Femoroacetabular Variations Are Predisposing Factors for Traumatic Posterior Hip Dislocation.

BACKGROUND: Although high-energy trauma mechanisms are generally considered to cause traumatic posterior hip dislocations, femoroacetabular variations are assumed to contribute to low-impact hip dislocations. Thus, the present study aimed to identify morphologic femoral and acetabular risk factors that may also contribute to posterior hip dislocations in high-energy trauma mechanisms. METHODS: The acetabular and femoral morphology of 83 hips with a traumatic posterior dislocation following a high-energy trauma mechanism were analyzed and matched to a control group of 83 patients who sustained high-energy trauma without a hip injury. The lateral center-edge angle, acetabular index, acetabular depth/width ratio, cranial and central acetabular version angles, and the anterior and posterior acetabular sector angles were measured on computed tomography to quantify femoroacetabular impingement (FAI) morphology, acetabular version, and coverage. The caput-collum-diaphyseal angle and the alpha angles in the coronal and axial planes were measured to detect cam-type FAI deformity. A receiver operating characteristic curve was utilized to determine threshold values for an increased risk of hip dislocation. RESULTS: Acetabular retroversion and posterior acetabular undercoverage were significantly increased in patients with hip dislocations compared with controls (p < 0.001). The central acetabular version angle and posterior acetabular sector angle that indicated an increased risk of hip dislocation were ≤9° and ≤90°, respectively. Cam-type FAI deformity and coxa valga were significantly increased in the dislocation group (p < 0.001). The anterolateral alpha angle that indicated an increased dislocation risk was ≥47°. CONCLUSIONS: Acetabular retroversion, posterior acetabular undercoverage, and cam-type FAI morphology may be risk factors contributing to traumatic posterior hip dislocation in high-energy trauma mechanisms. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Undersizing of the tibial component in Oxford unicompartmental knee arthroplasty (UKA) increases the risk of periprosthetic fractures.

INTRODUCTION: Tibial periprosthetic fractures (TPF) after unicompartmental knee arthroplasty (UKA) are a rare condition that affects about 1% of cases. Known risk factors include age, sex, body mass index (BMI), and bone density, as well as surgical technique and prosthesis design. The purpose of the study was to determine if undersizing of the tibial component in relation to the femoral component increases the risk of tibial periprosthetic fractures. MATERIAL AND METHODS: Over a 6-year-period 1542 patients with cemented (n = 363) and uncemented (n = 1179) medial UKA were retrospectively evaluated. Tibial periprosthetic fractures were identified and classified, and epidemiologic data were documented at follow-up. Undersizing was defined as a smaller tibial component compared to the femoral implant. The association of potential risk factors for TPF with the incidence of TPF was investigated with binominal logistic regression. RESULTS: Fourteen patients (0.9%) suffered from TPF at a median of 1 month after surgery. The mean follow-up period was 5.9 ± 1.7 years. Fractures were more common in cases with undersized tibial components [odds ratio (OR) 3.2, p < 0.05]. Furthermore, older age (OR 1.1, p < 0.05) and female sex (OR 6.5, p < 0.05) were identified as significant risk factors, while BMI (p = 0.8) and cemented implantation (p = 0.2) had no effect on fracture rate. Revision surgery included open reduction and internal fixation or conversion to total knee arthroplasty. CONCLUSIONS: Undersizing of implant sizes in UKA increases the risk for TPF especially in patients with small tibial implants. Therefore, mismatched implants should be avoided for UKA particularly when risk factors like obesity, older age, or female gender are present. Tibial periprosthetic fractures were successfully treated by open reduction and internal fixation or conversion to total knee arthroplasty.

Intermediate to Long-Term Results Following Traumatic Hip Dislocation: Characteristics, CT-Based Analysis, and Patient-Reported Outcome Measures.

