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Osteonecrosis Of The Femur - Hip Resurfacing Surgery, Alternatives to Hip Replacement
By Alampallam Venkatachalam

Osteonecrosis is a condition due arising from a diminution of blood supply to bone. It affects most importantly the upper end of the femur. If left untreated it progresses to bony collapse and arthritis. The causes are many like alcohol abuse, steroid intake, Caisson's disease, Gaucher's disease.

The patient can experience sudden pain in the hips which radiates to the knee and can be confused for knee pain. Gait is painful. In early cases, x- rays are negative and MR scans are diagnostic. Treatment in the early stages is controversial and there are no clear guidelines.

Prolonged bed rest and crutch walking have not been shown to relieve pain or halt progression of the disease.

Treatment in late cases

Core decompression does ameliorate symptoms. It is minimally invasive and does not involve a replacement. If it fails then a replacement is possible at a later date.

Treatment in late cases with advanced destruction

Treatment is by a total hip replacement if bony destruction is extensive. A partial or total surface hip replacement is done if destruction is confined to the surface cartilage alone. Since it occurs in young individuals, a Surface Hip replacement is a better option as it conserves bony stock and a total hip replacement can still be done at a later date. Resurfacing of the hip is restricted to those cases of osteo necrosis where the amount of destruction is less than 30 percent of the head. Where it exceeds thirty percent, a new type of hip prosthesis called the Proxima hip is available in Chennai. This Proxima hip is an uncemented metal on metal large diameter bearing. It has been performed for avascular necrosis and other conditions like ankylosing spondylitis, post traumatic arthritis following acetabular fracture. Vascularised fiblar graft is done with the help of a microvascular surgeon.

The author trained with eminent Hip experts in Cambridge, Manchester and Livepool. He performs Hip replacements, Hip resurfacing, Proxima hip replacements, Osteotomies, Fracture fixation, Core decompression, Birmingham replacements at Bharathiraja hospital. Visit http://www.hipsurgery.in and http://www.kneeindia.com Contact him at 00 91 9282165002

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Study: Surface replacement arthroplasty may offer advantages over THA

Canadian investigators said hip resurfacing resulted in greater patient activity after 2 years.

By Robert Trace
1st on the web (September 19, 2007)
September 2007

SEOUL — Total hip arthroplasty is an established procedure with well-documented complication rates and clinical results, but surface replacement arthroplasty may offer additional clinical benefits to many patients, according to a group of Canadian researchers.

"We decided in 2003 to do a comparative study of hip resurfacing, or surface replacement arthroplasty (SRA), to the gold standard of total hip arthroplasty (THA), since we were not aware of any direct prospective studies out there comparing the two procedures," said Pascal-André Venditolli, MD, of the Maisonneuve-Rosemont Hospital in Quebec.

He and his colleagues randomly assigned 210 hips to receive uncemented metal-on-metal THA (103 hips) or a hybrid metal-on-metal SRA (107 hips). All surgeries were performed by three orthopedic surgeons, who used a posterior approach.

The researchers prospectively collected perioperative and postoperative data, and analyzed the clinical data for a minimum of 2 years.

Postop complications included three isolated traumatic dislocations and one recurrent dislocation in the THA group, which required acetabular cup revision. Two SRAs required revision for late head collapse. No postop femoral neck fractures occurred in the SRA group, he said.

There was one case of loosening at 6 months postop in the resurfacing group, which had shifted varus. There were also two cases of deep venous thrombosis in both patient groups, he said.

Although the investigators did not report a significant difference in surgical time between the two procedures, patients' length of stay in the hospital was significantly shorter for the SRA group compared to the THA patients — 5 days vs. 6.1 days for the THA group (P=.001).

"There was also a significant difference in return to work: 96% of the SRA patients returned to their previous work within 1 year vs. 83% in the THA group," Venditolli said.

Although patients in both groups demonstrated a high satisfaction rate and achieved similar WOMAC and Merle d'Aubigné functional scores, "SRA patients had better UCLA activity scores (7.1 vs. 6.3; P=.037) and returned to heavier activities (P=.035)" after 2 years, he said.

