Demographics and medical burden of osteogenesis imperfecta: a nationwide database analysis.

The epidemiological data on osteogenesis imperfecta (OI) in Asia is limited. This study, representing the first comprehensive epidemiological investigation on OI in Taiwan, reveals high medical resource utilization and underscores the importance of early diagnosis to enhance care quality. INTRODUCTION: This study examines osteogenesis imperfecta, a hereditary connective tissue disorder causing pediatric fractures and limb deformities, using a nationwide database from Taiwan to analyze clinical features and medical burden. METHODS: The study identified validated OI patients from the Catastrophic Illness Registry in the National Health Insurance Research Database from 2008 to 2019. Demographic data and medical resource utilization were analyzed. A multivariate Cox model assessed the influence of sex, validation age, and comorbidities. RESULTS: 319 OI patients (M/F = 153/166) were identified, with 58% validated before age 20. Prevalence and incidence were 0.8-1.3/100,000 and 0.02-0.09/100,000, respectively, with higher rates in the pediatric demographic. In the study period, 69.6% of the patients had admission history, primarily to pediatric and orthopedic wards. The median admission number was 3, with a median length of stay of 12 days and a median inpatient cost of approximately 3,163 USD during the period. Lower limb fractures were the main reason for hospitalization. 57% of OI patients received bisphosphonate treatment. The leading causes of mortality were OI-related deaths, neurovascular disease, and cardiovascular disease. The median age of validation in the non-survival group was significantly higher compared to the survival group (33 vs. 14 years), and patients validated during childhood required more inpatient fracture surgeries than those validated during adulthood. CONCLUSION: This study provides comprehensive real-world evidence on the clinical characteristics and high medical resource utilization of OI patients in a low prevalence region like Taiwan. Early diagnosis is crucial for improving care quality and enhancing health outcomes.

Suture Contamination During Arthroscopic Rotator Cuff Repair Is Associated With Significantly Higher Retear Rates in Magnetic Resonance Imaging: A Matched-Pair Analysis.

PURPOSE: To evaluate the correlation between suture contamination and rotator cuff tendon retear after arthroscopic rotator cuff repair. METHODS: Patients undergoing primary arthroscopic rotator cuff repair from April 1, 2020, to September 30, 2022, were enrolled. Those younger than 18 years, with a history of shoulder surgeries or shoulder infection episodes, or who declined participation were excluded. A 5-cm section of the first-cut suture, originating from the anchor eyelet ends, in each rotator cuff repair surgery was subjected to bacteria culture and polymerase chain reaction analysis. Patients with positive culture findings were matched 1:1 to those with negative culture reports based on age, sex, tear size as well as involved tendons, preoperative fatty infiltration grade (Goutallier grade), and preoperative muscle atrophy grade (Warner score). Postoperative rotator cuff tendon retear assessments were conducted at the 6-month mark using the Sugaya classification via magnetic resonance imaging. The Wilcoxon signed-rank test was used for matched-pair comparisons between the groups. RESULTS: A total of 141 patients (60 men and 81 women) with a mean age of 61.0 ± 8 years were finally enrolled. Twenty-six patients (18 men and 8 women) had a positive culture, while 115 patients (42 men and 73 women) had a negative culture. After the propensity score matching process, 24 culture-negative patients (16 men and 8 women) were selected as the culture-negative group. Age, fatty infiltration grade, and muscle atrophy grade were not significantly different between matched groups. The retear grade in the culture-positive group was significantly higher than that in the culture-negative group (P = .020) under the matched-pair comparison. Cutibacterium acnes was the most prevalent bacterial species responsible for suture contamination. CONCLUSIONS: The matched-pair analysis revealed that the presence of bacterial contamination on sutures was associated with a higher risk of retear on magnetic resonance imaging following arthroscopic rotator cuff repair. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Biomechanical Comparisons of All-Suture Suspensory Button versus Interference Screw for Inlay Subpectoral Bicep tenodesis.

