Spero G. Karas

Scapular Kinematics During Supraspinatus Rehabilitation Exercise A Comparison of Full-Can Versus Empty-Can Techniques

Background Supraspinatus strengthening is an important component of shoulder rehabilitation. Previous work has determined that the full-can and empty-can exercises elicit the greatest amount of supraspinatus activity. However, scapular kinematics has not been considered when prescribing supraspinatus exercises. Hypothesis Scapular downward rotation, internal rotation, and anterior tipping during the empty-can exercise are increased when compared with the full-can exercise. Study Design Descriptive laboratory study. Methods Twenty participants performed full-can and empty-can exercises while an electromagnetic tracking system was used to collect three-dimensional scapular kinematic data. Scapular angles at 30 °, 60 °, and 90 ° of the ascending and descending phases of humeral elevation were compared using 2-way repeated measures analysis of variance. Results There was more scapular anterior tipping and internal rotation during the empty-can exercise at all sampled humeral elevation angles except at 30 ° of the descending phase for anterior/posterior tipping (P< .05). Conclusion Scapular anterior tipping and internal rotation are increased during the empty-can exercise, whereas scapular upward rotation was not different between exercises. Clinical Relevance Increased scapular internal rotation and anterior tipping decrease the volume of the supraspinatus outlet during the empty-can exercise. When maintenance of the subacromial space is important, use of the full-can exercise seems most appropriate for selective strengthening of the supraspinatus muscle.

Electrothermal Arthroscopic Shoulder Capsulorrhaphy: A Minimum 2-Year Follow-Up

Background Few studies have documented the outcomes of thermal capsulorrhaphy for shoulder instability. Purpose To examine prospective evaluate outcomes of the first 100 patients with glenohumeral instability treated with thermal capsulorrhaphy. Study Design Case series; Level of evidence, 4. Methods Between 1997 and 1999, 85 of 100 patients treated with thermal capsulorrhaphy for glenohumeral instability were available for review at 2-year minimum follow-up (average, 4 years). Fifty-one patients suffered from anterior instability; 24 had an associated Bankart lesion. Ten patients demonstrated posterior instability; 1 had an associated reverse Bankart lesion. Seventeen patients had multidirectional instability; 8 had an associated Bankart lesion. Seven patients demonstrated anterior and posterior instability without an inferior component; 2 had an associated Bankart lesion. Failures were defined as shoulders requiring revision stabilization (14) or with recurrent instability (18), recalcitrant pain (3), or stiffness (2). Results Forty-eight of 85 procedures were successful, and 37 of 85 failed. For patients with anterior instability plus a Bankart lesion, 7 of 24 (26%) had failed results. For those with anterior instability without a Bankart lesion, 10 of 27 (33%) had failed results. The failure rates for posterior, multidirectional instability, and anteroposterior were 60% (6/10), 59% (10/17), and 57% (4/7), respectively. Of the 48 successes, mean preoperative American Shoulder and Elbow Surgeons score improved from 71 to 96 postoperatively, and patient satisfaction was 9.1 on a 10-point scale. Conclusion Because of the high failure rates, we now augment thermal capsulorrhaphy with capsular plication and/or rotator interval closure in cases of posterior and multidirectional instability and have lengthened the initial immobilization period to improve outcomes. Failure rates for thermal capsulorrhaphy, even with labral repairs, are high especially for shoulders with multidirectional instability and posterior instability. When procedures were successful, however, patients were very satisfied with significant improvements in American Shoulder and Elbow Surgeons scores.

