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Research Article| Volume 10, ISSUE 3, P544-549, May 2019

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Does diabetes affect functional outcomes after shoulder arthroplasty?

Published:March 14, 2019DOI:https://doi.org/10.1016/j.jcot.2019.03.003

      Abstract

      Objectives

      The purpose of this study was to assess whether diabetes affects functional and physical outcomes following shoulder arthroplasty

      Methods

      A cohort of 140 patients were tested preoperatively, at an early follow-up visit (between 3-6 months) and at late follow-up visit (between 1-3 years) following shoulder arthroplasty. The American Shoulder and Elbow Surgeons (ASES) Standardized Shoulder Assessment Form measured shoulder pain and function and the Short-Form-12 (SF-12) measured physical health status. Shoulder goniometry and dynamometry were used to assess motion and strength. Diabetic status was self-reported.

      Results

      There were significant improvements in function and physical health status for both diabetic and nondiabetic patients at the late follow-up visit. For patients with diabetes, shoulder function (ASES: 0-30) improved from 5 (5) to 18 (6) scores (p < 0.001) and physical health status improved from 27 (6) to 38 (8) scores (p < 0.001). For patients without diabetes, shoulder function improved from 8 (5) to 19 (8) scores (p < 0.001) and physical health status improved from 31 (8) to 40 (12) scores (p < 0.001). No significant differences between diabetic and nondiabetic patients was detected at the late follow-up.

      Conclusion

      Patients with diabetes achieve large clinical benefits from shoulder arthroplasty, with follow-up outcomes equally positive to those without diabetes. Future prospective studies with a larger sample size of patients with diabetes are needed to confirm the results of this study.

      Level of evidence

      II

      Keywords

      1. Introduction

      Shoulder arthroplasty surgery replaces the damaged humeral head and glenoid with prosthetic implants. This surgical procedure has been shown to significantly reduce pain, restore joint function and improve shoulder range of motion (ROM) at 2 years and beyond in patients who underwent total shoulder arthroplasty (TSA) or hemiarthroplasty (HA).
      • Bartelt R.
      • Sperling J.W.
      • Schleck C.D.
      • Cofield R.H.
      Shoulder arthroplasty in patients aged fifty-five years or younger with osteoarthritis.
      • Deshmukh A.V.
      • Koris M.
      • Zurakowski D.
      • Thornhill T.S.
      Total shoulder arthroplasty: long-term survivorship, functional outcome, and quality of life.
      • Orfaly R.M.
      • Rockwood C.A.
      • Esenyel C.Z.
      • Wirth M.A.
      A prospective functional outcome study of shoulder arthroplasty for osteoarthritis with an intact rotator cuff.
      • Norris T.R.
      • Iannotti J.P.
      Functional outcome after shoulder arthroplasty for primary osteoarthritis: a multicenter study.
      Osteoarthritis is the primary diagnosis for 77% of shoulder arthroplasty and often occurs in middle-aged or older adults. Hence, comorbid health problem can be prevalent; including hypertension and diabetes which have been reported in 63% and 20%, respectively.
      • Kim S.H.
      • Wise B.L.
      • Zhang Y.
      • Szabo R.M.
      Increasing incidence of shoulder arthroplasty in the United States.
      Diabetes has been shown to be an independent risk factor for increased risk of non-home discharge and longer hospital stays following shoulder arthroplasty.
      • Ponce B.A.
      • Menendez M.E.
      • Oladeji L.O.
      • Soldado F.
      Diabetes as a risk factor for poorer early postoperative outcomes after shoulder arthroplasty.
      ,
      • Mahure S.A.
      • Quien M.M.
      • Karia R.
      • Zuckerman J.D.
      • Kwon Y.W.
      Impact of diabetes on perioperative complications in patients undergoing elective total shoulder arthroplasty.
      Further, diabetes, along with hypertension and obesity, are reported to predict increased postoperative complications such as humeral fracture and joint infection.
      • Jain N.B.
      • Guller U.
      • Pietrobon R.
      • Bond T.K.
      • Higgins L.D.
      Comorbidities increase complication rates in patients having arthroplasty.
      However, previous research found weak associations between patient satisfaction, physical impairment and patient-reported functional outcomes in patients who have undergone arthroplasty.
      • Roy J.-S.
      • MacDermid J.C.
      • Goel D.
      • Faber K.J.
      • Athwal G.S.
      • Drosdowech D.S.
      What is a successful outcome following reverse total shoulder arthroplasty?.
      This may reflect the diversity in presentation, patient priorities and expectations. While it is known that diabetes is associated with poor outcomes in ROM and patient-reported function after total knee arthroplasty,
      • Wada O.
      • Nagai K.
      • Hiyama Y.
      • Nitta S.
      • Maruno H.
      • Mizuno K.
      Diabetes is a risk factor for restricted range of motion and poor clinical outcome after total knee arthroplasty.
      it is unknown whether this is also true for shoulder arthroplasty.
      Given the fact that the number of patients with diabetes is increasing (from 11% in 2010 to 14% by 2030),
      • Shaw J.E.
      • Sicree R.A.
      • Zimmet P.Z.
      Global estimates of the prevalence of diabetes for 2010 and 2030.
      the negative impact of hyperglycemia on body tissue,
      • Abate M.
      • Schiavone C.
      • Pelotti P.
      • Salini V.
      Limited joint mobility in diabetes and ageing: recent advances in pathogenesis and therapy.
      and the adverse effect of diabetes on postoperative complications and length of hospital stays,
      • Mahure S.A.
      • Quien M.M.
      • Karia R.
      • Zuckerman J.D.
      • Kwon Y.W.
      Impact of diabetes on perioperative complications in patients undergoing elective total shoulder arthroplasty.
      ,
      • Jain N.B.
      • Guller U.
      • Pietrobon R.
      • Bond T.K.
      • Higgins L.D.
      Comorbidities increase complication rates in patients having arthroplasty.
      there is a need to investigate whether diabetes affects functional outcomes and motion after shoulder arthroplasty. The purpose of this study was to investigate the impact of diabetes on pain, patient-reported function, physical health status, and impairments in shoulder ROM and muscle strength in patients who underwent shoulder arthroplasty.

