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Bone grafting for glenoid bone deficiencies in shoulder arthritis: A review
Bone grafting for glenoid bone deficiencies in shoulder arthritis: A review Robert H. Cofield, MD, Rochester, MN
Bone loss in the glenoid in the face of shoulder arthritis can be managed in selected cases with bone grafting. This article reviews the literature and uses this clinical experience to make recommendations for the surgical management of glenoid bone loss in cases of osteopenia, dysplasia, bone loss created by the arthritis, and loss that occurs in the glenoid related to failed shoulder arthroplasty. (J Shoulder Elbow Surg 2007; 16:273S-281S.)
CLASSIFICATION OF GLENOID BONE DEFICIENCIES A variety of systemic disease processes lead to osteoporosis of the bone about the shoulder, including osteoporosis of the glenoid per se. This can simply occur with aging or disuse or be the effect of a disease process and its treatment; for example, rheumatoid arthritis and treatment with oral corticosteroids. This circumstance seems ideal for the application of the cancellous compaction technique using autograft from glenoid or humeral preparation to enhance the density of the bone in the glenoid neck before fixation of a glenoid component.9,25 Patients are also encountered who have had breast cancer and have received radiation therapy for treatment. The shoulder joint may have been included in the radiation field, which results in a mixture of tissues within the glenoid resulting from focal death of bone cells and replacement with fibrous tissue. The amount of change within the bone can often be detected on preoperative imaging, and in this circumstance, curetting fibrous tissue combined with autogenous compaction cancellous grafting can enhance fixation of the glenoid component.
From the Department of Orthopedic Surgery, Mayo Clinic. Reprint requests: Robert H. Cofield, MD, Department of Orthopedic Surgery, Mayo Clinic, 200 First St SW, Rochester, MN 55905 (E-mail: [email protected]). Copyright © 2007 by Journal of Shoulder and Elbow Surgery Board of Trustees. 1058-2746/2007/$32.00 doi:10.1016/j.jse.2007.03.005
Glenoid dysplasia
Dysplasia of the glenoid has a number of characteristics and may also include some alterations of the humeral side of the joint (Figure 1). These include decreased glenoid bone posteriorly and inferiorly and an irregular dentate glenoid surface, a prominent coracoid process, a curved distal clavicle, some degree of humeral head dysplasia, posterior glenohumeral subluxation, and importantly, secondary arthritis.22 In this description of primary glenoid dysplasia, the condition typically included osteoarthritis when the onset of symptoms was in a patient older than 40 years of age. Three of the 5 patients reported required shoulder arthroplasty. The operation was difficult and the results disappointing compared with arthroplasty for primary osteoarthritis, including substantial residual pain and moderate functional limitations. In a second report on shoulder arthroplasty for osteoarthritis related to glenoid dysplasia,23 4 shoulders had hemiarthroplasty and 3 subsequently were converted to a total shoulder arthroplasty because of unsatisfactory pain relief. One of 3 patients undergoing total shoulder arthroplasty underwent later glenoid component removal because of glenoid component loosening and a suspected infection. The other 2 had excellent results comparable with the more typical patients with primary osteoarthritis. These authors concluded that there probably would be more consistent results with addressing the cartilage wear and the glenoid bone deficiency with a special component or adjunctive bone grafting at the time of the initial surgical procedure. The third series has analyzed shoulder arthroplasty in patients with osteoarthritis and dysplastic glenoid morphology.7 These authors studied the patients preoperatively with computed tomography and placed a glenoid component when there was 15 mm or more glenoid bone depth at the mid-point of the glenoid as seen on the axial cuts. In their series, 11 shoulders underwent total shoulder arthroplasty and 4 underwent hemiarthroplasty. In 1 shoulder, glenoid component loosening by 2 years required glenoid component removal. In the remaining shoulders, average improvement occurred in all parameters measured, including motion, activities, and Constant score. With
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Figure 1 Glenoid dysplasia with secondary osteoarthritis. Note the pronounced loss of glenoid depth, (left) particularly inferiorly and (right) posteriorly.
the numbers of shoulders evaluated, they could not detect a significant difference between total shoulder arthroplasty and hemiarthroplasty. Of interest in this series was that none of the shoulders had findings indicative of shoulder instability. They mention that hypertrophic soft tissues were identified posteriorly, but this tissue was not altered during the surgical procedure. The authors believed these hypertrophic soft tissues were effective in preventing subluxation of the humeral head. Related to this lack of joint subluxation, no effort was made at the time of surgery to correct glenoid version. The authors do not comment on any alteration in humeral component position to match the alteration in glenoid morphology. This experience is thus somewhat different than that reported by the first 2 articles presenting materials on glenoid dysplasia. In line with the third article, there are certain developmental or congenital abnormalities where the glenohumeral joint position is greatly distorted. Secondary arthritis can occur, and resurfacing arthritic joint surfaces without substantively altering the joint position seems practical. These include, for example, Erb’s palsy and a variety of forms of dwarfism.15
Bone loss due to shoulder arthritis
Patients with juvenile rheumatoid arthritis may have extremely small bones and bones that are somewhat altered in shape. These may require special components and alteration in component positioning but seldom require bone grafting. Other patients with a variety of forms of arthritis may have extensive cyst formation within the glenoid vault, sometimes almost entirely replacing the cancellous bone of this portion of the glenoid. Except in a few instances, these can be addressed by autogenous corticocancellous grafts obtained from the humeral head at the time of shoulder arthroplasty or for smaller lesions filling the cysts with bone cement. Neer,14 in analyzing the effects of rheumatoid arthritis on the shoulder joint, described how wet and resorptive forms of rheumatoid arthritis can create marked intrusion of the humeral head into the glenoid and how it is nearly impossible in this situation to fix a glenoid component with standard methods. This continues to be an issue, and in most circumstances, surgeons are treating this condition of central glenoid wear with hemiarthroplasty.
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Figure 2 A, Eccentric posterior glenoid wear associated with posterior humeral subluxation. B and C, Standard components were placed in the usual orientation after adding a segmental humeral head bone graft to the deficient posterior aspect of the glenoid.
