Advertisement
Journal of Shoulder and Elbow Surgery

Reverse total shoulder arthroplasty in patients of varying body mass index

Published:October 02, 2013DOI:https://doi.org/10.1016/j.jse.2013.07.043

      Background

      Body mass index (BMI) is an independent predictor of complications after hip and knee arthroplasty. Whether similar trends apply to patients undergoing reverse total shoulder arthroplasty (RTSA) is unknown.

      Methods

      A retrospective review of primary RTSAs with a minimum 90-day follow-up were included. Complications were classified as major or minor and medical or surgical. Patients were classified into 3 groups: normal BMI (BMI <25 kg/m2), overweight or mildly obese (BMI 25-35 kg/m2), and moderately or severely obese (BMI >35 kg/m2).

      Results

      Of the 119 patients met our inclusion criteria, 30 (25%) had a BMI of less than 25 kg/m2; 65 (55%) had a BMI of 25 to 35 kg/m2, and 24 (20%) had BMI exceeding 35 kg/m2. Complications occurred in 30 patients (25%), comprising major in 11 (9%), minor in 19 (16%), surgical in 21 (18%), and medical in 14 (12%). The most common surgical complications were acute blood loss anemia requiring transfusion (8.4%) and dislocation (4.2%). The most common medical complications were atelectasis (2.5%) and acute renal insufficiency (2.5%). Patients with a BMI exceeding 35 kg/m2 had a significantly higher overall complication rate (P < .05) and intraoperative blood loss (P = .05) than the other groups. Patients with BMI of less than 25 kg/m2 had a greater overall complication rate than those with a BMI of 25 to 35 kg/m2 (P < .05). Multivariate regression analysis demonstrated BMI was the only significant determinant of overall complication rates and medical complication rates (P < .05).

      Conclusion

      Patients with a BMI exceeding 35 kg/m2 (severely obese) or a BMI of less than 25 kg/m2 have higher rates of complication after RTSA.

      Level of evidence

      Keywords

      The reverse total shoulder arthroplasty (RTSA) was first introduced in the 1980s by Grammont to treat rotator cuff tear arthropathy. Multiple series have shown significant improvement in pain and function after RTSA
      • Boileau P.
      • Gonzalez J.F.
      • Chuinard C.
      • Bicknell R.
      • Walch G.
      Reverse total shoulder arthroplasty after failed rotator cuff surgery.
      • Cuff D.
      • Clark R.
      • Pupello D.
      • Frankle M.
      Reverse shoulder arthroplasty for the treatment of rotator cuff deficiency: a concise follow-up, at a minimum of five years, of a previous report.
      • Gallo R.A.
      • Gamradt S.C.
      • Mattern C.J.
      • Cordasco F.A.
      • Craig E.V.
      • Dines D.M.
      Instability after reverse total shoulder replacement.
      • Matsen 3rd, F.A.
      • Boileau P.
      • Walch G.
      • Gerber C.
      • Bicknell R.T.
      The reverse total shoulder arthroplasty.
      • Matsen 3rd, F.A.
      • Boileau P.
      • Walch G.
      • Gerber C.
      • Bicknell R.T.
      The reverse total shoulder arthroplasty.
      • Nolan B.M.
      • Ankerson E.
      • Wiater J.M.
      Reverse total shoulder arthroplasty improves function in cuff tear arthropathy.
      • Wall B.
      • Nove-Josserand L.
      • O'Connor D.P.
      • Edwards T.B.
      Walch, G. Reverse total shoulder arthroplasty: a review of results according to etiology.
      Despite its success, complication rates ranging from 25% to 50% have been reported. Intraoperative, perioperative, postoperative, surgical, and medical complications have all been reported. These include, but are not limited to, hematoma formation, instability, superficial and deep infection, periprosthetic fracture, acromial fracture, neurologic compromise, implant loosening, and medical complications.
      • Affonso J.
      • Nicholson G.P.
      • Frankle M.A.
      • Walch G.
      • Gerber C.
      • Garzon-Muvdi J.
      • et al.
      Complications of the reverse prosthesis: prevention and treatment.
      • Cheung E.
      • Willis M.
      • Walker M.
      • Clark R.
      • Frankle M.A.
      Complications in reverse total shoulder arthroplasty.
      • Cuff D.
      • Pupello D.
      • Virani N.
      • Levy J.
      • Frankle M.
      Reverse shoulder arthroplasty for the treatment of rotator cuff deficiency.
      • Farshad M.
      • Gerber C.
      Reverse total shoulder arthroplasty-from the most to the least common complication.
      • Matsen 3rd, F.A.
      • Boileau P.
      • Walch G.
      • Gerber C.
      • Bicknell R.T.
      The reverse total shoulder arthroplasty.
      • Singh J.A.
      • Sperling J.W.
      • Cofield R.H.
      Risk factors for revision surgery after humeral head replacement: 1,431 shoulders over 3 decades.
      • Walch G.
      • Bacle G.
      • Ladermann A.
      • Nove-Josserand L.
      • Smithers C.J.
      Do the indications, results, and complications of reverse shoulder arthroplasty change with surgeon's experience?.
      • Zumstein M.A.
      • Pinedo M.
      • Old J.
      • Boileau P.
      Problems, complications, reoperations, and revisions in reverse total shoulder arthroplasty: a systematic review.
      Recent improvements in surgical techniques and implant design, however, have demonstrated lower overall complication and failure rates.
      • Cuff D.
      • Clark R.
      • Pupello D.
      • Frankle M.
      Reverse shoulder arthroplasty for the treatment of rotator cuff deficiency: a concise follow-up, at a minimum of five years, of a previous report.
      Body mass index (BMI) has been shown to be an independent predictor of postoperative complications in patients undergoing joint replacement.
      • Gallo R.A.
      • Gamradt S.C.
      • Mattern C.J.
      • Cordasco F.A.
      • Craig E.V.
      • Dines D.M.
      Instability after reverse total shoulder replacement.
      • Haverkamp D.
      • Klinkenbijl M.N.
      • Somford M.P.
      • Albers G.H.
      • van der Vis H.M.
      Obesity in total hip arthroplasty–does it really matter? A meta-analysis.
      Obesity predisposes patients to medical comorbidities such as cardiovascular disease, stroke, pulmonary embolism, and diabetes. These conditions may also serve as independent predictors of perioperative and postoperative medical and surgical complications. Preoperative medical comorbidity rates have also been shown to predict postoperative complication rates in patients undergoing orthopedic procedures.
      • Haverkamp D.
      • Klinkenbijl M.N.
      • Somford M.P.
      • Albers G.H.
      • van der Vis H.M.
      Obesity in total hip arthroplasty–does it really matter? A meta-analysis.
      • Jamsen E.
      • Nevalainen P.
      • Eskelinen A.
      • Huotari K.
      • Kalliovalkama J.
      • Moilanen T.
      Obesity, diabetes, and preoperative hyperglycemia as predictors of periprosthetic joint infection: a single-center analysis of 7181 primary hip and knee replacements for osteoarthritis.
      • Kerkhoffs G.M.
      • Servien E.
      • Dunn W.
      • Dahm D.
      • Bramer J.A.
      • Haverkamp D.
      The influence of obesity on the complication rate and outcome of total knee arthroplasty: a meta-analysis and systematic literature review.
      • Silber J.H.
      • Rosenbaum P.R.
      • Kelz R.R.
      • Reinke C.E.
      • Neuman M.D.
      • Ross R.N.
      • et al.
      Medical and financial risks associated with surgery in the elderly obese.
      Currently, there is a paucity of data describing the complications associated with RTSA in patients of varying BMIs. The purpose of the study was to analyze complication rates in the operative, perioperative, and early postoperative period in patients of varying BMIs undergoing RTSA. We hypothesized that BMI would serve as an independent risk factor for the development of early medical and surgical complications after RTSA.

