Thirteen year follow-up of a cementless femoral stem and a threaded acetabular cup in patients younger than fifty years of age.

PURPOSE: Compared to older patients undergoing total hip arthroplasty (THA) younger patients are considered to be more active, thereby exposing the implant to significantly higher loads over a much longer period of time. Additionally, cases of secondary osteoarthritis caused by hip dysplasia, femoral head necrosis or rheumatic diseases are much more frequent than among the average patient population. Therefore, durable implant fixation and low wear rates are extremely important to achieve good long-term implant survival in this group of patients. OBJECTIVE: The aim of this retrospective study was to evaluate the mid- to long-term survival of a cementless femoral stem (Zweymüller® SL stem) and a threaded cup (Bicon SL®) in patients younger than 50 years of age. METHODS: Therefore, a consecutive series of 100 patients (111 hips) aged 50 years or younger (range: 30 to 50 years) was analysed at a mean follow up of 13.5 years. Follow-up assessment included physical examination and radiographic workup. Hip disability osteoarthritis and outcome score (HOOS) and Harris hip score (HHS) were used to evaluate the pre- and post-operative functional outcome, respectively. Patient satisfaction with the surgical result was assessed by standardized questionnaires. RESULTS: The overall survival rate with any revision as endpoint was 96.8 % (95 % CI: 90.5 % to 98.9 %) at ten years. Gender, operation time and the occurence of osteolyses had no influence on joint function or patient satisfaction. We recorded an overall failure rate of 7.4 % (six cases). In four cases (5 %) the prosthesis had to be revised due to aseptic loosening of the cup after 12 years, eight years, 12 years and 11 years, in one case (1.2 %) recurrent luxation led to a revision operation (acetabular cup and head) after three years of primary implantation. In one case an implant failure was recorded (acetabular cup breakage after eight years of implantation). We recorded the occurence of asymptomatic radiolucent lines of the cup in 21 % and of the stem in 35 % in our series. The HOOS was influenced by the presence or abscence of radiolucent lines of the stem. Patients with radiolucent lines of the stem had a median HOOS score of (74 points) compared to those without radiolucent lines (89 points). Other factors, such as "diagnosis led to operation" and "previous operations" had no influence on the HHS and HOOS. CONCLUSION: Our study demonstrates excellent long-term survival of cementless femoral stem in combination with a threaded cup in young patients undergoing total hip arthroplasty.

Acetabular defect reconstruction in revision hip arthroplasty with a modular revision system and biological defect augmentation.

PURPOSE: Revision of failed total hip arthroplasty with severe acetabular bone loss represents a rare but challenging problem. Anatomic reconstruction with biological defect augmentation as solid bone transplants or cancellous bone restores bone stock while providing good component stability. The objective of this study was to present short- to mid-term results of revision total hip arthroplasty with a modular ring system in a consecutive series of patients with severe acetabular bone loss. METHODS: We retrospectively reviewed 39 consecutive patients (39 hips) with severe acetabular bone loss (Paprosky type 3 A and 3 B) reconstructed with revision total hip arthroplasty using the cementless modular ring system MRS-Titan®. The MRS-Titan® consists of independent ring systems that are adapted modularly to the defect situation. Combined with acetabular defect reconstruction by using cancellous bone in impaction grafting technique, the MRS-Titan® system offers a cement-free revision system that enables defect-adapted customization to individual anatomic matters, bridging of the acetabular bone defect and reconstruction of the centre of rotation. Initial stability of the implant was obtained by screw fixation. Harris hip score and sequential radiographs were used to evaluate clinical and radiographic results. RESULTS: At an average follow up of 31 months (range 12-69 months) 33 of 39 (84.6 %) of the implants were considered radiographically stable without signs of acetabular migration of more than 2 mm in the horizontal or vertical direction, implant rotation or screw breakage. Complications included six implant failures (15 %). We recorded one aseptic loosening of the MRS prosthesis after 20 months. Five patients (12.8 %) had to undergo revision surgery because of periprosthetic joint infection. Two patients had a dislocation postoperatively. The mean Harris hip score improved from 27 ± 14 points preoperatively to 76 ± 15 points at the time of last follow up. CONCLUSION: By achieving stable implant fixation and providing potential for biological fixation, treatment of severe acetabular bone loss in revision total hip arthroplasty with the modular ring system MRS-Titan provides a durable solution with good clinical and radiographic results and allows us to accomplish major goals of reconstruction.

