With current technology, prosthesis implants,
instrumentation, and expertise, it is expected that over 95% of dogs
with total hip replacements can resume a pain-free active life
without complications for the rest of their life. Total hip
replacement should be offered as the primary recommendation over FHO
with rare exceptions.
Based on published research, the following
conclusions can be drawn.
- To the
author’s knowledge, no literature is published in a referred
journal that objectively documents that function of a dog’s rear
leg after a FHO returns to a level comparable to normal, or to
that following a THR. Objective evidence has been reported that
dogs have significantly increased loading on the leg after total
hip replacement.
- A dog’s hip
joint is always severely biomechanically altered by the FHO
procedure.
- A dog’s leg
is shortened to a variable degree as a result of the FHO
procedure.
- Pain relief
after a FHO is unpredictable.
- Rehabilitation time after a FHO is prolonged – especially
compared to a THR.
- Small dogs
do not necessarily do better than large dogs after a FHO.
- Reported
“Excellent” results after a FHO is relatively low (37% excellent
and 26% good results reported by Gendreau and Cawley).
“Excellent” results in some reports may include those dogs
subjectively using the leg 75-100% of normal (not necessarily
objectively equal or close to100% of normal). This low
percentage of limb function after a FHO is unacceptably low
considering alternatives available.
- A veterinary
surgeon’s primary surgical recommendation to resolve hip pain
should be a THR over a FHO as an alternative salvage procedure.
Client constraints may preclude THR surgery.
To help make decisions, THR results must be compared to published
reports of the femoral head ostectomy (FHO) option. The following is
detailed referenced information about FHO in the veterinary
literature to support the conclusions drawn above.
1. Brinker states that an FHO is a nonreversible salvage
procedure that is used to improve quality of life. A fibrous false
joint forms and thus it does not maintain biomechanical function.
There is a tendency of overuse the procedure for conditions that are
repairable. Results vary considerably. A limp may remain because the
leg is shortened by removal of the femoral head and neck, some loss
of range of motion and a gait abnormality persists, and the thigh
and hip muscles remain somewhat atrophied.
The FHO is suitable if it is acceptable to have compromised hip
joint integrity, if lack of total pain relief is acceptable, or if
there are financial constraints. The text continues stating that
active use of the limb may take over 1 month and rehabilitation time
of 6 months or more are not uncommon.
2. Berzon et.al. reported the efficacy of FHO in 94 dogs and
cats. The five most common indications for a FHO included
degenerative joint disease, avascular necrosis of the femoral head,
capital epiphyseal and femoral neck fractures, comminuted acetabular
or pelvic fractures, and non-reducible or chronic coxofemoral
luxations. All of these indications, with the possible exception of
some acetabular fractures, are also indications for a THR. Acetabular
fractures and pelvic fractures are generally repairable injuries.
A majority of the evaluations were done subjectively by the
patient’s owners using a questionnaire. The results were considered
“Excellent” if dogs had 75-100% (but not necessarily 100%) limb
usage. Only 83% of the dogs were in the “Excellent” category. The
other 17% had “Good” (51-75% limb function), “Fair” (26-50% limb
function) or “Poor” (25 % limb function). It was acknowledged that
the procedure may be performed where primary repair would be
time-consuming, difficult, and economically prohibitive to the
owner.
3. Duff and Campbell reported shortened limbs, restricted hip
movement, and multiple other problems in a study of 267 FHO surgery
patients. Difficulty jumping and climbing stairs was not uncommon.
Muscle atrophy was reported in about 50% of the dogs and was a
frequent finding by dog owners even 8 years after surgery. This
atrophy can only indicate diminished limb function. Another common
finding was difficulty jumping and climbing stairs. 20% of the dogs
had hip pain when examined and the high incidence of pain was
present during the first year after surgery. 40% of the dogs had
reduced extension of the knee on the operated side. 51% of the dogs
had reduced hip extension and 50% had bony and or soft tissue crepitation in the joint. There was a high incidence of pain in the
first postoperative year. Patella instability was present 18% of the
time and all were small breed dogs that had limb shortening. 50% of
the dogs were walking “well” in 8-10 weeks and only 75% were running
in 4-5 months. 69% of the dogs examined had limb shortening –
especially in small breeds having surgery for avascular necrosis of
the femoral head. 60% of the dogs showed prominence of the greater
trochanter of the femur associated with true limb shortening. Only
50% of the dogs were walking “well” after 8-10 weeks and 75% by 3-4
months. 50% of the dogs were running well after 10-12 weeks and 75%
were considered to be running well by 4-5 months.
4. Gendreau and Cawley reported on 35 FHO operations with the
average follow-up interval of 3.1 years after surgery. Only 37.1% of
the dogs had “Excellent” function, which was defined as no
disability and inability to tell which limb had surgery. 25.7% had
“Good” function (slight gait abnormality that may occasionally be
more severe), 25.7% had “Fair” function (noticeable lameness or
carrying the leg in adverse weather conditions or when running), and
11.4% had “Poor” function (severe gait impediment and carrying the
leg most of the time). The conclusion was that the FHO does not
always return function to the operated limb. The outcome appears to
be less favorable in larger dogs, but some small dogs and a cat had
poor or fair results. Young dogs did not have better results than
older dogs.
5. Montgomery et. al. compared 3 different FHO surgical
techniques. They concluded the specific techniques compared did not
improve results between any of the groups for the percentage of leg
use during normal activity, mean postoperative time until leg use,
use of the leg or hopping while running, or lameness with exercise.