      2. Materials and methods

      2.1 Study design and patients

      A retrospective analysis of a prospective cohort of 140 patients undergoing shoulder arthroplasty at an upper extremity surgical unit was conducted. Patients' demographic characteristics were collected and recorded into a computerized database before the surgical intervention (Baseline), and at the time of early follow-up visit (3–6 months), and again at the time of their late follow-up visit (1–3 years). Shoulder pain, function, ROM, muscle strength, and physical health status were examined across these three time-points. In this study, patients were classified into two groups: patients with diabetes and patients without diabetes based on self-report using the Self-Administered Comorbidity Questionnaire (SCQ) which is an efficient method to classify comorbidity, and has been shown to concur with medical chart retraction.
      • Sangha O.
      • Stucki G.
      • Liang M.H.
      • Fossel A.H.
      • Katz J.N.
      The self-administered comorbidity questionnaire: a new method to assess comorbidity for clinical and health services research.
      This cohort included patients who were treated with a mix of surgical interventions such as TSA, HA, and reverse TSA (rTSA). The local Research Ethics Board (REB) approved the study and written consents were obtained from all patients before the study.

      2.2 Outcome measures

      2.2.1 Primary outcome

      The primary outcome measure of shoulder was pain and function assessed using the American Shoulder and Elbow Surgery (ASES) Standardized Shoulder Assessment Form.
      • Richards R.R.
      • An K.N.
      • Bigliani L.U.
      • et al.
      A standardized method for the assessment of shoulder function.
      The ASES has been shown to be a valid and responsive measure of shoulder pain and function after shoulder arthroplasty.
      • Angst F.
      • Pap G.
      • Mannion A.F.
      • et al.
      Comprehensive assessment of clinical outcome and quality of life after total shoulder arthroplasty: usefulness and validity of subjective outcome measures.
      A full description of this form is published.
      • Richards R.R.
      • An K.N.
      • Bigliani L.U.
      • et al.
      A standardized method for the assessment of shoulder function.
      The minimal clinically important difference (MCID) value for shoulder pain on the Visual Analogue Scale (VAS: 0–10) is a decrease of 1.6 points and for the 100-point ASES scale is an increase of 13.6 points.
      • Simovitch R.
      • Flurin P.-H.
      • Wright T.
      • Zuckerman J.D.
      • Roche C.P.
      Quantifying success after total shoulder arthroplasty: the minimal clinically important difference.
      In this study, information from patients' self-evaluation section were collected [pain severity (VAS: 0–10) and activities of daily living (0–30 scores per side)]. ASES scores were compared to norms established in an age-matched controls.
      • Sallay P.I.
      • Reed L.
      The measurement of normative American Shoulder and Elbow Surgeons scores.

