Revision total knee arthroplasty using the total condylar III prosthesis

Revision Total Knee Arthroplasty Using the Total Condylar Ill Prosthesis

J a m e s A. R a n d , M D

Abstract: hnplant selection for the severely damaged knee being treated by

revision is difficult. Fixed or rotating hinges have provided mixed results with a high frequency of complication. An alternative to a hinge implant is the total condylar III prosthesis, which can substitute for a deficient collateral ligament. Between August 1980 and April 1987 total condylar Ill prostheses were used for revision of failed total knee arthroplasties (TKA) of 21 knees in 19 patients. In the same time interval, 649 TKA revisions were performed for a frequency of 3.2% using this prosthesis. The indications for using this prosthesis were bone loss in 10 knees, instability in 9 knees, supracondylar femur fracture in 1 knee, and implant malposition in one knee. At a 4-year follow-up evaluation the knee scores were excellent in 25%, good in 25%, fair in 25%, and poor in 25%. Complications occurred in 33% of the knees. The total condylar III prosthesis provided results similar to other constrained implants used for revision in patients with severe bone loss and ligamentous instability. Key words: revision knee arthroplasty, knee arthrop]asty, total condylar 11I prosthesis

T h e results of revision total knee arthroplasty (TKA) have been variable and depend u p o n the reasons for failure, n u m b e r of previous implants, the extent of bone loss, and the quality of the soft tissues. Revisions of TKA in patients with extensive b o n e loss or ligamentous instability have frequently been performed using constrained prostheses. Unsatisfactory results following revision TKA are m o r e frequently observed with constrained implants (7). A previous review of revision TKA using a kinematic rotating hinge prosthesis found satisfactory results in 53% of 30 knees, followed for 4 years, and a 9% loosening rate (6). The total condylar III prosthesis provides increased constraint c o m p a r e d to the original total condylar

implant, but is not a linked hinge. The aim of the present study was to determine if satisfactory results can be achieved in revision surgery using a n o n linked constrained prosthesis with a lower frequency of loosening than a hinged arthroplasty.

Materials and Methods

A retrospective review was performed of 21 knees treated for failed TKA b e t w e e n August 1980 and April 1987 in which a total condylar III (TC-III) prosthesis was utilized. In the same time interval, 649 TKA revisions were performed. Thus, the frequency of utilization of the TC-III prosthesis was 3.2% in revision surgery. In the s a m e time interval, 107 TKAs were performed using custom constrained or hinged

From the Department of Orthopedic Surgery, Maya Clinic, Rochester, 1Hinnesota.

Reprint requests: James A. Rand, MD, Department of Orthopedic Surgery, Mayo Clinic,.Rochester, MN 55905.

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types of implants. The reason for selection of the total condylar III prosthesis as opposed to a hinged implant was based on physician preference. Either a hinged or TC-III prosthesis was selected for revision of knees with either bone loss or collateral ligament insufficiency, or both. In the later years of this study, the TC-III implant was utilized in preference to a hinged implant design. A total condylar Ill prosthesis provides anteroposterior and mediolateral stability by a large central tibial eminance that matches a recess in the femoral component (Fig. 1). The implant has an extended tibial stem and a femoral stem to improve purchase in deficient bone.

There were 21 knees in 19 patients. The m e a n age of the patients was 65 years (range, 5 6 - 7 1 years). There were 11 w o m e n and 8 men. The r i g h t k n e e was involved in 14 and the left knee in 7. The m e a n height of the patients was 165 cm (range, 1 4 2 - 1 8 0 cm), and the m e a n weight was 76 kg (range, 5 7 105 kg). Tile underlying diagnosis was osteoarthritis in 13 and rheumatoid arthritis in 6 patients. The two patients with bilateral TC-III implants had rheumatoid arthritis. Twelve of the knees had had Surgery prior to TKA. Sixteen of the nineteen patients had other lower-extremity joint disease (opposite knee 12, multiple joints 2, hip 1, and ankles 1) (Table 1.). Ten patients had bilateral TKA, but only two had

Fig. l. (A) AP and (B) lateral view of total condylar III prosthesis. The central post provides anteroposterior and varusvalgus stability in the presence of soft tissue imbalance. The extended stems provide for improved fixation in the presence of deficient bone.

