Ganz Periacetabular Osteotomy Research Articles

Complication management after periacetabular osteotomy

Hip dysplasia is the most common cause of secondary hip osteoarthritis. The Ganz periacetabular osteotomy (PAO) is awell-established procedure that allows areliable and reproducible correction of the complex pathology. The promising medium and long-term good treatment results are offset by the potential risk of complications from aninvasive pelvic procedure. Considering the mainly young age of the patients, knowledge of the possible complications and the resulting adequate therapy is crucial. The continuous development of surgical techniques and increase in overall surgical experience alongside the appreciation of critical surgical steps have led to asubstantial reduction of serious complications. In addition, to improve patient outcome, agreater understanding of the associated pathologies that may be related to hip dysplasia is essential.

Ganz osteotomy for treatment of hip dysplasia through intra-pelvic approach. Early results.

Ganz periacetabular osteotomy (PAO) is a technically demanding surgical procedure. It requires cutting around the acetabulum to mobilize it under fluoro- scopic control. The radiolucent table and good quality imaging are mandatory to perform this osteotomy in a safe way. Modification of Ganz osteotomy was developed a with minimal soft tissue exposure using intra-pelvic approach which allows direct visualization of the quadrilateral plate. The purpose of the present study was to review the early results in the initial group of patients who had this procedure. The Ganz PAO was performed on 8 cases painful dysplastic hips, using the intra-pelvic approach through the Pfannenstiel incision. All of the osteotomies were performed under fluoroscopic control and direct visualizing the osteotomy site from the same incision. The acetabular fragment was medialized and redirected anterolaterally then fixed with 3 screws. The pre-operative Harris hip score mean was 66.8 and improved to be 92.7 (p value <0.0005) and this was statistically significant. Radiologically the CEA improved in the pre-operative X-ray from mean of 13.12 degree to 28.37 degrees (p value <0.0005) and this was statistically significant. Painful dysplastic hips should be treated before function becomes seriously impaired. The Ganz osteotomy through an intra-pelvic approach, can be done with minimal exposure to radiation in a relatively short time.

Periacetabular Pelvic Osteotomy in Treatment of Patients with Developmental Dysplasia of the Hip

Background. Pelvic osteotomies are widely used for treatment of young active patients with developmental dysplasia of the hip (DDH) Type I according to the Crowe or type A according to Hartofilakidis classifications and the absence of severe degenerative cartilage lesions. Nowadays, Ganz periacetabular osteotomy (PAO) is the most common choice of surgeons around the world in treatment of such patients.The aim of the study was to evaluate the radiological and functional results of Ganz periacetabular osteotomy in patients with DDH.Material and Methods. A single-center retrospective analysis of 49 Ganz PAO was performed in 43 patients aged 36±9 years. The radiological evaluation criteria were Wiberg (AW), Lequesne (AL), Tonnis (AT) angles, and joint medialization. The results of treatment were evaluated using the Harris scale, iHOT-12, and VAS before treatment and 1 year after, the presence of complications was also monitored.Results. The average follow-up period was 35±15 months (from 1.0 to 6.9 years). Radiological parameters improved after surgery compared to preoperative ones: AW +19.9° (17.1° vs. 37.0°), AT -11.5° (19.9° vs. 8.4°), AL +14.1° (25.1° vs. 39.2°), joint medialization -5.5 mm (14.3 mm vs. 8.8 mm) (p0.001). Functional results and quality of life of patients also improved: the Harris scale +35.6 points (47 vs 83 points), iHOT-12 +40.9 points (44 vs 85 points), pain level -2.8 points (5 vs 2 points) (p0.001). Various complications developed in 20 out of 49 cases (40.8%). Neurological complications were resolved conservatively (22.4%). A direct correlation was evaluated between the surgical treatment of DDH in childhood and the development of neurological complications after PAO (R = 0.76; p0.001). In 9 cases out of 49 (18.4%), revision surgery was required: in 3 — total hip replacement, in 2 — reorientation of the acetabulum, in 4 — arthroscopic fixation of the anterior articular lip. In 93.9% of cases native hip joint surfaces were preserved.Conclusion. Ganz PAO has good reconstructive capabilities and sufficient efficiency. The operation allows to restore the coverage of the femoral head with the acetabulum, delays total hip replacement and provides improved functional results.

