The area of the tidemark in osteoarthritis--a three-dimensional stereological study in 21 patients.

We investigated the area of the tidemark in osteoarthritic and normal cartilage by stereology as well as the number of vessels penetrating the tidemark. The area of the tidemark was significantly increased in osteoarthritis, as was the number of vessels penetrating the tidemark. These three-dimensional findings are new compared to previous two-dimensional findings where it has been discussed whether there were any differences between osteoarthritic cartilage and normal cartilage with respect to duplications of the tidemark and vascularisation. The present findings using stereology may erase the uncertainty of previous findings, and support the hypothesis that primary osteoarthritis is partly of vascular origin.

Continuous popliteal sciatic nerve block for outpatient foot surgery--a randomized, controlled trial.

BACKGROUND: A major problem in outpatient foot surgery is severe postoperative pain that is not sufficiently treated by peroral analgesics. METHODS: Sixty-three patients underwent foot surgery under spinal anesthesia. Immediately on conclusion of the operation, sciatic and saphenous nerve blocks were performed. The sciatic nerve was blocked in the popliteal fossa with 30 ml of ropivacaine 5 mg ml(-1) and a perineural catheter was passed through the cannula. The patients were randomized to receive either ropivacaine 2 mg ml(-1) (n=30) or saline (n=30) in the catheter through a disposable elastomeric pump with a fixed infusion rate of 5 ml h(-1) for 55 h. RESULTS: Analgesia was excellent until 23 h 44 min (14 h 34 min) in the treatment group and 18 h 16 min (7 h) in the placebo group [mean (SD), P=0.07]. Thereafter, pain was significantly less in the treatment group on the first and second postoperative days (P=0.001). Sleep disturbances because of the pain in the foot were experienced by 25% of the treatment group on the first night at home and by 50% of the control group (P=0.29). There were no differences between the groups in their need for rescue opioid medication. None of the patients had any major problem with the catheter or pump, and none had any toxic effect referable to the technique. CONCLUSION: This randomized, double-blind study shows that continuous blockade of the sciatic nerve in the popliteal fossa reduces postoperative pain and has no untoward effects in a patient group known to experience severe pain after ambulatory surgery.

Increased bone mineral density adjacent to hydroxy-apatite-coated ankle arthroplasty.

We measured bone mineral density (BMD) in patients treated with a unilateral hydroxy-apatite-coated ankle arthroplasty. The study comprised 11 consecutive patients measured preoperatively and postoperatively after 3, 6, and 12 months (group I) and 17 patients measured once at 12 to 82 months follow-up (group II). BMD was measured in the distal tibia adjacent to the prosthesis and in the calcaneus. BMD of the calcaneus was measured bilaterally as an indicator of changes in foot load. In group I BMD was significantly increased in the distal tibia after 6 and 12 months compared to preoperative values. In group II BMD of the distal tibia was significantly higher compared to the non-operated side. No radiolucencies were detected during follow-up in any case. The increase in BMD and the radiographic findings after uncemented ankle arthroplasty indicates that it is being loaded by the prosthesis. This may indicate a well fixed prosthesis.

[The evolution of ankle arthroplasty]. / Die Entwicklung der Sprunggelenksarthroplastik.

The results of ankle arthroplasty have generally been disappointing compared to other forms of arthroplasty. The present survey of results of ankle arthroplasty deals with the anatomical, the kinemasiological the biomechanical and the biological features of the ankle joint. These features all seem important prerequisites for a successful total ankle prosthesis design. From the study of the results displayed in the literature and those of my own series it can be stated that a modern ankle arthroplasty should respect the normal anatomy and kinemasiology. Biomechanically it should work as a normal ankle joint i. e. cylindrical mobility, congruency and a possibility for normal torque within the ankle mortise. The prosthesis components should only be fixed in solid subchondral bone, and preferably without cement. Only compressible forces should act at the bone-prosthesis interface. The axis of the ankle joint as well as of that of the hindfoot should be aligned to normal. Meticulous surgery and special guide instruments are absolute necessities. Restoration of muscle power and gait postoperatively are essential for a good and lasting result. The indication for ankle arthroplasty is mainly cases of osteoarthritis (primary or traumatic) and rheumatoid arthritis. Contraindications are talus necrosis, Charcot joints, extreme osteoporosis, severe arteriosclerosis, and very aggressive arthritis. Mental disorders and neurological disorders may also be contraindications. Furthermore, the patients should agree not to perform sports involving jumping and running or other ankle demanding activities. The average annual failure rate should not exceed 1 % if these recommendations are followed.

