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Operative Times Have Remained Stable for Total Hip Arthroplasty for >15 Years

Systematic Review of 630,675 Procedures

Cantrell, William A. BS1; Samuel, Linsen T. MD, MBA1; Sultan, Assem A. MD1; Acuña, Alexander J. BS1; Kamath, Atul F. MD1

Author Information
doi: 10.2106/JBJS.OA.19.00047
  • Open
  • Disclosures

Abstract

Total hip arthroplasty (THA) procedural volume has surged considerably over the past few decades, with projections indicating that this growth will continue to increase in the years to come1-4. Part of this development can be attributed to the procedure’s widespread success and high rates of postoperative patient satisfaction5,6. However, in order to maintain its success, there has been an increased emphasis on ways of handling increased caseloads while minimizing complication rates7-9. The relationship between complications and operative time has been explored extensively in this regard. However, there has been a lack of information regarding what a typical duration for the procedure should be, with multiple studies indicating that both prolonged10-17 and shortened18,19 operative times can lead to various complications after total joint arthroplasty. Therefore, understanding how operative times have adjusted as procedural volume has grown can help providers better understand the interplay between complication rates and THA duration.

Understanding trends in THA operative times has become especially important over the recent decades when considering physician reimbursement. As the Centers for Medicare & Medicaid Services (CMS) continue to reevaluate compensation appraisals for total joint arthroplasties, and in light of THA being added to the CMS 2019 Potentially Misvalued Codes List, information regarding operative time can help inform this discussion20,21. Furthermore, while the American Association of Hip and Knee Surgeons (AAHKS) and the Relative Value Scale Update Committee (RUC) of the American Medical Association (AMA) have collaboratively provided intra-service times accompanying total joint arthroplasty coding, to the best of our knowledge there has yet to be an analysis of operative times reported across the current literature to add to this understanding.

The purpose of this review was to explore average operative times for THA as reported in the literature over the past 2 decades. Our aims were (1) to determine if operative times for THA have increased, decreased, or remained the same for patients reported on between 2000 and 2019 and (2) to determine what factors might contribute to the difference (or lack thereof) in THA operative time over this contemporary study period.

Materials and Methods

Literature Search

The PubMed and EBSCOhost databases were queried to identify all articles, published between January 1, 2000, and April 7, 2019, that reported on THA operative times in the United States, as defined and reported by the authors of the published study. The following keywords were used with the AND or OR Boolean operators: “operative,” “time,” and “total hip arthroplasty.” An article was included if the full text was available, it was written in English, and it reported operative times of THA procedures. An article was excluded if it did not discuss operative time; it reported only comparative, rather than absolute, operative times; or the cohort consisted of total knee arthroplasties (TKAs) and THAs, exclusively revision THAs, or exclusively robotic THAs. If data on manual or primary THAs could be extracted from an article on robotic or revision THAs, it was included.

Data Acquisition

The initial query yielded 1,335 manuscripts. Titles and abstracts were reviewed to identify articles that aligned with the purpose of our analysis. From this initial screening, 221 articles were selected for further review. After implementation of our inclusion and exclusion criteria, and thorough evaluation of each manuscript, 35 studies were included for our final review. A stepwise review of each article’s reference list was also conducted. However, no additional articles were included. Our final analysis therefore included 35 articles, reporting on a total of 630,675 hips that underwent THA between 1996 and 2016 (Table I). Figure 1 depicts the publication selection process.

