Anterior Acetabulum Research Articles

Anterior Combined Endopelvic (ACE) approach for the treatment of acetabular and pelvic ring fractures: A new proposal

PurposeWe present our experience of using the Anterior Combined Endopelvic (ACE) approach, which consists of a combination of a newly modified Stoppa approach with the lateral approach to the iliac crest. This approach is discussed in terms of fracture reduction and fixation, technical aspects, and the incidence of complications, and as an alternative to the ilioinguinal approach for the treatment of acetabular fractures. MethodsA consecutive group of 34 adult patients with acetabular fractures treated surgically with the ACE approach was compared with a group of 42 adult patients treated with the ilioinguinal approach between 2010 and 2013. Both approaches were performed by a single surgeon to fix the acetabular fractures with main anterior displacement and the anterior and lateral parts of the pelvis. All the patients were analysed with typical X-ray projections for acetabular fractures and CT-scan. Charts and radiographs were reviewed for fracture pattern. Operative time, blood loss, quality of reduction, functional outcomes and perioperative complications were compared between the two groups of patients. ResultsThe mean follow-up of patients was 26 months (range 6–49 months), with a median of 24.5 months. The types of acetabular fraction in the study were as follows: 32 anterior and posterior columns, 18 anterior columns, 10 anterior columns with posterior hemitransverse, 10 transverse associated with posterior walls, two transverse; two T-Type transverse and two anterior walls. Average blood loss was 1090mL in the ACE group and 1200mL in the ilioinguinal group. Anatomic or satisfactory reduction was achieved in 94% of the acetabular fractures. Two patients (one in each group) had mild symptoms of the lateral femoral cutaneous nerve and improved within 4–6 months; one patient in the ilioinguinal group developed ossification Brooks grade III. ConclusionThe ACE approach for the treatment of acetabular fractures is highly recommended when the fracture involves the quadrilateral surface and anterior column. This approach provides a direct good-to-excellent visualisation and access to the entire fracture, which makes reduction and fixation easier. The clinical outcomes were slightly better with ACE compared with the ilioinguinal approach. Complication rate was similar in the two groups. The ACE technique is a viable alternative to the ilioinguinal approach when exposure of the anterior acetabulum is required.

What are the functional results and complications from allograft reconstruction after partial hemipelvectomy of the pubis?

In patients undergoing hemipelvectomies including resection either of a portion of the pubis or the entire pubis from the symphysis to the lateral margin of the obturator foramen while sparing the hip (so-called Dunham Type III hemipelvectomies), reconstructions typically are not performed given the preserved continuity of the weightbearing axis and the potential complications associated with reconstruction. Allograft reconstruction of the pelvic ring may, however, offer benefits for soft tissue reconstruction of the pelvic floor and hip stability, but little is known about these reconstructions. (1) What is the postoperative functional status after allograft reconstruction of Type III pelvic defects? (2) What are the rates of hernia, infection, and hip instability? In this case series, we reviewed all patients with Type III pelvic resections (with or without anterior acetabular wall resections) who underwent allograft reconstruction between 2005 and 2013 at one center (N = 14). During the period in question, reconstruction was the general approach used in patients undergoing these resections; during that time, three other patients were treated without reconstruction as a result of either surgeon preference or the patient choosing to not have reconstruction after a discussion of the risks and benefits. Of the 14 patients treated with reconstruction, complete followup was available at a minimum of 1 year in 11 (other than those who died before the end of the first year; median, 19 months; range 16-70 months among those surviving), one was lost to followup before a year, and two others had partial telephone or email followup. Patient demographics, disease status, functional status, and complications were recorded. For a portion of the cohort (four patients) later in the series, we used a novel technique for anterior acetabular wall reconstruction using the concave cartilaginous surface of a proximal fibula allograft; the others received either a long bone (humerus or femur) or hemipelvis graft. Seven patients died of disease; two had local recurrence, and five died of metastatic disease. All patients remained ambulatory Pain at 12 months after surgery was reported as none in five, mild in two, moderate in two, and severe in one. Operative complications included infection in two, symptomatic hernia in one, hip instability in one, dislocated total hip arthroplasty on the first postoperative day in one, and graft failure in one. Allograft reconstruction after Type III pelvic resections can provide functional reconstruction of the pelvic ring, pelvic floor, and, in certain patients with partial anterior acetabular resections, the resected anterior acetabulum. This has implications in preventing the occurrence of hernia and hip instability in this patient population that is classically not reconstructed, although longer-term outcomes in a larger number of patients would help to better delineate this because infection, hernia, hip instability, and graft nonunion still remain concerns with this approach. The most important unanswered question remains whether, on balance, any benefits that may accrue to these patients as the result of reconstruction are offset by a relatively high likelihood of undergoing secondary or revision surgery.

