Lisa Chao, MD, FACOG

All Publications

• Laparoscopic Excision of Retroperitoneal Adnexal Cyst. Journal of minimally invasive gynecology Muir, T. M., Chao, L. 2023; 30 (8): 615

  Abstract

  To demonstrate the laparoscopic excision of a retroperitoneal adnexal cyst and describe the advanced surgical techniques and anatomic considerations in a patient with previous abdominopelvic surgery.Stepwise demonstration of advanced laparoscopic techniques with narrated video footage.Adnexal masses after hysterectomy are a common reason for repeat abdominal surgery.1 Up to 9% of patients may require future adnexal surgery if ovarian preservation was chosen at the time of hysterectomy.2 Indications for surgery can include persistent adnexal masses, masses with concern for malignancy, chronic pelvic pain, and risk-reducing surgery.2 This patient is a 53-year-old postmenopausal female with a history of a total abdominal hysterectomy and left salpingectomy who underwent excision of an 8 cm retroperitoneal left adnexal cyst (Still 1).Excision of a retroperitoneal adnexal cyst can be performed through a laparoscopic approach with several key strategies: CONCLUSION: Knowledge of retroperitoneal anatomy is crucial in the surgical management of retroperitoneal adnexal masses because dissection can be technically challenging and anatomy may be distorted due to pelvic adhesive disease. Use of advanced laparoscopic techniques and understanding surgical planes are important for safe dissection. High and early ligation of the infundibulopelvic ligament at the pelvic brim and a complete ureterolysis with parametrial excision are often necessary to remove all ovarian tissue to prevent an ovarian remnant.

  View details for DOI 10.1016/j.jmig.2023.05.011

  View details for PubMedID 37245674

• Growing pains: strategies for improving ergonomics in minimally invasive gynecologic surgery. Current opinion in obstetrics & gynecology Lin, E., Young, R., Shields, J., Smith, K., Chao, L. 2023; 35 (4): 361-367

  Abstract

  To evaluate factors contributing to the development of work-related musculoskeletal disorders (WMSDs) and review strategies for mitigating ergonomic strain in minimally invasive gynecologic surgery.Factors associated with increased ergonomic strain and the development of WMSDs include increasing patient body mass index (BMI), smaller surgeon hand size, noninclusive design of instruments and energy devices and improper positioning of surgical equipment. Each type of minimally invasive surgery (laparoscopic, robotic, vaginal) confers its own ergonomic risk to the surgeon. Recommendations have been published regarding optimal ergonomic surgeon and equipment positioning. Intraoperative breaks and stretching are effective in reducing surgeon discomfort. Formal training in ergonomics has not yet been widely implemented, but educational interventions have been effective in reducing surgeon discomfort and can improve surgeon recognition of suboptimal ergonomics.Considering the serious downstream effects of WMSDs on surgeons, it is imperative to implement strategies for WMSD prevention. Optimal positioning of the surgeons and operative equipment should be routine. Intraoperative breaks and stretching should be incorporated during procedures and between every case. Formal education in ergonomics should be provided to surgeons and trainees. Additionally, more inclusive instrument design by industry partners should be prioritized.

  View details for DOI 10.1097/GCO.0000000000000875

  View details for PubMedID 37144567

• Ice-POP: Ice Packs for Postoperative Pain: A Randomized Controlled Trial. Journal of minimally invasive gynecology Shields, J. K., Kenyon, L., Porter, A., Chen, J., Chao, L., Chang, S., Kho, K. A. 2023; 30 (6): 455-461