TABLE I - Summary of Articles Included in Our Analysis
Article (Year) Patient Population Years No. of Hips Average Operative Time (min) Study Details*
Woolson and Kang32 (2007) 1996-1999 230 66.95 Compared resident involved vs. only an attending involved
Matta et al.43 (2005) 1996-2004 494 75.00 Described case series of patients who underwent THA via single-incision anterior approach
Pagnano et al.48 (2005) 2003-2004 200 60.00 Compared 2-incision technique vs. standard posterior approach
Desser et al.49 (2010) 2004-2006 60 149.00 Compared 2-incision technique vs. anterolateral approach
Wang et al.50 (2013) 2004-2010 425 79.00 Compared operative time among 6 groups stratified by BMI
Bernasek et al.51 (2010) 2005-2006 92 59.07 Compared anterolateral vs. lateral approach
Goytia et al.52 (2012) 2005-2007 81 110.68 Compared learning curve for anterior approach
Restrepo et al.53 (2010) 2005-2007 100 55.65 Compared direct anterior vs. direct lateral approach in RCT
O’Malley et al.16 (2012) 2005-2008 4,281 101.00 Reported complications and length of stay, and predictors of each, via NSQIP Database query
Haughom et al.22 (2014) 2005-2012 13,109 96.21 Compared resident present vs. resident not present, NSQIP Database queried
Choi et al.23 (2012) 2006-2008 194 97.90 Compared THA and TKA patients and short-term outcomes, via single-center registry
Della Valle et al.24 (2010) 2006-2008 72 87.79 Compared mini-incision posterior approach vs. 2-incision technique in RCT
Belmont et al.25 (2014) 2006-2011 17,638 97.60 Reported M&M in 30-day postop. period of THA, NSQIP Database queried
Gholson et al.26 (2016) 2006-2012 30,361 105 NSQIP Database queried
Grosso et al.54 (2019) 2006-2016 135,964 93.88 NSQIP Database queried
Tischler et al.27 (2015) 2007-2010 341 56.45 Compared intraop. fluoroscopic guidance vs. no fluoroscopic guidance
Schairer et al.28 (2017) 2007-2013 42,692 92.13 Compared THA for femoral neck fracture vs. osteoarthritis, NSQIP Database queried
McLawhorn et al.29 (2018) 2007-2014 2,018 95.00 Matched primary population with population in NSQIP who underwent conversion THA
Graves et al.30 (2016) 2008-2010 221 79.78 Compared posterior vs. direct anterior approach
Yakubek et al.31 (2018) 2008-2014 64,796 93.13 Compared non-COPD vs. COPD patients for short-term THA complications, NSQIP Database queried
Sodhi et al.33 (2018) 2008-2015 103,702 94.00 NSQIP Database queried
Barrett et al.34 (2013) 2010-2011 87 72.26 Compared direct anterior vs. posterior approach in RCT
Basques et al.35 (2015) 2010-2012 20,936 94.31 Compared general vs. spinal anesthesia, NSQIP Database queried
Ponzio et al.36 (2018) 2010-2012 4,538 74.85 Compared direct anterior vs. posterior approach
Sibia et al.37 (2017) 2010-2015 2,698 88.51 Compared direct anterior vs. posterior approach, Crimson Continuum of Care electronic database queried
Raphael et al.38 (2013) 2011 50 69.86 Compared normal-weight vs. overweight vs. obese vs. morbidly obese patients
George et al.39 (2018) 2011-2015 94,326 93.30 Compared TKA vs. THA for readmissions, reoperations, and complications
Surace et al.47 (2019) 2011-2015 89,802 91 Examined association between short-term complications and operative time, NSQIP Database queried
Schwarzkopf et al.40 (2017) 2012-2015 251 129.00 Compared conversion vs. primary THA
York et al.41 (2017) 2012-2015 50 124.00 Reported learning curve from first 25 THAs to second 25 THAs conducted via direct anterior approach
Ryan et al.42 (2018) 2012-2015 163 110.00 Compared primary vs. conversion THA
Isaacson et al.44 (2016) 2013-2014 92 76.30 Compared primary vs. revision THA
Masonis et al.45 (2008) Not available 300 116.27 Compared first 100 vs. middle 100 vs. last 100 of 1 surgeon’s first 300 THAs conducted via direct anterior approach
Trinh et al.46 (2015) Not available 101 97.59 Compared anterior approach vs. other surgical approaches
Russo et al.17 (2015) Not available 210 81 Compared “normal and pre-obese” BMI vs. obese BMI
*
RCT = randomized controlled trial, M&M = morbidity and mortality, and COPD = chronic obstructive pulmonary disease.
Only median operative time reported.

Fig. 1
Fig. 1:
PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) flow diagram depicting the selection process for publications included in the final analysis.

Results

Overall Operative Time Values

In the articles that reported the mean operative time for their respective cohorts, the overall weighted average was 93.20 minutes (Fig. 2)16,17,22-25,27-54. The range for the average of the times in each study were 55.6553 to 149.0049, and the range of the operative times for all individual cohorts included in the studies (most studies contained multiple cohorts) spanned 52.8 minutes27 to 166 minutes49. Only one study26 reported a median instead of a mean operative time, and the median in that cohort was 105 minutes.

Fig. 2
Fig. 2:
Mean operative times for reported study periods. Each time period on the x axis corresponds to the time period of 1 included study (see Table I).

Table II shows the operative time ranges across the individual cohorts in the included studies. At the extremes, 6 cohorts showed average operative times of <60 minutes27,48,51,53 and 6 demonstrated average times of >120 minutes41,45,49,52. However, the range into which the most cohorts fell (n = 16) was 90 to 99 minutes. Similarly, this range was associated with the largest number of THAs (n = 582,965; 92.4%), with each large database study reporting a mean operative time within this range22,25,28,31,33,35,39,47. Interestingly, when we considered only studies that did not utilize a database, we found increased variability in the operative time reported for each contained cohort (Table III). The most common range in the articles reporting on institutional data or case series was 70 to 79 minutes (n = 10 cohorts), and the average operative time in those studies was 88 minutes.

