Sex differences in biomechanical properties of the Achilles tendon may predispose men to higher risk of injury: A systematic review.

IMPORTANCE: Men have a higher risk of Achilles tendon (AT) injury, and the impact of morphological and mechanical sex differences may play a role. AIM: The aim of this study is to systematically review the literature to determine whether there are sex-specific differences in AT morphological and mechanical properties and analyze how these differences may impact AT injury in both men and women. EVIDENCE REVIEW: A systematic literature search of articles published between 2001 and 2021, in the MEDLINE, EMBASE, and Cochrane databases was performed during May 2022 according to PRISMA. The primary outcome measures included sex-related differences in the mechanical and morphological properties of the Achilles tendon. Secondary outcomes included impact of sex on Achilles tendon properties and adaptation. FINDINGS: Nineteen studies with a total of 1,143 participants (613 men and 530 women) were included in this systematic review. Men had increased measurements when compared with women in the following: AT length, thickness, cross-sectional area (CSA), stiffness, peak force, loading rate, and voluntary muscle contraction. Women had an increase in CSA deformation, strain, and compliance. CONCLUSIONS AND RELEVANCE: Our study demonstrates that men have an increased AT length, thickness, and CSA, indicating that men may be subjected biomechanically to higher loads in their day-to-day activities. In addition, men have lower deformation and compliance properties, along with increased AT stiffness, reducing their capacity to adapt during loading, potentially increasing their risk of injury. LEVEL OF EVIDENCE: IV.

Musculotendinous ruptures of the achilles tendon had greater heel-rise height index compared with mid-substance rupture with non-operative management: A retrospective cohort study.

INTRODUCTION: Achilles tendon ruptures (ATRs) may occur at varying locations with ruptures at the mid-substance (MS) of the tendon most common, followed tears at the musculotendinous (MT) junction. There is scant literature about the outcome of MT ATR. This study compared the outcome of patients with a MT ATR with patients following a MS ATR. METHODS: The diagnostic features and clinical outcome of 37 patients with a MT ATR were compared with a cohort of 19 patients with a MS ATR. Patients in both groups were managed non-operatively and received the same rehabilitation protocol with weight-bearing rehabilitation in protective functional brace. RESULTS: From February 2009 to August 2023, 556 patients presented with an ATR. Of these, 37 (6.7 â€‹%) patients were diagnosed with a MT tear. At final follow-up, at 12 months following injury, the MT group reported an Achilles tendon total rupture score (ATRS) of mean (standard deviation (SD)) of 83.6 (3.5) (95 â€‹% confidence interval (CI) 81.8, 85.4) and median (inter-quartile range (IQR)) ATRS of 86 points (78-95.5) and the MS group mean (SD) of 80.3 (8.5) (95%CI) 76.1, 80.5) and median (IQR) of 87 points (59-95) (p â€‹= â€‹0.673). Functional evaluation, however, revealed statistically significant differences in mean (SD) heel-rise height index MT group 79 â€‹% (25) (95%CI 65.9, 92.1) and MS group 59 â€‹% (13) (95%CI 51.9, 67.1) (p â€‹= â€‹0.019). In the MT rupture group, there were considerably less complications than the MS rupture group. CONCLUSIONS: When managed non-operatively, with only a 6 weeks period of brace protection, patients have little limitation although have some residual reduction of single heel-rise at the one-year following MT ATR. LEVEL OF EVIDENCE: IV.

Testosterone replacement therapy is associated with increased odds of Achilles tendon injury and subsequent surgery: a matched retrospective analysis.