  Abstract

  To evaluate the benefit of ice packs as a supplement to standard pain management following laparoscopic hysterectomy (LH).This Institutional Review Board-approved randomized controlled trial involved patients undergoing LH for benign conditions. Subjects were randomized to receive standard enhanced recovery after surgery pain management or standard enhanced recovery after surgery plus ice packs.Two academic tertiary care centers PATIENTS: Patients undergoing planned outpatient LH with the minimally invasive gynecologic surgery team between February 2019 and November 2020 were considered. Patients with chronic pain, current opioid use ≥1 week, or planned overnight hospitalizations were excluded. Primary outcome data were available for 51 subjects (24 control, 27 intervention).Ice packs were placed on the abdomen in the operating room.Pain was assessed at multiple time points throughout the study using a visual analogue scale (VAS). Opioid requirement was assessed using morphine milligram equivalent. There was no difference between the groups on any demographic variables. Morphine milligram equivalent requirements were also not different between the groups (p = .63). Postoperative day 1 (POD#1) VAS scores were not different (p = .89). Eighty-five percent of subjects reported feeling that their pain was controlled. Subjects who reported that they did not feel their pain was controlled did not use more opioids on POD#1 (p = .37), nor did they have higher POD#1 VAS scores (p = .55). Eighty-seven percent of the intervention subjects said they would use ice again, and 82.6% of them said they would recommend ice to others. There were no adverse events related to ice. All subjects were prescribed 20 tablets oxycodone and averaged 2.9 (SD 3.4) tablets used after discharge.Ice packs are an acceptable supplement for postoperative pain control, but they do not reduce postoperative pain or opioid usage compared to standard pain management without ice packs.

  View details for DOI 10.1016/j.jmig.2023.01.015

  View details for PubMedID 36740018

• Raising the Bar: Ergonomics in Minimally Invasive Gynecologic Surgery OBG Management Lin, E. G., Young, R. J., Chao, L., Kho, K. A. 2023; 35 (6): SS3-SS9

  View details for DOI 10.12788/obgm.0287

• Laparoscopic Approach to a Large 44 cm Adnexal Mass Young, R. J., Muir, T. M., Wang, E. B., Chao, L. 2023: S930

  View details for DOI 10.1016/j.ajog.2022.12.222

• Tackling the Obliterated Posterior Cul-de-Sac: Steps for Getting Out Unharmed Lin, E., Kenyon, L., Chao, L. 2023: S928

  View details for DOI 10.1016/j.ajog.2022.12.216

• Impact of Minimally Invasive Gynecologic Surgery on the Management of Adnexal Masses in Pregnancy Fin, K., Muir, T. M., Pruszynski, J., Chao, L. 2023: S17

  View details for DOI 10.1016/j.jmig.2023.08.048

• Effect of Video-based Coaching on Gynecologic Resident Laparoscopic Salpingectomy: A Randomized Controlled Trial Muir, T. M., Kho, K. A., Ramirez, C. I., Donnellan, N. M., Pruszynski, J., Chao, L. 2023: S25

  View details for DOI 10.1016/j.jmig.2023.08.071

• Neural activity in trigeminal neuralgia patients with sensory and motor stimulations: A pilot functional MRI study. Clinical neurology and neurosurgery Liu, W. C., Winslow, N. K., Chao, L., Nersesyan, H., Zagardo, M. T., Tracy, P. T. 2022; 219: 107343

  Abstract

  Trigeminal neuralgia (TN) is a neuropathic pain syndrome that typically exhibits paroxysmal pain. However, the true mechanism of pain processing is unclear. We aim to evaluate the neural activity changes, before and after radiofrequency rhizotomy, in TN patients using functional MRI (fMRI) with sensory and motor stimulations.Six patients with classical TN participated in the study. Each patient underwent two boxcar paradigms of fMRI tasks: air-sensation and jaw-clenching around 1-3 weeks before and after the surgical intervention. McGill Pain Questionnaire (MPQ) was used to evaluate the pain intensity prior to fMRI study.Before rhizotomy, the jaw-clenching stimulation yielded reduced brain activation in primary motor (M1) and primary (SI) and secondary somatosensory (SII) cortices. Following intervention, activation in those regions returned to near normal levels observed in healthy subjects. For air-sensation stimulation, several pain and pain modulation regions such as right thalamus, right putamen, insula, and brainstem, were activated before the intervention, but subsided after the intervention. This correlated well with the change of MPQ scores (p < 0.01).In our study, we observed significant pain reduction accompanied by increased motor activities after rhizotomy in patients with TN. We hypothesize that the reduced motor activities identified in fMRI may be reversed after the treatment with radiofrequency rhizotomy. More research is warranted.

