Retrospective evaluation of biopsychosocial determinants and treatment response in patients receiving devil's claw extract (doloteffin).

In a retrospective evaluation of patients taking part for 2 months in a postmarketing surveillance study on the effectiveness and safety of Harpagophytum procumbens, associations were found to known explanators of pain, disability and depression. Therefore, treatment non-responders might best be referred to a multimodal pain relief program that deals with fear avoidance beliefs, enhances experiences that decrease perceptions linking disability and pain and forces the patients to rethink the way they deal with the problem. However, during treatment with the aqueous Harpagophytum extract, this decision might reasonably be postponed to the end of month 4, since it has been shown that the maximum pain relief occurs after 3-4 months.

A 1-year follow-up after a pilot study with Doloteffin for low back pain.

OBJECTIVE: To complete a year's follow-up on patients from a 6-week double-blind pilot comparison between 44 Doloteffin patients and 44 rofecoxib patients being treated for acute exacerbations of chronic low back pain. METHODS: 38 "ex-Doloteffin" (ex-D) and 35 "ex-rofecoxib" (ex-R) received Doloteffin containing 60 mg harpagoside per day for up to 54 weeks. Pain, additional analgesics, mobility, general health and adverse events were assessed from diary records and at 6-week visits. RESULTS: 53 patients remained in the follow-up at 24 weeks and 43 at 54 weeks. There was never any convincing difference between ex-D and ex-R patients in the number of patients remaining in follow-up, diary pain scores, additional analgesics, Arhus Index and health assessment questionnaire scores (HAQ). Individual fluctuations notwithstanding, the follow-up showed a slight overall improvement on the improvements in Arhus and HAQ scores achieved in the pilot study (MANOVA p = 0.016). Of the 21761 patient-days, the respective percentages with no, mild, moderate, severe and excruciating pain were 28%, 39%, 22%, 8.5% and 1.5%, respectively. Few patients requested additional treatments for their pain. Three patients suffered from minor adverse drug reactions. CONCLUSION: Long-term treatment with Doloteffin was well tolerated. Ex-R and ex-D patients behaved similarly during the follow-up.

Comparison of outcome measures during treatment with the proprietary Harpagophytum extract doloteffin in patients with pain in the lower back, knee or hip.

Besides checking estimates of effectiveness and safety of using the proprietary Harpagophytum extract Doloteffin, this postmarketing surveillance compared various disease-specific* and generic** measures of effect. We enrolled 250 patients suffering from nonspecific low back pain (Back group: n = 104) or osteoarthritic pain in the knee (Knee group: n = 85) or hip (Hip group: n = 61). They took an 8-week course of Doloteffin at a dose providing 60 mg harpagoside per day. The measures of effect on pain and disability included the percentage changes from baseline of established instruments (Arhus low back pain index*, WOMAC index*, German version of the HAQ**) and unvalidated measures (total pain index*, three score index*, the patient's global assessment** of the effectiveness of treatment). Patients also received a diary for the daily recording of their pain and any additional treatments for it. The three groups differed in age, weight and characteristics of initial pain. 227 patients completed the study. Multivariate analysis confirmed that several dimensions of effect were recorded by the several outcome measures but, in all groups, both the generic and disease-specific outcome measures improved by week 4 and further by 8. In multivariable analysis, the improvement tended to be more when the initial pain and disability score was more: older patients tended to improve less than younger, the hip group tended to improve convincingly more than the back group, whereas the improvement in the knee group was less readily differentiated from that in the back group. The subgroup of Back patients who required NSAIDs during the 8 weeks used significantly more per patient than patients in the other two groups, but that requirement also declined more with time. About 10% of the patients suffered from minor adverse events that could possibly have been attributable to Doloteffin. Between 50% and 70% of the patients benefitted from Doloteffin with few adverse effects. Thus, Doloteffin is well worth considering for osteoarthritic knee and hip pain and nonspecific low back pain.

Hydroxyapatite and tricalcium phosphate-coated cups with and without screw fixation: a randomized study of 64 hips.

Sixty-two patients (64 hips) were provided with porous press-fit cups (Trilogy), plasma-sprayed with a coating consisting of 70% hydroxyapatite and 30% tricalcium phosphate. The patients were randomized to a cup with cluster holes for adjunctive screw fixation (n = 30) or to a cup without holes (n = 34). Radiostereometry was used to study migration and wear. Up to 2 years median translations and rotations <0.2 mm and <0.2 degrees were recorded in the 2 groups, without any difference. The median annual proximal wear (0.11 and 0.12 mm) was within the expected range despite the use of a ceramic coating, and it did not differ between the 2 designs. Radiolucent lines were frequently seen postoperatively but diminished during the follow-up without any sign of migration into the gaps. At 2 years, the median Harris scores were 99 points (range, 51-100 points) in the group with and 98 points (range, 69-100 points) in the group without screws. The results indicate that early fixation can be achieved for ceramic-coated press-fit cups without using additional screw fixation.