BACKGROUND: Prescription of testosterone replacement therapy (TRT) has increased in the United States in recent years, and though anabolic steroids have been associated with tendon rupture, there is a paucity of literature evaluating the risk of Achilles tendon injury with TRT. This study aims to evaluate the associative relationship between consistent TRT, Achilles tendon injury, and subsequent surgery. METHODS: This is a one-to-one matched retrospective cohort study utilizing the PearlDiver database. Records were queried for patients aged 35-75 who were prescribed at least 3 consecutive months of TRT between January 1, 2010 and December 31, 2019. Achilles tendon injuries and subsequent surgeries were identified using ICD-9, ICD-10, and CPT billing codes. Multivariable logistic regression was used to compare odds of Achilles tendon injury, Achilles tendon surgery, and revision surgery, with a p-value < 0.05 representing statistical significance. RESULTS: A sample of 423,278 patients who filled a TRT prescription for a minimum of 3 consecutive months was analyzed. The 2-year incidence of Achilles tendon injury was 377.8 (95% CI, 364.8-391.0) per 100,000 person-years in the TRT cohort, compared to 245.8 (95% CI, 235.4-256.6) in the control (p < 0.001). The adjusted analysis demonstrated TRT to be associated with a significantly increased likelihood of being diagnosed with Achilles tendon injury (aOR = 1.24, 95% CI, 1.15-1.33, p < 0.001). Of those diagnosed with Achilles tendon injury, 287/3,198 (9.0%) of the TRT cohort subsequently underwent surgery for their injury, compared to 134/2,081 (6.4%) in the control cohort (aOR = 1.54, 95% CI, 1.19-1.99, p < 0.001). CONCLUSIONS: There is a significant association between Achilles tendon injury and prescription TRT, with a concomitantly increased rate of undergoing surgical management. These results provide insight into the risk profile of TRT and further research into the science of tendon pathology in the setting of TRT is an area of continued interest.

Incidence of Achilles tendon rupture: 25-year regional analysis with a focus on bilateral ruptures.

OBJECTIVE: We aimed to fill the research gap regarding the incidence of Achilles tendon rupture (ATR), which is reportedly increasing, as there is a lack of data on the incidence of ATR and no data on bilateral ruptures in our region. METHODS: We determined the incidence of complete ATR among 273,485 people during 1991 to 2015. RESULTS: In the study period, 524 patients (486 [92.75%] men and 38 [7.25%] women, average age 39.03±10.86 [range 20-83] years, = sex ratio 12.8:1) were treated for ATR in our study area. The average incidence was 7.77 per 100,000 person-years, with an increasing trend until 2008 and peak incidence of 11.33 per 100,000 person-years. Most injuries (67.04%) occurred while performing sports activities. In total, 7 (1.34%) patients (six men [1.23%] and one woman [2.63%]) experienced ruptures on both sides, an average of 5.1 years apart; the average age at the second rupture was 57.71±16.69 (range 39-83) years, with a calculated incidence for bilateral ATR of 0.1 per 100,000 person-years. CONCLUSIONS: The incidence of complete ATR in our study region increased gradually between 1991 and 2008, after which it declined. Bilateral ATR during that period was a very rare injury.

Increasing incidence of surgically treated hamstring injuries: a nationwide registry study in Sweden between 2001 and 2020.

BACKGROUND AND PURPOSE: Data on incidence and on trends in treatment of hamstring injuries, including proximal hamstring tendon avulsions (PHA), is limited. We aimed to investigate the incidence, trends in operative treatment, age, and sex distribution of hamstring injuries in Sweden between 2001 and 2020. PATIENTS AND METHODS: We obtained data recorded in the National Patient Register between 2001 and 2020 on patients between 18 and 90 years of age, with the ICD-10 code S76.3, to calculate the incidence of patients treated operatively for hamstring injuries in Sweden. Patients with the NOMESCO classification NFL49 were considered as having been treated operatively. Data on quadriceps and Achilles tendon injuries were obtained for comparison. To calculate incidences, adult population data for every year were obtained from the Statistics Sweden website. RESULTS: The incidence of patients diagnosed with hamstring injuries increased from 2.2 to 7.3 per 100,000 person-years. There was a rising trend of surgical treatment per diagnosed case from 3.0% to 14.2%. Patients diagnosed in units with the highest experience of surgical treatment of hamstring injuries tended to be operated on more often (22.2%) than patients diagnosed in units with limited experience (5.1%), although the fraction of operated patients was increasing in both groups. CONCLUSION: Between 2001 and 2020 there was an increase in the proportion of operatively treated hamstring injuries.

The relationship between plate prominence and need for removal after volar plate osteosynthesis of distal radius fractures.

