Percutaneous screw fixation of the iliosacral joint: A case-based preoperative planning approach reduces operating time and radiation exposure.

INTRODUCTION: A preoperative planning approach for percutaneous screw fixation of the iliosacral joint provides specific entry points (EPs) and aiming points (APs) of intraosseous screw pathways (as defined by CT scans) for lateral fluoroscopic projections used intraoperatively. The potential to achieve the recommended EPs and APs, to obtain an ideal screw position (perpendicular to the iliosacral joint), to avoid occurrence of extraosseous screw misplacement, to reduce the operating time and the radiation exposure by utilizing this planning approach have not been described yet. METHODS: On preoperative CT scans of eight human cadaveric specimen individual EPs and APs were identified and transferred to the lateral fluoroscopic projection using a coordinate system with the zero-point in the center of the posterior cortex of the S1 vertebral body (x-axis parallel to upper S1 endplate). Distances were expressed in relation to the anteroposterior distance of the S1 upper endplate (in%). In each specimen on one side a screw was placed with provided EP and AP (New Technique) whereas at the contralateral side a screw was placed without given EP and AP (Conventional Technique). Both techniques were compared using postoperative CT scans to assess distances between predefined EPs and APs and the actually obtained EPs and APs, screw angulations in relation to the iliosacral joint in coronal and axial planes and the occurrence of any extraosseous screw misplacement. The "operating time (OT)" and the "time under fluoroscopy (TUF)" were recorded. Statistical analysis was performed by the Wilcoxon signed-rank test. RESULTS: EPs were realized significantly more accurate using the new technique in vertical direction. The screw positions in relation to the iliosacral joint showed no significant difference between both techniques. Both techniques had one aberrantly placed screw outside the safe corridor. The (mean±SD) "OT" and the (mean±SD) "TUF" were significantly decreased using the new technique compared to the conventional technique (OT: 7.6±2min versus 13.1±5.8min, p=0.012; TUF: 1.5±0.8min versus 2.2±1.1min). CONCLUSION: The presented preoperative planning approach increases the accuracy in percutaneous screw fixation of the iliosacral joint, reduces operating time and minimizes radiation exposure to patient and staff.

Rationales for the Bernese approaches in acetabular surgery.

PURPOSE: To present two new approaches to acetabular surgery that were established in Berne, and which aim at enhanced visualization and anatomical reconstruction of acetabular fractures. METHOD: The trochanteric flip osteotomy allows for surgical hip dislocation, and was introduced as a posterior approach for acetabular fracture management involving the posterior column and wall. For acetabular fractures predominantly involving the anterior column and the quadrilateral plate, the Pararectus approach is described. RESULTS: Full exposure of the hip joint, as provided by the trochanteric flip osteotomy, facilitates anatomical reduction of acetabular or femoral head fractures and safe positioning of the anterior column screw in transverse or T-shaped fractures. Additionally, the approach enables osteochondral transplantation as a salvage procedure for severe chondral femoral head damage and osteoplasty of an associated inadequate offset at the femoral head-neck junction. The Pararectus approach allows anatomical restoration with minimal access morbidity, and combines advantages of the ilioinguinal and modified Stoppa approaches. CONCLUSIONS: Utilization of the trochanteric flip osteotomy eases visualization of the superior aspect of the acetabulum, and enables the evaluation and treatment of chondral lesions of the femoral head or acetabulum and labral tears. Displaced fractures of the anterior column with a medialized quadrilateral plate can be addressed successfully through the Pararectus approach, in which surgical access is associated with minimal morbidity. However, long-term results following the two presented Bernese approaches are needed to confirm that in the treatment of complex acetabular fractures the rate of poor results in almost one-third of all cases (as currently yielded using traditional approaches) might be reduced by the utilization of the presented novel approaches.

The Pararectus approach for anterior intrapelvic management of acetabular fractures: an anatomical study and clinical evaluation.

