Hinge total knee replacement revisited
Hugh U. Cameron, MB ChB;* Cungen Hu, MD;† Didier Vyamont, MD†
Canadian Journal of Surgery 1997;40(4):278-283
[résumé]
*Associate Professor, Department of Surgery, Department of Pathology
and Department of Engineering, University of Toronto. Staff Orthopedic
Surgeon, Orthopaedic & Arthritic Hospital, Toronto, Ont. †Clinical
Fellow, Orthopaedic & Arthritic Hospital, Toronto
Accepted for publication July 12, 1996
Correspondence and reprint requests to: Dr. Hugh U. Cameron,
Orthopaedic & Arthritic Hospital, 42 Wellesley St. E, Toronto ON M4Y
1H1
© 1997 Canadian Medical Association (text and abstract/résumé)
Contents
Abstract
Objective: To determine if aseptic loosening is a major problem in hinge
total knee replacement.
Design: A cohort study.
Setting: A university-affiliated institute, specializing in elective
orthopedic surgery.
Patients: Fifty-eight patients, mainly those requiring revision, in
whom the conditions were such that it was felt only a totally constrained
implant was appropriate. In 7 patients the implant was press-fitted; in
the remainder it was cemented. Five patients required fusion or revision,
and 8 died less than 2 years after implantation, leaving 45 for review.
Follow-up was 2 to 13 years.
Intervention: Total knee replacement with a Guepar II prosthesis.
Main outcome measures: Radiolucency determined by the Cameron system
and clinical scoring using the Hospital for Special Surgery system.
Results: Of the cemented components, 91% of femoral stems were type
IA (no lucency), 9% were type IB (partial lucency), with no type II or
III lucency. Tibial lucency was 87% type IA and 13% type IB, with no type
II or III lucency. Of the noncemented components, 58% of femoral components
were type IA and 42% type IB. Tibial lucency was 71% type IA and 29% type
IB. Lucency was mainly present in zones 1 and 2 adjacent to the knee. Clinical
rating was 18% excellent, 20% good, 20% fair and 42% poor. Postoperative
complications included infection (13%), aseptic loosening (7%), quadriceps
lag (16%) and extensor mechanism problems (16%).
Conclusions: Aseptic loosening is an uncommon problem in hinge total
knee replacement. The complication rate in cases of sufficient severity
as to require a hinge replacement remains high. Current indications for
a hinge prosthesis are anteroposterior instability with a very large flexion
gap, complete absence of the collateral ligaments and complete absence
of a functioning extensor mechanism.
Résumé
Objectif : Déterminer si le descellement aseptique pose un problème
important dans l'arthroplastie totale du genou.
Conception : Étude de cohortes.
Contexte : Établissement affilié à une université,
spécialisé en chirurgie orthopédique élective.
Patients : Cinquante-huit patients, surtout ceux qui avaient besoin
d'une révision, dont la condition était telle qu'on a jugé
que seule une prothèse avec contrainte totale convenait. Chez 7
patients, la prothèse a été ajustée sous pression.
Chez les autres, elle a été cimentée. Cinq patients
ont eu besoin d'une fusion et d'une révision et 8 sont morts moins
de 2 ans après l'implantation de la prothèse, ce qui en a
laissé 45 pour la révision. Le suivi a varié de 2
à 13 ans.
Intervention : Arthroplastie totale du genou avec prothèse Guepar
II.
Principales mesures des résultats : Transparence aux rayons X
déterminée par le système Cameron et évaluation
clinique au moyen du système de l'hôpital pour interventions
chirurgicales spéciales.
Résultats : Parmi les pièces cimentées, 91 % des
tiges fémorales étaient du type IA (aucune transparence),
9 % étaient du type IB (transparence partielle) et il n'y avait
aucune transparence de type II ou III. La transparence tibiale était
de 87 % dans le cas du type IA et 13 % dans celui du type IB et il n'y
avait aucune transparence de type II ou III. Parmi les pièces non
cimentées, 58 % des pièces fémorales étaient
de type IA et 42 % de type IB. La transparence tibiale était de
71 % dans le cas des pièces IA et de 29 % dans celui de type IB.
Il y avait transparence surtout dans les zones 1 et 2 adjacentes au genou.
Les évaluations cliniques ont été les suivantes :
excellent, 18 %, bon, 20 %, moyen, 20 % et médiocre, 42 %. Parmi
les complications postopératoires, mentionnons l'infection (13 %),
le descellement aseptique (7 %), une phase de latence du quadriceps (16
%) et les problèmes du mécanisme extenseur (16 %).
