Conservative Versus Operative Treatment of Proximal Humerus Fractures in Older Individuals­an Analysis of Insurance Data.

BACKGROUND: Little is known about the frequency and results of conservative treatment of proximal humerus fractures in older individuals. METHODS: Billing data of the BARMER health insurance carrier for all patients of age 65 and above with proximal humerus fractures in the years 2005-2021 were retrospectively analyzed with multivariable Cox regression models, taking account of the patients' age, sex, and comorbidity profiles. The defined primary endpoints were overall survival (OS), major adverse events (MAE), thromboembolic events (TE), and complications of surgery or of trauma. Multivariable p values for the effect of treatment on all primary endpoints were jointly adjusted with the Bonferroni-Holm method. RESULTS: 54% of 81 909 patients were treated conservatively. Conservative treatment was more common in those who received their diagnosis as outpatients (79.5%, vs. 37.2% for inpatients). Operative treatment was associated with significantly longer overall survival (long-term HR 0.89, 95% confidence interval [0,86; 0,91]) and fewer MAE (0.90; [0.88; 0.92]) and TE (0.89; [0.87; 0.92]), but more complications due to surgery or trauma (1.66; [1,.4; 1.78]; all p < 0.001). 3.1% of the patients who had been initially treated conservatively underwent surgery within 6 months of their diagnosis. Risk factors for the failure of conservative treatment included alcohol abuse, obesity, cancer, diabetes mellitus, Parkinson disease, and osteoporosis. CONCLUSION: The conservative treatment of proximal humerus fracture is associated with a lower overall rate of complications due to surgery or trauma, but also with more MAE and TE and higher overall mortality. These findings underline the need for individualized and risk-adjusted treatment recommendations.

[Satisfaction with continuing education at a level 1 trauma center-Results of a survey and development of a competency-based continuing education concept]. / Zufriedenheit mit der Weiterbildung an einem Level-I-Traumazentrum ­ Ergebnisse einer Umfrage und Entwicklung eines kompetenzbasierten Weiterbildungskonzeptes.

BACKGROUND: Structured competency-based training is one of the most frequently articulated wishes of residents. METHODS: A survey of 19 residents was conducted regarding their satisfaction with the resident education at a level 1 trauma center. In this article the development of a revised competency-based education concept was carried out. RESULTS: The survey reflected uncertainty as to whether the current structures could meet the requirements of the residency regulations. The improved competency-based education concept consists of clinical mentoring, competency-based catalogs of learning objectives, regular theoretical and practical workshops as well as regular and structured staff evaluations. CONCLUSION: The education concept presented reflects the attempt to establish a contemporary surgical training program which will be evaluated as it progresses.

The Long Head of the Biceps Has a Stabilizing Effect on the Glenohumeral Joint in Simulated Infraspinatus or Subscapularis but Not Supraspinatus Rotator Cuff Deficiency: A Biomechanical Study.

PURPOSE: To investigate the stabilizing role of the long head of the biceps (LHB) for different simulated rotator cuff (RC) tears. METHODS: Human cadaveric specimens (n = 8) were fixed in a robotic-based experimental setup with a static loading of the RC, deltoid, and the LHB. RC tears were simulated by unloading of the corresponding muscles. A throwing motion and an anterior load-and-shift test were simulated under different RC conditions by unloading the supraspinatus (SS), subscapularis (SSc), infraspinatus (IS), and combinations (SS + SSc, SS + IS, SS + SSc + IS). The LHB was tested in 3 conditions: unloaded, loaded, and tenotomy. Translation of the humeral head and anterior forces depending on loading of the RC and the LHB was captured. RESULTS: Loading of LHB produced no significant changes in anterior force or glenohumeral translation for the intact RC or a simulated SS tear. However, if SSc or IS were unloaded, LHB loading resulted in a significant increase of anterior force ranging from 3.9 N (P = .013, SSc unloaded) to 5.2 N (P = .001, simulated massive tear) and glenohumeral translation ranging from 2.4 mm (P = .0078, SSc unloaded) to 7.4 mm (P = .0078, simulated massive tear) compared to the unloaded LHB. Tenotomy of the LHB led to a significant increase in glenohumeral translation compared to the unloaded LHB in case of combined SS + SSc (2.6 mm, P = .0391) and simulated massive tears of all SS + SSc + IS (4.6 mm, P = .0078). Highest translation was observed in simulated massive tears between loaded LHB and tenotomy (8.1 mm, P = .0078). CONCLUSIONS: Once SSc or IS is simulated to be torn, the LHB has a stabilizing effect for the glenohumeral joint and counteracts humeral translation. With a fully loaded RC, LHB loading has no influence. CLINICAL RELEVANCE: With an intact RC, the condition of the LHB showed no biomechanical effect on the joint stability. Therefore, from a biomechanical point of view, the LHB could be removed from the joint when the RC is intact or reconstructable. However, since there was a positive effect even of the unloaded LHB in this study when SSc or IS is deficient, techniques with preservation of the supraglenoid LHB origin may be of benefit in such cases.