      Materials and methods

      Patients who had undergone primary RTSA with a minimum 90-day postoperative follow-up were included. Indications for RTSA included rotator cuff tear arthropathy, massive irreparable rotator cuff tear with pseudoparalysis, end-stage glenohumeral arthritis with an irreparable rotator cuff tear, inflammatory cuff tear arthropathy, and proximal humeral malunion/nonunion with associated irreparable rotator cuff tear. Excluded were patients with previous shoulder arthroplasty, if RTSA was performed as a revision procedure for a failed prior arthroplasty (hemiarthroplasty or total shoulder arthroplasty), prior deep space infection requiring explantation, or if perioperative or operative records were incomplete.
      The following data were recorded in Excel X (Microsoft Corp, Redmond, WA, USA): age, sex, BMI, laterality of the dominant extremity, laterality of the RTSA, indication for operative intervention, medical comorbidities, length of procedure in minutes, estimated intraoperative blood loss in milliliters measured by anesthesia and nursing, specific implants, concomitant procedures, and the need for intraoperative or postoperative transfusion. The operative reports and the intraoperative, perioperative inpatient, and postoperative outpatient records for each patient were reviewed in detail, and all noted complications were recorded. Our institution does not have a specific transfusion threshold, and the decision to transfuse was made case-by-case according to the clinical judgement and mutual agreement of the orthopedic and internal medicine teams.
      The Charlson Comorbidity Index (CCI) is a validated predictive tool for complications in patients undergoing surgical procedures.
      • Charlson M.E.
      • Pompei P.
      • Ales K.L.
      • MacKenzie C.R.
      A new method of classifying prognostic comorbidity in longitudinal studies: development and validation.
      Specifically, it predicts the 10-year mortality of an individual based on his or her comorbid conditions, including heart disease, diabetes mellitus, and cancer. Each condition is assigned a point value of 1, 2, 3, or 6 according to the risk of death associated with the comorbidity. The higher this value, the higher the risk of death. Each patient’s preoperative medical comorbidities were determined and used to calculate the CCI for planned multivariate regression analysis to determine the correlation between comorbidities and complications.

