Reverse total shoulder arthroplasty with proximal bone loss: a biomechanical comparison of partially vs. fully cemented humeral stems.

BACKGROUND: The appropriate amount of cementation at the time of reverse total shoulder arthroplasty with significant proximal bone loss or resection is unknown. Extensive cementation of a humeral prosthesis makes eventual revision arthroplasty more challenging, increasing the risk of periprosthetic fracture. We analyzed the degree of subsidence and torque tolerance of humeral components undergoing standard cementation technique vs. our reduced polymethyl methacrylate (PMMA) protocol. Reduced cementation may provide sufficient biomechanical stability to resist physiologically relevant loads, while still permitting a clinically attainable torque for debonding the prosthesis. METHODS: A total of 12 cadaveric humeri (6 matched pairs) underwent resection of 5 cm of bone distal to the greater tuberosity. Each pair of humeri underwent standard humeral arthroplasty preparation followed by either cementation using a 1.5-cm PMMA sphere at a location 3 cm inferior to the porous coating or standard full stem cementation. A 6-degree-of-freedom robot was used to perform all testing. Each humeral sample underwent 200 cycles of abduction, adduction, and forward elevation while being subjected to a physiologic compression force. Next, the samples were fixed in place and subjected to an increasing torque until implant-cement separation or failure occurred. Paired t tests were used to compare mean implant subsidence vs. a predetermined 5-mm threshold, as well as removal torque in matched samples. RESULTS: Fully and partially cemented implants subsided 0.49 mm (95% CI 0.23-0.76 mm) and 1.85 mm (95% CI 0.41-3.29 mm), respectively, which were significantly less than the predetermined 5-mm threshold (P < .001 and P < .01, respectively). Removal torque between fully cemented stems was 45.22 Nm (95% CI 21.86-68.57 Nm), vs. 9.26 Nm (95% CI 2.59-15.93 Nm) for partially cemented samples (P = .021). Every fully cemented humerus fractured during implant removal vs. only 1 in the reduced-cementation group. The mean donor age in our study was 76 years (range, 65-80 years). Only 1 matched pair of humeri belonged to a female donor with comorbid osteoporosis. The fractured humerus in the partially cemented group belonged to that donor. CONCLUSION: Partially and fully cemented humeral prostheses had subsidence that was significantly less than 5 mm. Partially cemented stems required less removal torque for debonding of the component from the cement mantle. In all cases, removal of fully cemented stems resulted in humeral fracture. Reduced cementation of humeral prostheses may provide both sufficient biomechanical stability and ease of future component removal.

Do local liposomal bupivacaine and interscalene nerve block provide similar pain control after shoulder arthroplasty? A dual-center randomized controlled trial.

BACKGROUND: Interscalene nerve block (INB) has become a popular technique for shoulder anesthesia. However, INB is associated with complication rates as high as 20%. Local liposomal bupivacaine (LLB) is an alternative to INB that potentially offers extended pain control with fewer adverse effects. METHODS: We conducted a dual-center randomized controlled trial of 108 participants who were treated with LLB (n = 54) or INB (n = 54) to control pain after shoulder arthroplasty. We assessed visual analog scale pain scores at 6-hour intervals from 6 to 96 hours postoperatively and at the first postoperative visit. We assessed opioid medication consumption intraoperatively and on days 1, 2, 3, and 4 postoperatively, as well as the duration of hospital and postanesthesia care unit (PACU) stays. RESULTS: At 6 hours postoperatively, the mean visual analog scale pain score was lower in the INB group (2.9 ± 3.1) than in the LLB group (5.1 ± 2.9, P < .01). The INB group consumed less opioid medication during the first 24 hours postoperatively (18 ± 12 morphine milligram equivalents) than did the LLB group (36 ± 48 morphine milligram equivalents, P = .01). The PACU stay was shorter in the INB group (102 ± 53 minutes) compared with the LLB group (139 ± 77 minutes, P < .01). CONCLUSIONS: Compared with LLB, INB provides better pain control immediately after shoulder arthroplasty as evidenced by shorter PACU stays, lower pain scores at 6 hours postoperatively, and less opioid medication consumption during the first 24 hours postoperatively. However, no differences in outcomes were observed between groups beyond 24 hours.

Anchorless Arthroscopic Transosseous and Anchored Arthroscopic Transosseous Equivalent Rotator Cuff Repair Show No Differences in Structural Integrity or Patient-reported Outcomes in a Matched Cohort.

