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We evaluated the radiological pelvic diameter after the bernese periacetabular osteotomy (PAO) and its influence on the modality of birth. Out of 93 woman, 17 had a total of 28 babies after PAO; 18 children were delivered spontaneously and 10 by caesarean section. The rate of section (36 %) was twice as high after PAO as in a normal population. In 50 % the indication to perform a section was made because the obstetrician anticipated problems during delivering after PAO. The average weight of birth was 3348 g +/- 285 g in the spontaneous delivery group, 3475 g +/- 356 g in the section group. The weight of birth didn't correlate neither with the duration of delivery nor with the indication to perform a section. The 17 woman who had a baby after PAO didn't show a significant change of the radiological diameters of the pelvis: pelvic entrance (before PAO 15. 4 cm, after PAO 15.7 cm), mid-pelvis (before PAO 11.8 cm, after PAO 11.8 cm) and pelvic outlet (before PAO 14.2 cm, after PAO 13.7 cm). We found that the PAO does not influence the anatomical diameters of the birth canal and therefore is not an indication for a section.

Lateral femoral insufficiency fractures in total hip arthroplasty occur due to osteopenia and varus positioning of the femoral component, the femur itself, or both. The presentation of these fractures can be unclear but usually involves the insidious onset of unexplained thigh or groin pain. The patients are likely to have significant comorbidities as well. Characteristic radiographic findings may be present, depending on when the patient presents. The insufficiency fractures generally occur at the level of the femoral stem tip on the lateral cortex of the femur. If left untreated, pain and loss of function continue. Eventually an insufficiency fracture can progress to a displaced periprosthetic fracture. Nonsurgical treatment is not successful. Recommended treatment involves revision to a long-stem femoral component. The risk of postoperative complications is significant.

We carried out the Bernese periacetabular osteotomy for the treatment of 13 dysplastic hips in 11 skeletally mature patients with an underlying neurological diagnosis. Seven hips had flaccid paralysis and six were spastic. The mean age at the time of surgery was 23 years and the mean length of follow-up was 6.4 years. Preoperatively, 11 hips had pain and two had progressive subluxation. Before operation the mean Tönnis angle was 33 degrees, the mean centre-edge angle was -10 degrees, and the mean extrusion index was 53%. Postoperatively, they were 8 degrees, 25 degrees and 15%, respectively. Pain was eliminated in 7 patients and reduced in four in those who had preoperative pain. One patient developed pain secondary to anterior impingement from excessive retroversion of the acetabulum. Four required a varus proximal femoral osteotomy at the time of the pelvic procedure and one a late varus proximal femoral osteotomy for progressive subluxation. Before operation no patient had arthritis. At the most recent follow-up one had early arthritis of the hip (Tönnis grade I) and one had advanced arthritis (Tönnis grade III). Our results suggest that the Bernese periacetabular osteotomy can be used successfully to treat neurogenic acetabular dysplasia in skeletally mature patients.

Free patellar tendon grafts used for the intra-articular replacement of ruptured anterior cruciate ligaments (ACL) lack perfusion at the time of implantation. The central core of the graft undergoes a process of ischaemic necrosis which may result in failure. Early reperfusion of the graft may diminish the extent of this process. We assessed the role of peritendinous connective tissue in the revascularisation of the patellar tendon graft from the day of implantation up to 24 days in a murine model using intravital microscopy. The peritendinous connective-tissue envelope of the graft was either completely removed, partially removed or not stripped before implantation into dorsal skinfold chambers of recipient mice. Initial revascularisation of the grafts with preserved peritendinous connective tissues began after two days. The process was delayed by five to six times in completely stripped patellar tendons (p < 0.05). Only grafts with preserved connective tissues showed high viability whereas those which were completely stripped appeared to be subvital. The presence of peritendinous connective tissues accelerates the revascularisation of free patellar tendon grafts.

We performed a vital microscopic study in mice bearing dorsal skinfold chambers to characterize microvascular perfusion and leukocyte/endothelium interaction and their effects on elongation and mineralization of neonatal isograft and allograft bone. Isograft (C57/BL to C57/BL) and allograft bone (C57/ BL to BALB/C) revascularized simultaneously. However, vascular perfusion and density were lower in allograft bone than in isograft bone. Leukocyte/endothelium interaction was the same in isograft and allograft bones. Revascularization was not detected in allograft bone transplanted to presensitized recipients. Moreover, in preexisting vessels at the transplantation site, leukocyte/endothelium interaction was altered in allograft bone of presensitized recipients, despite a normal systemic leukocyte count. Femoral growth resulting from thickening of both epiphyses did not differ between experimental groups, however, mineralization occurred in isograft bone only. Isograft bone was histologically intact, allograft bone hypovital and allograft bone in presensitized recipients necrotic 12 days after implantation. Our findings suggest that graft incorporation or rejection is mediated by the microvasculature and that presensitizing of recipients accelerates rejection of allograft bone.

Periacetabular osteotomy provides technical challenges in surgical exposure and reorientation of the acetabular fragment. There is evidence to indicate that the procedure is effective, but there is a recognized learning curve with respect to its performance. This analysis includes a retrospective review of the technical complications encountered in more than 500 cases. These problems were analyzed and then related to the stages of the procedure in which they occurred (surgical approach, osteotomy, fragment positioning, fragment fixation, and the postoperative period). Efforts are made to analyze the cause of the complications and to suggest preventative or remedial treatments. It is hoped that highlighting these complications will shorten the learning curve for surgeons trying this procedure for the first time.