Medial migration of the helical blade with penetration into the acetabulum: a rare complication using the TFNA nail.

PURPOSE: To determine the frequency and possible reasons of medial migration with penetration into the acetabulum (MMPA) of the helical blade when using the Trochanteric Fixation Nail Advanced (TFNA) is used for treatment of pertrochanteric fractures. METHODS: All patients with pertrochanteric femoral fracture, treated by intramedullary femoral nailing with the TFNA, were retrospectively reviewed for MMPA of the helical blade. Epidemiological parameters, additional procedures, distance of medial migration, time from primary operation to revision as well as type of revision were assessed. RESULTS: 4 of 153 patients treated with the TFNA developed an MMPA of the helical blade (risk = 2.6%), with a mean medial migration of the blade of 11.6 mm (SD 8.8). The mean time from initial operation to revision surgery was 70 days (SD 30). All patients were revised by conversion to cemented total hip arthroplasty. CONCLUSION: MMPA of the helical blade is a rare but potentially hazardous complication of femoral nailing with the TFNA femoral nail, resulting in the necessity for revision surgery and total hip arthroplasty.

[Intra-articular proximal tibia fractures]. / Intraartikuläre proximale Tibiafraktur.

The incidence of proximal intra-articular tibial fractures is continuously increasing. In addition to high-energy trauma in young patients, osteoporotic fractures occur more frequently in geriatric patients. After a thorough clinical examination including X­ray and computed tomography (CT) imaging, consolidation of the soft tissue is followed by surgical treatment to achieve the best possible anatomic reconstruction of the articular surface. Nonanatomic reduction with articular gaps >2.5 mm leads to a significantly increased risk of osteoarthritis. Selection of the surgical approach and planning of the osteosynthesis are based on the fracture morphology and the existing soft tissue damage. In addition to arthroscopically assisted percutaneous procedures, sophisticated osteosynthesis is often necessary, which requires several surgical approaches. In this context, posterior surgical approaches are becoming increasingly more important. Primary knee arthroplasty can also play a role, particularly in older patients.

The Anterior Fibers of the Superficial MCL and the ACL Restrain Anteromedial Rotatory Instability.

