Special Perioperative Considerations
One of the surgeon's main focuses in the perioperative period for THA in elderly patients is to avoid early complications. Perioperative surgical complications such as fracture, dislocation, infections and problematic wound healing may necessitate further surgical care, subject patients to undue physiological stress and slow their functional recovery. In addition, medical complications such as thromboembolic, cardiopulmonary and neurological events may at most be life threatening and at least preclude participation in physical therapy and delay discharge.
Our preference is to perform THA under spinal anesthesia. Compared with general anesthesia, this approach minimizes airway and pulmonary complications, reduces blood loss and transfusion requirements, and reduces the risk of thromboembolic events. When positioning the patient before the procedure, care should be taken to pad all extremities well. During the procedure, manipulation of the operative extremity and placement of retractors should be undertaken in a careful manner in order to prevent iatrogenic fractures.
From the standpoint of surgical technique, special considerations are important to note in the elderly population. Such patients often have thin friable skin and noncompliant soft tissues. The skin incision should be extended to a length that avoids the placement of substantial tension on the soft tissues by the retractors. In addition, special care must be taken when handling the soft tissues, which may be more susceptible to crush injury. During acetabular preparation, the surgeon should always expect to encounter osteoporotic bone. As such, the surgeon must recognize the sharpness of the acetabular reamers and proceed with little force during acetabular preparation. This technique prevents over-reaming and iatrogenic loss of bone that is necessary for structural support. Our preference is for the use of cementless acetabular components in all cases. To prevent iatrogenic fracture, the surgeon must take care in impacting and positioning the final component. In the elderly population, augmentation of the initial fixation with transacetabular screws is recommended in most cases.
The surgeon must also take special care during femoral preparation. Depending on the bone quality and morphology of each patient and on the preference of each individual surgeon, cementless or cemented femoral stems may be used. With use of a cementless stem, if substantial concern for iatrogenic fracture exists due to the degree of osteoporosis, a prophylactic cerclage cable may be placed in order to avoid this complication. In addition, care must be taken to avoid unnecessary force in impacting the final component and the proximal bone should be carefully inspected to explore for subtle fractures. The use of a cemented stem is another reasonable approach in avoiding complications associated with osteoporotic bone. This is particularly useful in patients with capacious 'stove-pipe' morphology of the proximal femoral canal.
One of the important decisions the surgeon makes in the preoperative planning process is the choice of the bearing surface. When considering the use of ceramic surfaces, it should be considered that they carry the unique risks of component fracture and squeaking. In addition, the main potential benefit of ceramic bearings is for component longevity, which is generally not a concern in the low-demand, elderly population. The choice of larger metal-on-metal bearings offers the potential advantage of reducing the risk of postoperative dislocation, but also carries the unique risks of local hypersensitivity reactions and elevated levels of blood cobalt and chrome, which have the potential to exacerbate renal failure. Because of the unique considerations for ceramic and metal-on-metal bearings, the metal-on-polyethelene bearing combination is an attractive consideration in this patient population. Owing to the increased risk of dislocation in elderly patients, optimization of the head-to-neck ratio of the femoral component through the use of a large femoral head is another important consideration.
Postoperative management is another critical factor in preventing perioperative complication. Again, because of the thin and friable nature of the soft tissues in this patient population, adhesive tape is avoided as much as possible to avoid skin abrasions and tears. One approach that may be used to achieve this goal is to use a skin sealant that would preclude the use of a surgical dressing. Careful postoperative pain management is one of the most critical elements of postoperative care and modern protocols are quite useful in this patient population. Avoiding narcotic pain medicines[30,31] as much as possible minimizes the risks of delirium, constipation and other related side effects that are particularly problematic in elderly patients. Yet, effective pain management with combinations of nonsteroidal anti-inflammatory medicines, central-acting analgesic agents and neuropathic pain medicines allow for early mobilization.
A multimodal approach to the prevention of postoperative thromboembolic events involves early mobilization, mechanical devices such as pneumatic compression stockings, and chemical agents. Elderly patients often require extended inpatient rehabilitation after surgery, although with appropriate family support and home nursing and therapy services, discharge to home may be a reasonable option.
Aging Health. 2011;7(6):803-811. © 2011 Future Medicine Ltd.