BACKGROUND: All-suture buttons (ASB) and interference screw (IS) are commonly utilized in the inlay subpectoral biceps tendon tenodesis. However, the biomechanical characteristics of these two methods have not been compared directly. The aim of present study was to compare the biomechanical properties of ASB versus IS for inlay subpectoral biceps tendon tenodesis in a human cadaveric model. METHODS: Sixteen fresh-frozen human cadaveric shoulders were randomly divided into two experimental inlay biceps tenodesis groups: ASB or IS. After tenodesis, every specimen was preloaded at 5 N for 2 minutes, followed with a cyclic loading test from 5 to 70 N for 500 load cycles. Then the load-to-failure test was performed. Afterwards, the humerus was placed in a cylinder tube and secured with anchoring cement. Lastly, a two-point bending test was performed to determine the strength of the humerus. Destructive axial force was applied, and the failure strength and displacement were recorded. RESULTS: No difference in stiffness was observed between the two groups (ASB=27.4 ± 3.5 N/mm vs IS= 29.7 ± 3.0 N/mm; P=.270). Cyclic displacement was significantly greater in the ASB group (6.8 ± 2.6 mm) than the IS group (3.8 ± 1.1 mm; P=.021). In terms of failure load, there were no statistical differences among the two groups (P=.234). The ASB group was able to withstand significantly greater displacement (11.9 ± 1.6 mm) before failure than the IS group (7.8 ± 1.5mm; P=.001). During the humeral bending test, the ASB group exhibited significantly greater maximal load (2354.8 ± 285.1 N vs 2086.4 ± 296.1 N; P=.046) and larger displacement (17.8 ± 2.8mm vs 14.1± 2.8 mm; P=.027) before fracture. CONCLUSIONS: In inlay subpectoral bicep tenodesis, ASB fixation appears to offer comparable stiffness and failure load to that of IS fixation. Additionally, the ASB group exhibited greater resistance to load and displacement before humeral fracture. However, the ASB group did demonstrate increased cyclic displacement compared to IS group.

Factors association with reparability of rotator cuff tears: A systematic review and meta-analysis.

PURPOSE: To identify and quantify the factors associated with the reparability of rotator cuff tears (RCTs). METHODS: PubMed, Scopus, and Web of Science databases were searched for clinical studies published in English focusing on RCT reparability by using the keywords "rotator cuff tear" and "reparability". A meta-analysis was conducted if ≥3 studies examined the same factor and provided enough data to assess RCT reparability. Quality assessment was completed using the QUADAS-2 tool. RESULTS: Eighteen studies (2700 patients) were enrolled, and 26 factors were included in the meta-analysis. The dichotomous variables associated with irreparability were Patte stage 3 (Odds ratio (OR): 8.0, 95% CI: 4.3-14.9), massive tear versus large tear (OR: 3.1, 95% CI: 1.3-7.2), Goutallier stage for each tendon, and tangent sign (OR: 11.1, 95% CI: 4.3-28.4). The continuous variables associated with irreparability were age (Mean difference (MD): 3.25, 95% CI: 1.4-5.1), mediolateral tear size (MD: 12.3, 95% CI: 5.8-18.9), anteroposterior tear size (MD: 10.4, 95% CI: 5.2-15.6), acromiohumeral distance on X-ray (MD: -2.3, 95% CI: -3.0 to -1.6) and magnetic resonance imaging (MD: -1.8, 95% CI: -2.8 to -0.9), and inferior glenohumeral distance on MRI (MD: 2.2, 95% CI: 1.4-3.0). CONCLUSION: This study revealed that older age, larger tear size, severe fatty infiltration, muscle atrophy, and advanced superior migration of the humeral head were strongly associated with irreparable RCTs. Conversely, clinical symptoms provided limited information for predicting reparability. Additionally, the tangent sign emerged as a powerful and simple tool for individual prediction, and several quantitative scoring systems also proved useful.

Extended skin cleaning on the shoulder with chlorhexidine reduces the cutaneous bacterial load but fails to decrease suture contamination in patients undergoing arthroscopy rotator cuff repair.

BACKGROUND: It remains unclear whether preoperative skin cleaning of the chin, neck, and chest with chlorhexidine soap can reduce suture contamination by Cutibacterium acnes in patients undergoing arthroscopic rotator cuff repair. METHODS: This study included patients who underwent primary arthroscopic rotator cuff repair. Exclusion criteria included age <18 years, previous shoulder surgery, history of shoulder infection, and allergy to chlorhexidine. Patients were randomized into 3 groups. Patients in the control group cleaned their skin with soap and water, as usual. Patients in the shoulder group cleaned their shoulders with chlorhexidine soap 3 days before surgery, whereas patients in the extended shoulder group additionally cleaned their chest, back, neck, and face with chlorhexidine soap. On the day of surgery, skin swab samples were obtained from the shoulder after surgical draping. After rotator cuff repair, sutures were cut from the anchor ends. Both traditional culture methods and polymerase chain reaction (PCR) were used. RESULTS: Ninety patients were enrolled (32 in the control group, 29 in the shoulder group, and 29 in the extended shoulder group) in the present study. The culture-positive rate from the posterior shoulder skin samples in the extended shoulder group (17.2%) was significantly lower than that in the control (40.6%) and shoulder (48.3%) groups (P = .036), whereas the culture-positive rates were not different among the 3 groups in other skin samples as well as the suture samples. The detection rates of C acnes in suture samples were 12.5%, 13.8%, and 17.2% in the control, shoulder, and extended shoulder groups, respectively (P = .603). CONCLUSION: Extensive skin cleaning of the shoulder region with chlorhexidine helps reduce the shoulder cutaneous bacterial load, but the detection of C acnes suture contamination in patients undergoing arthroscopic rotator cuff repair remained untouched regardless of the use of chlorhexidine soap in skin cleaning on the preoperative days.

