Reinhold Ganz

Ischial spine projection into the pelvis : a new sign for acetabular retroversion.

AbstractFemoroacetabular impingement may occur in patients with so-called acetabular retroversion, which is seen as the crossover sign on standard radiographs. We noticed when a crossover sign was present the ischial spine commonly projected into the pelvic cavity on an anteroposterior pelvic radiograph. To confirm this finding, we reviewed the anteroposterior pelvic radiographs of 1010 patients. Nonstandardized radiographs were excluded, leaving 149 radiographs (298 hips) for analysis. The crossover sign and the prominence of the ischial spine into the pelvis were recorded and measured. Interobserver and intraobserver variabilities were assessed. The presence of a prominent ischial spine projecting into the pelvis as diagnostic of acetabular retroversion had a sensitivity of 91% (95% confidence interval, 0.85%–0.95%), a specificity of 98% (0.94%–1.00%), a positive predictive value of 98% (0.94%–1.00%), and a negative predictive value of 92% (0.87%–0.96%). Greater prominence of the ischial spine was associated with a longer acetabular roof to crossover sign distance. The high correlation between the prominence of the ischial spine and the crossover sign shows retroversion is not just a periacetabular phenomenon. The affected inferior hemipelvis is retroverted entirely. Retroversion is not caused by a hypoplastic posterior wall or a prominence of the anterior wall only and this finding may influence management of acetabular disorders. Level of Evidence: Level II, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Twenty Years of Experience with the Bernese Periacetabular Osteotomy for Residual Acetabular Dysplasia

Residual acetabular dysplasia is known as the most frequent cause of early osteoarthritis of the hip. The degeneration starts with overload of the rim, leading to a variety of pathologies. This change may cause the femoral head to migrate further out of the socket, resulting in a loss of congruity and generating even higher pressure point loading, which finally leads to rapid destruction of the joint. It is well accepted today that the surgical increase of the load transmission area can slow down this process of destruction and postpone total hip replacement (THR) substantially. Among the different techniques available, reorientation procedures allow for the most physiological correction of the joint mechanics. Our proposition is a reorientation procedure, which was first executed in 1984. Techniques and results have been published on several occasions. Under the name of the Bernese periacetabular osteotomy, the technique has gained popularity, especially in North America. Our 20 years’ experience performing this osteotomy through a modified Smith-Peterson approach without dissection of the abductors has clearly shown that confound appreciation of joint mechanics is the key to a successful result. Addressing acetabular retroversion and an insufficient femoral head/neck offset has helped to avoid postosteotomy impingement and significantly improved our results. Today, in our armentarium of surgical techniques to preserve the natural hip joint, the periacetabular osteotomy leads to the most predictable results.

Conservative Hip Surgery

Joint preservation is an emerging field in orthopedics that evolved primarily due to the limitations in joint replacement technology. Hip preservation techniques aim to restore an optimal relationship between structure and joint kinematics, prevent or delay the onset of degenerative pathologic conditions, and provide a durable solution for pain and dysfunction [1]. The latter techniques avoid the limitations and disadvantages inherent to joint arthroplasty; however, they demand clear indications [2].

Slipped Capital Femoral Epiphysis and Its Variants

Although SCFE has been recognized and treated by orthopaedists for over a century, significant advances in the understanding and management have occurred in the past decade. Classically, the goals of treatment have been to stabilize the physis and prevent the iatrogenic complications of osteonecrosis and chondrolysis. This schema is currently undergoing re-evaluation due to the recognition that even mild stable SCFE can cause femoroacetabular impingement (FAI). Although the potential for impingement in SCFE has been recognized for some time, preventing impingement and the resultant damage to the cartilage and labrum is becoming a more important principle of SCFE treatment. Improved knowledge of the vascular anatomy responsible for femoral head perfusion allowed the development of a safe technique for open reduction and internal fixation of the displaced epiphysis. Although the surgical dislocation and open reduction are technically demanding, safe correction of the physis is now possible and the short to mid-term results are good. Long-term results should be similar, but may be influenced by the amount of cartilage and labral damage at the time of surgery.

Acetabular Protrusion and Surgical Technique

Acetabular protrusion is a severe hip deformity and remains even today difficult to treat, due to the complexity of deformities and the early occurrence of hip osteoarthritis (OA). This chapter outlines an algorithmic approach to the surgical treatment of acetabular protrusion. Individual treatment plans need to be based upon the entire clinical presentation including the appreciation of all skeletal deformities and the degree of OA. In this technical report, the focus is on protrusion in the young adult after closure of the growth plate and in the absence of advanced OA. The most severe protrusion not only reveals global acetabular overcoverage (pincer impingement), but can occur with a high-riding trochanter and even a negatively tilted acetabular roof with medially shifting femoral head. Surgical treatment needs to be tailored according to the presented deformities and usually begins with a surgical hip dislocation to address pincer impingement including labral reconstruction. Concomitant procedures such as relative neck lengthening for trochanteric advancement and periacetabular and even intertrochanteric osteotomies might become necessary to normalize joint mechanics. The amount of applied surgery needs to be well balanced with respect to age and symptoms of the patients, since the outcome will be largely determined by the preexisting OA of these hips. Minimally invasive surgical methods such as hip arthroscopy are unable to cope with structural deformities and should be carefully considered.