Pregnancy After Total Hip Arthroplasty BY CATHY M. MCDOWELL, RN, AND PAUL F. LACHIEWICZ, MD

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1 1490 COPYRIGHT 2001 BY THE JOURNAL OF BONE AND JOINT SURGERY, INCORPORATED Pregnancy After Total Hip Arthroplasty BY CATHY M. MCDOWELL, RN, AND PAUL F. LACHIEWICZ, MD Investigation performed at the Department of Orthopaedics, University of North Carolina School of Medicine, Chapel Hill, North Carolina Background: Younger patients are having total hip arthroplasty now, and a woman who has had such a procedure may want to become pregnant. The purposes of this study were to report on a series of women who had completed a pregnancy after a total hip arthroplasty and to determine if pregnancy affects the function and longevity of the prosthesis. Methods: Five women, with a total of seven uncemented total hip replacements, had six successful pregnancies. The mean age at the arthroplasty was twenty-nine years (range, twenty-two to thirty-eight years), and the mean time from the hip arthroplasty to the pregnancy was 2.5 years (range, one to seven years). These patients (Group A) were compared with a matched group of five women with a total of eight uncemented total hip prostheses (Group B) who had not completed a pregnancy. The mean follow-up time was eight years (range, two to thirteen years) for Group A and seven years (range, two to twelve years) for Group B. Patients were clinically evaluated with the Harris hip score. Radiographs were evaluated for component fixation and osteolysis. Results: The five women completed a total of six successful pregnancies. One patient, with a bilateral total hip arthroplasty, had two successful pregnancies, 2.5 years apart. Three children were delivered vaginally (with the mother in the lithotomy position) and three, by cesarean section. There were no complications related to the total hip arthroplasty after delivery. The mean weight gain during the pregnancy was 13 kg (range, 8 to 14.2 kg). In Group A, the mean Harris hip score was 94 points prior to the pregnancy and 97 points at the time of the most recent follow-up. In group B, the mean Harris hip score was 91 points at one to two years after the arthroplasty and it was unchanged at the time of the most recent follow-up. There were six excellent results and one good result of the hip arthroplasty in Group A and five excellent and three good results in Group B. The mean total arc of hip motion was 217 in Group A before the pregnancy and 241 at the time of the most recent follow-up. The mean total arc of hip motion was 193 in Group B at one to two years postoperatively and 190 at the time of the most recent follow-up. The difference in the total arc of hip motion between the two groups at the latest follow-up evaluation was significant (p = 0.025). There were no reoperations in either group. Radiographs showed osteolysis of the femur in three hips in Group A and three hips in Group B. Conclusions: It appears that successful pregnancy and normal vaginal delivery can occur safely after total hip arthroplasty. The overall result, function, and radiographic appearance after the total hip arthroplasty was not adversely affected by pregnancy in this small group of patients. Historically, women who had total hip arthroplasty were not usually of childbearing age 1. However, now women with inflammatory arthritis, osteonecrosis, or congenital hip dysplasia may require a total hip arthroplasty at a relatively young age and may later decide to become pregnant. According to Ostensen, approximately 6000 patients undergo total hip replacement in Norway each year and 2.2% of them are women of fertile age 2. Of a total of 138,000 total hip arthroplasties performed in the United States in 1996, 3000 were done in women who were younger than the age of forty-five years 3. It is not known how many women become pregnant after total hip arthroplasty, and there is little published information on the effect of pregnancy on the clinical result of the procedure. Wittich reported a successful pregnancy, with delivery by cesarean section, after bilateral total hip arthroplasty with cement 4. The method of delivery was selected on the basis of a history of a previous cesarean delivery. This patient required walking support in the last trimester of pregnancy. A second case report described a successful pregnancy, with vaginal delivery, following bilateral Charnley total hip arthroplasty with cement 5. This patient reduced her activity in the last trimester of pregnancy, when weight gain had exceeded 80 kg, but she remained able to walk. However, neither of these reports presented information on the clinical and radiographic results of the hip arthroplasty after the delivery. In another case report, a woman with a cemented total hip replacement had a successful pregnancy, but she was counseled to avoid breast-feeding because of concern about the possible presence of polymethylmethacrylate in the breast milk 6. The purposes

