In order to define the predisposing factors and outcome of infected arthroplasty of the knee, a retrospective analysis of a consecutive series of 471 knee arthroplasties was performed. There were 23 cases of superficial wound infection and 25 of deep infection. Superficial wound infection alone resulted in a painfree gait, with little limitation of movement. Rheumatoid arthritis, the use of constrained prostheses and the presence of a superficial wound infection, all predisposed to deep infection. Deep infection was eradicated by long-term antibiotics in only two patients in whom skin cover was successfully provided by a gastrocnemius musculocutaneous flap. Excision of a sinus track, wound debridement and exchange arthroplasty were universally unsuccessful. Arthrodesis, however, in 11 out of 12 cases, provided the painfree gait these patients desire

Advanced osteoarthritis of the wrist or the distal articulation of the lunate with the capitate has traditionally been treated surgically by arthrodesis. In order to maintain movement, we performed proximal row carpectomy with capsular interposition arthroplasty as an alternative to arthrodesis in eight patients with advanced arthritis and retrospectively reviewed their clinical and radiographic outcomes after a mean follow-up of 41 months (13 to 53). The visual analogue scale (VAS) for pain at its worst and at rest, and the patient-rated wrist evaluation score improved significantly after surgery, whereas ranges of movement and grip strength were maintained at the pre-operative levels. Progression of arthritis in the radiocapitate joint was observed in three patients, but their outcomes were not significantly different from those without progression of arthritis. Proximal row carpectomy with capsular interposition arthroplasty is a reasonable option for the treatment of patients with advanced arthritis of the wrist

Retrieval studies have shown that the use of fully congruent meniscal bearings reduces wear in knee replacements. We report the outcome of 143 knees with anteromedial osteoarthritis and normal anterior cruciate ligaments treated by unicompartmental arthroplasty using fully congruous mobile polyethylene bearings. At review, 34 knees were in patients who had died and 109 were in those who were still living. The mean elapsed time since operation was 7.6 years (maximum 13.8). We established the status of all but one knee. There had been five revision operations giving a cumulative prosthetic survival rate at ten years (33 knees at risk) of 98% (95% CI 93% to 100%). Considering the knee lost to follow-up as a failure, the ‘worst-case’ survival rate was 97%. No failures were due to polyethylene wear or aseptic loosening of the tibial component. One bearing which dislocated at four years was reduced by closed manipulation. The ten-year survival rate is the best of those reported for unicompartmental arthroplasty and not significantly different from the best rates for total knee replacement

We reviewed 508 consecutive total hip replacements in 370 patients with old developmental dysplasia of the hip, to relate the amount of leg lengthening to the incidence of nerve palsies after operation. There were eight nerve palsies (two femoral, six sciatic), two complete and six incomplete.

We found no statistical correlation between the amount of lengthening and the incidence of nerve damage (p = 0.47), but in seven of the eight hips, the surgeon had rated the intervention as difficult because of previous surgery, severe deformity, a defect of the acetabular roof, or considerable flexion deformity. The correlation between difficulty and nerve palsy was significant (p = 0.041). We conclude that nerve injury is most commonly caused by direct or indirect mechanical trauma and not by limb lengthening on its own.

Of the 11 054 Charnley low-frictional torque arthroplasties carried out at our hospital between 1962 and 1977, 110 (94 patients) had a minimum follow-up of 30 years with a mean of 32.3 years (30.0 to 40.5). The mean age of the patients at operation was 43.3 years (17.0 to 65.0) and 75.7 years (51.0 to 97.0) at follow-up. Overall, 90% of hips (99) were free from pain and activity was reported as normal in 58% of the patients. A total of 13 hips (11.8%) were revised at a mean follow-up of 32.3 years (30.0 to 39.5), with wear and loosening of the acetabular component as the main indications. The clinical results did not reflect the mechanical state of the implant. Follow-up with sequential radiographs of good quality is essential. Revision for radiological changes alone must be accepted if gross loss of bone stock is to be avoided. Improvements in the design, materials and operative technique, based on the long-term outcome, are highlighted

