Background: The asymmetry of the medial and lateral knee compartments contributes significantly to femorotibial biomechanics and pivoting, and it is reported to be a relevant risk factor for an anterior cruciate ligament (ACL) injury. Purpose: (1) To assess the role of femoral condyle sphericity as a risk factor for an ACL rupture and rerupture. (2) To compare the new risk factor with existing bony morphological risk factors via magnetic resonance imaging (MRI) and to assess the most predictive risk factor for an ACL rupture. Study Design: Cohort study; Level of evidence, 3. Methods: A retrospective case-control study of 60 patients was conducted. Three age- and sex-matched cohorts (each n = 20) were analyzed: ACL reruptures, primary ACL ruptures, and a control group consisting of isolated meniscal tears or patients with anterior knee pain without signs of trochlear dysplasia. The lateral femoral condyle index (LFCI) as a novel MRI measurement was developed to quantify femoral sphericity. In addition, previously known MRI risk factors associated with ACL injury were analyzed (notch width index, medial tibial slope, lateral tibial slope, medial tibial depth, and lateral tibial height). Differences among groups were compared; cutoff values were defined; and diagnostic performance of the risk factors was assessed. The risk factors were subsequently analyzed with multiple logistic regression. Results: The LFCI was significantly smaller in knees with ACL reruptures (median, 0.67; range, 0.59-0.75) and primary ACL ruptures (0.67; range, 0.60-0.75) than in the control group (0.76; range, 0.6-0.81; P < .01). The LFCI yielded the highest area under the curve among the analyzed risk factors: 0.82 (95% CI, 0.7-0.9). A cutoff of 0.70 yielded a sensitivity of 78% and a specificity of 80% to predict an ACL rupture or rerupture (odds ratio, 13.79; 95% CI, 3.67-51.75). In combination with lateral tibial height (cutoff, 3.8 mm) and lateral tibial slope (cutoff, 2.9°), the diagnostic performance was improved. The area under the curve was 0.86 (95% CI, 0.75-0.94), with a sensitivity of 90% and a specificity of 70% (odds ratio, 21.00; 95% CI, 5.10-85.80). Conclusion: A decreased LFCI is associated with an ACL injury. The LFCI, lateral tibial height, and lateral tibial slope are the most predictive risk factors for an ACL injury. These findings might aid clinicians in identifying patients at risk for an ACL injury and inform the patient after reconstruction for a higher risk of rerupture.

No abstract

Summary. Background: Major amputations in patients with peripheral arterial disease (PAD) carry a high risk for complications, including revision of the amputation, sometimes to a higher level. Determining a safe level for amputation with good wound healing potential depends largely on vascular measurements. This study evaluated potential predictive factors for revision of major lower extremity amputations in patients with PAD. Patients and methods: A retrospective chart review of all major lower extremity amputations at our institution was conducted. Amputations due to trauma or tumor and below-ankle amputations were excluded. Patient demographics, level/type of amputation, level/time of revision, comorbidities and risk factors were extracted. Results: 180 patients with PAD, mean age 66.48 (range: 31–93) years, 125 (69.4%) male were included. Most (154/180, 86.6%) underwent below-knee amputation. 71 (39.4%) patients had coronary arterial disease, 104 (57.8%) had diabetes. More than half of patients, (93/138; 51.7%) had undergone previous balloon angioplasty. 44 (30%) patients required revision surgery: 42/180 (23.3%) were revised at the same level, and in 12/180 (6.7%) a more proximal amputation was necessary. PAD stage was not associated with the level of reamputation (p = 0.4369). Significantly more patients who had previous balloon angioplasty required revision surgery (66.7% versus 45.2%, p = 0.009). 67 (37.2%) patients underwent preoperative TcPO2 measurement: 40/67 (59.7%) had TcPO2 ≥ 40 mmHg; 4/67 (6%) had TcPO2 < 10 mmHG. Three patients with TcPO2 ≥ 40 mmHg, one with 30 mmHg ≤ TcPO2 ≤ 40 mmHg and one with 10 mmHg ≤ TcPO2 ≤ 20 mmHg required re-amputation to a more proximal level. Conclusions: TcPO2 measurements are useful for determining level of lower limb amputation and predicting wound healing problems when an amputation level with TcPO2 < 40 mmHg is chosen. In transtibial amputations, TcPO2 ≥ 40 mmHg does not safely predict wound healing.

