Humeral surface replacement for the sequelae of fractures of the proximal humerus

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1 Humeral surface replacement for the sequelae of fractures of the proximal humerus G. Pape, F. Zeifang, T. Bruckner, P. Raiss, M. Rickert, M. Loew From University of Heidelberg, Heidelberg, Germany G. Pape, MD, Orthopaedic Surgeon F. Zeifang, MD, PhD, Head of the Division of Shoulder Surgery, Consultant Orthopaedic Surgeon P. Raiss, MD, Orthopaedic Surgeon M. Rickert, MD, PhD, Head of the Division of Endoprosthetic, Consultant Orthopaedic Surgeon Department of Orthopaedic Surgery, Division of Upper Limb Surgery University of Heidelberg, Schlierbacher Landstrasse 200A, Heidelberg, Germany. T. Bruckner, Dr, sc.hum., Dipl.-Math, Statistician Department of Medical Biometry and Informatics University of Heidelberg, INF 305, Heidelberg, Germany. M. Loew, MD, PhD, Consultant Orthopaedic Surgeon, Professor ATOS Klinik, Bismarckstrasse 9-15, Heidelberg, Germany. Correspondence should be sent to Dr G. Pape; British Editorial Society of Bone and Joint Surgery doi: / x.92b $2.00 J Bone Joint Surg [Br] 2010;92-B: Received 18 December 2009; Accepted after revision 19 April 2010 Fractures of the proximal humerus can lead to malalignment of the humeral head, necrosis and post-traumatic osteoarthritis. In such cases surface replacement might be a promising option. A total of 28 shoulders with glenohumeral arthritis subsequent to a fracture underwent surface replacement arthroplasty of the humeral head in patients with a mean age of 60 years (35 to 83). On the basis of the inclination of the impacted head, post-traumatic arthritis was divided into three types: type 1, an impacted fracture of the head in an anatomical position (seven cases); type 2, a valgus impacted fracture (13 cases); type 3, a varus impacted fracture (eight cases). The outcome was measured by means of the Constant score. According to the Boileau classification of the sequelae of fractures of the proximal humerus, all 28 patients had a final result of intra-capsular category 1. The mean Constant score for the 28 shoulders increased from 23.2 points (2 to 45) pre-operatively to 55.1 points (20 to 89) at a mean of 31 months (24 to 66) post-operatively. Valgus impacted fractures had significantly better results (p < 0.039). Surface replacement arthroplasty can provide good results for patients with posttraumatic osteoarthritis of the shoulder. Their use avoids post-operative complications of the humeral shaft, such as peri-prosthetic fractures. Further surgery can be undertaken more easily as the bone stock is preserved. Surface replacement of the head of the humerus has assumed increasing importance for the treatment of primary and secondary glenohumeral osteoarthritis as an alternative to anatomical stemmed prostheses. 1-8 In young and active patients, surface replacement arthroplasty is a viable, bone-preserving option for treatment. 1 Good medium- and long-term results have been reported in primary osteoarthritis, rheumatoid arthritis, osteonecrosis of the head and arthropathy following tears of the rotator cuff. 2-8 The advantages of surface replacement include a shorter operation time with a less demanding surgical technique, preservation of bone stock with no loss of strength and avoidance of potential complications such as peri-prosthetic fractures associated with a stemmed humeral prosthesis. Surface replacement arthroplasty is always possible if the epiand metaphyseal bone stock is maintained. In a multicentre study, Boileau et al 9 identified four sequelae of fracture of the proximal humerus which frequently lead to poor function and severe impairment. They were able to distinguish two categories of sequelae. Category 1 included the sequelae of an intracapsular/ impacted fracture associated with cephalic collapse or necrosis (type 1) or a chronic locked dislocation (type 2). Category 2 comprised the sequelae of an extracapsular/disimpacted fracture associated with nonunion of the surgical neck (type 3) or of the greater tuberosity (type 4). Currently, no standard procedure exists for the operative treatment of the sequelae of proximal humeral fractures. The insertion of a shoulder prosthesis is often the only reasonable therapeutic option. 9 In old trauma with a varus or valgus impacted humeral head (Boileau type 1), the insertion of an anatomical stemmed shoulder prosthesis is often difficult because of the bony distortion. In such cases surface replacement could be a useful option. The aim of this study was to analyse the results of surface replacement arthroplasty in the treatment of patients with a chronic impacted fracture of the head of the humerus. Patients and Methods Between January 2004 and June 2007, 68 shoulder arthroplasties for post-traumatic VOL. 92-B, No. 10, OCTOBER