      2.2.2 Secondary outcomes

      The secondary outcomes measured ROM, muscle strength and physical health status.
      Physical health status was assessed using the Physical Component Summary (PCS) of the Short Form-12 (SF-12) survey.
      • Ware J.
      • Kosinski M.
      • Keller S.D.
      A 12-item Short-Form health survey : construction of scales and preliminary tests of reliability and validity.
      The SF-12 has been shown to be a valid and reliable assessment tool
      • Ware J.
      • Kosinski M.
      • Keller S.D.
      A 12-item Short-Form health survey : construction of scales and preliminary tests of reliability and validity.
      and has been used to assess patients after shoulder arthroplasty.
      • Werner B.C.
      • Wong A.C.
      • Chang B.
      • et al.
      Depression and patient-reported outcomes following total shoulder arthroplasty.
      The MCID is 4.5 points for the PCS on the SF-12 survey.
      • Clement N.D.
      • MacDonald D.
      • Simpson A.
      The minimal clinically important difference in the Oxford knee score and Short Form 12 score after total knee arthroplasty.
      Shoulder ROM was assessed in flexion, abduction, and external and internal rotation using a standard goniometer. Shoulder ROM were measured using standardized procedures with known high reliability (Intraclass Correlation Coefficients (ICCs) > 0.97).
      • Sabari J.S.
      • Maltzev I.
      • Lubarsky D.
      • Liszkay E.
      • Homel P.
      Goniometric assessment of shoulder range of motion: comparison of testing in supine and sitting positions.
      • MacDermid J.C.
      • Chesworth B.M.
      • Patterson S.
      • Roth J.H.
      Intratester and intertester reliability of goniometric measurement of passive lateral shoulder rotation.
      • Cools A.M.
      • De Wilde L.
      • Van Tongel A.
      • Ceyssens C.
      • Ryckewaert R.
      • Cambier D.C.
      Measuring shoulder external and internal rotation strength and range of motion: comprehensive intra-rater and inter-rater reliability study of several testing protocols.
      The MCID values for shoulder active forward flexion is 12°, active abduction is 7°, and active external rotation is 3°.
      • Simovitch R.
      • Flurin P.-H.
      • Wright T.
      • Zuckerman J.D.
      • Roche C.P.
      Quantifying success after total shoulder arthroplasty: the minimal clinically important difference.
      Isometric muscle strength was assessed for shoulder flexors, abductors, and external and internal rotators using the JTech PowerTrack handheld dynamometer (JTech; JTech Medical, Salt Lake City, UT, USA), with known concurrent validity
      • Roy J.-S.
      • MacDermid J.C.
      • Orton B.
      • et al.
      The concurrent validity of a hand-held versus a stationary dynamometer in testing isometric shoulder strength.
      and reliability (ICCs 0.89–0.98).
      • Dollings H.
      • Sandford F.
      • O’conaire E.
      • Lewis J.S.
      Shoulder strength testing: the intra-and inter-tester reliability of routine clinical tests, using the PowerTrackTM II commander.
      Shoulder muscle strength and ROM scores were compared to norms established in an age-matched controls and with similar testing procedures.
      • Barnes C.J.
      • Van Steyn S.J.
      • Fischer R.A.
      The effects of age, sex, and shoulder dominance on range of motion of the shoulder.
      ,
      • Van Harlinger W.
      • Blalock L.
      • Merritt J.L.
      Upper limb strength: study providing normative data for a clinical handheld dynamometer.

      2.3 Inclusion and exclusion criteria

      Patients were included if they completed the SCQ to identify the presence of diabetes; the ASES and/or the SF-12 questionnaires; and if their shoulder muscle strength and ROM were measured at baseline, at early follow-up and at late follow-up visits. Exclusion criteria included inability or refusal to complete tests/measures.

      3. Statistical analysis

      Statistical analyses were performed using SPSS, version 23 (SPSS Inc., Chicago, IL, USA). Descriptive statistics were performed to evaluate normality using a Kolmogorov-Smirnov (K-S) test. Descriptive statistics were calculated for the patients' demographics, and for each outcome measure at each time point. Continuous measures were reported as means and standard deviations and categorical measures were reported as numbers and percentages. In bivariate analysis, patients with and without diabetes groups were compared using independent sample t-test for continuous data (age and all outcomes measures at baseline) and Chi-square test for categorical data. A General Linear Model (GLM) with repeated measures was used to assess significant differences in the primary and secondary measures over time, and between patients with and without diabetes at baseline, at early follow-up and at late follow-up visits while controlling for the type of surgery (total arthroplasty, reverse total arthroplasty, and hemiarthroplasty) and the indication for surgery. Mauchly's test was used to assess the assumption of sphericity. When sphericity was violated, degrees of freedom (df) were corrected using Huynh-Feldt estimates of sphericity.
      • Field A.
      Discovering Statistics Using IBM SPSS Statistics.
      To assess the effectiveness of surgical intervention, we calculated the between group effect sizes by reporting the Standardized Response Mean (SRM) = δᵪ/SDδᵪ. The δᵪ is the mean between-group differences, and the SDδᵪ is the pooled standard deviation reflecting the variability of change between the two groups. To allow and facilitate clinical decision making, benchmark values of trivial (<0.20), small (≥0.20 to < 0.50), moderate (≥0.50 to < 0.80) or large (≥0.80), proposed by Cohen, were utilized.
      • Cohen J.
      Statistical Power Analysis for the Behavioral Sciences.
      An alpha level (α) of 0.05 was used to indicate statistical significance. Significant interactions were followed by pairwise comparisons using a Bonferroni correction.

