Investigation performed at the Mayo Clinic and Mayo Foundation, Rochester, Minnesota

Transcription

1 1814 COPYRIGHT 2001 BY THE JOURNAL OF BONE AND JOINT SURGERY, INCORPORATED Shoulder Hemiarthroplasty for Glenohumeral Arthritis Associated with Severe Rotator Cuff Deficiency BY JOAQUIN SANCHEZ-SOTELO, MD, PHD, ROBERT H. COFIELD, MD, AND CHARLES M. ROWLAND, MS Investigation performed at the Mayo Clinic and Mayo Foundation, Rochester, Minnesota Background: Hemiarthroplasty for the treatment of shoulders with glenohumeral arthritis and severe rotator cuff deficiency has been reported to provide reasonable clinical results. The purposes of this study were to determine the clinical and radiographic results of hemiarthroplasty for this condition and to identify pathological and technical factors that may influence its outcome. Methods: Thirty patients (thirty-three shoulders) managed with hemiarthroplasty because of glenohumeral arthritis and a massive, irreparable tear of the rotator cuff were followed for an average of five years (range, two to eleven years). Eight shoulders had undergone a prior acromioplasty and resection of the coracoacromial ligament. A small prosthetic head was used in three shoulders; a medium head, in twenty-six; and a large head, in four. Clinical results were graded according to the limited-goals criteria of Neer et al. Results: The mean pain score decreased from 4.2 points preoperatively to 2.2 points at the time of the most recent follow-up (p = ). However, at the time of the most recent follow-up, nine shoulders (27%) had moderate pain at rest (four shoulders) or pain with activity (five shoulders). Mean active elevation improved from 72 (range, 30 to 150 ) to 91 (range, 40 to 165 ) (p = 0.008). Anterosuperior instability occurred in seven shoulders and was associated with a history of subacromial decompression (p = 0.04). The result was graded as successful for twenty-two shoulders (67%). Conclusions: Shoulder hemiarthroplasty provides marked pain relief in three-quarters of patients with glenohumeral arthritis and severe rotator cuff deficiency. It is a reconstructive option that provides durable results, but it may be complicated by instability and progressive bone loss. Some patients with a massive long-standing tear of the rotator cuff eventually have progressive degenerative changes of the glenohumeral joint. This phenomenon was first described in 1983 by Neer et al., who coined the term cufftear arthropathy 1. Neer et al. applied this diagnosis to patients with radiographic evidence of humeral head collapse after exclusion of other entities that might include both degenerative changes of the glenohumeral joint and a tear of the rotator cuff (such as inflammatory or posttraumatic arthritis, lowgrade infection, Charcot arthropathy, or metabolic disease). Glenohumeral arthritis secondary to severe cuff deficiency can be identified at different points in its natural history; some patients seek medical attention before the full radiographic picture with humeral head collapse has developed, whereas others present with very advanced loss of glenohumeral bone. Patients with glenohumeral arthritis, severe cuff deficiency, and disabling pain may be treated with shoulder arthrodesis or arthroplasty 2. Total shoulder arthroplasty can be complicated by loosening of the glenoid component and other problems 3,4. At the present time, several authors consider hemiarthroplasty to be the reconstructive technique of choice for the treatment of glenohumeral arthritis with severe rotator cuff deficiency 5-9. However, previous studies have included only a small number of patients with this condition, and the results in several of those reports have not been entirely satisfactory 5-7,9. The purposes of the present study were to determine the clinical and radiographic results of shoulder hemiarthroplasty for the treatment of glenohumeral arthritis in the presence of severe rotator cuff deficiency and to identify pathological and technical factors that may affect the outcome. Materials and Methods Patients Thirty-seven consecutive shoulder hemiarthroplasties performed for the treatment of glenohumeral arthritis with severe cuff deficiency in thirty-four patients between 1985 and 1996 were identified with the use of the joint registry at our institution. The senior author (R.H.C.) had performed thirtyone of the procedures, and three other surgeons had carried out the remaining six. Patients who were treated with shoulder hemiarthroplasty in the presence of a rotator cuff tear but had another underlying diagnosis were excluded from the

