Total shoulder arthroplasty can help provide function and pain relief to those with arthritis of the shoulder that has failed to respond to conservative treatment. Anatomic total shoulder arthroplasty (aTSA) usage rose 17% between 2011 and 2014 [1,2]. While the popularity of reverse TSA has outpaced aTSA, estimates of 2012–2017 census data indicate that aTSA still accounts for just over a third of all shoulder arthroplasty in the United States [3]. Primary indications for aTSA include degenerative joint disease (92% of cases) followed by rheumatoid arthritis (4.1%), and aseptic necrosis of the humerus (2.2%) [3]. Outcomes of aTSA depend on many variables including patient anatomy, prosthesis type, stem length, surgical technique, rotator-cuff integrity, and bone deficiency, and subscapularis management (e.g., osteotomy, peel-off, tenotomy) can also play a role in planning postoperative management [4]. There is a consensus in the orthopedic community with regard to the importance and effectiveness of postoperative physical therapy (PT) following aTSA. The exact protocol that patients follow often depends on the quality of the soft tissue, age, expectations of the patient, and physician preference [5]. While there are several PT protocols published for patients undergoing aTSA, there is no standardized protocol for aTSA rehabilitation [5-8].

This lack of standardization may prove to be problematic because it may lead to confusion between patients and their physicians and less than ideal functional outcomes for patients. Our purpose in this study was to evaluate the degree of variability in the PT protocols published by Accreditation Council for Graduate Medical Education (ACGME) accredited orthopedic programs. We hypothesized that the protocols will vary among programs, specifically regarding the timing of various exercises and functional milestones.

The requirements for Institutional Review Board approval and informed consent were waived since this does not involve human subjects research. A list of academic orthopedic surgery institutions was obtained from the ACGME website. A web-based search was performed using an internet search engine (https://www.Google.com) using the search phrase “[program/hospital/medical school] total shoulder arthroplasty rehabilitation protocol” to identify publicly available PT protocols. Protocols for reverse total shoulder arthroplasty were excluded. Out of 175 accredited orthopedic surgery programs included in the search, 24 institutions (13.7%) had protocols publicly available with 25 total protocols included for review.

A single researcher (KDP) reviewed each rehabilitation protocol to ensure consistency in the data-collection process. Each protocol was analyzed to assess recommendations of length of immobilization, range of motion (ROM) goals, start times and progression of therapeutic and resistance exercises, and timing for a return to functional activity. Start times and milestones for specific exercises within each category were recorded. Data were collected and analyzed using descriptive statistics in Microsoft Excel (Microsoft Corp.). 

Our study found that a significant amount of variability is present in publicly available rehabilitation protocols for aTSA with regard to the duration of immobilization, length of movement restriction, timing of range-of-motion milestones, and inclusion and recommended start times of various therapeutic exercises. The most consistent components of the different protocols appear to be a recommendation of at least some period of sling immobilization, beginning distal extremity motion, and Codman pendulums immediately postoperatively. The variation in components of these protocols indicates a lack of consensus on the standard of care for PT protocol following aTSA. This is consistent with trends seen in rehabilitation protocols for other orthopedic operations [9-12].

Although early ROM is important in the early recovery phase to prevent stiffness, care must be taken to protect the subscapularis repair. The rate of subscapularis re-tear following aTSA ranges from 3% to 46%, and failure may result in anterior shoulder instability and weakness with internal rotation [13-16]. In general, excessive passive external rotation and active internal rotation are avoided to prevent stress on the subscapularis. Unfortunately, there is a paucity of evidence regarding precautions for protecting the subscapularis repair [5]. In a systematic review of proposed rehabilitation guidelines for shoulder arthroplasty, Bullock et al. [17] found no consensus among protocols with regard to internal rotation recommendations. Additionally, multiple studies in the review did not mention external rotation precautions [17]. Our study demonstrated similar results with approximately half of the available protocols having recommended restricted internal rotation and only 8% initial restriction of external rotation.

Despite the consensus that postoperative PT plays a critical role in return of function after aTSA, there exists no standardized guideline for rehabilitation for patients who have undergone aTSA [17]. There is a paucity of prospective literature comparing outcomes of different protocols and a paucity of prospective evidence as to how the components of PT protocols impact outcomes. In a prospective trial, Denard and Lädermann [18] found that immediate passive ROM following aTSA results in a more rapid return of function compared to delayed passive ROM; however, there was no significant difference in the ultimate ROM or functional outcomes between the two groups. Our study further demonstrates that while general concepts of protocols used by various programs are the same, there is minimal standardization of protocols for aTSA rehabilitation.

Even though standardization may lead to increased therapy efficacy and less confusion among patients, postoperative therapy targets and pacing must be tailored to the individual patient based on age, education, joint laxity, and ability to pay for rehabilitation as a recovery trajectory following aTSA. It depends on a multitude of factors such as underlying pathology, soft tissue quality, patient age, and patient expectations [5]. Therefore, it is recommended that PT protocols should not be based on strict timelines, but rather specified clinical criteria [5,19]. Time frames should still be used as approximate time frames to inform the patient and physician that the patient is progressing appropriately [5,19]. However, our study found that there is limited clinical criteria to guide progression, and the suggested time frames are highly variable. Standardization and clarification of these details among protocols will decrease confusion among patients and lead to higher chances of successful rehabilitation and return of function.

With the current economic stress on the healthcare system in the United States, there has been a shift in emphasis from volume to value-based care systems that focus on producing high-quality care that maximizes outcomes while minimizing the cost associated with treatment [20-23]. One component of the total cost of aTSA is formal physical therapist-supervised rehabilitation. As such, there have been studies seeking to determine if formal PT is necessary to ensure good outcomes following aTSA. Mulieri et al. [24] compared outcomes of a standard PT with a physician-guided home-based program and found that there were no significant differences in outcomes scored between the two groups at a final follow-up. Additionally, it has been shown that the use of formal PT following aTSA is higher in privately ensured patients [25]. As cost concerns become increasingly important, there is likely to be an increase in patients that choose to undergo home-based PT. As patients are given a more independent role in the recovery process, they are likely to consult online resources, and the current variability of results may lead to confusion that could impede progress. Furthermore, protocols that are made publicly available should be based on evidence and contain clear details on performing exercises to ensure patient success.

This study has limitations. This review was conducted by a single researcher who may have held observer bias or made measurement errors. Although there are 175 accredited programs, only 24 had publicly available aTSA rehabilitation protocols. This accounts for only a minority of programs and may not be representative of all PT protocols available to patients. This study may thus be subject to availability bias and nonresponse bias. Additionally, this study does not account for protocols provided by private practice physicians. Furthermore, this study is unable to assess how protocols vary based on the surgical technique used. 

Significant variability exists among publicly available aTSA rehabilitation protocols with regard to range-of-motion goals, recommended exercises, and timing for the initiation of various exercises with the initiation of an active and passive internal rotation and external rotation among the most varied across protocols examined. More work is needed to identify which PT factors impact outcomes of aTSA to maximize patient outcomes.