BACKGROUND: There is limited knowledge about how the anterior cruciate ligament (ACL) and capsuloligamentous structures on the medial side of the knee act to control anteromedial rotatory knee instability. PURPOSE: To investigate the contribution of the medial retinaculum, capsular structures (anteromedial capsule, deep medial collateral ligament [MCL], and posterior oblique ligament), and different fiber regions of the superficial MCL to restraining knee laxity, including anteromedial rotatory instability. STUDY DESIGN: Controlled laboratory study. METHODS: Eight fresh-frozen human cadaveric knees were tested using a 6 degrees of freedom robotic testing system in a position-controlled mode. Loads of 10 N·m valgus rotation, 5 N·m tibial external rotation, 5 N·m tibial internal rotation, and 134 N anterior tibial translation in 5 N·m external rotation were applied at different flexion angles. The motion of the intact knee at 0° to 120° of flexion was replicated after sequential excision of the sartorial fascia; anteromedial retinaculum; anteromedial capsule; anterior, middle, and posterior fibers of the superficial MCL; the deep MCL; the posterior oblique ligament; and the ACL. The reduction in force/torque indicated the contribution of each resected structure to resisting laxity. A repeated-measures analysis of variance with a post hoc Bonferroni test was used to analyze the relative force and torque changes from the intact state. RESULTS: The superficial MCL was the most important restraint to valgus rotation from 0° to 120° and provided the largest contribution to resisting external rotation between 30° and 120° of knee flexion, gradually increasing from 25.2% ± 7.4% at 30° to 36.9% ± 15.4% at 90°. The posterior oblique ligament contributed significantly to resisting valgus rotation only in extension (17.2% ± 12.1%) but was the major restraint to internal rotation at 0° (46.7% ± 13.1%) and 30° (30.4% ± 17.7%) of flexion. The sartorial fascia and anteromedial retinaculum resisted ER at all knee flexion angles (P < .05) and was the single most important restraint in the extended knee (19.5% ± 11%). The capsular structures (anteromedial capsule and deep MCL) had a combined contribution of 20% ± 11.5% at 0° and 23.4% ± 10.5% at 120° of knee flexion but were less important from 30° to 90°. The ACL was the primary restraint to anterior tibial translation in external rotation between 0° and 60° of flexion (50.2% ± 16.9% at 30°), but the superficial MCL was more important at 90° to 120° of knee flexion (36.8% ± 16.4% at 90°). The anterior, middle, and posterior regions of the superficial MCL contributed differently to the simulated laxity tests. The anterior fibers were the most important part of the superficial MCL in resisting external rotation and combined anterior tibial translation in external rotation. CONCLUSION: The superficial MCL not only was the primary restraint to valgus rotation throughout the range of knee flexion but also importantly contributed to resisting anterior tibial translation in external rotation, particularly in deeper flexion in the cadaveric model. The anterior fibers of the superficial MCL are the most important superficial MCL fibers in resisting anterior tibial translation in external rotation. This study suggests that a medial reconstruction that reproduces the function of the posterior MCL fibers and posterior oblique ligament may not best control anteromedial rotatory instability. CLINICAL RELEVANCE: Based on these data, there is a need for an individualized medial reconstruction to address different types of medial injury patterns and instabilities.

Analysis of the Spinopelvic Parameters in Patients with Fragility Fractures of the Pelvis.

BACKGROUND: We investigated the spinopelvic parameters of lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT) and sacral slope (SS) in patients with fragility fractures of the pelvis (FFPs). We hypothesized that these parameters differ from asymptomatic patients. METHODS: All patients treated for FFPs in a center of maximal care of the German Spine Society (DWG) between 2017 and 2021 were included. The inclusion criteria were age ≥ 60 years and the availability of a standing lateral radiograph of the spine and pelvis in which the spine from T12 to S1 and both femoral heads were visible. The baseline characteristics and study parameters were calculated and compared with databases of asymptomatic patients. The two-sample t-Test was performed with p < 0.05. RESULTS: The study population (n = 57) consisted of 49 female patients. The mean age was 81.0 years. The mean LL was 47.9°, the mean PT was 29.4°, the mean SS was 34.2° and the mean PI was 64.4°. The mean value of LLI was 0.7. LL, LLI and SS were significantly reduced, and PI and PT were significantly increased compared to asymptomatic patients. CONCLUSIONS: The spinopelvic parameters in patients with FFPs differ significantly from asymptomatic patients. In patients with FFPs, LL, LLI and SS are significantly reduced, and PI and PT are significantly increased. The sagittal spinopelvic balance is abnormal in patients with FFPs.

[Severe injury type procedures-Influence of the cipher 11 "complications" and the COVID-19 pandemic on a center for maximum care of severe injuries]. / Schwerstverletzungsartenverfahren ­ Einfluss der Ziffer 11 "Komplikationen" sowie der COVID-19-Pandemie auf ein Haus der traumatologischen Maximalversorgung.

