header advert
Results 21 - 40 of 2544
Results per page:
Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_6 | Pages 38 - 38
2 May 2024
Buadooh KJ Holmes B Ng A
Full Access

The Revision Hip Complexity Classification (RHCC) was developed by modified Delphi system in 2022 to provide a comprehensive, reproducible framework for the multidisciplinary discussion of complex revision hip surgery. The aim of this study was to assess the validity, intra-relater and inter-relater reliability of the RHCC.

Radiographs and clinical vignettes of 20 consecutive patients who had undergone revision of Total Hip Arthroplasty (THA) at our unit during the previous 12-month period were provided to observers. Five observers, comprising 3 revision hip consultants, 1 hip fellow and 1 ST3-8 registrar were familiarised with the RHCC. Each revision THA case was classified on two separate occasions by each observer, with a mean time between assessments of 42.6 days (24–57). Inter-observer reliability was assessed using the Fleiss™ Kappa statistic and percentage agreement. Intra-observer reliability was assessed using the Cohen Kappa statistic. Validity was assessed using percentage agreement and Cohen Kappa comparing observers to the RHCC web-based application result.

All observers were blinded to patient notes, operation notes and post-operative radiographs throughout the process.

Inter-observer reliability showed fair agreement in both rounds 1 and 2 of the survey (0.296 and 0.353 respectively), with a percentage agreement of 69% and 75%.

Inter-observer reliability was highest in H3-type revisions with kappa values of 0.577 and 0.441.

Mean intra-observer reliability showed moderate agreement with a kappa value of 0.446 (0.369 to 0.773).

Validity percentage agreement was 44% and 39% respectively, with mean kappa values of 0.125 and 0.046 representing only slight agreement.

This study demonstrates that classification using the RHCC without utilisation of the web-based application is unsatisfactory, showing low validity and reliability. Reliability was higher for more complex H3-type cases. The use of the RHCC web app is recommended to ensure the accurate and reliable classification of revision THA cases.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_6 | Pages 55 - 55
2 May 2024
McCann C Ablett A Feng T Macaskill V Oliver W Keating J
Full Access

Subtrochanteric femoral fractures are a subset of hip fractures generally treated with cephalomedullary nail fixation\[1\]. Single lag screw devices are most commonly-used, but integrated dual screw constructs have become increasingly popular\[2,3\]. The aim of this study was to compare outcomes of fixation of subtrochanteric femoral fractures using a single lag screw (Gamma3 nail, GN) with a dual screw device (InterTAN nail, IN). The primary outcome was mechanical failure, defined as lag screw cut-out, back-out, nail breakage or peri-implant fracture.

Consecutive adult patients (18yrs) with subtrochanteric femoral fracture treated in a single centre were retrospectively identified using electronic records. Patients that underwent surgical fixation using either a long GN (2010–2017) or IN (2017–2022) were included. Medical records and radiographs were reviewed to identify complications of fixation. Cox regression analysis was used to determine the risk of mechanical failure and secondary outcomes by implant design. Multivariable regression models were used to identify predictors of mechanical failure.

The study included 622 patients, 354 in the GN group (median age 82yrs, 72% female) and 268 in the IN group (median age 82yrs, 69% female). The risk of any mechanical failure was increased two-fold in the GN group (HR 2.44 \[95%CI 1.13 to 5.26\]; _p=0.024_). Mechanical failure comprising screw cut-out (_p=0.032_), back-out (_p=0.032_) and nail breakage (_p=0.26_) was only observed in the GN group. Technical predictors of failure included varus >5° for cut-out (OR 19.98 \[2.06 to 193.88\]; _p=0.01_), TAD;25mm for back-out (8.96 \[1.36 to 58.86\]; p=0.022) and shortening 1cm for peri-implant fracture (7.81 \[2.92 to 20.91\]; _p=<0.001_).

Our results demonstrate that an intercalated screw construct is associated with a lower risk of mechanical failure compared with the a single lag screw device. Intercalated screw designs may reduce the risk of mechanical complications for patients with subtrochanteric femoral fractures.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_6 | Pages 59 - 59
2 May 2024
Adla SR Ameer A Silva MD Unnithan A
Full Access

Arthroplasties are widely performed to improve mobility and quality of life for symptomatic knee/hip osteoarthritis patients. With increasing rates of Total Joint Replacements in the United Kingdom, predicting length of stay is vital for hospitals to control costs, manage resources, and prevent postoperative complications. A longer Length of stay has been shown to negatively affect the quality of care, outcomes and patient satisfaction. Thus, predicting LOS enables us to make full use of medical resources.

