The use of metal on polyethylene articulations was a key development in establishing total hip arthroplasty as a successful and reproducible treatment for end stage osteoarthritis. In order to ensure implant durability in relatively younger populations, there is a need for alternative, wear resistant bearing surfaces. Oxidized Zirconium (Oxinium, Smith &
Nephew, Inc., Memphis, TN) is a relatively new material that features an oxidized ceramic surface chemically bonded to a tough metallic substrate. This material has demonstrated the reduced polyethylene wear characteristics of a ceramic, without the increased risk of implant fracture. The purpose of the current investigation was to assess early clinical outcomes following primary total hip arthroplasty with Oxinium versus Cobalt Chrome femoral heads. One-hundred primary THA procedures were prospectively performed in 100 patients. There were 52 males and 48 females. Using a process of sealed envelope randomization, patients were divided into 2 groups. Group 1 consisted of fifty patients, each receiving primary THA implants with an Oxinium femoral head (OX). The mean age of each patient was 51 years (SD 10.8, Range 22–74) with 26 males and 24 females. Group 2 also consisted of 50 patients. Within this group again each patient received primary THA implants however with a cobalt-chrome femoral head (CC). Demographics were similar with mean age 51 years (SD 11.0, Range 19–76) and again 26 males and 24 females. The current study reports clinical outcome measures for both the OX and CC groups at a minimum follow-up of 2 years postoperatively. At the time of latest follow-up, stem survival for both groups was 98%. There was a significant improvement in all clinical outcome scores between preoperative and 2 year postoperative time periods for both bearing groups (p<
0.003). There were no significant differences between bearing groups for any of the clinical outcome scores at final follow-up (p>
0.159). Mean Harris Hip Scores at 2 years postoperatively were 92 and 92.5 for OX and CC, respectively (range; 65–100 OX, 60–100 CC). For SF-12, both the Physical Component Summary Scale (PCS) and the Mental Component Summary Scale (MCS) are reported. Mean PCS scores at final follow-up were 45.2 and 49.21 for OX and CC (range; 27.1–56.7 OX, 26.3–61.8 CC). Mean MCS scores were 53.8 and 52.57 for OX and CC (range; 39.2–65.5 OX, 34.3–64 CC). Mean final WOMAC scores are reported as 84.9 and 87 for OX and CC, respectively. The current data suggest that total hip arthroplasty utilizing Oxinium femoral heads is safe and effective. Additional follow-up of the current cohort will be performed in order to fully assess mid- to long-term clinical outcomes.
Total hip replacement in the young active patient remains one of the major challenges in orthopaedics today. The use of ultra high molecular weight (UHMW) polyethylene acetabular liners is known to cause polyethylene wear related osteolysis, the major limiting factor in its use in the younger active patient. Modern alumina ceramic articulations have been developed in order to reduce wear and avoid polyethylene debris. This prospective randomized long-term study aims to compare the outcome between an alumina ceramic-on-ceramic (CC) articulation with a ceramic on UHMW polyethylene articulation (CP). In the younger active patient, is one option superior to the other with regard to patient satisfaction, osteolysis and implant longevity? 56 hips in 55 patients with mean age 42.2 (range 19–56) each received uncemented components (Wright Medical) and a 28mm alumina head with acetabular liner selected via sealed envelope randomization following anesthetic induction. Subsequent regular clinical and radiologic follow up measured patient outcome scores and noted any radiological changes. 26 CP hips and 30 CC hips were evaluated. One failure required revision in each group. Mean St Michael’s outcome score for each group with up to 10 years follow-up (median 8 years, range 1–10) was 22.8 and 22.9 respectively (p=0.057). Radiographs with a minimum 5 years post-operative follow-up were analyzed in 42 hips (23 CC and 19 CP). Radiolucency of all 3 acetabular zones was identified in one of the CP hips. There was no evidence of osteolysis or loosening identified in the remaining hips. The mean time of wear measurement for the CC group was 8.3 years (SD 1.3, Range 4.8–10.1 years) and for the CP group was 8.1 years (SD 0.9, Range 6.1–9.2 years)(p=0.471). Wear was identified in all but one of the CP replacements but only 12 of 23 CC articulations. The mean wear for the CC group was 0.14 mm (SD 0.16, Range 0–0.48 mm) and for the CP group was 0.89 mm (SD 0.6, Range 0–2.43 mm)(p<
0.001). Extrapolating the annual wear rate from these figures, the respective wear is 0.02mm for the CC group compared to 0.11mm per year for the CP group. To our knowledge this is the first long term randomized trial comparing in vivo ceramic-on-ceramic with ceramic-on-conventional polyethylene hip articulations. Other than significantly greater wear in the polyethylene group there was no significant difference in long-term outcome scores between the two groups with up to 10 years of follow-up. The use of a ceramic-on-ceramic bearing is a safe and durable option in the young patient avoiding the concerns of active metal ions and osteolytic polyethylene debris. These patients remain under review.