TABLE II - All Cohorts Stratified by Operative Time Ranges
Average Operative Time (min) No. of Cohorts*
<60 6
60-69 6
70-79 10
80-89 5
90-99 16
100-109 6
110-119 2
≥120 6
*
The number of cohorts does not equal the number of studies, as there were several cohorts in some studies.

TABLE III - Cohorts Without Formal Database Utilization Stratified by Operative Time Ranges
Average Operative Time (min) No. of Cohorts*
<60 6
60-69 6
70-79 10
80-89 3
90-99 6
100-109 2
110-119 2
≥120 6
*
The number of cohorts does not equal the number of studies, as there were several cohorts in some studies.

Change Over Time

We defined stability on the basis of the proximity of reported values to the overall weighted mean over the study period. As a whole, operative time was stable over the included study ranges, as seen in Figure 2. This trend can primarily be seen in the larger database studies that examined THA duration over multiple years. Belmont et al. reported on the earliest cohort of patients in the National Surgical Quality Improvement Program (NSQIP) and found a mean operative time of 97.6 minutes for 17,638 THA procedures performed between 2006 and 201125. In the database study with the latest and largest time frame (2006 to 2016) and the largest number of patients (n = 135,964), Grosso et al. demonstrated that operative time averaged 93.88 minutes and had not changed substantially over the study period54. In the second largest study, by Sodhi et al., the mean operative time was 94.00 minutes for 103,702 patients, further demonstrating a relative lack of change in THA duration33.

While these larger cohorts are more likely to reflect usual operative times, studies that did not utilize databases seemed to indicate the opposite of what is currently being espoused by CMS: i.e., these studies indicated an increase in operative time over the years. For example, in the earliest study, which included 230 hips that underwent the procedure between 1996 and 1999, Woolson and Kang found an average operative time of 66.95 minutes32. This lower procedure duration in earlier years was also shown by Matta et al.43, who found a mean operative time of 75.00 minutes in 494 patients treated between 1996 and 2004. Furthermore, 3 of the 4 most recent studies that did not utilize database data demonstrated some of the longest average operative times (>100 minutes)40-42,44. However, various confounding factors, such as small sample sizes and procedural learning curves, likely impacted these analyses. Grosso et al. presented conflicting findings, reporting that operative time had decreased between their 2006-to-2009 and 2014-to-2016 cohorts (p < 0.001), with the overall average for the 2 cohorts (93.88 minutes) remaining within the stable range described above54.

Surgical Technique

Differences in operative times across surgical techniques were examined in 10 studies24,30,34,36,37,46,48,49,51,53. Together, these studies indicated that technical approach had a variable influence on operative times.

Direct anterior and posterior approaches were compared in 4 studies30,34,36,37, with a lack of consensus regarding which method yielded a shorter operative time. Graves et al. found no difference in the mean operative time between 86 patients undergoing an anterior approach and 135 patients undergoing a posterior approach (79 versus 81 minutes, p = 0.411)30. An anterior approach resulted in longer operative times in the analyses by Barrett et al. (84.3 versus 60.5 minutes, p < 0.0001) and Sibia et al. (90.4 versus 86.3 minutes, p = 0.005)34,37. Furthermore, Ponzio et al., who reported on the largest number of patients among studies comparing anterior and posterior techniques (n = 4,538), found that a posterior approach yielded a longer operative time (75.1 versus 71.1 minutes, p < 0.001)36. However, it is noteworthy that there was a sizeable difference in the sample sizes of the anterior (n = 289) and posterior (n = 4,249) groups36.

The utilization of a 2-incision approach was analyzed in 3 studies24,48,49, all of which indicated that this method yielded a relatively longer procedure duration. Della Valle et al. found that THAs done with this technique took longer than those using a mini-incision posterior approach (98 versus 77 minutes, p = 0.0008)24, whereas Pagnano et al. and Desser et al. found that they took longer than those done through a standard posterior (68 versus 54 minutes, p = 0.01) or anterolateral (166 versus 132 minutes) approach48,49.

The remaining studies analyzed anterolateral versus lateral, direct anterior versus direct lateral, and anterior versus posterior, anterolateral, and lateral approaches46,51,53, with no differences found across these surgical techniques.

Learning Curve

The impact that the learning curve for THA procedures had on operative time was explored in 5 studies22,32,41,45,52. Three of these analyses examined the differences in operative time as a surgeon became more experienced41,45,52, whereas the remaining 2 examined the impact of the presence of a trainee on the duration of the procedure22,32. There was consensus among the studies that more experience, along with the absence of a trainee, led to decreased operative times. Masonis et al. examined a single surgeon’s experience with 300 consecutive THAs and found a significant difference between the first 100 (mean operative time: 132.8 minutes), second 100 (mean operative time: 109.9 minutes), and third 100 (mean operative time: 106.1 minutes) (p < 0.001)45. Similarly, York et al. found a significant difference in the mean surgical time between the first 25 procedures performed by a fellowship-trained surgeon (135.32 minutes) and the second 25 (113.91 minutes) (p = 0.0052)41. Furthermore, Woolson and Kang32 and Haughom et al.22 demonstrated that, when residents were present, operative time increased by 12 minutes (p < 0.0001) and 15 minutes (p < 0.001), respectively.