Hallazgos artroscópicos de la cadera en pacientes con indicación de osteotomía periacetabular

BackgroundDysplasia of the hip in development (DHD) produces anatomical changes that cause premature arthrosis. Within the surgical procedures indicated, Ganz periacetabular osteotomy has been described. It is designed to improve the architecture of the hip that, by itself, does not improve the damage to the articular cartilage, as well as possible lessions of the labrum. The objective was to describe the arthroscopic findings found in hips with dysplasia and indication of Ganz periacetabular osteotomy. MethodCase series type observational retrospective study based on the review of surgical descriptions and videos of all cases with diagnosis of hip dysplasia and indication of Ganz periacetabular osteotomy where arthroscopy of the hip was performed prior to the osteotomy. ResultsHip arthroscopy showed intra-articular compromise of 76.9% of the cases studied (10 of 13). Six cases had compromise of the articular cartilage in the 2, 3 and 4 geographic zones. In addition, compromise of the chondrolabral joint was observed in 6 cases and damage at the labrum level was detected in 5 cases. In regard to the femoral head-neck offset, it was found to be reduced in 5 cases. In one of the cases periacetabular osteotomy was contraindicated due to the level of compromise of the articular cartilage. ConclusionsDHD is a clinical condition that is very frequently predisposed to damage of the articular structures; they can be treated with arthroscopy with the aim of avoiding persistence of sypmtoms after a periacetabluar osteotomy or even contraindicating it.Level of Evidence: IV.

Management of Recurrent Posterior Hip Dislocation in a Down Syndrome Patient with Dysplastic Hip Using Ganz Periacetabular Osteotomy: Follow Up After 4 Years

Recurrent hip dislocation in a Down Syndrome patient with dysplastic hip is a very challenging case to treat even for an expert orthopaedic hip surgeon. Least compliant patient and family, lowly educated with low socioeconomic status and the dysplastic hip forces limited option as a treatment. This is the first case world wide reporting 4 year follow up of dysplastic hip with Down Syndrome treated successfully with PAO technique.Methods:An eighteen years old female with history of Down Syndrome had multiple posterior hip dislocation episodes since 3 years prior. Several attempts of close reduction and hip spica applications were performed upon dislocation despite no successful retaining of reduction. Acetabular index of right hip were 550 and epiphyseal plate hasclosed. PatientwasperformedopenreductionusingSouthern-Mooreposteriorapproachand osteotomy of ischium, continued with capsulorrhaphy followed with Smith-Peterson anterior approach and osteotomy of superior ramus pubis and iliac bone. Then, derotation maneuver was performed under image intensifier to obtain adequate coveragefollowedwithbonegraftandfixationusing2cannulatedscrewandhipspica castapplication.Results:Within four years after surgery, the hip has never been dislocated again, patient could sit without pain and walk with full weight bearing although Harris Hip Score could not be performed due to Down Syndrome. Leg length discrepancy was negligible,fracture has fully united and acetabularin dex was300.Conclusions:Ganz periacetabular osteotomy, although a technically demanding surgery, is a preferable treatment in recurrent hip dislocation for Down Syndrome patient with good to excellent clinical and radiological ou tcome

Periacetabular hip osteotomy for residual dysplasia treatment: preliminary results

ObjectiveTo evaluate whether the change in the CE angle of Wiberg and the acetabular index after Ganz periacetabular osteotomy is statistically significant. MethodsThe pre- and postoperative CE angle of Wiberg and acetabular index of 14 hips operated at a tertiary hospital in Curitiba, Paraná, Brazil were evaluated. ResultsThe postoperative measurements showed significant differences in relation to the preoperative period. There was a significant reduction in the CE angle of Wiberg in the postoperative period, as well as in the acetabular index. These differences were statistically significant for both the right and left sides. ConclusionThe radiographic evaluation of patients submitted to Ganz periacetabular osteotomy presented some statistically significant results; however, a larger sample is still necessary.

