In this study, we examined the impact of dual-mobility (DM) versus fixed-bearing (FB) implants on outcomes following total hip arthroplasty (THA), a common and successful operation. We examined all-cause revision, revision due to dislocation, postoperative complications and functional scores in patients undergoing primary and revision THA.

A systematic review was performed according to PRISMA guidelines, and was registered in PROSPERO (ID CRD42023403736). The Cochrane Library, Embase, MEDLINE, Web of Science, and Scopus were searched from inception to 12th March 2023. Eligible studies underwent meta-analysis and methodological assessment using the ROBINS-I tool. Data were pooled using a random-effects maximum-likelihood model.

Eight comparative, non-randomised studies involving 2,810 DM implants and 3,188 FB implants were included. In primary THA, the difference in all-cause revision was imprecise (OR 0.82, 95% CI 0.25–2.72), whilst the DM cohort had a statistically significant benefit in revision due to dislocation (OR 0.08, 95% CI 0.02–0.28). In revision THA, the DM cohort showed significant benefit in all-cause revision (OR 0.57, 95% CI 0.31–1.05) and revision due to dislocation (OR 0.14, 95% CI 0.04–0.53). DM implants were associated with a lower incidence of implant dislocation and infection. Functional outcome analysis was limited due to underreporting. No intraprosthetic dislocations were observed.

The results suggest that contemporary DM designs may be advantageous in reducing the risk of all-cause revision, revision due to dislocation, and postoperative complication incidence at mid-term follow-up. Further high-quality prospective studies are needed to evaluate the long-term performance of this design, especially in revision cases.

Surgical trainees are finding it increasingly more challenging to meet operative requirements and coupled with the effects of COVID-19, we face a future of insufficiently trained surgeons. As a result, virtual reality (VR) simulator training has become more prevalent and whilst more readily accepted in certain arthroscopic fields, its use in hip arthroscopy (HA) remains novel. This project aimed to validate VR high-fidelity HA simulation and assess its functional use in arthroscopic training.

Seventy-two participants were recruited to perform two basic arthroscopic tasks on a VR HA simulator, testing hip anatomy, scope manipulation and triangulation skills. They were stratified into novice (39) and experienced (33) groups based on previous arthroscopy experience. Metric parameters recorded from the simulator were used to assess construct validity. Face validity was evaluated using a Likert-style questionnaire. All recordings were reviewed by 2 HA experts for blinded ASSET score assessment.

Experienced participants were significantly faster in completing both tasks compared with novice participants (p<0.001). Experienced participants damaged the acetabular and femoral cartilage significantly less than novice participants (p=0.011) and were found to have significantly reduced path length of both camera and instrument across both tasks (p=0.001, p=0.007), demonstrating significantly greater movement economy. Total ASSET scores were significantly greater in experienced participants compared to novice participants (p=0.041) with excellent correlation between task time, cartilage damage, camera and instrument path length and corresponding ASSET score constituents. 62.5% of experienced participants reported a high degree of realism in all facets of external, technical and haptic experience with 94.4% advising further practice would improve their arthroscopic skills. There was a relative improvement of 43% in skill amongst all participants between task 1 and 2 (p<0.001).

This is the largest study to date validating the use of simulation in HA training. These results confirm significant construct and face validity, excellent agreement between objective measures and ASSET scores, significant improvement in skill with continued use and recommend VR simulation to be a valuable asset in HA training for all grades.

Introduction

We report the initial 2 and 3 year follow-up results of this randomised controlled trial of autologous chondrocyte implantation (ACI) using porcine-derived collagen membrane as a cover (ACI-C) versus matrix-carried autologous chondrocyte implantation (MACI) for the treatment of osteochondral defects of the knee.

We performed a retrospective review of 98 patients with malignant tumours of the periacetabular region, treated by resection and endoprosthetic reconstruction between 1971 and 2005 at the Royal National Orthopaedic Hospital, Stanmore and The Royal Orthopaedic Hospital, Birmingham.