Impact of Body Mass Index (BMI)

Of the 35 studies included in this review, 3 compared operative time between patient groups stratified by BMI17,38,50. Across these analyses, increasing BMI was associated with longer operative times. Wang et al. found that patients in the BMI category of Obese Class III had a significantly longer mean operative time (97 minutes) than those who were underweight (71 minutes, p < 0.001), normal weight (74 minutes, p < 0.001), overweight (75 minutes, p < 0.001), in Obese Class I (82 minutes, p < 0.001), or in Obese Class II (86 minutes, p = 0.011)50. Similarly, Russo et al. found that operating room time was significantly lower for a combined cohort of normal-weight and pre-obese patients (75.9 minutes) compared with a combined cohort of patients in Obese Classes I, II, and III (88.6 minutes, p < 0.0001)17. No difference was found across individual obese classes (p = 0.2908)17.

Discussion

As procedural volume for THA continues to rise, a better understanding of how operative times have changed over the years can help providers understand typical procedure duration. In our study, we found that the average operative time across included articles was approximately 95 minutes. Additionally, we found that operative time has been relatively stable over the past 2 decades. These findings are especially important given the fact that operative time is a main driver of cost (including the costs of the operating room time and the time of operating room staff, including nurses and surgical technologists).

Our study has some limitations. Since many of the included studies utilized the NSQIP, it is likely that operative times were double-counted in our review, potentially skewing the average. However, these articles reported on multiple time frames and included a high number of patients, suggesting that the reported average is likely an accurate estimate. Additionally, different hospitals may use different algorithms to calculate the duration of these surgical procedures. For example, while operative time should be recorded as the time from skin incision to skin closure, some institutions may begin recording at the time that anesthesia is administered or extend their recording to when dressings have been placed. Given that many of our included articles did not elaborate on the method of measuring operative time, the accuracy of the reported values cannot be validated. Furthermore, we focused only on operative times in the United States, which could limit the generalizability of our findings to international health-care systems. However, given the large number of hips included in this analysis, as well as the wide time range reported across studies, we believe that these findings can be useful for all surgeons performing THA.

An increase in operative time would be expected over a contemporary time frame given the increased BMI and higher comorbidity burden associated with modern-day total joint arthroplasty patient populations4,41,45,52,55-58. These characteristics can increase the difficulty of a procedure and thus prolong intra-service time. This was made evident by the articles included in our analysis that reported on BMI, which all demonstrated a direct relationship between BMI and operative time17,38,50. Additionally, various studies have indicated that increased patient comorbidity burden can result in a variety of adverse outcomes, such as increased complication rates, length of hospital stay, and mortality following total joint arthroplasty16,25,26,31,38,50,56,59-64. Increased complexity similarly prolongs operative times. Specifically, in our analysis, Gholson et al. found that congestive heart failure was associated with a 20-minute increase in operating room time26.

Other factors likely play a role in our findings regarding stable THA operative times. Notably, with the advent of various new technologies, along with an increased focus on preoperative planning modalities, providers are likely addressing the increased complexity of their patients’ medical conditions through perioperative management of potential risks. Subsequently, adult reconstruction surgeons are able to maintain safe operative times despite the higher level of difficulty associated with these comorbidities65.

An additional factor contributing to the stable operative time for THAs over the last 20 years could be related to the learning curve associated with implementing THA procedures in practice22,32,41,45,52,55. Although operative time decreases as surgeons become more comfortable and familiar with the procedure, having an innovative practice that incorporates the newest approaches and techniques likely contributes to increased operative times during this period of adjustment. For example, there has been an increase in the adoption of the anterior approach to THA66,67, which may be associated with an inherent learning curve. While additional analyses with larger cohorts are needed to determine the impact of this factor on operative time trends, it is important to consider the importance of continually trying new technologies and techniques. Notably, the transition from cementless to cemented THA approximately 20 years ago led to improved functional outcomes, prolonged implant survivability, and shortened operative times68-70.

Another factor affecting operative time may be that, as the procedural volume continues to rise, resident and fellowship programs may be more comfortable allowing trainees to participate in the procedure itself.

