ARTHRITIS AND JOINT REPLACEMENT CENTER
PHILIPPINE ORTHOPEDIC INSTITUTE
Makati City
RESEARCH ARTICLE
TITLE :
CRITICAL ANALYSIS OF SIXTY FIVE (65) HIP REVISION CASES
IN A PERIOD OF TWENTY THREE YEARS (1987-2008)
AUTHOR :
Marcelino T. Cadag, MD ; Ramon B. Gustilo, MD ; Liberato Antonio
C. Leagogo, MD
ABSTRACT
Background: Over a thousand Joint Replacement Surgeries have
been done by surgeons (Gustilo/Leagogo) of the Philippine
Orthopedic Institute in the Philippines since its inception over 20
years ago. Revision surgery of failed cemented hip replacement,
have been increasing in the last decade and constitute 7% of all
joint replacement surgeries performed.
Materials and Methods: All medical records of the patients were
reviewed to determine the following: 1. Etiology 2. Duration from
index surgery 3. Common anatomical pathology and amount of leg
length discrepancy encountered. 4. Revision implants used and use
of allograft. 5. Postoperative course and complications 6.
Preliminary results (How many are ambulatory with or without
assistive device). 7. Analysis of x-ray at last follow-up (two years
minimum).
Results: A total of sixty five (65) patients were included in the
study. Forty four (44/65) patients (67.7%) underwent revision due to
aseptic loosening of components and osteolysis (femoral or
acetabular). Ten (10/65) patients (15.4%) developed infection.
Three (3/65) patients (4.6%) developed protrusio acetabuli that
necessitated revision. Periprosthetic fracture was noted in three
(3/65) patients. Another three (3/65) had implant failure. Two (2/65)
patients (3%) had hip dislocation prior to revision. Average number
of years from index surgery is 6.44 years (1-19 years) for loosening
and osteolysis, and 9 years (1-20 years) for infection. Fifty seven
(57) patients (87.7%) underwent cemented total hip prior to revision
while eight (8) patients (13.3%) underwent cemented partial hip
replacement prior to revision. Fifty six (56) patients (81%) have
shortening on the affected side with an average of 3cm (1-6cm).
Twenty five (25) patients (38.5%) had proximal femoral bone loss
requiring structural allograft. Twenty one (21) patients (32.3%) had
acetabular defect (Paprosky Types I & II) but only nine (9) required
compaction bone grafting. In forty five (45/65) patients (69.2%),
cementless (ReflectionTM) cup was used. Cementless, modular,
revision stem (Active LockTM) was used in twenty nine (29/65)
patients (44.6%). All patients were allowed full weight-bearing after
revision surgery. Four patients (6%) developed acute post-op
infection. Two patients (3%) had dislocation after revision surgery.
Functional results at short-term follow-up (two years minimum [4.4
years average]), were excellent (ambulatory without assistance) in
52.4%, good (ambulatory with assistive device) in 43%, and poor
(non-ambulatory) in 4.6%. Follow-up radiographs showed implants
in excellent alignment, no signs of loosening, migration or
subsidence.
Conclusions: The main reason for revision hip arthroplasty is
aseptic loosening (67.7%) followed by infection (15.4%). The use of
long non-cemented, modular, calcar-replacing curved revision
stem, and strut allograft on the femoral side; jumbo, cementless
cup with compaction bone grafting on the acetabular side,
addressed the problem of anatomic pathologies as a result of
failed, cemented THR. Good to excellent functional results in 95.4%
at short-term (>2 years) follow-up. There is no association between
cause for revision with gender and age of the patients. Long term
follow-up study is still ongoing.
INTRODUCTION:
The need for revision arthroplasty is steadily rising. In the United States,
the rate of revision total hip arthroplasty increased by 3.7 procedures per
100,000 persons per decade, and that of revision total knee arthroplasties, by 5.4
procedures per 100,000 persons per decade1. In a related study in the US, The
demand for hip revision procedures is projected to double by the year 2026, while
the demand for knee revisions is expected to double by 2015. Overall, total hip
and total knee revisions are projected to grow by 137% and 601%, respectively,
between 2005 and 20302. The mean total hospital cost for revision hip surgery in
the United States, back in 2005, is $31,3413. The most recent epidemiological
study on revision hip surgery in the United States found out that the average
hospital stay was 6.2 days and the average total charges was $54,533 4.
