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Aim: The accurate preoperative diagnosis of occult sepsis in endoprosthetic loosening of total knee arthroplasty is the key to successful management of revision total knee arthroplasties. The aim of this study was to evaluate the results of preoperative aspiration in comparison with preoperative arthroscopic biopsy of the synovial tissue., Method: From 2000 to 2004 eighty-six revision total knee arthroplasties in 86 patients were performed. 60 patients had only a knee aspiration, 15 an arthroscopic biopsy and an aspiration, 11 only arthroscopic biopsy. The results of both methods were compared with the intraoperative cultures during revision surgery., Results: 69 aseptic and 17 septic knee exchange arthroplasties were performed. The preoperative aspiration of the prosthetic knee joint had a sensitivity of 68.8 %, specificity of 96.6 %, positive predictive value of 84.5 % and a negative predictive value of 92.2 %. The preoperative arthroscopic biopsy had a sensitivity of 100 %, specificity of 94.7 %, positive predictive value of 87.4 % and a negative predictive value of 100 %., Conclusion: Preoperative aspiration of the knee is a very helpful study for the diagnosis or exclusion of infection in a prosthetic knee joint and should be a standard procedure in the diagnosis of prosthetic loosening. If after aspiration a suspicion of infection remains, then the biopsy is an accurate procedure to diagnose or exclude periprosthetic sepsis.

Purpose: Aim of this study was the examination of clinical middle- and long-term results of total femoropatellar endoprostheses type Lubinus (Link, Germany)., Method: From 1983 to 1996 12 patients (15 joints) underwent total femoropatellar joint replacement (type Lubinus, Link, Hamburg). All of them have been controlled 7.2 +/- 2.6 years (2 to 12 years) after surgery. The indication was primary osteoarthritis in 6, chondrocalcinosis in 2 and rheumatoid arthritis in 7 cases. In addition to the femoropatellar implants femorotibial endoprostheses have been used in 10 knees: 2 unicondylar medial, 1 unicondylar lateral and 7 bicondylar unicompartimental ones., Results: According to a modified Hungerford knee rating scale 8 knees resulted excellent, 2 fair and 4 poor. One knee was excluded after revision surgery due to a loosened tibial component of a medial unicompartimental knee arthroplasty. The 4 poor outcomes resulted from femoropatellar replacements in chondrocalcinosis (2 cases), rheumatoid arthritis and osteoarthritis, (one case each), affecting the femorotibial joint as well., Conclusions: In those cases of simultaneous femorotibial joint affection--even if this is merely slight and beginning and if the femoropatellar complaints are actually clearly dominating--the sole femoropatellar surface replacement seems to be contraindicated according to our experiences. Providing correct and strict indications this endoprosthesis can be recommended for sole femoropatellar osteoarthritis especially since loosening of endoprosthetic components was not been found in this study.

Aim of the Study: The aim of this study was to evaluate the response of the femoral head to intraosseous pressure increases and to document blood flow of periarticular soft tissue after infusion of vasoactive substances. Beside that the value and imagery of native MRI after induced intraosseous pressure increase should be estimated for early detection of femoral head necrosis., Methods: The alteration of intraosseous pressure and peripheral blood flow of the femoral head of beagle dogs was examined after administration of bradykinin as a vasoactive substance followed by subsequent magnetic resonance imaging (MRI). Bradykinin was injected into the arteriae circumflexae femoris lateralis and medialis of six beagle dogs. The administrations were made using a standard protocol with simultaneous measurement of venous blood flow and intraosseous pressure distribution in the epiphysis of the femoral head. Bradykinin was applied in regular time intervals followed by MRI., Results: At a mean epiphyseal pressure 14.66 mmHg (sigma: 2.42) in the femoral head, a mean flow of 91.6 ml/min (sigma: 16.08) was measured in the vena femoralis. After an administration of a defined concentration of bradykinin an increased epiphyseal pressure was recorded in the measured area. An average increase blood flow of the vena femoralis was observed at the beginning of the bradykinin-injection, followed by a circulatory volume reduction. The post-experimental MRIs showed massive oedema in the femoral musculature after bradykinin-application, however without osseous signal alterations in T1- or STIR-weighted images., Conclusion and Clinical Relevance: Our results indicate that acute intraosseous pressure increases are not accompanied by signal alterations in MRI. Obviously more extensive pressure induced lesions are necessary for detectable signal alterations, as these have already been demonstrated in patients with diagnosed femoral head necrosis.