Clinical characteristics were retrospectively collected from 1,303 patients who received TKA and THR. A total of 21 variables were included, to develop predictive models for LOS by multiple machine learning (ML) algorithms, including Random Forest Classifier (RFC), K-Nearest Neighbour (KNN), Extreme Gradient Boost (XgBoost), and Na¯ve Bayes (NB). These models were evaluated by the receiver operating characteristic (ROC) curve for predictive performance. A feature selection approach was used to identify optimal predictive factors. Based on the ROC of Training result, XgBoost algorithm was selected to be applied to the Test set.

The areas under the ROC curve (AUCs) of the 4 models ranged from 0.730 to 0.966, where higher AUC values generally indicate better predictive performance. All the ML-based models performed better than conventional statistical methods in ROC curves. The XgBoost algorithm with 21 variables was identified as the best predictive model. The feature selection indicated the top six predictors: Age, Operation Duration, Primary Procedure, BMI, creatinine and Month of Surgery.

By analysing clinical characteristics, it is feasible to develop ML-based models for the preoperative prediction of LOS for patients who received TKA and THR, and the XgBoost algorithm performed the best, in terms of accuracy of predictive performance. As this model was originally crafted at Ashford and St. Peters Hospital, we have naturally named it as THE ASHFORD OUTCOME.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_6 | Pages 11 - 11
2 May 2024
Kolhe S Khanduja V Malviya A
Full Access

Hip dysplasia is a common cause of hip pain in young adults. Pelvic osteotomy (PO) techniques are the gold standard for treating symptomatic patients, albeit technically demanding. This study aimed to (1) evaluate the 90-day complication rate, and (2) investigate the reasons, frequency and timing of reoperations following primary PO procedures.

We retrospectively analysed the National Hospital Episode Statistics database, examining all patients aged over 14 who underwent PO in NHS England hospitals from 2010 to 2023. We identified index procedures and reoperations using relevant OPCS-4 codes. We analysed patient demographics, 90-day complications, and readmission rates for ipsilateral metalwork removal, revision PO, hip arthroscopy (HA), and THR conversion, and calculated the mean time to reoperations.

This study included 1,348 PO cases (mean age: 28.7±9.1 years, 89.5% female). The mean hospital stay was 5.4±3.9 days, with a 90-day readmission rate of 0.52% at a mean of 51.0±17.2 days. The most common causes were infection (0.22%) and reoperation (0.15%). The 90-day rate of pulmonary embolism and deep vein thrombosis was 0.074%. One patient died within 90 days.

Overall, 810 patients (60.1%) were readmitted for a subsequent hip procedure at a mean of 2.12±1.90 years following their primary PO. Metalwork removal was required in 616 patients (45.7%) at a mean of 1.70±1.19 years. Readmission rates for revision PO, HA, and THR, were 4.23% (mean time: 2.89±0.82 years), 4.15% (mean time: 2.91±2.28 years) and 6.01% (mean time: 5.24±3.08 years) respectively.

This study highlights a low 90-day complication rate following primary PO, but a high reoperation rate, mainly for metalwork removal. We provide the most up-to-date report of revision PO, HA and THR conversion rates in England. These findings provide valuable insight that can facilitate informed decision-making, expectation-setting, and post-operative planning, also establishing a benchmark for future quality improvement.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_6 | Pages 48 - 48
2 May 2024
Kolhe S Khanduja V Malviya A
Full Access

Hip arthroscopy (HA) and pelvic osteotomy (PO) are surgical procedures used to treat a variety of hip pathology affecting young adults, including femoroacetabular impingement and hip dysplasia respectively. This study aimed to investigate the trends and regional variation in the provision of HA and PO across England from 2010 to 2023 to inform healthcare resource allocation.

We analysed the National Hospital Episode Statistics database for all HA and PO procedures in NHS England using specific OPCS-4 codes: HA: ‘W83+Z843’ or ‘W84+Z843’; PO: ‘X222+Z75’. We collected patient demographics, age, sex, and region of treatment. We performed descriptive and regression analyses to evaluate temporal trends in PO volume, age, sex and regional variation.

22,401 HAs and 1,348 POs were recorded between 2010 and 2023. The annual number of HAs declined by 28.4%, whilst the number of POs increased by 64% (p<0.001). Significantly more females underwent PO vs HA (90% vs 61.3%) and were older than males undergoing the same procedure (PO: 29.0±8.7 vs 25.8±9.2 years; HA: 36.8±12.0 years vs 35.8±11.2 years, p<0.001). For HA, the mean age of both sexes decreased by 3.3 and 2.9 years respectively (p<0.001), whereas the age of PO patients did not change significantly over the study period. There were significant regional variations with a mean incidence of 1.60/100,00 for HA (ranging from 0.70–2.66 per 100,000) and 0.43/100,000 for PO (ranging from 0.08–2.07 per 100,000).

