Vol. 14 •Issue 10 • Page 6
Geriatric Function
Advances In Total Hip Replacement Rehab
The advances in technology in all areas of our lives are rapid and amazing. Hip joints were one of the first to be artificially created. Since they have been around for so long, literature abounds on updates and changes related to these amazing creations. This article will cover the latest in surgical and rehabilitation ramifications related to total hip arthroplasty (THA).
Surgical Considerations
The best surgical approach in terms of fewest dislocations for all patients is the anterior approach. The posterior approach gives the best results regarding postoperative limp. Masonis, et al showed dislocation rates of 3.2 percent with the posterior approach, 2.1 percent for the anteriorlateral approach, and 1.27 percent with the anterior approach. They also observed a postoperative limp in between 0.4 percent and 20 percent in the group receiving a lateral approach, versus between 0 percent to 16 percent in the posterior approach group.1
The gold standard for implant fixation is: cementless acetabulum and the surgeon’s preference regarding fixation type in the femoral stem. Rosenberg concluded that a cementless acetabulum is most effective. He also stated that fixation of the femoral component remains controversial. Revision components are largely cementless and extensively porous.2 Healy looked at THA in a four-year study of 204 older patients and concluded with a preference for cementless implant fixation.3
The average dislocation rate for all patients of all ages is 2 percent. Females dislocate twice as often as males. The majority of dislocations occur posteriorly. Factors that contribute to dislocation are increased age, cognition level, alcohol abuse and patient compliance.
Movement restriction to avoid dislocation is also controversial. Some patients have no movement restrictions and others have them for life. Talbot followed 497 patients with anteriorlateral surgical approach who were given no postoperative restriction. This group only had three dislocations within the initial six weeks. No restrictions were needed for the anteriorlateral approach but may be required with other approaches.4
This conclusion is validated by Lachiewcz’s study, which showed a 3.5 percent dislocation rate in patients over 75 with THA. This study recommended constrained components in older patients with dementia or abductor insufficiencies.5 Based on studies like these, there is at present no definitive answer as to movement restrictions. Decisions are often based on the preferences of the surgeon.
In our experience, the most important aspect to avoid in movement restrictions is the combination of movements; that is, flexion abduction and internal fixation for the posterior approach, and extension and external rotation for the anterior approach. If an anteriorlateral or direct lateral approach is done, the surgeon may perform a trochanteric osteotomy. If this is the case, then no hip abduction is allowed for a minimum of six weeks. From these various precautions, it is obviously critical that the surgeon communicate any specific surgical procedures to the therapist.
Rehabilitation Considerations
Probably the most controversial topics in all of orthopedics at present is whether to allow people who have cementless THA to weight bear. Patients with cemented THA are weight bearing as tolerated (WBAT). The decision for weight bearing considerations for cementless THA is ultimately the surgeon’s preference, based on the type of fixation and patient characteristics.
In some settings, the weight bearing status varies from touch down weight bearing (TDWB) to WBAT. A study in the Journal of Arthroplasty supports full weight bearing. Woolson found equivalent Harris Hip Scores in both the partial and full weight bearing groups. All stems showed radiographic bone ingrowth at follow-up (minimum follow-up of two years).6
Protocols abound for THA rehab. The table shows the first page of the Vanderbilt protocol. It includes home instructions and a few of the crucial exercises for patients with THA.
Mobilization for constrained implants is contraindicated because there is nothing to mobilize. If the patient has a standard implant, gentle mobilizations are appropriate for six to 12 weeks. The mobilizations can become more aggressive at 12 weeks. Soft tissue mobilization is an excellent adjunct after the incision is clean, dry and free of sutures.
A worse exercise is hip flexor strengthening. These muscles are usually too strong and should only be strengthened if the therapist conducts a muscle dynamometry test and detects significant weakness. The best exercises are hip abductor and extensor strengthening exercises that are incorporated into functional training.
References
1. Masonis, J., & Bourne, R. (2002). Surgical approach, abductor function and total hip arthroplasty dislocation. Clinical Orthopedics, (405), 46-53.
2. Rosenberg, A. (2002). Fixation for the millenium: The hip. Journal of Arthroplasty, 17(4 Suppl 1), 3-5.
3. Healy, W. (2002). Hip implant selection for total hip arthroplasty in elderly patients. Clinical Orthopedics, (405), 54-64.
4. Talbot, M., et al. (2002). Early dislocation after THA: Are postoperative restrictions necessary? Arthroplasty, 17(8), 1006-1008.
5. Lachiewcz, S. (2002). Stability of THA in patients 75 years or older. Clinical Orthopedics, (405), 65-69.
6. Woodson, S., & Adler, N. (2002). The effect of partial or full weight bearing ambulation after cementless THA. Journal of Arthroplasty, 17(7), 820-825.
• Look for the entire Vanderbilt protocol on the GreatSeminars Website, www.greatseminars.com. Select the Tip of the Month for April.
Dr. Lewis is a physical therapist in private practice and president of Physical Therapy Services of Washington, DC. She lectures exclusively for GREAT Seminars and Books, Inc. Dr. Lewis is also the author of numerous textbooks. Her Website address is www.greatseminarsandbooks.com. Snady Shelton is senior therapist for Vanderbilt Medical Center’s Orthopedic Unit, Nashville, TN.
Table: Vanderbilt University Medical Center Rehabilitation Services Physical Therapy Department Home Instructions Following Total Hip Replacement
1. Do not combine two or more of the following movements: bending over, turning toes inward or twisting the body.
2. When lying on the back, keep operative leg positioned so that toes and kneecap point toward the ceiling.
3. Do not lie on the operative hip for six weeks following surgery. When lying on the nonoperative side, make sure to use a pillow between the knees.
4. Do not sit in a low chair or recliner. Sit in firm, high chairs (or place cushions in lower chairs) preferrably with armrests. This will make it easier to get out of the chair.
5. Do not sit in booths or low chairs when dining out.
6. Do not sit on a low toilet. Use an elevated toilet seat for the first 12 weeks following surgery.
7. Walk in short sessions to gradually improve physical endurance.
8. Continue to use walker or crutches until surgeon specifies otherwise.
9. When climbing or dismounting stairs: Going up, step with nonoperative leg first, then raise operative leg up to the same step; going down, step down with operative leg first, then lower nonoperative leg to the same step.