  View details for DOI 10.1016/j.clineuro.2022.107343

  View details for PubMedID 35759909

• Enhanced Recovery After Surgery in Minimally Invasive Gynecologic Surgery. Obstetrics and gynecology clinics of North America Chao, L., Lin, E., Kho, K. 2022; 49 (2): 381-395

  Abstract

  Enhanced recovery after surgery (ERAS) is a multimodal, multidisciplinary approach to optimize patient outcomes by minimizing surgical stress with the goal of returning to normal physiologic function. Using minimally invasive surgery as the preferred route for gynecologic surgery is an integral component of ERAS and is strongly correlated with improved postoperative outcomes. Implementation of ERAS programs in minimally invasive gynecologic surgery results in substantial improvements in clinical outcomes with higher rates of same-day discharge, reduction in postoperative nausea and vomiting, improved patient satisfaction, and decreased opioid consumption without increase in complications, readmissions, or health care costs.

  View details for DOI 10.1016/j.ogc.2022.02.014

  View details for PubMedID 35636815

• Uterine Surgery and Risk of Adenomyosis: A Retrospective Study Sendukas, E. A., Allen, R. L., Ford, L., Xiao, H., Chao, L. 2022: S28

  View details for DOI 10.1016/j.jmig.2022.09.095

• The Effect of Obesity on the Accuracy of Uterine Weight Estimation and Impact on Hysterectomy Sendukas, E. A., Muir, T. M., Negrete Vasquez, O., Pruszynski, J., Chao, L. 2022: S132

  View details for DOI 10.1016/j.jmig.2022.09.432

• Navigating Cervical Fibroids during Laparoscopic Hysterectomy: Essential Tips & Tricks Lin, E. G., Chao, L. 2022: S50-51

  View details for DOI 10.1016/j.jmig.2022.09.170

• Omental evisceration in a gravid woman following second-trimester laparoscopy: A case report. Case reports in women's health Dilday, E. A., Allen, R. L., Manning, S. A., Chao, L. 2021; 29: e00283

  Abstract

  Surgeons performing laparoscopy in pregnancy are developing specific practices to improve care of gravid women. In this case, a pregnant 26-year-old patient underwent laparoscopic ovarian cystectomy in the second trimester, with cyst wall removal through an 8 mm umbilical port site incision. She returned four days later with pain and drainage from the umbilicus, and examination under anesthesia revealed omental evisceration through the umbilical incision. The patient healed well following excision of affected omentum, reapproximation of fascia in a simple, interrupted fashion, and closure of skin in a subcuticular fashion. Due to increased intra-abdominal pressure associated with a gravid uterus and other factors, port site closure for incisions smaller than 10 mm may improve healing and prevent complications of laparoscopic surgery in pregnancy.

  View details for DOI 10.1016/j.crwh.2020.e00283

  View details for PubMedID 33489784

  View details for PubMedCentralID PMC7809397

• Laparoscopic Appendectomy: Surgical Techniques for the Benign Gynecologist Wang, E. B., Sawyer, P., Chao, L. 2021: S75

  View details for DOI 10.1016/j.jmig.2021.09.498

• Laparoscopic Ureterolysis in the Setting of Endometriosis Allen, R. L., Chao, L. 2020: S22-23

  View details for DOI 10.1016/j.jmig.2020.08.303

• Surgical approach to distorted anatomy: What to do when nothing looks normal! Chen, J., Chao, L. 2020: S117

  View details for DOI 10.1016/j.jmig.2020.08.190

• Laparoscopic Approach to the Obliterated Anterior Cul-de-Sac Porter, A. E., Chao, L. 2020: S19

  View details for DOI 10.1016/j.jmig.2020.08.292

• Postoperative Bladder Filling After Outpatient Laparoscopic Hysterectomy and Time to Discharge: A Randomized Controlled Trial. Obstetrics and gynecology Chao, L., Mansuria, S. 2019; 133 (5): 879-887

