Laparoscopic Acetabular Surgery (LASY) - vision or illusion?

Displaced acetabular fractures usually require open surgical approaches. Aim of this cadaver study was to evaluate a laparoscopic approach to prepare the anterior acetabular column and the quadrilateral plate in analogy to the laparoscopic pelvic lymphadenectomy. The laparoscopic preparation and anatomy is presented and illustrated step by step in a human cadaver followed by a modular plate osteosynthesis of the anterior column involving the quadrilateral plate is performed via a minimally invasive approach using standard laparoscopic instruments. In conclusion we could demonstrate that the laparoscopic preperitoneal preparation of the acetabulum according to the laparoscopic pelvic lymphadenectomy provides more free range for the surgical instruments compared to a previously described total extraperitoneal approach. The development of specific reduction tools and implants is under investigation. Until then, at least the laparoscopic preparation could be introduced in the clinical setting in the near future. TYPE OF STUDY: Technical note - Cadaver study.

Early Decompression (<8 Hours) Improves Functional Bladder Outcome and Mobility After Traumatic Thoracic Spinal Cord Injury.

BACKGROUND: There is accumulating evidence of a potential beneficial effect of early surgical intervention after acute cervical spinal cord injury (SCI). However, around one third of all SCIs affect the thoracic spine. This cohort has not been extensively investigated, mainly because of less sensitive clinical readout measures. Apart from regaining full sensorimotor function, improvements in bladder and bowel management remain of the highest priority for patients with chronic paraplegia. Therefore, this study investigates the effect of early decompression (here defined as <8 hours) versus delayed management on neurologic and functional outcome. METHODS: We retrospectively analyzed data from the institutional database, in which follow-up data were collected prospectively according to the European Multicenter Study about Spinal Cord Injury standards. Within a 13-year period, we identified 43 patients who met inclusion and exclusion criteria. Of these, 32 (74%) were managed surgically within the first 8 hours. There was a trend toward a higher rate of patients with clinically complete SCI in the early group at baseline. RESULTS: After 1 year, we did not observe a benefit on the neurologic outcome as assessed via the American Spinal Injury Association Impairment Scale grade. Functional outcome was evaluated using the Spinal Cord Independence Measure (SCIM). The early decompressed group demonstrated significantly improved SCIM 6 (i.e., bladder management) (P < 0.045) and SCIM 9-11 subitems (i.e., mobility, transfer) (P < 0.019). CONCLUSIONS: Early decompression was an independent predictor for improved functional bladder outcome and mobility after 1 year. This effect needs to be studied in future prospective, multicenter studies.

EASY (endoscopic approach to the symphysis): a new minimally invasive approach for the plate osteosynthesis of the symphysis and the anterior pelvic ring-a cadaver study and first clinical results.

BACKGROUND: Minimally invasive surgical approaches to reduce approach-associated morbidity are an interdisciplinary goal in surgery. In principle, the endoscopic approach for the extraperitoneal repair of groin hernias is the minimally invasive variant of the modified Stoppa-approach, which is used for the treatment of pelvic ring injuries in traumatology. METHOD: Anatomical feasibility study regarding the plate osteosynthesis of the anterior pelvic ring via a minimally invasive variant of the modified Stoppa-approach. RESULTS: We present the minimally invasive variant of the modified Stoppa-approach in a human cadaver step by step, both photographically and radiologically. Feasibility of the plate osteosynthesis of the symphysis is presented in a patient with open book injury via the minimally invasive approach using standard laparoscopic instruments. CONCLUSION: The plate osteosynthesis of the anterior pelvic ring via the minimally invasive variant of the modified Stoppa-approach is feasible with existing standard laparoscopic instruments.

Virtual mapping of 260 three-dimensional hemipelvises to analyse gender-specific differences in minimally invasive retrograde lag screw placement in the posterior acetabular column using the anterior pelvic and midsagittal plane as reference.

