Douglas J. Wyland

Gender differences in lower extremity kinematics, kinetics and energy absorption during landing

OBJECTIVE To determine whether gender differences exist in lower extremity joint motions and energy absorption landing strategies between age and skill matched recreational athletes. DESIGN Mixed factor, repeated measures design. BACKGROUND Compared to males, females execute high demand activities in a more erect posture potentially predisposing the anterior cruciate ligament to greater loads and injury. The preferred energy absorption strategy may provide insight for this performance difference. METHODS Inverse dynamic solutions estimated lower extremity joint kinematics, kinetics and energetic profiles for twelve males and nine females performing a 60 cm drop landing. RESULTS Females demonstrated a more erect landing posture and utilized greater hip and ankle joint range of motions and maximum joint angular velocities compared to males. Females also exhibited greater energy absorption and peak powers from the knee extensors and ankle plantar-flexors compared to the males. Examinations of the energy absorption contributions revealed that the knee was the primary shock absorber for both genders, whereas the ankle plantar-flexors muscles was the second largest contributor to energy absorption for the females and the hip extensors muscles for the males. CONCLUSIONS Females may choose to land in a more erect posture to maximize the energy absorption from the joints most proximal to ground contact. RELEVANCE Females may be at a greater risk to anterior cruciate ligament injury during landing due to their energy absorption strategy.

Changes in passive range of motion and development of glenohumeral internal rotation deficit (GIRD) in the professional pitching shoulder between spring training in two consecutive years

BACKGROUND Pitching causes increased mechanical stress to the arm and is thought to result in alterations in range of motion (ROM) as a result of osseous and soft tissue adaptations. Understanding the factors that contribute to alterations in ROM will allow for improved understanding of the pitching shoulder. This study examined humeral torsion (HT) and shoulder mobility over 2 consecutive years. METHODS Bilateral shoulder mobility and HT were assessed in 33 asymptomatic professional pitchers over 2 spring trainings. A repeated-measures analysis of covariance was used to assess the change in motion of the dominant side/nondominant side across seasons while quantifying pre-existing HT. Prevalence of glenohumeral internal rotation deficit (GIRD) between seasons was compared with χ(2) analysis, and GIRD and non-GIRD pitchers were compared with the independent t test. RESULTS The dominant shoulder displayed increased external rotation (11.5° ± 0.1°, P = .02) and decreased internal rotation (-8.4° ± 11.0°, P = .03) and horizontal adduction (-17.6° ± 13.8°, P = .01). The nondominant shoulder remained the same. Mean HT was significantly different (P = .001) in the dominant (10° ± 11°) arm than in the nondominant arm (23° ± 11°). A significant number of pitchers had with GIRD (P < .01) at each assessment. CONCLUSIONS ROM was significantly altered between seasons of pitching. These changes likely resulted from soft tissue adaptations because we accounted for humeral retrotorsion. Pitchers who developed GIRD displayed a 7° increase in retrotorsion on the dominant shoulder. Changes in the pitching shoulder over time accounting for humeral retrotorsion may suggest pitching ROM is transient and should be monitored.

Bony Adaptation of the Proximal Humerus and Glenoid Correlate Within the Throwing Shoulder of Professional Baseball Pitchers

Background: Elite throwing athletes have increased proximal humeral retrotorsion (HRT) and glenoid retroversion (GRV) in their throwing shoulders compared with their nonthrowing shoulders. These adaptive morphologic changes are thought to be independently protective against shoulder injury; however, their relationship to each other is poorly understood. Purpose: To determine if an association exists between HRT and GRV within the same shoulders of professional pitchers. Study Design: Cross-sectional study; Level of evidence, 3. Methods: The HRT and GRV measurements were determined using published techniques in asymptomatic bilateral shoulders of 32 professional pitchers (mean age, 23 years). Three measurements for each variable were averaged, and the reliability of the techniques was verified. The relationship between HRT and GRV within the same shoulders was determined with Pearson correlation coefficients. Paired t tests were used to compare HRT and GRV between the throwing and nonthrowing shoulder. Simple ratios were calculated between HRT and GRV. Results: Humeral retrotorsion and GRV were both significantly greater on the throwing side compared with the nonthrowing side (HRT: throwing = 9.0° ± 11.4° and nonthrowing = 22.1° ± 10.7°, P < .001; GRV: throwing = 8.6° ± 6.0° and nonthrowing = 4.9° ± 4.8°, P = .001). Within the same shoulders, there was a statistically significant positive association between HRT and GRV on the throwing side (r = 0.43, P = .016) but not on the nonthrowing side (r = −0.13, P = .50). The HRT:GRV ratio was 2.3:1 for throwing shoulders and 7:1 for nonthrowing shoulders. Conclusion: The concurrent increases in dominant shoulder HRT and GRV were observed as a 2:1 “thrower’s ratio.” As this relationship was not observed on the nondominant shoulder, it suggests that bony adaptation of the proximal humerus and glenoid are coupled during skeletal development in the throwing shoulder. Longitudinal studies are needed to confirm this hypothesis.