PURPOSE: This study aimed to assess the incidence of plate-related complications and the need for plate removal after volar plate osteosynthesis of the distal radius in relation to Soong classification. METHODS: All consecutive patients (age > 16 years) in our level II trauma center treated with plate osteosynthesis for distal radius fractures from January 2017 until June 2019 were retrospectively evaluated. The main outcome measures were volar plate positioning according to Soong classification and incidence of plate removal. In addition, the incidence of tendon ruptures, reasons for volar plate removal, and improvement of complaints after removal were evaluated. RESULTS: The overall incidence of plate removal in the 336 included patients was 16.9% (n = 57). Removal incidence in Soong 2 plates (28.2%) was significantly higher compared to Soong 0 and 1 plates (8.0% and 14.4%, respectively), P = 0.003. Multivariable binary logistic regression analysis showed Soong grade 2 as an independent predictor for plate removal, OR 4.3 (95% CI 1.4-13.7, P = 0.013). Four cases of flexor and four cases of extensor tendon rupture were reported, all in Soong 2 grade plating. The main reasons for volar plate removal were pain (42%) and reduced functionality (12%). In cases where pain was the main reason for removal, 81% of patients reported a decrease in pain during follow-up after surgery. CONCLUSIONS: This study suggests an association between plate prominence graded by Soong and plate removal using a single plating system. Plate prominence should be reduced in volar plating whenever technically feasible.

Aetiopathogenesis of Rotator Cuff Tear in Patients Younger than 50 Years: Medical Conditions Play a Relevant Role.

Background and Objectives: Studies on rotator cuff tears (RCT) in patients younger than 50 years have focused on the post-operative outcomes. Little is known about cuff tear etiopathogenesis, although it is a common belief that most tears are due to trauma. We have retrospectively verified the prevalence of medical conditions, whose role in tendon degeneration development have been widely demonstrated, in a group of patients younger than 50 years with postero-superior RCT. Materials and Methods: 64 patients [44M-20F; mean age (SD): 46.90 (2.80)] were enrolled. Personal data, BMI, smoking habit, diseases (diabetes, arterial hypertension, hypercholesterolaemia, thyroid diseases, and chronic obstructive pulmonary disease) were registered. The possible triggering cause and the affected side and tear dimensions were recorded, and statistical analysis was then performed. Results: 75% of patients had one or more diseases and/or a smoking habit for more than 10 years. In the remaining 25%, only four patients referred had had a traumatic event, while in the other eight patients, both medical condition and trauma were registered. The presence of two or more diseases did not affect RCT size. Conclusions: In our series, three quarters of patients with RCT had a smoking habit or medical conditions predisposing them to a tendon tear; therefore, the role of trauma in RCT onset in patients younger than 50 years is markedly resized. It is plausible that in the remaining 25%, RCT may be due to trauma or to genetic or acquired degeneration. Level of Evidence: IV.

Risk Factors for Contralateral Tendon Rupture in Patients With Acute Achilles Tendon Rupture.

The present study was performed to determine the incidence and risk factors of contralateral Achilles tendon rupture after an initial tendon rupture, and to identify the associated patient characteristics. Medical records of 181 adult patients with acute Achilles tendon rupture were reviewed. We investigated the risk factors for contralateral Achilles tendon rupture and calculated the incidence density (per 100 person-years), survival rate, hazard ratios, and 95% confidence intervals. The risk factors were extracted, including blood type, age, body mass index (BMI), occupation, underlying comorbidities, history of alcohol intake or smoking, injury mechanism, and fluoroquinolone antibiotic or steroid use. Military personnel and manual laborers, including farmers and firefighters were considered to have an occupation involving physical activity. Ten patients (5.5%) were identified as having nonsimultaneous, contralateral Achilles tendon rupture a mean of 3.3 years (range 1.0-8.3 years) after the initial tendon rupture. The incidence density of contralateral tendon rupture was 0.89 per 100 person-years. The 8-year survival rate of contralateral tendon rupture was 92.2%. Unadjusted and adjusted hazard ratios (with 95% confidence intervals, p value) of blood type O were 3.71 (1.07-12.82, p = .038) and 2.90 (0.81-10.32, p = .101), respectively, and those of occupations involving physical activity were 5.87 (1.64-20.98, p = .006) and 4.69 (1.27-17.28, p = .02), respectively. Based on the present data, blood type O and occupations involving physical activity are significantly associated with an increased risk of contralateral tendon rupture in adult patients who have sustained Achilles tendon rupture.