INTRODUCTION: Ensuring the best treatment options for injured patients (healing process, Heilverfahren, HV) is the main goal and responsibility of the German statutory accident insurance (DGUV). The injury type catalogue is the tool to guide the HV. The development of the number of cases treated in a center for severe injury type procedures, the effects of the cipher 11 "complications" of the catalogue and the effects of the COVID-19 pandemic are presented. METHODS: A retrospective study of all patients treated in the context of the DGUV from January 2019 to December 2021 was carried out. The number of cases before and during the legal lockdown actions were compared. The case mix index, the mean number of operations, the mean time in the operating room and the hospital stay were analyzed. Additionally, the cases under the cipher 11 were classified according to the specific anatomical regions. RESULTS: Out of 2007 cases 67% were classified as severe injury type procedures (SAV). Of these cases 51% were categorized to the cipher 11 of the injury type catalogue. Complications were observed particularly in the anatomical regions of the shoulder girdle, elbow, hand, knee, ankle joint and foot. These complex cases are economically not sufficiently represented. During the governmental COVID-19 lockdown actions, the number of patients treated in the context of the DGUV significantly decreased. CONCLUSION: The injury type catalogue is used effectively in the catchment area of the present trauma center. Most of the cases treated in the present trauma center are severe injury type procedures; however, more than half of these cases are classified as complications. This development might show the need for a structural change or an adjustment of the HV. The current comments on the injury type catalogue offer important definitions and specifications; however, the conciseness of the entire catalogue should be maintained.

Treatment Reality of Proximal Humeral Fractures in the Elderly-Trending Variants of Locking Plate Fixation in Germany.

BACKGROUND: The surgical treatment of proximal humeral fractures (PHFs) with locking plate fixation (LPF) in the elderly is associated with high complication rates, especially in osteoporotic bone. Variants of LPF such as additional cerclages, double plating, bone grafting and cement augmentation can be applied. The objective of the study was to describe the extent of their actual use and how this changed over time. METHODS: Retrospective analysis of health claims data of the Federal Association of the Local Health Insurance Funds was performed, covering all patients aged 65 years and older, who had a coded diagnosis of PHF and were treated with LPF between 2010 and 2018. Differences between treatment variants were analyzed (explorative) via chi-squared or Kruskal-Wallis tests. RESULTS: Of the 41,216 treated patients, 32,952 (80%) were treated with LPF only, 5572 (14%) received additional screws or plates, 1983 (5%) received additional augmentations and 709 (2%) received a combination of both. During the study period, relative changes were observed as follows: -35% for LPF only, +58% for LPF with additional fracture fixation and +25% for LPF with additional augmentation. Overall, the intra-hospital complication rate was 15% with differences between the treatment variants (LPF only 15%, LPF with additional fracture fixation 14%, LPF with additional augmentation 19%; p < 0.001), and a 30-day mortality of 2%. CONCLUSIONS: Within an overall decrease of LPF by approximately one-third, there is both an absolute and relative increase of treatment variants. Collectively, they account for 20% of all coded LPFs, which might indicate more personalized treatment pathways. The leading variant was additional fracture fixation using cerclages.

Double Plating for Complex Proximal Humeral Fractures: Clinical and Radiological Outcomes.