Rotational Acetabular Osteotomy.

The approach combines the anterior iliofemoral and posterior approaches through a single skin incision. The pubic bone is cut independently, and the ilium and ischium are cut in continuity. The rotation of the acetabulum provides a more horizontal weight-bearing area and, at the same time, returns the superiorly subluxated femoral head to a more normal position. The Ganz periacetabular osteotomy involves the same concept as a rotational acetabular osteotomy with a different surgical approach. The rate of major complications, such as intra-articular osteotomy, nerve palsy, loss of fixation, malreduction, and symptomatic heterotopic ossification, is lower in rotational acetabular osteotomy (0% to 18%)2 than in periacetabular osteotomy (6% to 37%)3. Because of a wide surgical exposure, osteotomy can be performed under direct vision in rotational acetabular osteotomy. Rotational acetabular osteotomy for osteoarthritis secondary to hip dysplasia can alter the position of the acetabulum en bloc and cover the femoral head with cartilage. For the unstable hip with dysplasia, the surgical procedure is needed for the prevention of osteoarthritis.

Osteotomia periacetabular do quadril para tratamento da displasia residual: resultados preliminares

ObjectiveTo evaluate whether the change in the CE angle of Wiberg and the acetabular index after Ganz periacetabular osteotomy is statistically significant. MethodsThe pre‐ and postoperative CE angle of Wiberg and acetabular index of 14 hips operated at a tertiary hospital in Curitiba, Paraná, Brazil were evaluated. ResultsThe postoperative measurements showed significant differences in relation to the preoperative period. There was a significant reduction in the CE angle of Wiberg in the postoperative period, as well as in the acetabular index. These differences were statistically significant for both the right and left sides. ConclusionThe radiographic evaluation of patients submitted to Ganz periacetabular osteotomy presented some statistically significant results; however, a larger sample is still necessary.

Complications after periacetabular osteotomy

Aim. To study the frequency and structure of complications after periacetabular osteotomy in patients with hip dysplasia.Methods. Complications that arose after the Ganz periacetabular osteotomy, based on observation of 71 patients (83 operated joints): 58 women and 13 men, were analyzed. The average follow-up duration was 8 years, the mean age - 23 years (range 13 to 44 years). Complications after surgery were divided into two groups: minor and major. Functional state of the hip joint was evaluated by the Harris Hip Score (HHS) before and after surgery.Results. In 5 patients dysesthesia of external femoral nerve, in 1 - of sciatic nerve, was revealed, ossification grade 1-2 (according to Brucker) was found in 5 patients, grade 3-4 - in 2, ischial bone pseudarthrosis was determined in 2 patients, the ilium fracture - in 3, superficial abscess - in 2, screw penetration into the joint - in 2, femoral head subluxation - in 1, symptomatic screws - in 5 patients. In 71 adult patients (83 joints) with hip dysplasia and arthrosis after Ganz osteotomy, in 17 (20.4%) cases minor complications, in 11 (13.25%) - major complications were registered. In 66 patients out of 71 the joint preservation was achieved.Conclusion. Ganz osteotomy performed according to indications is effective and allows joint preservation in the majority of cases, however, the surgical complexity and the relatively high rate of complications require sufficient qualification and experience of the physician.

Safety of modified Stoppa approach for Ganz periacetabular osteotomy: A preliminary cadaveric study

ObjectiveThe aim of this cadaveric study was to investigate the efficacy of the modified Stoppa approach in Ganz periacetabular osteotomy (PAO). MethodsThe Ganz PAO was performed on 10 hemipelvises with normal hips, from 5 cadavers using the modified Stoppa approach through the Pfannenstiel incision. All of the osteotomies were performed under fluoroscopic control and direct visualizing the osteotomy site from the same incision. After the osteotomy, the acetabulum was medialized and redirected anterolaterally, and fixed with 2 screws. The neurovascular structures and the joints were examined by dissecting the soft tissues after fixation of the osteotomies. Outcome parameters were center-edge (CE) angle, the distances between the osteotomy and anterior superior iliac spine (ASIS), and between the osteotomy and the sciatic notch, neurovascular and joint penetrations. ResultsAfter the osteotomy, the mean CE angle was improved from 19.8° to 25.2°, mean distance between the osteotomy and ASIS was 3.1 cm, and the mean distance between the osteotomy and the sciatic notch was 10.2 mm. The neurovascular structures and the joints were examined by dissecting the soft tissues after fixation of the osteotomies. No damage to the joint, surrounding arteries, veins or nerves was detected in any of the cadavers. ConclusionsBilateral dysplastic hips can be treated with a 10 cm, cosmetically more acceptable incision in the same session using this approach. Quadrilateral surface of the acetabulum can be directly seen using this approach and the osteotomy can be safely performed.

