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Total hip arthroplasty for arthrodesed hips
The Journal of Arthroplasty Vol. 10 No. 4 1995
Total Hip A r t h r o p l a s t y for A r t h r o d e s e d Hips 5- to 13-Year Results Olav Reiker~s, MD, Ingjald Bjerkreim,
MD, and Ragnhild
Gundersson,
MD
Abstract: The functional outcome of total hip arthroplasty for arthrodesed hips was
evaluated. During the years 1979 to 1988, 55 arthrodesed hips were converted to total hip arthroplasties. Thirty-seven women and nine men were followed for a minimum of 5 years. Thirteen of the patients were very much satisfied with the operation, 19 were much satisfied, 7 were satisfied, 3 were less satisfied, and 4 were unsatisfied. The Harris hip score was improved from 51-83 at the time of operation to 53-93 at the follow-up examination. Before conversion, none of the patients used crutches. At the follow-up examination, 10 patients used two crutches, 24 used one crutch, and 12 did not need support. Muscle strength of the abductors ranged from 1 to 4. In 26 patients with major low back pain before conversion, the pain score improved from 3-10 at the time of operation to 0-8 at the follow-up examination. This study shows that with conversion of an arthrodesed hip to arthroplasty, most patients need support for walking; however, they are generally grateful for their new mobility, maneuverability, and improved ability to sit comfortably. K e y words: arthrodesis, arthroplasty, hip.
W h e n a hip has been fused, the neighboring joints are subjected to a b n o r m a l stress, and secondary degenerative changes m a y develop. With deterioration and disability, conversion to total hip arthroplasty (THA) m a y be indicated. It is technically d e m a n d i n g to convert an ankylosed hip to a THA, and complications and failures are reported to be freq u e n t J -7 Furthermore, i m p r o v e m e n t of function seems to be m o r e uncertain t h a n after conventional arthroplasty. The purpose of this study was to review patients operated on for THA in arthrodesed hips with a m i n i m u m follow-up period of 5 years and with spedal emphasis on the functional outcome.
ation, nine of the patients were lost, seven because of death and two because of senile dementia. This study, then, represents 37 w o m e n and 9 m e n w h o have b e e n followed from 5 to 13 years (mean, 8 years). At the time of conversion, the age of the patients ranged from 33 to 75 years (mean, 58 years), and they had h a d an arthrodesed hip for 7 to 28 years (mean, 17 years). The diseases that had led to arthrodesis were congenital dislocation in 22 cases, primary osteoarthritis in 16, Calvd-Legg-Perthes disease in 3, coxitis in 2, epiphysiolysis in 2 and fracture sequelae in 1 patient. The m a i n indication for conversion was disabling low back pain (LBP) in 26, generalized loss of function from immobility or malposition in 12, pain in the ipsilateral knee in 2, and pseudarthrosis of the fused hip in 1 case. Five patients were operated on because of fracture through the fused hip. The c o n v e r s i o n p r o c e d u r e was carried out t h r o u g h a lateral or posterior approach. In 39 cases, a c e m e n t e d prosthesis was used (Mfiller, 28; Mittelmeier, 6; Weber, 5), and in 7 cases, a n o n c e m e n t e d Harris-Galante prosthesis was used.
Materials and Methods During 1979 to 1988, we converted 55 arthrodesed hips to THAs (Fig. 1). During follow-up evaluFrom the National Hospital for Orthopaedics, Sophies Minde, Surgical and Radiological Departments, University of Oslo, Norway.
Reprint requests: O. Reiker~s, MD, Sophies Minde, Trondheimsvn 132, N-0570 Oslo, Norway.
529
530
The Journal of Arthroplasty Vol. 10 No. 4 August 1995
Results
Fig. 1. Arthrodesed hip converted to Harris-Galante arthroplasty.