In conclusion, the average operative time across the articles included in this systematic review was approximately 95 minutes, and this operative time was relatively stable over the past 2 decades. Increased BMI and less surgeon experience both were associated with increased operative times. Future studies should examine the relationship between operative time and patient-related factors and adverse outcomes over a similar study period. Given the stability in operative times found in our systematic review, and the relationship between operative time and cost, we cannot support lowering the procedural valuation by CMS.

References

1. Kurtz S, Ong K, Lau E, Mowat F, Halpern M. Projections of primary and revision hip and knee arthroplasty in the United States from 2005 to 2030. J Bone Joint Surg Am. 2007 Apr;89(4):780-5.
2. Singh JA. Epidemiology of knee and hip arthroplasty: a systematic review. Open Orthop J. 2011 Mar 16;5:80-5.
3. Maradit Kremers H, Larson DR, Crowson CS, Kremers WK, Washington RE, Steiner CA, Jiranek WA, Berry DJ. Prevalence of total hip and knee replacement in the United States. J Bone Joint Surg Am. 2015 Sep 2;97(17):1386-97.
4. Sloan M, Premkumar A, Sheth NP. Projected volume of primary total joint arthroplasty in the U.S., 2014 to 2030. J Bone Joint Surg Am. 2018 Sep 5;100(17):1455-60.
5. Krushell R, Bhowmik-Stoker M, Kison C, O’Connor M, Cherian JJ, Mont MA. Characterization of patient expectations and satisfaction after total hip arthroplasty. J Long Term Eff Med Implants. 2016;26(2):123-32.
6. Mancuso CA, Salvati EA, Johanson NA, Peterson MGE, Charlson ME. Patients’ expectations and satisfaction with total hip arthroplasty. J Arthroplasty. 1997 Jun;12(4):387-96.
7. Zhan C, Miller MR. Excess length of stay, charges, and mortality attributable to medical injuries during hospitalization. JAMA. 2003 Oct 8;290(14):1868-74.
8. Waters TM, Daniels MJ, Bazzoli GJ, Perencevich E, Dunton N, Staggs VS, Potter C, Fareed N, Liu M, Shorr RI. Effect of Medicare’s nonpayment for hospital-acquired conditions: lessons for future policy. JAMA Intern Med. 2015 Mar;175(3):347-54.
9. Duchman KR, Pugely AJ, Martin CT, Gao Y, Bedard NA, Callaghan JJ. Operative time affects short-term complications in total joint arthroplasty. J Arthroplasty. 2017 Apr;32(4):1285-91. Epub 2016 Dec 14.
10. Kessler S, Kinkel S, Käfer W, Puhl W, Schochat T. Influence of operation duration on perioperative morbidity in revision total hip arthroplasty. Acta Orthop Belg. 2003 Aug;69(4):328-33.
11. Namba RS, Inacio MCS, Paxton EW. Risk factors associated with deep surgical site infections after primary total knee arthroplasty: an analysis of 56,216 knees. J Bone Joint Surg Am. 2013 May 1;95(9):775-82.
12. Peersman G, Laskin R, Davis J, Peterson MGE, Richart T. Prolonged operative time correlates with increased infection rate after total knee arthroplasty. HSS J. 2006 Feb;2(1):70-2.
13. Horlocker TT, Hebl JR, Gali B, Jankowski CJ, Burkle CM, Berry DJ, Zepeda FA, Stevens SR, Schroeder DR. Anesthetic, patient, and surgical risk factors for neurologic complications after prolonged total tourniquet time during total knee arthroplasty. Anesth Analg. 2006 Mar;102(3):950-5.
14. Kurtz SM, Ong KL, Lau E, Bozic KJ, Berry D, Parvizi J. Prosthetic joint infection risk after TKA in the Medicare population. Clin Orthop Relat Res. 2010 Jan;468(1):52-6. Epub 2009 Aug 8.
15. Pulido L, Ghanem E, Joshi A, Purtill JJ, Parvizi J. Periprosthetic joint infection: the incidence, timing, and predisposing factors. Clin Orthop Relat Res. 2008 Jul;466(7):1710-5. Epub 2008 Apr 18.
16. O’Malley NT, Fleming FJ, Gunzler DD, Messing SP, Kates SL. Factors independently associated with complications and length of stay after hip arthroplasty: analysis of the National Surgical Quality Improvement Program. J Arthroplasty. 2012 Dec;27(10):1832-7. Epub 2012 Jul 17.
17. Russo MW, Macdonell JR, Paulus MC, Keller JM, Zawadsky MW. Increased complications in obese patients undergoing direct anterior total hip arthroplasty. J Arthroplasty. 2015 Aug;30(8):1384-7. Epub 2015 Mar 17.