"This randomized study shows that SRA and THA present a similar complication rate, but distinctive complications," Venditolli said. "It also suggests that SRA results in better function and improved patient activity in comparison to THA.

"However, the effect of long-term fixation related to increased activity levels is unknown. Long-term follow-up is necessary to determine the survivorship of SRA over THA," he said.

For more information:

Vendittoli P-A, Lavigne M, Lusignan D, Roy A-G. A randomized study comparing surface replacement arthroplasty to total hip arthroplasty: 2-4 years follow-up. F028-2. Presented at the 15th Triennial Congress of the Asia Pacific Orthopaedic Association. Sept. 9-13, 2007. Seoul.

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Metal-metal Hip Resurfacing Offers Advantages Over Traditional Arthroplasty in Selected Patients

By Robert L. Barrack, MD
ORTHOPEDICS 2007; 30:725
September 2007

Total hip arthroplasty (THA) is among the most successful interventions in medicine. It is the best option for most patients with end-stage arthritis of the hip. However, THA has some limitations, and problems with THA are far from nonexistent. Revisions account for almost 20% of hip cases in the United States, and this number is growing.1 These revision cases pose a greater risk for patients.

Avoiding the need for revision would be a substantial benefit, and diminishing the morbidity should revision become necessary would be equally important. Potential problems also exist in performing a THA in many young, active patients, and hip resurfacing offers advantages in many of these areas.

Indications and Advantages of Hip Resurfacing
Managing Femoral Deformity and Suboptimal Anatomy

An uncommon, but useful indication for hip resurfacing is for patients with proximal femoral deformity, in whom a total hip can be difficult if not impossible (Figure 1). More commonly, suboptimal anatomy is an issue, as with patients in whom even the smallest stem requires reaming, which puts patients at long-term risk for stem fracture (Figure 2). Conversely, a large canal presents problems for implanting a cementless stem (Figure 3).


Avoiding Stress Shielding

The presence of a femoral stem inevitably causes some degree of thigh pain, which is more common with larger stems.2 Stress shielding occurs over time from nonphysiologic hoop stresses. The long-term sequelae include bone loss, thigh pain, and stem fracture. The only hip arthroplasty associated with maintaining or increasing bone density is metal-metal hip resurfacing.3

Preventing Limb-length Difference and Dislocation

The major long-term complications of THA leading to more morbidity, dissatisfaction, and lawsuits are limb lengthening and dislocation. With hip resurfacing, the incidence of dislocations is markedly less than with THA. In the Medicare database, 4% of THA patients experience a dislocation in the first 6 months following surgery.4

Retaining Bone Stock for Future Revisions

Another major advantage of hip resurfacing is retaining bone stock for future revisions. Conversion to a THA is more similar to a primary than a revision procedure in terms of operative time, blood loss, and clinical success.5

Enabling Patients’ Return to a High Activity Level

The most compelling argument in favor of hip resurfacing is activity level. The fastest growing segment of the THA marketplace is patients <55 years. These patients want to maintain an active lifestyle, and they shun limitations.

In a study completed this year, a survey of the leading hip surgeons in the United States was performed regarding what activities they recommend to their patients. Activities prohibited by approximately 80%, even with the new bearing surfaces or large metal heads, included virtually every activity that required any impact.6

In contrast, surgeons generally do not limit activities after hip resurfacing. In a recently published study, following hip resurfacing, 92% of patients participated in sports, and none gave up their preferred sport.7 This high level of activity apparently does not compromise the clinical result. In a study of 446 hips in patients <55 years who were given no activity restrictions, 90% of patients returned to sports, and there was only 1 revision in 2 to 8 years of follow-up.8

We are now dealing with a new generation of hip patients. They are more informed and involved, educated, and active. The concepts of maintaining bone and less activity restriction resonate with them. They know others who have had hip replacement, and they have researched all of the available data on hip replacement, including the data on new bearing options. A high percentage of these patients have rejected THA and prefer the resurfacing concept.