In commenting on his early experience with total shoulder replacement, Neer et al16 identified the problem of uneven wear and erosion of the glenoid (Figure 2). Mention was made that lowering the less worn or eroded side of the glenoid might be possible, but it also might produce shortening of the glenoid vault to the extent that the keel part of the glenoid
component could not be securely fixed and might also create laxity between the components altering joint kinematics. Other alternatives included a custom prosthesis, which unfortunately is not fully developed to this day, the mechanically unsound thought of filling the defect with bone cement, or the preferred method of correcting the glenoid bone deficiency by
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applying and fixing a piece of the humeral head to the scapula with screws. Walch et al10,26,27 have categorized glenoid morphology in osteoarthritis, but this has application to the understanding of glenoid bone deficiencies and the planning for the potential need for glenoid bone grafting. The glenoids were divided into 3 types. In their type A, the humeral head is centered. In type A-1, only minor central erosion is present. Type A-2 has marked central erosion and, as implied from the above, is most commonly seen in rheumatoid arthritis. In type B, the humeral head is subluxated and in the case of osteoarthritis, subluxated posteriorly. Type B-1 shows narrowing of the posterior aspect of the glenohumeral joint with subchondral sclerosis, perhaps marginal osteophytes. Type B-2 has posterior humeral subluxation with more eccentric glenoid wear creating a biconcave glenoid shape. They define type C as glenoid retroversion of more than 25°, most typically seen in dysplasia. In their patients, the humeral head was either well centered or slightly subluxated posteriorly in this type of glenoid morphology. Glenoid bone deficiencies in failed total shoulder arthroplasty
Antuna et al2 have classified glenoid bone deficiencies after glenoid component removal into central, peripheral, or combined, each with mild, moderate, or severe degrees of bone loss (Figure 3). The deficiencies were classified as mild if they involved less than one third of the glenoid surface or rim, as moderate if they involved between one third and two thirds of the surface or rim, and severe if they involved more than two thirds. These authors enumerated the deficiencies in 43 shoulders undergoing removal of the glenoid component. Central deficiencies were most common and present in 29 shoulders: mild in 10, moderate in 10, and severe in 9. There were combined deficiencies in 14 shoulders. These were rather mild in a few: 1 shoulder had mild central and posterior deficiencies and 1 had moderate central and mild anterior and posterior deficiencies. In the others, though, the deficiencies were greater: 12 had severe central deficiencies associated with 3 moderate anterior deficiencies, 3 severe anterior deficiencies, 1 moderate posterior deficiency, 2 severe posterior deficiencies, 1 moderate anterior and posterior deficiency, and 2 severe anterior and moderate posterior deficiencies. Peripheral deficiencies were not seen in an isolated manner but only in combination with central bone loss.
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Figure 3 Classification of bone deficiencies in the glenoid after glenoid component loosening and osteolysis. Most deficiencies are central or combined. (From Antuna SA, Sperling JW, Cofield RH, Rowland CM. Glenoid revision surgery after total shoulder arthroplasty. J Shoulder Elbow Surg 2001;10:217-24. Reprinted with permission).
SURGICAL RECONSTRUCTION FOR GLENOID BONE DEFICIENCIES Bone grafting for eccentric glenoid wear
Three articles have been published on this technique (Figure 2). Neer and Morrison13 in 1988 were able to monitor 19 of 20 shoulders having a large segmental graft for eccentric glenoid wear. The patients were followed up for a minimum of 2 years (average, 4.4 years). The clinical outcome was excellent in 16 and satisfactory in 1. Two patients reached desired limited goals. None of the glenoid components clinically loosened or moved, and none have required further surgical treatment. On radiographs, 2 fixation screws broke and 1 screw showed wear, presumably by contact with the metal of the humeral component. The authors comment that this technique provided sufficient osseous support to allow secure fixation of a glenoid component in the face of eccentric glenoid wear. The 2 other reports are not so uniformly favorable. Steinmann and Cofield24 in 2000 reported 28 patients having glenoid bone grafting for segmental glenoid wear. The common diagnoses were osteoarthritis in 19 and arthritis associated with shoulder instability in 5. Follow-up evaluation was a minimum of 2 years (average, 5.3 years). Similar to the earlier report, autogenous humeral head grafts were used. Typically, fixation was with 3.5-mm cortical screws.
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On clinical evaluation, 25 patients had no or slight pain, and 3 had moderate pain. Postoperative active elevation averaged 126°, external rotation averaged 39°, and internal rotation averaged to T12. Applying Neer’s result rating, 13 shoulders had excellent results, 10 had satisfactory results, and 5 had unsatisfactory results due to glenoid loosening in 2, reoperation for instability in 2, and persistent pain in 1. On radiographic assessment, 13 shoulders had no glenoid lucencies, 11 had incomplete lucencies, but 4 had complete lucencies, and lucencies were at least 1.5 mm wide in 3 of these. Three glenoids were considered radiographically loose. Two of the 3 were symptomatic, as indicated above. Thus, in this series at this length of follow-up, 4 of 28 glenoids had not remained securely fixed, and the risk of recurrence of instability despite correction of glenoid component alignment was introduced. Of importance in this article is that the technique for applying a bone graft in this situation was codified: 1. After glenoid component exposure, the center of the glenoid is identified and a central hole is made perpendicular to neutral glenoid alignment. The depth of the glenoid neck is confirmed and measured with a depth gauge. If the depth of the glenoid is such that it cannot be shortened more than a few millimeters, the patient is identified as being a candidate for segmental bone grafting. If the glenoid neck is deep enough to allow central reaming, the glenoid may be reamed to a neutral orientation and the need for bone grafting would be avoided. 2. The anterior aspect of the glenoid is prepared with a reamer in the normal orientation of the glenoid. 3. The additional anchoring holes for columns or the keel are prepared. 4. The eroded area of bone on the posterior aspect of the glenoid is prepared to receive the bone graft. 5. A segment of the humeral head is tapered to fit into this deficiency. 6. The graft is positioned with small Steinmann pins. 7. The Steinmann pins are replaced with 3.5-mm cortical screws. After drilling, the screws are countersunk slightly. 8. The graft is contoured with a microsagittal burr to match the surface of the anterior portion of the glenoid. 9. The glenoid component is secured in position. The third study reporting on segmental bone grafting of the glenoid included a more difficult patient group12: all patients had preoperative instability. There were 12 posterior and 5 anterior glenoid bone
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defects. The humeral head was used for grafting in 15 shoulders, and the iliac crest was used in 2. All patients were followed up to revision or at least for 2 years (average, 5.8 years). Radiographs showed 5 glenoids had complete lucent lines, with a lucent line width of 2 mm or less around the component. Four others had a shift in component position. Five shoulders failed during the period of review related to component issues in 3, instability in 2, and recurrent rotator cuff tearing in 1. The authors comment that corticocancellous grafting of the glenoid can restore glenoid version and volume and did so effectively in 14 of the 17 shoulders in their study. Associated issues are often present, however, most notably, glenohumeral instability, which typically is present in the face of uneven glenoid wear and may persist or recur. Glenoid bone grafting in failed arthroplasty
When glenoid components fail, most often due to loosening with some degree of bone resorption, it may be possible to place a new glenoid component with or without some degree of bone grafting. On other occasions, glenoid component removal alone, and perhaps with upsizing of the humeral head, has been shown to be a reasonable concept.11,21 When considering patients we had treated who required revision surgery, we too identified a number of glenoids that could not be reconstructed because of such extensive bone loss. In a 1990 report, we outlined the use of autogenous iliac crest bone graft to correct glenoid bone deficiencies at the time of revision surgery in 9 shoulders.6 One of these shoulders did not achieve satisfactory pain relief, and 2 years later, it was possible to repeat her shoulder surgery with better bone present, refix a glenoid component in place, and more important, achieve a satisfactory result. Thus, the thought emerged that bone grafting a bonedeficient glenoid component at the time of revision surgery might be preferable to leaving the deficiency, because there was the option later for further reconstructive surgery should it be necessary. Similar thoughts were expressed in an article by Peterson and Hawkins19 in 1998. As published in 2001 by Antuna et al,2 we undertook a major review of our experience with glenoid revision surgery after total shoulder arthroplasty. Forty-eight shoulders underwent glenoid revision surgery and were followed up a minimum of 2 years (average, 4.9 years). The indications were symptomatic glenoid component loosening in 29, glenoid implant failure in 14, and instability in 5. A new glenoid implant could be placed in 30 shoulders; however, 18 had such substantial bone deficiencies that it was necessary to remove the glenoid component and
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Figure 4 A, Substantial glenoid bone deficiency associated with glenoid component loosening and osteolysis. B and C, The defect was packed with frozen allograft bone chips. A radiograph 9 months after insertion of the bone graft shows substantial concentric wear into the glenoid bone graft material. At this time, the patient had intermittent moderate pain, 90° of active elevation, and 45° of external rotation; this range of motion was not too different from her movement preoperatively.
