Although total shoulder arthroplasty (TSA) has proved to be a reliable solution in older patients, treatment in younger patients with glenohumeral arthritis remains controversial, and there are still few reliable long-term surgical options.1-8 These options include abrasion arthroplasty and arthroscopic management,9,10 biologic glenoid resurfacing,11,12 and humeral hemiarthroplasty with13 or without14,15 glenoid treatment and anatomical TSA.
In the younger cohort, 20-year TSA survivorship rates up to 84% have been reported, and unsatisfactory subjective outcomes have been unacceptably high.16 In addition, there is a paucity of literature addressing the impact of TSA on return to sport. Recommendations on returning to an athletic life style are based largely on surveys of expert opinion17,18 and heterogeneous studies of either older patients (eg, age >50-55 years) who are active19-21 or younger patients with no defined level of activity.5,7,8,16,22-24
To our knowledge, no one has evaluated the short-term morbidity and clinical outcomes within a young, high-demand patient population, such as the US military. Therefore, we conducted a study to evaluate the clinical success and complications of TSA performed for glenohumeral arthritis in a young, active population. We hypothesized that patients who had undergone TSA would have a low rate of return to duty, an increased rate of component failure, and a higher reoperation rate because of increased upper extremity demands.
Materials and Methods
After obtaining protocol approval from the William Beaumont Army Medical Center Institutional Review Board, we searched the Military Health System (MHS) Management Analysis and Reporting Tool (M2) database to retrospectively review the cases of all tri-service US military service members who had undergone primary anatomical TSA (Current Procedural Terminology code 23472) between January 1, 2007 and June 31, 2014. This was a multisurgeon, multicenter study. Patient exclusion criteria were nonmilitary or retired status at time of surgery; primary surgery consisting of limited glenohumeral resurfacing procedure, hemiarthroplasty, or reverse TSA; surgery for acute proximal humerus fracture; rotator cuff deficiency diagnosed before or during surgery; and insufficient follow-up (eg, <12 months, unless medically separated beforehand).
The M2 database is an established tool that has been used for clinical outcomes research on treatment of a variety of orthopedic conditions.25,26 The Medical Data Repository, which is operated by MHS, is populated by its military healthcare providers. The MHS, which offers worldwide coverage for all beneficiaries either at Department of Defense facilities or purchased using civilian providers, is among the largest known closed healthcare systems.
All active-duty US military service members are uniformly required to adhere to stringent and regularly evaluated physical fitness standards, which typically exceed those of average civilians. Routine physical training is required in the form of aerobic fitness, weight training, tactical field exercises, and core military tasks, such as the ability to march at least 2 miles while carrying heavy fighting loads. In addition to satisfying required height and weight standards, all service members are subject to semiannual service-specific physical fitness evaluations inclusive of timed push-ups, sit-ups, and an aerobic event. Service members may also be required to maintain a level of physical training above these baseline standards, contingent on their branch of service, rank, and military occupational specialty. If a service member is unable to maintain these standards, medical separation may be initiated.
Demographic and occupational data were extracted from the database. These data included age, sex, military rank, and branch of service. Line-by-line analysis of the Armed Forces Health Longitudinal Technology Application (Version 22; 3M) electronic medical record was then performed to confirm the underlying diagnosis, surgical procedure, and surgery date. Further chart review yielded additional patient-based factors (eg, laterality, hand dominance, presence and type of prior shoulder surgeries) and surgical factors (eg, surgery indication, implant design). We evaluated clinical and functional outcomes as well as perioperative complications, including both major and minor systemic and local complications as previously described27,28; preoperative and postoperative range of motion (ROM) and self-reported pain score (SRPS, scale 1-10) as measured by physical therapist and surgeon at follow-up; secondary surgical interventions; timing of return to duty; and postoperative deployment history. The primary outcome measures were revision reoperation after index procedure, and military discharge for persistent shoulder-related disability. Clinical failure was defined as component failure or reoperation. Medical Evaluation Board (MEB) is a formal separation from the military in which it is deemed that a service member is no longer able to fulfill his or her duty because of a medical condition.