2 1815 study. To be included, a patient had to have had a complete preoperative evaluation, available operative records, and a minimum of two years of clinical follow-up. Of the initial group of thirty-four patients, one died and three were lost to follow-up less than two years after the operation. The remaining thirty patients (thirty-three shoulders) were followed for an average of five years (range, two to eleven years) and represent the study population. The most recent follow-up evaluation was carried out with a physical examination for twenty shoulders, a written questionnaire for eight, and a telephone questionnaire for five. The average age of the patients at the time of the index arthroplasty was sixty-nine years (range, fifty to eighty-seven years), and the average height was 160 cm (range, 134 to 180 cm). There were thirteen men and seventeen women; two men and one woman underwent bilateral shoulder arthroplasty. Twenty right shoulders and thirteen left shoulders were treated, and twenty-four of the shoulders were on the dominant side. Eleven of the shoulders had undergone a previous procedure. Four of these shoulders had undergone one previous procedure, six had undergone two, and one had undergone four. The previous procedures included rotator cuff repair (performed once in three shoulders and twice in four); excision of a synovial cyst (performed twice in the same shoulder); open débridement because of postoperative infection (performed three times in the same shoulder); and resection of the distal part of the clavicle, repair of the long head of the biceps, repair of an acromioclavicular disruption, and open capsular release (performed once each). Eight of the eleven shoulders with a history of surgery had undergone an acromioplasty and resection of the coracoacromial ligament. Surgical Technique and Operative Findings All of the operations were performed through a deltopectoral approach. The subdeltoid bursa was incised vertically from the inferior edge of the coracoacromial ligament (when present) or the lateral aspect of the tip of the coracoid. The incision was continued distally, lateral to the conjoined tendons. The fibrous tissue that was present at the usual location of the rotator interval and the proximal portion of the subscapularis tendon were left intact. When passive external rotation was >30, the inferior fibrous tissue and any remaining subscapularis were incised about 1 cm medial to the lesser tuberosity; otherwise, it was released from the humerus. The anteroinferior aspect of the shoulder capsule was released from the humerus, and the humeral head was dislocated anteroinferiorly. The humeral canal was entered, and the humeral diaphysis was prepared. With use of a humeral head resection guide with both extramedullary and intramedullary referencing, the humeral head was resected in 35 of retrotorsion at the level of the previous insertion site of the supraspinatus tendon. The joint and the rotator cuff could then be inspected. A massive tear of the rotator cuff was found in all shoulders. The supraspinatus was torn and the tendon was absent in every shoulder. The status of the infraspinatus and the teres minor was graded by assigning the remaining posterior rotator cuff tissue an hourly position, with twelve o clock indicating that it was intact and seven o clock (for the right shoulder) or five o clock (for the left shoulder) indicating that it was completely absent. This allowed an estimation of the percentage of the external rotators that was still present: 60% was present in two shoulders; 40%, in eight; 20%, in two; and 0%, in twentyone. The subscapularis was completely present in sixteen shoulders, it was absent in six, and only the distal one-half remained in eleven. The biceps tendon was present but frayed in only seven of the thirty-three shoulders. As noted before, eight shoulders had undergone a previous subacromial decompression. Other findings included a fractured acromion, an os acromiale, and a fracture of the coracoid process. The humerus was reconstructed with a Cofield implant (Smith and Nephew Richards, Memphis, Tennessee) in twentyseven shoulders, a Bio-Modular implant (Biomet, Warsaw, Indiana) in four, a Neer-II implant (Kirschner Medical, Fairlawn, New Jersey) in one, and a Monospherical implant (Howmedica, Rutherford, New Jersey) in one. Polymethylmethacrylate bone cement was used for stem fixation in six shoulders. The size of the head was small (<42 mm in diameter) in three shoulders, medium (42 to 46 mm in diameter) in twenty-six, and large (>46 mm in diameter) in four. The median diameter of the humeral head was 44 mm, and the range was 41 to 54 mm. Glenoid bone loss was described as moderate (up to the base of the coracoid process) in three shoulders and severe (medial to the base of the coracoid process) in five. The glenoid was contoured with a rongeur or burr in six shoulders, and mechanical reaming of the glenoid and acromion was performed in three; this allowed