Ilioinguinal Approach: Indication and Technique.

This video on the ilioinguinal approach presents its indications and techniques for the operative treatment of acetabular fractures. The principle of the ilioinguinal approach is to work through 3 different windows. The lateral window gives access to the pelvic bone from the sacroiliac joint to the lateral border of the iliopsoas muscle, the middle window accesses the medial border of the iliopsoas muscle to the femoral artery, and the medial window allows for control of the anterior pelvic ring medially from the femoral vein to the symphysis pubis. In this video, we demonstrate anatomical reconstruction of the acetabulum in a patient with an associated both-column fracture using the ilioinguinal approach. Indications are all acetabular fracture types, where in addition to anterior column fracture, a fractured posterior column is reducible through the middle window, that is, there is no involvement of the posterior column or wall that would necessitate a direct posterior approach. The ilioinguinal approach is a standard anatomical approach that gives an excellent visual and palpatory exposure of the anterior column up to the symphysis pubis and of the quadrilateral plate. Indications and techniques, how to develop this approach for the anatomical reduction and fixation of appropriate acetabular fractures, are demonstrated in this video.

Malpositioning of the lag screws by 1- or 2-screw nailing systems for pertrochanteric femoral fractures: a biomechanical comparison of gamma 3 and intertan.

OBJECTIVES: The aim of this investigation was to perform a biomechanical comparison between 1- and 2-screw systems used for the treatment of intertrochanteric fractures for centralized and decentralized placement of femoral neck screws of failure loads, stiffness, survival rates, tip apex distance (TAD), and failure mode. METHODS: As fracture model, an AO 31A2.3 fracture was used. Twelve pairs of human cadaver femora were tested. Femoral neck screws were implanted in the femoral head in center/center, posterior/central, and anterior/superior position in axial/frontal plane. A single-screw system (Gamma 3 Locking Nail; Stryker GmbH & Co. KG) and a 2-screw system (Trigen-Intertan; Smith & Nephew GmbH) were used. To simulate the load in situ, a cyclic load was carried for 10,000 cycles in a material testing machine. If no cyclic failure occurred, femora were loaded until the failure. The systems were compared according to the stiffness, survivability through 10 k cycles, TAD, and load to failure. RESULTS: None of the tested bones failed at center/center location in the decentralized positions 3 Gamma Nail and 2 Intertan specimens failed during cyclic testing. The 2-screw system resisted higher forces in all positions (Gamma: 5370N ± 1924, Intertan: 7650N ± 2043; P = 0.014). CONCLUSIONS: Based on these data, it is clear that both the nail systems showed a higher biomechanical stability with a lower TAD. The 2 specimens that failed with the Intertan in the cyclic tests had a TAD ≥49 mm. The cutout failures that we detected during cyclic testing in the Gamma system had a TAD ≥30 mm. Thus, it is clear that the TAD affects failure independent of the implant used. With a less than ideal lag screw placement, however, the Intertan system with 2 integrated screws was able to withstand higher loads in this study.

Electromagnetic navigation provides high accuracy for transcoracoid-transclavicular drilling.

PURPOSE: A novel radiation-free electromagnetic navigation system (ENS)-based method was developed, and its feasibility and accuracy for transclavicular-transcoracoid drilling procedures were evaluated in an experimental setting. METHODS: Sixteen arthroscopically assisted electromagnetic navigated transcoracoid-transclavicular drilling procedures with subsequent TightRope device implantation were performed on eight human cadavers. Post-operative fluoroscopy and CT-scan analysis were acquired to determine tunnel placement accuracy. Optimal tunnel placement was defined as both the coracoid entry and exit point of the tunnel localized in the centre position of the coracoid base without cortical breach or fracture. RESULTS: Successful tunnel placement was accomplished in all 16 cases. The mean overall operation time was 30.3 ± 5.0 min. Regarding the coracoid exit point, 15 of 16 tunnels (93.8%) were localized in the desired base-centre position. During the navigated drilling procedure, no misguidance of the drill requiring directional readjustments or restarts occurred. No cortical breach, no fractures and no complications occurred. CONCLUSIONS: The electromagnetically navigated transcoracoid-transclavicular drilling procedure used in this study demonstrated high targeting accuracy, required no intraoperative radiographs, was associated with no complications and provided user-friendliness.

Retrograde drilling of talar osteochondritis dissecans lesions: a feasibility and accuracy analysis of a novel electromagnetic navigation method versus a standard fluoroscopic method.