Conclusions : Le descellement septique est un problème peu fréquent
dans les cas d'arthroplastie totale du genou. Le taux de complication dans
les cas suffisamment graves pour entraîner un remplacement de l'articulation
demeure élevé. Les indications courantes pour l'implantation
d'une prothèse de l'articulation sont l'instabilité antéropostérieure
avec un écart très important à la flexion, l'absence
totale des ligaments collatéraux et l'absence totale du mécanisme
extenseur fonctionnel. [ Contents ]
In a previous review of hinge total knee arthroplasty used as a salvage
procedure,1 the outcome exceeded expectations, with a low incidence
of loosening. Some of the earlier indications for hinge prostheses with
very long stems have been superseded by the introduction of modular stem
extensions for routine knee arthroplasty and the advent of intermediate
stabilized implants such as posterior stabilized and constrained condylar
prostheses for those who have had a prior patellectomy. Nonetheless, there
are occasionally cases in which a hinge is the only reasonable choice of
implant. More than 50 hinged implants have been inserted over the last
15 years, so a further review is appropriate to see if the previous outcome1
could be confirmed and to follow-up the original patients.
[ Contents ]
Patients and methods
All patients having Guepar II hinged implants (Benoit-Gerrard Company,
Caen, France) inserted by the senior author (H.U.C.) have been followed
up annually whenever possible by clinical and radiologic methods. Clinical
assessment was by the Hospital for Special Surgery (HSS) score,2
and radiologic assessment was by a previously described method,1
which, briefly, is as follows: type IA -- no lucency, type IB -- partial
lucency, type II -- complete lucency, the lines being parallel to the stem,
and type III -- complete lucency with divergent lines. For the purpose
of this study, the x-ray films were reviewed by an independent assessor
(D.V.).
Patients
There were 58 patients (18 men, 40 women), 4 of whom had bilateral implants.
The patients ranged in age from 41 to 84 years, 2 were under 50 years old,
5 under 60 and the majority 70 years or older. Only 1 patient had not previously
undergone knee surgery. She had a globally unstable knee resulting from
poliomyelitis. Two patients had nonunion of a high tibial osteotomy, and
2 had nonunion of supracondylar fractures. Four knees had been fused. Eleven
patients had undergone a tibial osteotomy and 8 a patellectomy. Nineteen
patients had had a single total knee replacement, 17 had undergone 2 total
knee replacements, 7 had undergone 3 total knee replacements, and 1 had
had 4 total knee replacements. Nine of the previous total knee replacements
had had significant constraint, including 3 hinge prostheses, 2 spherocentric
prostheses and 4 constrained condylar knee prostheses. Follow-up was 2
to 13 years (mean 4.2 years).
Preoperative complications included sepsis in 8 patients, patellar avascular
necrosis in 8, patellar dislocation in 6 and supracondylar fracture in
6.
Indications for hinge prostheses
The indications for a hinge with a very long stem were varied and often
there were 2 or more relative indications. These included the following:
nonunion in 4 patients (femur in 2 and tibia in 2); a shattered femur in
1 patient; lateral rotational dislocation of a total knee prosthesis in
3 patients; an absent medial collateral ligament in 4 patients; a huge
gap, usually in flexion, requiring more than 30 mm of polyethylene in 12
patients (Fig. 1 and Fig.
2); bone loss and ligament instability in 9 patients; an L-shaped tibia
with platform overhang as a result of previous high tibial osteotomy in
2 patients; a tibial diaphyseal slot required for previous tibial component
removal in 1 patient; absent patella with fusion in 4 patients; previous
hinge/constrained condylar knee prosthesis in 9 patients; and reflex sympathetic
dystrophy in 2 patients. (As both had no relief from lumbar sympathetic
blocks and had a well-functioning Guepar II prosthesis on the other side,
they were convinced that a hinge implant would solve their problem. In
fact it did not, reinforcing the belief that the treatment of reflex sympathetic
dystrophy should be nonsurgical.)
Operative details
Noncemented press-fit fixation was adopted in 7, mainly septic, cases.
In 2 cases, the tibia only was press-fitted because a linear fracture occurred
during canal preparation. Fifty-one implants were cemented by standard
techniques (i.e., canal plugging at the stem tip, water pick, canal brushing
and pressure injection of the cement). The original polyethylene patella
was left in place in 4 cases. In 10 cases, a press-fit all-polyethylene
patella was used and in 1 case a noncemented metal back patella was used.