The periacetabular osteotomy is a well established surgical procedure for the preventative treatment of degenerative joint disease caused by symptomatic acetabular dysplasia. Surgeons on several continents use varying surgical approaches to achieve the same effective osteotomy. Individual surgical approaches must provide accurate and adequate exposure for the osteotomy and the reorientation of the acetabular fragment. The aim of the surgical approach for such complex and expansive surgery is to minimize morbidity related to the approach. This article compares experiences among three common approaches including the modified Smith-Petersen, ilioinguinal, and direct anterior approaches and describes the double approach.

As experience with the Bernese periacetabular osteotomy has grown, an unexpected observation in a group of patients has alerted the authors to the risk of a secondary impingement syndrome that may occur some time after the periacetabular osteotomy. This possibly may explain residual pain and limited range of motion in a larger group of patients. The impingement is produced by abutment of the femoral head or head to neck junction on the anterior rim of the properly aligned acetabulum. The symptoms are those of restricted flexion, and limited or absent internal rotation in flexion, with variable groin pain. Magnetic resonance imaging studies may reveal acetabular labral disease and adjacent cartilage damage associated with the impingement. Lack of anterior or anterolateral offset between the femoral neck and head results in neck to rim contact when the hip is flexed and/or internally rotated. Before the periacetabular osteotomy this is compensated by the lack of anterior acetabular coverage, but after proper correction the mismatch becomes apparent. The authors recently have devised a routine during the periacetabular osteotomy procedure whereby after the acetabular fragment is corrected into the desired position, the joint is opened, visually inspected, and palpated for impingement with the hip flexed and internally rotated. When necessary, a resection osteoplasty of the femoral neck to head junction is performed to improve the head and neck offset and reduce the anterior contact. This, in the short term, has provided satisfactory prevention of postoperative impingement.

Seventy-five symptomatic dysplastic hip joints (63 patients) were treated with the Bernese periacetabular osteotomy during a period of 44 months. The mean patients' age was 29 years (range, 13-56 years) and the female:male ratio was 3.4:1. Group III dysplasia according to Severin was seen in 50% and Group IV dysplasia was seen in 44% of the patients. Osteoarthritis was present in 58% of the patients. Followup was obtained at a mean of 11.3 years (range, 10-13.8 years) in 71 hip joints (95%). Radiographic measurements of the lateral center edge angle, anterior center edge angle, acetabular index, lateralization of the femoral head, and intactness of Shenton's line showed a high correction potential of this type of osteotomy. In 58 patients (82%) the hip joint was preserved at last followup with a good to excellent result in 73%. Unfavorable outcome was significantly associated with higher age of the patient, moderate to severe osteoarthritis at surgery, a labral lesion, less anterior coverage correction, and a suboptimal acetabular index. Major complications were encountered in the first 18 patients including an intraarticular cut in two, excessive lateralization in one, secondary loss of correction in two and femoral head subluxation in three patients.

This study examined the clinical results and technical challenges associated with acetabular reconstruction in developmental dysplasia of the hip using the acetabular reinforcement ring with hook. We reviewed 33 consecutive reconstructions performed by a single surgeon. At an average follow-up of 6.7 years, the mean Merle-d'Aubigne score had increased from 7 to 16. Two revisions were performed for aseptic loosening. Of the unrevised hips, 1 was classified as definitely loose and 1 as possibly loose. These results compare favorably with others in the literature. The acetabular reinforcement ring may prevent graft resorption and cup migration, major causes of socket failure in reconstruction of the deficient acetabulum.

A consecutive series of 40 patients, who sustained 42 ipsilateral pelvic and femoral fractures, is reported. There were eight (26.6%) traumatic neurological deficits and three open femoral fractures. Two multiply injured patients died in the postraumatic period because of the severity of their injuries. No associated vascular injuries could be identified. All but two fractures of the femur, 8 of the 15 fractures of the pelvic ring and 17 of the 30 fractures of the acetabulum were treated by internal fixation. In 26 patients internal fixation was performed on both fracture components (in 17 patients this was done under the same period of anaesthesia). Postoperatively, a deep venous thrombosis in three patients, one deep wound infection and five (18.5%) iatrogenic neurological deficits had to be notified. In this series we could not identify any specific associated injuries and complications as known for the floating knee or the floating elbow. The term floating hip is inprecise and misleading, and its use is not recommended. The treatment of this fracture-combination follows the guidelines established for the individual lesions.

The timing of soft-tissue reconstruction for severe open fractures of the lower leg is considered crucial to the later outcome, and yet pertinent publications are few. The purpose of this study was to add some based on evidence arguments for the choice of the most adequate timing in the management of these injuries. Twenty-nine consecutive open fractures of the tibia, including 24 grade 3B and 5 grade 3C fractures, were treated using a protocol of immediate debridement, early definitive skeletal stabilisation and early soft-tissue reconstruction. Fifteen lower legs were reconstructed after a mean delay of 4.4 days (range 1-9 days), while 14 lower legs were reconstructed immediately, i.e. as an emergency procedure on the day of admission. Both groups were comparable for sex, age, type of trauma, associated general injuries, type of fracture, associated arterial lesion, associated tendon rupture, type of soft-tissue reconstruction and duration of follow-up. All patients were reviewed at a mean follow-up of 47 months (range 15-89 months). In the delayed reconstruction group the time to full, unprotected weight-bearing (P = 0.0021), the time to definitive union (P = 0.0049), the number of reoperations (P = 0.0001) and the infection rate (P = 0.0374) were significantly higher. The data suggest that immediate reconstruction is, the general condition of the patient permitting, the timing of choice for soft-tissue coverage.