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cement and bone graft the deficiencies (Figure 4). In these instances, frozen cancellous allograft was used in 14 shoulders, autograft in 1, and no grafting in 3. In the shoulders that underwent glenoid component removal and bone grafting, there was evidence of graft remodeling over time, with a mean of 7.5 mm of centralization of the humeral head into the glenoid on follow-up radiographs. Three of the patients who underwent component removal and bone grafting had continuing severe pain and, at an average of 20 months after insertion of the bone graft, had revision surgery and implantation of a new glenoid component. These 3 patients were quite satisfied with their reduction in pain at a mean follow-up of 2.6 years and had no evidence of component loosening.1 In the above patients, early in the series, frozen cancellous grafts were used from our institutional bone bank. As regulations increased regarding bone bank qualifications and handling of human tissues, we elected to switch to commercial sources but continued to use frozen corticocancellous chips. Typically, 15 to 50 cm3 of graft are used. The grafts are thawed and then bathed repetitively in sterile saline to remove most of the marrow and a number of cells, in the belief that this reduces the immunologic load to the patient and perhaps decreases the risk of disease transmission.3 It also reduces the lubrication between the particles, creating greater interdigitation between the corticocancellous particles and quite likely improving the strength of the compacted allograft. It is not known how long it is necessary for such a graft to incorporate. With bone scintigraphy, the uptake approaches normal at 2 to 3 years after surgery.3 In a recent case report, freeze-dried allograft with platelet-derived growth factor was used to fill the defect after failure of an unconstrained glenoid component. One year later, revision to a total shoulder arthroplasty was undertaken and despite the radiologic appearance of incorporation of the allograft, the histologic examination found no indication of new mature bone formation. There was necrotic bone surrounded by a fibrous tissue and no osteoblastic activity or osteoid formation. Despite this, 2 years after insertion of the total shoulder arthroplasty, the patient has a painless shoulder with reasonable function and no radiologic evidence of component loosening or graft resorption.20 We have recently expanded and extended the follow-up on our patients who have had revision surgery for glenoid component loosening.5 Amongst those studied, 35 shoulders had glenoid component removal and allograft bone grafting without glenoid reimplantation. Follow-up was a minimum of 2 years (average, 6.2 years). Pain relief occurred in 24 of these 35 shoulders; however, preoperative and postoperative range of motion did not change significantly. Nineteen of the patients were satisfied with their outcome. Survival free of
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Figure 5 A, Some surgeons prefer structural autogenous iliac crest or allogenic bone graft after glenoid component removal in the face of severe bone deficiency. B, These grafts are also subject to resorption.
reoperation was 78% at 5 years. Of the 7 shoulders that had reoperation, 6 had placement of a new glenoid component because of continuing pain at a mean of 3.5
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Figure 6 A, Subsequent to glenoid component removal and allograft cancellous bone grafting, the patient continued to have severe shoulder pain. B, After consolidation of the graft, a new glenoid component was placed 3 years later.
years after glenoid component removal and bone grafting. One patient with continuing pain had resection arthroplasty in the face of a positive culture for Propionibacterium acnes. Thirty-four shoulders had complete sets of radiographs. There was medial shifting of the humeral head to some degree in all patients; it was less than 5 mm in 10, 6 to 10 mm in 10, and greater than 10 mm in 14. It seems from the above that allograft bone grafting in the face of an unreconstructable glenoid after glenoid component failure will usually lead to pain relief, but if pain relief does not occur, reinsertion of a glenoid component seems to be possible. Although we have evolved to favor cancellous chips and allografts, others have favored structural autografts in this setting (Figure 5). The cortical grafts allowed reliable second-stage reconstruction of the shoulder with a glenoid implant. An additional benefit of a structural graft is that in certain situations, glenoid implants fixed with screws or special designs of implants can be performed as a single-stage procedure in some shoulders.8,17,18
Reimplantation of a glenoid component after component removal and bone grafting
Not a great deal of information is available on this subject.6 As described, there are occasional case reports as a part of larger series analyzing glenoid revision surgery. In 2002, we also offered a case report including 3 patients where this had been done after glenoid component removal and allograft cancellous chip bone graft.1 Reinsertion of a glenoid component occurred at 6 months, 20 months, and 3 years after the grafting procedure. In each instance, the graft seemed to be firmly incorporated but did contain some element of fibrous tissue. The new implants could be securely fixed in place. In 1 instance, it was apparent by 1 year after surgery that the newly placed glenoid component had loosened, and 2 years later, the glenoid component was yet again removed. Outcomes were excellent and satisfactory in the other 2 patients at 5 and 8 years after surgery. One patient had no lucent lines, and the other had an incomplete lucent line on radiographs.