Jigless Knotless Internal Brace Versus Other Minimal Invasive Achilles Tendon Repair Techniques in Biomechanical Testing Simulating the Progressive Rehabilitation Protocol.

The jigless knotless internal brace surgery (JKIB), an alternative method for minimal invasive surgery (MIS) repair of acute Achilles tendon rupture, has advantages of preventing sural-nerve injury in MIS and superficial wound infection in open surgery, as previous clinical research demonstrates. However, no comparative study on the biomechanical performance between JKIB and other MIS techniques has been reported until now. In this study, 50 fresh porcine Achilles tendons were used to compare the JKIB with open surgery (two-stranded Krachow suture) with other MIS techniques, including Percutaneus Achilles Repair System (PARS), Speedbridge (SB), and Achillon Achilles Tendon Suture System (ACH), using a biomechanical testing with cyclic loading at 1 Hz. This test was used to simulate a progressive rehabilitation protocol where 20 to 100 N was applied in the first 250 cycles, followed by 20 to 190 N in the second 250 cycles, and then 20 to 369 N in the third 250 cycles. The cyclic displacement after 10, 100 and 250 cycles were recorded. The survived cycles were defined as a sudden drop in measured load. In survived cycles, the JKIB group (552.3 ± 72.8) had significantly higher cycles than the open, PARS, and ACH groups (204.3 ± 33.3, 395.9 ± 96.0, and 397.1 ± 80.9, respectively, p < .01) as analyzed by post hoc analysis, but no significant difference as compared with the SB group (641.6 ± 48.7). In cyclic displacement after 250 cyclic loadings, the JKIB group (11.29 ± 1.29) showed no significant difference as compared with PARS, SB, and ACH groups (12.21 ± 1.18, 9.80 ± 0.80, and 11.57 ± 1.10 mm, respectively) and significant less displacement than the open group (14.50 ± 1.85, p < .01). These findings suggest that JKIB could be an option for acute Achilles tendon repair in the MIS fashion due to no larger cyclic elongation compared with other MIS techniques.

The characteristics and influence of iatrogenic fracture comminution following antegrade interlocking nailing for simple femoral shaft fractures, a retrospective cohort study.

AIM: The incidence and characteristics of iatrogenic comminution (IC) are unknown, and the influence of IC on fracture union is unclear. This study was aimed to investigate the (1) incidence and characteristics of IC and (2) the outcomes of IC following antegrade interlocking nailing of simple femoral shaft fractures. METHODS: We retrospectively collected data on patients who experienced simple femoral shaft fractures and underwent antegrade interlocking nailing between February 2009 and December 2016. The incidence and characteristics of IC were examined. According to the presence of IC, patients were divided into two groups: an IC group and a non-IC (NIC) group. Demographic information and nonunion rates were compared between the two groups. Potential risk factors for IC (age, gender, body mass index (BMI), nail fit ratio, reduction technique, and greater trochanter nail entry) were analyzed using univariate and multivariate logistic regression. The aforementioned variables, along with IC occurrence, were also assessed as potential risk factors for nonunion at 12 and 24 months after operation using multivariate logistic regression. RESULTS: Of the 211 total patients, IC occurred in 20.9% (n = 44) of patients. Most ICs were found at the level of the isthmus, and involved the medial cortex. Compared with the NIC group, higher nonunion rates were observed in the IC group at 12 months (31.8% vs. 12.5%, p = 0.002) and 24 months (18% vs. 6.5%, p = 0.017) after surgery. Age older than 35 years old was related with the occurrence of IC in univariate analysis. Multivariate analysis found no risk factor associated with IC. Open reduction technique, IC occurrence and higher BMI were identified as the risk factors of nonunion at 12 months and 24 months after surgery in multivariate analysis. CONCLUSION: IC is a non-rare complication in antegrade interlocking nailing of simple femoral shaft fractures and was associated with higher nonunion rate. Age older than 35 years old showed a trend toward increasing risk of iatrogenic fracture comminution. In multivariate analysis, open reduction technique, IC occurrence and higher BMI significantly correlated with fracture nonunion. LEVEL OF EVIDENCE: Level IV.

