Adam W. Anz

Correlation of Torque and Elbow Injury in Professional Baseball Pitchers

Background: During the pitching motion, velocity is generated by the upper extremity kinetic chain on internal rotation of the shoulder and trunk translational/rotational motion. This generation of power places significant forces and torques on the elbow and shoulder. Elbow valgus torque and shoulder rotational torque are theoretically linked to elbow injury. Hypothesis: Pitchers experiencing higher levels of elbow valgus torque and shoulder external rotation torque throughout the pitching motion are more likely to suffer elbow injury than pitchers with lower levels of torque. Study Design: Cohort study; Level of evidence, 3. Methods: With an established biomechanical analysis model, 23 professional baseball pitchers were videotaped during spring training games and followed prospectively for the next 3 seasons for elbow injury. A mixed statistical model using differences of least squares means and analysis of variance was used to analyze the association between elbow injury and torque levels throughout the pitching motion as well as at each major event within the pitching motion. Results: There were overall statistical trends relating elbow injury with both higher elbow valgus torque (P = .0547) and higher shoulder external rotation torque (P = .0548) throughout the entire pitching motion. More importantly, there was an individual significant correlation of elbow injury with both higher elbow valgus torque (P = .0130) and higher shoulder external rotation torque (P = .0018) at the late cocking phase (pitching event of maximum external rotation of the shoulder). Conclusion: This study provides information that supports existing theories about how and why certain injuries occur during the throwing motion in baseball. The late cocking phase appears to be the critical point in the pitching motion, where higher levels of torque at the shoulder and elbow can result in increased risk of injury. Manipulation of pitching mechanics to alter these torque levels or using these measures to identify pitchers at risk may help decrease injury rates.

Association of Maximum Pitch Velocity and Elbow Injury in Professional Baseball Pitchers

Background Recent literature has explored the association of upper extremity injury in baseball players with various aspects of the pitching motion. To our knowledge, no study has directly evaluated the connection between maximum pitch velocity and elbow injury in professional baseball pitchers. Hypothesis Professional pitchers throwing at higher maximum ball velocity will have a higher risk of elbow injury. Study Design Cohort study; Level of evidence, 3. Methods Twenty-three professional pitchers were analyzed during spring training games and the ball velocity of the fastest pitch thrown for a strike (maximum pitch velocity) was recorded. This group was then followed prospectively over the following 3 seasons for elbow injury significant enough to warrant inclusion on the disabled list and/or require surgery. The association between maximum pitch velocity and elbow injury was then analyzed using an unpaired Student t test. Results There were 9 players with elbow injuries in the group of pitchers studied, including 4 pitchers with an elbow muscle strain and/or joint inflammation and 5 pitchers with an ulnar collateral ligament sprain or tear. Three of the ulnar collateral ligament injuries required surgery. For the 14 pitchers in the noninjured group, the mean pitch velocity was 38.09 m/s (±1.45) or 85.22 mph (±3.24). For the 9 players in the injured group, the mean pitch velocity was 39.88 m/s (±2.39) or 89.22 mph (±5.36). There was a statistically significant association between maximum ball velocity and elbow injury (P = .0354). The injured group had a longer average career length (9.7 years) than the noninjured group (6.5 years; P = .0248). The 3 pitchers with the highest maximum ball velocity had the injuries requiring surgery. Conclusion A statistically significant association between maximum pitch velocity and elbow injury was noted in this study, providing further support of existing theories about injury in baseball.

Vascular injury associated with extremity trauma: initial diagnosis and management.

Abstract Vascular injury associated with extremity trauma occurs in <1% of patients with long bone fracture, although vascular injury may be seen in up to 16% of patients with knee dislocation. In the absence of obvious signs of vascular compromise, limb‐threatening injuries are easily missed, with potentially devastating consequences. A thorough vascular assessment is essential; an arterial pressure index <0.90 is indicative of potential vascular compromise. Advances in CT and duplex ultrasonography are sensitive and specific in screening for vascular injury. Communication between the orthopaedic surgeon and the vascular or general trauma surgeon is essential in determining whether to address the vascular lesion or the orthopaedic injury first. Quality evidence regarding the optimal fixation method is scarce. Open vascular repair, such as direct repair with or without arteriorrhaphy, interposition replacement, and bypass graft with an autologous vein or polytetrafluoroethylene, remains the standard of care in managing vascular injury associated with extremity trauma. Although surgical technique affects outcome, results are primarily dependent on early detection of vascular injury followed by immediate treatment.