In 145 patients with open dissectomies (virgin back) preoperative functional x-rays (flexion/extension) were available. 80 patients out of this group could be used for additional postoperative functional x-rays. The mean follow-up was 28 +/- 18 months. The segmental mobility was measured using the translation in the z- and the angular rotation about the x-axis (methods of Morgan/ King and Dupuis et al.). The patients were divided in 3 groups in respect to the level of operation. For each patient 3 segments (L3/4 to L5/S1) were analyzed. Segmental hypermobility was defined with a translation of more than 4 mm respectively a rotation of more than 18 degrees (ROM flexion/extension). In patients operated at the level of L4/5 (n = 62) segmental hypermobility was found in 12.9% at L3/4, in 8.1% at L4/5 and in 17.7% at L5/S1. Patients with a discectomy at the level of L5/S1 (n = 79) showed preoperative hypermobility in 10.1% at L3/4, in 15.1% at L4/5 and in 12.6% at L5/S1. In postoperative x-rays patients with discectomy at L4/5 (n = 34) showed no significant differences after operation, neither in translation nor in rotation. In the L5/S1-discectomy group (n = 45) the mobility for rotation at the level L4/5 increased significantly from 6.7 degrees to 10.2 degrees and in the level L5/S1 from 5.2 degrees to 8.4 degrees. There was no significant difference for the translation in all 3 segments. In both discectomy groups the number of segments with hypermobility didn't change significantly after operation.

In a prospective study 43 patients were reviewed 3 and 12 months after renal transplantation. The patients had MRI examinations and plain x-rays of the hips as well as punch biopsies of the iliac crest. In 9 patients diffuse, inhomogeneous bilateral changes of the MRI-signal patterns of the femoral diaphysis were seen. They were hypointense in the T1-weighted images and hyperintense in the STIR-images. All plain x-rays were inconspicuous. These changes of the femoral shaft were significantly more frequent in patients with renal osteodystrophy of the histological type Delling Ila. We conclude that these changes of MRI-signals patterns might be connected with an osteoidosis.

We evaluated growth, maturity of the skeleton and formation of skeletal deformities and epiphysiolysis of the femoral head in 22 children with end-stage renal failure undergoing haemodialysis, CAPD (continuous ambulatory peritoneal dialysis) and after kidney transplantation. We found growth retardation and disturbances of skeletal maturity in 64% of the children and skeletal deformities in 45%. Children undergoing haemodialysis showed a higher rate of retardation in growth and skeletal maturity than those undergoing CAPD and kidney transplantation. A high level of cortisone and frequent rejections after renal transplantation also lead to poorer growth and skeletal maturity. Children suffering from congenital renal dysfunction showed a higher rate of skeletal deformities. During haemodialysis the level of PTH (parathyroid hormone) was significantly higher than during CAPD and after renal transplantation. Epiphysiolysis capitis femoris lenta was found in 3 children, two of which occurred on both sides. These children had a significantly higher average level of PTH than the other 19.

Unlabelled: Based on the results of a retrospective study of 50 patients with mild lateral tracking and lateral compression of the patella (32 patients) and recurrent patellofemoral dislocation (18 patients), we present the technique, the results, the complications and the indications for the endoscopic lateral retinacular release and medial drawing tight of the capsule. The average age of the patients was 28.8 years (range: 10-53). At time of follow-up (m = 51 months) the patients were examined clinically as well as radiologically. The results were scored according to a score by Crosby and Insall. 73% of the patients with mild lateral tracking and lateral compression (lateral release) were satisfied with the operative results (visual analogue scale), as well as 66.6% of the patients with recurrent patellofemoral dislocation (lateral release and medial drawing tight of the capsule). Only 40% of the patients with patellofemoral arthritis (lateral release) reported about an improvement of this procedure. The score showed significantly good results but didn't raise the differences in between the groups of different indications. 28% of the patients showed an abnormal lateral tracking of the patella in active motion, the passive patella-glide-test (Hughston) raised a patella-hypermobility to the lateral side in 36% of the cases and to the medial side in 76%. X-rays of both knees showed an increased lateral patellofemoral angle of 10.8 degrees and an increased sulcus angle of 144 degrees. There was no progression in osteoarthritis in the operated side of the patellofemoral joint found. Complications revealed in a high number of hemarthrosis right after the operation, in 2 cases an open revision was necessary., Clinical Relevance: According to our results patients with patella compression syndrome without patellofemoral arthritis and patients with recurrent luxation or subluxation of the patella are good candidates for endoscopic lateral release and eventually medial drawing tight of the capsule. In a young population the endoscopic lateral release is a relatively simple surgical procedure making an open technique in failed cases possible.

X-rays were reviewed after callus distractions (50 cases) and distraction epiphysiolysis (10 cases) in 45 patients. With the aid of a computerized digitization system for analogue films, the relative x-ray density of the distraction area was determined in the medial, lateral, ventral and dorsal surface areas, and in the median line of the callus tissue. Bone formation became evident within 21.7 +/- 3.7 days post-distraction in the thigh and 25.4 +/- 4.9 days in the shank. The lowest density values were found at the end of the distraction phase followed by a continual increase in x-ray density in the fixation phase. There was a significant decrease in callus x-ray density in the shank from lateral to medial and from dorsal to ventral, and in the thigh from medial to lateral and from dorsal to ventral. When the corticotomized callus distraction is compared to the distraction epiphysiolysis without corticotomy it becomes apparent that the differences between lateral-medial x-ray densities and dorsal-ventral x-ray densities were significantly greater in the group with callus distraction. The deminished bone formation in the ventromedial area of the shank and the ventrolateral area of the thigh seems to be due to soft tissue damage and disturbances in local bone blood supply after the operative approach for corticotomy.