Increased Pitch Velocity Is Associated With Throwing Arm Kinetics, Injury Risk, and Ulnar Collateral Ligament Reconstruction in Adolescent, Collegiate, and Professional Baseball Pitchers: A Qualitative Systematic Review.

PURPOSE: To assess the relationship between pitch velocity and throwing arm kinetics, injury, and ulnar collateral ligament reconstruction (UCLr) among high school, collegiate, and professional baseball pitchers. METHODS: The Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, PubMed (2008-2019), and OVID/MEDLINE (2008-2019) were queried for articles that reported on pitch velocity predicting throwing arm kinetics, injury, or UCLr. The Methodological Index for Non-randomized Studies checklist was used to evaluate the quality of all included studies. Descriptive statistics with ranges were used to quantify data where appropriate. RESULTS: A total of 24 studies examining 2,896 pitchers, with Level of Evidence II-V were included. Intergroup analysis noted pitch velocity was significantly correlated with elbow varus torque in high school (R2 = 0.36), collegiate (R2 = 0.29), and professional (R2 = 0.076) pitchers. Elbow distraction force was positively associated with ball velocity in interpitcher analyses of high school (R2 = 0.373), professional (R2 = 0.175), and mixed-cohort evaluations (R2 = 0.624). Intragroup analysis demonstrated a strong association between pitch velocity and elbow varus torque (R2 = 0.922-0.957) and elbow distraction force (R2 = 0.910) in professional pitchers. Faster ball velocity was positively associated with a history of throwing arm injury (R2 = 0.194) in nonadult pitchers. In 2 studies evaluating professionals, injured pitchers had faster pitch velocity before injury compared with uninjured controls (P = .014; P = .0354). The need for UCLr was positively correlated with pitch velocity (R2 = 0.036) in professional pitchers. The consequences of UCLr noted little to no decrease in pitch velocity. CONCLUSIONS: Professional baseball pitchers with faster pitch velocity may be at the greatest risk of elbow injury and subsequent UCLr, potentially through the mechanism of increased distractive forces on the medial elbow complex. When a pitcher ultimately undergoes UCLr, decreases in pitching performance are unlikely, but may occur, which should encourage pitchers to caution against maximizing pitch velocity. LEVEL OF EVIDENCE: Level IV, systematic review of Level II-IV studies.

A Systematic Review of Lower-Body Kinematic and Strength Factors Associated With Pitch Velocity in Adult Baseball Pitchers.

CONTEXT: Ball velocity for baseball pitchers is influenced by a multitude of factors along the kinetic chain. While a vast amount of data currently exist exploring lower-extremity kinematic and strength factors in baseball pitchers, no previous study has systematically reviewed the available literature. OBJECTIVE: The aim of this systematic review was to perform a comprehensive assessment of the available literature investigating the association between lower-extremity kinematic and strength parameters and pitch velocity in adult pitchers. EVIDENCE ACQUISITION: Cross-sectional studies that investigated the association between lower-body kinematic and strength factors and ball velocity in adult pitchers were selected. A methodological index for nonrandomized studies checklist was used to evaluate the quality of all included studies. EVIDENCE SYNTHESIS: Seventeen studies met the inclusion criteria comprising a total of 909 pitchers (65%, professional, 33% college, and 3% recreational). The most studied elements were hip strength and stride length. The mean methodological index for nonrandomized studies score was 11.75 of 16 (range = 10-14). Pitch velocity was found to be influenced by several lower-body kinematic and strength factors including the following: (1) hip range of motion and strength of muscles around the hip and pelvis, (2) alterations in stride length, (3) alterations in lead knee flexion/extension, and (4) several pelvic and trunk spatial relationships throughout the throwing phase. CONCLUSIONS: Based on this review, we conclude that hip strength is a well-established predictor of increased pitch velocity in adult pitchers. Further studies in adult pitchers are needed to elucidate the effect of stride length on pitch velocity given mixed results across multiple studies. This study can provide a basis for trainers and coaches to consider the importance of lower-extremity muscle strengthening as a means by which adult pitchers can improve pitching performance.

Interval Throwing Programs at Distances Beyond 150 Feet Can Be Equivalent to Pitching Over Five Innings.

