Between April 1992 and November 1998 we used 34 massive proximal femoral allografts for femoral reconstruction at revision hip arthroplasty. Seven patients have died and two have been lost to follow-up. There were thus 25 grafts in 24 patients for review. The mean follow-up was 53 months (16 to 101). By the time of the review two patients had undergone a further revision for failure of the allograft. Another had required secondary plating and grafting at the graft-host junction for symptomatic nonunion. One had recurrence of deep sepsis and was being managed conservatively.

Trochanteric union was considered to have occurred radiologically in 16 of the 25 grafts and union at the host-graft junction in 20. Resorption of the allograft was significant in only two hips. We recommend this technique in cases in which femoral bone loss has been catastrophic.

We selected randomly a consecutive series of 162 patients requiring hip replacement to receive either a cementless, hemispherical, modular, titanium acetabular cup or a cemented, all-polyethylene cup. These replacements were performed by two surgeons in four general hospitals. The same surgical technique was used and a 26 mm metal-head femoral component was used in every case.

After exclusions, 115 hips were studied for differences in rates of wear and osteolysis. The mean clinical follow-up was eight years and the mean radiological follow-up, 6.5 years. The cementless cups wore at a mean rate of 0.15 mm per year and the cemented cups at 0.07 mm per year. This difference was significant (p < 0.0001).

Our findings in this mid-term study suggest that cementless cups wear more than cemented cups.

We investigated the effect of calcitonin in the prevention of acute bone loss after a pertrochanteric fracture and its ability to reduce the incidence of further fractures in the same patient.

Fifty women aged between 70 and 80 years who had a pertrochanteric fracture of the hip were randomly allocated to group A (200 IU of nasal salmon calcitonin daily for three months) or group B (placebo).

Patients in group A showed a significantly higher level of total alkaline phosphatase and osteocalcin on the 15th day after injury and a significantly higher level of bone alkaline phosphatase on the 90th day after surgery. These patients also had significantly lower levels of urinary C-telopeptide (CrossLaps) on the 15th, 45th and 90th days after injury and lower levels of urinary hydroxyproline on the 15th and 45th days after injury. Patients in group A had significantly higher bone mineral density at all recorded sites except the greater trochanter at three months and one year after operation. After a four-year period of clinical observation, five patients (24%) in group B sustained a new fracture, in four of whom (20%) it was of the contralateral hip.

Our findings show that calcitonin reduces acute bone loss in patients with pertrochanteric fractures and may prevent the occurrence of new fractures of the contralateral hip in the elderly.

We reviewed the outcome of curved intertrochanteric varus osteotomy in the treatment of osteonecrosis of the femoral head in 20 hips. A mean varus angulation of 31° was obtained by the osteotomy. The ratio of intact area on the weight-bearing portion increased from 19% to 61%. The mean elevation and lateral displacement of the greater trochanter were 1.2 cm and 0.5 cm, respectively. These changes in the position of the greater trochanter were very small when compared with those after conventional varus wedge osteotomy. Nonunion or delayed union was not observed. Quantitative analyses showed aggressive bone remodelling in the medial intertrochanteric region. Eighteen hips survived without collapse after a mean follow-up of 48 months.

We conclude that curved varus osteotomy can be used to preserve the hip joint in patients with osteonecrosis of the femoral head.

Our study evaluated the accuracy of an image-guided total knee replacement system based on CT with regard to preparation of the femoral and tibial bone using nine limbs from five cadavers. The accuracy was assessed by direct measurement using an extramedullary alignment rod without radiographs.

The mean angular errors of the femur and tibia, which represent angular gaps from the real mechanical axis in the coronal plane, were 0.3° and 1.1°, respectively. The CT-based system, provided almost perfect alignment of the femoral component with less than 1° of error and excellent alignment with less than 3° of error for the tibial component. Our results suggest that standardisation of knee replacement by the use of this system will lead to improved long-term survival of total knee arthroplasty.

We have compared a new technique of computer-assisted knee arthroplasty with the current conventional jig-based technique in 70 patients randomly allocated to receive either of the methods. Post-operative CT was performed according to the Perth CT Knee Arthroplasty protocol and pre- and post-operative Maquet views of the limb were taken. Intra-operative and peri-operative morbidity data were collected and blood loss measured.