The mean age of the patients was 43.6 years (10 to 76). 53 patients (54%) were male. The age distribution demonstrated peaks in the 2nd and 6th decades. The mean follow up was 65 months (2 to 405. The overall 10-year survival rate was 56% (determined by the Kaplan-Meier method).

54 patients (58.1%) had one or more complications. Infection was the most common (30%) with the majority occurring in the first 2 years. Dislocation occurred in 19 (20%) of our patients all in the first year following surgery. All were recurrent with a mean of 2.9 (2 to 6) episodes. Operations performed before 1994 were associated with a dislocation rate of 40.5% and after 1996 the rate was only 3.9% (p < 0.001).

Function was assessed according the Toronto Extremity Salvage Sore (TESS). The overall TESS was 59.4. In patients that had a major complication the TESS was 37.1 but in the group that did not the TESS was 70.3 (p < 0.001).

Men experienced higher rates of death, infection and revision than women (p < 0.05). The local recurrence rate was 31% with high grade tumours associated with higher recurrence rates (p < 0.05). Tumour resection in the ilium is associated with higher rates of infection than tumours located in the periacetabular region alone (p < 0.05).

This method of reconstruction is still associated with high complication rates. Function is good if a major complication can be avoided. The lower dislocation rate more recently is probably the result of improved surgical technique and the use of larger femoral heads.

Introduction: Conflicting opinions exist as to whether bone healing is affected by the administration of bisphosphonates for osteoporosis. In an animal model, we assessed the effect of bisphosphonates on osteoporotic fracture healing and whether the timing of administration made a difference.

Methods: 36 female Wistar rats underwent a mid-diaphyseal femoral osteotomy six weeks after ovariectomy. They were then divided into 3 groups:

no treatment (control);

Results: Of the 36 rats, 8 were unable to complete the study. Group 3 differed from control in three respects: higher bone mineral content (BMC) and density (BMD); larger callus; lower torsional stiffness. Group 2 did not differ significantly from control. There was a significant positive correlation between stiffness and change in BMC in group 1 (r=0.85, p< 0.001) but not so for group 2 (r=0.2, p> 0.05) and group 3 (r=0.04, p> 0.05). A similar trend existed for all radiographic parameters in the three groups.

Conclusion: The results suggest that, with early bisphosphonate treatment, although there is an increase in the size of the callus, that callus is biomechanically inferior. Furthermore, administration of bisphosphonates at either stage destroys the relationship between radiographic and mechanical parameters used to assess fracture healing.

Introduction: Autologous chondrocyte implantation (ACI) has been used to treat patella cartilage lesions but several studies have indicated poorer results compared to lesions on the femoral condyles. This paper investigates the effectiveness of two different methods of ACI; porcine-derived collagen membrane as a cover (ACI-C) and matrix-carried autologous chondrocyte implantation (MACI).

Methods: 124 patients (mean age 33.5) with symptomatic osteochondral lesions in the patella were selected to undergo either ACI (56 patients) or MACI (68 patients). 1 year following surgery patients underwent check arthroscopy to assess the graft. Functional assessment was performed pre-operatively, at 6 months and yearly by using the modified Cincinnati score (MCS).

Results: 37.5% of patients experienced good or excellent clinical results according to the MCS in the ACI group compared with 69.2% in the MACI group (p = 0.0011). The mean MCS improved from 43.7 pre-operatively to 49.8 2 years following surgery in the ACI group, whereas in the MACI group the improvement was from 44.6 to 60.6 (p=0.07). Arthroscopic assessment showed a good to excellent International Cartilage Repair Society score in 89.7% of ACI-C grafts and 69.6% of MACI grafts (p = 0.08). There was a higher re-operation rate (p = 0.044) in the ACI group (29%) compared with MACI (10%).

Conclusions: The results from this paper suggest that MACI is more successful in the treatment of patella cartilage lesions than ACI even though arthroscopic assessment showed the converse to be true. The higher complication and re-operation rate suggests that we should be treating such patients with MACI.