PURPOSE: To determine the cumulative elbow varus torque (EVT) experienced during created interval throwing programs (ITP) and derive innings pitched equivalent for each step. METHODS: High school pitchers wearing the motusBASEBALL sensor who had at least 50 throws at 90, 120, 150, and 180 ft and game pitches were included in this analysis. Means for EVT per throw and torque per minute were calculated at each distance. Three throwing programs were created using a template of 1 phase at each distance with 2 steps per phase. Programs varied only by number of throws per set (20, 25, and 30 throws for Program A, B, and C, respectively). Total EVT for each step, phase, and program were calculated using mean EVT per throw at each distance. Total EVT for each step and program were converted to a mean inning pitched equivalent (IPE) and maximum pitch count equivalent (MPE), respectively, using in-game pitching torque values and expected mean pitch counts (15 pitches/inning and maximum 105 pitches/game). RESULTS: In total, 3,447 throws were analyzed from 7 subjects (16.7 years ± 0.8 years). EVT per throw increased at each distance (range 36.9-45.5 N·m), comparable to game pitches (45.7 N·m). Mean EVT per minute was highest for 90 ft throws (193.4 N·m/min) and lowest for game pitches (125 N·m/min). Throwing Program A had the lowest range of IPE (Step 1: 2.0 and Step 8: 3.7), and Program C had the highest range (Step 1: 3.0 and Step 8: 5.6). The phases of Program A never exceeded 1MPE. Program B exceeded this threshold after Phase 1, and Program C exceeded 1MPE at every phase. Total program MPE ranged from 3.5 to 5.2 (Program A and C, respectively). CONCLUSIONS: Programs requiring 25 or more throws per set reached approximately 5 IPE per day. Increasing throwing repetitions by 10 throws resulted in a nearly 50% increase in IPE and MPE. LEVEL OF EVIDENCE: IV, retrospective cohort study.

Decreased Trunk Rotation at Foot Contact in Professional Baseball Pitchers With Prior Conservatively Managed SLAP Tears: A Propensity Score-Matched Analysis.

PURPOSE: To compare kinematic and kinetic parameters between a cohort of fully recovered professional pitchers with prior shoulder injury treated conservatively and a cohort with no prior shoulder injury. METHODS: Twenty-six fully recovered professional baseball pitchers with a history of shoulder injury treated conservatively pitched 8 to 10 fastball pitches using 3-dimensional motion capture (480 Hz). All shoulder injuries occurred within a 1- to 4-year time span from biomechanical evaluation and were severe enough to prevent pitchers from playing for between 1 and 12 months. These pitchers were propensity score matched by age, height, weight, handedness, and ball velocity to pitchers with no prior injury history (control) at a ratio of 1:4. We compared 21 kinematic and 11 kinetic parameters between groups using appropriate parametric testing. Subanalysis comparisons of pitchers with prior SLAP injury as well as rotator cuff tendinitis were also performed. RESULTS: SLAP tears (n = 11, 42.3%) were the most frequently reported injury, followed by rotator cuff tendinitis and/or shoulder impingement (n = 7, 26.9%). Compared with the control group, the 26 pitchers with prior injury showed no significant differences across the kinematic and kinetic factors. However, the SLAP tear subgroup did show significantly less trunk rotation at foot contact compared with controls (34.1° ± 4.9° vs 39.2° ± 10.2°, P = .0075). CONCLUSIONS: Fully recovered professional baseball pitchers with shoulder injuries treated conservatively showed no significant differences in kinetics or kinematics compared with their propensity score-matched counterparts, suggesting that shoulder injury alone may not greatly alter pitching mechanics. However, whereas prior groups have shown a decrease in trunk rotation at foot contact after surgical repair for SLAP tears, our study suggests that this kinematic change may alternatively originate with the injury itself. CLINICAL RELEVANCE: Understanding the cause of biomechanical adaptations by pitchers after injury can better aid clinicians and coaching staff in providing individualized and specific care to the throwing athlete.

Editorial Commentary: Platelet-Rich Plasma Shows Promise for Improving Shoulder Tendinopathy.