Vascularity and Tendon Pathology in the Rotator Cuff: A Review of Literature and Implications for Rehabilitation and Surgery

Objective To compile histological and imaging research detailing the microvascularity of the rotator cuff and determine the clinical application of these findings for clinicians. Methods A computer-assisted literature search of MEDLINE (1966 to September 2008) using keywords related to blood flow to the shoulder and limited to humans and English language. A hand search was also performed by three of the authors. Results Nineteen studies met inclusion and exclusion criteria. Conclusions The relationship between the variables of vascularity, age and degeneration remains unclear. Recent studies with stronger design and better technology support the fact that increased vascularity is a normal response to smaller tears, but that as tear size increases the healing response fails and decreased vascularity is observed. Also, impingement may cause hypovascularity. These studies support the possibility that people without symptoms may have normal blood flow even with ageing. Finally, exercise may increase blood flow to the rotator cuff. These findings have both surgical and rehabilitation implications.

Professional Pitchers With Glenohumeral Internal Rotation Deficit (GIRD) Display Greater Humeral Retrotorsion Than Pitchers Without GIRD

Background: Dominant shoulder glenohumeral internal rotation deficit (GIRD) has been associated with pitching arm injuries. The relationship of humeral torsion on development of GIRD is not clear. Hypothesis: Pitchers displaying GIRD will display greater humeral retrotorsion when compared with those without GIRD. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Humeral torsion and shoulder range of motion (ROM) were measured in 222 professional pitchers before spring training from 2009 to 2012. Shoulder external rotation (ER) and internal rotation (IR) ROM were assessed in 90° of abduction with the scapula stabilized. Humeral torsion was measured via ultrasound using previously described and validated methods. Side-to-side differences in total arc of motion (ER + IR), ER, and IR ROM and humeral torsion were calculated as nondominant minus dominant arm measures for analysis. Pitchers were classified as having GIRD if their dominant arm displayed an IR deficit ≥15° concomitant with a total arc of motion deficit ≥10° compared with their nondominant arm. A mixed-model analysis of variance (side × GIRD) was used to compare dominant and nondominant humeral torsion between pitchers with GIRD (n = 60) and those without GIRD (n = 162). Independent t tests were used to compare the side-to-side difference in humeral torsion between pitchers with GIRD and those without GIRD (α = 0.05). Results: Pitchers with GIRD displayed significantly less humeral torsion (ie, greater retrotorsion) in their dominant arm as compared with those without GIRD (GIRD = 4.5° ± 11.8°, no GIRD = 10.4° ± 11.7°; P = .002). Pitchers with GIRD also displayed a greater side-to-side difference in humeral torsion (GIRD = 19.5° ± 11.9°, no GIRD = 12.3° ± 12.4°; P = .001). However, pitchers with GIRD did not display an increase in dominant ER ROM (dominant ER = 131.8° ± 14.3°, nondominant ER 126.6° ± 13.1°) when compared with those without GIRD (dominant ER = 132.0° ± 14.2°, nondominant ER 122.6° ± 13.1°; P = .03). Pitchers with GIRD displayed expected alterations in ROM (IR = 28.8° ± 9.6°, total arc = 160.6° ± 15.4°; P < .01 for both) when compared with those without GIRD (IR = 39.9° ± 9.9°, total arc = 171.2° ± 15.5°). Conclusion: Pitchers with GIRD displayed greater side-to-side differences and dominant humeral retrotorsion as compared with those without GIRD. The greater humeral retrotorsion may place greater stress on the posterior shoulder resulting in ROM deficits. Pitchers with greater humeral retrotorsion appear to be more susceptible to developing ROM deficits associated with injury and may need increased monitoring and customized treatment programs to mitigate their increased injury risk.

