Spontaneous osteonecrosis of the medial compartment of the knee: a MRI follow-up after conservative and operative treatment, preliminary results.

Symptoms in patients suffering from spontaneous osteonecrosis of the knee (SONK) may be reduced by high tibial osteotomy (HTO). However, the fate of the necrotic lesion is unknown and needs further investigation. We conducted a prospective study to evaluate magnetic resonance imaging (MRI) changes after operative and nonoperative treatment. Ten consecutive patients suffering from SONK of the medial compartment were given two treatment options: either HTO (n = 6) or conservative treatment with partial weight bearing for 3 months (n = 4). We measured the greatest extent of well-defined subchondral low signal intensity abnormality, considered to represent necrosis, and the surrounding area of intermediate signal intensity, considered to represent perifocal bone marrow edema, on T1-weighted coronal MRI images before and after treatment. The MRI follow-up period was 17.5 months (range 12-27) in the HTO group and 14.5 months (range 8-25) in the nonoperative group. At follow-up the MRI evaluation revealed a decrease in the low signal intense areas (necrosis) in five of the six patients in the HTO group. Only one of the four nonoperative patients showed a decrease in the low signal intense area. The intermediate intense areas (edema) decreased in all patients in the HTO group and in three of four in the nonoperative group. The mean decrease in the area of perifocal edema was significantly greater in the HTO group than in the nonoperative group (P = 0.019). No statistically significant difference was found for the area of necrosis between the two groups (P = 0.171). A clinical improvement was observed in all patients of the HTO group but in only two of the four patients of the nonoperative group. We conclude that the decrease in perifocal bone marrow edema seems to be associated with improved patient comfort. The MRI appearance of the necrotic lesion does not alter with either treatment mode.

Treatment of proximal humerus fracture using multiple intramedullary flexible nails.

A total of 61 patients with a proximal humeral fracture was treated between January 1996 and March 1998 by closed reduction and fracture fixation with intramedullary Prévot (or Nancy) nails. Of these, 28 female and 25 male patients with a mean age of 52 years (range 3-91 years) were reviewed clinically and radiologically with a mean follow-up of 17 months (range 4-30 months). The mean Constant score was 63, the mean Neer score 74 and the mean visual analogue scale (VAS) 73. The 14 patients under 24 years old achieved a Constant score of 86, a Neer score of 99 and a VAS of 97, while 13 patients aged between 25 and 60 years had a Constant score of 67, a Neer score of 75 and a VAS of 71. The 26 patients older than 61 years had a Constant score of 48, a Neer score of 61 and a VAS of 61. One patient with total and 6 with partial humeral head necrosis as well as 5 pseudarthroses were noted. Proximal nail perforation of the humeral head due to fracture collapse was seen in 22 cases. Complications were more frequently observed in the elderly. End results were not related to the type of fracture. This minimally invasive technique decreases the rate of occurrence of avascular necrosis of the humeral head. However, fractures are not sufficiently stabilised, mainly because of bone loss induced by impaction and osteoporosis. Bone loss remains an unsolved problem, and alternative methods such as the use of bone substitute combined with minimally invasive techniques should be studied.

Accumulation of irrigation fluid in the calf as a complication during high tibial osteotomy combined with simultaneous arthroscopic anterior cruciate ligament reconstruction.

Extravasation of irrigation fluid during arthroscopy is a well-known complication. We report a case of accumulation of fluid into the calf during open wedge high tibial osteotomy combined with simultaneous arthroscopic anterior cruciate ligament (ACL) reconstruction. The main cause for fluid extravasation was the drilling of the tibial tunnel, which allowed the fluid to cross the osteotomy gap and invade the flexor compartments. Although an elevation of the intracompartmental pressure was measured, there was no clinical evidence of compartment syndrome. A subcutaneous release of the flexor compartment of the leg was performed. The patient suffered no further sequelae. High tibial osteotomy combined with simultaneous arthroscopic ACL reconstruction has to be performed carefully, and potential complications must be detected immediately to prevent compartment syndrome.