2 1404 G. PAPE, F. ZEIFANG, T. BRUCKNER, P. RAISS, M. RICKERT, M. LOEW Table I. Pathophysiological classification of impacted humerus head fractures Inclination angle ( ) Numbers 1, impacted humeral head fracture in physiological position 124 to , valgus impacted humeral head fracture > , varus impacted humeral head fracture < osteoarthritis were performed at our institution and were included in a prospective database. Post-traumatic osteoarthritis was defined as a chronic disorder of the joint with pain, loss of function and corresponding radiological changes such as narrowing of the joint, the formation of osteophytes and subchondral sclerosis as a consequence of a previous fracture. 10 Of these, 36 shoulders were managed with a surface replacement. Among the remaining 32 shoulders, there were 14 hemiarthroplasties using an anatomical stemmed prosthesis, six total replacements with cemented glenoid components, six trauma prostheses (hemiarthroplasties designed for proximal humeral fractures), five reversed shoulder replacements and one a bipolar prosthesis. Only the patients with a surface replacement were included in this study. The inclusion criteria were 1) post-traumatic osteoarthritis of the glenohumeral joint resulting from a previous fracture of the proximal humerus; 2) sufficient epi- and metaphyseal bone stock with no intra-osseous lesions and less than 40% necrosis of the head; 3) a minimum followup of two years; 4) an intact rotator cuff; and 5) glenoid type A1 or better according to the criteria of Walch et al. 11 The exclusion criteria were previous infection of the affected shoulder, neural injuries of the affected upper limb and glenoid type A2. 11 There were 28 shoulders in 28 patients which qualified for inclusion. All of these patients had pain and loss of function. There were 18 women and ten men, with a mean age of 60 years (35 to 83) at the time of arthroplasty. The patterns of fracture were classified according to the system described by Neer. 12 There were 21 two-part fractures, one three-part fracture and two four-part fractures as seen on anteroposterior radiographs. In four cases the initial fracture pattern could not be reconstructed and no Neer classification could be assigned. The mean time between the fracture and arthroplasty of the shoulder was 11 years (6 months to 40 years). Ten fractures had been treated primarily with open reduction and internal fixation, and the remaining 18 were managed non-operatively. In one case the metalwork was removed at the same time as the surface replacement was implanted. All patients were routinely evaluated before operation, six and 12 months after, and at the time of the most recent follow-up using the same standardised clinical and radiological protocol on each occasion. Radiographs of the shoulder were taken in true anteroposterior (AP) and axillary projections. For the AP view the x-ray tube was angled by 40 so that the anterior and posterior rims of the glenoid overlapped fully. For the axillary view, the patient sat and leaned with the arm raised over the end of the X-ray table. The beam was directed perpendicular to the cassette and the shoulder. The rotator cuff and the morphology of the glenoid were assessed pre-operatively by MRI, and this corresponded in all cases with the intra-operative findings. The clinical and functional outcomes were evaluated by means of the Constant score. 13 The active range of elevation, abduction and external rotation was recorded with the hanging arm in a neutral position and the elbow flexed to 90. The subjective result of surgery was rated by the patient as very satisfactory, satisfactory, somewhat disappointing or very disappointing. Operative technique and implants. The operation was performed via the deltopectoral approach using the technique described by Neer, Watson and Stanton. 