Proximal femoral osteotomy

The proximal femur has historically been the site of choice for the realignment of the hip. Intertrochanteric osteotomy (ITO) is the most established hip-joint–preserving procedure. In 1826, John Rhea Barton of Philadelphia performed the first osteotomy on a patient with posttraumatic ankylosis and successfully produced a painless pseudarthrosis. He and Kirmission (1894) were the first to describe proximal femoral osteotomy.

Early on, adult sequelae of developmental hip dysplasia were the most common indications for an ITO (Table 1-1). Early reports of realignment osteotomies of the proximal femur involved either displacement or angulation. Hip dysplasia was the first application of this procedure, although now it rarely constitutes an indication, at least for an isolated femoral osteotomy. Adolf Lorenz (1919) described his “bifurkation” operation, and Schanz (1922)—among others—also introduced a variation of Kirmission’s procedure, mainly for unreduced congenital dislocation of the hip. Both of these procedures were of the pelvic support osteotomy type. Lorenz outlined ten indications for his procedure, with advanced osteoarthritis being the eighth. In his report in 1935, McMurray from Liverpool adopted Lorenz’s procedure, and he is the one who popularized proximal femoral osteotomy for the treatment of osteoarthritis. The so-called Lorenz-McMurray procedure was described—but not performed in reality—as an excessively oblique cut (Figure 1-1). Although it was originally described as a purely displacement osteotomy, it did secondarily employ valgus angulation. McMurray believed that the primary mechanism of pain relief was the bypass of the proximal femur during the transmission of loads from the pelvis to the distal fragment. Displacement osteotomies were widely used in England, with Malkin (earlier) and Nissen (later) being their most eminent proponents.

Figure 1–1 The McMurray osteotomy. A, Level and orientation of osteotomy is shown. B, Final result, showing medial and proximal displacement of the distal fragment.

(Adapted from Pring D. Biomechanics of the hip. In: Barrett D, ed. Essential basic sciences for orthopedics. 1st ed. Oxford: Butterworth-Heinemann; 1994: 62-93)

The prototype angulation osteotomy was described in 1950 by Pauwels, who designed a varus osteotomy above the lesser trochanter without displacement; he initially applied this procedure to young adults with hip dysplasia associated with the subluxation of a spherical femoral head. In 1956, he introduced valgus osteotomy for those hips that obtained improved congruity in adduction and for nonunited fractures of the femoral neck. About 10 years after the original description by Pauwels, the procedure came to include the medial displacement of the distal fragment (Figure 1-2).

Figure 1–2 Action of varus intertrochanteric osteotomy, increasing transverse component Q and decreasing longitudinal component L. R, The resultant compressive force. R1, The joint reaction force.

(Adapted from Pring D. Biomechanics of the hip. In: Barrett D, ed. Essential basic sciences for orthopedics. 1st ed. Oxford: Butterworth-Heinemann; 1994: 62-93)

Early on, Pauwels realized the importance of medial displacement for relieving tension from the iliopsoas and adductor muscles. He was also aware of the necessity of maintaining the overall alignment of the hip. Pauwels’s contribution to the current understanding of hip biomechanics cannot be overemphasized. He was the first to explore the concept of reducing muscle moment arms by changing the orientation of the proximal femur, and he stated that a horizontal sourcil denotes biomechanical equilibrium.

His ideas were taken a step further by Bombelli, who reached the same conclusions through a modified consideration of the primary hip forces. In addition to his theoretical model, Bombelli also modified Pauwels’s valgus osteotomy by adding extension in the sagittal plane for improved femoral head coverage in dysplasia, for the relief of flexion contracture, and for the correction of hyperlordosis. He also suggested that, in the case of a valgus osteotomy, one should exploit the inferomedial capital drop osteophyte (Figure 1-3) and put the lateral capsule to enough stretch to stimulate the formation of the roof osteophyte, both for the purpose of increasing the weight-bearing area of the joint.

Figure 1–3 The effect of the capital drop osteophyte for increasing the weight-bearing area of the hip joint and decreasing the joint reaction force after a valgus intertrochanteric osteotomy.