Double plating for proximal humeral fractures (PHF) is an option to increase the primary fixation stability. Clinical data is missing for assessment of clinical and radiological outcome, as well as complications. We retrospectively examined 35 patients with unilateral PHF, who were treated with double plating for PHF between 2013 and 2019. The mean age was 59.5 ± 12 years and the leading fracture type was a varus dislocation (Resch type IV in 55.3%). A head-split was present in 22.9% of the cases. The primary outcome measurement was the radiological neck shaft angle (NSA). The radiological follow-up was 21 ± 16.6 months and the NSA did not differ between the intraoperative and follow-up time point (131.5 ± 6.9° vs. 136.6 ± 13.7°; p = 0.267). The clinical follow-up was 29.5 ± 15.3 months. The Constant-score was 78.5 ± 17 points, the simple-shoulder-test (SST) was 9.3 ± 3.2 points and the subjective shoulder value (SSV) was 78.8 ± 19.5%. The over-all complication rate was 31.4%, and without stiffness 14.3%. An avascular necrosis occurred in two patients (5.7%). In conclusion, this study shows good radiological and functional outcomes after double plating of highly complex proximal humeral fractures, while the complication rate is comparable to the literature. Double plating is a viable option especially for younger patients with complex fractures as a potential alternative to fracture arthroplasty.

Increased complication rates of salvage reverse total shoulder arthroplasty (RTSA) after failed locked plate fixation compared with primary RTSA in the treatment of proximal humeral fractures in elderly patients.

HYPOTHESIS: Common surgical treatment options for proximal humeral fractures in elderly patients include locked plate fixation (LPF) and reverse total shoulder arthroplasty (RTSA). It was hypothesized that secondary RTSA after LPF would be associated with higher complication rates and costs compared with primary RTSA. METHODS: We analyzed the health insurance data of patients aged ≥65 years who received RTSA for the treatment of a proximal humeral fracture between January 2013 and September 2019 with a pre-study phase of 5 years. Multivariable Cox, logistic, and linear regression models were used to evaluate the association between treatment group and complications, hospital length of stay, charges, and mortality rate during a 34-month follow-up period. RESULTS: A total of 14,220 patients underwent primary RTSA and 1282 patients underwent secondary RTSA after prior surgery using LPF for the treatment of proximal humeral fractures. After adjustment for patient characteristics, more surgical complications were observed after secondary RTSA during index hospitalization (odds ratio, 4.62; 95% confidence interval [CI], 4.00-5.34; P < .001) and long-term follow-up (hazard ratio, 1.52; 95% CI, 1.27-1.81; P < .001). Moreover, secondary RTSA was associated with an increased cumulative total cost of €6638.1 (95% CI, €6229.9-€7046.5; P < .001). If conversion from LPF to secondary RTSA occurred during index hospitalization, more major adverse events, more thromboembolic events, and a higher mortality rate were found in the short and long term (all P < .05). CONCLUSION: Secondary RTSA is associated with higher total costs and more complications. Hence, if surgical treatment of a proximal humeral fracture in an elderly patient is needed, prognostic factors for LPF need to be evaluated carefully. If in doubt, the surgeon should opt to perform primary RTSA as patients will benefit in the long term.

COVID-19 rapid molecular point-of-care testing is effective and cost-beneficial for the acute care of trauma patients.

PURPOSE: To evaluate the accuracy and cost benefit of a rapid molecular point-of-care testing (POCT) device detecting COVID-19 within a traumatological emergency department. BACKGROUND: Despite continuous withdrawal of COVID-19 restrictions, hospitals will remain particularly vulnerable to local outbreaks which is reflected by a higher institution-specific basic reproduction rate. Patients admitted to the emergency department with unknown COVID-19 infection status due to a- or oligosymptomatic COVID-19 infection put other patients and health care workers at risk, while fast diagnosis and treatment is necessary. Delayed testing results in additional costs to the health care system. METHODS: From the 8th of April 2021 until 31st of December 2021, all patients admitted to the emergency department were tested with routine RT-PCR and rapid molecular POCT device (Abbott ID NOW™ COVID-19). COVID-19-related additional costs for patients admitted via shock room or emergency department were calculated based on internal cost allocations. RESULTS: 1133 rapid molecular tests resulted in a sensitivity of 83.3% (95% CI 35.9-99.6%), specificity of 99.8% (95% CI 99.4-100%), a positive predictive value of 71.4% (95% CI 29-96.3%) and a negative predictive value of 99.9% (95% CI 99.5-100%) as compared to RT-PCR. Without rapid COVID-19 testing, each emergency department and shock room admission with subsequent surgery showed additional direct costs of 2631.25€, without surgery of 729.01€. CONCLUSION: Although rapid molecular COVID-19 testing can initially be more expensive than RT-PCR, subsequent cost savings, improved workflows and workforce protection outweigh this effect by far. The data of this study support the use of a rapid molecular POCT device in a traumatological emergency department.

