Shoulder replacement complications

Ross A. Hauser, MD., Danielle R. Steilen-Matias, PA-C.

Many patients have excellent outcomes following shoulder replacement surgery. Some people do not have success and have resulting complications. This article will review some of the more recent research surrounding complications.

People have very successful shoulder replacements, some doctors suggest, however, shoulder replacement surgery may make things worse. How do you know who you are?

Complications from shoulder replacement surgery are a risk factor of the surgery. That is well understood and has concerned doctors for many years.  Back in 2015, researchers from Texas Orthopedic Hospital, the University of Houston, University of Texas, (1) noted great increases in the number of shoulder replacements being performed and that with more shoulder replacements being done, more shoulder replacement revision surgeries with be needed to address complications from the first surgery.

• In this paper 21.6% of patients followed post-surgery  (8 out of 37 patients) required a second surgery for postoperative complications.
• Overall, 54% of patients (20 out of 37) suffered from intra- or postoperative complications.

The paper concluded that shoulder replacement improved function in many patients, but with a high rate of complications and reoperations.

That was then. In 8 years since the same complication rates and concerns exist.

In September 2022, research from the Medical College of Georgia at Augusta University published in the Journal of orthopaedics (2) assessed the risk factors for shoulder instability following reverse total shoulder replacement in patients with no history of shoulder surgery.

In this study of 194 reverse total shoulder replacements, a small number of patients, seven, just over 3.5% sustained a  post-surgery dislocation. On average that shoulder dislocation occurred 60 weeks after the surgery. Five of the seven patients had a re-operation using larger hardware to keep the shoulder in place, one had bone spurs removed, time to dislocation was 60.4 weeks. Five required open reduction with placement of either a larger humeral tray or polyethylene spacer. One required open reduction with osteophyte removal, and one was converted to a resection arthroplasty (the ball of the shoulder or prosthesis is removed and this is considered salvage operation of failed shoulder replacement). The researchers suggested based on data that dislocations were an uncommon complication, but were clearly associated with overweight and obese patients, worse health, and increased liner size (the part of the prosthetic was large).

The list of shoulder replacement complications – pain after shoulder replacement.

An October 2019 study (3) outlined to radiologists what they needed to look for in an MRI and x-rays of patients complaining of pain after shoulder replacement. The research came from the Angers University Hospital in France and was published in the European Society of Radiology’s journal Insights Into Imaging.

• Shoulder arthroplasties are divided into three categories: reverse shoulder arthroplasty, total shoulder arthroplasty, and partial shoulder joint replacement (including humeral hemiarthroplasty and humeral head resurfacing arthroplasty).
  • Each of these prostheses can present complications, either shared by all types of replacement or specific to each. The complications included:
    • Infection.
    • Periprosthetic fractures.
    • Humeral component loosening
    • Heterotopic ossification. (The development of bone in soft tissue where bone should not be. Typically treated with cortisone, physical therapy or surgery to remove the bone pieces).
    • Implant failure, and nerve injury.
  • Specific to reverse shoulder replacement implantation:
    • Instability.
    • Scapular notching. (The implant is rubbing against the scapular).
    • Acromial fractures.
  • Specific complications of total shoulder replacement:
    • Glenoid component loosening.
    • Rotator cuff tear
      • Side note reference: A February 2023 German paper (23) explained glenoid loosening, including protrusion (the prosthetic part of the replacement has loosened and is now sticking out), rotator cuff insufficiency, including instability, and early/late infection as primary concerns. These concerns can be addressed by replacing the bone of the glenoid socket defects but can still include post-operative complications including dislocation, component loosening, and infection. They do note: “Revision of anatomical to reverse arthroplasty shows better clinical outcomes and lower complication rates than anatomical revision.”
  • Specific to partial shoulder joint replacement:
    • Progressive wear of the native glenoid.