PURPOSE: A novel method using an electromagnetic navigation system (ENS) was developed, and its feasibility and accuracy for retrograde drilling procedures were evaluated and compared with the standard freehand fluoroscopic method in an experimental setting. METHODS: A controlled laboratory study of 16 standard freehand fluoroscopically guided and 16 electromagnetically navigated retrograde drilling procedures was performed on 4 cadaveric human ankle joints. Four artificial cartilage lesions were consecutively set, 2 on the medial and 2 on the lateral talar dome. Drilling accuracy was measured in terms of the distance from the final position of the drill bit to the tip of the probe hook and the distance between the tip of the drill bit and the center of the cartilage lesion on the articular cartilage surface. Intraoperative fluoroscopy exposure times were documented, as were readjustments of drilling directions or complete restarts. All procedures were timed with a stopwatch. RESULTS: Successful retrograde drilling was accomplished in 12 cases with the standard fluoroscopy-guided technique and in all 16 ENS-guided procedures. The overall mean time for the fluoroscopy-guided procedures was 660.00 ± 239.87 seconds and the overall mean time for the ENS method was 308.06 ± 54.03 seconds, providing a mean time benefit of 420.13 seconds. The mean distance from the final position of the drill bit to the tip of the probe hook was 3.25 ± 1.29 mm for the standard method and 2.19 ± 0.54 mm for the ENS method, and the mean distance between the tip of the drill bit and the center of the cartilage lesion on the articular cartilage surface was 2.50 ± 0.97 mm for the standard method and 0.88 ± 0.81 mm for the ENS method. CONCLUSIONS: Compared with the standard fluoroscopic technique, the ENS method used in this study showed higher accuracy and a shorter procedure time and required no X-ray radiation. CLINICAL RELEVANCE: The novel method considerably improves on the standard operating procedure in terms of safety, operation time, and radiation exposure.

Next generation distal locking for intramedullary nails using an electromagnetic X-ray-radiation-free real-time navigation system.

BACKGROUND: Distal locking marks one challenging step during intramedullary nailing that can lead to an increased irradiation and prolonged operation times. The aim of this study was to evaluate the reliability and efficacy of an X-ray-radiation-free real-time navigation system for distal locking procedures. METHODS: A prospective randomized cadaver study with 50 standard free-hand fluoroscopic-guided and 50 electromagnetic-guided distal locking procedures was performed. All procedures were timed using a stopwatch. Intraoperative fluoroscopy exposure time and absorbed radiation dose (mGy) readings were documented. All tibial nails were locked with two mediolateral and one anteroposterior screw. Successful distal locking was accomplished once correct placement of all three screws was confirmed. RESULTS: Successful distal locking was achieved in 98 cases. No complications were encountered using the electromagnetic navigation system. Eight complications arose during free-hand fluoroscopic distal locking. Undetected secondary drill slippage on the ipsilateral cortex accounted for most problems followed by undetected intradrilling misdirection causing a fissural fracture of the contralateral cortex while screw insertion in one case. Compared with the free-hand fluoroscopic technique, electromagnetically navigated distal locking provides a median time benefit of 244 seconds without using ionizing radiation. CONCLUSION: Compared with the standard free-hand fluoroscopic technique, the electromagnetic guidance system used in this study showed high reliability and was associated with less complications, took significantly less time, and used no radiation exposure for distal locking procedures. LEVEL OF EVIDENCE: Therapeutic study, level II.

Accuracy analysis of a novel electromagnetic navigation procedure versus a standard fluoroscopic method for retrograde drilling of osteochondritis dissecans lesions of the knee.

BACKGROUND: Retrograde drilling for osteochondritis dissecans (OCD) remains a challenging operation. PURPOSE: A novel radiation-free electromagnetic navigation system (ENS)-based method was developed and its feasibility and accuracy for retrograde drilling procedures evaluated and compared with the standard freehand fluoroscopic method in an experimental setting. STUDY DESIGN: Controlled laboratory study. METHODS: A controlled laboratory study with 16 standard freehand fluoroscopically and 16 electromagnetically guided retrograde drilling procedures was performed on 8 cadaveric human knees. Four artificial cartilage lesions (2 on each condyle) were set per knee. Drilling accuracy was determined by final distance from the tip of the drill bit to the tip of the probe hook (D1) and distance between the tip of the drill and the marked lesion on the cartilage surface (D2). Intraoperative fluoroscopy exposure times were documented, as were directional readjustments or complete restarts. All procedures were timed using a stopwatch. RESULTS: Successful retrograde drilling was accomplished in all 16 cases using the novel ENS-based method and in 11 cases using the standard fluoroscopic technique. The overall mean time for the fluoroscopy-guided procedures was 10 minutes 55 seconds ± 3 minutes 19 seconds and for the ENS method was 5 minutes 34 seconds ± 38 seconds, providing a mean time benefit of 5 minutes 35 seconds (P < .001). Mean D1 was 3.8 ± 1.6 mm for the standard and 2.3 ± 0.6 mm using the ENS technique (P = .021), and mean D2 was 2.5 ± 1.3 mm for the standard and 0.9 ± 0.7 mm for the ENS-based method (P < .001). CONCLUSION: Compared with the standard fluoroscopic technique, the novel ENS-based method used in this study showed superior accuracy, required less time, and utilized no radiation. CLINICAL RELEVANCE: The novel method improves a standard operating procedure in terms of accuracy, operation time for the retrograde drilling procedure, and radiation exposure.