We have observed a decline in HA volume in England, likely due to improved patient selection and the impact of COVID-19, whilst PO volume has significantly increased, with regional variation persisting for both procedures. These trends highlight the need for equitable HA and PO access to improve patient outcomes and call for strategic healthcare planning and resource allocation to reduce disparities and improve training opportunities.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_6 | Pages 13 - 13
2 May 2024
Wijesekera M East J Chan CD Hadfield J As-Sultany M Kassam A Petheram T Jones HW Palan J Jain S
Full Access

This large UK multicentre study evaluates clinical outcomes and identifies factors associated with local complication following PFR for non-oncological conditions.

132 patients across four UK centres underwent PFR from 01/08/2004-28/03/2023 with median follow-up of 1.9 (Q10.5-Q34.2) years. 75 (56.8%) patients were female and the mean age was 74.0 (SD 11.7) years. 103 (78%) patients had Charleston Comorbidity Index ≥3. ASA class was III or IV in 66.6%. Indications were infected revision (39, 29.5%), periprosthetic fracture (36, 27.3%), acute trauma (30, 22.7%), aseptic revision (17, 12.9%), failed trauma (nine, 6.8%) and complex primary arthroplasty (one, 0.8%). The primary outcome was the local complication rate. Secondary outcomes were systemic complications, reoperation and mortality rates. Comparisons were made with t-tests and Chi2 tests to investigate patient and surgical factors associated with local complication. Statistical significance was p<0.05.

There were 37(28.0%) local complications. These were 18 (13.6%) dislocations, eight (6.1%) prosthetic joint infections, four (3.0%) haematomas, three (2.3%) superficial infections, one (0.8%) wound dehiscence, one (0.8%) sciatic nerve palsy and one (0.8%) femoral perforation. Dislocation mostly occurred in conventional articulations (12, 9.1%) followed by dual-mobility cups (three, 2.3%), constrained cups (two, 1.5%) and hemiarthroplasty (one, 0.8%). Median time to local complication was 30 (Q14-Q3 133) days. Seven (5.3%) patients developed a systemic complication. Thirty-three (25.0%) patients underwent reoperation. Thirty-day and one-year mortality rates were 3.8% and 12.1%, respectively. Longer surgical waiting times (7.9 \[SD 16.9) versus 2.6 \[SD 4.4\] days, p<0.001) and longer operating times (212.5 \[SD 71.8\] versus 189.4 \[SD 59.3\] mins, p=0.0450) were associated with local complication.

Due to its high complication rate, PFR should be a salvage option when performed for non-oncological indications. Conventional articulations should be avoided. PFR should be delivered in a timely manner and ideally as dual-consultant cases to reduce operating time.


Current advice regarding implant choice is based on estimates of cost-benefit derived from implant survival to an endpoint of revision. Current estimates do not account for many implant failures which are treated with non-revision surgery and may not be accurate. The aim of this study was to estimate survival of major stem implant design groups to an endpoint of reoperation.

Primary total hip replacement and linked revision form the National Joint Registry (NJR) and Hospital Episode Statistics (HES) data linked by unique identifier were used. Survival of femoral implant groups (cemented stainless steel polished taper [PTSS], cemented cobalt chrome polished taper [PTCC], cemented composite beam [CB], collarless cementless [NCOL] and collared cementless [COL]) was estimated using Kaplan-Meier method.

809,832 patients with valid NJR and HES data from England, were included. Cumulative failure at ten years for PTSS increased overall from 2.9% (95%CI 2.8–2.9) to 3.6% (95%CI 3.6–3.7) after inclusion of reoperations. Cumulative failure at ten years for PTSS increased from 2.5% (95%CI 2.5–2.6) to 3.3% (95%CI 3.2–3.4), for PTCC increased from 3.8% (95%CI 3.5–4.0) to 5.4% (95%CI 5.1–5.6), for CB increased from 3.1% (95%CI 2.9–3.3) to 4.1% (95%CI 3.8–4.3), for NCOL increased from 3.4% (95%CI 3.3–3.5) to 3.9% (95%CI 3.8–4.0), and for COL increased from 2.5% (95%CI 2.4–2.6) to 3.1% (95%CI 2.9–3.2), after inclusion of reoperations.