  Abstract

  To determine whether backfilling the bladder postoperatively will reduce time to discharge in patients undergoing outpatient laparoscopic hysterectomy.In a single-blind, randomized, controlled trial among women undergoing outpatient laparoscopic hysterectomy, patients were randomly assigned to a backfill-assisted void trial or a trial of spontaneous voiding. The primary outcome was time to discharge assessed by length of time spent in the postanesthesia care unit. Secondary outcomes included time to first spontaneous void, urinary retention rates, and postoperative complications within 8 weeks. We estimated that 152 patients (76/group) would provide greater than 80% power to identify a 30-minute difference in the primary outcome with a SD of 56 minutes and a two-sided α of 0.05.Between June 2017 to May 2018, 202 women were screened, 162 women were randomized, and results were analyzed for 153 women. Seventy-five patients (group A) who had a backfill-assisted voiding trial and 78 patients (group B) who had a spontaneous voiding trial were included in the analysis. The mean time to discharge was 273.4 minutes for group A vs 283.2 minutes for group B, which was not found to be significant (P=.45). The mean time to first spontaneous void was 181.1 minutes in group A vs 206.0 minutes in group B. There was a statistically significant reduction of 24.9 minutes in time to first spontaneous void with patients randomized to the backfill group (P=.04). Five of 75 patients (6.7%) in group A and 10 of 78 patients (12.8%) in group B developed urinary retention postoperatively and required recatheterization before discharge, which was also not significant (P=.20).Bladder filling before removing the Foley catheter is a simple procedure shown to reduce time to first spontaneous void, but not time to discharge in patients undergoing outpatient laparoscopic hysterectomy.ClinicalTrials.gov, NCT03126162.

  View details for DOI 10.1097/AOG.0000000000003191

  View details for PubMedID 30969209

  View details for PubMedCentralID PMC6483897

• A Novel Technique: Mesh Repair after Excision of Rectus Muscle Endometriosis Melnyk, A., Chao, L., Lee, T. 2019: S167

  View details for DOI 10.1016/j.jmig.2019.09.299

• Laparoscopic Approach to the Difficult Trachelectomy: Surgical Tips and Tricks Shields, J., Porter, A., Chao, L. 2019: S51-52

  View details for DOI 10.1016/j.jmig.2019.09.614

• Perforated IUDS: Diagnosis and management Chao, L., Rindos, N., Mansuria, S. MOSBY-ELSEVIER. 2018: S967

  View details for DOI 10.1016/j.ajog.2017.12.168

  View details for Web of Science ID 000430684200161

• Laparoscopic management of ovarian remnant syndrome Chao, L., Lee, T. 2018: S961

  View details for DOI 10.1016/j.ajog.2017.12.143

• Laparoscopic Excision of Rectus Muscle Endometriosis Chao, L., Lee, T. 2018: S159

  View details for DOI 10.1016/j.jmig.2018.09.302

• Laparoscopic Excision of Ovarian Remnants: An Expanded Case Series Chao, L., Lee, T. 2018: S172

  View details for DOI 10.1016/j.jmig.2018.09.500

• Prevalence of Leiomyosarcoma Following Hysterectomy at a Single-Site Institution Chao, L., Lum, D. LIPPINCOTT WILLIAMS & WILKINS. 2017: 47S

  View details for DOI 10.1097/01.AOG.0000514368.06987.9c

  View details for Web of Science ID 000402705800164

• Monopolar Energy Simulation – Chicken Thigh Model Chao, L., Donnellan, N. M., Ecker, A., Lee, T., Lum, D. A., Ramirez, C. I. American College of Obstetrics and Gynecology. 2017 ; Contributing Subject Matter Expert to the ACOG Simulations Working Group for SWG Content
• Partial Vaginectomy for Excision of Rectovaginal Endometriosis Chao, L., Lee, T. 2017: S16

  View details for DOI 10.1016/j.jmig.2017.08.055

• Laparoscopic Excision of an Abdominal Wall Fibroid Chao, L., Rindos, N., Mansuria, S. 2016: S118

  View details for DOI 10.1016/j.jmig.2016.08.293

• Antenatal corticosteroids for preterm premature rupture of membranes: single or repeat course? American journal of perinatology Brookfield, K. F., El-Sayed, Y. Y., Chao, L., Berger, V., Naqvi, M., Butwick, A. J. 2015; 32 (6): 537-544

  Abstract

  Objective The aim of this article is to determine the risk of maternal chorioamnionitis and neonatal morbidity in women with preterm premature rupture of membranes (PPROM) exposed to one corticosteroid course versus a single repeat corticosteroid steroid course. Study Design Secondary analysis of a cohort of women with singleton pregnancies and PPROM. The primary outcome was a clinical diagnosis of maternal chorioamnionitis. Using multivariate logistic regression, we controlled for maternal age, race, body mass index, diabetes, gestational age at membrane rupture, preterm labor, and antibiotic administration. Neonatal morbidities were compared between groups controlling for gestational age at delivery. Results Of 1,652 women with PPROM, 1,507 women received one corticosteroid course and 145 women received a repeat corticosteroid course. The incidence of chorioamnionitis was similar between groups (single course = 12.3% vs. repeat course = 11.0%; p = 0.8). Women receiving a repeat corticosteroid course were not at increased risk of chorioamnionitis (adjusted odds ratio, 1.28; 95% confidence interval, 0.69-2.14). A repeat course of steroids was not associated with an increased risk of any neonatal morbidity. Conclusion Compared with a single steroid course, our findings suggest that the risk of maternal chorioamnionitis or neonatal morbidity may not be increased for women with PPROM receiving a repeat corticosteroid course.