Platelet-rich plasma (PRP) injections continue to be used at increasing rates to treat common musculoskeletal conditions. PRP has a low-risk profile and emerging in vitro evidence to support its positive effects on soft-tissue healing. PRP has been shown to be of benefit for knee osteoarthritis, but less has been published regarding the shoulder. PRP delivers a high concentration of growth factors, cytokines, and other important inflammatory modulators. Its use is appealing for treating partial-thickness rotator cuff tears, subacromial bursitis, and rotator cuff tendinopathy since rotator cuff tendons often have poor healing capacity due to intrinsic degeneration. PRP has been shown to increase cell proliferation and matrix synthesis in tenocytes, which may aid tendon regeneration and healing. Adult tendons also contain a small amount of tendon progenitor cells, which can be induced to an active state by PRP. In addition, PRP is an autologous biologic agent and easy to acquire and administer in an outpatient clinical setting. Clinical studies continue to lag and are often heterogenous in quality and in results. PRP can vary widely based on multiple intrinsic and extrinsic factors, including patient age, sex, activity level, centrifugation speed, and number of centrifugation cycles. Thus, quality research methods should include reporting using the PAW (platelets/activation/white blood cells) system. Clinicians should remain cautiously optimistic about the future role of PRP injections in the shoulder.

Editorial Commentary: Shoulder Rotator Cuff Tendon Repair Using Bone Marrow Aspirate: Stem Cell Quantity Does Not Equal Quality.

The use of biological agents in orthopaedic surgery is rapidly evolving. The potential to augment the healing environment at a surgical repair site is an especially exciting possibility. There are a few popular biological agents, including platelet-rich plasma, concentrated bone marrow aspirate (BMA), and adipose-derived connective tissue progenitor cells. BMA is an especially appealing biological agent because it can be harvested from a variety of sources, including the iliac crest, distal femur, and proximal humerus. As a result, BMA is readily accessible with minimal added surgical time and morbidity during surgical procedures on the hip, knee, and shoulder. In particular, the surgically repaired rotator cuff tendon is a prime candidate for biological augmentation, and the proximal humerus is an appealing source of concentrated BMA given its ease of access and low harvesting morbidity at the time of arthroscopic repair. The nucleated cell count may be considered a surrogate for the quality of BMA and can be readily calculated at the time of harvest. However, the quantity of nucleated cells does not necessarily equate to the quality of nucleated cells as colony-forming units after cell culture, nor do we know how ex vivo cell culture correlates with in vivo stem cell proliferation and healing. Most of all, future research must determine what factors (if any) do positively correlate with the number of colony-forming units.

The association of stride length to ball velocity and elbow varus torque in professional pitchers.

Professional basebal pitchers (n =315) were divided into quartiles based on increasing stride length and random intercept linear mixed-effect models were used to correlate stride length with ball velocity, pelvis and trunk rotation at foot contact, and throwing arm kinetics. Average stride length among all pitchers was 78.3±5.3%body height (%BH). For every 10% increase in stride length, ball velocity increased by 0.9 m/s (B =0.089, ß =0.25, p <0.001) and trunk rotation initiation occurred 4.23 ms earlier (B =-0.42, ß =-0.14, p <0.001). When divided into quartiles pelvis rotation was less towards home plate in Q1 compared to Q3 and Q4 (70.0±10.7° vs. 60.9±8.9° and 58.6±9.1°, p <0.001). No significant differences in shoulder internal rotation torque (p =0.173) or elbow varus torque (p =0.072) were noted between quartiles. Professional baseball pitchers who reached stride lengths of 80%BH or greater achieved faster ball velocity without an increase in elbow varus torque. This may, be a byproduct of rotating the pelvis for a greater proportion of the pitching motion and thereby more effectively utilising the lower extremities in the kinetic chain. Encouraging players to achieve this threshold of stride length may enhance ball velocity outcomes.

PROMIS Global-10 performs poorly relative to legacy shoulder instruments in patients undergoing total shoulder arthroplasty for glenohumeral arthritis.