BACKGROUND: Due to complex pelvic geometry, percutaneous screw placement in the posterior acetabular column can pose a major challenge even for experienced surgeons. METHODS: The present study examined the preformed bone stock of the posterior acetabular column in 260 hemipelvises. Retrograde posterior column screws were virtually implanted using iPlan CMF (BrainLAB AG, Feldkirchen, Germany); maximal implant length, maximal implant diameter and angles between the screw trajectories and the reference planes anterior pelvic plane as well as the midsagittal plane were assessed for gender-specific differences. RESULTS: The virtual analysis of the preformed bone stock column showed two constrictions of crucial clinical importance. These were located 49.6 ± 3.4 (41.0-60.2) mm (inferior margin of acetabulum) and 77.0 ± 5.6 (66.5-95.3) mm (centre of acetabulum) from the entry point of the implant in men and respectively 43.7 ± 2.3 (38.3-49.3) mm as well as 71.2 ± 3.5 (63.5-79.99) mm in women (men vs. women: p < 0.001). The entry point of the retrograde posterior column screw was located dorsal from the transition of the lower margin of the ischial tuberosity to ramus inferior pointing to the medial margin of the ischial tuberosity. In female patients, the entry point was located significantly closer to the medial margin of the ischial tuberosity. However, 7.3 mm screws can generally be used in men and women. The angle between the screw trajectory and the anterior pelvic plane in sagittal section was 14.0 ± 4.9 (2.5-28.6) °, the angle between the screw trajectory and the midsagittal plane in axial section was 31.1 ± 12.8 (1.5-77.9) ° and the angle between the screw trajectory and the midsagittal plane in coronal section was 8.4 ± 3.8 (1.5-20.0) °. For all angles, significant gender-specific differences were found (p < 0.001). CONCLUSION: Therefore, the anterior pelvic plane as well as the midsagittal plane can facilitate intraoperative orientation for retrograde posterior column screw placement considering gender-specific differences in preformed bone corridor, implant length as well as angles formed between screw trajectory and these reference planes.

Retrograde lag screw placement in anterior acetabular column with regard to the anterior pelvic plane and midsagittal plane -- virtual mapping of 260 three-dimensional hemipelvises for quantitative anatomic analysis.

Percutaneous screw placement can be used for minimally invasive treatment of none or minimally displaced fractures of the anterior column. The complex pelvic geometry can pose a major challenge even for experienced surgeons. The present study examined the preformed bone stock of the anterior column in 260 hemipelvises (130 male and 130 female). Screws were virtually implanted using iPlan(®) CMF (BrainLAB AG, Feldkirchen, Germany); the maximal implant length and the maximal implant diameter were assessed. The study showed, that 6.5mm can generally be used in men; in women however individual planning is essential in regard to the maximal implant diameter since we found that in 15.4% of women, screws with a diameter less than 6.5mm were necessary. The virtual analysis of the preformed bone stock corridor of the anterior column showed two constrictions of crucial clinical importance. These can be found after 18% and 55% (men) respectively 16% and 55% (women) measured from the entry point along the axis of the implant. The entry point of the retrograde anterior column screw in our collective was located lateral of tuberculum pubicum at the level of the superior-medial margin of foramen obturatum. In female patients, the entry point was located significantly more lateral of symphysis and closer to the cranial margin of ramus superior ossis pubis. The mean angle between the screw trajectory and the anterior pelvic plane in sagittal section was 31.6 ± 5.5°, the mean angle between the screw trajectory and the midsagittal plane in axial section was 55.9 ± 4.6° and the mean angle between the screw trajectory and the midsagittal plane in coronal section was 42.1 ± 3.9° with no significant deviation between both sexes. The individual angles formed by the screw trajectory and the anterior pelvic and midsagittal plane are independent from anthropometric parameters sex, age, body length and weight. Therefore, they can be used for orientation in lag screw placement keeping in mind that the entry point differs in both sexes.

Computer-assisted periacetabular screw placement: Comparison of different fluoroscopy-based navigation procedures with conventional technique.