The acetabular component in total hip arthroplasty. Evaluation of different fixation principles.

Initial stability is necessary for permanent fixation of acetabular cups. Biologic reactions to submicron particles such as localized bone resorption may lead to implant failure. The aim of the study was to evaluate different fixation principles of acetabular components. Four randomized studies and one case-control study were performed to evaluate different bone cements, different cup designs, use of ceramic coating or not, different type of screws and the need of additional screw fixation or not. Radiostereometry (RSA) makes it possible to analyze small translations and rotations of implants with a high accuracy. This method is suitable for evaluation of early stability and was used in four of the studies. Clinical and radiological follow-up were performed regularly. The cements were tested in the laboratory. 30 patients (mean age 71 years, range: 63-76) received total hip arthroplasties and were randomised to fixation with Boneloc (14) or Palacos cum gentamicin (16) bone cement. The curing temperature was 23 degrees lower for the Boneloc cement but the tensile strength was reduced and the elastic modulus was lower compared to Palacos. The proximal cup migration was greater in the Boneloc group up to 12 months (p 0.04) and these cups migrated medially in contrast to a small lateral migration seen in the Palacos group (p 0.04). Radiolucencies were more pronounced in the Boneloc group at 12 months (p 0.04). 155 patients (171 hips, mean age 50 years, range: 24-64) received uncemented hip arthroplasties. 84 hips were randomised to the PCA and 87 to the Harris-Galante I designs. The 10-year survival rates were 85% for the PCA and 99% for the Harris-Galante I cups (revision as end-point). The wear and clinical results did not differ. 43 patients (mean age 60 years, range 44-68) received uncemented porous cups with a titanium mesh in pure titanium (Harris-Galante II) and were randomised to additional fixation with either biodegradable screws (23, poly-L-lactic acid, PLLA) or screws made of titanium alloy (20). Increased proximal and medial-lateral translations (p 0.02, 0.04) but less rotation around the longitudinal axis (p 0.04) were seen in the PLLA group up to 2 years. There were also more pronounced radiolucencies anteriorly in this group at 2 years. The clinical results did not differ. 23 uncemented porous cups (Harris-Galante II) with hydroxyapatite-tricalciumphosphate coating (HA/TCP) were pair-wise matched to uncoated cups. Up to 2 years, decreased rotations around the horizontal axis were recorded in the HA/TCP-coated cups. Central postoperative gaps were more frequently seen in the HA/TCP group (p < 0.01), but at 2 years radiolucencies were more pronounced in the uncoated group (p < 0.01). The wear and clinical results did not differ. 62 patients (64 hips, mean age 56 years, range: 32-75) were randomized to porous Trilogy cups with (30) and without (34) cluster holes for additional screw fixation. Up to 2 years there were no differences in migration, wear, radiographic findings or clinical results. In conclusion Boneloc cement was associated with poor fixation due to inferior mechanical properties. The PLLA screws did not provide sufficient stability. Unacceptably high failure rates were recorded for the PCA cup. HA/TCP coating improved the fixation and the interface of porous cups. HA/TCP coated porous cups can be fixed without adjunctive screw fixation.

Poor outcome of the PCA and Harris-Galante hip prostheses. Randomized study of 171 arthroplasties with 9-year follow-up.

155 patients (171 hips) with a mean age of 50 years (24-64) were randomized to uncemented PCA (84 hips) or Harris-Galante type I (87 hips) total hip arthroplasty. Clinical and radiographic evaluations were done regularly. The improvements in the Harris hip and pain scores did not differ. Osteolysis developed in 5 PCA and 17 Harris-Galante hips. 13 hips in the PCA and 16 in the Harris-Galante (HG) group were revised because of mechanical failures and 1 hip (HG) because of infection after a mean follow-up of 9 years. Decreased 10-year survival rate, based on revision as end-point, was noted for the PCA (85%), compared with the Harris-Galante cup (99%). The corresponding survival rate of the PCA stem (96%) was higher than that observed for the Harris-Galante design (86%). When radiographic failures were included, the survival rates of the 4 different components dropped to between 73% and 94%. These findings indicate that further revisions will be necessary and continuous radiographic follow-up is indicated to enable revision before severe bone destruction has occurred. Although the PCA and the Harris-Galante designs differed as regards the survival of the individual components, the overall clinical and radiographic survival rates of these cementless total hip arthroplasties were poor.