BACKGROUND: Anchored transosseous equivalent suture-bridge technique (TOE) is widely used for arthroscopic rotator cuff repair. It is unknown how patient outcomes scores, ROM, and integrity of the rotator cuff after repair using this anchored technique compare with those after repair using an anchorless transosseous technique (TO). QUESTIONS/PURPOSES: (1) What are the differences in patient-reported outcomes (American Shoulder and Elbow Surgeons [ASES] score) and shoulder ROM between TO and TOE rotator cuff repair techniques at 1 and 2 years after surgery? (2) What is the difference in repair integrity as measured by the re-tear rate, assessed ultrasonographically at 1 year, between these two techniques? (3) What is the difference in procedure duration between the two techniques when performed by a surgeon familiar with each? METHODS: We reviewed 331 arthroscopic rotator cuff repairs performed by one surgeon from December 2011 to July 2016 in this retrospective, matched-pair study. Of these patients, 63% (208 of 331) underwent repair with standard anchored technique (anchors placed in a double-row, TOE manner) and 37% (123 of 331) underwent anchorless TO repair, with the same indications for surgery between groups. Forty-four percent (91 of 208) of patients in the TOE group and 61% (75 of 123) of patients in the TO group met the inclusion criteria. Eighty percent (73 of 91) of patients in the TOE group and 88% (66 of 75) in the TO group had minimum 2-year follow-up. We matched each group to a cohort of 50 patients by sex, age, smoking status, and tear size (by Cofield classification: small, < 1 cm; medium, 1-3 cm; large, > 3-5 cm; or massive, > 5 cm). The resulting cohorts did not differ in mean age (TO, 62 years [range 53-65 years]; TOE, 58 years [range 53-65 years]; p = 0.79), mean BMI value (TO, 30 [range 27-33]; TOE, 29 [range 27-35]; p = 0.97), or dominant arm involvement (TO, 80%; TOE, 78%; p = 0.81). The cohorts were followed for at least 2 years (median, 3.2 years [interquartile range (IQR) 2.2-4.3] for TO and 2.9 years [IQR 2.0-3.5 years] for TOE). ASES scores and ROM were evaluated before surgery and at follow-up visits and were recorded in a longitudinally maintained institutional database. Repair integrity was assessed using ultrasonography at 1 year, as is standard in our practice. For each tear-size group, we calculated the proportion of intact tendon repairs versus the proportion of re-tears. Duration of surgery was recorded for each patient. RESULTS: At 1 year, we observed no difference in median ASES scores (90 [IQR 92-98] for TO and 88 [IQR 72-98] for TOE; p = 0.44); external rotation (50° [IQR 45°-60°) for TO and 50° [IQR: 40°-60°] for TOE; p = 0.58); forward flexion (165° [IQR 160°-170°] for both groups; p = 0.91); or abduction (100° [IQR 90°-100°] for TO and 90° [IQR 90°-100°] for TOE; p = 0.06). Fourteen percent of shoulders (seven of 50) in each treatment group had evidence of re-tear at 1 year (p > 0.99): 0 of 2 small tears in each group, 0 of 7 medium tears in each group, five of 32 large tears in each group, and two of 9 massive tears in each group (all, p > 0.99). At 2 years, we found no differences in median ASES scores (92 [IQR 74-98)] for TO and 90 [IQR 80-100] for TOE; p = 0.84); external rotation (60° [IQR 50°-60°] for both groups; p = 0.74); forward flexion (170° [IQR 160°-170°] for both groups; p = 0.69); or abduction (100° [IQR 90°-100°] for both groups; p = 0.95). We found no differences between groups in mean ± SD procedure time, which was 103 ± 20 minutes for TO repair and 99 ± 20 minutes for TOE repair (p = 0.45). CONCLUSIONS: TO and TOE techniques for arthroscopic rotator cuff repair results in no differences in ROM, ASES scores, re-tear rates, and surgical time. Randomized control trials are needed to confirm these similarities or determine a superior method of repair. Future cost analyses may also help to determine the relative value of each technique. LEVEL OF EVIDENCE: Level III, therapeutic study.

Missing Data in the National Surgical Quality Improvement Program Database: How Does It Affect the Identification of Risk Factors for Shoulder Surgery Complications?

PURPOSE: The main purpose of this study was to establish whether different approaches to handling missingness affect the determination of risk factors associated with 30-day postoperative major and minor complications. A secondary purpose was to determine the frequency of missingness in the National Surgical Quality Improvement Program (NSQIP) records of patients who underwent shoulder surgery. METHODS: We queried the American College of Surgeons NSQIP database using Current Procedural Terminology codes to identify patients who underwent shoulder surgery from 2011 to 2016 (n = 61,963). Data on major and minor postoperative complications were extracted. We also extracted data on patient characteristics, comorbidities, American Society of Anesthesiologists classifications, and preoperative laboratory values. We calculated the percentages of missingness for each variable. Each variable was then evaluated for associations with major and minor complications by using multivariable regression and 4 methods of handling missingness (involving imputation or exclusion, depending on the completeness of the data set). For 10 variables, the method using no exclusion or imputation produced higher odds of major complications compared with imputation. For 5 variables, the method using no exclusion or imputation produced higher odds of minor complications compared with imputation. RESULTS: Only 6.5% of all patients had no missing data (n = 4,042), whereas 44% had <10% missingness (n = 27,165). Fewer variables were associated with both major and minor complications after shoulder surgery when patient records with missing data were excluded from analysis. CONCLUSIONS: Different methods of handling missingness produced different odds ratios for some variables when determining risk factors for complications after shoulder surgery. LEVEL OF EVIDENCE: III, Case control study.