In 22 cases, a patelloplasty was done, trimming the patella to match the
trochlea.
Intraoperative complications included 2 longitudinal tibial fractures,
fat embolism in 1 press-fit case and 1 shattered femur during attempted
previous implant removal. Twenty-four patients required a lateral retinacular
release.
Exclusions
Five patients required knee fusion or revision to a non-Guepar prosthesis
and 8 were lost to follow-up, mainly through death within 2 years of the
index operation. This left 45 patients for review. Six others had also
died, but because the follow-up was longer than 2 years and they had a
functioning knee at the time of death, they were included in this review.
[ Contents ]
Results
Radiologic assessment
In the cemented components, femoral lucency was 91% type IA and 9% type
IB, with no cases of type II or type III. Tibial lucency was 87% type IA,
13% type IB, with no cases of type II or type III. Of the 7 noncemented
cases, femoral lucency was 58% type IA and 42% type IB. Tibial lucency
was 71% type IA and 29% type IB. Lucency when present was mainly in zones
1 and 2 adjacent to the knee.
Clinical assessment
Using the HSS rating system, we found that the results were 18% excellent,
20% good, 20% fair and 42% poor. This is not a true reflection of the knee
itself as most patients had significant comorbidities that considerably
lessened the function score. Pain score was as follows: no pain in 58%
of patients, minimal pain not requiring analgesics 16%, mild pain requiring
analgesics but not affecting function in 9% and moderate to severe pain
in 17%. Two of these patients had reflex sympathetic dystrophy of the knee.
The range of movement was greater than 100° in 44% of cases, greater
than 90° in 84% and greater than 75° in 92%. The patella or patellar
tendon tracked in the trochlea in 42 patients and was subluxed in 3.
Complications
Postoperative complications included infection in 6 patients (13%).
In 2 of them the infection occurred many years postoperatively. and they
are currently being treated with antibiotic suppression. The other 4 patients
had infection subsequent to additional surgery that was required after
the index operation. Two patients required repeat fusion and 2 required
revision, 1 of which was a Girdlestone procedure. A quadriceps lag was
present in 7 (16%) patients and was generally less than 10°; however,
2 patients had complete loss of extension power. Extensor mechanism problems
occurred in 7 (16%). These included a patellar tendon avulsion in 1, patellar
avascular necrosis requiring patellectomy in 1, patellectomy for reflex
sympathetic dystrophy in 1, patellar tendon avascular necrosis with attempted
allograft in 1, quadriceps tendon rupture in 2 and patellar dislocation
requiring repair in 1. Three patients (7%) had aseptic loosening. A press-fit
tibial prosthesis was used for a longitudinal fracture in 1 of the patients;
when the fracture healed, the stem was simply cemented in place 1 year
later. One patient who had a shattered femur had an additional 2 unsuccessful
attempts at reconstruction. She required a Girdlestone procedure. Another
patient had a fall and broke the lateral femoral condyle. His implant subsequently
loosened. Although culture specimens taken at the time of re-revision were
negative, infection was suspected and became obvious subsequently. All
these patients had type III lucency prior to revision. A stress fracture
of the ipsilateral femoral neck developed several months postoperatively
in 2 patients. One patient required a total hip replacement3
and in the other patient the fracture healed with conservative management Fig. 3 and Fig. 4).
[ Contents ]
Discussion
Initially, loosening was thought to have been the main problem with a fixed-axis
prosthesis, but a striking fact emerging from this study is that loosening
is really not a problem. In retrospect, the loosening reported in earlier
series was almost certainly due to stems that were too short and cementing
techniques that were inadequate. In the initial report on this group of
patients, the senior author was concerned about the rapid development of
lucency close to the knee where a previous stem component had been used.
However, the lucency does not seem to have progressed. One factor that
may be important is that the replacements were done as salvage procedures
in patients who were generally elderly with multiple comorbidity and hence
made relatively low demands on their knees. Also remarkable is that whereas
the occurrence rate of lucency in press-fit stems is much higher than in
cemented stems, none have required revision for symptomatic loosening except
2 predictable cases. The Guepar II prosthesis is not designed as a press-fit
stem, a fact that makes this finding all the more surprising and indicates
the potential for a noncemented hinge-type prosthesis.
