A new 3D software for analysis and planning of lower limb and patellofemoral alignment: Reliability and accuracy.

BACKGROUND: The new software, mediCAD® 3D Knee Sport (mediCAD Hectec GmbH, Altdorf/Landshut, Germany), promises to combine automated digital 3D bone model generation, 3D analysis of lower limb geometry including analysis of the patellofemoral joint, and osteotomy planning. The aim of this study was to evaluate its reliability and accuracy. METHODS: In this retrospective multi-observer study, three post-mortem CTs were analysed by three observers at three points in time. Reliability was evaluated by calculating the intraclass correlation coefficient (ICC) of interobserver agreement. Accuracy was evaluated using the mean deviation D from the mean and the standard deviation SD from D. RESULTS: Ten of 18 alignment parameters showed excellent, two good and three moderate interobserver agreement. Poor agreement was found for the mechanical medial proximal tibial angle, the trochlear sulcus angle and trochlea depth. Mean interobserver ICC of all parameters ranged from 0.32 to 0.99. Fifteen of 18 parameters showed a low mean deviation D from the mean of < 2 mm / 2°. Three parameters related to the patellofemoral joint showed medium or high D (patella tilt, trochlear sulcus angle, patellar ridge angle). These parameters also showed the highest values for the SD of D. The trochlear sulcus angle was found to be the only parameter with high mean deviation (D ≥ 5 mm/5°) with D being 5.67 ± 3.23°. CONCLUSIONS: The current version of the software achieves good interobserver reliability and accuracy with the exception of a few measurement parameters.

Three-dimensional assessment of patellofemoral anatomy: Reliability and reference ranges.

BACKGROUND: Three-dimensional (3D) imaging and analysis offer new possibilities in preoperative diagnostics and surgical planning. Simultaneous 3D analysis of the joint angles and the patellofemoral anatomy allow for a realistic assessment of bony pathologies in patients with patellofemoral complaints. This study aims to develop a standardized and validated assessment of the 3D patellofemoral morphology and to establish reference ranges. METHODS: Thirteen patellofemoral anatomic landmarks were defined on 3D bone models of the lower limbs based on computer tomography data and evaluated regarding inter- and intra-observer variability. Further, 60 3D models of the lower limbs of young subjects without any previous knee operation/injury were assessed and rescaled reference values for relevant patellofemoral indices were obtained. RESULTS: The mean inter- and intra-observer deviation of all landmarks was below 2.3 mm. The interobserver intraclass correlation coefficient (ICC) was between 0.8 and 1.0 and the intra-observer ICC between 0.68 and 0.99 for all patellofemoral parameters. The calculated reference ranges are: Insall-Salvati index 1.0-1.4; patella tilt 6-18°; patella shift -4 to 3 mm; patella facet angle 118-131°; sulcus angle 141-156°; trochlear depth 3-6 mm; tibial-tuberosity to trochlear groove distance(TT-TG) 2D 14-21 mm; TT-TG 3D 11-18 mm; lateral trochlear inclination 13-23°; trochlear facet angle 43-65°. CONCLUSION: The demonstrated 3D analysis of the patellofemoral anatomy can be performed with high inter- and intra-observer correlation. Applying the obtained reference ranges and using existing 3D assessment tools for lower limb alignment, a preoperative 3D analysis and planning for complex knee procedures now is possible.

[Locking plate fixation of distal periprosthetic femoral fractures : Clinical outcome and mortality]. / Winkelstabile Plattenosteosynthese bei distalen periprothetischen Femurfrakturen : Klinisches Outcome und Mortalität.

BACKGROUND: The care of distal periprosthetic femoral fractures (PFF) is becoming a major interdisciplinary challenge due to demographic developments. The operative treatment is often performed (depending on the type of fracture) by means of locking plate fixation (LPF), although little data on the clinical outcome exist by now. The aim of the study is to identify risk factors for a poor outcome and increased mortality METHODS: In this retrospective study, 36 cases with distal PFF were examined. Exclusively treatment with LPF were included. Relevant previous illnesses (ASA score, Charlson index), fracture morphology and major complications were recorded as well as 1- and 3- year mortality. The clinical outcome was detected by using the Lysholm score. RESULTS: The 1- and 3- year mortality were 9% and 26% - exclusively affecting ASA 3 and 4 patients. The Lysholm Score showed a high variability (65 ± 27 points) with higher values in the ASA 1-2 subgroup (82 vs. 63 points) but independent of fracture type. The preoperative ASA score, the Charlson comorbidity index, and the patient age were determined to be decisive for 3-year mortality. CONCLUSION: This case series displayed a high absolute mortality even if the rate was slightly lower compared to previously published data. The rate of secondary dislocations, lack of fracture healing or follow-up operations were also low. The LPF therefore appears to be a suitable treatment for fractures with a stable prosthesis. However, there is a high variability in the clinical outcome regardless of the type of fracture and significantly increased mortality rates in previously ill patients.

[Gluteal compartment syndrome after immobilization following opioid abuse]. / Gluteales Kompartmentsyndrom nach Liegetrauma bei Opiatabusus.

This article reports the case of a 42-year-old male patient, who sustained a gluteal compartment syndrome after drug-induced immobilization with subsequent rhabdomyolysis and sciatic nerve palsy. Unlike compartment syndrome of the forearm or lower leg, this is a rare condition. After immediate surgical decompression and installation of negative pressure wound treatment, hemofiltration in acute renal failure could be averted using forced diuresis. The sensorimotor function of the lower extremity improved already after the first treatment and secondary wound closure was possible after 1 week. The patient was discharged 11 days after admission with complete recovery of sensorimotor and renal functions.

Hyperbaric oxygen therapy for iatrogenic arterial gas embolism after CT-guided lung biopsy : A case report.

Iatrogenic arterial gas embolism (AGE) can be life-threatening. The only causal treatment is immediate hyperbaric oxygen therapy (HBOT). This article reports on a case of a 74-year-old male patient who underwent computed tomography (CT)-guided lung biopsy of suspect nodules after squamous cell carcinoma of the tonsils. During puncture, sudden cardiovascular arrest occurred. The CT scan documented severe arterial gas embolism in the aorta, spinal canal, left heart ventricle, and brain. The patient was then transferred to our hospital for HBOT. After the first HBOT, an additional CT scan showed regression of all gas inclusions. In the treatment of gas embolism, HBOT is considered the gold standard and is indispensable. It is primarily used to reduce acute bubble effects and to avoid secondary bubble effects. Unfortunately, the long persisting gas occlusions and perfusion deficits led to severe hypoxic brain damage and a poor prognosis for the patient. In this case report we present the management of (iatrogenic) arterial gas embolism and point out the necessity of immediate HBOT. Furthermore, we discuss the pathophysiology leading to arterial gas embolism on the basis of the gas laws.

[Peri-implant femoral fracture following hip arthrodesis in adolescence]. / Periimplantäre Femurfraktur nach Hüftarthrodese im Jugendalter.

This article presents the case of an 83-year-old woman with a peri-implant femoral fracture after hip arthrodesis in adolescence. Due to the rarity of such operations, there is no standardized approach for these cases. In order to secure the treatment goal of rapid pain-adapted full weight bearing despite reduced bone quality, it was decided to perform a new osteosynthesis with a retrograde femoral nail after removal of some fixation screws of the existing arthrodesis plate. Due to this type of treatment, the preservation of activity and independence of an older trauma patient could be sustainably secured despite operative challenges. Taking an extended osteoporosis treatment into consideration, a bony fracture consolidation and complete convalescence of activity and autonomy were ultimately achieved.