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We recently expanded review of patients with this situation and identified 7 shoulders in which a glenoid component was reinserted after allograft bone grafting.4 Two received rather standard allpolyethylene glenoid components and 5 had metal backed components with screw fixation. During the follow-up period, it was evident that a low-grade infection Propionibacterium acnes infection had developed in 2 patients, and they underwent re-revision procedures. The remaining 5 patients expressed satisfaction with their procedure and had reduced pain. Motion was essentially unchanged. Radiographically, 2 of the 5 patients without infections had an incomplete 1-mm lucent line at the glenoid– bone cement interface. No lucent lines were present in the other patients. Thus, reimplantation of a glenoid component in this setting can offer an improved clinical condition in most patients, particularly reduction in pain and improvement in satisfaction (Figure 6). We must be continually vigilant in revision arthroplasty about the possibility of a lowgrade infection being present at the time of revision surgery. SUMMARY AND CONCLUSIONS Bone grafting has been quite useful as a part of reconstructive shoulder surgery in the face of shoulder arthritis. In the face of osteopenia in the glenoid vault, autogenous impaction grafting may improve component fixation. Autogenous segmental grafts have proven useful to improve glenoid position and enhance component fixation in selected cases with dysplasia or eccentric glenoid wear from arthritis. In failed total shoulder arthroplasty, occasionally 1-stage but usually 2-stage procedures are necessary. Some surgeons prefer structural autografts; others prefer particulate compressed allografts for the first-stage of reconstruction. Case reports and clinical series are available to document the rate of success using these techniques and, from a clinical standpoint, seem to be a viable option as a part of the reconstructive surgeon’s armamentarium. REFERENCES
1. Antuna SA, Sperling JW, Cofield RH. Reimplantaton of a glenoid component after component removal and allograft bone grafting. A report of three cases. J Shoulder Elbow Surg 2002;11:637-41. 2. Antuna SA, Sperling JW, Cofield RH, Rowland CM. Glenoid revision surgery after total shoulder arthroplasty. J Shoulder Elbow Surg 2001;10:217-24. 3. Board TN, Rooney P, Kearney JN, Kay PR. Impaction allografting in revision total hip replacement. J Bone Joint Surg Br 2006;88: 852-7. 4. Cheung EV, Sperling JW, Cofield RH. Reimplantation of a glenoid component following component removal and bone grafting. J. Bone Joint Surg Am (Submitted). 5. Cheung EV, Sperling JW, Cofield RH. Revision shoulder arthroplasty for glenoid component loosening (pending publication).
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6. Cofield RH, Edgerton BC. Total shoulder arthroplasty. Complications and revision surgery. Instr Course Lect 1990;39:449-62. 7. Edwards TB, Boulahia A, Kempf JF, Boileau P, Nemoz C, Walch G. Shoulder arthroplasty in patients with osteoarthritis and dysplastic glenoid morphology. J Shoulder Elbow Surg 2004;13:1-4. 8. Gagey O, Pourjamasb B, Court C. Revision arthroplasty of the shoulder for painful glenoid loosening: a series of 14 cases with acromial prostheses reviewed at four year follow-up. Rev Chir Orthop Reparatrice Appar Mot 2001;97:221-8. 9. Gazielly DF, Allende C, Pamelin E. Results of cancellous compaction technique for glenoid resurfacing [abstract]. Proceedings of the 9th International Congress on Surgery of the Shoulder, 1st International Congress of Shoulder Therapists. Washington, DC, May 2-5; 2004. p. 1. 10. Godenèche A, Poileau P, Favard L, et al. Prosthetic replacement in the treatment of osteoarthritis of the shoulder. Early results of 268 cases. J Shoulder Elbow Surg 2002;11:11-8. 11. Hawkins RJ, Greis PE, Bonutti PM. Treatment of symptomatic glenoid loosening following unconstrained shoulder arthroplasty. Orthopedics 1999;22:229-34. 12. Hill JM, Norris TR. Long-term results of total shoulder arthroplasty following bone-grafting of the glenoid. J Bone Joint Surg Am 2001;83:877-83. 13. Neer CS 2nd, Morrison DS. Glenoid bone-grafting in total shoulder arthroplasty. J Bone Joint Surg Am 1988;70:1154-62. 14. Neer CS II. Reconstructive surgery and rehabilitation of the shoulder. In: Harris ED Jr, Ruddy S, Sledge CB, editors. Textbook of rheumatology, Vol II. Philadelphia, PA: W. B. Saunders; 1981. p. 1944-59. 15. Neer CS II. Shoulder reconstruction. Philadelphia, PA: W. B. Saunders; 1990. p. 238-46. 16. Neer CS II, Watson KC, Stanton FJ. Recent experience in total shoulder replacement. J Bone Joint Surg Am 1982;64:319-37. 17. Neyton L, Sirveaux F, Roche O, Mole D, Boileau P, Walch G. Results of revision surgery for glenoid loosening: a multicentric series of 37 shoulder prosthesis. Rev Chir Orthop Reparatrice Appar Mot 2004;90:111-21. 18. Page RS, Haines JF, Trail IA. Impaction bone grafting of the glenoid in revision shoulder arthroplasty [abstract]. Proceedings of the 9th International Congress on Surgery of the Shoulder, 1st International Congress of Shoudler Therapists. Washington DC; May 2-5, 2004. p. 2. 19. Petersen SA, Hawkins RJ. Revision of failed total shoulder arthroplasty. Orthop Clin North Am 1998;29:519-33. 20. Peidro L, Segur JM, Poggio D, Fernandez de Retana P. Use of freeze-dried bone allograft with platelet-derived growth factor for revision of a glenoid component. J Bone Joint Surg Br 2006;88: 1228-31. 21. Rodosky MW, Bigliani LU. Surgical treatment of nonconstrained glenoid component failure. Oper Tech Orthop 1994;4:226-36. 22. Smith SP, Bunker TD. Primary glenoid dysplasia. A review of 12 patients. J Bone Joint Surg Br 2001;83:868-72. 23. Sperling JW, Cofield RH, Steinmann SP. Shoulder arthroplasty for osteoarthritis secondary to glenoid dysplasia. J Bone Joint Surg Am 2002;84:541-6. 24. Steinmann SP, Cofield RH. Bone grafting for glenoid deficiency in total shoulder replacement. J Shoulder Elbow Surg 2000;9: 361-7. 25. Szabo I, Buscayret F, Edwards TB, Nemoz C, O’Connor DP, Boileau P, Walch G. Radiographic comparison of two glenoid preparation techniques in total shoulder arthroplasty. Clin Orthop 2005:104-10. 26. Walch G, Badet R, Boulahia A, Khoury A. Morphologic study of the glenoid in primary glenohumeral osteoarthritis. J Arthroplasty 1999;14:756-60. 27. Walch G, Boulahia A, Boileau P, Kempf JF. Primary glenohumeral osteoarthritis: clinical and radiographic classification. The Aequalis Group. Acta Orthop Belgica 1998;64(suppl 2):46-52.
