Arthroscopic-Assisted Core Decompression of Humeral Head Osteonecrosis With Bone Marrow Aspirate Concentrate Augmentation

Abstract

Background:

The proximal humerus is the second-most common anatomic site for osteonecrosis, a condition of disrupted blood supply leading to death of bone tissue, with resultant shoulder pain and dysfunction. Core decompression is a viable joint-preserving surgical intervention that aims to improve local blood supply and restore bone health prior to bony collapse.

Indications:

Humeral head osteonecrosis has numerous underlying causes, most commonly the sequelae of prior trauma, chronic use of systemic corticosteroids, sickle cell disease, and alcohol abuse. Core decompression may be indicated in the early, pre-collapse stages of osteonecrosis, whereas more advanced stages of disease are commonly indicated for joint reconstruction procedures, such as bone grafting or arthroplasty.

Technique Description:

With the patient in the beach chair position, bone marrow aspirate concentrate (BMAC) is harvested through a percutaneous incision along the anterolateral proximal humerus. While viewing through a standard posterior portal, a transtibial anterior cruciate ligament (ACL) guide is placed through an anterior portal at a site on the humeral head surface, centered at the area of greatest humeral head bone edema as identified on preoperative magnetic resonance imaging. A guide pin is placed through a lateral portal within the ACL guide, to the subchondral bone. A 7.0-mm reamer is applied over the guidewire, followed by administration of demineralized bone matrix soaked in BMAC into the reamed channel within the proximal humerus.

Results:

In patients with early stages of humeral head osteonecrosis, core decompression confers superior clinical outcomes with reduced rates of subsequent surgical procedures compared with nonoperative treatment. Core decompression has shown to reduce the radiographic progression of osteonecrosis. Further research is necessary to determine the additional clinical benefits of augmentation with orthobiologic agents, such as BMAC.

Conclusion:

Arthroscopic-assisted core decompression is a valuable, minimally invasive surgical treatment for early-stage proximal humerus osteonecrosis. Adjunctive treatment with BMAC and demineralized bone matrix may enhance clinical outcomes.

Patient Consent Disclosure Statement:

The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Graphical Abstract

This is a visual representation of the abstract.

Video Transcript

The following is a video presentation describing our surgical technique for arthroscopic-assisted humeral head core decompression augmented with bone marrow aspirate concentrate (BMAC) for osteonecrosis.

These are our disclosures and the authors’ full disclosures are available online.

In this video, we will provide a brief overview of humeral head osteonecrosis, review indications for core decompression, discuss a case presentation along with surgical pearls, describe our postoperative management, and review patient-reported outcomes.

Osteonecrosis, also known as avascular necrosis, is a pathologic condition characterized by disrupted blood supply to subchondral bone. After the femoral head, the humeral head is the second-most frequently affected anatomic site. Humeral head osteonecrosis has numerous underlying causes, most commonly the sequelae of prior trauma, chronic use of systemic corticosteroids, sickle cell disease, and alcohol abuse. ¹ Cruess et al ² characterized the progression of humeral head osteonecrosis into 5 stages. In stages 1 to 3, the humeral head maintains its sphericity on radiographic imaging, whereas humeral head flattening and collapse denote stages 4 and 5, respectively. Unlike the femoral head, the humeral head is a nonweightbearing joint, and therefore the onset of symptoms associated with humeral head osteonecrosis may occur at a more advanced stage of disease.

Magnetic resonance imaging (MRI) is used commonly to identify patterns of subchondral bone edema that predate radiographic changes. The size and location of signal changes within the humeral head that are identified on MRI dictate the location of a planned core decompression.

Core decompression may be indicated in the early, pre-collapse stages of osteonecrosis, such as stages 1 to 3. Decompression, which can be performed via an open or arthroscopic approach, aims to promote and restore vascularization of the humeral head subchondral bone through local stimulation and by reducing pressure within the subchondral bone marrow.^4,6,7 For more advanced stages of disease, joint reconstruction options are favored over core decompression.

In this case presentation, a 16-year-old left hand–dominant male presented with 4 months of bilateral, right greater than left, shoulder pain. He first noticed pain while performing overhead weightlifting exercises. The patient's medical history was notable for acute lymphoblastic leukemia, first diagnosed approximately 15 months prior to presentation and now in remission. Throughout 1 year of treatment, he was prescribed a high-dose steroid regimen consisting of 60 mg twice per day for 5 days each month. The patient complained primarily of diffuse shoulder pain, exacerbated with overhead activities.

On physical examination of the right shoulder, the patient demonstrated active forward elevation to 160°, external rotation to 70°, and internal rotation to T10 with pain. He demonstrated 5 out of 5 rotator cuff strength in all planes and had no tenderness over his bicipital groove or acromioclavicular joint. He was neurovascularly intact.