The periacetabular osteotomy is a strategy for the treatment of residual hip dysplasia in young adults with the aim of preventing secondary coxarthrosis. This polygonal, juxta-articular osteotomy respects the vascular blood supply to the acetabular fragment and thus facilitates an extensive acetabular reorientation with improvement of the insufficient coverage of the femoral head, including medial displacement of the fragment. All osteotomies are performed by one approach, the modified Smith-Petersen, which allows an anterior capsulotomy. Inspection of the joint not only provides information on acetabular rim pathologies, but also facilitates the control of impingement-free range of motion after the correction. The posterior column remains partially intact, allowing minimal internal fixation of the acetabular fragment and early mobilization similar to that after an intertrochanteric osteotomy. The dimensions of the true pelvis are unchanged, providing the capacity to have an unimpeded delivery in women. This paper describes the preoperative evaluation, current indications, surgical technique, postoperative care, and the results of this osteotomy.

To assist surgeons performing pelvic osteotomies for the treatment of dysplastic hips, an image guided freehand navigation system has been developed. Preoperative computed tomographic scan images are presented in various ways to the surgeon together with real time display of the instruments and surgical action on the computer screen. The system supports the preoperative plan and provides optimized control of surgical action. The main focus of the image guidance has been placed on the execution of the different required cuts and the reorientation of the acetabular fragment. Special attention also has been given to the development of a sophisticated surgeon-machine interface. Fourteen surgeries have been performed with image guidance so far. The visualization aids provided by the system are able to help reduce potential risk and thus increase safety and accuracy for this difficult class of surgical interventions.

There has been an evolution in the AO/Association for the Study of Internal Fixation plating technique during the past 3 decades that includes the use of longer plates and fewer plate screws, fewer lag screws outside the plate, fewer unicortical screws at the plate periphery, and greater use of the 95 degrees blade plate to achieve balanced fixation of proximal and distal shaft fractures. These changes reflect an evolving technique of plate osteosynthesis that emphasizes indirect reduction techniques, biologic internal fixation, and improved biomechanics. Outcome data suggest that there has been an improvement with time that is reflected by shorter time to union, a decrease in the frequency of implant failures, delayed unions, nonunions, malunions, number of reoperations, and in overall rate of failure. The best predictor of success was the length of plate by logistic regression analysis. With the evolution of plating techniques and a greater emphasis on biology of fracture healing, the incidence of complications and failures has decreased after femoral shaft plating. Plate osteosynthesis of the femoral shaft is particularly advantageous in many situations and can be quite successful (87% success rate in Group III).

Objectives: To develop an intraoperative technique to predict the development of avascular necrosis after internal fixation of femoral neck fractures., Design: Prospective study., Setting: All patients were treated at the same hospital., Patients/participants: Sixty-four patients who presented for internal fixation of a femoral neck fracture were enrolled in the study., Intervention: A 2.0-millimeter drill was used to assess the presence and character of bleeding from the femoral head at open reduction and internal fixation of a femoral neck fracture., Main Outcome Measurements: Patients were evaluated postoperatively by history, examination, and roentgenography for the development of avascular necrosis of the femoral head fragment. A minimum two-year follow-up with radiography was required for entry into the study, with an average follow-up of 3.2 years., Results: None of the fifty-six patients with bleeding from the drill holes in the femoral head fragment developed avascular necrosis. Eight of eight patients with no bleeding after reduction developed avascular necrosis. There were no infections or nonunions., Conclusions: Intraoperative drilling of the femoral head is a highly sensitive and specific predictor for the development of avascular necrosis after femoral neck fractures.

Objective: To describe the advantages and surgical technique of a trochanteric flip osteotomy in combination with a Kocher-Langenbeck approach for the treatment of selected acetabular fractures., Design: Consecutive series, teaching hospital., Methods: Through mobilization of the vastus lateralis muscle, a slice of the greater trochanter with the attached gluteus medius muscle can be flipped anteriorly. The gluteus minimus muscle can then be easily mobilized, giving free access to the posterosuperior and superior acetabular wall area. Damage to the abductor muscles by vigorous retraction can be avoided, potentially resulting in less ectopic ossification. Ten consecutive cases of acetabular fractures treated with this approach are reported. In eight cases, an anatomic reduction was achieved; in the remaining two cases with severe comminution, the reduction was within one to three millimeters. The trochanteric fragment was fixed with two 3.5-millimeter cortical screws., Results: All osteotomies healed in anatomic position within six to eight weeks postoperatively. Abductor strength was symmetric in eight patients and mildly reduced in two patients. Heterotopic ossification was limited to Brooker classes 1 and 2 without functional impairment at an average follow-up of twenty months. No femoral head necrosis was observed., Conclusion: This technique allows better visualization, more accurate reduction, and easier fixation of cranial acetabular fragments. Cranial migration of the greater trochanter after fixation with two screws is unlikely to occur because of the distal pull of the vastus lateralis muscle, balancing the cranial pull of the gluteus medius muscle.

Nailing of femoral fractures before closure of the growth plates may lead to avascular necrosis of the femoral head in 3-4% of cases. In addition to the 14 cases described in the literature we present 3 more. Analysis of these cases reveals a common pathogenesis. The nails were all inserted anterograde and were designed for the adult femur. The problem appears to be related to the large diameter of the nail and its entry point in the relatively small femoral neck basis, close to the vessels supplying the femoral head. The role of the open physis remains unclear. Even though the complication of femoral head necrosis is rare, it is a severe complication. Therefore we do not recommend anterograde femoral nailing, using the classic entry point, in children or adolescents. We believe that there is a need for a new design of femoral nail. If both femoral head necrosis and coxa valga are to be avoided, we suggest that the entry point of the nail should be dorsolateral, below the trochanteric physis.