  View details for DOI 10.1055/s-0034-1396690

  View details for PubMedID 25545441

• Antenatal Corticosteroids for Preterm Premature Rupture of Membranes: Single or Repeat Course? AMERICAN JOURNAL OF PERINATOLOGY Brookfield, K. F., El-Sayed, Y. Y., Chao, L., Berger, V., Naqvi, M., Butwick, A. J. 2015; 32 (6): 537-543

  Abstract

  Objective The aim of this article is to determine the risk of maternal chorioamnionitis and neonatal morbidity in women with preterm premature rupture of membranes (PPROM) exposed to one corticosteroid course versus a single repeat corticosteroid steroid course. Study Design Secondary analysis of a cohort of women with singleton pregnancies and PPROM. The primary outcome was a clinical diagnosis of maternal chorioamnionitis. Using multivariate logistic regression, we controlled for maternal age, race, body mass index, diabetes, gestational age at membrane rupture, preterm labor, and antibiotic administration. Neonatal morbidities were compared between groups controlling for gestational age at delivery. Results Of 1,652 women with PPROM, 1,507 women received one corticosteroid course and 145 women received a repeat corticosteroid course. The incidence of chorioamnionitis was similar between groups (single course = 12.3% vs. repeat course = 11.0%; p = 0.8). Women receiving a repeat corticosteroid course were not at increased risk of chorioamnionitis (adjusted odds ratio, 1.28; 95% confidence interval, 0.69-2.14). A repeat course of steroids was not associated with an increased risk of any neonatal morbidity. Conclusion Compared with a single steroid course, our findings suggest that the risk of maternal chorioamnionitis or neonatal morbidity may not be increased for women with PPROM receiving a repeat corticosteroid course.

  View details for DOI 10.1055/s-0034-1396690

  View details for Web of Science ID 000354342400005

  View details for PubMedID 25545441

• Maternal characteristics and neonatal outcomes in women with eclampsia versus severe preeclampsia Judy, A., Chao, L., Girsen, A., O'Malley, K., Lyell, D., Blumenfeld, Y., Butwick, A., El-Sayed, Y. MOSBY-ELSEVIER. 2014: S188–S189

  View details for DOI 10.1016/j.ajog.2013.10.404

  View details for Web of Science ID 000330322600372

• Chorioamnionitis and antenatal steroid therapy: single vs repeat course? Brookfield, K., Chao, L., Berger, V., Naqvi, M., El-Sayed, Y., Butwick, A. MOSBY-ELSEVIER. 2014: S16

  View details for DOI 10.1016/j.ajog.2013.10.058

  View details for Web of Science ID 000330322600028

• Outpatient total hip arthroplasty. The Journal of arthroplasty Dorr, L. D., Thomas, D. J., Zhu, J., Dastane, M., Chao, L., Long, W. T. 2010; 25 (4): 501-6

  Abstract

  Patients younger than 65 years were studied to determine what percentage of patients would enroll in a study of outpatient total hip arthroplasty, its safety, and benefits of the program. Of 192 eligible patients, 69 (36%) enrolled, and 53 (77%) of these went home the same day of surgery. Of 53, 44 maintained a diary for the first 3, weeks and 52 completed a satisfaction questionnaire at 6 weeks. Patients were followed for 6 months for occurrence of complications. There were no medical readmissions. Of 52 patients who completed a 6 week questionnaire, 50 (96%) were satisfied with the decision to have outpatient total hip arthroplasty. There were no objective physical benefits identified. This study reports the distribution of acceptance and completion of same day discharge for patients with total hip arthroplasty in a metropolitan population. It confirms safety in selected patients.

