We have made a retrospective study of 1001 custom-made prostheses used as replacements after surgery for bone tumours. There were 493 distal femoral, 263 proximal femoral and 245 proximal tibial prostheses. Aseptic loosening was shown to be the principal mode of failure of the implants, and 71 patients had revision for aseptic loosening of a cemented intramedullary stem.

The probability of a patient surviving aseptic loosening for 120 months was 93.8% for a proximal femoral replacement, 67.4% for a distal femoral prosthesis and 58% for a proximal tibial implant. In patients with distal femoral replacements the age of the patient at the time of operation and the percentage of bone resected were related to the risk of aseptic loosening. Young patients with distal femoral prostheses in whom a high percentage of the femur had been replaced had the poorest prognosis for survival without aseptic loosening. The percentage of bone removed had a significant effect in the proximal tibial replacement group, but the age of the patient did not. By contrast, neither the age nor the percentage of bone removed was a factor after proximal femoral replacement.

The significance of these findings is discussed in relation to mechanical factors.

Previous studies have shown that the activity of the cytostatic drug methotrexate (MTX) embedded in acrylic cement is not affected by thermal changes in the cement. MTX is slowly released from the cement for several months and remains biologically active throughout this period. Our aim was to determine whether MTX embedded in cement would control the local growth of a tumour.

In 15 rabbits we injected 0.1 ml of VX₂ tumour suspension into the proximal tibia. At 3, 5, 7, 10 and 14 days three animals were killed and the tibiae removed and examined histologically. With increasing growth of the VX₂ carcinoma there was increased bone destruction and a rise in the numbers of osteoclasts, but after 14 days the numbers of osteoclasts had decreased.

We then injected VX₂ into the tibiae of another 45 rabbits. After 5 days most of the tumour was curetted out and the defect filled with cement containing either 0 g, 0.1 g, 0.5 g, 1.0 g or 2.0 g MTX/40 g cement. The rabbits were divided into three groups and killed at 3, 7 or 10 days after implantation of cement. The number of osteoclasts and the amount of bone destruction were measured in each tibia. In all three groups bone destruction and osteoclast proliferation were markedly decreased with higher doses of MTX, but bone destruction was not eliminated.

Our findings show that in the higher doses used, which were not toxic to the animal, MTX-embedded cement may be of value in minimising the amount of tumour-induced osteolysis and may be a useful adjunct in the surgical management of pathological fractures.

We measured the levels of cobalt and chromium in the serum in three groups of patients after uncemented porous-coated arthroplasty. Group 1 consisted of 14 consecutive patients undergoing revision for aseptic loosening. Group 2 comprised 14 matched patients in whom the arthroplasty was stable and group 3 was 14 similarly matched patients with arthritis awaiting hip replacement. Specimens were analysed using atomic absorption spectrophotometry.

Aseptic loosening of a component resulted in a significant elevation of serum cobalt (p < 0.05), but not of serum chromium. The relative risk of a component being loose, if the patient had a serum cobalt greater than 9.0 nmol/l, was 2.8.

Infection of human cartilage with HIV in vivo has not previously been reported. Specimens of articular cartilage taken at postmortem from ten patients who were HIV-positive were examined. Two had AIDS and eight were believed to have stage-2 disease.

The standard polymerase chain reaction (PCR) protocol was modified to allow semiquantitative analysis of the samples. Oligonucleotide primers labelled with ³²P gamma-ATP were used to detect a segment of HIV DNA and a control DNA gene segment (HLA genome) to estimate the ratio of infected cells. The ³²P-labelled PCR products were separated on acrylamide gels and visualised directly by autoradiography and computer densitometry.

Infection of human cartilage in vivo was demonstrated in nine of the ten samples in which the PCR analysis was positive. The other did not react sufficiently to produce detectable radiolabelled PCR product despite repeated DNA digestion and extraction. Cartilage infected with HIV could be a potential source of HIV when used in operations.

We have developed a bioactive bone cement (BA cement) consisting of Bis-GMA resin and bioactive glass powder. It has high compressive and tensile strengths, a low curing temperature and its bioactivity allows it to bond directly with bone.

We operated on the 18 femora of nine mongrel dogs for intercalary replacement of part of the bone by a metal prosthesis using either PMMA cement or BA cement for fixation. Three dogs were killed at each of 4, 12 and 26 weeks after surgery for the evaluation of fixation strength by a push-out test and for histological examination by Giemsa surface staining and SEM.