The lateral femoral notch sign and coronal lateral collateral ligament sign in magnetic resonance imaging failed to predict dynamic anterior tibial laxity.

PURPOSE: To investigate the relationship between the lateral femoral notch sign as well as the coronal lateral collateral ligament (LCL) sign and anterior tibial translation using the GNRB arthrometer in patients with anterior cruciate ligament (ACL) injuries. METHODS: Forty-six patients with ACL injuries were retrospectively included from May 2020 to February 2022; four patients were excluded due to incomplete data. Magnetic resonance imaging (MRI) were reviewed for the lateral femoral notch sign and the coronal LCL sign. The GNRB arthrometer was used to evaluate the dynamic anterior tibial translation of the knee, and the side-to-side differences (SSDs) in tibial translation between the injured knee and healthy knee were calculated at different force levels. Two types of slopes for displacement-force curves were acquired. RESULTS: Six patients (14.3%) had the positive lateral femoral notch sign (notch depth > 2.0 mm), and 14 patients (33.3%) had the positive coronal LCL sign. The SSD of the anterior tibial translations under different loads as well as the slopes of displacement-force curves were the same in the positive and negative notch sign groups (p all > 0.05) and between the positive and negative coronal LCL sign groups (p all > 0.05). Meanwhile, the measured notch depth and notch length were also not significantly correlated with the anterior tibial translation SSD in the GNRB. CONCLUSION: The presence of the lateral femoral notch sign and the coronal LCL sign did not indicate greater dynamic tibial laxity as measured using the GNRB.

Editorial Commentary: All-Suture Anchor for Shoulder Biceps Tenodesis Results in Excellent Outcomes.

Patients have a strong preference for biceps tenodesis rather than a tenotomy in both Eastern and Western countries, regardless of age, and the annual number of biceps tenodeses has significantly increased in recent years. Previous studies have supported the use of suture anchors in biceps tenodesis. All-suture anchors are also a viable option because of their comparable biomechanical properties and the lower risk of humerus fractures. Recent research has evaluated the clinical outcomes after subpectoral biceps tenodesis using all-suture anchors. Encouragingly, satisfactory clinical outcomes have been reported, making this technique more attractive in clinical practice.

Owen, Sugaya, and Hayashida Classifications Give Poor Intra- and Inter-Rater Agreement on a Magnetic Resonance Imaging Evaluation of Subscapularis Tendon Retears.

PURPOSE: To investigate the intra- and inter-rater agreements for magnetic resonance imaging (MRI) evaluations of subscapularis tendon integrity at 6 months after arthroscopic rotator cuff repairs. METHODS: Patients who had isolated or combined subscapularis tears and had undergone arthroscopic rotator cuff repairs were retrospectively included. The exclusion criteria included revision of arthroscopic surgery, minor subscapularis tears without repair, and inadequate postoperative images. MRI scans 6 months after surgery were used for the purpose of accessing the integrity of the subscapularis tendons. Three orthopaedic surgeons blindly evaluated the images twice at 2-week intervals. Three currently available classifications were used: the Owen classification, the Sugaya classification, and the Hayashida classification. Dichotomization and trichotomization methods were used for the Sugaya classification and Hayashida classifications. The aforementioned classification scores were combined for the agreement evaluation. Intra- and inter-rater agreement was assessed by calculating the Fleiss' kappa coefficients. RESULTS: A total of 35 patients were included. Both the Owen and Hayashida classifications had poor inter-rater agreements (κ = 0.10 and 0.04, respectively) and poor-to-weak intra-rater agreements (κ = 0.27-0.44 and 0.16-0.45, respectively). The Sugaya classification had poor inter-rater agreement (κ = 0.10) and poor intra-rater agreements (κ = 0.16-0.32). Dichotomization and trichotomization of Sugaya and Hayashida classifications did not lead to superior agreements. The classification combination resulted in poor inter- and intra-rater agreements (κ = 0.01-0.12 and 0.08-0.39, respectively). CONCLUSIONS: The Owen classification, Sugaya classification, and Hayashida classification had poor intra- and inter-rater agreement in terms of evaluating subscapularis tendon re-tears on 6 months' postoperative MRI. The dichotomized and trichotomized classifications as well as the combined classifications from currently available classifications did not lead to superior agreements. LEVEL OF EVIDENCE: Level IV, diagnostic: case series.

