Anterior deltoid deficiency in reverse total shoulder replacement: a biomechanical study with cadavers.

Reverse total shoulder replacement (RTSR) depends on adequate deltoid function for a successful outcome. However, the anterior deltoid and/or axillary nerve may be damaged due to prior procedures or injury. The purpose of this study was to determine the compensatory muscle forces required for scapular plane elevation following RTSR when the anterior deltoid is deficient. The soft tissues were removed from six cadaver shoulders, except for tendon attachments. After implantation of the RTSR, the shoulders were mounted on a custom-made shoulder simulator to determine the mean force in each muscle required to achieve 30° and 60° of scapular plane elevation. Two conditions were tested: 1) Control with an absent supraspinatus and infraspinatus; and 2) Control with anterior deltoid deficiency. Anterior deltoid deficiency resulted in a mean increase of 195% in subscapularis force at 30° when compared with the control (p = 0.02). At 60°, the subscapularis force increased a mean of 82% (p < 0.001) and the middle deltoid force increased a mean of 26% (p = 0.04). Scapular plane elevation may still be possible following an RTSR in the setting of anterior deltoid deficiency. When the anterior deltoid is deficient, there is a compensatory increase in the force required by the subscapularis and middle deltoid. Attempts to preserve the subscapularis, if present, might maximise post-operative function.

Anterior cruciate ligament injuries in the female athlete.

With the participation of women in athletics growing rapidly over the last two decades, a disturbing gender-specific pre-disposition has emerged regarding anterior cruciate ligament (ACL) injuries of the knee. Female athletes have a two- to eightfold higher incidence of ACL injury than their male counterparts. It is estimated that 38,000 women sustain ACL tears per year. The majority of ACL injuries in female athletes occur through noncontact mechanisms, most often during deceleration activities, such as landing from a jump or cutting. The risk factors for noncontact ACL injuries can be categorized as intrinsic (anatomic and hormonal) and extrinsic (environmental and biomechanical). This article will discuss these risk factors that are thought to contribute to the higher incidence of ACL injuries in women, the development of prevention strategies, and the outcomes of ACL reconstruction in women.

Overuse injuries of the upper extremity in tennis players.

Several overuse injuries can affect the upper extremity of tennis players. A thorough understanding of anatomy and knowledge of these common conditions and their treatment facilitates the management of these athletes.

Rotator cuff repair as an outpatient procedure.

The purpose of this study was to evaluate outpatient rotator cuff repair on the basis of patient satisfaction, pain control, early postoperative complications, and cost control. Patients were considered good candidates for an outpatient repair if they were in good health and had adequate support at home. Seventy-five rotator cuff repairs were performed on an outpatient basis. The average age of the patients was 58 years. Patients with tears smaller than 2 cm in diameter were excluded. Postoperative pain was managed effectively in 74 of 75 outpatients. There were no cases of deltoid origin compromise, deep infection, or early failure of repair, and no outpatient required readmission to the hospital. This study demonstrates that outpatient rotator cuff repair is possible in the appropriately selected patient and can be performed safely and effectively with a 43% reduction in overall cost.

Understanding multidirectional instability of the shoulder.

OBJECTIVE: To provide an overview of the evaluation and treatment of the patient with multidirectional shoulder instability. DATA SOURCES: I searched MEDLINE for the years from 1980 to 2000 using the key words "shoulder joint," "instability," "dislocation," "multidirectional shoulder instability," and "inferior capsular shift." DATA SYNTHESIS: Multidirectional instability is symptomatic glenohumeral subluxation or dislocation in more than 1 direction: anterior, inferior, or posterior. The primary pathology is a loose and patulous capsule, and the entity is more common than previously recognized. Multidirectional instability affects young, sedentary patients with generalized ligamentous laxity, often with bilateral symptoms and an atraumatic history, but it also affects athletes, many of whom have sustained injuries. Patients with multidirectional instability may also have Bankart lesions and humeral head impression defects. CONCLUSIONS/RECOMMENDATIONS: Patients with multidirectional instability must be identified before appropriate treatment can be initiated. If a course of rehabilitation fails to improve the patient's symptoms, an inferior capsular shift procedure has been demonstrated to be an effective surgical option.

The treatment of failed rotator cuff repairs.