Postoperative Care and Outcomes in Solid-Organ Transplant Patients Undergoing Lower Extremity Fracture Treatment.

OBJECTIVES: To determine the postoperative outcomes in solid-organ transplant (SOT) patients undergoing operative treatment of lower extremity fractures. DESIGN: Retrospective comparative study. SETTING: Academic Level 1 trauma center. PATIENT SELECTION CRITERIA: Patients who underwent SOT and operative treatment of lower extremity fracture from 2013 to 2021 were identified, excluding pathologic fractures. OUTCOME MEASURES AND COMPARISONS: Postoperative complications, length of stay, time to death, 90-day and 1-year readmission rates, readmission causes, discharge location, and immunosuppressive regiments. RESULTS: Sixty-one patients with an average age of 67 years (range 29-88) were included. The mortality rate was 37.7%. The average follow-up was 15.2 months (range of 2 weeks-10 years). The majority of patients (32.8%) had received a liver transplant, and femoral neck fractures constituted the largest fracture group. The average length of stay was 10 days, with the shortest being 1 day and the longest being 126 days (SD 18). The majority of patients (57.3%) were not discharged home. Only 2 suffered from a postoperative complication requiring another procedure: hardware removal and liner exchange for periprosthetic joint infection, respectively. There was a 27.9% 90-day readmission rate with 2 deaths within that period with the most common being altered mental status (29.4%), genitourinary infections (17.6%), repeat falls (11.8%), and low hemoglobin requiring transfusion (11.8%). The longest average time to death analyzed by transplant type was found among lung transplant patients (1076 days, 62.5% mortality), followed by liver transplant patients (949 days, 35.0% mortality), and then kidney transplant patients (834 days, 38.9% mortality). The shortest time to death was 71 days from index procedure. CONCLUSIONS: Family members of SOT patients undergoing operative treatment of lower extremity fractures should be made aware of the high risk for 90-day readmission postoperatively (27.9%) and overall mortality (12.5%). Providers should be aware of the need for multidisciplinary involvement for inpatient care, monitoring postoperative complications, and facilitating discharge planning. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

The Effects of Unitizing Nail-Plate Constructs in Distal Femur Fractures: A Biomechanical Study.

OBJECTIVES: To assess the biomechanical differences between linked and unlinked constructs in young and osteoporotic cadavers in addition to osteoporotic sawbones. METHODS: Intraarticular distal femur fractures with comminuted metaphyseal regions were created in three young matched pair cadavers, three osteoporotic matched pair cadavers, and six osteoporotic sawbones. Precontoured distal femur locking plates were placed in addition to a standardized retrograde nail, with unitized constructs having one 4.5 mm locking screw placed distally through the nail. Nonunitized constructs had seven 4.5 mm locking screws placed through the plate around the nail, with one 5 mm distal interlock placed through the nail alone. Cadaveric specimens were subjected to axial fatigue loads between 150 and 1500 N (R Ratio = 10) with 1 Hx frequency for 10,000 cycles. Sawbones were axially loaded at 50% of the ultimate load for fatigue testing to achieve runout, with testing performed with 30 and 300 N (R Ratio = 10) loads with 1 Hz frequency for 10,000 cycles. RESULTS: In young cadavers, there was no difference in the mean cyclic displacement of the unitized constructs (1.51 ± 0.62mm) compared to the non-unitized constructs (1.34 ± 0.47mm) (Figure 4A), (p = 0.722). In osteoporotic cadavers, there was no difference in the mean cyclic displacement of the unitized constructs (2.46 ± 0.47mm) compared to the non-unitized constructs (2.91 ± 1.49mm) (p =0.639). There was statistically no significant difference in cyclic displacement between the unitized and non-unitized groups in osteoporotic sawbones(p = 0.181). CONCLUSIONS: Linked constructs did not demonstrate increased axial stiffness or decreased cyclical displacement in comparison to unlinked constructs in young cadaveric specimens, osteoporotic cadaveric specimens, or osteoporotic sawbones.

Fracture Lines and Patterns in Intra-articular Distal Femur Fractures.