Venous Thromboembolism in Lower Extremity Arthroscopy

Venous thromboembolism (VTE) is a relatively rare complication of arthroscopic surgery of the lower extremity, but it does have the potential to result in significant morbidity and possible mortality. VTE has been reported to occur with knee arthroscopy, and guidelines for VTE prophylaxis before and after knee arthroscopy have been proposed. There are much fewer data regarding the incidence of VTE occurring after arthroscopy of the ankle and the hip. This article reviews the literature on the incidence, treatment, and prevention of VTE in association with arthroscopy of the lower extremity.

Application of Biologics in the Treatment of the Rotator Cuff, Meniscus, Cartilage, and Osteoarthritis

&NA; Advances in our knowledge of cell signaling and biology have led to the development of products that may guide the healing/regenerative process. Therapies are emerging that involve growth factors, blood‐derived products, marrow‐derived products, and stem cells. Animal studies suggest that genetic modification of stem cells will be necessary; studies of cartilage and meniscus regeneration indicate that immature cells are effective and that scaffolds are not always necessary. Current preclinical animal and clinical human data and regulatory requirements are important to understand in light of public interest in these products.

Management of venomous snakebite injury to the extremities.

Pit vipers (subfamily Crotalinae) are responsible for most venomous snakebites in the United States. The mixture of proteins with cytotoxic, proteolytic, and/or neurotoxic enzymes in snake venom varies by species. Treatment in the field consists of safe identification of the species of snake and rapid transport of the patient to the nearest health care facility. Swelling, bruising, and systemic symptoms are seen following snakebite. Most patients respond to elevation of the affected extremity and observation. Some require the administration of antivenin. Crotalidae Polyvalent Immune Fab (Ovine) (CroFab, BTG International, West Conshohocken, PA) antivenin is safe and effective for the management of local and systemic effects of envenomation. Rarely, compartment syndrome may develop in the affected limb because of edema and tissue necrosis. Close monitoring of the extremity via serial physical examination and measurement of compartment pressure is a reliable method of determining whether surgical intervention is required.

Biomechanical Comparison of Arthroscopic Repair Constructs for Meniscal Root Tears

Background: Complete meniscal root tears render the meniscus nonfunctional. Repair constructs have been presented and tested; however, prior studies have evaluated suture patterns placed ex vivo without simulating an in vivo surgical setting. This study introduces a new double-locking loop suture pattern and compares its biomechanical properties and execution time with commonly used suture patterns. All constructs were performed using an all-inside arthroscopic technique. Hypothesis: Complex suture repair constructs have higher failure loads, stiffness, and execution times compared with simple constructs. Study Design: Controlled laboratory study. Methods: Sutures were placed arthroscopically into the posterior horn root region of the medial and lateral menisci in 21 cadaveric knees. Four repair constructs were evaluated: 2 simple sutures (2SS), 1 inverted mattress suture (1MS), 1 double-locking loop suture (1DLS), and 2 double-locking loop sutures (2DLS). In total, 40 posterior meniscal roots were tested, with 10 trials for each construct. After arthroscopic placement of the root repair constructs, each meniscus was explanted and tested to failure on a uniaxial materials testing machine. The Kruskal-Wallis test was used to evaluate for the significance of maximum failure loads and stiffness between groups. Results: The mean maximum failure loads were 137 ± 49 N (2SS), 126 ± 44 N (1MS), 186 ± 43 N (1DLS), and 368 ± 76 N (2DLS). Interconstruct comparison revealed a statistical difference between 2DLS and all 3 remaining constructs (P < .01) and 1DLS when compared with 2SS and 1MS (P < .01 for both). Statistical significance was not found between 2SS and 1MS (P = .8). The mean times for repair of the 4 fixation techniques were 1.8 ± 0.9 minutes (2SS), 2.4 ± 1.9 minutes (1MS), 4.7 ± 2.0 minutes (1DLS), and 5.4 ± 0.6 minutes (2DLS). Conclusion: The double-locking loop suture repair technique had significantly higher failure loads compared with the 3 other methods tested. As the complexity of repair constructs increases, failure loads and surgical times increase. Clinical Relevance: Complex suture patterns can be placed via an all-inside arthroscopic technique delivering higher failure loads for meniscal root repair with little increase in surgical time.