A Comparison of Glenoid Morphology and Glenohumeral Range of Motion Between Professional Baseball Pitchers With and Without a History of SLAP Repair

PURPOSE We sought to examine the relation among glenoid morphology, glenohumeral range of motion (ROM), and history of shoulder injury in professional baseball pitchers. METHODS We studied 58 professional baseball pitchers. Internal rotation (IR) and external rotation (ER) ROM was measured at 90° of abduction. Horizontal adduction (HAdd) ROM was also measured. Glenoid superior inclination and glenoid retroversion (GRV) were then measured radiographically. Separate mixed-model analyses of variance were used to compare dependent measures between the dominant and nondominant shoulders of pitchers with or without a history of SLAP repair. Significant interaction effects were interpreted by use of a test for simple main effects (α = .05). RESULTS GRV was significantly greater on the dominant side (8.7° ± 5.6°) versus nondominant side (5.5° ± 5.2°) (P = .001), whereas glenoid superior inclination was equivalent (99.5° ± 4.3° for dominant side v 99.2° ± 4.4° for nondominant side, P = .853). Post hoc analysis indicated that pitchers with a history of SLAP repair did not display an adaptive increase in dominant GRV compared with nondominant GRV (P = .016). There were no statistical differences between groups for ER (P = .29), IR (P = .39), or HAdd (P = .39). The dominant shoulder displayed greater ER (mean increase, 6.2° ± 12.2°) with a complementary decrease in IR (mean decrease, 5.8° ± 13.2°) and HAdd (mean decrease, 8.9° ± 13.7°) compared with the nondominant side. CONCLUSIONS Our findings suggest that the development of increased GRV in the dominant shoulder of professional baseball pitchers may be a protective adaptive change not reflected in glenohumeral ROM measures. LEVEL OF EVIDENCE Level IV, therapeutic case series.

Humeral Torsion as a Risk Factor for Shoulder and Elbow Injury in Professional Baseball Pitchers

Background: Numerous studies have demonstrated that humeral retrotorsion is increased in the dominant arms of throwing athletes. No study has clearly defined the relationship between humeral retrotorsion and shoulder and elbow injury. Hypothesis: Uninjured professional pitchers will display more dominant humeral torsion (HT) than professional pitchers who sustain shoulder injuries but less than pitchers who sustain elbow injuries. Study Design: Case-control study; Level of evidence, 3. Methods: Pitchers from the Colorado Rockies professional baseball organization were recruited for participation for this prospective injury study from 2009 to 2013. HT was assessed using indirect ultrasonographic techniques and was measured prospectively in 255 pitchers before each spring training (average of 2 trials). From the beginning of the preseason to the end of the postseason, overuse upper extremity injuries (shoulder or elbow) were tracked for each participating athlete. All athletes who reported pain or injury to their coach were referred to the organization’s athletic trainer for evaluation and classification of each injury. The difference in HT was calculated by subtracting measurement of the dominant arm from the nondominant arm, and 3 separate mixed-model analyses of variance (side × injury group) were used to compare the dominant and nondominant HT between all pitchers who developed an arm injury (shoulder and elbow combined), as well as comparing pitchers who developed a shoulder or elbow injury to those who did not miss games due to shoulder or elbow injury (α = .05). Results: During the course of the study, 60 arm (30 shoulder; 30 elbow) injuries were observed; 195 pitchers did not suffer an injury. There were no differences when HT was compared between all injured (shoulder and elbow injuries combined) and uninjured pitchers (P = .13; effect size 0.14). There was a significant interaction effect showing that pitchers who suffered a shoulder injury displayed 4° less dominant humeral retrotorsion compared with pitchers without injury (P = .04) and that pitchers with elbow injury displayed 5° greater humeral retrotorsion (P = .04). In addition, those who suffered an ulnar collateral ligament injury requiring reconstruction (n = 17) also displayed 4o greater dominant retrotorsion and 5° less nondominant humeral retrotorsion compared with pitchers who did not suffer an injury (n = 195; P = .05). There was not a significant difference between nondominant HT among pitchers who sustained shoulder and elbow injuries and pitchers without injury. Conclusion: The results of this study show a contrast in dominant humeral retrotorsion between pitchers who suffered shoulder and elbow injuries compared with those without an injury. Pitchers who sustained shoulder injuries had less dominant humeral retrotorsion compared with noninjured pitchers. In contrast, pitchers who sustained time-loss elbow injuries displayed increased humeral retrotorsion compared with noninjured pitchers. Together, these results suggest that increased adaptive humeral retrotorsion is protective against shoulder injuries but a harmful contributor for elbow injuries in professional pitchers. This is the first study to show differing injury risk profiles for shoulder and elbow injury.