Background:Subsidence of cementless femoral stems in hemiarthroplasty (HA) and increased fracture rates are ongoing concerns of orthopedic surgeons when treating fractures in very old patients. Additionally, bone cement implantation syndrome may result in perioperative cardiac or pulmonary complications, especially in older patients, leading to morbidity and mortality. This study was performed to analyze possible subsidence and intraoperative fractures in a cohort of very old patients treated with cementless stems.Methods:We retrospectively analyzed a consecutive cohort of patients aged ≥90 years with femoral neck fractures treated by uncemented HA and an anterior minimally invasive approach. Immediate full-weight bearing was allowed postoperatively. Pelvic radiographs were examined for subsidence immediately postoperatively and 6 weeks later.Results:We treated 109 patients (74% women; mean age, 93 years; range, 90-102 years) by HA from January 2010 to March 2016. The 30-day mortality rate was 16%, and the morbidity rate was 47%. There were 11 (12%) intraoperative fractures: 8 (Vancouver B2) had to be addressed immediately during the primary operation, while 3 (1 Vancouver B1 and 2 Vancouver AG) were treated conservatively. One periprosthetic femoral fracture (Vancouver B1) was documented during follow-up. In 17 patients, subsidence of >2.0 mm (median, 3.9 mm; range, 2.5-9.0 mm) was documented.Conclusion:Early subsidence was low in this very old cohort treated with an uncemented stem and not showing a periprosthetic fracture. The risk of intraoperative periprosthetic fractures was high. The use of uncemented implants in osteoporotic bone continues to be an intervention with high risk and should only be performed by experienced surgeons.Level of Evidence:Level III, Therapeutic study.

Zusammenfassung. Sportliche Aktivitäten mit Sprungabläufen stellen für die Kniegelenke eine mechanische Herausforderung dar. Häufig projizieren sich chronisch auftretende, atraumatische Beschwerden auf den Patellaunterpol, welcher pathomorphologisch eine patellare Tendinopathie entspricht. Extrinsische und intrinsische Risikofaktoren können unterschieden werden. In der klinischen Untersuchung zeigt sich ein meist unauffälliges Knie mit einer Druckdolenz am kaudalen Teil der Kniescheibe beim Übergang zum Ligamentum patellae. In der Bildgebung ist sonografisch ein degenerierter Sehnenanteil der tiefen Patellarsehne zu erkennen, der magnettomografisch mit Hyperintensität des Hoffa-Körpers einhergehen kann. Abhängig von der klinischen Entwicklung wird das Jumper’s Knee nach Blazina Grad I–IV eingeteilt. Bis zu 90 % der Patienten können konservativ therapiert werden. Operativ stehen offene und arthroskopische Verfahren mit ordentlichem Resultat zur Verfügung.

Over the past years the development of biodegradable polymeric stents has made great progress; nevertheless, essential problems must still be solved. Modifications in design and chemical composition should optimize the quality of biodegradable stents and remove the weaknesses. New biodegradable poly-L-lactide/poly-4-hydroxybutyrate (PLLA/P4HB) stents and permanent 316L stents were implantedendovascularly into both common carotid arteries of 10 domestic pigs. At 4 weeks following implantation, computed tomography (CT) angiography was carried out to identify the distal degree of stenosis. The PLLA/P4HB group showed a considerably lower distal degree of stenosis by additional oral application of atorvastatin (mean 39.81 ± 8.57 %) compared to the untreated PLLA/P4HB group without atorvastatin (mean 52.05 ± 5.80 %). The 316L stents showed no differences in the degree of distal stenosis between the group treated with atorvastatin (mean 44.21 ± 2.34 %) and the untreated group (mean 35.65 ± 3.72 %). Biodegradable PLLA/P4HB stents generally represent a promising approach to resolving the existing problems in the use of permanent stents. Restitutio ad integrum is only achievable if a stent is completely degraded.

No abstract

No abstract