Pediatric scaphoid fractures

&NA; Fractures of the immature carpal scaphoid can be challenging to manage. The diagnosis may be missed or delayed because of absent or minimal symptoms. Once diagnosed, most pediatric scaphoid fractures can be successfully treated with cast immobilization. However, this is inadequate for difficult and unique cases. Nonunion may occur as a result of a missed diagnosis or delayed presentation as well as in patients who receive appropriate treatment. Because the natural history in children remains incompletely characterized, the optimal treatment of established pediatric scaphoid nonunions is controversial. Surgical intervention should be considered for displaced fractures in patients who are at or near skeletal maturity or in those in whom nonsurgical treatment has failed.

High Tibial Osteotomy in Combination With Chondrogenesis After Stem Cell Therapy: A Histologic Report of 8 Cases

PURPOSE To histologically evaluate the quality of articular cartilage regeneration from the medial compartment after arthroscopic subchondral drilling followed by postoperative intra-articular injections of autologous peripheral blood stem cells (PBSCs) and hyaluronic acid with concomitant medial open-wedge high tibial osteotomy (HTO) in patients with varus deformity of the knee joint. METHODS Eight patients with varus deformity of the knee joint underwent arthroscopic subchondral drilling of International Cartilage Repair Society (ICRS) grade 4 bone-on-bone lesions of the medial compartment with concomitant HTO. These patients were part of a larger pilot study in which 18 patients underwent the same procedure. PBSCs were harvested and cryopreserved preoperatively. At 1 week after surgery, 8 mL of PBSCs was mixed with 2 mL of hyaluronic acid and injected intra-articularly into the knee joint; this was repeated once a week for 5 consecutive weeks. Three additional intra-articular injections were administered weekly at intervals of 6, 12, and 18 months postoperatively. Informed consent was obtained at the time of hardware removal for opportunistic second-look arthroscopy and chondral biopsy. Biopsy specimens were stained with H&E, safranin O, and immunohistochemical staining for type I and II collagen. Specimens were graded using the 14 components of the ICRS Visual Assessment Scale II, and a total score was obtained. RESULTS Second-look arthroscopy showed satisfactory healing of the regenerated cartilage. Histologic analysis showed significant amounts of proteoglycan and type II collagen. The total ICRS Visual Assessment Scale II histologic scores comparing the regenerated articular cartilage (mean, 1,274) with normal articular cartilage (mean, 1,340) indicated that the repair cartilage score approached 95% of the normal articular cartilage score. There were no infections, delayed unions, or nonunions. CONCLUSIONS Chondrogenesis with stem cells in combination with medial open-wedge HTO for varus deformity correction of the knee joint regenerates cartilage that closely resembles the native articular cartilage. LEVEL OF EVIDENCE Level IV, therapeutic case series.

Biomechanical Comparison of Arthroscopic Repair Constructs for Radial Tears of the Meniscus

Background: Radial tears of the meniscus represent a challenging clinical scenario because benign neglect and partial meniscectomy have both been shown to have negative biomechanical and long-term clinical consequences. Hypothesis: Complex suture repair constructs have higher failure loads and stiffness values compared with simple constructs. Study Design: Controlled laboratory study. Methods: After radial transection of human cadaveric menisci, simulated tears were repaired arthroscopically by use of 1 of 4 repair constructs: (1) 2 inside-out horizontal sutures, (2) 2 all-inside horizontal sutures, (3) an all-inside Mason-Allen construct consisting of 4 sutures, or (4) an all-inside construct consisting of a figure-of-8 suture plus 1 horizontal suture. Meniscus specimens were harvested and tested to failure on an Instron machine. The Kruskal-Wallis test was used to evaluate for significance of maximal failure load and stiffness between groups. Results: The mean maximum failure loads were 64 ± 20 N (inside-out horizontal construct), 75 ± 16 N (all-inside horizontal construct), 86 ± 19 N (Mason-Allen construct), and 113 ± 22 N (figure-of-8 plus horizontal construct). Interconstruct comparison revealed a statistically significant difference between the figure-of-8 plus horizontal construct and all 3 remaining constructs (P < .02) as well as the Mason-Allen construct when compared with the inside-out horizontal construct (P < .01). Statistical significance was not found between the all-inside horizontal construct and the Mason-Allen construct or between the all-inside horizontal construct and the inside-out horizontal construct (P = .2 and .7, respectively). Stiffness values were lower for the inside-out construct compared with the all-inside constructs (P < .05). Conclusion: Complex all-inside repair constructs had significantly higher failure loads than a conventional, simple inside-out suture repair construct for repair of radial meniscal tears. Stiffness values among the all-inside groups were greater than those for the inside-out group. Clinical Relevance: Arthroscopic techniques are presented to produce stronger radial meniscal tear repairs.