Bone loss in the glenoid in the face of shoulder arthritis can be managed in selected cases with bone grafting. This article reviews the literature and uses this clinical experience to make recommendations for the surgical management of glenoid bone loss in cases of osteopenia, dysplasia, bone loss created by the arthritis, and loss that occurs in the glenoid related to failed shoulder arthroplasty. (J Shoulder Elbow Surg 2007; 16:273S-281S.)
CLASSIFICATION OF GLENOID BONE DEFICIENCIES A variety of systemic disease processes lead to osteoporosis of the bone about the shoulder, including osteoporosis of the glenoid per se. This can simply occur with aging or disuse or be the effect of a disease process and its treatment; for example, rheumatoid arthritis and treatment with oral corticosteroids. This circumstance seems ideal for the application of the cancellous compaction technique using autograft from glenoid or humeral preparation to enhance the density of the bone in the glenoid neck before fixation of a glenoid component.9,25 Patients are also encountered who have had breast cancer and have received radiation therapy for treatment. The shoulder joint may have been included in the radiation field, which results in a mixture of tissues within the glenoid resulting from focal death of bone cells and replacement with fibrous tissue. The amount of change within the bone can often be detected on preoperative imaging, and in this circumstance, curetting fibrous tissue combined with autogenous compaction cancellous grafting can enhance fixation of the glenoid component.
From the Department of Orthopedic Surgery, Mayo Clinic. Reprint requests: Robert H. Cofield, MD, Department of Orthopedic Surgery, Mayo Clinic, 200 First St SW, Rochester, MN 55905 (E-mail: [email protected]). Copyright © 2007 by Journal of Shoulder and Elbow Surgery Board of Trustees. 1058-2746/2007/$32.00 doi:10.1016/j.jse.2007.03.005
Glenoid dysplasia
Dysplasia of the glenoid has a number of characteristics and may also include some alterations of the humeral side of the joint (Figure 1). These include decreased glenoid bone posteriorly and inferiorly and an irregular dentate glenoid surface, a prominent coracoid process, a curved distal clavicle, some degree of humeral head dysplasia, posterior glenohumeral subluxation, and importantly, secondary arthritis.22 In this description of primary glenoid dysplasia, the condition typically included osteoarthritis when the onset of symptoms was in a patient older than 40 years of age. Three of the 5 patients reported required shoulder arthroplasty. The operation was difficult and the results disappointing compared with arthroplasty for primary osteoarthritis, including substantial residual pain and moderate functional limitations. In a second report on shoulder arthroplasty for osteoarthritis related to glenoid dysplasia,23 4 shoulders had hemiarthroplasty and 3 subsequently were converted to a total shoulder arthroplasty because of unsatisfactory pain relief. One of 3 patients undergoing total shoulder arthroplasty underwent later glenoid component removal because of glenoid component loosening and a suspected infection. The other 2 had excellent results comparable with the more typical patients with primary osteoarthritis. These authors concluded that there probably would be more consistent results with addressing the cartilage wear and the glenoid bone deficiency with a special component or adjunctive bone grafting at the time of the initial surgical procedure. The third series has analyzed shoulder arthroplasty in patients with osteoarthritis and dysplastic glenoid morphology.7 These authors studied the patients preoperatively with computed tomography and placed a glenoid component when there was 15 mm or more glenoid bone depth at the mid-point of the glenoid as seen on the axial cuts. In their series, 11 shoulders underwent total shoulder arthroplasty and 4 underwent hemiarthroplasty. In 1 shoulder, glenoid component loosening by 2 years required glenoid component removal. In the remaining shoulders, average improvement occurred in all parameters measured, including motion, activities, and Constant score. With
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Figure 1 Glenoid dysplasia with secondary osteoarthritis. Note the pronounced loss of glenoid depth, (left) particularly inferiorly and (right) posteriorly.
the numbers of shoulders evaluated, they could not detect a significant difference between total shoulder arthroplasty and hemiarthroplasty. Of interest in this series was that none of the shoulders had findings indicative of shoulder instability. They mention that hypertrophic soft tissues were identified posteriorly, but this tissue was not altered during the surgical procedure. The authors believed these hypertrophic soft tissues were effective in preventing subluxation of the humeral head. Related to this lack of joint subluxation, no effort was made at the time of surgery to correct glenoid version. The authors do not comment on any alteration in humeral component position to match the alteration in glenoid morphology. This experience is thus somewhat different than that reported by the first 2 articles presenting materials on glenoid dysplasia. In line with the third article, there are certain developmental or congenital abnormalities where the glenohumeral joint position is greatly distorted. Secondary arthritis can occur, and resurfacing arthritic joint surfaces without substantively altering the joint position seems practical. These include, for example, Erb’s palsy and a variety of forms of dwarfism.15
Bone loss due to shoulder arthritis
Patients with juvenile rheumatoid arthritis may have extremely small bones and bones that are somewhat altered in shape. These may require special components and alteration in component positioning but seldom require bone grafting. Other patients with a variety of forms of arthritis may have extensive cyst formation within the glenoid vault, sometimes almost entirely replacing the cancellous bone of this portion of the glenoid. Except in a few instances, these can be addressed by autogenous corticocancellous grafts obtained from the humeral head at the time of shoulder arthroplasty or for smaller lesions filling the cysts with bone cement. Neer,14 in analyzing the effects of rheumatoid arthritis on the shoulder joint, described how wet and resorptive forms of rheumatoid arthritis can create marked intrusion of the humeral head into the glenoid and how it is nearly impossible in this situation to fix a glenoid component with standard methods. This continues to be an issue, and in most circumstances, surgeons are treating this condition of central glenoid wear with hemiarthroplasty.
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Figure 2 A, Eccentric posterior glenoid wear associated with posterior humeral subluxation. B and C, Standard components were placed in the usual orientation after adding a segmental humeral head bone graft to the deficient posterior aspect of the glenoid.
