The 2-incison THA is a novel surgical technique that combines two standard orthopaedic surgical approaches with fluoroscopic guidance, conventional hip implants and specialized instrumentation. The goal of this procedure is to minimize soft tissue trauma, thereby reducing postoperative morbidity and accelerate rehabilitation.

The surgical procedure is performed with the patient supine on a radiolucent table. Two separate, 4-5 cm incisions are used to create a direct pathway to the acetabulum and the femur. An oblique incision along the femoral neck allows the acetabulum to be exposed through a traditional Smith-Peterson approach. This surgical interval is both internervous and intermuscular and therefore requires no muscle dissection. After removal of the femoral head, the entire acetabulum can be visualized, prepared with specialized reamers and a conventional cementless cup and liner can be implanted with an offset inserter. Aside from the skin incision and femoral neck cut, fluoroscopy is not essential for exposure and implantation of the acetabular component.

The second incision is used to prepare and implant the femoral component.  A point coaxial to the femur in both the coronal and sagittal planes is used to create an oblique incision in the posterior lateral buttock. Using both the anterior and posterior incisions, a pathway from the posterior incision, through the piriformis fossa and into the femoral canal is created. This surgical approach is analogous to a femoral rodding and requires only incising the Gluteus Maximus fascia and a small split in the muscle. Then with the aid of fluoroscopy, palpation and direct visualization from the anterior incision, the femur is prepared with specialized instrumentation and a conventional cementless femoral component is implanted. The prosthetic neck is then brought through the capsule with traction to allow placement of the head and reduction of the hip through the anterior incision.

8:26 a.m.

Anterior Approach for THA on the Orthopedic Table

Joel M. Matta, M.D., Tania Ferguson, M.D. and Cambize Shahrdar, M.D.

The anterior approach is also called the Heuter Approach or the Short Smith-Pete Approach. It is performed on the OSI PROfx table to facilitate femoral access.  It is minimally invasive because it preserves the muscle attachments to the pelvis and femur and also does not disrupt the “Hip Deltoid”.  I adopted this technique to minimize the chance of post-op dislocation and to accelerate the recovery rate.

From September 1996 through September 2004 I performed 651 anterior approach THA including 523 primaries (the subject of this report), 98 hips with previous surgery, and 29 revisions.

This is a consecutive unselected series of 523 primary THA in 465 patients (58 bilateral).  The maximum BMI is 57.  Operative time averages 1.5 hours.   The incision length averages 10 cm.  Leg length discrepancy averages 3 mm, with a standard deviation of 4 and a maximum of 10 mm.  Acetabular abduction averages 41° with a standard deviation of 4 (range 33° to 49°).  Acetabular anteversion averages 23°, with a standard deviation of 5 (range 9° to 38°).  Complications include: 1 infection, 2 anterior dislocations, 1 posterior dislocation, 0 recurrent dislocations, and 1 femoral nerve palsy (recovered).

The time for patients to begin walking without external support at a median of 8 days.  Patients terminate the use of external support at a median of 15 days.

The anterior approach requires no post-op dislocation precautions and facilitates early functional recovery.  It is a minimally invasive technique applicable to all primary hip patients, does not increase complications or operative time or compromise accuracy of acetabular position or leg length.

Consult: www.hipandpelvis.com

8:32 a.m.

Minimally Invasive Total Joint Arthroplasty

Conservative hip surgery has lost popularity in the seventies of the last century although some centers have continued to perform osteotomies around the hip. Today, conservative hip surgery can be defined as the surgical treatment of prearthritic deformity and/or of early osteoarthritis of the hip by preserving the biological joint. Hips with established osteoarthritis are not anymore an indication except for situations where alignment is the problem and pain is little. While proximal femoral osteotomies are constantly decreasing in number, some indications remain strong, especially valgus-type osteotomies in post traumatic deformities and non-unions near the hip. Pelvic osteotomies have gained increasing interest during the last 20 years but only the few powerful reorientation procedures have been performed in bigger numbers.

During the last 10 years the impingement concept for the origin of osteoarthritis of the hip has been established. This was possible with a safe technique of surgical dislocation of the hip joint allowing not only new insights into the pathoanatomy but opening a door to a new generation of intra- and juxtacapsular reconstruction procedures. Some of these procedures are already established like the acetabular resection osteoplasty, the debridement and refixation of the labrum as well as the head contouring osteochondroplasty. If the deformity is not too global, the described steps are more and more performed with arthroscopy or with a semi-open procedure. Other techniques are about to emerge from early clinical testing like relative neck lengthening, subcapital reorientation of the slipped epiphysis, femoral neck osteotomy and finally femoral head reduction osteotomy in post Perthes coxa plana.