Post-operative CT showed a significant improvement in the alignment of the components using computer-assisted surgery in regard to femoral varus/valgus (p = 0.032), femoral rotation (p = 0.001), tibial varus/valgus (p = 0.047) tibial posterior slope (p = 0.0001), tibial rotation (p = 0.011) and femorotibial mismatch (p = 0.037). Standing alignment was also improved (p = 0.004) and blood loss was less (p = 0.0001). Computer-assisted surgery took longer with a mean increase of 13 minutes (p = 0.0001).

The relationship between the bone mineral density (BMD) and Charcot arthropathy is unclear. Prospectively, 55 consecutive diabetic patients presenting with a Charcot arthropathy of the foot or ankle were classified as having a fracture, dislocation, or a combination fracture-dislocation pattern of initial destruction. In these groups we used dual-energy x-ray absorptiometry to compare the peripheral bone of the affected and unaffected limbs. The clinical data relating to diabetes and related major comorbidities and the site of the arthropathy (ankle, hindfoot, midfoot, forefoot) were also compared. There were 23 patients with a fracture pattern, 23 with a dislocation pattern, and nine with a combination.

The age-adjusted odds ratio for developing a Charcot joint with a fracture pattern as opposed to a dislocation pattern in patients with osteopenia was 9.5 (95% confidence interval 2.4 to 37.4; p = 0.0014). Groups also differed as to the site of the arthropathy. Fracture patterns predominated at the ankle and forefoot whereas dislocations did so in the midfoot. Diabetic Charcot arthropathy of the foot and ankle differs according to the pattern of the initial destruction. The fracture pattern is associated with peripheral deficiency of BMD. The dislocation pattern is associated with a normal BMD.

The upper three-quarters of the fibula is commonly used as a non-vascularised autograft. Subsequent to this isolated weakness of extensor hallucis longus may occur. We have studied 26 patients in whom the upper and middle thirds of the fibula had been harvested as a graft through Henry’s posterolateral approach.

Isolated weakness of extensor hallucis longus was found after operation in ten patients but not in the remainder. EMG and nerve-conduction studies confirmed injury of the nerve to extensor hallucis longus in those with weakness. We dissected 40 cadaver limbs and found that those in which the nerve to extensor hallucis longus ran close to the fibular periosteum were at risk. The injury is mostly incomplete and recovery occurs within four to six months.

We reviewed 80 shoulders (77 patients) at a mean follow-up of 44 months after insertion of a Grammont inverted shoulder prosthesis. Three implants had failed and had been revised. The mean Constant score had increased from 22.6 points pre-operatively to 65.6 points at review. In 96% of these shoulders there was no or only minimal pain. The mean active forward elevation increased from 73° to 138°. The integrity of teres minor is essential for the recovery of external rotation and significantly influenced the Constant score. Five cases of aseptic loosening of the glenoid and seven of dissociation of the glenoid component were noted.

This study confirms the promising early results obtained with the inverted prosthesis in the treatment of a cuff-tear arthropathy. It should be considered in the treatment of osteoarthritis with a massive tear of the cuff but should be reserved for elderly patients.

Heterotopic ossification which may develop around the elbow in patients with burns may lead to severe functional impairment. We describe the outcome of early excision of such heterotopic ossification in 28 patients (35 elbows), undertaken as soon as the patient’s general and local condition allowed. The mean age at operation was 42 years. The mean area of burnt body surface was 49%. The mean pre-operative range of movement was 22° in flexion/extension and 94° in pronation/supination. The mean time between the burn and operation was 12 months with the median being 9.5. The mean follow-up period was for 21 months.

At the last review, the mean range of movement was 123° in flexion/extension and 160° in pronation/supination. Clinical evidence of recurrence was seen in four patients, occurring within the first two months after operation. Nevertheless, three of these elbows gained 60° or more in flexion/extension and in pronation/supination. Based on this experience, we recommend early surgical treatment of heterotopic ossification of the elbow in patients with severe burns.

We describe two patients with claw hand as a result of a bee sting. It is likely that this was caused by the apamin in the sting which has an effect on the upper limb, at the spinal cord and on the peripheral nerves. It is important to recognise that the claw hand is not owing to compartment syndrome. Both patients were treated conservatively with full resolution within 48 hours, without any lasting effects.

We reviewed 13 patients with a complex fracture-dislocation of the proximal interphalangeal joint of a finger and one patient with a complex fracture-dislocation of the interphalangeal joint of thumb. We had treated these injuries using a pins and rubbers traction system which had been modified to avoid friction of the pins against the bone during mobilisation of the joint in order to minimise the risk of osteolysis. A Michigan hand outcome questionnaire was used for subjective assessment. The active range of movement (AROM) of the proximal and distal interphalangeal joints and the grip strength were used for objective assessment.

