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Pain worsens peripartum after hip arthroscopy for femoroacetabular impingement and may not return to pre-pregnancy improvement
⁎Corresponding author: Allison M. Morgan. allison.morgan@nyulangone.org
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Received: ,
Accepted: ,
This article was originally published by Reed Elsevier India Pvt. Ltd. and was migrated to Scientific Scholar after the change of Publisher.
Abstract
Abstract
To assess hip symptomatology during the perioperative and peripregnancy periods and postoperative outcomes among reproductive age females undergoing arthroscopic treatment for femoroacetabular impingement syndrome (FAIS) and pregnancy complications in females after hip arthroscopy.
Females aged 18–44 years who underwent hip arthroscopy for the treatment of FAIS with a single surgeon were included in the study. Postoperatively, patients were surveyed regarding obstetric history, hip symptomology, and post-surgery pregnancy experiences. Subjects were classified as nulligravid (Group 1), pregnant at least once before hip surgery but never again following surgery (Group 2), or pregnant at least once following hip surgery (Group 3). Hip pain intensity was reported on a 10-point Visual Analog Scale (VAS) and hip function was reported using the modified Harris Hip Score (mHHS). Patients self-reported pregnancy outcomes and complications.
85 patients were enrolled with a mean age of 32.3 ± 6.5 years at the time of surgery. Mean follow-up time was 51.9 ± 34.5 months. There were 39 subjects in Group 1 (45.9 %), 20 in Group 2 (23.5 %), and 26 in Group 3 (30.6 %). There were no significant inter-group differences in mHHS preoperatively or at final follow-up (p = 0.95). Group 3 subjects reported that both postoperative and post-pregnancy VAS remained significantly lower than the preoperative baseline (p < 0.001). 69.2 % and 73.1 % report worsened hip pain during the third trimester and postpartum, respectively. 57.9 % reported that their hip pain returned to the pre-pregnancy baseline by time of survey completion.
Females of reproductive age with FAIS can expect clinical improvements relative to their baseline after hip arthroscopy regardless of pregnancy timing relative to surgical intervention. A majority of patients who become pregnant post-arthroscopy experience a peripartum recurrence of their symptoms. Most but not all of these patients return to the level of maximal improvement they had initially experienced postoperatively.
Keywords
Hip arthroscopy
Pregnancy
Sex-based differences
Patient reported outcome measures
1 Introduction
Femoroacetabular impingement syndrome (FAIS) is marked by the presence of abnormal contact between the proximal femur and acetabulum and may be successfully addressed with hip arthroscopy.1–6 A majority of hip arthroscopy patients are female and half are them are below the age of 44; therefore, the majority of hip arthroscopy patients have the potential to have previously been or become pregnant.7–10 However, the role of pregnancy on FAI and vice versa is poorly understood. Numerous studies have reported total hip arthroplasty (THA) has no negative effects on pregnancy or childbirth and pregnancy after THA and is considered safe, though worsening peripartum hip pain for THA patients which subsides after birth has been described.11–14
In contrast, the hip arthroscopy and pregnancy literature is limited to a handful of case reports. In one series of three patients and a second series of ten patients, the authors report on patients with labral tears who experienced onset of hip pain during pregnancy or delivery.15,16 Two other cases reports have described two female patients with hip dysplasia who underwent hip arthroscopy who experienced rapid progression of pain and osteoarthritis during pregnancy.17,18
Beyond these few reports, there is a dearth of knowledge regarding the impact of hip arthroscopy on pregnancy and vice versa, despite reproductive age females comprising the majority of patients undergoing surgery for FAIS. The purpose of this study was to assess pregnancy-related hip symptomatology during the perioperative and peri-pregnancy periods among reproductive age females seeking arthroscopic treatment for femoroacetabular impingement syndrome (FAIS) and pregnancy's effects on postoperative outcomes.
2 Methods
2.1 Study design and setting
A retrospective cross-sectional review was conducted of a single surgeon's patients at an urban academic medical center. Institutional review board approval was obtained (approval # 20–01686).
2.2 Patient population and eligibility criteria
A prospectively collected database of patients undergoing hip arthroscopy performed by the senior author between 2010 and 2020 was reviewed for eligible patients. Females of reproductive age (18–44 years old)19 at the time of arthroscopic hip surgery for FAIS were included. This was a cross-sectional study, thus all follow up intervals were included.