14 The biceps tendon was dissected close to its glenoid attachment and was tenodesed in the bicipital groove in all cases. The head was reamed with hemispherical reamers on the basis of the individual anatomical circumstances. The prostheses were adapted to the potential distorted anatomy of the proximal humerus and impacted by a press-fit technique. The subscapularis muscle was repaired using three to five nonabsorbable tendon-to-tendon sutures. The senior author (ML) was principal or assistant surgeon in all operations. The Aequalis Resurfacing Head (Tornier Inc., Edina, Minnesota) was used in nine cases, the Epoca RH Cup (Argomedical, Cham, Switzerland) in 14, and a Copeland Surface Replacement (Biomet Inc., Warsaw, Indiana) in five. The selection criterion for the type of prosthesis was its availability. Before February 2005 we implanted only the Copeland Surface Replacement, between March 2005 and September 2006 the EPOCA RH prosthesis, and after October 2006 exclusively the Aequalis Resurfacing Head. All the designs offered a spherical joint surface and were coated with hydroxyapatite on the inner aspect. The Aequalis Resurfacing Head and the Copeland Surface Replacement, both use a centred peg to gain primary stability, whereas the EPOCA Cup uses a conical crown-shaped ring. After operation all patients underwent a standard rehabilitation programme. The arm was placed in a splint in 45 abduction for four weeks. Immediately after operation the shoulder was treated by active assisted exercises with limitation of abduction and flexion to 90 and no external rotation for four weeks. After six weeks all patients attended or stayed as in-patients in a specialised rehabilitation centre for 21 days, with free passive and active movement to build up their muscle strength. THE JOURNAL OF BONE AND JOINT SURGERY

3 HUMERAL SURFACE REPLACEMENT FOR THE SEQUELAE OF FRACTURES OF THE PROXIMAL HUMERUS 1405 Table II. Pre-operative status (mean (range)) p-value Constant score (points) 32 (22 to 45) (2 to 34) 22.5 (15 to 32) * Constant score (%) 42.6 (24 to 62) 25 (3 to 41) 29 (16 to 46) * Pain (points) 3.86 (0 to 10) 2.77 (0 to 5) 0.63 (0 to 5) Activity (points) (9 to 16) 6.23 (0 to 10) 9 (5 to 13) * Mobility (points) (8 to 36) 8.31 (0 to 12) (8 to 16) * Power (points) 1 (0 to 4) 1.46 (0 to 7) 0.63 (0 to 3) Flexion ( ) (50 to 150) (0 to 90) 77.5 (50 to 100) Abduction ( ) 80 (50 to 150) (0 to 90) (40 to 90) External rotation ( ) 10 (0 to 20) 2.31 (0 to 20) 2.5 (0 to 10) * * statistically significant Table III. Group comparison pre-operatively 1/2 1/3 2/3 p-value Constant score (points) * * * Constant score (%) * * Pain (points) Activity (points) * * Mobility (points) * * * Power (points) Flexion ( ) Abduction ( ) External rotation ( ) * * * * statistically significant (p < 0.05) Pathophysiological classification. On the basis of the angle of inclination, the cohort was divided into three pathophysiological types of lesion: type 1, with an impacted fracture of the head in a physiological position; type 2, with a valgus impacted fracture and type 3, with a varus impacted fracture (Table I). The anatomical difficulties caused by the post-traumatic deformity did not permit complete correction of the head of the humerus into the physiological position. In order to achieve inclination and retroversion of the prostheses malposition of the head was needed, and the prostheses were adapted to the distorted anatomy of the proximal humerus. We classified the alignment of the head on the basis of the AP radiograph obtained immediately after operation. The angle of inclination was determined by measuring the angle between the central spike of the prosthesis and the long axis of the humerus, as described by Fink et al 3 and Fuerst, Finkord and Rüther. 15 Because the Epoca prosthesis had no central spike, a perpendicular line was drawn through the middle of the area of resection. Statistical analysis. Two-way repeated-measures analysis of variance was used to assess differences between the groups using the pre-operative value (= baseline value) as the covariate. The level of significance was set at p = 0.05 (5%). All analyses were performed using SPSS version 13.0 (SPSS Inc., Chicago, Illinois). Results According to the classification of Boileau et al, 9 all 28 patients had the sequelae of a category 1 intra-capsular, impacted fracture. Table I shows the pathophysiological classification with the number of cases and the determination of the angle of inclination for each type of lesion. There were 11 patients with post-traumatic necrosis of the head, four in group 1 (type 1), five in group 2 (type 2) and two in group 3 (type 3). The mean extent of necrosis of the head was 17.6% (10.0% to 28.4%) and was measured according to the method of Raiss et al. 7 In all cases the necrotic zones were located at the articular surface between the apex and the lower third of the head and were fully covered by the surface replacement. Survival and complications. There were no intra- or perioperative complications. The mean operation time was 75 minutes (48 to 128). One patient died of unknown causes and two had incomplete follow-up. All three were excluded, leaving 25 prostheses available for study. In one case of type 3 necrosis the replacement had to be revised two years after implantation