Revision TKA Using the Total Condylar III Prosthesis

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T a b l e I . R e s u l t s o f 21 K n e e s R e v i s e d W i t h t h e Total C o n d y l a r III P r o s t h e s i s

Patient

Bilateral Number Revisions TKA Side L R L L L

2 1 1 2 2

5 6

R

R

2 2

7

L

1

8

L

2

9

R

2

l0

R

1

L

1

11

L

l

12

R

2

13 14

R R

1 2

15 16

R R

1 1

17

L

I

18

R

1

19

R

4

l

2 3 4

Prior TKA Types

Reason for Revision

Geometric Geometric Geometric Insall-Burstein Spherocentric

Loosening Loosening Loosening Instability Loosening and instability Geometric Loosening Guepar Loosening and bone loss Total condylar Loosening and instability Tavernetti Loosening and bone loss Muhiradius Loosening and bone loss Polycentric Loosening and bone loss Polycentric Loosening and bone loss Geometric Supracondylar femur fracture Kinematic Loosening and rotating bone loss hinge Total cofidylar Instability Duopatellar Loosening and instability Anametric Loosening Geometric Loosening and instability Variable axis Loosening and instability Total condylar Component lit malposition LCS rotating Loosening and platform bone loss

Knee HSS Knee Score Society Category Prerevision Follow-up B C

Knee Society Knee Score Prerevision

Follow-up

B A2

39 19 28 30 34

88 63 63 75 66

16/5 15/0 8/0 0/0 8/5

64/80 74/5 74/5 88/40 72/25

A2 B

56 43

78 84

37/60 23•40

811100 93190

A2

44

63

22/45

57/45

C

NA

86

NA

95/60

A2

41

89

2/40

93/75

A2

55

97

33/60

99/100

59

97

43/60

99/100

Az

19

59

18/0

65•45

B

45

84

4610

95/50

A~ Ai

28 46

Amputation 56

9/0 8/60

Amputation 28160

C B

49 44

77 37

35/60 18/10

69/60 3/10

Al

39

NA

28/5

NA

C

35

64

25/50

46/60

B

60

59

46•40

50155

TKA, total knee anhroplasty; HSS, Hospital for Special Surgery; L, left; R, right; A~, unilateral arthroplasty with opposite normal knee; A2, bilateral arthroplasty with satisfactory function of opposite knee; B, unilateral arthroplasty with opposite knee impaired; C, multiple arthritis or medical infirmity

bilateral TC-III implants. The other implant types in the bilateral group included kinematic condylar in three, and one each of Insall-Burstein posterior stabilized, kinematic stabilizer, total condylar II, cruciate condylar, and geometric. Three were primary, and five were first revisions of failed TKA. Five of these operations had been performed at our clinic. They were followed for a mean of 6 years (range, 510 years) after arthroplasty. The revision using the TC-III prosthesis w a s the first revision in 11, second revision in 9, and fourth revision in 1 knee. The implant prior to the TC-III revision was a resurfacing prosthesis in 15 and constrained prosthesis in 6 knees. The reasons for revision and use of a total condylar III prosthesis were loosening with bone loss in 10, instability in 9, supracondylar femur fracture in I, and malposition of the TC-III implant in 1 knee,The last evaluation was

performed at a mean of 48 months (range, 24-84 months) after the revision procedure. The method of follow-up evaluation was examination by the author or his colleagues in seven (nine knees), examination by the referring physician in eight, telephone in two, and questionnaire in two patients. Patients were classified into functional classes, and knee scores were calculated using the Knee Society Scoring System (3)' and the Hospital for Special Surgery Knee Scoring System (4). In the Hospital for Special Surgery (HSS) Scoring System, a score of 85 or higher is excellent, 70-84 good, 60-69 fair, and less than 60 poor. The Knee Society functional categories are: At, unilateral arthroplasty with opposite normal knee; A2, bilateral arthroplasty with satisfactory function of opposite knee; B, unilateral arthroplasw with opposite knee impaired; and C, multiple arthritis or medical infirmity. The Knee Society

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(KS) Scoring System provides two numerical scores equal to 100 points each, one for pain, motion, and stability, and one for function of walking and stair climbing. The functional categories of the patients was A in nine, B in six, and C in four patients. Radiographs were evaluated according to the technique of Ewald (2). The femur is divided into seven zones and the tibia into twelve zones.

