Part 1 - Dr. Gross Interview by Patricia Walter
August 26, 2011 in Baltimore, MD at the 5th Hip Joint Course
Part 2 - Dr. Gross Interview by Patricia Walter
August 26, 2011 in Baltimore, MD at the 5th Hip Joint Course
Dr. Gross Interview by Patricia Walter
Sept. 5, 2009 in Baltimore, MD at the 3rd Hip Resurfacing
Course
Dr. Gross Video Interview by Patricia Walter November 13,
2008
Click the white arrow to start the video
HIP RESURFACING SURVIVORSHIP
Thomas P. Gross, MD 2480 cases over 10 years August 2011
Survivorship of hip resurfacing continues to improve as we gain
more experience and find measures to prevent failures. Theses survivorship curves give the reader an
opportunity to see what the odds are that their implant will still be functioning at some time point after
implantation. We have used three implant systems in the last 10 years. The first were hybrid fixation
Corin devices (blue), the second were hybrid fixation Biomet devices (red), the latest are completely
uncemented Biomet devices (green).
In the last 10 years we have learned what patients with
particular characteristics are at higher risk for failure. The strategy of many experts is patient selection. If
they avoid performing hip resurfacing on higher risk patients, their overall results will improve. I disagree
with this defeatist strategy.
My improving results are
not
achieved by patient selection. I have always
practiced minimal patient selection and my criteria have not changed much over the last 10
years. Instead, my goal is to find treatment modifications to improve the results in patients that are
traditionally identified as higher risk. In some cases, we have already accumulated scientific evidence of improved
results; in other cases, we still need more time to gather data to be certain that our treatment modifications
have improved results. Examples of our innovations include:
1. Femoral neck fracture: stratifying risk of femoral neck
fracture by bone density and BMI and treating higher risk patients with slower weight bearing and
bisphosphonate drugs. We have demonstrated that this substantially reduces risk.
2. Failure of acetabular implant attachment: dysplasia patients
are at higher risk because of socket deformities. Use of Trispike acetabular components in severely
deficient sockets has eliminated these failures in this high‐risk group.
3. Femoral cysts: Bone grafting cysts instead of filling them
with cement has resulted in eliminating femoral cysts as a risk factor for failure in our patients.
4. Femoral Loosening: The major source of late failure in my
cemented femoral components. We have demonstrated that uncemented femoral components are equally as
good as cemented ones at up to four years follow‐up. Our hypothesis is that uncemented femoral
components will be less likely to loosen in the long term.
5. Adverse wear failure: This has been linked to acetabular
component position, particularly high inclination angles (AIA). We have developed an intraoperative XR
technique that has lowered the chance of implanting a component with an AIA>50 from 26% to 4%.
Recent improvements in our technique are focused on still further improvements in the odds
of achieving ideal component position.
I have been performing hip resurfacing for over 10 years and
have maintained an accurate database of current patients with an overall >90% rate of follow‐up. This chart presents
the results for 2480 cases.
Updated August 2011
Dr. Gross 2011 Summary of Outcomes for 2500 Hip Resurfacings
Dr. Gross has now performed over 2500 Hip Surface Replacement (HSR)
procedures over the last 12 years. Most failures occur during the first 6 months of the healing period. However, there is a
slow rate of failure that occurs over time. Therefore the overall failure rate increases for a group of patients as the length of follow-up
increases. In our recent publication in the Journal of Arthroplasty 2011, we reported that our Corin Hybrid HSR achieved a 93% survivorship
at 11 years follow-up. Longer-term data is not available. Multiple improvements have been made since this initial patient group.
Our most recent cases use the Biomet uncemented Recap /Magnum. We report here the early results of the first 1000 done between
March 2007 and July 2010 with a 99.4% rate of follow-up (90% completely up to date on their follow-up, and 64 % achieving at least 2 years
follow-up). Not all complications lead to failure. Below is a complete list ofmajor complications (not just failures) in the first 1000 uncemented HSR using the Biomet system:
A.) Failures Requiring Revision Surgery (1000 cases):
1. Femoral neck fracture: 6
2. Early femoral collapse (avascular necrosis): 2
3. Failure of acetabular ingrowth: 5
4. Adverse wear failure: 2
5. Deep infection with loss of implant: 0
6. Recurrent dislocations requiring revision: 0
7. Femoral component loosening: 0
8. Acetabular component loosening 0
9. Subtrochanteric femur fracture 1
(related to hardware removal)
TOTAL: 16 1.6%
B.) Cases requiring significant repeat surgery (1000 cases):
1. Traumatic intertrochanteric fracture 2
(5 and 11 months postop):
2. Deep infection (cured): 2
2. Significant superficial infection (cured): 1
3. Frostbite from ice machine: 2
TOTAL: 7 0.7%
C) Other Complications (1000 cases):
1. Dislocations: 2
2. Pulmonary emboli: 3
3. Deep vein thrombosis: 2
4. GI bleed requiring transfusion: 1
5. Minor stroke: 1
4. Nerve injuries: 0
5. Postoperative transfusions: 0
6. Femoral notches: 0
7. Vascular injuries: 0
8. Deaths: 0
TOTAL: 9 0.9%
What is the Best Bearing Type by Dr. Gross 2011
What is the Best Bone Fixation Type by Dr. Gross 2011
The controversy regarding adverse wear in metal-metal
bearings by Dr. Gross 2010
Should You Have Uncemented Hip Resurfacing by Dr. Gross. Click link to learn more.