The authors noted: “Knowledge of (these) different types of shoulder (replacement implants) prostheses and their complications’ radiological signs are crucial for the radiologist to initiate prompt and adequate management.” In other words, the above provides a list to radiologists looking for the source of pain following a shoulder replacement.

Complication challenges some patients face after reverse shoulder replacement

A March 2021 paper in the journal Clinics in Shoulder and Elbow (4)  lists the complication challenges some patients face after reverse shoulder replacement. Here is what these researchers wrote:

“Reverse shoulder arthroplasty is an ideal treatment for glenohumeral dysfunction due to cuff tear arthropathy (degenerative disease). As the number of patients treated with reverse shoulder arthroplasty is increasing, the incidence of complications after this procedure also is increasing.

The rate of complications in reverse shoulder arthroplasty was reported to be 15%-24%.

Recently, the following complications have been reported in order of frequency:

• periprosthetic infection,
• dislocation,
• periprosthetic fracture,
• neurologic injury,
• scapular notching (a wearing away of the scapular)
• acromion or scapular spine fracture,
• and aseptic loosening of the prosthesis.

However, the overall complication rate has varied across studies because of different prostheses used, improvement of implant and surgical skills, and different definitions of complications.”

Understanding the reverse total shoulder replacement and conventional shoulder replacement surgery.

When conventional total shoulder replacement is judged not to be effective, a reverse total shoulder replacement may be suggested as an option.

The procedure of a reverse shoulder replacement sounds exactly as it is named. In a traditional shoulder replacement,  a plastic “cup” is fitted into the shoulder socket (glenoid), and a metal “ball” is attached to the top of the upper arm bone (humerus). In a reverse total shoulder replacement, the socket and metal ball are switched.

Let’s look at the last few years of research to see the development in popularity of the reverse shoulder replacement. The benefits and realistic application use of the reverse procedure are studied in a paper published in the medical journal Orthopedics (5) in 2016.

• The paper suggests that a reverse total shoulder arthroplasty is better suited for older patients with glenohumeral arthritis and a deficient rotator cuff.
• However, as a semi-constrained prosthesis, (that is implants that create artificial stability by limiting the prosthesis range of motion) a conventional reverse total shoulder replacement in a young patient could fail over time because of the polyethylene wear and subsequent osteolysis – the joint replacement causes accelerated bone loss. 

Postoperative outcomes are disappointing, and the complication rate is high

• The researchers in the current study suggest at first that a metal-on-metal prosthesis may avoid this type of failure. However, they concluded: “Although metal-on-metal total shoulder replacement may appear to be an attractive choice in the treatment of young patients with limited reconstructive options, postoperative outcomes are disappointing, and the complication rate is high.”

Shoulder strength after reverse shoulder replacement

A November 2019 study (6) from Turkish doctors compared the isometric strength and endurance of shoulder abduction and internal and external rotation in a patient’s shoulder that had a reverse shoulder replacement because of rotator cuff failure and the same patient’s other shoulder that did not have a shoulder replacement surgery.

These patients had degenerative rotator cuff disease, the group of 41 patients had an average age of about 71 years old. Each patient had the rotator cuff damage significant enough for shoulder replacement in one shoulder but not the other. The point of the study was to see how close the shoulder replacement could get the strength of the operated shoulder to that of the non-operated shoulder. After an average 34 month follow-up, many patients showed marked improvement in functional ability in the operated shoulder. The researchers found in this group of patients, durability and strength of abduction (Straightening your arm outwards and lifting your arm from the side as high as it will go), similar results with the unaffected shoulder may be accomplished (just as good as the non-operated shoulder); nonetheless, the surgeon should be aware that durability and strength of rotation would be weak. (Rotational ability of the shoulder did not meet that of the non-operated shoulder).

Finding out why strength could not be returned to certain range of motions of the shoulder has lead some researchers to explore subscapularis repair. The subscapularis is the tendon that runs in front of the shoulder.

