A systematic review about long-term results after meniscus repair.

PURPOSE: Aim of this systematic review was to analyze long-term results after meniscus refixation. METHODS: A systematic literature search was carried out in various databases on studies on long-term results after meniscus refixation with a minimum follow-up of 7 years. Primary outcome criterion was the failure rate. Secondary outcome criteria were radiological signs of osteoarthritis (OA) and clinical scores. RESULTS: A total of 12 retrospective case series (level 4 evidence) were identified that reported about failure rates of more than 7 years follow-up. There was no statistical difference in the failure rates between open repair, arthroscopic inside-out with posterior incisions and arthroscopic all-inside repair with flexible non-resorbable implants. In long-term studies that examined meniscal repair in children and adolescents, failure rates were significantly higher than in studies that examined adults. Six studies have shown minor radiological degenerative changes that differ little from the opposite side. The reported clinical scores at follow-up were good to very good. CONCLUSION: This systematic review demonstrates that good long-term outcomes can be obtained in patients after isolated meniscal repair and in combination with ACL reconstruction. With regard to the chondroprotective effect of meniscus repair, the long-term failure rate is acceptable. LEVEL OF EVIDENCE: IV.

[Image and report quality of outpatient MRI examinations : Evaluation of organizational, technical and report-related parameters in patients with arthroscopically secured rotator cuff rupture]. / Bild- und Befundqualität von ambulanten MRT-Untersuchungen : Auswertung organisatorischer, technischer und befundbezogener Parameter bei Patienten mit arthroskopisch gesicherter Rotatorenmanschettenruptur.

BACKGROUND: MRI is commonly used to diagnose and assess prognosis for rotator cuff (RM) pathology in addition to history and clinical examination. AIM: This study investigates the image and report quality of shoulder MRIs with regard to prognosis-relevant parameters in outpatients who subsequently underwent surgical treatment for RM rupture. MATERIALS AND METHODS: Using a defined questionnaire, both the MR images and the original reports of 94 patients were evaluated by an experienced radiologist with regard to referral information, MRI technology and quality of the MRI reports. RESULTS: Questions or comments on RC were noted in 39% (general practitioners) and 48% (orthopaedics/UCH) of referrals. In MRI reports with the diagnosis "complete rupture of the RC", no information on the size of the defect was available in 47% of cases. In 18 and 30% of the reports, respectively, a fatty infiltration of the RM musculature or atrophy of the musculature was mentioned. When a partial RC rupture (n = 25) was diagnosed; the depth diameter (< or > 50% of the tendon thickness) was determined in only one case. The protocol recommendations valid today for MRI diagnostics of the shoulder were implemented in 60% of the examinations. According to the evaluating radiologist, 93-97% of the available MRI examinations were able to answer prognostic-relevant questions of an RC rupture. DISCUSSION: The questions by physicians referring to the MRI examination of a shoulder with a subsequently arthroscopically verified RC rupture were predominantly unspecific or insufficient. In the radiological reports of these MRI examinations, prognosis-relevant parameters could not be extracted in sufficient form and number, although the MRI technique would have allowed this.

Subgroups of patients with osteoarthritis and medial meniscus tear or crystal arthropathy benefit from arthroscopic treatment.

