Rotator cuff injuries: clinical relevance of measurement of ROM

 Introduction

Rotator cuff (RC) is a dynamic stabilizer of the glenohumeral joint. Repetitive micro or macro-trauma placed on these structures can cause various degrees of injuries or tears. Rotator cuff injuries are common in overhead throwing and contact athletes. Up to 7000 to 8000 deg/s of humeral angular velocities can be seen with baseball pitching¹. This can result into tremendous stress on rotator cuff during acceleration and deceleration phase of throwing in order to keep humeral head centered on glenoid.¹

Besides some specific imaging modalities like MRI, arthrography, and ultrasonography, assessment of rotator cuff tear (RCT) is still challenging as the clinicians must correlate non-specific physical examinations ( such as the painful arc of motion, range of motion (ROM) deficit, muscle weakness) for proper evaluation, diagnosis, and treatment.

Research

Seo at al³ found a significant degree of preoperative stiffness in 39 (32 .7%) patients out of 119 patients with rotator cuff repair (RCR). Out of 39 stiffness result, 37 (37.7 ) patient had full thickness tear and 2 (2-5%) had partial thickness tear. In the same study, only one (14.2%) had stiffness in a group with anterosuperior RCT compare to 10 (58.8%) in posterosuperior RCT. Thus, this study suggests that assessment of ROM can indicate the type and direction of rotator cuff injuries and hence can be the indicator for the need of surgery.

Tauro⁴ examined pre-operative total ROM deficit (TROMD), an addition of ROM deficit of elevation, abduction, external and internal rotation of 72 patients and divided into; Group 1 with 0^o to 20^o TROMD, Group 2 with 25^o to 70^o TROMD and Group 3 with greater than 70^o TROMD. All patients underwent arthroscopic rotator cuff repair (RCR). Postoperatively, the average TROMD deficit decreased significantly in group 1 and 2. In group 3; 3 out of 6 patients show minimal or no improvement in postoperative ROM. Therefore, this study indicates that preoperative stiffness affects postoperative prognosis. It is therefore, important to restore preoperative ROM till possible before considering surgical RCR, for better postoperative prognosis and rehabilitation.

Dadson et al⁴ have highlighted focusing on restoration of ROM immediately after pain and inflammation subside following RCI. It should be then followed by extensive strengthening exercises as a non-operative treatment protocol to rotator cuff injuries.

Expansion

Rotator cuff injuries are common in overhead throwing and contact sports^2,5-8. Rotator cuff must be strong enough in order to provide additional dynamic stability in overhead athletes. They acquire laxity of a glenohumeral joint capsule to achieve the extreme range of motions.⁸  So, ROM and strength of RC throughout full ROM are primary concern before athletes go back to competitions after RCI.

Measurement of ROM helps to predict the location, type, and direction of rotator cuff injuries. As highlighted by Hertel et al,⁹ greater passive than active internal rotation indicates a tear of subscapularis while greater passive than active external rotation in abducted shoulder indicates a tear of infraspinatus. Seo et al³ found RCT in 30% of patients with shoulder stiffness. Thus, shoulder stiffness may be due to possible RCT and hence can be an indication for surgery. Seo et al³ also demonstrated significant stiffness in posterosuperior than in anterosuperior tears and in full thickness than in partial thickness tears. The study of McCabe et al¹⁰ has concluded that more than 50% of shoulder abduction strength and loss of AROM at 10^o abduction compared to normal side can be the indication of large or massive RCT.

Preoperative ROM affects prognosis

Preoperative limitation of motion affects postoperative prognosis. The retrospective evaluation of 72 arthroscopic RCR case studies by Tauro⁸ has shown minimal or no improvement in postoperative ROM with the patients having more than 70^o of preoperative total ROM deficit (addition of abduction, flexion, external and internal rotation). Namdari et al¹¹ demonstrated similar results with the mean 3 months post-RCR active flexion and external rotation in sitting and passive internal rotation with patient reaching behind the back were 90%, 78% and 80% of the contralateral shoulder respectively compared to 88%, 87% and 80% preoperatively. Similarly, significant postoperative loss of ROM was found in a patient with restriction of ROM for pre-operative hand behind the back test.¹² Many studies have suggested that ROM deficit may be treated as primary problem before considering a RCR.^13-15

Restoration of ROM is primary

 Restoration of ROM should be the primary focus when possible after rotator cuff injury. It should be then followed by strengthening of muscles throughout full ROM.^2,16 Evaluation of ROM following RCR is very important. Loss of active motion with intact passive motion may indicate RCR failure, muscle atrophy or nerve injuries. Loss of both active and passive motion with good muscle strength indicates postoperative adhesions or contractures.¹⁴ Limitation of motion after RCR is a function limiting complication.¹⁶  So, regular measurement of ROM and possible early ROM exercises/joint mobilization is important to regain ROM. Similarly, rehabilitation regimen proposed by Koo et al¹³ with early closed chain passive overhead motion have a significant reduction in the incidence of postoperative stiffness.

Summary

In conclusion, patient dissatisfaction with his/her ROM after rotator cuff injuries is the most clinical relevant aspect of defining ROM and its clinical importance. Also, goniometric measurement of shoulder ROM shows significant reliability and validity.¹⁷ Thus, objective measurement of shoulder ROM has significant clinical value during an assessment, conservative rehabilitation, and postoperative prognosis and rehabilitation of rotator cuff injuries.

Reference