2 1491 TABLE I Comparison of Cohorts Group A (Pregnancy) Group B (No Pregnancy) No. of women 5 5 No. of hips 7 8 Mean age (range) (yr) 29 (22-38) 27 (22-35) Mean weight (range) (kg) 63 (53-74) 68 (60-71) Mean height (range) (cm) ( ) ( ) Preoperative diagnosis (no. of patients) Inflammatory arthritis 3 3 Osteonecrosis 1 2 Arthritis secondary to dysplasia 1 0 Mean duration of follow-up (range) (yr) 8 (2-13) 7 (2-12) Occupation (no. of patients) Sedentary 3 3 Homemaker 1 2 Disabled 1 0 Hip implants (no. of hips) Acetabulum HGP-I* 4 7 Trilogy* 3 1 Femur HGP-I* 4 5 Multilock* 2 2 VerSys* 1 1 *Manufactured by Zimmer, Warsaw, Indiana. of the present study were to evaluate a series of patients with an uncemented total hip replacement who had successfully completed a pregnancy and to determine if the pregnancy affected the function and durability of the prosthesis. Materials and Methods ive women, with seven arthritic hips, had six successful F pregnancies after primary total hip arthroplasty. All of the arthroplasties were performed by one surgeon (P.F.L.). These five patients (Group A) were compared with another group of five women, with eight uncemented total hip replacements, who had not completed a pregnancy (Group B). The Group-B patients, selected from the surgeon s total hip arthroplasty database, were matched as closely as possible for age (within five years), preoperative diagnosis, type of prosthesis, and duration of follow-up. There were no significant differences (p > 0.05) between the two groups in terms of age, mean weight or height, preoperative diagnosis, occupation, or duration of follow-up (Table I). All patients had uncemented, titanium fiber-metal-coated acetabular and femoral components. The five women in Group A completed a questionnaire concerning the pregnancy, labor, and delivery. Pertinent obstetrical records were also reviewed. The patients were specifically questioned concerning their activity level throughout the pregnancy. The three patients with rheumatoid arthritis were also questioned specifically about the clinical status of the arthritis during the pregnancy and the postpartum period. All patients were clinically evaluated prospectively with use of the Harris hip score. The total arc of hip motion was determined by summing the amounts of flexion, abduction, adduction,

3 1492 and internal and external rotation and subtracting the amount of any flexion contracture. The differences between the two groups were analyzed with use of the Student t test Satterthwaite method. Standardized anteroposterior pelvic radiographs and anteroposterior and lateral radiographs of the femoral component were evaluated for component fixation and osteolysis, as previously described 7,8. Results ive women completed a total of six successful pregnancies. F The mean time to the pregnancy after the total hip arthroplasty was 2.5 years (range, one to seven years). One of the two patients with a bilateral total hip arthroplasty before the pregnancy had two successful pregnancies 2.5 years apart. Two women had a successful pregnancy both before and after the total hip arthroplasty. Three children were successfully delivered vaginally with the mother in the lithotomy position, and three were delivered by cesarean section (one, because of fetal distress; one, because the fetus was in a breech position; and one, because labor failed to progress). There were no problems or complications with the hip arthroplasty during the pregnancy or delivery. Specifically, there were no dislocations or clinically evident thromboembolisms. Two women breastfed their infants one, for six weeks, and the other, for three months. The mean weight gain during the pregnancy was 13 kg (range, 8 to 14.2 kg). The three women with rheumatoid arthritis had a subjective moderate decrease in joint pain and stiffness during the pregnancy. Only one had an increase in joint pain after the delivery. This symptom was treated with a temporary increase in corticosteroid and nonsteroidal antiinflammatory medication. For the patients in Group A, the mean Harris hip score was 94 points (range, 86 to 98 points) six months to six years before the pregnancy and 97 points (range, 83 to 100 points) at the time of the most recent follow-up (mean, eight years; range, two to thirteen years). On the basis of the Harris hip score, six hips were rated as excellent and one, as good. The mean total arc of hip motion was 217 prior to the pregnancy and 241 at the most recent follow-up evaluation (p > 0.05). The total arc of hip motion in all of the women increased or was essentially unchanged after the pregnancy (see Appendix). At the most recent examination, four women (six hips) had no pain and one woman (one hip) had slight pain with no limitation of activities. Four women (six hips) had no limp, and one woman (one hip) had a slight limp. No patient used a walking support. Four patients (six hips) were able to walk an unlimited distance, and one patient (one hip) was able to walk only two to three blocks because of low-back pain. The five women (eight hips) who had not completed a pregnancy (Group B) had a mean Harris hip score of 91 points (range, 88 to 97 points) at one to two years after the surgery, and the score was unchanged (mean, 91 points; range, 86 to 97 points) at the time of the most recent follow-up (mean, seven years; range, two to twelve years). On the basis of the Harris hip score, five hips were rated as excellent and three, as good. The mean total arc of hip motion was 193 at one to two years postoperatively and 190 at the time of the most recent follow-up (p > 0.05), with the value at the most recent follow-up examination differing significantly from that in Group A (p = 0.025) (Table II). At the time of the most recent follow-up, four hips in Group B were not painful, three were slightly painful without compromising activity, and one was mildly painful, for which the patient occasionally took acetaminophen. Four patients had a slight limp. All patients stated that they were able to walk an unlimited distance. Complications One woman in Group A who had had bilateral total hip arthroplasty because of rheumatoid arthritis had a nondisplaced TABLE II Hip Range of Motion at the Time of the Most Recent Follow-up Group A (Pregnancy)* Group B (No Pregnancy)* Significance of Difference Between Groups Total arc 241 ( ) 190 ( ) p = Flexion 123 ( ) 108 (90-120) Not significant Abduction 41 (30-55) 40 (20-45) Not significant Adduction 25 (10-30) 15 (10-20) Not significant Internal rotation 25 (15-30) 10 (0-30) Not significant External rotation 30 (25-45) 20 (15-30) Not significant Flexion contracture 3 (0-5) 3 (0-5) Not significant *The values, in degrees, are given as the mean, with the range in parentheses.