Fixation strengths with PMMA cement at 4, 12 and 26 weeks after surgery were 46.8 ± 18.9, 50.0 ± 24.7, and 58.2 ± 28.9 kgf (mean ±SD), respectively. Those with BA cement were 56.8 ± 26.1, 67.2 ± 19.2, and 72.8 ± 22.2 kgf, respectively. Fibrous tissue intervened between bone and PMMA cement but BA cement had bonded directly to bone at 12 and 26 weeks. This suggests that BA cement will be useful in providing long-lasting fixation of implants to bone under weight-bearing conditions.

In ten male rats we inserted ceramic ‘drawing-pin’ implants in weight-bearing positions within the right proximal tibia. Two animals were killed 6 weeks after surgery and two more 14 weeks after surgery. The remaining six received intra-articular injections of either high-density polyethylene (4 rats) or saline (2 rats) at 8, 10 and 12 weeks after surgery. These animals were killed two weeks after the last injection.

Histological examination of the bone-implant interface in the control animals showed appositional bone growth around the implant at both 6 and 14 weeks. Polyethylene, but not saline, caused a chronic inflammatory response with numerous foreign-body giant cells in periprosthetic tissues.

Our model of a stable, weight-bearing bone-implant interface provides a simple and reliable system in which to study in vivo the effects of particulate materials used in orthopaedic surgery.

We performed biopsies during reoperation for minor complications in two active young patients 9 and 19 months after massive bone allograft implantation for bone tumour. The grafts were dead and resorption-apposition activity, when present, was predominantly in subperiosteal areas. Inflammatory infiltration was very seldom found.

Features considered as ‘microfractures’ or ‘microcracks’ were noted in the cortical ring together with the formation of woven bone, in areas with remodelling. Such cracks are likely to be of mechanical origin and do not inevitably lead to complications.

We used a rabbit model to investigate the mechanism by which the angulation of fractures is corrected in children. We produced a transverse proximal tibial fracture in one leg of 12 eight-week-old New Zealand white rabbits and measured bone alignment and length and the patterns of bone growth and remodelling.

The angle between the joint surfaces changed rapidly to correct the alignment of the limb as a result of asymmetrical growth of epiphyseal plates. In an adult with closed plates, the angle between the joint surfaces cannot therefore improve. The angle at the fracture itself showed slow improvement because of bone drift and the asymmetrical growth of the epiphyseal plates. Remodelling corrected the shape of the bone in the region of the fracture.

Periosteal division on the convex side increased the growth of the epiphyseal plate on that side, thus slowing the correction. The effect was relatively small, providing an indication that factors other than the periosteum are important in inducing correction.

External torsional deformities developed because of helical growth at the plate. This was probably caused by abnormal posture which induced a torque at the growth plate. Helical growth is the mechanism by which rotational deformities can occur and correct.

We reviewed all patients with a clinically infected foot ulcer attending a specialised neuropathic foot clinic. Neuropathy was confirmed by the inability to feel a 5.07 Semmes-Weinstein hair, areflexia and impaired vibration sense, as measured by a biothesiometer.

Of 40 patients who attended the clinic over a two-year period, six with ischaemic ulcers were excluded. The remaining 34 had plain radiographs of the foot followed by a ^99mTc-MDP bone scan. If the latter was positive, an ¹¹¹In-labelled WBC scan was performed with planar and/or tomographic dual-isotope studies where appropriate. Bone and WBC scans were performed in 31 patients. In ten, isotope imaging showed infection localised to the soft tissues only and conservative treatment was successful in them all. Eighteen patients were treated surgically with excision of the involved bone, which was sent for culture and histological examination.

Dual-isotope scans had a sensitivity of 93% and a specificity of 83%. ^99mTc-MDP bone scans with the appropriate ¹¹¹In-labelled WBC scans can reliably determine the site and extent of osteomyelitis in the neuropathic diabetic foot.

We investigated a new method of stress radiography of the subtalar joints using forced maximum dorsiflexion of the ankle in a supinated position. We measured transposition of the lateral process of the talus at the posterior subtalar joint in lateral views of normal amputated ankles, normal control subjects and patients with recurrent ankle sprains. The mean displacement in the control groups (n = 36) was 29.9%, significantly different from the 43.0% in patients with recurrent ankle sprains (n = 24).