Hospital charges for revision total hip arthroplasty and revision total knee
arthroplasty were projected to increase by 290% to $3.8 billion and by 450% to
$4.1 billion5. However, there are no available data on the prevalence of revision
arthroplasty in the Philippines.
This study aims to describe cases of hip arthroplasty that necessitated
revision surgery, in terms of problems presented, etiology, duration from index
surgery, anatomical pathology, surgical approach, choice of implant, antibiotics
used, post-operative course and complications, preliminary results and analysis
of radiographs at last follow-up. We will also determine if there’s an association
between cause for revision hip surgery with gender and age of the patients.
MATERIALS AND METHODS:
We reviewed the medical records of adult patients seen at the Philippine
Orthopedic Institute (POI) who underwent hip joint reconstruction in affiliated
hospitals, developed early or late complications and underwent revision surgery
for the past twenty (20) years. A total of sixty five (65) patients were included in
the study.
Patient Demographics
There were 76 patients initially but only 65 had minimum of 2 years followup. There were 44 females and 21 males. Average age is 58.4 years (18-85
years).
Etiology
Forty four (44/65) patients (67.7%) underwent revision due to aseptic
loosening of components and osteolysis (femoral or acetabular). Ten (10/65)
patients (15.4%) developed infection. Three (3/65) patients (4.6%) developed
protrusio acetabuli that necessitated revision. Periprosthetic fracture was noted in
three (3/65) patients. Another three (3/65) had implant failure. Two (2/65)
patients (3%) had hip dislocation prior to revision. (Table 1)
Table 1. Etiology for Revision Hip Surgery
CAUSE OF REVISION
NUMBER OF
CASES
PERCENTAGE
Aseptic Loosening
Infection
Protrusio Acetabuli
Periprosthetic Fracture
Implant Failure
Dislocation
44/65
10/65
3/65
3/65
3/65
3/65
67.7%
15.4%
4.6%
4.6%
4.6%
3%
Duration from index surgery
The average number of years from index surgery is 6.44 years (1-20
years). For loosening and osteolysis, the average is 4.6 years (1-19 years), and 9
years (1-20 years) for infection.
Anatomical Pathology
Fifty six (56) patients (81%) have shortening on the affected side with an
average of 3cm (1-6cm). Twenty five (25) patients (38.5%) had proximal femoral
bone loss requiring structural allograft. Twenty one (21) patients (32.3%) had
acetabular defect (Paprosky Types I [57%] & Type II [43%] ) but only nine (9)
required compaction bone grafting.
Revision Implants Used
In forty five (45/65) patients (69.2%), cementless (Reflection TM) cup was
used. Cementless, modular, calcar-replacing, curved revision stem (Active
LockTM) was used in twenty nine (29/65) patients (44.6%). Cemented stem was
used in 24 patients (37%), and cemented cup in 11 patients (17 %). We retained
the cup in 8 patients (12.3%), and retained the stem in 11 patients (17 %).
RESULTS:
Since 1984, the most number of hip revision surgery performed was in
1997 with nine (9) cases, the number of cases dropped in 1998 with only one
revision surgery. From then, there was a gradual increase in number of cases
until 2005 and a decreasing trend until 2007 (Figure 1). The age group with most
number of revision cases was the 40 - 79 year old group, and the least were the
group of patients less than 40 years and more than 80 years (Figure 2).
Number of Patients with Hip Revision Surgery Per Year
10
9
Number of Patients
8
7
6
5
4
3
2
1
2002
2003
2004
2005
2006
2007
2002
2003
2004
2005
2006
2007
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
1989
1988
1987
1986
1985
1984
0
Year of Revision
Number of Patients
Figure 1.
Distribution of Patients Per Age Group Per Year
Number of Patient
5
4
3
2
1
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
1989
1988
1987
1986
1985
1984
0
Year of Revision
1 - below 30
2 - 30 - 39
3 - 40 - 49
5 - 60 - 69
6 - 70 - 79
7 - 80 and above
4 - 50 - 59
Figure 2.
More hip revision surgery were performed in women than men (200%),
and this has been constant since 1991 – 2007 (Figure 3). As previously stated,
the main cause of hip revision surgery was aseptic loosening followed by
infection. (Figure 4).
