Introduction: Digital X-rays have become increasingly prevalent in Hospitals throughout the UK and Ireland in the past 10 years. We have devised a semi quantitative analysis of digital radiographs that measures the extent of healing across the fracture gap.

Methods: 48 CD 1 mice underwent a femoral fracture and subsequent fixation with an external fixator. A standardised radiograph was taken. A radiographic analysis was carried out. For each radiograph taken a pixel density graph was generated at five individual points across the fracture gap, along the longitudinal axis of the femur.

A stastical analysis of intra and inter-observer variability was tested using the linearly-weighted kappa statistic for each of the 240 pixel density graphs taken and for the summation total in the 48 radiographs.

Results: For the individual pixel density graphs we expected an agreement of 67.82%. An agreement of 95.42% was recorded showing a kappa statistic of 0.8576 and a standard error of 0.0531.

On analysis of the summation scores we expected an agreement of 75.54% and observed an actual agreement of 96.30%. This showed a kappa statistic of 0.8545 and a standard error of 0.0849.

Conclusion: The results are very similar in the two analyses and indicate excellent agreements. As a result we offer a radiographic, semi-quantative analysis of bone healing across a fracture gap that is highly reproducible. Thus it has the potential for application to future research in this field and possibly to clinical practice with the increased use of digital radiographs in hospital departments

There is a known association between femoroacetabular impingement (FAI) and osteoarthritis of the hip. What is not known is whether arthroscopic excision of an impingement lesion can significantly improve a patient’s symptoms.

This study compares the one-year results of hip arthroscopy for cam-type FAI in two groups of patients. The study (osteoplasty) group comprised 24 patients (24 hips) with cam-type FAI who underwent arthroscopic debridement with excision of their impingement lesion. The control (no osteoplasty) group comprised 47 patients (47 hips) who underwent arthroscopic debridement without excision of their impingement lesion. In both groups, the presence of FAI was confirmed on pre-operative plain radiographs. The modified Harris hip score (MHHS) was used for evaluation pre-operatively and at one year’s follow-up. Non-parametric tests were used for statistical analysis.

A tendency towards higher median post-operative MHHS scores was observed in the study than in the control group (83 vs. 77, p = 0.11). This was supported by a significantly higher portion of patients in the osteoplasty group with excellent/good results (83% vs. 60%, p = 0.043). It appears that even further symptomatic improvement may be obtained after hip arthroscopy for FAI by means of the femoral osteoplasty. When treating cam impingement arthroscopically, both central and peripheral compartments of the hip should always be accessed.

Problems with chondral toxicity caused by prolonged exposure to local anaesthetics have been increasingly recognised. However, day-case hip arthroscopic surgery is frequently carried out using an intraarticular depot of local anaesthetic as post-operative analgesia plus additional opiate or oral analgesia as required. We aimed to evaluate the efficacy of three different post-operative analgesic regimes at hip arthroscopy, in particular examining whether intraarticular local anaesthetics gave any benefit.

We investigated 71 consecutive patients undergoing day-case hip arthroscopy and prospectively audited their post-operative analgesic requirements. Each patient was given one of three alternative post-operative analgesic regimes. Group A (n=29) received bupivicaine 0.25% 10ml intraarticular and 20ml peri-portal skin infiltration, group B (n=23) had bupivicaine 0.25% 20ml peri-portal skin infiltration only, and group C (n=19) had no infiltration. Outcome measures were visual analogue scores (VAS) at time-points T1 (immediate post-operatively), T2 (one hour post-operatively), T3 (two hours post-operatively), and T4 (four hours post-operatively). Total opiate consumption was also recorded.

There was significantly less post-operative pain in group A, compared with group C at T1 (p=0.03) and T2 (p=0.004), and compared with group B at T3 (p=0.02) and T4 (p=0.03). There were no significant differences in VAS between groups B and C at any time-points. Group A used significantly less opiates post-operatively compared with group B (p=0.008) or C (p< 0.001) but there was no significant difference in opiate use between groups B and C.

There are no previous studies relating to hip arthros-copy post-operative analgesic requirements. Intraarticular local anaesthetic significantly reduces post-operative pain, but at what cost to the chondral surface? Local skin infiltration of the arthroscopy portals does not significantly alter pain levels or opiate requirements. Avoidance of intararticular local anaesthetic raises opiate requirements. We require improved alternative analgesic regimes.

Introduction and Aims: Although the association between femoroacetabular impingement and osteoarthritis is established, it is not yet clear which hips have the greatest likelihood to rapidly progress to end-stage disease. We investigated the possible relation of specific radiological parameters, each indicative of a structural aspect of the hip joint, to progression of osteoarthritis.