Conclusion
Resurfacing is not for every patient or for every surgeon. However, it offers substantial advantages in properly selected patients. Because of this, metal-metal hip resurfacing has become the fastest growing arthroplasty procedure in the world in recent years outside the United States. With the US Food and Drug Administration granting approval in 2006 for one component, and approval for a second component pending, this trend will continue for the foreseeable future.

References

Zhan C, Kaczmarek R, Loyo-Berrios N, Sangl J, Bright RA. Incidence and short-term outcomes of primary and revision hip replacement in the United States. J Bone Joint Surg Am. 2007; 89:526-533.
Vresilovic EJ, Hozack WJ, Rothman RH. Incidence of thigh pain after uncemented total hip arthroplasty as a function of femoral stem size. J Arthroplasty. 1996; 11:304-311.
Kishida Y, Sugano N, Nishii T, Miki H, Yamaguchi K, Yoshikawa H. Preservation of the bone mineral density of the femur after surface replacement of the hip. J Bone Joint Surg Br. 2004; 86:185-189.
Phillips CB, Barrett JA, Losina E, et al. Incidence rates of dislocation, pulmonary embolism, and deep infection during the first six months after elective total hip replacement. J Bone Joint Surg Am. 2003; 85:20-26.
Ball ST, Le Duff MJ, Amstutz HC. Early results of conversion of a failed femoral component in hip resurfacing arthroplasty. J Bone Joint Surg Am. 2007; 89:735-741.
Klein GR, Levine BR, Hozack WJ, et al. Return to athletic activity after total hip arthroplasty. Consensus guidelines based on a survey of the Hip Society and American Association of Hip and Knee Surgeons. J Arthroplasty. 2007; 22:171-175.
Narvani AA, Tsiridis E, Nwaboku HC, Bajekal RA. Sporting activity following Birmingham hip resurfacing. Int J Sports Med. 2006; 27:505-507.
Daniel J, Pynsent PB, McMinn DJ. Metal-on-metal resurfacing of the hip in patients under the age of 55 years with osteoarthritis. J Bone Joint Surg Br. 2004; 86:177-184.
Author
Dr Barrack is from the Department of Orthopedic Surgery, Washington University School of Medicine, Barnes-Jewish Hospital, St Louis, Mo.

“Orthopaedic Crossfire” is a registered trademark of A. Seth Greenwald, DPhil(Oxon).

Correspondence should be addressed to: Robert L Barrack, MD, Dept of Orthopedic Surgery, Washington University School of Medicine, One Barnes-Jewish Hospital Plaza, 11300 W Pavilion, St Louis, MO 63110.

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R. De Haan, MD, Orthopaedic Resident¹; P. Campbell, PhD, Research Scientist, Associate Professor²; S. Reid, MD, PhD, Sports Medicine Physician³; A. K. Skipor, MS, Research Scientist⁴; and K. De Smet, MD, Orthopaedic Surgeon¹

1 ANCA Medical Center, Krijgslaan 181, 9000 Gent, Belgium.
2 J Vernon Luck Snr MD, Orthopaedic Research Center, Orthopaedic Hospital, 2400 S., Flower Street, UCLA, Los Angeles 90007, California, USA.
3 St. Helen’s Private Hospital, 186, Macquarie Street, Hobart, Tasmania 7000, Australia.
4 Department of Orthopaedic Surgery, Rush Presbyterian St Luke’s, Medical Center, Room 756, Cohn Research Building, 1735 West Harrison Street, Chicago, Illinois 60612-3833, USA.

A prospective study of serum and urinary ion levels was undertaken in a triathlete who had undergone a metal-on-metal resurfacing arthroplasty of the hip four years previously. The one month study period included the final two weeks of training, the day of the triathlon, and the two weeks immediately post-race. Serum cobalt and chromium levels did not vary significantly throughout this period, including levels recorded on the day after the 11-hour triathlon. Urinary excretion of chromium increased immediately after the race and had returned to pre-race levels six days later. The clinical implications are discussed.

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