Radiological dorsal tilt analysis of AO type A, B, and C fractures of the distal radius treated conservatively or with extra-focal K-wire plus external fixateur.

OBJECTIVE: Fractures of the distal radius are amongst the most common injury patterns. The dorsal tilt represents an important co-factor determining functional outcome. The purpose of this study was to analyze the radiological dorsal tilt and identify critical time frames in conservative and operative treatment of distal radius fractures. MATERIALS AND METHODS: Eighty-seven conservatively treated (hematoma block assisted reduction and splinting) and 37 operatively treated (reduction, extra-focal K-wire fixation, bridging external fixateur) AO type A, B, and C fractures of the distal radius in 124 females were retrospectively analyzed. The dorsal tilt at the initial, post-reduction, and 2 weeks post-reduction stages was correlated with the final radiographic outcome at 6 weeks. RESULTS: Mean initial dorsal tilt was 16.53° in the conservatively treated group and 26.76° in the operatively treated group. Mean dorsal tilt after 6 weeks showed significant differences from the mean initial dorsal tilt at time of presentation within both groups (both groups p < 0.000). No significant differences between the two groups were found after 6 weeks of treatment (p = 0.194) regardless of the underlying AO fracture type. Conservatively treated radius fractures showed a significantly higher slip rate within the first 2 weeks (primary slip rate), whereas the operative group presented a significantly higher slip rate between the 2-week and 6-week radiographic checks (secondary slip rate). CONCLUSION: In terms of dorsal tilt, conservative (cast immobilization) and operative (K-wire fixation plus external fixateur) treatment demonstrated no significant differences at the final radiographic examination (6 weeks) regardless of the underlying AO fracture type. Both treatment groups showed treatment-associated different primary and secondary slip rates, indicating a need for more frequent radiographic checks within these critical time frames.

Arthroscopically assisted retrograde drilling for osteochondritis dissecans (OCD) lesions of the knee.

PURPOSE: Accurate retrograde drilling for osteochondritis dissecans lesions remains technically challenging. A novel, radiation-free method using an electromagnetic guidance system was developed, and its feasibility and accuracy for retrograde drilling procedures evaluated in an experimental setting. METHODS: Sixteen arthroscopically assisted, electromagnetically guided retrograde drilling procedures were performed in 4 human cadaveric knee joints. Therefore, two artificial cartilage lesions were set consecutively on each condyle. Final drill bit position was documented in two planes using fluoroscopy. Subsequently, drilling accuracy was measured in terms of distance from the final position of the drill bit to the articular cartilage surface (D1), and distance between the tip of the drill bit to the centre of the cartilage lesion on the articular cartilage surface (D2). All procedures were timed using a stopwatch. RESULTS: Successful retrograde drilling was accomplished in all 16 cases. The overall mean time for the retrograde drilling procedures was 361.6 ± 34.7 s. Mean D1 was 2.2 ± 0.5 mm; mean D2 was 0.8 ± 0.7 mm. No complications occurred. CONCLUSIONS: The novel electromagnetic guidance system used in this study showed accurate targeting results, required no radiation, was associated with no complications and demonstrated user-friendliness. LEVEL OF EVIDENCE: II.

A comparative biomechanical analysis of fixation devices for unstable femoral neck fractures: the Intertan versus cannulated screws or a dynamic hip screw.