Nandrolone Decanoate and Load Increase Remodeling and Strength in Human Supraspinatus Bioartificial Tendons

Background To date, no studies document the effect of anabolic steroids on rotator cuff tendons. Study Design Controlled laboratory study. Hypothesis Anabolic steroids enhance remodeling and improve the biomechanical properties of bioartificially engineered human supraspinatus tendons. Methods Bioartificial tendons were treated with either nandrolone decanoate (nonload, steroid, n = 18), loading (load, nonsteroid, n = 18), or both (load, steroid, n = 18). A control group received no treatment (nonload, nonsteroid [NLNS], n = 18). Bioartificial tendons’ remodeling was assessed by daily scanning, cytoskeletal organization by staining, matrix metalloproteinase-3 levels by ELISA assay, and biomechanical properties by load-to-failure testing. Results The load, steroid group showed the greatest remodeling and the best organized actin cytoskeleton. Matrix metallo-proteinase-3 levels in the load, steroid group were greater than those of the nonload, nonsteroid group (P < .05). Ultimate stress and ultimate strain in the load, steroid group were greater than those of the nonload, nonsteroid and nonload, steroid groups (P < .05). The strain energy density in the load, steroid group was greater when compared to other groups (P < .05). Conclusions Nandrolone decanoate and load acted synergistically to increase matrix remodeling and biomechanical properties of bioartificial tendons. Clinical Relevance Data suggest anabolic steroids may enhance production of bioartificial tendons and rotator cuff tendon healing in vitro. More research is necessary before such clinical use is recommended.

Shoulder External Rotation Fatigue and Scapular Muscle Activation and Kinematics in Overhead Athletes

CONTEXT Glenohumeral external rotation (GH ER) muscle fatigue might contribute to shoulder injuries in overhead athletes. Few researchers have examined the effect of such fatigue on scapular kinematics and muscle activation during a functional movement pattern. OBJECTIVE To examine the effects of GH ER muscle fatigue on upper trapezius, lower trapezius, serratus anterior, and infraspinatus muscle activation and to examine scapular kinematics during a diagonal movement task in overhead athletes. SETTING Human performance research laboratory. DESIGN Descriptive laboratory study. PATIENTS OR OTHER PARTICIPANTS Our study included 25 overhead athletes (15 men, 10 women; age = 20 ± 2 years, height = 180 ± 11 cm, mass = 80 ± 11 kg) without a history of shoulder pain on the dominant side. INTERVENTION(S) We tested the healthy, dominant shoulder through a diagonal movement task before and after a fatiguing exercise involving low-resistance, high-repetition, prone GH ER from 0° to 75° with the shoulder in 90° of abduction. MAIN OUTCOME MEASURE(S) Surface electromyography was used to measure muscle activity for the upper trapezius, lower trapezius, serratus anterior, and infraspinatus. An electromyographic motion analysis system was used to assess 3-dimensional scapular kinematics. Repeated-measures analyses of variance (phase × condition) were used to test for differences. RESULTS We found a decrease in ascending-phase and descending-phase lower trapezius activity (F(1,25) = 5.098, P = .03) and an increase in descending-phase infraspinatus activity (F(1,25) = 5.534, P = .03) after the fatigue protocol. We also found an increase in scapular upward rotation (F(1,24) = 3.7, P = .04) postfatigue. CONCLUSIONS The GH ER muscle fatigue protocol used in this study caused decreased lower trapezius and increased infraspinatus activation concurrent with increased scapular upward rotation range of motion during the functional task. This highlights the interdependence of scapular and glenohumeral force couples. Fatigue-induced alterations in the lower trapezius might predispose the infraspinatus to injury through chronically increased activation.

Subpectoral Biceps Tenodesis for the Treatment of Type II and IV Superior Labral Anterior and Posterior Lesions