Evidence of MRSE on a gentamicin and vancomycin impregnated polymethyl-methacrylate (PMMA) bone cement spacer after two-stage exchange arthroplasty due to periprosthetic joint infection of the knee.

BACKGROUND: Periprosthetic joint infections (PJI) are often treated by two stage exchange with the use of an antibiotic impregnated spacer. Most of the two-stage exchange algorithms recommend the implantation of an antibiotic-impregnated spacer during the first stage for a period of 2-24 weeks before reimplantation of the new prosthesis. For the spacer to have a therapeutic effect, the local antibiotic concentration must be greater than the minimal inhibition concentration (MIC) against the pathogens causing the PJI. It must remain so for the entire spacer period, otherwise recurrence of infection or resistances might occur. The question as to whether a sufficient concentration of antibiotics in vivo is reached for the entire spacer period has not been answered satisfactorily. CASE PRESENTATION: We here present a case of a histologically confirmed chronic PJI 20 month after primary arthroplasty. The primary knee arthroplasty was performed due to osteoarthritis of the joint. Initial assessment did not detect a causative pathogen, and two stage exchange with a vancomycin-gentamycin impregnated spacer was performed. At the time of reimplantation, sonication of the explanted spacer revealed a multi-resistant strain of staphylococcus epidermidis on the device and in the joint. Adaption of the therapy and prolonged treatment successfully eradicated the infection. CONCLUSION: According to the authors' knowledge, the case presented here confirms for the first time the surface contamination (proven through sonication) of a vancomycin-/gentamicin- impregnated Vancogenx®-spacer with a MRSE after ten weeks of implantation.This case study demonstrates the difficulties still associated with the diagnostics of PJI and the published different two stage treatment regimes with the use of antibiotic impregnated spacers.

Multiple Myeloma - Current Standards in Surgical Treatment. / Multiples Myelom ­ aktuelle Standards der operativen Therapie.

BACKGROUND: Multiple myeloma is a haematological blood cancer in elderly patients, in which neoplastic cell populations cause osteolytic destruction in the bone skeleton. More than 50% of all patients sustain pathological fractures during the course of their disease. Of all malignant lesions of the spine, multiple myeloma is the most frequent spinal tumour and accounts for approximately 15% of all cases. 8 - 10% of the patients develop neurological deficits. In addition to systemic antineoplastic therapy, surgical treatment is often required in order to reconstruct and stabilise bone defects associated with multiple myeloma, as well as to address tumour-related complications. METHODS: A comprehensive literature search was performed in PubMed using the keywords "multiple myeloma" and "surgery" or "fracture". This served to evaluate the available primary and secondary literature on the current status of the surgical therapy of multiple myeloma. Systematic reviews, meta-analyses and clinical studies and international recommendations for therapy were included - from 1975 until the spring of 2018. DISCUSSION: Stabilising surgery is essential in order to retain and restore function and mobility in bone sections affected by myeloma and for tumour-related osseous defects due to pathological fracture or instability. Absolute and relative indications for surgical treatment are distinguished and are based on the extent and localisation of bone lesions, manifest fractures, accompanying side effects and complications such as neurological deficits and bone pain that is intractable to conservative treatment. The range of options in surgical treatment of myeloma-related bone damage within the upper and lower extremities ranges from hybrid stabilisation procedures combining bone cement and various implants, to conventional and modular tumour prostheses systems. In spinal surgery, minimally invasive procedures such as kyphoplasty or vertebroplasty, as well as selective decompressive operations, dorsal spinal fusion and vertebral replacement are performed in cases of osseous defects and related fractures or instabilities. The surgical treatment and time of operation is determined by the general individual risk profile and prognosis of the patient with multiple myeloma. The surgical approach should have the objective of a final and load stable solution for the patient, which takes into account the frequent long-term course of the disease. Radiotherapy is often recommended after surgery. CONCLUSION: In therapy of multiple myeloma, surgical treatment is often required in order to reduce distress and retain the function and flexibility of myeloma affected bone sections and the mobility and quality of life of the cancer patient. The range of surgical strategies is complex and demanding.