In the initial series reported in 1989, the clinical results were 66.6%
good or excellent, 29.7% fair, and 7.7% poor. The current rating is 38%
good or excellent, 20% fair and 42% poor. One reason for this change is
that many patients in the initial series are now very elderly with consequent
reduction in activity level. Furthermore, in the last 5 years, as the degree
of constraint offered by constrained condylar type knees has increased,
the indications for a fixed-axis knee have decreased. Consequently, patients
requiring a fixed-axis prosthesis have had much more severe disease with
a predictably poorer outcome.
In reviewing the world's literature on the subject of hinges, we felt
that the early reports would simply reflect poor design and poor cementation.
Hence, only reports published in the last 10 years were considered. Cases
of tumour were also excluded as these obviously present a somewhat different
situation.
Blauth and Hassenpflug,4 using the Blauth hinge in 497 knees with a
mean follow-up of 45 months, found an aseptic loosening rate of 1.2%, a
deep infection rate of 3% and extensor mechanism problems in 10%. Eighty-eight
percent of the patients had knee flexion greater than 90°. No indications
for operation were given. Hoikka and associates,5 using the
Guepar I prosthesis, reported on 55 cases, with a follow-up of 5 years.
The rate of loosening was 14.5%. In 3 cases, arthrodesis was carried out.
Patellar subluxation and dislocation were noted in 45.5% of cases. Indications
were not given, but it was recommended that a hinge only be used in aged
patients with extremely damaged and unstable knees. Karpinski and Grimer,6
using the Stanmore hinge, followed up 52 patients after knee revision.
Infection was noted in 4% of patients, and 2 patients had aseptic loosening.
Poor results were obtained in 29% of patients.
Shindell and colleagues,7 using the Noiles knee, reviewed
18 patients with knee replacement. In 56%, the operation failed within
32 months. No indications were given. Egsted, Olsen and Krogh8
reported on the use of the St. George hinge prosthesis in 38 knees. There
was a loosening rate of 3.5% and an infection rate of 3.8%. Indications
were not given.
The St. George hinge, the original Guepar prosthesis, and the original
Noiles knees are now obsolete. Except with these components, loosening
has not been a major problem. Extensor mechanism problems do exist and
may in part be due to the fixed-axis nature of these prostheses. When most
of these prostheses were used, however, the need to externally rotate the
femoral component slightly was probably unrecognized. A rotating platform
tibial component may help with patellar mechanics. The majority of extensor
mechanism problems we experienced, however, related more to multiple surgeries
with consequent problems with blood supply to the extensor mechanism than
to the prosthesis.
Infection remains a concern, and the problems experienced in removing
a cemented long stem may be formidable and make re-revision exceedingly
difficult, although the advent of the modular hinge prosthesis may render
this possible.
With the availability of posteriorly stabilized knees, constrained condylar
knees and other knees with modular stems, some of the original indications
used in this series no longer apply. The main indication that we still
feel exists is anteroposterior instability, especially if there is a very
large flexion gap in comparison to the extension gap, complete absence
of the medial collateral ligament and lateral rotational instability due
to complete absence of any lateral stabilizing structures. Complete absence
of any functional extensor mechanism also requires a hinge prosthesis capable
of slight hyperextension to allow a swing-through gait.
[ Contents ]
References
-
Cameron HU, Jung YB. Hinged total knee replacement indications
and results. Can J Surg 1990;33(1):53-7.
-
Insall JN, Ranawat CS, Aglietti P, Shine J. A comparison
of four models of total knee replacement prostheses. J Bone Joint Surg
[Am] 1976;58(6):754-65.
-
Cameron HU. Femoral neck stress fracture after total knee
replacement. Am J Knee Surg 1991;34:625-6.
-
Blauth W, Hassenpflug J. Are unconstrained components essential
in total knee arthroplasty? Long-term results of the Blauth knee prosthesis.
Clin Orthop 1990;258:86-94.
-
Hoikka V, Vankka E, Eskola A, Lindholm TS. Results and complications
after arthroplasty with a totally constrained total knee replacement. Ann
Chir Gynaecol 1989; 78:94-6.
-
Karpinski MR, Grimer RJ. Hinged knee replacement in revision
arthroplasty. Clin Orthop 1987;220:185-91.
-
Shindell R, Neumann R, Connolly JF, Jardon OM. Evaluation
of the Noiles hinged knee prosthesis. A five-year study of seventeen knees.
J Bone Joint Surg [Am] 1986;68(4):579-85.
-
Ejsted R, Olsen NJ, Krogh P. St. George hinge knee prosthesis.
A 2.5 to 8 year follow-up. Arch Orthop Trauma Surg 1985;104:218-23.