       Complication classification

      Complications were defined as any event that deviated from a normal postoperative course and were further classified as “major” or “minor” and “medical” or “surgical.” Complications were categorized according a validated classification scheme described by Dindo et al
      • Dindo D.
      • Demartines N.
      • Clavien P.A.
      Classification of surgical complications: a new proposal with evaluation in a cohort of 6336 patients and results of a survey.
      :
      • Minor complication: any deviation from the normal postoperative course requiring pharmacologic treatment.
      • Major complication: any deviation from the normal postoperative course requiring prolonged pharmacologic treatment or surgical intervention.
      • Medical complications: systemic events such as pulmonary emboli, cardiac events, renal failure, and atelectasis, which was a combined clinical and radiographic diagnosis.
      • Surgical complications: local events that stemmed from the surgical site such as need for transfusion, wound complications, periprosthetic fractures, and dislocations.

       Statistical analysis

      Analyses were performed in SPSS 18 software (IBM Inc, Armonk, NY, USA), and descriptive statistics were calculated. An a priori decision was made to divide patients into 3 groups by BMI (kg/m2): group 1, normal BMI (BMI <25); group 2, BMI classified as overweight or “mildly obese” or class I (World Health Organization Classification) obesity (BMI 25-35), and group 3, BMI classified as moderately or severely obese or class II or greater obesity (BMI >35).

      World Health Organization. Classification of obesity. Available from: http://apps.who.int/bmi/index.jsp?introPage=intro_3.html. Accessed February 17, 2013.

      This decision was based on our anecdotal clinical experience, the mean and standard deviation BMI of the average patient undergoing TSA and RTSA in the senior authors’ practice (∼30.5), as well as evidence from the hip and knee arthroplasty literature suggesting complication rates may not be increased until severe obesity is reached.
      • Jamsen E.
      • Nevalainen P.
      • Eskelinen A.
      • Huotari K.
      • Kalliovalkama J.
      • Moilanen T.
      Obesity, diabetes, and preoperative hyperglycemia as predictors of periprosthetic joint infection: a single-center analysis of 7181 primary hip and knee replacements for osteoarthritis.
      Kolmogorov-Smirnov analysis was performed on continuous variables and all variables that significantly differed from the normal distribution (P < .05). Thus Kruskal-Wallis tests were performed to compare continuous variables among the BMI groups. Statistical comparison of categoric variables was done using χ2 tests.
      Given concern that multiple variables may predict complication rates, multivariable logistic regression was planned for those variables that differed between our a priori defined BMI groups to determine whether these covariates or BMI served as the primary determinant of complication rates.

      Results

       Demographics and intraoperative variables

      Of 150 possible patients assessed, 31 were revisions from a prior failed arthroplasty, leaving 119 who met the inclusion criteria. Of the total cohort, 30 patients (25%) had a normal body mass (BMI <25 kg/m2; Fig 1), 24 (20%) were moderately or severely obese (BMI >35 kg/m2), and 65 (55%) were overweight or mildly obese (BMI 25-35 kg/m2). The mean BMI was 29.6 ± 5.8 kg/m2. Men and women were evenly distributed among BMI groups (P = .148). Rates of prior surgery were not significantly different among BMI groups (P = .789). Patients in group 3 (BMI >35 kg/m2) tended to be significantly younger (P = .025), with a higher comorbidity burden (P = .009) than in groups 1 and 2.
      Figure thumbnail gr1
      Figure 1Patients were grouped according to body mass index (BMI) <25 kg/m2 (red bars), BMI 25 to 35 kg/m2 (green bars), and BMI >35 kg/m2 (purple bars), with the graph showing the percentage of patients sustaining a complication, sustaining a major complication, sustaining a medical complication, sustaining a surgical complication, and the total population in that subgroup. *Indicates statistically significant differences.
      Indications for RTSA were similar among BMI groups (P = .837). Patients in group 3 had longer operative times than groups 1 and 2, but this difference did not reach statistical significance (P = .104; Table I). Estimated blood loss significantly differed among BMI groups, with group 3 demonstrating the greatest mean intraoperative blood loss (P = .050). The transfusion rate was higher in group 3 than in groups 1 and 2, but this difference did not reach statistical significance. (P = .174).
      Table IDemographic and intraoperative characteristics segregated by body mass index (BMI)
      VariableBMI <25 kg/m2BMI 25-35 kg/m2BMI >35 kg/m2Total patientsP value
      (n = 30)(n = 65)(n = 24)(n = 119)
      Age, mean ± SD y75.7 ± 8.274.1 ± 9.868.4 ± 10.573.3 ± 9.8.025
       Female, %73577564.148
      CCI, mean ± SD score0.10 ± 0.310.28 ± 0.550.54 ± 0.660.29 ± 0.54.009
      Patients with prior shoulder surgery, %23231622.789
      Indications, No..837
       Cuff tear arthropathy1323945
       Glenohumeral osteoarthritis with irreparable cuff tear1017835
       Massive/irreparable cuff tear312419
       Sequelae of a proximal humeral fracture36312
       Inflammatory arthropathy, etc.1506
      Operative time, mean ± SD min98 ± 4196 ± 43120 ± 29101 ± 41.104
      Estimated blood loss, mean ± SD mL261 ± 138321 ± 161386 ± 185324 ± 166.050
      Patients requiring transfusion, % (No.)3.3 (1)3.1 (2)12.5 (3)5.0 (6).174
      CCI, Charlson Comorbidity Index; SD, standard deviation.