2.3 Surgical indications, technique, and postoperative protocol
All patients underwent surgery by the senior author, a fellowship trained sport surgeon experienced in hip arthroscopy. Indications for performing hip arthroscopy for FAIS were based on physical exam findings, such as anterior impingement test and Patrick test, and radiographic findings on standard radiographs of the pelvis as well magnetic resonance imaging (MRI) or magnetic resonance arthrography (MRA), and failure of at least six weeks of physical therapy. Hip arthroscopy was contraindicated in patients with evidence of hip osteoarthritis which included Tönnis grade >1 or hip dysplasia indicated by LCEA <20°. The senior author's preferred operative technique and postoperative protocol have been described previously.20,21
2.4 Data collection surveys
REDCap data collection software was used for study survey design and administration (Vanderbilt University, Nashville, TN, U.S.A.).22,23 Demographics and operative information were obtained from clinic visit notes and intraoperative reports. For pregnancy data, patients were initially contacted via phone to assess willingness to participate; those who agreed received surveys via email. Written informed consent was obtained. Subjects were asked for demographic data including how many times they had been pregnant (gravida) and how many of those pregnancies resulted in a live birth (para). Patients were asked if they experienced pregnancy after surgery and if they were considering pregnancy in the future. The survey assessed clinical presentation of hip symptoms at the following time points: before surgery, after surgery, during pregnancy (specifically the first pregnancy following hip surgery), and after pregnancy. Severity of hip pain was rated using a 10-point Visual Analog Scale (VAS). The survey was designed to display or omit questions related to specific time points based on whether the respondent fell in one of three categories: nulligravid (Group 1), pregnant at least once before hip surgery but never again following hip surgery (Group 2), or pregnant at least once following hip surgery (Group 3). Group 3 subjects were asked additional questions regarding postoperative pregnancy, labor, and delivery outcomes. A detailed description of the study survey is provided in Appendix I. In addition to the main study survey, subjects completed the modified Harris Hip Score (mHHS) preoperatively and at standard postoperative visits and at final follow-up as part of the senior author's clinical practice.
2.5 Statistical analysis
SAS Studio version 9.4 was used for statistical analysis (SAS Institute, Cary, NC, U.S.A). For all variables, descriptive statistics were calculated. Normality of continuous variables was evaluated via Shapiro-Wilk test. Analysis of variance (ANOVA) was used for normally distributed continuous variables, with Tukey post-hoc testing. For intra-group comparisons at various time points, Student's one-sample t-test was used. Continuous variables that were not normally distributed were evaluated using a Kruskal-Wallis test. Additionally, Dwass-Steel-Critchlow-Fligner (DSCF) post-hoc testing was completed and the Wilcoxon signed rank test allowed comparisons at different time points within groups. The Fisher's exact test allowed comparison of categorical variables. For all analyses, significance was deemed p-values <0.05.
3 Results
3.1 Patient flow
Fig. 1 summarizes patient flow through this investigation. 402 subjects were eligible for inclusion, of which 85 (21.1 %) participated.
3.2 Demographics and operative findings
39 of the 85 participants were in Group 1, 20 were in Group 2, and 26 were in Group 3 (45.9 %, 23.5 %, and 30.6 %, respectively). Within Group 3, 19 had not been pregnant prior to their hip surgery (73.1 %), while 7 had been pregnant both before and after surgery (26.9 %). Mean age of the study sample was 32.3 ± 6.5 years (range 18–44) with Group 1 subjects being significantly younger (29.6 ± 6.6 years) than Group 2 subjects (36.6 ± 5.4 years) and Group 3 subjects (33.2 ± 5.1 years) (p = 0.002). There were no significant differences between groups in BMI, procedure characteristics including laterality, intraoperative interventions, or primary versus revision procedures. Mean follow-up time for the study sample was 51.9 ± 34.5 months (range 6–146), with no significant differences in follow up time between groups. Demographics are summarized in Table 1.