Introduction: Indentation fractures of the femoral head, are known to be rare with poor long-term prognosis. This study aimed to demonstrate that intertrochanteric osteotomy allowed improvement of late outcome after indentation fractures of the femoral head., Patients and Methods: Between 1980 and 1984, four patients with a femoral head fracture after traumatic hip dislocation were treated by intertrochanteric osteotomy. The mean age at time of surgery was 24 years. The injury was a traffic accident in 2 out of 4 cases. All of four had indentation fractures of the left femoral head. All patients underwent immediate reduction of the dislocation. The intertrochanteric osteotomy, was delayed between 1 months to 3 years. Four Müller's osteotomies and one Sugioka's osteotomy were performed. One patient had 2 successive procedures. Mean pre-operative Merle d'Aubigne score was 13.5. In this retrospective study, results were assessed according to Merle d'Aubigne score and Epstein clinical and radiological method., Results: Mean follow-up was 9 years (7 to 12). Three patients had a good result and one had two successive poor results in the same hip. Mean last follow-up Merle's score was 16.3 (15 to 18). The only poor result occurred because of late femoral head necrosis, in one hip with 2 successive osteotomies., Discussion: As indentation fractures occurred in the upper part of the femoral head, the goal of the osteotomy was to displace the impacted articular surface out of the weight-bearing area. The prognosis of such lesions was usually poor, because in previously reported series, patients received no treatment. In our experience, intertrochanteric osteotomy could be proposed as an efficient therapy in femoral head indentation fractures.

Residual hip dysplasia in the adult is characterized by deficient anterior and lateral acetabular coverage with subsequent hip joint incongruity and instability. The frequency of periacetabular osteotomy for the treatment of residual hip dysplasia is increasing. In certain morphologic conditions preoperative abduction or intraoperative radiographs reveal that congruency after a periacetabular osteotomy is not optimum; at this point the surgeon may consider the addition of an intertrochanteric osteotomy. In a retrospective study, the radiographs of 25 patients who had a femoral osteotomy with or after periacetabular osteotomy were analyzed and the results were compared with a control group of 34 patients who had periacetabular osteotomy without a femoral osteotomy. The analyzed parameters included: the femoral head extrusion index and the acetabular index, before and after periacetabular osteotomy; the femoral neck shaft angle; the presence of femoral head deformity; the presence of osteoarthrosis; the presence of a secondary acetabulum; the influence of previous ipsilateral hip surgery; the effect of hip adduction or abduction on joint congruency; and the age of the patient. The variables that had a statistically significant association with the performance of an intertrochanteric osteotomy included a femoral head extrusion index and an acetabular index after periacetabular osteotomy outside the normal limits, a neck shaft angle outside the limits of the control group, a deformed femoral head, an osteoarthritic hip, a secondary acetabulum, and a joint space height and congruency dependent on position of the proximal femur. When using statistically significant variables, a discriminant analysis predicted the correct group (periacetabular osteotomy with femoral osteotomy, or periacetabular osteotomy without femoral osteotomy) for 89% of the cases.

We report the technical details and clinical results of twelve patients who had deep infections of implants in the hip joint and were treated by two-stage revision, using a gentamicin-loaded, hand-moulded cement spacer inserted for the period between resection and reimplantation arthroplasty. During management with the spacer, usually for 4 months, patients were almost free of pain and mobile with good leg control, spending 2/3 of the treatment period at home. Six of twelve spacers failed locally due to dislocation [5] or cement fracture [1], and more than two further episodes of surgery were required in 3 patients. Problems with dislocation of the spacer were significantly higher when the head to neck offset was lacking (P < 0.05) or when anchorage in the femoral shaft was poor. Nevertheless, infection after reimplantation arthroplasty did not occur by the time of follow-up (2.2 years). Based on these data, we consider that the use of the cement spacer is a promising approach to the treatment of complicated infections of the hip joint.

This article describes the current managed care environment for gastroenterologists, and also explains the various merger and networking options that are currently available. The article contains a detailed discussion of regional versus national merger options. Specific integration models are outlined for forming a regional, single-specialty, gastroenterology network.

A new technique to achieve a reliable fusion of the hip joint through an anterior approach with use of a ventral low contact dynamic compression plate and a lateral 6.5 mm lag screw is presented in detail. The advantages of this technique are that the approach does not jeopardize the vascularity of the femoral head, that the fixation on the pelvic side uses the strong bone stock of the sciatic buttress, and that the hip abductor muscles and greater trochanter are preserved. The authors also present the indications and the results of their experience with 12 patients. The followup period averaged 24.8 months (range, 10-42 months). Ten patients (83%) achieved a solid fusion by radiologic and clinical criteria. Although a moderately symptomatic nonunion developed in 1 patient, another patient went on to a painful nonunion to whom another attempt for fusion has been recommended. According to the hip score of Merle d'Aubigné and Postel, the average figures for pain and ambulation increased from 3.2 points to 5.0 points and from 2.7 points to 4.5 points, respectively, after surgery. Six of the 12 patients regained the ability to work in their former jobs or in new occupations. Eight patients felt no or minor restrictions in doing their former sports activities. Patient satisfaction was high with a majority reporting minor discomfort mainly around the fused hip.

The Bernese periacetabular osteotomy was developed for precise spatial reorientation of the adult dyplastic acetabulum and improvement of the femoral head coverage. The osteotomy has a large correction potential (average decrease of acetabular index: 22 degrees) but is technically demanding. With appropriate patient selection, the results obtained are promising. Therefore, the technique described should be considered in the treatment plan for the acetabular dysplasia of the young adult.

