Aim

Periprosthetic Joint Infection (PJI) is a devastating complication in hip and knee joint arthroplasty. The “JS BACH” classification system was developed in 2021 to stratify the complexity of PJI, and more importantly, to act as a tool to guide referrals to specialist centers. The “JS BACH” classification has not been validated in an external cohort. This study aimed to do so using a large prospective cohort from Australia and New Zealand.

Aim

The intention of suppressive antimicrobial therapy (SAT) for prosthetic joint infection (PJI) is to minimise symptoms, maintain function and prevent further surgery in patients who cannot undergo further attempts at curative treatment(1). There is little high-quality evidence examining the role and efficacy of SAT for patients with PJI(1,2). The objective of this study was to describe the use of and outcomes after SAT in a large prospective PJI cohort.

Introduction

Tibial Pilon fractures are potentially limb threatening, yet standards of care are lacking from BOFAS and the BOA. The mantra of “span, scan, plan” describes staged management with external fixation to allow soft tissue resuscitation, followed by a planning CT-scan. Our aim was to evaluate how Tibial Pilon fractures are acutely managed.

Introduction

This is a multi-centre, prospective, observational study of 503 INFINITY fixed bearing total ankle arthroplasties. We report the minimum two-year results of this prosthesis which was introduced to the UK Market in 2014 and is now the most used ankle arthroplasty in the National Joint Registry of England and Wales.

In a clinical setting, there is a need for simple gait kinematic measurements to facilitate objective unobtrusive patient monitoring. The objective of this study is to determine if a learned classification model's output can be used to monitor a person's recovery status post-TKA.

The gait kinematics of 20 asymptomatic and 17 people with TKA were measured using a full-body Xsens model¹. The experimental group was measured at 6 weeks, 3, 6, and 12 months post-surgery. Joint angles of the ankle, knee, hip, and spine per stride (10 strides) were extracted from the Xsens software (MVN Awinda studio 4.4)¹.

Statistical features for each subject at each evaluation moment were derived from the kinematic time-series data. We normalised the features using standard scaling². We trained a logistic regression (LR) model using L1-regularisation on the 6 weeks post-surgery data2–4.

After training, we applied the trained LR- model to the normalised features computed for the subsequent timepoints. The model returns a score between 0 (100% confident the person is an asymptomatic control) and 1 (100% confident this person is a patient). The decision boundary is set at 0.5.

The classification accuracy of our LR-model was 94.58%. Our population's probability of belonging to the patient class decreases over time. At 12 months post-TKA, 38% of our patients were classified as asymptomatic.

This study aimed to identify the success rate of debridement, antibiotics and implant retention (DAIR) for prosthetic joint infection (PJI) in a large prospective cohort of patients undergoing total knee arthroplasty (TKA). The ability for different PJI classification systems to predict DAIR success was assessed.

A prospective, multicenter study of PJIs occurring between July 2014 and December 2017 in 27 hospitals across Australia and New Zealand was performed. First time PJIs following primary TKA that were managed with DAIR were analyzed. DAIR success was defined as the patient being alive with documented absence of clinical or microbiological evidence of infection and no ongoing antibiotics for the index joint at 2-year follow-up. Multivariate analysis was performed for multiple PJI classification systems to assess their ability to predict DAIR success using their respective definitions of “early” PJI (Coventry ≤1 month, International Consensus Meeting ≤90 days or Auckland <1 year), or as hematogenous versus chronic PJI (Tsukayama).

189 PJIs were managed with DAIR, with an overall success rate of 45% (85/189). Early PJIs had a higher rate of DAIR success when analyzed according to the Coventry system (adjusted odds ratio = 3.85, p = 0.008), the ICM system (adjusted odds ratio = 3.08, p = 0.005) and the Auckland system (adjusted odds ratio = 2.60, p = 0.01). DAIR success was lower in both hematogenous (adjusted odds ratio = 0.36, p = 0.034) and chronic PJIs (adjusted odds ratio = 0.14, p = 0.003) occurring more than one year since the primary TKA.

DAIR success is highest when performed in infections occurring within one year of the primary TKA. Late infections had a high DAIR failure rate irrespective of their classification as hematogenous or chronic. Time since primary is a useful predictor of DAIR success.

The optimum indications for debridement, antibiotics and implant retention (DAIR) are unclear. Previous studies have demonstrated higher success rate of DAIR within one year of the primary arthroplasty. This study aimed to compare the success rate of DAIR vs revision in “early” and “late” infections to provide guidance for clinical decision making.