Gender Distribution Per Year of Patients Who Underwent Hip Revision
Surgery
6
Number of Patient
5
4
3
2
1
2001
2002
2003
2004
2005
2006
2007
2001
2002
2003
2004
2005
2006
2007
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
1989
1988
1987
1986
1985
1984
0
Year of Revision
1 - Male
2 - Female
Figure 3.
Causes of Hip Revision Surgery Per Year
10
8
7
6
5
4
3
2
1
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
1989
1988
1987
1986
1985
0
1984
Cause of Revision
9
Year of Revision
1 - aseptic loosening
2 - protrusio acetabuli
3 - infected THA
4 - others (hip dislocation, periprosthetic fracture)
Figure 4.
Statistical Analysis
Chi-square test for independence (Pearson chi-square) with 5% level of
significance, was used to determine if there’s an association between the cause
of revision, with the gender of the patients.
A. Association Between Reason for Hip Revision Surgery and Gender
Crosstab
Hip Revision
Surgery
As eptic Loosening
Protrus io Acetabuli
Infected THA
Others
Total
Count
% within Hip
Revision Surgery
Count
% within Hip
Revision Surgery
Count
% within Hip
Revision Surgery
Count
% within Hip
Revision Surgery
Count
% within Hip
Revision Surgery
Gender
Male
Female
15
29
34.1%
65.9%
Total
44
100.0%
3
3
100.0%
100.0%
4
4
8
50.0%
50.0%
100.0%
2
8
10
20.0%
80.0%
100.0%
21
44
65
32.3%
67.7%
100.0%
Crosstab
Hip Revision
Surgery
As eptic Loosening
Others
Total
Count
% within Hip
Revision Surgery
Count
% within Hip
Revision Surgery
Count
% within Hip
Revision Surgery
Gender
Male
Female
15
29
Total
44
34.1%
65.9%
100.0%
6
15
21
28.6%
71.4%
100.0%
21
44
65
32.3%
67.7%
100.0%
Chi-Square Tests
Pearson Chi-Square
Continuity Correction a
Likelihood Ratio
Fis her's Exact Test
Linear-by-Linear
As sociation
N of Valid Cases
Value
.198b
.026
.200
.195
df
1
1
1
1
As ymp. Sig.
(2-sided)
.656
.872
.654
Exact Sig.
(2-sided)
Exact Sig.
(1-sided)
.780
.441
.659
65
a. Computed only for a 2x2 table
b. 0 cells (.0%) have expected count less than 5. The minimum expected count is
6.78.
We can see that at 95% level of significance, a p-value of 0.780 is not significant
(greater than 0.05). This means there is no association between gender and revision hip
surgery.
The Fisher’s Exact Test with 5% level of significance, was used to
determine if there’s an association between cause of revision and age of the
patients.
B. Association Between Reason for Hip Revision Surgery and Age
Descriptive Statistics
Hip Revision Surgery
(Age)
Aseptic Loos ening
Protrusio Acetabuli
Infected THA
Others
N
44
3
8
10
Minimum
18
55
36
43
Maximum
87
78
80
85
Mean
56.23
67.67
57.63
65.80
Std. Deviation
14.48
11.68
18.02
11.97
Age * Hip Revision Surgery Crosstabulation
Age
60 and below
above 60
Total
Count
% within Age
Count
% within Age
Count
% within Age
Hip Revision Surgery
As eptic
Loosening
Others
29
8
78.4%
21.6%
15
13
53.6%
46.4%
44
21
67.7%
32.3%
Total
37
100.0%
28
100.0%
65
100.0%
Chi-Square Tests
Pearson Chi-Square
Continuity Correction a
Likelihood Ratio
Fis her's Exact Test
Linear-by-Linear
As sociation
N of Valid Cases
Value
4.485b
3.422
4.485
4.416
df
1
1
1
1
As ymp. Sig.
(2-sided)
.034
.064
.034
Exact Sig.
(2-sided)
Exact Sig.
(1-sided)
.060
.032
.036
65
a. Computed only for a 2x2 table
b. 0 cells (.0%) have expected count less than 5. The minimum expected count is
9.05.
At 95% level of significance, there is no association between hip revision surgery
and age (p-value=0.06 is greater than 0.05).
Post-operative and Clinical Outcome
All patients were allowed weight-bearing as tolerated with walker or cane,
after revision surgery. Four patients (6%) developed acute post-op infection.