(Adapted from Pring D. Biomechanics of the hip. In: Barrett D, ed. Essential basic sciences for orthopedics. 1st ed. Oxford: Butterworth-Heinemann; 1994: 62-93)

The skeletal fixation of femoral osteotomies was first described by Schanz in 1924, who devised a simple external fixation system composed of one screw on either fragment. Because of the obvious biomechanical instability of his device, Schanz’s patients still relied on a plaster-of-Paris spica cast. Blount of Milwaukee popularized the use of internal fixation in 1943 with the use of the “V” blade plate. Interestingly, McMurray used two casts for fixation, whereas Pauwels used a short intramedullary nail until the application of the cast. In 1955, Müller introduced fixed-angle blade plates; the 95- and 110-degree versions are still the ones that are most commonly used for the fixation of varus and valgus ITOs, respectively, although a dynamic hip screw is now also used. The advantage of today’s blade plates is inherent in their design, which allows for the appropriate translation of the distal fragment. Pauwels, Müller, and Bombelli are the surgeons who set forth the principles of femoral osteotomy.

Recent refinements of the varus osteotomy have focused on the amelioration of abductor weakness, which is the major drawback of this procedure. Müller (1984) recommended a simultaneous distal transfer of the greater trochanter, and Nishio (1984) described a dome osteotomy of the femoral neck, which leads to distalization and lateralization of the greater trochanter. The Morscher osteotomy (1999) combines the distal transfer of the greater trochanter and the lengthening of the femoral neck without reorienting the femoral head.

Salvage femoral osteotomies include hip joint resection, Colonna’s trochanteric reconstruction (1960), and pelvic support osteotomies. These osteotomies were originally described by Lorenz and Schanz, and they were popularized by Milch and Bachelor. However, they fell into disfavor because of the significant shortening and valgus malalignment that they produced. Ilizarov (1992) modified the procedure by adding extension in the sagittal plane and a second more distal femoral osteotomy for lengthening and realignment. The best indication for this operation today is the sequela of neonatal hip sepsis in the older child or adolescent.

With the development of so many different types of osteotomies, it is easy to forget the principle stated in 1964 by Blount in his article published in the Journal of Bone and Joint Surgery: “… all of them are in fact variations of one procedure which must be modified according to the clinical and roentgenographic findings.” Depending on the underlying pathology, a number of combined corrections in the frontal and sagittal planes may be implemented and may even be coupled with derotation.

Thus, it is imperative that the surgeon be familiar with the basic tenets of deformity correction. When the osteotomy is at a level that is different from the center of rotation or angulation, the secondary translation of the fragments at the level of the osteotomy will occur (this is the second osteotomy rule, according to Paley and colleagues). When one considers the proximal femur, this corresponds with the medial or lateral displacement of the shaft in the case of a varus or valgus osteotomy, respectively (i.e., displacement–angulation osteotomy). This ensures the optimal alignment of the entire lower extremity, provided that no other deformity is present. Despite the clinical and geometric documentation of the beneficial effect of femoral translation, some surgeons do not advocate this principle, because there are concerns about the technical feasibility of a future total hip replacement.

Acetabular Osteotomy

Much like femoral osteotomies, acetabular osteotomies are divided into reconstructive (e.g., redirectional, reshaping) procedures and salvage procedures. These operations are intended for patients whose main pathology is on the acetabular side; congruously dysplastic hips comprise the prototype indication for these osteotomies. Unlike osteoarthritis, for which improved congruence is the goal, dysplastic hips require improved coverage to reduce contact pressure within the joint. Numerous reconstructive pelvic osteotomies were devised during the twentieth century, with each trying to address the problems of the previously described procedures (Table 1-2).

Salter introduced his single innominate osteotomy in 1961. Among other drawbacks, this osteotomy pivots on the symphysis pubis, thus severely limiting the degree of correction that can be obtained in adult patients. The Pemberton acetabuloplasty (1965) hinges at the triradiate cartilage, thereby allowing for a change in both the volume and orientation of the acetabulum. The Dega osteotomy (1965) resembles the Pemberton procedure but leaves a posterior portion of the iliac cortex intact, thereby forming the hinge. The double pelvic osteotomy was introduced by Sutherland and Greenfield in 1977, who added to Salter’s technique a cut of the pubis medial to the obturator foramen; this bone cut is the pivot point of this osteotomy. The use of single and double pelvic osteotomies in adult patients has now been abandoned.

Triple pelvic osteotomies were described in an effort to overcome the drawbacks of single and double osteotomies, especially the lateralization of the hip. The operations described by LeCoeur (1965), Hopf (1966), and Steel (1973) are all slight variations on this theme, with the ischial bone cuts made close to the symphysis pubis. Steel popularized the triple osteotomy in the United States. The problem that these procedures share is the significant deformity that is created after large corrections; Tönnis (1977) and Carlioz (1982) addressed this problem by describing juxta-articular triple pelvic osteotomies. Although these procedures avoid the strong sacropelvic ligaments, thereby enhancing the mobility of the acetabular fragment, they may create a considerable gap between the ischium and the acetabular fragment that will necessitate special measures for stabilization.

