Replacement Arthroplasty: Cannon SR

Cannon SR. · No affiliation provided · J Bone Joint Surg Br. · Pubmed #19190043 No free full text.

This publication has no abstract.

Anmin A, Suresh S, Sanghrajka A, Cannon SR, Briggs TW, Unwin P. · Department of Orthopaedic Oncology, Royal National Orthopaedic Hospital Trust, Stanmore, United Kingdom. · Acta Orthop Belg. · Pubmed #18811025 No free full text.

Abstract: Eight patients underwent custom-made endoprosthetic elbow reconstruction between 1989 and 2006 either for failed primary total elbow replacements or following complex fracture complications. A functional assessment using the Toronto Extremity Salvage (TES) score was performed. Patients were followed for a mean of 46.1 months (range : 25 to 88). One patient who presented with an infected periprosthetic fracture around a total elbow replacement, failed two-stage reconstruction and underwent excision arthroplasty. The remaining seven patients were available for functional follow-up. Average flexion deformity was 15 degrees (range: 7 to 35) and average flexion arc was 85 degrees (range : 70 to 130). The mean TES score was 67.3 (range: 36.6 to 95.9). Custom made endoprosthetic reconstruction allowed for a satisfactory outcome in all but one of these eight patients with severe bony destruction around the elbow in the absence of tumour infiltration.

Jaiswal PK, Blunn G, Pollock R, Skinner JA, Cannon SR, Briggs TW. · Bone Tumor Unit, The Royal National Orthopedic Hospital, Brockley Hill, Stanmore, Middlesex, UK. · J Arthroplasty. · Pubmed #18555650 No free full text.

Abstract: Radiographs of 33 patients who had an expandable prosthesis inserted after tumor resection in the distal femur were evaluated. We hypothesized that, when a sleeve was present, there was greater stem migration and cortical reaction. The thickness of medial and lateral cortices of the tibia was measured at 6 months and on the last follow-up radiograph. The distance from the edge of the prosthesis to the cortical edge was also compared. When a sleeve was present, there was greater stem migration (P < .001) and a greater increase in lateral cortical thickness (P < .001). There was a higher revision rate when a sleeve was used, but this was not statistically significant. There was no difference in function according to the Toronto Extremity Salvage Score (TESS) between the 2 groups. This is the first study to demonstrate that the presence of a polyethylene sleeve is associated with a tendency for the tibial prosthesis to migrate laterally and cause a greater sclerotic reaction.

Whittingham-Jones PM, Dunstan E, Altaf H, Cannon SR, Revell PA, Briggs TW. · Royal National Orthopaedic Hospital, London, United Kingdom. · J Arthroplasty. · Pubmed #18534468 No free full text.

Abstract: Metal-on-metal (MoM) hip bearings are being inserted into ever-younger patients. The effects on the immune system of chronic exposure are unknown. We investigated the immune response of patients with MoM hip bearings. In patients with MoM implants, the expression of antigen-presenting cell (APC) surface molecules (CD86 and HLA-DR) was seen to be significantly higher (P < .05) than control group. High levels of APC surface molecules suggest an activated state and attempts to propagate an immune response. However, in the same group, the expression of T-cell markers (CD3 and CD28) was low, indicating a small T-cell population. This suggests, despite the activation of APCs, that T cells down-regulate immune responses in MoM articulations. Conversely, in metal-on-polyethylene articulations, expression of T-cell molecules was elevated and expression of APC molecules lowered.

Jaiswal PK, Jagiello J, David LA, Blunn G, Carrington RW, Skinner JA, Cannon SR, Briggs TW. · Royal National Orthopaedic Hospital Trust, Brockley Hill, Stanmore, Middlesex HA7 4LP, UK. · J Bone Joint Surg Br. · Pubmed #18160492 No free full text.

Abstract: We have managed 27 patients (16 women and 11 men) with a mean age of 68.4 years (50 to 84), with failed total hip replacement and severe proximal femoral bone loss by revision using a distal fix/proximal wrap prosthesis. The mean follow-up was for 55.3 months (25 to 126). The mean number of previous operations was 2.2 (1 to 4). The mean Oxford hip score decreased from 46.2 (38 to 60) to 28.5 (17 to 42) (paired t-test, p < 0.001) and the mean Harris Hip score increased from 30.4 (3 to 57.7) to 71.7 (44 to 99.7) (paired t-test, p < 0.001). There were two dislocations, and in three patients we failed to eradicate previous infection. None required revision of the femoral stem. This technique allows instant distal fixation while promoting biological integration and restoration of bone stock. In the short term, the functional outcome is encouraging and the complication rates acceptable in this difficult group of patients.