Characterization of Achilles Tendon Ruptures in Collegiate Women's Gymnastics.

Collegiate female gymnasts are at high risk of Achilles tendon injuries. Achilles tendon ruptures can negatively impact an athlete's ability to return to competitive sport. Understanding the natural history of Achilles tendon tears in collegiate female gymnasts is important in the development of preventive treatment. To expand our knowledge of the natural history of Achilles tendon ruptures among collegiate female gymnasts, a REDCap retrospective survey was emailed to athletic trainers on all 80 National Collegiate Athletic Association (NCAA) women's gymnastics teams. The survey gathered information regarding number of Achilles tendon injuries, pain prior to injuries, events and skills on which injuries occurred, and functional outcome after injuries among athletes competing in the 2013 to 2018 NCAA seasons. Forty-two of 80 (52.5%) programs responded to the survey. Seventy-one Achilles tendon ruptures were reported between 2013 and 2018. Among these, 46% had antecedent pain. Gymnasts sustained 95% of Achilles tendon ruptures while performing on floor exercise, with 98% of ruptures occurring during the take-off portion of a tumbling skill. Of the 61% of gymnasts who were able to return to competition, 59% were able to achieve the same level of function after injury. Achilles tendon ruptures in collegiate female gymnasts primarily occur during the take-off motion while tumbling on the floor exercise. Future studies should evaluate degenerative Achilles tendon changes in collegiate female gymnasts. A collaborative effort among gymnasts, coaches, judges, and medical experts is required to identify at-risk athletes and develop and implement injury prevention programs. [Orthopedics. 2023;46(4):205-210.].

Aponeurotic expansion of the supraspinatus tendon and concomitant shoulder pathologies.

OBJECTIVES: We investigated the correlation of aponeurotic expansion of the supraspinatus tendon (AESST) with shoulder pathologies such as long head of biceps tendon (LHB), supraspinatus tendon (SST), and subscapularis tendon (SSc). METHODS: We retrospectively evaluated 47 healthy patients and 163 patients with shoulder symptoms from August 2014 to March 2021. First, the presence of AESST was evaluated based on Moser et al.'s classification. Second, the presence of abnormal findings of including LHB tendinitis, LHB subluxation, SST tendinitis, SST tear, SSc tendinitis, and SSc tendon tear was evaluated. We analyzed the prevalence and type of AESST between the two study groups and the relationship between abnormal findings and the presence of AESST. RESULTS: The prevalence of AESST for readers 1 and 2 was 26.1% and 30.4% in the asymptomatic group, respectively, and 22.8% and 31.3% in the symptomatic group. Type 1 was most common (17.3-23.9%) followed by types 2a and 2b. There were no significant differences in the distribution of aponeurosis type between the two groups. In the AESST-positive groups, 45.9% and 47.1% had SST tears on examination by readers 1 and 2, respectively, whereas only 26.4% and 27.9% had SST tears in the AESST-negative group suggesting AESST is associated with SST tear. The odds ratio for SST tear in the presence of AESST was 2.370 and 2.294 (readers 1 and 2). CONCLUSIONS: There is an association between SST tears and the presence of AESST. KEY POINTS: • We evaluated the prevalence of aponeurotic expansion of the supraspinatus tendon (AESST) on MR imaging by type in both symptomatic and asymptomatic groups. • We investigated the correlation of AESST with shoulder pathologies such as biceps tendon and supraspinatus tendon tears. • There is an association between SST tears and the presence of AESST. • Radiologists should be aware of the risk of rotator cuff pathology if AESST is detected.

Increased incidence of acute achilles tendon ruptures in the peri-pandemic COVID era with parallels to the 2021-22 NFL season.