Patient safety is a critical issue in elective total joint replacement surgery. Identifying risk factors that might predict complications and intensive care unit (ICU) admission proves instrumental in reducing morbidity and mortality. The institution’s experience with risk stratification and pre-operative ICU triage has resulted in a reduction in unplanned ICU admissions and post-operative complications after total hip replacement. The application of the prediction tools to total knee replacement has proven less robust so far. This work also reviews areas for future research in patient safety and cost containment. . Cite this article: Bone Joint J 2013;95-B, Supple A:74–6

A 34-year-old woman with a benign form of osteopetrosis developed osteoarthritis of the hip. In order to avoid the difficulties associated with inserting the femoral component of a conventional total hip arthroplasty, a hybrid metal-on-metal resurfacing was performed. There were several technical challenges associated with the procedure, including the sizing of the component, press-fit fixation of the acetabular component and femoral head preparation, as well as trying to avoid a fracture. No surgical complication occurred. After more than a year following surgery, the patient showed excellent clinical function and remained satisfied with the outcome. We conclude that the hybrid metal-on-metal resurfacing arthroplasty represents a valuable option for the treatment of patients with osteopetrosis and secondary hip osteoarthritis

This paper considers the increased risk of the development of lymphoma in patients with chronic inflammatory disease who undergo metal-on-metal arthroplasty

Sixty-six patients are presented who have had a total hip replacement by the Charnley low-friction technique after injuries of the hip, the majority of which were fracture-dislocations. The clinical results of the arthroplasties in this relatively young group of patients are shown to be very good. The selection of young patients for total hip replacement arthroplasty is discussed

We performed 96 Birmingham resurfacing arthroplasties of the hip in 71 consecutive patients with avascular necrosis of the femoral head. A modified neck-capsule-preserving approach was used which is described in detail. The University of California, Los Angeles outcome score, the radiological parameters and survival rates were assessed. The mean follow-up was for 5.4 years (4.0 to 8.1). All the patients remained active with a mean University of California, Los Angeles activity score of 6.86 (6 to 9). Three hips failed, giving a cumulative survival rate of 95.4%. With failure of the femoral component as the endpoint, the cumulative survival rate was 98.0%. We also describe the combined abduction-valgus angle of the bearing couple, which is the sum of the inclination angle of the acetabular component and the stem-shaft angle, as an index of the optimum positioning of the components in the coronal plane. Using a modified surgical technique, it is possible to preserve the femoral head in avascular necrosis by performing hip resurfacing in patients with good results

Objectives. Recently, high failure rates of metal-on-metal (MOM) hip implants have raised concerns of cobalt toxicity. Adverse reactions occur to cobalt nanoparticles (CoNPs) and cobalt ions (Co. 2+. ) during wear of MOM hip implants, but the toxic mechanism is not clear. Methods. To evaluate the protective effect of zinc ions (Zn. 2+. ), Balb/3T3 mouse fibroblast cells were pretreated with 50 μM Zn. 2+. for four hours. The cells were then exposed to different concentrations of CoNPs and Co. 2+. for four hours, 24 hours and 48 hours. The cell viabilities, reactive oxygen species (ROS) levels, and inflammatory cytokines were measured. Results. CoNPs and Co. 2+. can induce the increase of ROS and inflammatory cytokines, such as tumour necrosis factor α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6). However, Zn pretreatment can significantly prevent cytotoxicity induced by CoNPs and Co. 2+. , decrease ROS production, and decrease levels of inflammatory cytokines in Balb/3T3 mouse fibroblast cells. Conclusion. These results suggest that Zn pretreatment can provide protection against inflammation and cytotoxicity induced by CoNPs and Co. 2+. in Balb/3T3 cells. Cite this article: Y. Liu, H. Zhu, H. Hong, W. Wang, F. Liu. Can zinc protect cells from the cytotoxic effects of cobalt ions and nanoparticles derived from metal-on-metal joint arthroplasties? Bone Joint Res 2017;6:649–655. DOI: 10.1302/2046-3758.612.BJR-2016-0137.R2