At f o l l o w - u p e x a m i n a t i o n , pain, hip mobility, a n d w a l k i n g ability w e r e r a t e d o n a n u m e r i c a l scale according to the m e t h o d of d ' A u b i g n e a n d Postel, 8 as m o d i f i e d b y Charnley. 9 Grade 1 d e n o t e s disability, a n d grade 6 indicates n o r m a l findings. The result was j u d g e d to be excellent w h e n the s u m of the t h r e e e v a l u a t i o n s was 15 to 18, good w h e n it was 11 to 14, fair w h e n it was 7 to 10, a n d p o o r w h e n it was 3 to 6. The subjective b e n efits w e r e g r a d e d as v e r y m u c h satisfied, m u c h satisfied, satisfied, less satisfied, a n d unsatisfied; a n d t h e s e w e r e t h e t e r m s p r e s e n t e d to the patients. The f u n c t i o n a l o u t c o m e was classified according to the m o d i f i e d Harris hip score? ° Furt h e r m o r e , the use of s u p p o r t for w a l k i n g was n o t e d , as w a s t h e T r e n d e l e n b u r g test. T h e strength of the a b d u c t o r s was g r a d e d w i t h the p a t i e n t in lateral position o n a s t a n d a r d scale for m a n u a l m u s c l e testing, w h e r e O p o i n t d e n o t e s n o muscle c o n t r a c t i o n S : a n d 5 p o i n t s indicates n o r mal m u s c l e strength. In the cases w i t h LBP as the m a j o r p r e o p e r a t i v e complaint, the degree of p a i n was r a t e d o n a 10-point scale r a n g i n g f r o m 0 (no pain) to 10 (intense pain). In the evaluation of radiographs, socket demarcation or migration was recorded according to Carlsson and Gentz." For definite socket loosening (Carlsson and Gentz grade 3), migration exceeding 2 m m or other such obvious changes in position w e r e required. Radiographic s t e m loosening was defined as subsidence of 2 m m or m o r e w i t h or within the cement, or a varus tilt, substantiated by a zone b e t w e e n the stem and b o n e - c e m e n t exceeding 1 m m . 12,13 Multiple regression analysis was p e r f o r m e d to elucidate a n y influence of p r e s u m a b l y predictive variables on the outcome. The significance level was p r e d e t e r m i n e d to be .05.
D u r i n g the o b s e r v a t i o n period, s e v e n cases required revison for m e c h a n i c a l failure, five w i t h a Mittelmeier prosthesis, one w i t h a Mtiller prosthesis, and one w i t h a Weber prosthesis. At the follow-up e x a m i n a t i o n one Mfiller s t e m and one Harris-Galante s t e m w e r e radiographically loose; the corresponding cups w e r e not. The subjective evaluations s h o w e d that 13 of the patients w e r e v e r y m u c h satisfied, 19 w e r e m u c h satisfied, 7 w e r e satisfied, 3 w e r e less satisfied, a n d 4 w e r e unsatisfied. Poor subjective results w e r e significantly associated w i t h h o w long the patients h a d h a d the arthrodesis. The objective evaluations based on the s u m of the three indices of d'Aubigne and Postel, 8 as modified by Charnley, 9 s h o w e d excellent results in 6, good in 29, and fair in 11 cases. Poor results in this respect w e r e significantly associated with b o t h a d v a n c e d age at fusion of the hip and duration of the arthrodesis. The m e a n Harris hip score i m p r o v e d f r o m 69 (range, 51-83) at the time of conversion to 78 (range, 53-93) at the follow-up examination. In the patients with m a j o r LBE the m e a n score significantly i m p r o v e d f r o m 5.6 (range, 3-10) to 3.3 (range, 0-8) at the follow-up e x a m i n a t i o n . Before conversion n o n e of the patients used crutches. At follow-up examination, 10 patients used two crutches, 24 used one crutch, and 12 used no support. The need for external support was significantly associated w i t h a d v a n c e d age at fusion of the hip a n d h o w long the patients h a d h a d arthrodesis. Forty hips w e r e associated with a positive Trendelenburg sign a n d six w i t h a negative sign; Muscle strength of the abductors ranged f r o m 1 to 4 ~mean, 3). Poor strength was significantly associated with advanced age at fusion-and duration of the arthrodesis.
