Background: A continuing controversy in total knee arthroplasty is the question whether the posterior cruciate ligament should be retained or substituted. This report reviews a series of total knee arthroplasties with a fixed bearing posterior cruciate ligament retaining implant (Nex Gen^© CR, Zimmer Inc., Warsaw, IN).

Methods: Between May 1997 and April 2001 197 patients were provided with 218 primary implants. There were 142 females and 55 males with an average age of 71 years (range 53–88 years) and a BMI of 28,9 kg/m² (range 19,1–41,2 kg/m²). The diagnosis was osteoarthritis in 212 patients, 3 cases of aseptic osteonecrosis, 1 fracture of the tibia plateau, 1 prior infection and 1 psoriatic arthritis. 84 knees had prior operations including high tibial osteotomies and menisectomies.

The operations were performed by 11 surgeons, with more than 80% done by 5 surgeons. 162 (74%) femur components and 181 (83%) tibia components were cemented. Patella resurfacing was performed in 135 (62%) cases.

We evaluated the results prospectively with a clinical inspection, radiographs (AP and lateral, longleg standing, patella sunrise view), and the use of the Knee Society Score, Quality-of-Life Short Form-36 and WOMAC rating score.

149 patients were examined at a mean follow up of 5,9 years (range 4,1–8,2 years). 29 were questioned on the telephone, 29 deceased, 7 revisions had to be performed and 4 (2%) were lost to follow up.

Results: The range of motion improved from 101° to 115° (range 80°–140°). All knees had sufficient antero-posterior and mediolateral stability. The Knee society score improved from 35 to 83 (good result) and the function score improved from 52 to 76 (good result).

Early complications included 12 haematoma, 10 wound healing problems, 5 early infections, 2 thrombosis and 1 non lethal pulmonary embolism. 7 revisions had to be performed: 3 late infections (2 one-stage revisions with synovectomy and exchange of polyethylene inlay, one two-stage revision with semi-constrained implant LCCK© Zimmer Inc.), 3 patella resurfacing due to anterior knee pain and 1 exchange of cemented tibia plateau due to aseptic loosening. Survivorship at 6 years including any reason of failure was 96,5%.

Conclusion: At a mid term follow up of 6 years this fixed bearing posterior cruciate retaining implant achieved a reasonable survivorship with good clinical results, kinematics and patient satisfaction.

Two Durasul highly crosslinked polyethylene liners were exchanged during revision surgery four and five years after implantation, respectively. The retrieved liners were evaluated macroscopically and surface analysis was performed using optical and electron microscopy. A sample of each liner was used to determine the oxidation of the material by Fourier transform infrared spectroscopy. Samples of the capsule were examined histologically.

The annual wear rate was found to be 0.010 and 0.015 mm/year, respectively. Surface analysis showed very little loss of material caused by wear. Histological evaluation revealed a continuous neosynovial lining with single multinucleated foreign-body giant cells. Our findings showed no unexpected patterns of wear on the articulating surfaces up to five years after implantation and no obvious failure of material.

Introduction: Irradiation crosslinking of UHMWPE has been developed as an improvement over conventional UHMWPE to provide improved wear resistance, demonstrated during in-vitro studies as well as in early clinical results [1, 2]. The analysis of explants made of highly crosslinked UHMWPE yields valuable information about their clinical utility.

Material: 26 explanted highly crosslinked UHMWPE inlays (Durasul, Zimmer) from various sources were surgically retrieved and analyzed. All inlays articulated with 28 mm CoCr heads except one (32 mm) and had an implantation time from 3 to 43 months (mean 14 months). The reasons for revision were: 9 for infection, 2 for ossification, 4 for luxation, 2 for pain, 4 for bone fracture and 5 for aseptic loosening.