Hanna SA, David LA, Aston WJ, Gikas PD, Blunn GW, Cannon SR, Briggs TW. · The Royal National Orthopaedic Hospital, Stanmore, England. · J Bone Joint Surg Br. · Pubmed #17998189 No free full text.

Abstract: Between 1988 and 2006, 18 patients had a custom-made endoprosthetic replacement of the distal humerus for bone tumours at our institution. There were 11 primary malignant neoplasms, six secondary deposits, and one benign aggressive tumour. The mean follow-up was for 4.4 years (1 to 18.2). Complications occurred in nine patients and included aseptic loosening in three (16.6%), local recurrence in two (11%), infection in two (11%), neuropraxia of the radial nerve in one (5.5%) and a peri-prosthetic fracture in one (5.5%). Excision was inadequate in four patients (22%), all of which developed local recurrence and/or metastases. There were seven deaths from the primary disease after a mean of 2.3 years (1 to 5), one of whom had an above-elbow amputation for local recurrence seven months before death. The remaining six had satisfactory elbow function at their last follow-up. The 11 living patients were evaluated using the Musculoskeletal Tumour Society and Toronto Extremity Salvage scoring systems. The mean scores achieved were 76% (67% to 87%) and 73% (59% to 79%), respectively. Overall, 17 of 18 patients had significant improvement in the degree of their pain following operation. Custom-made endoprosthetic reconstruction of the elbow for bone tumours is a viable treatment in carefully selected patients. It maintains satisfactory function and provides good pain relief.

Back DL, David L, Hilton A, Blunn G, Briggs TW, Cannon SR. · North East Thames Rotation, United Kingdom. · Knee. · Pubmed #17945500 No free full text.

Abstract: Revision total knee arthroplasty using a second generation modular rotating hinge design was done on thirty two knees in 30 patients over an 8-year period. Twenty-nine knees in 29 patients were followed up for 4.5-11 years (mean, 58 months). Four prostheses failed and two patients had died and one patient was lost to followup. Indications for revision were recurrent sepsis (five knees), component failure (four knees), ligamentous instability (two knees), aseptic loosening (10 knees), fracture (six knees), and gross bone loss (five knees). Early results have demonstrated improvement in both the Knee Society knee and function Scores and range of movement. The Knee Society knee score improved from 26 preoperatively to 68 postoperatively. The function score improved from 27 preoperatively to 75 postoperatively. One patient had evidence of aseptic loosening on radiographs, and the patellofemoral complication rate was low at 6%. This short-term clinical and radiographic review has demonstrated encouraging results in the use of a custom-made second generation rotating hinge component when used in revision knee surgery.

Ropars M, Kaila R, Cannon SR, Briggs TW. · London Bone Tumour Unit, The Royal National Orthopaedic Hospital, Stanmore, Middlesex, London, UK. · J Hand Surg Eur Vol. · Pubmed #17222953 No free full text.

Abstract: Primary giant cell tumours involving digital bones of the hand are rare lesions which are generally diagnosed at an advanced stage. Accurate diagnosis requires clinical evaluation, imaging studies and histopathological assessment. Conservative treatment by digit-sparing surgery is associated with high recurrence rates. In a ten year retrospective review, this study identified only four cases. Three cases involved a phalanx and were treated by distal amputation of the involved digit. None recurred. One involved the metacarpal and recurred twice following repeated curettage and bone grafting. No further recurrence has been detected after resection and replacement with a non-vascularised fibular graft and Silastic implant replacement of the metacarpophalangeal joint. Our small series of cases supports a policy of aggressive primary surgery, including amputation or en bloc resection and reconstruction.

Abuzakuk T, Senthil Kumar V, Shenava Y, Bulstrode C, Skinner JA, Cannon SR, Briggs TW. · Royal National Orthopaedic Hospital, Brockley Hill Stanmore, Middlesex HA7 4LP, UK. · Int Orthop. · Pubmed #16761149 links to  free full text

Abstract: We prospectively randomised 104 consecutive patients undergoing primary cemented total knee arthroplasty into two groups of 52 patients each, with one group to receive a standard suction drain (Redivac) and the other, an autologous transfusion drain (Bellovac). Randomisation was achieved using the software programme MINIM: , which was set to randomly allocate patients to either of the two groups based on their age, sex and body mass index (BMI). All procedures were performed under pneumatic tourniquet. Drains were released in the recovery room 20 min after surgery and removed 24 h following surgery. Blood collected in the standard suction drain (control group) was discarded, while blood collected in the autologous transfusion drains (study group) was transfused unwashed back to the patient within 6 h of collection. Thirteen patients (25%) in the study group had two or more units of homologous blood transfused in addition to the blood collected postoperatively and re-transfused (average: 438 ml). Twelve patients (23%) in the control group had two or more units of homologous blood transfused. No sepsis, transfusion reactions or coagulopathies were associated with the autologous blood transfused in the study group. The use of the autologous transfusion system (Bellovac) proved to be safe but failed to reduce the need for postoperative homologous blood transfusion following uncomplicated total knee arthroplasty.