Discussion In this study, special attention was paid to the benefits our patients gained f r o m the restored m o t i o n of the arthrodesed hip. Before surgery, the p a t i e n t s h a d fairly g o o d function, a n d t h e i r i m p r o v e m e n t was less t h a n w h a t we h a v e observed in patients w h o h a v e u n d e r g o n e THA for other conditions? 4 Hip mobility in particular was somew h a t restricted as c o m p a r e d with our results w i t h routine arthroplasty. Such an observation has also b e e n reported by other authors, 1,2,4,~a n d it seems to be the result of the diseases that h a d led to seco n d a r y degenerative changes of the hip, operations, a n d long-standing soft tissue contractions in
THAforArthrodesed Hips
•
Reiker~s et al.
531
ankylosed hips. In general, however, the patients ever, after conversion, most patients m a y n e e d were grateful for their increased range of motion, external support for walking because of inadequamaneuverability, and improved ability to sit with cies of the abductor muscles. W h e n this is emphacomfort. F u r t h e r m o r e , the w o m e n had special sized to patients before surgery, they are generally problems with the arthrodesed hip. M a n y of t h e m grateful for their n e w mobility, maneuverability, developed a misdirected urine stream during micand improved ability to sit with comfort. turition, which can result in their wetting the inside of the thigh. In addition, it is possible for t h e m to experience discomfort during sexual intercourse. References With conversion arthroplasty, these problems were m o r e or less solved. The best results seemed to be 1. Amstutz HC, Sakai DN: Total joint replacement obtained in those w h o were y o u n g w h e n they for ankylosed hips. J Bone Joint Surg 57A:619, u n d e r w e n t fusion of the hip and w h o had had a 1975 rather short period with hip arthrodesis. 2. Brewster RC, Coventry MB, Johnson EW Jr: ConAn essential factor in the evaluation of converversion of the arthrodesed hip to a total hip arthrosion arthroplasty is the stability of the hip. In this plasty. J Bone Joint Surg 57A:27 1975 respect, the abductor muscle p o w e r is most essen3. Courpied JP, Kerboul M, Ber G, Postel M: Arthroplastic totale sur hanche anlylosee. Rev Chir tial. We therefore focused on the strength of the hip Orthop 67:289, 1981 abductors. Preoperative strength of the abductors is 4. Itardinge K, Williams D, Etienne A et al: Converdifficult to measure. After conversion, our patients sion of fused hips to low friction arthroplasty. J regained strength slowly over years. At the followBone Joint Surg 59B:385, 1977 up examination, strength of the abductor muscles 5. Lubahn JD, Evarts CMCC, Feltner JB: Conversion was still inadequate in most of the patients. This of ankylosed hips to total hip arthroplasty, Clin was characterized by inability to stand on one leg, a Orthop 153:146, 1980 Trendelenbug limp, and the n e e d for external sup6. Picard J J, Vidal J, Jacoulet P: Desarthrodeses de port. Four patients reported that they were totally hanche et arthroplastie totale. Rev Chit Orthop dissatisfied with this situation and felt that t h e y had 68(suppl II):161, 1982 not at all benefited from the conversion procedure. 7. Strathy GM, Fitzgerald RH Jr: Total hip arthroplasty In 24 patients, LBP was the main indication for in ankylosed hip: a ten-year follow-up. J Bone hip reconstruction. In most of these patients, pain Joint Surg 70A:963, 1988 relief was achieved. It was, however, moderate on 8. D'Aubigne RM, Postel M: Functional results of hip average, and only two patients had complete pain arthropiasty with acrylic prosthesis. J Bone Joint relief..On the o t h e r , h a n d . }wo:pa:tients w e r e e v e n Surg 36A:451, 1954 worse, a t the f o l l o w - u p examina-tioii:-These 0bser2 9. Charnley J:~ The~ tong.