and converted to a reverse prosthesis because of anterosuperior instability with persistent pain. MR arthrography before revision showed complete degeneration with fatty atrophy of the supraspinatus and infraspinatus muscles, and partial rupture of the subscapularis muscle. The findings at the last follow-up before revision (24 months) were included in the analysis. The mean follow-up was 31 months (24 to 66). Functional and clinical outcome. The mean Constant score for the entire cohort (n = 25) improved from 23.2 points (2 to 45) pre-operatively to 55.1 points (20 to 89) postoperatively (p < 0.001), and, adjusted by age and gender, from 30.5% (3% to 62%) to 72.1% (29% to 114%) (p < 0.001). There was a statistically significant improvement in all subscores of the Constant score and in the range of movement. Table II shows the pre-operative Constant score and subscores with range of movement for each different type of impacted fracture. Significant differences were found among the three groups for the total and the age- and gender-adjusted Constant score, as well as for activity, mobility and external rotation (Table III). There VOL. 92-B, No. 10, OCTOBER 2010

4 1406 G. PAPE, F. ZEIFANG, T. BRUCKNER, P. RAISS, M. RICKERT, M. LOEW Table IV. The subjective assessment and the clinical and functional results (mean (range)), significance values and improvement at the end of follow-up compared to baseline p-value Patient satisfaction 2 (1 to 4) 1.54 (1 to 3) 2.5 (1 to 4) Constant score (points) 54 (20 to 74) 62 (30 to 89) 45 (27 to 67) Δ Constant score (points) compared to pre-operative status 22 (-12 to 46) 43.1 (15 to 76) 22.5 (4 to 44) Constant score (%) 69.9 (29 to 100) (33 to 114) 57.5 (29 to 92) * Δ Constant score (%) compared to pre-operative status 27.3 (-17 to 50) 57.2 (16 to 100) 28.5 (5 to 56) Pain (points) 10.6 (5 to 15) 11.6 (5 to 15) (5 to 15) Δ Pain (points) 6.7 (-2 to 14) 8.85 (4 to 15) 9.5 (2 to 15) Activity (points) 14.6 (7 to 20) (10 to 20) 12.1 (6 to 18) * Δ Activity (points) compared to pre-operative status 3.7 (-4 to 10) 11 (4 to 20) 3.13 (-6 to 8) Mobility (points) 25.7 (8 to 38) 27.7 (12 to 40) (10 to 32) Δ Mobility (points) compared to pre-operative status 9.5 (-6 to 22) 19.4 (4 to 34) 8 (-4 to 24) Power (points) 3.43 (0 to 10) 5.62 (0 to 16) 3.63 (0 to 8) Δ Power (points) compared to pre-operative status 2.43 (-2 to 10) 4.16 (-1 to 16 3 (0 to 8) Flexion ( ) (40 to 170) (90 to 170) (35 to 170) * Δ Flexion ( ) compared to pre-operative status 33 (-50 to 80) 70.4 (0 to 130) (-20 to 90) Abduction ( ) (40 to 170) 125 (80 to 170) 86.9 (40 to 170) * Δ Abduction ( ) compared to pre-operative status 27.1 (-20 to 70) 66.5 (10 to 130) 23 (-20 to 90) External rotation ( ) 23.6 (0 to 45) 33.9 (0 to 50) (0 to 45) Δ External rotation ( ) compared to pre-operative status 13.6 (0 to 30) 31.5 (0 to 50) (-5 to 45) * statistically significant (p < 0.05) Table V. Group comparison after 24 months Pairwise analysis of covariance (closed testing procedure) 1/2 1/3 2/3 p-value Constant score (points) Constant score (%) * * Pain (points) Activity (points) * * Mobility (points) Power (points) Flexion ( ) * * Abduction ( ) * * External rotation ( ) * statistically significant (p < 0.05) was no significant difference with regard to functional and clinical outcome between patients with previous surgery on the affected shoulder and those without (p < 0.001). Table IV shows the post-operative findings in the three groups after 24 months. There was a trend towards better results for all outcome criteria in the type 2 fractures, in contrast to the type 3 fractures (Table V). In all groups the Constant score, the subcategories of the Constant score and the range of movement improved significantly. The improvement relative to the baseline status in patients with a valgus impacted fracture (type 2) showed significantly greater benefit in their age- and gender-adjusted Constant score, their subcategory activity of the Constant score, and their range of flexion and abduction than in patients with a varus impacted fracture (type 3). On the subjective assessment, on a numerical rating scale (from 1, very satisfied to 4, very disappointed ) patients with type 1 fractures had a mean value of 2 (SD 1.15), patients with type 2, 1.54 (SD 0.66), and patients with type 3, 2.4 (SD 0.93). Only the patient who underwent revision surgery rated the result before re-operation as very disappointing. Radiographic results. Apart from the one revision, there were no signs of aseptic loosening or decentralisation on radiographic evaluation at the most recent follow-up (Figs 1 to 3a). One patient had a secondary glenoid erosion after 17 months