A new anterior intrapelvic approach for the surgical management of displaced acetabular fractures involving predominantly the anterior column and the quadrilateral plate is described. In order to establish five 'windows' for instrumentation, the extraperitoneal space is entered along the lateral border of the rectus abdominis muscle. This is the so-called 'Pararectus' approach. The feasibility of safe dissection and optimal instrumentation of the pelvis was assessed in five cadavers (ten hemipelves) before implementation in a series of 20 patients with a mean age of 59 years (17 to 90), of whom 17 were male. The clinical evaluation was undertaken between December 2009 and December 2010. The quality of reduction was assessed with post-operative CT scans and the occurrence of intra-operative complications was noted. In cadavers, sufficient extraperitoneal access and safe instrumentation of the pelvis were accomplished. In the patients, there was a statistically significant improvement in the reduction of the fracture (pre- versus post-operative: mean step-off 3.3 mm (sd 2.6) vs 0.1 mm (sd 0.3), p < 0.001; and mean gap 11.5 mm (sd 6.5) vs 0.8 mm (sd 1.3), p < 0.001). Lesions to the peritoneum were noted in two patients and minor vascular damage was noted in a further two patients. Multi-directional screw placement and various plate configurations were feasible in cadavers without significant retraction of soft tissues. In the treatment of acetabular fractures predominantly involving the anterior column and the quadrilateral plate, the Pararectus approach allowed anatomical restoration with minimal morbidity related to the surgical access.

[Minimally invasive unicondylar knee arthroplasty with simultaneous ACL reconstruction : treatment of medial compartment osteoarthritis and cruciate ligament defect]. / Mediale Gonarthrosen mit Kreuzbanddefekt : Kombinierte Versorgung mittels unikondylärer Endoprothese und additivem Kreuzbandersatz.

BACKGROUND: Low postoperative pain level, decreased length of hospital stay and accelerated rehabilitation are the major benefits of unicondylar knee arthroplasty. Especially in comparably young, not yet retired and still active patients with an isolated medial gonarthrosis, these prostheses offer many advantages. However, one important requirement to be treated with such implants is a well functioning stability system of the muscles and ligaments. Thus in patients with degenerated or destroyed anterior cruciate ligaments it is contraindicated to use this method. In order to still take advantage of this therapy for treatment of isolated arthrosis, reestablishment of the proprioceptive structures through simultaneous or staged ACL reconstruction is mandatory. PATIENTS AND METHODS: Pursuing this goal we performed unicondylar knee arthroplasty with simultaneous ACL reconstruction on eligible patients. Between 2003 and 2006 we treated 32 knees with this combined surgery and followed them for a mean of 31 months (range: 10-38). RESULTS: The mean Knee Society Score significantly improved from 83.2 (44-103) to 167.6 (145-177) at a mean follow-up of 31 months (10-38). CONCLUSIONS: Preliminary results of this short-term follow-up are promising. Especially the predominant number of patients who were able to return to work soon after rehabilitation and the significantly improved score postoperatively reflect the benefits of this prosthesis system in select patients. However, long-term follow-up and larger case numbers are necessary to confirm these encouraging results in the future.

Application of surgical navigation to total hip arthroplasty.

Instability, impingement, and leg-length discrepancy are among the most common early problems following total hip arthroplasty (THA). Component positioning is the primary factor affecting all three of these issues and, therefore, all three can be potentially addressed using surgical navigation. While the advent of less invasive surgical techniques performed through smaller incisions has been shown to accelerate recovery, these techniques have also been associated with a further increase in the incidence of these three problems. Acetabular component malpositioning has been a particular problem with less invasive surgical techniques. Nonetheless, it is clear that maximal preservation of the soft tissues around the hip joint may accelerate recovery following surgery and confer greater hip joint stability. Accomplishing these goals without compromising component positioning is the single greatest potential advantage to the application of surgical navigation to THA. The present paper describes the general principles of surgical navigation in THA with respect to methods of tracking, methods of registration, the role of image-free and image-based navigation, and methods of measuring leg-length change during surgery. Further, a description is given of the clinical effect of combining surgical navigation with use of the superior capsulotomy technique of performing THA, which aims maximally to preserve the soft tissues surrounding the hip joint, allowing unrestricted progression of motion and weight-bearing following surgery. These methods have led to statistically significant acceleration of recovery, improvement in acetabular component positioning, and reductions in peri-operative surgical complications.