In the amputated specimens with intact ligaments movement was similar to that in normal subjects. Section of the calcaneofibular and the interosseous ligaments allowed much the same movement as in patients with recurrent ankle sprains.

The new method is simple and useful for detecting subtalar instability.

A comparison was made of the results produced by the circumtibial and interosseous routes of transfer of tibialis posterior for the correction of foot drop due to leprosy neuritis. The findings in 69 feet, of which 63 also had elongation of tendo Achillis, showed that the interosseous route gave a much lower incidence of recurrent inversion deformity of the foot. The results, in terms of improvement in gait and prevention of trophic changes, were satisfactory.

We describe a syndrome combining abnormalities of the pelvis, knee and foot in three related patients with a familial history of small dislocated patellae. The clinical and radiological appearance of the patella and pelvis is consistent with the ‘small-patella’ syndrome, a rare autosomal dominant disorder. There were also previously unreported deformities affecting the feet.

We report a prospective study of gait and tibial component migration in 45 patients with osteoarthritis treated by total knee arthroplasty (TKA). Migration was measured over two years using roentgen stereophotogrammetry. We used the previously established threshold of 200 μm migration in the second postoperative year to distinguish two groups: a risk group of 15 patients and a stable group of 28 patients.

We performed gait analysis before operation and at six months and at two years after TKA. On all three occasions we found significant differences between the two groups in the mean sagittal plane moments of the knee joint. The risk group walked with higher peak flexion moments than the stable group. The two groups were not discriminated by any clinical or radiological criteria or other gait characteristics.

The relationship which we have found between gait with increased flexion moments and risk of tibial component loosening warrants further study as regards the aetiology of prosthetic loosening and possible methods of influencing its incidence.

Total hip and total knee arthroplasty both provide a considerable improvement in quality of life, but there is no evidence to suggest that one is more successful than the other. We studied 72 patients in a prospective trial before and after total hip or total knee replacement. We recorded scores for disability and distress derived from the Harris hip score and the British Orthopaedic Association knee assessment score, and used them to generate quality of life (QoL) scores using the Rosser Index Matrix immediately before and at one year after surgery.

The patients awaiting knee replacement had significantly lower QoL scores than those awaiting hip replacement (p = 0.011). The QoL scores at one year were high and almost identical for both groups (p = 0.46). Further analysis showed that gender and weight were not significant predictors of improvement of QoL scores, but age (p = 0.03) and whether the hip or knee was replaced (p = 0.006) were significant factors.

In a prospective trial we studied 176 consecutive patients having a primary total hip arthroplasty to compare the quality of life before and after operation in non-obese and obese groups. We used a modified Harris hip score and the Rosser Index Matrix to generate these scores, and found that the median preoperative quality of life score for both groups was similar.

During review, both groups showed a corresponding marked improvement in quality of life scores at one and three years. There was no statistically significant difference in the improvement in scores between the non-obese and obese groups. It appears that relative body-weight on its own does not influence the benefit derived from primary total hip arthroplasty.

We studied wear in the ultra-high-molecular-weight polyethylene offset bore socket in 54 hips which had had Charnley low-friction arthroplasty. At an average follow-up of 8.1 years, the mean penetration rate was 0.04 mm per year. Correlation between the depth of socket penetration and the incidence of socket migration was confirmed, but socket migration occurred with lower penetration than had been previously reported.

A consecutive series of 30 total hip replacements using a hydroxyapatite (HA)-coated, modular implant (Omnifit) was followed clinically and by roentgen stereophotogrammetric analysis for two years and compared with two control groups, one of 27 cemented Charnley sockets and one of 40 cemented Charnley stems.

Omnifit sockets with a central gap between the dome of the socket and the acetabular bone in the postoperative radiographs, migrated less than sockets without such gaps (p = 0.01). After adjustment for patient-related factors (age, gender and weight), no significant difference was found between the two prostheses with respect to micromotion and wear.

We conclude that the early fixation of the HA-coated Omnifit prosthesis compares with that of the cemented Charnley prosthesis.

Despite the use of ultraclean air, there are still cases of infection in total joint arthroplasty. One possible route by which bacteria may enter the wound is indirectly by contamination of instruments during skin preparation and draping.

