Tadato Kido

Immobilization in external rotation after shoulder dislocation reduces the risk of recurrence. A randomized controlled trial.

BACKGROUND An initial anterior dislocation of the shoulder becomes recurrent in 66% to 94% of young patients after immobilization of the shoulder in internal rotation. Magnetic resonance imaging and studies of cadavera have shown that coaptation of the Bankart lesion is better with the arm in external rotation than it is with the arm in internal rotation. Our aim was to determine the benefit of immobilization in external rotation in a randomized controlled trial. METHODS One hundred and ninety-eight patients with an initial anterior dislocation of the shoulder were randomly assigned to be treated with immobilization in either internal rotation (ninety-four shoulders) or external rotation (104 shoulders) for three weeks. The primary outcome measure was a recurrent dislocation or subluxation. The minimum follow-up period was two years. RESULTS The follow-up rate was seventy-four (79%) of ninety-four in the internal rotation group and eighty-five (82%) of 104 in the external rotation group. The compliance rate was thirty-nine (53%) of seventy-four in the internal rotation group and sixty-one (72%) of eighty-five in the external rotation group (p = 0.013). The intention-to-treat analysis revealed that the recurrence rate in the external rotation group (twenty-two of eighty-five; 26%) was significantly lower than that in the internal rotation group (thirty-one of seventy-four; 42%) (p = 0.033) with a relative risk reduction of 38.2%. In the subgroup of patients who were thirty years of age or younger, the relative risk reduction was 46.1%. CONCLUSIONS Immobilization in external rotation after an initial shoulder dislocation reduces the risk of recurrence compared with that associated with the conventional method of immobilization in internal rotation. This treatment method appears to be particularly beneficial for patients who are thirty years of age or younger.

A new method of immobilization after traumatic anterior dislocation of the shoulder: a preliminary study

This preliminary prospective study was conducted to determine whether immobilization with the arm in external rotation would decrease the rate of recurrence after initial traumatic anterior dislocation of the shoulder. Forty patients with initial shoulder dislocations were assigned to (1) conventional immobilization in internal rotation (IR group, n = 20) or (2) a new method of immobilization in external rotation (ER group, n = 20). The recurrence rate was 30% in the IR group and 0% in the ER group at a mean 15.5 months. The difference in recurrence rate was even greater among those who were aged less than 30 years (45% in the IR group and 0% in the ER group). Immobilization with the arm in external rotation is effective in reducing the rate of recurrence after initial dislocation of the shoulder.

Humeral attachment of the supraspinatus and infraspinatus tendons: an anatomic study

We investigated the anatomic relationship of the supraspinatus (SSP) and infraspinatus (ISP) tendons to the three facets of the greater tuberosity. After removing the superficial layer of the cuff to expose the tendon fibers in 10 embalmed shoulders, the cuff tendon attachment to the facets was examined, and the location of attachment was measured in reference to (1) the anterior margin of the greater tuberosity and (2) the superior margin of the sulcus (anatomic neck without cartilage). The SSP tendon attached to the superior facet and the superior half of the middle facet. The ISP tendon attached to the entire middle facet, covering a portion of the SSP tendon. Thus, the anterior half of the superior cuff tendon (12.6 +/- 1.1 mm) was composed of only the SSP tendon, whereas the posterior half (9.8 +/- 3.2 mm) was composed of both the SSP and ISP tendons. The sulcus was located not at the SSP-ISP interval but slightly posterior to the posterior margin of the SSP tendon (4.3 +/- 2.4 mm). We conclude that (1) there is an overlap between the SSP and ISP tendons identifiable by the facets or the distance from the anterior greater tuberosity and (2) the sulcus is located slightly posterior to the posterior margin of the SSP tendon.

Which is More Useful, the “Full Can Test” or the “Empty Can Test,” in Detecting the Torn Supraspinatus Tendon?

