Isolated patellofemoral osteoarthritis accounts for 10% of knee osteoarthritis. Many of these will not require arthroplasty solutions, but for those who are sufficiently symptomatic, patellofemoral joint (PFJ) replacement has been shown to be an effective procedure. The National Joint Registry (NJR) has shown a higher revision rate for this operation, particularly in younger patients (males <55 years 13.3% failure at 5 years, females 9.6%). The aim of this study is to report on the medium-term outcome of the Avon patellofemoral joint arthroplasty in patients under 55 from a non-design centre. There is no other published case series on this young patient cohort. 50 Avon PFJ replacements (Stryker, Kalamazoo USA) were undertaken in 46 patients under 55 years old (range 35 – 54, mean 48.8) between 2010 and 2022 for end-stage isolated PFJ arthritis shown on Xray and MRI scan. The outcome measure was all-cause revision rate. This was assessed by review of clinical notes, imaging and NJR data.Abstract
Introduction
Methodology
Medial patellofemoral ligament (MPFL) reconstruction is an effective procedure to address patellofemoral instability, however there remains no clear consensus on the optimum technique. Variations in patella tunnel and the use of patella fixation devices are reported in the literature, as are the associated complications of patella fracture and hardware irritation. We present the early results using a two tunnel, Endobutton free technique. 24 MPFL reconstructions (14 female, 10 male) were performed by a single surgeon, using two 3.5mm medial patellar tunnels exiting anteriorly and a looped, extra-synovial hamstring autograft. Femoral fixation was achieved using an non-absorbable interference screw. Mean age was 25.5 years, with a mean follow-up of 21.7 months. Mean Kujala scores were 60.8 preoperatively and 87.9 postoperatively (p<0.0001). No patient experienced further dislocation or patella fracture post-operatively. One patient required interference screw removal. The surgical technique presented has outcomes comparable with the literature. It requires a shorter tendon graft, and removes the need for a patellar fixation device, reducing potential irritation and cost.
In September 2011 our departmental protocol for peri-operative prophylactic antibiotic administration was altered from cefuroxime to gentamicin/flucloxacillin, in response to reported links between cephalosporin use and Clostridium difficile (C. diff) infection. As both gentamicin and flucloxacillin are known to be nephrotoxic in some patients, we investigated whether the new regimen increases the risk of Acute Kidney Injury (AKI) in patients undergoing elective and trauma hip and knee surgery, classified by severity (AKI Network criteria). The incidence of C. diff was noted. 10 out of 202 (5%) patients receiving cefuroxime (group A) developed AKI, compared with 23 of 210 (11%) patients receiving gentamicin and flucloxacillin (group B) (p=0.012). The severity of the renal injury was higher in the group B patients with 16 sustaining stage II/III AKI, whereas in Group A only one patient sustained a stage II injury and none stage III. The increased AKI rate in group B was observed equally in hip fracture patients and elective hip/knee replacement patients. However, 3 of 80 (4%) patients with hip fractures who received doses of cefuroxime developed C. diff, with none in the other groups (p=0.04). The choice of prophylactic antibiotics depends on a careful assessment of benefits and risks. Our data suggests that whereas hip fracture patients may have benefitted from the protocol change with reduced C. diff incidence, elective hip and knee replacement patients sustained additional harm. Different antibiotic regimens may be appropriate for these two groups.
The introduction of direct thrombin inhibitors in arthroplasty surgery has reignited the debate on the risk of wound complications when using chemical thromboprophylaxis. It has been suggested that direct thrombin inhibitors might lead to an increased risk of systemic and operative site bleeding and wound sepsis when compared to low molecular weight heparin. In July 2009, departmental thromboprophylaxis policy for patients undergoing hip and knee replacement surgery (including revision) was changed from subcutaneous enoxaparin for the duration of inpatient stay to dabigatran for 10 days (knees) or 28 days (hips) unless contraindicated. In the 2 years prior to policy change, 1091 patients underwent hip or knee arthroplasty (Group A), with1150 patients undergoing the same procedures in the 2 years following July 2009 (Group B). A minority of patients were already on warfarin (2% in group 1, 3% in group 2). This study presents a retrospective analysis of all patients who returned to theatre within 30 days of joint replacement surgery to assess whether the change in unit policy caused any discernible increase in bleeding-related complications. In group A, 20/1091 patients (1.8%) returned to theatre within 30 days. 9 were for reasons unrelated to thromboprophylaxis (mainly dislocated hips), 4 for gastrointestinal bleeding and 7 for wound complications (haematoma, wound breakdown, or infection). In group B, 22/1150 patients (1.9%) returned to theatre within 30 days. 13 were for unrelated reasons, 4 for gastrointestinal bleeding, and 5 for wound complications. One patient with a wound complication was on warfarin and therefore did not receive dabigatran. The lower wound complication rate in group B was not statistically different. This study, in a large heterogeneous group of patients, suggests that a change from enoxaparin to dabigatran does not increase the incidence of local or systemic complications of sufficient severity to warrant return to theatre.