~term .results of' ioW-fi'icfi'.~ vati0ns indicate that i n 'Cases W i t h . i o n g / s t a n d i n g ....: : ' : ar{hmplast~ 6iithe: hid peffoiYned a s ~ primary intervention. J B o n e Joint Surg 54B:6I. 1972 hip arthrodesis and s e c o n d a r y LBE pain relief can Harris WH: Traumatic arthritis of the hip after disonly be anticipated to some degree by conversion to 10. location and acetabular fractures: treatment by arthroplasty. mold arthroplasty. J Bone Joint Surg 51A:737, In a 7-year follow-up study of THA for ankylosed 1969 hips, the rate of mechanical failure was reported to 11. Carlsson kS. Gentz CF: Radiographic versus clinical be 4 of 41. t~ Six of our revised prostheses were the loosening ot the acetabular component in noninMittelmeier type. If this inferior prosthesis is fected total hip arthroplasty Clin Orthop 185:145, excluded, the rate of aseptic loosening in our mate1984 rial is in accordance with these figures. Also, it 12. Charnley J: Low friction arthroplasty of the hip. should be emphasized that the overall results of our Springer-Verlag, Berlin, 1979 study include those patients w h o were subjected to 13. Tapadiya D, Walker RH, Schurman DJ: Prediction revision during the follow-up evaluation. With of outcome of total hip arthroplasty based on initial more appropriate prostheses, our results w o u l d postoperative radiographic analysis: matched, possibly have b e e n even better. paired comparisons of failed versus successful femoral components. Clin Orthop 186:5, 1984 14. Reiker~s O: Ten-year follow-up ot Mfiller hip Conclusion replacements. Acta Orthop Scand 53:919, 1982 15. Kilguis JD, Amstutz HC, Wolgin MA, Dorey FJ: This study indicates that THA can be p e r f o r m e d Joint replacement for ankylosed hips. J Bone Joint with reasonable results on arthrodesed hips; howSurg 72A:45, 1990
Total Hip A r t h r o p l a s t y for A r t h r o d e s e d Hips 5- to 13-Year Results Olav Reiker~s, MD, Ingjald Bjerkreim,
MD, and Ragnhild
Gundersson,
MD
Abstract: The functional outcome of total hip arthroplasty for arthrodesed hips was
evaluated. During the years 1979 to 1988, 55 arthrodesed hips were converted to total hip arthroplasties. Thirty-seven women and nine men were followed for a minimum of 5 years. Thirteen of the patients were very much satisfied with the operation, 19 were much satisfied, 7 were satisfied, 3 were less satisfied, and 4 were unsatisfied. The Harris hip score was improved from 51-83 at the time of operation to 53-93 at the follow-up examination. Before conversion, none of the patients used crutches. At the follow-up examination, 10 patients used two crutches, 24 used one crutch, and 12 did not need support. Muscle strength of the abductors ranged from 1 to 4. In 26 patients with major low back pain before conversion, the pain score improved from 3-10 at the time of operation to 0-8 at the follow-up examination. This study shows that with conversion of an arthrodesed hip to arthroplasty, most patients need support for walking; however, they are generally grateful for their new mobility, maneuverability, and improved ability to sit comfortably. K e y words: arthrodesis, arthroplasty, hip.
W h e n a hip has been fused, the neighboring joints are subjected to a b n o r m a l stress, and secondary degenerative changes m a y develop. With deterioration and disability, conversion to total hip arthroplasty (THA) m a y be indicated. It is technically d e m a n d i n g to convert an ankylosed hip to a THA, and complications and failures are reported to be freq u e n t J -7 Furthermore, i m p r o v e m e n t of function seems to be m o r e uncertain t h a n after conventional arthroplasty. The purpose of this study was to review patients operated on for THA in arthrodesed hips with a m i n i m u m follow-up period of 5 years and with spedal emphasis on the functional outcome.
