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

Abstract

ObjectiveThe 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 methodsWith 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 12–67).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.ResultsPatients 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 = 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 = 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).ConclusionIn 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.Level of evidenceLevel III, Therapeutic Study.

Shoulder strength outcomes after reverse total shoulder arthroplasty: a systematic review and descriptive synthesis

“…1,6 Regarding surgical techniques for J o u r n a l P r e -p r o o f subscapularis management, some authors support tenotomy and subsequent reattachment 6 , while other authors suggest no significant difference in outcomes based on treatment with lesser tuberosity osteotomy or tenotomy, or no repair. 4 Other studies have examined the relationship between rTSA subscapularis management and shoulder strength outcomes 7,8,10,16 . A study conducted by Ersen et al 10 found that isokinetic strength of the shoulder did not significantly improve following subscapularis tendon repair, and that internal and external rotational strength were significantly lower in operated shoulders than in patients' contralateral shoulders.…”

“…4 Other studies have examined the relationship between rTSA subscapularis management and shoulder strength outcomes 7,8,10,16 . A study conducted by Ersen et al 10 found that isokinetic strength of the shoulder did not significantly improve following subscapularis tendon repair, and that internal and external rotational strength were significantly lower in operated shoulders than in patients' contralateral shoulders.…”

Medialized versus Lateralized Center of Rotation in Reverse Total Shoulder Arthroplasty: A Systematic Review and Meta-Analysis

“…Both the selected RCTs resulted in having a "low risk of bias" [25,46]. Out of the 22 NRCTs, nine were identified as "low risk of bias" studies [12,19,38,39,43,45,[47][48][49]; eight were identified as "moderate risk of bias" studies [15,29,36,37,44,46,52,53]; four studies resulted in having a "serious risk of bias" [18,35,40,41]; and only one study was identified as a "critical risk of bias" study [39].…”

Morphometry of the shoulder joint and justification of new modular reverse shoulder endoprosthesis sizes using computed tomography data

“…Найчастіше шийково-діафізарний кут проксимального відділу плечової кістки визначають під час планування хірургічного втручання за рентгенограмою в передньо-задній проєкції. Доведено, що його значення становить у середньому 135° [13,14]. Водночас більшість реверсивних систем мають кут 145°-150°, що викликає дискусію [15].…”