Porous cups with and without hydroxylapatite-tricalcium phosphate coating: 23 matched pairs evaluated with radiostereometry.

Migration, wear, and presence of radiolucencies were studied in 23 matched pairs of patients operated with porous-coated acetabular cups with additional screw fixation. All implants had the same type of titanium fiber mesh. In each pair, one of the cups was plasma-sprayed with a coating consisting of 70% hydroxylapatite (HA) and 30% tricalcium phosphate (TCP). Radiostereometric analysis up to 2 years after the operation revealed smaller rotations around the horizontal axis in cups with HA/TCP coating. The migration of the cup center was not significantly influenced. Evaluation of femoral head penetration in 12 of the matched pairs did not reveal any significant difference. Immediately after operation, implants with HA/TCP coating had more central radiolucencies, which, despite minimal migration, disappeared during the follow-up. The clinical results did not differ between the 2 groups. The findings of less tilting and diminishing radiolucencies in the cups with HA/TCP coating suggest a more complete ingrowth of bone and a better sealing of the interface.

Radiostereometry of hip prostheses. Review of methodology and clinical results.

Radiostereometric analysis is a science that enables reliable measurements to be made from radiographs. The method involves several steps including insertion of spheric tantalum markers, radiographic examinations, measurements of radiographic films, and calculations of three-dimensional movements. The precision of the method corresponding to the 99% significance interval varies between 0.15 and 0.6 mm and 0.3 degree and 2 degrees when applied to total hip replacement depending on the technique used. Measurements of implant micromovement during 1 to 2 years after surgery have proved to be of value to predict later clinical failure because of aseptic loosening and revision. Subsidence of the femoral stem or proximal migration of the acetabular cup between 1 and 2 mm has indicated increased risk of early or intermediate term revisions in those prosthetic designs studied so far. Minimum early migration has been recorded for clinically well documented nonpolished stems and polyethylene cups, which probably is one explanation for their long term success. This small amount of early micromotion also has been found in porous coated and screw fixated press fit cups and all hydroxyapatite coated designs hitherto studied. As a first step in a clinical evaluation of new implants or surgical techniques, the predictive value of radiostereometric analysis measurements can be used to reduce the number of patients exposed to the potential risk of clinical failure.

Migration of press-fit cups fixed with poly-L-lactic acid or titanium screws: a randomized study using radiostereometry.

The early migration of porous acetabular cups was studied in 43 patients with osteoarthrosis. The patients were randomly allocated to additional fixation of the cup with either biodegradable poly-L-lactic acid screws or titanium screws. Radiostereometric evaluation was done during the first 2 years after the procedure in 43 hips (23 with poly-L-lactic acid screws and 20 with titanium screws). At the 2-year follow-up, cups fixed with poly-L-lactic acid screws had migrated significantly more in the proximal-distal (p < 0.05) and medial-lateral (p < 0.05) directions. Cups with titanium screws displayed more pronounced rotations around the longitudinal axis (p < 0.05). Postoperatively, on the lateral view, there was an increased occurrence of radiolucencies at the dome of the cups fixed with poly-L-lactic acid screws (p < 0.05). The clinical result did not differ between the two groups. Inferior implant-bone contact in the poly-L-lactic acid group, local changes of the bone quality, and diminishing support of the poly-L-lactic acid screws caused by their degradation with time could be reasons for the different pattern of migration observed.

Evaluation of Boneloc. Chemical and mechanical properties, and a randomized clinical study of 30 total hip arthroplasties.

We evaluated the mechanical, chemical and clinical properties of Boneloc cement using radiostereometry and a series of laboratory tests. Compared to a standard cement (Palacos) the new cement displayed reduced tensile strength, elastic modulus, curing and glass transition temperatures. The amount of MMA extracted during 3 weeks in methanol was smaller for the Boneloc, but the total amount of released monomers was larger. The adhesion to stainless steel and bone did not differ. Radiostereometric analysis during the first postoperative year in 30 patients randomized to fixation of hip prostheses using either of the 2 cements displayed increased proximal migration of the cup and increased stem subsidence when Boneloc had been used. Part of the stem subsidence occurred inside the cement mantle. On the basis of these findings, we conclude that the inferior fixation in the Boneloc group is mainly caused by its mechanical properties. Other mechanisms, such as increased release of monomers, may also be important.