Gupta A, Meswania J, Blunn G, Cannon SR, Briggs TW. · The Department of Orthopaedic Oncology, The Royal National Orthopaedic Hospital NHS Trust, Stanmore, Middlesex, HA7 4LP, UK. · Knee. · Pubmed #16631369 No free full text.

Abstract: As the number of primary and revision arthroplasties performed each year increases, the complexity of the reconstructive efforts also increases. A case of a patient with a total knee arthroplasty complicated with infection, deficient extensor mechanism, bone loss and limb shortening of 5.5 cm is reported. We describe an alternative surgical technique of reconstruction of the knee and lengthening of the limb using the Stanmore Non-Invasive Growing-Distal Femoral Prosthesis. The prosthesis had a magnetic disc attached to a gearbox. The generation of an external electromagnetic field caused the magnetic disc to rotate and lengthen the prosthesis. This reconstructive technique has not been described in the literature.

Rogers BA, Thornton-Bott P, Cannon SR, Briggs TW. · Royal National Orthopaedic Hospital, Stanmore, UK. · J Bone Joint Surg Br. · Pubmed #16567783 No free full text.

Abstract: We assessed the reproducibility and accuracy of four ratios used to measure patellar height, namely the Blackburne-Peel, Caton-Deschamps, Insall-Salvati and modified Insall-Salvati, before and after total knee arthroplasty. The patellar height was measured, by means of the four ratios, on the pre- and post-operative lateral radiographs of 44 patients (45 knees) who had undergone total knee arthroplasty. Two independent observers measured the films sequentially, in identical conditions, totalling 720 measurements per observer. Statistical analysis, comparing both observers and ratios, was carried out using the intraclass correlation coefficient. Before operation there was greater interobserver variation using either the Insall-Salvati or modified Insall-Salvati ratios than when using the Caton-Deschamps or Blackburne-Peel methods. This was because of difficulty in identifying the insertion of the patellar tendon. Before operation, there was a minimal difference in reliability between these methods. After operation the interobserver difference was greatly reduced using both the Caton-Deschamps and Blackburne-Peel methods, which use the prosthetic joint line, compared with the Insall-Salvati and modified Insall-Salvati, which reference from the insertion of the patellar tendon. The theoretical advantage of using the Insall-Salvati and modified Insall-Salvati ratios in measuring true patellar height after total knee arthroplasty needs to be balanced against their significant interobserver variability and inferior reliability when compared with other ratios.

Dunstan E, Sanghrajka AP, Tilley S, Unwin P, Blunn G, Cannon SR, Briggs TW. · Royal National Orthopaedic Hospital, Brockley Hill, Stanmore, Middlesex HA7 4LP, UK. · J Bone Joint Surg Br. · Pubmed #15855362 No free full text.

Abstract: Metal-on-metal hip bearings are being implanted into younger patients. The consequence of elevated levels of potentially carcinogenic metal ions is therefore a cause for concern. We have determined the levels of cobalt (Co), chromium (Cr), titanium (Ti) and vanadium (Va) in the urine and whole blood of patients who had had metal-on-metal and metal-on-polyethylene articulations in situ for more than 30 years. We compared these with each other and with the levels for a control group of subjects.We found significantly elevated levels of whole blood Ti, Va and urinary Cr in all arthroplasty groups. The whole blood and urine levels of Co were grossly elevated, by a factor of 50 and 300 times respectively in patients with loose metal-on-metal articulations when compared with the control group. Stable metal-on-metal articulations showed much lower levels. Elevated levels of whole blood or urinary Co may be useful in identifying metal-on-metal articulations which are loose.

Hilton AI, Back DL, Espag MP, Briggs TW, Cannon SR. · South East Thames Rotation, Guys Hospital, London, United Kingdom. · Orthopedics. · Pubmed #14763527 No free full text.