The different techniques which all depend on precise knowledge of the vascular anatomy are presented.

9:17 a.m.

Femoral and Acetabular Osteotomy

Richard Santore, M.D.

Both femoral and acetabular osteotomies have enduring useful roles in the surgical management of patients with various hip conditions. The original, and ongoing, indication for intertrochanteric valgus osteotomy is to induce healing of femoral neck non-unions by converting the high shear forces of a vertical fracture into compressive forces by repositioning into a more horizontal position. Avascular necrosis of the head, in the absence of segmental collapse and secondary arthritis, is not a contraindication to such a valgus osteotomy (Marti). Additional indications for intertrochanteric osteotomies include post-traumatic deformity, limb length inequality, adult sequellae of Legg-Calve-Perthes (high riding trochanter, shortening and varus), grade II posterior head displacement, apparent varus, and malrotation/impingement due to Slipped Capital Femoral Epiphysis, and certain cases of osteonecrosis. Isolated intertrochanteric osteotomy is only occasionally indicated for the management of arthritis secondary to dysplasia.

Rotational osteotomy of the pelvis (Bern or Ganz-type periacetabular osteotomy, Tönnis or juxta-articular type or dome type) has overtaken the role once historically played by intertrochanteric osteotomy in the surgical management of dysplasia-related hip anomalies. It is imperative that the hip joint be congruous, free of fixed subluxation and located in the native, not false, acetabulum. Ideal candidates have pre-arthritic, activity related pain associated with radiographic dysplasia. Early arthritic (Tönnis I) is not a contraindication. Surgical management of associated acetabular labral tears/detachments, and impingement lesions can be done at the same time via antecedent hip arthroscopy (same anesthetic) or open arthrotomy. The nature of the dysplasia, i.e. global, or primarily frontal plane, or primarily anterior, needs to be assessed pre-operatively with specially obtained plane radiographs that include a conventional AP, a standing AP pelvis, an AP hip in internal rotation/abduction, a false profile and a lateral. Any associated retroversion has to be assessed. CT scan is often helpful. The directions of the coverage enhancements and their magnitudes need to be customized to fit the nature of the dysplasia. A ‘standard’ method of correction is likely to result in unwanted iatrogenic retroversion is some cases; especially if a pre-existing retroversion has not been taken into account. Intertrochanteric osteotomy is now used as a complement to rotational osteotomy at a rate of approximately one in ten cases, for the indications outlined above. In most cases, the pelvic and intertrochanteric osteotomies are done under the same anesthetic.

All osteotomies should be done with the concept that conversion to total hip replacement might be necessary in the future. Displacements, osteosynthesis and hardware removal should be planned in such a way as to minimize future technical difficulties. Femoral and Chiari osteotomies can pose great difficulty at the time of conversion if major displacement were performed. In the event of iatrogenic severe retroversion after a periacetabular osteotomy, it may be desirable, in fact essential, to perform a reversal of the PAO before the THR, in order to avoid major malposition of the acetabular component that would be the source of untreatable recurrent dislocation.

9:25 a.m.

Hip Arthroscopy

Joseph C. McCarthy, M.D.

Hip arthroscopy is an excellent way to evaluate, diagnose, and treat an evolving number of hip conditions including loose bodies, synovial chondromatosis, post trauma, foreign body removal, and post total hip arthroplasty.  Radiographic studies are not sensitive enough; however, contrast agents used in conjunction with CT and MRI may aid in the diagnosis of intra-articular hip pathology.  Labral tears are the most common cause of mechanical hip symptoms. A review of 1246 cases revealed 98% of all labral tears and 95% of all chondral lesions occur in the anterior quadrant.  The most frequently observed chondral lesion is the watershed lesion, which consists of a labral tear with separation of the labrum from the articular surface at the labral-cartilage junction. The severity of the chondral lesion is highly correlated with the surgical outcome. The lateral approach requires that the patient be positioned in the lateral decubitus position with the affected hip up.  Most intra-articular lesions occur in the anterior quadrant (medial or superior) of the hip and can be treated via two superior paratrochanteric portals.  The paratrochanteric portals pass through fewer muscle planes, avoid potential injury to the adjacent neurovascular structures, and punctures the superior hip capsule which is slightly thinner. A thorough knowledge of positioning and anatomic relationships to portal placement is necessary to prevent potential neurovascular complications from occurring during hip arthroscopy.   Complications are best avoided by sufficient distraction (7-10mm), dedicated hip instruments, and precise surgical skills.  Further improvements in instruments and long-term outcome measurements will define and clarify the role of arthroscopic hip surgery.