BACKGROUND: The PROMIS Global-10 is a 10-item questionnaire that assesses general health-related quality of life. There is a paucity of research on the utility of the PROMIS Global-10 in the evaluation of orthopedic conditions. The aim of this study is to compare PROMIS Global-10 and legacy shoulder-specific patient-reported outcome measures (PROMs) in patients undergoing total shoulder arthroplasty (TSA) for shoulder arthritis. METHODS: This retrospective cohort study included patients who underwent TSA for shoulder arthritis and completed preoperative and 1-year postoperative surveys. Primary outcome measures were the physical (PROMIS-P) and mental (PROMIS-M) components of PROMIS Global-10. The legacy PROMs included the American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) score, the Single Assessment Numeric Evaluation (SANE), and the Shoulder Activity Scale (SAS). Analyses included postoperative changes for each outcome, correlations between measures and a responsiveness assessment. RESULTS: A total of 170 patients met inclusion criteria. Average age and body mass index were 67.7 ± 7.8 years and 28.0 ± 4.9, respectively. All legacy PROMs and PROMIS-P were significantly higher at 1-year follow-up compared with the preoperative level (P < .0001), whereas PROMIS-M did not change (P = .06). Preoperatively, both PROMIS components were either poorly correlated with all legacy PROMs (r < .04, P < .05) or not correlated at all (P > .05). Postoperatively, PROMIS-M was poorly correlated with all legacy PROMs (r < .04, P < .01), whereas PROMIS-P had fair correlation with ASES (r = .5, P < .0001) and poor correlation with SANE and SAS (r < .04, P < .01). A floor effect was observed for SANE, and SANE and ASES had a ceiling effect. The effect sizes for SANE and ASES were high (d = 2.01 and 2.39 respectively), whereas the effect size for SAS was moderate (d = 0.65), and the effect sizes for the PROMIS measures were small (d < .5). ASES was the most responsive measure and PROMIS-M was the least responsive. CONCLUSION: PROMIS Global-10 had limited correlation with legacy PROMs and was less responsive at 1-year follow-up in patients following TSA. The Global-10 appears to have limited utility in the evaluation of patients with shoulder arthritis both preoperatively and after TSA.

Elbow Ulnar Collateral Ligament Injuries: Indications, Management, and Outcomes.

Ulnar collateral ligament (UCL) injuries continue to be a major source of morbidity in baseball players. The throwing motion creates nearly supraphysiological levels of valgus stress on the medial elbow, placing these athletes at high risk of UCL injury. The incidence of injury continues to rise at an alarming rate, especially among adolescent baseball pitchers. Certain risk factors for UCL injury have been identified, including pitch velocity, fewer days between outings, and overall workload. Treatment of UCL injuries depends on the type of tear. Low- to medium-grade partial UCL tears (i.e., grade I or II tears) are usually amenable to a period of rest and a graduated throwing program. Recently, platelet-rich plasma has been described as another treatment modality to consider in a throwing athlete with a partial UCL tear, although robust clinical data are currently lacking. Most athletes can return to competitive throwing in 3 to 4 months after nonoperative management of a low-grade partial UCL tear. Indications for surgical management of a UCL injury are a complete (type III) tear or failure of extensive conservative management after a partial UCL tear. UCL reconstruction remains the gold standard for operative management of a complete UCL tear. Both the modified Jobe technique and the docking technique have shown excellent results with return-to-play rates between 80% and 90%. Recently, UCL repair with collagen-dipped suture tape augmentation has gained some popularity. However, long-term results are lacking, especially in elite athletes. Time to return to play after UCL reconstruction is variable. Most athletes return to full competition in 12 to 15 months, although professional pitchers often require 15 to 18 months to return to their previous level of competition. Revision rates remain low (1%-7%), yet the revision rate is expected to rise as the number of UCL reconstructions performed in the United States continues to increase.

Incidence of thyroid disease in patients with forefoot deformity.

BACKGROUND: Hallux valgus and lesser toe deformities are common foot disorders with substantial functional consequences. While the exact etiologies are multi-factorial, it is unknown if certain endocrine abnormalities, such as thyroid dysfunction, may be associated with these pathologies. The current study sought to investigate the prevalence of thyroid disease in patients with hallux valgus or lesser toe deformities. METHODS: Every new patient who presented to our institution's foot and ankle clinic during a three-month time period was given a survey to determine the presence of a known thyroid disorder. The diagnosis for each visit was then recorded. Additionally, a national, publicly available database was queried for patients diagnosed with thyroid disease and concomitant hallux valgus or specific forefoot pathology. Odds ratios for the presence of thyroid dysfunction were then calculated for each patient group. RESULTS: Three-hundred and fifty initial visit patient surveys were collected, and 74 (21.1%) patients had a known diagnosis of thyroid disease. The most common diagnoses were primary hypothyroidism (n = 61, 17.4%), secondary hypothyroidism (n = 6, 1.7%), thyroiditis (n = 4, 1.1%), and hyperthyroidism (n = 3, 0.9%). Thyroid disease was present in 16 of 26 patients (61.5%) with a diagnosis of hallux valgus (OR 7.3, CI[3.16-16.99], p < 0.0001). Lesser toe deformities, including hammertoes, mallet toes, bunionettes and crossover toes, were also significantly associated with thyroid disease (OR 5.45, CI[1.83-16.26], p < 0.002). The national database revealed 905,924 patients with a diagnosis of a specific forefoot deformity, and 321,656 of these patients (35.5%) had a concomitant diagnosis of a thyroid condition (OR 2.11, CI[2.10-2.12], p < 0.0001). CONCLUSIONS: The current study suggests a significant association between forefoot pathology and thyroid dysfunction, especially hallux valgus and lesser toe deformities. Increased understanding of these correlations may offer an important opportunity in population health management, both in diagnosis and treatment. While further studies with long-term outcomes are necessary, the early diagnosis of thyroid disease may provide an opportunity to predict and potentially alter the course of forefoot pathology.