INTRODUCTION: Distal femur fractures are complex injuries that often present with multiple fragments, posing notable challenges to fixation. This study aimed to (1) use preoperative CT scans to graphically display fracture lines in intra-articular distal femur fractures and (2) identify common fracture patterns in these injuries. METHODS: All skeletally mature patients that underwent surgical fixation of Orthopaedic Trauma Association type 33C distal femur fractures between 2012 and 2022 were identified across two level 1 trauma centers (n = 63). Preoperative axial, sagittal, and coronal computed tomography scans were obtained. Fracture lines in each plane were traced out and superimposed on standardized distal femur cross-sections, generating a fracture map for each plane. Injury and fracture characteristics were summarized and compared between fracture patterns. RESULTS: On axial scans, 59 of 63 fractures contained a central intercondylar split from the intercondylar notch to the trochlea. On coronal scans, fracture lines originated at the notch and exited laterally and medially in the supracondylar region, creating a Y-shape. One-third of all fractures contained coronal fracture lines, with most involving the lateral condyle. Based on fracture line orientation and location, fractures were divided into four main fracture pattern types. Type 4 fractures (central split and medial coronal fracture line) were associated with lower average medial fracture height and a lower rate of medial metaphyseal comminution. DISCUSSION: We found that C-type distal femur fractures can present with four main fracture patterns. Most fractures contain a central sagittal intercondylar split, and a high proportion of fractures contain either medial or lateral coronal fracture lines. Fracture pattern was associated with mechanism of injury, presence of medial comminution, and medial fracture line height. Future studies should focus on clinical outcomes and surgical management of these distinct fracture patterns. LEVEL OF EVIDENCE: IV.

Similar Medium-Term Revision Rates Following Acute Total Hip Arthroplasty Versus Open Reduction and Internal Fixation for Acetabular Fractures in the Elderly.

BACKGROUND: The management of elderly acetabular fractures is complex, with high rates of conversion total hip arthroplasty (THA) after open reduction and internal fixation (ORIF), but potentially higher rates of complications after acute THA. METHODS: The California Office of Statewide Health Planning and Development database was queried between 2010 and 2017 for all patients aged 60 years or older who sustained a closed, isolated acetabular fracture and underwent ORIF, THA, or a combination. Chi-square tests and Student t tests were used to identify demographic differences between groups. Multivariate regression was used to evaluate predictors of 30-day readmission and 90-day complications. Kaplan-Meier (KM) survival analysis and Cox proportional hazards model were used to estimate the revision surgery-free survival (revision-free survival [RFS]), with revision surgery defined as conversion THA, revision ORIF, or revision THA. RESULTS: A total of 2,184 surgically managed acetabular fractures in elderly patients were identified, with 1,637 (75.0%) undergoing ORIF and 547 (25.0%) undergoing THA with or without ORIF. Median follow-up was 295 days (interquartile range, 13 to 1720 days). 99.4% of revisions following ORIF were for conversion arthroplasty. Unadjusted KM analysis showed no difference in RFS between ORIF and THA (log-rank test P = 0.27). RFS for ORIF patients was 95.1%, 85.8%, 78.3%, and 71.4% at 6, 12, 24 and 60 months, respectively. RFS for THA patients was 91.6%, 88.9%, 87.2%, and 78.8% at 6, 12, 24 and 60 months, respectively. Roughly 50% of revisions occurred within the first year postoperatively (49% for ORIF, 52% for THA). In propensity score-matched analysis, there was no difference between RFS on KM analysis ( P = 0.22). CONCLUSIONS: No difference was observed in medium-term RFS between acute THA and ORIF for elderly acetabular fractures in California. Revision surgeries for either conversion or revision THA were relatively common in both groups, with roughly half of all revisions occurring within the first year postoperatively. LEVEL OF EVIDENCE: III.

Novel bisphosphonate-based cathepsin K-triggered compound targets the enthesis without impairing soft tissue-to-bone healing.

Background: Osteoadsorptive fluorogenic sentinel 3 (OFS-3) is a recently described compound that contains a bone-targeting bisphosphonate (BP) and cathepsin K (Ctsk)-triggered fluorescence signal. A prior study in a murine Achilles repair model demonstrated its effectiveness at targeting the site of tendon-to-bone repair, but the intrinsic effect of this novel bisphosphonate chaperone on tendon-to-bone healing has not been previously explored. We hypothesized that application of this bisphosphonate-fluorophore cargo conjugate would not affect the biomechanical properties or histologic appearance of tendon-bone repairs. Materials and Methods: Right hindlimb Achilles tendon-to-bone repair was performed on 12-week old male mice. Animals were divided into 2 groups of 18 each: 1) Achilles repair with OFS-3 applied directly to the repair site prior to closure, and 2) Achilles repair with saline applied prior to closure. Repaired hindlimbs from 12 animals per group were harvested at 6 weeks for biomechanical analysis with a custom 3D-printed jig. At 4 and 6 weeks, repaired hindlimbs from the remaining animals were assessed histologically using H&E, immunohistochemistry (IHC) staining for the presence of Ctsk, and second harmonic generation (SHG) imaging to evaluate collagen fibers. Results: At 6 weeks, there was no significant difference in failure load, stiffness, toughness, or displacement to failure between repaired hindlimbs that received OFS-3 versus saline. There was no difference in tissue healing on H&E or Ctsk staining on immunohistochemistry between animals that received OFS-3 versus saline. Finally, second harmonic generation imaging demonstrated no difference in collagen fiber parameters between the two groups. Conclusion: OFS-3 did not significantly affect the biomechanical properties or histologic appearance of murine Achilles tendon-to-bone repairs. This study demonstrates that OFS-3 can target the site of tendon-to-bone repair without causing intrinsic negative effects on healing. Further development of this drug delivery platform to target growth factors to the site of tendon-bone repair is warranted.