| Variable | All subjects | Group 1 | Group 2 | Group 3 | P-valuec |
| # of subjects | 85 | 39 | 20 | 26 | – |
| Age (years) | 32.3 ± 6.5 | 29.6 ± 6.6 | 36.6 ± 5.4 | 33.2 ± 5.1 | 0.002∗1 < 32 < 3 |
| BMI (kg/m2) | 24.5 ± 4.7 | 24.2 ± 4.2 | 26.5 ± 6.8 | 23.2 ± 2.6 | 0.62 |
| Procedure laterality | L: 32 (37.7 %)R: 53 (62.4 %) | L: 12 (30.8 %)R: 27 (69.2 %) | L: 8 (40.0 %)R: 12 (60.0 %) | L: 12 (46.2 %)R: 14 (53.9 %) | 0.48 |
| Revision procedures | 8 (9.4 %) | 6 (15.4 %) | 1 (5.0 %) | 1 (3.9 %) | 0.31 |
| Acetabular Outerbridge grade | I/II: 82 (96.5 %)III: 3 (3.5 %) | I/II: 38 (97.4 %)III: 1 (2.6 %) | I/II: 19 (95.0 %)III: 1 (5.0 %) | I/II: 25 (96.2 %)III: 1 (3.9 %) | 1.00 |
| Cam resection | 80 (94.1 %) | 36 (92.3 %) | 20 (100.0 %) | 24 (92.3 %) | 0.60 |
| Pincer resection | 84 (98.8 %) | 38 (97.4 %) | 20 (100.0 %) | 26 (100.0 %) | 1.00 |
| Labral repair | 82 (96.5 %) | 38 (97.4 %) | 18 (90.0 %) | 26 (100.0 %) | 0.23 |
| Labral debridement | 2 (2.4 %) | 0 (0.0 %) | 1 (5.0 %) | 1 (3.9 %) | 0.29 |
| Labral reconstruction | 7 (8.2 %) | 5 (12.8 %) | 2 (10.0 %) | 0 (0.0 %) | 0.15 |
| Follow-up time (months) | 51.9 ± 34.5 | 46.8 ± 33.6 | 48.1 ± 31.3 | 62.6 ± 36.8 | 0.23 |
3.3 Obstetric history
Of the 46 patients experiencing pregnancy at any time point, most subjects reported a gravidity of 1 (16 subjects, 34.8 %) or 2 (16 subjects, 34.8 %); highest gravidity was 6. There was a higher proportion of primigravids in Group 3 (11 subjects, 42.3 %) compared to Group 2 (5 subjects, 25.0 %). Most subjects reported a parity of 1 (13 subjects, 28.9 %) or 2 (20 subjects, 44.4 %). Five patients reported nulliparity (10.9 %) of whom four were in Group 2 (4 of 20 subjects, 20.0 %). 43 subjects (50.6 %) were considering pregnancy in the future, of which the highest proportion was within Group 1 (71.8 %) followed by Group 3 (50.0 %) and Group 2 (10.0 %).
3.4 VAS pain scores and pain location
VAS pain scores at each study time point are presented in Table 2. There was no significant difference in preoperative VAS scores between the three groups (p = 0.15). However, Group 3 subjects reported significantly lower postoperative VAS compared to Group 2 subjects (mean 1.9 vs. 3.9, p = 0.03). While all three groups experienced significant pre-to-postoperative reduction in VAS score (p < 0.001), Group 3 subjects reported greater pre-to-postoperative reduction in VAS score compared to Group 2 subjects (mean −5.6 vs. −3.8, p = 0.04). Group 3 subjects reported an average increase in VAS score from the postoperative time point to the post-pregnancy time point (mean 1.9 to 3.0), but post-pregnancy VAS remained significantly lower than the preoperative baseline (mean 7.5 to 3.0, p < 0.001).
