Aims: The objective of this study was to clinically assess the outcome of CADCAM femoral components in the revision hip replacement. Methods: Between 1991 and 2000, 125 revision total hip replacements using CAD-CAM femoral components were performed. Clinical assessment was performed using the Harris Hip score, by direct patient consultation, and telephone or postal questionnaire. Survivorship was defined as the requirement for revision. Results: The patients were reviewed at a mean of 5.2 yrs (1 to 10)

The mean Harris hip score increased from 44 points (range, 27 to 71 points) preoperatively to 71 points (range, 21 to 98 points) at the time of the most recent follow-up. 9 patients required subsequent revision; 4 for aseptic loosening, 1 for septic loosening and 4 for fracture of the femoral component. Conclusions: CAD-CAM technology provides a viable alternative to the challenge of revision hip surgery, with results comparable to other cementless techniques.

Autologous chondrocyte implantation (ACI) and mosaicplasty are both claimed to be successful for the repair of defects of the articular cartilage of the knee but there has been no comparative study of the two methods. A total of 100 patients with a mean age of 31.3 years (16 to 49) and with a symptomatic lesion of the articular cartilage in the knee which was suitable for cartilage repair was randomised to undergo either ACI or mosaicplasty; 58 patients had ACI and 42 mosaicplasty. Most lesions were post-traumatic and the mean size of the defect was 4.66 cm². The mean duration of symptoms was 7.2 years and the mean number of previous operations, excluding arthroscopy, was 1.5. The mean follow-up was 19 months (12 to 26).

Functional assessment using the modified Cincinatti and Stanmore scores and objective clinical assessment showed that 88% had excellent or good results after ACI compared with 69% after mosaicplasty. Arthroscopy at one year demonstrated excellent or good repairs in 82% after ACI and in 34% after mosaicplasty. All five patellar mosaicplasties failed.

Our prospective, randomised, clinical trial has shown significant superiority of ACI over mosaicplasty for the repair of articular defects in the knee. The results for ACI are comparable with those in other studies, but those for mosaicplasty suggest that its continued use is of dubious value.

Autologous Chondrocyte Implantation (ACI) is a technique for repair of isolated symptomatic articular cartilage defects in the young adult knee. The knee is arthroscopically assessed and a sample of cartilage is harvested from the margin of the joint, this is digested and the liberated chondrocytes expanded in culture. At subsequent arthrotomy, the articular cartilage lesion is debrided and the cells injected behind a sutured flap. A concern regarding ACI is the iatrogenic insult to non-injured healthy cartilage adjacent to that harvested for culture.

Damaged cartilage around the lesion is routinely debrided and discarded at the second stage operation. The purpose of this study was to determine whether this damaged debrided cartilage could yield an adequate number of equivalent chondrocytes for ACL.

Cells from 11 patients were analysed. The debrided “waste” from around the lesion was collected, enzymatically digested and the liberated chondrocytes cultured in monolayer.

The cells were recovered and placed in a 3D-pellet culture in a defined medium.

Chondrocytes obtained from the routine harvest of healthy cartilage were placed in a similar culture system. The two groups were compared using DNA and GAG assays, histological and immunohistochemical techniques.

Chondrocytes obtained from the debrided cartilage lesion were equivalent to those obtained from the harvested healthy cartilage. Sufficient cell numbers for implantation were achieved for all patients, however cells cultured from the debrided defect in patients who had a large degenerate lesion required significantly longer in culture to attain the required number of cells.

For many patients undergoing ACI, the potential iatrogenic insult to the joint cartilage of the harvesting procedure could be avoided by harvesting the damaged tissue from around the defect itself.

Mosaicplasty¹ and Autologous Chondrocyte Implantation² (ACI) are both modern cartilage repair techniques used to repair symptomatic articular cartilage defects in the knee, based on small osteochondral grafts and cultured chondrocytes respectively. The aim is the restoration of articular cartilage, but until now there is no data comparing the two methods.

100 consecutive patients aged 15–45 with a symptomatic articular cartilage lesion in the knee suitable for cartilage repair were randomised at arthroscopic assessment to undergo either mosaicplasty or ACI. 42 patients underwent mosaicplasty, 58 had ACI. Mean age at time of surgery was 31 years and the average defect size 4. 66 cm².