Two patients (3%) had dislocation after revision surgery. Functional results at
short-term follow-up (two years minimum [4.4 years average]), were excellent
(ambulatory without assistance) in 52.4%, good (ambulatory with assistive
device) in 43%, and poor (non-ambulatory) in 4.6%. Sixteen (16) patients
(24.6%) had more than 1 revision surgery and one (1) patient developed a
chronic draining sinus who later underwent resection arthroplasty.
Analysis of Radiographs at Last Follow-up
Follow-up radiographs showed implants in good alignment, no signs of
loosening, migration or subsidence. There were six (6) patients (9.2%) who
developed heterotopic ossification (HO) around the hip joint but did not affect the
functional outcome of the patients.
DISCUSSION:
Aseptic loosening secondary to wear-debris-induced osteolysis has been
identified before, as the leading cause of late failure of total hip arthroplasty6.
Osteolysis can be divided into several categories: patient-specific, implantspecific, and the result of surgical factors7. With recent advances in polyethylene
manufacturing and processing, alternative bearing surfaces, implant design, early
clinical results are encouraging, demonstrating 50% to 81% decreases in
radiographic wear rates8.
It is well known that wear particles are the primary driving force in aseptic
loosening of orthopedic implants. Wear particles are generated by the primary
articulation between the polyethylene liner and the metal head, as well as from
the metal back and polyethylene insert. Considerable evidence has emerged
demonstrating that various other factors can modulate the biologic activity of
orthopedic wear particles. Two of the most studied modulating factors are
bacterial endotoxins and implant motion9.
Infection is fairly common in primary arthroplasty cases, and has a higher
incidence in revision surgery. In the management of infected implant sites,
antibiotic-impregnated cement used in one-stage exchange arthroplasties has
lowered reinfection rates. In two-stage procedures, use of beads and either
articulating or nonarticulating antibiotic-impregnated cement spacers also has
lowered reinfection rates. Spacers also reduce "dead space," help stabilize the
limb, and facilitate reimplantation. Problems associated with antibioticimpregnated cement in total joint arthroplasty include weakening of the cement
and the generation of antibiotic-resistant bacteria in infected implant sites10.
Implant design and positioning are important factors in maintaining stability
and minimizing dislocation after total hip arthroplasty. Recent prosthesis designs
can cause intra-articular prosthetic impingement within the arc of motion required
for normal daily activities and thus lead to limited motion, increased wear,
osteolysis, and subluxation or dislocation. Minimizing impingement involves
avoiding skirted heads, appropriate size of the head and acetabular implant,
maximizing the head-to-neck ratio, and, when possible, using a chamfered
acetabular liner and a trapezoidal, rather than circular, neck cross-section.
Computer modeling studies indicate the optimal cup position is 45° to 55°
abduction. Angles <55° require anteversion of 10° to 20° of both the stem and
cup to minimize the risk of impingement and dislocation11.
Recently, in the United States, the most common causes of hip revision
were instability/dislocation (22.5%), mechanical loosening (19.7%), and infection
(14.8%)4. And the most common type of revision total hip arthroplasty procedure
performed was all-component revision (41.1%)4.
Revision surgery of failed cemented total hip can be approached
systematically. On the femoral side, the problem of aseptic loosening and bone
loss may be solved by using a fully-coated, curved, modular revision system and
strut allograft augmentation.
Modular femoral component systems typically provide accurate bone
preparation through independent proximal metaphyseal machining (milling) and
distal reaming providing improved line-to-line preparation. This facilitates precise
fit and fill that allows for reliable and accurate seating of the femoral component,
enhancing more accurate reproduction of appropriate neck offset, length, and
version. In addition, the ActiveLockTM technology provides a unique locking
strength that does not generate metallic wear debris (fretting). This technology
also allows the component position to be adjusted intraoperatively which can be
advantageous when doing revision surgery.
On the acetabular side, the problem of aseptic loosening and bone loss
remains to be a challenge. In this study, two treatment options were used, a
jumbo cementless acetabular socket and a regular cementless acetabular cup
placed superiorly, relative to the true hip center (high hip center).
In the presence of severe acetabular bone loss, other treatment options
include the use of an anti-protrusio cage, an oblong cup and structural allograft.
In one report, a custom triflange acetabular prosthesis was used to treat massive
acetabular bone loss and pelvic discontinuity in twenty eight (28) consecutive
patients (30 hips), and provided a durable solution with good clinical results12.