The Prosthetic Joint Infection in Australia and New Zealand Observational (PIANO) cohort prospectively recorded PJIs between July 2014 and December 2017 in 27 hospitals. This study included PIANO patients with first time PJIs occurring after primary TKA. Treatment success was defined as the patient being alive, free from further revision and without clinical or microbiological evidence of reinfection at two years follow-up.

“Early” and “late” infections were analyzed separately. Univariate analysis compared demographic and disease specific factors between the DAIR and Revision groups. Multivariate binary logistic regression identified whether treatment strategy and other risk factors were associated with treatment success in “early” and “late” infections.

In 117 “early” (<1 year) infections, treatment success rate was 56% in the DAIR group and 54% in the revision group (p=0.878). No independent risk factors were associated with treatment outcome on multivariate analysis.

In 134 “late” (>1 year) infections, treatment success rate was 34.4% in the DAIR group and 60.5% in the revision group (OR 3.07 p=0.006). On multivariate analysis, revision was associated with 2.47x higher odds of success (p=0.041) when compared to DAIR, patients with at least one significant co-morbidity (OR 2.27, p=0.045) or with Staphylococcus aureus PJIs (OR 2.5, p=0.042) had higher odds of failure.

In “late” PJIs occurring >1 year following primary TKA, treatment strategy with revision rather than DAIR was associated with greater success. Patients with significant comorbidities and Staphylococcus aureus PJIs were at higher risk of failure regardless of treatment strategy.

Aim

There is a lack of both epidemiological data and of high-quality evidence to guide the management of Prosthetic joint infection (PJI). We hypothesised that there is substantial heterogeneity in the clinical presentation and management of PJI in Australia and New Zealand, and that the proportion with clinical cure at 24 months is independently associated with modifiable variables in surgical and antibiotic management.

Introduction:

25% of patients with an unknown primary tumour present to the orthopaedic surgeon with skeletal metastases. The onus is on the orthopaedic surgeon to establish the diagnosis, not only to decrease the patient's anxiety but also because the median survival increases from 6–9 months to 23 months when the primary is identified and allows for specific cancer treatment. The diagnostic work up of an unknown primary includes a multitude of special investigations.

Since PET/CT has high sensitivity and specificity for detecting the primary tumours, we asked the question: Can you diagnose the unknown primary in patients with skeletal metastases with a PET/CT?

Foot and ankle surgery is a rapidly evolving specialty. As the number and complexity of cases increases, the number of complaints, litigation and pay-outs has also risen. We aim to assess any learning points discerned from NHS litigation data to allow us help improve patient care.

All claims made to the NHS Litigation Authority between 2007 and 2012 relating to foot and ankle problems were obtained under the Freedom of Information Act. These were reviewed, coded and split into subgroups to allow analysis.

There were 232 successful litigation cases between 2007 and 2012. The total amount paid out was almost £18.5 million (range £112 to £1.6 million). A significant number of successful cases were due to patients not having full, informed consent.

A large amount of money is spent in the NHS is spent on litigation. The amount of litigation and payout in foot and ankle surgery compares favourably with hip and knee surgery.

Lack of informed consent is an easily reversible problem that should be decreasing but is actually on the rise. In our trust, we advocate the use of consent clinics which provide a robust and patient-centred approach to informed consent in foot and ankle surgery.

Proximal interphalangeal joint arthrodesis for lesser toe deformity is commonly stabilised using a Kirschner wire passed through the tip of the toe. Recently, a number of all-inside intramedullary fusion devices have been developed, with the aim of decreasing infection risk through avoiding exposed metalwork. We report our early experience with Stayfuse™ (Nexa Orthopaedics).

Case records of patients undergoing Stayfuse™ proximal interphalangeal joint arthrodesis between July 2009 and November 2011 were examined. Twenty-eight Stayfuse™ proximal interphalangeal joint arthrodesis procedures in 14 patients were performed. Overall, 8 (29%) procedures required revision within 6 months. Of these, 3 (11%) intraoperative failures occurred, requiring immediate revision (Kirschner wire stabilisation or excision arthroplasty). All involved bending failure of the implant clip mechanism. A further 5 (18%) toes required revision procedures within 6 months of the index procedure, 3 (11%) for dissociation of the implant clip mechanism and 2 (7%) for periprosthetic fracture.

For patients perceived to be at higher risk of infective complications, all-inside stabilisation systems are an attractive concept. However, with 29% of patients undergoing revision procedures within 6 months, we question the safety of choosing Stayfuse™ implants over Kirschner wire stabilisation.