BACKGROUND: Traumatic hip dislocation is a rare yet severe injury. As the long-term morbidity, subsequent complications, and clinical outcomes are nearly unknown, we aimed to analyze traumatic hip dislocations and identify specific factors that may predict the clinical outcome. METHODS: Data on injury-related characteristics and computed tomographic (CT) scans for all consecutive adult patients who had been managed for traumatic hip dislocation between 2009 and 2021 were analyzed. At the time of follow-up, the patients were assessed with regard to osteonecrosis, posttraumatic osteoarthritis (OA), further operations and complications, return to sports and work, and patient-reported outcome measures (PROMs), including the Tegner Activity Scale and modified Harris hip score. RESULTS: One hundred and twelve patients (mean age [and standard deviation], 43.12 ± 16.6 years) were included. Associated acetabular rim and femoral head fractures (Pipkin Type I to IV) were observed in 44% and 40% of patients, respectively. Concomitant injuries occurred in 67% of the patients, most commonly involving the knee (29% of patients). Sixty-nine patients (61.6%) were available for follow-up; the mean duration of follow-up was 6.02 ± 3.76 years. The rates of osteonecrosis and posttraumatic OA were 13% and 31.9%, respectively, and were independent of the timing of hip reduction, leading to subsequent total hip arthroplasty (THA) in 19% of patients. Sciatic nerve injury occurred in 27.5% of the patients who were available for follow-up. Both THA and sciatic nerve injury were associated with posterior acetabular rim or Pipkin Type-IV fractures (p < 0.001). Only 33.3% of the patients returned to their pre-injury level of sports, 24.6% did not return to work, and 27.5% reported having sexual dysfunction. PROMs (Tegner Activity Scale, modified Harris hip score) were significantly worse in patients with osteonecrosis, posttraumatic OA, or residual sciatic nerve injury (p < 0.05). CONCLUSIONS: Traumatic hip dislocations are predominantly associated with Pipkin and acetabular rim fractures, leading to overall limitations of activities of daily living, sports, and sexual function at intermediate to long-term follow-up. Patients with associated acetabular rim or Pipkin Type-IV fractures are most likely to require THA for the treatment of osteonecrosis or posttraumatic OA and are at greater risk for sustaining sciatic nerve injury. LEVEL OF EVIDENCE: Prognostic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Early Stabilization Does Not Increase Complication Rates in Acetabular Fractures of the Elderly: A Retrospective Analysis from the German Pelvis Registry.

Background: The incidence of acetabular fractures in geriatric patients has increased. Although there are strong data supporting the early operative treatment of hip fractures in geriatric patients, the optimal timing for acetabular fractures remains unclear and for several reasons, delayed treatment after trauma is common. Methods: A retrospective analysis of the German Pelvis Registry between 2008 and 2017 was performed. Ultimately, 665 patients with fractures of the anterior column or anterior column and posterior hemitransverse were enrolled. Patients above and below 65 years of age with these fracture types were analyzed regarding surgery day (within 48 hours, between 2 and 4 days, after 4 days), complication rate, reduction quality, and hospital stay. Results: The complication rate of the geriatric group was twice as high as that of younger patients; however, this finding was independent of the timing of surgery. Reduction quality and hospital stay were independent of surgical timing. Conclusions: In contrast to other fracture types, such as proximal femur fractures, the timing of surgery for acetabular fractures does not have a significant impact on the patient's outcome. The optimal time for surgery cannot be determined using the current data. However, as expected, there is a significantly higher risk for postoperative complications in the geriatric population.

The SAlzburg PEritoneal SUrface CAlculator (SAPESUCA): The First Web-Based Application for Peritoneal Surface Area Quantification.

(1) Background: Peritoneal metastasized colorectal cancer is associated with a worse prognosis. The combination of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) showed promising results in selected patients, but standardization is lacking so far. We present the first tool enabling standardized peritoneal surface area (PSA) quantification in patients undergoing CRS and HIPEC: The SAlzburg PEritoneal SUrface CAlculator (SAPESUCA). (2) Methods: SAPESUCA was programmed using the R-Shiny framework. The application was validated in 23 consecutive colon cancer patients who received 27 closed oxaliplatin-based HIPECs between 2016 and 2020. The programming algorithm incorporates the patient's body surface area and its correlated peritoneal surface area (PSA) based on the 13 Peritoneal Cancer Index (PCI) regions. (3) Results: Patients' median age was 56 years. Median PCI was 9. SAPESUCA revealed a mean PSA of 18,613 cm2 ± 1951 of all patients before compared to 13,681 cm2 ± 2866 after CRS. The Central PCI region revealed the highest mean peritonectomy extent (1517 cm2 ± 737). The peritonectomy extent correlated significantly with PCI score and postoperative morbidity. The simulated mean oxaliplatin dose differed significantly before and after CRS (558 mg/m2 ± 58.4 vs. 409 mg/m2 ± 86.1; p < 0.0001). (4) Conclusion: SAPESUCA is the first free web-based app for standardized determination of the resected and remaining PSA after CRS. The tool enables chemotherapeutic dose adjustment to the remaining PSA.

