Peter Diel

SWISSspine—a nationwide health technology assessment registry for balloon kyphoplasty: methodology and first results

BACKGROUND CONTEXT The Swiss Federal Office of Public Health demanded a nationwide health technology assessment registry for cervical and lumbar total disc arthroplasty and for balloon kyphoplasty (BKP) to make a decision about reimbursement of these interventions. PURPOSE The goal of the SWISSspine registry is to generate evidence about the safety and effectiveness of these technologies. We report on results of patients with balloon kyphoplasty. STUDY DESIGN/SETTING Prospective, multicenter, observational case series. PATIENT SAMPLE From March 2005 until June 2008, 331 interventions with 391 treated levels in 320 patients have been documented. 75.6% of patients were females with mean age of 74 years (range 43-95.2 years); mean age of males was 72.6 years (range 41.4-93 years). OUTCOME MEASURES Surgeon-administered outcome instruments were primary intervention form for BKP, implant, and follow-up form; patient self-reported measures were Euroqol-5D, North American Spine Society, and a comorbidity questionnaire. METHODS Data were recorded perioperative, at 3 months, 1 year, and annually thereafter. Wilcoxon signed-rank test was used for comparison of preoperative to postoperative measurements. Multivariate regression was used for identifying factors with a significant influence on the outcome. RESULTS Significant and clinically relevant reduction of back pain, improvement of quality of life (QoL), and reduction of pain killer consumption were seen in the 1-year follow-up. Improvement of preoperative segmental kyphosis was achieved in the majority of cases. There were three symptomatic cement extrusions with radiculopathy documented. CONCLUSIONS Balloon kyphoplasty is a safe and effective treatment concerning pain reduction, QoL improvement, and pain killer consumption. The SWISSspine registry proved to be an excellent tool for evaluation of this new technology, and its results, in combination with an elaborate health technology assessment report, led to a permanent coverage of BKP by the basic health insurance.

Safety and efficacy of vertebroplasty: early results of a prospective one-year case series of osteoporosis patients in an academic high-volume center.

Background: Vertebroplasty (VP) is a cost-efficient alternative to kyphoplasty. However, it is considered inferior when it comes to maintaining safety and in vertebral body (VB) height restoration. We assess the safety and efficacy of VP in alleviating pain, improving quality of life (QoL), and restoring alignment. Materials and Methods: In a prospective monocenter case series, from April 2007 until July 2008, 1,422 vertebroplasties were performed, during 307 interventions, in 279 patients with traumatic, lytic, and osteoporotic fractures with 28 repeat interventions, for new fractures after the primary surgery, in 28 patients. The 226 interventions (n=203 patients) done for osteoporotic fractures were analyzed for demographics, treatment and radiographic details, pain alleviation, QoL improvement [NASS and Euroqol (EQ-5D)] and complications. Results: Osteoporotic patient sample consisted of 77.8% (n=158) females with a median age of 78 years and 45 males who had the same median age. Around 69% of these patients were ASA (American Society of Anesthesiologists) grade 3 and above. On an average there were 1.8 VBs fractured and five VBs treated,whereas the most frequently performed cementations were in six (35.6%, n=80) or five (19.6%, n=44) levels. About 36.5%, (n=414) of the interventions were localized at the thoraco–lumbar junction (Th12–L2). On applying the Genant classification, there was a slight height reduction in 13.1% (n=29), a medium loss in 34.3% (n=78), and a severe loss of height in 52.6% (n=119). The pre-operative pain was assessed by the visual analog scale (VAS) and decreased from 56.7 to 41.4 pts after two months. Accordingly, the QoL on the EQ-5D measure (0.6 to 1) improved from 0.32 pts before surgery to 0.58 pts after two months. The pre-operative Beck index (anterior height/posterior height) improved from a mean of 0.66 preoperative to 0.80 post-operative and remained stable at two months post-operatively. There were cement leakages in 33% of the fractured VBs and in 0.8% of the prophylactically cemented VBs; there were symptoms in 7.1%, and most of them were temporary hypotension and one pulmonary cement embolism that remained asymptomatic. Conclusion: If routinely used, VP is a safe and efficient treatment option for osteoporotic vertebral fractures with regard to pain relief and improvement of the QoL. Even segmental re-alignment can be achieved to a certain extent with proper patient positioning.

The influence of tibial morphology on the design of an anatomical tibial baseplate for TKA

BACKGROUND Finding the right balance between tibial coverage and minimal implant overhang is an important factor in TKA. Another significant cause of failure is component malrotation. METHODS An average master shape of the proximal tibia at TKA resection level was calculated using fine slice computed tomographies of 117 cadaveric knees. To find out whether alternate implant contours would be necessary depending on the patients body size, we established five subgroups to compare. CAD-Analysis was performed to simulate the overhang produced after ±4°/±7°/±10° rotation. RESULTS A master shape for the tibial resection cut (with a 5° posterior slope, 7 mm under lateral joint line) could be determined. Neither left vs. right knee joint, nor male vs. female nor the size subdivision appears to alter the calculated master shape significantly. The optimized shape allowing for ±4° of rotational freedom was found to be the best variant. CONCLUSIONS Valid methods have been obtained to design a two-dimensional average shape of the tibial plateau. The modifications described in this study might come in useful, when designing future implant designs. CLINICAL RELEVANCE An optimized fit at the tibial plateau and lower rates of component malrotation may result in better outcomes after TKA.

The International Documentation and Evaluation System IDES: a single center observational case series for development of an ankle prosthesis documentation questionnaire and study of its feasibility and face validity.

BackgroundThe number of implanted total ankle replacements is increasing and most articles present short- and mid-term results. Comparison of outcomes is difficult because of inconsistent terminology and different use of parameters.Materials and methodsWe created a module for total ankle prostheses in the framework of the International Documentation and Evaluation System (IDES). Content development was conducted with an iterative process based on a single surgeon series of 74 HINTEGRA© total ankle replacements and expert opinions.ResultsThe IDES ankle module comprises three forms A, B and C for recording of primary (A), revision (B) and followup (C) procedures. 74 primary interventions, 28 revisions and 92 followups could be documented in detail with the final version of the questionnaires.ConclusionThe IDES-forms facilitate a structured and standardized data collection for total ankle arthroplasties. Implemented on the academic MEMdoc portal http://www.memdoc.org of the University of Bern, all registered users can make use of IDES in its online or paper based versions.