Re-operation for internal fixation is as significant life event for the patient as revision. When a more inclusive metric is used, the patient and clinician's perspective on what constitutes a GIRFT implant may not be the same. Further work is required to update implant selection guidance in view of the change in implant performance.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_6 | Pages 26 - 26
2 May 2024
Al-Naib M Afzal I Radha S
Full Access

As patient data continues to grow, the importance of efficient and precise analysis cannot be overstated. The employment of Generative Artificial Intelligence (AI), specifically Chat GPT-4, in the realm of medical data interpretation has been on the rise. However, its effectiveness in comparison to manual data analysis has been insufficiently investigated.

This quality improvement project aimed to evaluate the accuracy and time-efficiency of Generative AI (GPT-4) against manual data interpretation within extensive datasets pertaining to patients with orthopaedic injuries.

A dataset, containing details of 6,562 orthopaedic trauma patients admitted to a district general hospital over a span of two years, was reviewed. Two researchers operated independently: one utilised GPT-4 for insights via prompts, while the other manually examined the identical dataset employing Microsoft Excel and IBM® SPSS® software. Both were blinded on each other's procedures and outcomes. Each researcher answered 20 questions based on the dataset including injury details, age groups, injury specifics, activity trends and the duration taken to assess the data.

Upon comparison, both GPT-4 and the manual researcher achieved consistent results for 19 out of the 20 questions (95% accuracy). After a subsequent review and refined prompts (prompt engineering) to GPT-4, the answer to the final question aligned with the manual researcher's findings. GPT-4 required just 30 minutes, a stark contrast to the manual researcher's 9-hour analytical duration.

This quality improvement project emphasises the transformative potential of Generative AI in the domain of medical data analysis. GPT-4 not only paralleled the accuracy of manual analysis but also achieved this in significantly less time. For optimal accurate results, data analysis by AI can be enhanced through human oversight. Adopting AI-driven approaches, particularly in orthopaedic data interpretation, can enhance efficiency and ultimately improve patient care. We recommend future investigations on large and more varied datasets to reaffirm these outcomes.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_6 | Pages 24 - 24
2 May 2024
Lawrence J Woods S Roberts K Tuck E Balogh P Predeus A He P Polanski K Prigmore E Zhou D Webb S Jardine L
Full Access

The reliable production of _in vitro_ chondrocytes that faithfully recapitulate _in vivo_ development would be of great benefit for orthopaedic disease modelling and regenerative therapy(1,2). Current efforts are limited by off-target differentiation, resulting in a heterogeneous product, and by the lack of comparison to human tissue, which precludes detailed evaluation of _in vitro_ cells(3,4).

We performed single-cell RNA-sequencing of long bones dissected from first-trimester fetal limbs to form a detailed ‘atlas’ of endochondral ossification. Through 100-gene in-situ sequencing, we placed each sequenced cell type into its anatomical context to spatially resolve the process of endochondral ossification. We then used this atlas to perform deconvolution on a series of previously published bulk transcriptomes generated from _in vitro_ chondrogenesis protocols to evaluate their ability to accurately produce chondrocytes.

We then applied single-nuclear RNA-sequencing to cells from the best performing protocol collected at multiple time points to allow direct comparison between the differentiation of _in vitro_ and _in vivo_ cells.

We captured 275,000 single fetal cells, profiling the development of chondrocytes from multipotent mesenchymal progenitors to hypertrophic cells at full transcriptomic breadth. Using this atlas as the ground truth for evaluating _in vitro_ cells, we found substantial variability in cell states produced by each protocol, with many showing little similarity to _in vivo_ cells, and all exhibiting off-target differentiation.

Trajectory alignment between _in vivo_ and _in vitro_ single-cell data revealed key differences in gene expression dynamics between _in vitro_ and _in vivo cells,_ with several osteoblastic transcription factors erroneously unregulated _in vitro,_ including _FOXO1._

Using this information, we inhibited _FOXO1_ in culture to successfully increase chondrocyte yield _in vitro._

This study presents a new framework for evaluating tissue engineering protocols, using single-cell data to drive improvement and bring the prospect of true engineered cartilage closer to reality.


Different techniques have been described to address massive bone loss of the acetabulum in revision hip surgery. aMace has gained popularity as it provides customization aiming to restore hip centre and provide good initial stability in cases of large non-contained defects. It takes into account quality of host bone. Its porous defect filling scaffold provides an excellent surface for osteointegration.

Our aim was to assess the short and mid-term outcomes of patients who underwent revision surgery using aMace system.

Ethical approval was obtained. A retrospective study included all patients who had aMace between June 2013 and October 2022 allowing for a minimum of 12-months follow-up. Patients’ demographics, indication, bone-loss severity, reconstruction details, re-operation, complications, mortality, pain and function were assessed.

52 cases were performed by 13 surgeons with median 51 months follow-up. Median age was 72.7 years. 86.5% were female. Average BMI was 25.3. Average ASA grade was 3.

