George F. Rick Hatch

Effect of humeral component version on impingement in reverse total shoulder arthroplasty

HYPOTHESIS Reverse shoulder arthroplasty is growing in popularity for patients with deficient rotator cuffs; however, the phenomenon of scapular notching continues to be a concern. This study examined the effects of humeral component version in the Aequalis Reversed Shoulder Prosthesis (Tornier, Edina, MN) on impingement of the humeral prosthesis against the scapula to test the hypothesis that the mechanical contact of the humeral component with the scapular neck is influenced by the version of the humeral component. MATERIALS AND METHODS Seven shoulders from deceased donors were tested after the Aequalis Reversed Shoulder was implanted. The deltoid, pectoralis major, and latissimus dorsi were loaded based on physiologic cross-sectional area. The degree of internal and external rotation when impingement, subluxation, or dislocation occurred was measured at 0°, 30°, and 60° glenohumeral abduction in the scapular plane. Testing was performed with the humeral component placed in 20° of anteversion, neutral version, 20° of retroversion, and 40° of retroversion. RESULTS Maximum external rotation at 0° abduction was -1° ± 4° at 20° anteversion, 15° ± 3° at neutral, 28° ± 4° at 20° retroversion, and 44° ± 5° at 40° retroversion (P < .05). Maximum internal rotation at 0° abduction was 128° ± 9° at 20° anteversion, 112° ± 9° at neutral, 99° ± 8° at 20° retroversion, and 83° ± 8° at 40° retroversion (P < .05). Maximum external rotation at 30° abduction was 70° ± 6° at 20° anteversion, 84° ± 7° at neutral, 97° ± 6° at 20° retroversion, and 110° ± 5° at 40° retroversion (P < .05). There was no limitation to internal rotation at 30° abduction. No impingement occurred at 60° abduction. DISCUSSION Version of the humeral component plays a role in range of motion and impingement in reverse total shoulder arthroplasty. Anteversion can significantly decrease the amount of external rotation achievable after reverse total shoulder surgery. CONCLUSION Placing the Aequalis Reversed Shoulder humeral component at between 20° and 40° of retroversion more closely restores a functional arc of motion without impingement.

Management of chronic shoulder infections utilizing a fixed Articulating antibiotic-loaded spacer

BACKGROUND Literature on management of chronic shoulder infections is limited. The purpose of this study was to examine the efficacy of a standardized protocol for the management of chronic shoulder infections, including periprosthetic infections, utilizing an articulating antibiotic-loaded spacer. MATERIAL AND METHODS Thirty patients with chronic shoulder infections (4 primary and 26 postoperative) were treated with aggressive debridement, implantation of an antibiotic-loaded articulating spacer, and systemic antibiotics. Twenty-seven patients (90%) were compromised hosts. Eighteen patients (group I) elected to keep the spacer but three patients later underwent reimplantation, thus fifteen patients (group IA) were using the spacer as a prosthesis at their latest follow-up of 2.4 years. Twelve patients (group II, follow-up of 2.3 years) underwent reimplantation of a prosthesis. RESULTS Eradication of infection was accomplished in all 30 patients. Group IA patients had a Disability of Arm Shoulder and Hand (DASH) score of 50, Simple Shoulder Test (SST) score of 5, forward flexion of 73 degrees, abduction of 71 degrees, and external rotation of 29 degrees. Group II patients had a DASH score of 58, SST score of 5, forward flexion of 78 degrees, abduction of 83 degrees, and external rotation of 19 degrees. The differences between these 2 groups were not significant. DISCUSSION Chronic shoulder infections can be successfully treated with a protocol of aggressive debridement, antibiotic-loaded articulating spacer, and systemic antibiotics. Prolonged implantation of an articulating spacer may be a viable option in select low-demand patients with comorbidities.