Fracture at the Ischio-Pubic Junction After Periacetabular Osteotomy in the Adolescent Population.

The Ganz periacetabular osteotomy (PAO) is a well-accepted surgical intervention for hip dysplasia. In the adolescent population it is performed in patients who are skeletally mature with symptoms related to acetabular dysplasia. Redistribution of stresses through the hemipelvis after PAO can lead to a fracture at the ischio-pubic junction (IPJ). This is an IRB-approved, retrospective analysis of adolescent patients treated with a PAO for acetabular dysplasia from 1999 to 2012 at a single institution. Radiographic measurements were performed to include the lateral center-edge angle, Sharp acetabular index, and acetabular index of the weight-bearing zone. These were measured preoperatively and at 6-weeks and 1 year postoperatively from a standing anterior posterior pelvis radiograph. Postoperative modified Harris hip scores (mHHS) were also analyzed. Patients over the age of 21 at time of surgery and those with <2 years of follow-up were excluded. One hundred sixty-six patients (187 operated hips) at an average age of 15.6±2.5 were included. Twelve (6.4%) fractures at the IPJ were identified in 12 patients. Seven were identified on the initial postoperative films, whereas 5 were identified after the 6-week visit. Seven (58.3%) fractures had an associated superior posterior ramus nonunion. Six (50%) healed by 2 years after surgery; the remaining 6 (50%) went on to nonunion. Compared with those without a fracture, there was no significant difference in preoperative, 6 weeks postoperative, and final center-edge angle (P=0.94, 0.29, 0.27), Sharp acetabular index (P=0.95, 0.38, 0.16), or AIBWZ (P=0.37, 0.21, 0.54). There was no difference in postoperative mean modified Harris hip scores (P=0.63). Analysis of predisposing factors demonstrated that patients with Charcot-Marie-Tooth (CMT) disease were more likely to develop an IPJ fracture (P=0.001). Patients with an IPJ fracture were older (17.1 vs. 15.5, P=0.05). There was no difference based on patient sex (P=0.22). The incidence of fracture at the IPJ after PAO in the adolescent population is 6.4% with some occurring at the time of surgery. These fractures are also associated with a nonunion at the superior posterior ramus cut and an underlying diagnosis of Charcot-Marie-Tooth. These fractures are not clinically significant and in this series did not merit further intervention when identified. Level III.

The safety of the modified Stoppa approach for the Ganz periacetabular osteotomy: A preliminary cadaveric study

The safety of the modified Stoppa approach for the Ganz periacetabular osteotomy: A preliminary cadaveric study

Komplikationen nach Beckenosteotomien

Complex deformities of the acetabulum are one of the most common reasons for secondary pelvic osteoarthritis. One option of treatment is osteotomy of the acetabulum close to the joint. The correction of the spatially reduced roof of the femoral head resulting from pelvic dysplasia can minimize the risk of developing secondary osteoarthritis or reduce the progression of an already existing osteoarthritis. The Ganz periacetabular osteotomy (PAO) and Tönnis triple osteotomy procedures are the predominant methods used to correct hip dysplasia in adolescents. Both are complex procedures which bear specific risks and complications, thus requiring very experienced surgeons.