The results were similar for large and small dogs, although the
lameness tended to be milder in small dogs. Most of the small dogs
were lap dogs with little opportunity for extreme exercise. The
incidence of postoperative problems did not vary with increased body
weight. Dogs (hunting dogs) whose intended use included vigorous
exercise had a higher frequency of moderate to severe lameness.
6. Vasseur states in his publication that in mature dogs with
severe degenerative joint disease involving the hip joints, total
hip replacement restores hip function more consistently, and much
more rapidly, than FHO. He recommends a vigorous rehabilitation
program and maintenance of normal body weight to help restore
function. Complications include shortening of the operated limb,
with prominence of the greater trochanter, decreased range of motion
in the pseudoarthrosis as compared to the normal hip, muscle
atrophy, and impaired function. Occasional lameness is not unusual
in larger dogs, and they may have difficulty jumping and climbing
stairs. In addition, hunting dogs or dogs expected to perform other
challenging physical tasks should not anticipate a complete return
to normal function. Vasseur also states that it may take as long as
6 to 12 months for the animal to achieve an optimal result after FHO,
with only fair return of function.
7. Lewis also evaluated different surgical techniques for
performing the FHO surgery. An overview of the FHO procedure
shortcomings was presented. He concluded that previously reported
improved results with new techniques provided inconsistent results.
8. Grisneaux et.al. obtained objective data using force plate
computerized gait analysis on limb function 3, 15, and 120 days
after FHO with (for 21 days) and without the use of postoperative
anti-inflammatory medication. The results show that operated dogs
had significantly lower peak vertical, peak propulsive, and impulse
propulsive forces on the limb and lower angles of hip joint
abduction and extension than did normal dogs. Most of the limbs
treated by FHO were unable to regain normal function and muscle mass
after surgery. Body weight did not appear to be associated with the
outcome of the FHO. The extent of muscle atrophy at the time of
surgery correlated with prolonged recovery time. Dogs with the
lesser trochanter preserved functioned better than those where it
was partially or completely removed. Although all owners
subjectively expressed complete satisfaction with results of surgery
at the end of the study, operated dogs still had objectively
significantly lower peak vertical, peak propulsive, and impulse
propulsive forces and lower angles of hip joint abduction and
extension than did control dogs at day 120. Owners noticed worsening
of the lameness following cessation of anti-inflammatory medication.A conclusion states that active physical therapy may be a
life-long necessity of dogs undergoing FHO. The hypothesis of the
study was that promotion of active physical therapy during the first
postoperative weeks combined with administration of an NSAID would
minimize the reduction of mobility and, therefore, result in treated
dogs having greater impulse propulsive forces and hip joint
abduction and extension angles than dogs receiving a placebo. The
hypothesis could not be demonstrated.
9. Plante et.al. reported force plate objective data comparing
conservative management, FHO, and triple pelvic osteotomy treatment
of hip dysplasia in immature dogs. The dogs in the FHO group showed
ground reaction force abnormalities, most likely due to the absence
of a coxofemoral joint. The FHO group had decreased peak propulsive
and impulsive force compared to the triple pelvic osteotomy and
control group.10. Budsberg et.al. reported a study that compared the results
of treating 16 dogs with bilateral coxofemoral osteoarthritis using
total hip replacement on one side versus not on the other side. The
ground reaction forces (weight bearing) indicated that dogs had
significantly increased loading function of the treated side after
unilateral total hip replacement. The data also indicated that force
was transferred from the untreated side to the treated side during
the study period. Loading rates increased indicating an increased
willingness to load the treated hip over time. The study data
provided substantial evidence of improvement in dogs after total hip
replacement.
1. Brinker W, Piermattei D, and Flo G: Handbook of Small Animal
Orthopedics and Fracture Treatment, Second Edition, p371
2. Berzon JL, Howard PE, Covell SJ, et.al: Retrospective Study
of the Efficacy of Femoral Head and Neck Excisions in 94 Dogs and
Cats. Vet Surg, Vol 9 No3, p88-92, 1980
3. Duff R, Campbell JR: Long term results of excision
Arthroplasty of the canine hip. Veterinary Record, 101, p181-184,
1977
4. Gendreau C, Cawley AJ: Excision of the femoral head and neck:
the long term results of 35 operations: J Am Animal Hospital Assn,
13:605-608, 1977
5. Montgomery RD, Milton JL, Horne RD, et.al.: A retrospective
comparison of three techniques for femoral head and neck excision in
dogs, 16,6,423-426, 1987
6. Vasseur PB: Femoral Head and Neck Ostectomy, In Current
Techniques in Small Animal Surgery, Ed 4, MJ Bojrab Editor,
p1170-1173
7. Lewis D: Femoral head and neck excision and the controversy
concerning adjunctive soft tissue interposition. Compendium on Cont
Ed, Vol14, 11, 1463-1470, 1992
8. Grisneaux E, Dupuis J, Pibarot P, et.al.: Effects of
postoperative administration of ketoprofen or carprofen on short-
and long-term results of femoral head and neck excision in dogs.
JAVMA, Vol 223, 7, p1006-1012, 2003
9. Plante J, Dupuis J, Beauregard G, et.al.: Long-term results
of conservative treatment, excision arthroplasty and triple pelvic
osteotomy for the treatment of hip dysplasia in the immature dog.
VCOT, 10: p130-135, 1997
10. Budsberg S, Chambers J, Van Lue S, Foutz, T, and Reece L:
Prospective evaluation of ground reaction forces in dogs undergoing
unilateral total hip replacement. AJVR, Vol 57:1781-1785, 1996 |