PURPOSE: The purpose of this study was to perform a systematic review of prospective randomized controlled trials comparing arthroscopic treatment for knee osteoarthritis (OA) with either other therapeutic interventions or sham treatment. METHODS: A systematic search for randomized controlled trials (RCT) about arthroscopic treatment (AT) for knee OA was performed according to the PRISMA guidelines. Arthroscopic treatment included procedures such as lavage, debridement and partial meniscectomy of the knee. Data source was PubMed central. RESULTS: Fourteen articles could be included. Five studies compared interventive AT with either sham surgery, lavage or diagnostic arthroscopy. Nine trials compared AT with another active intervention (exercise, steroid injection, hyaluronic acid injection). In ten trials, the clinical scores improved after arthroscopic treatment of knee OA in comparison to the baseline. In seven trials, there was a significant difference in the final clinical outcome with higher scores for patients after arthroscopic OA treatment in comparison to a control group. In four trials, the intention to treat analysis revealed no significant difference between arthroscopic OA treatment and the control group. In one of those trials, which compared arthroscopic partial meniscectomy (APM) with exercise, the cross over rate from exercise to AT was 34.9%. The clinical scores of cross-over patients improved after APM. In one study, the subgroup analysis revealed that patients with tears of the anterior two-thirds of the medial meniscus or any lateral meniscus tear had a higher probability of improvement after arthroscopic surgery than did patients with other intraarticular pathology. There was no difference in the side effects between patients with AT and the control group. Despite acceptable scores in the methodological quality assessment, significant flaws could be found in all studies. These flaws include bad description of the exact surgical technique or poor control of postoperative use of non-steroidal anti-inflammatory drugs (NSAID). CONCLUSION: Results of RCTs comparing AT with other treatment options were heterogeneous. AT in OA patients is not useless because there is evidence that a subgroup of patients with non-traumatic flap tears of the medial meniscus or patients with crystal arthropathy benefit from arthroscopy. This topic has a high relevance because several health insurances do not reimburse arthroscopy for patients with OA anymore. The results of these randomized studies, however, should be interpreted with care because in many studies, the use of other therapeutic variables such as pain killers or NSAIDs was not controlled or reported. LEVEL OF EVIDENCE: I.

Femoral cement extraction in revision total hip arthroplasty--an in vitro study comparing computer-assisted freehand-navigated cement removal to conventional cement extraction.

BACKGROUND: Revision surgery of cemented femoral stems in total hip arthroplasty is gaining more and more importance, but cement removal in revision hip arthroplasty may be technically challenging. Conventional manual cement removal can be time consuming and be associated with complications such as cortical perforation, fracture, or bone loss. The aim of this study was to investigate the practicability of computer-navigated cement removal. MATERIAL AND METHODS: In an in vitro study, we examined the removal of the bone cement out of composite bones. To evaluate accuracy, the bones were scanned before and after cement removal with the ISO-C three-dimensional C-arm computed tomography system to determine the amount of unremoved cement and the loss of bone stock. The data of freehand-navigated cement removal is compared to conventionally extracted cement using levers and drills under X-ray control. RESULTS: The mean time for cement removal was 29 ± 5 min for the conventional method and 32 ± 8 min for the freehand-navigated cement removal. Here, excepting the preparatory examinations, the navigated cement removal only took 13 ± 5 min. The measured temperature during polymerization was 36 ± 5 °C and during navigated cement removal was 37 ± 8 °C. In the distal part of the femur, cement removal was more accurate with the conventional method compared to the navigated one. CONCLUSION: The freehand-navigated cement removal, with the exception of the preparatory examinations, is time saving compared to the conventional method. However, a potential for technical development especially for the milling device and accuracy exist.

Bioreactor cultivation and remodelling simulation for cartilage replacement material.

For the development of articular cartilage replacement material, it is essential to study the dependence between mechanical stimulation and cell activity in cellular specimens. Bioreactor cultivation is widely used for this purpose, however, it is hardly possible to obtain a quantitative relationship between collagen type II production and applied loading history. For this reason, a bioreactor system is developed, measuring applied forces and number of loading cycles by means of a load cell and a forked light barrier, respectively. Parallel to the experimental study, a numerical model by means of the finite element method is proposed to simulate the evolution of material properties during cyclic stimulation. In this way, a numerical model can be developed for arbitrary deformation cases.

[Fluoroscopic navigation versus conventional manual positioning of the femoral component for hip resurfacing: first experimental trial]. / Fluoroskopische Navigation versus konventionelle manuelle Positionierung der Femurkomponente beim Oberflächenersatz der Hüfte: erste experimentelle Erprobung.