Purpose: We attempted to identify whether patients with early evidence of osteoarthritis (OA) on their pre-operative radiographs were associated with poorer outcomes after Autologous Chondrocyte Implantation (ACI).

Methods: We retrospectively reviewed radiographs of 94 consecutive patients who underwent ACI and had already had their knee function assessed according to the Modified Cincinatti Score 2 years following surgery. Changes were graded according to The Kellgren and Lawrence (K& L) and the Stanmore grading system. Two independent observers analysed the films to assess the reproducibility and accuracy of these grading systems for assessment of OA in the knee.

Results: Patients were divided into 2 groups; Group A were patients with excellent/good outcome (52 patients), those with fair/poor outcome were Group B (42 patients).13 patients in Group A and 21 patients in Group B had radiographic evidence of OA (p< 0.025). In 34 patients who had OA (mean age 33.6) the increase in Cincinatti score following surgery was minimal (33.5 to 37.5). In 60 patients where there was no evidence of OA (mean age 33.7) the score increased from 40 to 53.4. The inter-observer variation was greater using K& L (Kappa=0.31) compared with the Stanmore grading systems (Kappa=0.72).

Conclusions: Patients with early radiographic evidence of OA are unlikely to gain maximum benefit from ACI. Furthermore, we recommend the use of Stanmore grading system for the assessment of OA as it is more reproducible than the K& L grading system.

Introduction: Smoking is associated with impaired wound healing, delayed bony union following fractures and an adverse effect on the immune system. Furthermore, smoking is an important risk factor for the development pulmonary complications following major surgical procedures, as well as wound complications. We determined whether smoking had a deleterious effect on outcome after autologous chondrocyte implantation (ACI) in the treatment of ostechondral defects of the knee.

Methods: We identified 103 (54 females and 49 males) patients with a mean age of 34.2 (range 18 to 49) who had undergone ACI between January 2001 and August 2004 who also had their smoking status recorded. The patients were divided into 3 groups according to their smoking status. The Visual Analogue Score, Bentley Functional Rating Score and Modified Cincinatti Scores were used to assess function pre-operatively, 6 months and then yearly thereafter.

Results: Group 1 consisted of 31 smokers (mean pack years of 13.4), group 2 consisted of 63 non-smokers and group 3 contained 9 ex-smokers. In Group 1, the Modified Cincinatti Score pre-operatively, 6 months, 1 year and 2 years following surgery were 34.1, 42.6, 43.5 and 46.7 respectively. In group 2 the scores were 47.4, 59.6, 59.1, 65.3, and in group 3 the scores were 39.8, 50, 53.3, 51.8. At the 1 year check arthroscopy, the graft failure rate in group 1 was 12% and biopsies revealed mixed hyaline and fibrocartilage in only 25% (there were no patients with hyaline cartilage). There were no graft failures in group 2 and 43.8% of the biopsies performed were either hyaline (12.5%) or mixed hyaline and fibrocartilage (31.3%). The wound complication rate was 24% in group 1 and 8% in group 2.

Conclusions: The results of this study suggest that people who smoke have a worse functional outcome and a higher complication rate following chondrocyte implantation. This association has not been previously described and should be included in the pre-operative counselling of patients undergoing the procedure.

Introduction: Several studies have implicated excessive weight as a negative predictor of success of total knee arthroplasty. In addition, obese patients are known to have increased risk of wound complications after orthopaedic and general surgery. The purpose of this study was to compare the clinical and functional outcomes of autologous chondrocyte implantation for treatment of osteochondral defects of the knee performed in obese patients with those performed in non-obese patients.