Periacetabular spherical osteotomies include those described by Wagner (1965), Eppright (1975), and Ninomiya and Tagawa (1984). These operations are technically demanding, and, because they are partly intra-articular, they jeopardize the vascular supply to the acetabular fragment. A concomitant arthrotomy for intra-articular pathology is therefore not recommended when these procedures are undertaken.

The Bernese periacetabular osteotomy, which was developed in 1983 by Swiss and American surgeons and described in 1988 by Ganz and colleagues, addresses many of the problems described previously, and it is currently the acetabular osteotomy of choice in most centers worldwide. Purported advantages include (but are not limited to) the retention of vascularity, the integrity of the posterior column, the reproducibility of technique, and the need for minimal internal fixation. The most serious complication is considered by Ganz himself to be the intra-articular extension of the osteotomy, with a reported rate of 2.7%. The main difficulty of this procedure is to determine intraoperatively the desired degree of reorientation of the acetabular fragment. To this end, computer navigation may be a valuable aid in the future.

Salvage acetabular osteotomies are indicated for patients with acetabular pathology and incongruous joints, with no more than moderate degenerative changes. Shelf operations, which are designed to increase coverage by laterally extending the roof of the acetabulum, were first described by König (1891) and performed by Albee (1915) in patients with dislocated hips. They were subsequently popularized by Gill (1926) from the University of Pennsylvania. Their sole indication today may be for the adult patient in need of a salvage osteotomy whose hip is not deformed enough for a Chiari procedure.

The medial displacement iliac osteotomy was developed by Karl Chiari from Vienna in 1953, but it was only reported in the English-speaking literature in 1974. This procedure is essentially a capsular arthroplasty. Abduction is increased, and, although head coverage by the true acetabulum is decreased, total coverage is augmented by part of the femoral head articulating with newly formed fibrocartilage.

Hip Arthroscopy

Michael S. Burman (1931) is credited with the first recorded attempts of hip arthroscopy on cadavers. His technique encompassed the distention of the joint with fluid and the use of a 4-mm arthroscope. He described an anterior paratrochanteric portal that was not dissimilar to today’s anterolateral portal. Because of the lack of distraction, he was unable to visualize the acetabular fossa and the ligamentum teres.

Takagi (1939) first reported about the clinical application of hip arthroscopy in four patients: two patients with Charcot joints, one tuberculous patient, and one patient with septic arthritis. It took more than 30 years from the time of Takagi’s report for another report to emerge. In 1976, Aigman described an attempt at diagnostic arthroscopy and biopsy. Richard Gross was the first to report about hip arthroscopy in the North American literature in 1977. Subsequently, it was James Glick and his partner, Thomas Sampson, who pioneered hip arthroscopy in North America and who modified the surgical technique by positioning the patient in the lateral decubitus position rather than the supine position. Further key technical refinements took place during the mid-1980s and are attributed to Ejnar Eriksson and colleagues, who estimated the distraction forces needed, and to Lanny Johnson, who described anatomic landmarks and techniques of needle placement. Although the conventional technique involves the use of distraction, Dorfmann and Boyer (1988), who were both rheumatologists in Paris, developed a technique without distraction for entry into the peripheral compartment. In Great Britain, hip arthroscopy was first attempted by the senior author (RNV) in 1988, and its use has been increasing ever since. Technical suggestions for the optimal use of supine patient positioning were made by J.W. Thomas Byrd during the 1990s, and Marc Phillipon recently modified supine positioning by placing the extremity in 15 degrees of internal rotation, 10 degrees of flexion, neutral abduction, and 10 degrees of lateral tilt.

A common indication for hip arthroscopy has been the presence of loose bodies causing mechanical symptoms. In the absence of associated major structural abnormalities, hip arthroscopy is the preferred treatment for intra-articular disorders, with labral lesions being the most common. Other indications include extra-articular disorders that affect the iliopsoas tendon and bursa and the tensor fasciae latae and its adjacent trochanteric bursa (Figure 1-4). An endoscopically assisted technique for triple innominate osteotomy has also been described by Wall and colleagues. Clearly, the technique and applications of hip arthroscopy are still evolving.

Figure 1–4 Some of the modern uses of hip arthroscopy. A, Labral repair. B, Osteoplasty of femoral head–neck junction. C, Microfractures. D, Release of iliopsoas tendon.