Since January 1993 we have carried out MR arthrography on 23 patients with clinical symptoms and signs of abnormality of the acetabular labrum. Most of the patients were young adults. Such symptoms are known precursors of osteoarthritis, and therefore early and accurate evaluation is required. We assessed the value of MR arthrography of the hip as a minimally-invasive diagnostic technique, in a prospective study and compared the findings with those at subsequent operations. All the patients complained of groin pain; 22 had a positive acetabular impingement test and 15 had radiological evidence of hip dysplasia. In 21 of the patients, MR arthrography suggested either degeneration or a tear of the labrum or both. These findings were confirmed at operation in 18 patients, but there was no abnormality of the labrum in the other three. In two of the patients, MR arthrography erroneously suggested an intact labrum. Both MR arthrography and intraoperative inspection located lesions of the superior labrum most often, and these appeared slightly larger on arthrography than at operation. We consider that MR arthrography is a promising diagnostic technique for the evaluation of abnormalities of the acetabular labrum.

Goal of Surgery: Easy access to the posterior, superior and anterior joint capsule through an osteotomy which reduces the risk of complications and the incidence of non-union., Indications: Hip joint revision with or without intertrochanteric osteotomy, periarticular ossifications, difficult total hip procedures, exchange procedures., Contraindications: Absolute: None Relative: Distal transfer of the trochanter., Preoperative Work Up: Radiographs in 2 planes (anterior-posterior pelvis+"false profile" hip)., Positioning and Anaesthesia: Lateral decubitus. General anaesthesia., Surgical Technique: In lateral decubitus the greater trochanter will be osteotomized from posterior leaving a 1 to 1.5 cm thick bony wafer uniting the insertion of the gluteus medius and minimus with the origin of the vastus lateralis. The trochanteric crest remains untouched. After refixation with nonresorbable sutures #3 the fragment is not subjected to a unidirectional tension by the abductors which could interfere with the consolidation., Postoperative Management: Bed rest with lower limb in neutral position. Mobilization with 2 canes on the 2nd postoperative day. The timing of partial weight bearing depends on the type of surgery. Abductor exercises after 6 weeks., Possible Complications: Bony wafer too thin or too thick. Inadequate refixation. Delayed consolidation. Cranial migration of the greater trochanter., Results: Between 1991 and 1994 41 patients were operated. Diagnoses, see Table 1. Method of refixation: see Table 2. After 21+/-9 months 39 patients could be reexamined clinically, and radiological after 17+/-11 months: 38 osteotomies consolidated. Cranial migration varied between 0 and 8 mm. 25 patients were free of symptoms, 12 had slight and 2 moderate pain over the trochanter. Avulsion of wire cerclage: 2, foreign body irritation: 2 necessitating implant removal.

We have treated 42 consecutive complex ununited fractures of the femoral shaft by wave-plate osteosynthesis at five different medical centres. There were 13 with previous infection, 12 with segmental cortical defects, and 3 were pathological fractures. In 39 cases there had been previous internal fixation and 21 patients had had more than one earlier operation. Union was achieved in 41 patients at an average of six months, although three had required a second bone graft. Two patients had recurrence of infection and in one this resulted in the persistence of nonunion. There were no failures of the implant. All 41 patients with union are now fully weight-bearing, but four have a leg-length discrepancy, one has axial malalignment, and nine have residual stiffness of the knee. These results are surprisingly good, despite the complexity of the initial problem, and appear to confirm the biological and mechanical advantages of the wave plate over the conventional plate for such cases.

Image guided freehand navigation of surgical instruments has been applied to the Bernese periacetabular osteotomy, a complex surgical technique for the treatment of dysplastic hips. This navigation system has been introduced into the operating room and has so far been used for 12 patients. Image data from computed tomography (CT) scans are presented in various ways to support the preoperative plan and to provide optimized control of surgical action. Special attention has been paid to the implementation of a sophisticated surgeon-machine interface. This paper describes the features of this novel surgical navigation system and its introduction into the clinical environment.

Extending Bernstein's spatial conception of the degrees-of-freedom problem in the human motor system, we introduce a method developed from the theory of non-linear dynamics that allows one to quantify the spatio-temporal, i.e. dynamic, complexity of visuo-motor coordination. The correlation dimension D is used to measure the effective number of dynamic degrees of freedom in the coordination that a subject uses when performing a visuo-motor tracking task. The validity of the estimator employed is demonstrated. Visuo-motor coordination had a low-dimensional (mean D-SD=6.07 -0.82) dynamic structure, which was consistent with deterministic chaos rather than with pure stochastic noise. D correlated with tracking performance, P. Both D and P were closely related to the degree of visuo-motor compatibility that the task presented to the subject. However, for short periods of training P increased, but D did not. As these seemingly contradictory results suggest, our dynamic conception of the degrees-of-freedom problem may reveal far more intricate visuo-motor interactions than Bernstein could identify on the basis of his spatial analyses of bodily movement patterns and by the methods of evaluation that were available to him at the time.

