Bone injuries due to tetany or convulsions during hemodialysis

Two patients with long standing uremia sustained bone injuries due to tetany in one, and convulsions secondary to hemodialysis-induced alkalosis and hypomagnesemia in the other. In the former, there were multiple fractures involving the scapula, clavicles and femoral necks. In the latter, there was a slipped capital femoral epiphysis. Caution should be exercised against tetany or convulsive episodes which may cause bone injuries during hemodiaylsis in severely osteoporotic patients. In patients with progressive renal osteodystrophy, prevention of severe osteopenia by timely kidney transplant or subtotal parathyroidectomy is an important preventative measure.

Secondarily infected total joint replacements by hematogenous spread

Three fatal cases of infections that followed total joint replacement are repoarted, in each of which a hematogenous source of infection was identified. There also were five non-fatal cases presumable arising hematogenously which were reported in the literature. It is emphasized that concomitant disease, including active rheumatoid arthritis, may predispose to this complication.

High tibial osteotomy for osteoarthritis of the knee: a changing concept

High tibial osteotomy is most successful in patients with osteoarthritis with mild varus deformity which is not associated with subluxation of flexion contracture. Success in the valgus knee is limited. If tibial osteotomy is indicated, undercorrection is undesirable in the varus knee while overcorrection is undesirable in the valgus knee.

Further observations on 85Sr scintimetry in intracapsular fracture of the hip

Sixty-seven hip joints with intracapsular fracture and the 67 opposite, normal hip joints were studied with 85Sr scintimetry from two weeks to six years after fracture. Consistently, fractures that developed osteonecrosis showed extremely high counts at the fracture site and the femoral head; fractures that failed to unite also showed extremely high counts at the fracture site and somewhat lower counts in the femoral head; fractures that were healing normally showed counts at the fracture site that were higher than those of the normal, uninjured hip but lower than those at fracture sites where osteonecrosis or nonunion was present. Prediction of complications by 85Sr scintimetry is not reliable within the first few months on injury; thereafter, however, the procedure has definite diagnostic value, particularly for osteonecrosis.

Kinematics of the knee after prosthetic replacements

A method was developed for describing the flexion-extension motion of the knee joint in a sagittal plane, by employing ciné radiography and then plotting the loci of three points on the femur relative to the tibia. Normal knees displayed similar patterns, the curves were smooth, and flexion-extension curves superimposed. A standard knee outline with standard curves was defined, with which to compare the abnormal and prosthetic knees. Arthritic knee patterns differed significantly from the normals. The curves were irregular and the flexion-extension curves were different. Instability, joint surface irregularity and muscle spasm were thought to be the main causes. The curves for the MacIntosh tibial plateaus were abnormal in a similar way to the arthritics. This may have been due to residual instability and to the replacement of only one bearing surface. The condylar replacement prostheses (the uni-condylar, duo-condylar and Geometric) tended to produce close-to-normal knee patterns, probably due to restoration of a relatively normal geometry, and to replacement of both bearing surfaces. The knees with fixed hinge prostheses (Walldius, Shiers and Guépar) showed abnormalities of motion and of the relative postion of the femur on the tibia. These features would be undesirable for the correct functioning of soft tissues around the knee. The stabilo-condylar hinge, which did not require much bone resection, gave a motion comparable to the condylar replacements.

Spontaneous septic arthritis complicating rheumatoid arthritis

Thirteen cases (in twelve patients) of septic arthritis complicating rheumatoid arthritis are reported. One ankle, one metacarpopophalangeal joint, one shoulder, and ten knees were involved. Staphylococcus aureus was cultured from twelve joints and Escherichia coli, from one. Treatment consisted of repeated needle aspirations in two patients, arthrotomy with Penrose drainage in six, and arthrotomy with through-and-through irrigation in four. Needle aspiration was the least effective therapy. The authors recommend as the treatment of choice: systemic antibiotic therapy and immediate arthrotomy followed by through-and-through irrigation with fluid containing the appropriate antibiotics.