Modified ilioinguinal approach for anterior wall fractures of the acetabulum

Objective To evaluate the modified ilioinguinal approach in the treatment of anterior acetabulum wall fractures.Methods From February 2004 to February 2011,12 patients with comminuted acetabular fracture were treated with modified ilioinguinal approach.They were 10 men and 2 women,26 to 60 years of age (mean,33.5 years).All the fractures were anterior acetabulum wall ones according to Letournel classification.The time from injury to surgery ranged from 1 to 15 days (mean,5.4 days).All the operations were conducted via the modified ilioinguinal approach.In 6 patients whose fragments of the anterior wall were relatively large,fixation was done with lag screws and a reconstruction plate; in another 6 patients who had severely comminuted fragments and were complicated with compression in 4,fixation was done with lag screws and a spring plate following leverage reduction and filling the defect with iliac bone.The outcomes were assessed at the last follow-up with improved Merle d'Aubigne and Postel evaluation system.Results The mean operation time and the mean blood loss during operation for the 12 patients was 100 minutes and 350 mL.The average follow-up time for the 12 patients was 1.8 years (range,1 to 5 years).By the Matta scoring,the postoperative reduction was rated as excellent in 9 and good in 3 cases.The fracture healing time averaged 15 weeks (from 11 to 18 weeks).By the Merle d'Aubigne and Postel system,the outcomes were excellent in 8 cases,good in 3 cases and fair in one.One case of heterotopic ossification (Brooker degree Ⅰ) was observed and one case of traumatic arthritis occurred 3 years after operation.No infection,implant failure,or neurovascular lesion was found.Conclusion The modified ilioinguinal approach is good for comminuted or impacted fractures of the anterior acetabulum wall,because it can better expose the anterior parts of the acetabulum and allow direct visualization of open reduction of the anterosuperior fractures of the hip joint. Key words: Acetabulum; Fractures, bone; Fracture fixation, internal; Bone plates; Surgical approach

Comparison of Acetabular Anterior Coverage After Salter Osteotomy and Pemberton Acetabuloplasty: A Long-term Followup

The Salter osteotomy and Pemberton acetabuloplasty are common procedures for a deficient acetabulum in patients with developmental dysplasia of the hip. However, the degree of increasing retroversion and anterior acetabular coverage of these two procedures remains unanswered. The purpose of this study is to show the change in anterior coverage and relevant parameters in measuring pain and function among patients who have undergone either a Salter osteotomy or Pemberton acetabuloplasty. Forty-two patients who underwent either a Salter or Pemberton procedure at one institution between January 1981 and December 2000 and were available for followup at least 10years later (mean, 18years; range, 12-28years) were evaluated retrospectively. This represented 12% of the Salter and Pemberton procedures performed in patients between 12 and 36months old at our institution during the study period. We measured vertical-center-anterior margin angle, anterior acetabular head index, and weightbearing zone acetabular index, and we made comparisons using the radiographic parameter ratio (the division of each radiographic measurement of the operative side by that of the nonoperated side). All patients completed SF-36 and Harris hip score questionnaires at followup. In the Salter group, there were no differences in vertical-center-anterior margin angle, anterior acetabular head index, or weightbearing zone acetabular index. In the Pemberton group, there was no difference in vertical-center-anterior margin angle or anterior acetabular head index, but the weightbearing zone acetabular index decreased, suggesting increased anterior acetabular coverage (surgically treated side, 6 [95% CI, 4.84, 7.16]; nonoperated side, 12 [95% CI, 10.07, 13.39]; p<0.001). Compared with that in the Salter group, the weightbearing zone acetabular index ratio was smaller in the Pemberton group, which means more acquired anterior coverage after a Pemberton acetabuloplasty (Salter procedure, 0.94 [95% CI, 0.70, 1.17], Pemberton procedure, 0.53 [95% CI, 0.40, 0.65]; p<0.001). Three patients in the Pemberton group had an anterior impingement sign at followup, whereas none in the Salter group did. The SF-36 and Harris hip scores were good and showed no differences between the two groups. Our study suggests the weightbearing zone acetabular index on false profile radiographs of the hip, a parameter focusing on morphologic features of the anterior acetabulum, decreased after Pemberton acetabuloplasty compared with the nonoperated side and after the Salter acetabuloplasty. This suggests that by modifying the shape of the acetabulum with a hinge in the triradiate cartilage, a Pemberton acetabuloplasty may result in increasing acetabular anterior coverage and the risk of hip impingement. However, the functional results with at least 10years followup were good and similar for both procedures. Level III, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.

