Prophylactic Conjoint Tendon Lengthening During Reverse Shoulder Arthroplasty Outcomes

Prophylactic Conjoint Tendon Lengthening During Reverse Shoulder Arthroplasty: is There a Difference in Anterior Shoulder Pain At One Year After Surgery?

Some patients may experience persistent pain in the front of their shoulder after reverse shoulder replacement. One of the possible reasons for this is that the surgery causes a change in the alignment of the shoulder joint, which may cause increased tension and compression on one of the biceps tendon called the conjoint tendon. The purpose of this study is to evaluate whether conjoint tendon lengthening, a surgical procedure that involves cutting and lengthening the conjoint tendon in order to reduce tension and compression, is able to prevent or reduce the risk of anterior shoulder pain at one year after surgery.

Reverse shoulder arthroplasty (RSA) is a surgical procedure that is used to treat severe shoulder arthritis with rotator cuff damage. RSA involves reversing the ball and socket of the shoulder joint, such that the ball is attached to the shoulder blade and the socket is attached to the upper arm bone. This allows the deltoid muscle to take over the function of the rotator cuff and provide more stability and mobility to the shoulder. RSA has been shown to improve pain, function, and quality of life in patients with various shoulder conditions, such as rotator cuff tear arthropathy, glenohumeral osteoarthritis, complex proximal humeral fractures, pseudoparalysis, and revision shoulder arthroplasty.

However, some patients may experience persistent anterior shoulder pain after RSA, which can limit their function and quality of life. The exact cause and prevalence of this complication are not well understood, but several possible mechanisms have been proposed, such as impingement, instability, infection, nerve injury, fracture, scapular notching, and conjoint tendinitis.

Conjoint tendinitis is a condition where the tendon that connects the coracoid process to the upper arm bone, called the conjoint tendon, becomes inflamed and painful. The conjoint tendon is part of the biceps muscle and the coracobrachialis muscle, and it plays a role in shoulder flexion and internal rotation. Conjoint tendinitis may occur after RSA due to the increased tension and compression on the anterior shoulder caused by the shift in the center of rotation of the joint. Conjoint tendinitis may manifest as anterior shoulder pain, tenderness over the coracoid process, and decreased range of motion and strength.

Conjoint tendon lengthening (CTL) is a surgical procedure that involves cutting or lengthening the conjoint tendon, which may relieve the pain by reducing the tension and compression on the anterior shoulder. CTL can be performed as a primary procedure during RSA, or as a secondary procedure after RSA. The rationale for performing CTL as a primary procedure is to prevent the development of conjoint tendinitis and anterior shoulder pain after RSA. The rationale for performing CTL as a secondary procedure is to treat the patients who have failed conservative treatments, such as physical therapy, injections, or medications, and have persistent anterior shoulder pain after RSA.

The literature on CTL for anterior shoulder pain after RSA is scarce and mostly consists of case reports and case series. There is no randomized controlled trial or systematic review on this topic. The existing studies have reported favorable results of CTL, with improvement in pain, function, and patient-reported outcomes. However, the studies have also acknowledged the limitations of their methods, such as small sample size, lack of control group, short follow-up, and potential bias. Therefore, the evidence for the effectiveness of CTL for anterior shoulder pain after RSA is weak and inconclusive.

The gap or problem that this research aims to address is the lack of high-quality evidence on the effectiveness of prophylactic CTL during RSA for preventing or reducing anterior shoulder pain at one year after surgery. The investigators hypothesize that patients who undergo prophylactic CTL during RSA will have less anterior shoulder pain at one year after surgery than those who do not. The investigators will test this hypothesis by conducting a randomized controlled trial with two groups: CTL group and control group. The investigators will compare the pain intensity, range of motion, strength, activity level, and patient-reported outcomes of the two groups at 6 months and 12 months after RSA. The investigators will also identify the factors that predict the response to CTL, such as age, gender, body mass index, comorbidities, duration of pain, and severity of arthritis. This research will contribute to the knowledge in the field of shoulder surgery by providing high-quality evidence on the effectiveness of prophylactic CTL during RSA for anterior shoulder pain. This research will also have practical implications for the field of shoulder surgery by providing a viable option for patients who suffer from anterior shoulder pain after RSA, and enhancing their function and quality of life.

Inclusion Criteria:

• Patients who are at least 18 years old undergoing primary reverse total shoulder arthroplasty
• Operations that occur at Loyola University Medical Center (Maywood, IL), Loyola Ambulatory Surgery Center (Maywood, IL), or Gottlieb Memorial Hospital

Exclusion Criteria:

• Patients younger than 18 years old
• Patients who had prior coracoid transfer procedure
• Patients who are undergoing revision surgery from a prior arthroplasty
• Current pregnancy As per standard protocol with all surgeries, a urine pregnancy test is performed prior to surgery. If positive, the surgery will be cancelled and the patient will be excluded from the research study.