In December 2021 (7) doctors from The University of California Los Angeles, Dartmouth College, The Steadman Philippon Research Institute suggested in patients examined that “There is no differences in abduction, internal rotation, or external rotation strength after reverse total shoulder arthroplasty with or without subscapularis repair. . . However, consensus has yet to be reached on whether postoperative strength after reverse total shoulder replacement differs based on subscapularis management.

Overuse or “radical use of reverse total shoulder replacement in patients without rotator cuff deficiency may cause more harm than good.

When considering a shoulder replacement, many people are given the choice or are suggested one or another type of shoulder replacement. An August 2022 study in the journal Medicine (8),

“Reverse total shoulder replacement, which was originally designed mainly for irreparable rotator cuff damage, has gained popularity in recent years for the treatment of advanced shoulder osteoarthritis instead of the clinically standard total shoulder replacement. However, this Reverse total shoulder replacement has some nonnegligible flaws such as higher complication rates and economic cost (this means that the patient required much more medical services), not to mention the following problems caused by irreversible physical structural damage. Therefore, the employment of reverse total shoulder replacement needs to be carefully considered.”

What the researchers did in this study was to compare reverse total shoulder replacement with standard total shoulder replacement in osteoarthritis patients with or without rotator cuff damage. The focus being on rotator cuff damage and recommendations that could help surgeons in their clinical decision-making process.

What the researchers noted was that they believed the overuse of “radical use of reverse total shoulder replacement in patients without rotator cuff deficiency may cause more harm than good. The researchers then assessed the medical records of 57,156 shoulder replacement patients. Patients were divided into 2 groups according to the presence of rotator cuff deficiency.

• Reverse total shoulder replacement patients in the rotator cuff deficiency group had significantly higher transfusion rates and longer hospital stays.
• Reverse total shoulder replacement patients without rotator cuff deficiency had a statistically significantly higher number of implant-related mechanical complications, acute upper respiratory infections, and postoperative pain.
• Overall, reverse total shoulder replacement incurred higher costs in both groups.
• For osteoarthritis patients with rotator cuff deficiencies, Reverse total shoulder replacement has its benefits as complication rates were comparable to total shoulder replacement. For those patients without rotator cuff deficiencies, the use of reverse total shoulder replacement should be reconsidered as there were more complications with higher severity.

Acromial fractures and scapular spine fractures post-operatively

Doctors at the Rothman Orthopaedic Institute, University of Florida and the Mayo Clinic, Jacksonville (9) examined complications following reverse total shoulder replacement and how osteoarthritis and bone spurs at the acromioclavicular joint could lead to acromial and scapular spine fractures. This study was conducted on 11 patients who underwent primary reverse shoulder replacements (8 women and 3 men) with six of the patients having acromial fractures post-operatively and five having scapular spine fractures. The average age of the patient was about 70 years old. When these patients were compared to 44 control patients who did not suffer a post-surgical fracture the researchers found that patients with the fractures had worse acromioclavicular joint osteoarthritis osteoarthritis and larger bone spur formation. The researchers concluded, “acromioclavicular joint osteoarthritis  is common in patients undergoing reverse shoulder replacements. Severe acromioclavicular joint osteoarthritis  with completely spanning or fused osteophytes (bone spurs) may predispose patients to acromial or scapular spine fractures after reverse shoulder replacements.”

Shoulder replacement works better for older patients…but complications, and painkiller use, are still a concern to surgeons

A September 2023 paper (10) suggested that shoulder replacement in patients 80 years and older “are safe and effective, demonstrating low rates of perioperative mortality and reoperation, durability that exceeds patient longevity, satisfactory postoperative range of motion, and excellent pain relief.”

An August 2023 paper in the journal Cureus (11) aimed to determine the change in functional capacity and quality of life in patients who underwent reverse shoulder replacement due to rotator cuff tear damage and degeneration.  The researchers found that reverse shoulder replacement for rotator cuff tear damage leads to an improvement in functional outcomes and quality of life. Although there was a considerable improvement after surgery the shoulder in patients 65 years or younger, many did not achieve a “normal” shoulder based on function and pain scores. Many patients over the age of 65 did.