Changes in the incidence of stress reactions and fractures among intercollegiate athletes after the COVID-19 pandemic.

PURPOSE: The purpose of this study was to characterize the impact of detraining due to the COVID-19 pandemic on incidence of bony injuries and stress fractures in collegiate athletes. METHODS: A comprehensive collegiate athletic conference injury database was queried for all in-season, sport-related bony injuries (defined as all stress reactions and fractures) that occurred across all sports from January 2016 to June 2021. The bony injury rate per 1000 athlete exposure hours (AEH) was calculated and compared between the immediate post-hiatus season and historic rates from pre-hiatus seasons (2016-2019). Injury characteristics were also compared between the pre- and post-hiatus time periods. RESULTS: A total of 868 bony injuries across 23 sports were identified. The sports with highest overall baseline bony injury rates in historic seasons were women's cross country (0.57 injuries per 1000 AEH) and men's cross country (0.32). Compared to historic pre-hiatus rates, female cross-country runners demonstrated a significantly lower bony injury incidence rate in the post-hiatus season (0.24 vs. 0.57, p = 0.016) while male swimming athletes demonstrated a statistically significant increase in bony injury rate (0.09 vs. 0.01, p = 0.015). The proportion of bony injuries attributed to repetitive trauma increased; while, the proportion of injuries attributed to running decreased between the pre- and post-hiatus seasons. CONCLUSION: Across all sports, there was no consistent trend toward increased rates of bony injury in the immediate post-hiatus season. However, female cross-country runners demonstrated lower rates of bony injury in the post-hiatus season while male swimmers demonstrated higher rates. Furthermore, bony injuries in the post-hiatus season were more likely to be the result of repetitive trauma and less likely to be from running. LEVEL OF EVIDENCE: Level III, retrospective, cross sectional study.

Higher Rates of Readmission After Acute Total Hip Arthroplasty Versus Open Reduction Internal Fixation for Elderly Acetabular Fractures, a National Study From 2010 to 2019.

OBJECTIVES: To evaluate the initial complications and short-term readmissions and reoperations after open reduction internal fixation (ORIF) versus acute total hip arthroplasty (THA) for elderly acetabular fractures. DESIGN: Retrospective database review. SETTING: All hospitalizations in the National Readmissions Database and National Inpatient Sample. PATIENTS/PARTICIPANTS: Patients 60 years of age or older with closed acetabular fractures managed surgically identified from the National Readmissions Database or National Inpatient Sample between 2010 and 2019. INTERVENTION: Acute THA with or without ORIF. MAIN OUTCOME MEASUREMENTS: 30-, 90-, and 180-day readmissions and reoperations and index hospitalization complications. RESULTS: An estimated 12,538 surgically managed acetabular fractures in elderly patients occurred nationally between 2010 and 2019, with 10,008 (79.8%) undergoing ORIF and 2529 (20.2%) undergoing THA. Length of stay was 1.7 days shorter ( P < 0.001) and probability of nonhome discharge was reduced (OR 0.68, P = 0.009) for THA patients than for ORIF patients. THA was associated with lower rates of pneumonia (4.6 vs. 9.1%, P < 0.001) and other respiratory complications (10.2 vs. 17.6%) when compared with ORIF. At 30 days, THA patients had higher rates of readmission (13.9 vs. 10.1%, P = 0.007), related readmission (5.4 vs. 1.2%, P < 0.001), readmission for dislocation (3.1 vs. 0.3%, P < 0.001), and reoperations (2.9 vs. 0.9%, P = 0.002). At 180 days, THA patients had higher rates of related readmission (10.1% vs. 3.9%, P < 0.001), readmission for dislocation (5.1% vs. 1.3%, P < 0.001), and readmission for SSI (3.4 vs. 0.8%, P = 0.005). CONCLUSIONS: Acute THA is associated with lower length of stay and certain index hospitalization complications, but higher rates of readmissions for related reasons and specifically for dislocation. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Geriatric Distal Femur Fractures: Equivalent Long-Term Reoperation Rates Between Fixation and Primary Arthroplasty.