18. Ong KL, Lau E, Manley M, Kurtz SM. Effect of procedure duration on total hip arthroplasty and total knee arthroplasty survivorship in the United States Medicare population. J Arthroplasty. 2008 Sep;23(6)(Suppl 1):127-32. Epub 2008 Jun 13.
19. Småbrekke A, Espehaug B, Havelin LI, Furnes O. Operating time and survival of primary total hip replacements: an analysis of 31,745 primary cemented and uncemented total hip replacements from local hospitals reported to the Norwegian Arthroplasty Register 1987-2001. Acta Orthop Scand. 2004 Oct;75(5):524-32.
20. Centers for Medicare & Medicaid Services. Medicare program; revisions to payment policies under the physician fee schedule and other revisions to Part B for CY 2019; Medicare Shared Savings Program requirements; Quality Payment Program; Medicaid Promoting Interoperability Program; Quality Payment Program. Fed Regist. 2018;83:59452-60303. Accessed 2019 Nov 15. https://www.govinfo.gov/content/pkg/FR-2018-11-23/pdf/2018-24170.pdf
21. American Medical Association. Summary: 2019 Medicare Physician Fee Schedule and Quality Payment Program Final Rule. 2019. Accessed 2019 Oct 31. https://www.ama-assn.org/system/files/2018-11/pfs-qpp-final-rule-sum11-8.pdf
22. Haughom BD, Schairer WW, Hellman MD, Yi PH, Levine BR. Resident involvement does not influence complication after total hip arthroplasty: an analysis of 13,109 cases. J Arthroplasty. 2014 Oct;29(10):1919-24. Epub 2014 Jun 6.
23. Choi JK, Geller JA, Yoon RS, Wang W, Macaulay W. Comparison of total hip and knee arthroplasty cohorts and short-term outcomes from a single-center joint registry. J Arthroplasty. 2012 Jun;27(6):837-41. Epub 2012 Mar 3.
24. Della Valle CJ, Dittle E, Moric M, Sporer SM, Buvanendran A. A prospective randomized trial of mini-incision posterior and two-incision total hip arthroplasty. Clin Orthop Relat Res. 2010 Dec;468(12):3348-54. Epub 2010 Jul 29.
25. Belmont PJ Jr, Goodman GP, Hamilton W, Waterman BR, Bader JO, Schoenfeld AJ. Morbidity and mortality in the thirty-day period following total hip arthroplasty: risk factors and incidence. J Arthroplasty. 2014 Oct;29(10):2025-30. Epub 2014 May 27.
26. Gholson JJ, Shah AS, Gao Y, Noiseux NO. Morbid obesity and congestive heart failure increase operative time and room time in total hip arthroplasty. J Arthroplasty. 2016 Apr;31(4):771-5. Epub 2015 Nov 10.
27. Tischler EH, Orozco F, Aggarwal VK, Pacheco H, Post Z, Ong A. Does intraoperative fluoroscopy improve component positioning in total hip arthroplasty? Orthopedics. 2015 Jan;38(1):e1-6.
28. Schairer WW, Lane JM, Halsey DA, Iorio R, Padgett DE, McLawhorn AS. The Frank Stinchfield Award : total hip arthroplasty for femoral neck fracture is not a typical DRG 470: a propensity-matched cohort study. Clin Orthop Relat Res. 2017 Feb;475(2):353-60.
29. McLawhorn AS, Schairer WW, Schwarzkopf R, Halsey DA, Iorio R, Padgett DE. Alternative payment models should risk-adjust for conversion total hip arthroplasty: a propensity score-matched study. J Arthroplasty. 2018 Jul;33(7):2025-30. Epub 2017 Dec 6.
30. Graves SC, Dropkin BM, Keeney BJ, Lurie JD, Tomek IM. Does surgical approach affect patient-reported function after primary THA? Clin Orthop Relat Res. 2016 Apr;474(4):971-81. Epub 2015 Nov 30.
31. Yakubek GA, Curtis GL, Sodhi N, Faour M, Klika AK, Mont MA, Barsoum WK, Higuera CA. Chronic obstructive pulmonary disease is associated with short-term complications following total hip arthroplasty. J Arthroplasty. 2018 Jun;33(6):1926-9. Epub 2018 Jan 9.
32. Woolson ST, Kang MN. A comparison of the results of total hip and knee arthroplasty performed on a teaching service or a private practice service. J Bone Joint Surg Am. 2007 Mar;89(3):601-7.
33. Sodhi N, Piuzzi NS, Khlopas A, Newman JM, Kryzak TJ, Stearns KL, Mont MA. Are we appropriately compensated by relative value units for primary vs revision total hip arthroplasty? J Arthroplasty. 2018 Feb;33(2):340-4. Epub 2017 Sep 19.