      4. Results

      4.1 Descriptive statistics

      Patients who underwent shoulder arthroplasty and met the inclusion criteria were included in the analysis of ASES (n = 140), SF-12 (n = 103), shoulder ROM (n = 140), and shoulder muscle strength (n = 127). The demographic characteristics of patients who completed one or both surveys are summarized in Table 1 and the demographic characteristics of patients whose shoulder ROM and muscle strength were measured are summarized in Table 2. No significant differences between patients with and without diabetes were observed for age, sex, affected side, reason for surgery, and the type of surgical intervention. Within this cohort, 55% of the patients were treated with total shoulder arthroplasty, 30% of the patients were treated with reverse total shoulder arthroplasty, and 15% of the patients were treated with hemiarthroplasty. The main reason for surgery was joint arthritis (73%) while other reasons included shoulder fractures, dislocation and rotator cuff tear resulting from falls (27%). Patients were tested at baseline (pre-operative), and at two time-point post-surgery: at the late follow-up visit (3–6 months), and again at the late follow-up visit (1–3 years).
      Table 1Demographic characteristics of patients who underwent shoulder arthroplasty and completed one or both of the self-reported surveys.
      VariableASESSF-12
      DiabetesDiabetes
      YesNoYesNo
      Total number (n)28 (20%)112 (80%)20 (19%)83 (81%)
      Age (years)75 (9)70 (11)73 (9)73 (8)
      Sex
       Male10 (7%)47 (34%)9 (9%)36 (35%)
       Female18 (13%)65 (46%)11 (11%)47 (46%)
      Dominant side
       Right24 (17%)104 (74%)18 (18%)*75 (74%)
       Left4 (3%)8 (6%)2 (2%)*7 (7%)
      Affected side
       Right21 (15%)66 (47%)17 (17%)47 (46%)
       Left7 (5%)46 (33%)3 (3%)36 (35%)
      Medical problems:
      Heart disease7 (5%)22 (16%)7 (7%)*11 (11%)
      Hypertension18 (13%)*36 (26%)14 (14%)*25 (24%)
      Lung disease6 (4%)*5 (4%)3 (3%)4 (4%)
      Primary osteoarthritis24 (17%)83 (59%)17 (17%)55 (53%)
      Rheumatoid arthritis2 (1%)22 (16%)2 (2%)11 (11%)
      Others (cancer, depression, kidney and blood disease)34 (24%)116 (83%)26 (26%)81 (79%)
      Reason for surgery:
      Arthritis16 (13%)60 (47%)11 (11%)51 (50%)
      Rotator cuff tear3 (2%)4 (3%)1 (1%)3 (3%)
      Others (fracture, dislocation, revised surgery)9 (6%)48 (33%)8 (8%)29 (28%)
      Type of surgery:n = 26n = 110
      Total arthroplasty16 (12%)63 (47%)11 (11%)50 (49%)
      Reverse total arthroplasty8 (6%)36 (26%)6 (6%)23 (23%)
      Hemiarthroplasty2 (2%)11 (9%)3 (3%)9 (9%)
      Independent sample t-test was used to detect difference in age (mean (SD)) between groups. Chi-square test was used to detect differences between groups in all categorical data (reported as number and percentage). *Significant difference between groups, p < 0.05. ASES: American Shoulder and Elbow Surgeons, SF-12: Short Form-12 survey.
      Table 2Demographic characteristics of patients who underwent shoulder arthroplasty and whose shoulder motion and/or muscle strength were measured.
      VariableROMMuscle strength
      DiabetesDiabetes
      YesNoYesNo
      Total number (n)27 (19%)113 (81%)23 (18%)104 (82%)
      Age (years)73 (8)71 (9)74 (9)70 (9)
      Sex
       Male12 (9%)54 (39%)11 (9%)51 (40%)
       Female15 (11%)59 (42%)12 (9%)53 (42%)
      Dominant side
       Right24 (17%)104 (74%)21 (17%)97 (76%)
       Left3 (2%)9 (6%)2 (2%)7 (6%)
      Affected side
       Right23 (16%)*70 (50%)20 (16%)*66 (52%)
       Left4 (3%)*43 (31%)3 (2%)*38 (30%)
      Medical problems:
      Heart disease8 (6%)*14 (10%)5 (4%)14 (11%)
      Hypertension17 (12%)*34 (24%)16 (13%)*35 (28%)
      Lung disease5 (4%)*3 (2%)4 (3%)7 (6%)
      Primary osteoarthritis23 (16%)*62 (44%)20 (16%)*68 (54%)
      Rheumatoid arthritis3 (2%)12 (9%)2 (2%)12 (9%)
      Others (cancer, depression, kidney and blood disease)32 (23%)90 (64%)27 (22%)89 (69%)
      Reason for surgery:
      Arthritis16 (13%)60 (46%)14 (14%)63 (54%)
      Rotator cuff tear2 (2%)1 (1%)1 (1%)1 (1%)
      Others (fracture, dislocation, revised surgery)10 (8%)46 (35%)7 (6%)40 (33%)
      Type of surgery:
      Total arthroplasty19 (14%)65 (48%)15 (12%)62 (50%)
      Reverse total arthroplasty6 (5%)36 (26%)6 (5%)31 (25%)
      Hemiarthroplasty2 (1%)11 (8%)2 (2%)9 (7%)
      Independent sample t-test was used to detect difference in age (mean (SD)) between groups. Chi-square test was used to detect differences between groups in all categorical data (reported as number and percentage). *Significant difference between groups, p < 0.05. ROM: range of motion.

