Michael A. Wirth

Complications of total shoulder arthroplasty.

umeroscapular arthrodesis is a well-established operative procedure that involves fusion of the humeral head to the glenoid. In some procedures, the fusion also includes an acromiohumeral arthrodesis. Humeroscapular arthrodesis is commonly called “shoulder arthrodesis,” and we use that term in this paper for simplicity. Indications for this procedure early in the twentieth century included the treatment of residual glenohumeral destruction resulting from tuberculosis and the treatment of upper-extremity paralysis resulting from poliomyelitis. Additional historical indications included osteoarthritis, rheumatoid arthritis, irreparable injury of the rotator cuff, and severely comminuted fracture of the proximal aspect of the humerus. The advent of shoulder arthroplasty has resulted in a marked reduction in the number of shoulder arthrodeses performed, although there are instances when arthrodesis is favored over joint-replacement arthroplasty. This article reviews the indications for shoulder arthrodesis, the pertinent features of the preoperative evaluation, the controversial issue of the desirable position of the arthrodesis, the various techniques for shoulder arthrodesis, and the management of complications.Total shoulder arthroplasty, originally used by Pean in 1893 to treat tuberculous arthritis1 and subsequently modernized by Neer et al. in the 1950s for the treatment of three and four-part proximal humeral fractures2, has demonstrated clinical efficacy when used for the treatment of primary and secondary degenerative conditions of the shoulder. The overall number of shoulder replacements has increased in parallel to the total number of total joint arthroplasties. Approximately 7000 total shoulder replacements were performed annually in the United States from 1996 through 2002. This represents a 40% increase compared with the 5000 arthroplasties per year performed from 1990 through 19923-11. Despite the increase in the annual volume of shoulder arthroplasties, data have suggested that nearly three-fourths of the operations are performed by surgeons who do two or fewer procedures a year12,13. The favorability of the clinical outcomes of total shoulder arthroplasty as well as the decision to proceed with a total shoulder replacement instead of a hemiarthroplasty have been shown to depend on surgeon experience and hospital volume12-16. Patient readmission rates, complication rates, and lengths of hospital stays have all been shown to …

Current Concepts Review - Complications of Total Shoulder-Replacement Arthroplasty*

Complications associated with orthopaedic prostheses or implants account for approximately 5 per cent of the more than 3.5 million hospitalizations for musculoskeletal conditions82. This is important in light of the increasing number of patients who receive prostheses and the fact that the average age of patients who have a total shoulder arthroplasty is the lowest among those for all major joint replacements28,73. Like replacement procedures in other major joints, total shoulder arthroplasty is associated with numerous complications, including prosthetic loosening, glenohumeral instability, tears of the rotator cuff, periprosthetic fracture, infection, neural injury, and dysfunction of the deltoid. In recent years, mirroring the increase in the number of total joint arthroplasties in general, the number of shoulder-replacement procedures has increased substantially28,71-73. However, despite this growth, fewer than 5000 total shoulder replacements were performed annually in the United States from 1990 through 1992, compared with 136,000 total hip and total knee arthroplasties28,71-73. Although the short-term (less than two-year) and mid-term (two to five-year) results of total shoulder arthroplasties have been encouraging, with some authors reporting good and excellent results in more than 90 per cent of shoulders, widespread experience and long-term evaluations approaching those for joint replacements in the lower extremities have not been published1,5,6,13,23,44,53,64,65,78. Our review of forty-one series involving 1858 total shoulder arthroplasties reported from 1975 through 1995 revealed an average duration of follow-up of only 3.5 years3-6,12,13,15,16,19,25,26,32,34,38,40-42,44,48,53, …

Cyclic loading of anchor-based rotator cuff repairs: Confirmation of the tension overload phenomenon and comparison of suture anchor fixation with transosseous fixation

