Factors of patellar instability: An anatomic radiographic study

We analyzed the radiographs and computed tomography (CT) scans of 143 knees operated on for symptomatic patellar instability and 67 contralateral asymptomatic knees, togcther with 190 control knee radiographs and 27 control knee scans, to determine the factors affecting patellar instability. Four factors were relevant in knees with symptomatic patellar instability: (1)Trochlear dysplasia (85%), as defined by the crossing sign (96%) and quantitatively experessed by the trochlear bump, pathological above 3 mm or more (66%), and the trochlear depth, pathologic at 4 mm or less. (2)Quadriceps dysplasia (83%), defined as present when the patellar tilt in extension is more than 20% on the CT scans. (3)Patella alta (Caton-Deschamps) index greater than or equal to 1.2 (24%). (4)Tibial tuberosity-trochlear groove, pathological when greater than or equal to 20 mm (56%). The factors appeared in only 3%–6.5% of the control knees. The etiology of patellar instability is multifactorial. Determination of the factors permits an effective elective therapeutic plan which aims at correcting the anomalies present.     

Extra-abdominal desmoid tumors. Therapeutic indications. Apropos of 28 cases

Between 1965 and 1989, 46 desmoid tumors were observed in the hospitals of Lyon. Twenty-eight patients with an extra-abdominal tumor, with a follow-up of at least 6 months were observed. In this group, there were 12 males and 16 females with an average of 26.7 years. Surgical treatment was performed in 26 cases (in one case no treatment was given and in another case isolated chemotherapy was given). In 21 cases (80%) a recurrence of the tumor was seen after the first excision, incomplete in 6 cases. The highest rate of recurrence was seen in the neck, the girdles and the lower limbs; at the end of our review, 9 patients still had a tumor. No primary amputation were performed but two late amputations, one of which was major, were necessary. One tumor evolved into a sarcoma and in another case, lung metastases were seen. Associated radiotherapy was given in 9 cases with resolution in 55%. Tamoxifen was used in 5 cases with stabilization of the tumor. The risk of recurrence was higher in males (p = 0.0147). Age less than 30 years, and incomplete removal of the tumor were the other predictive factors for recurrence (the difference was not significant).