We found that bacterial air counts were 4.4 times higher during preparation and draping for hip or knee arthroplasty using an unscrubbed, ungowned leg holder than during the operation itself. With the leg holder scrubbed and gowned during preparation and draping, the air counts were reduced but were still 2.4 fold greater than intraoperatively. On some occasions, the air counts during preparation and draping exceeded the standards for ultraclean air irrespective of the attire of the leg holder.

We recommend that the leg is held by a scrubbed and gowned member of the team. More importantly, we consider that instrument packs should be opened only after skin preparation and draping have been completed.

We reviewed 25 patients with tibial diaphyseal fractures which had been complicated by an acute compartment syndrome. Thirteen had undergone continuous monitoring of the compartment pressure and the other 12 had not.

The average delay from injury to fasciotomy in the monitored group was 16 hours and in the non-monitored group 32 hours (p < 0.05). Of the 12 surviving patients in the monitored group, none had any sequelae of acute compartment syndrome at final review at an average of 10.5 months. Of the 11 surviving patients in the non-monitored group, ten had definite sequelae with muscle weakness and contractures (p < 0.01). There was also a significant delay in tibial union in the non-monitored group (p < 0.05).

We recommend that, when equipment is available, all patients with tibial fractures should have continuous compartment monitoring to minimise the incidence of acute compartment syndrome.

We made a prospective study of 116 patients with tibial diaphyseal fractures who had continuous monitoring of anterior compartment pressure for 24 hours. Three patients had acute compartment syndrome (2.6%).

In the first 12 hours of monitoring, 53 patients had absolute pressures over 30 mmHg and 30 had pressures over 40 mmHg, with four higher than 50 mmHg. Only one patient had a differential pressure (diastolic minus compartment pressure) of less than 30 mmHg; he had a fasciotomy.

In the second 12-hour period 28 patients had absolute pressures over 30 mmHg and seven over 40 mmHg. Only two had differential pressures of less than 30 mmHg; they had fasciotomies. None of our 116 patients had any sequelae of the compartment syndrome at their latest review at least six months after injury.

A threshold for decompression of 30 mmHg would have indicated that 50 patients (43%) would have required fasciotomy, and at a 40 mmHg threshold 27 (23%) would have been considered for an unnecessary fasciotomy.

In our series, the use of a differential pressure of 30 mmHg as a threshold for fasciotomy led to no missed cases of acute compartment syndrome. We recommended that decompression should be performed if the differential pressure level drops to under 30 mmHg.

We present a series of ten hypertrophic nonunions in which bony alignment and length were restored and union induced by external fixation and callus distraction. The mean length gained was 3.5 cm (1 to 6) and the mean angular correction was 13.5° (0 to 40). The mean treatment time was 10.2 months (3 to 15) and mean follow-up was 40 months (6 to 71). There have been no refractures or loss of correction or length.

The technique of callus distraction at a site of hypertrophic nonunion can correct shortening and angulation as well as induce bony union. No extra equipment is needed beyond readily-available external fixation systems.

We performed a prospective, randomised controlled trial of the operative versus non-operative treatment of 42 displaced fractures of the distal femur in elderly patients.

Excellent or good results were achieved in 53% of the operated group and in 31% of the non-operated group. There were more complications in the latter, and the time to discharge was considerably longer.

We report a prospective study of 232 consecutive patients with hip fractures. All were over 64 years of age and living independently before admission to a geriatric orthopaedic ward. We assessed the value, at admission, of predicting factors for independent living at one year after injury.

The most important factors were: (1) preinjury function in activities of daily living (grade A or B on the Katz et al (1963) scale); (2) absence of other medical conditions which would impair rehabilitation; and (3) cognitive function better than 7 on the Pfeiffer (1975) mental questionnaire. The odds ratios (95% CI) for these three predictors were 3.5 (1.3 to 9.1), 2.9 (1.3 to 6.1) and 2.4 (1.9 to 4.9), respectively. When all predictors were positive at admission, 92% were living independently at one year; with one, two or three negative predictors, the percentages living independently were 76, 61 and 27, respectively.

The median values of the total number of days in hospital, irrespective of diagnosis, during the first year were 12, 24, 29 and 149 days for the four groups. The mortality at one year was predictable on admission only by the number of medical conditions: with no other diagnosis than the fracture the mortality was 0%; with one or two additional conditions the mortality was 14%; and with three or more additional diagnoses it was 24%.

These simple and robust predictors can be used to optimise resources for rehabilitation.