Previous experimental studies of failure of rotator cuff repair have involved single pull to ultimate load. Such an experimental design does not represent the cyclic loading conditions experienced in vivo. We created 1 x 2 cm rotator cuff defects in 16 cadaver shoulders, repaired each defect with three Mitek-RC suture anchors (Mitek Surgical Products, Inc, Westwood, MA) using simple sutures of No. 2 Ethibond, and cyclically loaded the repairs by a servohydraulic materials test system actuator at physiological rates and loads (rate of 33 mm/s, load 180 N). A progressive gap was noted in each specimen, for a 100% rate of failure of the repairs. The central suture always failed first and by the largest magnitude, confirming tension overload centrally. One specimen exhibited combined bone and tendon failure, but the other 15 specimens failed through the tendon. Overall, the repairs failed to 5 mm and 10 mm at an average of 61 cycles and 285 cycles, respectively. Half the specimens were less than 45 years of age and had a 5-mm and 10-mm failure at an average of 107 and 478 cycles, respectively. The other half were over 45 years of age and failed to 5 mm and 10 mm at an average of 17 and 91 cycles, respectively, indicating more rapid failure of the rotator cuff tendons in the older group, and this was statistically significant (P < or = .02). Comparison of suture anchor fixation in this study with transosseous bone tunnel fixation in a previous cyclic loading study at this institution indicates that bone fixation by suture anchors is significantly less prone to failure than bone fixation through bone tunnels (P = .0008). Changing the bone fixation from bone tunnels to suture anchors effectively transferred the weak link from bone to tendon.

Margin convergence: a method of reducing strain in massive rotator cuff tears.

Increases security of fixation in rotator cuff repair is usually achieved by increasing the strength of fixation. Paradoxically, the problem can be approached by techniques that decrease the strain at the margins of the tear so that weaker fixation will still be adequate. Such techniques provide greater safety tolerances for the strength characteristics of suture, tendon, and bone. The principle of margin convergence can be applied to rotator cuff repair as a means to enhance the security of fixation by decreasing the mechanical strain at the margins of the tear. This strain reduction should also contribute to pain reduction by virtue of decreased stimulation of mechanoreceptors in the rotator cuff. The cliché no pain, no strain can be converted to a paradigm by reversal of its components to no strain, no pain.

Operative treatment of irreparable rupture of the subscapularis.

Between 1980 and 1994, 221 shoulders with recurrent anterior glenohumeral subluxation or dislocation were reconstructed at our institution. At the time of the operation, thirteen shoulders were found to have an irreparable injury of the subscapularis muscle, which we believed to be a contributing factor to the ongoing instability. All but three of the thirteen patients had had two to six previous reconstructions. Operative treatment of the irreparable rupture included a dynamic muscle transfer using the pectoralis major in seven shoulders, the pectoralis minor in five, and both of these muscles in one. According to a modification of the grading system of Neer and Foster, the result was satisfactory for ten shoulders and unsatisfactory for three at a mean of five years after the operation. All shoulders with a satisfactory result demonstrated active contraction of the transferred pectoralis muscle and diminished anterior glenohumeral translation. On the basis of our analysis, we concluded that transfer of the pectoralis muscle is effective for reconstruction of the shoulder in patients who have loss of the subscapularis muscle.

Knot security in simple sliding knots and its relationship to rotator cuff repair : How secure must the knot be?

We sought to determine which simple sliding knot configurations would have adequate strength for rotator cuff repair. Four knot configurations were tied with both No. 1 polydioxanone suture and No. 2 Ethibond suture (Ethicon, Somerville, NJ) using 3 different tying techniques: hand-tie, standard knot pusher, and cannulated double-diameter knot pusher. The knots were then tested to failure on a materials testing system. The weakest standard knot configuration was S=S=S=S. The other 3 knot configurations (S//S//S//S, SxSxSxS, and S//xS//xS//xS) generally failed in the 35 to 50 N range. Ultimate strength in this range can be shown to be adequate to withstand, without suture failure, a maximal contraction of a repaired rotator cuff tear within the rotator crescent, assuming certain conditions are met (suture anchors placed 1 cm apart, 2 sutures per anchor). More complex knots are not necessary for adequate knot security. However, the same configuration with only 1 suture per anchor will not be strong enough because the suture will fail under maximum physiological load. This study shows that we can predict the adequacy of a given knot configuration under maximum physiological loading conditions.