Obstructive sleep apnea affects complication rates following knee arthroscopy but use of continuous positive airway pressure is not protective against complications.

PURPOSE: Obstructive sleep apnea (OSA) has not been studied as a risk factor for complications following knee arthroscopy. The goals of this study were to: (1) compare complication rates after knee arthroscopy between patients with and without OSA and (2) evaluate whether continuous positive airway pressure (CPAP) mitigated complication rates. METHODS: A national private insurance database was queried for patients undergoing simple knee arthroscopy from 2007 to 2016. Patients with a diagnosis of OSA were then identified using ICD-9/10 codes. Patients with OSA were then subdivided into cohorts with and without a billing code for a CPAP device. Adverse events within 30 days postoperatively related to OSA were then assessed in all groups: (1) emergency room (ER) visit, (2) hospital admission, (3) pulmonary embolism (PE), (4) myocardial infarction, (5) respiratory arrest and (6) in-hospital mortality within 6 months postoperatively. Adverse event rates were compared between the control and study groups using a multivariable regression analysis. RESULTS: 97,036 patients underwent simple knee arthroscopy with 8656 patients having a diagnosis of OSA. Of these, 3820 (44%) had orders for CPAP machines. After controlling for confounders, patients with OSA had significantly higher risk of ER visits, PE and respiratory arrest compared to controls (p < 0.05). The majority of these significant findings persisted regardless of CPAP use. There were no significant differences in complication rates between OSA patients with and without CPAP orders. CONCLUSIONS: OSA appears to be independently associated with a higher risk for ER visits, PE and respiratory arrest following knee arthroscopy after controlling for demographic and comorbidity confounders. An order for CPAP was not associated with a significant reduction the risk for these complications. CPAP noncompliance may not be as important a factor when risk stratifying patients undergoing ambulatory knee arthroscopy compared to more significant medical comorbidities. LEVEL OF EVIDENCE: III.

The role of biologic agents in the management of common shoulder pathologies: current state and future directions.

The field of orthopedic surgery has seen a rapid increase in the use of various biologic agents for the treatment of common musculoskeletal injuries. Most biologic agents attempt to harness or mimic naturally occurring growth factors, cytokines, and anti-inflammatory mediators to improve tissue healing and recovery. The most commonly used biologic agents are platelet-rich plasma and cells derived from bone marrow aspirate and adipose tissue. These agents have become increasingly popular despite a relative dearth of clinical data to support their use. Much confusion exists among patients and physicians in determining the role of these agents in treating common shoulder pathologies, such as glenohumeral osteoarthritis, rotator cuff tears, and tendinopathy. This article reviews the basic science and clinical evidence for the most commonly used biologic agents in the management of common shoulder pathology.

Primary Anterolateral Ligament Rupture in Patients Requiring Revision Anterior Cruciate Ligament Reconstruction: A Retrospective Case-Control Magnetic Resonance Imaging Review.

