Unplanned Admissions Following Hip Arthroscopy: Incidence and Risk Factors


      To determine the rate of and risk factors for 30-day unplanned admissions following hip arthroscopy in a U.S. population.


      Patients undergoing hip arthroscopy were identified in the American College of Surgeons National Surgical Quality Improvement Program database using validated Current Procedural Terminology and International Classification of Diseases, Ninth Revision and Tenth Revision codes. Patient demographics, comorbidities, preoperative laboratory values, surgical details, and postoperative outcomes were compared between patients with unplanned admissions and those without. Univariate analysis comparing study cohorts was performed using 2-tailed Student t tests with Levene's test for equality of variance or χ2/Fisher exact tests as appropriate. Using variables that were significant in the univariate analysis, we created Cox proportional hazard models to identify independent predictors for unplanned admission.


      A total of 1931 cases of hip arthroscopy were identified. There were 18 cases of unplanned admissions within 30 days of index procedure (0.9%). The median time to unplanned admission was 14.5 days (interquartile range: 3.875-25.125 days). The most common reasons for admission were surgical-site infection (11.1%), wound complications (11.1%), and thromboembolic events (11.1%). There were 4 patients who required reoperation (22.2%). There were 7 cases (39.0%) that were readmitted for reasons unrelated to the index hip arthroscopy procedure. Multivariate analysis identified increasing body mass index, chronic corticosteroid use, and perioperative blood transfusion as factors independently associated with increased risk for unplanned admission.


      There exists a low incidence of 30-day unplanned admission, predominantly secondary to surgical-site infections, wound complications, and thromboembolic events. Independent risk factors for unplanned admission include greater body mass index, chronic corticosteroid use, and perioperative transfusions.