This study looked at the effect on referral for surgical opinion of introducing ESP Physiotherapy (1 physiotherapist) and Podiatry (2 podiatrists) clinics on the number of foot and ankle patients who were seem for a surgical opinion and subsequently surgery.

Prior to the introduction of the ESP clinics the number of patients was approximately 1 in every 8 was listed for surgery. At the time of the study the ESP clinics accounted for half of the new patients seen in orthopaedic foot & ankle clinics. The other half was seen by the surgical team (3 surgeons).

Minimally Invasive foot surgery remains controversial

Potential benefits include a reduced incidence of wound complications, faster return to employment and normal footwear. There are no studies published regarding the results of minimally invasive dorsal cheilectomy.

Introduction

Minimally Invasive foot surgery remains controversial. Potential benefits include a reduced incidence of wound complications, faster return to employment and normal footwear. There are no studies published regarding the results of minimally invasive dorsal cheilectomy.

Introduction

Uncontrolled deep sepsis in the diabetic foot often leads to below knee amputation (BKA). However, for deep sepsis in the forefoot, a transmetatarsal amputation can be curative while preserving the native ankle and hindfoot and allowing mobility without a prosthesis. We critically examined the outcome of transmetatarsal amputation in our diabetic patients with forefoot ulceration and proven osteomyelitis.

The addition of Extended Scope Practitioner (ESP) clinics was proposed to review new Foot and Ankle referrals, to reduce time consultants spend in clinic and free them up for theatre. There would be a cost benefit to the Primary Care Trusts (PCT), a clinic appointment with the consultants cost's around £140 and ESPs around £70.

We prospectively collected data from the ESP clinics for two months in 2009. We looked at the number of patients referred on to the consultants and how many of these needed surgery.

During this period one hundred and forty one patients were booked into ESP clinics, forty three were referred to the consultants, ninety one were managed by the ESPs and seven patients failed to attend. The estimated saving to the PCT during the 2 month period was £6860 which would be £41,160 over a year. Twenty nine of the patients referred to the consultants required surgery giving a 74% conversion rate.

The use of ESPs in Foot and Ankle Clinic reduces the number of new referrals seen by consultants, therefore being cost effective to the PCTs. This also increased the consultant's surgical conversion rate producing a more efficient service.

Patient satisfaction is a driving force behind setting up and developing day case procedures. Ten months ago a service for day surgery SCARF procedures was set up in Torbay day surgery unit.

We analysed patient pre and post operative pain scores and patient satisfaction scores in respect to pain, appearance and overall satisfaction.

A questionnaire was sent to all sixty patients who had undergone a SCARF osteotomy in day surgery. Outcomes assessed were: reason for SCARF osteotomy; adequate preoperative information; pain scores pre and post operatively; satisfaction scores and admission rates.

53 patients responded (88% response rate). 79% of patients had their operation for pain, 19% for appearance and footwear, and 2% for function of their foot. 100% of patients were given adequate information by the surgeon preoperatively and 27% also used other sources for information. 62% of patients scored 6 or more on a linear pain score preoperatively. 85% of patients have a current pain score of 0 or 1. 87% were highly satisfied (scoring 9 or 10 on linear scale) with the outcome regarding their pain, 83% highly satisfied with appearance and 72% highly satisfied with function despite the questionnaire being completed less than one year post surgery. 83% of patients were highly satisfied with the overall procedure and 91% said they would have a SCARF as a day case procedure again. 9 patients were admitted, 3 due to living alone, 3 for wound problems and 3 for post anaesthetic problems including pain, nausea and vomiting.

From these figures we concluded that SCARF osteotomy in day surgery is a successful, feasible and worthwhile undertaking in our unit.

We used the questionnaires and results to further analyse our service and we have made modifications to improve it. We have now put in place a dedicated anaesthetist with an interest in foot and ankle blocks, as well as a comprehensive post operative analgesic regime and a stringent day surgery protocol.

We now run a prospective questionnaire from clinic, including AAOFAS scores, to continue analysis of our service. With these changes in place we would like to see our satisfaction scores rising towards 100%.

Background: Acquired patella baja occurs after both trauma and surgery of the knee including TKA, with prevalences between 30%–60%. The inferior position of the patella leads to alterations in the joint mechanics, reduction of range of motion, anterior knee pain, and can cause increased wear of the tibial and patellar polyethylene. Our aim was to evaluate the prevalence of patella baja after TKA and to assess the clinical effects of patella tendon torsion and twisting during surgical exposure of the knee.