      4.2 Effect of surgical interventions

      4.2.1 Primary outcome

      Table 3 presents the means and SD of the responses for the ASES pain and function scores at each point in time. There was significant improvement over time (from baseline to late follow-up visit) on pain scores (VAS: 0–10) for patients with diabetes [7 (3.3) to 2 (2.4), p < 0.001], and for patients without diabetes [6 (3.0) to 2 (2.3), p < 0.001].
      Table 3A comparison of changes in pain, function, ROM, and muscle strength between patients with and without diabetes who underwent shoulder arthroplasty.
      VariableBaselineEarly follow-up visit (3–6 months)Late follow-up visit (1–3 years)Effect size
      DiabetesDiabetesDiabetes
      YesNoYesNoYesNo
      ASES
      Pain (0–10)7 (3)6 (3)2 (1)2 (2)2 (2)2 (2)1.0
      Function: Affected side (0–30)5 (5)8 (5)13 (5)15 (7)18 (6)19 (8)0.9
      Un-affected side (0–30)21 (8)22 (8)24 (5)24 (6)25 (4)25 (6)
      SF-12
      Physical health status (0–100)27 (6)31 (8)35 (8)39 (9)38 (8)40 (12)0.6
      Mental health status (0–100)48 (13)53 (11)48 (12)55 (9)53 (6)53 (10)
      Shoulder ROM (degrees):
      Flexion: Affected85 (31)98 (24)108 (18)112 (26)132 (28)132 (32)2.2
      Unaffected146 (33)153 (22)156 (19)158 (21)156 (21)155 (22)
      Abduction: Affected65 (23)76 (25)90 (21)96 (28)115 (33)119 (36)0.7
      Unaffected137 (39)150 (26)150 (25)152 (27)150 (32)152 (26)
      External rotation: Affected20 (12)24 (12)36 (18)36 (18)47 (16)47 (23)0.5
      Unaffected57 (21)61 (21)64 (21)62 (22)70 (15)68 (19)
      Internal rotation: Affected3 (3)6 (10)24 (11)27 (15)37 (14)38 (19)0.2
      Unaffected53 (19)51 (16)55 (16)52 (15)60 (13)55 (19)
      Shoulder muscle strength (kg):
      Flexors: Affected2 (1)4 (3)4 (2)5 (4)4 (2)5 (3)1.4
      Unaffected5 (2)7 (5)5 (2)7 (4)5 (2)6 (3)
      Abductors: Affected2 (1)4 (3)4 (2)5 (3)4 (1)5 (3)1.0
      Unaffected5 (2)8 (5)6 (2)8 (4)5 (2)7 (3)
      External rotators: Affected2 (1)3 (1)3 (2)3 (2)4 (2)4 (2)1.0
      Unaffected4 (2)6 (3)5 (2)6 (2)5 (1)6 (2)
      Internal rotators: Affected3 (2)4 (2)4 (2)5 (2)4 (2)6 (3)1.4
      Unaffected6 (2)8 (7)6 (2)8 (4)6 (2)7 (3)
      General linear modules-repeated measures were used to detect changes over time and between groups. Values are reported as mean (SD). significant effect of time (p < 0.05) between baseline and early follow-up visit and between baseline and late follow-up visit. significant mean difference between groups as detected by independent sample t-test.
      ROM: Range of Motion, ASES: American Shoulder and Elbow Surgeons, SF-12: Short From-12 survey.
      Similarly, there were significant improvements over time on function scores (ASES: 0–30) of the affected shoulder for patients with diabetes [5 (4.6) to 18 (6.3), p < 0.001] and for patients without diabetes [7 (4.9) to 19 (7.3), p < 0.001]. Pairwise comparisons revealed a significant improvement between each time point (p < 0.001) for the function score of the affected shoulder, and between baseline and late follow-up visit for pain scores.
      Despite the higher pain (non-significant) and poorer function (mean difference (MD) = 3 points, p = 0.032) of patients with diabetes at baseline, the differences between groups became nonsignificant at the late follow-up visit (Table 3).
      When we controlled for the type of surgery and indication for surgery the improvement over time in ASES pain and function scores remained significant (p < 0.001) and the differences in pain and function between patients with and without diabetes remained nonsignificant. In addition, the interaction between time and type of surgery and between time and reason for surgery were nonsignificant, indicating that surgical subgroups experienced similar patterns of recovery.

      4.2.2 Secondary outcomes

      There was significant improvement over time, between baseline and early follow-up visit and between baseline and late follow-up visit on the physical health status for patients with diabetes [27 (5.7) to 38 (8.2), p < 0.001] and for patients without diabetes [31 (7.5) to 40 (11.5), p < 0.001] (Table 3). Despite the significant poorer physical health status of patients with diabetes at baseline (MD = 4 points, p < 0.033), both groups recovered to a similar physical health status at the late follow-up visit (Table 3).
      As shown in Table 3, there was significant improvement over time of the affected shoulder ROM for both groups (p < 0.001). The independent sample t-test revealed significant differences between groups at baseline in flexion (MD = 13°, p < 0.02), and abduction (MD = 11°, p < 0.044). However, these differences became nonsignificant at the late follow-up visit.
      Similar to shoulder ROM, muscle strength of the affected shoulder significantly improved over time for both groups (p < 0.001) as shown in Table 3. Despite the significantly weaker shoulder flexors (MD = 2 kg, p < 0.013), abductors (MD = 2 kg, p < 0.001), and external (MD = 1 kg, p < 0.009) and internal (MD = 1 kg, p < 0.006) rotator muscle groups at baseline, patients with diabetes regain similar muscle strength as patients without diabetes at the late follow-up visit.
      The analysis of covariance, when the type of surgery and indication for surgery were controlled for, revealed that the improvements over time in physical health status, ROM and muscle strength remained significant (p < 0.001) and the differences between diabetic and non-diabetic patients remained nonsignificant for physical health status, ROM and for muscle strength. In addition, the interaction between time and type of surgery and between time and reason for surgery were non-significant for the secondary outcome measures.