Methods: We analysed the data on all our patients that have been followed up for a minimum of 2 years and had their height and weight recorded initially in our database. Functional assessment consisted of Bentley Functional Rating Score, Visual Analogue Score, and the Modified Cincinatti Scores (collected prospectively at 6 months, 1 year, 2 years and 3 years following surgery). Patients were placed into 3 groups according to their body mass index (BMI). Group A consisted of patients with BMI of 20 to 24.9, group B patients with BMI of 25 to 29.9 and Group C are patients with BMI of 30 to 39.9.

Results: There were 80 patients (41 males and 39 females) with a mean age of 35.4 (range 18 to 49). The mean BMI for the entire group was 26.6. The pre-operative, 6 month, 1 year, 2 year, and 3 year Modified Cincinatti Score in Group A (32 patients) was 54.4, 80.3, 82.7, 74.7 and 72.6. Similarly in Group B, the scores were 53, 41, 54, 56, 49.5 and in Group C the scores were 36.3, 36.3, 49.6, 36, and 35.7. The wound infection rate in Group A was 6.25%, in Group B was 17.6% and Group C was 14.3%.

Conclusions: Initial results from this study suggest that BMI is an important predictor of outcome after chondrocyte implantation. The group of patients that would gain most benefit from ACI are patients that are not overweight (defined by BMI in the range of 20 to 24.9). Further work is being carried out to support the hypothesis that surgeons should strongly consider not operating on patients unless the BMI is less than 25.

Introduction: ACI is used widely as a treatment for symptomatic chondral and osteochondral defects of the knee. Variations of the original periosteum-cover technique include the use of porcine-derived type I/type III collagen as a cover (ACI-C) and matrix-induced autologous chondrocyte implantation (MACI) using a collagen bilayer seeded with chondrocytes. We report the minimum 2 year follow-up results of 192 patients randomised to autologous chondrocyte implantation (ACI) using porcine-derived collagen membrane as a cover (ACI-C) and matrix-induced autlogous chondrocyte implantation (MACI) for the treatment of osteochondral decfects of the knee.

Methods: 192 patients (mean age 34.2) were randomised to have either ACI (86 patients) or MACI (106 patients). 1 year following surgery patients underwent check arthroscopy (with or without biopsy) to assess the graft. Functional assessment was performed yearly by using the modified Cincinatti knee score, the Bentley functional rating score and the visual analogue score.

Results: 24 patients were excluded from the study as they underwent additional procedures (e.g. high tibial osteotomy). In the ACI group the modified Cincinatti score increased from 42.5 pre-operatively to 56.7, 54.1, and 60.4 at 1 year, 2 years and 3 years respectively. In the MACI group the Cincinatti scores increased from 46.0 pre-operatively to 59.9, 58.9, and 58.4. Arthroscopic assessment showed a good to excellent International Cartilage Repair Society score in 90.7% of ACI-C grafts and 68.4% of MACI grafts. Hyaline-like cartilage or hyaline-like with fibrocartilage was found in biopsies of 51.9% of ACI-C grafts and 25.9% of MACI grafts.

Conclusions: ACI grafts are more likely to produce hyaline-like or mixed hyaline-like cartilage and fibro-cartilage with better ICRS grades than MACI grafts. However, this does not translate to better a clinical functional outcome. More importantly, ACI and MACI had similar results that were maintained at 3 years.

We aimed to determine whether proximal femoral bone remodelling, as measured by DEXA scan for each Gruen Zone, differed for 3 different femoral stem designs. These were:

Group 1 – Triple taper polished (C-stem J& J DePuy)

Ethical Committee approval was obtained and all patients gave informed consent. All operations were performed by 3 surgeons using a standard lateral approach, third generation cementing technique and a standard post-operative regime.

Seventy-five patients were randomised prospectively using a stratified randomisation programme for known risk factors in bone density. The randomisation was stratified by age, sex, Charnley Group (A or B), BMI and femoral neck bone mineral density. There were 25 patients in each Group, 5 patients did not have complete data sets and were therefore withdrawn from evaluation.

