Background

Revision total hip arthroplasty is a technically demanding procedure and especially removing a well fixed femoral stem is a challenge for revision surgeons. There are various types of trochanteric osteotomies used during revision surgery; extended trochanteric osteotomy (ETO) is being more popular.

Introduction: Between 1990 and 2000 we reconstructed 123 hips in 110 patients using impaction bone grafting with frozen, morsellised irradiated femoral heads and cemented sockets. This review presents the medium to long term survivorship of irradiated allograft in acetabular reconstruction in our cohort of patients.

Patients and Methods: Patients were reviewed in out-patients. Radiographs were examined for union, lucency and component migration.

The mean age at revision with allograft was 64.3 years (26 to 97). 86 hips (70%) in 74 patients were reviewed both clinically and radiologically.

At the time of review 28 patients (29 hips) had died and 5 patients (5 hips) were lost to follow up. Of those patients who had died 18 hips had been followed up to a mean of 66 months (12–145). A further 3 hips were unable to attend for clinical review but had accurate implant-allograft survivorship data.

Their data were included in survivorship analysis to the time of last clinical review.

Results: There have been 19 revisions; 9 for infection, 7 for aseptic loosening and 3 for dislocation. In surviving acetabular reconstructions, union of the graft had occurred in 64 out of 67 hips (95.5%). Radiolucent lines at the bone cement interface were seen in 12 hips (17.9%; 9 in a single DeLee zone and 3 in multiple zones) but none were considered loose. Migration of the acetabular component greater than 5mm was seen in 3 hips (4.5%). Survivorship analysis using revision as an end point for all indications at 10 years was 83.3% (95% C.I. 68 to 89%) and 71.3% (95% C.I. 58 to 84%) at 15 years

Conclusion: Acetabular reconstruction using irradiated allograft and a cemented cup is an effective reliable technique with good results in the medium to long term comparable to series using non irradiated freshly frozen bone.

Aim: A prospective study to quantify the functional outcome of the Aequalis Shoulder Arthroplasty in our local population.

Method: 110 Aequalis shoulder arthroplasties have been performed in 99 patients by a single surgeon in a district general hospital. Rheumatoid arthritis was the indication in 61 shoulders, Osteoarthritis in 26 and 23 for other indications. There were 78 females and 32 males.

Patients were assessed using the Constant-Murley (CM) Score, the corrected Constant-Murley (CM) Score and the American Shoulder and Elbow Society (ASES) function score pre and post-operatively. Pain was measured on a reverse Visual Analogue Scale (VAS) and a range of movement was clinically assessed. All these parameters including standard radiographs were regularly assessed during the follow up period.

Results: Mean length of follow up is 2.29 years (range 6 months to 8 years). 27/110 (24.55%) had a Glenoid replacement.

There have been steady and significant improvements in all parameters over the follow up period. Improvements have been sustained and continue to increase the longer the prosthesis has been in situ. The pain score is measured on a reverse analogue score, which accounts for the increasing scores. There have been 2 cases complicated by deep infection requiring revision and 2 cases of peri-prosthetic fracture.

Conclusion: The Aequalis shoulder prosthesis gives good, reliable results which are reproducable outside specialised centres.

The inhibition of neural input by infiltration of local anaesthetic around the operation site prior to the trauma of an operation may reduce subsequent pain post-operatively. Prevention of the normal phenomenon of central and peripheral sensitisation in the nervous system stops the post operative hypersensitivity state that manifests as a decrease in the pain threshold at the site of injury. The underlying clinical principle is for therapeutic intervention to be made in advance of the pain rather than as a reaction to it ¹. We performed a prospective double blind randomised clinical trial to measure the effect of pre operative infiltration of local anaesthetic around arthroscopy wounds compared to post-operative infiltration on post operative pain relief.

Thirty six patients undergoing day case unilateral knee arthroscopy between October 2000 and March 2001 were studied. All patients gave written informed consent. They were randomised into 2 groups using block randomisation to ensure equal group sizes. The sealed envelope technique was used. The pre-operative group had 10ml 0.25% bupivicaine infiltrated around the arthroscopy portal site following induction of general anaesthesia (G.A.), the post-operative group received 10ml 0.25% bupivicaine after the procedure but before reversal of the G.A. The injection technique and G.A. used were standardised. Pain was assessed using a 10cm Visual Analogue Score (VAS) at pre-operative, 1, 2 and 24h post-operative. At each assessment the patients were blinded to the previous scores that they had submitted. Oral analgesic use in the post-operative 24 hours was also recorded.

There were 18 patients in each group. Demographic details did not differ between the 2 groups. One patient in the post-operative group was excluded, as intravenous sedation was required in recovery due to an extreme anxiety state. The mean Visual Acuity Pain Scores (VAS) were lower in the post-operative group (1.3) compared to the pre-operative group (1.58) at pre-operative assessment. However this difference was not statistically significant (p =0.5607). At 1h post op the mean VAS in the post op group was 1.58 and in the pre op group 2.59 (p =0.18). The mean VAS at 2h post op in the pre op group was 1.76 compared to 1.82 in the post op group (p =0.9932).

At 24h the pre op group had a lower mean VAS (2.25) than the post op group (2.4). This difference was however not statistically significant (p =0.7418).

Analysis of the postoperative analgesia requirement in both groups failed to reveal a statistically significant difference (p =0.3965). In day case knee arthroscopy under general anaesthesia there is no beneficial role in the use of pre-emptive local anaesthetic infiltration around the arthroscopy portal sites as compared to post-operative infiltration.

The aim of this study was to investigate if the rotational axis of normal human shoulders moves during flexion in the sagittal plane.

Twenty four shoulders were measured in twelve normal volunteers, aged 25-42, height range 1.65-1.88 m and weight range 63–120 Kg. Each subject had surface markers placed on their iliac crests, mastoid processes and upper arms. Joint movement was video recorded as shoulders were actively flexed and extended in the sagittal plane. For each joint, a typical flexion sweep was selected and replayed into a computerised imaging system, where still frames were captured at 20 degree intervals from 20 to 120 degrees. These images were analysed to extract the co-ordinates of each marker. The coordinates were then processed to determine the Instant Centres of Rotation (ICR) for each angle of flexion. These ICR’s were then plotted to derive the Rotational Axis Pathway (RAP) for each shoulder joint.

The results indicate that throughout the flexion arc, the rotational axis is located in the region of the humeral head. At the start of the arc the rotational axis is in the anterio-superior part of the shoulder joint. As the shoulder flexes forward the rotational axis moves posteriorly following a curved pathway. In 18 cases the RAPs moved posterio-inferiorly and in six cases the RAPs moved posterio-superiorly. The pathways can be quantified in terms of their curved pathway lengths and the displacements of their end points from their start points. In the case of the 18 posterio-inferior pathways, the mean pathway length was 98.3 mm (SD=31.5) and the mean posterior/inferior displacements were 59.6 mm (SD=34.7) and 43.2 mm (SD=24.6) respectively. In the case of the 6 posterior-superior pathways, the mean pathway length was 109.4 mm (SD=40.2) and the mean posterior/ superior displacements were 94.7 mm (SD=43.9) & 20.9 mm (SD=11.1) respectively. The variation in inferior-superior displacement of the axis may be due to normal variations in scapula movement during forward flexion.

This investigation indicates that in normal subjects, the rotational axis moves posteriorly during flexion.