We have devised a new scoring system using visual analogue scales (VAS) to determine the functional outcome in 15 patients with 20 displaced intra-articular calcaneal fractures, confirmed by CT. The average follow-up was 19 months.

A VAS was completed separately by the patient, the surgeon and an independent assessor. It showed satisfactory agreement between observers and strong correlations with a General Health Survey (SF36), a pain scale (McGill Pain Questionnaire) and a disease-specific, historical scale for calcaneal fractures (the Rowe score).

A bipolar spacer was inserted for severe arthritic destruction of the shoulder in 14 patients, and followed up for a mean of 5.9 years. In one patient the operation failed because of infection. Two others required revision for loss of low-friction properties which caused loosening of the humeral component.

At the end of the follow-up all the patients showed improvement. The Hospital for Special Surgery pain score had increased from 5.3 to 18.9 and the movement score from 7.5 to 20.1.

We performed a prospective, randomised trial on 106 patients to compare the effects of local corticosteroid injections with physiotherapy as advocated by Cyriax in the treatment of tennis elbow. The main outcome measures were the severity of pain, pain provoked by resisted dorsiflexion of the wrist, and patient satisfaction.

At six weeks 22 of 53 patients in the injection group were free from pain compared with only three in the physiotherapy group. In the corticosteroid-treated group 26 patients had no pain on resisted dorsiflexion of the wrist compared with only three in the physiotherapy group. Thirty-five patients who had injections and 14 who had physiotherapy were satisfied with the outcome of treatment at six weeks. At the final assessment there were 18 excellent and 18 good results in the corticosteroid group and one excellent and 12 good results in the physiotherapy group. There was a significant increase in grip strength in both groups but those with injections had a significantly better result.

After one year there were no significant differences between the two groups. Half of the patients, however, had received only the initial treatment, 20% had had combined therapy and 30% had had surgery.

We conclude that at six weeks, treatment with corticosteroid injections was more effective than Cyriax physiotherapy and we recommend it because of its rapid action, reduction of pain and absence of side-effects.

In nine patients of median age 34 years who had sustained an amputation of the thumb at a median 24 (5 to 131) months previously, we lengthened the first metacarpal by 30 (17 to 36) mm. Seven amputations had been through the proximal phalanx and two through the metacarpal.

The first two patients had autogenous grafting at a second stage, but the other seven had callotasis alone. In these patients the external fixators were removed at a median 189 (115 to 271) days after osteotomy. In six cases the adductor pollicis tendon was transferred proximally and the first web deepened. There was late fracture or palmar flexion of the callus in five patients, but this required further surgery in only one. Treatment was complete at 326 (140 to 489) days after osteotomy. The extended thumb retained its sensitivity; both grasp and key-pinch strength were satisfactory and only one patient felt that the result did not warrant the long course of treatment.

Metacarpal lengthening by this method is a prolonged procedure, but provides a valuable alternative to more complex reconstructions.

Several authors have reported complications from screw removal after treatment of slipped upper femoral epiphysis by single screw fixation, and have attributed these to poor screw design. We have developed a simple and reliable method of screw removal which uses a cannulated 8.0 mm end-threaded cancellous screw (Smith & Nephew Richards Medical, Memphis, Tennessee) and a specially designed cannulated trephine.

The method has been successful, with minimal complications, and a limited surgical exposure.

We have used the Ilizarov technique for severe flexion deformity of the knee in 11 patients (13 knees) between 1986 and 1994 and have followed them up for an average of 4.1 years. The age of the patients at operation ranged from 1.7 to 18.8 years.

The femoral and tibial components were connected by two anterior hinges, medial and lateral, and two posterior distraction rods. The deformity was corrected to a femorotibial lateral shaft angle of less than 20°. A permanent orthosis was applied after removal of the fixator. Fractures occurred in four patients and paralysis of the common peroneal nerve in another. There was a recurrence of the deformity in four patients.

At the last review all patients were able to walk on their operated leg with or without an orthosis.

We have found the Ilizarov method to be helpful in correcting severe fixed flexion deformity of the knee, with relatively few complications, but the basic principles of the method must be carefully followed.

We describe three sisters in a family who presented with a clinical form of osteomesopycnosis which is a rare, benign osteosclerotic bone disorder limited to the axial skeleton. It must be distinguished from other osteosclerotic conditions which carry a worse prognosis. This is the first report of the condition in a Japanese family, and we believe it to be the first to be identified in Asian races.