34. Barrett WP, Turner SE, Leopold JP. Prospective randomized study of direct anterior vs postero-lateral approach for total hip arthroplasty. J Arthroplasty. 2013 Oct;28(9):1634-8. Epub 2013 Mar 19.
35. Basques BA, Toy JO, Bohl DD, Golinvaux NS, Grauer JN. General compared with spinal anesthesia for total hip arthroplasty. J Bone Joint Surg Am. 2015 Mar 18;97(6):455-61.
36. Ponzio DY, Poultsides LA, Salvatore A, Lee YY, Memtsoudis SG, Alexiades MM. In-hospital morbidity and postoperative revisions after direct anterior vs posterior total hip arthroplasty. J Arthroplasty. 2018 May;33(5):1421-1425.e1. Epub 2017 Dec 9.
37. Sibia US, Turner TR, MacDonald JH, King PJ. The impact of surgical technique on patient reported outcome measures and early complications after total hip arthroplasty. J Arthroplasty. 2017 Apr;32(4):1171-5. Epub 2016 Nov 1.
38. Raphael IJ, Parmar M, Mehrganpour N, Sharkey PF, Parvizi J. Obesity and operative time in primary total joint arthroplasty. J Knee Surg. 2013 Apr;26(2):95-9. Epub 2013 Jan 28.
39. George J, Chughtai M, Khlopas A, Klika AK, Barsoum WK, Higuera CA, Mont MA. Readmission, reoperation, and complications: total hip vs total knee arthroplasty. J Arthroplasty. 2018 Mar;33(3):655-60. Epub 2017 Oct 5.
40. Schwarzkopf R, Chin G, Kim K, Murphy D, Chen AF. Do conversion total hip arthroplasty yield comparable results to primary total hip arthroplasty? J Arthroplasty. 2017 Mar;32(3):862-71. Epub 2016 Sep 1.
41. York PJ, Logterman SL, Hak DJ, Mavrogenis A, Mauffrey C. Orthopaedic trauma surgeons and direct anterior total hip arthroplasty: evaluation of learning curve at a level I academic institution. Eur J Orthop Surg Traumatol. 2017 Apr;27(3):421-4. Epub 2017 Mar 3.
42. Ryan SP, DiLallo M, Attarian DE, Jiranek WA, Seyler TM. Conversion vs primary total hip arthroplasty: increased cost of care and perioperative complications. J Arthroplasty. 2018 Aug;33(8):2405-11. Epub 2018 Mar 15.
43. Matta JM, Shahrdar C, Ferguson T. Single-incision anterior approach for total hip arthroplasty on an orthopaedic table. Clin Orthop Relat Res. 2005 Dec;441:115-24.
44. Isaacson MJ, Bunn KJ, Noble PC, Ismaily SK, Incavo SJ. Quantifying and predicting surgeon work input in primary vs revision total hip arthroplasty. J Arthroplasty. 2016 Jun;31(6):1188-93. Epub 2015 Dec 9.
45. Masonis J, Thompson C, Odum S. Safe and accurate: learning the direct anterior total hip arthroplasty. Orthopedics. 2008 Dec;31(12)(Suppl 2).
46. Trinh TQ, Ferrel JR, Pulley BR, Fowler TT. Short-term outcomes of femoral neck fractures treated with hemiarthroplasty using the anterior approach. Orthopedics. 2015 Dec;38(12):e1091-7.
47. Surace P, Sultan AA, George J, Samuel LT, Khlopas A, Molloy RM, Stearns KL, Mont MA. The association between operative time and short-term complications in total hip arthroplasty: an analysis of 89,802 surgeries. J Arthroplasty. 2019 Mar;34(3):426-32. Epub 2018 Nov 20.
48. Pagnano MW, Leone J, Lewallen DG, Hanssen AD. Two-incision THA had modest outcomes and some substantial complications. Clin Orthop Relat Res. 2005 Dec;441:86-90.
49. Desser DR, Mitrick MF, Ulrich SD, Delanois RE, Mont MA. Total hip arthroplasty: comparison of two-incision and standard techniques at an AOA-accredited community hospital. J Am Osteopath Assoc. 2010 Jan;110(1):12-5.
50. Wang JL, Gadinsky NE, Yeager AM, Lyman SL, Westrich GH. The increased utilization of operating room time in patients with increased BMI during primary total hip arthroplasty. J Arthroplasty. 2013 Apr;28(4):680-3. Epub 2012 Nov 9.
51. Bernasek TL, Lee WS, Lee HJ, Lee JS, Kim KH, Yang JJ. Minimally invasive primary THA: anterolateral intermuscular approach versus lateral transmuscular approach. Arch Orthop Trauma Surg. 2010 Nov;130(11):1349-54. Epub 2010 Jan 13.
52. Goytia RN, Jones LC, Hungerford MW. Learning curve for the anterior approach total hip arthroplasty. J Surg Orthop Adv. 2012 Summer;21(2):78-83.