9:33 a.m.

Fusion of the Adult Hip

Dennis. W. Burke, M.D.

Despite remarkable advances in the technology of total joint arthroplasty, arthrodesis of the adult hip remains a viable option in selected individuals.

The major indications for hip arthrodesis are unilateral hip disease in adolescents with closed growth plates or in the young adult.  Further requirements are that the patient be motivated and have a full understanding of the scope of the surgery, the details of recuperation and long term function patterns.  Some contraindications to hip fusions are bilateral hip disease, significant back or ipselateral knee disease.  A person with avascular necrosis should have a quiescent interval of 18 months with a negative MRI on the contralateral hip before proceeding with hip fusion.  Reasons which are not contraindications to hip fusions are the female gender, the height stature of a patient or avascular necrosis as a disease entity as long as the contralateral hip has been proved normal by an MRI.

The techniques are many and variable.  The so-called cobra technique is an established and proven technique of high success rate.

One of the essential technical aspects of hip arthrodesis is positioning.  The ideal hip position of the hip fusion is 30 degrees of forward flexion, neutral or slight abduction of the hip and slight external rotation of the hip.  Even a solid arthrodesis will have a poor functional outcome if it is in the wrong position.  Although after a hip arthrodesis the abductors have little function, it is important to preserve their attachment for potential later conversion to a total hip replacement. The “double bean bag” technique of positioning is quite useful and allows accurate reproducible positioning of the hip during the fusion operation.

A cobra plate is used to gain internal fixation.  Male and female bell type reamers are used to conform the acetabulum and femoral head. Be sure to ream the head first. The abductors are preserved by performing a trochanteric osteotomy and reattaching the trochanter over the cobra plate.

9:41 a.m.

Algorithm for Nonarthroplasty Surgery of the Hip

John C. Clohisy, M.D. and Perry L. Schoenecker, M.D.

The management of adolescent and young adult hip disorders has rapidly evolved over the past decade. This is due to enhanced understanding of pre-arthritic and early arthritic hip disease combined with improved diagnostic skills, better patient selection criteria and refinements in alternative surgical techniques. Despite this, there remains a major need to develop optimal diagnostic and treatment algorithms for young patients with compromised hip function. It should be emphasized that comprehensive care of young adult hip patients must employ a diversity of surgical techniques including arthroscopy, osteoplasty, surgical dislocation, pelvic osteotomies, femoral osteotomies, grafting procedures, arthrodesis and prosthetic replacement. Optimal clinical results are dependent upon the combination of careful patient selection and successful execution of the appropriate surgical procedure. The purpose of this presentation is to outline an algorithm for the diagnosis and treatment of adolescent and young adult patients with symptomatic disorders of the hip.

Detailed history, physical exam and imaging of the hip are essential to develop an optimal surgical strategy for the patient. Initial evaluation must confirm the hip joint as the source of clinical symptoms. A symptomatic hip in the absence of a significant osseous deformity (isolated labral tear, loose body, chondral flap) can be managed effectively with hip arthroscopy. In the presence of an osseous abnormality and a mechanically jeopardized hip, the planned surgical procedure addresses the bony deformity in conjunction with treating the associated intra-articular disease. Such procedures (osteoplasty, debridement and osteotomy) are utilized to treat impingement lesions (reduced head-neck offset, aspherical femoral head, retroverted acetabulum, SCFE) as well as joint overload disorders (classic DDH, Perthes-like deformities). The endstage arthritic hip in the young patient presents a difficult clinical problem that is most commonly treated with prosthetic replacement surgery, yet hip arthrodesis remains an option for the occasional, carefully selected patient. A comprehensive treatment strategy, utilizing a variety of surgical techniques, should provide effective management for the wide spectrum of hip disease encountered in this very challenging patient population.        

10:02 a.m.

Presidential Guest Speaker :

Metal-Metal THR has the longest clinical history of any of the currently used articular couples. Long-term follow-up of what are now considered sub-optimal designs (e.g., McKee Farrar, Ring, Sivash) has produced a wealth of knowledge regarding the safety and efficacy of this articular combination.