| VAS Time Point | Group 1 | Group 2 | Group 3 | P-valuec |
| Number of subjects | 39 | 20 | 26 | – |
| Preoperative | 7.2 ± 1.8 | 7.9 ± 2.3 | 7.5 ± 1.4 | 0.15 |
| Postoperative | 2.7 ± 2.2 | 3.9 ± 2.5 | 1.9 ± 2.5 | 0.02 (2 > 3: p = 0.03) |
| Pre-to-postoperative Δ | −4.5 ± 3.1 | −3.8 ± 2.7 | −5.6 ± 2.2 | 0.053 (3 > 2: p = 0.04) |
| During pregnancy | – | – | 3.2 ± 3.2 | – |
| After pregnancy | – | – | 3.0 ± 3.0 | – |
| Preoperative to post-pregnancy Δ | – | – | −4.4 ± 3.2 | – |
Preoperatively, pain was most commonly at the anterior thigh (48 subjects, 56.5 %) followed by the lateral thigh (13 subjects, 15.3 %) and the groin/medial thigh (12 subjects, 14.1 %). Postoperatively, the pain was primarily at the anterior thigh (32 subjects, 37.7 %) followed by the lateral thigh (11 subjects, 12.9 %) and the groin/medial thigh (9 subjects, 10.6 %) while 24 patients (28.2 %) reported having no pain. Among the Group 3 subjects at the intra-pregnancy time point, pain was most commonly of the anterior thigh (7 subjects, 26.9 %) followed by the sacrum/superior gluteal region (4 subjects, 15.4 %) and the groin/medial thigh (4 subjects, 15.4 %) while nine subjects (34.6 %) reported having no pain. At the post-pregnancy time point, the most commonly-reported pain location was the anterior thigh (10 subjects, 38.5 %) followed by the sacrum/superior gluteal region (4 subjects, 15.4 %) and the groin/medial thigh (3 subjects, 11.5 %) while seven subjects (26.9 %) reported having no pain.
Across all time points, the least commonly reported pain location was the perineum with one Group 2 patient reporting perineal pain at the postoperative time point and one Group 3 patient reporting perineal pain at the intra-pregnancy time point.
3.5 Postoperative pregnancy, labor, and delivery experiences (group 3 only)
Group 3 subjects reported getting pregnant an average of 6.3 ± 1.4 months after hip arthroscopy (range: 2–8 months). Most subjects had not been pregnant prior to hip surgery (19 subjects, 73.1 %). Five subjects (19.2 %) experienced at least one miscarriage after surgery; all five were 32–44 years old at the time of surgery.
The majority of patients experienced hip pain during the pregnancy (69.2 %). Of these 18 subjects, most experienced the most severe and/or frequent hip pain during the 3rd trimester (16 subjects, 88.9 %) while two subjects (7.7 %) reported worst pain in the 1st trimester.
Of the seven subjects who had been pregnant both before and after their hip surgery, three (42.9 %) reported that their hip pain during their post-surgery pregnancy was less severe than their pre-surgery pregnancies, one (14.3 %) reported that the pain was about the same, two (28.6 %) reported that it was worse, and one (14.3 %) did not respond. Three of these seven subjects (42.9 %) reported they had experienced a labral tear during a pregnancy that occurred prior to their hip surgery.
Most subjects had a vaginal delivery (21 subjects, 80.8 %). Of the seven subjects who had pregnancies both before and after hip surgery, six (85.7 %) reported that their overall pain during postoperative labor and delivery was about the same as their pre-surgery pregnancies and one (14.3 %) reported that it was worse. Complications that subjects experienced during labor and/or delivery are listed in Table 3.
| Complication | Incidence | ||
| All subjects (n = 26) | Nulliparous (n = 7) | Primiparous or multiparous (n = 19) | |
| Breech birth | 4 (15.4 %) | 1 (14.3 %) | 3 (15.8 %) |
| Vaginal or perineal tear | 13 (50.0 %) | 4 (57.1 %) | 9 (47.4 %) |
| Preterm premature rupture of membranes (PPROM) | 1 (3.9 %) | 0 (0.0 %) | 1 (5.3 %) |
| Prolonged labora | 5 (19.2 %) | 1 (14.3 %) | 4 (21.1 %) |
| Postpartum hemorrhage | 5 (19.2 %) | 1 (14.3 %) | 4 (21.1 %) |
| Uterine rupture | 0 (0.0 %) | 0 (0.0 %) | 0 (0.0 %) |
| Preeclampsia or eclampsia | 4 (15.4 %) | 3 (42.9 %) | 1 (5.3 %) |
| Low birth weightb | 0 (0.0 %) | 0 (0.0 %) | 0 (0.0 %) |
| Stillbirth | 1 (3.9 %) | 0 (0.0 %) | 1 (5.3 %) |
3.6 Post-pregnancy experiences and decision-making
Among the 26 subjects in Group 3, eight (30.8 %) reported complete resolution of their hip pain at the time of survey completion. Of the 18 subjects without complete pain resolution, 13 (72.2 %) reported that their current level of hip pain was better than their preoperative baseline, one (5.6 %) reported that it was about the same, and four (22.2 %) reported that it was worse. Of those same 18 subjects, 11 (61.1 %) reported that their current level of hip pain was about the same as their pre-pregnancy baseline and seven (38.9 %) reported that it was worse.