Acromioclavicular and coracoclavicular ligamentous insertion distances depend on the scapular tilt and decrease with anterior direction of the inferior scapula angle.

PURPOSE: A variety of reconstruction techniques exist for the operative treatment of a ruptured acromioclavicular and coracoclavicular ligamentous complex. However, the complication rate remains high; between 5 and 89%. The intraoperative distance between the clavicle, acromion and coracoid is important for the refixation quality. In this study, the influence of scapular deflection on coracoclavicular and acromioclavicular distances was analysed. METHODS: The ligamentous insertions of 24 fresh-frozen human scapulae were exposed. The coracoclavicular and acromioclavicular ligaments were referenced and captured in a rigid body system using a three-dimensional (3D) measurement arm. The inferior angle of the scapula was manually pulled into maximum anterior and posterior deflection, simulating a patient positioning with or without dorsal scapular support, respectively. Based on the rigid body system, the distances between the ligamentous insertions were calculated. Statistical evaluation was performed by setting the distances in anterior deflection to 100% and considering the other distances relative to this position. RESULTS: The scapular deflection had a considerable impact on the distance between the ligamentous insertions. Concerning the conoid ligament, the mean distance was almost doubled when the inferior angle pointed posteriorly compared to anterior deflection (195.3 vs 100.0%; p = 0.028). The insertion of the acromioclavicular capsule also showed a significant association with the direction of deflection (posterior = 116.1% vs. anterior = 100%; p = 0.008). CONCLUSION: Dorsal support shifting the inferior angle of the scapula anteriorly reduces the distance between the ligamentous insertions. Therefore, a patient position on a shoulder table with posterior support of the scapula is recommended to reliability reduce the acromioclavicular joint.

Biomechanical Analysis of Coracoid Stability After Coracoplasty: How Low Can You Go?

Background: Arthroscopic coracoplasty is a procedure for patients affected by subcoracoid impingement. To date, there is no consensus on how much of the coracoid can be resected with an arthroscopic burr without compromising its stability. Purpose: To determine the maximum amount of the coracoid that can be resected during arthroscopic coracoplasty without leading to coracoid fracture or avulsion of the conjoint tendon during simulated activities of daily living (ADLs). Study Design: Controlled laboratory study. Methods: A biomechanical cadaveric study was performed with 24 shoulders (15 male, 9 female; mean age, 81 ± 7.9 years). Specimens were randomized into 3 treatment groups: group A (native coracoid), group B (3-mm coracoplasty), and group C (5-mm coracoplasty). Coracoid anatomic measurements were documented before and after coracoplasty. The scapula was potted, and a traction force was applied through the conjoint tendon. The stiffness and load to failure (LTF) were determined for each specimen. Results: The mean coracoid thicknesses in groups A through C were 7.2, 7.7, and 7.8 mm, respectively, and the mean LTFs were 428 ± 127, 284 ± 77, and 159 ± 87 N, respectively. Compared with specimens in group A, a significantly lower LTF was seen in specimens in group B (P = .022) and group C (P < .001). Postoperatively, coracoids with a thickness ≥4 mm were able to withstand ADLs. Conclusion: While even a 3-mm coracoplasty caused significant weakening of the coracoid, the individual failure loads were higher than those of the predicted ADLs. A critical value of 4 mm of coracoid thickness should be preserved to ensure the stability of the coracoid process. Clinical Relevance: In correspondence with the findings of this study, careful preoperative planning should be used to measure the maximum reasonable amount of coracoplasty to be performed. A postoperative coracoid thickness of 4 mm should remain.

Double plating is associated with higher fixation strength than single plating in osteoporotic fractures of the scapular spine: a biomechanical study.