       Complication rates

      Among the overall patient cohort, 30 (25%) sustained 1 or more complications (Table II), including 11 (9%) with a major complication and 19 (16%) with 1 or more minor complications, mostly in the perioperative (inpatient) and postoperative period. Twenty-one patients (18%) sustained a surgical complication, 14 (12%) experienced 1 or more medical complications, and 6 (5%) sustained a medical and surgical complication. The most common surgical complications were acute blood loss anemia requiring transfusion (8.4%) and dislocation (4.2%). Infections occurred in 0.8%. The most common medical complications were atelectasis (2.5%) and acute renal insufficiency (2.5%). No deaths occurred during the study period.
      Table IIComplications segregated by body mass index (BMI) groups
      ComplicationBMI <25 kg/m2BMI 25-35 kg/m2BMI >35 kg/m2Total patientsP value
      Patients sustaining
       A complication, % (No.)33 (10)15 (10)42 (10)25 (30).020
       A major complication, % (No.)10 (3)8 (5)13 (3)9 (11).775
       A medical complication, % (No.)13 (4)5 (3)29 (7)12 (14).006
       A surgical complication, % (No.)23 (7)11 (7)29 (7)18 (21).083
       An infection, % (No.)0 (0)1.5 (1)0 (0)0.8 (1).664
       A dislocation, % (No.)3.3 (1)3.1 (2)8.3 (2)4.2 (5).528
      Mortality before final follow-up, % (No.)0 (0)0 (0)0 (0)0 (0)>.99
      Complication rates differed significantly among BMI groups, with patients in groups 1 (BMI <25 kg/m2) and 3 (BMI >35 kg/m2) experiencing greater complication rates (P = .020). This significant difference held true when the group 1 and 2 cohorts were directly compared (P = .046). No significant difference was seen between groups 1 and 3 in complication rates (P = .529). No significant differences were seen between rates of major complications (P = .775), infection (P = .395), dislocation (P = .664), or death (>.99). Significantly more medical complications occurred in group 3 (P = .006). A trend toward increased rates of surgical complications was seen in patients in groups 1 and 3 compared with group 2 (P = .083). The mean CCI was significantly greater for group 3 (P = .009). Although medical complication rates significantly correlated with CCI (P = .011), rates for overall complications (P = .115), major complications (P = .695), and surgical complications (P = .983) did not.
      A subgroup analysis for the patients with a BMI of less than 25 kg/m2 showed among the patients with medical or surgical complications, or both, 6 had isolated hypertension (controlled on medication), 1 had diabetes mellitus and coronary artery disease (CAD), and 2 had isolated CAD. The remaining patients had no comorbidities (Table III).
      Table IIIAll complications, classifications, and associated comorbidities
      BMI (kg/m2)ComplicationClassificationComorbidities
      18.6Intraoperative humeral shaft fracture—cableMajor surgicalHTN
      19.8Blood loss anemia—transfusionMinor surgicalHTN
      20.0Blood loss anemia requiring erythropoietin, no transfusion requiredMinor surgicalCAD, DM
      22.2Altered mental status requiring restraintsMinor medicalHTN
      22.7PE—anticoagulationMajor medicalHTN
      23.6Wound dehiscence—local wound careMinor surgicalHTN
      23.8Hypotension, recurrent dislocation—conversion to hemiarthroplastyMinor medical, major surgicalCAD
      24.0Drill bit broken in the scapulaMinor SurgicalNone
      24.9Respiratory failure requiring supplemental oxygenMinor medicalHTN
      24.9Intraoperative glenoid fractureMinor surgicalHTN
      25.8Acromial stress fractureMinor surgicalHTN
      27.1Acromial stress fractureMinor surgicalHTN
      27.9Superficial wound infectionMinor surgicalHTN
      28.2Respiratory failure requiring a 2-day ICU stayMajor medicalHTN
      28.3PE, blood loss anemia—transfusionMajor medical, minor surgicalHTN
      29.7Blood loss anemia–transfusionMinor surgicalHTN, CAD
      30.0Acromial stress fracture, dislocation—closed reductionMinor surgical, major surgicalKidney cancer
      31.6CRPS in the ulnar nerve distributionMinor surgicalHTN, DM
      32.3Asystole requiring pacemaker placementMajor medicalHTN, DM
      32.4Dislocation–closed reductionMajor surgicalHTN
      35.0Dislocation–required revision to a hemiarthroplastyMajor surgicalHTN
      35.3Persistent tachycardiaMinor medicalHTN, DM
      36.0Respiratory failure requiring supplementary oxygenMinor medicalHTN, CKD
      36.9Respiratory failure, renal failure, transfusionMinor medical and surgicalHTN
      37.3Renal failure–resolved with medical managementMinor medicalHTN
      37.8Hemorrhagic traumatic hematomaMajor surgicalHTN
      37.9Acromial stress fractureMinor surgicalHTN
      40.7Hypotension, brachial plexus palsy, dislocationMajor/minor, medical/surgicalHTN, PE, DM
      42.4Blood loss anemia–transfusion, atelectasisMinor surgical and medicalHTN, PE
      43.0Blood loss anemia–transfusion, atelectasisMinor surgical and medicalCAD, HTN
      CAD, coronary artery disease; CKD, chronic kidney disease; CRPS, complex regional pain syndrome; DM, diabetes mellitus; HTN, hypertension; I+D, irrigation and debridement; ICU, intensive care unit; PE, pulmonary embolism.
      No significant difference was found in hospital length of stay among BMI subgroups groups 1 (mean 2.4 ± 1.1, 2.3 ± 0.8, and 2.3 ± 0.9 days, respectively, for groups 1, 2, and 3; P = .15). No group 1 patients required admission to the intensive care unit (ICU). ICU admission was required immediately after surgery for 3 patients in group 2 and 2 patients in group 3. All ICU stays were for 1 night only except for 1 patient (BMI 39.6 kg/m2) who required a 2-day stay in the ICU for postoperative cardiac monitoring owing to a history of paroxysmal ventricular tachycardia. Among the 5 patients admitted to the ICU, the total hospital length of stay ranged from 2 to 4 days (Table IV).
      Table IVHospital length of stay (LOS) and number of intensive care unit (ICU) admissions for each body mass index (BMI) subcategory
      BMI, kg/m2LOS, d (Mean ± SD)ICU admission (No.)
      Group 1 (BMI <25)2.4 ± 1.10
      Group 2 (BMI 25-35)2.3 ± 0.83
      Group 3 (BMI >35)2.3 ± 0.92
      SD, standard deviation.