Nineteen subjects in Group 3 (73.1 %) reported specifically experiencing hip pain following delivery. Of these nineteen subjects, eleven (57.9 %) reported that their hip pain returned to the pre-pregnancy baseline by time of survey completion. Nine subjects (47.4 %) reported that the hip pain they experienced following their pregnancy that required medical attention; treatments included physical therapy (5 subjects, 55.6 %), further surgery (2 subjects, 22.2 %), and steroid injections (2 subjects, 22.2 %). Five subjects (26.3 %) stated that hip pain following pregnancy had dissuaded them from further pregnancy.
Thirteen subjects in Group 3 (50.0 %) reported that they were considering pregnancy in the future. When asked how long they themselves would wait after hip surgery before getting pregnant, they reported the following lengths of time: 3–6 months (2 subjects, 15.4 %), 6–9 months (1 subject, 7.7 %), 1–2 years (8 subjects, 61.5 %), and 2–3 years (2 subjects, 15.4 %).
3.7 mHHS at follow-up
Preoperative and follow-up mHHS values are presented in Table 4. Out of 85 subjects, 33 (38.9 %) had completed the mHHS survey preoperatively and 78 (91.8 %) completed the follow-up mHHS survey. There were no significant inter-group differences in preoperative scores (p = 0.56) or follow-up scores (p = 0.95), and postoperative scores were higher than preoperative scores in all groups.
| mHHS time point | All subjects | Group 1 | Group 2 | Group 3 | P-valuec |
| Preoperative | 58.6 ± 14.0 (n = 33) | 57.6 ± 15.2 (n = 19) | 58.2 ± 15.1 (n = 9) | 63.1 ± 7.2 (n = 5) | 0.56 |
| Follow-up | 79.6 ± 13.8 (n = 78) | 79.6 ± 14.3 (n = 37) | 80.0 ± 11.6 (n = 17) | 79.3 ± 15.0 (n = 24) | 0.95 |
4 Discussion
Reproductive age female patients with FAIS reported a significant decrease in VAS hip pain and significant increase in mHHS following hip arthroscopy whether never pregnant, pregnant prior to, or pregnant after hip arthroscopy. There were no differences between groups in pre or postoperative mHHS scores or preoperative VAS scores. There was a greater pre-to-postoperative decrease in VAS among subjects who became pregnant after their surgery (Group 3) versus those who had been pregnant before their surgery but not after (Group 2).
While patients who became pregnant postoperatively ultimately had good results as evidenced by their VAS and mHHS, a majority of them reported increased hip pain in the third trimester (69.2 %) and following delivery (73.1 %). Nearly half (47.4 %) specifically sought treatment for their hip pain. At final follow up, a majority (72.2 %) reported their symptom state had improved from the peripartum time period and was better than their initial preoperative state. However, a significant number (42.1 %) reported they still had not returned to their prior post-surgery, pre-pregnancy state of maximal improvement.