INTRODUCTION: The number of atraumatic stress fractures of the scapular spine associated with reverse shoulder arthroplasty is increasing. At present, there is no consensus regarding the optimal treatment strategy. Due to the already weakened bone, fractures of the scapular spine require a high fixation stability. Higher fixation strength may be achieved by double plating. The aim of this study was to evaluate the biomechanical principles of double plating in comparison to single plating for scapular spine fractures. METHODS: In this study, eight pairs (n = 16) of human shoulders were randomised pairwise into two groups. After an osteotomy at the level of the spinoglenoid notch, one side of each pair received fracture fixation with a single 3.5 LCP (Locking Compression Plate) plate. The contralateral scapular spine was fixed with a 3.5 LCP and an additional 2.7 LCP plate in 90-90 configuration. The biomechanical test protocol consisted of 700 cycles of dynamic loading and a load-to-failure test with a servohydraulic testing machine. Failure was defined as macroscopic catastrophic failure (screw cut-out, plate breakage). The focus was set on the results of specimens with osteoporotic bone quality. RESULTS: In specimens with an osteoporotic bone mineral density (BMD; n = 12), the mean failure load was significantly higher for the double plate group compared to single plating (471 N vs. 328 N; p = 0.029). Analysis of all specimens (n = 16) including four specimens without osteoporotic BMD revealed no significant differences regarding stiffness and failure load (p > 0.05). CONCLUSION: Double plating may provide higher fixation strength in osteoporotic bone in comparison to a single plate alone. This finding is of particular relevance for fixation of scapular spine fractures following reverse shoulder arthroplasty. LEVEL OF EVIDENCE: Controlled laboratory study.

Does Cement Augmentation of the Sacroiliac Screw Lead to Superior Biomechanical Results for Fixation of the Posterior Pelvic Ring? A Biomechanical Study.

Background and Objectives: The stability of the pelvic ring mainly depends on the integrity of its posterior part. Percutaneous sacroiliac (SI) screws are widely implanted as standard of care treatment. The main risk factors for their fixation failure are related to vertical shear or transforaminal sacral fractures. The aim of this study was to compare the biomechanical performance of fixations using one (Group 1) or two (Group 2) standard SI screws versus one SI screw with bone cement augmentation (Group 3). Materials and Methods: Unstable fractures of the pelvic ring (AO/OTA 61-C1.3, FFP IIc) were simulated in 21 artificial pelvises by means of vertical osteotomies in the ipsilateral anterior and posterior pelvic ring. A supra-acetabular external fixator was applied to address the anterior fracture. All specimens were tested under progressively increasing cyclic loading until failure, with monitoring by means of motion tracking. Fracture site displacement and cycles to failure were evaluated. Results: Fracture displacement after 500 cycles was lowest in Group 3 (0.76 cm [0.30] (median [interquartile range, IQR])) followed by Group 1 (1.42 cm, [0.21]) and Group 2 (1.42 cm [1.66]), with significant differences between Groups 1 and 3, p = 0.04. Fracture displacement after 1000 cycles was significantly lower in Group 3 (1.15 cm [0.37]) compared to both Group 1 (2.19 cm [2.39]) and Group 2 (2.23 cm [3.65]), p ≤ 0.04. Cycles to failure (Group 1: 3930 ± 890 (mean ± standard deviation), Group 2: 3676 ± 348, Group 3: 3764 ± 645) did not differ significantly between the groups, p = 0.79. Conclusions: In our biomechanical setup cement augmentation of one SI screw resulted in significantly less displacement compared to the use of one or two SI screws. However, the number of cycles to failure was not significantly different between the groups. Cement augmentation of one SI screw seems to be a useful treatment option for posterior pelvic ring fixation, especially in osteoporotic bone.

Is Anterior Plating Superior to the Bilateral Use of Retrograde Transpubic Screws for Treatment of Straddle Pelvic Ring Fractures? A Biomechanical Investigation.

