Mid-term outcomes of a stemless ceramic head anatomic total shoulder replacement

Background In an anatomic shoulder replacement (aTSR) good results have been reported with the use of a stemless humeral prosthesis. In vitro a ceramic articulation with polyethylene has been shown to produce less polyethylene wear particles than with metal. This study aims to evaluate clinical and radiographic results of a stemless aTSR with a ceramic head articulating with a polyethylene glenoid component, with mid-term follow-up. Methods All patients (n = 92) in this prospective study had an aTSR utilizing a stemless humeral component with a ceramic head and a cemented double pegged cemented polyethylene glenoid component for glenohumeral osteoarthritis. Pre- and postoperative clinical evaluations at 2 years were performed using the ASES score, Constant score, SPADI score, DASH score, VAS pain score, patient satisfaction and range of motion. There was a 5-year evaluation of SPADI, ASES, pain, and satisfaction, plus radiographic assessment of glenoid component radiolucent lines and humeral osteolysis. Results Seventy-four cases (68.1 ± 7.1 years) had a five-year follow-up and demonstrated active elevation improvement from 91.3° preoperatively to 151.1° (p < 0.001). Further improvement was identified with the ASES from 41.6 to 94.3, the SPADI from 62.9 to 4.3, VAS pain from 5.6 to 0.4 (0–10), and satisfaction levels were at 96%. Sixty-two cases had no glenoid radiolucent lines with a maximum Lazarus score of 2 in one patient. Constant scores, available up to 2 years, improved significantly from 30.3 to 77.9 (p < 0.001). There was one case that required revision for glenoid loosening. Conclusions Overall, the 5-year results of this ceramic head prosthesis demonstrated good radiographic and clinical outcomes. Trial registration ACTRN12613001183774. Registered: 29 October 2013 - Retrospectively registered. Australian New Zealand Clinical Trials Registry (ANZCTR).

Zurich Cementless Dual Mobility Cup for Canine Total Hip Prosthesis: Implant Characteristics and Surgical Outcome in 105 Cases

Dislocation after total hip arthroplasty (THA) remains a troublesome complication, and a source of frustration for the owner and the surgeon. The dislocation rate of hip prostheses in dogs is reported to range from 4 to 15%, representing the most common short-term complication. This is especially true in large and giant breed dogs, usually requiring revision surgery. With the increase in the number of THA being performed in veterinary surgery, reducing or preventing complications such as postoperative THA dislocation will be of paramount importance. The Zurich cementless dual mobility (DM) system allows impingement-free range of angulation of 80 to 132 degrees between the ceramic head and the polyether ether ketone (PEEK) cup when combined with the range of the PEEK cup in the outer metal cup. In this article, we review the use of the DM cup in THA in large and giant breed dogs, in terms of its history, biomechanics, outcomes and complications based on 105 cases.

The Wear Rate and Survivorship in Total Hip Arthroplasty using a Third- Generation Ceramic Head on a Conventional Polyethylene liner: A Minimum of 15-year Follow-up

Background: Recently, the use of ceramic-on-polyethylene (CoP) bearing surfaces has increased in the United States with the development of material properties. However, it remains controversial which bearing couples are effective. The purpose of this study was to evaluate the wear and survival rates of third-generation ceramic heads on a conventional polyethylene liner. Methods: We retrospectively reviewed 160 hips (147 patients with a mean age of 56 years) who underwent total hip arthroplasty using the third-generation ceramic head on a conventional polyethylene liner from March 1998 to August 2003. The wear rate was evaluated using the PolyWare program Version 8 (Draftware Developers Inc., IN, USA) in 32 hips followed-up for at least 15 years. In addition, we evaluated the Kaplan-Meier survivorship.Results: Linear wear and volumetric wear rates were 0.102±0.57 mm/year and 30.2±27.5 mm3/year, respectively. Fourteen reoperations due to all causes and 10 revisions were performed during the follow-up period. The 15-year survival rate was 84.1% for any surgery as the endpoint and 87.6% for the revision surgery as the endpoint. Most of the causes of revision were cup loosening, and no ceramic head fracture occurred.Conclusions: The CoP bearing surface maintains the advantages of the soft polyethylene surface and has good resistance to wear. Therefore, alumina ceramic on newer polyethylene could certainly be a good alternative bearing couple without any concern for ceramic fractures, especially in younger patients.Level of evidence: Level III, retrospective cohort design

Metal Ion Release after Hip and Knee Arthroplasty – Causes, Biological Effects and Diagnostics

All metal implants in human bodies corrode which results in metal ions release. This is not necessarily a problem and represents for most patients no hazard. However, if a critical metal ion concentration is exceeded, local or rarely systemic problems can occur. This article summarizes the mechanisms of metal ion release and its clinical consequences. Several situations can result in increased metal ion release: metal-on-metal hip arthroplasties with increased wear, increased micromotion at taper interfaces, direct metal-metal contact (polyethylene wear, impingement), erroneously used metal heads after ceramic head fracture. Possible problems are in most cases located close to the concerned joint. Furthermore, there are reports about toxic damage to several organs. Most of these reports refer to erroneously used metal heads in revisions after a broken ceramic head. There is currently no evidence of carcinogenic or teratogenic effects of implants but data is not sufficient to exclude possible effects. Cobalt and chromium blood levels (favorably in whole blood) should be measured in patients with suspected elevated metal ions. According to current knowledge levels below 2 µg/l seem to be uncritical, levels between 2 and 7 µg/l are considered borderline with unknown biological consequences and levels above 7 µg/l indicate a local problem which should be further diagnosed. Metal ion levels always need to be interpreted together with clinical symptoms and imaging results.