Treatment options in non-unions of the pelvis: A retrospective analysis of a single center experience over 12 years.

BACKGROUND: Non-unions and chronic instability of the pelvis remain rare complications after complex high velocity injuries with vertical and rotational instability of the pelvis. Treatment options are insufficiently supported by data evidence due to the rareness of this condition. PATIENTS AND METHODS: we conducted a single center, retrospective study of all non-unions and pelvic instabilities between 1.1.2008 and 1.1.2019, excluding fragility fractures. Patients' characteristics, fracture patterns, procedures and outcomes with regard to developing treatment options and successful union in the follow-up were obtained. RESULTS: 26 patients were included in this retrospective analysis. The mean age was 55 years (range 34-78 years). Seventy-seven percent of the patients were male. The standard procedure consisted of radical debridement of the non-union, interposition of autologous bone graft and rigid stabilization systems. Three patients were lost to follow up. In the remaining n = 23 patients (88%) consolidation of the non-union was achieved. The mean follow up was 31.3 months (range 6-144). Follow up showed that an iliolumbar fixation seems to be favorable regarding outcome and complications. DISCUSSION: Non-union and remaining instability of the pelvic ring represent a rare complication after high grade pelvic trauma. There are only limited data regarding the incidence and the treatment regimen is based on small study populations only. Based on our findings we recommend to combine autologous bone grafts with rigid fixation systems especially for non-union of the pelvis to restore the posterior sacroiliac arch.

Mid-Term Results following Traumatic Knee Joint Dislocation.

PURPOSE: Although treatment strategies of knee joint dislocations have evolved, there is still no consensus on the best method and timing. New therapeutic concepts suggest that early one-stage treatment, including suturing and bracing of the cruciate ligaments in acute knee joint dislocation, are leading to improved functional results. This study aimed to evaluate the midterm functional outcome following traumatic knee joint dislocation and to determine whether the outcome is influenced by the surgical management, patient habitus or concomitant injuries. METHODS: In this retrospective single center study, 38 patients with acute Schenck type II to IV knee dislocations were treated over an eight-year period in a level I trauma center. At follow-up, various clinical scores, such as the International Knee Documentation Committee (IKDC) Score, Lysholm Score, and Tegner Activity Scale (TAS), and individual questions about rehabilitation and activity levels of 38 patients were evaluated. RESULTS: Mean follow-up was 5.5 ± 2.7 years. The mean IKDC Score was 65.6 ± 15.7 points, the average Lysholm Score was 70.5 ± 16.4 points and the median TAS was 4 (0-7), resulting in a loss of activity of 2 (range 0-6) points. There was no significant difference between a one-stage treatment compared to a two-stage approach. Ligament reconstruction of the ACL in a two-stage approach was required in only 33.3%. Further operations (early and late) were performed in 37% of cases. Being overweight was associated with more complications and worse outcomes, and external fixation with arthrofibrosis. CONCLUSIONS: Knee dislocation is a severe trauma that often leads to a prolonged loss of function and increased knee pain over years, affecting the patient's activity. Clinical outcome is influenced significantly by concomitant injuries. Severe cases with initial external fixation are associated with a higher risk of knee stiffness and should be considered during rehabilitation. Obese patients present a challenge due to higher complication rates and lower postoperative knee function. LEVEL OF EVIDENCE: Retrospective single center study, level III.

Case Report: Adult Right-Sided Bochdalek Hernia Complicated by Intrathoracic Bowel Perforation.