better congruency among the osseous glenoid, the undersurface of the acromion process, and the prosthetic humeral head. Partial repair of the subscapularis was possible in twenty-three shoulders, and partial repair of the infraspinatus was possible in three. The supraspinatus remnants were sutured to the subscapularis muscle in three shoulders. Eight shoulders had additional procedures, which included synovectomy (four shoulders), excision of associated synovial cysts (three shoulders), and a limited acromioplasty (one shoulder). Postoperatively, the limb was placed in a shoulder immobilizer, which was used during the daytime and at night for one month. Passive range-of-motion exercises were started on the day after surgery, with elevation limited to 120 and external rotation limited to 20. Pulley exercises for flexion, selfassisted wand exercises, and isometric strengthening exercises were started at five to six weeks. Strengthening exercises with an elastic strap were added at eight to ten weeks after surgery. Clinical Evaluation At our institution, the results of clinical assessment of all patients who have undergone shoulder surgery are recorded on a standard shoulder analysis sheet that includes entries for pain, range of motion, and strength 10,11. Pain is graded as none, slight, moderate after unusual activity, moderate, or severe. Active elevation and external rotation are recorded in degrees, and internal rotation is recorded as the vertebral segment that the

3 THE JOUR NAL OF BONE & JOINT SURGER Y JBJS.ORG VO L U M E 83-A N U M B E R 12 D E C E M B E R 2001 S H O U L D E R H E M I A R T H RO P L A S T Y F O R G L E N O H U M E R A L A R T H R I T I S A S S O C I A T E D W I T H S E VE RE R O T A T O R C U F F D E F I C I E N C Y Fig. 1-A Preoperative (Fig. 1-A) and immediate postoperative (Fig. 1-B) radiographs of a seventy-three-year-old patient in whom a right hemiarthroplasty was performed for the treatment of glenohumeral arthritis and severe rotator cuff deficiency. patient can reach with his or her thumb. Paralysis of the shoulder is given 0 points; a trace of strength, 1 point; poor strength with gravity eliminated, 2 points; fair strength against gravity, 3 points; good strength against resistance, 4 points; and normal strength, 5 points. The overall results were graded according to the limited-goals criteria proposed by Neer et al.11 for evaluation of patients with a deficient rotator cuff. The result was considered to be successful when the patient had no or slight pain or had moderate pain only with vigorous activity, had external rotation of >20, and had active abduction of >70. Radiographic Analysis The shoulders were evaluated on an axillary radiograph, a 40degree posterior oblique radiograph with external rotation of the humerus, and a 40-degree posterior oblique radiograph with internal rotation of the humerus. Two shoulders had a complete set of preoperative and immediate postoperative radiographs but no recent radiographs. The remaining thirty-one shoulders (94%) had a complete set of preoperative, immediate postoperative, and most recent radiographs; the mean duration of radiographic follow-up of these patients was 3.4 years (range, one to ten years). The preoperative radiographs were used to confirm the diagnosis of glenohumeral arthritis and to evaluate the degree of bone loss. They were also assessed to determine if the humeral Fig. 1-B head was absent or had collapsed. The acromion was assessed for the presence of erosion, a fracture, or an os acromiale. Glenoid bone loss was classified as central or superior and as mild, moderate, or severe. The distance between the acromion and the humeral head was measured in millimeters on the external rotation radiograph. Finally, glenohumeral subluxation was evaluated with regard to the direction and according to the amount of translation of the humeral head (mild, moderate, or severe). The postoperative radiographs were used to evaluate progression of bone loss and subluxation of the prosthesis, with use of the criteria described above, and to assess the fixation of the component. The humeral interface was divided into eight zones12. The presence of radiolucent lines was recorded, and their zonal location as well as their maximum thickness within 0.5 mm were noted. Zonal sclerosis and a shift in component position were recorded as present or absent. Statistical Methods Preoperative versus postoperative changes in continuous or ordinal variables were assessed with the Wilcoxon signed-rank test. Comparisons of pairs of categorical variables were performed with the Fisher exact test. Comparisons of a categorical variable paired with either an ordinal or a continuous variable were performed with the Wilcoxon rank-sum test. Comparisons of pairs of ordinal or continuous variables were performed