The coronal lateral collateral ligament sign in the anterior cruciate ligament-injured knees was observed regardless of the knee laxity based on the quantitative measurements.

PURPOSE: The coronal lateral collateral ligament (LCL) sign has been reported to be associated with deviated position of the tibia on MRI due to anterior cruciate ligament (ACL) injuries. However, the relationships between LCL sign and clinical knee laxity evaluations are still unclear. The purpose of the study was to investigate the relationship between the coronal LCL sign and knee laxity measurements. METHODS: A retrospective review of unilateral ACL injured patients who underwent ACL reconstruction was performed. The coronal LCL sign was determined using magnetic resonance imaging (MRI). Clinical grading of the pivot-shift test, KT-1000 measurements, and quantitative measurements of the Lachman test and the pivot-shift test using an electromagnetic system, were compared between patients with positive and negative coronal LCL sign. A subgroup analysis of different age groups was then performed, dividing patients to adolescent (age ≤ 18 years) and adult (age > 18 years) groups. RESULTS: A total of 85 patients were enrolled, of which 45 patients had coronal LCL signs. The coronal LCL sign was not associated with the pivot-shift test clinical grading (n.s), KT-1000 measurement (n.s), the tibial translation during the Lachman test (n.s), or with tibia acceleration (n.s) and translation (n.s) during the pivot-shift test. The subgroup analysis also showed that the aforementioned parameters were not associated with the coronal LCL sign in either adolescent or adult subgroups. CONCLUSION: The occurrence of coronal LCL sign in MRI did not imply greater clinical knee laxity evaluations in patients with ACL tears. The knee laxity should routinely be evaluated regardless the coronal LCL sign. LEVEL OF EVIDENCE: Level III.

Biomechanical comparison between various screw fixation angles for Latarjet procedure: a cadaveric biomechanical study.

BACKGROUND: The Latarjet procedure is a reliable treatment for the management of anterior glenohumeral instability with glenoid bone loss. However, the biomechanical properties of different fixation angles between screw and glenoid surface (α angle) have rarely been studied. The aim of the study was to investigate and compare the fixation stability, failure load, and failure mechanism between different α angles for Latarjet procedures, which were performed on cadaver specimens. METHODS: Twenty-four shoulder specimens (8 in each of 3 groups) were dissected free of all soft tissue, and a 25% glenoid defect was created. The coracoid process was osteomized and fixed with 2 screws at 3 different α angles: 0° (group A), 15° (group B), and 30° (group C). Specimens were mounted to a testing apparatus, and cyclic loading (100 cycles at 1 Hz) was applied with a staircase protocol (50, 100, 150, and 200 N). Gross graft displacement and interface displacement were measured. The ultimate failure loads and failure mechanisms were recorded. RESULTS: There was no significant difference in gross displacement under any cyclic load between 3 groups. However, a significant larger interface displacement was noted in group C than in group A in 150-N cyclic loading (P = .017). Under failure strength testing, all 24 specimens failed because of screw cutout from the glenoid, and the ultimate failure load was similar among the three groups. CONCLUSION: Compared with the 0° α angle, the displacement after cyclic loading did not significantly increase when the α angle was increased to 15° but significantly increased at 30° for Latarjet procedures, which were performed on cadaver specimens. The results suggest that surgeons should apply the screws as parallel as possible to the glenoid surface when performing the Latarjet procedure. Although mild deviation may not reduce fixation stability, α angles greater than 30° should be avoided.

Biomechanical comparisons of hook plate and screw fixations in split-type greater tuberosity fractures of the humerus.

BACKGROUND: Screws and plate are commonly utilized for the fixation of split-type humeral greater tuberosity (GT) fractures. However, the mechanical properties of these 2 types of fixation methods have not been compared directly. The aim of the present study was to evaluate the classic 2 screws fixation with hook locking plate from a mechanical perspective. METHODS: Sixteen synthetic humerii (Sawbones Pacific Research Laboratories, Vashon, WA, USA) were divided into 2 groups. An osteotomy was performed to simulate a split-type GT fracture. Group A (n = 8) was fixed with 2 standard parallel screws. Group B (n = 8) was fixed with a hook plate. Each specimen was tested with traction force at 45° shoulder abduction. Following the 20-N preload, a 500-cycle loading test was applied with a force ranging from 20 to 200 N (valley/peak), and the interfragmental displacement was measured periodically at intervals of 100 cycles. Finally, all the specimens were pulled with destructive force at a rate of 5 mm/min until catastrophic failure. RESULTS: The hook plate exhibited greater construct stiffness than the screw fixation (63.2 ± 6.1 N/mm vs. 40.9 ± 3.4 N/mm, P < .001). All of the specimens completed the entire cyclic loading test without catastrophic failure, and the fragment displacement after 500 cycles was 0.4 ± 0.2 mm for the hook plate and 2.1 ± 0.3 mm for screw fixation, which was statistically lower in the plate group (P < .001). In terms of failure load, the hook plate group exhibited a significantly greater value than the screw group (770.6 ± 94.6 vs. 427.5 ± 45.1 N/mm, P < .001). The failure modes of both fixation methods were distinct. CONCLUSION: In humeral GT fracture fixation, hook plate fixation appears to offer greater construct stiffness and failure load while maintaining fragment stability to resist a physiological traction force. The current study provides support from a mechanical perspective for the clinical application of the hook plate.