PURPOSE: Acute Achilles tendon ruptures (AATRs) are a common sporting injury, whether for recreational athletes or elite athletes. Prior research has shown returning to physical activity after extended periods of inactivity leads to increased rates of musculoskeletal injuries. The purpose of this study was to investigate rates of acute Achilles' tendon ruptures at a single academic institute in the peri-COVID era, with corollary to the recent NFL season. METHODS: A retrospective search was conducted using current procedural terminology to identify the total number of Achilles acute primary repair surgeries performed from years 2017 to 2021. Non-operatively managed AATRs were identified from the same electronic medical record using ICD-10 codes. NFL data were obtained from publicly available sites according to previously validated studies. RESULTS: A total of 588 patients who sustained AATRs and underwent primary surgical repair were identified, primarily men (75.7%, n = 445), with an average age of 43.22 ± 14.4 years. The number and corresponding incidence of AATR repairs per year was: 2017: n = 124 (21.1%), 2018: n = 110 (18.7%), 2019: n = 130 (22.1%), 2020: n = 86 (14.6%), 2021: n = 138 (23.5%), indicating a 7.5% decrease in rate of AATRs from 2019 to 2020, followed by an 8.9% increase in incidence from 2020 to 2021. Within the NFL, the number of AATRs resulting in an injured reserve stint increased every regular season from 2019 to 2020: n = 11 (21.2%), to 2020-2021: n = 17 (32.7%), to this past 2021-2022 season: n = 24 (46.2%). CONCLUSION: AATR surgeries seem to have increased in 2021 following a 2020 COVID pandemic-induced quarantine for recreational athletes at a single academic institution and for professional athletes in the NFL, although these results are of questionable clinical significance. This provides prognostic information when counseling patients and athletes on return to activity or sport. LEVEL OF EVIDENCE: Level IV.

Flexor Tendon Injuries in the Pediatric Population.

Flexor tendon injuries are rare in children, posing specific diagnostic and therapeutic challenges. This study aims to describe epidemiologic characteristics of flexor tendon injuries in children and evaluate the outcomes of surgical treatment. We conducted a retrospective study of patients with acute traumatic flexor tendon injuries treated between 2012 and 2019. We analyzed demographics, lesion mechanism, surgical technique, clinical results, complications, and secondary surgical procedures. Functional results were assessed through the Total Active Mobilization score. Twenty patients were included (n=34 tendons), with median follow-up of 7 months (range, 3-34 months) and median age at time of surgery of 13 years (range, 1-17 years). Male sex was predominant (n=16). The most prevalent injury mechanism was a cut (n=17), mostly affecting the 4th digit (n=10) and Verdan's zone II (n=13). Modified Kessler was the suture technique most commonly used (n=31), and polypropylene was the preferred suture material (n=19). All patients were immobilized with a splint for a median time of 4 weeks (range, 1-7 weeks). According to the Total Active Mobilization score, 15 patients reached a score greater than 75%, independently of age (P>.05). Stiffness was the main complication observed. Complications were identified in 37% of patients and were most common in those older than age 10 years (P>.05) and those with zone II lesions (P>.05). Four patients (20%) needed a second surgical intervention. Flexor tendon injuries in children are relatively uncommon and prevail in the male sex, similarly to the adult population. The principal complication observed was stiffness, which was more prevalent in children older than age 10 years, although without relevant functional implications, as surgical treatment enabled good or excellent outcomes in 75% of patients. [Orthopedics. 2023;46(2):82-85.].

The influence of the COVID pandemic on the epidemiology of Achilles tendon ruptures in east Shropshire, United Kingdom.