ation, nine of the patients were lost, seven because of death and two because of senile dementia. This study, then, represents 37 w o m e n and 9 m e n w h o have b e e n followed from 5 to 13 years (mean, 8 years). At the time of conversion, the age of the patients ranged from 33 to 75 years (mean, 58 years), and they had h a d an arthrodesed hip for 7 to 28 years (mean, 17 years). The diseases that had led to arthrodesis were congenital dislocation in 22 cases, primary osteoarthritis in 16, Calvd-Legg-Perthes disease in 3, coxitis in 2, epiphysiolysis in 2 and fracture sequelae in 1 patient. The m a i n indication for conversion was disabling low back pain (LBP) in 26, generalized loss of function from immobility or malposition in 12, pain in the ipsilateral knee in 2, and pseudarthrosis of the fused hip in 1 case. Five patients were operated on because of fracture through the fused hip. The c o n v e r s i o n p r o c e d u r e was carried out t h r o u g h a lateral or posterior approach. In 39 cases, a c e m e n t e d prosthesis was used (Mfiller, 28; Mittelmeier, 6; Weber, 5), and in 7 cases, a n o n c e m e n t e d Harris-Galante prosthesis was used.
Materials and Methods During 1979 to 1988, we converted 55 arthrodesed hips to THAs (Fig. 1). During follow-up evaluFrom the National Hospital for Orthopaedics, Sophies Minde, Surgical and Radiological Departments, University of Oslo, Norway.
Reprint requests: O. Reiker~s, MD, Sophies Minde, Trondheimsvn 132, N-0570 Oslo, Norway.
529
530
The Journal of Arthroplasty Vol. 10 No. 4 August 1995
Results
Fig. 1. Arthrodesed hip converted to Harris-Galante arthroplasty.
At f o l l o w - u p e x a m i n a t i o n , pain, hip mobility, a n d w a l k i n g ability w e r e r a t e d o n a n u m e r i c a l scale according to the m e t h o d of d ' A u b i g n e a n d Postel, 8 as m o d i f i e d b y Charnley. 9 Grade 1 d e n o t e s disability, a n d grade 6 indicates n o r m a l findings. The result was j u d g e d to be excellent w h e n the s u m of the t h r e e e v a l u a t i o n s was 15 to 18, good w h e n it was 11 to 14, fair w h e n it was 7 to 10, a n d p o o r w h e n it was 3 to 6. The subjective b e n efits w e r e g r a d e d as v e r y m u c h satisfied, m u c h satisfied, satisfied, less satisfied, a n d unsatisfied; a n d t h e s e w e r e t h e t e r m s p r e s e n t e d to the patients. The f u n c t i o n a l o u t c o m e was classified according to the m o d i f i e d Harris hip score? ° Furt h e r m o r e , the use of s u p p o r t for w a l k i n g was n o t e d , as w a s t h e T r e n d e l e n b u r g test. T h e strength of the a b d u c t o r s was g r a d e d w i t h the p a t i e n t in lateral position o n a s t a n d a r d scale for m a n u a l m u s c l e testing, w h e r e O p o i n t d e n o t e s n o muscle c o n t r a c t i o n S : a n d 5 p o i n t s indicates n o r mal m u s c l e strength. In the cases w i t h LBP as the m a j o r p r e o p e r a t i v e complaint, the degree of p a i n was r a t e d o n a 10-point scale r a n g i n g f r o m 0 (no pain) to 10 (intense pain). In the evaluation of radiographs, socket demarcation or migration was recorded according to Carlsson and Gentz." For definite socket loosening (Carlsson and Gentz grade 3), migration exceeding 2 m m or other such obvious changes in position w e r e required. Radiographic s t e m loosening was defined as subsidence of 2 m m or m o r e w i t h or within the cement, or a varus tilt, substantiated by a zone b e t w e e n the stem and b o n e - c e m e n t exceeding 1 m m . 12,13 Multiple regression analysis was p e r f o r m e d to elucidate a n y influence of p r e s u m a b l y predictive variables on the outcome. The significance level was p r e d e t e r m i n e d to be .05.