65% were classified as Paprosky IIIB and 32% were IIIA.

73% were found to have poor bone quality on CT. Main indication for aMace was massive bone loss/discontinuity secondary to aseptic loosening in 88.5%.

77% underwent single-stage revision. 53.8% had 2 or more previous revisions. 71% underwent stem revision in the same setting. 77% received a dual mobility bearing.

Re-operation rate was 5.7% for instability and femoral PPF. LLD was reported in 9.6%.

Permanent Sciatic nerve palsy occurred in 3.8% of the cases.

30-days mortality was 1.9%.

Statistically significant post-op improvements in pain and mobility were reported (p<0.001). None of the acetabular components have been revised.

Our study shows satisfactory surgical outcomes with a relatively low complication rate and significant pain and mobility improvements in the early to mid-term stages.

We recommend these costly cases to be done in highly specialist centres adopting MDT approach.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_6 | Pages 46 - 46
2 May 2024
Palmer A Fernquest S Logishetty K Rombach I Harin A Mansour R Dijkstra P Andrade T Dutton S Glyn-Jones S
Full Access

The primary treatment goal for patients with femoroacetabular impingement syndrome, a common hip condition in athletes, is to improve pain and function. In selected patients, in the short term following intervention, arthroscopic hip surgery is superior to a pragmatic NHS- type physiotherapy programme. Here, we report the three-year follow-up results from the FemoroAcetabular Impingement Trial (FAIT), comparing arthroscopic hip surgery with physiotherapy in the management of patients with femoroacetabular impingement (FAI) syndrome.

Two-group parallel, assessor-blinded, pragmatic randomised controlled study across seven NHS England sites. 222 participants aged 18 to 60 years with FAI syndrome confirmed clinically and radiologically were randomised (1:1) to receive arthroscopic hip surgery (n = 112) or physiotherapy and activity modification (n = 110). We previously reported on the hip outcome score at eight months. The primary outcome measure of this study was minimum Joint Space Width (mJSW) on Anteroposterior Radiograph at 38 months post randomisation. Secondary outcome measures included the Hip Outcome Score and Scoring Hip Osteoarthritis with MRI (SHOMRI) score.

Minimum Joint Space Width data were available for 101 participants (45%) at 38 months post randomisation. Hip outcome score and MRI data were available for 77% and 62% of participants respectively. mJSW was higher in the arthroscopy group (mean (SD) 3.34mm (1.01)) compared to the physiotherapy group (2.99mm (1.33)) at 38 months, p=0.017, however this did not exceed the minimally clinically important difference of 0.48mm. SHOMRI score was significantly lower in the arthroscopy group (mean (SD) 9.22 (11.43)) compared to the physiotherapy group (22.76 (15.26)), p-value <0.001. Hip outcome score was higher in the arthroscopy group (mean (SD) 84.2 (17.4)) compared with the physiotherapy group (74.2 (21.9)), p-value < 0.001).

Patients with FAI syndrome treated surgically may experience slowing of osteoarthritisprogression and superior pain and function compared with patients treated non- operatively.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_6 | Pages 61 - 61
2 May 2024
Shah JZ Bubak S Sami WA Quraishi S
Full Access

Alcohol hand rubs, endorsed by WHO and NICE guidelines, are integral to modern surgical practices. Our objective was to assess how different scrubbing methods impact overall water usage by the surgical team, shedding light on variations among team members and their environmental implications.

Over three consecutive arthroplasty lists spanning a week, water usage during scrubbing was observed for the operating team. Blinding all team members, including the anesthetist, consultant surgeon, orthopaedic registrar, orthopaedic SHO, and scrub nurse, during water usage calculations was implemented. Automated taps, using motion sensors, posed a challenge due to variable water quantity, necessitating water flow calculations per sensor movement. The senior surgeon, with over 20 years of experience, follows a traditional approach, starting with a morning prescrub and using an alcohol tub for each case, except when hands are soiled.

We observed a total of 14 cases of lower limb primary arthroplasty. The cumulative water usage for scrubbing by the entire team was 193 liters, yielding a mean of 13.8 liters (±1.85) per case. The anaesthetist demonstrated the most conservative water usage, utilizing a total of 11.85 liters with a mean of 0.84 liters per case. Notably, alcohol rub was employed for half of the observed time, contributing to this efficient use. The senior operating surgeon used a total of 15.6 liters, averaging 1.1 liters per case. In contrast, the SHO and the registrar exhibited the highest water consumption, totaling 121.6 liters and yielding a mean of 5.7 liters per case. The nurses’ collective water usage for scrubbing amounted to 44.8 liters.

