- See:
-
Bipolar Arthroplasty:
-
Checklist
- Discussion:
- indications: indicated for patients w/ a
femoral neck frx who meet the following criteria:
- poor general health thay would prevent a second operation;
-
pathologic hip fractures:
- parkinson's disease, hemiplegia, or other neurological disease;
- physiologic age > 70 yrs;
- severe osteoporosis w/ loss of primary trabeclae in femoral head (see
Sigh Index);
- inadequate closed reduction;
- displaced frx which is several days old;
- pre-existing hip disease (DJD, RA, AVN);
- contraindications:
- preexisting sepsis
- young patient
- failure of internal fixation devices;
- pre-existing dz of the acetabulum;
- even w/ normal preoperative cartilagenous space, many patients will become symptomatic at 5 years
due to metal induced degradation;
- Pre Op Planning:
-
femoral head size:
- if too large, equatorial contact occurs, resulting in a tight joint with a decreased motion and pain;
- if head is too small, polar contact occurs with increased stress over reduced area;
- leads to erosion, superomedial prosthetic migration & pain;
- ref:
Hemiarthroplasty of the hip for fracture-What is the appropriate sized femoral head?
-
neck length:
- if the neck is left excessively long, reduction may be difficult and pressure on acetabular cartilage is increased;
- prostheses should be inserted so that the distance between the greater trochanter and center of the femoral head is restored;
- alternatively, attempt to restore the distance between the lesser trochanter and the acetabulum;
- this will restore the length of the abductor mechanism and thereby help to prevent postoperative limp;
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to cement or to not cement ? (
cement technique)
- patients w/ a "stove pipe" type of femur (w/ no tapering of medullary canal) are not good candidates for press fit arthroplasty;
- patients who are good ambulators may complain of thigh pain if press fit stems are inserted;
- probably the best candidate for a press fit stem is a relatively ill patient who is a poor ambulator (ie bed to chair) who does not have a stove pipe femur;
- if cement is not used, the case can be completed in under 30 min;
- if a press fit stem is to be used, then consider using a
lateral approach since the fragile osteoporotic bone requires
that the stem be placed in the patients native anteversion (which may or may not provide sufficient stability);
- references:
- Moore hemiarthroplasty with and w/o bone cement in femoral neck frx: a controlled trial. Acta Orthop. Scand. Vol 53. 1982. p 953-956.
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Treatment of femoral neck fractures with total hip replacement versus cemented and noncemented hemiarthroplasty.
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Treatment of femoral neck fractures with total hip replacement versus cemented and noncemented hemiarthroplasty.
- Surgical Approaches:
-
Anterolateral Approach to Hip Joint: (Watson Jones)
- difficult to perform w/ straight femoral stems, esp if patient is even slightly obese;
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Lateral Approach:
- may be associated w/ limp unless care is taken to minimize dissection of the medius off of the trochanter;
- the main advantage of this approach is that there is virtually no risk of posterior instability, and therefore,
patients do not need hip precautions;
- probably the approach of choice in patients who are demented or who have neurological disorders;
- may be the approach of choice when the stem is to be press fitted since the fragile osteoporotic bone requires
that the stem be placed in the patients native anteversion (which may or may not provide sufficient stability);
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Posterior Approach to the Hip Joint
- attempt to re-approximate hip capsule to reduce dislocation;
- note that w/ a displaced femoral neck fracture, the trochanter may be shifted slightly
anteriorly, and therefore, consider making the incision slightly more posterior than usual;
- further, it will be easier to broach the femoral canal thru a smaller incision, if the incision is curved more posterior than usual (towards
the sciatic notch rather than the PSIS);
- ref: The Moore self locking Vitallium prosthesis in femoral neck frx: A new low posterior approach. AT Moore. Instrc Course Lectures. 16. 1959. p 309-321.
- Complications after Hemiarthroplasty:
- mortality:
- Kenzora et. al. report: 14% mortality during first year after hip frx compared to the 9% mortality rate in normal population of similar age;
- mortality after hemiarthroplasty is 10 to 40%;
- fractue of the Femur: 4.5%
- almost all frx occur when surgeon attempts to reduce prosthesis;
- most are non displaced and involve either greater troch or neck;
- w/ femoral shaft frx consider methy methacrylate combined w/ a long stem prosthesis;
- dislocation:
- less than 10%.
- more common w/ too much anteversion or retroversion, posterior capuslectomy, & excessive postoperative flexion or rotation w/ hip adducted;
- post op: sepsis: 2% to 20%
- more common w/ posterior surgical approach;
- infections may be superficial or deep -
- loosening and migration:
- presence of a radiolucent zone around the prosthesis;
- if clinical signs and symptoms are present and loosening or migration is present, then consider revision to THR;
- erosion tends to occur in active pts with cemented Thompson hemiarthroplasty;
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painful hemiarthroplasty - conversion to THR
Treatment of displaced subcapital fractures with the Charnley-Hastings hemiarthroplasty.
Displaced subcapital fractures of the femur: a prospective randomized comparison of internal fixation, hemiarthroplasty and total hip replacement.
Thompson hemiarthroplasty and acetabular erosion.
Treatment of manifest and impending pathologic fractures of the femoral neck by cemented hemiarthroplasty.
Acetabular revision with a bipolar prosthesis.
Modular hemiarthroplasty for fractures of the proximal part of the humerus.
A comparison of total hip arthroplasty and hemiarthroplasty for treatment of acute fracture of the femoral neck.
Rate of degeneration of human acetabular cartilage after hemiarthroplasty.
Medullary lavage reduces embolic phenomena and cardiopulmonary changes during cemented hemiarthroplasty.
Treatment of Displaced Hip Fractures with THA: Comparison of Primary Arthroplasty with Early Salvage Arthroplasty After Failed Internal Fixation.
Total Hip Arthroplasty and Hemiarthroplasty in Mobile, Independent Patients with a Displaced Intracapsular Fracture of the Femoral Neck.