Abstract: Sixty-five patients aged > 80 years were compared to 65 patients aged between 60 and 70 years to assess total knee arthroplasty (TKA) outcome using the octogenarian postoperative Knee Society knee and function scores. Knee Society knee scores showed excellent outcomes with no statistically significant difference in the younger cohort (preoperative score, P = .7156; 5-year score, P = -.0677). Knee Society function scores also showed good outcomes with no statistically significant difference between the groups (preoperative score, P = .1147; 5-year score, P = .1348). Average length of stay increased by 3 days for octogenarians. Octogenarians had more pre-existing medical conditions and suffered more postoperative confusion. All but 1 patient rated the result as good/excellent. Patients maintained their independence for approximately 3.5 years before requiring more social input. With careful preoperative planning and counseling, TKA is recommended for the octogenarian.

Bankes MJ, Back DL, Cannon SR, Briggs TW. · Royal National Orthopaedic Hospital, Brockley Hill, Stanmore HA7 4LP, UK. · Knee. · Pubmed #12649028 No free full text.

Abstract: Component angles of 198 Kinemax total knee replacements were measured from standard short leg radiographs. An ideal tibio-femoral angle of between 4 and 10 degrees of valgus was achieved in 64.6% of patients. After an average follow-up of 6.5 years (range 4.5 to 9.5), there was no significant difference between knees in acceptable and suboptimal alignment in terms of pre- and post-operative knee and function scores and prevalence of radiolucent lines. Varus placement of the tibial component was significantly more common by trainee surgeons (P<0.001).

Back DL, Cannon SR, Hilton A, Bankes MJ, Briggs TW. · Royal National Orthopaedic Hospital Trust, Stanmore, England. · J Bone Joint Surg Br. · Pubmed #11341420 links to  free full text

Abstract: We reviewed the outcome of 422 primary cemented Kinemax total knee arthroplasties implanted into 369 patients over a period of five years, from January 1989. The operations were carried out at two NHS district general hospitals and one teaching hospital by 31 surgeons. During the period of review, 49 patients died and ten knees were lost to follow-up (68 knees). The mean Knee Society score improved from 28 before to 89 after surgery, and the mean function score increased from 23 to 79. The range of flexion improved from 92 degrees to 105 degrees. These improvements were maintained throughout the period of study. At the latest review radiolucent lines of 1 mm were seen around 15% of tibial components, 1.4% of patellar components and 9.5% of femoral components. In no case were these changes progressive. Using revision as the endpoint, cumulative survival was 99% after five years and 96.95% after nine years. All revisions were undertaken for deep infection or secondary trauma. Our study has shown that the Kinemax total knee replacement, when carried out with retention of the posterior cruciate ligament by surgeons of varying experience, produces very satisfactory results in the medium term.

Kendall SJ, Singer GC, Briggs TW, Cannon SR. · London Bone and Soft Tissue Tumour Unit, Royal National Orthopaedic Hospital, United Kingdom. · J Arthroplasty. · Pubmed #11021451 No free full text.

Abstract: We performed a functional analysis of massive knee replacements after extra-articular resection of primary bone tumors. Patients did not score as highly on the Musculoskeletal Tumour Society Score and Knee Society Score (P < or = .01) as patients who had undergone intra-articular resection. Lower scores were achieved for emotional acceptance (P < or = .01), functional restriction (P < or = .05), walking distance (P < or = .05), and managing stairs (P < or = .05). These patients had a significantly greater extension lag (P < or = .01) and greater fixed flexion (P < or = .05). This functional deficit is primarily due to a compromised extensor mechanism inherent in the type of surgical resection necessary to achieve adequate removal of the tumor.

Walker PS, Yoon WW, Cannon SR, Bentley G, Muirhead-Allwood SK. · Centre for Biomedical Engineering, University College London, Royal National Orthopaedic Hospital Trust, Stanmore, United Kingdom. · J Arthroplasty. · Pubmed #10614885 No free full text.

Abstract: Cases in which there is a total hip arthroplasty and a stemmed total knee arthroplasty in the same femur, with loosening of 1 or both components, with serious endosteal bone loss or even a fracture between the stems present a difficult reconstruction problem. We describe a reconstruction using a combined hip and stemmed knee, designed so that they could be rigidly connected during the surgical procedure. The advantages of this implant design are that the entire femur with its muscle attachments is preserved, and the inherent stability allows for immediate weight bearing. To determine the viability of the connection between the hip and the knee, a stress analysis was carried out using finite element analysis. Guidelines were thus provided for the required metal and cement thicknesses. Three case examples are presented with an average follow-up of 3 years. It was shown that the combined hip-knee implant could provide successful results for these difficult reconstructive problems in appropriately selected cases.