In commenting on his early experience with total shoulder replacement, Neer et al16 identified the problem of uneven wear and erosion of the glenoid (Figure 2). Mention was made that lowering the less worn or eroded side of the glenoid might be possible, but it also might produce shortening of the glenoid vault to the extent that the keel part of the glenoid
component could not be securely fixed and might also create laxity between the components altering joint kinematics. Other alternatives included a custom prosthesis, which unfortunately is not fully developed to this day, the mechanically unsound thought of filling the defect with bone cement, or the preferred method of correcting the glenoid bone deficiency by
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applying and fixing a piece of the humeral head to the scapula with screws. Walch et al10,26,27 have categorized glenoid morphology in osteoarthritis, but this has application to the understanding of glenoid bone deficiencies and the planning for the potential need for glenoid bone grafting. The glenoids were divided into 3 types. In their type A, the humeral head is centered. In type A-1, only minor central erosion is present. Type A-2 has marked central erosion and, as implied from the above, is most commonly seen in rheumatoid arthritis. In type B, the humeral head is subluxated and in the case of osteoarthritis, subluxated posteriorly. Type B-1 shows narrowing of the posterior aspect of the glenohumeral joint with subchondral sclerosis, perhaps marginal osteophytes. Type B-2 has posterior humeral subluxation with more eccentric glenoid wear creating a biconcave glenoid shape. They define type C as glenoid retroversion of more than 25°, most typically seen in dysplasia. In their patients, the humeral head was either well centered or slightly subluxated posteriorly in this type of glenoid morphology. Glenoid bone deficiencies in failed total shoulder arthroplasty
Antuna et al2 have classified glenoid bone deficiencies after glenoid component removal into central, peripheral, or combined, each with mild, moderate, or severe degrees of bone loss (Figure 3). The deficiencies were classified as mild if they involved less than one third of the glenoid surface or rim, as moderate if they involved between one third and two thirds of the surface or rim, and severe if they involved more than two thirds. These authors enumerated the deficiencies in 43 shoulders undergoing removal of the glenoid component. Central deficiencies were most common and present in 29 shoulders: mild in 10, moderate in 10, and severe in 9. There were combined deficiencies in 14 shoulders. These were rather mild in a few: 1 shoulder had mild central and posterior deficiencies and 1 had moderate central and mild anterior and posterior deficiencies. In the others, though, the deficiencies were greater: 12 had severe central deficiencies associated with 3 moderate anterior deficiencies, 3 severe anterior deficiencies, 1 moderate posterior deficiency, 2 severe posterior deficiencies, 1 moderate anterior and posterior deficiency, and 2 severe anterior and moderate posterior deficiencies. Peripheral deficiencies were not seen in an isolated manner but only in combination with central bone loss.
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Figure 3 Classification of bone deficiencies in the glenoid after glenoid component loosening and osteolysis. Most deficiencies are central or combined. (From Antuna SA, Sperling JW, Cofield RH, Rowland CM. Glenoid revision surgery after total shoulder arthroplasty. J Shoulder Elbow Surg 2001;10:217-24. Reprinted with permission).
SURGICAL RECONSTRUCTION FOR GLENOID BONE DEFICIENCIES Bone grafting for eccentric glenoid wear
Three articles have been published on this technique (Figure 2). Neer and Morrison13 in 1988 were able to monitor 19 of 20 shoulders having a large segmental graft for eccentric glenoid wear. The patients were followed up for a minimum of 2 years (average, 4.4 years). The clinical outcome was excellent in 16 and satisfactory in 1. Two patients reached desired limited goals. None of the glenoid components clinically loosened or moved, and none have required further surgical treatment. On radiographs, 2 fixation screws broke and 1 screw showed wear, presumably by contact with the metal of the humeral component. The authors comment that this technique provided sufficient osseous support to allow secure fixation of a glenoid component in the face of eccentric glenoid wear. The 2 other reports are not so uniformly favorable. Steinmann and Cofield24 in 2000 reported 28 patients having glenoid bone grafting for segmental glenoid wear. The common diagnoses were osteoarthritis in 19 and arthritis associated with shoulder instability in 5. Follow-up evaluation was a minimum of 2 years (average, 5.3 years). Similar to the earlier report, autogenous humeral head grafts were used. Typically, fixation was with 3.5-mm cortical screws.
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On clinical evaluation, 25 patients had no or slight pain, and 3 had moderate pain. Postoperative active elevation averaged 126°, external rotation averaged 39°, and internal rotation averaged to T12. Applying Neer’s result rating, 13 shoulders had excellent results, 10 had satisfactory results, and 5 had unsatisfactory results due to glenoid loosening in 2, reoperation for instability in 2, and persistent pain in 1. On radiographic assessment, 13 shoulders had no glenoid lucencies, 11 had incomplete lucencies, but 4 had complete lucencies, and lucencies were at least 1.5 mm wide in 3 of these. Three glenoids were considered radiographically loose. Two of the 3 were symptomatic, as indicated above. Thus, in this series at this length of follow-up, 4 of 28 glenoids had not remained securely fixed, and the risk of recurrence of instability despite correction of glenoid component alignment was introduced. Of importance in this article is that the technique for applying a bone graft in this situation was codified: 1. After glenoid component exposure, the center of the glenoid is identified and a central hole is made perpendicular to neutral glenoid alignment. The depth of the glenoid neck is confirmed and measured with a depth gauge. If the depth of the glenoid is such that it cannot be shortened more than a few millimeters, the patient is identified as being a candidate for segmental bone grafting. If the glenoid neck is deep enough to allow central reaming, the glenoid may be reamed to a neutral orientation and the need for bone grafting would be avoided. 2. The anterior aspect of the glenoid is prepared with a reamer in the normal orientation of the glenoid. 3. The additional anchoring holes for columns or the keel are prepared. 4. The eroded area of bone on the posterior aspect of the glenoid is prepared to receive the bone graft. 5. A segment of the humeral head is tapered to fit into this deficiency. 6. The graft is positioned with small Steinmann pins. 7. The Steinmann pins are replaced with 3.5-mm cortical screws. After drilling, the screws are countersunk slightly. 8. The graft is contoured with a microsagittal burr to match the surface of the anterior portion of the glenoid. 9. The glenoid component is secured in position. The third study reporting on segmental bone grafting of the glenoid included a more difficult patient group12: all patients had preoperative instability. There were 12 posterior and 5 anterior glenoid bone
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defects. The humeral head was used for grafting in 15 shoulders, and the iliac crest was used in 2. All patients were followed up to revision or at least for 2 years (average, 5.8 years). Radiographs showed 5 glenoids had complete lucent lines, with a lucent line width of 2 mm or less around the component. Four others had a shift in component position. Five shoulders failed during the period of review related to component issues in 3, instability in 2, and recurrent rotator cuff tearing in 1. The authors comment that corticocancellous grafting of the glenoid can restore glenoid version and volume and did so effectively in 14 of the 17 shoulders in their study. Associated issues are often present, however, most notably, glenohumeral instability, which typically is present in the face of uneven glenoid wear and may persist or recur. Glenoid bone grafting in failed arthroplasty
When glenoid components fail, most often due to loosening with some degree of bone resorption, it may be possible to place a new glenoid component with or without some degree of bone grafting. On other occasions, glenoid component removal alone, and perhaps with upsizing of the humeral head, has been shown to be a reasonable concept.11,21 When considering patients we had treated who required revision surgery, we too identified a number of glenoids that could not be reconstructed because of such extensive bone loss. In a 1990 report, we outlined the use of autogenous iliac crest bone graft to correct glenoid bone deficiencies at the time of revision surgery in 9 shoulders.6 One of these shoulders did not achieve satisfactory pain relief, and 2 years later, it was possible to repeat her shoulder surgery with better bone present, refix a glenoid component in place, and more important, achieve a satisfactory result. Thus, the thought emerged that bone grafting a bonedeficient glenoid component at the time of revision surgery might be preferable to leaving the deficiency, because there was the option later for further reconstructive surgery should it be necessary. Similar thoughts were expressed in an article by Peterson and Hawkins19 in 1998. As published in 2001 by Antuna et al,2 we undertook a major review of our experience with glenoid revision surgery after total shoulder arthroplasty. Forty-eight shoulders underwent glenoid revision surgery and were followed up a minimum of 2 years (average, 4.9 years). The indications were symptomatic glenoid component loosening in 29, glenoid implant failure in 14, and instability in 5. A new glenoid implant could be placed in 30 shoulders; however, 18 had such substantial bone deficiencies that it was necessary to remove the glenoid component and
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Figure 4 A, Substantial glenoid bone deficiency associated with glenoid component loosening and osteolysis. B and C, The defect was packed with frozen allograft bone chips. A radiograph 9 months after insertion of the bone graft shows substantial concentric wear into the glenoid bone graft material. At this time, the patient had intermittent moderate pain, 90° of active elevation, and 45° of external rotation; this range of motion was not too different from her movement preoperatively.
