Erkki Laasonen

The growth rate of intracranial meningiomas and its relation to histology. An analysis of 43 patients

The growth rate of intracranial meningiomas was studied in 43 patients against a histologic grading based on the degree of anaplasia. The mean time for doubling of the tumor volume was 415 days (138-1045) in grade I (benign), 178 days (34-551) in grade II (atypical), and 205 days (30-472) in grade III (anaplastic). The difference between grade I and the combined grades II-III was highly significant. Both the mitotic index and the absence of calcification on the computed tomography scan correlated strongly with the doubling time. The growth rate should be carefully considered in planning therapy and timing computed tomography studies for patients with meningioma.

Acute dislocation of the patella : a prospective review of operative treatment

We report a prospective study of 55 patients with acute primary patellar dislocation, all treated by operation and followed up for at least two years. Diagnosis was based on the history of a lateral displacement, with medial tenderness and a positive apprehension test; redislocations were excluded. Before operation, the difference in lateral shift on skyline views of the injured and control patellae was highly significant. At operation, rupture of the medial retinaculum of the patella was seen in all but one case. There were medial marginal fractures of the patella in 23 cases. Subjective results of the operation were excellent or good in 44 of the 55 at two years with a redislocation rate of only 9%. Most patients were able to return to the same level of sporting activity as before the injury.

Hormone treatment of meningiomas: lack of response to medroxyprogesterone acetate (MPA): a pilot study of five cases

SummaryMedroxyprogesterone acetate (MPA) has been used in high doses as hormone treatment for metastatic breast cancer. We treated five intracranial meningiomas with MPA expecting that MPA would reduce the volume or decrease the growth rate. All five patients were postmenopausal women, aged 47 to 73 years. Before treatment, the growth rate of each tumour was assessed by two consecutive CT scans (CT 1 and CT 2). Tumours 1 to 4, histologically benign meningiomas, grew slowly as the tumour volumes were not found to increase in 21 to 45 months between CT 1 and CT 2. Tumour 5 was an anaplastic meningioma the rapid growth of which was evident in 8 weeks between CT 1 and CT 2. After CT 2, MPA was given 1,000 mg intramusculary once weekly for 17 to 29 weeks until CT 3 which showed the response. Tumours 1 to 4 had neither reduced in volume nor developed necroses, and tumour 5 continued its fast growth at the same rate as before.

Acute dislocation of the patella: Clinical, radiographic and operative findings in 64 consecutive cases

The clinical, radiographic and operative findings in 64 consecutive acute dislocations of the patella were analyzed. Both patellofemoral joints were symptomless before dislocation in 58 patients. The sulcus angle of the femur on the affected side was larger than on the contralateral side in one half, and a fresh marginal patellar fracture was demonstrated in one third of the cases. The stability of the patella could not be reliably estimated in tangential views taken with the knee in 20 degrees flexion; especially false negative findings were numerous.

Lumbar spine interbody fusion with reinforced hydroxyapatite implants

SummaryPorous coralline and synthetic hydroxyapatite blocks reinforced with either self-reinforced polyactide or polyglycolide were implanted into 15 lumbar intervertebral disc spaces in five minipigs in order to determine whether they could provide an osteoconductive bridge for interbody fusion. Histological examination and radiological analysis with plain films, computed tomography and magnetic resonance imaging were carried out. The osteoconductive properties were promising; creeping bone formation could be observed, although no complete fusion had been achieved at 24 weeks.

Allogeneic grafts for bone tumor: 21 cases of osteoarticular and segmental grafts

We treated 21 aggressive and malignant bone tumors by wide resection and replacement with deep-frozen osteoarticular and segmental (intercalary and block) allografts. Radiologic and histologic studies showed a gradual accretion of new bone on the graft trabeculae, sometimes with total creeping substitution. Substantial resorption of grafted condylar bone occurred in 3 of 14 cases. One of them ended with arthrodesis; in the other 2 the result after augmentation autografts was fair. Radiographically, a gradual joint surface destruction was observed in all the osteoarticular grafts after 5 years, not correlating with joint function, however. Biopsies showed some cartilage regeneration. Each patient underwent, on an average, two operations. Function after osteoarticular grafts at 3-16 years was excellent in 1 case, good in 4, fair in 6, and poor in 1 case; 2 cases were too recent for evaluation. Function 3-12 years after segmental grafts was excellent in 3 cases and poor in 3 cases (1 amputation due to nonunion, 1 amputation due to recurrence, and 1 prosthetic replacement due to recurrence); 1 case was too recent for evaluation. We conclude that an allograft is an acceptable alternative in the reconstruction of large tumor defects. However, it still presents unsolved immunologic and preservation problems, which make the prognosis guarded.

Why a Meniscectomy Fails

The clinical and roentgenological data on 30 patients with unsatisfactory recovery or recurrent symptoms after meniscectomy were analysed. The meniscectomy was regarded as having been the wrong choice of therapy in four patients and as ineffective therapy in 11. In 10 patients other knee lesions dominated postoperatively, in three the recovery was delayed for no obvious reason but the symptoms slowly disappeared, and in the remaining two patients a degenerative osteoarthritis developing some time after the meniscectomy was regarded as the cause of the recurring symptoms. We conclude that with an optimal clinical and arthrographic analysis and with careful operative tecnique as many as 17 arthrotomies (out of 30 primary and 13 reoperations) in the material presented could have been avoided.

The identity of Incurvaria vetulella (Zetterstedt, 1839) and I. circulella (Zetterstedt, 1839), two distinct species (Lepidoptera: Incurvariidae)

Material from Fennoscandia currently identified as Incurvaria vetulella (Zetterstedt, 1839) appears to comprise two superficially very similar species: 1. vetulella and I. circulella (Zetterstedt, 1839), the latter having been regarded as conspecific with or a form of vetulella for the last century. Lectotypes of both species are designated, the two species are briefly redescribed, differences are discussed, and adults, male and female genitalia are illustrated. I. circulella is reported from northern Norway, Sweden, Finland and the USSR.

Allogeneic Osteoarticular Grafts About the Knee

Osteoarticular resection of bone tumor results in a reconstruction problem which has not been solved satisfactorily. Allogeneic deep-frozen osteoarticular transplant is one of the alternatives.