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.

Introduction: A novel computerized algorithm for hip joint motion simulation and collision detection, called the Equidistant Method, has been developed. This was compared to three pre-existing methods having different properties regarding definition of the hip joint center and behavior after collision detection. It was proposed that the Equidistant Method would be most accurate in detecting the location and extent of femoroacetabular impingement. Materials and Methods: Five plastic pelves and ten plastic femora with modified acetabula and head-neck junctions, allowing for 50 different morphologic combinations, were examined, along with six cadaver hips. First, motions along anatomically relevant paths were performed. These motions were tracked by a navigation system and impingement locations were digitized with a pointer. Subsequently, previously generated 3D models of all the specimens, together with the recorded anatomic motion paths, were applied to all four simulation algorithms implemented in a diagnostic computer application. Collisions were detected within the motion paths, and the linear and angular differences regarding the location as well as the size of the detected impingement areas were compared and analyzed. Results: The Equidistant Method detected impingement with significantly higher linear and angular accuracy compared to the other methods ( p 5 0.05). The size of the detected impingement area was smaller than that detected with the other methods, but this difference was not statistically significant. Conclusions: The increased accuracy of the Equidistant Method is achieved by implementing a dynamic hip joint center, more closely resembling the natural characteristics of the hip joint. Clinical application of this algorithm might serve as a diagnostic adjunct and support in the planning of joint-preserving surgery in patients with femoroacetabular impingement.

Background Legg-Calvé-Perthes disease (LCPD) often results in a deformity that can be considered as a complex form of femoroacetabular impingement (FAI). Improved preoperative characterization of the FAI problem based on a noninvasive three-dimensional computer analysis may help to plan the appropriate operative treatment. Questions/purposes We asked whether the location of impingement zones, the presence of additional extraarticular impingement, and the resulting ROM differ between hips with LCPD and normal hips or hips with FAI. Methods We used a CT-based virtual dynamic motion analysis based on a motion algorithm to simulate the individual motion for 13 hips with LCPD, 22 hips with FAI, and 27 normal hips. We then determined the motion and impingement pattern of each hip for the anterior (flexion, adduction, internal rotation) and the posterior impingement tests (extension, adduction, external rotation). Results The location of impingement zones in hips with LCPD differed compared with the FAI/normal groups. Intra-and extraarticular impingement was more frequent in LCPD (79% and 86%, respectively) compared with normal (15%, 15%) and FAI hips (36%, 14%). Hips with LCPD had decreased amplitude for all hip motions (flexion, extension, abduction, adduction, internal and external rotation) compared with FAI or normal. Conclusions Hips with LCPD show a decreased ROM as a result of a higher prevalence of intra-and extraarticular FAI. Noninvasive assessment of impingement characteristics in hips with LCPD may be helpful in the future for establishment of a surgical plan.

Seventeen years of experience with a nonoperative treatment protocol for acute rupture of the Achilles tendon confirmed good functional outcome and patient satisfaction. Reruptures mostly occurred with new traumatic events in the vulnerable phase from 6 to 12 weeks after the initial injury. Muscle strength correlated to tendon length, making its assessment a crucial follow-up parameter. The protective equinus cast and boot can protect against excessive tendon lengthening during the healing process.

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we performed 194 total hip arthroplasties on 173 patients using alumina ceramic-onceramic bearings as part of a prospective United States Food and Drug Administration/Investigational Device Exemption study. The average patient age at surgery was 49.9 years. Minimum followup time was 2 years (mean 4.3 years, range 2−9 years). We evaluated survival rate, implant-and nonimplant-related complications. Clinical outcomes included the Merle d'Aubigné score. We assessed radiographs for signs of osteolysis, component loosening, and implant wear. No patients had osteolysis and there were no hip dislocations. Implant survivorship for all hips with aseptic revision of any component was 96% (CI, 91-100) at 9 year; survivorship for hips without prior surgery was 99.3%, (CI, 98-100). There was a 1.7% incidence of implant-related complications. Our data help confirm two United States FDA/IDE studies on alumina ceramic-on-ceramic total hip arthroplasty that reported low aseptic revision rates and low revision rates for instability. Total hip arthroplasty using alumina ceramic-onceramic implants is a safe and reliable procedure in the comparably young and active patient.Level of Evidence: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.Traditional total hip arthroplasty (THA) using metal-onpolyethylene bearings has been established as a reliable procedure. 6 However, wear and wear debris-associated osteolysis are still among the most common complications affecting these devices. Several alternative bearings have been used clinically to reduce wear and osteolysis.39 The alternatives include cross-linked polyethylene acetabular liners, metal-on-metal bearings, and alumina ceramic-onceramic bearings. Although metal-on-cross-linked polyethylene is most commonly used, these bearings have the shortest clinical experience of the available alternative bearings. 10Generally, good results with these improved polyethylene implants have been reported by several authors, 10,27,33 especially compared to the older-generation conventional polyethylene bearings. However, theoretical concerns include a relatively poor resistance to scratching and thirdbody wear compared with hard bearings. Cross-linked polyethylene bearings may be more susceptible to fracture and dissociation as compared to conventional polyethylene because of their low resistance to crack propogation. 16Whether these material factors will substantially affect long-term clinical outcomes remains to be seen.Metal-on-metal bearings have demonstrated substantially improved wear characteristics as compared to metalon-conventional polyethylene bearings. Long-term clinical studies also suggest these bearings represent a promising alternative method of achieving improved THA longevity. 3,8 Yet, theoretical concerns about wear from these bearings remain because wear debris produces an inflammatory response of the surrounding tissue.38 Some authors have suggested this response may lead to component loosening or implant-induced osteol...

Leg length inequality after hip arthroplasty is a major source of patient dissatisfaction and dysfunction. Despite numerous reported methods to intraoperatively determine leg length change, it remains a challenge. We developed a reliable and reproducible method to measure leg length change using surgical navigation. The method measures the change in position of the femur relative to the pelvis and the pelvic coordinate system without the need to establish a femoral coordinate system. We replaced 112 hips in 107 patients using the new leg length measurement algorithm. Leg length change measured at surgery was compared with leg length change as measured on magnification-corrected pre- and postoperative radiographs. Compared with radiographically measured leg length change, the leg length changes measured intraoperatively had a mean difference of -0.5 +/- 1.77 mm (range, -5-3.9 mm). We found no difference between radiographic data and navigation data. Leg length change measured using surgical navigation, measuring the change in position of the femur relative to the pelvic coordinate system, without establishing a femoral coordinate system is easy and reliable.