Results Knee Scores The Hospital for Special Surgery Knee Score improved from a prerevision m e a n of 41 ( 1 9 - 6 0 ) to a m e a n of 73 ( 5 9 - 9 7 ) at last evaluation. Prior to revision there were 19 p o o r and i fair knee score. One knee had insufficient data to calculate a k n e e score. At the last evaluation there w e r e five excellent, five good, five fair, and four p o o r knee,scores. One k n e e score was unavailable. One knee u n d e r w e n t an a b o v e - k n e e a m p u t a t i o n for d e e p infection. Of the nine second revisions, there were three excellent, four good, one fair, and two p o o r knee scores. The fourth revision patient had a poor knee score. Using the Knee Society Scoring System, the knee score improved from a prerevision m e a n of 21 ( 0 - 4 6 ) for pain and 11 ( 0 - 6 0 ) for function to a final evaluation m e a n of 71 ( 3 - 9 9 ) for pain a n d 56 for ( 5 - 1 0 0 ) function.

Effect of Previous Implant Type The results of revision of the 15 resurfacing knees were compared with those of the 6 m o r e constrained implant types. The resurfacing group HSS knee scores were improved from a preoperative m e a n of 40 ( 1 9 - 5 9 ) , with 15 poor scores, to a postoperative m e a n of 72 ( 3 7 - 9 7 ) , with 4 excellent, 3 good, 3 fair, 3 poor, 1 unavailable, and 1 failed (amputation) knee scores. In contrast, the constrained group HSS knee score improved from a preoperative m e a n of 43 ( 3 4 - 6 0 ) , with one fair, four poor, and one unavailable knee s c o r e . t o a postoperative m e a n of 74 ( 5 8 - 8 6 ) , with one excellent, t w o good, two fair, and one poor knee score. The KS knee score in the resurfacing group improved from a preoperative m e a n of 20 ( 0 - 4 3 ) for pain and 27 ( 0 - 6 0 ) for function to a postoperative m e a n of 69 ( 3 - 9 9 ) for pain and 56 ( 1 0 - 1 0 0 ) for function. In contrast, the KS knee score

in the constrained group improved from a preoperative m e a n of 30 ( 8 - 4 6 ) for pain and 27 ( 0 - 5 0 ) for function to a postoperative m e a n of 75 ( 4 6 - 9 5 ) for pain and 57 ( 2 5 - 9 0 ) for function.

Effect of Number of Revisions A comparison of the 11 knees with 1 revision and the 9 knees with 2 revisions was performed. Of the 11 first revisions, the HSS knee score i m p r o v e d from a prerevision m e a n of 38 ( 1 9 - 5 9 ) , with all p o o r knee scores, to a follow-up m e a n of 69 ( 3 7 - 9 7 ) , with two excellent, one good, four fair, t w o poor, o n e unavailable, and one amputation. In the first revisions, the KS knee score improved from a prerevision m e a n of 23 ( 8 - 4 3 ) for pain and 26 ( 0 - 6 0 ) for function to a follow-up m e a n of 65 ( 3 - 9 9 ) for pain and 48 ( 5 100) for function. Of the nine second revisions, the HSS knee score improved from a prerevision m e a n of 42 ( 3 0 - 5 6 ) , with eight poor and one unavailable knee score, to a follow-up m e a n of 78 ( 5 6 - 8 9 ) , with four excellent, three good, one fair, and one p o o r knee score. In the second revisions, the KS k n e e score improved from a prerevision m e a n of 18 ( 0 46) for pain and 26 ( 0 - 6 0 ) for function to a followup m e a n of 79 ( 2 8 - 9 5 ) for pain and 64 ( 2 5 - 1 0 0 ) for flmction.