People have failed shoulder surgeries and researchers say: “no adequate explanation in the literature” can provide a reasonable explanation why.

Now let’s look at a University of Copenhagen paper published in June 2022 (12). Here the study team found: “worse outcomes for patients with previous surgery for instability independent of age, sex, and arthroplasty (the type of shoulder surgery, whether it was shoulder resurfacing or shoulder replacement, reverse or traditional) type. The reason cannot be deduced from our study and there is no adequate explanation in the literature. Several factors could, in theory, have an adverse effect on the outcome for these patients. A long history of instability and previous surgery may lead to eccentric glenoid wear and subsequently a technically demanding operation with risk of persisting instability, subluxation of the humeral component, or loosening of the glenoid component.”

Soft tissue damage after shoulder replacement, a leading cause of surgery failure

In September 2019, a paper in the Clinics in Orthopedic Surgery (13) noted that “The majority of patients with shoulder instability after anatomic shoulder arthroplasty (replacement) have both soft tissue imbalance and component malposition. Rotator cuff (surgical) repair after shoulder replacement has also had a poor success rate. Additionally, revision surgery with anatomic components and soft tissue reconstruction has had a high failure rate. Consequently, both instability and symptomatic rotator cuff dysfunction after anatomic shoulder arthroplasty are preferably treated with revision to a reverse prosthesis.” In common terms, Reverse shoulder surgery.

Obesity is a complication concern in shoulder replacement

• Doctors at the University of Alabama at Birmingham found that patients suffering from Metabolic syndrome, that is large waistlines (obesity), high triglyceride levels, high cholesterol, high blood pressure, and high cholesterol, are associated with considerable complication risk before, during, and after shoulder replacement surgery. (14)

Doctors from the Mayo Clinic writing in the Journal of Bone and Joint Surgery discuss the problems of obesity caused in patients after shoulder replacement surgery.

Here is what they said:

• Increasing Body Mass Index (Obesity) was associated with an increased risk of the need for a second or revision surgical procedure, reoperation, revision for mechanical failure, and superficial infection.
• Increased BMI was also associated with an increased risk of revision for mechanical failure.
• The most marked association between increasing BMI and any complication in shoulder arthroplasty was its association with superficial wound infection.
• It is important to consider these findings when counseling patients, estimating risks and estimating complication risks in policy decisions. (15)

Malnutrition, obesity, and anemia

A January 2022 study published in the Journal of Shoulder and Elbow Surgery (16) added to this by suggesting: “Malnutrition, obesity, and anemia contribute to significantly higher costs after shoulder arthroplasty. Medical strategies to optimize patients before shoulder arthroplasty are warranted to reduce total 90-day encounter charges, length of stay, and risk of readmission within 90 days of surgery. Optimizing patient health before shoulder surgery will positively impact outcomes and cost containment for patients, institutions, and payors after shoulder arthroplasty.”

Obese patients do get benefits

Another January 2022 study published in the Journal of Shoulder and Elbow Surgery (17) suggested: “Both non-obese and obese patients can expect clinically significant improvements in pain, motion, and functional outcome scores following (shoulder and reverse shoulder replacement). Obese patients reported significantly more postoperative pain, lower outcome scores, and less ROM compared with non-obese patients after both (shoulder and reverse shoulder replacement) at an average follow-up of 5 years.”

Treatment after you had shoulder replacement

In this section, we will address how we may be able to help a patient after they had shoulder replacement surgery. It makes our job here at Caring Medical a little more difficult when treating a patient who has had an extensive procedure, but it is still possible to achieve healing after surgery.