BACKGROUND: First introduced in 2005, the "Intertan" (IT), an intramedullary nail with two cephalocervical screws, has become an increasingly popular option for treating intertrochanteric fractures. The purpose of this study was to identify the utility of this device for stabilization of unstable femoral neck fractures compared with cannulated screws (CS) and a dynamic hip screw (DHS). METHODS: Twenty-four human cadaveric femurs were harvested and assigned to three groups that were matched with regard to bone mineral density (BMD). Standardized Pauwels-Type-III fractures were osteomized with a custom-made saw guide and fixated by an "IT," three CS, or a DHS. All constructs were biomechanically tested in a servohydraulic testing machine with a physiologic mechanical axis loading of the femoral head (700 N), cyclical compression to 1,400 N (10,000 cycles; 2 Hz), and loading to failure. All specimens were compared with respect to the number of survived cycles, mechanical strength, head displacement, load to failure, and failure mechanism. RESULTS: Regardless of the fixation, the mechanical strength of the stabilized femurs was significantly decreased to 71% compared with the intact femurs (100%). During cyclical testing 46% of the constructs (6 CS, 4 DHS, and 1 IT) failed. There was no difference between the mechanical strength of all survived constructs regarding the BMD, but the BMD of the failed specimens was significantly reduced compared with the surviving femurs (0.71 g/cm² ± 0.18 g/cm² vs. 1.07 g/cm² ± 0.33 g/cm²; p < 0.05). IT femurs survived significantly longer than CS specimens (IT, 9,063 cycles ± 2,480 cycles vs. CS, 3,325 cycles ± 3,885 cycles vs. DHS, 5,716 cycles ± 4,448 cycles; p < 0.01), endured higher failure loads (IT, 4,929 N ± 1,105 N vs. CS, 3,421 N ± 20 N vs. DHS, 3,505 N ± 905 N; p < 0.05), and presented a less inferior head displacement (IT, 8.5 mm ± 1.6 mm vs. CS, 16.4 mm ± 6.7 mm vs. DHS, 14.5 mm ± 6.4 mm; p < 0.05). CONCLUSION: Our results suggest that (1) none of the tested devices restore a comparable mechanical strength in the fractured specimens compared with the intact femurs, and (2) the "IT" possesses some biomechanical benefits for internal fixation of unstable femoral neck fractures compared with DHS and CS. Because the IT constructs failed with an inferior femoral neck fracture, complicating the mandatory anchorage of a prosthetic stem in a revision operation, more biomechanical experiments using the IT in the presence of a posterior comminution defect are required, along with clinical outcome studies.

Computer-assisted surgery and intraoperative three-dimensional imaging for screw placement in different pelvic regions.

BACKGROUND: The purpose of this study was to assess the feasibility and accuracy of computer-assisted surgery (CAS) for screw placement in different pelvic regions using intraoperative three-dimensional (3D) imaging and to evaluate the influence of surgeons' experience with such a system on procedure time, radiation time, radiation dose, and misplacement rate. METHODS: Experimental study in a human cadaveric model (n=5) for percutaneous screw placement in the anterior column of the acetabulum, the posterior pelvic ring (S1, S2), and the superior pubic ramus via 3D fluoroscopic navigated procedure. Accuracy of screw placement was assessed by 3D image intensifier, including the reconstruction of multiplanar images and by computer tomography (CT) scan. Influence of surgeons' experience was assessed by direct comparison of a low- and high-volume surgeon using the same technical setting. RESULTS: In 100% of all procedures, intraoperative Iso-C3D image analysis was sufficient to confirm a correct screw placement. The postoperative CT scan revealed no further screw misplacement. However, for a correct supraacetabular screw placement, the intraoperative 3D scan was essential. In this group, the 3D scan showed screw misplacement in three cases. Procedure time for all indications and screw failure rate were significantly lower for the higher experienced surgeon. CONCLUSION: The 3D fluoroscopic navigated procedure in pelvic surgery seems to be a useful tool for all surgeons and especially for less experienced ones. Furthermore, the intraoperative reconstruction of multiplanar 3D images allows a secure control of implant positioning.

3D fluoroscopic navigated reaming of the glenoid for total shoulder arthroplasty (TSA).

Survival rates for total shoulder arthroplasty are critically dependent on the correct placement of the glenoid component. Especially in osteoarthritis, pathological version of the glenoid occurs frequently and has to be corrected surgically by eccentric reaming of the glenoid brim. The aim of our study was to evaluate whether eccentric reaming of the glenoid can be achieved more accurately by a novel computer assisted technique. Procedures were conducted on 10 paired human cadaveric specimens presenting glenoids with neutral version. To identify the correction potential of the navigated technique compared to the standard procedure, asymmetric reaming of the glenoid to create a version of -10° was defined as the target. In the navigated group, asymmetric reaming was guided by a 3D fluoroscopic technique. Postoperative 3D scans revealed greater accuracy for the eccentric reaming procedure in the navigated group compared to the freehand group, resulting in glenoid version of -9.8 ± 3.8° and -5.1 ± 4.1°, respectively (p < 0.05). Furthermore, deviation from preoperative planning was significantly reduced in the navigated group. These data indicate that our navigated procedure offers an excellent tool for supporting glenoid replacement in TSA.

