It is probable that both genetic and environmental factors play some part in the aetiology of most cases of degenerative hip disease. Geneticists have identified some single gene disorders of the hip, but have had difficulty in identifying the genetics of many of the common causes of degenerative hip disease. The heterogeneity of the phenotypes studied is part of the problem. A detailed classification of phenotypes is proposed. This study is based on careful documentation of 2003 consecutive total hip replacements performed by a single surgeon between 1972 and 2000. The concept that developmental problems may initiate degenerative hip disease is supported. The influences of gender, age and body mass index are outlined. Biomechanical explanations for some of the radiological appearances encountered are suggested. The body weight lever, which is larger than the abductor lever, causes the abductor power to be more important than body weight. The possibility that a deficiency in joint lubrication is a cause of degenerative hip disease is discussed. Identifying the phenotypes may help geneticists to identify genes responsible for degenerative hip disease, and eventually lead to a definitive classification.

Metallosis is a rare cause of failure after total knee replacement and has only previously been reported when there has been abnormal metal-on-metal contact. We describe 14 patients (15 knees) whose total knee replacement required revision for a new type of early failure caused by extensive metallosis. A modification of a cementless rotating platform implant, which had previously had excellent long-term survival, had been used in each case. The change was in the form of a new porous-beaded surface on the femoral component to induce cementless fixation, which had been used successfully in the fixation of acetabular and tibial components. This modification appeared to have resulted in metallosis due to abrasive two-body wear. The component has subsequently been recalled and is no longer in use. The presentation, investigation, and findings at revision are described and a possible aetiology and its implications are discussed.

Pulmonary embolism is a serious complication after arthroscopy of the knee, about which there is limited information. We have identified the incidence and risk factors for symptomatic pulmonary embolism after arthroscopic procedures on outpatients. The New York State Department of Health Statewide Planning and Research Cooperative System database was used to review arthroscopic procedures of the knee performed on outpatients between 1997 and 2006, and identify those admitted within 90 days of surgery with an associated diagnosis of pulmonary embolism. Potential risk factors included age, gender, complexity of surgery, operating time defined as the total time that the patient was actually in the operating room, history of cancer, comorbidities, and the type of anaesthesia. We identified 374 033 patients who underwent 418 323 outpatient arthroscopies of the knee. There were 117 events of pulmonary embolism (2.8 cases for every 10 000 arthroscopies). Logistic regression analysis showed that age and operating time had significant dose-response increases in risk (p < 0.001) for a subsequent admission with a pulmonary embolism. Female gender was associated with a 1.5-fold increase in risk (p = 0.03), and a history of cancer with a threefold increase (p = 0.05).

These risk factors can be used when obtaining informed consent before surgery, to elevate the level of clinical suspicion of pulmonary embolism in patients at risk, and to establish a rationale for prospective studies to test the clinical benefit of thromboprophylaxis in high-risk patients.

Between 1982 and 1997, 403 consecutive patients (522 elbows) with rheumatoid arthritis underwent Souter-Strathclyde total elbow replacement. By the end of 2007, there had been 66 revisions for aseptic loosening in 60 patients. The mean time of follow-up was 10.6 years (0 to 25) The survival rates at five-, ten, 15 and 19 years were 96% (95%, confidence interval (CI) 95 to 98), 89% (95% CI 86 to 92), 83% (95% CI 78 to 87), and 77% (95% CI 69 to 85), respectively. The small and medium-sized short-stemmed primary humeral components had a 5.6-fold and 3.6-fold risk of revision for aseptic loosening respectively, compared to the medium-sized long-stemmed component. The small and medium-sized all-polyethylene ulnar components had respectively a 28.2-fold and 8.4-fold risk of revision for aseptic loosening, compared to the metal-backed ulnar components.

The use of retentive ulnar components was not associated with an increased risk of aseptic loosening compared to non-retentive implants.

Cementless acetabular fixation has demonstrated superior long-term durability in total hip replacement, but most series have studied implants with porous metal surfaces. We retrospectively evaluated the results of 100 consecutive patients undergoing total hip replacement where a non-porous Allofit component was used for primary press-fit fixation.

This implant is titanium alloy, grit-blasted, with a macrostructure of forged teeth and has a biradial shape. A total of 81 patients (82 hips) were evaluated at final follow-up at a mean of 10.1 years (8.9 to 11.9). The Harris Hip Score improved from a mean 53 points (23 to 73) pre-operatively to a mean of 96 points (78 to 100) at final review. The osseointegration of all acetabular components was radiologically evaluated with no evidence of loosening. The survival rate with revision of the component as the endpoint was 97.5% (95% confidence interval 94 to 100) after 11.9 years. Radiolucency was found in one DeLee-Charnley zone in four acetabular components. None of the implants required revision for aseptic loosening. Two patients were treated for infection, one requiring a two-stage revision of the implant. One femoral stem was revised for osteolysis due to the production of metal wear debris, but the acetabular shell did not require revision.

This study demonstrates that a non-porous titanium acetabular component with adjunct surface fixation offers an alternative to standard porous-coated implants.

We retrospectively reviewed 11 consecutive patients with an infected reverse shoulder prosthesis. Patients were assessed clinically and radiologically, and standard laboratory tests were carried out. Peroperative samples showed Propionbacterium acnes in seven, coagulase-negative Staphylococcus in five, methicillin-resistant staphylococcus aureus in one and Escherichia coli in one. Two multibacterial and nine monobacterial infections were seen. Post-operatively, patients were treated with intravenous cefazolin for at least three days and in all antibiotic therapy was given for at least three months. Severe pain (3 of 11) or severe limitation of function (3 of 11) are not necessarily seen. A fistula was present in eight, but function was not affected. All but one patient were considered free of infection after one-stage revision at a median follow-up of 24 months, and without antibiotic treatment for a minimum of six months. One patient had a persistent infection despite a second staged revision, but is now free of infection with a spacer. Complications included posterior dislocation in one, haematoma in one and a clavicular fracture in one. At the most recent follow-up the median post-operative Constant-Murley score was 55, 6% adjusted for age, gender and dominance.

A one-stage revision arthroplasty reduces the cost and duration of treatment. It is reliable in eradicating infection and good functional outcomes can be achieved.

Between 1995 and 2006, five intra-articular osteotomies of the head of the radius were performed in patients with symptomatic healed displaced articular fractures. Pre-operatively, all patients complained of persistent painful clicking on movement. Only patients with mild or no degenerative changes of the radial head and capitellum were considered for osteotomy. The operations were performed at a mean of 8.2 months (4 to 13) after injury and the patients were reviewed at a mean of 5.5 years (15 months to 12 years) after the osteotomy.

The average Mayo Elbow Performance Index Score improved significantly from 74 before to 88 after operation, with four patients rated as good or excellent (p < 0.05). The subjective patient satisfaction score was 8.4 on a ten-point scale. All osteotomies healed and there were no complications.

In this small series intra-articular osteotomy of the head of the radius was a safe and effective treatment for symptomatic intra-articular malunion without advanced degenerative changes.

We compared the outcome of peri-operative humeral condylar fractures in patients undergoing a Coonrad-Morrey semiconstrained total elbow replacement with that of patients with rheumatoid arthritis undergoing the same procedure without fractures. In a consecutive series of 40 elbows in 33 patients, 13 elbows had a fracture in either condyle peri-operatively, and 27 elbows were intact. The fractured condyle was either fixed internally or excised. We found no statistical difference in the patients’ background, such as age, length of follow-up, immobilisation period, Larsen’s radiological grade, or Steinbrocker’s stage and functional class. There was also no statistical difference between the groups in relation to the Mayo Elbow Performance Score, muscle strength, range of movement, or radiolucency around the implants at a mean of 4.8 years (1.1 to 8.0) follow-up.

We conclude that fractured condyles can be successfully treated with either internal fixation or excision, and cause no harmful effect.

We carried out a prospective study to assess the clinical outcome, complications and survival of the NexGen Legacy posterior-stabilised-Flex total knee replacement (TKR) in a consecutive series of 278 knees between May 2003 and February 2005. Mean follow-up for 259 TKRs (98.2%) was 3.8 years (3.0 to 4.8). Annual follow-up showed improvement in the Knee Society scores (paired t-test, p < 0.05). At the last follow-up, the mean maximum flexion was 135° (110° to 150°). Two knees showed radiolucent lines, but revision was not required because the patients were asymptomatic. Revision was required in one case because of infection, but there were no prosthesis-related revisions. There were no other complications. The estimated survival rate at four years with revision for any reason and prosthesis-related problems was 99.6% and 100%, respectively.

This relatively large study indicates that the legacy posterior stabilised-Flex design provides excellent short-term outcome but warrants ongoing evaluation to confirm the long-term durability and functioning of the implant.

We evaluated the long-term fixation of 64 press-fit cemented stems of constrained total knee prostheses in 32 young patients with primary malignant bone tumours. Initial stable fixation, especially in rotation, was achieved by precise fit of the stem into the reamed endosteum, before cementation. Complementary fixation, especially in migration and rotation, was obtained by pressurised antibiotic-loaded cement. The mean age at operation was 33 years (13 to 61). No patient was lost to follow-up; 13 patients died and the 19 survivors were examined at a mean follow-up of 12.5 years (4 to 21). Standard revision press-fit cemented stems were used on the side of the joint which was not involved with tumour (26 tibial and six femoral), on this side there was no loosening or osteolysis and stem survival was 100%. On the reconstruction side, custom-made press-fit stems were used and the survival rate, with any cause for revision as an end point, was 88%, but 97% for loosening or osteolysis. This longevity is similar to that achieved at 20 years with the Charnley-Kerboull primary total hip replacement with press-fit cemented femoral components.

We recommend this type of fixation when extensive reconstruction of the knee is required. It may also be suitable for older patients requiring revision of a total knee replacement or in difficult situations such as severe deformity and complex articular fractures.

Between June 1991 and January 1995, 42 hydroxyapatite-coated CAD-CAM femoral components were inserted in 25 patients with inflammatory polyarthropathy, 21 of whom had juvenile idiopathic arthritis. Their mean age was 21 years (11 to 35). All the patients were reviewed clinically and radiologically at one, three and five years. At the final review at a mean of 11.2 years (8 to 13) 37 hips in 23 patients were available for assessment.

A total of four femoral components (9.5%) had failed, of which two were radiologically loose and two were revised. The four failed components were in patients aged 16 years or less at the time of surgery. Hydroxyapatite-coated customised femoral components give excellent medium- to long-term results in skeletally-mature young adults with inflammatory polyarthropathy. Patients aged less than 16 years at the time of surgery have a risk of 28.5% of failure of the femoral component at approximately ten years.

We analysed the long-term clinical and radiological results of 63 uncemented Low Contact Stress total knee replacements in 47 patients with rheumatoid arthritis. At a mean follow-up of 12.9 years (10 to 16), 36 patients (49 knees) were still alive; three patients (five knees) were lost to follow-up. Revision was necessary in three knees (4.8%) and the rate of infection was 3.2%. The mean clinical and functional Knee Society scores were 90 (30 to 98) and 59 (25 to 90), respectively, at final follow-up and the mean active range of movement was 104° (55° to 120°). The survival rate was 94% at 16 years but 85.5% of patients lost to follow-up were considered as failures. Radiological evidence of impending failure was noted in one knee.

This study describes 146 primary total knee replacements, either fully or partially coated with hydroxyapatite of which 74 knees in 68 patients were available for clinical and radiological assessment at a mean of 11.2 years (10 to 15). The global failure rate was 1.37% and survival rate with mechanical failure as the end-point was 98.14%. Radiological assessment indicated intimate contact between bone and the hydroxyapatite coating. Over time the hydroxyapatite coating appears to encourage filling of interface gaps remaining after surgery. Our results compare favourably with those of series describing cemented or porous-coated knee replacements, and suggest that fixation with hydroxyapatite is a reliable option in primary total knee replacement.

We report the clinical and radiographic outcome of a consecutive series of 138 hydroxyapatite-coated total knee replacements with a mean follow-up of 11 years (10 to 13). The patients were entered into a prospective study and all living patients (76 knees) were evaluated. The Hospital for Special Surgery knee score was obtained for comparison with the pre-operative situation. No patient was lost to follow-up. Radiographic assessment revealed no loosening. Seven prostheses have been revised, giving a cumulative survival rate of 93% at 13 years. We believe this to be the longest follow-up report available for an hydroxyapatite-coated knee replacement and the first for this design of Insall-Burstein II knee.

A modular layered acetabular component (metal-polyethylene-ceramic) was developed in Japan for use in alumina ceramic-on-ceramic total hip replacement. Between May 1999 and July 2000, we performed 35 alumina ceramic-on-ceramic total hip replacements in 30 consecutive patients, using this layered component and evaluated the clinical and radiological results over a mean follow-up of 5.8 years (5 to 6.5). A total of six hips underwent revision, one for infection, two for dislocation with loosening of the acetabular component, two for alumina liner fractures and one for component dissociation with pelvic osteolysis. There were no fractures of the ceramic heads, and no loosening of the femoral or acetabular component in the unrevised hips was seen at final follow-up. Osteolysis was not observed in any of the unrevised hips. The survivorship analysis at six years after surgery was 83%. The layered acetabular component in our experience, has poor durability because of unexpected mechanical failures including alumina liner fracture and component dissociation.

The Control of Infection Committee at a specialist orthopaedic hospital prospectively collected data on all episodes of bacteriologically-proven deep infection arising after primary hip and knee replacements over a 15-year period from 1987 to 2001.

There were 10 735 patients who underwent primary hip or knee replacement. In 34 of 5947 hip replacements (0.57%) and 41 of 4788 knee replacements (0.86%) a deep infection developed. The most common infecting micro-organism was coagulase-negative staphylococcus, followed by Staphylococcus aureus, enterococci and streptococci. Of the infecting organisms, 72% were sensitive to routine prophylactic antimicrobial agents.

Of the infections, 29% (22) arose in the first three months following surgery, 35% between three months and one year (26), and 36% (27) after one year. Most cases were detected early and treated aggressively, with eradication of the infection in 96% (72). There was no significant change in the infection rate or type of infecting micro-organism over the course of this study.

These results set a benchmark, and importantly emphasise that only 64% of peri-prosthetic infections arise within one year of surgery. These results also illustrate the advantages of conducting joint replacement surgery in the isolation of a specialist hospital.

We retrospectively compared wrist arthrodesis using the Mannerfelt technique in 19 or an AO-plate in 23 patients with long-standing rheumatoid arthritis. The mean follow-up was for 76 months.

Compared with the Mannerfelt fusion group, patients in the AO-plate group reported greater satisfaction with their wrist function (74% vs 37%, p = 0.015). Complications were reported in six wrists in the AO-plate group and two wrists in the Mannerfelt fusion group (p = 0.258). At final follow-up, 95% of patients (41) reported either no pain or only mild pain. There was improvement in flexion of the finger joints in both groups but no significant improvement in the extension lag in either group.

Both methods relieve pain and improve function. Overall, the activities of daily living scores and the patients’ subjective assessment of outcome tended to be higher in the AO-plate group than in the Mannerfelt fusion group, although the difference was not statistically significant. Similarly, although more postoperative complications occurred in the AO-plate group, the difference between the two groups was not statistically significant.

We carried out a prospective study of 118 hydroxyapatite-coated, cementless total knee replacements in patients who were ≤ 55 years of age and who had primary (92; 78%) or post-traumatic (26; 22%) osteoarthritis. The mean period of follow-up was 7.9 years (5 to 12.5). The Knee Society clinical scores improved from a pre-operative mean of 98 (0 to 137) to a mean of 185 (135 to 200) at five years, and 173 (137 to 200) at ten years. There were two revisions of the tibial component because of aseptic loosening, and one case of polyethylene wear requiring further surgery. There was no osteolysis or progressive radiological loosening of any other component. At 12 years, the overall rate of implant survival was 97.5% (excluding exchange of spacer) and 92.1% (including exchange of spacer).

Cementless total knee replacement can achieve excellent long-term results in young, active patients with osteoarthritis. In contrast to total hip replacement, polyethylene wear, osteolysis and loosening of the prosthesis were not major problems for these patients, although it is possible that this observation could change with longer periods of follow-up.

A series of 100 consecutive osteoarthritic patients was randomised to undergo total knee replacement using a Miller-Galante II prosthesis, with or without a cemented polyethylene patellar component. Knee function was evaluated using the American Knee Society score, Western Ontario and McMaster University Osteoarthritis index, specific patellofemoral-related questions and radiographic evaluation until the fourth post-operative year, then via questionnaire until ten years post-operatively. A ten-point difference in the American Knee Society score between the two groups was considered a significant change in knee performance, with α and β levels of 0.05.

The mean age of the patients in the resurfaced group was 71 years (53 to 88) and in the non-resurfaced group was 73 years (54 to 86).

After ten years 22 patients had died, seven were suffering from dementia, three declined further participation and ten were lost to follow-up. Two patients in the non-resurfaced group subsequently had their patellae resurfaced. In the resurfaced group one patient had an arthroscopic lateral release. There was no significant difference between the two treatment groups: both had a similar deterioration of scores with time, and no further patellofemoral complications were observed in either group.

We are unable to recommend routine patellar resurfacing in osteoarthritic patients undergoing total knee replacement on the basis of our findings.

This review describes the development of arthroscopy of the hip over the past 15 years with reference to patient assessment and selection, the technique, the conditions for which it is likely to prove useful, the contraindications and complications related to the procedure and, finally, to discuss possible developments in the future.