Adopting alcohol rub, as endorsed by WHO, results in a remarkable 10-fold reduction in water usage, aligning with global health guidelines. This highlights significant potential for resource conservation in surgical procedures, presenting a practical and environmentally conscious approach to surgical scrubbing practices.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_6 | Pages 17 - 17
2 May 2024
Whitehouse M Patel R French J Beswick A Navvuga P Marques E Blom A Lenguerrand E
Full Access

Hip bearing surfaces materials are typically broadly reported in national registry (metal-on-polyethylene, ceramic-on-ceramic etc). We investigated the revision rates of primary total hip replacement (THR) reported in the National Joint Registry (NJR) by detailed types of bearing surfaces used.

We analysed THR procedures across all orthopaedic units in England and Wales. Our analyses estimated all-cause and cause-specific revision rates. We identified primary THRs with heads and monobloc cups or modular acetabular component THRs with detailed head and shell/liner bearing material combinations. We used flexible parametric survival models to estimate adjusted hazard ratios (HR).

A total of 1,026,481 primary THRs performed between 2003–2019 were included in the primary analysis (Monobloc cups: n=378,979 and Modular cups: n=647,502) with 20,869 (2%) of these primary THRs subsequently undergoing a revision episode (Monobloc: n=7,381 and Modular: n=13,488).

Compared to implants with a cobalt chrome head and highly crosslinked polyethylene (HCLPE) cup, the overall risk of revision for monobloc acetabular implant was higher for patients with cobalt chrome or stainless steel head and non-HCLPE cup. The risk of revision was lower for patients with a delta ceramic head and HCLPE cup implant, at any post-operative period.

Compared to patients with a cobalt chrome head and HCLPE liner primary THR, the overall risk of revision for modular acetabular implant varied non-constantly. THRs with a delta ceramic or oxidised zirconium head and HCLPE liner had a lower risk of revision throughout the entire post-operative period.

The overall and indication-specific risk of prosthesis revision, at different time points following the initial implantation, is reduced for implants with a delta ceramic or oxidised zirconium head and a HCLPE liner/cup in reference to THRs with a cobalt chrome head and HCLPE liner/cup.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_6 | Pages 15 - 15
2 May 2024
Williams S Smeeton M Isaac G Anderson J Wilcox R Board T Williams S
Full Access

Dual Mobility (DM) Total Hip Replacements (THRs), are becoming widely used but function in-vivo is not fully understood.

The aim of this study was to compare the incidence of impingement of a modular dual mobility with that of a standard cup.

A geometrical model of one subject's bony anatomy \[1\] was developed, a THR was implanted with the cup at a range of inclination and anteversion positions (Corail® stem, Pinnacle® cup (DePuy Synthes)). Two DM variants and one STD acetabular cup were modelled. Joint motions were taken from kinematic data of activities of daily living associated with dislocation \[2\] and walking. The occurrence of impingement was assessed for each component combination, orientation and activity. Implant-implant impingement can occur between the femoral neck and the metal or PE liner (DM or STD constructs respectively) or neck-PE mobile liner (DM only).

The results comprise a colour coded matrix which sums the number of impingement events for each cup position and activity and for each implant variant.

Neck-PE mobile liner impingement, occurred for both DM sizes, for all activities, and most cup placement positions indicating that the PE mobile liner is likely to move at the start of all activities including walking.

For all constructs no placement positions avoided neck-metal (DM) or neck-PE liner (STD) impingementevents in all activities. The least number of events occurred at higher inclination and anteversion component positions. In addition to implant-implant impingement, some instances of bone-bone and implant-bone impingement were also observed.

Consistent with DM philosophy, neck-PE mobile liner impingement and liner motion occurred for all activities including walking. Neck-liner impingement frequency was comparable between both DM sizes (metal liner) and a standard cup (PE liner).


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_6 | Pages 22 - 22
2 May 2024
Logishetty K Whitwell D Palmer A Gundle R Gibbons M Taylor A Kendrick B
Full Access

There is a paucity of data available for the use of Total Femoral Arthroplasty (TFA) for joint reconstruction in the non-oncological setting. The aim of this study was to evaluate TFA outcomes with minimum 5-year follow-up.

This was a retrospective database study of TFAs performed at a UK tertiary referral revision arthroplasty unit. Inclusion criteria were patients undergoing TFA for non-oncological indications. We report demographics, indications for TFA, implant survivorship, clinical outcomes, and indications for re-operation.

