Objective

Carpal tunnel release surgery is a commonly performed procedure for alleviating symptoms of median nerve compression and restoring hand function. With pressure on theatre time these procedures are now commonly performed in a step-down out-patient facility under local anaesthetic. The choice of suture for skin closure in this procedure can impact the quality of wound healing, patient outcomes and the follow-up required however the question of the best type of suture remains unanswered. The purpose of this study was to compare the outcomes of absorbable and non-absorbable sutures using a randomised control trial design.

Proximal tibial bone mineral density (BMD) has been shown to decrease following Total Knee Arthroplasty (TKA) by both dual-energy x-ray absorbtiometry (DEXA) and quantitative computed tomography (qCT)-assisted osteodensitometry. Little is known about changes in BMD following unicompartmental knee arthroplasty (UKA). Additionally, there are proposed differences in stress transmission between cemented metal and polyethylene (PE) components. We proposed two hypotheses. First, that proximal tibial BMD decreases following UKA. Second, that BMD loss would be greater below metal tibial components.

We performed a prospective clinical trial of 50 consecutive UKAs in 49 patients performed by two surgeons at one institution. There were 25 mobile bearing Oxford and 25 fixed bearing Accuris arthroplasties, all were medial. BMD was assessed with qCT-assisted osteodensitometry scans prior to discharge and then at 1 and 2 years post surgery. Each CT slice was divided into medial and lateral halves and cortical and cancellous bone was analysed separately. The six 2mm slices immediately beneath the tibial implant were analysed using previously validated software to create a three-dimensional assessment of BMD. The lateral half was used as a control.

There were a total of 30 females (60%), with an average age of 70 (49–84). One patient was lost to follow-up and another was unable to be analysed due to failure requiring revision before follow-up was complete. Preliminary results showed no significant change in BMD at either 1 or 2 years follow-up. There was no difference in BMD change between the mobile and fixed bearing prostheses, between the medial and lateral halves nor between cortical and cancellous bone. Final results will be presented at the AONZOA conference.

This trial shows that UKA does not result in significant change to BMD at 2 years. The preservation of BMD may indicate that UKA is better at maintaining physiologic stress transfer than a TKA, which has been shown to be associated with a reduction in BMD.

Since September 1964, neonates born in New Plymouth have undergone clinical examination for Neonatal Instability of the Hip (NIH) in a structured clinical screening programme. Forty one thousand, five hundred and sixty three babies were born during the period of this study, of which 1,638 were diagnosed as having unstable hips. Six hundred and thirty three with persisting instability were splinted (1.6%), with five hips failing splintage. In addition, three unsplinted hips progressed to CDH, and there were four late-presenting (walking) cases of CDH, giving an overall failure rate for the programme of 0.29 per 1000 live births, with a late-presenting (walking) CDH incidence of 0.1 per 1000 live births. This study confirms that clinical screening for NIH by experienced orthopaedic examiners significantly lowers the incidence of late-presenting (walking) CDH.

Since September 1964, neonates born in New Plymouth have undergone clinical examination for instability of the hip in a structured clinical screening programme. Of the 41 563 babies born during this period, 1639 were diagnosed as having unstable hips and 663 (1.6%) with persisting instability were splinted, five of which failed. Also, three unsplinted hips progressed to congenital dislocation, and there were four late-presenting (walking) cases, giving an overall failure rate of 0.29 per 1000 live births, with an incidence of late-walking congenital dislocation of the hip of 0.1 per 1000 live births.

This study confirms that clinical screening for neonatal instability of the hip by experienced orthopaedic examiners significantly reduces the incidence of late-presenting (walking) congenital dislocation of the hip.

The aim was to determine the longterm results of the Oxford unicompartmental knee replacement implanted by a single surgeon in a community hospital setting.

The results of the first 97 cases performed by a single surgeon between Feb 1991 Feb 1999 were retrospectively reviewed. Demographic and operative data were recorded and patients were assessed with Knee Society knee score and x-ray.

Ninety seven operations were performed on 83 patients. Antero-medial osteoarthritis was the predominant preoperative diagnosis present in 96, gout was present in 2 and avascular necrosis in one. The average age was 70, follow-up 104.3 months with maximum 170 months. Kaplan-Meier analysis was performed and survival was 88% at 124 months. 20 patients (21 knees) had died and 10 (9 patients) had required revision leaving 65 knees available for review. No cases were lost to follow-up. Of the 10 revisions 7 had been revised to a total knee, 4 for lateral wear or pain, one for femoral loosening, 1 for tibial subsidence and 1 for infection. Four of these patients had a previous high tibial osteotomy. The remaining 3 revisions included 2 1iner exchanges for fracture and wear in one patient with varus knees at 11 years and 1 liner exchange for dislocation.

The Oxford UKA gives satisfactory longterm results in antero-medial osteoarthritis. We would caution against using this prosthesis where a previous high tibial osteotomy has been performed.

In 2002, one hundred and thirty nine patients had their names removed from the orthopaedic surgical waiting list at Taranaki Base Hospital for financial reasons. They fell below the “financially sustainable threshold” for access to publicly funded services. We wished to determine the status of these patients and the effects of this management decision.

