Evaluation and Arthroscopic Treatment of Partial Rotator Cuff Tears

Interobserver Agreement in the Classification of Partial-Thickness Rotator Cuff Tears Using the Snyder Classification System

BACKGROUND

At present, there is no widely accepted classification system for partial-thickness rotator cuff tears, and as a result, optimal treatment remains controversial.

PURPOSE

To examine the interobserver reliability and accuracy of classifying partial rotator cuff tears using the Snyder classification system. We hypothesized that the Snyder classification would be reproducible with high reliability and accuracy.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 2.

METHODS

Twenty-seven orthopaedic surgeons reviewed 10 video-recorded shoulder arthroscopies. Each surgeon was provided with a description of the Snyder classification system for partial-thickness rotator cuff tears and was then instructed to use this system to describe each tear. Interrater kappa statistics and percentage agreement between observers were calculated to measure the level of agreement. Surgeon experience as well as fellowship training was evaluated to determine possible correlations.

RESULTS

A kappa coefficient of 0.512 indicated moderate reliability between surgeons using the Snyder classification to describe partial-thickness rotator cuff tears. The mean correct score was 80%, which indicated "very good" agreement. There was no correlation between the number of shoulder arthroscopies performed per year and fellowship training and the number of correct scores.

CONCLUSION

The Snyder classification system is reproducible and can be used in future research studies in analyzing the treatment options of partial rotator cuff tears.

Partial articular-sided rotator cuff tears: in situ repair versus tear completion prior to repair

Uncertainty exists over the ideal surgical treatment method for partial articular-sided rotator cuff tears, with options ranging from debridement to in situ repair to tear completion prior to repair. The purpose of this study was to determine whether in situ repair was a viable biomechanical treatment option compared with tear completion prior to repair of partial articular-sided rotator cuff tears. Fourteen fresh-frozen cadaveric shoulders were dissected. Partial articular-sided tears were created and repaired using in situ repair or tear completion prior to the repair. Strain and displacement were measured at 45°, 60°, and 90° of glenohumeral abduction. Testing was performed with a load of 100 N applied for 30 cycles. Data from the biomechanical testing displayed 4 conditions that showed improved characteristics of in situ repair over completion and repair: bursal-sided strain anteriorly at 45°, bursal-sided strain anteriorly at 90°, bursal-sided displacement anteriorly at 45°, and bursal-sided displacement anteriorly at 90°. The data indicate that in situ repair is a viable biomechanical treatment option compared with tear completion prior to repair of partial articular-sided rotator cuff tears. When clinically appropriate, the in situ repair may offer some biomechanical advantages, with lower strain and displacement observed on the bursal side compared with tear completion prior to repair.

Predictive factors of subtle residual shoulder symptoms after transtendinous arthroscopic cuff repair: a clinical study

BACKGROUND

Transtendinous repair is a well-known technique for the arthroscopic management of partial rotator cuff tear. However, there are not a lot of clinical follow-up studies in the literature reporting data on this approach, and, moreover, potential factors responsible to influence the outcomes have not been investigated.

PURPOSE

To evaluate clinical outcomes after arthroscopic transtendinous repair and to identify predictive factors of residual shoulder symptoms.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Fifty-four patients with a mean age of 56.7 +/- 8.8 years (range, 31-71 years) who had undergone an arthroscopic transtendon repair for a painful articular-sided rotator cuff tear with a minimum of 2 years of follow-up were contacted. Clinical outcomes using a patient-based questionnaire, the Constant score, University of California at Los Angeles score, Simple Shoulder Test, and visual analog scale were evaluated. The influence of patient age, presence or absence of a trauma responsible for the cuff tear, presence of associated shoulder lesions, millimeters of exposed footprint, and millimeters of torn tendon retraction on the outcomes were assessed.

RESULTS

The mean cuff tear exposure footprint was 5.2 mm, and the mean retraction of the torn part of the tendon was 8 mm. Only one patient reported dissatisfaction with surgery because of persistence of pain during overhead activities. After arthroscopic repair, University of California at Los Angeles, Constant, and Simple Shoulder Test scores were significantly improved from 14.1, 45.3, and 9.8 to 32.9, 90.6, and 0.8, respectively (P < .001). Twenty-two patients (41%) reported occasional shoulder discomfort at the extremes of range of motion (particularly at extremes of abduction and internal rotation) occurring during some daily living and sports activities. The best multivariate model showed that residual shoulder discomfort is strongly linked with a partial thickness supraspinatus tendon avulsion-type articular-sided rotator cuff lesion consisting of a large tendon retraction and/or a relatively small exposure footprint area in an older patient in the absence of a specific trauma (P < .001).

CONCLUSION

Arthroscopic transtendon partial articular supraspinatus tendon avulsion-type rotator cuff repair was a reliable procedure that resulted in a good outcome in terms of pain relief and shoulder scores in 98% of the 54 patients. Better results could be expected in patients with less tendon retraction, a larger footprint exposure, of younger age, and with a clinical history of trauma.

Intra-articular partial-thickness rotator cuff tears: analysis of injured and repaired strain behavior

BACKGROUND

There are few biomechanical studies regarding partial-thickness rotator cuff tears and subsequent repair.

HYPOTHESIS

Partial-thickness intra-articular supraspinatus tendon tears increase articular-sided tendon strain as they increase in size. Repair of these tears will return strain to the intact state.

STUDY DESIGN

Controlled laboratory study.

METHODS

Twenty fresh-frozen human cadaveric shoulders were prepared by dissecting to the supraspinatus tendon and leaving the native footprint intact. The tendon footprint was measured with digital calipers and divided into thirds (anterior, middle, and posterior). The middle third was the area where a consistent partial tear was created based on the thickness of the specimens' particular footprint. Created were 25%, 50%, and 75% tears. Image analysis software and differential variable reluctance transducers strain gauges were used to measure strain. A 100 N load at 1 Hz for 30 cycles was conducted for glenohumeral angles of 45 degrees, 60 degrees, and 90 degrees. This was completed for the intact tendon, 25%, 50%, and 75% tears. Shoulders were then repaired using the in situ fixation method. The in situ method consisted of either a parachute anchor or metal corkscrew anchor. Eight shoulders were examined for load-to-failure testing with the Materials Testing System.

RESULTS

There was a significant difference (P < .05) in rotator cuff strain between the intact rotator cuff tendon and 50% and 75% partial-thickness tears. The cuff strain was returned to the intact state with repair. This was consistent for 3 different glenohumeral abduction angles and for all 3 intra-articular tendon areas. The bursal strain did not have any significant differences between groups.

CONCLUSION

Articular-sided tendon strain increases consistently across the supraspinatus tendon with greater partial tears. Repair returned strain close to the intact state.

CLINICAL RELEVANCE

This study may add credence to the clinical practice of repairing intra-articular partial-thickness rotator cuff tears greater than 50%.