with moderate symptoms (pain, nine points; Constant score, 36 points) and refused further surgical treatment (Fig. 3b). The mean angle of inclination was (128 to 133 ) for type 1, 143 (137.1 to 155 ) for type 2 and (110.5 to ) for type 3. The mean humeral offset was 10.9 mm (2.3 to 20.3) for type 1, 1.7 mm (-26 to 15) for type 2, and 18.5 mm (8.1 to 4.1) for type 3. Humeral offset was measured as the distance between the centre of rotation of the head and the long axis of the humerus. In accordance with the study of Rozing and Obermann, 16 templates with circles of differing radii were used to locate the geometric centre of the head. Discussion The surgical treatment of the sequelae of fractures of the proximal humerus is one of the most challenging situations in shoulder reconstruction. 9,10 Several options have been described including arthroscopy with debridement, reorientation of the humeral head with a rotation osteotomy, replenishment of a major defect with allograft to restore joint congruency and bone transfer techniques. 9,17-19 THE JOURNAL OF BONE AND JOINT SURGERY

5 HUMERAL SURFACE REPLACEMENT FOR THE SEQUELAE OF FRACTURES OF THE PROXIMAL HUMERUS 1407 Fig. 1a Fig. 1b Fig. 1c Fig. 1d Pre-operative anteroposterior a) and axillary b) radiographs of an impacted humeral head fracture in the physiological position and Anteroposterior c) and axillary d) radiographs two years after surface replacement. Fig. 2a Fig. 2b Fig. 3a Fig. 3b Anteroposterior radiographs of a) a valgus impacted humeral head fracture 15 years after trauma and b) 25 months after surface replacement. Anteroposterior radiographs of a) a varus impacted humeral head fracture with slight signs of post-traumatic osteoarthritis but severe pain and loss of function and b) a varus impacted humeral head fracture 17 months after implantation of surface replacement, with superior erosion in the glenoid. Arthroplasty has become an established alternative, with good results in terms of function and relief of pain Alongside the insertion of a conventional stemmed prosthesis, resurfacing arthroplasty is an established form of shoulder hemiarthroplasty for arthritis. 1-8 The results of surface replacement as a treatment for prior trauma have been published for the management of fixed anterior dislocation of the shoulder, and to a lesser extent for necrosis of the head. 7,23 In most cases previous trauma results in malposition of the head, as described by Boileau et al. 9 Surface replacement is possible only for chronic category 1 fractures of the head as described by Boileau and is technically not feasible for category 2 fractures because of nonunion of the surgical neck or malunion of the tuberosity. 9 The orientation of the surface arthroplasty into inclination and retroversion in our series is intended to reconstruct the predefined anatomy. Malposition of the joint surface and the tuberosities limits the potential for anatomical reconstruction. The results differ significantly among the individual types of impacted fracture. For the age- and genderadjusted Constant score (p = 0.039), activity (p = 0.027), flexion (p = 0.046) and abduction (p = 0.041), impacted fractures in a valgus position (type 2) showed significantly better results than those in varus (type 3). Patients with a type 2 fracture were the most satisfied with the operation and had a mean score of 1.54 (1 = very satisfied, 4 = very disappointed). The results of surface replacement for impacted fractures are comparable with the short- and mid-term results for other aetiologies. 3,6,7,23,24 Raiss et al 23 recently recorded good results with resurfacing arthroplasty for the treatment of fixed anterior glenohumeral dislocation. The mean Constant score improved from 20 points before to 61 points after operation. In 2008, Buchner et al 24 described the VOL. 92-B, No. 10, OCTOBER 2010

6 1408 G. PAPE, F. ZEIFANG, T. BRUCKNER, P. RAISS, M. RICKERT, M. LOEW results of surface replacement for osteoarthritis of the shoulder. The mean Constant score increased from 33.1 points before surgery to points 12 months later. Two years earlier, Fink et al 3 presented the results of humeral surface replacement in rheumatoid shoulders with or without additional tearing of the rotator cuff. In the group with an intact cuff the mean Constant score improved from 21.5 points to 66.1 points, in the group with partial tearing from 19.6 points to 64.9 points and in those with massive tears from 17.5 points to 56.9 points. After a follow-up of five to ten years, Levy and Copeland 5 observed in patients with osteoarthritis a Constant score of 57.7 points for hemi-prostheses and 64.2 points for TSA and the