46% of the defects were post-traumatic, 19% had osteochondritis dissecans, 14% had chondromalacia patella and 16% had lesions of unknown aetiology. 53% had a medial femoral condyle lesion, 25% patella, 18% lateral femoral condyle, 3% trochlea and there was one defect of the lateral tibial plateau.

The mean duration of symptoms was 7. 2 years and the average number of previous operations (excluding arthroscopies) was 1. 5. Only 6 patients had no prior surgical interventions to the affected knee. The mean follow-up was 1. 7 years.

Patients were evaluated using Modified Cincinnati and Stanmore Functional rating systems, visual analogue scores and clinical assessment. Arthroscopy and biopsy was performed at one year and repair assessed with the International Cartilage Repair Society grading system.

Clinical results at one year showed 70% of mosaic-plasty patients and 87% of ACI patients had a good or excellent result. Arthroscopy at one year demonstrated more complete healing in ACI patients. Eleven (26%) of the mosaicplasty group subsequently failed clinically and arthroscopically, with peak failure at 2 years.

At one year follow-up, both techniques of articular cartilage repair can be useful in selected patients. ACI is preferred for lesions of the patella. Long-term follow-up is needed to assess the durability of articular cartilage repair using these methods, in particular mosaicplasty which showed signs of progressive failure over 2 years.

Autologous Chondrocyte Implantation’ (ACI) is a cartilage repair technique that involves implantation of cultured chondrocytes beneath a membrane of autologous periosteum. In this study a porcine biodegradable membrane was also used to assess its effectiveness. The aim is to restore articular cartilage to symptomatic defects, rather than initiating a fibrocartilagenous repair.

We undertook a prospective study of 125 consecutive patients who underwent ACI. Average age at the time of surgery was 30. 9 years (range 14 – 49), 55% of patients were male. The average size of the defect was 4. 35 cm².

44% of defects were attributable to known traumatic incidents, 2 1 % had osteochondritis dessicans, 18% chondromalacia patella, 12% had defects of unknown aetiology and 5% other.

The average duration of symptoms prior to this surgery was 7. 16 years. The mean number of previous operations (excluding arthroscopies) was 1. 6. Only 9 patients had no previous major surgery to the affected knee. 44% had defects of the medial femoral condyle, 31% patella, 20% lateral femoral condyle and 5% had a trochlea lesion. 26% of the defects were covered with periosteum and 74% with a porcine collagen membrane (chondrogide)

Minimum follow-up was six months, 70 patients had minimum follow-up of one year. Mean follow-up 18 months.

Patients were assessed using Modified Cincinnati and Stanmore Functional rating systems, visual analogue scores and clinical evaluation.

Arthroscopy and biopsy was performed at one year and the repair assessed using the International Cartilage Research Society grading system.

At one year follow-up overall 41 % patients had an excellent result, 48% good, 8% fair and 3% poor. For defects of the medial femoral condyle, 88% had a good or excellent result, 85% for the lateral femoral condyle and 80% for the patella.

61 patients were arthroscopically assessed at one year. 50/61 (82%) demonstrated ICRS grade 1 or 2 repair. Healing of the defect occurred with either a periosteum or chondrogide defect cover.

Results at one year suggest that ACI is a successful articular cartilage repair technique in selected patients. Long-term follow-up is required to assess the durability of the repair.

The clinical results of carbon matrix support prostheses for treatment of articular cartilage defects of the femoral condyle and patella were assessed in 97 patients (100 prostheses) between 1989–99. Patients were independently reviewed by subjective and objective criteria. Pre-operative and current visual analogue scores for pain (VAPS); Stanmore and modified Cincinnati functional rating scores were obtained. Forty-nine patients had lesions of the patella, forty-four patients of the medial femoral condyle and seven patients of the lateral femoral condyle.

Patella group – subjectively 49% reported they were improved, 8% unchanged and 43% worse. Stanmore score: 6 excellent and 17 good (47%), 5 fair and 21 were poor. The Cincinnati score increased from 26. 5 pre-operatively to 47. 5 currently (p< 0. 001). The mean VAPS decreased from 8. 1 to 5. 0 (p< 0. 001).

Medial femoral condyle group – subjectively 60% reported they were improved, 14% unchanged and 26% worse. Stanmore score: 8 excellent and 16 good (55%), 8 fair and 12 poor. The Cincinnati score increased from 22. 3 pre-operatively to 48. 5 currently (p< 0. 001). The mean VAPS decreased from 8. 6 to 5. 1 (p< 0. 001).