       Multivariate regression analysis

      Because age and the CCI differed significantly among the BMI groups (P = .009), multivariate logistic regression was performed to determine whether BMI, age, or CCI served as the primary determinant of the presence or absence of all complications, major complications, medical complications, and surgical complications. These analyses confirmed BMI was the only significant covariate with overall complication rates and medical complication rates, whereas no covariate reached significance for major complications or surgical complications (Table V).
      Table VSignificance (P values) of multivariate logistic regression analyses performed to determine whether age, body mass index (BMI) subgroup (<25, 25-35, and 35 kg/m2), or Charlson Comorbidity Index (CCI) served as significant covariates with all complications, major complications, medical complications, and surgical complications after reverse total shoulder arthroplasty
      VariableP value
      AgeBMI subgroupCCI
      All complications.476.025.230
      Major complications.996.775.613
      Medical complications.561.015.269
      Surgical complications.535.083.370

      Discussion

      Surgical intervention on the obese population can be technically demanding. Obesity has been correlated with an increased complication rate in reports on hip and knee arthroplasty.
      • Cheung E.
      • Willis M.
      • Walker M.
      • Clark R.
      • Frankle M.A.
      Complications in reverse total shoulder arthroplasty.
      • Haverkamp D.
      • Klinkenbijl M.N.
      • Somford M.P.
      • Albers G.H.
      • van der Vis H.M.
      Obesity in total hip arthroplasty–does it really matter? A meta-analysis.
      • Jamsen E.
      • Nevalainen P.
      • Eskelinen A.
      • Huotari K.
      • Kalliovalkama J.
      • Moilanen T.
      Obesity, diabetes, and preoperative hyperglycemia as predictors of periprosthetic joint infection: a single-center analysis of 7181 primary hip and knee replacements for osteoarthritis.
      • Kerkhoffs G.M.
      • Servien E.
      • Dunn W.
      • Dahm D.
      • Bramer J.A.
      • Haverkamp D.
      The influence of obesity on the complication rate and outcome of total knee arthroplasty: a meta-analysis and systematic literature review.
      • Silber J.H.
      • Rosenbaum P.R.
      • Kelz R.R.
      • Reinke C.E.
      • Neuman M.D.
      • Ross R.N.
      • et al.
      Medical and financial risks associated with surgery in the elderly obese.
      The purpose of this study was to determine if BMI correlates with complications after primary RTSA. Patients in our cohort with a BMI of less than 25 kg/m2 or greater than 35 kg/m2 had higher overall complication rates than those with a BMI of 25 to 35 kg/m2. In addition, patients with a BMI greater than 35 kg/m2 had significantly more blood loss intraoperatively and trended toward longer operations and more postoperative transfusions. Multivariate regression revealed BMI was the sole determinant of complications, without contributions from age or CCI. Our hypothesis that BMI would serve as an independent risk factor for the development of early medical and surgical complications after RTSA was supported.
      To our knowledge, this is the first series specifically evaluating varied BMI and the associated medical and surgical complications in patients undergoing RTSA. In a previous series examining outcomes of TSA in obese patients, Linberg et al
      • Linberg C.J.
      • Sperling J.W.
      • Schleck C.D.
      • Cofield R.H.
      Shoulder arthroplasty in morbidly obese patients.
      demonstrated improved pain and function in the morbidly obese population, although with increased intraoperative surgical time, hospital length of stay, and ICU use.
      Similar findings have been demonstrated in nonshoulder arthroplasty studies. Silber et al
      • Silber J.H.
      • Rosenbaum P.R.
      • Kelz R.R.
      • Reinke C.E.
      • Neuman M.D.
      • Ross R.N.
      • et al.
      Medical and financial risks associated with surgery in the elderly obese.
      demonstrated that obesity increases the intraoperative and postoperative risk and financial burden in patients undergoing a variety of major operations, including hip and knee surgery, colectomy, and thoracotomy. Studies specific to hip and knee arthroplasty have shown obesity is associated with longer operative time, perioperative infection, ICU admission, and slower postoperative recovery.
      • AbdelSalam H.
      • Restrepo C.
      • Tarity T.D.
      • Sangster W.
      • Parvizi J.
      Predictors of intensive care unit admission after total joint arthroplasty.
      • Jamsen E.
      • Nevalainen P.
      • Eskelinen A.
      • Huotari K.
      • Kalliovalkama J.
      • Moilanen T.
      Obesity, diabetes, and preoperative hyperglycemia as predictors of periprosthetic joint infection: a single-center analysis of 7181 primary hip and knee replacements for osteoarthritis.
      • Jones C.A.
      • Cox V.
      • Jhangri G.S.
      • Suarez-Almazor M.E.
      Delineating the impact of obesity and its relationship on recovery after total joint arthroplasties.
      In a level 2 prognostic study, Jain et al
      • Jain N.B.
      • Guller U.
      • Pietrobon R.
      • Bond T.K.
      • Higgins L.D.
      Comorbidities increase complication rates in patients having arthroplasty.
