Bone morphology of the proximal femoral canal: ethnicity related differences and the influence on cementless tapered wedge stem designs

BACKGROUND

Differences in proximal femoral morphology between ethnicities may have implications on the design of cementless tapered wedge stems. This study analyses the differences in Asian and Caucasian bone morphology as well as the related fit of various cementless tapered wedge stem designs.

METHODS

A computed tomography database and modelling software was used to retrospectively analyse a total of 1345 femora. Ethnicity related comparisons as well as the fit of the stem designs were analysed.

RESULTS

Statistically significant differences between canal shape of Caucasian and Japanese as well as non-Japanese Asians were observed. The fit of the stems within the femoral canal was highly dependent on the respective stem shape.

CONCLUSIONS

The shape differences in stem designs had a larger influence on the fit within the femoral canal than the differences in ethnicity related to bone morphology.

The simplest method to classify CAM lesions

CAM lesions are now seen as a significant pathology that could cause osteoarthritis of the hip joint. Currently there is no gold standard for classifying these lesions. We aim to show a simple method for classifying these lesions based on shape and position. Using CT 3D reconstruction, 91 preoperative CT scans from patients who had undergone hip arthroscopy for femoroacetabular impingement, were reconstructed to produce 3D images. Two senior hip surgeons have devised a simple four type classification system from previous experience. The system highlights the position and shape of different CAM lesions present in patients. The two senior surgeons and one junior surgeon reviewed the scans individually to assess whether the system could be used at all levels of surgical experience. The two senior surgeons agreed on which type of CAM lesion was present in all 91 cases. Intra observer reliability scores for the senior surgeons were 0.90 and 0.91. The junior surgeon reviewed the scans and disagreed on eight cases. This gave a Kappa co-efficient score of 0.87, which confirms a reliable system. We believe this classification system is simple and reproducible. It will aid surgeons in pre and intra-operative management of CAM lesions. Surgeons will be able to select the optimal portal placement and resect less capsule depending on the exact CAM lesion identified. This will potentially reduce complications and improve outcomes in junior hip arthroscopy surgeons.

Incidence and aetiology of talipes equino-varus with recent population changes

This study looks at the changing incidence and aetiology of congenital talipes equinovarus due to the recent population changes within the area. Between 1st June 1992 and the 31st May 2006, 83 consecutive children (121 feet) born with fixed talipes equinovarus (TEV) were assessed and treated (an incidence of 1.6 per 1000 live births) in an observational longitudinal cohort study assessing associated factors. There were 17 syndromal cases in the fixed group (20.8%), 6 cases of non-syndromal distal arthrogryposis (7.2%), and a strong family history in 12 cases (14.5%). This study would suggest that genetic and primary causes of fixed TEV are more common than previously considered. Many of the primary aetiologies were diagnosed months or years after birth.

The validity, reliability, responsiveness, and bias of the Manchester-Modified Disability of the Arm, Shoulder, and Hand score in hand injuries

The Manchester-Modified Disability of Arm, Shoulder and Hand questionnaire (M(2) DASH) was developed by the authors as a modification to the original DASH questionnaire. In this study, we assessed the validity, reliability, responsiveness, and bias of the M(2) DASH questionnaire for hand injuries using completed M(2) DASH, Patient Evaluation Measure, and Michigan Hand Outcome questionnaires from 40 patients. The M(2) DASH scores showed significant positive correlations with the Patient Evaluation Measure and Michigan Hand Outcome scores suggesting validity. There was also no evidence of a statistical difference in the M(2) DASH scores when the condition had stabilized suggesting good test-retest reproducibility and reliability. The effect size and the standardized response mean for the M(2) DASH score were greater than those for the Patient Evaluation Measure and Michigan Hand Outcome scores establishing that the M(2) DASH is highly responsive. There was no gender, hand dominance, or dominant side injured bias for the M(2) DASH score. There was, however, a relatively weak association between age and the M(2) DASH score at presentation. We conclude that the M(2) DASH questionnaire is a robust region-specific outcome measure. It is a valid and responsive questionnaire with test-retest reliability proven for hand injuries in this study. Gender, handedness, and side injured did not cause bias in the responses.

The 'M2 DASH'-Manchester-modified Disabilities of Arm Shoulder and Hand score

The Disability of the Arm, Shoulder, and Hand (DASH) questionnaire was originally designed as a measure of disability in patients with disorders of the upper limb, but the DASH score is also affected by disability because of lower limb disorders. The aim of this study was to investigate the construct validity of the DASH questionnaire and to create a revised DASH questionnaire, the Manchester-modified or M2 DASH, with fewer questions that is more specific to the upper limb. Patients were asked to fill in the DASH questionnaire in a fracture clinic after ethical approval. This included 79 patients with upper limb injuries, 61 patients with lower limb injuries, and 52 control subjects. The mean DASH scores for the three groups varied significantly, and the lower limb group had a mean score of 16. The M2 DASH questionnaire was developed using questions more specific to the upper limb and included questions 1-4, 6, 13-17, 21-23, and 26-30 from the original questionnaire. The mean M2 DASH score for the lower limb group was 9 and, unlike the original DASH score, was not statistically different from the control group. The M2 DASH scores were then calculated for the upper limb group and a correlation study showed highly significant correlation between the original DASH scores and the M(2) DASH scores. Our study shows that the original DASH questionnaire is not specific for the upper limb. The M2 DASH questionnaire has the advantage of being more specific for the upper limb than the DASH questionnaire, and it correlates well with the original DASH questionnaire when looking at isolated upper limb injuries.

Total knee arthroplasty in patients with severe haemophilia

We reviewed the perioperative records of haemophiliac patients who underwent total knee replacement (TKR) over the period 1990-1999 and followed up the surviving patients. Nine knees were replaced in eight patients. Seven of the nine patients did not require blood transfusion. Mean perioperative haemoglobin drop was 2.9 g/dl. There were no significant complications. All surviving patients (eight TKRs) were reviewed clinically using a standard scoring system. The mean follow-up period was 51 months. All patients scored excellent (>90/100) in the functional category. The frequency of haemarthroses fell significantly from the rate experienced prior to TKR, and pain scores were zero.