4 1817 Fig. 1-C Radiograph made two years after the index procedure, showing a stable reconstruction with no further migration or bone loss. with the Spearman rank correlation coefficient. Logistic regression was used to assess whether head size was associated with various outcome measures (mild or moderate instability, greater than mild pain, migration, and an unsuccessful Neer rating) adjusted for the height of the patient. Data are presented as the mean and standard deviation unless otherwise specified. A significance level of 0.05 was used for all comparisons. Results Complications and Reoperations One patient had an intraoperative nondisplaced fracture of the medial aspect of the humeral diaphysis that healed uneventfully. Another shoulder required surgical evacuation of a hematoma twenty-four days after the index arthroplasty. One of the patients who had undergone two attempted rotator cuff repairs prior to the index hemiarthroplasty had increased pain and decreased shoulder strength after an initially satisfactory postoperative recovery. He was treated with another partial rotator cuff repair four months after the index arthroplasty. Three years later, he had moderate pain after unusual activities, 45 of active elevation, 10 of active external rotation, and an unsuccessful result. There were no other complications, and none of the patients required revision of the component or another reoperation. Clinical Results Shoulder hemiarthroplasty was significantly associated with pain relief. The mean score for pain decreased from 4.2 points before the operation to 2.2 points at the most recent evaluation (p = ). Preoperatively, pain was severe in eleven shoulders, moderate in nineteen, and occurred mainly after activity in three. At the most recent follow-up evaluation, six shoulders had no pain, eighteen had slight pain, and nine (27%) had moderate pain at rest (four) or pain with activity (five). Of the four shoulders with moderate pain, one had progressive proximal migration and an acromial fracture, two had anterosuperior instability on physical examination, and one was not followed radiographically and an explanation for the pain could not be identified. Active elevation increased significantly in most patients. The mean active elevation improved from 72 (range, 30 to 150 ) before the hemiarthroplasty to 91 (range, 40 to 165 ) at the most recent follow-up evaluation (p = 0.008). At the most recent evaluation, three shoulders had 150 of active elevation; three, 120 to 149 ; twelve, 90 to 119 ; nine, 70 to 89 ; and six, <70. The mean internal rotation improved from the third lumbar level (range, the iliac crest to the sixth thoracic level) preoperatively to the first lumbar level (range, the sacrum to the fourth thoracic level) at the most recent follow-up evaluation (p = 0.02). The mean active external rotation improved from 36 (range, 0 to 80 ) to 41 (range, 0 to 90 ); however, with the numbers available, this change was not found to be significant (p = 0.1). Strength in external rotation increased significantly from a median of 3 points (range, 2 to 5 points) preoperatively to a median of 4 points (range, 3 to 5 points) at the most recent follow-up evaluation (p < 0.01). No difference was detected between the strength in abduction or flexion before the shoulder arthroplasty and that after it. The median strength in abduction was 4 points (range, 2 to 5 points) preoperatively and 4 points (range, 3 to 5 points) at the most recent evaluation. The median strength in flexion was 4 points (range, 3 to 5 points) preoperatively and 4 points (range, 3 to 5 points) at the most recent evaluation. The overall result was graded as successful in twentytwo shoulders (67%) and unsuccessful in eleven. The reasons for an unsuccessful result were moderate pain in three shoulders; moderate pain, active elevation of <70, and active external rotation of <20 in one shoulder; active elevation of <70 in two shoulders; active external rotation of <20 in two shoulders; and active elevation of <70 and active external rotation of <20 in three shoulders. The eight shoulders that had an unsuccessful result because of poor motion had had a mean of 47 (range, 30 to 75 ) of elevation and 24 (range, 0 to 60 ) of external rotation preoperatively. According to the patients assessments, fifteen shoulders were much better than before the operation, fourteen shoulders were better, and four shoulders were the same or worse because of persistent moderate pain. Of the twenty shoulders that were physically examined at the time of the most recent follow-up, seven had mild-to-