Thirty-seven operatively treated patients with residual acetabular dysplasia without arthritis had a labrum tear in the antero-lateral quadrant. A sensation of hip locking, or of a "dead leg" and episodes of "giving-way" were found to predict the presence of the tear. 95% of patients had an acute onset of pain. We treated the patients with a peri-acetabular osteotomy and in 12 cases the tear was repaired with a transosseous suture. We excised the labrum lesion in 21 cases with an extended avulsion from the bony rim and 4 tears were not severe enough to require attention. Twenty-two patients were available for a 4.5-year follow-up (range 2-8 years): 18 patients had no pain, 3 had mild pain and one had severe pain. Final pain outcome was not influenced by intraarticular treatment of the tear. The labrum tear is responsible for a well-defined clinical presentation of hip dysplasia and precedes secondary arthrosis. Early diagnosis helps to define the time to perform reconstructive surgery. The treatment consists of improving the coverage and stability of the femoral head by means of a multiplanar peri-acetabular osteotomy. The osteotomy unloads the torn fibrocartilage and allows it to heal by moving it out of the weight-bearing area.

The purpose of this study was to determine if any differences existed in the early complication rate, short term clinical outcome, and total length of hospital stay between patients who had bilateral total hip arthroplasty performed under a single anesthetic (during 1 patient visit to the operating room) and patients who had the procedure performed under 2 anesthetics (during 2 patient visits to the operating room). Patients operated on bilaterally were divided into 3 groups: Group A (1 stage procedure)--hips that were operated on simultaneously (128 hips); Group B (2 stage procedure)--surgeries performed less than 6 weeks apart (126 hips); and Group C (2 stage procedure)--surgeries performed between 6 weeks and 6 months apart (256 hips). All patients were evaluated after an average followup of 1.5 years. There were no differences in operative, early local, or general complications among the 3 groups. In particular, no higher incidence of pulmonary embolism or deep vein thrombosis was found in the 1 stage group. Preoperatively, very stiff hips (total range of motion < 50 degrees) gained significantly more motion in the 1 stage group than in the 2 stage groups, whereas hips with better preoperative motion (total range of motion > 50 degrees) improved the most in Group B, without a significant difference occurring between Groups A and C. The degree of pain reduction was the same in all groups, but patients in the 1 stage group had a significantly better capacity for walking after their procedure. Average total hospital stay was 5 to 6 days less for the patients in Group A than those in the other groups, which, combined with using the operating room only once, resulted in a reduction of overall hospital costs by more than 30% when using the 1 stage procedure.

We studied the relation between central-autonomic adaptability (largest Lyapunov exponent of heart rate dynamics) and visual learning capability (total net score in Kimura's Recurring-Figures-Test) in 15 healthy subjects and 35 patients with cerebral white matter diseases (12 with optic neuritis and 23 with multiple sclerosis), aged between 18 and 39 years. In optic neuritis patients and in those with very early, clinically asymptomatic multiple sclerosis, we found high correlations between these central-autonomic and cognitive functions (r = .66 and r = .86, respectively, p < .02). In contrast, in healthy subjects and in patients suffering from an already clinically symptomatic multiple sclerosis, there were no such significant correlations. These results are interpreted in terms of stochastic resonance within a postulated meta-system which integrates autonomic and cognitive functions.

The authors present a new technique for fusion of the hip joint through an anterior approach (Smith-Petersen) with the use of a ventral plate and a lateral compression screw. The indications for fusion of the hip joint are discussed and some cases are presented. The advantages of this technique are that strong bone stock for fixation is used on the pelvic side, that the abductor muscles and vascularization of the femoral head are left intact, and that no external fixation (cast) is routinely used for after-treatment.

We propose a specially optimized computer program for the user-independent calculation of the correlation dimension D and the largest Lyapunov exponent L of heart rate dynamics on the basis of only 1024 electrocardiographically recorded RR intervals (heartbeat intervals). The validity of our program was established by analyzing a set of artificial standard signals. Our norm values of the correlation dimension (D = 5.37 +/- 0.62) and the largest Lyapunov exponent (L = 0.561 +/- 0.037 bits/beat) of RR dynamics, obtained from 79 healthy adults aged 26.3 +/- 4.8 years, were independent of gender and age; D and L correlated slightly with each other (Pearson correlation coefficient r = 0.26). Short-term reliability, tested for 25 of our subjects by two successive recordings, was fair: the intraclass correlation coefficients (ICCs) were 0.45 and 0.41 for D and L of RR dynamics, respectively. However, long-term reliability, tested for eight of our subjects by ten weekly recordings, was acceptable for L (ICC = 0.40) but not for D (ICC = 0.01). These results permit group comparisons on the basis of single measurements of L of RR dynamics. A reliable differentiation between young healthy individuals requires four measurements of L.

An unstable pelvic ring injury was stabilized with the AO C-clamp in thirty multiply injured patients. The average ISS was 29 (19-57). Transfusions totalled 24 units of blood/fresh frozen plasma/platelets (0-117) on average. In 12 cases, the application was for an unstable fracture alone, in 18 patients there was an unstable haemodynamic situation in addition. The application was haemodynamically effective in 10 cases. In 66% of cases, the initial reduction was good and the anatomy of the pelvic ring was adequately restored. Ten patients (33%) died; five during the first hours after admission due to haemorrhagic shock; the remaining five from multiple organ failure, fat embolism and head injury. Definitive stabilization was accomplished after 4.5 days on average (0-15). Complications relating directly to the clamp did not occur. The application of the C-clamp has a clear place in the management of polytraumatized patients with linear unstable pelvic ring injuries.

Advances in the operative stabilization of pelvic ring injuries, particularly by the development of special surgical techniques and implants, call for clear indications. These require the thorough analysis of the injury and its classification. Classification systems facilitate communication and the comparison of treatment concepts and results. Although a number of classification systems have been proposed, none of them has found universal acceptance. The following is a proposal for a comprehensive classification of pelvic ring injuries which, at the same time, accommodates the requirements of the AO/ASIF classification guidelines. The proposal is based primarily on radiographic morphology and secondarily on certain deductions made from it pertaining to the pathomechanics of the injury. To accommodate the extremely wide variety of possibilities, an open system was created by dividing the pelvic ring into anterior and posterior ring segments. Lesions of both segments can be freely combined for the definition of any given pelvic ring injury.