Augmented cerclage wire improves the fixation strength of a two-screw construct for humerus split type greater tuberosity fracture: a biomechanical study.

BACKGROUND: Poor functional outcome can result from humeral greater tuberosity (GT) fracture if not treated appropriately. A two-screw construct is commonly used for the surgical treatment of such injury. However, loss of reduction is still a major concern after surgery. To improve the biomechanical strength of screw fixation in GT fractures, we made a simple modification of the two-screw construct by adding a cerclage wire to the two-screw construct. The purpose of this biomechanical study was to analyze the effect of this modification for the fixation of GT fractures. MATERIALS AND METHODS: Sixteen fresh-frozen human cadaveric shoulders were used in this study. The fracture models were arbitrarily assigned to one of two fixation methods. Group A (n = 8) was fixed with two threaded cancellous screws with washers. In group B (n = 8), all screws were set using methods identical to group A, with the addition of a cerclage wire. Horizontal traction was applied via a stainless steel cable fixed directly to the myotendinous junction of the supraspinatus muscle. Displacement of the fracture fixation under a pulling force of 100 N/200 N and loading force to construct failure were measured. RESULTS: The mean displacements under 100 N and 200 N traction force were both significantly decreased in group B than in group A. (100 N: 1.06 ± 0.12 mm vs. 2.26 ± 0.24 mm, p < 0.001; 200 N: 2.21 ± 0.25 mm vs. 4.94 ± 0.30 mm, p < 0.001) Moreover, the failure load was significantly higher in group B compared with group A. (415 ± 52 N vs.335 ± 47 N, p = 0.01), CONCLUSIONS: The current biomechanical cadaveric study demonstrated that the two-screw fixation construct augmented with a cerclage wire has higher mechanical performance than the conventional two-screw configuration for the fixation of humeral GT fractures. TRIAL REGISTRATION: Retrospectively registered.

Does posterior configuration have similar strength as parallel configuration for treating comminuted distal humerus fractures? A cadaveric biomechanical study.

BACKGROUND: The posterior plating technique could be used as a clinical alternative to parallel plating for treating comminuted distal humerus fractures (DHFs) successfully with good clinical results. However, the biomechanical characteristics for posterior fixation are still unclear. The purpose of this study is to evaluate the biomechanical properties of the posterior fixation and to make comparisons between the parallel and the posterior fixation systems. MATERIALS AND METHODS: We performed a cadaveric biomechanical testing with two posterior plating systems (a posterior two plating and a single posterior pre-contoured Y plating system) and one parallel two plating system to treat AO/OTA type-C2.3 DHFs. Among three groups, we compared construct stiffness, failure strength, and intercondylar width changes after 5000-cycle fatigue loading and failure loads and failure modes after destructive tests in both the axial compression and (sagittal) posterior bending directions. The correlations between construct failure loads and bone marrow density (BMD) were also compared. RESULTS: In axial direction, there were no significant differences in the stiffness and failure load between the posterior and the parallel constructs. However, in sagittal direction, the two-plate groups (posterior two plating and parallel plating group) had significant higher stiffness and failure loads than the one-plate group (single posterior Y plating). There was no fixation failure after 5000-cyclic loading in both directions for all groups. Positive correlation was noted between BMD and failure loads on parallel fixation. CONCLUSIONS: We found that when using two plates for treating comminuted DHFs, there were no significant differences in terms of most biomechanical measurements between posterior and parallel fixation. However, the single pre-contoured posterior Y plate construct was biomechanically weaker in the sagittal plane than the parallel and the posterior two-plate constructs, although there was no fixation failure after the fatigue test for all groups regardless of the fixation methods. LEVEL OF EVIDENCE: Biomechanical study.

The Chinese version of the American shoulder and elbow surgeons standardized shoulder assessment form questionnaire, patient self-report section: a cross-cultural adaptation and validation study.

