
osteotomy systems function in relation to bone regeneration in the open-wedge created as
part of the procedure by utilising CT imaging techniques rather than standard clinical X-ray
imaging. The primary aim of osteotomy is realignment of the joint and thereby preserves the
joint so that the patient can continue to enjoy the active life style, sports and
recreational activities. After an osteotomy procedure, whenever a patient asks for advice to
the clinician when they can start participating in unrestricted sports activities,
clinicians often find it very difficult to answer this question. This is primarily because
it is often very difficult to quantify the bone healing process precisely on radiographs. By
quantifying the amount of bone healing on CT scan which is more clear and accurate, the
clinician can confidently advise the patient regarding the participation in various sports
activities without ambiguity.
Further, by comparing the bone healing process between Tomofix plate and Ellipse nail,
investigators can make more informed judgement regarding their performance. This research
will also enhance the choice of implant selection in osteotomy patients based on the
duration of bone healing.
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Allocation: Non-Randomized, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Diagnostic
| Status | Clinical Trial | Phase | |
|---|---|---|---|
| Recruiting |
NCT03835000 -
Customized Biomechanical Models of the Musculoskeletal System Before and After Surgery
|