With total hip replacement (THR), varus alignment of an uncemented stem will increase offset which can have significant detrimental effects on muscular balance, leg length and overall satisfaction. Thus, we used 3D planning software to determine the change in joint offset with increasing varus stem placement.Eight patients undergoing THR had routine computed tomography (CT) scans to allow for 3D hip planning. Each set of CTs was templated with a straight stem and an uncemented acetabular cup. Initial templating was performed to reproduce native leg length and offset. The templated stem was then rotated into varus at 1° intervals, up to 6° varus while offset changes for all varus positions were noted. This was repeated for each of 3 neck angles, 125°, 135° and 135° lateral and for each stem sizes 1, 3, 5 and 7.Overall, there was a mean 1.5 mm increase in offset for every 1° of varus. The stems with a 125° neck angle had the greatest increase in mean offset at 1.6 mm for every 1° of varus. The stem neck angles of 135° lateral offset and 135° standard offset, had a mean increase in offset of 1.5 mm and 1.4 mm respectively for every 1° of varus. A greater mean increase in offset for every 1° of varus was observed with increasing stem size.We have quantified the relationship between alignment and offset with every 1° of varus placement increasing hip offset for straight stems by 1.5 mm. This can be used as a guide for surgeons during THR so that they have a better quantitative understanding of how varus placement of the stem affects the hip offset.
Joint Registries are a valuable resource for defining the survivorship of prostheses and procedures undertaken for the treatment of joint disease. However, the use of this data as a basis for advocating specific implant designs is controversial because of the confounding effects of variations in patient selection, the training, skill and experience of surgeons, and the priorities of individual patients. Despite these challenges, the Australian Joint Registry has utilized its early survivorship data to identify specific designs that are expected to exhibit lower than average durability in the long term. The aim of this study was to assess the accuracy of this practice in identifying implants providing inferior long-term performance. Over the period 2004–8, the Australian Registry identified 48 prosthetic components used in primary THA, HRA, TKA or UKA which exhibited a statistically significant increase in the early revision rate. For each of these components, we compared the rate of revisions per 100 “component-years” when it was first identified by the Registry, to its ultimate fiveyear cumulative survival in 2008. These survival parameters were also compared to average values based on procedure (eg.THR) and fixation method (i.e. cemented, cementless, hybrid). Regression analysis was performed to determine the accuracy of initial relative revisions per 100 OCY as a predictive measure of eventual component revision rate. Five year survival data was available on 30 of the 48 implants identified by the registry. There was a strong correlation (R2=0.9614) between initial revisions per 100 component-years and the 5-yr survival of the identified designs. 29 of 30 designs (97%) exhibited lower than average survivorship at 5 years. Six designs (20%) had failure rates within 2% of average values, and 7 (23%) had a 5–year failure rate less than 50% above average values. Although, when identified by the Registry, 80% of identified components exceeded the average rate of revision by 100%, only 60% displayed more than twice the cumulative revision rate at 5 years post-op. These results demonstrate that early data collected by Joint Registries can form the basis of accurate identification of designs which ultimately prove to be clinically unsuccessful. Predictions made by the Australian Registry concerning inferior designs have an accuracy of approximately 80%. Further work is recommended to enhance the valuable potential of Registry data in predicting the outcome of both implants and procedures.
The Australian Safety and Efficacy Register of New Interventional Procedures-Surgical (ASERNIP-S) undertook to systematically review the literature regarding arthroscopic subacromial decompression (ASD) using a holmium:YAG laser for patients with impingement syndrome, with respect to the safety and efficacy of the procedure.Studies on ASD with a holmium:YAG laser were identified using MEDLINE (1984 to July 2000), EMBASE (1974 to August 2000) and Current Contents (1993 to week 33 2000). A number of search terms were used: (laser and shoulder) and (surgery or arthroscop* or acromioplasty or orthopaed* or orthoped* or subacromial decompression or impingement syndrome). The Cochrane Library was searched from 1966 to issue 3 2000, using the search terms 'shoulder and surgery'. Human studies were included for patients with impingement syndrome but without full-thickness rotator cuff tears or rheumatological disorders, and where shoulder pain had been experienced for more than 3 months. A surgeon and reviewer independently assessed the retrieved articles for their inclusion in the review.Seven papers were identified that related to ASD with a holmium:YAG laser. None of the papers for review offered high-quality evidence. There were no properly designed randomized controlled studies. The highest level of evidence came from time series studies. No quantitative analysis could be undertaken for this review.Given the extremely low level of evidence available for this procedure it was recommended that further research be conducted to establish the safety and efficacy of the technique. This reinforces the conclusion reached in the Cochrane review of interventions for shoulder pain where insufficient evidence was found to either support or refute the efficacy of other interventions for shoulder pain.
Abstract: Total hip arthroplasty (THA) is a successful surgical option for the management of end stage degenerative joint disease allowing. Registry data reveals that the international trend is toward THA in an ever-younger patient population but the long-term outcomes may not be as good in this age group, with a lifetime risk of revision of 35% in patients younger than 55. The mean age at surgery, according to registry data is 68 for males and 70 for females. Patients under the age of 55 are considered young while patients under 30 are considered very young. We present a literature-based discussion of the various THA options available and consider the relative merits of each with regards to longevity, revision rate and overall outcomes in the younger patient. Cost effectiveness is also considered. Metal-on-metal hip resurfacing continues to have a place, but the use of uncemented THA with a ceramic head matched to a highly-crosslinked polyethylene or ceramic liner is safe; and offers excellent results in the majority of cases.
220 consecutive hip resurfacing procedures were reviewed at a minimum of two years follow up to assess the incidence of heterotopic ossification and its effect on function and clinical outcome. We also reviewed the pre-operative diagnosis, gender and previous surgery. The overall percentage of heterotopic ossification was 58.63%. The incidence of Brooker 1 was 37.27%, Brooker 2 was 13.18% and Brooker 3 was 8.18%. Male osteoarthritics had the highest incidence of heterotopic bone formation. Three males underwent excision of heterotopic bone, two for pain and stiffness and one for decreased range of movement. Both antero-posterior and lateral radiographs were reviewed for evidence of heterotopic bone formation. 12.7% had no evidence of heterotopic bone formation on one view but clearly had on the second view. Overall we found no evidence that heterotopic bone formation affected the clinical or functional outcome of the hip resurfacing at a mean of 3 years follow up.
Introduction & aims Patient specific instrumentation (PSI) is a useful tool to execute pre-operatively planned surgical cuts and reduce the number of trays in surgery. Debate currently exists aroun...