Revision rotator cuff repair: factors influencing results

BACKGROUND

Revision rotator cuff repair is a surgical challenge, and the results have generally been inferior to those of primary repair. We examined the results of revision rotator cuff repair in a large series of patients and assessed which subgroups of patients had the greatest chance for a satisfactory functional outcome.

METHODS

A revision rotator cuff repair was performed in eighty patients after the failure of a previous operative repair. The average age of the patients at the time of the revision was fifty-nine years. Prior to revision, the average pain score was 7.4 points (with 0 points indicating no pain and 10 points, severe pain) and the active range of motion of the shoulder averaged 105 degrees of elevation, 39 degrees of external rotation, and internal rotation to the eleventh thoracic vertebra. All patients underwent repeat repair of the rotator cuff tendons to bone. Additional procedures included revision acromioplasty (fifty-three patients; 66%) and distal clavicular excision (twenty-six patients; 33%), among others.

RESULTS

After an average duration of follow-up of forty-nine months, the result was rated as satisfactory (excellent, good, or fair) in fifty-five patients (69%) and as unsatisfactory (poor) in twenty-five (31%). At the time of the latest follow-up, the average pain score had improved to 3.0 points and the active range of motion averaged 130 degrees of elevation, 53 degrees of external rotation, and internal rotation to the tenth thoracic vertebra. Improved results were associated with an intact deltoid origin, good-quality rotator cuff tissue, preoperative active elevation of the arm above the horizontal, and only one prior procedure. All seventeen patients who met all four of these criteria had a satisfactory result.

CONCLUSIONS

The results of revision rotator cuff repair are inferior to those of primary repair. While pain relief can be reliably achieved in most patients, the functional results are improved principally in patients with an intact deltoid origin, good-quality rotator cuff tissue, preoperative elevation above the horizontal, and only one prior procedure.

The incidence of ganglion cysts and other variations in anatomy along the course of the suprascapular nerve

When the diagnosis of suprascapular nerve entrapment syndrome is being considered, variations in anatomy are possible etiologic factors. Seventy-nine shoulders from 41 cadavers were examined for anatomic variations and for ganglion cyst formation in the suprascapular notch, superior transverse scapular ligament, and inferior transverse scapular ligament. The morphologic evaluation of the suprascapular notch revealed a "U" shape in 77% and a "V" shape in 23%, with 89% of cadavers having the same notch shape bilaterally. In 23% of shoulders a variation of the superior transverse scapular ligament was demonstrated such as partial and complete ossification and multiple bands including the first report of a trifid superior transverse scapular ligament. An inferior transverse scapular ligament was observed in only 14% of shoulders. One ganglion cyst was identified, for an incidence of 1%. The mass was located in the supraspinatus fossa adjacent to the superior transverse scapular ligament and appeared to compress and alter the course of the suprascapular nerve. When operative treatment is elected for suprascapular nerve entrapment syndrome and an open surgical approach is undertaken, the location and source of disease and morphologic and anatomic variants must be recognized to ensure adequate access and complete decompression of the suprascapular nerve. The classical description of the superior transverse scapular ligament as a completely nonossified single band should be expected, on average, in approximately three fourths of the cases. Partial or complete ossification and anomalous bands of the superior transverse scapular ligament or a ganglion cyst along the course of the suprascapular nerve may be encountered. Although a superior transverse scapular ligament should be anticipated in all shoulders, an inferior transverse scapular ligament will be a much less frequent finding. The role and significance of suprascapular notch morphologic characteristics warrant further investigation.

Knee joint immobilization decreases aggrecan gene expression in the meniscus

Aggrecan is the major proteoglycan of the meniscus, and its primary function is to give the meniscus its viscoelastic compressive properties. The objective of this study was to determine the effect of joint immobilization on aggrecan gene expression in the meniscus. The right hindlimbs of six mature beagles were knee cast-immobilized in 90 degrees of flexion and supported by a sling to prevent weightbearing, while the contralateral limb was left free to bear weight. The animals were sacrificed at 4 weeks, and the anterior and posterior halves of the medial and lateral menisci were analyzed separately. Analysis of aggrecan gene expression by quantitative polymerase chain reaction showed decreased aggrecan gene expression in menisci from immobilized knees (P < 0.01, two-way analysis of variance). Aggrecan gene expression decreased by a factor of 2 to 5.5 in the different regions examined. Analysis of the composition of the meniscus also showed decreased proteoglycan content and increased water content with immobilization (P < 0.05, two-way analysis of variance). These results show that joint immobilization can significantly affect meniscal cellular activity and composition and can therefore potentially affect meniscal function.

Hemiarthroplasty for glenohumeral osteoarthritis: results correlated to degree of glenoid wear

Thirty patients (31 shoulders) were retrospectively reviewed after hemiarthroplasty for glenohumeral osteoarthritis. Ten shoulders had primary osteoarthritis, and 21 shoulders had secondary osteoarthritis. Glenoid surface wear was evaluated and classified as either type I, concentric, (15 shoulders) or type II, nonconcentric, (16 shoulders). Postoperative results were reviewed with the American Shoulder and Elbow Surgeons' evaluation form, Neer classification, and the Constant score. Overall, 23 (74%) shoulders achieved satisfactory results, and 8 (26%) shoulders had unsatisfactory results. Results were similar in the primary and secondary osteoarthritis groups. Outcome correlated most significantly with the status of posterior glenoid wear. Patients with concentric, type I glenoids achieved 86% satisfactory results, whereas patients with nonconcentric, type II glenoids had only 63% satisfactory results. Although pain relief was similar in both groups, the unsatisfactory results were attributed to loss of forward elevation and external rotation in patients with type II glenoids. On the basis of these results hemiarthroplasty can be an effective treatment for both primary and secondary arthritis but should be reserved for patients with a concentric glenoid, which affords a better fulcrum for glenohumeral motion.

Biology of the rotator cuff tendon

Tendons are complex composite material composed primarily of water, collagen, proteolycans, and cells, designed to transmit tensile loads from muscle to bone. Although rotator cuff tendons differ in many ways from other tendons in the body, a knowledge of basic tendon structure and function is helpful in understanding rotator cuff tendon biology, injury, and repair. In addition to type I collagen, rotator cuff tendons contain small amounts of type III collagen, which play a role in healing and repair. In comparison with other tendons, the increased glycosaminoglycan and proteoglycan content seen in rotator cuff tendons may be adaptive, pathologic, or both. The etiology of rotator cuff pathology is probably related to trauma, aging, and degeneration. As our understanding of these processes increases, we will be able to develop and implement improved preventative and therapeutic interventions for rotator cuff pathology.