4 1493 fracture of the greater trochanter associated with an osteolytic defect and a fall at twelve years postoperatively. One patient in Group B who also had had bilateral total hip arthroplasty because of rheumatoid arthritis sustained a minimally displaced fracture of the greater trochanter in a fall fourteen years postoperatively. Both patients were treated nonoperatively and had full recovery. Radiographic Results At the time of the latest follow-up, no acetabular component had migrated or shifted in any hip in Group A or B. In Group A, a radiolucent line of <1 mm in width was seen in zone 1 of the acetabulum in two hips and acetabular osteolysis was seen in zone 2 in one hip 7. There was stable fixation, without subsidence, of all of the uncemented femoral components in Group A. Calcar resorption was seen in five hips and femoral osteolysis was seen in three hips in Group A. The femoral osteolysis was localized to zones 5 and 6 in one hip, to zones 2 and 7 in another, and to zones 3 and 5 in the third 7. Heterotopic ossification was classified as Brooker grade 1 in three hips and as Brooker grade 2 in two 9. In Group B, acetabular osteolysis was seen in zone 3 in two hips. There was stable fixation of all eight femoral components without evidence of subsidence on the most recent radiograph. Calcar resorption was seen in six hips. Osteolysis of the femur was seen in three hips; it was localized to zone 7 in one hip, to zones 2 and 3 in another, and to zones 3, 6, and 7 in the third. There was no heterotopic ossification in this group. Discussion irtually every woman has some degree of musculoskeletal discomfort during pregnancy 10. Anterior pain in the V hip, probably due to stretching of muscles and ligaments in the anterior aspect of the hip, is a common symptom during pregnancy. However, osteonecrosis and regional transient osteoporosis of the hip may cause serious hip pain and disability during pregnancy 10. The pain and synovitis due to rheumatoid arthritis generally decrease during pregnancy, possibly as a result of the increased secretion of endogenous cortisone. Approximately two-thirds of women with rheumatoid arthritis have a substantial decrease in joint pain and swelling, usually beginning as soon as they become pregnant and continuing until approximately six weeks after delivery 10. In a study of seventy-six pregnancies of fifty women with juvenile rheumatoid arthritis, a decrease in disease activity was noted in 59% of those with polyarticular disease 11. Following delivery, the symptoms of rheumatoid arthritis may recur with increased severity. In our study, the three women with rheumatoid arthritis had moderate relief of symptoms during pregnancy. In the present study, there was very little difference in the clinical and radiographic results at the most recent follow-up evaluation between the women who had completed a pregnancy and a comparable group who had not. However, there was a significant difference in the mean total arc of hip motion between the two groups (p = 0.025). This finding may be related to an increase in joint laxity around the pelvis due to the hormone relaxin secreted by the corpus luteum during pregnancy 10. No hip in either group dislocated or required revision. In Ostensen s study of pregnant patients with juvenile rheumatoid arthritis, all eight women with a hip replacement had a cesarean section because of obstetrical concern about the stress of delivery on the prosthesis 11. However, in our study, three children were delivered vaginally without any problem. Although it has been recommended that pregnant women with a total hip replacement restrict weight gain and restrict physical activity in late pregnancy 5, none of the five women in our study altered their physical activity during the course of the pregnancy. Anecdotally, to minimize weight gain during pregnancy one woman increased her amount of walking and another, her amount of swimming. In conclusion, this study, although limited by its small size, demonstrated that a successful pregnancy and a normal vaginal delivery can safely occur after a total hip arthroplasty without cement. There was a significant increase in the total arc of hip motion after pregnancy compared with that in a matched control group of women who had not completed a pregnancy (p = 0.025). However, the overall clinical result, complications, and radiographic appearance of the total hip replacement did not appear to have been adversely affected by pregnancy. Appendix Graphs showing the arcs of motion in the two groups of patients are available with the electronic versions of this article, on our web site ( and on our CD-ROM (call , ext. 140, to order). Cathy M. McDowell, RN Paul F. Lachiewicz, MD Department of Orthopaedics, University of North Carolina School of Medicine, 242 Burnett Womack Building, CB 7055, Chapel Hill, NC The authors did not receive grants or outside funding in support of their research or preparation of this manuscript. They did not receive payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity. A commercial entity (Zimmer, Warsaw, Indiana) paid or directed, or agreed to pay or direct, benefits to a research fund, foundation, educational institution, or other charitable or nonprofit organization with which the authors are affiliated or associated. References 1. Chandler HP, Reineck FT, Wixson RL, McCarthy JC. Total hip replacement in patients younger than thirty years old. A five-year follow-up study. J Bone Joint Surg Am. 1981;63: Ostensen M. [Hip prostheses in women of fertile age. Consequences for sexuality and reproduction]. Tidsskr Nor Laegeforen. 1993;113: Norwegian.

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