      5. Discussion

      This study demonstrated that patients with and without diabetes have equally positive improvements in shoulder function, ROM, strength and in physical health status following shoulder arthroplasty, despite the small but significantly poorer function and physical health status that patients with self-reported diabetes present with prior to surgery. In addition, the improvements in shoulder pain, function, and ROM of the current study all reached statistical and clinical significance with large effects size (Table 3), confirming prior studies that indicate a large benefit to shoulder arthroplasty. The overall improvements in shoulder pain, function, ROM, and strength as well as physical health status were comparable to previous studies despite the differences in sample size, outcome assessment tools, the follow up periods, and the inclusion criteria.
      • Bartelt R.
      • Sperling J.W.
      • Schleck C.D.
      • Cofield R.H.
      Shoulder arthroplasty in patients aged fifty-five years or younger with osteoarthritis.
      ,
      • Deshmukh A.V.
      • Koris M.
      • Zurakowski D.
      • Thornhill T.S.
      Total shoulder arthroplasty: long-term survivorship, functional outcome, and quality of life.
      ,
      • Orfaly R.M.
      • Rockwood C.A.
      • Esenyel C.Z.
      • Wirth M.A.
      A prospective functional outcome study of shoulder arthroplasty for osteoarthritis with an intact rotator cuff.
      ,
      • Norris T.R.
      • Iannotti J.P.
      Functional outcome after shoulder arthroplasty for primary osteoarthritis: a multicenter study.
      ,
      • Werner B.C.
      • Wong A.C.
      • Chang B.
      • et al.
      Depression and patient-reported outcomes following total shoulder arthroplasty.
      However, none of these studies have examined a subset of patients with diabetes for comparison.
      Similar to previous research,
      • Orfaly R.M.
      • Rockwood C.A.
      • Esenyel C.Z.
      • Wirth M.A.
      A prospective functional outcome study of shoulder arthroplasty for osteoarthritis with an intact rotator cuff.
      ,
      • Norris T.R.
      • Iannotti J.P.
      Functional outcome after shoulder arthroplasty for primary osteoarthritis: a multicenter study.
      different types of surgery (TSA, HA, rTSA) were not significantly different in terms of functional improvements following surgery This may be because the indications for different surgeries successfully allocates them to the type of surgery providing the optimal outcome for that clinical presentation. However, our results differ from one study that reported a greater shoulder ROM and less pain following TSA as compared to hemiarthroplasty.
      • Bartelt R.
      • Sperling J.W.
      • Schleck C.D.
      • Cofield R.H.
      Shoulder arthroplasty in patients aged fifty-five years or younger with osteoarthritis.
      Despite the reported improvements in shoulder ROM and strength, patients with and without diabetes had below-normal scores when compared to age-matched people with unaffected shoulder.
      • Barnes C.J.
      • Van Steyn S.J.
      • Fischer R.A.
      The effects of age, sex, and shoulder dominance on range of motion of the shoulder.
      ,
      • Van Harlinger W.
      • Blalock L.
      • Merritt J.L.
      Upper limb strength: study providing normative data for a clinical handheld dynamometer.
      The lower scores can be attributed to several factors including the quality of the surrounding musculotendinous structures, the type of implant and fixation used, the general health status of patients, and the presence of comorbidities.
      • Deshmukh A.V.
      • Koris M.
      • Zurakowski D.
      • Thornhill T.S.
      Total shoulder arthroplasty: long-term survivorship, functional outcome, and quality of life.
      ,
      • Norris T.R.
      • Iannotti J.P.
      Functional outcome after shoulder arthroplasty for primary osteoarthritis: a multicenter study.
      ,
      • Jain N.B.
      • Guller U.
      • Pietrobon R.
      • Bond T.K.
      • Higgins L.D.
      Comorbidities increase complication rates in patients having arthroplasty.
      ,
      • Matsen III, F.A.
      • Antoniou J.
      • Rozencwaig R.
      • Campbell B.
      • Smith K.L.
      Correlates with comfort and function after total shoulder arthroplasty for degenerative joint disease.
      Patients should be made aware that improvement, not normality, is the expected outcome of surgery.
      The clinical improvements in outcomes between patients with and without diabetes was previously investigated following total knee arthroplasty (TKA).
      • Wada O.
      • Nagai K.
      • Hiyama Y.
      • Nitta S.
      • Maruno H.
      • Mizuno K.
      Diabetes is a risk factor for restricted range of motion and poor clinical outcome after total knee arthroplasty.
      The TKA study included 20 diabetic patients with a mean age of 72 years. Similar to our study, there were small (non-significant) differences in knee ROM, muscle strength and Knee Society Score questionnaire scores between groups at baseline. However, at one year follow-up, TKR patients with and without diabetes had similar outcomes except for knee flexion which was significantly 10° less in patients with diabetes.
      • Wada O.
      • Nagai K.
      • Hiyama Y.
      • Nitta S.
      • Maruno H.
      • Mizuno K.
      Diabetes is a risk factor for restricted range of motion and poor clinical outcome after total knee arthroplasty.
      According to the authors, the difference in the rehabilitation program intensity explained the poorer knee flexion in patients with diabetes.
      • Wada O.
      • Nagai K.
      • Hiyama Y.
      • Nitta S.
      • Maruno H.
      • Mizuno K.
      Diabetes is a risk factor for restricted range of motion and poor clinical outcome after total knee arthroplasty.
      Overall, our findings concur with results found in the TKA study, that patients with diabetes achieve similar clinical benefits, as compared to their nondiabetic counterparts.