BACKGROUND: The patient self-report section of the American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASESp) is one of the most validated and reliable assessment tools. This study aimed to establish a validated Chinese version of ASESp (ASESp-CH). METHODS: A clinical prospective study was performed (ClinicalTrials.gov Identifier: NCT04755049; registered on 2021/02/11). Following the guidelines of forward-backward translation and cross-cultural adaptation, a Chinese version of ASESp was established. Patients older than 18 years with shoulder disorders were included. Patients who could not complete test-retest questionnaires within the interval of 7-30 days and patients who received interventions were excluded. Intraclass correlation (ICC) was calculated for test- retest reliability, whereas internal consistency was determined by Cronbach value. Construct validity was evaluated by comparing the corresponding domains between the ASESp-CH and a validated Chinese version of 36-Item Short Form Health Survey (SF-36). RESULTS: A total of 86 patients were included with a mean test-retest interval of 12 ± 5.4 days. Test-retest reliability was excellent with an ICC of 0.94. Good internal consistency was found, with a Cronbach alpha of 0.86. Construct validity of the ASESp-CH questionnaire was good. The major domains of the ASESp-CH were significantly correlated with the respective domains in the SF-36 (p <  0.01), except for the domain of stability of ASESp-CH. CONCLUSIONS: The Chinese version of ASESp questionnaire is a highly validated and reliable tool for shoulder disorder assessment.

Jigless knotless internal brace versus other open Achilles tendon repairs using a progressive rehabilitation protocol: a biomechanical study.

BACKGROUND: The jigless knotless internal brace surgery (JKIB), a modified minimal invasive surgery (MIS) for acute Achilles tendon injury, has advantages of preventing sural-nerve injury in MIS and superficial wound infection in open surgery, as demonstrated in previous clinical research. However, to date, biomechanical testing has not yet been validated. MATERIALS AND METHODS: Sixty fresh porcine Achilles tendons were used to compare the JKIB with other open surgery techniques, the four-stranded Krackow suture (4sK) and the triple-bundle suture (TBS) in biomechanical testing with cyclic loading set at 1 Hz. This approach simulated a progressive rehabilitation protocol where 20-100 N was applied in the first 1000 cycles, followed by 20-190 N in the second 1000 cycles, and then 20-369 N in the third 1000 cycles. The cycles leading to repair gaps of 2 mm, 5 mm, and 10 mm were recorded. The survival cycles were defined as repair gap of 10 mm. RESULTS: With respect to survival cycles, a significant difference was found among the three groups, in which the TBS was the most robust, followed by the JKIB and the 4sK, where the mean survived cycles were 2639.3 +/- 263.55, 2073.6 +/- 319.92, and 1425.25 +/- 268.96, respectively. Significant differences were verified via a post hoc analysis with the Mann-Whitney U test after the Bonferroni correction (p < 0.017). CONCLUSIONS: The TBS was the strongest suture structure in acute Achilles tendon repair. However, the JKIB could be an option in acute Achilles tendon repair with the MIS technique due to it being more robust than the 4sK, which has been typically favored for use in open repair.

A biomechanical comparison of two screw fixation methods in a Letenneur type I Hoffa fracture.

BACKGROUND: The treatment of Hoffa fractures is challenging, for which the ideal fixation and approach are still controversial. Osteosynthesis with plate or screws fixation in different trajectories have been described in previous literature. The purpose of this study was to compare the biomechanical strength and stability of two types of screw trajectories used to stabilize displaced coronal fractures of the lateral femoral condyle. METHODS: Sixteen synthetic femurs (Sawbones Pacific Research Laboratories, Vashon, WA) were divided into two groups. A vertical osteotomy was performed to mimic a Letenneur type I Hoffa fracture. Group A (n = 8) was fixed with screw in anteroposterior direction (A-P) screws. Group B (n = 8) was fixed with crossed screws. Both groups were tested with a nondestructive axial compression aligned with the femur axis. After that, 10,000 cyclic loading tests were applied to the specimen with a force ranging between 200 to 600 N, and the interfragmental displacement was recorded, respectively, after 10, 100, 1000 and 10,000 cycles. Finally, a destructive axial compression test was applied until catastrophic failure. RESULTS: There were no statistical between-group differences in regard to the average axial stiffness, interfragmental displacement, and ultimate failure load. The average axial stiffness of the A-P screw was comparable to that of the crossed screw (361 ± 113 N/mm vs. 379 ± 65 N/mm, p = 0.753). All specimens completed the entire cyclic loading test without catastrophic failure, and the interfragmental displacement after loading for 10,000 cycles was 1.36 ± 0.40 mm for the A-P screw and 1.29 ± 0.61 mm for the crossed screw, there were no statistical differences between the groups (p = 0.823). The average ultimate failure loads for the A-P and crossed screws were 1214 ± 127 N and 1109 ± 156 N, respectively (p = 0.172). CONCLUSIONS: Based on our in vitro study, the crossed screws can provide comparable mechanical performance as traditional A-P screws in Hoffa fracture fixation. Considering the screws trajectories are commonly determined by the choice of surgical approach, the current study provides support from a biomechanical perspective for the application of crossed screws in direct lateral approach.

