We thank Dr Alam and colleagues for their comments on our recent article[1]. We have responded to each of their questions below:

1. We agree that the wording may have been confusing so we will clarify. We revised 57 patients with a failed hemiarthroplasty done originally for fracture to a reverse shoulder arthroplasty over our entire experience from 1999-2005 (this manuscript was written at the end of 2005). There were 32 patients that underwent reverse shoulder arthroplasty for this indication from 1999-2003 (i.e. at least 24 months post surgery at the time this manuscript was written) and all were included in this study. Three of the patients died before obtaining 2 years of follow-up leaving 29 for analysis. We did not exclude 49% of the patients.

2. Apropos of Dr. Alam’s inquiry, we too were pleasantly surprised at the low incidence of complications. In retrospect many factors were responsible for our low rate of complication including: 1) The anatomical center of rotation of the glenosphere used in this group of patients provides for a smaller dead space accounting for a lower likelihood of postoperative hematoma and prevents mechanical abrasion of the humerus against the scapular neck thus preventing scapular notching found with other reverse shoulder arthroplasties with medial centers of rotation [2-6]. 2) The humeral component used in this group of patients was small in diameter so the majority of humeral implants were cemented into the previous cement mantle thus avoiding humeral complications associated with cement removal of the humerus. 3) Finally, our clinical practice has allowed us to have a large experience in shoulder arthroplasty. The familiarity we have in performing complex arthroplasties has provided an ideal environment to become technically comfortable in treating this difficult group of patients. The authors state that our short follow-up may explain the low complication rate but the average length of follow-up on the study they cite with a 45% complication rate was 40 months while our follow up was 35 months.

3. Indeed statistically we did not prove that the allograft is better. We do feel that based on our experience that restoration of the bone loss seen on the proximal humerus is advantageous for the patient. Based on the improvement in function, reduction of pain, relatively low complication rate and overall patient satisfaction we continue to utilize the Reverse Shoulder Prosthesis to treat the previously untreatable triad of a hemiarthoplasty used to treat a proximal humeral fracture in which the rotator cuff has structurally failed leading to glenohumeral instability and the progression of erosion of the glenoid articular cartilage.

References:

1. Levy J, Frankle M, Mighell M, Pupello D. The use of Reverse Shoulder Prosthesis for the treatment of failed hemiarthroplasty for proximal humeral fracture. J Bone Joint Surg Am. 2007;89:292-300

2. Valenti P, Boutens D, Nerot C. Delta III prosthesis for osteoarthritis with massive rotator cuff tear: Long term results. Shoulder Prosthesis 2000 2000:253-8.

3. Boulahia A, Edwards TB, Walch G, Baratta RV. Early results of a reverse design prosthesis in the treatment of arthritis of the shoulder in elderly patients with a large rotator cuff tear. Orthopedics 2002;25-2:129-33.

4. Sirveaux F, Favard L, Oudet D, Huquet D, Walch G, Mole D. Grammont inverted total shoulder arthroplasty in the treatment of glenohumeral osteoarthritis with massive rupture of the cuff. J Bone Joint Surg Br. 2004;86:388-95

5. Werner CM, Steinmann PA, Gilbart M, Gerber C. Treatment of painful pseudoparesis due to irreparable rotator cuff dysfunction with the Delta III reverse-ball-and-socket total shoulder prosthesis. J Bone Joint Surg Am. 2005;87(7):1476-86.

6. Boileau P, Watkinson D, Hatzidakis AM, Hovorka I. The Grammont reverse shoulder prosthesis: results in cuff tear arthritis, fracture sequelae and revision arthroplasty. J Shoulder Elbow Surg. 2006;15:527-40.

To The Editor:

We read with interest the article by Levy et al.(1)and the editorial by Rockwood CA Jr (2). We would like to make the following additional points:

1. During the study period, fifty-seven patients underwent revision to the Reverse Shoulder Prosthesis after developing problems following primary hemiarthroplasty for proximal humeral fractures but only twenty-nine of the fifty seven patients (a drop out rate of 49%) were included in the study. We feel the inclusion and exclusion criteria need more explanation.

2. Of great interest, only eight of the twenty-nine study patients(28%) had a complication. This is a surprisingly low result for such a difficult group of patients. Complication rates for revision surgery using a reverse shoulder prosthesis in experienced hands have been reported as high as 45%(3) and 33%(4). However, it is possible that this low complication rate may be explained by the short follow-up, (minimum 24 months with an average of 35 months). Complications reported in the literature following reverse shoulder prosthesis but not listed in this report include scapular spine fracture, glenoid loosening, haematoma, postoperative stiffness and venous thrombosis(3,4). Late complications, such as glenoid notching and acromial fatigue fractures(5), may not appear until follow-up times beyond those reported in this study.

3. The authors recommend the use of proximal humeral allograft augmentation for patients with associated extensive proximal humeral bone loss. However, only eight patients underwent augmentation surgery and only four showed radigraphic evidence of bone integration. This is not strong evidence on which to base a recommendation for proximal humeral allograft augmentation.

In light of our concerns regarding this study, we do not believe the authors have shown that the the Reverse Shoulder Prosthesis is efficacious in this group of patients.

The authors did not receive any outside funding or grants in support of their research for or preparation of this work. Neither they nor a member of their immediate families received payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity. No commercial entity paid or directed, or agreed to pay or direct, any benefits to any research fund, foundation, division, center, clinical practice, or other charitable or nonprofit organization with which the authors, or a member of their immediate families, are affiliated or associated.

References:

1.Jonathan Levy, Mark Frankle, Mark Mighell, and Derek Pupello, The use of the Reverse Shoulder Prosthesis for the treatment of failed hemiarthroplasty for proximal humeral fracture, J Bone Joint Surg Am 2007 Feb;89(2):292-300.

2. Rockwood CA Jr. The Reverse Total Shoulder Prosthesis: The new kid on the block. J Bone Joint Surg Am 2007 Feb;89(2):233-5.

3. Boileau P, Watkinson D, Hatzidakis AM, Hovorka I. The Grammont reverse shoulder prosthesis: results in cuff tear arthritis, fracture sequelae and revision arthroplasty. J Shoulder Elbow Surg. 2006;15:527-40.

4. Walch G, Wall B, Mottier F. Complications and revision of the reverse prosthesis, a multicentre study of 457 cases. In: Walch G, Boileau P, Mole D, Favard L, Levigne C, Sirveaux F, editors. Reverse shoulder arthroplasty: clinical results, complications, revision. Montpellier, France: Sauramps Medical; 2006. Page 335-52.

5. McFarland EG, Sanguanjit P, Tasaki A, Keyurapan E, Fishman EK, Fayad LM. The Reverse Shoulder Prosthesis: A review of imaging features and complications, Skeletal Radiol 2006;35(7):488-96.