The purpose of this study was to determine the clinical usefulness of the full can and empty can tests for determining the presence of a torn supraspinatus tendon. The two tests were performed in 143 shoulders of 136 consecutive patients. In each test, the muscle strength was determined by manual muscle testing, and the presence of pain during the maneuver was recorded. We interpreted the tests as positive when there was 1) pain, 2) muscle weakness, or 3) pain or muscle weakness or both. Shoulders were examined by high-resolution magnetic resonance imaging with 95% accuracy for full-thickness rotator cuff tears. There were 35 shoulders with full-thickness tears of the supraspinatus tendon. The accuracy of the tests was the greatest when muscle weakness was interpreted as indicating a torn supraspinatus tendon in both the full can test (75% accurate) and the empty can test (70% accurate). However, there was no significant difference between the accuracy of the tests when this criterion was used. Pain was observed in 62 shoulders (43%) during the full can test and in 71 shoulders (50%) during the empty can test, but the difference was not statistically significant. Muscle weakness should be interpreted as indicative of supraspinatus tendon tear. Using this indicator, both tests are equivalent in terms of accuracy, but considering pain provocation, the full can test may be more beneficial in the clinical setting.

Position of Immobilization After Dislocation of the Shoulder. A Cadaveric Study

BACKGROUND After reduction of a shoulder dislocation, the torn edges of a Bankart lesion need to be approximated for healing during immobilization. The position of immobilization has traditionally been adduction and internal rotation, but there is little direct evidence to support or discredit the use of this position. The purpose of the present study was to determine the relationship between the position of the arm and the coaptation of the edges of a simulated Bankart lesion created in cadaveric shoulders. METHODS Ten thawed fresh-frozen cadaveric shoulders were used for experimentation. All of the muscles were removed to expose the joint capsule. A simulated Bankart lesion was created by sectioning the anteroinferior aspect of the capsule from the labrum. With linear transducers attached to the anteroinferior and inferior portions of the Bankart lesion, the opening and closing of the lesion were recorded with the arm in 0, 30, 45, and 60 degrees of elevation in the coronal and sagittal planes as well as with the arm in rotation from full internal to full external rotation in 10-degree increments. RESULTS With the arm in adduction, the edges of the simulated Bankart lesion were coapted in the range from full internal rotation to 30 degrees of external rotation. With the arm in 30 degrees of flexion or abduction, the edges of the lesion were coapted in neutral and internal rotation but were separated in external rotation. At 45 and 60 degrees of flexion or abduction, the edges were separated regardless of rotation. CONCLUSIONS The present study demonstrated that, in the cadaveric shoulder, there was a so-called coaptation zone in which the edges of a simulated Bankart lesion were kept approximated without the surrounding muscles.

The depressor function of biceps on the head of the humerus in shoulders with tears of the rotator cuff

We investigated the function of biceps in 18 patients (19 shoulders) with lesions of the rotator cuff. Their mean age was 59 years. Another series of 18 patients (19 shoulders) with normal rotator cuffs as seen on MRI acted as a control group. Their mean age was 55 years. A brace was used to maintain contraction of biceps during elevation. Anteroposterior radiographs were obtained with the arm elevated at 0 degrees , 45 degrees and 90 degrees with and without contraction of biceps. The distance between the centre of the head of the humerus and the glenoid was compared in the two groups. We found that in the group with tears there was significantly greater proximal migration of the head of the humerus at 0 degrees and 45 degrees of elevation without contraction of biceps but depression of the head of the humerus at 0 degrees, 45 degrees and 90 degrees when biceps was functioning. We conclude that biceps is an active depressor of the head of the humerus in shoulders with lesions of the rotator cuff.