Retrieval analysis of metal-metal THR articular couples have demonstrated wear between 1 and 5 microns per year, after initial wear-in, in comparison with 100-­200 microns per year associated with metal-polyethylene wear. Equally important, the histologic response to metal wear debris (which are substantially smaller than polyethylene wear debris) is not associated with a histiocytic response as seen with polyethylene wear, and thus, is rarely associated with osteolysis.

The constituent metal ions released through wear of the metal-metal THR are excreted primarily in the urine, and in general the serum levels have been 3 to 5 times higher than control subjects. However, cobalt and chromium serum levels are also seen in patients who have metal-polyethylene couples in conventional THR or TKR. No adverse physiologic effects have been identified in the long-term follow-up of patients exposed to cobalt-chrome implants.

10:48 a.m.

Avoiding Femoral Fractures in Total Hip Resurfacing

Thomas P. Schmalzried, M.D.

Total hip resurfacing with metal-metal bearing components is considered investigational by the Food and Drug administration.  To date, a total of 147 hips have been implanted by the senior author in 121 patients using the Conserve Plus hybrid hip resurfacing system (cementless socket; cement femur) under an FDA and IRB approved protocol.  This is the initial cohort of patients treated with metal-metal resurfacing by this surgeon.  Eighty-one hips in 70 patients have a minimum of 2 years follow-up, with a maximum follow-up of 50 months.  There have been no femoral fractures.  There was one femoral component that was radiographically loose at 12 months and revised at 17 months post-op.  All other components are in situ.

Careful case selection and minimizing surgical trauma can reduce the occurrence of femoral neck fractures, even in the surgeon’s initial experience.  Pre-operative characteristics of the low-risk proximal femur include favorable shape (head:neck >1.2 and neck length >2cm); good bone density; no cysts >1cm; and favorable mechanics (>120 valgus).  Valgus and anteversion positioning, with anterior/superior translation of the femoral component, minimizes tension stresses on the neck.  Intra-osseous proximal femoral suction keeps the bone dry and promotes consistent cementing.  Aggressive impaction during the insertion of femoral components can be avoided by assuring adequate clearance at the implant-bone interface.

10:56 a.m.

Highly Cross-Linked Polyethylene

William J. Maloney, M.D.

Highly cross-linked polyethylene has now been commercially available for approximately five years.  Currently the majority of polyethylene inserts that are implanted in North America are highly cross-linked products.  Clinical data is now available on several of these implants.  Although there are fundamental differences between the commercially available products in terms of manufacturing technique and sterilization, wear testing has been encouraging.  Randomized clinical trials have demonstrated that the various highly cross-linked materials have lower wear rates than their conventional counterparts approaching in some cases what was seen in the laboratory.  There have been no reports of rapid wear or premature osteolysis at this time.

Concerns over the mechanical properties are ongoing.  There has been a very small number of liner fracture which appear to be more a factor of the unintended consequences of the use of large femoral heads with unsupported polyethylene and not specifically related to the mechanical properties of the highly cross-linked material.  Finite element studies have shown that in the conditions in which fractures have been clearly documented, conventional polyethylene would have also failed.

11:04 a.m.

Oxinium on Cross-Linked PE

Several wear studies have noted that cross-linked polyethylene is less resistant to a roughened counterface.  It seems reasonable to select the most scratch resistant counterface to articulate against cross-linked polyethylene in patients who are expected to outlive their total hip arthroplasties.  Both ceramic and Oxinium femoral heads seem well suited to this role.  Oxinium femoral heads have all the advantages of ceramic without the risk of fracture.

11:12 a.m.

THA: Alumina-on-Alumina Ceramic Bearings: 3-7 Year Follow-up

Surgeons have a strong influence on patient choice in anesthetic type.  Newly developed catheters for continuous medication delivery, specialized infusion pumps, and expertise in the field of Anesthesiology have made regional anesthesia more attractive to patients and surgeons.  Regional anesthesia for major lower extremity reconstruction includes the use of single shot and continuous epidural injection, single shot and continuous spinal injection, continuous lumbar plexus blockade, and continuous peripheral blockade of the femoral and sciatic nerves.  These developments have led to the application of regional anesthetic technique in conjunction with major lower extremity reconstructive procedures such as multi-ligament knee reconstruction, tibial osteotomy, unicompartmental replacement, ankle fusion, and ankle replacement, as well as hip and knee replacement.  Surgeons without experience in the use of regional anesthesia are hesitant to adopt the technique because of perceived inefficiency and prolonged room turnover, while also indicating great satisfaction with the pain relief provided by continuous peripheral nerve blockade.  Recent evidence indicates a high degree of reliability, safety, effectiveness, and patient satisfaction with regional anesthesia.  Widespread adoption of regional technique will require continued demonstration of safety, the possibility of early mobilization with weight-bearing, the early return of proprioceptive function, and system efficiency.

