We have studied damage to the tibial articular surface after replacement of the femoral surface in dogs. We inserted pairs of implants made of alumina, titanium and polyvinyl alcohol (PVA) hydrogel on titanium fibre mesh into the femoral condyles. The two hard materials caused marked pathological changes in the articular cartilage and menisci, but the hydrogel composite replacement caused minimal damage. The composite osteochondral device became rapidly attached to host bone by ingrowth into the supporting mesh. We discuss the clinical implications of the possible use of this material in articular resurfacing and joint replacement

We evaluated the potential of a vastus lateralis muscle flap in controlling infection after resection arthroplasty of the hip. We retrospectively reviewed 119 patients with 120 chronic infections after resection arthroplasty treated with this procedure. The flap was fixed with Mitek anchors in the acetabular cavity. The mean duration of infection after resection before the muscle flap procedure was 6.5 months (2 to 13). The patients had previously undergone a mean of 4.9 operations (2 to 25). In all patients the infected cavity was the origin of the persistent infection. The mean follow-up was for 2.6 years (1.0 to 4.7). No patient had recurrent infection post-operatively and all had an improvement in the pain and better quality of life

We studied 100 patients who had undergone endoprosthetic replacement of the proximal humerus between 1976 and 1998. The outcome was assessed with regard to the survivorship of the patients, the salvaged limbs and the prostheses. Function was determined in the 47 surviving patients, of whom 30 were assessed using the Musculo-Skeletal Tumour Society (MSTS) rating scale and 38 completed the Toronto Extremity Salvage Score (TESS) questionnaire. The median age of the patients was 34 years (10 to 80). The mean follow-up period for surviving patients was nine years (2 to 20). The mean MSTS score at follow-up was 79% and the mean TESS score was 72%. The length of bone which was resected influenced the functional outcome. Abduction of the shoulder was to 45° in most patients. The overall survival was 42% at ten years and that of the limb without amputation 93%. The survival of the prostheses using mechanical failure as the endpoint was 86.5% at 20 years. Endoprosthetic replacement of the proximal humerus is a predictable procedure providing reasonable function of the arm with a low rate of complications at long-term follow-up

Our aim was to examine the potential of autologous perichondral tissue to form a meniscal replacement. In 18 mature sheep we performed a complete medial meniscectomy. The animals were then divided into two groups: 12 had a meniscal replacement using strips of autologous perichondral tissue explanted from the lower rib (group G) and six (group C) served as a control group without a meniscal replacement. In all animals restriction from weight-bearing was achieved by means of transection and partial resection of tendo Achillis. Six animals (four from group G and two from group C) were each killed at 3, 6 and 12 months. The grafts and the underlying articular cartilage were removed and studied by gross macroscopic examination, light microscopy, SEM, polarised light examination, and by biomechanical tests. In all the transplanted animals a new perichondral meniscus developed. After three months the transplants resembled normal menisci in size and thickness, while in the control animals only small rims of spontaneously grown tissue were seen. Microscopically, the perichondral menisci showed a normal orientation of collagen fibres and normal cellular characteristics, but in the central region, areas of calcification disturbed the regular tissue differentiation. Healing tissue in control animals lacked the normal fibre orientation and cellularity. SEM of perichondral menisci showed surface characteristics similar to those of normal sheep menisci without fissures and lacerations; the control specimens had these defects. The femoral and tibial cartilage in contact with the new menisci had normal surface characteristics apart from one animal with slight surface irregularities. Control animals showed superficial lesions after three months which increased at six to 12 months postoperatively. Microangiography of the newly grown tissue demonstrated a less intense vascularisation after three months when compared with normal menisci. The failure stress and tensile modulus of perichondral menisci were significantly lower than those of normal contralateral menisci, and spontaneously regenerated tissue in meniscectomised animals had even lower values. There were no significant differences in values between newly grown perichondral menisci and spontaneously grown tissue

We used Laser Doppler flowmetry to measure the effect on the blood flow to the femoral head/neck junction of two surgical approaches during resurfacing arthroplasty. We studied 24 hips undergoing resurfacing arthroplasty for osteoarthritis. Of these, 12 had a posterior approach and 12 a trochanteric flip approach. A Laser probe was placed under radiological control in the superolateral part of the femoral head/neck junction. The Doppler flux was measured at stages of the operation and compared with the initial flux. In both groups the main fall in blood flow occurred during the initial exposure and capsulotomy of the hip joint. There was a greater reduction in blood flow with the posterior (40%) than with the trochanteric flip approach (11%)

A study of excision arthroplasty (Girdlestone's pseudarthrosis) for infected total hip replacements is presented. Twenty-two patients were reviewed with a minimum follow-up of one year. Reduction in pain was significant but the functional results were poor. Factors contributing to poor function were old age, poor medical condition and arthritis of the contralateral hip; these were in addition to the gross instability resulting from the pseudarthrosis. The patients were easily fatigued and dependent on external supports; calipers were found to be unacceptable. The symptoms after excision arthroplasty are compared with those before the original hip replacement

Fifty-four hips converted to low friction arthroplasty between 1965 and 1975 have been reviewed one to eleven years after operation. In many cases malposition had led to degenerative changes in the opposite hip, the lumbar spine or the knee, often with severe loss of function due to pain. It was found that total replacement could give useful relief of pain and improved function, though the range of movement obtained was not as good as in primary replacement. An outstanding feature was the correction of inequality of leg length. In general, the results were much better in cases of ankylosis acquired in adult life than in cases of spontaneous fusion after sepsis in childhood. The most important complication was a single case of sciatic palsy

1. Two hundred and seventeen low-friction arthroplasties performed between November 1962 and April 1969 in 203 patients with failed previous operations have been analysed. 2. The technical details of operation in relation to these conversion problems have been outlined. 3. The quality of the results in relation to pain, mobility and ability to walk has been assessed before operation and one year afterwards, with small numbers at three and five years. 4. Pain was completely relieved or was minimal in 96·3 per cent of the patients, and in no case was the pain worse. 5. The total range of movement was 100 degrees or more in 98·5 per cent. No hip lost movement after conversion. 6. The failures were principally due to infection and to technical difficulties. There were no mechanical failures without a technical or radiological explanation. 7. Low-friction arthroplasty is an excellent salvage procedure, especially for failed cup arthroplasty

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

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

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

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

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

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

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

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.