OBJECTIVE: Our primary objectives were to (1) determine the rate of requiring conversion to arthroplasty after open reduction internal fixation (ORIF) of geriatric distal femur fractures and (2) compare 10-year reoperation rates after ORIF versus primary arthroplasty for geriatric distal femur fractures. DESIGN: Propensity-matched retrospective cohort study. SETTING: All centers participating in the California Office of Statewide Health Planning and Development (OSHPD) database. PATIENTS/PARTICIPANTS: All patients 65 years of age or older who underwent operative management of a distal femur fracture between 2000 and 2017. INTERVENTION: ORIF, total knee arthroplasty (TKA), or distal femur replacement (DFR). MAIN OUTCOME MEASUREMENTS: Reoperation. RESULTS: A total of 16,784 patients with geriatric distal femur fracture were identified, of which 16,343 (97.4%) underwent ORIF. The cumulative incidence of conversion to arthroplasty within 10 years of ORIF was found to be 3.5%, with young age and female sex identified as risk factors for conversion. There was no significant difference in 10-year reoperation-free survival rate between propensity-matched patients undergoing ORIF versus primary arthroplasty (94.5% vs. 96.2%, P = 0.659). There were no differences in short-term complication or readmission rates between matched treatment cohorts, but arthroplasty was associated with a higher rate of wound infection within 90 days (2.0% vs. 0.2%, P = 0.011). CONCLUSIONS: The 10-year cumulative incidence of conversion to arthroplasty after ORIF was found to be low. There was no significant difference in long-term reoperation-free survival rates between patients undergoing ORIF versus primary arthroplasty. Primary arthroplasty was associated with significantly higher rates of acute wound or joint infection. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Multicenter Analysis of the Epidemiology of Injury Patterns and Return to Sport in Collegiate Gymnasts.

Background: Gymnastics requires intense year-round upper and lower extremity strength training typically starting from an early age. As such, the injury patterns observed in these athletes may be unique. Purpose: To characterize the types of injuries and provide return-to-sport data in male and female collegiate gymnasts. Study Design: Descriptive epidemiology study. Methods: A conference-specific injury database was utilized to perform a retrospective review of injuries for male and female National Collegiate Athletic Association (NCAA) Division I gymnasts within the Pacific Coast Conference between 2017 and 2020 (N = 673 gymnasts). Injuries were stratified by anatomic location, sex, time missed, and injury diagnoses. Relative risk (RR) was used to compare results between sexes. Results: Of the 673 gymnasts, 183 (27.2%) experienced 1093 injuries during the study period. Injuries were sustained in 35 of 145 male athletes (24.1%) as compared with 148 of 528 female athletes (28.0%; RR, 0.86 [95% CI, 0.63-1.19]; P = .390). Approximately 66.1% (723/1093) of injuries occurred in a practice setting, compared with 84 of 1093 injuries (7.7%) occurring during competition. Overall, 417 of 1093 injuries (38.2%) resulted in no missed time. Shoulder injuries and elbow/arm injuries were significantly more common in male versus female athletes (RR, 1.99 [95% CI, 1.32-3.01], P = .001; and RR, 2.08 [95% CI, 1.05-4.13], P = .036, respectively). In total, 23 concussions affected 21 of 673 athletes (3.1%); 6 concussions (26.1%) resulted in the inability to return to sport during the same season. Conclusion: For the majority of musculoskeletal injuries, the gymnasts were able to return to sport during the same season. Male athletes were more likely to experience shoulder and elbow/arm injuries, likely because of sex-specific events. Concussions occurred in 3.1% of the gymnasts, highlighting the need for vigilant monitoring. This analysis of the incidence and outcomes of injuries observed in NCAA Division I gymnasts may guide injury prevention protocols as well as provide important prognostic information.

MELD score predicts short-term outcomes after surgical management of proximal humerus fractures: a matched analysis.

Objective: We aimed to evaluate the difference in 30-day outcomes after surgical management of proximal humerus fractures (PHFs) between patients with and without chronic liver disease as defined by a MELD score greater than 10. Design: This was a retrospective database review. Setting: All centers participating in the American College of Surgeons National Surgical Quality Improvement Program database were included. Patients/Participants: Patients with proximal humerus fractures who (1) underwent ORIF, HA, or SA and (2) had calculable MELD scores were included. Intervention: Open reduction and internal fixation, hemiarthroplasty, or shoulder arthroplasty was used for treatment. Main outcome measurements: Thirty-day complications, mortality, readmission, and reoperation rates were measured. Results: Of the total 1732 PHF patients identified, 300 had a MELD score higher than 10. After propensity matching by significant covariates, MELD score higher than 10 was found to be significantly associated with higher rates of 30-day mortality, 30-day readmission, transfusion within 72 hours, and systemic complications. Among patients with a MELD score higher than 10, treatment with SA or HA instead of ORIF was associated with a higher rate of transfusion and longer operative time. There were no significant differences between treatment cohorts regarding mortality, reoperation, readmission, or complications. Conclusions: A MELD score higher than 10 is associated with higher risk of surgical complications, transfusion, and death in patients undergoing surgery for proximal humerus fractures. Among patients with a MELD score higher than 10, ORIF was associated with a lower transfusion rate and shorter operative time than arthroplasty or hemiarthroplasty. Level of Evidence: Prognostic Level III.