OBJECTIVES: Management strategies of the COVID pandemic included isolation to prevent transmission. This study aimed to determine if the pandemic of 2020 influenced the epidemiology of Achilles tendon rupture (ATR). METHODS: The demographics of presentations from the local population to Princess Royal Hospital, Shrewsbury & Telford Hospital NHS Trust hospital, Shropshire, United Kingdom, with an ATR were analysed and compared together with the season, month, and year of the injury. RESULTS: From 2009 to 2019, there was no significant change in the incidence of ATR over time with a mean (SD) incidence of 13.3 per 100,000. In 2020, there was a decrease in injuries with an incidence of 8.4 per 100,000, with an increase in 2021 to 22.4 per 100,000. In 2021, there was an increase in injuries from March with numbers maintained until October. The most common activity of ATR was team sport (36.2%), followed by the activities of daily living (28.9%), other physical activities (21.0%), and racket sports (13.9%). In 2020, there was the lowest number of injuries sustained in team and racket sports; however, in 2021, they accounted for over half of injuries. CONCLUSIONS: There were significantly more patients sustaining ATR in 2021, the year after the COVID pandemic and mandatory isolation. This was considered to be related to altered activity and team and racket sports during 2020. LEVELS OF EVIDENCE: IV case series.

Rates of Operative Management for Achilles Tendon Rupture Over the Last Decade and the Influence of Gender and Age.

BACKGROUND: With emerging evidence supporting functional rehabilitation for Achilles tendon ruptures (ATRs), this study sought to evaluate the treatment trends for patients sustaining an acute ATR and whether gender and age may influence the rates of operative repair. METHODS: A retrospective database review identified ATRs from 2010 through 2019. Patients were then stratified into three cohorts based on age (18-30, 30-45, and 46 and older), separated by gender, and then assessed whether patients were treated operatively or not. Cochran-Armitage Trend test was performed to analyze the trends of operative management. Chi-square analyses were performed to assess whether the proportion of patients who received operative management in each age cohort differed from 2010 to 2019. Logistic regression analyses were performed to assess whether gender influenced treatment. RESULTS: Over the previous decade, the total rates of operative treatment for ATR significantly decreased (18.3%-12.3%, P < .0001). Each individual age cohort experienced a proportional decrease in operative management when comparing 2010 with 2019 (all P < .0001). Within all age cohorts, males were significantly more likely to receive operative treatment for an ATR over the previous decade (odds ratios: 2.63-3.22). Conclusion. Overall rates of operative management for ATR decreased across all cohorts likely due to previous studies providing evidence of similar results between operative and nonoperative managements. Over the previous decade, males were demonstrated to be far more likely than females to undergo operative management. Why females are less likely to receive an operation for ATR is likely multi-factorial and requires further exploration. LEVEL OF EVIDENCE: Level III: Retrospective comparative study.

Incidence and clinical results of tendinous injuries in calcaneus and pilon fractures.

PURPOSE: The aims of this study were: (1) to define the incidence of tendinous injuries in calcaneus and pilon fractures with different fracture severity and (2) to determine the clinical impact of such injuries. STUDY DESIGN AND METHODS: CT-scans of 121 patients with calcaneus and pilon fractures were retrospectively analyzed over a 4-year period. The tendinous injuries were identified and correlated with the type of fracture (location and classification). Clinical analysis was performed using the American Orthopedic Foot and Ankle Society (AOFAS) and SF-36 (Short Form-36 Health Survey) scores. RESULTS: Tendinous injuries were observed in 36% of all CT-scans analyzed, with the most common injury being incarceration (n = 20) and dislocation (n = 24). Calcaneus fractures sanders type 3/4 were 9 times more prone to tendon injury (p < 0.001; OR 8.67; 95% CI 2.49-30.24). Pilon fractures Ruedi-Allgower type 2/3 were 8 times more prone to tendon injury (p = 0.005; OR 7.5; 95% CI 1.72-32.80). No significant differences (p > 0.05) were found in AOFAS and SF-36 scores between patients with/without tendon injuries for fractures with the same severity. CONCLUSION: The incidence of tendon injuries in calcaneus/pilon fractures is high and may be underreported. Calcaneus fractures are prone to peroneal tendon injury. In pilon fractures, it is important to look for tibialis posterior tendon injury, especially entrapment. The presence of tendinous injuries does not affect function and pain for the same type of calcaneus and pilon fractures at the long term. LEVEL OF EVIDENCE: Level 3 retrospective study.

Trends and epidemiology of knee extensor mechanism injuries presenting to United States emergency departments from 2001 to 2020.