Results following surgical management of failed rotator cuff tears are clearly inferior to those obtained in the treatment of primary repairs. Conservative management may be the treatment of choice in selected patients with failed rotator cuff repairs. The primary goal for revision rotator cuff surgery should be relief of pain, not improvement in function. If the level of pain is manageable, and the patient is functioning with respect to activities of daily living, additional surgery may not be helpful. As there are multiple etiologies associated with failure of the initial repair, each patient should be carefully evaluated on an individual basis to determine if a subsequent procedure would be appropriate. Repeat repair is more likely to succeed in patients with an intact and functioning deltoid, an intact lateral portion of the acromion, and good quality of rotator cuff tissue. Conversely, patients who have had a lateral or radical acromionectomy, a detached or nonfunctioning deltoid, or poor quality of remaining rotator cuff tissue are less likely to have a successful result after repeat repair. It is evident that some of the factors associated with failure are avoidable. As the best chance for a successful result is at the time of the primary repair, the following points will briefly review these factors. The skin incision should be made in the flexion creases which are perpendicular to the deltoid fibers. The deltoid origin should be meticulously protected during the repair and lateral or radical acromionectomy should not be performed. Adequate anterior acromioplasty is essential for removal of the impingement lesion and to prevent subsequent wear on the repaired cuff tendon. The acromioclavicular joint should be evaluated preoperatively and treated as indicated at the time of the surgery. Adequate release of adhesions and mobilization of rotator cuff tissue should be performed using the coracohumeral ligament release and interval slide when necessary. The rotator cuff should be repaired to bone using tendon to bone sutures and/or secure suture anchors. In large and massive tears, there appears to be a role for the reattachment of the coracohumeral ligament. Early phase I range of motion should be initiated following rotator cuff repair and early resistance exercise with weights should be avoided.

The rotator cuff. Large and massive tears. Technique of open repair.

Symptomatic large and massive rotator cuff tears can be successfully managed with operative repair. Five factors that facilitate favorable results include: (1) performing an adequate subacromial decompression; (2) maintaining the integrity of the deltoid origin; (3) mobilizing the torn tendons, performing an interval slide when indicated; (4) repairing the tendons to bone; and (5) carefully staging and supervising the rehabilitation program.

An electromyographic analysis of the shoulder during a medicine ball rehabilitation program.

We used dynamic electromyography and a motion analysis system to describe the muscle firing patterns in 10 shoulder muscles and the basic kinematics of a two-handed overhead medicine ball throw. Ten healthy male subjects with no history of shoulder injury were evaluated. The two-handed medicine ball throw was divided into three phases for analysis: cocking, acceleration, and deceleration. The average duration of the throw was 1.92 seconds; the cocking phase represented 56%, the acceleration phase 15.5%, and the deceleration phase 28.5% of the throw. In the cocking phase, the upper trapezius, pectoralis major, and anterior deltoid muscles showed high activity ( > 40% to 60% maximum manual test), and the rotator cuff muscles had moderate activity ( > 20% to 40%). In the acceleration phase, five of the muscles demonstrated high levels of activity ( > 40% to 60%) and the upper trapezius and lower subscapularis muscles had very high levels of activity ( > 60%). Analysis of the deceleration phase revealed high activity in the upper trapezius muscle and moderate activity in all other muscles except the pectoralis major. Our findings support the use of medicine ball training as a bridge between static resistive training and dynamic throwing in the rehabilitation of the overhead athlete. This training technique provides a protective method of strengthening that closely simulates portions of the throwing motion.

An anatomic study of the subscapular nerves: A guide for electromyographic analysis of the subscapularis muscle.

Fifty shoulders from 36 human cadavers were examined to identify the nerves innervating the subscapularis muscle and their point of entry into the muscle. Most of the specimens (82%) revealed three independent nerves to the subscapularis, 16% of the specimens demonstrated four nerves, and 2% of the shoulders demonstrated two nerves to the subscapularis. Variability was noted at the level of origin (division or cord) of each primary nerve branch to the muscle. The point of entry of each nerve into the subscapularis was measured from three clinical anatomic landmarks. The entry points were found to closely follow a line running parallel to the vertebral border of the scapula and inferior from the medial surface of the base of the coracoid. Previous electromyogram studies of the subscapularis have used one electrode to study its dynamic function. The anatomic data in this and other series suggest that multiple electrodes may be required for a complete electromyogram study of the subscapularis. The findings of this study facilitate the placement of two intramuscular fine wire electrodes for electromyogrophic analysis, which permits the investigation of the subscapularis muscle as two functional units.

Arthroscopic treatment of glenoid labral tears.

We reviewed 52 consecutive patients who had undergone arthroscopic labral debridement. The average age was 29 and there were 35 men and 17 women. At operation, 27 patients had superior labrum anterior and posterior (SLAP) lesions, 20 patients had anteroinferior labral lesions, and 5 patients had posterior labral lesions. Despite the fact that, preoperatively, none of these patients had a history of dislocations or clinically evident instability, 70% of the patients with superior labral lesions, and all of those with anteroinferior and posterior lesions had instability on examination under anesthesia. The average followup was 36 months. At 1 year after arthroscopy, 78% of the patients with superior lesions had excellent relief compared with 30% of the patients in the anteroinferior group. At 2 years followup, these results decreased to 63% and 25%, respectively, and only 45% of the patients with superior labral lesions and 25% of those with anteroinferior lesions had returned to their previous athletic performance level. Four patients required a reoperation: 2 for instability and 2 for impingement. We conclude that occult instability is frequently present in patients with glenoid labral tears. The overall results are not encouraging, but this procedure may have an indication for short-term goals in competitive athletes or those who are willing to accept some compromise in function.