rheumatoid patients a Constant score of 48.4 points with hemiarthroplasty and 52.7 points for total endoprostheses using the cementless Copeland Surface Replacement. In another study, Raiss et al 7 followed patients treated with humeral surface replacement for nontraumatic or post-traumatic osteonecrosis over an average of three years. The mean Constant score improved from 31 to 62 points. Comparing the findings from our study with the results reported in the literature for humeral surface replacement, varus impacted fractures (type 3) showed the worst clinical outcome. Boileau et al 9 described 71 cases in which patients with chronic fractures of the head of the humerus were treated with a conventionally stemmed prosthesis (46 hemiprostheses, 25 total endoprostheses). Patients with category 1 sequelae achieved better results than those in category 2. In the group with necrosis of the humeral head as a consequence of impacted fracture (Boileau type 1), the age- and gender-adjusted Constant score improved from 37% to 75%, and the mean pain value at the end of follow-up was 12 points (0 = maximum pain, 15 = painless). In this group the active flexion recovered from 87 to 133 and the active external rotation from 0 to 40. In our current study there was an improvement of mean active anterior elevation from 76 to 124 and of active external rotation from 4 to 26. The age- and gender-adjusted Constant score improved from 30% to 72%, with a mean pain value at the end of follow-up of 10.9 points. Comparing our findings to those of previous publications, the results of humeral surface replacement arthroplasty for the treatment of necrosis of the humeral head were comparable with those achieved using conventionally stemmed prostheses. These results reveal significantly less improvement in the age- and gender-adjusted Constant score, the subcategory activity, and the range of flexion and abduction for patients with a varus impacted fracture (type 3). The relatively poor results in patients with this injury might be connected with the superior migration of the greater tuberosity, with consequent narrowing of the subacromial space and potential damage to the tendons there. The patient who required revision with a complete rupture of the superoposterior tendon with fatty atrophy of the supraspinatus and infraspinatus muscles had a varus impacted fracture (type 3). The joint kinematics are changed by, among other factors, medialisation of the centre of rotation. This could result in diminished function and less gain of strength. In cases of valgus impacted fracture the centre of rotation of the humeral head moved distally with better strain on the rotator cuff and the deltoid muscle. Moreover, with a valgus malpositioned head the humeral surface replacement prosthesis articulates under the acromion, with a probable prevention of rupture of the cuff tendons. Although the number of cases in our study was small and prostheses from three different manufacturers were used, the treatment of impacted fractures of the head (Boileau category 1) with a surface replacement is a feasible alternative to other methods, such as reversed shoulder replacement or implantation of a conventional stemmed prosthesis. However, the clinical and functional outcome depends on the degree of the malalignment. Patients with a varus impacted fracture (Boileau type 3) had significantly worse results than those with a valgus impacted fracture (Boileau type 2). This finding should be taken into account when considering the further treatment of arthritis of the shoulder following a fracture of the head of the humerus. Listen live Listen to the abstract of this article at This study was supported by the non-commercial research fund of the Deutsche Arthrose-Hilfe e.v. The fund supports clinical investigations using the shoulder arthroplasty register of the Orthopaedic Department of the University of Heidelberg. No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article. References 1. Bailie DS, Llinas PJ, Ellenbecker TS. Cementless humeral resurfacing arthroplasty in active patients less than fifty-five years of age. J Bone Joint Surg [Am] 2008;90-A: Levy O, Copeland SA. Cementless surface replacement arthroplasty (Copeland CSRA) for osteoarthritis of the shoulder. J Shoulder Elbow Surg 2004;13: Fink B, Singer J, Lamla U, Rüther W. Surface replacement of the humeral head in rheumatoid arthritis. Arch Orthop Trauma Surg 2004;124: Jerosch J, Schunck J, Morsy MG. Shoulder resurfacing in patients with rotator cuff arthropathy and remaining subscapularis function. Z Orthop Unfall 2008;146: Levy O, Copeland SA. 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