An irreparable massive rotator cuff tear is a relatively common shoulder injury characterized by a torn and retracted tendon associated with muscle atrophy and impaired mobility. The symptoms can include pain due to subacromial impingement, muscle weakness in the shoulder joint, and limitation of arm elevation.
Despite the remarkable advances in arthroscopic techniques and technologies achieved over the last several years, irreparable massive rotator cuff tears remain challenging for surgeons to treat. Due to the tendon retraction and the resulting lack of healing potential, direct reattachment of the torn tendon to the humeral footprint is not possible. However, the superior capsule of the shoulder joint complements the insertion of the rotator cuff. With further insight into the anatomy of the superior capsule, surgeons can gain a better understanding of the function, injury, and repair of this structure.
An Acclaimed Shoulder Surgeon Pioneering New Treatment Techniques
Christopher C. Schmidt, MD, is a board-certified orthopedic shoulder surgeon who practices in Pittsburgh, Pennsylvania. Widely regarded as an expert among experts, Dr. Schmidt performs extensive research with a goal to improve the arthroscopic treatment of irreparable massive rotator cuff tears.
Working in collaboration with a multidisciplinary team of orthopedic surgeons, bioengineers, mechanical engineers, fellows, and residents, Dr. Schmidt recently performed a study to further explore the anatomy of the superior capsule and its role in the treatment of an irreparable massive rotator cuff tear. The abstract of this study is reproduced below.
Morphology of the Insertion of the Superior Capsule
M Smolinski1, S Delserro 1, PJ McMahon 3, MC Miller1, P Smolinski1,2, CC Schmidt1,2
1 Department of Mechanical Engineering and Material Science, University of Pittsburgh, PA
2 Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA
3 Veterans Administration Pittsburgh Healthcare System, Pittsburgh, PA
Disclosures: None.
INTRODUCTION: Reconstruction of the superior capsule for the treatment of cuff tears has been shown to improve patient-reported outcomes [1]. However, advanced measurement systems have yet to be used to study the insertion site anatomy of the superior capsule and additional information may be able to improve repair methods. Using advanced measurement techniques [2] this study was performed to precisely locate and measure the humeral and scapular insertions of the superior capsule.
METHODS: Following institutional approval, nine (n=9) fresh-frozen cadaveric specimens (average age 67.3 ± 2.6) without rotator cuff pathology were used in this study. The rotator cuff muscles were dissected individually from the capsule. Following the removal of each tendon, the superior capsule was carefully removed and outlined on the humerus and scapula. A laser scanning system (Faro, Inc.) was used to make three-dimensional models of each specimen [2]. Points along the perimeter of each footprint were digitized with a probe and incorporated into the models. The capsular insertion for each specimen was divided into three regions: spine, mid capsule, and coracohumeral ligament (CHL). The surface area was calculated, then the centroids for the spine and mid capsule on the humerus were calculated and measurements of the major (largest) dimension, the perpendicular dimension, and distance from each region’s centroid to the apex of the bicipital groove (BG) were taken (Fig. 1). For the CHL insertion on the humerus, the major and perpendicular dimensions were taken for each half of the insertion and the total area was measured (Fig. 1).
Figure 1: Superior capsule humeral insertion measurements of the spine (left), mid-capsule (middle) and coracohumeral ligament (right).
On the scapula, the centroid for each region was calculated and measurements along the surface of the major dimension and perpendicular dimension were taken as well as surface area (Fig. 2).
Figure 2: Superior capsule scapular insertion measurements of the spine (left), mid-capsule (middle) and coracohumeral ligament (right).
RESULTS: The major and perpendicular dimensions, surface area, and distance from the bicipital groove for each region of the superior capsule footprint are given in Table 1.
Table 1: Measurements of insertion site dimensions and areas on the humerus and scapula, position and area (Mean±S.D.).
DISCUSSION: The superior capsule has prominent insertion sites on the humerus and scapular having large areas but with varying geometries.
SIGNIFICANCE/CLINICAL RELEVANCE: Information on the anatomy of the superior capsule can provide surgeons with a better understanding of the function, injury, and repair of these structures.
REFERENCES: [1] Mihata, et al., Arthroscopy, 2013 [2] Fujimaki, et al., AJSM, 2016
If you would like to learn more about the superior capsule anatomy and its role in the arthroscopic treatment of irreparable rotator cuff tears, contact Dr. Schmidt’s office in Pittsburgh, PA, at (877) 471-0935 to request an appointment.