Ankle arthroplasty in patients younger and older than 50 years: a prospective series with long-term follow-up.

One hundred consecutive cases treated with ankle arthroplasty for osteoarthritis (OA) or rheumatoid arthritis were followed prospectively and annually for up to 15 years. Survivorship analysis was performed, with the endpoint being prosthesis revision or change to arthrodesis. Patients who were younger than 50 years at the first implantation constituted one group (group A, 30 ankles). The other group (group B, 70 ankles) consisted of patients aged 50 years or older at the first implantation. All patients were assessed clinically according to the Kofoed Ankle Score. The distribution of OA/rheumatoid arthritis in group A was 18/12, and in group B it was 43/27 (not significant). The median age in group A was 46 years (range, 22-49 years), and in group B it was 63 years (range, 51-83 years). In group A, one case was revised, and three cases were converted to arthrodesis after a median of 5 years (range, 5-9 years). In group B, four cases were revised, and four cases were converted to arthrodesis after a median of 5.5 years (range, 2-8 years). The results of cases with traumatic OA did not differ between groups A and B. It was concluded that the results of ankle arthroplasty were of equal quality in patients younger than 50 years and those who were older.

The evolution of ankle arthroplasty.

The results of ankle arthroplasty have generally been disappointing compared to other forms of arthroplasty. The present survey of results of ankle arthroplasty deals with the anatomical, the kinemasiological the biomechanical and the biological features of the ankle joint. These features all seem important prerequisites for a successful total ankle prosthesis design. From the study of the results displayed in the literature and those of my own series it can be stated that a modern ankle arthroplasty should respect the normal anatomy and kinemasiology. Biomechanically it should work as a normal ankle joint i. e. cylindrical mobility, congruency and a possibility for normal torque within the ankle mortise. The prosthesis components should only be fixed in solid subchondral bone, and preferably without cement. Only compressible forces should act at the bone-prosthesis interface. The axis of the ankle joint as well as of that of the hindfoot should be aligned to normal. Meticulous surgery and special guide instruments are absolute necessities. Restoration of muscle power and gait postoperatively are essential for a good and lasting result. The indication for ankle arthroplasty is mainly cases of osteoarthritis (primary or traumatic) and rheumatoid arthritis. Contraindications are talus necrosis, Charcot joints, extreme osteoporosis, severe arteriosclerosis, and very aggressive arthritis. Mental disorders and neurological disorders may also be contraindications. Furthermore, the patients should agree not to perform sports involving jumping and running or other ankle demanding activities. The average annual failure rate should not exceed 1 % if these recommendations are followed.

Ankle arthroplasty for rheumatoid arthritis and osteoarthritis: prospective long-term study of cemented replacements.

We performed 52 cemented ankle arthroplasties for painful osteoarthritis (OA) (25) or rheumatoid arthritis (RA) (27) using an ankle prosthesis with a near-anatomical design. We assessed the patients radiologically and clinically for up to 14 years using an ankle scoring system. The preoperative median scores were 29 for the OA group and 25 for the RA group and at ten years were 93.5 and 83, respectively. Six ankles in the OA group and five in the RA group required revision or arthrodesis. Survivorship analysis of the two groups showed no significant differences with 72.7% survival for the OA group and 75.5% for the RA group at 14 years.

Avulsion fracture of the calcaneus: report of a case using a new tension band technique.

We report a case of avulsion fracture of the calcaneus in an 83-year-old woman. Nonoperative treatment was not considered satisfactory. However, the os calcis was osteoporotic, and internal fixation therefore was performed with a transverse Kirschner pin through the os calcis, securing a figure-of-8 metal tension band wiring to the fragment. We suggest that this technique provides a strong internal fixation in selected cases.

Cylindrical cemented ankle arthroplasty: a prospective series with long-term follow-up.

From 1981 to 1985 28 ankle arthroplasties were performed using a congruent and cylindrical ankle design. The talus component was an anatomically shaped cap to cover the talus dome and the facets. The tibial component was congruent toward the talus and had two parallel bars on the back for fixation into the distal tibia. The diagnosis was osteoarthritis in 15 cases and rheumatoid arthritis in 11 cases (two bilateral cases). There were seven failures, giving a cumulative estimated survival rate of 70% for the prosthesis at 12 years.