Ideally, the true hip center should be restored to address both the shortening and
the biomechanical imbalance brought about by an eccentric (high) hip center.
In this study, the problem of shortening and leg length inequality was
addressed by using a calcar-replacing stem, a +10 femoral head, a thick,
eccentric, off-set acetabular liner and by restoration of the true hip center.
Revision hip arthroplasty entails a lot of surgical skills and financial burden
to patients. In one study done in the US, hospital resource utilization for revision
total hip arthroplasty was found to be significantly higher than that for primary
arthroplasty3.
The economic and clinical impact of revision total hip surgery in the
Philippines is beginning to dawn.The cost of revision total hip surgery, let alone
primary total hip surgery, is too much for the average Filipino (GDP per capita of
$3,200). Clinically, only a handful of surgeons are equipped with the proper
training, knowledge, experience and skills to perform revision hip surgery in the
Philippines.
Proper indication for primary total hip surgery, proper surgical technique
(including asepsis and antisepsis), appropriate implant selection, good cementing
technique and adequate surgical prophylaxis, all contribute to reduction of cases
requiring revision hip surgery. Considering the economic and clinical burden of
revision total hip surgery, doing a good primary total hip surgery is paramount in
preventing future revisions. All total hip systems are designed to last for 10-15
years, but we found out in this study that average number of years from index
surgery to revision is much less (6.4 years) than expected. Factors that may
affect long term outcome of arthroplasty include surgical approach, technical
expertise of surgeon, duration of operation, choice of implant, cementing
technique, condition of bone stock, administration of antibiotics and pre-existing
medical condition of the patient.
Cementless acetabular system has been used extensively in primary total
hip as well as revision surgery. However, the problem of polyethylene wear
brought about by metal-backing (backside wear) has yet to be addressed.
Backside wear can be significantly reduced by improving the locking mechanism
of the polyethylene insert to the metal back acetabular socket. Presently, all
cementless acetabular systems use the “press-fit”, passive locking mechanism.
The development of a better locking mechanism remains to be an engineering
challenge.
Alternative bearing surfaces, such as highly cross-linked polyethylene,
ceramic-on-ceramic, and metal-on-metal articular surfaces, have been introduced
in an attempt to reduce wear and osteolysis following total hip arthroplasty.
Intermediate-term follow-up data available suggest that the prevalence and
severity of osteolysis may be reduced with these materials compared with
conventional metal-on-polyethylene bearing surface couples. However, long-term
data are presently unavailable; the future performance of these bearings awaits
clinical validation13. Currently, only alumina-on-alumina bearings can claim
virtually no biologic risk14.
CONCLUSIONS:
The main reason for revision hip arthroplasty in the Philippines is aseptic
loosening (67.7%) followed by infection (15.4%), protrusio (4.6%), periprosthetic
fracture (4.6%), implant failure (4.6%) and dislocation (4%).
The use of long, modular, noncemented, calcar-replacing, curved revision
stem, with the use of strut allograft, addressed the problem of anatomic
pathologies on the femoral side as a result of failed, cemented THA.
On the acetabular side, jumbo, cementless cup with compaction bone
grafting, and eccentric placement of the hip center, addressed the problem of
loosening and bone loss. The use of an Anti-Protrusio Cage (APC), oblong cup,
and structural allograft, in revision of the acetabular side is very promising.
Good to excellent functional results in 95.4% at short-term (>2 years)
follow-up.
There is no association between cause for revision with gender and age of
the patients.
Doing a good primary total hip surgery is paramount in preventing future
revisions.
BIBLIOGRAPHY:
1. Prevalence of Primary and Revision Total Hip and Knee
Arthroplasty in the United States From 1990 Through 2002
J. Bone Joint Surg. Am., Jul 2005; 87: 1487 - 1497.
2. Projections of Primary and Revision Hip and Knee Arthroplasty
in the United States from 2005 to 2030
J. Bone Joint Surg. Am., Apr 2007; 89: 780 - 785.
3. Hospital Resource Utilization for Primary and Revision Total Hip
Arthroplasty
J. Bone Joint Surg. Am., Mar 2005; 87: 570 - 576.
4. The Epidemiology of Revision Total Hip Arthroplasty in the
United States
J. Bone Joint Surg. Am., Jan 2009; 91: 128 - 133.
5. Future Clinical and Economic Impact of Revision Total Hip and
Knee Arthroplasty
J. Bone Joint Surg. Am., Oct 2007; 89: 144 - 151.
6. Clinical Performance of Highly Cross-Linked Polyethylenes in
Total Hip Arthroplasty
J. Bone Joint Surg. Am., Dec 2007; 89: 2779 - 2786.
7. What Patient and Surgical Factors Contribute to Implant Wear
and Osteolysis in Total Joint Arthroplasty?