5 1818 TABLE I Reported Results of Shoulder Hemiarthroplasty for Treatment of Glenohumeral Arthritis with Severe Rotator Cuff Deficiency Study No.* Age (yr) Duration of Follow-up (yr) No or Mild Postoperative Pain (no. of shoulders) Arntz et al. 5 (1993) (54-84) 3 (2-10) 11 (61%) Williams and Rockwood 8 (1996) (59-80) 4 (2-7) 18 (86%) Field et al. 6 (1997) (62-83) 3 (2-5) 13 (81%) Zuckerman et al. 9 (2000) (65-81) 2 (1-5) 7 (47%) Present study (50-87) 5 (2-11) 24 (73%) *The number of shoulders with glenohumeral arthritis and severe rotator cuff deficiency that were included in the study. The values are given as the mean, with the range in parentheses. According to the limited-goals criteria described by Neer et al. 11. For the unrevised shoulders. moderate anterosuperior instability. Four of them had undergone prior surgery involving the rotator cuff once (two shoulders) or twice (two shoulders). Two of the seven shoulders had no pain, three had mild pain, and the other two had moderate pain. Active elevation was 90 in all but one of them. The Neer rating was successful for five of these shoulders and unsuccessful for two. Radiographic Analysis Preoperatively, the humeral head had collapsed in eight shoulders. Twenty-five shoulders had superior glenoid bone loss, which was graded as mild in nineteen, moderate in two, and severe in four. All shoulders had superior subluxation, which was graded as mild in two, moderate in six, and severe in twenty-five. In addition, eleven shoulders had mild and three had moderate anterior subluxation. The acromiohumeral distance was 0 mm (no separation between the humeral head and the acromion) in twenty-three shoulders, 2 mm in four, 3 mm in four, 4 mm in one, and 5 mm in one. The acromion had mild erosion in twenty-one shoulders, had moderate erosion in five, and was fractured in one. One shoulder had an os acromiale. Immediately postoperatively, superior subluxation was mild in one shoulder, moderate in nine, and severe in twentythree. Fourteen shoulders had mild anterior subluxation, and three had moderate anterior subluxation. At the most recent radiographic evaluation, nineteen shoulders had the same amount and direction of subluxation as they had had immediately postoperatively (Figs. 1-A, 1-B, and 1-C). Superior subluxation increased from moderate to severe in seven shoulders between the immediate postoperative and most recent examinations. Anterior subluxation increased in one shoulder with and in two without increased superior migration. The anterior subluxation increased from mild to moderate in two of these shoulders and from none to mild in one shoulder. Two shoulders did not have recent radiographs. At the most recent radiographic evaluation, eight shoulders had progressive superior erosion of the glenoid (Figs. 2-A, 2-B, and 2-C), fourteen had progressive erosion of the acromion (Figs. 2-A, 2-B, and 2-C), and two had an acromial fracture. In addition, eight shoulders had notching of the medial aspect of the proximal part of the humerus at the level of the inferior rim of the glenoid (Figs. 3-A, 3-B, and 3-C). Nineteen had no changes at the periprosthetic interface, three had a 1-mm radiolucent line in one zone (one shoulder) or two zones (two shoulders), and one had a 2-mm radiolucent line in two zones. Ten shoulders had reactive sclerotic lines in one zone (eight shoulders) or two zones (two shoulders). None of the humeral components was considered to be loose radiographically. Associations A history of subacromial decompression was significantly associated with clinically detectable instability (p = 0.04) and less active elevation at the time of follow-up (79 ± 37 compared with 95 ± 31 for the shoulders without a history of subacromial decompression; p = 0.03). Clinically detectable instability was also significantly associated with less damage of the infraspinatus and teres minor at the time of surgery (p = 0.005) and with a surgical attempt to partially repair the rotator cuff (p = 0.04). A decreased distance between the humeral head and the acromion was a significant predictor of decreased strength in external rotation at the most recent follow-up evaluation (p = 0.03). Progression of bone loss at the scapula or the proximal part of the humerus was not significantly associated with longer radiographic follow-up, pain, or an unsuccessful Neer rating. No significant associations were found between the size of the humeral head and pain, range of motion, instability, or Neer rating. Although the size