Results: On all explants, scratches on the articulation area as well as machining marks were visible; the latter have sometimes been smoothed out in the loaded area. There were no signs of delamination or oxidation. The loaded area, analyzed by SEM, exhibits microscopic changes in the morphology which have been reported to be potential microcracks [3]. When analyzed by TEM, it was seen that these surface features are ripples and folds, which are induced by normal adhesive-abrasive wear behavior and have a maximum size of 5 m [4]. Mechanisms like folding are reported also from conventional UHMWPE [5]. In order to separate wear from deformation, the shape memory behavior of UHMWPE was employed. After thermal treatment, smoothed machining marks were observed to recover. After about two years in-vivo, some of the machining marks in the loaded area do not recover, which indicates that minimal wear in the range of the height of the machining marks (approx. 10 m) has occurred. In comparison, after this time, 200–600 m of wear would be expected for conventional UHMWPE [6].

Conclusions: The findings from the retrievals showed that there is no adverse wear or material failures due to delamination or cracks at 3 to 43 months. The accumulated scratches are due to the fact that the wear of this highly crosslinked polyethylene is very small. The scratches do not polish out over time as with conventional UHMWPE and do not show adverse effects on the long-term behaviour of the implant. These results are consistent with the performed in-vitro studies.

The Chevron osteotomy was described in 1976. There have, however, been only short- to mid-term follow-up reviews, often with small numbers of patients.

We looked at 112 feet (73 patients) with a minimum follow-up of ten years following Chevron osteotomy with a distal soft-tissue procedure. Clinical evaluation was calculated using the hallux score of the American Orthopedic Foot and Ankle Society (AOFAS). For 47 feet (30 patients), the results were compared with those from an interim follow-up of 5.6 years.

The AOFAS-score improved from a pre-operative mean of 46.5 points to a mean of 88.8 points after a mean of 12.7 years. The first metatarsophalangeal (MTP) angle showed a mean pre-operative value of 27.6° and was improved to 14.0°. The first intermetatarsal (IM) angle improved from a pre-operative mean value of 13.8° to 8.7°. The mean pre-operative grade of sesamoid subluxation was 1.7 on a scale from 0 to 3 and improved to 1.2. Measured on a scale from 0 to 3, arthritis of the first MTP joint progressed from a mean of 0.8 to 1.7. Comparing the results in patients younger and older than 50 years, the Chevron osteotomy performed equally in both age groups. Analysing the subgroup of 47 feet with a post-operative follow-up of both 5.6 and 12.7 years, the AOFAS pain and the overall score showed a further improvement between both follow-up evaluations. The MTP angle, first IM angle and sesamoid position remained unchanged. The progression of arthritis of the first MTP joint between 5.6 and 12.7 years post-operatively was statistically significant. Only one patient required a revision procedure due to painful recurrence of the deformity.

Excellent clinical results following Chevron osteotomy not only proved to be consistent, but showed further improvement over a longer follow-up period. The mean radiographic angles were constant without recurrence of the deformity. So far, the statistically significant progression of first MTP joint arthritis has not affected the clinical result, but this needs further observation.

Aims: To solve the major problems of osteolysis due to particle debris in total hip arthroplasty, highly cross-linked UHMWPE were developed. Investigations on early retrieved components of Durasul™ (Centerpulse Orthopedics Ltd.) provide the opportunity to evaluate the highly crosslinked components for wear damage or other effects on the material. Methods: 12 Durasul™ alpha cups were surgically retrieved and analyzed. The range of in-vivo duration of the cups was between 3 and 15 months. The reasons for revision were not related to material failure. The investigations were made by microscopy and CMM measurement. To differentiate between creep and wear, the memory effect was used. Results: In the articulation, machining marks look partly flattened, or show a highly scratched surface. The loaded area shows some microscopic changes of the morphology like ripples and folds, which are shear-induced ripple formations and material overlappings. In some cases the retrieved cups show a yellow discoloration, indicating the in-vivo absorption of synovial liquid proteins. Conclusion: The findings from the retrievals showed that there is no adverse wear at 3–15 months and there were no material failures due to wear, delamination or cracks. All the effects are accumulating on the articulating surface and lead to the dull scratched morphology. Mechanisms like material overlapping and yellowing are reported also from conventional UHMWPE and do not show adverse effects on the long-term behaviour of the material.