Methods: Postoperative changes in patella height were measured on serial radiographs of 74 TKA implanted without patella eversion (group 1) and 57 TKA implanted with patella eversion (group 2). Pre- and postoperative Knee Society Scores, operative data, and complications were compared.

Results: With a cut-off level of 5% shortening, the prevalence was 12% (9 cases) in group 1 and 37% (21 cases) in group 2 (p=0.001). With the 10% cut-off level the prevalences were 5% (4 cases/group 1) and 14% (8 cases/group2) (p=0.1). The presence of patella baja was related to reduced flexion and increased pain 1 year after TKA.

Conclusion: Our study has shown that tension and twisting of the patellar tendon leads to shortening which was associated with reduced flexion and increased pain after TKA. By avoiding patella eversion the prevalence of acquired patella baja was reduced significantly.

Background: Recently, less invasive techniques for total knee arthroplasty (TKA) were introduced and the early results suggest a more rapid return of flexion and functional activities, while requiring fewer analgesics after surgery. Despite these findings, there is concern over the possibility of a steep learning curve and the potential risks of implant misalignment or poor fixation that may compromise long-term results. The purpose of this study was to analyze the potential learning curve effect on clinical and radiographic Results: Methods: This retrospective review compares the first 30 (Group 1) to the latest 30 cases (Group 2) in one surgeon’s consecutive series of 152 mini-incision mid-vastus TKA. Pre- and postoperative Knee Society Scores were compared, implant alignment was measured, and flexion was evaluated during hospital stay, at 6 weeks and 3 months after surgery. Complications and operative data were collected.

Results: Flexion was significantly higher in group 2 during hospitalization and at all clinical follow-up evaluations. At last follow-up mean flexion was 111° ± 8 (95–125) in group 1 and 121° ± 11 (90–140) in group 2 (p= 0.001). The mean length of skin incision was 11.7 cm ± 1.5 (8–15) with a mean incision length of the vastus medialis oblique muscle of 3.2 cm ± 1.0 (1–5). A steady improvement of knee and function scores was found in the entire series which were significantly greater in group 2. There were no complications and the radiographic evaluation found no implant or limb misalignment, or signs of early loosening.

Conclusion: The introduction of a mini-incision technique is an evolutionary process. The clinical and functional results show continued improvement after more than 100 cases. There was no classical learning curve effect and no increased complication rate in the earlier series. Thus far, the benefits of the mini-incision mid-vastus approach outweigh the new technique related difficulties and possible new risks. There are no signs of compromise that will affect the long-term results of mini-incision TKA.

Study design: Cross-sectional study of 10 patients to measure the serum levels of cobalt and chromium after TDA.

Summary of Background Data: In total hip endoprosthetics and consequently for TDA (total disc arthroplasty), metal-on-metal combinations are used with the aim of reducing wear debris. In metal-on-metal TDA the release of metal ions has until now been secondary to the main discussion.

Objectives: To investigate the release of cobalt and chromium ions into the serum following implantation of the metal-on-metal MaverickTM type artificial lumbar disc.

Materials and methods: We investigated the serum cobalt and chromium concentration following implantation of 15 Maverick™ TDAs (monosegmental L5/S1 n=5; bisegmental L4/5 and L5/S1 n=5; average age = 36.5 years). 5 healthy subjects (no metal implants) acted as a control group. The measurements of the metals were carried out using the HITACHI Z-8200 AAS polarized Zeeman atomic absorption spectrometer after an average of 14,8months.

Results: The concentrations of cobalt and chromium ions in the serum amounted on average to 4.75μg/l (standard deviation 2,71) for cobalt and 1.10μg/l (standard deviation 1,24) for chromium. Compared to the control group, both the chromium and cobalt levels in the serum showed significant increases (Mann-Whitney Rank Sum Test, p=0.0120). At follow-up the Oswestry Disability Score was on average significantly decreased by 24.4 points (L5/S1) (t-test, p < 0.05) and by 26.8 points (L4-S1)(t-test, p < 0.05). The improved clinical situation is also represented by a significant decrease of the Visual Analog Pain Scale of 42,2points after the follow-up (t-test, p< 0,05).

Conclusion: Significant systemic release of Cr/Co was proven in the serum compared to the control group. The concentrations of Cr/Co measured in the serum are similar in terms of their level to the values measured in THA metal-on-metal combinations or exceed these values given in the literature. Long-term implication of this metal exposuere in unknown and should be studied further.