Bilateral Total Knees A comparison b e t w e e n the TC-III and the opposite total knee of the eight patients with bilateral arthroplasties w h o had a different implant type in the opposite knee was performed. The non-TC-III HSS knee score improved from a preoperative m e a n of 51 ( 3 9 - 7 1 ) , with one good, one fair, four p o o r and two unavailable knee scores to a postoperative m e a n of 80 ( 6 5 - 8 6 ) , with two excellent, five good, and one fair knee score. In contrast, the TC-III HSS k n e e score improved from a preoperative m e a n of 40 ( 1 9 56), with seven p o o r and one unavailable k n e e score, to a postoperative m e a n of 77 ( 5 9 - 8 9 ) , with three excellent, one good, three fair, and one p o o r knee score. The non-TC-III KS knee score improved f r o m a preoperative m e a n of 35 ( 1 9 - 5 8 ) for pain and 34 ( 5 - 6 0 ) for function to a postoperative m e a n of 82 ( 5 6 - 9 3 ) for pain and 66 ( 4 5 - 9 0 ) for function. In contrast, the TC-III KS knee score improved from a preoperative m e a n of 21 ( 2 - 4 6 ) for pain and 22 ( 0 60) for function to a postoperative m e a n of 78 ( 5 7 95) for pain and 60 ( 4 5 - 1 0 0 ) for function.

Revision TKA Using the Total Condylar III Prosthesis

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Motion

Complications

Knee extension improved from a prerevision mean of - 5 ° (ie, 5 ° flexion contracture) (20 ° to - 15 °) to - 4 ° (0 ° to - 2 0 °) at final evaluation. Knee flexion decreased from a prerevision mean of 108 ° (80 ° 130 °) to 102 ° (75°-130 °) at final evaluation.

Complications consisted of two atraumatic patellar fractures, one patellar tendon rupture, one transient skin ischemia, one superficial infection, one deep infection, and one n o n u n i o n of a preexisting supracondylar femur fracture. Of the two patellar fractures, one had a 10 ° extensor lag and the other a 45 ° extensor lag. The patient with the patellar t e n d o n rupture had a 30 ° extensor lag. Two of the extensor mechanism complications adversely affected the results with two poor and only one good knee score. The one transient skin ischemia resolved with cessation of knee motion, and tile patient had an excellent knee score. The one deep infection required an above-knee amputation for control of sepsis. The patient w h o had revision using a cemented longstem femoral c o m p o n e n t for a preexisting supracondylar femur fracture developed n o n u n i o n at the fracture site and had a poor knee score.

Alignment

The axial alignment (tibial-femoral angle) of the limb as measured on the standing anteroposterior (AP) radiograph improved from a prerevision mean of varus 3 ° (varus 20 ° to valgus 40 °) to valgus 3 ° (yams 2 ° to valgus 7 °) at last evaluation. The coronal position of the femoral c o m p o n e n t was a mean of valgus 4 ° (varus 4 ° to valgus 8 °) and the coronal position of the tibial c o m p o n e n t was a mean of varus 2 ° (varus 9 ° to valgus 5°). The mean sagittal position of the femoral c o m p o n e n t was posterior rotation of 3 ° (varus 3 ° to valgus 16°) and the tib[al c o m p o n e n t was 0 ° (anterior 10 ° to posterior 7°).

Radiolucent Lines

No radiolucent lines were present adjacent to the femoral c o m p o n e n t in 12 knees or tibial c o m p o n e n t in 6 knees. Seven femoral and 11 tibiai components had radiolucent lines (Fig. 2A,B). One knee had a complete radiolucent line adjacent to the tibial component of I - 2 m m in width. A shift in implant position was not identified.

Discussion A previous review of a 10-year experience with 427 revision TKAs revealed the best chance for a functioning implant w h e n a resurfacing prosthesis was used rather than a constrained prosthesis (7). The n u m b e r of satisfactory results decreased with an increasing n u m b e r of revision procedures (7). Bone loss and ligamentous instability are usually more frequently encountered in severely afflicted multiple revision TKAs. Since bone loss and ligamentous instability are the usual indications for a more constrained prosthesis, either ihe patient's anatomical problems or the implant may be responsible for the decreased

Media]

Width,

Zone

No.

Zone

No.

mm

1-4,8, 12

8

1

1

1-2

5-7, 9-11-

3

7

1

<1

Complete

1

lateral

;--~

;-3--; °.°.. 6

9

A

q:~

B

11

,o

. .@ ...

Fig. 2. Location of radiolucent lines adjacent to (A) the femur and (B) the tibia following revision with the total condylar I11 prosthesis.

