Anatomic total shoulder arthroplasty for B2 glenoids treated with asymmetric reaming has equivalent survivorship and patient outcomes compared with type A glenoids at a mean 9-year follow-up.

BACKGROUND: Walch B2 glenoids can present a challenge to shoulder arthroplasty surgeons. Short-term studies have demonstrated that corrective reaming to 10° of retroversion in anatomic total shoulder arthroplasty (aTSA) can result in good outcomes; however, there is little data reporting the long-term outcomes in this cohort. B2 glenoids treated with high-side reaming present a theoretical risk of early glenoid component failure as one may ream into the subchondral bone. This study aimed to demonstrate that (1) B2 glenoids treated with corrective reaming have durable results and (2) offer similar results to Walch A1/2 in long-term follow-up. METHODS: Patients who underwent aTSA by a single surgeon (E.L.F.) were identified from a shoulder arthroplasty registry. Inclusion criteria included Walch A1, A2, or B2 glenoid; a diagnosis of primary shoulder osteoarthritis; and a minimum radiographic and clinical follow-up of 5 years. Forty-three patients with B2 glenoids were compared to a cohort of 42 patients with A1 or A2 glenoids. Preoperative computed tomography (CT) and radiographs were used to assess deformity, glenoid version, and posterior subluxation of the humeral head. Postoperatively, patients were assessed with radiographs and patient-reported outcome measures including American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) score, Simple Shoulder Test (SST) score, and visual analog scale (VAS). RESULTS: Eighty-five shoulders (82 patients, 42 B2 and 43 A1/A2 glenoids) with an average follow-up of 9.4 years were included. In the B2 cohort, the average retroversion was 21.1° and posterior subluxation was 69.4% compared with 10.6° (P < .001) and 57.5% (P < .001), respectively, in the A1 or A2 cohort. The cohort demographics were similar except for male sex (B2 69.8% vs. A1 or A2 37.2%, P = .008). There was no difference between the cohorts in their improvement in ASES (P = .807), SST (P = .586), and VAS (P = .930) scores. There was no difference in lateral humeral offset (P = .889) or acromial humeral interval (P = .468) between initial postoperative and final follow-up visits. Survivorship for B2 glenoids was 97.6%, 94.1%, and 73.3% at 5, 10, and 15 years, respectively, compared with 97.6%, 91.9%, and 83.5% in type A glenoids. The revision rate was similar between the 2 groups (P = .432). Lazarus score (P = .682) and rates of humeral radiolucency (P = .366) and humeral osteolysis (P = .194) were similar between the 2 cohorts at final follow-up. CONCLUSION: Asymmetric reaming of patients with B2 glenoids is a reliable method of glenoid preparation with excellent mid- to long-term clinical results, patient-reported outcomes, and low revision rates similar to their A1 and A2 counterparts.

Survivorship of total shoulder arthroplasty vs. hemiarthroplasty for the treatment of avascular necrosis at greater than 10-year follow-up.