BACKGROUND: The most essential improvement of modern hip resurfacing arthroplasty is the metal-on-metal bearing as well as the integration of a procedure for the exact and repeatable positioning of the femoral component through a specific mechanical alignment instrument. Nevertheless, the main reasons for early implant failure are mal-positioning of the femoral component and notching of the femoral neck during femoral head preparation. MATERIALS AND METHODS: In the context of an in vitro study, in each case six DUROM-Hip resurfacing prostheses were implanted in artificial femora with the prosthesis-specific mechanical alignment instrument, as well as under navigation control. The aim of the study was to evaluate the functionality and accuracy of a computer-assisted planning and navigation system on the basis of a navigation module library from Surgitaix AG (Aachen, Germany), as well as a comparison with the prosthesis-specific mechanical alignment instrument. RESULTS: The main angulation error between planning and navigation of the stem-shaft angle was 0.2+/-1.2 degrees for the navigation system and 6.5+/-4.1 degrees for the mechanical alignment instrument, the main anterior offset error was 1.2+/-1.2 mm vs. -0.83+/-4.1 mm. The mean time for all five planning and navigation steps was 17+/-1.2 min vs. 14+/-0.8 min. The main distance error between planning and navigation was 1.9+/-0.6 mm for the navigation system, and 5.3+/-2.4 mm for the mechanical alignment instrument. Femoral notching was not observed for navigational or conventional positioning. CONCLUSION: The computer-assisted fluoroscopic planning and navigation system for hip resurfacing showed, within the scope of this in vitro study, first promising experiences. The system approves a practicable planning with a high accuracy in implementation. Nevertheless, the potential benefit has to be evaluated in further clinical studies, especially from the perspective of a possible integration of this navigation system into the clinical workflow. Further studies should consider a fluoroscopy-assisted range of motion assessment under consideration of an additional cup-module to enhance the postoperative range of motion after hip resurfacing procedures.

Amphiphilic bonder improves adhesion at the acrylic bone cement-bone interface of cemented acetabular components in total hip arthroplasty: in vivo tests in an ovine model.

INTRODUCTION: Even following the introduction of the "third generation" cementing technique, an improvement of the fixation of the acetabular component similar to that of the femoral has not been shown in clinical studies. The goal of the present study was to achieve a better stability with the use of an amphiphilic bonder while preserving the mechanically important subchondral sclerosis. MATERIALS AND METHODS: In a total of 20 sheep, a cemented total hip replacement was implanted. In the treatment group (n = 10), the implantation was carried out following surface conditioning of the acetabular bed with an amphiphilic bonder. All the sheep were followed for 9 months. To assess the biocompatibility, the osseous ingrowth at the cement-bone interface was depicted with the help of an in vivo fluorescent marking of the osteoblasts. Additionally, conventional radiographs were obtained over the course of treatment. Finally, the ovine pelvic regions were split following a standardized technique allowing for histological evaluation of the cement-bone interfaces. RESULTS: The acetabular components of the treatment group revealed a stable cement-bone compound. In the control group, the implants were easily dislodged from their beds. This finding was consistent with the radiological and histological results, which had revealed increased, progressive lytic radiolucent lines and the interposition of fibrous tissue at the cement-bone interface in the control group compared to the treatment group. The bonder was biocompatible. CONCLUSION: Following the application of the bonder, the cemented acetabular components revealed an improved stability without signs of inflammation or neoplasia in a viable acetabular osseous bed. With the help of this technique, the in vivo longevities of cemented acetabular components can be increased in the clinical setting without sacrificing the biomechanical relevant subchondral sclerosis.

[ Improvement of femoral bone-cement adhesion in cemented revision hip arthroplasty by application of an amphiphilic bonder in a dynamic femur expulsion testing in vitro ]. / Steigerung der femuralen Knochen-Knochenzement-Verbundfestigkeit in der zementierten Revisionshüftendoprothetik durch einen amphiphilen Knochenhaftvermittler im dynamischen in-vitro Ausstossversuch.