Optimization of the position of the acetabulum in a ganz periacetabular osteotomy by finite element analysis

Periacetabular osteotomy (PAO) is a surgical procedure to correct acetabular orientation in developmental dysplasia of the hip (DDH). It changes the position of the acetabulum to increase femoral head coverage and distribute the contact pressure over the cartilage surface. The success of PAO depends significantly on the surgeon's experience. Using computed tomography data from patients with DDH, we developed a 3D finite element (FE) model to investigate the optimal position of the acetabulum following PAO. A virtual PAO was performed with the acetabulum rotated in increments from the original center edge (CE) angle. Contact area, contact pressure, and Von Mises stress in the femoral and pelvic cartilage were analyzed. Five dysplastic hips from four patients were modeled. Contact area, contact pressure, and Von Mises stress in the cartilage all varied according to the change of CE angle through virtual PAO. An optimal position could be achieved for the acetabulum that maximizes the contact area while minimizing the contact pressure and von Mises stress in the pelvic and femoral cartilage. The optimal position of the acetabulum was patient dependent and did not always correspond to what would be considered a "normal" CE angle. We demonstrated for the first time the interrelation of correction angle, contact area, and contact pressure between the pelvic and femoral cartilage in PAO surgery.

Pelvic Osteotomy Techniques and Comparative Effects on Biomechanics of the Hip: A Kinematic Study

Dysplasia of the hip is characterized by malpositioning of the proximal femur in a shallow acetabulum, providing deficient femoral head coverage. This abnormal relationship leads to altered biomechanics of the hip joint, as predicted by measurement of kinematic parameters such as increased load over reduced acetabular weight-bearing area, leading to increased joint contact stresses, which subsequently results in secondary osteoarthrosis, pain, and disability. To prevent these sequelae, particularly in children and younger adults, various osteotomies have been performed with varying degrees of success. The goal of this study was to devise a simple and reproducible laboratory method to perform a kinematic analysis of the individual and comparative effects of 5 commonly performed pelvic osteotomy techniques: Chiari pelvic osteotomy, Salter innominate bone wedge osteotomy, Steel triple pelvic osteotomy, Tönnis triple pelvic osteotomy, and Ganz periacetabular pelvic osteotomy. The aim was to determine which of the osteotomy techniques caused greater correction in most of the kinematic parameters used to estimate changes in the biomechanics of the hip joint. Our hypothesis was that pelvic osteotomies such as Chiari and Salter produced favorable changes and were relatively easily reproducible, but that more biomechanical correction in all planes would be achieved by the relatively more complex triple innominate bone and Ganz osteotomy.

Gait, Hip Strength and Functional Outcomes After a Ganz Periacetabular Osteotomy for Adolescent Hip Dysplasia

The Ganz (Bernese) periacetabular osteotomy was first described for the treatment of adult patients with hip dysplasia; however, it has also been used for adolescent patients. Its effectiveness in improving patients in the short term has not been fully established and no studies, to our knowledge, have analyzed gait and functional outcome in patients with adolescent hip dysplasia. An Institutional Review Board-approved prospective study of a consecutive series of patients undergoing a Ganz (Bernese) periacetabular osteotomy for adolescent hip dysplasia was carried out. Standard radiographic parameters were analyzed. Harris hip scores, gait analysis, hip abductor, and flexion strength testing preoperatively and at 6 months and 1 year postoperatively were performed. Statistical analysis compared the 6-month and 1-year data to the preoperative values and a second analysis was performed comparing the patients with hip dysplasia to normative data of similarly aged patients. Twenty-one patients (24 hips) underwent a Ganz periacetabular osteotomy at an average age of 16.1 years for a primary diagnosis of hip dysplasia and pain. There was a significant improvement in all radiographic parameters from preoperation to 1 year in lateral center edge angle (5.5 to 33.0 degrees) (P<0.05), acetabular index of the weight-bearing zone (29.0 to 10.5 degrees) (P<0.05), ventral center edge angle (-1.1 to 32.5 degrees) (P<0.05), and medialization of the joint center relative to the contralateral side (1.12 to 1.05) (P<0.05). Isokinetic abductor strength decreased initially from 62 Nm/kg preoperatively to 58 Nm/kg at 6 months but was improved to 64 Nm/kg at 1 year. Flexion strength decreased from 92 Nm/kg preoperatively to 58 Nm/kg at 6 months but improved to 69 Nm/kg at 1 year. Abductor impulse decreased from 0.26 Nm/kg-s preoperatively to 0.23 Nm/kg-s at 6 months but improved to 0.29 Nm/kg-s at 1 year. Flexion pull-off power decreased from 1.35 Watts/kg to 1.27 Watts/kg and then improved to 1.29 Watts/kg. The Harris hip scores improved from 64.6 at the preoperative evaluation to 74.5 at the 1-year evaluation (Max 89). The Bernese periacetabular osteotomy is effective in significantly improving radiographic parameters for adolescent hip dysplasia with improvement in functional outcome. Because the osteotomy allows for medialization of the hip joint center and limited abductor muscle dissection the abductor strength improved at follow-up, however, the hip flexion pull-off was decreased. Strategies to improve hip flexion power preoperatively and postoperatively in the future are necessary. Level IV.