OBJECTIVES: Injuries to the native extensor mechanism (EM) of the knee are potentially disabling and often require surgical treatment. Large-scale, updated epidemiological data on these injuries is lacking. The objective of the current study was to examine recent trends in EM injuries presenting to United States (US) Emergency Departments (EDs) over the last 20 years using a nationally representative sample. METHODS: This study retrospectively analyzed the National Electronic Injury Surveillance System (NEISS) database to identify cases of EM injuries (defined as either a quadriceps tendon rupture, a patella fracture, or a patellar tendon rupture) presenting to EDs in the US from 2001 to 2020. RESULTS: During the study period, an estimated 214,817 EM injuries occurred in an at-risk population of 6,183,899,410 person-years for an overall incidence rate of 3.47 per 100,000 person-years. Patella fractures (PFs) were the most common injury type, representing 77.5% of all EM injuries (overall incidence rate: 2.69), followed by patellar tendon ruptures (PTRs; 13.5%; incidence: 0.48) and quadriceps tendon ruptures (QTRs; 9%; incidence: 0.31). Demographic characteristics and mechanisms of injury differed between injury types. Annual incidence rates increased significantly during the study period for all EM injury types, with PTRs demonstrating the largest relative increase (average annual percent increase: PF, 2.8%; PTR, 7.2%; QTR, 5.3%). Accounting for population growth yielded an increasing incidence of all EM injuries combined from 3.65 in 2001 to 4.9 in 2020. The largest relative increases in incidence rates were observed in older age groups. CONCLUSION: Extensor mechanism injuries of the knee are increasing in the US, which likely reflects an aging and more active population. These types of injuries are associated with substantial functional impairment and recent increases in incidence rates highlight the need for injury prevention and management strategies.

Socioeconomic deprivation status predicts both the incidence and nature of Achilles tendon rupture.

PURPOSE: The aim of this study was to describe the epidemiology of Achilles tendon rupture (ATR) and its relationship with socioeconomic deprivation status (SEDS). The hypothesis was that ATR occurs more frequently in socioeconomically deprived patients. Secondary aims were to determine variations in circumstances of injury between more and less deprived patients. METHODS: A 6-year retrospective review of consecutive patients presenting with ATR was undertaken. The health-board population was defined using governmental population data and SEDS was defined using the Scottish Index of Multiple Deprivation. The primary outcome was an epidemiological description and comparison of incidence in more and less deprived cohorts. Secondary outcomes included reporting of the relationship between SEDS and patient and injury characteristics with univariate and binary logistic regression analyses. RESULTS: There were 783 patients (567 male; 216 female) with ATR. Mean incidence for adults (≥ 18 years) was 18.75/100,000 per year (range 16.56-23.57) and for all ages was 15.26/100,000 per year (range 13.51 to 19.07). Incidence in the least deprived population quintiles (4th and 5th quintiles; 18.07 per 100,000/year) was higher than that in the most deprived quintiles (1st and 2nd; 11.32/100,000 per year; OR 1.60, 95%CI 1.35-1.89; p < 0.001). When adjusting for confounding factors, least deprived patients were more likely to be > 50 years old (OR 1.97; 95%CI 1.24-3.12; p = 0.004), to sustain ATR playing sports (OR 1.72, 95%CI 1.11-2.67; p = 0.02) and in the spring (OR 1.65, 95%CI 1.01-2.70; p = 0.045) and to give a history of preceding tendinitis (OR 4.04, 95%CI 1.49-10.95; p = 0.006). They were less likely to sustain low-energy injuries (OR 0.44, 95%CI 0.23-0.87; p = 0.02) and to be obese (OR 0.25-0.41, 95%CI 0.07-0.90; p ≤ 0.03). CONCLUSIONS: The incidence of ATR was higher in less socioeconomically deprived populations and the hypothesis was therefore rejected. Significant variations in patient and predisposing factors, mechanisms of injury and seasonality were demonstrated between most and least deprived groups, suggesting that circumstances and nature of ATR may vary with SEDS and these are not a homogenous group of injuries. LEVEL OF EVIDENCE: Prognostic Study Level III.

Risk Factors of Flexor Tendon Rupture After ORIF of Distal Radius Fracture.