6 1819 TABLE I (continued) Preop./Postop. Active Elevation (deg) Successful Results (no. of shoulders) Comments 66 (44-90)/112 (70-160) Not reported Two reoperations for symptomatic glenoid erosion, one for symptomatic anterior instability, and one for postoperative traumatic fracture of the acromion 70 (0-155)/120 (15-160) 18 (86%) No cases of instability or reoperations reported 60 (40-80)/100 (80-130) 10 (63%) One intraoperative humeral shaft fracture; four cases of instability, two of them requiring reoperation (subscapularis advancement in one and resection arthroplasty in other) 69 (20-140)/86 (45-140) Not reported Eleven patients (thirteen shoulders; 87%) satisfied with the operation, one case of anterior instability 72 (30-150)/91 (40-165) 22 (67%) One intraoperative humeral shaft fracture, seven cases of anterosuperior instability of the humeral head could have been expected to be related to the size of the patient to some extent, no association was found between patient height and humeral head size. In addition, humeral head size was not found to be associated with any of the outcome parameters when corrected for the height of the patient. Discussion lenohumeral arthritis in the presence of severe rotator Gcuff deficiency is one of the most difficult conditions to treat with a shoulder arthroplasty 4,13. In the article in which cuff-tear arthropathy was first formally described, Neer et al. stated that total shoulder arthroplasty had helped all but one of twenty-six shoulders 1. However, some years later, Franklin et al. 14 and Hawkins et al. 15 noted increased glenoid loosening rates when total shoulder arthroplasty had been performed in the presence of a deficient rotator cuff. Brownlee and Cofield 13 and Lohr et al. 4 compared the results of total shoulder arthroplasty with those of hemiarthroplasty in patients with cuff-tear arthropathy and concluded that the former procedure provided better pain relief but was associated with a substantial rate of glenoid failure. In contrast, Pollock et al. 7 reported that hemiarthroplasty provided similar pain relief and better active elevation than did total shoulder arthroplasty in a series of seventeen shoulders with inflammatory arthritis and thirteen with cuff-tear arthropathy. Although bipolar hemiarthroplasty has been used for the treatment of cuff-tear arthropathy 16, the results have not been reproducible 17. For the reasons stated above, at the present time many consider hemiarthroplasty to be the procedure of choice for patients with glenohumeral arthritis, severe cuff deficiency, and adequate deltoid function 2,5-9. However, shoulder hemiarthroplasty has not provided consistent pain relief in patients with this condition 4-6,9,10. In addition, previous authors have not analyzed in detail the relationship between the outcome of the operation and the status and management of the coracoacromial arch, the size of the prosthetic head, the extent and reconstruction of the cuff tissue, and the potential for postoperative instability and progressive migration and bone loss. Our study confirmed that shoulder hemiarthroplasty provides satisfactory pain relief in about three-quarters of patients and moderate gains in range of motion and strength. It also showed that clinically detectable instability or progression of scapular and humeral bone loss are to be expected in a substantial number of patients. Finally, it identified two factors that were associated with a less satisfactory outcome: prior subacromial decompression and the extent of proximal migration of the humeral head. The reported results of shoulder hemiarthroplasty in patients with glenohumeral arthritis and a deficient cuff have not been uniform (Table I). The percentage of patients with no or mild pain at the most recent follow-up evaluation after hemiarthroplasty has ranged from 47% to 86% 5,6,8,9, although the rate of subjective satisfaction generally has been higher. Shoulder hemiarthroplasty has also provided moderate gains in motion and strength 5-9. On the basis of the limited-goals criteria described by Neer et al. 11, a successful result was achieved in 86% of the shoulders reported on by Williams and Rockwood 8 and 63% of the shoulders in the study by Field et al. 6. In our series, 73% of the shoulders had no or mild postoperative pain and 67% were rated as having a successful result. Shoulder instability was reported in all but one of the previously mentioned studies. In the series of Arntz et al. 5, one shoulder had a reoperation because of symptomatic anterior instability. Four of the sixteen shoulders reported on by Field et al. 6 had postoperative instability, and two of them required additional surgery. Instability was also noted in one of the shoulders included in the report by Zuckerman et al. 9