BACKGROUND: Avascular necrosis (AVN) of the humeral head is a debilitating pathology that can be managed with an array of treatments depending on disease staging. Humeral head arthroplasty for AVN has demonstrated good short-term improvements in pain and range of motion, but the published long-term outcomes data are limited. The objective of this study was to report long-term survivorship and outcomes for patients undergoing hemiarthroplasty (HA) or total shoulder arthroplasty (TSA) for the treatment of AVN of the humeral head. METHODS: The practice of one fellowship-trained shoulder surgeon was queried for the surgical treatment of AVN of the humeral head via appropriate International Classification of Diseases, Ninth and Tenth Revision, codes. Sixteen shoulders that met inclusion criteria were identified. Demographics included the radiographic stage, age, sex, American Society of Anesthesiologists (ASA) score, and body mass index. The primary endpoint was survivorship of the implant. Secondary endpoints were range of motion in forward elevation, internal and external rotation, visual analog scale for pain, American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form score, and the Simple Shoulder Test score. RESULTS: Of the 16 shoulders included in the study, 10 underwent HA and 6 underwent TSA. The TSA cohort was significantly older (mean 60.5 vs. 44.2, P = .005), with a higher mean ASA score (mean 3.0 vs. 2.13, P = .02) than the HA group. The 10-year survivorship rates were 88.9% for HA and 80% for TSA with no significant difference between groups. Survivorship data were available for a mean 13.0 ± 5.6 years' follow-up in the HA group and 13.8 ± 4.8 years in the TSA group. When compared to one another, the results between HA and TSA only differed in internal rotation, which was statistically significantly improved in the TSA group compared with HA (2.3 ± 2.6 compared with -3.0 ± 5.0, P = .03). CONCLUSION: The survivorship of both TSA and HA for the treatment of AVN was at least 80% at 10 years. Secondary endpoints, such as range of motion, pain, and shoulder function, improved significantly postoperatively in each cohort and were similar between the 2 groups, except for internal rotation, which had improved significantly more in the TSA group than in HA. Both TSA and HA are viable options for the treatment of AVN, each with durable long-term survival.

Comprehensive Clinical Examination of ACL Injuries.

A comprehensive clinical examination of the potentially anterior cruciate ligament (ACL)-deficient knee should proceed as follows: inspection; palpation; range of motion; varus and valgus stress; neurovascular status; and finally provocative maneuvers. The Lachman, anterior drawer, Lever, and pivot shift tests are all greater than 90% specific for ACL pathology. Due to the relatively high coincidence of ACL injuries and those to the posterior cruciate ligament, posterolateral corner , posteromedial corner , and menisci, it is critical that the examiner perform provocative maneuvers to evaluate the integrity of these structures as well.

Modified Bridge-Enhanced Anterior Cruciate Ligament Repair.

Historically, the treatment of anterior cruciate ligament (ACL) injuries shifted from primary repair to reconstruction because the native, intrasynovial location of the ACL precluded the formation of a fibrin-rich clot needed for ligament healing. However, increasing attention has been paid to augmenting the biological environment surrounding the ACL to facilitate its healing after arthroscopic repair. The bridge-enhanced ACL restoration implant uses resorbable collagen mixed with autologous blood to provide a biological scaffold for tissue healing. The short-term results of this procedure are promising, showing noninferiority to traditional ACL reconstruction at 2 years postoperatively and a higher rate of return to sport at 6 months. Our technique for performing the bridge-enhanced ACL repair is efficient, is easy to learn, and achieves excellent fixation of the ACL stump augmented with an internal brace.

Increased rate of out-of-network surgeon selection for hip arthroscopy compared to more common orthopedic sports procedures.

Background: Demand for hip arthroscopy (HA) has increased, but shortfalls in HA training may create disparities in care access. This analysis aimed to (1) compare out-of-network (OON) surgeon utilization for HA with that of more common orthopedics sports procedures, including rotator cuff repair (RCR), partial meniscectomy (PM), and anterior cruciate ligament reconstruction (ACLR), (2) compare the HA OON surgeon rate with another less commonly performed procedure, meniscus allograft transplant (MAT), and (3) analyze trends and predictors of OON surgeon utilization. Methods: The 2013-2017 IBM MarketScan database identified patients under 65 who underwent HA, RCR, PM, ACLR, or MAT. Demographic differences were determined using standardized differences. Cochran-Armitage tests analyzed trends in OON surgeon utilization. Multivariable logistic regression identified predictors of OON surgeon utilization. Statistical significance was set to p < 0.05 and significant standardized differences were >0.1. Results: 410,487 patients were identified, of which 12,636 patients underwent HA, 87,607 RCR, 233,241 PM, 76,700 ACLR, and 303 MAT. OON surgeon utilization increased for HA, rising from 7.98 % in 2013 to 9.37 % in 2017 (p = 0.026). Compared to RCR, PM, and ACLR, HA was associated with higher likelihood of OON surgeon utilization. Usage of ambulatory surgery centers (ASCs) was predictive of higher OON surgeon rates along with procedure year, insurance plan type, and geographic region. HA performed in an ASC was 13 % less likely to have an OON surgeon (p = 0.047). Conclusion: OON surgeon utilization generally declined but increased for HA. HA was a predictor of OON surgeon status, possibly because HA is a technically complicated procedure with fewer trained in-network providers. Other predictors of OON surgeon status included ASC usage, PPO/EPO plan type, and Northeast geographic region. There is a need to improve access to experienced HA providers-perhaps with prioritization of HA training in residency and fellowship programs-in order to address rising OON surgeon utilization.