PURPOSE: To compare the initial rate of anterolateral ligament (ALL) injury at the time of anterior cruciate ligament (ACL) rupture in patients who subsequently experienced ACL reconstruction graft failure versus patients who did not experience subsequent ACL reconstruction graft failure. METHODS: Our institution's electronic medical record database was queried for patients who underwent primary ACL reconstruction with subsequent ACL graft rupture. Exclusion criteria included unavailable MRI scan, chronic ACL injury, multi-ligamentous injury, previous ACL reconstruction, and age younger than 13 or older than 50 years. Each patient was paired with an age-, gender-, and graft-matched control who underwent ACL reconstruction without subsequent graft rupture. Each patient was diagnosed with an intact, partially injured, or fully ruptured ALL on initial MRI. The location of ALL injury was also noted. The incidence and location of ALL rupture were compared using χ2 analysis. RESULTS: 1,967 patients underwent primary ACL reconstruction. 128 patients experienced ACL graft rupture, and 55 patients (43%) had MRI scans available for review. 39 of these patients fulfilled inclusion criteria and were matched with a control patient. In the revision group, the ALL was diagnosed as intact, partially torn, and completely torn in 17, 14, and 8 patients, respectively, compared to 18, 13, and 8 patients, respectively in the control group. No difference was found in frequency of ALL rupture (Pearson χ2 = 0.066; P = .968) or rupture location (Pearson χ2 = 4.00, P = 0.135). CONCLUSIONS: The incidence of initial ALL injury as documented on MRI was not different in patients who experienced subsequent ACL graft rupture compared with patients who did not experience ACL graft rupture after primary ACL reconstruction. The ALL was more commonly injured on the tibial side in patients with ACL graft rupture and femoral-sided lesions were more common in control patients. LEVEL OF EVIDENCE: Level III, prognostic case-control study.

Trends and Outcomes in the Treatment of Failed Septic Total Knee Arthroplasty: Comparing Arthrodesis and Above-Knee Amputation.

BACKGROUND: Options for treatment of a failed septic total knee arthroplasty (TKA) include arthrodesis and above-knee amputation (AKA). Little comparative data exist to help clinicians when considering these alternatives. METHODS: A national database was queried for patients who underwent either knee arthrodesis or AKA for an infected TKA between 2005 and 2012. Procedure volumes, postoperative complications, hospital charges, length of stay, and 90-day readmission rates were evaluated. RESULTS: A total of 2634 patients underwent arthrodesis and 5001 patients underwent AKA for septic TKA. The percentage of total patients who underwent AKA increased significantly throughout the study period compared to knee arthrodesis. Patients who underwent AKA tended to be older and have more medical comorbidities. Arthrodesis patients had a significantly higher rate of postoperative infection (14.5% vs 8.3%, P < .0001) and transfusion (55.1% vs 46.8%, P < .0001), whereas AKA patients had a higher rate of systemic complications (31.5% vs 25.9%, P < .0001) and in-hospital mortality (3.7% vs 2.1%, P < .0001). The AKA cohort had lower hospital charges ($79,686 vs $84,747, P = .004), longer length of stay (11 vs 7 days, P < .0001), and higher 90-day readmission rate (19.4% vs 16.9%). CONCLUSION: Our data suggest that there is an increasing trend toward AKA for the treatment of a failed infected TKA when compared to arthrodesis. Comparative analysis of the outcomes of these procedures should help the clinician when weighing these alternatives.

Increased Failure Rate of Modified Double Arthrodesis Compared With Triple Arthrodesis for Rigid Pes Planovalgus.

For rigid pes planovalgus deformities, modified double and triple arthrodeses have had high union rates and subjective outcomes reported. Increased rates of talonavicular nonunions after modified double arthrodesis have led to concern regarding this procedure. A retrospective medical record review was performed of patients who had undergone either a modified double (n = 9) or triple (n = 7) arthrodesis for stage 3 pes planovalgus deformity. Radiographs were reviewed for hindfoot alignment, bony union, and hardware failure. Data from questionnaires, including the Foot and Ankle Ability Measure and the Foot and Ankle Outcome Score, were obtained. No significant differences were found between the cohorts in terms of preoperative radiographic parameters or patient characteristics. The modified double arthrodesis cohort demonstrated a nonunion rate of 44% (4 of 9), but the triple arthrodesis cohort had a 0% (0 of 7) nonunion rate (p = .042). The Foot and Ankle Ability Measure activities of daily living, Foot and Ankle Outcome Score activities of daily living, and Foot and Ankle Outcome Score quality of life scores were significantly worse for the modified double arthrodesis than for the triple arthrodesis group. For patients with stage 3 pes planovalgus, modified double arthrodesis resulted in significantly greater rates of nonunion and incomplete union, with significantly inferior subjective outcome scores compared with triple arthrodesis for the same indication.

Manipulation Under Anesthesia After Total Knee Arthroplasty is Associated with An Increased Incidence of Subsequent Revision Surgery.