7 THE JOUR NAL OF BONE & JOINT SURGER Y JBJS.ORG VO L U M E 83-A N U M B E R 12 D E C E M B E R 2001 Fig. 2-A S H O U L D E R H E M I A R T H RO P L A S T Y F O R G L E N O H U M E R A L A R T H R I T I S A S S O C I A T E D W I T H S E VE RE R O T A T O R C U F F D E F I C I E N C Y Fig. 2-B Preoperative (Fig. 2-A) and immediate postoperative (Fig. 2-B) radiographs of a seventy-five-year-old patient in whom a left hemiarthroplasty was performed for the treatment of glenohumeral arthritis and severe rotator cuff deficiency. and in seven of the twenty shoulders that were examined at the time of the most recent follow-up in our study. In addition, we identified progressive migration of the humeral head in nine of the thirty-one shoulders with complete radiographic follow-up. As noted by Wiley18 and by Field et al.6, prior surgical violation of the anterior aspect of the acromion and the coracoacromial ligament seems to be the main predisposing factor for this complication. In our study, a history of subacromial decompression was significantly associated with clinically detectable instability (p = 0.04) and less active elevation at the time of follow-up (p = 0.03). Progressive bone loss is another potential problem after hemiarthroplasty in shoulders with a deficient cuff. Unfortunately, detailed radiographic information was not included in some of the previously published studies. Symptomatic glenoid erosion developed in two of the eighteen shoulders reported on by Arntz et al.5, and a revision was performed to modify the size or position of the humeral implant; a third shoulder had radiographic evidence of medial erosion. In our study, progressive bone loss was seen at the glenoid in eight shoulders and at the acromion in sixteen, with a resultant fracture of the acromion in two of them. In addition, notching at the medial aspect of the proximal part of the humerus, a radiographic finding that has not been previously described to our knowledge, developed in eight shoulders. With longer follow-up than the average two to five years reported so far in the literature, progressive bone loss may become an important mode of failure of hemiarthroplasty in this population. In contrast, loos- ening of the humeral component does not seem to be a problem. The ideal size of the humeral head and the management of the remaining cuff tissue are two technical factors that need to be addressed at the time of surgery. A larger humeral head Fig. 2-C Radiograph made four years after the index procedure, demonstrating increased bone loss at the superior aspect of the glenoid and of the undersurfaces of the distal part of the clavicle and the acromion.

8 THE JOUR NAL OF BONE & JOINT SURGER Y JBJS.ORG VO L U M E 83-A N U M B E R 12 D E C E M B E R 2001 S H O U L D E R H E M I A R T H RO P L A S T Y F O R G L E N O H U M E R A L A R T H R I T I S A S S O C I A T E D W I T H S E VE RE R O T A T O R C U F F D E F I C I E N C Y Fig. 3-A Figs. 3-A and 3-B Preoperative (Fig. 3-A) and immediate postoperative (Fig. 3-B) radiographs of a sixty-three-year-old patient in whom a left hemiarthroplasty was performed for treatment of glenohumeral Fig. 3-B arthritis and severe rotator cuff deficiency. Fig. 3-C Radiograph made two years after the index arthroplasty, showing bone loss and notching of the medial aspect of the proximal part of the humerus at the site of contact with the inferior rim of the glenoid. may result in a more stable reconstruction by increasing softtissue tension and fully articulating with the glenoid and acromion. However, the resultant overstuffing of the joint impairs the ability to partially reconstruct the anterior aspect of the rotator cuff and theoretically may lead to increased joint reactive forces with resultant pain and more rapid bone loss. A medium-size head was used in most of the patients in our study. With the numbers available, we did not find any association between the head size and the outcome of the operation. Regarding the management of the remaining cuff tissue, in our series attempts to partially reconstruct the cuff were significantly associated with clinically detectable instability (p = 0.04), as was less damage to the posterior part of the cuff (p = 0.005). Resulting imbalanced force couples may explain these two associations, and our data do not seem to justify the use of a small humeral head to facilitate cuff reconstruction. In conclusion, shoulder hemiarthroplasty provides marked pain relief in about three-quarters of patients with glenohumeral arthritis and severe rotator cuff deficiency. It also provides modest improvements in range of motion and strength. Persistent pain, anterosuperior instability, and progressive bone loss may complicate the procedure. A less satisfactory outcome should be expected in patients with prior violation of the coracoacromial arch. The use of either a small humeral head in an attempt to facilitate reconstruction of the cuff or a large head to maximize joint stability does not seem Fig. 3-C to be justified. Although shoulder hemiarthroplasty is not a perfect solution for patients with glenohumeral arthritis and severe cuff deficiency, it probably represents the best available reconstructive option for this difficult problem at the present time.