The introduction of direct thrombin inhibitors in arthroplasty surgery has reignited the debate on the risk of wound complications when using chemical thromboprophylaxis. It has been suggested that direct thrombin inhibitors might lead to an increased risk of systemic and operative site bleeding and wound sepsis when compared to low molecular weight heparin. In July 2009, departmental thromboprophylaxis policy for patients undergoing hip and knee replacement surgery (including revision) was changed from subcutaneous enoxaparin for the duration of inpatient stay to dabigatran for 10 days (knees) or 28 days (hips) unless contraindidated. In the 2 years prior to policy change, 1091 patients underwent hip or knee arthroplasty (Group 1), with1150 patients undergoing the same procedures in the 2 years following July 2009 (Group 2). A minority of patients were already on warfarin (2% in group 1, 3% in group 2). This study presents a retrospective analysis of all patients who returned to theatre within 30 days of joint replacement surgery to assess whether the change in unit policy caused any discernible increase in bleeding-related complications. In group 1, 23/1091 patients (2.1%) returned to theatre within 30 days. 8 were for reasons unrelated to thromboprophylaxis (mainly dislocated hips), 5 for gastrointestinal bleeding (mainly upper GI endoscopy) and 10 for wound complications (haematoma, wound breakdown, or washout of early infection). In group 2, 22 / 1150 patients (1.9%) returned to theatre within 30 days. 12 were for unrelated reasons, 5 for GI bleeding, and 5 for wound complications. The lower return to theatre rate in the second group was not statistically different. This study, in a large heterogeneous group of patients, suggests that a change from enoxaparin to dabigatran does not increase the incidence of early infection, or the risk of bleeding at the operative site or the gastrointestinal tract.
Our aim was to assess the use of intra-operative fluoroscopy
in the assessment of the position of the tibial tunnel during reconstruction
of the anterior cruciate ligament (ACL). Between January and June 2009 a total of 31 arthroscopic hamstring
ACL reconstructions were performed. Intra-operative fluoroscopy
was introduced (when available) to verify the position of the guidewire
before tunnel reaming. It was only available for use in 20 cases,
due to other demands on the radiology department. The tourniquet
times were compared between the two groups and all cases where radiological
images lead to re-positioning of the guide wire were recorded. The
secondary outcome involved assessing the tibial interference screw
position measured on post-operative radiographs and comparing with
the known tunnel position as shown on intra-operative fluoroscopic
images.Objectives
Methods
The outcome following arthroscopic anterior cruciate (ACL) reconstruction is dependant on a combination of surgical and non-surgical factors. Technical error is the commonest cause for graft failure, with poor tunnel placement accounting for over 80% of those errors. A routine audit of femoral and tibial tunnel positions following single bundle hamstring arthroscopic ACL reconstruction identified apparent inconsistent positioning of the tibial tunnel in the sagittal plane. Intra-operative fluoroscopy was therefore introduced (when available) to verify tibial guide wire position prior to tunnel reaming. This paper reports a comparison of tibial interference screw position measured on post-operative radiographs with known tunnel position as shown on intra-operative fluoroscopic images in 20 patients undergoing routine primary ACL reconstruction between January and June 2009. Surgery took a mean of 5 minutes longer when intra-operative fluoroscopy was used. In 3/20 patients, fluoroscopy led to re-positioning of the tibial guide wire prior to tunnel reaming. The mean tibial tunnel position as indicated by the tunnel reamer was 41 +/− 2.7 % of the total plateau depth (range 37% to 47%). The mean position projected from the tibial screw on post operative radiographs was 46 +/− 9.2% (range 38% to 76%). A paired t-test showed a significant difference (p = 0.022) between true tunnel position and tibial screw position. 6/20 patients had post operative screw positions that were > 5% more posterior than the known position of the tibial tunnel. The position of the tunnel should be measured at its mid-point where this is evident. On most early radiographic images, the margins of the tunnel are not clear and therefore a line projected from the centre of the screw is used. This audit demonstrates the potential inaccuracy associated with this.
