Anatomical total knee arthroplasty alignment
We report the results of the use of the Long Gamma Nail in the treatment of complex proximal femoral fractures in our hospital. All patients at one hospital treated with the Long Gamma Nail were reviewed. Information collected included the age, sex, type of injury, fracture classification, intra-operative complications, post-operative complications, and survival of the implant and patient. One hundred nails were reviewed which were inserted in 97 patients. 70 patients were followed up for 1 month or more and their mean follow up was 8 months (range 3 months to 6 years). The mean age was 74 (range 16–98). Twenty were inserted into femurs with metastatic malignancy and four patients were victims of poly-trauma. The average length of the operation was 2 hours 22 minutes. Blood transfusion was required in 74% and on average was 2.5 units. There were 7 significant complications. Five patients underwent revision, 2 to Total Hip Arthroplasty after proximal screw migration and 2 patients required exchange nailing. There was one broken nail and two peri-prosthetic fractures at the tip of the nail. Success was defined as achievement of stability of fracture until union or death; this was achieved in 15% of cases. The mortality was 7% at 30 days and 17% at one year. One death was directly related to the nail and the rest due to medical co-morbidities. Complication rate fell with increasing experience in the unit. The training of surgeons had no detrimental effect on outcome. Complex proximal femoral fractures including pathological lesions, subtrochanteric fractures and pertrochanteric fractures with subtrochanteric extensions are difficult to treat, with all implants having high failure rates. The long gamma nail allows early weight bearing and seems effective in treating these difficult fractures. Furthermore the majority of these unstable fractures tend to occur in the very elderly with osteoporosis and other medical co-morbidity. Care should be taken to avoid malpositioning of the implant, as this was the major cause of failure and revision. The length of time surgery may take and the anticipated blood loss should not be underestimated especially when dealing with challenging fractures in frail and elderly patients or those with medical co-morbidity.
In Total Knee Arthroplasty (TKA) and Total Hip Arthroplasty (THA) the total blood loss is composed of ‘visible’ blood loss from the surgical field and wound drainage, and blood loss into the tissues which is ‘hidden’. Blood management should be aimed at addressing the total blood loss. 56 TKAs and 46 THAs were prospectively studied. TKAs were performed with tourniquet. After tourniquet release, all drained blood was salvaged and significant volumes reinfused. No reinfusion was used for THAs. The true total blood loss was calculated in the following way: Patient Blood Volume (PBV) is: [1] PBV = k1 x height3 + k2 x weight + k3 Therefore patient total Red Blood Cell volume (RBCv) is: RBCv = PBV x Hct. (where Hct is Haematocrit) Total RBCv loss = PBV x (Hct preop – Hct postop) + ml RBC transfused The result is reconverted to Whole Blood volume. Hidden Loss = Total Loss – Visible Loss. In TKA, the mean total true blood loss was 1474ml. The mean hidden loss was 735ml. Therefore hidden loss is 50% of the total loss and the total true loss following TKA is twice the visible volume. In THA, the mean total true blood loss was 1629ml. The mean hidden loss was 343ml. Thus hidden loss in THA is much smaller. (21%) Total loss is 1.3 times the visible loss. In the TKA group, comparing patients with large losses receiving reinfusion and those with small losses not receiving reinfusion, the proportion of total true loss which was hidden was the same, at 50%. Patients with Body Mass Index (BMI) >
30 were compared with those with a BMI <
30 and no correlation was found between BMI and Hidden Loss. Joint Replacement Surgery involves a ‘hidden’ blood loss which is not revealed and cannot be measured or reinfused in practice, but which should be taken into account when planning blood loss management. In TKA it is substantial. In THA it is much smaller and probably not of as much clinical concern. Hidden loss is no greater in the Obese patient.
