The use of acetabular screws in total hip arthroplasty and its influence on wear and periacetabular osteolysis in the long-term follow-up

Purpose The cementless implantation of hip replacement cups may be performed with and without the additional use of acetabular screws. If the surgeon uses screws or not depends on variable factors. In general, the use of screws is intended to increase the primary stability of the cup. Whether screws increase the initial stability of the cup construct, or even reduce it in part, is the subject of considerable debate in the literature. It is also unclear whether the additional screws lead to increased wear or increased periacetabular osteolysis over the long-term course. Methods Two hundred eleven patients from a previous study with a minimum follow-up of 10.7 years were included. Of these, 68 patients with 82 total hip arthroplasties (THA) were given clinical and radiological follow-up examinations. Of these, 52 had been fitted without screws and 30 with screws. On the basis of radiographs, annual wear and osteolysis were quantified. The clinical results were recorded by means of VAS, HHS, and WOMAC scores. Results Significantly more periacetabular osteolysis was found if additive acetabular screws had been used. No difference was found in relation to the volumetric wear per year. Likewise, no difference was found with regard to the clinical scores. Conclusions The use of additive acetabular screws leads to increased osteolysis in the periacetabular bone stock. Insofar as the primary stability of the cementless cup construct allows it, no additional acetabular screws should be used.

Midterm Results of Cementless and Cemented Unicondylar Knee Arthroplasty with Mobile Meniscal Bearing: A Prospective Cohort Study

Background:Cemented unicompartmental knee arthroplasty (UKA) yields good clinical outcome but common revision reasons are loosening and pain. Cementless UKA may reduce the revision rate.Objective:The current study was designed to assess clinical and radiographic outcome of cemented and cementless UKA, using bone quality as determined by the Bone Hardness Test (BHT) as selection criterion for cementless implantation.Methods:In this prospective comparative cohort study we analyzed 50 cementless and 29 Oxford consecutive UKA cases. Patients with sufficient bone quality were eligible for cementless UKA. Bone quality was assessed with the BHT, which consisted of exercising pressure with the thumb on the bone surface created after resection of the tibia.Results:The average surgical times were 62.5 ± 12.6 and 78 ± 16 minutes in the cementless and the cemented group, respectively (p < 0.01). The average thickness of the polyethylene insert was 4.3 ± 1.2 (range, 3 – 9) and 3.7 ± 0.8 (range, 3 – 6) mm, respectively (p = 0.02). Both types of implants yielded excellent clinical and functional results. At an average follow-up time of seven years, we found non-significant differences between clinical results of cementless versus cemented implants.Conclusion:Shorter surgical time makes cementless implantation more attractive to surgeons when considering UKA options for their patients. The average thickness of the polyethylene insert in cementless group was 0.6 mm thinner than in the cemented group. The BHT is a simple and useful test to assess whether patients are eligible for cementless UKA.

Navigated Cementless Total Knee Arthroplasty - Medium-Term Clinical and Radiological Results§

Purpose: The objective of this prospective study was to evaluate the medium-term clinical and radiological results after navigated cementless implantation, without patella resurfacing, of a total knee endoprosthesis with tibial and femoral press-fit components, with a focus on survival rate and clinical outcome. The innovation is the non-cemented fixation together with the use of a navigation system. Scope and Methods: Sixty patients with gonarthrosis were included consecutively in this study. In all cases, the cementless Columbus total knee endoprosthesis with a coating out of pure titanium was implanted, using a navigation system. The Knee Society Score showed a statistically significant increase from 75 (± 21.26) before surgery to 180 (± 16.15) after a mean follow-up of 5.6 (± 0.25) years. The last radiological examination revealed no osteolysis. No radiolucent lines were seen at any time in the area of the femoral prosthetic components. In the tibial area, radiolucent lines were seen in 24.4 % of the cases, mostly in the distal uncoated part of the stem. During follow-up, no prosthesis had to be replaced because of aseptic loosening while in 2 cases revision surgery was necessary due to septic loosening and in 1 case due to unexplainable pain. Results and Conclusions: Navigated cementless implantation of the Columbus total knee endoprosthesis yielded good clinical and radiological results in the medium term. The excellent radiological osteointegration of the prosthetic components, coated with a microporous pure titanium layer and implanted with a press-fit technique, should be emphasized.

EXPERIMENTAL STUDY OF STABILITY AT CEMENT AND CEMENTLESS IMPLANTATION OF TRANSPEDICULAR SCREWS INTO VERTEBRAE WITH LOW MINERAL DENSITY OF BONE

The stability of cemented and noncemented transpedicular screw implantations in vertebra with low mineral bone density was studied in experiment. We analyzed the destabilization of screw under distraction load, attached along longitudal axis of the screw on universal servo-hydraulic test machine «Walter+bay ag» LFV-10-T50. The factors of bone-cement-metallic block rigidity of cemented screw was in 2,10-2,38 times more then in situation with traditional transpedicular screw.

Primary Hip Replacement with Cementless «ESI» Implants

Comparative analysis of the outcomes of cementless implantation of total metal-polymeric structurized hip implants «ESI» of various generations was performed. Results of 1095 implantations (876 patients) performed during the period from 1995 to 2008 were evaluated. Follow-up was from 6 months to 12 years (mean term 7.3 years). Comparison of the results was performed between four groups differed by the modification of applied «ESI» implant. Characteristics for every of four «ESI» implant generations were presented. In the first group (1st generation of implants) assessment of treatment outcomes by Harris showed no excellent and good results, satisfactory results made up 4%, poor results - 96%. In the second group (2nd generation) excellent results were achieved in 3% of cases, good one in 18%, satisfactory - in 36% and poor result was noted in 43% of cases. In the third group (3rd generation) the results made up 27, 63, 8 and 2%, respectively. In group four (4th generation) excellent results made up 32%, good - 64%, satisfactory - 4% with no poor results observed.

Cementless Implantation of Zweymueller-Endler Total Endoprostheses of the Hip - Clinical, Radiological and Scintigraphic Follow-Up for 2 Years

Sixty-four patients with cementless Zweymueller-Endler total endoprostheses of the hip underwent follow-up postoperatively for 2 years. In 3 patients loosening or infection occurred. In 61 patients no complications were observed. However, in 74% of these patients increasing activity uptake at the tip of the shaft was found by scintigraphy. This was associated with hypertrophy of the corticalis and/or with a marrow cavity reaction, observed radiologically. The results show that scintigraphic evaluation of cementlessly implanted Zweymueller-Endler endoprostheses of the hip must be interpreted differently compared to isoelastic or to cemented prostheses.