The mean follow-up was 34 months (12 to 49). The mean normalised Michigan hand outcome score was 84. The mean AROM of the proximal interphalangeal joint was 85° and that of the distal interphalangeal joint 48°. The mean grip strength was 92% of the uninvolved hand.

Twelve patients have returned to their original occupations. There has been no radiological osteolysis or clinical osteomyelitis. This modified traction system has given acceptable results with a low rate of complications. It is light, cheap, effective and easy to apply.

Existing classifications of fractures of the head of the humerus are inadequate in terms of interobserver reliability and the predictability of the clinical outcome. From a combined study of 73 fracture specimens in museums and 84 CT-three-dimensional reconstructions in patients, we have devised a classification which appears to be more useful clinically. Common patterns of fracture and a plausible mechanism of injury were observed.

In 3-D most proximal humeral fractures can be organised into five basic types. These correspond in some degree to the Codman/Neer classification, but differ significantly in regard to the more complex patterns of fracture. We observed a logical progression from simple to complex fractures. An interobserver reliability study was carried out which indicated the improved usefulness of this new 3-D concept in providing a common language among clinicians for classifying these injuries. When surgery is indicated, the 3-D concept is also invaluable in guiding the restitution of anatomy through either open or percutaneous means.

It has recently been postulated that thrombophilia may have a role in the aetiology of Perthes’ disease. The published reports, however, remain conflicting. In this study a retrospective analysis of the coagulation parameters was made in 47 patients with Perthes’ disease and the results compared with the clinical data. Five patients with Factor V Leiden mutation were found (10.6%) and surprisingly four of them had a homozygous pattern. These four patients showed the most severe form of the disease, Catterall group IV, with flattening of the entire epiphysis, involvement of the metaphysis, shortening and broadening of the femoral neck, trochanteric overgrowth and developed mushroom-shaped aspherical laterally displaced femoral heads in dysplastic acetabula.

We would like to suggest that the homozygous form of Factor V Leiden mutation has some role in the clinical course of Perthes’ disease and particularly its most severe form.

The results of the Ferguson medial approach for open reduction of developmental dysplasia of the hip (DDH) were reviewed for 49 hips with a follow-up of more than 48 months. The mean age at operation was 12.3 months (6 to 23). The mean length of clinical and radiological follow-up was 82 months (48 to 148). Three redislocations occurred. Group I avascular necrosis according to the classification of Kalamchi and MacEwen was seen in four hips, group II in two hips and group III in one hip; 92% of the hips were classified as Severin class I and II. The acetabular index and centre edge (CE) angles were within normal limits at final follow-up, but were still significantly different from the unaffected side.

We conclude that the Ferguson procedure is safe and reliable for low dislocations in children aged six to 18 months.

Reimers’ hip migration percentage is commonly used to document the extent of subluxation of the hip in children with spasticity. In this study, two measurers, with six months paediatric orthopaedic experience, measured the migration percentage on 44 pelvic radiographs of children with cerebral palsy, aged between two and eight years. Unknown to the measurers, each radiograph was duplicated, giving 22 non-identical radiographs (44 hips) which were measured twice at time 0 and twice six weeks later. The intra-measurer, intra-sessional absolute differences between the first and second measurements ranged from 0% to 23%, with median values of 2.5% to 3.6%. The intra-sessional median absolute differences were not statistically different between the two measurers and measuring sessions (p = 0.42, Kruskal-Wallis test). The inter-sessional absolute differences for measurements made by the same measurers ranged from 0% to 18% with a median absolute difference of 1.7% to 3.2%. Overall, only 5% of the intra-measurer measurement differences, within and between sessions, were above 13%. Repeated measurements by one measurer over time must, therefore, vary by more than 13% in order to be 95% confident of a true change. The inter-measurer error was higher with median absolute differences between the two measurers’ measurements of the same hip of 3.25% to 5% (0% to 26%) and a 95^th upper confidence interval of 21% to 23%. Averaging the four separate measurements over the two sessions reduced the inter-measurer error to a median absolute difference of 2.8%, but did not improve the 95^th upper confidence interval, which measured 22.4%.

Such inter-measurer errors may be clinically unacceptable.