Prior to the current investigation, literature on patient outcomes and pregnancy after hip arthroscopy was limited to two case reports describing rapid progression of osteoarthritis during pregnancy for patients after hip arthroscopy, though these were notably dysplastic hips.17,18 In the hip arthroplasty literature, both peripartum worsening, particularly in the third trimester, and overall good post pregnancy outcomes have been described.11,24 This is consistent with our results, where the majority of patients experienced most severe and/or frequent pain in the third trimester. However while Sierra et al. reported that females with pain after pregnancy with prior THA located their pain to the groin,11 subjects in our study primarily localized pain to the anterior thigh across all time points. An important caveat when comparing pregnancy-related studies between hip arthroplasty versus arthroscopy is the differences between these populations, with THA in females of reproductive age often reserved for congenital hip dysplasia, avascular necrosis, advanced degenerative joint disease, and/or systematic inflammatory arthropathies.24
In addition to symptom worsening during pregnancy postoperatively, three patients in our cohort reported their index symptomology occurred during a previous pregnancy. This phenomenon has been described in two case series of 13 patients who experienced injury or FAIS onset requiring arthroscopic intervention during labor and delivery.15,16 Multiple mechanisms have been hypothesized to underly this FAIS disease onset and/or progression during pregnancy. First, both mechanical and hormonal changes to the pelvis are observed in pregnancy, including increased joint laxity and changes in pelvic alignment.25–28 This underlying altered cartilage matrix peripartum may predispose pregnant females to hip injury.15,16 Additionally, weight gain and activity changes alter loading patterns through the hip.16,29 Finally, while common positions of delivery such as lithotomy use external rotation of the hip, the extreme nature of such positioning or inadvertent sudden internal rotation while changing positions may predispose to direct injury or the incitement of pain from a previously asymptomatic lesion during labor itself.15,28,30
Of patients who experienced pregnancy postoperatively, patients became pregnant on average 6 months postoperatively. However, most subjects (76.9 %) stated that they would have preferred to wait at least 1 year after hip arthroscopy. Currently, there are no guidelines or literature regarding optimal pregnancy timing after hip arthroscopy. Thus, the collective experience of this cohort provides some insight with which to counsel patients.
This cohort experienced a miscarriage rate of 19.2 % following hip arthroscopy, which was higher than the multinational pooled risk estimate of 15.3 % for clinically-recognized pregnancies.31 However, miscarriage rates increase with maternal age, and all patients who experienced postoperative miscarriages in our sample were >32 years old at the time of surgery and pregnancy.31 The most commonly reported pregnancy-related complication among subjects who became pregnant after hip arthroscopy was vaginal and perineal tears (nulliparous 57.1 %, multiparous 47.4 %), and these rates were lower than those reported in OB/GYN literature (nulliparous 90.4 %, multiparous 68.8 %).32 While there are currently no recommendations from the Centers for Disease Control and Prevention or The American College of Obstetricians and Gynecologists regarding pregnancy following hip arthroscopy or arthroplasty, there is consistent evidence of safety during pregnancy and vaginal delivery following hip arthroplasty.11,12,24,25 Our results suggest similar safety of pregnancy after hip arthroscopy.
4.1 Limitations
First, the retrospective design of our study meant that outcomes could not be directly measured at each of the study time points and instead had to be retrospectively recalled by the survey respondents. This does make the present investigation susceptible to recall bias and inter-group comparisons of VAS and other outcomes should be interpreted as such. Additionally, the survey response rate was low with only 85 of 402 eligible patients responding (21.1 %). Our results may be affected by non-response bias, where patients with worse postoperative outcomes may have been more often lost to follow up. Future studies should focus on prospective collection of outcomes in larger cohorts to further elucidate the interrelations of pregnancy and arthroscopic interventions on clinical outcomes.
5 Conclusion
Females of reproductive age with FAIS can expect clinical improvements relative to their baseline after hip arthroscopy regardless of pregnancy timing relative to surgical intervention. However, a majority of patients who become pregnant post-arthroscopy experience a peripartum recurrence of their symptoms that may not return to the level of maximal improvement they had initially experienced postoperatively. Given the majority of hip arthroscopy patients are females of childbearing age, it is crucial that further investigation in this topic is pursued to best counsel patients facing both FAIS and pregnancy.
CRediT authorship contribution statement
Allison M. Morgan: Writing – original draft, Visualization. Dhruv S. Shankar: Writing – original draft, Visualization, Formal analysis. Andrew S. Bi: Visualization, Writing – review & editing. Zachary I. Li: Conceptualization, Formal analysis. Jairo Triana: Conceptualization, Formal analysis. Thomas Youm: Resources, Supervision.
Guardian/patient's consent
Informed consent was obtained from human subjects. The privacy rights of human subjects was observed.
Ethical statement
All procedures were performed in compliance with relevant laws and institutional guidelines and have been approved by the New York University Institutional Review Board (IRB #i20-01686_MOD07 obtained August 19, 2022).
Funding statement
No funding was obtained for this study.
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