BACKGROUND: Fractures of the four anterior pubic rami are described as "straddle fractures". The aim of this study was to compare biomechanical anterior plating (group 1) versus the bilateral use of retrograde transpubic screws (group 2). METHODS: A straddle fracture was simulated in 16 artificial pelvises. All specimens were tested under progressively increasing cyclic loading, with monitoring by means of motion tracking. RESULTS: Axial stiffness did not differ significantly between the groups, p = 0.88. Fracture displacement after 1000-4000 cycles was not significantly different between the groups, p ≥ 0.38; however, after 5000 cycles it was significantly less in the retrograde transpubic screw group compared to the anterior plating group, p = 0.04. No significantly different flexural rotations were detected between the groups, p ≥ 0.32. Moreover, no significant differences were detected between the groups with respect to their cycles to failure and failure loads, p = 0.14. CONCLUSION: The results of this biomechanical study reveal less fracture displacement in the retrograde transpubic screw group after long-term testing with no further significant difference between anterior plating and bilateral use of retrograde transpubic screws. While the open approach using anterior plating allows for better visualization of the fracture site and open reduction, the use of bilateral retrograde transpubic screws, splinting the fracture, presents a minimally invasive and biomechanically stable technique.

The Surgical Treatment of Proximal Humeral Fractures in Elderly Patients.

BACKGROUND: The goal of this study is to compare mortality, major adverse events, and complication rates after the surgical treatment of proximal humeral fractures with locked plate fixation (LPF) versus reverse total shoulder arthroplasty (RTSA) in elderly patients. METHODS: Health insurance data from patients aged 65 and above for the period January 2010 to September 2018 were retrospectively evaluated. The median follow-up duration after LPF (40 419 patients) or RTSA (13 552 patients) was 52 months. Hazard ratios adapted to the patients' risk profiles were determined with the aid of multivariable Cox regression models. The p-values were adjusted using the Bonferroni-Holm method. RESULTS: After adaptation to the patients' risk profiles, reverse shoulder replacement showed statistically significantly lower mortality (HR 0.92, 95% confidence interval [0.88; 0.95]; p <0.001) and fewer major adverse events (HR 0.92 [0.89; 0.95]; p<0.001). Eight years after surgery, the risk of surgical complications was twice as high for LPF (12.2% [11.9; 12.7]; HR for RTSA versus LPF 0.5 [0.46; 0.55]; p<0.001 for both), with 3.8% [3.6; 4.0] of the patients receiving a secondary RTSA. Surgical complications were more common (p<0.05) in patients with a diagnosis of osteo - porosis, obesity, alcohol abuse, chronic polyarthritis, or frozen shoulder. CONCLUSION: The long-term findings are in agreement with clinical short-term findings from other studies and support the current trend toward more liberal use of reverse shoulder replacements in elderly patients.

The Anatomy of Glenoid Concavity-Bony and Osteochondral Assessment of a Stability-Related Parameter.

Glenoid concavity is a crucial factor for glenohumeral stability. However, the distribution of this stability-related parameter has not been focused on in anatomical studies. In this retrospective study, computed tomography (CT) data and tactile measurements of n = 27 human cadaveric glenoids were analyzed with respect to concavity. For this purpose, the bony and osteochondral shoulder stability ratio (BSSR/OSSR) were determined based on the radius and depth of the glenoid shape in eight directions. Various statistical tests were performed for the comparison of directional concavity and analysis of the relationship between superoinferior and anteroposterior concavity. The results proved that glenoid concavity is the least distinctive in anterior, posterior, and anterosuperior direction but increases significantly toward the superior, anteroinferior, and posteroinferior glenoid. The OSSR showed significantly higher concavity than the BSSR for most of the directions considered. Moreover, the anteroposterior concavity is linearly correlated with superoinferior concavity. The nonuniform distribution of concavity indicates directions with higher stability provided by the anatomy. The linear relationship between anteroposterior and superoinferior concavity may motivate future research using magnetic resonance imaging (MRI) data to optimize clinical decision-making toward more personalized treatment of glenoid bone loss.