The treatment of intertrochanteric fractures: results using an intramedullary nail with integrated cephalocervical screws and linear compression.

OBJECTIVE: A new device for the treatment of intertrochanteric fractures that uses 2 cephalocervical screws in an integrated mechanism allowing linear intraoperative compression and rotational stability of the head/neck fragment has been developed. The aim of this study was to describe the results using this device for the treatment of stable and unstable intertrochanteric fractures. DESIGN: Prospective, consecutive. SETTING: Academic Trauma Center. METHODS: Between March 1, 2005, and July 31, 2006, 100 consecutive patients with an intertrochanteric fracture were treated with a new trochanteric antegrade nail (InterTan; Smith-Nephew, Memphis, TN). All living patients were followed up for a minimum of 1 year postoperatively (range 12-27 months). Clinical and radiographic examinations were performed until healing and at the 1-year anniversary of the index procedure. Healing, pain with ambulation, return to activities of daily living, the modified Harris hip score, and Barthel Index were used to evaluate outcomes. RESULTS: The mean age of the patients was 81.2 (+/-11.3) years. Thirty-seven patients died, 12 were too infirmed for follow-up, and 3 could not be located, leaving 48 patients available for final evaluation. The average surgical time was 41 minutes (13-95 minutes). This rose significantly with the complexity of the fracture (OTA/AO classification: A1 versus A3, P = 0.016). All fractures healed within 16 weeks (range 10-16 weeks). Radiographic analysis at healing revealed no loss of reduction, no uncontrolled collapse of the neck, no nonunions, no femoral shaft fractures, and no implant failures. Two cases in the series were poorly reduced and settled into varus malalignment. There was no varus malposition seen in the remaining 46 fractures. The mean prefracture Harris hip score (75.1 +/- 13.4) was significantly reduced at the time of follow-up (70.3 +/- 14.5, P = 0.003); 58% of the patients recovered their prefracture status. No significant difference was seen for the Barthel Index. CONCLUSIONS: The InterTan device appears to be a reliable implant for the treatment of intertrochanteric femoral fractures. Its design provides for stability against rotation and minimizes neck malunions (shortening) through linear intraoperative compression of the head/neck segment to the shaft. As a result of the negligible complication rate and improved clinical outcomes, this implant is now the standard treatment for all intertrochanteric fractures at our institution.

Distal Tibial Fractures: Intramedullary Nailing.

The tibia is an exposed bone with vulnerable soft tissue coverage and is therefore predisposed to local soft tissue problems and delayed bone healing. The objective in distal tibial fracture treatment is to achieve stable fixation patterns with a minimum of soft-tissue affection. Thus, the risk of soft tissue breakdown and bone healing complications is more likely related to open reduction and plating. Percutaneous, minimally invasive intramedullary nailing is a proven fixation mode for fracture stabilization in tibial shaft fractures. Anticipating the pitfalls, intramedullary nailing meets the requirements of the method of choice in distal tibial fracture fixation. In conclusion, intramedullary nailing of distal tibial fractures is a reliable method of fixation, possessing the advantages of closed reduction and symmetric fracture stabilization of an area with a delicate soft tissue situation, but prospective randomized trials are needed to compare modern intramedullary fracture fixation with modern plate fixation in distal tibial fractures.

Mechanical evaluation of different techniques for Achilles tendon repair.

INTRODUCTION: One aim of the surgical treatment of acute Achilles tendon ruptures is to obtain a maximum primary stability of the sutured tendon. Therefore, we investigated the primary stability of sutured human Achilles tendons depending on different applied techniques. METHODS: The strength of 60 repaired cadaveric human Achilles tendons was tested depending on either the suture technique (Bunnell or Kessler), the suture material (PDS-thread or PDS-cord) or an additional plantaris tendon augmentation (PDS-thread with or without augmentation). Following anatomic reconstruction the repaired specimens were loaded to failure. RESULTS: The use of Bunnell's technique resulted in a stronger primary suture stability compared to Kessler's technique. Sutures carried out with a PDS-thread were of lower strength than those accomplished with a PDS-cord (Bunnell: thread 139 N +/- 29.8; cord 291 N +/- 55.2/Kessler: thread 137 N +/- 37.3; cord 180 N +/- 41.1). Sutures performed according to Bunnell's technique with a PDS-thread and an additional autologous plantaris tendon augmentation reached the highest primary stability (326 N +/- 124.9). CONCLUSIONS: The findings identify the Achilles tendon suture with a PDS-cord according to Bunnell's technique as a mechanically strong method. A plantaris tendon augmentation in addition to a PDS-thread can even add more stability to the Achilles tendon suture.