Ensuring correct rotation of the femoral component is a challenging aspect of patellofemoral replacement surgery. Rotation equal to the epicondylar axis or marginally more external rotation is acceptable. Internal rotation is associated with poor outcomes. This paper comprises two studies evaluating the use of the medial malleolus as a landmark to guide rotation. We used 100 lower-leg anteroposterior radiographs to evaluate the reliability of the medial malleolus as a landmark. Assessment was made of the angle between the tibial shaft and a line from the intramedullary rod entry site to the medial malleolus. The femoral cut was made in ten cadaver knees using the inferior tip of the medial malleolus as a landmark for rotation. Rotation of the cut relative to the anatomical epicondylar axis was assessed using CT. The study of radiographs found the position of the medial malleolus relative to the tibial axis is consistent. Using the inferior tip of the medial malleolus in the cadaver study produced a mean external rotation of 1.6° (0.1° to 3.7°) from the anatomical epicondylar axis. Using the inferior tip of the medial malleolus to guide the femoral cutting jig avoids internal rotation and introduces an acceptable amount of external rotation of the femoral component

1 . The results of transplanting the greater trochanter in 225 "low-friction" arthroplasties of the hip have been examined. 2. Non-union occurred in an average of 7 per cent of cases. 3. When non-union occurred the results still showed improvement. 4. Four different methods of fixation were used, of which that using two wires, crossed in the horizontal and coronal planes, never failed to secure union. 5. Transplantation of the greater trochanter to the best position is only possible if the neck of the femur is shortened or if the centre of motion of the arthroplasty is displaced medially by deepening the acetabulum, or by a combination of both. 6. In the best position the transplanted trochanter considerably improved active abduction against gravity

Aims. The place of thromboprophylaxis in arthroplasty surgery remains controversial, with a challenging requirement to balance prevention of potentially fatal venous thrombo-embolism with minimising wound-related complications leading to deep infection. We compared the incidence of fatal pulmonary embolism in patients undergoing elective primary total hip arthroplasty (THA) between those receiving aspirin, warfarin and low molecular weight heparin (LMWH) for the chemical component of a multi-modal thromboprophylaxis regime. Patients and Methods. A prospective audit database was used to identify patients who had died within 42 and 90 days of surgery respectively between April 2000 and December 2012. A case note review was performed to ascertain the causes of death. Results. During this period 7983 THAs were performed. The rate of mortality was 0.43% and 0.58% at 42 and 90 days respectively. The groups comprised 1571 patients (19.7%) on warfarin, 1838 (23.0%) on LMWH and 4574 (57.3%) on aspirin. The 90-day mortality for these three groups was 0.38%, 1.09% and 0.43% respectively. The higher mortality rate for LMWH was significant (p < 0.05). There were six fatal pulmonary emboli (PEs) (0.08%). A total of three occurred within 42 days, all in the LMWH group. A total of three occurred between 42 and 90 days; one on warfarin, two on LMWH. The leading causes of death in all three groups were lower respiratory tract infections and myocardial infarction. Conclusion. We confirmed that fatal PE following elective THA with a multi-modal prophylaxis regime is rare. We further found that LMWH conferred no benefit over aspirin in this context, and is associated with a higher all-cause rate of mortality. Take home message: This study proposes that aspirin may be an appropriate thromboprophylaxis agent when used as part of a multi-modal regimen, suggesting current guidelines should be reviewed. Cite this article: Bone Joint J 2016;98-B:585–8

1. In this series of 150 cases of arthritis of the hip joint treated by vitallium mould arthroplasty (182 arthroplasties), 80 per cent. of late results are satisfactory to both patient and surgeon. 2. Striking features are the relative painlessness, smooth hip joint movement, progressive improvement in function, and reformation of the joint lines as seen radiographically in the post-operative period. 3. Function after arthroplasty for traumatic and degenerative arthritis approaches the normal hip joint much more closely than in cases of infective and rheumatoid arthritis. 4. There is a complete absence of low back symptoms or postural difficulties, and there is no difficulty in preventing stiffness of the knee joint. 5. Different technical procedures are indicated according to the degree of absorption of the femoral head or neck, and the stability of the mould in the acetabulum. 6. The operative mortality rate in this series was nil, and during the six-year follow-up period only one case died as the result of a complication of the arthroplasty. 7. In addition to meticulous operative technique and the use of special instruments, the importance of careful and prolonged after-treatment must be stressed. 8. It must also be emphasised that secondary operative revisions are often necessary, particularly in cases of infective and rheumatoid arthritis

