Hip resurfacing: A fresh look at an alternative to total joint arthroplasty

Andrew H. Patterson, PA-C, Jackie H. Coleman, CST

September 02, 2010

PDF of CME Hip 0910

Hip resurfacing: A fresh look at an alternative to total joint arthroplasty

SURGICAL APPROACH 

The posterior approach provides excellent exposure for positioning the specialized cutting jigs required to make accurate bone cuts. The posterior approach also allows the surgeon to repair instead of remove the capsule and soft tissues, which can lower the risk of dislocation.⁷ 

The direct anterior approach utilizes a true internervous/intermuscular plane that allows for complete preservation of the posterior soft tissues, which helps to prevent dislocations. In addition, the procedure can be performed on a specialized table that allows for the use of intraoperative fluoroscopy. Matta and coauthors describe how this method allows the components to be accurately and reproducibly positioned in all patients undergoing a first-time hip replacement.⁸ Fluoroscopy provides a good anteroposterior view of the pelvis, which helps confirm the placement of the acetabular cup in a reasonable degree of abduction. In metal-on-metal hip resurfacing, cup abduction angles of 55 degrees and higher have an increased risk of wear.⁶ Furthermore, real-time radiography during surgery should lower the risk of notching the femoral neck, a problem that could lead to femoral neck fracture or possibly decrease the blood supply to the femoral head.  

Implant selection Several companies produce hip resurfacing implants. Currently, two hip resurfacing devices are FDA approved in the United States: the Birmingham Hip Resurfacing (BHR) System (Smith and Nephew, Memphis, Tennessee) and the Cormet Hip Resurfacing System (Corin USA, Tampa, Florida).  

The AOA National Joint Replacement Registry tracks data on joint replacement implants in an unbiased fashion, including the number of implants placed, percentage of implants that required revision, and the number of revisions per 100 observed component years. The revision rate at 10 years for the BHR device is similar to the revision rate at 10 years for total hip replacements when used in the appropriate patients.² Cormet had three different components listed in the Australian registry in 2007: Cormet, Cormet 2000 (HAP), and Cormet (Bi-Coated). The first Cormet device and the Cormet 2000 had significantly higher revision rates compared with the BHR. The Cormet (Bi-Coated) has a better revision percentage but a similar revision rate (same as the BHR) when comparing revisions per 100 component years for the two brands. Surgeons should research the history/instrumentation when selecting the system to use in a patient. 

Case study

In July 2007, a 52-year-old man presented to the clinic with a chief complaint of right hip pain. The patient had had pain since 2004, but the pain had become progressively worse over the past 18 months and now limited his ability to do his job. His job was to help train foreign police forces in antinarcotics trafficking tactics and required that he spend significant amounts of time in the field. He had to traverse various types of terrain while carrying a 35- to 50-lb pack for durations of 3 to 4 hours. Although he had been performing his job, the arthritis in his hip had begun to cause him pain during working hours, as well as wake him up 4 to 5 times during the night. He had been told that he needed a hip replacement several years prior to his decision to seek surgery.

On physical examination, the patient was a healthy male who walked with an antalgic gait that favored the right lower extremity. The range of motion in the patient's right hip was significantly decreased with 5 degrees of internal rotation and 20 degrees of external rotation. His flexion/extension and abduction/adduction were also poor. Examination findings in the patient's back and knee were normal. Radiographs of his pelvis and right hip showed a moderate decrease in the chondral space with bone on bone arthropathy (Figure 1). The patient had normal head and neck ratio without avascular necrosis.

After a review of the risks and benefits of both hip resurfacing and total hip arthroplasty, the patient decided on the resurfacing procedure. The direct anterior approach was used to place a Birmingham Hip resurfacing System (Figure 2). The postoperative course went well. The patient was back to desk work within 2 weeks of surgery. At 1 month postsurgery, he was free of all assistive walking devices (he had used crutches) and was pain-free. At 2 months postsurgery, he was both walking and jogging significant distances on a treadmill. At 3 months, the patient reported that he had 85% to 90% of his original ability to perform his job requirements.

To date, this patient has returned to full activity. He is working full time and again carrying heavy packs over difficult terrain. He also recently competed in a sprint triathlon (quarter-mile swim, 10-mile bike ride, and a 5K run) and placed third in his division. The patient is very pleased with his recovery and surgical outcome.

CONCLUSION 

The goal of a resurfacing procedure is to enable the patient to live a pain-free, active life. Appropriate patient selection, use of an FDA-approved implant, and clinician familiarity with the surgical approach are important to achieving a successful outcome. Hopefully, these criteria will enable most patients who undergo hip resurfacing to achieve results similar to the patient in our case. JAAPA 

Andrew Patterson is a PA in orthopedics and Jackie Coleman is a certified surgical technician at OrthoCarolina Hip & Knee Center, Charlotte, North Carolina. They have indicated no relationships to disclose related to the content of this article. 

IMPORTANT NOTE: JAAPA CME activities consist of 2 articles. To obtain credit, you must also read Stress management: Helping patients to find effective coping strategies; the post-test will include questions related to both articles. AAPA Fellow members should complete and submit the post-test on the AAPA Web site by going to www.aapa.org and searching for keyword JAAPA post-tests. All others may complete and submit the post-test online at no charge at www.mycme.com. To obtain 1 hour of AAPA Category I CME credit, PAs must receive a score of 70% or better on each test taken.

REFERENCES 

1. Kishida Y, Sugano N, Nishii T, et al. Preservation of the bone mineral density of the femur after surface replacement of the hip. J Bone Joint Surg Br. 2004;86(2):185-189. 

2. 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(2):177-184. 

3. Amstutz HC, Ball ST, Le Duff MJ, Dorey FJ. Resurfacing THA for patients younger than 50 year: results of 2- to 9-year followup. Clin Orthop Relat Res. 2007;460:159-164. 

4. Australian Orthopaedic Association. National Joint Replacement Registry. http://www.dmac.adelaide.edu.au/aoanjrr/. Accessed August 4, 2010. 

5. Little CP, Ruiz AL, Harding IJ, et al. Osteonecrosis in retrieved femoral heads after failed resurfacing arthroplasty of the hip. J Bone Joint Surg Br. 2005;87(3):320-323. 

6. Mont MA, Ragland PS, Etienne G, et al. Hip resurfacing arthroplasty. J Am Acad Orthop Surg. 2006;14(8):454-463. 

7. Kwon MS, Kuskowski M, Mulhall KJ, et al. Does surgical approach affect total hip arthroplasty dislocation rates? Clin Orthop Relat Res. 2006;447:34-38. 

8. Matta JM, Shahrdar C, Ferguson T. Single-incision anterior approach for total hip arthroplasty on an orthopaedic table. Clin Orthop Relat Res. 2005;441:115-124. 