Newly modified Stoppa approach for acetabular fractures

We present our experience of using a newly modified Stoppa approach combined with a lateral approach to the iliac crest in patients with acetabular fractures in reference to fracture reduction and fixation, technical aspects, and the incidence of complications. We used a consecutive group of 29 adult patients with acetabular fractures treated operatively with a newly modified Stoppa approach between 2009 and 2011. The newly modified Stoppa approach was performed to fix the acetabular fractures with main anterior displacement and the anterior and lateral parts of the pelvis. This approach was combined with a lateral approach on the iliac crest for fractures of the iliac wing. All the patients were followed up for at least 1.5 years. Of the 29 patients, ten anterior column, two associated both column, seven anterior column with posterior hemi-transverse, four transverse, and six T-type fractures. The average blood loss was 950 mL, and average operative time was 155 minutes. Anatomic or satisfactory reduction was achieved in 96 % of the acetabular fractures. Two patients had mild symptoms of the lateral femoral cutaneous nerve and improved within three months. The newly modified Stoppa approach provides excellent visualization to the anterior column, quadrilateral surface and permits good postoperative results for treatment of acetabular fractures. We considered this technique as a viable alternative for the ilioinguinal approach when exposure of the anterior acetabulum is needed.

Subchondral cysts in dysplastic osteoarthritic hips communicate with the joint space: analysis using three-dimensional computed tomography

Bone cyst formation in hips increases as osteoarthritis worsens. Although bone cysts in hips have been described in many studies, their etiology remains unclear and under debate. The purpose of this study was to investigate the communication between a bone cyst and the joint space, as well as the relationship between the severity of osteoarthritis and the formation of subchondral bone cysts in dysplastic hips. We studied bone cysts from 150 dysplastic hips in 97 patients by computed tomography (CT) and plain radiography. We investigated the distribution of the bone cysts and the presence or absence of a communication path between the cysts and the joint space by three-dimensional (3D) CT. Of the 150 hips, 94 acetabula and 55 femoral heads were found to contain cysts. Of the 94 hips containing acetabular cysts, 89 and 5 hips showed black lines and gray lines connecting the cyst and the joint space, respectively, on 3D-CT. The rate of cyst presentation in the hip increased as the joint space became narrower. The number of hips that possessed cysts in the anterior and/or middle portion was significantly higher than that in the posterior portions. Bone cysts in dysplastic osteoarthritic hips were found to communicate with the joint space in all cases. This suggests that the formation and enlargement of the cysts in dysplastic hips may be greatly influenced by the joint fluid. Cyst formation was initially observed in the anterior acetabulum, gradually progressing to involve the entire joint, including the posterior acetabulum and the femoral head, with worsening of the osteoarthritis.

New Radiographic Parameters to Describe Anterior Acetabular Rim Trimming During Hip Arthroscopy