Cognitive dysfunction has been well documented following total knee replacement. Possible causes that have been postulated include cerebral emboli, post-operative complications and pain. The aim of this study is to compare cognitive decline in patients undergoing conventional total knee replacement (TKR), navigated total knee replacement and total hip replacement (THR). We prospectively analysed 75 patients undergoing lower limb arthroplasty. Group 1 consisted of 25 conventional TKR’s, group 2 consisted of 25 navigated TKR’s and group 3 consisted of 25 THR’s. Cognitive function was assessed by 11 validated neuropsychological tests preoperatively, at 1 week post-operatively and at 6 months post-operatively. Testing was carried out by a clinical psychologist. At day 6 post-operatively 55% of group 1, 83% of group 2 and 61% of group 3 patients had a significant cognitive decline. Group 2 had a significantly greater cognitive decline at day 6 compared to the other 2 groups. At 6 months significant cognitive decline was found in all 3 groups to 21%, 16% and 34% respectively. Group 2 demonstrated the greatest improvement in cognition from day 6 to 6 months post-operatively Significant cognitive decline occurs in two-thirds (66%) of all patients undergoing lower limb arthroplasty at day 6 and remains significant in a quarter (25%) of patients at 6 months. There was no significant difference in cognitive decline in patients undergoing hip and knee arthroplasty.
Private companies now offer risk assessment packages to Trusts. Data are collected using ICD coding and complication rates for individual surgeons are calculated and published. A risk assessment document was recently published at the Royal Gwent Hospital presenting complication rates and misadventures on league tables of specialty and consultants. Serious concerns were raised about the quality of the data. We undertook a study to independently evaluate the accuracy of data used to calculate these complication rates. Two Orthopaedic Surgeons with the highest published complication rates were studied. The notes of patients who had suffered complications were retrieved and the published complication data was compared with the clinical interpretation of the actual complication. One hundred and fifty reported complications were analyzed. In most cases data accuracy was woefully inadequate. For example revision procedures were counted as complications for the revision surgeon irrespective of who carried out the primary procedure. The normal work-up of these patients including procedures to investigate the presence of infection are recorded as complications with some patients being recorded as having up to four separate complications. Misadventures published for surgeons included dural tap during epidural anesthesia. The results of this study highlight the potentially devastating consequences of data inaccuracy. Inaccurate published data on complications, used to form league tables for individual surgeons, can be career- jeopardizing. We advocate that consultation with the clinicians involved should always occur before data are published so that these inaccuracies can be picked up and the potentially damming consequences of falsely high complication rates can be avoided.
To identify any shoulder joint pathology on MRI of young patients (<
35 yrs) with a single simple antero- inferior dislocation of the shoulder at minimum 5-year follow-up. Patients aged 16–35 years with a single antero-inferior shoulder dislocation with a minimum 5-year (range5–9 yrs) follow-up were identified. A history of recurrent dislocation or surgery excluded patients from study. Ethical approval was obtained and identified patients were asked to volunteer for clinical review and have an MRI scan. Shoulders were clinically examined, noting specifically any signs/symptoms of rotator cuff pathology or instability. All shoulders were imaged with a 1.5 Tesla open MRI scan to assess any pathology. In a 5-year period (1994–1998), 349 patients sustained an antero-inferior dislocation. 251 were in patients aged 35 years or less. 136 of these were excluded either due to recurrent dislocations. 62 patients were lost to follow-up of 53 eligible patients 7 could attend for study. Only one patient had a positive anterior apprehension sign but he did not have any symptoms of instability in his daily activities or sport. The only abnormality demonstrated on MRI was of a united greater tuberosity fracture in one shoulder. The glenolabral and bicipitolabral complexes were normal in all shoulders imaged. Bankart lesions, both bony and labral, are known to be associated with recurrent anterior shoulder dislocations.This study has shown no shoulder joint pathology on MRI at minimum 5-year follow-up in young patients who have sustained a single antero-inferior shoulder dislocation, confirming that labral pathology seems to be important in recurrent dislocations. Further study to image more patients is underway. These results indicate that acute imaging of dislocated shoulders may be useful to help predict young patients who are unlikely to re-dislocate and thus unlikely to require surgery.