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cement and bone graft the deficiencies (Figure 4). In these instances, frozen cancellous allograft was used in 14 shoulders, autograft in 1, and no grafting in 3. In the shoulders that underwent glenoid component removal and bone grafting, there was evidence of graft remodeling over time, with a mean of 7.5 mm of centralization of the humeral head into the glenoid on follow-up radiographs. Three of the patients who underwent component removal and bone grafting had continuing severe pain and, at an average of 20 months after insertion of the bone graft, had revision surgery and implantation of a new glenoid component. These 3 patients were quite satisfied with their reduction in pain at a mean follow-up of 2.6 years and had no evidence of component loosening.1 In the above patients, early in the series, frozen cancellous grafts were used from our institutional bone bank. As regulations increased regarding bone bank qualifications and handling of human tissues, we elected to switch to commercial sources but continued to use frozen corticocancellous chips. Typically, 15 to 50 cm3 of graft are used. The grafts are thawed and then bathed repetitively in sterile saline to remove most of the marrow and a number of cells, in the belief that this reduces the immunologic load to the patient and perhaps decreases the risk of disease transmission.3 It also reduces the lubrication between the particles, creating greater interdigitation between the corticocancellous particles and quite likely improving the strength of the compacted allograft. It is not known how long it is necessary for such a graft to incorporate. With bone scintigraphy, the uptake approaches normal at 2 to 3 years after surgery.3 In a recent case report, freeze-dried allograft with platelet-derived growth factor was used to fill the defect after failure of an unconstrained glenoid component. One year later, revision to a total shoulder arthroplasty was undertaken and despite the radiologic appearance of incorporation of the allograft, the histologic examination found no indication of new mature bone formation. There was necrotic bone surrounded by a fibrous tissue and no osteoblastic activity or osteoid formation. Despite this, 2 years after insertion of the total shoulder arthroplasty, the patient has a painless shoulder with reasonable function and no radiologic evidence of component loosening or graft resorption.20 We have recently expanded and extended the follow-up on our patients who have had revision surgery for glenoid component loosening.5 Amongst those studied, 35 shoulders had glenoid component removal and allograft bone grafting without glenoid reimplantation. Follow-up was a minimum of 2 years (average, 6.2 years). Pain relief occurred in 24 of these 35 shoulders; however, preoperative and postoperative range of motion did not change significantly. Nineteen of the patients were satisfied with their outcome. Survival free of
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Figure 5 A, Some surgeons prefer structural autogenous iliac crest or allogenic bone graft after glenoid component removal in the face of severe bone deficiency. B, These grafts are also subject to resorption.
reoperation was 78% at 5 years. Of the 7 shoulders that had reoperation, 6 had placement of a new glenoid component because of continuing pain at a mean of 3.5
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Figure 6 A, Subsequent to glenoid component removal and allograft cancellous bone grafting, the patient continued to have severe shoulder pain. B, After consolidation of the graft, a new glenoid component was placed 3 years later.
years after glenoid component removal and bone grafting. One patient with continuing pain had resection arthroplasty in the face of a positive culture for Propionibacterium acnes. Thirty-four shoulders had complete sets of radiographs. There was medial shifting of the humeral head to some degree in all patients; it was less than 5 mm in 10, 6 to 10 mm in 10, and greater than 10 mm in 14. It seems from the above that allograft bone grafting in the face of an unreconstructable glenoid after glenoid component failure will usually lead to pain relief, but if pain relief does not occur, reinsertion of a glenoid component seems to be possible. Although we have evolved to favor cancellous chips and allografts, others have favored structural autografts in this setting (Figure 5). The cortical grafts allowed reliable second-stage reconstruction of the shoulder with a glenoid implant. An additional benefit of a structural graft is that in certain situations, glenoid implants fixed with screws or special designs of implants can be performed as a single-stage procedure in some shoulders.8,17,18
Reimplantation of a glenoid component after component removal and bone grafting
Not a great deal of information is available on this subject.6 As described, there are occasional case reports as a part of larger series analyzing glenoid revision surgery. In 2002, we also offered a case report including 3 patients where this had been done after glenoid component removal and allograft cancellous chip bone graft.1 Reinsertion of a glenoid component occurred at 6 months, 20 months, and 3 years after the grafting procedure. In each instance, the graft seemed to be firmly incorporated but did contain some element of fibrous tissue. The new implants could be securely fixed in place. In 1 instance, it was apparent by 1 year after surgery that the newly placed glenoid component had loosened, and 2 years later, the glenoid component was yet again removed. Outcomes were excellent and satisfactory in the other 2 patients at 5 and 8 years after surgery. One patient had no lucent lines, and the other had an incomplete lucent line on radiographs.