Background: Surgical repair remains the gold standard for most type II and type IV superior labral anterior and posterior (SLAP) lesions that fail nonoperative management. However, most recently, there have been data demonstrating unacceptably high failure rates with primary repair of type II SLAP lesions. Biceps tenodesis may offer an acceptable, if not better, alternative to primary repair of SLAP lesions. Hypothesis: Subpectoral biceps tenodesis provides satisfactory, reproducible outcomes for the treatment of type II and type IV SLAP lesions. Study Design: Case series; Level of evidence, 4. Methods: Patients who underwent subpectoral biceps tenodesis and labral debridement for type II and type IV SLAP lesions by a single board-certified shoulder surgeon from 2006 to 2012 were evaluated. Exclusion criteria included those patients who underwent biceps tenodesis with an associated rotator cuff repair, anterior labral repair, or posterior labral repair. Outcome measures included the visual analog scale (VAS) for pain, the American Shoulder and Elbow Surgeons (ASES) score, and demographic data. Results: Between 2006 and 2012, a total of 36 subpectoral biceps tenodesis procedures were performed in 33 patients for type II or IV SLAP lesions. Twenty-six patients with 29 shoulder surgeries were available for follow-up. The average age was 46.7 years, with 16 male and 10 female patients participating in the study. The average follow-up was 40.17 months. There was a significant improvement in ASES and VAS scores: 48.1 and 6.4 preoperatively compared with 87.5 and 1.5 postoperatively, respectively (P < .001). There was no significant difference based on SLAP lesion type, patient age, or patient sex. Of 29 shoulders, 26 (89.66%) were able to return to the previous level of activity. Conclusion: This study adds to the evolving literature supporting biceps tenodesis as a viable treatment for type II and IV SLAP lesions. Patient age had no effect on the outcomes. Based on these results, biceps tenodesis is a safe, effective, and technically straightforward alternative to primary SLAP repair in patients with type II and IV SLAP tears.

The repeatability of scapular rotations across three planes of humeral elevation

Measurement of scapular kinematics is an important component in the assessment of shoulder function; however, repeatability of these measurements has not been established. The purpose of this study, therefore, was to determine the repeatability of scapular rotation measures for different humeral elevation planes between trials, sessions, and days. Three-dimensional scapular rotations were collected using an electromagnetic tracking system in three planes of humeral elevation. Coefficient of multiple correlation (CMC) values were calculated between trials, sessions, and days for curves of scapular rotations. CMC values were compared with repeated measures analysis of variance (ANOVAs) and Tukeys post-hoc procedures. Tests of simple main effects were performed for significant interaction effects. Our results suggest that scapular rotation measures are repeatable between trials within the same testing session, but less repeatable between testing sessions and days. Sagittal plane elevation consistently yielded the highest CMC values for all scapular rotations. These results suggest sagittal plane elevation should be considered to evaluate differences in scapular rotations.

Transacromial erosion of a locked subacromial hook plate: Case report and review of literature

Consensus on the technique for surgical reduction of highgrade acromioclavicular (AC) joint separations (Tossy III, Rockwood III-V) has remained elusive and controversial for several decades. It has been estimated that 50 to 70 procedures have been described to treat AC joint separations. These range from transarticular Kirschner wires with cerclage to coracoclavicular (CC) screw fixation to a variety of CC cerclage techniques with or without AC wire stabilization and capsule reconstruction. Beginning in the 1980s, reports emerged in the German-language literature of AC plates that were used independently or in combination with AC or CC ligament repair or reconstruction. The Rahmanzadeh plate used a ball-and-socket design in an effort to improve AC mobility. The Wolter plate had a ‘‘C’’-shaped crook, which was positioned inferior to the acromion. The tip of the crook was placed into a hole in the acromion, which was predisposed to widening and made the procedure technically challenging. The Balser plate had a distal hook, which was also positioned beneath the acromion. It most resembles the recently introduced AO AC hook plate, which has become increasingly popular during the last decade. We report a case of hook plate erosion through the acromion. To our knowledge, this is the first description of this complication.

