Femorotibial rotation and the Q-angle related to the dislocating patella.

PURPOSE: To compare the femorotibial rotation, the patellar translation, the hip-knee-ankle angle and the Q-angle in patients with a dislocation of the patella with those of healthy volunteers. Further, the clinically measured Q-angle was compared to that measured by radiography. MATERIAL AND METHODS: A system for measurement of patellar variables was previously developed and applied to 80 healthy volunteers. In the present study, 28 patients (20 women, 8 men) with dislocation of the patella were examined bilaterally. Fourteen patients had habitual dislocations (20 affected knees) and 14 patients traumatic dislocations (17 affected knees). In 20 patients the clinical Q-angle was measured bilaterally by an orthopaedic surgeon and in 9 of these patients also by a second independent orthopaedic surgeon. RESULTS: The most striking finding was that dislocating knees in both groups showed a smaller Q-angle than the healthy knees. Further, the habitual group showed greater relative rotation between the tibia and the femur and an increased patellar translation compared to the traumatic group and to the healthy volunteers. There was a poor correlation between clinical and radiographic measurements of the Q-angle and no correlation was found between two independent clinical measurements. CONCLUSION: Surgical operations aiming at decreasing the Q-angle should be challenged.

The use of isolated patellar prostheses in Sweden 1977-1986.

During 1977 to 1986, 106 patients had isolated patellar prostheses, with both patellar and femoral components, inserted in 20 different hospitals in Sweden. At follow up, 7 years (range 3 to 14 years) after operation, 9 patients had died so that 97 patients with operations on 113 knees were included in this study. Thirty-three (38 knees) had been operated on before or after a prosthesis had been inserted. At follow-up, 75% were satisfied with the operation; 83% had improved, 59% could walk without an aid and 44% had no, or only occasional, pain in the knee. These results encourage the use of an isolated patellar prosthesis in cases of advanced and disabling localised patellar arthrosis. There is no place for this operation in the treatment of chondromalacia.

The natural history of recurrent dislocation of the patella. Long-term results of conservative and operative treatment.

From 1970 to 1978, 29 patients had a unilateral operation for bilateral recurrent dislocation of the patella. We examined 21 of them at a mean of 14 years postoperatively. Eighteen of these patients had evidence of generalised joint laxity. Six of the operated knees and four of the unoperated knees still had recurrent dislocations. The operated knees were clinically worse, with a significantly higher incidence of osteoarthritis. We concluded that the operations used to treat recurrent dislocation of the patella may have had short-term benefits, but did not cure the patients in the long term.

Lateral meniscal lesions in patients with clinically suspected medial lesions.

Double-contrast arthrography and arthroscopy were performed in a prospective study on 46 consecutive patients clinically suspected of having a medial meniscal tear only. At arthrography, 38 torn medial menisci were found; four of them were, however, false-positive and another false-negative as compared with arthroscopic examination. Moreover, seven unsuspected lateral meniscal tears were diagnosed at both arthrography and arthroscopy. The diagnostic accuracy of the double-contrast arthrography was well above the clinical accuracy, and we conclude that arthrography is a reliable method for diagnosing both medial and lateral tears.

Thyroid cancer incidence in relation to volcanic activity.

Environmental or genetic factors are sought to explain the high incidence of thyroid cancer in Iceland. At present, it is impossible to cite any environmental factor, particularly one related to the volcanic activity in the country, which could explain the high incidence of thyroid cancer in Iceland. However, the thyroid gland in Icelanders is very small due to the high intake of iodine from seafood. It is, therefore, easier for physicians to find thyroid tumors. Furthermore, genetic factors are very likely to be of great importance in the small, isolated island of Iceland.