All patients were invited to attend clinic for assessment. They completed the SF-36 Health Survey and were interviewed regarding effects of not having surgery. In addition, hips were assessed using Harris Hip Scores and knees were assessed using Knee Society Scores.

These standardised methods of assessment allowed comparisons to be made with overseas data. Our group of patients are experiencing significant impairment as a result of not being able to have surgery. A number of resulting medical and social problems were identified in the course of assessment. Patients also expressed a high level of discontent with the process.

Removing patients who have been assessed and placed on an orthopaedic surgical waiting list is an inefficient means of utilising health resources. It has also been met with a high level of patient dissatisfaction.

Urinary tract infection is a source of organisms responsible for deep infection of hip and knee joint prostheses. In an attempt to reduce the occurrence of post operative urinary sepsis, some orthopaedic surgeons insert indwelling urethral catheters (IDC) immediately prior to surgery with the aim of avoiding urine retention. The purpose of this study was to determine if preoperative indwelling urethral catheterisation reduces the incidence of urine retention following total hip and total knee arthroplasty.

124 patients who underwent total hip and total knee arthroplasty in New Plymouth between April 2001 and July 2002, were randomly allocated to either have an indwelling urethral catheter inserted preoperatively (IDC group), or no catheter (control group). Prior to surgery all patients completed a questionnaire enquiring about a history of urinary obstructive symptoms, or previous urinary tract infection. The two groups were compared with regard to demographic data, questionnaire findings and the amount of post operative opiate usage. The primary outcome measure for the study was post operative urine retention. Urinary tract infection post operatively was considered as a secondary outcome measure.

No difference was noted between the two groups with regard to age sex arthroplasty type, history of urinary obstruction, or previous urinary tract infection. Post operative urinary retention occurred in a significantly less number of patients in the IDC group compared with the control group. No difference in post operative urinary tract infection was noted between the groups with the sample size used in this study.

Our study suggests that the prophylactic use of indwelling urethral catheters prior to total hip and total knee arthroplasty is effective in reducing the occurrence of post operative urine retention.

This is a retrospective study on the Taranaki experience with the Harris-Galante uncemented total hip joint replacement.

Ninety-six Harris-Galante total hip joint replacements were performed in ninety patients between September 1986 and September 1989. Twenty-nine patients died during the study and thirteen patients left the Taranaki area and were lost to follow-up. This left forty-eight patients (fifty hips) for evaluation with an average follow-up of fourteen years (range, thirteen to sixteen years). Results were analysed by questionnaire, clinical examination and x-rays.

Four hips were revised giving a Kaplan-Meier survivorship analysis of 89% at 14 years. Two femoral component was revised due to aseptic loosening at six and eleven years and two acetabular components were revised at 10 and 11 years due to liner dissociation.

The average Harris Hip score improved from 47 points preoperatively to 90 points at six years follow-up then declined to 83 at 14 years follow-up.

Osteolytic lesions were identified adjacent to 17% of acetabular components at follow-up and all were confined to zone two. Eighty-nine percent of femoral radiographs showed evidence of stress shielding however there were no grade four changes.

Osteolytic lesions were identified adjacent to 17% of femoral components at follow-up and were predominantly seen distally in zones three, four and five.

This study demonstrates satisfactory results for the Harris-Galante 1 total hip joint replacement at fourteen years follow-up. Cases should be kept under annual review to assess for progressive osteolysis, liner dissociation and the need for revision surgery.

Unicompartmental knee arthroplasty has been a popular treatment option for osteoarthritis, since popularised by Marmor in the early 1970’s. The Miller-Galante prosthesis has been in widespread use in Taranaki since 1992. The initial results were encouraging, however, recently a number of failures have caused us to review our results.

The indications for the procedure were osteonecrosis or osteoarthritis limited to one tibiofemoral compartment of the knee. 145 patients were available for assessment from January 1992 – December 2001. Patients were retrospectively reviewed with a clinical assessment, questionnaire and radiographic examination. The Knee Society Scoring System was used. There were 175 knees available for review.

There was 100% follow-up. The average age of patient was 69 years. The average follow-up time was 6 years. The10 year survival was 94%. The major cause for failure was polyethylene wear (4.5). There was no statistical difference between age, tibial insert size and different surgeons.

The unicompartmental Miller-Galante knee prosthesis has very good results at 10 years. However, a high percentage of polyethylene wear is a concern and requires further investigation into the possible causes for this.

The Harris-Galante II acetabular prosthesis was used in Taranaki from 1992 until 1999. An increasing number of failures were noted due to liner dissociation. This lead us to retrospectively review the 237 patients with the Harris-Galante II acetabular prosthesis inserted for primary arthroplasty to assess true failure rates and mechanism of failure.

All of the cases were followed up with clinic interview, home interview, phone interview or review of notes. Harris hip scores were performed and radiographs were taken.

Forty-eight failures were found of which 66% were due to liner dissociation. The Kaplan-Meier 10 year estimate of implant survival was 72.9% ± 7.8%.

Several methods of revision were performed. Forty per cent of cases managed with polyethylene liner exchange alone required further revision for liner dissociation.

The poor survival of the Harris-Galante II cup appeared primarily due to failure of the capture mechanism of the cup. Dislocation and small shell size were both found to be significant independent factors which contributed to the incidence of failure.