Robert E. McLaughlin

Blood Clearance and Acute Pulmonary Toxicity of Methylmethacrylate in Dogs after Simulated Arthroplasty and Intravenous Injection

Clearance of 14C-labeled methylmethacrylate monomer from the blood was determined in beagles during simulated hip arthroplasty and after intravenous injection of the monomer. Pulmonary function after intravenous administration of the monomer was also studied. Blood clearance was rapid, and the lungs apparently functioned as a major clearing organ. Decreased pulmonary function (decreased Po2, elevated Pco2, and metabolic acidosis) only occurred when the dosage of monomer was more than thirty-five times the amount liberated in humans during total hip replacement.

Transfibular compression arthrodesis of the ankle joint.

Eleven ankle arthrodeses were performed on ten patients using a transfibular technique. This technique employs a lateral approach in which the distal fibula is resected while preserving the peroneal tendon sheath, allowing excellent exposure and contouring of the tibiotalar joint. Compression is attained by using a T-plate placed across the tibiotalar joint with the aid of an AO compression apparatus. At 2.5 years after operation, fusion was achieved in ten ankles. Average time in immobilization was 11.8 weeks, and the fused ankle was cosmetically pleasing. Fusion occurred in nine of 11 ankles fused using other methods during this period. Pin tract infection occurred in three, the time in immobilization averaged 16.2 weeks, and the cosmetic result was inferior.

Demineralized Bone Matrix in the Stabilization of Porous-Coated Implants in Bone Defects in Rabbits

Three types of grafts were investigated in rabbits to measure fixation strength of bony ingrowth into porous-coated titanium alloy implants. Autogeneic iliac crest bone (ABG), allogeneic demineralized bone matrix (DBM), and DBM augmented with fibrin glue (DBM + FG) grafts were compared with a press-fit implant control group. Initially, the ABG group required eight weeks and the DBM and DBM + FG groups 12 weeks to achieve fixation strength similar to that of the press-fit group at four weeks. Strength increased with time and at 16 weeks reached 83 kg in the ABG group, 71 kg in the DBM group, and 79 kg in the DBM + FG group, compared with 86 kg for the press-fit group. The ratio of the DBM and the DBM + FG group push-out forces to the ABG push-out force improved from 40% at four weeks to more than 80% at 16 weeks. Histologic analysis of bone ingrowth showed that at 12 weeks, bony ingrowth accounted for 21%, 22%, 16%, and 32% of the porous area in the ABG, DBM, DBM + FG, and press-fit groups, respectively. After eight weeks, there was no statistical difference between DBM, DBM + FG, and ABG grafts in either strength or bony ingrowth. The results demonstrate that over long periods, DBM grafts provide fixation stability comparable with that of autogeneic bone graft.

CLAVICULAR FRACTURES AND ACROMIOCLAVICULAR JOINT DISLOCATIONS IN LACROSSE: PREVENTABLE INJURIES

Clavicular fractures and acromioclavicular joint dislocations occur frequently in high school lacrosse players. This injury is restricted to attackmen who are struck in the clavicular region by the stick of the defensemen. The conventional foam shoulder pads with or without flexible plastic inserts worn by the attackmen did not protect them from this injury. On the basis of this clinical experience, a new protective shoulder pad containing high-density polyethylene over the clavicle and acromioclavicular joint has been designed and manufactured to prevent these injuries. Our initial experience with this new shoulder pad indicates that it will protect lacrosse players from clavicular fractures and acromioclavicular joint dislocations.

An Algorithm for the Management of Ligamentous Injuries of the Knee Associated With Common Peroneal Nerve Palsy

Peroneal nerve palsy is the result of traction of the nerve at the fibular head and can be seen after varus injuries of the knee. The complication is uncommon and spontaneous, useful recovery is unusual. The treatment of either the ligamentous injury or the nerve injury alone is uncomplicated. However, when these injuries are seen in combination, management is more complicated. The clinical and laboratory findings of the nerve palsy in such a situation are reviewed. In addition, an algorithm has been constructed that is useful in determining the appropriate diagnostic and therapeutic steps in managing combined injuries.

Protracted survival in chondrosarcoma despite an unusual metastasis that regressed spontaneously.

tumor occurs in a child, its behavior often is different, and obvious tumor that involved the terminal part of the ileum and its adja it runs a rapidly fatal course with early metastases to the centmesenterywasremoved.It wasspecificallynotedthat therewereno lungs much like osteosarcoma. involved nodes along the internal iliac chain on either side. The mass The presently reported case is one of chondrosarcoma arose at a point approximately eight to ten centimeters from the of the femur from which metastases occurred to the mesenileocaecal valve and it involved the ileum and several loops of adjacent

Femoral neck fractures in the elderly patient: A preventable injury

There is growing evidence that many fractures of the femoral neck in the elderly occur spontaneously because of stresses imposed on osteoporotic bone, rather than because of the trauma of the fall. A case of a spontaneous femoral neck fracture (Garden type IV) in an elderly woman with osteoporosis is presented. Early detection and medical management of osteoporosis complemented with assistive technology could have prevented this common injury.