Lateral femoral condyle group – subjectively 42% reported they were improved, 29% unchanged and 29% worse.

Stanmore score: 2 excellent and 1 good (43%), 2 fair and 2 poor. The Cincinnati score increased from 35. 0 pre-operatively to 52. 0 currently (p< 0. 25). The mean VAPS decreased from 6. 5 to 4. 0 (p< 0. 25).

There were no statistical differences in outcome based upon gender, site, pre-operative functional rating score, diagnosis, or any correlation with age or length of follow up, or when comparing excellent/good with fair/ poor subgroups in patellae or femoral condyles in relation to these variables.

This study demonstrated that 49% improved in the patella group, 60% in the medial femoral condyle and 43% in the lateral femoral condyle groups. The use of these prostheses was effective on the medial femoral condyle for periods up to 10 years but the use in the patella and lateral femoral condyle was less successful.

The use of intra-articular hyaluronic acid injections for the treatment of early osteoarthritis is in widespread clinical use. Hyaluronate (HA) is a major component of connective tissue¹ and is available commercially for the intra-articular injective treatment of osteoarthritis of the knee and periarthritis of the shoulder. Although it is known to improve intra-articular lubrication it is also thought to promote articular cartilage structure and prevent catabolism of matrix proteoglycans in osteoarthritis. Clinical studies have shown beneficial effects lasting for many months after cessation of therapy unlike anti-inflammatory drugs that have relatively short term relieving effects^2,3 . Documentation of the true chondroprotective effects of hyaluronic acid (HA) at the cellular level is lacking and therefore this study aimed to identify the effects of HA on chondrocytes cultured in vitro.

Bovine articular chondrocytes were isolated by sequential digestion with pronase and collagenase and seeded in 2% alginate at 1x10⁷ cells/ml. The constructs were cultured for up to 14 days in standard culture medium (DMEM + 20% Fetal calf serum) containing varying concentrations of HA (Sigma), including doses equivalent to those found in vivo. The medium was replaced every 3 days and representative constructs were removed from culture, digested and assayed for DNA, glycosaminoglycans and Collagen. Further constructs were fixed in 4% paraformaldehyde for standard histology and immunolocalisation of collagen types I, II and chondroitin-6-sulphate.

Chondrocytes cultured in the HA system proliferated (increase in DNA) at a faster rate than the controls. There was a 2.2 fold increase in cell concentration at 14 days compared to a 1.2 fold increase in the controls. Total GAG levels at each time point were significantly greater for cells cultured in HA than in controls. Histologically, constructs were characterised by extensive cell cluster formation and intense Safranin-O staining. The newly synthesised matrix also stained positive for type II collagen. By contrast, control constructs exhibited minimal cluster formation, Safranin-O and type II collagen staining.

Cells maintained with HA exhibited a significantly greater rate of proliferation and matrix production. The presence of matrix rich in type II collagen indicates maintenance of chondrocytic phenotype. By contrast, cells cultured without HA did not show these features. These results support the use of intra-articular injections for the treatment of osteoarthritis. The benefits of HA injections may be due to cellular mechanisms as well as mechanical.

The use of intra-articular corticosteroid injections for their anti-inflammatory effects is widespread amongst clinicians. Despite their use in both rheumatoid arthritis and osteoarthritis, the effect of these agents on articular chondrocytes is not fully established. Previous reports suggest a detrimental effect on cartilage explants resulting from inhibition of matrix synthesis¹. However it has also been suggested that the beneficial effects in vivo may be due to prevention of inflamed synovium causing cartilage degradation². Our aim was to assess the effect of a commercially available preparation of methylprednisolone (MP), at clinical doses, on articular chondrocytes cultured in vitro.

Bovine articular chondrocytes were isolated by sequential digestion with pronase and collagenase and seeded in 2% alginate at 1x10⁷ cells/ml. The constructs were cultured for up to 15 days in standard culture medium (DMEM + 20% Fetal calf serum) containing varying concentrations of MP, including doses equivalent to those found in vivo. The medium was replaced every 3 days and representative constructs were removed from culture, digested and assayed for DNA and glycosaminoglycans. Further constructs were fixed in 4% paraformaldehyde for standard histology and immunolocalisation of collagen types I, II and chondroitin-6-sulphate.