A total of 39 TFAs were performed in 38 patients between 2015–2018 (median age 68 years, IQR 17, range 46–86), with 5.3 years’ (IQR 1.2, 4.1–18.8) follow-up; 3 patients had died. The most common indication (30/39, 77%) for TFA was periprosthetic joint infection (PJI) or fracture-related infection (FRI); and 23/39 (59%) had a prior periprosthetic fracture (PPF). TFA was performed with dual-mobility or constrained cups in 31/39 (79%) patients. Within the cohort, 12 TFAs (31%) required subsequent revision surgery: infection (7 TFAs, 18%) and instability (5 TFAs, 13%) were the most common indications. 90% of patients were ambulatory post-TFA; 2 patients required disarticulation due to recurrent PJI. While 31/39 (79%) were infection free at last follow-up, the remainder required long-term suppressive antibiotics.

This is the largest series of TFA for non-oncological indications. Though TFA has inherent risks of instability and infection, most patients are ambulant after surgery. Patients should be counselled on the risk of life-long antibiotics, or disarticulation when TFA fails.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_6 | Pages 37 - 37
2 May 2024
Green J Malviya A Reed M
Full Access

OpenPredictor, a machine learning-enabled clinical decision aid, has been developed to manage backlogs in elective surgeries. It aims to optimise the use of high volume, low complexity surgical pathways by accurately stratifying patient risk, thereby facilitating the allocation of patients to the most suitable surgical sites. The tool augments elective surgical pathways by providing automated secondary opinions for perioperative risk assessments, enhancing decision-making. Its primary application is in elective sites utilising lighter pre-assessment methods, identifying patients with minimal complication risks and those high-risk individuals who may benefit from early pre-assessment.

The Phase 1 clinical evaluation of OpenPredictor entailed a prospective analysis of 156 patient records from elective hip and knee joint replacement surgeries. Using a polynomial logistic regression model, patients were categorised into high, moderate, and low-risk groups. This categorisation incorporated data from various sources, including patient demographics, co-morbidities, blood tests, and overall health status.

In identifying patients at risk of postoperative complications, OpenPredictor demonstrated parity with consultant-led preoperative assessments. It accurately flagged 70% of patients who later experienced complications as moderate or high risk. The tool's efficiency in risk prediction was evidenced by its balanced accuracy (75.6%), sensitivity (70% with a 95% confidence interval of 62.05% to 76.91%), and a high negative predictive value (96.7%).

OpenPredictor presents a scalable and consistent solution for managing elective surgery pathways, comparable in performance to secondary consultant opinions. Its integration into pre-assessment workflows assists in efficient patient categorisation, reduces late surgery cancellations, and optimises resource allocation. The Phase 1 evaluation of OpenPredictor underscores its potential for broader clinical application and highlights the need for ongoing data refinement and system integration to enhance its performance.


To examine whether Natural Language Processing (NLP) using a state-of-the-art clinically based Large Language Model (LLM) could predict patient selection for Total Hip Arthroplasty (THA), across a range of routinely available clinical text sources.

Data pre-processing and analyses were conducted according to the Ai to Revolutionise the patient Care pathway in Hip and Knee arthroplasty (ARCHERY) project protocol (https://www.researchprotocols.org/2022/5/e37092/). Three types of deidentified Scottish regional clinical free text data were assessed: Referral letters, radiology reports and clinic letters. NLP algorithms were based on the GatorTron model, a Bidirectional Encoder Representations from Transformers (BERT) based LLM trained on 82 billion words of de-identified clinical text. Three specific inference tasks were performed: assessment of the base GatorTron model, assessment after model-fine tuning, and external validation.

There were 3911, 1621 and 1503 patient text documents included from the sources of referral letters, radiology reports and clinic letters respectively. All letter sources displayed significant class imbalance, with only 15.8%, 24.9%, and 5.9% of patients linked to the respective text source documentation having undergone surgery. Untrained model performance was poor, with F1 scores (harmonic mean of precision and recall) of 0.02, 0.38 and 0.09 respectively. This did however improve with model training, with mean scores (range) of 0.39 (0.31–0.47), 0.57 (0.48–0.63) and 0.32 (0.28–0.39) across the 5 folds of cross-validation. Performance deteriorated on external validation across all three groups but remained highest for the radiology report cohort.

Even with further training on a large cohort of routinely collected free-text data a clinical LLM fails to adequately perform clinical inference in NLP tasks regarding identification of those selected to undergo THA. This likely relates to the complexity and heterogeneity of free-text information and the way that patients are determined to be surgical candidates.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_6 | Pages 14 - 14
2 May 2024
Menakaya C Durand-Hill M Carrington R Hart A Donaldson J Miles J Briggs T Skinner J
Full Access

The management of femoral bone loss is challenging during revision hip arthroplasty. In patients with Paprosky grade IIIB and IV defects, obtaining fixation and rotational stability using traditional surgical constructs is difficult. The use of a custom-made internal proximal femoral replacement prostheses has been proposed as a solution in patients, with severe femoral bone stock loss. However, there is a paucity in the literature on their use and long-term outcomes. We report on the clinical and radiological results of our cohort.