D u r i n g the o b s e r v a t i o n period, s e v e n cases required revison for m e c h a n i c a l failure, five w i t h a Mittelmeier prosthesis, one w i t h a Mtiller prosthesis, and one w i t h a Weber prosthesis. At the follow-up e x a m i n a t i o n one Mfiller s t e m and one Harris-Galante s t e m w e r e radiographically loose; the corresponding cups w e r e not. The subjective evaluations s h o w e d that 13 of the patients w e r e v e r y m u c h satisfied, 19 w e r e m u c h satisfied, 7 w e r e satisfied, 3 w e r e less satisfied, a n d 4 w e r e unsatisfied. Poor subjective results w e r e significantly associated w i t h h o w long the patients h a d h a d the arthrodesis. The objective evaluations based on the s u m of the three indices of d'Aubigne and Postel, 8 as modified by Charnley, 9 s h o w e d excellent results in 6, good in 29, and fair in 11 cases. Poor results in this respect w e r e significantly associated with b o t h a d v a n c e d age at fusion of the hip and duration of the arthrodesis. The m e a n Harris hip score i m p r o v e d f r o m 69 (range, 51-83) at the time of conversion to 78 (range, 53-93) at the follow-up examination. In the patients with m a j o r LBE the m e a n score significantly i m p r o v e d f r o m 5.6 (range, 3-10) to 3.3 (range, 0-8) at the follow-up e x a m i n a t i o n . Before conversion n o n e of the patients used crutches. At follow-up examination, 10 patients used two crutches, 24 used one crutch, and 12 used no support. The need for external support was significantly associated w i t h a d v a n c e d age at fusion of the hip a n d h o w long the patients h a d h a d arthrodesis. Forty hips w e r e associated with a positive Trendelenburg sign a n d six w i t h a negative sign; Muscle strength of the abductors ranged f r o m 1 to 4 ~mean, 3). Poor strength was significantly associated with advanced age at fusion-and duration of the arthrodesis.
Discussion In this study, special attention was paid to the benefits our patients gained f r o m the restored m o t i o n of the arthrodesed hip. Before surgery, the p a t i e n t s h a d fairly g o o d function, a n d t h e i r i m p r o v e m e n t was less t h a n w h a t we h a v e observed in patients w h o h a v e u n d e r g o n e THA for other conditions? 4 Hip mobility in particular was somew h a t restricted as c o m p a r e d with our results w i t h routine arthroplasty. Such an observation has also b e e n reported by other authors, 1,2,4,~a n d it seems to be the result of the diseases that h a d led to seco n d a r y degenerative changes of the hip, operations, a n d long-standing soft tissue contractions in
THAforArthrodesed Hips
•
Reiker~s et al.
