Purpose: Pigmented Villonodular Synovitis (PVNS) is an uncommon presentation characterised by hyperplastic synovium, bloody effusions and bone erosions. Incompletely resected localised and diffuse lesions have a high recurrence rate. The management of recurrent lesions depends on the expertise of the surgeon and severity of the lesion. The imaging characteristics of PVNS and experience of British knee surgeons in managing these lesions is presented in our study.

Methods: A postal questionnaire was sent to 100 knee surgeons of the British Association of Surgeons of the Knee (BASK) with questions relating to their experience in managing localised and recurrent PVNS. The options included either arthroscopic or open synovectomy with or without radiotherapy, radical excision or referral.

Results: 74 responses were included in the study. 73 out of the total cohort of 74 surgeons (98.7%) had seen less than 5 presentations in their career.

Localised lesions were treated primarily by arthroscopic synovectomy [N=58(78.4%)] or open synovectomy [N=12(16.2%)] with radiotherapy being utilised in 4 lesions (5.4%).

For local recurrence the management was arthroscopic [N=26(35.1%)] and open [N= 19(25.7%)] synovectomy. Radiotherapy was used in 18 (24.3%) of patients with localised recurrence and 8 (10.8%) of were referred to specialist units.

Infiltrating lesions were treated with open synovectomy and radiotherapy [N=22(29.7%)] and 20 cases [27.02%] were referred to specialist units.

Imaging of PVNS and Conclusions: The role of imaging is invaluable in early diagnosis and treatment due to limited experience in managing such presentations. Routine radiography and Computerised Axial Tomography (CT scan) often demonstrate non-marginal pressure erosions with sclerotic margins as well as nodular soft tissue masses. Sonography shows non-specific focal or nodular synovial thickening with increased flow on colour doppler. Magnetic Resonance imaging characteristics of PVNS are nodular, synovial masses which are low signal on T1-weighted and T2-weighted imaging.

Background: Arthroscopic visualisation of the postero-medial and posterolateral compartments of the knee through the intercondylar notch using the anterolateral and anteromedial portals respectively is not commonly practiced. The purpose of this study was to prospectively evaluate whether these views are useful either diagnostically, therapeutically or both in a routine knee arthroscopy.

Patients and Methods: It is a prospective study of two hundred consecutive patients who underwent a routine knee arthroscopy in our unit using the standard portals following an appropriate clinical and radiological evaluation. Posteromedial and posterolateral compartment visualisation through the intercondylar notch was undertaken in all the patients. An evaluation of the ease of the technique, the usefulness of visualisation and the morbidity associated with the procedure were recorded.

Results: The technique was deemed simple to perform in 91% of the patients. It was found to be more difficult in knees with degenerative joint disease. Posteromedial and posterolateral compartment visualisation was found to be useful for diagnosis or treatment in 15% and 6% of the diagnosed conditions respectively. The technique was most useful for tears of the posterior horn of the medial meniscus, most of which were not detected by visualisation from the anteromedial compartment alone. Visualisation of the compartments was deemed adequate in 98% of the patients. There was no morbidity associated with this procedure.

Conclusion: We believe that visualisation of the pos-teromedial and posterolateral compartment in a routine knee arthroscopy is beneficial; and an easy and safe procedure to perform.

Introduction We describe an arthroscopic technique of excising a lesion from within the posterior septum of the knee. To our knowledge this has not been described in the literature.

Case History A 35-year old male taxi-driver presented with pain in the back of his right knee. Examination did not reveal any abnormality except pain on flexing the knee beyond 90-degrees. MRI showed a multiloculated ganglion in the posterior compartment of the knee. The ganglion was located within the posterior septum and successfully excised arthroscopically. 6-months postoperatively the patient is assyptomatic.

Anatomy of the posterior septum The posterior septum is located between the posterior cruciate ligament (PCL) and the posterior capsule dividing the posterior cavity of the knee into seperate posteromedial and posterolateral compartments. It is triangular in shape, formed by the reflections of the synovium from the PCL.

The Technique The posterior septum of the knee was approached through the intercondylar notch by the anterior portals. Slow and careful dissection was carried out in the V-shaped space between the anterior and the posterior cruciate ligaments. The synovium of the septum was resected and the space within the septum entered. The ganglion was successfully removed. There was no complication. The relatively central placement of the anterior portals is important to gain access to the posterior septum via the notch.

Discussion and conclusion Intra-articular ganglion cysts are uncommon. Reported prevalence ranges from 0.2% to 1.3%. Ganglion cysts arising from the anterior and the posterior cruciate ligaments have been well described. The ganglion cyst within the posterior septum has not been reported.

The anatomy of the posterior septum makes it inaccessible to routine arthroscopic examination. It has close proximity to the vascular structures. We approached the posterior septum from the anterior portals through the intercondylar notch. The ganglion was successfully excised.

Introduction: Seven patients underwent successful revision total knee replacement for aseptic loosening. Bovine bone graft was used to reconstruct bony defects in all.

Materials and methods: This is a retrospective review. Between April 2000 and March 2003, bovine bone (Tutobone™, Wescott-Medical, UK) was used in 7 revision arthroplasty cases (4 right knees & 3 left). There were 5 males and 2 females. The average age was 70.4 years. All revisions were carried out for aseptic loosening of the prostheses associated with massive osteolysis and bone loss.

The bone defects on the tibia and femur were as follows: (Obtained from operative records. Classified according to Anderson Orthopaedic Research Institute classification)

The tibial defects were corrected by impaction grafting and femoral condyle defects were corrected by using bovine bone as bulk grafts. Semi-constrained constrained stemmed cemented modular knee prostheses (TC3, Depuy) were used in all. Clinical outcomes were recorded by the Oxford Knee Score. Serial radiographs were evaluated for graft density, integration, implant loosening, alignment and subsidence.

Results: At recent follow-up, radiographs showed good graft integration, no loosening, and no subsidence of the implant and good prostheses alignment. The average Oxford Knee Score was 20.4.

Conclusion & discussion: Bovine bone substitute is an alternative. The bone defects in these patients were successfully reconstructed with bovine bone. It is an osteo-conductive matrix with intact type-I collagen that provides mechanical stability. It is also cost effective.

Early results are encouraging but long-tem follow-up is needed.