We investigated the long-term changes in the Harris Hip and Knee Society scores (HSS and KSS) to determine whether they result from overall functional decline rather than actual changes in the condition of the prosthesis. The HHS for 106 total hip arthroplasties with a minimum follow-up of ten years, no medical complications after operation and no evidence of radiological loosening, and the KSS for 264 total knee arthroplasties with a minimum follow-up of 12 years and no medical complications after operation or signs of radiographical loosening were evaluated.

There were statistically significant drops in the functional scoring components of the joint evaluation systems despite no loosening of the prostheses or other significant medical complications. The HHS declined at an average of 0.67 points per year from between three and ten years after operation (p < 0.0001). Contributing to this were deterioration in gait and limp (p < 0.0004), the use of support aids (p < 0.0001), the distance walked (p < 0.0001) and the ability to climb stairs (p < 0.0455). The functional component of the KSS declined significantly at an average 0.88 points per year betwen the third and 12th years (p < 0.0001). There were significant declines in every component of the functional score including the distance walked (p < 0.0001), the ability to climb stairs (p < 0.0001) and the use of support aids (p < 0.0001). The knee score component of the KSS did not decline significantly (p < 0.9750). The combination of functional and pain scores within the HHS system leads to an inaccurate decline in the entire score. The decline of HHS and Knee Society functional scores in total joint arthroplasties, in the absence of implant-related problems, suggests that deterioration in the functional capacity of ageing patients is an important factor in longitudinal studies using these scoring systems.

There is increasing evidence that non-steroidal anti-inflammatory drugs (NSAIDs) can adversely affect bone repair. We have, therefore, studied the in vitro effects of NSAIDs, which differentially inhibit cyclooxygenases (COX), the prostaglandin/thromboxane synthesising enzymes, on human osteoblasts. Indomethacin and the new nitric oxide (NO)-donating NSAIDs block the activity of both COX-1 and COX-2. Indomethacin and 5,5-dimethyl-3-(3 fluorophenyl)-4-(4 methylsulphonal) phenyl-2 (5H)-furanone (DFU) reduced osteoblast numbers in a dose-dependant manner and increased collagen synthesis and alkaline phosphatase activity. The reduction in osteoblast numbers was not caused by loss of adhesion and was reversible. Neither NSAID influenced DNA synthesis. There was no difference between the effects of indomethacin and DFU. NO-NSAIDs did not affect cell numbers.

These results suggest that care should be taken when administering NSAIDs to patients with existing skeletal problems and that NO-NSAIDs may be safer.

The posterior cruciate ligament (PCL) was imaged by MRI throughout flexion in neutral tibial rotation in six cadaver knees, which were also dissected, and in 20 unloaded and 13 loaded living (squatting) knees. The appearance of the ligament was the same in all three groups. In extension the ligament is curved concave-forwards. It is straight, fully out-to-length and approaching vertical from 60° to 120°, and curves convex-forwards over the roof of the intercondylar notch in full flexion. Throughout flexion the length of the ligament does not change, but the separations of its attachments do.

We conclude that the PCL is not loaded in the unloaded cadaver knee and therefore, since its appearance in all three groups is the same, that it is also unloaded in the living knee during flexion. The posterior fibres may be an exception in hyperextension, probably being loaded either because of posterior femoral lift-off or because of the forward curvature of the PCL. These conclusions relate only to everyday life: none may be drawn with regard to more strenuous activities such as sport or in trauma.

We examined the radiographs from a prospective clinical study of fixation by pedicle screws and those from an experimental study in a sheep model. In the clinical study, instruments were removed from 21 patients after implantation for 11 to 16 months and the extraction torques of the screws were recorded. A structured protocol was used for the radiological examinations. In the experimental study, loaded pedicle screw instrumentations were implanted in the sheep for six or 12 weeks. After radiological examination the pull-out resistance and the histological characteristics were studied.

In the clinical study, all screws with radiolucent zones had a significantly reduced mean extraction torque compared with screws without radiolucent zones (16 ± 10 Ncm v 403 ± 220 Ncm; p < 0.0001). In the experimental study the mean maximum pull-out resistance for the screws with radiolucent zones was significantly lower than for those with no radiolucency (243 ± 156 N v 2214 ± 578 N; p = 0.0006) and the mean bone-to-screw contact was reduced for screws with zones compared with those without zones (8 ± 9% v 55 ± 29%; p = 0.0002).

Our findings showed that all screws with radiolucent zones had low extraction torques or low pull-out resistance. A radiolucent zone is a good indicator of loosening of a pedicle screw.