531
ankylosed hips. In general, however, the patients ever, after conversion, most patients m a y n e e d were grateful for their increased range of motion, external support for walking because of inadequamaneuverability, and improved ability to sit with cies of the abductor muscles. W h e n this is emphacomfort. F u r t h e r m o r e , the w o m e n had special sized to patients before surgery, they are generally problems with the arthrodesed hip. M a n y of t h e m grateful for their n e w mobility, maneuverability, developed a misdirected urine stream during micand improved ability to sit with comfort. turition, which can result in their wetting the inside of the thigh. In addition, it is possible for t h e m to experience discomfort during sexual intercourse. References With conversion arthroplasty, these problems were m o r e or less solved. The best results seemed to be 1. Amstutz HC, Sakai DN: Total joint replacement obtained in those w h o were y o u n g w h e n they for ankylosed hips. J Bone Joint Surg 57A:619, u n d e r w e n t fusion of the hip and w h o had had a 1975 rather short period with hip arthrodesis. 2. Brewster RC, Coventry MB, Johnson EW Jr: ConAn essential factor in the evaluation of converversion of the arthrodesed hip to a total hip arthrosion arthroplasty is the stability of the hip. In this plasty. J Bone Joint Surg 57A:27 1975 respect, the abductor muscle p o w e r is most essen3. Courpied JP, Kerboul M, Ber G, Postel M: Arthroplastic totale sur hanche anlylosee. Rev Chir tial. We therefore focused on the strength of the hip Orthop 67:289, 1981 abductors. Preoperative strength of the abductors is 4. Itardinge K, Williams D, Etienne A et al: Converdifficult to measure. After conversion, our patients sion of fused hips to low friction arthroplasty. J regained strength slowly over years. At the followBone Joint Surg 59B:385, 1977 up examination, strength of the abductor muscles 5. Lubahn JD, Evarts CMCC, Feltner JB: Conversion was still inadequate in most of the patients. This of ankylosed hips to total hip arthroplasty, Clin was characterized by inability to stand on one leg, a Orthop 153:146, 1980 Trendelenbug limp, and the n e e d for external sup6. Picard J J, Vidal J, Jacoulet P: Desarthrodeses de port. Four patients reported that they were totally hanche et arthroplastie totale. Rev Chit Orthop dissatisfied with this situation and felt that t h e y had 68(suppl II):161, 1982 not at all benefited from the conversion procedure. 7. Strathy GM, Fitzgerald RH Jr: Total hip arthroplasty In 24 patients, LBP was the main indication for in ankylosed hip: a ten-year follow-up. J Bone hip reconstruction. In most of these patients, pain Joint Surg 70A:963, 1988 relief was achieved. It was, however, moderate on 8. D'Aubigne RM, Postel M: Functional results of hip average, and only two patients had complete pain arthropiasty with acrylic prosthesis. J Bone Joint relief..On the o t h e r , h a n d . }wo:pa:tients w e r e e v e n Surg 36A:451, 1954 worse, a t the f o l l o w - u p examina-tioii:-These 0bser2 9. Charnley J:~ The~ tong.~term .results of' ioW-fi'icfi'.~ vati0ns indicate that i n 'Cases W i t h . i o n g / s t a n d i n g ....: : ' : ar{hmplast~ 6iithe: hid peffoiYned a s ~ primary intervention. J B o n e Joint Surg 54B:6I. 1972 hip arthrodesis and s e c o n d a r y LBE pain relief can Harris WH: Traumatic arthritis of the hip after disonly be anticipated to some degree by conversion to 10. location and acetabular fractures: treatment by arthroplasty. mold arthroplasty. J Bone Joint Surg 51A:737, In a 7-year follow-up study of THA for ankylosed 1969 hips, the rate of mechanical failure was reported to 11. Carlsson kS. Gentz CF: Radiographic versus clinical be 4 of 41. t~ Six of our revised prostheses were the loosening ot the acetabular component in noninMittelmeier type. If this inferior prosthesis is fected total hip arthroplasty Clin Orthop 185:145, excluded, the rate of aseptic loosening in our mate1984 rial is in accordance with these figures. Also, it 12. Charnley J: Low friction arthroplasty of the hip. should be emphasized that the overall results of our Springer-Verlag, Berlin, 1979 study include those patients w h o were subjected to 13. Tapadiya D, Walker RH, Schurman DJ: Prediction revision during the follow-up evaluation. With of outcome of total hip arthroplasty based on initial more appropriate prostheses, our results w o u l d postoperative radiographic analysis: matched, possibly have b e e n even better. paired comparisons of failed versus successful femoral components. Clin Orthop 186:5, 1984 14. Reiker~s O: Ten-year follow-up ot Mfiller hip Conclusion replacements. Acta Orthop Scand 53:919, 1982 15. Kilguis JD, Amstutz HC, Wolgin MA, Dorey FJ: This study indicates that THA can be p e r f o r m e d Joint replacement for ankylosed hips. J Bone Joint with reasonable results on arthrodesed hips; howSurg 72A:45, 1990