Exercise and physical therapy after reverse shoulder replacement

A January 2023 paper (18) in the Journal of shoulder and elbow surgery compared range of motion (ROM) and patient-reported outcomes (PROs) between a structured home exercise program (HEP) and active, supervised physiotherapy (PT) after primary Reverse Total Shoulder Arthroplasty. 89 patients were randomized, 43 to PT, and 46 to the home exercise program (HEP).

Patients undergoing primary Reverse Total Shoulder Arthroplasty at two medical centers were randomized to either a home exercise program group (46 patients), in which they were given a handout and a rope pulley, or a supervised physiotherapy group (43 patients), in which they were given a standardized program.

• Complications occurred in 13% of home exercise programs and 17% of supervised physiotherapy (PT) patients. Elsewise, there were no significant differences between groups at the final follow-up. These findings suggest that it may not be necessary to recommend PT as a protocol for all patients after Reverse Total Shoulder Arthroplasty.

We see many patients following failed surgery or failed physical therapy. Not every treatment will work for every patient. Some people will experience great surgical results, some will not. Some people will experience great physical therapy results, some will not. Our own treatments offered here at our center show patients who experienced outstanding outcomes, some people had good outcomes, and some people had poor outcomes. Why there are many factors to treatment success and failure.

In this video, Danielle R. Steilen-Matias, MMS, PA-C discusses treating nerve pain following shoulder surgery.

It is not uncommon for us to see patients after shoulder surgery who continue to have shoulder instability issues. Other times we will see patients after shoulder surgery who have continued pain. It may be the same pain that they had before surgery or it may be a different type of pain. What we find in many of these people is that even though healing is occurring and the shoulder looks well, the pain they are having is related to the nerves that may have been impacted during the surgery. We treat these patients with Nerve release injection therapy or more commonly hydrodissection.

Nerve Release & Regeneration Injection Therapy

NRRIT is a nerve hydrodissection technique that is highly successful in releasing peripheral nerve entrapments. It is a quick, straightforward process injection procedure often providing instant relief results for the patient! In the procedure, the practitioner uses ultrasound guidance to identify the nerves being entrapped. Next, simple dextrose is injected around the nerve to nourish the nerve and mechanically release it from the surrounding tissue, fascia, or adjacent structures.

What are we seeing in this image?

Nerve Release Injection Therapy (hydrodissection) of an entrapped nerve. In this image, a 5% dextrose solution is injected around the nerve which releases or separates it from the surrounding tissue. The nerve, which is the central circular object has a dark ring forming around it, as seen strongly in the B image. That is the dextrose solution from the needle, the straight image from the right of the screen. The nerve as seen in B is now surrounded by the nerve-release fluid and therefore “released.”

Revision Surgery

Another study from Dr. Pascal Boileau of the Department of Orthopedic and Sports Surgery Pasteur 2 Hospital, University Institute of Locomotion and Sports in France examined outcomes and complications in young patients undergoing revision reverse total shoulder arthroplasty (RTSA) for failed prior total shoulder arthroplasty or ball replacement and compared them with those of older patients undergoing the same procedure.

• While reverse total shoulder arthroplasty is effective in reducing pain and improving function after failed arthroplasty in young patients, complication rates are high and expectations should be managed appropriately. Subjective outcome scores are worse for older patients. (19)

German orthopedic surgeons noted in their January 2023 paper (20) that “current data show a mean complication rate for reverse shoulder replacement of around 4%. The most common complications are instability, infection, component loosening, and periprosthetic fracture. . . Also, “Revision surgery for reverse shoulder replacement is challenging, and an individual treatment plan is necessary.”

Complications leading to re-operation are often multiple and underestimated

• Shoulder replacement infection: In another study, doctors say that one of the greatest risk factors for infection after shoulder replacement was a history of prior failed shoulder surgery. So replacing the shoulder in an attempt to fix the first shoulder surgery had a high risk of infection.