Chondrocytes cultured in MP containing medium showed a significant abnormality in cell morphology compared to controls at the day 15 time point. Histologically there was evidence of cell necrosis, reduced amounts of extracellular matrix and loss of collagen type II staining. The effects were dose dependant, with significant damage occurring even at clinical doses. Biochemical analysis revealed a reduction in DNA content and an inhibition of glycosaminoglycan and collagen type II synthesis. In contrast, in the controls, there was cell proliferation with a cell doubling time of 14 days, collagen type II containing extracellular matrix synthesis occurred and the chondrocytes maintained their phenotype throughout the culture period.

Methylprednisolone has a significant detrimental effect on cultured articular chondrocytes in vitro. There was significant cell necrosis associated with inhibition of extracellular matrix synthesis. Based on these results, intra-articular corticosteroid injections should be used with extreme caution.

Nicotine is a constituent of tobacco smoke and is present in the body fluids of smokers^1,2. Numerous studies have confirmed that smoking is a strong risk factor for back pain³. The most widely accepted explanation for the association is that smoking leads to malnutrition of spinal discs due to carboxyhaemoglobin formation. However, other constituents of smoke, such as nicotine, may also be responsible for intervertebral disc (IVD) degeneration by leading to cell necrosis in both the nucleus pulposus and annulus fibrosis. Despite evidence suggesting the detrimental effect on a variety of tissues, the effect of nicotine on IVD cells has not previously been investigated. This study investigated the influence of nicotine on the metabolism and viability of IVD cells cultured in vitro.

Bovine nucleus pulposus (NP) intervertebral disc cells were isolated by sequential digestion of caudal spinal disc nuclei with pronase and collagenase and seeded in 2% alginate at 5x10⁶ cells/ml. The constructs were cultured for 21 days in standard culture medium (DMEM + 20% Fetal calf serum) containing free base nicotine (Sigma) at concentrations ranging from 25nM and 300nM, which reflected the normal physiological concentrations found in the serum of smokers. The medium was replaced every 3 days and representative constructs were removed from culture, digested and assayed for DNA, glycosaminoglycan (GAG) and hydroxyproline content at time points 3, 7, 14 and 21 days. Further constructs were processed for standard histology and immunolocalisation of collagen types I, II and chondroitin-6-sulphate.

The results were analysed statistically using an ANOVA test followed by a non-parametric Dunnit’s test. NP cells demonstrated a dose dependent response. At 25nM dose of nicotine there was a significant increase (p< 0.05) in DNA content, GAG and collagen synthesis in the constructs. At 100nM, 200nM and 300nM doses, there was a significant dose dependent decrease (p< 0.05) in all of these parameters compared to controls cultured under nicotine free conditions. In addition, adverse morphological changes were observed on histology, which included reduced cell proliferation, disrupted cell architecture, disintegration of cells and extracellular matrix. Immunohistochemistry showed the production of type I collagen rather than type II collagen as in the controls.

Nicotine has an overall detrimental effect on cultured nucleus pulposus disc cells in vitro. There was significant inhibition of cell proliferation and extracellular matrix synthesis. Nicotine in tobacco smoke may therefore play a role in the aetiology of disc degeneration that leads to back pain in smokers.

Deep infection is a devastating complication of total joint arthroplasty. In a significant proportion of cases it remains a diagnostic challenge. Haematological tests are not specific, particularly in chronic cases, and radiological investigations such as bone scan and radiographs are of only limited value. The most common infective organisms are staphylococcus and some streptococcus species. Acidity is a well established occurrence in infective processes and is caused by the direct production of acid by the organism or by enzymatic degradation of tissues ^1,2. In wound infections, peritonitis and some other conditions pH is used as an indicator of infection in clinical practice³. The aim was to assess whether fluid biochemistry (pH, pCO2, pO2, Lactate and Glucose) is altered in infected total knee replacements and whether it could be used as a diagnostic test.

Nineteen consecutive patients undergoing either revision total knee replacement (TKR) or arthroscopic synovial biopsy were included in the study. All had had their primary joint replacement within the previous 3 years. All had a painful total knee replacement and some had evidence of loosening of the prosthesis on radiological investigations. The following investigations were performed on each patient, White cell count (WCC), Erythrocyte Sedimentation Rate (ESR), C-Reactive Protein (CRP), interface synovial biopsy for histology and microbiology and a synovial fluid aspiration from the affected joint prior to application of a tourniquet. A blood gas analyser was used to measure pH, pCO2, pO2, Lactate and Glucose in all synovial fluid specimens.