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We recently expanded review of patients with this situation and identified 7 shoulders in which a glenoid component was reinserted after allograft bone grafting.4 Two received rather standard allpolyethylene glenoid components and 5 had metal backed components with screw fixation. During the follow-up period, it was evident that a low-grade infection Propionibacterium acnes infection had developed in 2 patients, and they underwent re-revision procedures. The remaining 5 patients expressed satisfaction with their procedure and had reduced pain. Motion was essentially unchanged. Radiographically, 2 of the 5 patients without infections had an incomplete 1-mm lucent line at the glenoid– bone cement interface. No lucent lines were present in the other patients. Thus, reimplantation of a glenoid component in this setting can offer an improved clinical condition in most patients, particularly reduction in pain and improvement in satisfaction (Figure 6). We must be continually vigilant in revision arthroplasty about the possibility of a lowgrade infection being present at the time of revision surgery. SUMMARY AND CONCLUSIONS Bone grafting has been quite useful as a part of reconstructive shoulder surgery in the face of shoulder arthritis. In the face of osteopenia in the glenoid vault, autogenous impaction grafting may improve component fixation. Autogenous segmental grafts have proven useful to improve glenoid position and enhance component fixation in selected cases with dysplasia or eccentric glenoid wear from arthritis. In failed total shoulder arthroplasty, occasionally 1-stage but usually 2-stage procedures are necessary. Some surgeons prefer structural autografts; others prefer particulate compressed allografts for the first-stage of reconstruction. Case reports and clinical series are available to document the rate of success using these techniques and, from a clinical standpoint, seem to be a viable option as a part of the reconstructive surgeon’s armamentarium. REFERENCES
1. Antuna SA, Sperling JW, Cofield RH. Reimplantaton of a glenoid component after component removal and allograft bone grafting. A report of three cases. J Shoulder Elbow Surg 2002;11:637-41. 2. Antuna SA, Sperling JW, Cofield RH, Rowland CM. Glenoid revision surgery after total shoulder arthroplasty. J Shoulder Elbow Surg 2001;10:217-24. 3. Board TN, Rooney P, Kearney JN, Kay PR. Impaction allografting in revision total hip replacement. J Bone Joint Surg Br 2006;88: 852-7. 4. Cheung EV, Sperling JW, Cofield RH. Reimplantation of a glenoid component following component removal and bone grafting. J. Bone Joint Surg Am (Submitted). 5. Cheung EV, Sperling JW, Cofield RH. Revision shoulder arthroplasty for glenoid component loosening (pending publication).
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6. Cofield RH, Edgerton BC. Total shoulder arthroplasty. Complications and revision surgery. Instr Course Lect 1990;39:449-62. 7. Edwards TB, Boulahia A, Kempf JF, Boileau P, Nemoz C, Walch G. Shoulder arthroplasty in patients with osteoarthritis and dysplastic glenoid morphology. J Shoulder Elbow Surg 2004;13:1-4. 8. Gagey O, Pourjamasb B, Court C. Revision arthroplasty of the shoulder for painful glenoid loosening: a series of 14 cases with acromial prostheses reviewed at four year follow-up. Rev Chir Orthop Reparatrice Appar Mot 2001;97:221-8. 9. Gazielly DF, Allende C, Pamelin E. Results of cancellous compaction technique for glenoid resurfacing [abstract]. Proceedings of the 9th International Congress on Surgery of the Shoulder, 1st International Congress of Shoulder Therapists. Washington, DC, May 2-5; 2004. p. 1. 10. Godenèche A, Poileau P, Favard L, et al. Prosthetic replacement in the treatment of osteoarthritis of the shoulder. Early results of 268 cases. J Shoulder Elbow Surg 2002;11:11-8. 11. Hawkins RJ, Greis PE, Bonutti PM. Treatment of symptomatic glenoid loosening following unconstrained shoulder arthroplasty. Orthopedics 1999;22:229-34. 12. Hill JM, Norris TR. Long-term results of total shoulder arthroplasty following bone-grafting of the glenoid. J Bone Joint Surg Am 2001;83:877-83. 13. Neer CS 2nd, Morrison DS. Glenoid bone-grafting in total shoulder arthroplasty. J Bone Joint Surg Am 1988;70:1154-62. 14. Neer CS II. Reconstructive surgery and rehabilitation of the shoulder. In: Harris ED Jr, Ruddy S, Sledge CB, editors. Textbook of rheumatology, Vol II. Philadelphia, PA: W. B. Saunders; 1981. p. 1944-59. 15. Neer CS II. Shoulder reconstruction. Philadelphia, PA: W. B. Saunders; 1990. p. 238-46. 16. Neer CS II, Watson KC, Stanton FJ. Recent experience in total shoulder replacement. J Bone Joint Surg Am 1982;64:319-37. 17. Neyton L, Sirveaux F, Roche O, Mole D, Boileau P, Walch G. Results of revision surgery for glenoid loosening: a multicentric series of 37 shoulder prosthesis. Rev Chir Orthop Reparatrice Appar Mot 2004;90:111-21. 18. Page RS, Haines JF, Trail IA. Impaction bone grafting of the glenoid in revision shoulder arthroplasty [abstract]. Proceedings of the 9th International Congress on Surgery of the Shoulder, 1st International Congress of Shoudler Therapists. Washington DC; May 2-5, 2004. p. 2. 19. Petersen SA, Hawkins RJ. Revision of failed total shoulder arthroplasty. Orthop Clin North Am 1998;29:519-33. 20. Peidro L, Segur JM, Poggio D, Fernandez de Retana P. Use of freeze-dried bone allograft with platelet-derived growth factor for revision of a glenoid component. J Bone Joint Surg Br 2006;88: 1228-31. 21. Rodosky MW, Bigliani LU. Surgical treatment of nonconstrained glenoid component failure. Oper Tech Orthop 1994;4:226-36. 22. Smith SP, Bunker TD. Primary glenoid dysplasia. A review of 12 patients. J Bone Joint Surg Br 2001;83:868-72. 23. Sperling JW, Cofield RH, Steinmann SP. Shoulder arthroplasty for osteoarthritis secondary to glenoid dysplasia. J Bone Joint Surg Am 2002;84:541-6. 24. Steinmann SP, Cofield RH. Bone grafting for glenoid deficiency in total shoulder replacement. J Shoulder Elbow Surg 2000;9: 361-7. 25. Szabo I, Buscayret F, Edwards TB, Nemoz C, O’Connor DP, Boileau P, Walch G. Radiographic comparison of two glenoid preparation techniques in total shoulder arthroplasty. Clin Orthop 2005:104-10. 26. Walch G, Badet R, Boulahia A, Khoury A. Morphologic study of the glenoid in primary glenohumeral osteoarthritis. J Arthroplasty 1999;14:756-60. 27. Walch G, Boulahia A, Boileau P, Kempf JF. Primary glenohumeral osteoarthritis: clinical and radiographic classification. The Aequalis Group. Acta Orthop Belgica 1998;64(suppl 2):46-52.