A national database was used to evaluate the risk for manipulation under anesthesia (MUA) after total knee arthroplasty (TKA), the association of demographics and comorbidities with needing MUA, and the risk of revision TKA after MUA. Of the 141,016 patients who underwent TKA, 4.3% required MUA within 6 months. Age under 50 years (OR: 2.79, P<0.0001), age 50-65 years (OR: 2.03, P<0.0001), and female gender (OR: 1.12, P<0.0001) were all associated with increased rates of MUA. In patients under age 65 years, smoking (OR: 1.47, P<0.0001) was associated with an increased rate of MUA. Patients who require MUA within 6 months after TKA have a significantly increased risk of early revision TKA (OR: 2.43, P<0.0001).

Incidence of Vitamin D Deficiency in Foot and Ankle Arthrodesis Nonunions.

Background Vitamin D has been found to be crucial in musculoskeletal health. The role of vitamin D levels in orthopedic patients has become a growing area of interest given its negative impact on fracture healing which can contribute to the development of nonunion following surgery. We sought to investigate the incidence of hypovitaminosis D in a cohort of patients who experienced a nonunion following a foot and ankle arthrodesis procedure. Methodology Patients who underwent a major elective foot and ankle arthrodesis procedure and developed a nonunion were given the opportunity to obtain serum vitamin D levels. All vitamin D levels were reported from percutaneous venous blood samples and compared to our institution's range of accepted normal values (25-80 ng/mL). Results A total of 13 patients who developed a nonunion agreed to have a vitamin D level obtained, and 11 of 13 patients had a low vitamin D level (average = 14.6 ng/mL, range = 9-24 ng/mL). Five patients underwent revision arthrodesis after normalization of vitamin D levels, and four out of five patients went on to successful union. Conclusions Hypovitaminosis D may be a modifiable risk factor for nonunion following a major foot and ankle arthrodesis procedure. Orthopedic surgeons should consider vitamin D screening and supplementation in patients undergoing elective arthrodesis procedures.

An Analysis of Intrapitch Variation in Joint and Segment Velocities With Throwing Arm Kinetics in High School and Professional Baseball Pitchers.

BACKGROUND: Improper sequencing order of maximal joint and segment velocities has been identified as an important predictor for both throwing arm kinetics and ball velocity. PURPOSE: To investigate the intrapitcher variation of maximal segment velocities and the relationship to throwing arm kinetics and ball velocity in high school (HS) and professional (PRO) pitchers. STUDY DESIGN: Descriptive laboratory study. METHODS: HS (n = 59) and PRO (n = 338) pitchers, instructed to throw 8 to 12 fastball pitches, were evaluated with 3-dimensional motion capture (480 Hz). Maximal joint and segment velocities were calculated for each pitch, and the standard deviation of the maxima was calculated per pitcher. These standard deviations were used to classify pitchers as "low variance" or "high variance" for each segmental velocity subgroup, "overall low variance" or "overall high variance" based on cumulative segment velocity variation, or "population," with any pitcher eligible to be included in multiple subcategories. Maximal velocities and throwing arm kinetics were compared among the various subgroups. RESULTS: The HS low-variance shoulder internal rotation velocity subgroup (4949 ± 642 deg/s) had significantly lower maximal shoulder internal rotation velocity compared with HS population (5774 ± 1057 deg/s) (P < .001); similar findings were observed for PROs (5269 ± 835 vs 5824 ± 1076 deg/s; P < .001), as well as lower shoulder superior force compared with the PRO population (14.8% ± 8.8% vs 17.8% ± 8.8% body weight; P = .001). The PRO low-variance lead knee extension velocity subgroup had significantly lower maximal lead knee extension velocity (216 ± 135 vs 258 ± 125 deg/s; P = .001) and shoulder distractive force (111.5% ± 14.4% vs 115.6% ± 15.9% body weight; P = .003) compared with the PRO population. The PRO overall low-variance subgroup had significantly lower shoulder distractive force (111.8% ± 14.1% vs 119.6% ± 15.5% body weight; P = .008) and elbow anterior force (40.6% ± 5.0% vs 43.6% ± 6.2% body weight; P = .008) compared with the PRO overall high-variance subgroup. CONCLUSION: HS and PRO pitchers with low variance for joint and segment velocities achieved significantly lower maximal velocities in the subgroup of interest, while preserving ball velocity. PRO pitchers with overall low variance among multiple maximal joint and segment velocities demonstrated decreased shoulder distractive and elbow anterior force. CLINICAL RELEVANCE: PRO pitchers with low intrapitch variation in maximal joint and segment velocities may be viewed as kinetically conservative throwers. These pitchers with similarly maintained mechanics between pitches may have an increasingly regimented form that preserves kinetic forces about the throwing arm. The opposite may be true for PRO pitchers with increased variability in segmental velocities during their pitching motion, as they showed increased throwing arm kinetics including shoulder distractive and elbow anterior force compared with the overall low-variance group, theoretically increasing their risk of injury.