Short-Term Outcomes and Long-Term Implant Survival After Inpatient Surgical Management of Geriatric Proximal Humerus Fractures.

Introduction: The most common surgical options for geriatric proximal humerus fractures are open reduction and internal fixation (ORIF), hemiarthroplasty (HA), and reverse total shoulder arthroplasty. We used a longitudinal inpatient discharge database to determine the cumulative incidence of conversion to arthroplasty after ORIF of geriatric proximal humerus fractures. The rates of short-term complications and all-cause reoperation were also compared. Patients and Methods: All patients 65 or older who sustained a proximal humerus fracture and underwent either ORIF, HA, or shoulder arthroplasty (SA) as an inpatient from 2000 through 2017 were identified. Survival analysis was performed with ORIF conversion to arthroplasty and all-cause reoperation as the endpoints of interest. Rates of 30-day readmission and short-term complications were compared. Trends in procedure choice and outcomes over the study period were analyzed. Results: A total of 27 102 geriatric patients that underwent inpatient surgical management of proximal humerus fractures were identified. Among geriatric patients undergoing ORIF, the cumulative incidence of conversion to arthroplasty within 10 years was 8.2%. The 10-year cumulative incidence of all-cause reoperation was 12.1% for ORIF patients and less than 4% for both HA and SA patients. Female sex was associated with increased risk of ORIF conversion and younger age was associated with higher all-cause reoperation. ORIF was associated with higher 30-day readmission and short-term complication rates. Over the study period, the proportion of patients treated with ORIF or SA increased while the proportion of patients treated with HA decreased. Short-term complication rates were similar between arthroplasty and ORIF patients in the later cohort (2015-2017). Conclusion: The 10-year cumulative incidence of conversion to arthroplasty for geriatric patients undergoing proximal humerus ORIF as an inpatient was found to be 8.2%. All-cause reoperations, short-term complications, and 30-day readmissions were all significantly lower among patients undergoing arthroplasty, but the difference in complication rate between arthroplasty and ORIF was attenuated in more recent years. Younger age was a risk factor for reoperation and female sex was associated with increased risk of requiring conversion to arthroplasty after ORIF.

Modifiable and non-modifiable risk factors for failure of non-operative treatment of pediatric forearm fractures: Where can we do better?

Introduction: Distal third forearm fractures are common fractures in children. While outcomes are generally excellent, some patients fail initial non-operative management and require intervention. The purpose of this study is to identify independent risk factors associated with failure of closed reduction. Methods: We conducted a retrospective review of distal third forearm fractures in children treated with closed reduction and casting. Patients were divided into two cohorts-those who were successfully closed reduced and those who failed initial non-operative management. Demographic characteristics, cast type, cast index, radiographic fracture, soft tissue characteristics, and quality of reduction were analyzed between groups. Results: A total of 207 children treated for distal third forearm fractures were included for analysis. A total of 190 (91.8%) children maintained their reduction while 17 (8.2%) failed initial non-operative management. Modifiable risk factors associated with loss of reduction on univariate analysis included the use of a long arm cast (p = 0.003), increased post-reduction displacement (p = 0.02), and increased post-reduction angular deformity (p = 0.01). Non-modifiable risk factors included increased body mass index (p = 0.02), increased presenting fracture displacement (p = 0.002), and increased width of the soft tissue envelope at the fracture site (p = 0.0001). The use of long arm casts (13% vs 2%, odds ratio = 6.44) and soft tissue width (60.6 vs 50.4 mm, odds ratio = 1.1) remained significant risk factors for loss of reduction after multivariate analysis. Conclusion: Both larger soft tissue envelope at the site of the fracture and long arm cast immobilization are independently associated with an increased risk of failing initial closed reduction in distal third forearm fractures in the pediatric population. Level of evidence: level III Case Control Study.

Impact of the COVID-19 Pandemic Hiatus From Sports Activities on Injuries Observed Among Division I NCAA Athletes.

