Ali ERŞEN, Fevzi BİRİŞİK, Serkan BAYRAM, Türker ŞAHİNKAYA, Mehmet DEMİREL, Ata Can ATALAR, Mehmet DEMİRHAN

Isokinetic Evaluation of Shoulder Strength and Endurance after Reverse Shoulder Arthroplasty: A Comparative Study

Objective: The present study aimed to compare the isometric strength and endurance of shoulder abduction and internal and external rotation between operated shoulders and nonoperated, contralateral shoulders of patients who underwent reverse shoulder replacement due to unilateral rotator cuff tear arthropathy. Patients and methods: With a diagnosis of cuff tear arthropathy, 41 consecutive patients (mean age of 70.8 years; age range, 57 to 84; 36 females, 5 males) who underwent unilateral reverse shoulder arthroplasty were reviewed based on functional and radiological data. In all cases, cuff tear arthropathy was unilateral and contralateral shoulder was asymptomatic, with normal shoulder function. The average length of follow-up was 34 months (range of 12e67). To assess patients' functional level, the Constant score and the Disabilities of the Arm, Shoulder, and Hand (the Quick-DASH) outcome measure were used preoperatively and at the final examination. The primary outcomes of the present study were measurement of isokinetic strength and endurance of shoulder abduction and internal and external rotation using an isokinetic evaluator. Results: Patients exhibited marked improvement in functional level as reflected by a significant increase in the mean Constant score from 38 preoperatively to 65 at the final follow-up (p ¼ 0.03). The functional improvement was supported by a decrease in the mean Quick-DASH from 64 preoperatively to 26 at the final follow-up (p ¼ 0.018). In the comparison of the isokinetic strength and endurance of shoulder abduction, no statistical difference was observed between operated shoulders and contralateral shoulders (p > 0.05). However; the strength and endurance of internal and external rotation were lower in operated shoulders than in contralateral shoulders (p < 0.05). Similarly, there was no statistically significant difference in comparisons of the durability of abduction (p > 0.05); however, the durability of internal and external rotation were significantly lower in operated shoulders (p < 0.05). Conclusion: In terms of durability and strength of abduction, similar results with the unaffected shoulder may be accomplished; nonetheless, the surgeon should be aware that durability and strength of rotation would be weak.

___

1. Jain NB, Yamaguchi K. The contribution of reverse shoulder arthroplasty to utilization of primary shoulder arthroplasty. J Shoulder Elbow Surg. 2014;23e12:1905e1912.

2. McFarland EG, Huri G, Hyun YS, Petersen SA, Srikumaran U. Reverse total shoulder arthroplasty without bone-grafting for severe glenoid bone loss in patients with osteoarthritis and intact rotator cuff. J Bone Joint Surg Am. 2016;98e21:1801e1807.

3. Grubhofer F, Wieser K, Meyer DC, Catanzaro S, Schurholz K, Gerber C. Reverse total shoulder arthroplasty for failed open reduction and internal fixation of fractures of the proximal humerus. J Shoulder Elbow Surg. 2017;26e1:92e100.

4. Favard L, Levigne C, Nerot C, Gerber C, De Wilde L, Mole D. Reverse prostheses in arthropathies with cuff tear: are survivorship and function maintained over time? Clin Orthop Relat Res. 2011;469e9:2469e2475.

5. Ek ET, Neukom L, Catanzaro S, Gerber C. Reverse total shoulder arthroplasty for massive irreparable rotator cuff tears in patients younger than 65 years old: results after five to fifteen years. J Shoulder Elbow Surg. 2013;22e9:1199e1208.

6. Wellmann M, Struck M, Pastor MF, Gettmann A, Windhagen H, Smith T. Short and midterm results of reverse shoulder arthroplasty according to the preoperative etiology. Arch Orthop Trauma Surg. 2013;133e4:463e471.

7. Boileau P, Chuinard C, Roussanne Y, Bicknell RT, Rochet N, Trojani C. Reverse shoulder arthroplasty combined with a modified latissimus dorsi and teres major tendon transfer for shoulder pseudoparalysis associated with dropping arm. Clin Orthop Relat Res. 2008;466e3:584e593.

8. Matsen III FA, Boileau P, Walch G, Gerber C, Bicknell RT. The reverse total shoulder arthroplasty. Instr Course Lect. 2008;57:167e174.

9. Jobin CM, Brown GD, Bahu MJ, et al. Reverse total shoulder arthroplasty for cuff tear arthropathy: the clinical effect of deltoid lengthening and center of rotation medialization. J Shoulder Elbow Surg. 2012;21e10:1269e1277.

10. De Wilde L, Audenaert E, Barbaix E, Audenaert A, Soudan K. Consequences of deltoid muscle elongation on deltoid muscle performance: a computerised study. Clin Biomech (Bristol, Avon). 2002;17e7:499e505.

11. De Wilde LF, Audenaert EA, Berghs BM. Shoulder prostheses treating cuff tear arthropathy: a comparative biomechanical study. J Orthop Res. 2004;22e6: 1222e1230.

12. Kurowicki J, Triplet JJ, Momoh E, Moor MA, Levy JC. Reverse shoulder prosthesis in the treatment of locked anterior shoulders: a comparison with classic reverse shoulder indications. J Shoulder Elbow Surg. 2016;25e12: 1954e1960.

13. Riley C, Idoine J, Shishani Y, Gobezie R, Edwards B. Early outcomes following metal-on-metal reverse total shoulder arthroplasty in patients younger than 50 years. Orthopedics. 2016;39e5:957e961.

14. Liou W, Yang Y, Petersen-Fitts GR, Lombardo DJ, Stine S, Sabesan VJ. Effect of lateralized design on muscle and joint reaction forces for reverse shoulder arthroplasty. J Shoulder Elbow Surg. 2017;26:564e572.

15. Ferrel JR, Trinh TQ, Fischer RA. Reverse total shoulder arthroplasty versus hemiarthroplasty for proximal humeral fractures: a systematic review. J Orthop Trauma. 2015;29e1:60e68.

16. Vourazeris JD, Wright TW, Struk AM, King JJ, Farmer KW. Primary reverse total shoulder arthroplasty outcomes in patients with subscapularis repair versus tenotomy. J Shoulder Elbow Surg. 2017;26:450e457.

17. Yamaguchi K, Ditsios K, Middleton WD, Hildebolt CF, Galatz LM, Teefey SA. The demographic and morphological features of rotator cuff disease. A comparison of asymptomatic and symptomatic shoulders. J Bone Joint Surg Am. 2006;88e8: 1699e1704.

18. Constant CR, Murley AH. A clinical method of functional assessment of the shoulder. Clin Orthop Relat Res. 1987;214:160e164.

19. Hudak PL, Amadio PC, Bombardier C. Development of an upper extremity outcome measure: the DASH (disabilities of the arm, shoulder and hand) [corrected]. The Upper Extremity Collaborative Group (UECG). Am J Ind Med. 1996;29:602e608.