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The Journal of Arthroplasty Vol. 6 No. 3 September 1991

frequency of good results compared to less constrained implants. A kinematic rotating hinge provided only 53% satisfactory results i n 30 revision knees in one series (6), and 61% satisfactory results in 18 revision knees (9) in another series at 4 years following revision. Using the kinematic rotating hinge, radiolucent lines were present in 50% (6) of one series and 47% (9) of the other series. The total condylar III prosthesis is the potential alternative to a hinged prosthesis for the patient with bone loss and ligamentous instability. Donaldson et al. reported only 50% good to excellent results in 14 revision TKAs compared to 100% good to excellent results in 17 primary TKAs (1). Rosenberg et al. reported good to excellent results in 44% of 33 revision TKAs compared to 72% of nine primary TKAs (8). Kim reported an improvement in knee score from 58 prior to revision to 81 following revision in 14 failed hinged prostheses that were revised with the total condylar III prosthesis (5). In the present series, 50% of the knees had good or excellent knee scores following revision, confirming other authors' experience. The comparison of the TC-III prosthesis with the implant of another design in the opposite limb of bilateral knee arthroplasty patients was revealing. The knee score in the knees selected for the TC-III implant were worse before operation than the contralateral knee. In the knees with designs other than a TC-III, the HSS knee score improved a mean of 29 points, while the TC-III knee score improved a mean of 37 points. Although the knee scores were higher with a prosthesis other than a TC-III, the more severely afflicted knee received the TC-III design and improved more than the contralateral knee. Since the total condylar III prosthesis provides similar results to the previously studied rotating hinge implants, the results of revision in these severely afflicted patients appear to be more related to patient selection than implant design. Although our prior stUdy (7) of revision surgery suggested less satisfactory results for knees treated b y two (60%) than for those treated by one (52%) revision, the previous study found similar results using the TC-III prosthesis. The mean i m p r o v e m e n t in the HSS knee score was 31 points for the first revision compared to 36 points for two revisions. NO significant difference was identified following revision to a TC-III prosthesis between a prior resurfacing prosthesis and a more constrained design. Complications with the kinematic rotating hinge occurred in 52% of the knees (6). With the TC-III prosthesis, complications occurred in 23% in one series (I) and 38% of a'nofller series (8). In the present

series, 33% of the knees had complications. Complications in complex revision cases are frequent and emphasize the need for extreme care in surgical technique. In conclusion, revision of a failed total knee arthroplasty with associated ligamentous instability or extensive bone loss presents a problem for salvage. Only 50% of these knees will have good or excellent results, with a high frequency of complications. Newer implant designs that allow more options for management of bone loss and soft tissue instability are needed. The author is currently evaluating n e w e r modular implant designs for complex primary and revision total knee arthroplasty. These n e w e r modular implants allow independent augmentation of file distal and posterior femur as well as modular wedges for tibial bone deficiencies. Modular stems allow the potential of fitting the stem length an°d diameter to the individual patient's needs. Some of these newer designs allow the option of varying degrees of anteroposterior and mediolateral stability by differing the design of the tibial polyethylene insert. The early results of these implants have been encouraging, and these designs have replaced the original total condylar Ill design described in the current report.

References 1. Donaldson WF, Sculco TP, In~:allJN, Ranawat CS: Total condylar IlI knee prosthesis: long term follow-up study. Clin Orthop 226:21, 1988 2. Ewald FC: The Knee Society total knee arthroplasty radiographic evaluation and scoring system. Clin Orthop 248:9, 1989 3. Insall JN: Rationale of the Knee Society clinical rating system. Clin Orthop 248:13, 1989 4. Insall JN, Ranawat CJ, Aglietti P, Shine J: A comparison of four models of total knee replacement prostheses. J Bone Joint Surg 58A:754, 1976 5. Kim Ytt: Salvage of failed hinge knee arthroplasty with a total condylar III type prosthesis. Clin Orthop 221:272, 1987 6. Rand JA, Chao EYS, Stauffer RN: Kinematic rotating hinge total knee arthroplasty. J Bone Joint Surg 69A:489, 1987 7. Rand JA, Peterson LFA, Bryan RS, llstrup DM: Revision total knee arthroplasty. Instr Course Leer. 35:305, 1986 8. Rosenberg AG, Bush-Joseph CA, Barden R et al: Toial condylar Ill knee arthroplasw. Presented at Seventh Annual Meeting of Mid-America Orthopaedic Association, ttamilton, Bermuda, April 22, 1989 9. Shaw JA, Balcom W, Greer RB: Total knee arthroplasty using the kinematic rotating hinge prosthesis. Orthopedics 12:647, 1989