Single-stage revision for the infected total knee replacement: results from a single centre.

Peri-prosthetic infection is amongst the most common causes of failure following total knee replacement (TKR). In the presence of established infection, thorough joint debridement and removal of all components is necessary following which new components may be implanted. This can be performed in one or two stages; two-stage revision with placement of an interim antibiotic-loaded spacer is regarded by many to be the standard procedure for eradication of peri-prosthetic joint infection. We present our experience of a consecutive series of 50 single-stage revision TKRs for established deep infection performed between 1979 and 2010. There were 33 women and 17 men with a mean age at revision of 66.8 years (42 to 84) and a mean follow-up of 10.5 years (2 to 24). The mean time between the primary TKR and the revision procedure was 2.05 years (1 to 8). Only one patient required a further revision for recurrent infection, representing a success rate of 98%. Nine patients required further revision for aseptic loosening, according to microbiological testing of biopsies taken at the subsequent surgery. Three other patients developed a further septic episode but none required another revision. These results suggest that a single-stage revision can produce comparable results to a two-stage revision. Single-stage revision offers a reduction in costs as well as less morbidity and inconvenience for patients.

Posterior dislocation of the Oxford knee meniscal bearing: a treatment option.

Unicompartmental knee replacement (UKR) is now established as a treatment for medial compartment arthritis. The Oxford UKR (Biomet Orthopedics, Inc, Warsaw, IN, USA) has a mobile-bearing system, which minimizes wear. This has been shown to provide excellent long-term results. Dislocation of the mobile-bearing device is rare with an incidence of 1 in 200 (0.5 %). The treatment usually involves exploration of the knee through the original anteromedial incision, removal of the dislocated bearing and rectification of the underlying cause for the dislocation. We describe two cases of a posterior dislocation in which the mobile bearing could not be retrieved and was left in situ. In both cases a good outcome was achieved. We conclude that in extremely rare cases where a dislocated bearing has migrated posteromedially and cannot be retrieved, it can be left in place rather than exploring the joint acutely through a separate posterior incision.

Squamous cell cancers contain a side population of stem-like cells that are made chemosensitive by ABC transporter blockade.

Cancers are a heterogeneous mix of cells, some of which exhibit cancer stem cell-like characteristics including ATP-dependent drug efflux and elevated tumorigenic potential. To determine whether aerodigestive squamous cell carcinomas (SCCs) contain a subpopulation of cancer stem cell-like cells, we performed Hoechst dye efflux assays using four independent cell lines. Results revealed the presence of a rare, drug effluxing stem cell-like side population (SP) of cells within all cell lines tested (SCC-SP cells). These cells resembled previously characterised epithelial stem cells, and SCC-SP cell abundance was positively correlated with overall cellular density and individual cell quiescence. Serial SCC-SP fractionation and passaging increased their relative abundance within the total cell population. Purified SCC-SP cells also exhibited increased clonogenic potential in secondary cultures and enhanced tumorigenicity in vivo. Despite this, SCC-SP cells remained chemotherapeutically sensitive upon ATP-dependent transporter inhibition. Overall, these findings suggest that the existence of ATP transporter-dependent cancer stem-like cells may be relatively common, particularly within established tumours. Future chemotherapeutic strategies should therefore consider coupling identification and targeting of this potential stem cell-like population with standard treatment methodologies.

Patello-femoral joint pain due to unusual location of localised pigmented villonodular synovitis-a case report.

Localised pigmented villonodular synovitis (PVNS) is a rare condition usually affecting the knee. It can be a difficult condition to manage with an average delay in diagnosis of 4.4 years. We describe a case of a localised PVNS lesion interposed between the patello-femoral joint, presenting as 'anterior knee pain'. To our knowledge this has not previously been reported. The lesion was completely excised at arthroscopy resulting in complete resolution of symptoms. Solitary lesions of PVNS should also be considered in the differential diagnosis of unexplained 'anterior knee pain'.

Acute calcific tendinitis of the popliteus tendon--an unusual site and clinical syndrome.

Three cases of acute calcific tendinitis of the popliteus tendon presenting in the accident and emergency department as 'locked knee' are described. All patients presented with acute pain, flexion deformity and marked limitation of movements of the knee. All patients were unable to weight-bear on the affected side. The radiographs revealed well circumscribed calcification in two patients and faint stippled calcification in the third. All patients were referred to the next fracture clinic with a diagnosis of a mechanical problem within the knee joint due either to a 'loose body' or a meniscal tear. All patients responded to an injection of corticosteroids and local anaesthetic with immediate pain relief and lasting resolution of symptoms.

The pneumatic tourniquet in arthroscopic surgery of the knee.

In a randomized study 56 patients undergoing arthroscopic surgery of the knee were randomly allocated to one of 2 groups: surgery with a tourniquet and surgery without a tourniquet. No significant difference was found between the 2 groups with regard to operating times, technical intraoperative difficulties, identification of intraarticular structures, postoperative pain or postoperative complications. In neither group was the procedure abandoned due to technical difficulties. The pain scores in the non-tourniquet group were lower than those in the group of patients operated on with the use of a pneumatic tourniquet. The study suggests that the use of a tourniquet in arthroscopic surgery of the knee is unnecessary.