This retrospective review covers global aspects of reconstructive efforts to salvage severely injured legs. Eighteen patients with traumatic lower leg amputation were compared to 21 patients who underwent complex microvascular reconstruction. The mean number of interventions was 3.5 for amputation and 8 for reconstruction (p < 0.009). Total rehabilitation time was 12 months for amputation and 30 months for reconstruction (p < 0.009). Changes in lifestyle were consistently more important in the amputee group. The mean annual hospital costs for amputated patients were 15,112 Swiss Francs (SD 7,094 SF) for the first 4 years. The mean annual hospital costs for reconstructed patients were 17,365 Swiss Francs (SD 8,702 SF) for the first 4 years. Fifty-six percent of the amputees and 19% of the reconstructed patients were retrained to a different profession (p < 0.025). Fifty-four percent of the amputees and 16% of the reconstructed patients were drawing an extremely costly and life long invalidity pension (p < 0.02). We conclude that for potentially salvageable legs reconstruction is advisable because the functional outcome was better than for amputation and there was no permanent social disintegration due to the long treatment. Total costs (including pensions) for reconstruction were far lower than for amputation.

Major rim pathology is a precursor of osteoarthritis of the hip secondary to residual acetabular dysplasia. The symptoms are acute pain in the groin and impaired function; the anatomopathologic lesions consist in avulsions of the labrum from the bony rim, and separated bone fragments or "Os acetabuli", as well. A detailed radiographic, comparative inquiry to assess the preoperative morphology of 178 dysplastic hips which underwent a multiplanar periacetabular osteotomy was undertaken. The study showed that the 37 hips with a labral avulsion had a less pronounced anterior and lateral insufficiency of the acetabulum and a less pronounced lateral subluxation than dysplastic hips without these lesions. No specific radiologic features could be found in the 23 hips with bony fragments of the acetabular rim. The instability of the joint exerts abnormal stress on the acetabular rim which tends to tear it. This condition leads to rapid arthrotic degeneration of the hip; early diagnosis increases our ability to preserve the integrity of the joint through reliable reconstructive surgery.

In this study, a retrospective analysis of patients with trochanteric fractures fixed with a dynamic hip screw was performed (n = 238). Analysis of the complete X-rays (n = 115) revealed rotation of the head-neck fragment in 12% of the cases (n = 14). Patients with complex fracture types were more often affected by this complication (p < 0.05). The distance of lateral impaction was significantly higher in the group with rotation of the proximal fragment compared to patients without rotation (p < 0.001). The rate of cutting-out (p < 0.01), the rate of delayed union (p < 0.01) and the rate of varus angulation (p < 0.01) was significantly higher. Reoperation was necessary in 14% of the patients compared to 2% in the group without rotation. We conclude that rotational instability of a gliding implant system is a severe complication in the treatment of trochanteric fractures.

To help to determine the natural history of residual dysplasia of the hip after skeletal maturity, we followed the status of the contralateral hip in 286 patients who had had a total hip replacement for osteoarthrosis secondary to dysplasia. The initial radiographic findings in seventy-four patients in whom advanced osteoarthrosis later developed in the contralateral hip were compared with those in forty-three patients who had reached the age of sixty-five years without having had severe osteoarthrosis. No patient in whom the hip functioned well until the age of sixty-five years had had a center-edge angle of less than 16 degrees, an acetabular index of depth to width of less than 38 per cent, an acetabular index of the weight-bearing zone of more than 15 degrees, uncovering of the femoral head of more than 31 per cent, or an acetabulum in which the most proximal point of the dome had been at the lateral edge (zero peak-to-edge distance).

Owing to gradual aging of the population, the incidence of osteoporosis-related fractures of the proximal femur has increased. Trochanteric fractures are encountered in more than 50% of hip fractures. In this study, a comparative epidemiological analysis of patients with trochanteric fractures treated in the orthopedic department of the university hospital of Berne was performed. The time period from 1972 to 1978 (group 1, n = 205), was compared with the period from 1981 to 1989 (group 2, n = 444). Group 2 experienced a significant age-related increase of the number of patients with trochanteric fractures in the age group 30-49 years (p < 0.0001) and a significant increase of the number of patients in the age group over 80 years (p < 0.0001). In group 2, the female/male ratio was 0.24/1 for patients aged 30-49 years, 0.88/1 in the age group 50-59 years, 0.92/1 and 2.47/1 for patients in the age groups 60-69 and 70-79 years, respectively, and 3.59/1 in individuals over 80 years of age. The increased incidence in older women with trochanteric fractures is related to a higher grade of osteoporosis and agrees with the findings in the literature. The marked increase in the incidence of fractures in young males could be due to a higher risk of high-energy trauma sustained in traffic accidents and sports. Another explanation is the increase of risk factors for early osteoporosis related to low-energy traumas over the past two decades. Overall, there was a tendency towards more complicated fracture types (AO classification) in group 2 than in group 1.