OBJECTIVES: To analyze the risk factors associated with postoperative flexor tendon rupture, after a volar plate fixation of distal radius fractures. DESIGN: Retrospective observational case-control study. SETTING: Tertiary Care University Hospital in the Republic of Korea (2009-2020). PATIENTS: Sixteen referred patients were treated for flexor tendon rupture, following previously performed volar plating of distal radius fractures at other institutions. 16 patients were randomly selected from our database as controls, and were matched based on the Soong grade of the case group. INTERVENTION: Not applicable. MAIN OUTCOME MEASUREMENTS: Radial tilt and radial height were measured on anteroposterior radiographs. The volar tilt, tear drop angle, carpal translation, and Soong grade were measured in a lateral view. RESULTS: Quantitative measurements of the volar tilt, carpal translation, and tear drop angle were positively correlated with the flexor tendon rupture. The mean volar tilt and tear drop angle in the tendon rupture group were significantly smaller than those in the control group. The mean carpal translation in the tendon rupture group was significantly greater than that in the control group. CONCLUSIONS: This study demonstrated that volar tilt, carpal translation, and tear drop angle are significant risk factors for flexor tendon rupture, especially for plates placed at Soong grade 1 or 2. We suggest that the potential for tendon rupture because of incomplete reduction of the distal radius fracture along with implant prominence volar to the watershed line aggravates flexor tendon irritation at the distal edge of the plate because of distorted flexor tendon paths. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Sex differences in patients' recovery following an acute Achilles tendon rupture - a large cohort study.

INTRODUCTION: The incidence of Achilles tendon ruptures (ATR) has increased over the past few decades. Treatment may be individualised based upon multiple factors including age, pre-injury activity level and the separation of the ruptured tendon ends. Several studies indicate that women may have a poorer self-reported and clinical outcome compared with men, but the number of women in these studies is often small due to the different incidence of ATR between the genders. AIMS: The primary aim of this study was to evaluate whether there is a difference in self-reported outcome after an acute ATR between women and men at one to five years following injury. The second aim was to compare the outcome between the surgically and non-surgically treated patients. METHODS: Data were obtained from the medical charts of patients treated for an acute ATR between 1 and 2015 and 31 December 2020 at Sahlgrenska University Hospital/Mölndal. The Achilles tendon total rupture score (ATRS) and additional questions relating to treatment and recovery were determined. A multiple regression analysis was performed to isolate the impact of sex when comparing the patient-reported outcome between women and men. RESULTS: A total of 856 patients were included of which 66% participated prospectively. Sex, BMI and age were found to be significant factors influencing the total ATRS score. Female gender resulted in a lower ATRS, 7.8 points (CI = 3.3 to 12.3), than male gender. It was found that treatment did not significantly predict the results of the ATRS. CONCLUSION: To our knowledge, this is the first report with a larger number of women included showing that female sex predicts inferior self-reported results after an acute ATR.

'Hook' Shape Lister Tubercle Is Associated with a Greater Incidence of Extensor Pollicis Longus Tendon Rupture after Distal Radius Fracture.

Background: A rupture of the extensor pollicis longus (EPL) tendon located close to the Lister tubercle is an uncommon complication of distal radius fractures. This study aimed to determine whether the size and shape of Lister tubercle in patients with EPL rupture differs from a matched group of patients with distal radius fractures without EPL rupture. Methods: We identified 15 patients with EPL rupture (3.5%) out of 426 with distal radius fractures treated conservatively at our hospital over 4 years. Out of the remaining 411 patients with distal radius fractures without EPL rupture, we selected patients using simple random sampling and pseudo-randomised them such that their age, sex and fracture type were matched with patients exhibiting EPL rupture. The size and shape of the Lister tubercle and the size of the EPL groove were measured in both groups using computed tomographic scans and compared. Results: There was no difference in the size of the Lister tubercle or the EPL groove between both groups. A 'hook'-shaped Lister tubercle was noted in 8 out of 15 patients with EPL rupture but in only 1 out of 15 matched patients without EPL rupture. Conclusions: A 'hook'-shaped Lister tubercle was seen more often in patients with EPL rupture following distal radius fracture. Level of Evidence: Level III (Therapeutic).