Operative treatment of failed repairs of the rotator cuff.

Thirty-one patients had a repeat repair after a failure of a previously performed repair of the rotator cuff, and the causes of the original failure and the results of the repeat repair were analyzed. The clinical situation was complex, with multiple factors contributing to the failures. A large or massive tear of the cuff in thirty patients (97 per cent) and persistent subacromial impingement in twenty-eight patients (90 per cent) were the most common factors associated with failure. The over-all result of the repeat repair was satisfactory in sixteen patients (52 per cent) and unsatisfactory in fifteen (48 per cent). Twenty-five patients (81 per cent) had satisfactory relief of pain. However, fourteen patients (45 per cent) had persistent weakness that led to an unsatisfactory result. The factors that were associated with a better result were an intact acromion, an intact origin of the deltoid muscle, and the finding that the remaining tissue of the rotator cuff was of good quality. The factors that were associated with an inferior result were a previous lateral acromionectomy, a previously detached origin of the deltoid muscle, and the finding that the tissue of the rotator cuff that was available at the time of the repeat operation was of poor quality. Persistent pain is the primary indication for a repeat repair. The functional results are not as predictable, especially when the tissue of the cuff is poor and the deltoid origin has been detached previously.

Arthroscopic resection of the outer end of the clavicle from a superior approach: a critical, quantitative, radiographic assessment of bone removal.

The technique of arthroscopic resection of the outer end of the clavicle through a superior approach is evaluated to determine whether adequate bone removal can be achieved. Furthermore, the results are compared with open resection. Twelve patients with osteolysis of the outer end of the clavicle refractory to conservative treatment underwent resection: six open and six arthroscopically through a superior approach. The distances from the acromial side of the AC joint to the lateral edge of the clavicle at its superior and inferior cortices were measured before and after surgery on anteroposterior radiographs. Bone removal was assessed by the difference between pre- and postoperative measurements. Satisfactory bone removal was possible arthroscopically and averaged 17 mm. This compared favorably with 18-mm average bone removal in the open group. Comparable pain relief and function were achieved in both groups. However, pain relief was achieved on average 3.4 months earlier in the arthroscopic group. Hospital stay was significantly shortened because the arthroscopic resections were outpatient procedures, whereas the open procedures had an average hospital stay of 3 days.

Operative repair of massive rotator cuff tears: Long-term results.

Sixty-one patients had operative repair of a massive rotator cuff tear and were followed an average of 7 years (range 3 to 13 years). The mean age of the patients was 62 years; there were 40 male and 21 female patients. All patients had significant pain, 31 patients had insidious onset of pain, and 30 patients recalled a traumatic event. Preoperatively, average active forward elevation was 88°, and average active external rotation was 27°. Forty-nine (80%) patients had marked atrophy of the supraspinatus and infraspinatus muscles. All patients had subacromial decompression as well as mobilization and transposition of rotator cuff tendons with tendon repair to bone. Fifty-two (85%) patients had satisfactory results, with 32 (52%) rated excellent and 20 (33%) rated good. Nine (15%) patients had unsatisfactory results, with four (7%) rated fair and five (8%) rated poor. Ninety-two percent of patients had satisfactory pain relief. The mean gain in forward elevation was 76%, and in active external rotation it was 30°. Adequate pain relief and the ability to raise the arm above the horizontal plane were achieved in 56 (92%) patients. Two patients tore their rotator cuff again after significant trauma.

Medical and economic parameters of motorcycle-induced trauma.

A retrospective study was conducted on all patients injured in a motorcycle accident who were admitted to the authors' institution during a one-year period. The 71 patients evaluated averaged 26 years of age; 79% were men, 75% were not wearing a helmet, and 24% were legally intoxicated. Sixty-six percent required surgical intervention and 36% a second procedure. There were 167 fractures, with an average of 2.4 per patient. The 27 patients requiring a blood transfusion averaged 10.5 units per patient. Motorcyclists not wearing a helmet had an increased risk of head injury (p less than .01). Those with head injuries had an increased need for intensive care (p less than .0001) and a ventilator (p less than .001). Patients with head injuries more commonly sustained fractures about the shoulder (p less than .015) than fractures to the lower extremity (p less than .005). The average hospital stay was 13 days, with a cost of $16,408 per patient. The cost was significantly higher in patients with a head injury ($21,945) than in patients without a head injury ($11,941). Patients sustaining a head injury were less likely to return to baseline functioning (p less than .001).