Mediator kinase inhibition impedes transcriptional plasticity and prevents resistance to ERK/MAPK-targeted therapy in KRAS-mutant cancers.

Acquired resistance remains a major challenge for therapies targeting oncogene activated pathways. KRAS is the most frequently mutated oncogene in human cancers, yet strategies targeting its downstream signaling kinases have failed to produce durable treatment responses. Here, we developed multiple models of acquired resistance to dual-mechanism ERK/MAPK inhibitors across KRAS-mutant pancreatic, colorectal, and lung cancers, and then probed the long-term events enabling survival against this class of drugs. These studies revealed that resistance emerges secondary to large-scale transcriptional adaptations that are diverse and cell line-specific. Transcriptional reprogramming extends beyond the well-established early response, and instead represents a dynamic, evolved process that is refined to attain a stably resistant phenotype. Mechanistic and translational studies reveal that resistance to dual-mechanism ERK/MAPK inhibition is broadly susceptible to manipulation of the epigenetic machinery, and that Mediator kinase, in particular, can be co-targeted at a bottleneck point to prevent diverse, cell line-specific resistance programs.

Mediator Kinase Inhibition Impedes Transcriptional Plasticity and Prevents Resistance to ERK/MAPK-Targeted Therapy in KRAS-Mutant Cancers.

Acquired resistance remains a major challenge for therapies targeting oncogene activated pathways. KRAS is the most frequently mutated oncogene in human cancers, yet strategies targeting its downstream signaling kinases have failed to produce durable treatment responses. Here, we developed multiple models of acquired resistance to dual-mechanism ERK/MAPK inhibitors across KRAS-mutant pancreatic, colorectal, and lung cancers, and then probed the long-term events enabling survival against this class of drugs. These studies revealed that resistance emerges secondary to large-scale transcriptional adaptations that are diverse and cell line-specific. Transcriptional reprogramming extends beyond the well-established early response, and instead represents a dynamic, evolved process that is refined to attain a stably resistant phenotype. Mechanistic and translational studies reveal that resistance to dual-mechanism ERK/MAPK inhibition is broadly susceptible to manipulation of the epigenetic machinery, and that Mediator kinase, in particular, can be co-targeted at a bottleneck point to prevent diverse, cell line-specific resistance programs.

Incidence and risk factors for pseudosubluxation of the humeral head following proximal humerus fracture.

Background: Humeral head pseudosubluxation (HHPS) in relation to the glenohumeral joint is a common finding following fractures of the proximal humerus. The temporary inferior subluxation of the humeral head may be secondary to a transient axillary nerve neuropraxia, pain inhibition of the deltoid, or hemarthrosis or capsular disruption that alters the physiologically negative pressure in the glenohumeral joint. Despite the frequency of this finding, it is not well described in the literature. This study sought to describe the incidence, risk factors, and rate of resolution of HHPS following proximal humerus fracture. Methods: The practice of two fellowship-trained shoulder and elbow surgeons was queried for proximal humerus fractures. Patient radiographs were reviewed at the time of injury and all subsequent follow-ups through one year after injury. Data collection included the presence of HHPS, type of fracture based on the Neer classification, operative vs. nonoperative management, and resolution of HHPS. Exclusion criteria included skeletally immature patients, fracture-dislocations, patients treated with reverse shoulder arthroplasty, inadequate follow-up, or those patients with incorrect International Classification of Diseases coding. Results: The incidence of HHPS was 20.0% (103 out of 515 patients) overall. Patients who required surgical intervention were more likely to develop pseudosubluxation than those who were treated conservatively (P < .001). There was an increasing incidence of pseudosubluxation based on the Neer classification, with 0-part fractures demonstrating a 2.56% (2/78) rate, whereas 4-part fractures were found to have HHPS in 35.1% (20/57) of cases (P < .001). All patients were found to have resolution of their HHPS at the final follow-up or one year after injury. None of age, sex, obesity, or injury to the dominant arm was associated with the occurrence of HHPS. There was, however, a statistically significant difference in the body mass index of those who developed HHPS (28.4, ± 5.77) vs. those who did not (26.2, ± 5.32, P < .01). Conclusion: This retrospective radiographic study is the largest to date investigating the incidence of HHPS following proximal humerus fracture and first to correlate with Neer classification and operative intervention. We found that HHPS occurs in one-fifth of acute proximal humerus fractures and resolves regardless of intervention. More complex fractures, including those with increasing Neer parts or requiring operative intervention, developed HHPS at higher rates than simpler fracture patterns. This study will help both general orthopedists as well as shoulder surgeons understand the epidemiology of HHPS and provide reassurance to patients that PS is a benign finding with expected spontaneous resolution by one year.

Defining Platelet-Rich Plasma Usage by Team Physicians in Elite Athletes.

BACKGROUND: The indications for the use of platelet-rich plasma (PRP) are vaguely defined despite the frequency of its use as a treatment for athletes. While select studies have advocated for its efficacy, the majority of orthopaedic research conducted on the topic has been equivocal. PURPOSE: To define the use of PRP in elite athletes by team physicians from professional sports leagues. STUDY DESIGN: Cross-sectional study. METHODS: A survey assessing treatment timing, usage patterns, indications, and complications was generated by fellowship-trained sports medicine orthopaedic surgeons. The survey was distributed to team physicians from the National Football League, National Basketball Association, Major League Baseball, National Hockey League, Major League Soccer, and the "Power 5" Division I conferences of the National Collegiate Athletic Association. From a compilation of publicly available email addresses and those available from professional team physician associations, 149 team physicians were sent this PRP assessment tool. RESULTS: Of the 149 professional and collegiate team physicians contacted, 59 started the survey and 46 completed it, resulting in a 39.6% participation rate and a 30.9% completion rate. Approximately 93% of physicians stated that they use PRP in their practices, and 72% use ultrasonography for injection guidance. On average, collegiate team physicians and National Football League physicians treated the most players per season with PRP (69.4 and 60.4 players, respectively), while National Hockey League physicians treated the fewest (18.0 players). The majority of respondents reported no complications from PRP injections (70%), with pain being the most common complication reported (26%). There was no consensus on the most important aspect of PRP formulation, with the top 2 responses being platelet concentration (48%) and white blood cell concentration (39%). When grading the importance of indications to use PRP, physicians found athlete desire on average (7.5 ± 2.2 [SD]; out of 10) to be more important than reimbursement (2.2 ± 2.2) (P < .001). Importantly, physicians stated that they moderately (5.4 ± 2.3) believed in the evidence behind PRP. Physicians listed hamstring injuries as the most common injury treated with PRP. Hamstring injuries were treated with a mean 3.14 PRP injections, as opposed to 2.19 injections for nonhamstring injuries. CONCLUSION: Professional and collegiate team physicians frequently use PRP despite a lack of consensus regarding the importance of the formulation of the product, the timing of treatment, and the conditions that would most benefit from PRP treatment.

Variability of United States Online Rehabilitation Protocols for Proximal Hamstring Tendon Repair.

BACKGROUND: The optimal postoperative rehabilitation protocol following repair of complete proximal hamstring tendon ruptures is the subject of ongoing investigation, with a need for more standardized regimens and evidence-based modalities. PURPOSE: To assess the variability across proximal hamstring tendon repair rehabilitation protocols published online by United States (US) orthopaedic teaching programs. STUDY DESIGN: Cross-sectional study. METHODS: Online proximal hamstring physical therapy protocols from US academic orthopaedic programs were reviewed. A web-based search using the search term complete proximal hamstring repair rehabilitation protocol provided an additional 14 protocols. A comprehensive scoring rubric was developed after review of all protocols and was used to assess each protocol for both the presence of various rehabilitation components and the point at which those components were introduced. RESULTS: Of 50 rehabilitation protocols identified, 35 satisfied inclusion criteria and were analyzed. Twenty-five protocols (71%) recommended immediate postoperative bracing: 12 (34%) prescribed knee bracing, 8 (23%) prescribed hip bracing, and 5 (14%) did not specify the type of brace recommended. Fourteen protocols (40%) advised immediate nonweightbearing with crutches, while 16 protocols (46%) permitted immediate toe-touch weightbearing. Advancement to full weightbearing was allowed at a mean of 7.1 weeks (range, 4-12 weeks). Most protocols (80%) recommended gentle knee and hip passive range of motion and active range of motion, starting at a mean 1.4 weeks (range, 0-3 weeks) and 4.0 weeks (range, 0-6 weeks), respectively. However, only 6 protocols (17%) provided specific time points to initiate full hip and knee range of motion: a mean 8.0 weeks (range, 4-12 weeks) and 7.8 weeks (range, 0-12 weeks), respectively. Considerable variability was noted in the inclusion and timing of strengthening, stretching, proprioception, and cardiovascular exercises. Fifteen protocols (43%) required completion of specific return-to-sport criteria before resuming training. CONCLUSION: Marked variability is found in both the composition and timing of rehabilitation components across the various complete proximal hamstring repair rehabilitation protocols published online. This finding mirrors the variability of proposed rehabilitation protocols in the professional literature and represents an opportunity to improve patient care.

Athletic Hip Injuries in Major League Baseball Pitchers Associated With Ulnar Collateral Ligament Tears.

BACKGROUND: Ulnar collateral ligament (UCL) reconstruction is a reliable treatment for elite overhand throwers with UCL tears. In recent years, this procedure has become increasingly common among Major League Baseball (MLB) pitchers. Predisposing factors and associated comorbidities, however, have not been fully elucidated. PURPOSE/HYPOTHESIS: The purpose of this study was to determine whether professional baseball pitchers who underwent UCL reconstruction had an increased incidence of hip or groin injuries 4 years before or after surgery. We hypothesized that MLB pitchers who sustain hip or groin injuries may be more likely to develop UCL tears because of alterations and overcompensation in the kinetic chain during overhand throwing. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A comprehensive list of all 247 MLB players who underwent UCL reconstruction between 2005 and 2017 was created using publicly accessible online data. The application of inclusion criteria yielded a final sample size of 145 athletes. These athletes' injury histories were identified and cross-referenced with the official MLB disabled list. Matched controls were generated for a comparison of results. RESULTS: Of the 145 MLB pitchers who underwent UCL reconstruction between 2005 and 2017, 40 (27.6%) endured a proximal lower extremity injury within 4 years of their surgery. Specifically, 16 pitchers sustained hip injuries, 13 suffered hamstring injuries, and 14 experienced groin injuries. A significantly lower rate of hip- and groin-related injuries (17.9%) was identified in matched controls during a similar time frame (P = .049). CONCLUSION: The results of this study demonstrate that MLB pitchers who required UCL reconstruction sustained a higher frequency of proximal lower extremity injuries both before and after surgery compared with matched controls. This finding is significant as the treatment of antecedent hip lesions, as well as an emphasis on hip and core muscle mobility and strengthening, may help reduce injuries to the UCL.