The purpose of this study was to describe additional radiographic parameters that may detect changes within the acetabular cavity during acetabular rim trimming for pincer-type femoroacetabular impingement. Cadaveric hips that met the inclusion criteria were stripped of all tissue and had a portion of their labra removed; 5 mm of anterior acetabulum was measured in the 12- to 3-o'clock position and resected with a Dremel device (Robert Bosch Tool, Mount Pleasant, IL). Anteroposterior radiographs were obtained with a C-arm image intensifier. Radiographic measurements were subsequently obtained using the anterior rim angle (ARA), anterior wall angle (AWA), and anterior margin ratio (AMR). Statistically significant changes were seen in the ARA, AWA, and AMR. Mean pre- and post-trimming changes were 81.0° and 85.7°, respectively, for the ARA; 34.8° and 29.2°, respectively, for the AWA; and 0.66 and 0.57, respectively, for the AMR. Although much attention has been focused on the center-edge angle, the anterior aspect of the acetabulum has not previously been characterized. In conjunction with the center-edge angle and Tönnis angle, the new parameters of ARA, AWA, and AMR can be used to provide a more comprehensive description of the acetabulum. The ARA, AWA, and AMR can be used to guide the surgeon intraoperatively and postoperatively in further clarifying acetabular morphology and in determining whether the rim resection was adequate. This study determined that there exist new radiographic parameters with significant changes in the anterior acetabulum as quantified by the ARA, AWA, and AMR that can be used to describe the radiographic changes after acetabular rim resection. The new parameters of ARA, AWA, and AMR can be used to provide a more comprehensive description of the acetabulum. These radiographic measurements can also be used by hip arthroscopists to better describe their surgical contribution to anterior rim trimming.

Immediate Full Weightbearing After Percutaneous Fixation of Anterior Column Acetabulum Fractures

Immediate Full Weightbearing After Percutaneous Fixation of Anterior Column Acetabulum Fractures

Prevalence of labral tears and cartilage loss in patients with mechanical symptoms of the hip: evaluation using MR arthrography

To determine the prevalence of labral tears and cartilage lesions in patients with mechanical symptoms of the hip using magnetic resonance (MR) arthrography. A total of 100 patients with mechanical symptoms of the hip such as pain, clicking, locking and giving way underwent MR arthrography of the hip to rule out a labral tear. Hip joints were evaluated for labral alterations, bone marrow edema (BME), and other pathology using a novel semi-quantitative scoring system. Cartilage changes were graded separately for the acetabulum and femoral head in the anterior, posterior, central, medial, and lateral hip joint regions (10 locations) on a 6-point scale: 0=normal; 1=signal heterogeneity; 2=fissuring, 3=thinning <50% of the normal thickness; 4=thinning >50% of the normal thickness; 5=full thickness cartilage loss. Labral tears were categorized into normal, intrasubstance degeneration, simple tear or complex tear with two or more tear regions. Statistical methods were contingency tables, Fisher's exact test for discrete outcomes (based on grade scores), Spearman's rank correlation (r) and t tests for continuous outcomes, using pooled and stratified analyses. On MR arthrography, labral tears were found in 66 patients (66% prevalence) with 13 having more than one location involved. Locations were 19 lateral (13 simple, six complex), 54 anterior (39 simple, 15 complex), eight posterior (six simple, two complex). Cartilage lesions were found in 76 patients (76% prevalence) with 53 demonstrating involvement of more than one compartment. The most common finding was cartilage thinning <50% in 99 regions in 44 patients. Cartilage thinning >50% was shown in 34 patients in 67 areas. When we correlated the grade of cartilage abnormality with the grade of labral tear, we found a statistically significant correlation (r=0.29; P< or =0.01). The size of cartilage abnormality was correlated with the grade of labral tear in the lateral acetabulum (r=0.38; P<0.001), anterior acetabulum (r=0.22; P< or =0.002), and lateral femoral head (r=0.29; P< or =0.004). The grade of cartilage loss was correlated with the grade of BME (r=0.44; P< or =0.001). Labral tears and cartilage loss are common in patients with mechanical symptoms in the hip. Cartilage loss, labral tears and BME appear interrelated and may represent important risk factors that may affect the development and progression of osteoarthritis in the hip joint.

The false profile arthrogram in developmental dysplasia of the hip.

Arthrography is useful in the evaluation and treatment of developmental dysplasia of the hip. The authors describe the additional diagnostic value obtained from a "false profile" arthrogram. The "false profile" arthrogram allows assessment of anterior acetabulum cover, femoral neck anteversion and hip joint subluxation (instability), which may not be apparent on other views. (Hip International 2005; 15: 177-81).

The false profile arthrogram in developmental dysplasia of the hip

Arthrography is useful in the evaluation and treatment of developmental dysplasia of the hip. The authors describe the additional diagnostic value obtained from a "false profile" arthrogram. The "false profile" arthrogram allows assessment of anterior acetabulum cover, femoral neck anteversion and hip joint subluxation (instability), which may not be apparent on other views. (Hip International 2005; 15: 177-81).