Meniscal Allograft Transplantation With Soft Tissue in Bone Socket Fixation: Arthroscopic Technique With Technical Pearls

Meniscal allograft transplantation may slow the progression of degenerative changes in the meniscus-deficient knee. The current literature suggests patients can experience good early to mid-term satisfaction and patient-reported outcomes with reasonable expectations of return to work. More ambitious applications in athletes have also shown good results although long-term data are lacking. Traditionally, meniscal allograft transplantation has been considered an open procedure with incorporation of bone blocks from the allograft source. However, as arthroscopic techniques have advanced, it has become possible to perform this procedure through a predominantly arthroscopic approach while securing the soft tissue graft in bone tunnels. The current demonstration provides this background and technical pearls for success in arthroscopic meniscal allograft transplantation.

“Proprietary Processed” Allografts: Clinical Outcomes and Biomechanical Properties in Anterior Cruciate Ligament Reconstruction

Background: The processing of allograft tissues in anterior cruciate ligament (ACL) reconstruction continues to be controversial. While high-dose irradiation of grafts has received scrutiny for high failure rates, lower dose irradiation and “proprietary-based” nonirradiated sterilization techniques have become increasingly popular, with little in the literature to evaluate their outcomes. Recent studies have suggested that the specifics of allograft processing techniques may be a risk factor for higher failure rates. Purpose: To assess these proprietary processes and their clinical outcomes and biomechanical properties. Study Design: Systematic review. Methods: A systematic review was performed using searches of PubMed, EMBASE, Google Scholar, and Cochrane databases. English-language studies were identified with the following search terms: “allograft ACL reconstruction” (title/abstract), “novel allograft processing” (title/abstract), “allograft anterior cruciate ligament” (title/abstract), “anterior cruciate ligament allograft processing” (title/abstract), or “biomechanical properties anterior cruciate ligament allograft” (title/abstract). Duplicate studies, studies not providing the allograft processing technique, and those not containing the outcomes of interest were excluded. Outcomes of interest included outcome scores, complication and failure rates, and biomechanical properties of the processed allografts. Results: Twenty-four studies (13 clinical, 11 biomechanical) met inclusion criteria for review. No demonstrable difference in patient-reported outcomes was appreciated between the processing techniques, with the exception of the Tutoplast process. The clinical failure rate of the Tutoplast process was unacceptably high (45% at 6 years), but no other difference was found between other processing techniques (BioCleanse: 5.4%; AlloTrue: 5.7%; MTF: 6.7%). Several studies did show an increased failure rate, but these studies either combined processing techniques or failed to delineate enough detail to allow a specific comparison for this study. The biomechanical studies showed overall maintenance of satisfactory biomechanical properties throughout multiple testing modes with normalization to the percentage of control specimens. Conclusion: A comparison of proprietary allograft processing techniques is difficult because of the variability and lack of specificity of reporting in the current literature. Among the available literature, except for the Tutoplast process, no notable differences were found in the clinical outcomes or biomechanical properties. Future study with a longer follow-up is necessary to determine the role and limitations of these grafts in the clinical setting.

Return to play after nonoperative management for a severe type III acromioclavicular separation in the throwing shoulder of a collegiate pitcher

Abstract Background. Treatment of type III acromioclavicular (AC) separations is controversial, especially in the dominant shoulder of a high-level throwing athlete. This case report describes the return to play after nonoperative management of a collegiate baseball pitcher with a severe type III AC separation in his throwing shoulder. Hypothesis/purpose. Case report of return to play with nonoperative management of a type III AC separation in the throwing shoulder of a collegiate pitcher. Study design. A case report of a single patient. Methods. Prospective data were recorded in the case of a collegiate pitcher who suffered an acute injury to the dominant shoulder, resulting in a severe type III AC separation. He was initially treated with a figure-of-8 brace and a sling. Postinjury, strengthening of the wrist, hand, and elbow began at 3½ weeks, and shoulder range of motion (ROM) and a periscapular strengthening program began at 6 weeks. At 2 months postinjury, a deformity was still present, but the athlete was pain free, with full shoulder ROM and strength without tenderness at the AC joint. Formal physical therapy was initiated to include an accelerated interval throwing program. Results. At 12 weeks postinjury, the athlete was pitching asymptomatically, and gradually returned to regular play. At 6 months and now through 24 months postinjury, the athlete reported full strength, full ROM, and return to his previous level of throwing and velocity without complication. He volunteered that he was 100% satisfied with the result, and feels he is the same pitcher as, if not stronger than, prior to this injury. Conclusions. This case demonstrates a collegiate baseball pitcher who returned to his preinjury level of pitching with nonoperative treatment of a severe type III AC separation.