The orientation of the acetabular component is influenced not only by the orientation at which the surgeon implants the component, but also the orientation of the pelvis at the time of implantation. Hence, the orientation of the pelvis at set-up and its movement during the operation, are important. During 67 hip replacements, using a validated photogrammetric technique, we measured how three surgeons orientated the patient’s pelvis, how much the pelvis moved during surgery, and what effect these had on the final orientation of the acetabular component. Pelvic orientation at set-up, varied widely (mean (± 2, standard deviation (. sd. ))): tilt 8° (2. sd . ±32), obliquity –4° (2. sd . ±12), rotation –8° (2. sd . ±14). Significant differences in pelvic positioning were detected between surgeons (p < 0.001). The mean angular movement of the pelvis between set-up and component implantation was 9° (. sd. 6). Factors influencing pelvic movement included surgeon, approach (posterior >  lateral), procedure (hip resurfacing > total hip replacement) and type of support (p < 0.001). Although, on average, surgeons achieved their desired acetabular component orientation, there was considerable variability (2. sd. ±16) in component orientation. We conclude that inconsistency in positioning the patient at set-up and movement of the pelvis during the operation account for much of the variation in acetabular component orientation. Improved methods of positioning and holding the pelvis are required. Cite this article: Bone Joint J 2014; 96-B:876–83

Aims

Patients with metabolic syndrome (MetS) are known to be at increased risk of postoperative complications, but it is unclear whether MetS is also associated with complications after total hip arthroplasty (THA) or total knee arthroplasty (TKA). Here, we perform a systematic review and meta-analysis linking MetS to postoperative complications in THA and TKA.

It remains a matter of debate whether displaced fractures of the neck of the femur should be treated by internal fixation or arthroplasty. We have compared the two methods with regard to complications, mortality and functional outcome. We studied 409 patients, aged 70 years and over, with subcapital fractures graded as Garden 3 or 4, in a two-year prospective multicentre study from 12 Swedish hospitals. They were randomised to internal fixation or arthroplasty. Patients who were mentally confused, bedridden or in a nursing-home were excluded from the survey. After two years the rate of failure was 43% in the internal fixation (IF) and 6% in the arthroplasty group (p < 0.001). In the IF group 36% had impaired walking and 6% had severe pain compared with 25% and 1.5%, respectively, in the arthroplasty group (both p < 0.05). There was no difference in mortality. With a high rate of failure and poor functional outcome after IF, we recommend primary arthroplasty for displaced fractures of the neck of the femur in patients over 70 years of age

Increasing follow-up identifies the outcome in younger patients who have undergone total hip replacement (THR) and reveals the true potential for survival of the prosthesis. We identified 28 patients (39 THRs) who had undergone cemented Charnley low friction arthroplasty between 1969 and 2001. Their mean age at operation was 17.9 years (12 to 19) and the maximum follow-up was 34 years. Two patients (4 THRs) were lost to follow-up, 13 (16 THRs) were revised at a mean period of 19.1 years (8 to 34) and 13 (19 THRs) continue to attend regular follow-up at a mean of 12.6 years (2.3 to 29). In this surviving group one acetabular component was radiologically loose and all femoral components were secure. In all the patients the diameter of the femoral head was 22.225 mm with Charnley femoral components used in 29 hips and C-stem femoral components in ten. In young patients who require THR the acetabular bone stock is generally a limiting factor for the size of the component. Excellent long-term results can be obtained with a cemented polyethylene acetabular component and a femoral head of small diameter

A series of 400 patients (average age 57.7 years) with bilateral low-friction arthroplasties of the hip has been reviewed. Comparison was made with similar unilateral operations. The results showed that the bilateral arthroplasties can be carried out as a single operation without higher risk of local or general complications. However, this excludes the incidence of pulmonary embolism which is higher for the bilateral replacements