      found obesity was an independent predictor of increased postoperative complications and nonhomebound discharge in patients undergoing shoulder, hip, or knee arthroplasty. Interestingly, we did not see a significant association between hospital length of stay and BMI in this study. The mean hospital length of stay was close to 2 days for all subgroups. This difference between our findings and those in the hip and knee arthroplasty literature may be explained by the ease of mobility associated with upper extremity vs lower extremity surgery. In addition, each patient who underwent shoulder arthroplasty had a multidisciplinary approach to their care (ie, internal medicine and physical and occupational therapy consultation) to allow for expeditious management of postoperative medical or mobility issues, or both. In countries where this is not available, hospital stays for such subgroups may be prolonged, with greater expense to stakeholders.
      The cause for the association between an increased complication rate and a BMI of less than 25 kg/m2 is unclear. Included among a variety of possible explanations are unmeasured or unaccounted covariates, such as malnutrition, and type I error. Our subgroup analysis did not demonstrate any patterns to suggest a correlation between a BMI of less than 25 kg/m2 and a specific comorbidity that could have accounted for the associated complication. Only one patient had a BMI of less than 18.5 kg/m2 (classified as “underweight” by the World Health Organization classification).
      The hip arthroplasty literature has established that malnutrition can account for failed debridement in the setting of postoperative drainage after total hip arthroplasty.
      • Jaberi F.M.
      • Parvizi J.
      • Haytmanek C.T.
      • Joshi A.
      • Purtill J.
      Procrastination of wound drainage and malnutrition affect the outcome of joint arthroplasty.
      This subgroup did have 2 patients with deep space infection and 1 with wound dehiscence. Therefore, there is a possibility that those specific patients suffered from malnutrition. However, to accurately assess a patient for malnutrition requires a preoperative laboratory workup (ie, serum total protein, albumin, prealbumin, and transferrin level) and caloric intake counts. These data were not available for the patients in our subgroup, and therefore, a malnutrition assessment could not be performed. However, given the clinical relevance of this finding in our study, evaluation of the preoperative nutritional status of patients undergoing RSA and its association with postoperative complications including, but not limited to, infection and wound problems may be warranted in future studies.
      A variety of plausible causes exist to explain the complication rate in the group with a BMI exceeding 35 kg/m2. In addition to the added technical complexity, including difficulty in gaining adequate exposure and increased intraoperative blood loss leading to increased rates of acute blood loss anemia and other surgical complications, obese patients may be less able to physiologically cope with the cardiovascular physiologic stress of surgery, leading to higher rates of postoperative medical complications such as acute renal failure. Obese patients also mobilize less readily, leading to increased rates of atelectasis.
      • Alab H.F.
      • Zabani I.A.
      • Abdelrahman H.S.
      • Bukhari W.L.
      • Mamoun I.
      • Ashour M.A.
      • et al.
      Intraoperative ventilatory strategies for prevention of pulmonary atelectasis in obese patients undergoing laparoscopic bariatric surgery.
      • Flier S.
      • Knape J.T.
      How to inform a morbidly obese patient on the specific risk to develop postoperative pulmonary complications using evidence-based methodology.
      As the United States population ages and becomes increasingly obese, the number of RTSAs performed in obese individuals will increase.
      • Kaiser M.J.
      • Bauer J.M.
      • Ramsch C.
      • Uter W.
      • Guigoz Y.
      • Cederholm T.
      • et al.
      Mini Nutritional Assessment International Group
      Frequency of malnutrition in older adults: a multinational perspective using the mini nutritional assessment.
      • Singh J.A.
      • Sperling J.W.
      • Cofield R.H.
      Risk factors for revision surgery after humeral head replacement: 1,431 shoulders over 3 decades.
      This is also true in other nations, such as Australia.
      • Duncan M.J.
      • Vandelanotte C.
      • Caperchione C.
      • Hanley C.
      • Mummery W.K.
      Temporal trends in and relationships between screen time, physical activity, overweight and obesity.
      Surgeons need to be aware of the risks associated with RTSA in such patients in order to provide accurate, evidence-based informed consent. Individuals determining health care policy need to be aware of the increased complication rates because they may affect overall health care expenditures. In addition, because complications are costly and time-consuming, individuals determining future public policy may want to consider altered premiums for the morbidly obese population and adjustments in surgeon compensation.
      Limitations of this study include short-term follow-up, varied indications for RTSA, and the possibility of missed complications due to the retrospective nature of the study. Lastly, a cost-analysis comparing RTSA in the nonobese obese populations would have strengthened the study.