Reimplantation is a well-established procedure in reconstructive surgery. This is especially so after amputation of the upper limb since prostheses provide limited function. In unilateral amputation of the lower leg orthotopic reimplantation is the treatment of choice. With bilateral amputation, in which orthotopic reimplantation is not possible because of the complexity of the trauma, heterotopic reimplantation is an option.

We report five patients who received orthotopic and two who received heterotopic reimplantations of the lower leg. We assessed the functional outcome with reference to cutaneous sensation, mobility, pain, and the cosmetic result.

The functional outcome was good, as was the patients’ satisfaction. Their mobility, stability, and psychological state were satisfactory. Patients with heterotopic reimplantations preferred the reimplanted leg to a prosthesis. Although reimplantation of the lower leg requires prolonged hospitalisation, delayed mobilisation and secondary operations, we conclude that there is an indication for this operation in order to improve the patient’s quality of life.

The bone-marrow oedema syndrome is associated with local vascular disturbances and may be treated either conservatively or by core decompression after which recovery may take several weeks. We describe a 15-year-old girl with bone-marrow oedema of the left acetabulum which was confirmed by MRI. She presented with a four-week history of severe constant pain. Routine blood tests and plain radiographs were normal. She was treated with intravenous infusions of iloprost on five consecutive days (20 μg administered in 500 ml of sodium chloride). Iloprost causes vasodilatation with reduction of capillary permeability and it inhibits platelet aggregation. She had relief from pain at rest after three days of treatment and was completely free from symptoms after two weeks. MRI after six weeks showed almost complete resolution of the marrow oedema and was normal after four months. This is the first report of the pharmacological treatment of the bone-marrow oedema syndrome in children.

We have compared different types of intertrochanteric osteotomy for avascular of necrosis of the hip and evaluated their performance in the light of improving outcome after total hip arthroplasty (THA). During a period of 14 years we performed 63 flexion osteotomies (partly combined with varus or valgus displacement), 29 rotational osteotomies, 13 varus osteotomies, eight medialising osteotomies and two extension osteotomies. The mean period of follow-up for all 115 operations was 7.3 years (maximum 24.6).

At follow-up, 27 of 29 patients with a rotational osteotomy had already undergone a THA, compared with 36 of 63 after flexion osteotomy. A high incidence of complications (55.2%) was seen early after rotational osteotomy, compared with 17.5% after flexion osteotomy.

For all osteotomies there was a high correlation between the size of the necrotic area and the incidence of failure, which also correlated with the preoperative Ficat and Steinberg stages. Using Kaplan-Meier survivorship analysis, Sugioka’s rotational osteotomy showed a survival probability after five years of 0.26 (95% confidence interval 0.49 to 0.14), and after ten years of 0.15 (CI 0.36 to 0.06). The survival probability for flexion osteotomy was 0.70 (CI 0.83 to 0.59) after five years and 0.50 (CI 0.65 to 0.38) after ten years. The subgroup of flexion osteotomy with a necrotic sector of less than 180° achieved the best survival probability of 0.90 (CI 1.00 to 0.80) after five years and 0.61 (CI 0.84 to 0.45) after ten years.

The indications for intertrochanteric osteotomy for avascular necrosis of the hip have to be addressed critically. Even flexion osteotomy in cases with small areas of necrosis provides only temporary benefit. Rotational osteotomy was associated with a high incidence of complications.

Bone marrow oedema syndrome of the talus is a rare cause of pain in the foot, with limited options for treatment. We reviewed six patients who had been treated with five infusions of 50 μg of iloprost given over six hours on five consecutive days. Full weight-bearing was allowed as tolerated. The foot score as described by Mazur et al was used to assess function before and at one, three and six months after treatment. The mean score improved from 58 to 93 points. Plain radiographs were graded according to the Mont score and showed grade-I lesions before and after treatment, indicating that no subchondral fracture or collapse had occurred. MRI showed complete resolution of the oedema within three months.

We conclude that the parenteral administration of iloprost may be used in the treatment of this syndrome.