The Effect of Tennis Racket Grip Size on Forearm Muscle Firing Patterns

Background Inappropriately sized tennis racket grip is often cited in the popular media as a risk factor for overuse injuries about the forearm and elbow. Currently, a hand measurement technique developed by Nirschl is commonly used by tennis racket manufacturing companies as the method for determining a players “recommended” grip size. Hypothesis Quarter-inch changes from that recommended by Nirschl in tennis racket grip size will have no significant effect on forearm muscle firing patterns. Study Design Controlled laboratory study. Methods Sixteen asymptomatic Division I and II collegiate tennis players performed single-handed backhand ground strokes with rackets of 3 different grip sizes (recommended measurement, undersized 1/4 in, and oversized 1/4 in). Fine-wire electromyography was used to measure muscle activity in extensor carpi radialis longus and brevis, extensor digitorum communis, flexor carpi radialis, and pronator teres. Repeated-measure analysis of variance was used for within-group comparisons, comparing different grips in specified phases for backhand ground strokes (P [.lessequal]. 05). Results There were no significant differences in muscle activity between small, recommended, or big grips in any muscle tested. Conclusion Based on these findings, tennis racket grip size 1/4 in above or below Nirschls recommended measurement does not significantly affect forearm muscle firing patterns. Clinical Relevance Alterations in tennis racket grip size within 1/4 in of Nirschls recommended sizing do not have a significant effect on forearm muscle activity and therefore may not represent a significant risk factor for upper extremity cumulative trauma, such as lateral epicondylitis.

Serum interleukin-6 as a marker of periprosthetic shoulder infection.

BACKGROUND Infection after shoulder arthroplasty can be a devastating complication, and subacute and chronic low-grade infections have proven difficult to diagnose. Serum marker analyses commonly used to diagnose periprosthetic infection are often inconclusive. The purpose of this study was to evaluate the effectiveness of serum interleukin-6 (IL-6) as a marker of periprosthetic shoulder infection. METHODS A prospective cohort study of thirty-four patients who had previously undergone shoulder arthroplasty and required revision surgery was conducted. The serum levels of IL-6 and C-reactive protein (CRP), the erythrocyte sedimentation rate (ESR), and the white blood-cell count (WBC) were measured. The definitive diagnosis of an infection was determined by growth of bacteria on culture of intraoperative specimens. Two-sample Wilcoxon rank-sum (Mann-Whitney) tests were used to determine the presence of a significant difference in the ESR and WBC between patients with and those without infection, while the Fisher exact test was used to assess differences in IL-6 and CRP levels between those groups. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of each marker were also calculated. RESULTS There was no significant difference in the IL-6 level, WBC, ESR, or CRP level between patients with and those without infection. With a normal serum IL-6 level defined as <10 pg/mL, this test had a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 0.14, 0.95, 0.67, 0.61, and 0.62, respectively. CONCLUSIONS IL-6 analysis may have utility as a confirmatory test but is not an effective screening tool for periprosthetic shoulder infection. This finding is in contrast to the observation, in previous studies, that IL-6 is more sensitive than traditional serum markers for periprosthetic infection.

Cruciate ligament avulsion fractures: Anatomy, biomechanics, injury patterns, and approach to management

Injury to the ACL or PCL of the knee most commonly involves a tear of the collagenous fibers of the ligament. Less frequently, a cruciate ligament injury involves an avulsion fracture at the origin or insertion of the ligament, usually from the insertion site on the tibial surface. Avulsion fractures of the cruciate ligaments are important, as they can be identified on radiographs, allowing a specific diagnosis. Although more common in children, when they occur in adults, they are more commonly associated with other injuries. The treatment of cruciate ligament avulsion fractures is different than the treatment of intrasubstance tears of the cruciate ligaments. These injuries can be treated conservatively or surgically with good outcomes. Recently arthroscopic fixation of these injuries with various fixation devices has become more frequent. Treatment largely depends on the type of fracture, particularly, the size, displacement, comminution, and orientation of the avulsed fracture fragment, in addition to the integrity of the attached cruciate ligament. This review article covers the anatomy and biomechanics of the cruciate ligaments, their injury patterns, and approach to management.