Cystic changes of the humeral head on MR imaging: Relation to age and cuff-tears

We obtained MR images of 140 painful shoulders in 134 patients to determine the relationship between cystic changes of the humeral head and integrity of the rotator cuff. Cystic changes were observed in 49 shoulders (35%) and the commonest site was in the bare bone area of the anatomical neck, and the second commonest site was at the attachment of the supraspinatus tendon. Cystic changes in the bare bone area were observed equally often in shoulders with or without rotator cuff tears (27% and 18%, respectively) and were more frequently observed in the elderly. Cystic changes at the attachment of the supraspinatus and subscapularis tendons were specific to rotator cuff tears: they were observed in 28% of rotator cuff tears, but in none of those with an intact cuff. We conclude that there are two distinct types of cystic changes: one at the attachment of the supraspinatus and subscapularis tendons, which is closely related to tears of these tendons, and the other in the bare bone area of the anatomical neck, which is related to aging.

Electromyographic activities of the biceps during arm elevation in shoulders with rotator cuff tears

We investigated electromyographic activities of the biceps in 40 shoulders with full-thickness tears of the rotator cuff and 40 asymptomatic shoulders, with a normal rotator cuff on MRI, to determine the role of the biceps in cuff-deficient shoulders. Using surface electrodes, biceps activities were recorded during arm elevation in the scapular plane with and without a 1-kg load. The percentages of integrated electromyograms to the maximum voluntary contraction (%MVC) were obtained at 30 degrees, 60 degrees, 90 degrees, and 120 degrees of elevation. In the normal shoulders, %MVC of the biceps was always less than 10% through the arc of elevation both with and without load. Among 40 shoulders with rotator cuff tears, 14 showed increased activities of the biceps more than 10% in %MVC (p < 0.0001), whereas the remaining 26 shoulders had activities similar to the normal shoulders. The biceps activities in these 14 shoulders increased with load application and at higher angles of elevation. The muscle strength tended to be weaker in shoulders with increased biceps activities than in those without. Our findings suggest a potential supplemental function of the biceps in shoulders with rotator cuff tears.

Limaprost or pregabalin: preoperative and postoperative medication for pain due to lumbar spinal stenosis

We aimed to evaluate the incidence of (and risk factors for) postoperative pregabalin and/or limaprost to treat persistent numbness and/or pain of the lower extremities after lumbar spinal stenosis (LSS) surgery.

ACDF with a PEEK cage clinically provides a good outcome with minor donor site morbidity despite unsatisfactory radiological findings-A prospective cohort study of a PEEK cage in stand-alone usage-

Study Design A prospective cohort study was conducted on patients with anterior cervical decompression and fusion (ACDF) with a polyetheretherketone cage (PEEKc). Background Advantages of a PEEKc have been proposed in the study. However, benefits of using a PEEKc in ACDF are still controversial. Objective To investigate the advantages of a PEEKc in ACDF. Materials and Methods A total of 27 patients was enrolled in the study. The mean age of patients was 55±10 years (mean±standard deviation). The mean duration of symptoms was 17±21 months. Surgery was conducted at C3/4 in 1, C4/5 in 3, C5/6 in 11, C6/7 in 9, C7/T1 in 2, and C5/6/7 in 1 patient. The mean follow-up period was 2.1±1.3 years. Clinical outcomes were analyzed by the Japanese Orthopedic Association Scores (JOA scores) and its recovery rate. Perioperative complications were also investigated. Radiologically, studies were conducted on interbody lordotic angle (IBLA), interbody height (IBH), and bone fusion rates. Results The JOA score was 14.7±1.4 preoperatively and 16.3±1.3 at the final follow-up. A significant improvement was observed (p<0.05). The mean recovery rate of JOA scores was 74.0±25.0%. The preoperative IBLA was 0.5±6.1°. The mean IBLA at the final follow-up was 1.9±5.6°. The preoperative IBH was 34.2±3.5 mm. The mean IBH at the final follow-up was 34.3±3.5 mm. No significant improvement in IBLA and IBH was observed. A complete union rate at 1 year and 2.3 years (range, 2.0-6.0) after surgery was 29% (8/28 segments) and 61% (11/18 segments). No major complications were observed. Conclusions Despite an unsatisfactory bone union rate and no significant improvement in IBLA and IBH at the final follow-up, ACDF with a PEEKc clinically provided a stable outcome with less surgical invasion and minor donor-site morbidity.