Standard shoulder radiographs demonstrate preserved glenohumeral joint space with early evidence of humeral head subchondral lucency without collapse.

The MRI of the right shoulder was consistent with stage 3 humeral head osteonecrosis, with subchondral bony edema and crescent sign.

Given the combination of the patient's symptoms and MRI evidence of humeral head osteonecrosis, the patient was indicated for a right shoulder diagnostic arthroscopy and arthroscopic-assisted humeral head core decompression with injection of demineralized bone matrix (DBM) and BMAC.

In the operating room, the patient was placed in the beach chair position. After standard preparation and sterile draping, bone marrow aspirate was harvested from the proximal humeral metaphysis and centrifuged using a commercial kit (Arthrex Inc.) to a total volume of 5 mL. Next, a diagnostic shoulder arthroscopy was performed via a posterior viewing portal. While inspection of the cartilaginous surface of the humeral head did not reveal fissures or an overt defect, an arthroscopic probe illustrated a sizeable ballotable area along its surface, indicating subchondral pathology. Intraoperative fluoroscopy was available to aid in identification of the targeted site for decompression and is often used for this purpose; however, given this arthroscopic finding and ease of access, the senior author believed that this was not necessary in this instance. To guide subsequent reaming of the subchondral bone at this site identified via arthroscopy, a standard transtibial anterior cruciate ligament (ACL) guide, set to 60°, was passed via an anterior portal onto the humeral head surface. The guidetip was placed at this site, which also corresponded with the greatest humeral head bone edema as identified on preoperative MRI. On the opposite end of the ACL guide, a trochar was introduced and placed along the lateral shoulder to denote placement of a lateral portal. Care was taken to ensure that this portal was superior to the projected course of the axillary nerve, which can be variable and as close as 4 cm to the edge of the acromion. ⁵ After creation of a vertically oriented 2-cm portal, the trochar was advanced through the ACL guide to abut the lateral cortex of the proximal humerus. A 2.4-mm guide pin was advanced through the trochar, with care taken not to penetrate the articular surface. A 7.0-mm reamer was used to drill a channel of bone centered over the guidewire. Next, a sterile preparation of commercial DBM was mixed with 5 mL of previously harvested BMAC on a sterile back table. A plastic cannula was inserted through the lateral portal to ensure that DBM and BMAC were inserted into the reamed tunnel, rather than into more superficial soft tissue. The BMAC-soaked DBM was then passed through the cannula and packed into the reamed bone channel with a switching stick. Adequate depth of switching stick insertion confirms that DBM and BMAC are placed in the desired location within the reamed bone channel. Furthermore, inspection and palpation of the arthroscopic portal site are also performed to assess for deposition into soft tissues. Following this procedure, arthroscopic portals were closed in standard fashion and a sterile dressing was applied.

The authors recommend 3 technical pearls to ensure efficient completion of the procedure.

1. Diagnostic shoulder arthroscopy can enhance and corroborate MRI findings regarding the location of planned core decompression.

2. A transtibial ACL guide can aid in accurate placement of guidewire for subchondral bone reaming.

3. Backfilling of the reamed humeral head channel with BMAC-infused DBM can provide structural and biological support to promote local revascularization.

Postoperatively, patients are immobilized in a shoulder abduction brace, which can be discontinued as soon as tolerated, typically in 1 week. Passive range of motion is initiated immediately, along with closed-chain scapular stabilization exercises. Active-assisted range of motion exercises are commenced typically at 3 to 4 weeks postoperatively. Full active range of motion is typically achieved by 8 weeks. Strengthening exercises are initiated at approximately 4 to 6 weeks, and full return to activities is anticipated at 3 months postoperatively.

At 3 months postoperatively, our patient reported that his pain had improved to a visual analog scale score of 2 out of 10. He had achieved full, painless active shoulder motion and strength in all planes.

In patients with early stages of humeral head osteonecrosis, core decompression confers superior clinical outcomes with reduced rates of subsequent surgical procedures compared with nonoperative treatment. In a systematic review published in 2023 of 9 studies with a mean follow-up of approximately 8 years, 77% of patients with stage 1 to 3 osteonecrosis who underwent core decompression did not require additional surgery. ³ Moreover, core decompression has shown to reduce the radiographic progression of osteonecrosis. Further research is necessary to determine the additional clinical benefits of augmentation with orthobiologic agents, such as BMAC.

In conclusion, arthroscopic-assisted humeral head core decompression aided by a transtibial ACL guide and augmentation with BMAC provides an efficient, reproducible surgical strategy in the management of early humeral head osteonecrosis. Here are our references. Thank you for your attention.