J. Am. Acad. Ortho. Surg., July 2008; 16: S7 - S13.
8. How Prevalent are Implant Wear and Osteolysis, and How Has
The
Scope
of
Osteolysis
Changed
Since
2000?
J. Am. Acad. Ortho. Surg., July 2008; 16: S1 - S6.
9. What Other Biologic and Mechanical Factors Might Contribute To
Osteolysis?
J. Am. Acad. Ortho. Surg., July 2008; 16: S56 - S62.
10. Use of Antibiotic-Impregnated Cement in Total Joint Arthroplasty
J. Am. Acad. Ortho. Surg., January/February 2003; 11: 38 - 47.
11. Dislocation After Total Hip Arthroplasty: Implant Design and
Orientation
J. Am. Acad. Ortho. Surg., March/April 2003; 11: 89 - 99.
12. Revision Total Hip Arthroplasty for Pelvic Discontinuity
J. Bone Joint Surg. Am., Apr 2007; 89: 835 - 840.
13. How Have Alternative Bearings (Such as Metal-On-Metal, Highly
Cross-Linked Polyethylene, and Ceramic-On-Ceramic) Affected
The
Prevention
and
Treatment
of
Osteolysis?
J. Am. Acad. Ortho. Surg., July 2008; 16: S33 - S38.
14. How Do Alternative Bearing Surfaces Influence Wear Behavior?
J. Am. Acad. Ortho. Surg., July 2008; 16: S86 - S93.
REPRESENTATIVE CASES:
Case 1
V.T., 54 y.o., female; underwent total hip arthroplasty with acetabular roof
augmentation, right, for dysplastic hip, 12 years prior to revision;
Patient presented with groin & thigh pain with shortening (3cm) of the right
lower extremity.
Pre-revision radiographs revealed aseptic loosening on both acetabular
side & femoral side with proximal femoral bone loss.
PRE-REVISION
3 YEARS POST-REVISION
Patient underwent revision surgery using cementless acetabular (10mm
offset cup) and femoral component (modular mid-length stem, fully coated) with
30mm calcar, 22mm head +10mm and proximal femoral cortical allograft. At
three years post revision, the patient is ambulating without assistive device,
functional range of motion on the right hip joint, no shortening and no pain.
Radiographs revealed that the implants are in good alignment, no sign of
loosening, migration or subsidence. Patient developed type 2 heterotopic
ossification but did not affect the functional outcome.
Case 2
N.M., 61 y.o., male; underwent cemented hemi-arthroplasty, right, 18
years prior to revision. Slipped and fell necessitating conversion to a cemented
total hip. Sustained periprosthetic fracture and underwent revision hip surgery
using a longer stem, a new acetabular cup cemented into the existing cup, and
fibular strut graft. Patient developed infection 2 months after revision surgery.
Patient presented with draining sinus, groin pain with shortening (4cm) of
the right lower extremity.
Pre-revision radiographs revealed protrusion of the endoprosthesis into
the supero-medial wall of the left acetabulum. There’s also proximal femoral
bone loss.
Pre-revision radiographs revealed loosening on both acetabular side &
femoral side.
Patient underwent staged revision wherein the 1st stage entailed
removal of all components and application of antibiotic spacer. Second stage
involved removal of the antibiotic spacer and application of cementless
acetabular (52mm) cup and femoral component (modular revision, curved stem,
fully coated) with 30mm calcar, 28mm head +10mm and proximal femoral cortical
allograft. At three years post revision, the patient is ambulating without assistive
device, functional range of motion on the right hip joint, no shortening and no
pain. Radiographs revealed that the implants are in good alignment, no sign of
loosening, migration or subsidence. Patient developed type 2 heterotopic
ossification but did not affect the functional outcome.
INJURY FILM
PRE-REVISION
1ST STAGE
3 YEARS POST 2ND STAGE