Unstable intertrochanteric fractures are associated with a greater hemoglobin drop during the perioperative period: a retrospective case control study.

BACKGROUND: With an increase in the elderly population, the occurrence of hip fractures, femoral neck fractures, and intertrochanteric fractures (ITFs) is also increasing. It is important to establish effective perioperative methods that would help reduce the morbidity and mortality rates associated with ITFs. The purpose of this study was to determine the effects of ITFs according to the AO classification for perioperative hemoglobin drop. METHODS: Seventy-six patients with ITFs classified as AO 31-A1 or A2 and fixated with intramedullary nails participated in this retrospective cohort study. Medical records of these patients were retrospectively reviewed from September 2016 to August 2018. The perioperative hemoglobin drop was chosen as the main outcome measure and calculated as the difference between pre- and postoperative hemoglobin levels. Multivariate linear regression analysis was performed and included the following variables: AO classification (A1.1-A2.1 [stable] vs. A2.2-A2.3 [unstable]), time interval between injury and surgery, age, body mass index, and the use of anticoagulants. RESULTS: Among the 76 patients who met the inclusion criteria, a significantly higher hemoglobin drop was observed in the AO 31 A2.2-A2.3 (unstable) group than in the AO 31 A1.1-A2.1 (stable) group (p = 0.04). The multivariate analysis also showed a greater hemoglobin drop in the unstable group (p < 0.05). CONCLUSIONS: Patients with unstable ITFs exhibited a greater hemoglobin drop and a hidden blood loss was suspected around the fracture site. We believe that this should be taken into consideration when presurgical blood transfusion is being planned for patients with unstable ITFs, to reduce associated postoperative complications, especially in patients with severe anemia or high risk of mortality.

The Double Krackow Suture Technique Does Not Offer a Significant Benefit Compared to the Krackow Suture Technique in Subpectoral Biceps Tenodesis Using a Double-Loaded Suture Anchor.

PURPOSE: To compare the biomechanical properties of the double simple suture (DSS) technique, Krackow suture (KS) technique, and double Krackow suture (DKS) technique in subpectoral biceps tenodesis using a double-loaded suture anchor in a porcine tendon model. METHODS: A total of 30 artificial composite (polymer and glass fiber) humeri and porcine flexor profundus tendons with diameter of 4.5 mm were used. The sample size was determined based on the results of the pilot study. Metallic suture anchors with double-loaded No. 2 braided sutures were inserted at the subpectoral tenodesis site, 5 cm from the superomedial corner of the greater tuberosity. Three suture techniques were used to fix the tendons: a DSS used as the control, a KS, and a DKS, which is an alternative tendon graft fixation technique. A preload of 5 N was applied for 2 minutes, followed by cyclic loading for 500 cycles ranging from 5 to 70 N; next, a load-to-failure test at 1 mm/s was performed. RESULTS: The KS (283.5 ± 57 N) and DKS (270.4 ± 50 N) groups had significantly greater ultimate failure loads as compared with the DSS group (84.1 ± 6.4 N) (P < .001). Meanwhile, the peak displacement at failure loads in the KS group (9.3 ± 2.2 mm) and DKS group (7.8 ± 1.7 mm) were significantly smaller than that of the DSS group (11.3 ± 2.9 mm) (P = .015). Stiffness in the DSS group (36.4 ± 3.0 N/mm), KS group (39.6 ± 2.5 N/mm), and DKS group (36.9 ± 4.6 N/mm) was not significantly different (P = .125). All DSS constructs and 6 KS constructs failed with tendons being cut through by the sutures, whereas the other 4 KS constructs and all DKS constructs failed resulting from suture breakage. CONCLUSIONS: In this subpectoral biceps tenodesis model, both the KS technique and the DKS technique had similar time 0 biomechanical properties that were better than those of the double simple suture technique. CLINICAL RELEVANCE: A sturdy suture-tendon structure could prevent clinical failure of a subpectoral biceps tenodesis using a suture anchor.