3.0-Tesla MRI and Arthroscopy for Assessment of Knee Articular Cartilage Lesions

The purpose of this study was to evaluate the ability of 3.0-Tesla magnetic resonance imaging (MRI) to accurately assess knee articular cartilage lesions. Sixteen patients who had knee 3.0-T MRI and underwent knee arthroscopy for partial meniscectomy were included. Three fellowship-trained sports medicine orthopedic surgeons reviewed all images. Articular lesions on MRI were graded from I to IV and compared with arthroscopic grading using the Outerbridge and the International Cartilage Repair Society (ICRS) classifications. The articular surface was divided into 6 regions. Based on MRI findings, of the 288 articular surface evaluations, 113 (39%) surface evaluations were classified as disease-positive (grade 2 to 4). Kappa interrater reliability scores for MRI evaluation, Outerbridge classification, and ICRS classification were 0.13, 0.54, and 0.41, respectively. Using the Outerbridge classification as a reference standard, the sensitivity, specificity, and accuracy were 57%, 71%, and 63%, respectively. Using the ICRS classification, sensitivity, specificity, and accuracy were 59%, 71%, and 69%, respectively. When isolating the articular grading to the senior author on MRI evaluation vs Outerbridge classification, the sensitivity, specificity, and accuracy were 54%, 92%, and 75%, respectively. Based on the current findings, 3.0-T MRI is as an invaluable noninvasive tool with good diagnostic value for assessing articular cartilage lesions of the knee, although it may not be as sensitive and accurate as previously reported.

Latissimus dorsi tendon transfer for irreparable rotator cuff tears: a modified technique using arthroscopy.

Latissimus dorsi transfer is a well-established method for the treatment of posterosuperior massive irreparable rotator cuff tears. We propose using an arthroscopically assisted technique that avoids insult to the deltoid. With the patient in the lateral decubitus position, an L-shaped incision is made along the anterior belly of the latissimus muscle and then along the posterior axillary line. The latissimus and teres major are identified and separated. The tendon insertion of the latissimus is isolated, and a FiberWire traction suture (Arthrex, Naples, FL) is placed, facilitating dissection of the muscle to the thoracodorsal neurovascular pedicle and subsequent mobilization. The interval deep to the deltoid and superficial to the teres minor is developed into a subdeltoid tunnel for arthroscopic tendon transfer. The latissimus tendon is then transferred and stabilized arthroscopically to the lateral aspect of the infraspinatus and supraspinatus footprints by multiple suture anchors.

Is Supplementary Fixation Necessary in Anterior Cruciate Ligament Reconstructions

Background: There has been concern regarding the fixation of anterior cruciate ligament reconstruction, with soft tissue grafts being strong and stiff enough to allow for early accelerated postoperative rehabilitation. Therefore, some have recommended supplementary fixation for soft tissue tibia interference screw fixation with a staple, to improve the strength and stiffness of the fixation. Unfortunately, with staple supplementation, there is a risk for symptomatic hardware, which may require a second surgery to remove the staple. Hypothesis: Supplementary fixation with a bioabsorbable knotless suture anchor will improve the structural properties of soft tissue tibia bioabsorbable interference screw (BIS) fixation and be comparable with supplementary fixation with a staple. Study Design: Controlled laboratory study. Method: Fifteen porcine tibias and flexor profundus tendons were randomized into 3 fixation study groups: group 1, BIS; group 2, BIS + staple; and group 3, BIS + push-lock screw. The structural properties of the 3 fixation groups were tested under displacement-controlled cyclic loading and load to failure. Results: No significant difference in mean stiffness (N/mm ± SEM) under cyclic loading was found for BIS (335.31 ± 15.43), BIS + staple (344.81 ± 44.97), and BIS + push-lock (353.28 ± 38.93). Under load-to-failure testing, there were no differences found in stiffness, yield load, displacement at yield load, displacement at ultimate load, and energy absorbed among the 3 fixation methods. BIS + push-lock fixation had a significantly higher ultimate load than BIS alone and BIS + staple (917.85 ± 58.30 N vs 479.83 ± 66.04 N, P = .0003 vs 618.89 ± 8.94 N, P = .004). Conclusion: Supplementary fixation with staple or push-lock screw did not significantly increase the structural strength and stiffness of the BIS soft tissue graft fixation under cyclic loading, but it did show improvement under load-to-failure testing for ultimate tensile load. Clinical Relevance: The indication for supplementary fixation for tibial BIS soft tissue graft fixation depends on the fixation that the BIS achieves at the time of the surgery because the tensile load is transferred to the secondary fixation if and only when there is slippage of graft at the primary fixation. The supplementary fixation may be of value in those cases with poor bone quality, such as revision surgery with tunnel widening and/or graft-tunnel mismatch, or possibly in cases with older patients or patients with disorders affecting bone mineral density.

Prevalence of abnormal vitamin D levels among division I NCAA athletes.