9 1822 Joaquin Sanchez-Sotelo, MD, PhD Robert H. Cofield, MD Charles M. Rowland, MS Departments of Orthopedic Surgery (J.S.-S. and R.H.C.) and Biostatistics (C.M.R.), Mayo Clinic and Mayo Foundation, 200 First Street S.W., Rochester, MN The authors did not receive grants or outside funding in support of their research or preparation of this manuscript. They did not receive payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity. There is an agreement between Smith and Nephew and Mayo Medical Ventures for royalty payments on some of the implants used in this study. References 1. Neer CS 2nd, Craig EV, Fukuda H. Cuff-tear arthropathy. J Bone Joint Surg Am. 1983;65: Arntz CT, Matsen FA, Jackins S. Surgical management of complex irreparable rotator cuff deficiency. J Arthroplasty. 1991;6: Laurence M. Replacement arthroplasty of the rotator cuff deficient shoulder. JBone Joint Surg Br. 1991;73: Lohr JF, Cofield RH, Uhthoff HK. Glenoid component loosening in cuff tear arthropathy. J Bone Joint Surg Br. 1991;73(Suppl II): Arntz CT, Jackins S, Matsen FA. Prosthetic replacement of the shoulder for the treatment of defects in the rotator cuff and the surface of the glenohumeral joint. J Bone Joint Surg Am. 1993;75: Field LD, Dines DM, Zabinski SJ, Warren RF. Hemiarthroplasty of the shoulder for rotator cuff arthropathy. J Shoulder Elbow Surg. 1997; 6: Pollock RG, Deliz ED, McIlveen SJ, Flatow EL, Bigliani LU. Prosthetic replacement in rotator cuff-deficient shoulders. J Shoulder Elbow Surg. 1992;1: Williams GR Jr, Rockwood CA Jr. Hemiarthroplasty in rotator cuff-deficient shoulders. J Shoulder Elbow Surg. 1996;5: Zuckerman JD, Scott AJ, Gallagher MA. Hemiarthroplasty for cuff tear arthropathy. J Shoulder Elbow Surg. 2000;9: Cofield RH. Total shoulder arthroplasty with the Neer prosthesis. J Bone Joint Surg Am. 1984;66: Neer CS 2nd, Watson KC, Stanton FJ. Recent experience in total shoulder replacement. J Bone Joint Surg Am. 1982;64: Sperling JW, Cofield RH, O Driscoll SW, Torchia ME, Rowland CM. Radiographic assessment of ingrowth total shoulder arthroplasty. J Shoulder Elbow Surg. 2000;9: Brownlee RC, Cofield RH. Shoulder replacement in cuff tear arthropathy. Orthop Trans. 1986;10: Franklin J, Barrett W, Jackins SE, Matsen FA 3rd. Glenoid loosening in total shoulder arthroplasty. Association with rotator cuff deficiency. J Arthroplasty. 1988;3: Hawkins RJ, Bell RH, Jallay B. Total shoulder arthroplasty. Clin Orthop. 1989;242: Worland RL, Jessup DE, Arredondo J, Warburton KJ. Bipolar shoulder arthroplasty for rotator cuff arthropathy. J Shoulder Elbow Surg. 1997;6: Vrettos BC, Wallace WA, Neumann L. Bipolar hemiarthroplasty of the shoulder for the elderly patient with rotator cuff tear arthropathy. From the Proceedings of the British Elbow and Shoulder Society. J Bone Joint Surg Br. 1998;80 (Suppl I): Wiley AM. Superior humeral dislocation. A complication following decompression and debridement for rotator cuff tears. Clin Orthop. 1991;263: