Substantial clinical benefit values demonstrate a high degree of variability when stratified by time and geographic region.

Background: A Substantial Clinical Benefit (SCB) value is the amount of change in a patient-reported outcome measure required for a patient to feel they significantly improved from an intervention. Previously published SCB values are often cited by researchers when publishing outcomes data. Where these SCB values are set can have a large impact on the conclusions drawn from a study citing them. As such, the goal of this study was to determine the generalizability of SCB values for a procedure when stratified by time from surgery and geographic region. Methods: A nationwide outcomes database was utilized to obtain preoperative, one-year, and two-year postoperative outcome measurements for patients who underwent anatomic total shoulder arthroplasty (TSA) or reverse TSA. The data were divided into three geographic regions: the South, the Midwest, and the West. An East region was not included due to its limited number of patients. SCB values were calculated for four outcomes measures: Single Assessment Numeric Evaluation score, American Shoulder Elbow Surgeons score, Visual Analog Scale, and Western Ontario Osteoarthritis of the Shoulder score. SCB values were calculated for each region, for each procedure, and at both one and two years postoperatively. To determine the variability of potential SCBs within each region, simulated datasets were created to determine a distribution of possible calculated SCBs. Results: A total of 380 anatomic TSA patients and 543 reverse TSA patients were included for analysis. There was a high degree of variability of SCB values when stratified by procedure, time, and region. While some simulated datasets did produce homogenous SCB distributions among regions, some outcome measures demonstrated a large heterogeneity in distribution among regions, with concomitant large distributions of values within individual regions. Conclusions: There is notable heterogeneity of SCB values when stratified by region or time. The current method of citing previously published SCB values for determining the efficacy of an intervention may be inappropriate. It is likely that this variability holds true in other areas of orthopedics.

The Role of the Innate Immune System in Wear Debris-Induced Inflammatory Peri-Implant Osteolysis in Total Joint Arthroplasty.

Periprosthetic osteolysis remains a leading complication of total hip and knee arthroplasty, often resulting in aseptic loosening of the implant and necessitating revision surgery. Wear-induced particulate debris is the main cause initiating this destructive process. The purpose of this article is to review recent advances in understanding of how wear debris causes osteolysis, and emergent strategies for the avoidance and treatment of this disease. A strong activator of the peri-implant innate immune this debris-induced inflammatory cascade is dictated by macrophage secretion of TNF-α, IL-1, IL-6, and IL-8, and PGE2, leading to peri-implant bone resorption through activation of osteoclasts and inhibition of osteoblasts through several mechanisms, including the RANK/RANKL/OPG pathway. Therapeutic agents against proinflammatory mediators, such as those targeting tumor necrosis factor (TNF), osteoclasts, and sclerostin, have shown promise in reducing peri-implant osteolysis in vitro and in vivo; however, radiographic changes and clinical diagnosis often lag considerably behind the initiation of osteolysis, making timely treatment difficult. Considerable efforts are underway to develop such diagnostic tools, therapies, and identify novel targets for therapeutic intervention.

Bicortical suspensory button fixation yields greater ultimate load to failure over unicortical all-suture anchor fixation in distal biceps brachii tendon repair.

BACKGROUND: Various distal biceps tendon repair techniques exist, each with their own biomechanical profile. Recently, all-suture anchor fixation has recently become an intriguing option for distal biceps fixation, compared with the proven track record of the suspensory cortical button. In addition, intramedullary techniques have been utilized as a means to avoid complications such as nerve damage seen with extramedullary fixation. PURPOSE: The purpose of this study is to perform a comparative biomechanical analysis of 4 unique distal biceps tendon fixation methods: Unicortical/intramedullary all-suture anchor fixation (UIAS), Bicortical/extramedullary all-suture anchor fixation (BEAS), Unicortical/intramedullary suspensory button fixation (UISB), and Bicortical/extramedullary suspensory button fixation (BESB). STUDY DESIGN: Controlled Laboratory study. METHODS: 24 fresh-frozen cadaveric elbows were randomized into 4 groups providing data from 6 specimens, with each group undergoing a different repair technique. The specimens underwent 2 studies: Cyclic loading and Ultimate Load to failure (ULTF) testing. The repaired elbows were cycled 3000 times between 0 and 90 degrees of flexion, with displacement under cyclic loading at the repair site measured using a differential variable reductance transducer. ULTF test was performed with the elbow flexed at 90 degrees. The modes of failure were recorded. RESULTS: The mean cyclic displacements between the 4 groups were as follows: UIAS: 1.45 ± 1.04 mm; BEAS: 2.75 ± 1.32 mm; UISB: 1.45 ± .776 mm; BESB: 2.66 ± 1.18 mm (p= 0.077). Bicortical repairs displayed greater displacement after cyclic loading when compared with unicortical repairs regardless of anchor used (p= 0.007). The mean ULTF for each group was as follows: all-suture intramedullary: 200 N; all-suture extramedullary: 330 N; cortical-button intramedullary: 256 N; cortical-button extramedullary: 342 N). All-suture unicortical/intramedullary repair had a significantly lower ULTF (200 N) compared with cortical-button Bicortical/extramedullary repair (342 N) (p=0.043). CONCLUSION: Bicortical/extramedullary suspensory button fixation demonstrated a greater ultimate load to failure when compared with unicortical/intramedullary all-suture anchor fixation. These findings suggest that bicortical/extramedullary suspensory cortical button fixation is a biomechanically superior construct as compared to unicortical/intramedullary all-suture anchor fixation. However, there was no significant difference in ULTF between extra-medullary, Bicortical button or Bicortical, all-suture anchor fixation.

Transient Exertional Compressive Radial Neuropathy in a Collegiate Baseball Pitcher: A Case Report.

CASE: A 21-year-old collegiate baseball pitcher presented with transient lateral arm pain and wrist extension weakness after pitching more than 1 inning. Physical examination was unremarkable at rest. Ultrasound-guided injection of the radial nerve at the level of the lateral intramuscular septum improved his symptoms. After decompression of the radial nerve, the patient noted resolution of his symptoms while pitching. CONCLUSION: Atraumatic radial neuropathy is a rare but documented phenomenon. As far as we know, this is the first reported case of a transient exertional radial neuropathy in an athlete at the level of the lateral intermuscular septum.

Glenohumeral Arthrodesis for Treatment of Unique Instability with Axillary Nerve Injury: A Case Report.

Introduction: Traumatic shoulder dislocations in elderly patients can result in significant shoulder pathology. Rotator cuff tears and recurrent instability are common complications follow a dislocation event, while axillary nerve injury is less common. While there have been rare cases of recurrent shoulder instability with concomitant axillary nerve injury, there have been no prior cases, in which concurrent fracture fragmentation resulted in the initial gross instability. Case Report: A 68-year-old male with painful gross instability presents following a traumatic dislocation. The patient sustained an axillary nerve injury to the ipsilateral side resulting in a non-functioning deltoid. Pre-operative X-rays showed recurrent chronic glenohumeral dislocation, computerized tomography imaging showed a greater tuberosity fracture, and magnetic resonance imaging showed a massive cuff tear with retraction and atrophy. Given the level of instability and deltoid dysfunction, the patient was treated with shoulder arthrodesis. Intraoperatively, a large fragment of greater tuberosity with ligamentous attachments was found adhered to the anterior glenoid. After arthrodesis, the patient's pain and function improved significantly. Conclusion: When treating elderly patients with gross instability following a traumatic dislocation, surgeons should keep in mind the high likelihood of concomitant avulsion fracture, and that migratory cortical fragments can be a nidus for a patient's instability. When selected for appropriately, these patients can be effectively treated with shoulder arthrodesis with excellent improvements of pain and functionality.