Suture Plication, Thermal Shrinkage, and Sclerosing Agents Effects on Rat Patellar Tendon Length and Biomechanical Strength

Background Shortening or tightening of dense, collagenous tissues is often desirable in the treatment of laxity. Purpose To compare the effect of stress-protection suture, radiofrequency thermal shrinkage combined with stress-protection suture, and a 5% sodium morrhuate sclerosing injection on the length and biomechanical strength of the rat patellar tendon. Hypothesis Sclerosing agents will increase tendon mechanical strength. Thermal shrinkage combined with stress-protection suture and stress-protection suture only will cause a short-term decrease in tendon strength. All 3 methods will produce equivalent shortening of the tendon. Study Design Controlled laboratory study. Methods Forty-six female retired breeder rats were split into 4 groups, each receiving 1 of the 3 aforementioned treatments plus a control group that received a saline injection. After 4 weeks’ survival, the length and biomechanical properties of the patellar tendons were measured and compared to the contralateral untreated tendon. Results Rats treated with stress-protection suture had shorter tendons. Radiofrequency thermal shrinkage combined with stress-protection suture yielded tendons that were both shorter and stronger than were the untreated contralateral tendons. The sodium morrhuate-injected tendons were stronger whereas the saline-treated tendons were weaker than were their respective untreated contralateral tendons. Conclusion Surgical stress-protection suture without radiofrequency shrinkage is most effective at shortening the length of the rat patellar tendon, whereas radiofrequency thermal shrinkage combined with stress-protection suture as well as sodium morrhuate are effective at increasing the strength of rat patellar tendons. Clinical Relevance Judicious use of thermal shrinkage in combination with stress protection may improve ligament strength and decrease laxity.

Evaluating and managing muscle contusions and myositis ossificans

IN BRIEF: Muscle contusions almost always completely heal, but sometimes they give rise to hematomas or myositis ossificans. Warning signs of severe quadriceps contusion include marked decreased knee range of motion and a sympathetic knee effusion. Management consists of rest, cooling, compression, and elevation. Corticosteroids should be avoided, but nonsteroidal anti-inflammatory drugs may reduce edema and the risk of myositis ossificans. Rehabilitation protocols that include early flexion exercise can hasten recovery and decrease the likelihood of myositis ossificans. Asymptomatic myositis ossificans needs no treatment, but when it is associated with decreased range of motion, muscle atrophy, and continued pain, lesions may be excised after they mature.

Posterior Shoulder Instability: Does Glenoid Retroversion Predict Recurrence and Contralateral Instability?

PURPOSE To determine whether glenoid retroversion is a predictor of posterior shoulder instability, contralateral instability, or recurrent instability in patients with traumatic, contact-related posterior shoulder instability. METHODS Patients who underwent shoulder stabilization by 2 senior orthopaedic sport surgeons were identified retrospectively. Patients with a connective tissue disorder, multidirectional instability, or non-trauma-induced pathology were excluded. Patients with a glenoid lesion involving greater than 25% of the glenoid or an engaging humeral lesion were also excluded. Thus patients with a traumatic injury and a magnetic resonance imaging scan available for review were included. Magnetic resonance imaging scans were reviewed, and glenoid version was measured using the glenoid vault method. Charts were reviewed for epidemiologic data, recurrent instability requiring reoperation, evidence of glenoid/humeral bone lesions, and contralateral shoulder instability requiring surgery. Both recurrence and contralateral injury were defined based on having repeat surgery. RESULTS We identified 143 patients who met the inclusion criteria. Twenty-eight patients had posterior instability, whereas 115 patients had anterior instability. Patients with posterior instability had significantly more glenoid retroversion than patients with anterior instability (-15.4° ± 5.14° v -12.1° ± 6.9°; P < .016). Patients with retroversion of more than -16° showed a higher incidence of contralateral injuries (P < .036). However, no difference in postsurgical recurrent instability was noted. CONCLUSIONS Our data show that patients with posterior instability have a higher incidence of having a retroverted glenoid. Patients with increased retroversion showed increased posterior contralateral instability. Furthermore, patients with posterior instability and no humeral bone lesions may be more likely to incur contralateral injuries than those with humeral lesions. These data suggest that glenoid version and concomitant injury patterns may be used to help physicians counsel patients on their future risks of contralateral injury. LEVEL OF EVIDENCE Level IV, therapeutic case series.