Seven patients were diagnosed as having an infected TKR on clinical and laboratory investigations. The mean synovial fluid biochemistry results were pH = 7.09, pO2= 5.08kPa, pCO2=10.40kPa, Lactate = 5.33 mmol/l, Glucose = 2.30 mmol/l. In the non-infected group the results were pH = 7.23, pO2 = 7.72kPa, pCO2 = 8.41kPa, Lactate = 4.03 mmol/l, Glucose = 3.42 mmol/l. The differences in pH, pCO2/pO2 ratio, and glucose levels were statistically significant (t-Test p < 0.05) between the two groups. Lactate levels were not significantly different. There was no correlation between high WCC’s and synovial fluid biochemistry or laboratory results for infected cases. Using laboratory results as a gold standard and a synovial fluid pH of less than 7.20, the sensitivity was 85% and specificity 77% for diagnosing an infection. Using a combination of the synovial fluid biochemistry results these values were greater.

Synovial fluid biochemistry is significantly altered in infected total knee replacements. pH levels below 7.2, pCO2/pO2 ratio above 2.5 and Glucose levels below 2.5 mmol/l are strong indicators of an infected TKR. Synovial pH assessment may prove to be a quick, cheap and effective method of diagnosing an infected TKR and may also apply to other joints. Further studies using non-problematic TKR’s as controls are required.

Many methods have been described over the past 5 years for repair of articular cartilage defects. The best reported results have been from the use of autologous chondrocyte transplantation (ACT)(1) and mosaicplasty.(2) There have, however, been no prospective clinical trials of these two methods. In this trial 70 patients were prospectively randomized to receive either autologous chondrocyte transplantation (37) or mosaicplasty (33) in the knee. 37 patients were female and 33 male. The average age was 32 years (16 – 44). The indications for surgery were persistent pain and mechanical symptoms in the knee with an isolated defect of the articular cartilage. 38 (56%) were post-traumatic, 12 (16%) due to osteochondritis dissecans, 10 (14%) due to previous meniscectomy, and 10 (14%) due to chondromalacia patellae. The size of the defects ranged from 2cm2 to 12cm2 (mean 4.8cm2). There were 35 defects on the medial femoral condyle, 13 on the lateral femoral condyle, 17 on the patella and 5 on the trochlear. 31 patients were undergoing primary surgery and 39 secondary surgery. All were independently reviewed using the Visual Analogue Pain Score, the Cincinatti Pain Score and the Stanmore Score. Patients were arthroscoped at one year with MRI scan and biopsies where possible.

Results: The visual analogue pain score improved overall from a mean of 5.4 (range 3.4 – 7.4) pre-operatively to 3.9 (1.8 – 5.1) at one year review. Similarly the Cincinatti pain score improved from 6.5 pre-operatively to 10.2 post-operatively and the Cincinatti function score improved from 46 to 62 at one year before sport commenced. Overall 71% (49) patients were excellent or good on the clinical scoring scales, 15% (11) were fair, and 14% (10) were poor. The 10 poor results were no different from the main group with regard to age, sex, pain level or site or size of lesion. However, 5 were secondary procedures, 2 had multiple lesions, and 3 had had previous ruptured anterior cruciate ligaments. Arthroscopy and biopsy of 21 lesions so far after one year has shown mature articular cartilage in 2, and immature cartilage in 19. In all cases there was bonding of the repair tissue to the underlying bone. This study is already clarifying the role of ACT and mosaicplasty in the management of cartilage defects in the knee and also the necessity for the use of periosteal covering membrane.

The purpose of this study was to evaluate the influence of trochlear design in total knee replacement with and without patellar resurfacing.

Methods and Results: In 1992 a trial was set up, including all patients undergoing primary PFC (Johnson & Johnson) total knee replacement. Patients were randomised to either patellar resurfacing or retention. The patients were assessed using the American Knee Society rating, a clinical anterior knee pain score and BOA patient satisfaction score. Assessment was performed without knowing whether the patella had been resurfaced.

In July 1998 we began using the PFC Sigma. This incorporates a deeper trochlear groove with a 5° valgus angle.

We compared the results for the two types of prosthesis. In the PFC group there were 474 knees in 390 patients. Follow-up was from 2 to 9 years (mean 5.5 years). The overall prevalence of anterior knee pain) was 25.1% (58 knees) and 5.3% (13 knees) in the non-resurfaced group (n=231) versus the resurfaced group (n=243) respectively. Anterior knee pain became apparent in all cases within 18 months.

In the PFC sigma group there were 67 knees in 62 patients. Follow-up was from 18 months to 3 years (mean 2 years). The incidence of anterior knee pain was 0 in the resurfaced group (n=30) versus 37.8% (14 knees) in the non-resurfaced group (n=37). Knee scores were lower in the non-resurfaced groups for each prosthesis.

Conclusion: The prevalence of anterior knee pain was significantly higher in knees with non-resurfacing of the patella. The asymmetrical, deeper femoral groove improves anterior knee pain with the resurfaced patella but may contribute to it if not resurfaced. We recommend patellar resurfacing in all cases where technically possible.

The issue of preservation or sacrifice of the posterior cruciate ligament in total knee arthroplasty remains unresolved.

We report the results of 200 consecutive total knee arthroplasties performed at our hospital under the direction of the senior author. Pre-operatively, patients were randomly chosen to receive either a Kinemax (posterior cruciate retaining) or a Press-Fit-Condylar (posterior cruciate sacrificing) prosthesis. We implanted 97 Kinemax and 103 Press-Fit-Condylar prostheses which were prospectively followed-up by clinical and radiographic assessment. Review at mean follow-up of 2.7 years showed a satisfactory clinical result in both groups [Surace, et al., 1994].

We present the results of our further review, with maximum follow-up of over nine years (mean: 5.9 years). Revision of the implant has been performed in five knees (three Kinemax and two Press-Fit-Condylar). The polythene spacer had to be replaced in one patient with a Press-Fit-Condylar implant.

Patients were assessed with the Hospital for Special Surgery Knee Score and radiologically assessed with the Knee Society Roentgenographic Evaluation and Scoring System. Pre-operative demographics and disease states of the patients were similar, with an average Hospital for Special Surgery Knee Score of 63. At the latest assessment the average knee score was good (85). Remarkably, the mean knee score for the posterior cruciate sacrifice and the PCL groups remains similar (mean: 85). Radiographic evaluation demonstrated that the prosthetic components of both groups were in comparable alignment. The posterior cruciate ligament retained (Kinemax) patient group showed a mean 5.9 degrees of the valgus angle at the knee. The angle in the posterior cruciate ligament sacrifice (PFC implant) group was 6.2 degrees. Evaluation of the radiolucent depths below the femoral, tibial and any patella component showed a mean total depth of 1.5 mm (pcl retaining) and 1.7 mm (pcl sacrificing).

Our study presents a quantitative perspective of the results of total knee replacement with proven implant systems and performed in a general orthopaedic unit by both consultants and surgeons in training. The Kinemax (Howmedica) and Press-Fit-Condylar (DePuy Johnson and Johnson) implant systems have both previously demonstrated good results and continue to be available with little subsequent modification.

To our knowledge, there have been no other large prospectively randomised studies of posterior cruciate ligament preservation or sacrifice in total knee replacement.

We clinically and radiologically reviewed 79 uncemented PFC acetabular components inserted by our unit during a seven-year period, June 1991 to June 1998. Of these, 50 (63.3%) were primary and 29 (26.7%) were revision arthroplasties. The mean follow-up was five years (60 months), with a range of 12 to 95 months. Sixteen (20%) were excluded from the study, leaving 63 (26.7%) for review. Three (4.7%) cases were deemed to have failed (at 63, 69, 79 months), all of which were primary arthroplasties. One of them was found to be loose at revision and the other two cups had 2 mm of periacetabular radiolucency in only one zone, but had no definite evidence of loosening.

The remaining 60 (95.3%) cases showed no radiological evidence of migration of any cups, and no hip had a radiolucent line in all three zones of the acetabulum. Clinical review gave a mean Harris hip score of 96.5. Fifty (79.4%) reported no pain from the hip. One case (1.6%) had undergone recent revision of the stem, at which time the cup was found to be stable. Three (4.7%) reported slight, occasional pain. Another three (4.7%) described mild pain that did not compromise their average activities and was relieved by simple analgesia. Two cases (3.2%) complained of moderate pain that placed some limitations on their activities and required regular analgesia, and one elderly patient who had an ankylosed contralateral hip and ipsilateral sciatic nerve palsy described marked pain (1.6%), and these were considered poor outcomes. In all of these cases the cups were clinically and radiologically stable.