A Seven-Year Follow-up Study Metal-on-Metal Hip Resurfacing with an
Uncemented Femoral Component Sept. 2008
Between 1999 and 2000, eighteen patients (twenty hips) underwent primary
metal-on-metal hip resurfacing with uncemented femoral and acetabular
components. One patient was lost to follow-up. This left eleven men and six
women, who had a mean age of forty-five years at the time of surgery. Clinical
and radiographic examinations were performed prospectively, and the results were
analyzed.
READ MORE
How many surgeries do you feel doctor needs to do
to be proficient?
100 HSR would be a good benchmark.
Several US surgeons allow all
activities after 6 mos. What are your guidelines?
I allow virtually all activities at 6
months.
Does the insertion of the acetabular component
require more bone removal in a resurfacing procedure as opposed to a THR.
I do both procedures and remove the same
amount of bone on the acetabular side whether it is a HSR or THR.
Do you prescribe Physical Therapy post op. Can you explain why?
With the minimally invasive posterior
approach no formal physical therapy is necessary. I think it can be counter
productive in the first 6 weeks, after 6 weeks I am happy to prescribe this.
What is your opinion about running and jogging after
hip resurfacing?
I do not recommend marathon
running but light jogging is permitted.
What is the difference between the Biomet device and
the BHR device?
I designed the Biomet
device and feel the instrumentation makes it easier for the surgeon to implant
because of their accuracy. Implants are thinner and require less bone removal.
Biomet was the first to offer 2mm sizing with 12 implant choices, now it is the
only one currently available with an uncemented component in the US.
What anesthesia do you normally prefer?
I recommend spinal
anesthesia with sedation plus multiple pre-emptive anti-nausea medications.
What Blood thinning method do you prefer?
Blood thinning is highly
controversial, there are many acceptable alternatives. My preference is 10 days
of Arixtra followed by one month of 81 mg aspirin. My DVT rate is less than 1%
with no pulmonary embolism in 1500 cases.
How long before complete bone in growth has occured for
the socket component?
I estimate the process is 90%
complete at 6 months and 100% complete at 1 year post op.
Do you suggest Fosamax to increase bone density
post op?
There is good basic science
data in animals that Fosamax increases bone deposition around uncemented
implants. Therefore, I recommend it in osteopenic patients.
What the safe levels of chromium and cobalt ions after
hip resurfacing?
No one knows what safe levels are. These are normal elements in
our body. They are elevated after placing metal implants. There is no value to
measuring and following levels at this point.
What
types of daily exercise do you suggest?
At 2 years virtually all exercise is good
except possibly extreme repetitive impact sports such as marathon running. No
one knows for sure.
Is recovery from a hip resurfacing slower than recovery for a THR?
The recovery is identical. I would recommend waiting 6 months to return to
vigorous activity. I perform both resurfacing and THRs.
What amount
and type of activity is helpful in the initial week after surgery? Is
stretching important?
Walking is a great
exercise for the hip, you should gradually be able to walk longer distances
outside, I would be very careful with stretching, hip range of motion will
return to normal with or without stretching.
How soon after resurfacing can one start stretching to regain
ROM? Do you
recommend any type of physical therapy?
You may start stretching at 6 weeks, but no extreme flexion
exercises for at least 6 months. Physical therapy is not required after a
posterior approach, the muscles recover quickly with walking and a simple home
exercise program.
What activity should I be doing during the first week post op hip resurfacing
surgery?
You should be
up out of bed, walking around in your house, and sitting in a chair most of the day.
Walking outside for one to two blocks a day is a good idea. You can gradually
progress your walking from there. You should also ice and
elevate.