We retrospectively reviewed all patients who underwent internal proximal femoral replacement for revision hip arthroplasty between April 1996 and April 2019. All patients had at least 2 years of follow-up time.

160 patients underwent limb salvage at our institution using internal proximal femoral replacement. The mean follow-up was 79.7 months (S.D 41.3). Indications for revision included periprosthetic fractures, aseptic loosening, and deep infection. The mean Oxford hip score increased from 13.8 (0–22) to 31.5 (18–43) (paired t-test, p < 0.001). Kaplan-Meier prosthesis survival analysis with revision as the endpoint was 87% at 5 years. None required revision of the femoral stem. There were four dislocations (5%) and there was failure to eradicate the deep infection in four.

This technique allows instant distal fixation, allowing for early mobilisation. Long-term clinical and radiological outcomes are encouraging and the complication rates are acceptable for this patient group.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_6 | Pages 19 - 19
2 May 2024
Shaarani S Moriarty P Vles G Haddad F Konan S
Full Access

We had previously reported on early outcomes on a new fluted, titanium, monobloc stem with a three degree taper that has been designed for challenging femoral reconstruction in the setting of extensive bone loss. The aim of this study was to report its mid-term clinical and radiographic outcomes.

This is a retrospective review of prospectively collected data carried out at a single institution between Jan 2017 and Dec 2019. 85 femoral revisions were performed using a new tapered, fluted, titanium, monobloc (TFTM) revision stem. Complications, clinical and radiographic data were obtained from medical records and a locally maintained database. Clinical outcomes were assessed using the Oxford Hip Score (OHS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). All post-operative radiographs were analysed for subsidence, osteolysis and femoral cortical bone remodelling.

Mean follow-up was 60 months (range 28–84 months). Subsidence of 1.2 mm was noted in one patient. No cases of clinically significant subsidence (10 mm) were observed. At final follow-up, a statistically significant improvement was noted in functional outcome scores. The mean OHS preoperatively and at final follow-up were 24 (SD 13) and 42 (SD15). p = 0.04 mean difference 18 (95% CI 15–22). The mean WOMAC scores preoperatively and at final follow-up were 62 (SD23) and 88 (SD7) respectively (p < 0.001, mean difference 26; 95% CI 21–34). No stem fractures were noted within the follow-up period. Two patients had revision of the stem's one for infection and another for persistent pain.

Positive mid-term clinical and radiological outcomes have been observed with this tapered, fluted, titanium, monobloc stem. Based on these results, this implant may be considered as a viable option in the majority of uncemented femoral revisions.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_6 | Pages 33 - 33
2 May 2024
Dickenson E Griffin J Wall P McBryde C
Full Access

The 22 year survivorship of metal on metal hip resurfacing arthroplasty (RSA) is reported to be 94.3% with expert surgeons, in males with head sizes greater than 48mm. The 2023 National Joint Registry (NJR) report estimates survivorship of all RSA at 19 years to be 85%. This estimate includes all designs, head sizes and females. Our aim was to estimate the survivorship of RSA currently available for implantation (males only, head size >48mm, MatOrtho Adept or Smith and Nephew Birmingham Hip Resurfacing (BHR)) in those under 55 years, performed by all surgeons, compared to conventional THR.

We performed a retrospective analysis of the NJR. We included all males under 55 years who had undergone BHR or Adept RSA with head size greater than 48mm. Propensity score matching was used to produce two comparable groups of patients for RSA or conventional THR. We matched in a 3:1 ratio (THR:RSA) using sex, ASA, BMI group, age at primary procedure, surgeon volume, diagnosis and surgeon grade as covariates. The primary analysis was survivorship at 18 years. Time-to-revision was assessed using Kaplan-Meier curves. Cox's proportional hazard models were used to investigate between group differences.

4839 RSA were available for analysis. After matching the RSA and THR groups were well balanced in terms of covariates. Survivorship at 18 years was 93.7% (95% CI 89.9,96.2) in the RSA group and 93.9% (90.5,96.0) in the THR group. Despite these similar estimates the adjusted hazard ratio was 1.40 (95% CI 1.18, 1.67 p<0.001) in favour of THR.

Survivorship of the currently available RSA in males under 55 was 93.7% at 18 years, however THR survivorship was superior to RSA. These results, generalisable to UK practice, should be set against perceived benefits in functional status offered in RSA when counselling patients.