Three-dimensional measures of posterior bone loss and retroversion in Walch B2 glenoids predict the need for an augmented anatomic glenoid component

The Use of Glenoid Structural Allografts for Glenoid Bone Defects in Reverse Shoulder Arthroplasty

Background: The use of reverse shoulder arthroplasty as a primary and revision implant is increasing. Advances in implant design and preoperative surgical planning allow the management of complex glenoid defects. As the demand for treating severe bone loss increases, custom allograft composites are needed to match the premorbid anatomy. Baseplate composite structural allografts are used in patients with eccentric and centric defects to restore the glenoid joint line. Preserving bone stock is important in younger patients where a revision surgery is expected. The aim of this article is to present the assessment, planning, and indications of femoral head allografting for bony defects of the glenoid. Methods: The preoperative surgical planning and the surgical technique to execute the plan with a baseplate composite graft are detailed. The preliminary clinical and radiological results of 29 shoulders which have undergone this graft planning and surgical technique are discussed. Clinical outcomes included visual analogue score of pain (VAS), American Shoulder and Elbow Surgeons score (ASES), Constant-Murley score (CS), satisfaction before and after operation, and active range of motion. Radiological outcomes included graft healing and presence of osteolysis or loosening. Results: The use of composite grafts in this series has shown excellent clinical outcomes, with an overall graft complication rate in complex bone loss cases of 8%. Conclusion: Femoral head structural allografting is a valid and viable surgical option for glenoid bone defects in reverse shoulder arthroplasty.

Clinical outcome of wedged glenoid reconstruction in anatomic total shoulder arthroplasty for osteoarthritic retroverted glenoid: a minimum 2-year follow-up

Background

Glenoid retroversion and humeral head subluxation is a progressive disorder due to abnormal force coupling and increased contact force. In situ placement of anatomic total shoulder arthroplasty (TSA) components in this scenario results in edge loading, progressive subluxation, and early failure. Wedged glenoid components have been demonstrated to improve glenohumeral alignment, but have not been correlated with mid-term clinical outcomes.

Methods

Patients undergoing TSA using a wedged all-polyethylene glenoid component for retroverted glenoid deformity were identified from a prospectively maintained database. Preoperative planning computed tomography was routinely performed and compared to postoperative correction on radiographic evaluation. Evidence of loosening was correlated to prospectively collect clinical outcome using patient-reported outcome measures. A matched group of neutrally aligned glenohumeral joints undergoing anatomic TSA was used to compare improvement in clinical outcomes.

Results

Over a 5-year period, 17 patients with mean age 60 (range 43-81, standard deviation 10.5) were identified with a mean preoperative neoglenoid retroversion of 16.7° (standard deviation 4.5). At a mean follow-up of 43.8 months (range 27-60), no revision surgeries were undertaken. Improvement in the Oxford Shoulder Score was 18 points (P < .0001). The mean improvement was compared to a matched control group demonstrating a comparable magnitude of improvement of 20.4 points.

Conclusion

Wedged polyethylene components for Walch B2-type glenoids in TSA yield acceptable correction of the joint line, excellent clinical outcomes, and survivorship is maintained in the short term. The clinical and radiological outcome demonstrated similar improvement to that seen in A type deformities.

Maximizing Implant Stability in the Face of Glenoid Bone Stock Deficiency

As the incidence of shoulder arthroplasty continues to rise, encountering significant glenoid bone loss in the primary and revision setting is becoming a common occurrence. To effectively treat these difficult scenarios, surgeons must understand the common patterns of glenoid bone loss and be aware of the various techniques available for treatment. Understanding bone loss requires careful pre-operative evaluation with appropriate imaging and pre-operative planning software. Treatment algorithms consist of primary anatomic and reverse arthroplasty as well as the use of allograft or autograft bone grafting, augmented glenoid components, specialized surgical techniques, or custom implant designs. Ultimately, good outcomes are able to be obtained with various techniques when applied to the appropriate clinical situation.

Editorial Commentary: Posterior Shoulder Instability Surgical Treatment Outcomes Are Inferior to Outcomes of Anterior Instability: Standardization of Patient Evaluation and Indications Could Improve Results

Arthroscopic capsulolabral repair remains the mainstay of treatment in patients with refractory shoulder posterior instability. In addition, glenoid bone block augmentation procedures for posterior shoulder instability are gaining momentum. Unfortunately, results from anterior glenoid bone block augmentation procedures have enjoyed much better success than posterior, and it is unclear why surgical treatment of posterior instability with either congenital or acquired retroversion, with or without posterior bone loss, can result in complications or poor outcomes. It is essential to standardize evaluation and reporting of clinical presentation, radiographic assessment, indications, and mid- to long-term follow-up in patients who undergo posterior shoulder bony augmentation procedures. Current literature suggests that greater than 11% posterior glenoid bone loss increases risk of surgical failure 10 times, and 15% posterior bone loss increases risk of surgical failure 25 times, suggesting a possible threshold for posterior bony augmentation. However, in the end, the problem is complex, and work remains to better define optimal patient indications in consideration of congenital or acquired pathology, retroversion, amount of bone loss, and patient demographics and risk factors.