Evaluation of isometric strength and fatty infiltration of the subscapularis in latarjet surgery

Abstract

OBJECTIVE: To evaluate the function of the subscapularis muscle by means of isometric strength, clinical examination and analysis of fatty infiltration in patients with recurrent anterior dislocation of the shoulder undergoing Latarjet-Patte surgery. METHODS: 38 patients operated from March 2011 to March 2012, with minimum follow-up of two years were evaluated, being 26 males and 12 females, with a mean age of 28.7 years old. Isometric strength was measured using a portable dynamometer and measuring the distance from the back of the hand during the lift-off test. We used the Rowe and Walch-Duplay scores for clinical evaluation. The degree of fatty infiltration of the subscapularis belly was assessed by computed tomography. RESULTS: The mean scores in the Walch-Duplay and Rowe were 84.7 and 89.4, respectively. The mean distance to the back of the hand was 7.34 cm on the operated side and 8.72 cm on the opposite side (p <0.0001). The mean strength measured in the lift-off test was 0.38 kg lower than on the contralateral side (p = 0.001). There was no fatty infiltration of the subscapularis in 16 patients (42.1%). Sixteen patients (42.1%) were classified as Goutallier grade 1 and six (15.8%) as grade 2. We found that the measured isometric strength decreases with increasing the degree of fatty infiltration (p <0.0001). CONCLUSIONS: The decrease in subscapularis strength, albeit of low magnitude (0.38 kg), was directly related to the degree of fatty infiltration and worse clinical outcomes. Level of Evidence III, Therapeutic Study - Investigating the Results of Treatment.

Subscapularis structural integrity and function after arthroscopic Latarjet procedure at a minimum 2-year follow-up

“…In spite of satisfactory clinical and radiographic results, 4,29 one of the disadvantages of Latarjet is the potential dysfunction of the subscapularis muscle owing to atrophy, fatty degeneration, or tearing. 5,11,39 The arthroscopic technique could increase these risks because of the specific difficulties in some of the surgical steps, such as the subscapularis split and graft positioning. 9 Consequences of subscapularis split had been widely studied in the context of open instability surgeries and open Latarjet.…”

“…9 Consequences of subscapularis split had been widely studied in the context of open instability surgeries and open Latarjet. 5,[11][12][13]17,[36][37][38][39] However, outcomes of arthroscopic subscapularis split are still relatively unknown. This is the first study on the clinical, radiologic, and isokinetic performance of the subscapularis after arthroscopic Latarjet procedure at long-term follow-up.…”

“…33 Function of the subscapularis muscle has been widely studied after total shoulder replacements, open capsular shifts, Bankart repair, and more recently after open Latarjet procedures. 2,5,11,12,17,31,36,38,40 In Bristow-Latarjet procedures, subscapularis tenotomy seems to be related to weakness of the muscle confirmed by means of an isokinetic study. On the other hand, the outcomes of the splitting technique are controversial.…”

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“…O tempo de seguimento médio dos pacientes calculado por média ponderada foi de 35,4 meses. Nenhum estudo fazia seguimento com o tempo de avaliação padronizado, e 5 estudos [16][17][18][19][20] (42%) tinham tempo de seguimento mínimo dos pacientes maior do que 2 anos. Dez estudos 17,18,[20][21][22][23][24][25][26][27] (83%) eram séries de caso (nível de evidência IV), 1 (8%) estudo caso-controle 16 (nível de evidência III), e 1 coorte retrospectivo 19 (nível de evidência III).…”

“…Quatro estudos 16,22,24,26 (33%) avaliaram os resultados do tratamento da instabilidade glenoumeral anterior por via aberta, 3 (25%) estudavam a cirurgia de Latarjet-Patte, 16,22,26 e 1 (8%) estudou o reparo da lesão labial. 24 Em 8 publicações, [17][18][19][20][21]23,25,27 (66%) o reparo artroscópico das lesões labiais anteriores foi a técnica empregada, um desses avaliava o resultado desse procedimento associado ao remplissage da lesão de Hill-Sachs.…”