Fracture of the femoral neck: identification of the optimal screw position by migration ratio.

A consecutive series of fractures of the femoral neck treated with sliding screw and plate osteosynthesis were evaluated radiographically for the optimal position of the screw by use of migration indices. A naturally occurring optimal position of the screw was discovered. It was characterized by four positional indices in the head-neck region which were significantly correlated with minimal migration (or best stability). This optimal screw position gave a better prognostication of reduced risk of early fracture failure compared with the usual sectional division of the femoral head as indicator of screw position.

Failure of metal-backed patellar arthroplasty. 47 AGC total knees followed for at least 1 year.

A prospective series of 47 total knee arthroplasties in 44 patients with gonarthrosis were followed for at least 1 year to detect patellar complications. In five knees the metal-backed patellar component failed, in one knee the cement fractured, and in one knee there was a spontaneous fracture of the patella. We regard this failure rate as unacceptable.

Intramuscular lipoma of the lower limb. Long-term follow-up after local resection.

We report 12 patients with infiltrating muscular lipomas of the lower limbs all treated by wide resection. During follow-up averaging seven years, the tumour recurred in five patients. Our results and those reported by others suggest that, in order to avoid recurrence, this tumour, although benign, should be treated by total excision of the muscle or by compartmental resection. Hormonal imbalance was suspected in 9 of the patients but an oestrogen receptor analysis of the histological samples proved negative.

Passive ankle mobility. Clinical measurement compared with radiography.

We compared goniometric assessment of passive ankle movement with radiographic measurements in 100 normal ankles. Significant differences were recorded in both dorsiflexion and plantarflexion; clinical measurements overestimated the range of movement. For scientific documentation of tibiotalar mobility, radiographic measurements should be used.

Transcutaneous reduction and external fixation of displaced fractures of the proximal humerus. A controlled clinical trial.

A consecutive series of 31 displaced fractures of the proximal humerus were randomly selected for treatment either by closed manipulation or by transcutaneous reduction and external fixation. Follow-up assessed the quality of reduction and healing as well as the functional outcome. The external fixation method gave better reduction, safer healing and superior function.

Strength of implanted carbon fibers. Studies of the lumbar spine in goats.

The L3-4 supraspinous and interspinous ligaments in 10 goats were replaced with carbon fibers stabilized with silk-suture seizing. The implants were removed after 3 weeks in 5 animals and after 3 months in the other 5. The maximum traction strength of nonimplanted slings was 157 +/- 9 kg (M +/- SD). After implantation, the strength was reduced to 136 +/- 17 kg, and after 3 months to 107 +/- 9 kg. However, the maximum strength of the spinous processes was 71 +/- 19 kg, which was less than the strength of 3-month implants. We concluded that the carbon fiber sling stabilized with silk sutures could be used for replacement of the interspinous ligament.

External fixation of displaced fractures of the proximal humerus. Technique and preliminary results.

A new technique for the treatment of displaced fractures of the proximal humerus is described. Twelve fractures in 11 patients were managed by transcutaneous reduction using a Steinmann pin, and external fixation with a Hoffmann-type neutralising bar connected to two half-pins in the humeral head and three half-pins in the shaft. The pins were removed after four weeks. Two patients sustained redisplacement after a further injury, but in the others reduction was maintained. Two cases of pin-track infection resolved after antibiotics, but delayed union resulted. There were no neurovascular injuries and at follow-up of 6 to 12 months no refractures had been seen. The early functional results were excellent or satisfactory in nine cases.

Respiratory gas pressures in the spine. Measurements in goats.

Normal values of pO2, pCO2, pH, and intraosseous pressure were measured in situ in the lumbar spine of goats. In the lumbar bodies and discs no difference existed between values found cranially and caudally. pO2 was lower and pCO2 higher in the nucleus pulposus than in the adjacent lumbar bodies. This emphasizes the nutritional route to the disc via the vertebral end plate. Intraosseous pressures in the cranial and caudal levels of the lumbar spine did not differ, and the pressures were the same as otherwise found in cancellous bone. These are the first combined in situ measurements of several basic metabolic parameters in the normal spine using recordings with continuous mass spectrometry. They may constitute a basis for further investigation of metabolism in the structures of the spine.