      5.1 Strength and limitations

      This study provides new information on the impact of diabetes on shoulder pain, function, ROM, strength and physical health status after shoulder arthroplasty. The data of this study were prospectively collected using valid and reliable outcome measures; and the ASES scale and SF-12 survey have been used to assess functional outcomes and physical health status after shoulder arthroplasty. We evaluated a relatively large cohort of patients and used an independent assessor to evaluate outcomes. However, several limitations of the current cohort should be recognized. First, diabetes status was classified based on self-report which is subject to reporting errors. However, the Katz self-administered comorbidity scale (SCQ) has been validated to assess comorbid conditions and health services research; and shown to be equivalent to extracting this information from medical records.
      • Sangha O.
      • Stucki G.
      • Liang M.H.
      • Fossel A.H.
      • Katz J.N.
      The self-administered comorbidity questionnaire: a new method to assess comorbidity for clinical and health services research.
      Diabetes is the type of condition that is more likely that patients would accurately self-report, given the treatment requirements. Second, and potentially more limiting, was the fact that we did not have data about the type, the duration, the treatments of diabetes, and the level of glycemic control. It is possible that negative effects of diabetes would be selectively present in with longer duration or poorer control. Therefore, we cannot preclude that negative effects may occur in this subgroup. Lastly, although we controlled for the type of surgery and the indication for surgery and found no effect, recovery could be affected by other uncontrolled factors such as the quality and type of implant and the post-operative complications.
      • Bartelt R.
      • Sperling J.W.
      • Schleck C.D.
      • Cofield R.H.
      Shoulder arthroplasty in patients aged fifty-five years or younger with osteoarthritis.
      ,
      • Deshmukh A.V.
      • Koris M.
      • Zurakowski D.
      • Thornhill T.S.
      Total shoulder arthroplasty: long-term survivorship, functional outcome, and quality of life.

      6. Conclusion

      Patients with and without diabetes are expected to gain similar large clinical improvements in shoulder function, motion, and strength as well as physical health status following shoulder arthroplasty. However, these improvements are not expected to reach normal values. Future large cohort studies with larger numbers of patients with diabetes and more rigorous evaluation of diabetic duration, type, and the level of glycemic control over a longer period of time could more accurately estimate the prognosis of different subgroups of patients with diabetes; and whether a dose-response relationship between glycemic control and outcomes is present.

      The name of the approval giving authority

      The University of Western Ontario Research Ethics Board for Health Sciences Research Involving Human Subjects (HSREB).

      Study number

      13935E

      Declaration of conflicting interests

      The authors declare that there is no conflict of interest.

      Acknowledgment

      Dr. Joy C MacDermid was supported by a Canadian Institutes of Health Research (CIHR), Canada Chair in Gender, Work and Health and the Dr. James Roth Research Chair in Musculoskeletal Measurement and Knowledge Translation during the conduct of this study. CIHR FRN: SCA-145102.

