We present our experience with HA-coated total hip prosthesis in a minimum follow-up of eight years.

From 1989 to 1991 we performed 92 THRs in 83 patients. The mean age was 62 years (range 32–75). The preoperative diagnosis was: O.A. 68, AVN 12, CDH 8, and post-traumatic arthropathy 4. Pre-operative mean was HHS 43.

A posterior approach was used. The ARC 2F Cup, an HA coated spherical cup with thread around the equator, was used. Initial stabilisation is achieved by screwing the cup into the acetabulum. If necessary, a secondary fixation is enhanced by one or two bone screws to the ilium. The Omnifit stem is HA-coated in the proximal third and gives good immediate metaphysical fixation and optimal filling of the metaphysis. Three doses of Cefuroxime for prophylaxis and low molecular weight heparine were used in all cases. All patients had non-weight-bearing on the second postoperative day, partial weight-bearing in six weeks and full weight-bearing in 12 weeks.

Four patients were lost to follow-up. Mean H.H.S. was 91 in the first six months, 93 in the first year, and 95 in the second and third year. In the fifth year 97.93% were symptom-free in the first six months and 97% from the third to the fifth post-operative year. 3.7% of the patients complained of mild or moderate activity related to hip pain.

No patients suffered marked or disabling pain. Four patients complained of thigh pain six and eight months post-operatively. There were no major complications except for two superficial and two symptomatic deep vein thromboses. All patients returned to their prior activities within four to six months post-operatively. Radiographic evaluation of acetabular components revealed bone condensation in all three Charnley zones. We had no component migration or screw breakage. Calcar resorption was detected on the femoral side in seven patients. During the first post-operative year, AP radiographs of eleven patients indicated cortical hypertrophy in zones 3 and 5. There was no subsidence of the femoral stem.

We believe our results are encouraging although the follow-up period is short. We have had no revisions and the functional results are quite good. All patients are asymptomatic and satisfied with the result.

The capacity of the lumbar spine canal has direct relation to space-compromising conditions. Primary narrowing of the canal may produce no symptoms, but a slight reduction in capacity as a result of degenerative lesions, age, or disc bulging may result in symptomatic spinal canal stenosis. We studied the dimensions in the adult Greek population in order to find the variability factor in the capacity of the lumbar spinal canal.

The dimensions of the lumbar spinal canal were measured in 27 adult men and 42 adult women, all under the age of 50. MRI was used to measure four levels of the spine (L2 through L5). The AP and transverse diameters, as well as the cross section area, were measured at each level. Mean age (sd) of females was 34.8 (6.8) years. Mean age for males was 35.2 (7.3) and was comparable to women (P0.8). Mean age of a third group of 11 males over the age of 50 was 54.5 (2.6). All individuals included in the study were healthy and without any apparent degenerative changes in the lumbar spine or any symptoms related to it. Hotelling’s tests (Anderson, 1958), in terms of multivariate measurements of the spinal canal, were used to compare both genders and the two age levels. Tests for trends in the lumbar levels L2 through L5 were based on the exact binomial distribution for the number of cases exhibiting a complete trend from L2 to L5. The reported significance levels are adjusted for multiplicity of tests.

The relation of spinal width to lumbar levels is shown separately for the groups of males and females women under the age of 50 and for the group of males under over the age of 50. In all four lumbar levels, the group of men over 50 years old had a narrower spinal canal compared with men under 50 years old (2=0.005). This was particularly evident in levels L2 and L5 where the spinal canal for older men was narrower by factors of 15.5% and 13.1%, respectively. In the two gender groups of comparable age, spinal width was found to differ between men and women (2< 0.0001). In particular, the females had a wider spinal canal than males in levels L2, L3 and L4 and a narrower canal in level L5. Spinal width was found to exhibit a decreasing trend in lumbar levels L2 through L5. The evidence for this trend was strong for all three groups: females under the age of 50 (P< 0.0001), men under 50 (2< 0.005), and the older men (P< 0.0001). A similar trend was present for the anteroposterior diameter, as well as for the Transverse diameter. A numerical summary (mean, sd) of all spinal measurements is reported.

We believe this study to be an important one that provides useful information regarding the capacity of the lumbar spinal canal, thus helping the surgeon to properly evaluate the stenotic patient.