The current gold standard for operatively treated acetabular fractures is open reduction and internal fixation. Fractures with minimal displacement may be stabilised by minimally invasive methods such as percutaneous periacetabular screws. However, their placement is a demanding procedure due to the complex pelvic anatomy. The aim of this study was to evaluate the accuracy of periacetabular screw placement assessing pre-defined placement corridors and comparing different fluoroscopy-based navigation procedures and the conventional technique. For each screw an individual periacetabular placement corridor was preoperatively planned using the planning software iPlan CMF(©) 3.0 (BrainLAB). 210 screws (retrograde anterior column screws, retrograde posterior column screws, supraacetabular ilium screws) were placed in an artificial Synbone pelvis model (30 hemipelves) and in human cadaver specimen (30 hemipelves). 2D- and 3D-fluoroscopy-based navigation procedures were compared to the conventional technique. Insertion time and radiation exposure to specimen were also recorded. The achieved screw position was postoperatively assessed by an Iso-C(3D) scan. Perforations of bony cortices or articular surfaces were analysed and the screw deviation severity (difference of the operatively achieved screw position and the preoperatively planned screw position in reference to the pre-defined corridors) was determined using image fusion. Using 3D-fluoroscopy-based navigation, the screw perforation rate (7%) was significantly lower compared to 2D-fluoroscopy-based navigation (20%). For all screws, the deviation severity was significantly lower using a 3D- compared to a 2D-fluoroscopy-based navigation and the conventional technique. Analysing the posterior column screws, the screw deviation severity was significantly lower using 3D- compared to 2D-fluoroscopy-based navigation. However, for the anterior column screw, the screw deviation severity was similar regardless of the imaging method. Despite the advantages of the 3D-fluoroscopy-based navigation, this method led to significantly longer total procedure and fluoroscopic times, and the applied radiation dose was significantly higher. Percutaneous periacetabular screw placement is demanding. Especially for posterior column screws, due to a lower perforation rate and a higher accuracy in periacetabular screw placement, 3D-fluoroscopy-based navigation procedure appears to be the method of choice for image guidance in acetabular surgery.

Changes in the treatment of acetabular fractures over 15 years: Analysis of 1266 cases treated by the German Pelvic Multicentre Study Group (DAO/DGU).

Epidemiological, clinical and radiological data of 1266 patients with a unilateral acetabular fracture of up to 29 hospitals was reviewed. Three time periods, 1991-1993 (Registry I; n=359), 1998-2000 (Registry II; n=503), and 2005-2006 (Registry III; n=404) were compared with regard to injury pattern and severity, fracture type, and chosen nonoperative vs. operative treatment to elucidate changes over time in the treatment of acetabular fractures. In the operatively treated group, time to operation, surgical approach, fracture fixation implants and fracture reduction quality were examined. 641 (50.6%) patients with isolated acetabular fractures, 410 (32.4%) multiple injured and 215 (17.0%) polytrauma patients with 642 (50.7%) simple and 624 (49.3%) associated acetabular fractures were evaluated. In the time period from 1991 to 2006, the rate of operative treatments increased nationwide to 77% (rho<0.001). The distribution of fracture types involving the anterior and posterior wall changed with age (rho<0.001). Across all registries, 583 (68.0%) operations were performed within 7 days, 212 (24.7%) operations between 7 and 14 days and 54 (6.3%) operations were performed later than 14 days after injury. An anatomical reduction (0-1mm displacement) was achieved in 551 (64%) acetabular fractures. The obtained reduction quality did not correlate with time to operation, was lower in associated than in simple fracture types, and also lower in patients with isolated acetabular fractures than in polytrauma patients. Most importantly, the fracture reduction quality did not improve over time despite a higher frequency of surgical interventions. The Kocher-Langenbeck approach was preferred in the nineties in nearly three quarters of all operative procedures. Currently, the Kocher-Langenbeck and the ilioinguinal approaches are used equally often. The fracture fixation did not change over time and is achieved in 51% with plates in combination with single screws. This multisurgeon series illustrates a nationwide performance in acetabular fracture management. Despite changes in the chosen approaches and an increased surgical frequency, the operative treatment of acetabular fractures of the last 15 years did not lead to an increased reduction quality. Therefore, the rarity and complexity of acetabular fractures demands further specific teaching by experienced acetabular surgeons, scientific research and clinical outcome evaluation.