53. Restrepo C, Parvizi J, Pour AE, Hozack WJ. Prospective randomized study of two surgical approaches for total hip arthroplasty. J Arthroplasty. 2010 Aug;25(5):671-9.e1. Epub 2010 Apr 8.
54. Grosso MJ, Neuwirth AL, Boddapati V, Shah RP, Cooper HJ, Geller JA. Decreasing length of hospital stay and postoperative complications after primary total hip arthroplasty: a decade analysis from 2006 to 2016. J Arthroplasty. 2019 Mar;34(3):422-5. Epub 2018 Nov 12.
55. Stone AH, Sibia US, Atkinson R, Turner TR, King PJ. Evaluation of the learning curve when transitioning from posterolateral to direct anterior hip arthroplasty: a consecutive series of 1000 cases. J Arthroplasty. 2018 Aug;33(8):2530-4. Epub 2018 Mar 8.
56. Partridge T, Jameson S, Baker P, Deehan D, Mason J, Reed MR. Ten-year trends in medical complications following 540,623 primary total hip replacements from a national database. J Bone Joint Surg Am. 2018 Mar 7;100(5):360-7.
57. Hales CM, Fryar CD, Carroll MD, Freedman DS, Ogden CL. Trends in obesity and severe obesity prevalence in us youth and adults by sex and age, 2007-2008 to 2015-2016. JAMA. 2018 Apr 24;319(16):1723-5.
58. Flegal KM, Kruszon-Moran D, Carroll MD, Fryar CD, Ogden CL. Trends in obesity among adults in the United States, 2005 to 2014. JAMA. 2016 Jun 7;315(21):2284-91.
59. Knoedler MA, Jeffery MM, Philpot LM, Meier S, Almasri J, Shah ND, Borah BJ, Murad MH, Larson AN, Ebbert JO. Risk factors associated with health care utilization and costs of patients undergoing lower extremity joint replacement. Mayo Clin Proc Innov Qual Outcomes. 2018 Jul 31;2(3):248-56.
60. Pugely AJ, Martin CT, Gao Y, Belatti DA, Callaghan JJ. Comorbidities in patients undergoing total knee arthroplasty: do they influence hospital costs and length of stay? Clin Orthop Relat Res. 2014 Dec;472(12):3943-50. Epub 2014 Sep 5.
61. Haynes J, Nam D, Barrack RL. Obesity in total hip arthroplasty: does it make a difference? Bone Joint J. 2017 Jan;99-B(1)(Supple A):31-6.
62. Sloan M, Sheth NP. Length of stay and inpatient mortality trends in primary and revision total joint arthroplasty in the United States, 2000-2014. J Orthop. 2018 May 7;15(2):645-9.
63. Gonzalez Della Valle A, Chiu YL, Ma Y, Mazumdar M, Memtsoudis SG. The metabolic syndrome in patients undergoing knee and hip arthroplasty: trends and in-hospital outcomes in the United States. J Arthroplasty. 2012 Dec;27(10):1743-1749.e1. Epub 2012 Jun 5.
64. D’Apuzzo M, Westrich G, Hidaka C, Jung Pan T, Lyman S. All-cause versus complication-specific readmission following total knee arthroplasty. J Bone Joint Surg Am. 2017 Jul 5;99(13):1093-103.
65. Sodhi N, Anis HK, Coste M, Ehiorobo JO, Chee A, Freund B, Sultan AA, Moskal JT, Scuderi GR, Mont MA. A nationwide analysis of preoperative planning on operative times and postoperative complications in total knee arthroplasty. J Knee Surg. 2019 Feb 20. Epub 2019 Feb 20.
66. Patel NN, Shah JA, Erens GA. Current trends in clinical practice for the direct anterior approach total hip arthroplasty. J Arthroplasty. 2019 Sep;34(9):1987-93.e3. Epub 2019 Apr 18.
67. Abdel MP, Berry DJ. Current practice trends in primary hip and knee arthroplasties among members of the American Association of Hip and Knee Surgeons: a long-term update. J Arthroplasty. 2019 Jul;34(7S):S24-7. Epub 2019 Feb 12.
68. Kim YH, Oh SH, Kim JS. Incidence and natural history of deep-vein thrombosis after total hip arthroplasty. A prospective and randomised clinical study. J Bone Joint Surg Br. 2003 Jul;85(5):661-5.
69. Abdulkarim A, Ellanti P, Motterlini N, Fahey T, O’Byrne JM. Cemented versus uncemented fixation in total hip replacement: a systematic review and meta-analysis of randomized controlled trials. Orthop Rev (Pavia). 2013 Mar 15;5(1):e8.
70. Laupacis A, Bourne R, Rorabeck C, Feeny D, Tugwell P, Wong C. Comparison of total hip arthroplasty performed with and without cement: a randomized trial. J Bone Joint Surg Am. 2002 Oct;84(10):1823-8.

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