Safe fixation with two acetabular screws after Ganz periacetabular osteotomy

Background and purpose With Ganz periacetabular osteotomy, the osteotomized acetabular fragment is reoriented in an adducted, extended, and rotated position. The acetabular fragment is fixated with 2 screws and the patients are allowed 30 kg of weight bearing immediately after surgery. We were interested in examining the stability of the reoriented acetabulum after Ganz osteotomy; thus, the migration of the acetabular fragment was assessed by radiostereometry.Patients and methods 32 dysplastic patients (27 females; 32 hips) were included in the study. Median age was 39 (20–57) years. Radiostereometric examinations were done at 1 week, 4 weeks, 8 weeks and 6 months. Data are presented as mean (SD).Results 6 months postoperatively, the acetabular fragment had migrated 0.7 (0.8) mm medially, and 0.7 (0.5) mm proximally. Mean rotation in adduction was 0.5° (1.3). In other directions, mean migration was below 0.5 mm/°. There were no statistically significant differences in migration at 8 weeks and 24 weeks postoperatively regarding translation and rotation.Interpretation Due to the limited amount of migration, we find our postoperative partial weight-bearing regime safe.

Perianesthesia nursing considerations for Ganz periacetabular osteotomy patients

Various approaches have been proposed, developed, and implemented for patients suffering from chronic and sometimes incapacitating hip pain. This article explores the history of surgical procedures for hip pain related to developmental dysplasia, with a focus on the Ganz periacetabular osteotomy. Finally, some future approaches that may offer ways to improve the results of periacetabular osteotomies are explored.

A Comparison of the Fixation Stability of Multiple Screw Constructs for Two Types of Pelvic Osteotomies

Periacetabular osteotomies are performed to improve femoral head coverage in a variety of clinical conditions. The stability of the osteotomy fragment between Ganz's periacetabular osteotomy was compared with that of Tonnis's triple innominate osteotomy under simulated weight-bearing conditions with a variety of screw constructs using three-dimensional analysis of fragment displacement and angular rotation. Generally, small amounts of displacement (<2 mm) and angular rotation (<3 degrees) were encountered for each fixation technique. Because the Ganz procedure violates the triradiate cartilage, it is not feasible in the immature patient. Thus, an understanding of fixation requirements in other available osteotomies to maintain fragment position is necessary.

Changes in load-bearing area after Ganz periacetabular osteotomy evaluated by multislice CT scanning and stereology.

We used a stereologic method based on 3D CT scanning to estimate the projected load-bearing surface in the hip joint. 6 normal hip joints and 6 dysplastic hips were examined. The latter were CT-scanned before and after periacetabular osteotomy. We found that the average area of the projected load-bearing surface of the femoral head preoperatively was 7.4 (6.5-8.4) cm2 and postoperatively 11 (9.8-14) cm2, which was similar to the load-bearing surface in the normal control group. We performed double measurements and the coefficient of error of the mean was estimated at 1.6%. Due to overprojection, an overestimation of about 3.8% on the projected load-bearing surface occurred. Consequently, the stereologic method proved to be precise and unbiased. Our findings indicate that this method is of value for monitoring the load-bearing area in the hip joint of patients undergoing periacetabular osteotomy.