Resection of pulmonary metastases has previously been reported to improve outcome in high grade osteosarcoma (OS) patients with pulmonary metastases. In this study factors influencing survival in OS patients with pulmonary metastases were determined. One hundred ninety seven patients with OS treated at our institution between 1990 and 2008 under the age of 40 were included. Excluded were patients with insufficient follow-up data (n=12) and irresectable primary tumour (n=11). Of the 174 remaining patients, 26 patients had pulmonary metastases at diagnosis and 62 developed pulmonary metastases during follow-up. Twenty-two of 88 patients (25%) also had extra-pulmonary metastases. Almost all patients with primary non-metastatic OS who experienced a relapse within 310 days (first tertile) died of disease, whereas patients with a relapse free interval of more than 310 days (second and third tertiles) have a significantly better overall survival at about 20% (p=0.02). In total, 56 (63.6%) of 88 patients with pulmonary metastases were treated by metastasectomy. The main reason not to perform metastasectomy was irresect-ability by number and site. Patients with irresectable pulmonary metastases had higher numbers of pulmonary nodules (mean of six vs. three nodules) and more frequent bilateral involvement than patients eligible for surgery (p-values respectively 0.002 and 0.06). Independent risk factors determining survival after metastasectomy in multivariate analysis were male sex (p=0.05), higher numbers of pulmonary nodules (p=0.03) and necrotic metastases (p=0.04). Patients undergoing repeated metastasectomies had a similar chance of survival as patients who underwent metastasectomy once. This well-defined cohort of patients with extensive follow-up data enabled us to identify important risk factors determining survival in OS patients with pulmonary metastases. Risk factors determining poor survival after pulmonary metastasectomy were male sex, higher numbers of pulmonary nodules and resection of vital metastases. Furthermore, we demonstrate that even after repeated metastasectomies, curation can be achieved.
This paper describes a simple new MRI measurement of the axial patellar tendon angle (APTA), and compares this angle in patients with and without patello-femoral instability.
In PFI, the patella is commonly tilted laterally. This is matched by the orientation of the patellar tendon. The increased tilt of the tendon is only partially corrected at its distal insertion with an abnormal angle of tibial attachment. When performing distal realignment procedures, angular correction as well as displacement may be appropriate.
This paper reports the angle between the EF and the horizontal (the extension facet angle- EFA) in normal knees and in knees with early AMOA.
A sagittal image at the midpoint of the femoral condyle was used to determine the EFA.
There is an association between an increased EFA (ie a steeper EF) and MRI evidence of AMOA. Although a causal link is not proven, we speculate that a steeper angle increases the duration of loading on the EF in stance and tibio-femoral interface shear. This may initiate cartilage breakdown.
This paper describes a simple new MRI measurement of the axial patellar tendon angle (APTA), and compares this angle in patients with and without patello-femoral instability.
In PFI, the patella is commonly tilted laterally. This is matched by the orientation of the patellar tendon. The increased tilt of the tendon is only partially normalized at its distal insertion with an abnormal angle of tibial attachment. When performing distal realignment procedures, angular correction as well as displacement may be appropriate.
Cemented, polished, tapered stems have produced excellent results, but some early failures occur in younger patients. The CPS-Plus stem (Plus Orthopedics AG, Switzerland) is a polished double taper with rectangular cross section for improved rotational stability. A unique proximal stem centraliser increases cement pressurisation, assists alignment and creates an even cement mantle. Radiostereometric analysis has demonstrated linear subsidence in a vertical plane, without any rotation or tilt. These features should improve implant durability. Midterm (5 years) results of a prospective international multicentre study are presented.
The mean Harris hip score improved from 42 preoperatively to 91. There have been no revisions for aseptic loosening and none of the stems have radiographic evidence of loosening. There has been one revision for deep sepsis. With revision for aseptic loosening as an endpoint, stem survivorship is 100%.
Patello-femoral instability (PFI) and pain may be caused by anatomical abnormality. Many radiographic measurements have been used to describe the shape and position of the patella and femoral trochlea. This paper describes a simple new MRI measurement of the axial patellar tendon angle (APTA), and compares this angle in patients with and without patello-femoral instability.
In PFI, the patella is commonly tilted laterally. This is matched by the orientation of the patellar tendon. The increased tilt of the tendon is only partially normalized at its distal insertion with an abnormal angle of tibial attachment. When performing distal realignment procedures, angular correction as well as displacement may be appropriate.
This paper reports the angle between the EF and the horizontal (the extension facet angle - EFA) in normal knees and in knees with early AMOA.
A sagittal image at the midpoint of the femoral condyle was used to determine the EFA. Repeat measurements were taken by two observers.
There is an association between an increased EFA (ie a steeper EF) and MRI evidence of AMOA. Although a causal link is not proven, we speculate that a steeper angle increases the duration of loading on the EF in stance and tibio-femoral interface shear. This may initiate cartilage breakdown.
We report a multi-centre prospective clinical trial. 231 hips in 223 patients have been entered into the study. 151 of these have reached 3 years follow-up.
In particular, the RSA subsidence characteristics, cement pressurisation and rotational stability already associated with this implant in-vitro have been supported by excellent survivorship analysis, and the authors believe that increasing familiarity with the concepts raised by this implant will result in clinical benefits in relation to polished taper cemented stem longevity.
Data on the CPS-Plus stem has been obtained from a multi-centre prospective clinical trial. 231 hips in 223 patients have been entered into the study. 151 of these have reached 3 years follow-up.
In particular, the RSA subsidence characteristics, cement pressurisation and rotational stability already associated with this implant in-vitro have been supported by excellent survivorship analysis, and the authors believe that increasing familiarity with the concepts raised by this implant will result in clinical benefits in relation to polished taper cemented stem longevity.