Loss of external rotation following anterior capsulorrhaphy of the shoulder

A retrospective study was performed on twenty shoulders in nineteen patients who had been managed for severe loss of external rotation of the glenohumeral joint after a previous anterior capsulorrhaphy for recurrent instability. All patients had noted a restricted range of motion, and seventeen shoulders had been painful. In seven shoulders, the humeral head had been subluxated or dislocated posteriorly, and sixteen shoulders had been affected by mild to severe glenohumeral osteoarthrosis. All twenty shoulders were treated with a reoperation, which consisted of a release of the anterior soft tissue. In addition, eight shoulders had a total arthroplasty and one had a hemiarthroplasty. At an average duration of follow-up of forty-eight months, all shoulders had an improvement in the ratings for pain and range of motion. The average increase in external rotation was 45 degrees (range, 25 to 65 degrees). Patients who have a major loss of external rotation following anterior capsulorrhaphy of the shoulder may be at risk for the development of posterior subluxation and glenohumeral osteoarthrosis. The performance of an anterior release should be considered for these patients.

The capsular imbrication procedure for recurrent anterior instability of the shoulder

One hundred and thirty-eight patients (142 shoulders) who had recurrent anterior instability of the shoulder that was unresponsive to a specific physician-directed rehabilitation program were managed with an anatomical capsular imbrication reconstruction. The procedure included repair of the capsulolabral injury, when present, and reinforcement of the anteroinferior capsular ligaments with an imbrication technique that decreases the over-all capsular volume. The shoulders were divided into two groups: 108 shoulders in which the recurrent instability was related to a defined traumatic episode (Group I) and thirty-four shoulders with no distinct history of trauma (Group II). The anatomical capsular imbrication was the primary procedure in ninety shoulders and was used to treat at least one failed previous reconstruction in fifty-two shoulders. According to the grading system of Rowe et al., 93 per cent (132) of the shoulders had a good or excellent result at an average of five years (range, two to twelve years) after the operation. The results after a previous failed reconstruction were especially encouraging. Of the fifty-two shoulders that had had at least one previous reconstructive procedure, forty had an excellent result, five had a good result, four had a fair result, and three had a poor result. The results of this study suggest that this procedure restores stability while preserving a functional range of motion in patients who have symptomatic recurrent anterior instability of the shoulder, regardless of the etiology.

Resection arthroplasty of the sternoclavicular joint.

The results of resection of the medial end of the clavicle to treat a painful sternoclavicular joint in fifteen patients were retrospectively reviewed. The patients fell into two groups: eight patients who had had a primary arthroplasty of the sternoclavicular joint in which the costoclavicular ligament was left intact (group I), and seven patients who had had revision of a failed arthroplasty of the sternoclavicular joint and in whom the costoclavicular ligament had to be reconstructed (group II). The results for these two groups were compared at an average of 7.7 years postoperatively. All eight patients in group I had an excellent result. In sharp contrast, three patients in group II had an excellent result, three had a fair result, and one had a poor result. We conclude that preservation or reconstruction of the costoclavicular ligament is essential at the time of resection of the medial portion of the clavicle in order to obtain a satisfactory result.

Loop Security as a Determinant of Tissue Fixation Security

Secure arthroscopic repair of rotator cuff tears and Bankart lesions requires tight knots (knot security). Equally important, but usually overlooked, is the tightness of the suture loop (loop security). This study compared loop security in knots tied with No. 1 PDS suture using three different methods: (1) hand-tied, (2) single-hole standard knot pusher, and (3) cannulated double-diameter knot pusher. The results of this study show that the double-diameter knot pusher maintained tight suture loops that were equivalent in circumference to hand-tied loops and were significantly tighter than suture loops tied with a standard single-hole knot pusher. This study highlights the fact that loop security is equally important to knot security in tissue fixation.