      Conclusion

      Patients with a BMI exceeding 35 kg/m2 (severe obesity) or a BMI of less than 25 kg/m2 have higher rates of complication after RTSA. Future studies evaluating the association between causative factors, such as malnutrition in patients with a BMI of less than 25 kg/m2, are needed.

      Disclaimer

      G.P.N. is a paid consultant for Tornier, Inc. The other authors, their immediate families, and any research foundations with which they are affiliated have not received any financial payments or other benefits from any commercial entity related to the subject of this article.

      References

        • AbdelSalam H.
        • Restrepo C.
        • Tarity T.D.
        • Sangster W.
        • Parvizi J.
        Predictors of intensive care unit admission after total joint arthroplasty.
        J Arthroplasty. 2012; 27: 720-725https://doi.org/10.1016/j.arth.2011.09.027
        • Affonso J.
        • Nicholson G.P.
        • Frankle M.A.
        • Walch G.
        • Gerber C.
        • Garzon-Muvdi J.
        • et al.
        Complications of the reverse prosthesis: prevention and treatment.
        Instr Course Lect. 2012; 61: 157-168
        • Alab H.F.
        • Zabani I.A.
        • Abdelrahman H.S.
        • Bukhari W.L.
        • Mamoun I.
        • Ashour M.A.
        • et al.
        Intraoperative ventilatory strategies for prevention of pulmonary atelectasis in obese patients undergoing laparoscopic bariatric surgery.
        Anesth Analg. 2009; 109: 1511-1516https://doi.org/10.1213/ANE.0b013e3181ba7945
        • Boileau P.
        • Gonzalez J.F.
        • Chuinard C.
        • Bicknell R.
        • Walch G.
        Reverse total shoulder arthroplasty after failed rotator cuff surgery.
        J Shoulder Elbow Surg. 2009; 18: 600-606https://doi.org/10.1016/j.jse.2009.03.011
        • Charlson M.E.
        • Pompei P.
        • Ales K.L.
        • MacKenzie C.R.
        A new method of classifying prognostic comorbidity in longitudinal studies: development and validation.
        J Chronic Dis. 1987; 40: 373-383
        • Cheung E.
        • Willis M.
        • Walker M.
        • Clark R.
        • Frankle M.A.
        Complications in reverse total shoulder arthroplasty.
        J Am Acad Orthop Surg. 2011; 19: 439-449
        • Cuff D.
        • Clark R.
        • Pupello D.
        • Frankle M.
        Reverse shoulder arthroplasty for the treatment of rotator cuff deficiency: a concise follow-up, at a minimum of five years, of a previous report.
        J Bone Joint Surg Am. 2012; 94: 1996-2000https://doi.org/10.2106/JBJS.K.01206
        • Cuff D.
        • Pupello D.
        • Virani N.
        • Levy J.
        • Frankle M.
        Reverse shoulder arthroplasty for the treatment of rotator cuff deficiency.
        J Bone Joint Surg Am. 2008; 90: 1244-1251https://doi.org/10.2106/JBJS.G.00775
        • Dindo D.
        • Demartines N.
        • Clavien P.A.
        Classification of surgical complications: a new proposal with evaluation in a cohort of 6336 patients and results of a survey.
        Ann Surg. 2004; 240: 205-213
        • Duncan M.J.
        • Vandelanotte C.
        • Caperchione C.
        • Hanley C.
        • Mummery W.K.
        Temporal trends in and relationships between screen time, physical activity, overweight and obesity.
        BMC Public Health. 2012; 12: 1060https://doi.org/10.1186/1471-2458-12-1060
        • Farshad M.
        • Gerber C.
        Reverse total shoulder arthroplasty-from the most to the least common complication.
        Int Orthop. 2010; 34: 1075-1082https://doi.org/10.1007/s00264-010-1125-2
        • Flier S.
        • Knape J.T.
        How to inform a morbidly obese patient on the specific risk to develop postoperative pulmonary complications using evidence-based methodology.
        Eur J Anaesthesiol. 2006; 23: 154-159
        • Gallo R.A.
        • Gamradt S.C.
        • Mattern C.J.
        • Cordasco F.A.
        • Craig E.V.
        • Dines D.M.
        Instability after reverse total shoulder replacement.
        J Shoulder Elbow Surg. 2011; 20: 584-590https://doi.org/10.1016/j.jse.2010.08.028
        • Haverkamp D.
        • Klinkenbijl M.N.
        • Somford M.P.
        • Albers G.H.
        • van der Vis H.M.
        Obesity in total hip arthroplasty–does it really matter? A meta-analysis.
        Acta Orthop. 2011; 82: 417-422https://doi.org/10.3109/17453674.2011.588859
        • Jaberi F.M.
        • Parvizi J.
        • Haytmanek C.T.
        • Joshi A.
        • Purtill J.
        Procrastination of wound drainage and malnutrition affect the outcome of joint arthroplasty.
        Clin Orthop Relat Res. 2008; 466: 1368-1371https://doi.org/10.1007/s11999-008-0214-7
        • Jain N.B.
        • Guller U.
        • Pietrobon R.
        • Bond T.K.
        • Higgins L.D.
        Comorbidities increase complication rates in patients having arthroplasty.
        Clin Orthop Relat Res. 2005; 435: 232-238
        • Jamsen E.
        • Nevalainen P.
        • Eskelinen A.
        • Huotari K.
        • Kalliovalkama J.
        • Moilanen T.
        Obesity, diabetes, and preoperative hyperglycemia as predictors of periprosthetic joint infection: a single-center analysis of 7181 primary hip and knee replacements for osteoarthritis.
        J Bone Joint Surg Am. 2012; 94: e101https://doi.org/10.2106/JBJS.J.01935
        • Jones C.A.
        • Cox V.
        • Jhangri G.S.
        • Suarez-Almazor M.E.
        Delineating the impact of obesity and its relationship on recovery after total joint arthroplasties.
        Osteoarthritis Cartilage. 2012; 20: 511-518https://doi.org/10.1016/j.joca.2012.02.637
        • Kaiser M.J.
        • Bauer J.M.
        • Ramsch C.
        • Uter W.
        • Guigoz Y.
        • Cederholm T.
        • et al.
        • Mini Nutritional Assessment International Group
        Frequency of malnutrition in older adults: a multinational perspective using the mini nutritional assessment.
        J Am Geriatr Soc. 2010; 58: 1734-1738https://doi.org/10.1111/j.1532-5415.2010.03016.x
        • Kerkhoffs G.M.
        • Servien E.
        • Dunn W.
        • Dahm D.
        • Bramer J.A.
        • Haverkamp D.
        The influence of obesity on the complication rate and outcome of total knee arthroplasty: a meta-analysis and systematic literature review.
        J Bone Joint Surg Am. 2012; 94: 1839-1844https://doi.org/10.2106/JBJS.K.00820
        • Linberg C.J.
        • Sperling J.W.
        • Schleck C.D.
        • Cofield R.H.
        Shoulder arthroplasty in morbidly obese patients.
        J Shoulder Elbow Surg. 2009; 18: 903-906https://doi.org/10.1016/j.jse.2009.02.006
        • Matsen 3rd, F.A.
        • Boileau P.
        • Walch G.
        • Gerber C.
        • Bicknell R.T.
        The reverse total shoulder arthroplasty.
        J Bone Joint Surg Am. 2007; 89: 660-667
        • Matsen 3rd, F.A.
        • Boileau P.
        • Walch G.
        • Gerber C.
        • Bicknell R.T.
        The reverse total shoulder arthroplasty.
        Instr Course Lect. 2008; 57: 167-174
        • Nolan B.M.
        • Ankerson E.
        • Wiater J.M.
        Reverse total shoulder arthroplasty improves function in cuff tear arthropathy.
        Clin Orthop Relat Res. 2011; 469: 2476-2482https://doi.org/10.1007/s11999-010-1683-z
        • Silber J.H.
        • Rosenbaum P.R.
        • Kelz R.R.
        • Reinke C.E.
        • Neuman M.D.
        • Ross R.N.
        • et al.
        Medical and financial risks associated with surgery in the elderly obese.
        Ann Surg. 2012; 256: 79-86https://doi.org/10.1097/SLA.0b013e31825375ef
        • Singh J.A.
        • Sperling J.W.
        • Cofield R.H.
        Risk factors for revision surgery after humeral head replacement: 1,431 shoulders over 3 decades.
        J Shoulder Elbow Surg. 2012; 21: 1039-1044https://doi.org/10.1016/j.jse.2011.06.015
        • Walch G.
        • Bacle G.
        • Ladermann A.
        • Nove-Josserand L.
        • Smithers C.J.
        Do the indications, results, and complications of reverse shoulder arthroplasty change with surgeon's experience?.
        J Shoulder Elbow Surg. 2012; 21: 1470-1477https://doi.org/10.1016/j.jse.2011.11.010
        • Wall B.
        • Nove-Josserand L.
        • O'Connor D.P.
        • Edwards T.B.
        Walch, G. Reverse total shoulder arthroplasty: a review of results according to etiology.
        J Bone Joint Surg Am. 2007; 89: 1476-1485https://doi.org/10.2106/JBJS.F.00666
      1. World Health Organization. Classification of obesity. Available from: http://apps.who.int/bmi/index.jsp?introPage=intro_3.html. Accessed February 17, 2013.

        • Zumstein M.A.
        • Pinedo M.
        • Old J.
        • Boileau P.
        Problems, complications, reoperations, and revisions in reverse total shoulder arthroplasty: a systematic review.
        J Shoulder Elbow Surg. 2011; 20: 146-157https://doi.org/10.1016/j.jse.2010.08.001