Background: Up to 1 billion people have insufficient or deficient vitamin D levels. Despite the well-documented, widespread prevalence of low vitamin D levels and the importance of vitamin D for athletes, there is a paucity of research investigating the prevalence of vitamin D deficiency in athletes. Hypothesis: We investigated the prevalence of abnormal vitamin D levels in National Collegiate Athletic Association (NCAA) Division I college athletes at a single institution. We hypothesized that vitamin D insufficiency is prevalent among our cohort. Study Design: Cohort study. Level of Evidence: Level 1. Methods: We measured serum 25-hydroxyvitamin D (25(OH)D) levels of 223 NCAA Division I athletes between June 2012 and August 2012. The prevalence of normal (≥32 ng/mL), insufficient (20 to <32 ng/mL), and deficient (<20 ng/mL) vitamin D levels was determined. Logistic regression was utilized to analyze risk factors for abnormal vitamin D levels. Results: The mean serum 25(OH)D level for the 223 members of this study was 40.1 ± 14.9 ng/mL. Overall, 148 (66.4%) participants had sufficient 25(OH)D levels, and 75 (33.6%) had abnormal levels. Univariate analysis revealed the following significant predictors of abnormal vitamin D levels: male sex (odds ratio [OR] = 2.83; P = 0.0006), Hispanic race (OR = 6.07; P = 0.0063), black race (OR = 19.1; P < 0.0001), and dark skin tone (OR = 15.2; P < 0.0001). Only dark skin tone remained a significant predictor of abnormal vitamin D levels after multivariate analysis (adjusted OR = 15.2; P < 0.0001). Conclusion: In a large cohort of NCAA athletes, more than one third had abnormal vitamin D levels. Races with dark skin tones are at much higher risk than white athletes. Male athletes are more likely than female athletes to be vitamin D deficient. Our study demonstrates a high prevalence of vitamin D deficiency among healthy NCAA athletes. Clinical Relevance: Many studies indicate a significant prevalence of vitamin-D insufficiency across various populations. Recent studies have demonstrated a direct relationship between serum 25(OH)D levels and muscle power, force, velocity, and optimal bone mass. In fact, studies examining muscle biopsies from patients with low vitamin D levels have demonstrated atrophic changes in type II muscle fibers, which are crucial to most athletes. Furthermore, insufficient 25(OH)D levels can result in secondary hyperparathyroidism, increased bone turnover, bone loss, and increased risk of low trauma fractures and muscle injuries. Despite this well-documented relationship between vitamin D and athletic performance, the prevalence of vitamin D deficiency in NCAA athletes has not been well studied.

Rates and Determinants of Return to Play after Anterior Cruciate Ligament Reconstruction in Division 1 College Football Athletes: A Study of the ACC, SEC, and PAC-12

Background: For competitive athletes, return to play (RTP) and return to preinjury levels of performance after anterior cruciate ligament (ACL) reconstruction are the main goals of surgery. Although outcomes of ACL surgery are well studied, details on factors influencing RTP in elite college football players have not been evaluated thoroughly. Purpose: To determine the rate of RTP following ACL surgery among National Collegiate Athletic Association (NCAA) Division 1 collegiate football athletes and to examine variables that may affect these rates. The hypothesis was that the RTP rate in this cohort will be influenced by factors reflecting skill and accomplishment; that is, athletes higher on the depth chart, those on scholarship, and those later in their careers will have higher RTP rates. It was also predicted that graft type and concomitant procedures may have an effect on RTP rates. Study Design: Case series; Level of evidence, 4. Methods: Using athlete- and surgery-specific data from participating institutions in 3 major Division 1 college football conferences, information on athletes who had ACL reconstruction from 2004 through 2010 was collected. Statistical analyses were performed to determine the RTP rate as a function of the variables, such as depth chart position, in the data collected. Results: Of the 184-player cohort, 82% of the athletes, including 94% of starters, were able to RTP. Rates were greater among athletes higher on the depth chart (P = .004) and on scholarship (P = .008). Year of eligibility also affected RTP rates (P = .047), which increased from the redshirt and freshman year to the sophomore and junior years, but then decreased slightly into the senior and fifth-year senior seasons. The use of an autograft versus allograft was associated with increased RTP (P = .045). There was no significant difference (P = .18) between players who underwent an isolated ACL reconstruction versus those who underwent additional procedures. Conclusion: More than 80% of football players at the Division 1 level were able to RTP following ACL reconstruction. Factors representative of a player’s skill were associated with higher rates of RTP. Surgery-specific variables, in general, had no effect on RTP, except for the use of autograft, which was associated with a greater RTP rate.