In conclusion, 81% of outcomes were excellent, painfree THRs. A further 4.75% had good and 4.75% fair results. 4.75% had poor outcomes and 4.75% of cases failed. We conclude that the PFC cup merits continued use and follow-up, and together with other uncemented cup designs, may produce benefits in the form of quality and longevity of results in total hip arthroplasty.

The purpose of this study was to evaluate the role of patellar resurfacing in total knee replacement surgery. We reviewed 48 patients who had undergone bilateral knee replacement with patellar resurfacing on only one side. Follow-up was from 18 months to 9.5 years and the patients were assessed using the Knee Society rating, a clinical anterior knee pain score and BOA patient satisfaction score. Patients were also asked specifically if they had a preference for either knee. Assessment was performed without knowing which patella had been resurfaced.

52.1% of patients favoured the resurfaced knee, 8% the unresurfaced knee and 39.9% had no particular preference. The overall prevalence of anterior knee pain was 8.3% in the resurfaced cases (3 mild, 1 moderate) and 27.1% in the unresurfaced knees (8 mild, 3 moderate, 2 severe). No significant difference was found between knee scores.

This study shows a significantly higher rate of anterior knee pain in unresurfaced patellae and preference for the resurfaced side.

We have treated 101 patients with scoliosis secondary to muscular dystrophy over a 13-year period; 64 had Duchenne’s muscular dystrophy, 33 spinal muscular atrophy and four congenital muscular dystrophy.

The patients underwent a modified Luque (87) or Harrington-Luque instrumentation (14) combined with a limited Moe fusion in all except 27 cases. A mean of 13 levels was instrumented. The mean preoperative sitting Cobb angle was 84° (10 to 150) and the mean postoperative angle 40° (52% correction). Most patients (96%) were able to discard their braces and there was a high level of patient satisfaction (89.6%).

Less correction was seen for severe curves, and there was a greater recurrence of postoperative pelvic tilt in those patients not instrumented to the sacrum. Although the incidence of minor or temporary complications was high, these occurred chiefly in the early high-risk patients with very severe curves and considerable pre-existing immobility.

The formation of restrictive adhesions around the musculotendinous unit after injury is one of the most vexing processes faced by the surgeon. In flexor tendons it has been shown that the synovial tissue is the source of aggressive fibroblasts which contribute to this process. Using a rabbit model, we have examined the effects of treating the synovial sheath with the antimetabolite 5-fluorouracil (5-FU) for five minutes. Inflammatory, proliferative and molecular markers were compared in the response of the treated and control tendons to injury. Compared with a control group we found that the proliferative and inflammatory responses were significantly reduced (p < 0.001) in the treated tendons. Not only was there a reduction in the cellular and cytokine response, but there also was a significant (p < 0.001) reduction in the level of activity of the known pro-scarring agent, transforming growth factor beta 1 (TGF-β1). These pilot studies indicate that the formation of restrictive adhesions may be modulated using a simple single-touch technique in the hope of producing a better return of function.

We reviewed the outcome of 146 Insall-Burstein II total knee replacements carried out in 121 patients over a period of nearly four years in a general orthopaedic unit. At a mean follow-up of ten years, 94 knees in 78 patients were available for review. Six patients (7 knees) were lost to follow-up and 37 (45 knees) had died.

The clinical outcome using the scoring system of the Hospital for Special Surgery (HSS) was excellent or good in 79% of patients, fair in 14% and poor in 7%. The mean preoperative HSS score was 31, improving to 79 at the latest review. Using the newer rating system of the Knee Society, the mean score at ten years was 87 and the mean functional score 56. The arc of flexion improved from a mean preoperative value of 88° to 100°. The 18 patients who had had a previous high tibial osteotomy were analysed separately and were found to have benefited equally from the operation. Nine prostheses were revised, giving a cumulative survival rate of 92.3% at ten years. Radiological evaluation of 104 radiographs showed radiolucent lines around ten tibial components, none of which required revision. Anterior knee pain was a significant problem.