Kinematic Parameters Predictive of Pitch Velocity in Youth to Professional Baseball Pitchers: A Qualitative Systematic Review.

Background: Specific kinematic factors have been found to contribute to faster pitch speeds, with poor mechanics leading to injury. Purpose: To discuss the kinematic parameters that predict faster ball velocity among baseball pitchers. Study Design: Systematic review. Methods: Using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, the authors utilized the Cochrane Database of Systematic Reviews, PubMed (2008-2019), and OVID/MEDLINE (2008-2019) databases. Eligible articles included those that reported on kinematic factors predictive of ball velocity across youth, high school, collegiate, and professional levels of play. The quality of all included studies was evaluated by 2 reviewers using the Appraisal tool for Cross-Sectional Studies (AXIS). The lack of consistent study design or outcome variables precluded meta-analysis. Results: A total of 584 studies were identified from the initial search with 12 included in final analysis (930 pitchers in total; 429 [46.1%] youth, 164 [17.6%] high school, 153 [16.5%] collegiate and 184 [19.8%] professional) with mean ball velocity of 71.1 mph (114.4 km/h). The average AXIS score was 16 out of a possible 20. The shoulder played a significant role in the generation of velocity-induced torques. Hip and shoulder separation was associated with a 2.6 ± 0.5 mph (4.1 ± 0.8 km/h) increase in velocity, whereas increased shoulder movement of the nonthrowing arm was negatively correlated with initial ball velocity (r2 = 0.798). Furthermore, hip/shoulder separation, decreased movement of the nonthrowing shoulder, trunk power and timing of maximum trunk rotation, increased contralateral trunk tilt and increased sagittal-plane trunk tilt, and decreased knee flexion at ball release were all associated with higher fastball speeds. Conclusion: Multiple upper extremity and trunk kinematic parameters affect ball velocity, with significant contributions from the throwing shoulder and trunk, as well as nondominant arm. Understanding kinematic predictors of faster ball velocity can help guide training regimens.

Forearm Pronation at Foot Contact: A Biomechanical Motion-Capture Analysis in High School and Professional Pitchers.

Background: It has previously been speculated that baseball pitchers who display excessive forearm pronation at foot contact (FC) have a higher propensity toward ulnar collateral ligament injury and subsequent surgery. Purpose: To evaluate the association between degree of forearm pronation/supination at FC and throwing arm kinetics in high school and professional pitchers, at both the individual (intrapitcher) and the group (interpitcher) level. Study Design: Descriptive laboratory study. Methods: High school (n = 41) and professional (n = 196) pitchers threw 8 to 12 fastballs while being assessed with a 3-dimensional motion-capture system (480 Hz). Pitchers at each playing level were divided into a supination or pronation subgroup depending on degree of forearm pronation at FC. Regression models were built to observe the relationship between forearm pronation at FC and kinetic and kinematic parameters of interest. Results: At both the individual and the group level of high school and professional pitchers, there was no significant correlation between forearm pronation at FC and elbow varus torque (P min = .21). For every 10° increase in forearm pronation at FC in the individual high school pitcher, elbow flexion at FC decreased by 5°, whereas maximum elbow extension velocity was achieved 0.6% later in the pitch. In addition, elbow medial force increased by 4.1 N and elbow varus torque increased by 0.8 N·m for every 10° increase in forearm supination at FC. For every 10° increase in forearm supination in the individual professional pitcher, ball velocity increased by 0.5 m/s, shoulder external rotation at FC decreased by 11°, and elbow medial force decreased by 5.5 N. Conclusion: Supination- or pronation-predominant forearm motion during the pitch did not significantly differ between playing levels. Excessive forearm pronation at FC was not a significant risk factor for increased throwing arm kinetics for high school or professional pitchers. There was a weak positive association between forearm supination at FC and elbow varus torque in the individual high school pitcher. Ultimately, coaches and pitchers may be better served by redirecting their focus to other mechanical aspects of the pitch that may have stronger associations with injury risk implications as well as performance.