Back to the study from Dr. Boileau: The most common causes of revision surgery after reverse total shoulder arthroplasty (RTSA) are:

• prosthetic instability (38%),
• infection (22%),
• humeral problems (21%) including loosening, unscrewing, and fracture,
• and, lastly, problems of polyethylene glenoid loosening (13%).

Why was the patient sent to a revision shoulder replacement? What were the revision surgery complication rates?

An August 2021 study comes to us from the Brighton and Sussex Medical School and the University Hospitals Sussex and Dorset in the United Kingdom. It was published in the journal Bone & joint open. (21)

The researchers of this paper told their fellow physicians that “it is important to understand the rate of complications associated with the increasing burden of revision shoulder arthroplasty (replacement). Currently, this has not been well quantified. This review aims to address that deficiency (lack of understanding of what is causing the complications and what can realistically be done about it) with a focus on complication and reoperation rates, shoulder outcome scores, and comparison of anatomical and reverse prostheses (should you get the anatomically correct shoulder replacement of the reverse shoulder replacement) when used in revision surgery.”

Why was the patient sent to a revision shoulder replacement? According to the researchers, the indications for revision include:

• Component loosening 20% (601/3,041 patients),
• Shoulder instability 19% (577/3,041 patients),
• Rotator cuff failure 17% (528/3,041 patients), and
• infection 16% (490/3,041 patients).

The complications after the revision shoulder replacement were recorded as:

• Intraoperative complication (a complication that arose during the revision surgery, during surgery) was 8% (this was measured as 230 shoulder complications out of 2,915 patients in the study).
• Postoperative complication was 22% (825 of 3,843 patients in the study).
• Reoperation rates were 13% (584 of 3,843 patients in the study).

The researchers then left us with these take-home messages:

• Revision to reverse total shoulder arthroplasty is associated with better outcomes than revision to anatomical total shoulder arthroplasty (better to have a reverse shoulder replacement the second time around).
• Intraoperative complication rate was 8%, postoperative complications rate was 22%, and reoperation rate was 13% following revision shoulder arthroplasty. (Revision shoulder surgery has a high complication rate).
• Outcomes from revision shoulder arthroplasty show clinically important improvement in patient-reported outcome measures. (Many people got great benefits from the revision shoulder replacement).
• Revision to reverse geometry total shoulder replacement rather than to anatomical total shoulder replacement from any index (primary procedure whether reverse or anatomically correct shoulder replacement)  procedure appears to result in lower complication rates and better postoperative outcome scores.

The realistic assessment of revision total shoulder replacement. The revision surgery is a high risk, if it works out the patient is better off. If it does not work out?

A June 2020 study in the journal Current Reviews in Musculoskeletal Medicine (22) offers a surgeon’s eye view of the realistic outcomes following failed shoulder surgery:

“Despite relatively high complication and reoperation rates with revision shoulder replacement, revision of failed hemiarthroplasty or total shoulder arthroplasty to reverse total shoulder arthroplasty improves outcomes for many patients. A failed hemiarthroplasty or total shoulder arthroplasty is frequently disabling for the patient and because the surgical revision options are often limited only to reverse total shoulder arthroplasty, the potential improvement is often worth the higher surgical complication or reoperation rate.”

The revision surgery is a high risk, if it works out the patient is better off. If it does not work out?

A June 2019 study in the Journal of Shoulder and Elbow Surgery (24) found good results for the revision surgery. The learning points of this study were:

• In the 110 patients involved in the study, the revision surgery implant survival was 92% at 2 years and 74% at 5 years.
• Seventy percent of patients were “very satisfied” or “satisfied with their outcome.
• Complications occurred in 18 patients (20%), and 10 patients (11%) underwent re-operation.

It is the last group of people that we usually see in our office looking for non-surgical help.

Also see these articles

Shoulder replacement complications in the Ehlers-Danlos Syndrome Patient

Shoulder replacement options

References

• Surgery
• NSAIDs
• Cortisone Shots
• R.I.C.E.