Background: The coronavirus disease 2019 (COVID-19) pandemic significantly disrupted athletic activities, including those in the Pacific 12 (Pac-12) Conference of the National Collegiate Athletic Association. It is currently unknown how the disruption in training and competition impacted athletes' risk of injury upon resumption of activities. Purpose: To describe and compare the rate, timing, mechanism, and severity of injuries among collegiate athletes across multiple sports in the Pac-12 Conference before and after the COVID-19 pandemic-associated hiatus of intercollegiate athletic activities. Study Design: Descriptive epidemiology study. Methods: Descriptive and injury data among intercollegiate athletes from both the season before the hiatus and the season after the hiatus were acquired from the Pac-12 Health Analytics Program database. Injury elements (timing of injury onset, injury severity, mechanism, recurrence, outcome, need for procedural intervention, and event segment during which the injury took place) were compared by time using the chi-square test and a multivariate logistic regression model. Subgroup analyses were performed on knee and shoulder injuries among athletes participating in sports with traditionally high rates of knee and shoulder injuries. Results: A total of 12,319 sports-related injuries across 23 sports were identified, with 7869 pre-hiatus injuries and 4450 post-hiatus injuries. There was no difference in the overall incidence of injury between the pre-hiatus and post-hiatus seasons. However, the proportion of noncontact injuries was higher in the post-hiatus season for football, baseball, and softball players, and the proportion of nonacute injuries in the post-hiatus season was higher among football, basketball, and rowing athletes. Finally, the overall proportion of injuries sustained by football players in the final 25% of competition or practice was higher in the post-hiatus season. Conclusion: Athletes competing in the post-hiatus season were observed to have higher rates of noncontact injuries and injuries sustained in the final 25% of competition. This study demonstrates that the COVID-19 pandemic has had varied effects on athletes from different sports, suggesting that many factors must be considered when designing return-to-sports programs for athletes after an extended absence from organized training.

Biologically-coupled bisphosphonate chaperones effectively deliver molecules to the site of soft tissue-bone healing.

Tendon injuries are common and often treated surgically, however, current tendon repair healing results in poorly organized fibrotic tissue. While certain growth factors have been reported to improve both the strength and organization of the repaired enthesis, their clinical applicability is severely limited due to a lack of appropriate delivery strategies. In this study, we evaluated a recently developed fluorescent probe, Osteoadsorptive Fluorogenic Sentinel-3 that is composed of a bone-targeting bisphosphonate (BP) moiety linked to fluorochrome and quencher molecules joined via a cathepsin K-sensitive peptide sequence. Using a murine Achilles tendon-to-bone repair model, BP-based and/or Ctsk-coupled imaging probes were applied either locally or systemically. Fluorescence imaging was used to quantify the resultant signal in vivo. After tendon-bone repair, animals that received either local or systemic administration of imaging probes demonstrated significantly higher fluorescence signal at the repair site compared to the sham surgery group at all time points (p < 0.001), with signal peaking at 7-10 days after surgery. Our findings demonstrate the feasibility of using a novel BP-based targeting and Ctsk-activated delivery of molecules to the site of tendon-to-bone repair and creates a foundation for further development of this platform as an effective strategy to deliver bioactive molecules to sites of musculoskeletal injury.

Nail Plate Combination Fixation Versus Lateral Locked Plating for Distal Femur Fractures: A Multicenter Experience.

OBJECTIVES: To (1) report on clinical, radiographic, and functional outcomes after nail-plate fixation (NPF) of distal femur fractures and (2) compare outcomes after NPF with a propensity matched cohort of fractures treated with single precontoured lateral locking plates. DESIGN: Multicenter retrospective cohort study. SETTING: Ten Level 1 trauma centers. PATIENTS/PARTICIPANTS: Patients with OTA/AO 33A or 33C fractures. INTERVENTION: Fixation with (1) retrograde intramedullary nail combined with lateral locking plate (n = 33) or (2) single precontoured lateral locking plate alone (n = 867). MAIN OUTCOME MEASUREMENTS: The main outcomes of interest were all-cause unplanned reoperation and presence of varus collapse at final follow-up. RESULTS: One nail-plate patient underwent unplanned reoperation excluding infection and 2 underwent reoperation for infection at an average of 57 weeks after surgery. No nail-plate patients required unplanned reoperation to promote union and none exhibited varus collapse. More than 90% were ambulatory with no or minimal pain at final follow-up. In comparison, 7 of the 30 matched lateral locked plating patients underwent all-cause unplanned reoperation excluding infection (23% vs. 3%, P = 0.023), and an additional 3 lateral locked plating patients were found to have varus collapse on final radiographs (10% vs. 0%, P = 0.069). CONCLUSIONS: Despite a high proportion of high-energy, open, and comminuted fractures, no NPF patients underwent unplanned reoperation to promote union or demonstrated varus collapse. Propensity score matched analysis revealed significantly lower rates of nonunion for NPF compared with lateral locked plating alone. Larger studies are needed to identify which distal femur fracture patients would most benefit from NPF. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Meniscus Repair in Pediatric Athletes.

Meniscus tears are common in the pediatric population, typically occur after noncontact injuries, and can be diagnosed clinically with MRI confirmation. Surgery should be offered to patients with loss of range of motion, persistent symptoms, or displaced/complex tears. Given poor long-term outcomes reported after meniscectomy, repair should be attempted when possible as pediatric menisci are well vascularized and have better outcomes after repair than their adult counterparts. The location of the tear is an important determining factor when deciding on the type of repair to use. Pediatric meniscus repair techniques will be discussed noting differences between pediatric and adult procedures. Further studies are needed to explore the role of biologics and define postoperative protocols.