Bo E. Nilsson

Epidemiology of Fracture of the Upper End of the Humerus

The age and sex specific indicence was calculated in 729 cases of fracture of the upper end of the humerus. The prevalence of other fractures and conditions in these patients was investigated. The age and sex specific incidence is as that of femoral neck fracture with a rapid increase with age, twice as fast in women as in men. Only fractures which include evulsion of the greater tuberosity deviate somewhat from that pattern. The more displaced fractures have a tendency to occur later in life. The prevalence of other fractures is about doubled in patients with fracture of the proximal end of the humerus as compared to age and sex matched controls. This is true for fracture of the distal end of the forearm and fracture of the upper end of the femur but also for other fractures. The prevalence of severe alcoholism was significantly greater than in controls. A history of gastric resection was in these patients about three times as frequent as in a control sample. We conclude that fracture of the upper end of the humerus must be assigned a prominent place in the category of bone fragility fractures.

The Natural Course of Untreated Osteoarthritis of the Knee

Ninety-four knee joints in 71 patients had primary gonarthrosis (osteoarthritis of the knee) for periods of 10-18 years. The course of gonarthrosis was unfavorable in that a majority of the cases became worse over the years and some also developed pain at rest. The prognosis in gonarthrosis seemed worse than in coxarthrosis (osteoarthritis of the hip). The radiographic changes in the affected knee joint progressed over the years. However, in most knees the changes remained limited to the compartment first affected so that knees with initially medial involvement had exclusively medial involvement even 10-18 years later. Varus deformity was related to poor stability and to a generally poor prognosis. An early onset of symptoms was unfavorable with regard to development of pain. The majority of otherwise healthy patients became incapable of using public transportation because of knee pain on walking.

Bone Mineral Content in Children with Fractures

Bone mineral content was measured in the forearms of 90 children who had recent fractures. The data were compared with those of age-matched healthy children. Bone mineral content was significantly reduced in children in whom fractures were caused by low-energy trauma. Bone mineral content in children in whom fractures were caused by high-energy trauma was also reduced, but the difference was not significant. Correction for other parameters of growth and maturation, e.g., height and weight, did not eliminate the difference in bone mineral content. These findings indicate that endogenous factors contribute to fracture not only in the elderly but also in children.

Bone mineral content and fragility fractures.

In 249 patients with fractures characteristic of bone fragility, i.e. femoral neck fracture, vertebral crush fracture, fracture of the upper end of the humerus, Colles fracture, fracture of the lateral condyle of the tibia and various ankle fractures, and forearm bone mineral content was measured by gamma absorptiometry. Vertebral crush fracture, fracture of the upper end of the femur and fracture of the distal end of the forearm are associated with a generally decreased bone mineral mass. In young women with femoral neck fracture the difference between fracture cases and control cases was greater than in older women. In Colles fracture, the difference from normal controls was the greatest in the youngest and the oldest women. Bone mass in the forearms is low also in cases of fracture in the upper end of the humerus, of the ankle and of the lateral tibial condyle. In each of the above groups, however, there was so much over-lap between fracture cases and control cases that the measurement of mineral in the forearm cannot be recommended as a very good tool for determination of fracture susceptability in individual subjects.

Chondrocalcinosis following osteochondritis dissecans in the femur condyles.

Chondrocalcinosis, defined as radiopaque deposits in the joint cartilages and in semilunar cartilages of the knee joint, develops frequently in patients in whom osteochondritis dissecans is diagnosed after the epiphyseal line of the distal end of the femur is closed. Chondrocalcinosis occurred in 2/3 of the cases surgically treated for osteochondritis. The incidence was greater than in knees treated by arthrotomy for ruptured semilunar cartilages. However, the latter show chondrocalcinosis much more frequently in patients without history of injury or arthrotomy. Osteochondritis patients with chondrocalcinosis more often may have joint effusion than patients with other conditions. The chondrocalcinosis is not confined to that part of the joint which was the site of the osteochondritis lesion. The presence of chondrocalcinosis can be correlated with a poor prognosis of the knee including severe gonarthrosis.

Changes in bone mineral content in the femur following total hip arthroplasty.

Bone mineral content (BMC) in the distal end of the femoral shaft was monitored with single-photon gamma-absorptiometry for 72 weeks after surgery in 46 patients with coxarthrosis treated by total hip arthroplasty (THA). After an initial increase, which was greater in men than in women, BMC decreased during the first postoperative year to approximately the initial value in men, whereas in women the final outcome was a 10% net loss. No influence of the type of operation or of the preoperative or postoperative capacity of the patients could be demonstrated. The loss of bone mineral was surprisingly low compared with that noted after other injuries of similar or even less magnitude.