Right-sided Bochdalek hernia is a mostly congenital condition of the diaphragm caused by a persistence of the pleuroperitoneal cavity and a rare disease in adults. As it often presents as an emergent situation, urgent diagnostics and surgical intervention are essential to reduce morbidity and mortality rates. Choosing the right surgical approach (abdominal, thoracic, or a combination of both) can be very challenging for clinicians. Here, we report a case of a 40-year-old woman, who presented with severe abdominal pain and tachypnoea. Imaging revealed a right-sided Bochdalek hernia. Emergency laparotomy was performed followed by reduction of hernia content, right-sided hemicolectomy, and side-to-side anastomosis from the ileum to the transverse colon due to intestinal ischemia and intrathoracic bowel perforation. The post-operative course was complicated by a pleural empyema. Therefore, the patient underwent thoracotomy. One year after surgical repair the patient had no recurrence. Here, we discuss feasible approaches for the surgical management of complicated Bochdalek hernias.

Endoscopically assisted implant removal of a symphyseal pelvic plate - A case report.

INTRODUCTION: The approach-related morbidity rate in the care of pelvic fractures is still high. Endoscopic procedures are known to significantly reduce access-related complications. Recently, a new endoscopically assisted implantation technique for plate osteosynthesis on the anterior pelvic ring has been described as the "Endoscopic Approach to the Symphysis". CASE REPORT: We present a case of a 29-year old male with a pelvic injury (AO type 61B2.3a) initially treated with a supraacetabular external fixator. After one week the definitive stabilization was performed by an endoscopically assisted symphyseal plating as well as a percutaneous iliosacral screw on the right side. One year after primary surgery, we performed an endoscopically assisted removal of the symphyseal plate using standard laparoscopic instruments. RESULTS: We demonstrate the feasibility of an endoscopically assisted implant removal at the anterior pelvic ring. No complications occurred during the procedure. The patient was discharged after a regular time of surveillance and with an adequate decline of pain. DISCUSSION: While we were able to show that the endoscopically assisted implantation as well as the removal of a plate osteosynthesis on the anterior pelvic ring is possible, there is still further research necessary, especially regarding the development of specific endoscopic instruments. This should enable operating times similar to the standard open procedures.

Cytotoxic drugs in combination with the CXCR4 antagonist AMD3100 as a potential treatment option for pediatric rhabdomyosarcoma.

Rhabdomyosarcoma (RMS) is the most common type of pediatric soft tissue sarcoma. The prognosis of advanced stage RMS remains poor, and metastatic invasion is a major cause of treatment failure. Therefore, there is an urgent need for treatment alternatives focusing on metastatic invasion and drug resistance. The stromal cell­derived factor­1 (SDF­1)/chemokine receptor 4 (CXCR4) axis is a crucial factor for metastatic invasion in RMS. Clinical data has revealed that high CXCR4 expression is associated with a poor outcome and a high metastatic rate in several malignancies, including RMS. Thus, targeting CXCR4 in addition to classical chemotherapy may improve the effectiveness of RMS treatment. In the present study, flow cytometry and reverse transcription­quantitative PCR were used to assess the effects of the combined treatment with a CXCR4 antagonist and chemotherapy on CXCR4 expression in the embryonal RMS (RME) cell line RD and in the alveolar RMS (RMA) cell line RH30. The functional effect of CXCR4 expression on the migratory behavior of RMS cells was analyzed using Transwell assays. Treatment with cytotoxic agents modulated CXCR4 expression in RMS cells in a dose­, drug­ and cell line dependent manner; however, this was not observed in RD cells with vincristine. The expression levels of CXCR4 significantly increased the migratory behavior of RMA and did not affect RME cell migration towards stromal cell­derived factor­1α (SDF­1α). AMD3100 markedly reduced the migration of RH30 cells in the Transwell assays compared with SDF­1α alone, and the cytotoxic agents doxorubicin and vincristine increased this effect. The results of the combined treatment in RMS cells using the CXCR4 antagonist AMD3100 together with cytotoxic drugs demonstrated that this approach may be a promising alternative for the treatment of advanced stage pediatric RMS. The observed effects of circumventing metastatic invasion and drug resistance should be further investigated in vivo.