The results of periacetabular osteotomy, with and without intertrochanteric osteotomy, performed between January 1984 and December 1990, were reviewed for forty-two patients who had osteoarthrosis in a congenitally dysplastic hip. There were eight male and thirty-four female patients. The average age of the patients at the time of the operation was thirty-seven years (range, eleven to fifty-six years). Ten patients had combined periacetabular and intertrochanteric osteotomies. The preoperative severity of the osteoarthrosis, according to the criteria of Tönnis, was grade 1 in fifteen patients, grade 2 in eighteen, and grade 3 in nine. The average duration of follow-up was four years (range, two to eight years). Complications included heterotopic ossification in fourteen patients (33 per cent), non-union of the pubic osteotomy in two patients (5 per cent), and pain related to the hardware that led to its removal in nine patients (21 per cent). There were no major neurovascular complications. One patient had dysesthesias in the area supplied by the lateral femoral cutaneous nerve. Six patients had a subsequent total hip arthroplasty and three patients had an additional intertrochanteric osteotomy. five of the nine patients who had a second major operation had had grade-3 osteoarthrosis before the periacetabular osteotomy. The Harris hip score improved from an average of 62 points (range, 33 to 95 points) preoperatively to an average of 86 points (range, 29 to 100 points) postoperatively (p < 0.0001, paired t test). The result was excellent or good for thirty-two of the thirty-three patients who had had grade-1 or 2 osteoarthrosis. Eight of the nine patients who had had grade-3 osteoarthrosis had a Harris hip score of less than 70 points at the latest follow-up evaluation.

Extrusion of the femoral head during late childhood and adolescence can be caused by tissue interposition following traumatic hip dislocation, inflammatory joint disease, or avascular necrosis with flattening of the femoral head. We report our experience of treatment by reorientation of the extruded femoral head with combined open-reduction and intertrochanteric osteotomy in seven young patients with Ficat stage III or IV avascular necrosis. Six of the seven patients showed improvement of pain and limp. They also had radiographic improvement of joint space and congruency, which suggests that the degenerative process and further surgery may be delayed.

Acetabular reconstructions using frozen femoral head allografts and the acetabular reinforcement ring of M. E. Müeller (Protek AG, Bern) have been analyzed after an average follow-up period of 7.2 years (range, 5.5-10 years) in 27 patients/hips. The deficiencies, according to the American Academy of Orthopaedic Surgeons classification, were 1 segmental, 14 cavitary, and 12 combined cavity and segmental. Twenty-two (82%) of the reconstructions were classified as adequate and five (18%) as inadequate based on the operative report and radiographic assessment, including anteroposterior, oblique, and lateral views. Reconstructions were considered adequate if an appropriate sized ring had been used in accordance with the recommendations of the authors (contact on host pelvic bone cranially, posteriorly, and inferomedially). Radiographic evaluation revealed acetabular component migration of more than 2 mm in 12 reconstructions (44%). Of these, cranial migration averaged 4 mm (range, 2-9 mm) in inadequate reconstructions, whereas it averaged only 2 mm (range, 1-4 mm) in adequate reconstructions. The incidence of migration in adequate reconstructions for segmental only and combined cavitary and segmental defects was 6 of 12 (50%), whereas it was 1 of 10 in reconstructions of cavitary deficiencies. Kaplan-Meier survivorship analysis revealed a 79.6% probability of survival at 10 years with revision as the endpoint for failure. It is concluded that durability of the reconstruction can be expected if support of the metallic reinforcement device is provided by host-bone. Segmental and combined deficiencies may require additional internal fixation by plates and screws.

In a study of central autonomic organization in interictal states of idiopathic generalized epilepsy, we measured the spontaneous oscillations of the heart rate in 8 young epileptics with normal interictal electroencaphalograms (EEGs), 6 young epileptics with epileptiform discharges in the interictal EEGs and 8 healthy controls. The temporal structure of the heart rate (HR) dynamics was operationalized through the estimation of the largest Lyapunov exponent (LLE). For all patients and controls, the LLEs of the HR dynamics were positive, indicating chaotic oscillations. The patients with interictal epileptiform discharges showed significantly lower LLEs of the HR dynamics than the epileptics with normal EEGs and the healthy controls. By comparison, the values of the epileptics with normal EEGs und those of the healthy controls did not differ significantly. This finding suggests a more rigid and thus less adaptable central cardio-autonomic organization in epileptics with epileptiform discharges in the interictal EEG.

Injury to the acetabular triradiate physeal cartilage is a rare but potentially serious injury. When it occurs in young children acetabular growth may be delayed, leading to incongruency of the hip and subsequent subluxation. This series reviews 5 patients who sustained injury to the triradiate cartilage and subsequently developed acetabular dysplasia. The radiographic appearance of post-traumatic dysplasia is distinctly different than that of developmental dysplasia. In post-traumatic dysplasia the acetabular teardrop width and inner wall of the acetabulum is significantly increased with the femoral head being lateralized. Four patients have undergone acetabular reconstruction, with 3 patients having a periacetabular osteotomy and 1 having a Chiari osteotomy. The remaining patient with posttraumatic dysplasia has severe and symptomatic osteoarthritis and awaits a total hip replacement.

In a study of central autonomic organization in early stages of experimental meningitis in rabbits, the temporal oscillations of the momentary heart rate (heart rate dynamics) were measured. In 10 anesthetized rabbits an experimental meningitis was induced by intracisternal injection of complement-C5a-fragment in a carrier solution of sodium chloride and bovine serum albumin. 10 rabbits were injected with the above carrier solution only and served as controls. The temporal structure of the heart rate dynamics was operationalized phase-space analytically through the estimation of the largest Lyapunov exponent. Without exception, positive Lyapunov exponents of the heart rate dynamics were found, which revealed chaotic oscillations. In contrast to the controls, the intracisternal injection of C5a caused a significant decrease of the analytical index and reduced its reproducibility significantly. This result suggests a subtle central-autonomic dysfunction and a loss of the autonomic steady-state induced by the acute inflammatory process.