Materials and Methods: Pairs of plain anteroposterior pelvic radiographs, spaced at least 10 years apart, of 43 patients (47 hips) with pistol-grip deformity of the femur and mild (Tönnis grade 1) or moderate (Tönnis grade 2) arthritis were reviewed. Radiological measurements included the α-angle, the neck-shaft angle, the Tönnis angle, the centre-edge angle of Wiberg and the anatomical medial proximal femoral angle (MPFA). The presence of the cross-over sign and the posterior wall sign was also recorded. Grading of osteoarthritis was repeated on the final films. A logistic regression analysis model was constructed, to investigate the predictive ability of radiological parameters on progression of osteoarthritis.

Results: Of the 47 hips, 31 (66%) showed evidence of progression of arthritis. There was no difference in the prevalence of progression between hips with initial grade 1 and grade 2 arthritis (p = 0.32). Comparison of the hips that progressed and those that did not revealed a significant difference for the MPFA (82° vs. 85°, p = 0.006) and the presence of the posterior wall sign (39% vs. 6%, p = 0.04) only. The regression analysis model demonstrated a predictive ability of 32% for those two parameters, with an accuracy of 78.3%.

Discussion and Conclusion: Mild-to-moderate osteoarthritis in hips with a pistol-grip deformity will not progress rapidly in all patients. In one third of them, progression will take more than ten years to manifest. Other structural aspects, relating to the geometry of the proximal femur and the acetabulum, influence in part this phenomenon. A hip with cam impingement is not always destined to end-stage arthritic degeneration.

Introduction: Unicompartmental knee arthroplasty (UKA) remains a cost effective option for treatment of medial compartment osteoarthritis of the knee. In carefully selected patients survival rates exceed 90% survivorship at ten years. Main indications for revision include progressive osteoarthritis in other compartments, component loosening and polyethylene bearing failure. However, within those patients who have been revised, there is a cohort of patients who are revised early, usually under seven years. Mechanical mal-alignment has been cited recently as a reason for early failure and revision. The introduction of computer assisted surgery (CAS) has allowed us to more accurately restore the normal mechanical axis of the limb in UKA.

Aims and Hypothesis: The aim of this study was to identify whether, within our cohort of early failures, the failure mechanism differed from patients in the late revision group and specifically to examine whether mechanical mal-alignment contributed to the mechanism of early failure.

Materials and Methods: We undertook this retrospective review of a single surgeon series of 87 revised unicompartmental knee replacements carried out over 15 years. We collated the indications for revision, mechanisms of failure, and methods of revision from medical notes and compared the early and late revisions by mechanism of failure. We considered an early failure to be any UKA revised before seven years

Results: There were 50 late failure UKAs and 37 early failures. We found no significant differences between groups in age, activity or demographics at time of primary UKA. The main implants in the late failure group were 19 (38%) Miller Galante, 22 (44%) PCA Duracon, and 9 (18%) others while the early failures consisted 21 (57%) Miller Galante, 5 (14%) Oxford, 3 (8%) PCA Duracon, and 8 (22%) others. 60% of late failures were cemented while 89% of early failures were cemented. Mechanism of late failure was 46% bearing wear, 22% progression of OA, 14% malalignment and 14% loosening, while mechanism of early failure was 41% loosening, 27% bearing wear and 14% malalignment.

Discussion: Many historical bearing failures were due to oxidised polyethylene following sterilization. These should now have been eliminated by modern polyethylene and sterilization techniques. Mechanical mal-alignment is also now measurable and preventable by the use of CAS. We believe that avoidance of these two pitfalls will have an impact on the rate of early revision of UKA.

Conclusion: We conclude that patients who underwent early UKA revision had a different failure mechanism from late UKA revisions. In the early failure group the main mechanisms were mechanical loosening and bearing wear. In the late revision group, bearing failures, progressive osteoarthritis and component loosening were the main reasons for failure. Mechanical malalignment failed to differ between the groups.

Introduction and Aims: There is a known association between femoroacetabular impingement (FAI) and osteoarthritis of the hip. What is not known is whether arthroscopic excision of an impingement lesion can significantly improve a patient’s symptoms.

Materials and Methods: This study compares the one-year results of hip arthroscopy for cam-type FAI in two groups of patients. The study (osteoplasty) group comprised 24 patients (24 hips) with cam-type FAI who underwent arthroscopic debridement with excision of their impingement lesion. The control (no osteoplasty) group comprised 47 patients (47 hips) who underwent arthroscopic debridement without excision of their impingement lesion. In both groups, the presence of FAI was confirmed on pre-operative plain radiographs. The modified Harris hip score (MHHS) was used for evaluation pre-operatively and at one year’s follow-up. Non-parametric tests were used for statistical analysis.

Results: A tendency towards higher median post-operative MHHS scores was observed in the study than in the control group (83 vs. 77, p = 0.11). This was supported by a significantly higher portion of patients in the osteoplasty group with excellent/good results (83% vs. 60%, p = 0.043).

Conclusions: It appears that even further symptomatic improvement may be obtained after hip arthroscopy for FAI by means of the femoral osteoplasty. When treating cam impingement arthroscopically, both central and peripheral compartments of the hip should always be accessed.