      References

        • Bartelt R.
        • Sperling J.W.
        • Schleck C.D.
        • Cofield R.H.
        Shoulder arthroplasty in patients aged fifty-five years or younger with osteoarthritis.
        J Shoulder Elb Surg. 2011; 20: 123-130
        • Deshmukh A.V.
        • Koris M.
        • Zurakowski D.
        • Thornhill T.S.
        Total shoulder arthroplasty: long-term survivorship, functional outcome, and quality of life.
        J Shoulder Elb Surg. 2005; 14: 471-479
        • Orfaly R.M.
        • Rockwood C.A.
        • Esenyel C.Z.
        • Wirth M.A.
        A prospective functional outcome study of shoulder arthroplasty for osteoarthritis with an intact rotator cuff.
        J Shoulder Elb Surg. 2003; 12: 214-221
        • Norris T.R.
        • Iannotti J.P.
        Functional outcome after shoulder arthroplasty for primary osteoarthritis: a multicenter study.
        J Shoulder Elb Surg. 2002; 11: 130-135
        • Kim S.H.
        • Wise B.L.
        • Zhang Y.
        • Szabo R.M.
        Increasing incidence of shoulder arthroplasty in the United States.
        JBJS. 2011; 93: 2249-2254
        • Ponce B.A.
        • Menendez M.E.
        • Oladeji L.O.
        • Soldado F.
        Diabetes as a risk factor for poorer early postoperative outcomes after shoulder arthroplasty.
        J Shoulder Elb Surg. 2014; 23: 671-678
        • Mahure S.A.
        • Quien M.M.
        • Karia R.
        • Zuckerman J.D.
        • Kwon Y.W.
        Impact of diabetes on perioperative complications in patients undergoing elective total shoulder arthroplasty.
        Bull NYU Hosp Jt Dis. 2017; 75: 173
        • 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
        • Roy J.-S.
        • MacDermid J.C.
        • Goel D.
        • Faber K.J.
        • Athwal G.S.
        • Drosdowech D.S.
        What is a successful outcome following reverse total shoulder arthroplasty?.
        Open Orthop J. 2010; 4: 157
        • Wada O.
        • Nagai K.
        • Hiyama Y.
        • Nitta S.
        • Maruno H.
        • Mizuno K.
        Diabetes is a risk factor for restricted range of motion and poor clinical outcome after total knee arthroplasty.
        J Arthroplast. 2016; 31: 1-4
        • Shaw J.E.
        • Sicree R.A.
        • Zimmet P.Z.
        Global estimates of the prevalence of diabetes for 2010 and 2030.
        Diabetes Res Clin Pract. 2010; 87: 4-14
        • Abate M.
        • Schiavone C.
        • Pelotti P.
        • Salini V.
        Limited joint mobility in diabetes and ageing: recent advances in pathogenesis and therapy.
        Int J Immunopathol Pharmacol. 2010; 23: 997-1003
        • Sangha O.
        • Stucki G.
        • Liang M.H.
        • Fossel A.H.
        • Katz J.N.
        The self-administered comorbidity questionnaire: a new method to assess comorbidity for clinical and health services research.
        Arthritis Care Res. 2003; 49: 156-163
        • Richards R.R.
        • An K.N.
        • Bigliani L.U.
        • et al.
        A standardized method for the assessment of shoulder function.
        J Shoulder Elb Surg. 1994; 3: 347-352
        • Angst F.
        • Pap G.
        • Mannion A.F.
        • et al.
        Comprehensive assessment of clinical outcome and quality of life after total shoulder arthroplasty: usefulness and validity of subjective outcome measures.
        Arthritis Care Res. 2004; 51: 819-828
        • Simovitch R.
        • Flurin P.-H.
        • Wright T.
        • Zuckerman J.D.
        • Roche C.P.
        Quantifying success after total shoulder arthroplasty: the minimal clinically important difference.
        J Shoulder Elb Surg. 2018; 27: 298-305
        • Sallay P.I.
        • Reed L.
        The measurement of normative American Shoulder and Elbow Surgeons scores.
        J Shoulder Elb Surg. 2003; 12: 622-627
        • Ware J.
        • Kosinski M.
        • Keller S.D.
        A 12-item Short-Form health survey : construction of scales and preliminary tests of reliability and validity.
        Med Care. 1996; 34: 220-233
        • Werner B.C.
        • Wong A.C.
        • Chang B.
        • et al.
        Depression and patient-reported outcomes following total shoulder arthroplasty.
        JBJS. 2017; 99: 688-695
        • Clement N.D.
        • MacDonald D.
        • Simpson A.
        The minimal clinically important difference in the Oxford knee score and Short Form 12 score after total knee arthroplasty.
        Knee Surg Sports Traumatol Arthrosc. 2014; 22: 1933-1939
        • Sabari J.S.
        • Maltzev I.
        • Lubarsky D.
        • Liszkay E.
        • Homel P.
        Goniometric assessment of shoulder range of motion: comparison of testing in supine and sitting positions.
        Arch Phys Med Rehabil. 1998; 79: 647-651
        • MacDermid J.C.
        • Chesworth B.M.
        • Patterson S.
        • Roth J.H.
        Intratester and intertester reliability of goniometric measurement of passive lateral shoulder rotation.
        J Hand Ther. 1999; 12: 187-192
        • Cools A.M.
        • De Wilde L.
        • Van Tongel A.
        • Ceyssens C.
        • Ryckewaert R.
        • Cambier D.C.
        Measuring shoulder external and internal rotation strength and range of motion: comprehensive intra-rater and inter-rater reliability study of several testing protocols.
        J Shoulder Elb Surg. 2014; 23: 1454-1461
        • Roy J.-S.
        • MacDermid J.C.
        • Orton B.
        • et al.
        The concurrent validity of a hand-held versus a stationary dynamometer in testing isometric shoulder strength.
        J Hand Ther. 2009; 22: 320-327
        • Dollings H.
        • Sandford F.
        • O’conaire E.
        • Lewis J.S.
        Shoulder strength testing: the intra-and inter-tester reliability of routine clinical tests, using the PowerTrackTM II commander.
        Shoulder Elbow. 2012; 4: 131-140
        • Barnes C.J.
        • Van Steyn S.J.
        • Fischer R.A.
        The effects of age, sex, and shoulder dominance on range of motion of the shoulder.
        J Shoulder Elb Surg. 2001; 10: 242-246
        • Van Harlinger W.
        • Blalock L.
        • Merritt J.L.
        Upper limb strength: study providing normative data for a clinical handheld dynamometer.
        PM&R. 2015; 7: 135-140
        • Field A.
        Discovering Statistics Using IBM SPSS Statistics.
        fourth ed. Sage, London,UK2013
        • Cohen J.
        Statistical Power Analysis for the Behavioral Sciences.
        first ed. Academic Press, New York1977
        • Matsen III, F.A.
        • Antoniou J.
        • Rozencwaig R.
        • Campbell B.
        • Smith K.L.
        Correlates with comfort and function after total shoulder arthroplasty for degenerative joint disease.
        J Shoulder Elb Surg. 2000; 9: 465-469