  View details for DOI 10.1016/j.arth.2009.06.005

  View details for PubMedID 19640672

• Significance of elevated CEA levels as a marker for splenic metastases in a patient with colorectal carcinoma Carle Selected Papers Yang, C. H., Chao, L., Magsalin, R. M., Dawson, S. 2010; 53 (1): 30-33
• Imaging and navigation measurement of acetabular component position in THA. Clinical orthopaedics and related research Wan, Z., Malik, A., Jaramaz, B., Chao, L., Dorr, L. D. 2009; 467 (1): 32-42

  Abstract

  There are six different definitions of acetabular position based on observed inclination and anteversion made in either the (1) anterior pelvic plane or (2) coronal planes and based on whether each of the observations made in one of these two planes is (1) anatomic, (2) operative, or (3) radiographic. Anteroposterior pelvic tilt is the angle between the anterior pelvic plane and the coronal plane of the body. The coronal plane is a functional plane and the anterior pelvic plane is an anatomic pelvic plane. A cup may be in the "safe zone" by one definition but may be out of the "safe zone" by another definition. We reviewed published studies, analyzed the difference in varying definitions, evaluated the influence of the anterior pelvic tilt, and provided methods to convert from one definition to another. We recommend all inclination and anteversion measurements be converted to the radiographic inclination and anteversion based on the coronal plane, which is equivalent to the inclination and anteversion on the anteroposterior pelvic radiograph.

  View details for DOI 10.1007/s11999-008-0597-5

  View details for PubMedID 18979147

  View details for PubMedCentralID PMC2600979

• Metal-on-metal hip arthroplasty does equally well in osteonecrosis and osteoarthritis. Clinical orthopaedics and related research Dastane, M. R., Long, W. T., Wan, Z., Chao, L., Dorr, L. D. 2008; 466 (5): 1148-53

  Abstract

  Many previous reports suggest total hip arthroplasty performs suboptimally in young patients with osteonecrosis. We retrospectively compared the performance of metal-on-metal articulation in a select group of 107 patients with 112 hips (98 uncemented and 14 cemented stems) 60 years of age or younger with either osteonecrosis (27 patients, 30 hips) or primary osteoarthritis (80 patients, 82 hips). We evaluated all patients with patient-generated Harris hip score forms and serial radiographs. Five mechanical complications were caused by impingement, two with pain, two dislocations, and one liner dissociation. At a minimum followup of 2.2 years (mean, 5.5 years; range, 2.2-11.7 years), we observed no osteolysis or aseptic loosening in the osteonecrosis group, whereas one osteoarthritic hip had cup revision for loosening (none showed evidence of osteolysis). None of the stems were loose. Patients with osteonecrosis or primary osteoarthritis were similar in clinical and radiographic performance. The patients with metal-on-metal hip arthroplasty for osteonecrosis had no revisions for aseptic loosening, but did have one liner change in a cup for painful impingement.

  View details for DOI 10.1007/s11999-008-0180-0

  View details for PubMedID 18350348

  View details for PubMedCentralID PMC2311458

• The emotional state of the patient after total hip and knee arthroplasty. Clinical orthopaedics and related research Dorr, L. D., Chao, L. 2007; 463: 7-12

  Abstract

  The new processes of total hip and knee arthroplasty partly engendered by mini-incision surgery have helped patients achieve all three goals of their operation: pain relief, improvement in function, and satisfaction. Satisfaction means the patient is no longer self-conscious about their disability and has regained the ability to live in their world in their usual way. The emotional state of the patient preoperatively, in the hospital, and during recovery will affect their feeling of satisfaction. Proper preoperative education makes patients more optimistic, and they anticipate fewer problems. In the hospital, a multimodal pain management program limits the use of parenteral narcotics and avoids the side effects of nausea and vomiting, which is the most important factor for in-hospital satisfaction. Recovery with an active physical therapy program individualized for the abilities and goals of the patient improves function and satisfaction. Surgeons must understand the expectations of the patient, direct them to realistic goals, and use the new processes of patient care to allow patients to exceed their expectations.

  View details for PubMedID 17960669

• Commentary & Perspective: Rapid-inflation intermittent pneumatic compression for prevention of deep venous thrombosis by Eisele et al. The Journal of Bone and Joint Surgery Dorr, L. D., Chao, L. 2007; 89: 1050-6
• Developments in Imageless Computer Navigation for Acetabular Component Position in Total Hip Replacement US Musculoskeletal Review Dorr, L. D., Chao, L. 2006; 2: 50-51