Giovanni Merolla1,2,3, Francesco Cuoghi4, George S Athwal5, Ilaria Parel6, Maria V Filippi7, Andrea G Cutti8, Elisabetta Fabbri9, Antonio Padolino10, Paolo Paladini10, Fabio Catani4, Giuseppe Porcellini4. 1. Shoulder and Elbow Unit, Cervesi Hospital, Cattolica - AUSL Romagna, Via L. v. Beethoven 5, Code: 47841, Cattolica, Italy. giovannimerolla@hotmail.com. 2. Biomechanics Laboratory, Cervesi Hospital, Cattolica - AUSL Romagna, Cattolica, Italy. giovannimerolla@hotmail.com. 3. International Doctorate School (PhD) in Clinical and Experimental Medicine, Modena, Italy. giovannimerolla@hotmail.com. 4. Department of Orthopaedics and Traumatology, University of Modena and Reggio Emilia, Modena, Italy. 5. St Joseph's Hospital, Roth McFarlane Hand & Upper Limb Center, London, ON, Canada. 6. Biomechanics Laboratory, Cervesi Hospital, Cattolica - AUSL Romagna, Cattolica, Italy. 7. Functional Recovery and Rehabilitation Unit - AUSL Romagna, Forlì, Italy. 8. INAIL Prostheses Center, Vigorso di Budrio, Italy. 9. Research and Innovation Department, AUSL Romagna, Rimini, Italy. 10. Shoulder and Elbow Unit, Cervesi Hospital, Cattolica - AUSL Romagna, Via L. v. Beethoven 5, Code: 47841, Cattolica, Italy.
Abstract
PURPOSE: To assess kinematic and electromyographic findings of two designs of reverse total shoulder arthroplasty (RTSA). We tested two hypotheses: (H1) Grammont-style (RTSA) with l'Episcopo tendon transfer gains similar postoperative kinematic findings of a lateralized humeral component RTSA without a tendon transfer; (H2) RTSA with lateralized humeral component induces earlier shoulder muscle activation during shoulder motion compared with standard Grammont prosthesis with l'Episcopo transfer. METHODS: Twenty-five patients with a cuff tear arthropathy, pseudoparalysis, and a positive dropping sign were sequentially included. A Grammont-style RTSA with a l'Episcopo tendon transfer was implanted in 13 patients (medialized humerus and transfer group) and an on-lay curved-stem RTSA in 12 (lateralized humerus group). Constant score; the disabilities of the arm, shoulder, and hand (DASH) score; and active shoulder range of motion (flexion, abduction, external rotation, and internal rotation) were measured pre- and postoperatively. Upper limb kinematic and surface electromyography (EMG) (anterior and posterior deltoid; upper, middle, and lower trapezius; and the upper and lower latissimus dorsi muscles) were recorded during active range of motion. RESULTS: At > 24 months of follow-up, the Constant and DASH scores and active shoulder range of motion improved in both groups (p < 0.0001). Internal rotation was significantly higher in the lateralized humerus group than in the medialized humerus and transfer group (p = 0.004). The dropping sign was found in 0/12 patients in the lateralized humerus group and in 5/13 patients in the medialized humerus and transfer group (p < 0.001). Kinematic findings were similar between groups (p = 0.286). A pattern of earlier muscle activation in the lateralized humerus group was found as compared to the transfer group as follows: (i) posterior deltoid during external rotation (p = 0.004); (ii) upper latissimus dorsi and middle and lower trapezius during flexion (p = 0.004, p = 0.005, and p = 0.042, respectively); (iii) lower latissimus dorsi during abduction (p = 0.016). CONCLUSION: RTSA with a lateralized humeral component provided similar active external rotation restoration to a Grammont-style RTSA with a l'Episcopo procedure in patients with a dropping sign. The posterior deltoid muscle underwent earlier activation during active external rotation in the lateralized humerus RTSA group as compared to the tendon transfer group. Our findings demonstrated the H1 and only partially demonstrated the H2 of the study.
PURPOSE: To assess kinematic and electromyographic findings of two designs of reverse total shoulder arthroplasty (RTSA). We tested two hypotheses: (H1) Grammont-style (RTSA) with l'Episcopo tendon transfer gains similar postoperative kinematic findings of a lateralized humeral component RTSA without a tendon transfer; (H2) RTSA with lateralized humeral component induces earlier shoulder muscle activation during shoulder motion compared with standard Grammont prosthesis with l'Episcopo transfer. METHODS: Twenty-five patients with a cuff tear arthropathy, pseudoparalysis, and a positive dropping sign were sequentially included. A Grammont-style RTSA with a l'Episcopo tendon transfer was implanted in 13 patients (medialized humerus and transfer group) and an on-lay curved-stem RTSA in 12 (lateralized humerus group). Constant score; the disabilities of the arm, shoulder, and hand (DASH) score; and active shoulder range of motion (flexion, abduction, external rotation, and internal rotation) were measured pre- and postoperatively. Upper limb kinematic and surface electromyography (EMG) (anterior and posterior deltoid; upper, middle, and lower trapezius; and the upper and lower latissimus dorsi muscles) were recorded during active range of motion. RESULTS: At > 24 months of follow-up, the Constant and DASH scores and active shoulder range of motion improved in both groups (p < 0.0001). Internal rotation was significantly higher in the lateralized humerus group than in the medialized humerus and transfer group (p = 0.004). The dropping sign was found in 0/12 patients in the lateralized humerus group and in 5/13 patients in the medialized humerus and transfer group (p < 0.001). Kinematic findings were similar between groups (p = 0.286). A pattern of earlier muscle activation in the lateralized humerus group was found as compared to the transfer group as follows: (i) posterior deltoid during external rotation (p = 0.004); (ii) upper latissimus dorsi and middle and lower trapezius during flexion (p = 0.004, p = 0.005, and p = 0.042, respectively); (iii) lower latissimus dorsi during abduction (p = 0.016). CONCLUSION: RTSA with a lateralized humeral component provided similar active external rotation restoration to a Grammont-style RTSA with a l'Episcopo procedure in patients with a dropping sign. The posterior deltoid muscle underwent earlier activation during active external rotation in the lateralized humerus RTSA group as compared to the tendon transfer group. Our findings demonstrated the H1 and only partially demonstrated the H2 of the study.
Authors: Mark Frankle; Steven Siegal; Derek Pupello; Arif Saleem; Mark Mighell; Matthew Vasey Journal: J Bone Joint Surg Am Date: 2005-08 Impact factor: 5.284
Authors: Bryan Wall; Laurent Nové-Josserand; Daniel P O'Connor; T Bradley Edwards; Gilles Walch Journal: J Bone Joint Surg Am Date: 2007-07 Impact factor: 5.284