Cemented femoral stems have shown decreased longevity compared to cementless implants in hip revision arthroplasty. The aim of this study was to evaluate the effect of an amphiphilic bonder on bone cement stability in a biomechanical femur expulsion test. A simplified hip simulator test setup with idealised femur stem specimens was carried out. The stems were implanted into bovine femurs (group 1: no bonder, n=10; group 2: bonder including glutaraldehyde, n=10; group 3: bonder without glutaraldehyde, n=10). A dynamic loading (maximum load: 800 N; minimum load: 100 N; frequency: 3 Hz; 105 cycles) was performed. Subsequently, the stem specimens were expulsed axially out of their implant beds and maximum load at failure was recorded. The static controls showed a mean maximum load to failure of 4123 N in group 1, 8357.5 N in group 2 and 5830.8 N in group 3. After dynamic loading, the specimens of group 2 reached the highest load to failure (8191.5 N), followed by group 3 (5649.5 N) and group 1 (3462 N), respectively. In group 2, we observed nine periprosthetic fractures at a load of 8400 N without signs of interface loosening. Application of an amphiphilic bonder led to a significant improvement of bonding stability, especially when glutaraldehyde was added to the bonder. This technique might offer an increased longevity of cemented femur revision stems in total hip replacement.

Uncemented femoral revision arthroplasty using the modular revision prosthesis MRP-TITAN revision stem.

OBJECTIVE: Restoration of a painless hip joint capable of bearing weight by uncemented implantation of a rotationally stable, modular revision stem anchored in the diaphysis. INDICATIONS: Prosthetic stem loosening with osteolytic bone defects (defect classification types I-III according to Paprosky). Material failure with broken prosthesis. Sub- and/or periprosthetic femoral fractures. Tumors. CONTRAINDICATIONS: Extensive osteolysis preventing diaphyseal anchorage of the prosthesis. SURGICAL TECHNIQUE: Transgluteal approach to the hip joint. Removal of the loose prosthetic stem and, if cemented, the bone cement as well. Excision of intramedullary granulation tissue. Reaming of the medullary cavity with flexible reaming shafts and form-fit, uncemented implantation of the star-shaped modular revision stem with diaphyseal press fit. If there is extensive loss of metaphyseal bone stock, augmentation with autogenous/allogenic bone should be performed. POSTOPERATIVE MANAGEMENT: Mobilization on two underarm crutches from the 1st postoperative day. Removal of the Redon drains after 48 h. Partial loading with 20 kg for 6 weeks postoperatively. If plain radiographs show unchanged seating of the prosthesis after 6 weeks, loading can be increased by 10 kg per week until full weight bearing is achieved; thrombosis prophylaxis is continued throughout. Radiologic checkups after 3, 6, and 12 months. After that, the patient should be checked annually. RESULTS: 45 patients (n = 48 prostheses) with an average age of 67.2 years (min.-max. 42.4-87.4 years) were investigated. The average implantation time of the Modular Revision Prosthesis MRP-TITAN revision stem was 4.7 years (min.-max. 1.0-9.0 years). The Harris Hip Score for Paprosky bone defect types I-III had increased from 25.6 preoperatively to 71.4 postoperatively at the time of the final follow-up (< or = 0.05). Extensively defective bone was diagnosed preoperatively in 32 patients (> or = Paprosky IIB). Plain radiographs showed stable anchorage without migration in 44 patients. In one case, the stem (implantation time 2.36 years) was replaced due to increasing axial subsidence (> or = 5 mm). Good integration of bone graft with subsequent defect regeneration was seen in all patients with bone transplant (n = 30). Postoperative dislocation occurred in six patients and required closed reduction in four cases. Open reduction was performed in two patients, whereby the external rotation angle of the prosthetic neck was corrected without dismantling the distally anchored prosthetic stem components. The mechanical failure rate over the follow-up period of 9 years was one out of the 48 prospectively investigated prostheses. Rate of survival according to Kaplan-Meier was 97%.