The Oxford club-foot programme.

We treated 63 club feet in 44 patients by a defined programme of strapping from birth followed by one of two operations performed at six weeks, either a simple calcaneal tendon lengthening or a subtalar realignment, and reviewed them prospectively. The decision as to which operation to perform was taken at four weeks after radiographic measurement of the talocalcaneal angle. All but eight patients (ten feet) were followed for a mean of 8.7 years. The overall results after calcaneal tendon lengthening were satisfactory. The re-operation rate after subtalar realignment was high (39%) due to over or undercorrection of the deformity.

Day care surgery for the correction of hallux valgus.

This paper reports the experience of performing Wilson's osteotomy on a day care basis, and explores the potential and pragmatism of day surgery in orthopaedic practice. Fifty one patients (58 feet) were treated by a Wilson's osteotomy for the correction of hallux valgus. The results show an overall success with day care surgery and compare favourably with other series.

Soft tissue surgery in Charcot-Marie-Tooth disease.

Ten patients with Charcot-Marie-Tooth disease have been reviewed at an average of 14 years after soft tissue procedures to correct foot deformities. No patient has so far required triple arthrodesis and the overall results as regards function, appearance and symptoms are satisfactory in all patients. It is concluded that soft tissue procedures can certainly postpone the need for triple arthrodesis and in many cases may obviate it altogether.

Unicompartmental Oxford Meniscal knee arthroplasty.

Unicompartmental knee arthroplasty is an attractive concept, but some reports on its use are unfavorable. A meniscal bearing prosthesis has many advantages in this mode of arthroplasty. The authors present preliminary results of 25 unicompartmental knee replacements done with the Oxford Meniscal knee, with a follow-up period of 12-54 months (mean, 21 months). They discuss the scientific basis of unicompartmental knee arthroplasty, which they conclude may be the most appropriate treatment for selected cases of degenerative arthritis of the knee.

Treatment of giant cell tumour of the femoral head and neck.

Giant cell tumours of the femoral head and neck treated at the Nuffield Orthopaedic Centre between 1970 and 1982 were reviewed to evaluate the effectiveness of primary treatment by curettage and bone grafting. All 4 cases recurred within two years, necessitating the likelihood of recurrence following curettage and bone grafting, particularly at this anatomical site, is stressed, and the possibility that hip replacement arthroplasty be considered the primary treatment of choice is discussed.

Bilateral Oxford Meniscal Knee arthroplasty.

Thirty-two patients who underwent bilateral bicompartmental Oxford Meniscal Knee arthroplasty have been followed up prospectively for a mean period of 51 months from the time of their first operation. Pain relief was obtained in all but one knee; walking ability was improved in more than two-thirds. Overall patient satisfaction with the results was good. Two knees failed. The results demonstrate that bilateral knee arthroplasty can be expected to give good functional results.

Lumbar intervertebral disc heights in normal subjects and patients with disc herniation.

A method for the measurement of intervertebral disc heights from lateral radiographs obtained in controlled conditions was examined for intra- and interobserver errors. The use of a strict criterion for the positioning of marks on the images of the vertebrae was shown to enable reproducible measurements to be made with a maximum error of 0.7 mm. Measurements of anterior and posterior disc heights and disc depths were made for 11 normal subjects and ten male patients with prolapsed intervertebral discs, while standing upright. The level of the prolapsed discs were shown to have reduced height compared with normal before surgery, and further narrowing 3 months after surgery. The unaffected discs of the patients were the same height as those of the controls. The technique is proposed as suitable for the investigation of the effect on intervertebral discs of procedures such as the injection of chymopapain.

A prospective study of lumbar spinal movements before and after discectomy using biplanar radiography. Correlation of clinical and radiographic findings.

The significance of alteration of lumbar spinal motion in cases of herniated disc was examined using a three-dimensional x-ray technique (biplanar radiography) before and 3 months after discectomy. Fifteen consecutive cases of disc herniation were studied prospectively. Predictions of clinical examination, myelography, and motion study for the level and site of the lesion were correlated with the operative findings for their accuracy in localization of the lesion. Changes in lumbar spinal motion after surgery were also correlated with the clinical results. The clinical and myelographic predictions were similar to previously published studies. The present study showed that patients with a sequestrated or prolapsed disc lesion (as opposed to bulging disc) had an abnormally large lateral bend or axial rotation during flexion and extension at the level above, which reduced after surgery. Primary lumbar spinal motions (flexion and extension) were generally reduced to half of the normal value and were not significantly altered by surgery. The restriction of lumbar spinal motion was not significantly reflected in the clinical results, which were satisfactory in most cases. Discectomy by fenestration and minimal resection of the lamina did not produce instability.

Posterior intertransverse fusion assessed clinically and with biplanar radiography.

Biplanar radiography was used to assess bony union after intertransverse fusion. The patients were assessed clinically and the fusion status was compared with the clinical result. Posterolateral intertransverse fusion was shown to be capable of fusing the motion segment almost completely. However, the strictly measured fusion rate was only 27%, but this increased to 91% when partial fusions were included. The fusion rate from conventional plain films assessed by the radiologist was 82%, which is similar to other reports. On clinical examination, a satisfactory result was obtained in 82%, but there was no clear correlation with fusion status.