[Innervation disturbances of the quadriceps muscle in chondropathia patellae. A critical appraisal of the current concept of chondropathia].

In a group of patients with typical histories of chondropathy, but in whom no other criteria of selection were applied, evidence of neurogenic damage in the quadriceps muscle was found. Innervational damage was also found regularly in the corresponding segments of the paravertebral musculature. Only in three cases, in which horn cell damage was suspected, were there no changes in the paravertebral musculature. There were abnormal structural or functional findings in the lumbar spine in all the patients. A disequilibrium between the median and lateral vastus groups, attributable to innervation, was postulated and subsequently confirmed by electromyography. The nature of chondropathia patellae as an insertion tendopathy is discussed, taking the lack of concomitance of chondropathy and chondromalacia into consideration as well as the findings in the group of patients examined. Phenomena associated with chondropathy which have hitherto incongruous may be explained on the basis of an asymmetrical innervation disturbance.