11:42 a.m.

Postoperative Pain Management

Douglas A. Dennis, M.D.

Successful management of perioperative pain is critical for accelerated rehabilitation following total hip arthroplasty (THA).  Perioperative pain management programs must minimize pain without creation of excessive sedation or motor blockade while avoiding treatment complications.  A multimodal program including method of anesthesia and postoperative pain management is necessary to maximize patient recovery.

Numerous methods of anesthesia are available for use in THA including general and various methods of regional anesthesia (spinal, epidural, lumbar plexus blocks, etc.).  Regional anesthesia offers the advantage of continued analgesia postoperatively by use of intrathecal opiods, continuous epidural infusions, or peripheral nerve blocks and has been shown to reduce postoperative pain and the need for parenteral opiods.  Postoperative epidural infusions of either local anesthetics or opiods can be utilized.  Epidural administered Ropivicaine has been shown to lessen motor blockade when compared with Bupivacaine.  Potential complications associated with regional anesthetics include nausea, pruritis, and urinary retention.

Understanding that pain is mediated via neurogenic and inflammatory pathways has resulted in improved analgesia following joint replacement.  Administration of preoperative medications (pre-emptive analgesia) such as nonsteroidal anti-inflammatory drugs (NSAIDs) and opiods which attempt to reduce sensitization of both the inflammatory and neurogenic pain pathways before surgical intervention has been shown to substantially reduce postoperative pain in numerous studies.  COX-2 NSAIDs are frequently chosen due to their reduced risk of interfering with anticoagulation regimens.

Lastly, use of cryotherapy, local wound injection (local anesthetics and opiods), and preoperative education programs are also valuable adjuncts in the treatment of postoperative pain following THA.

11:49 a.m.

Accelerated Rehabilitation for Total Hip Replacement

Richard H. Rothman, M.D., Ph.D.

The current focus of both patients and physicians is on rapid recovery, minimization of post operative pain, and improved function. These goals, although laudable, should never be secondary to excellence in long-term outcomes.

The strategies full in obtaining rapid return to recreational and occupational function include the following:

1. Surgical considerations include obtaining optimal stability, use of implants that are compatible with full weight bearing, gentle atraumatic surgery, and careful hemostasis.

2. Improved pain management encompasses minimization of injectable narcotics, oral analgesics, the use of anti-inflammatory drugs, local pain blocks and injections.

3. Patient selection and education is central. Morbid obesity and habituation to narcotics are contra-indications to a "fast track." Patient education, intensive physical therapy and inculcation of appropriate goals are all utilized.

4. A team approach is helpful and includes the surgeon, social worker, pain physicians, physical therapist, home-care coordinators, and the family.

5.  Critical care pathways should be well delineated and explained to families, patients, and the entire patient care team.

11:56 a.m.

Patient Education to Promote Success

Richard D. Coutts, M.D., Thomas R. Turgeon, M.D., Bindesh Shah, M.D. and Mary Elington, R.N.

Preoperative education programs have been used extensively in an effort to improve outcomes following total hip and knee arthroplasty.  Evaluations of length of stay, rate of discharge to home and complication rate were performed on consecutive patients from January to April, 1995 and 1996.  A mandatory multidisciplinary pre-operative education program was instituted in May, 1995.  Mean length of stay was reduced from 5.4 days to 4.7 days for primary hip arthroplasty (p=0.008) and from 5.6 days to 4.5 days for primary knee arthroplasty (p<0.001).  Discharge to home rates did not vary between the groups.  A significant reduction in the complication rate was seen among patients undergoing primary total knee arthroplasty (p=0.03), but not among primary hip arthroplasty (p=0.76).  The institution of a mandatory preoperative education program for total joint arthroplasty was associated with shorter hospital stays for both primary knee and hip arthroplasty as well as a reduced complication rate among total knee arthroplasty patients.