      Level of Evidence

      Level III Retrospective Cohort Study.
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        • Maradit Kremers H.
        • Schilz S.R.
        • Van Houten H.K.
        • et al.
        Trends in utilization and outcomes of hip arthroscopy in the United States between 2005 and 2013.
        J Arthroplasty. 2017; 32: 750-755
        • Ganz R.
        • Parvizi J.
        • Beck M.
        • Leunig M.
        • Notzli H.
        • Siebenrock K.A.
        Femoroacetabular impingement: A cause for osteoarthritis of the hip.
        Clin Orthop Relat Res. 2003; : 112-120
        • Mather 3rd, R.C.
        • Nho S.J.
        • Federer A.
        • et al.
        Effects of arthroscopy for femoroacetabular impingement syndrome on quality of life and economic outcomes.
        Am J Sports Med. 2018; 46: 1205-1213
        • Cvetanovich G.L.
        • Chalmers P.N.
        • Levy D.M.
        • et al.
        Hip arthroscopy surgical volume trends and 30-day postoperative complications.
        Arthroscopy. 2016; 32: 1286-1292
      1. 111th Congress. Patient Protection and Affordable Care Act, HR 3590.
        (Available at:) (Accessed April 20, 2019)
        • Malviya A.
        • Raza A.
        • Jameson S.
        • James P.
        • Reed M.R.
        • Partington P.F.
        Complications and survival analyses of hip arthroscopies performed in the national health service in England: A review of 6,395 cases.
        Arthroscopy. 2015; 31: 836-842
        • Williams J.
        • Kester B.S.
        • Bosco J.A.
        • Slover J.D.
        • Iorio R.
        • Schwarzkopf R.
        The association between hospital length of stay and 90-day readmission risk within a total joint arthroplasty bundled payment initiative.
        J Arthroplasty. 2017; 32: 714-718
        • Roth A.
        • Khlopas A.
        • George J.
        • et al.
        The effect of body mass index on 30-day complications after revision total hip and knee arthroplasty.
        J Arthroplasty. 2019; 34: S242-S248
        • Wagner R.A.
        • Hogan S.P.
        • Burge J.R.
        • Bates C.M.
        • Sanchez H.B.
        The radiographic prepatellar fat thickness ratio correlates with infection risk after total knee arthroplasty.
        J Arthroplasty. 2018; 33: 2251-2255
        • Kluczynski M.A.
        • Bisson L.J.
        • Marzo J.M.
        Does body mass index affect outcomes of ambulatory knee and shoulder surgery?.
        Arthroscopy. 2014; 30: 856-865
        • American College of Surgeons
        ACS NSQIP participant use data file.
        (Available at:) (Accessed April 20, 2019)
        • Webb M.L.
        • Lukasiewicz A.M.
        • Samuel A.M.
        • et al.
        Overall similar infection rates reported in the physician-reported Scoliosis Research Society database and the chart-abstracted American College of Surgeons National Surgical Quality Improvement Program Database.
        Spine (Phila Pa). 2015; 40: 1431-1435
        • Shiloach M.
        • Frencher S.K.
        • Steeger J.E.
        • et al.
        Toward robust information: Data quality and inter-rater reliability in the American College of Surgeons National Surgical Quality Improvement Program.
        J Am Coll Surg. 2010; 210: 6-16
        • American College of Surgeons
        ACS NSQIP Data Tracks Surgical Patient Readmission Data Better.
        (Available at:) (Accessed April 4, 2019)
        • McIlvennan C.K.
        • Eapen Z.J.
        • Allen L.A.
        Hospital readmissions reduction program.
        Circulation. 2015; 131: 1796-1803
        • Noureldin M.
        • Habermann E.B.
        • Ubl D.S.
        • Kakar S.
        Unplanned readmissions following outpatient hand and elbow surgery.
        J Bone Joint Surg Am. 2017; 99: 541-549
        • Axon R.N.
        • Williams M.V.
        Hospital readmission as an accountability measure.
        JAMA. 2011; 305: 504-505
        • Centers for Medicare and Medicaid Services
        30-day unplanned readmission and death measures.
        (Available at:) (Accessed April 20, 2019)
        • Bozic K.J.
        • Chan V.
        • Valone 3rd, F.H.
        • Feeley B.T.
        • Vail T.P.
        Trends in hip arthroscopy utilization in the United States.
        J Arthroplasty. 2013; 28: 140-143
        • Nakano N.
        • Lisenda L.
        • Jones T.L.
        • Loveday D.T.
        • Khanduja V.
        Complications following arthroscopic surgery of the hip: A systematic review of 36 761 cases.
        Bone Joint J. 2017; 99-b: 1577-1583
        • Harris J.D.
        • McCormick F.M.
        • Abrams G.D.
        • et al.
        Complications and reoperations during and after hip arthroscopy: A systematic review of 92 studies and more than 6,000 patients.
        Arthroscopy. 2013; 29: 589-595
        • Gupta A.
        • Redmond J.M.
        • Hammarstedt J.E.
        • Schwindel L.
        • Domb B.G.
        Safety measures in hip arthroscopy and their efficacy in minimizing complications: A systematic review of the evidence.
        Arthroscopy. 2014; 30: 1342-1348
        • Merkow R.P.
        • Ju M.H.
        • Chung J.W.
        • et al.
        Underlying reasons associated with hospital readmission following surgery in the United States.
        JAMA. 2015; 313: 483-495
        • Rosenberger L.H.
        • Politano A.D.
        • Sawyer R.G.
        The surgical care improvement project and prevention of post-operative infection, including surgical site infection.
        Surg Infect (Larchmt). 2011; 12: 163-168
        • Tillman M.
        • Wehbe-Janek H.
        • Hodges B.
        • Smythe W.R.
        • Papaconstantinou H.T.
        Surgical care improvement project and surgical site infections: can integration in the surgical safety checklist improve quality performance and clinical outcomes?.
        J Surg Res. 2013; 184: 150-156
        • Kapadia B.H.
        • Cherian J.J.
        • Issa K.
        • Jagannathan S.
        • Daley J.A.
        • Mont M.A.
        Patient compliance with preoperative disinfection protocols for lower extremity total joint arthroplasty.
        Surg Technol Int. 2015; 26: 351-354
        • Clarke M.T.
        • Arora A.
        • Villar R.N.
        Hip arthroscopy: Complications in 1054 cases.
        Clin Orthop Relat Res. 2003; : 84-88
        • Mehta A.I.
        • Babu R.
        • Karikari I.O.
        • et al.
        2012 Young Investigator Award Winner: The distribution of body mass as a significant risk factor for lumbar spinal fusion postoperative infections.
        Spine (Phila Pa 1976). 2012; 37: 1652-1656
        • Salt E.
        • Wiggins A.T.
        • Rayens M.K.
        • et al.
        Moderating effects of immunosuppressive medications and risk factors for post-operative joint infection following total joint arthroplasty in patients with rheumatoid arthritis or osteoarthritis.
        Semin Arthritis Rheum. 2017; 46: 423-429
        • Souza B.G.S.E.
        • Dani W.S.
        • Honda E.K.
        • et al.
        Do complications in hip arthroscopy change with experience?.
        Arthroscopy. 2010; 26: 1053-1057
        • Dietrich F.
        • Ries C.
        • Eiermann C.
        • Miehlke W.
        • Sobau C.
        Complications in hip arthroscopy: Necessity of supervision during the learning curve.
        Knee Surg Sports Traumatol Arthrosc. 2014; 22: 953-958
        • Jamil M.
        • Dandachli W.
        • Noordin S.
        • Witt J.
        Hip arthroscopy: Indications, outcomes and complications.
        Int J Surg. 2018; 54: 341-344
        • Truntzer J.N.
        • Hoppe D.J.
        • Shapiro L.M.
        • Abrams G.D.
        • Safran M.
        Complication rates for hip arthroscopy are underestimated: A population-based study.
        Arthroscopy. 2017; 33: 1194-1201

      Linked Article

      • Editorial Commentary: Readmission Rate After Hip Arthroscopy: Is There a Cause for Concern?
        ArthroscopyVol. 35Issue 12
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          Readmission after hip arthroscopic surgery is an undesired and unusual event. The causes may range from wound-related issues, deep infection, increasing pain, complications of surgery, to medical events. It adds to the economic burden of the procedure and causes unnecessary anguish to the patients and indeed clinicians. It is also one of the less-studied areas of hip arthroscopic surgery because of its rarity. There would be benefit in being able to identify the risk factors of readmission such that pre-emptive measures can be put in place to prevent or indeed counsel the patients before the surgery.
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