The Groups were similar with regard to age, sex, BMI, BMD and Charnley Group. Patients were followed up at 3, 6, 12 and 24 months by Nurse Practitioners for clinical and radiological evaluation and DEXA scan at each time of follow-up. There were no catastrophic failures of sepsis or dislocation. All patients functioned well at 24 months by Harris Hip Score.

The bone remodelling pattern will be described for each stem design. Findings are summarised thus. In the lateral Gruen Zones the triple taper and collared stem design faired better and both behaved differently to the double taper design. In Gruen Zone 7, all stems demonstrated reduced bone density as compared to pre-operative scans but this was less with the triple taper design.

Aims: To compare the clinical and functional outcomes of autologous chondrocyte implantation for treatment of osteochondral defects of the knee performed in overweight, obese and patients of ‘ideal weight’as defined by their BMI.

Methods: We analysed the data on all our patients that have been followed up for a minimum of 2 years and had their height and weight recorded initially in our database. Functional assessment consisted of the Modified Cincinatti Scores (collected prospectively at 6 months, 1 year, 2 years and 3 years following surgery). Patients were placed into 3 groups according to their body mass index (BMI). Group A consisted of patients with BMI of 20 to 24.9, group B patients with BMI of 25 to 29.9 and Group C are patients with BMI of 30 to 39.9.

Results: There were 80 patients (41 males and 39 females) with a mean age of 35.4 (range 18 to 49). The mean BMI for the entire group was 26.6. The pre-operative, 6 month, 1 year, 2 year, and 3 year Modified Cin-cinatti Score in Group A (32 patients) was 54.4, 80.3, 82.7, 74.7 and 72.6. Similarly in Group B, the scores were 53, 41, 54, 56, 49.5 and in Group C the scores were 36.3, 36.3, 49.6, 36, and 35.7. The wound infection rate in Group A was 6.25%, in Group B was17.6% and Group C was 14.3%.

Conclusions: Initial results from this study suggest that BMI is an important predictor of outcome after chon-drocyte implantation. The group of patients that would gain most benefit from ACI are patients that are not overweight (defined by BMI in the range of 20 to 24.9). Further work is being carried out to support the hypothesis that surgeons should strongly consider not operating on patients unless the BMI is less than 25.

Aim: To study the remodelling of cortical bone around the passive growing component of an expandable endoprosthesis.

Introduction: When inserting the passive component of an expandable prosthesis a polyethylene sleeve is commonly used. The sleeve migrates towards the lateral cortex and causes a cortical reaction and hence the use of the sleeve has been discarded recently. This study quantifies the amount of cortical reaction and degree of cortical drift in patients that had sleeves and those that did not.

Material And Methods: We reviewed X-rays and case notes of all patients that had an expandable endoprosthesis in a 20 year period. The thickness of medial and lateral cortices of the tibial diaphysis was measured at 6 months and on the last follow up radiograph. The distance from the edge of the sleeve (or prosthesis) from the cortical edge was also compared. Retrieved components also had their histology reviewed.

Results: The sleeve shifted laterally on average by 2mm (range 0.5 – 3mm) and touched the cortex. This was associated with an increase in lateral cortical thickness by 2.27mm (range 1 – 3mm). When the sleeve was used the prosthesis was inserted in the mid-line. When the sleeve was not used the tibial component tended to be inserted in valgus.

Conclusions: The presence of a sleeve is associated with a cortical reaction and the sleeve tends to migrate laterally. The clinical implications of this and the evolution of the design will be discussed in the meeting.

Purpose: We report a series of 58 patients with metastatic bone disease treated with resection and endoprosthetic reconstruction over a 5 year period at our institution.

Introduction: The recent advances in adjuvant and neo-adjuvant therapy in cancer treatment has resulted in improved prognosis of patients with bone metastases. Most patients who have an actual or impending pathological fracture should have operative stabilisation or reconstruction. According to BOA guidelines patients should undergo a single procedure which allows early full weight bearing and lasts the expected lifespan of the patient. The use of modern modular endoprostheses allows these criteria to be met.

Methods and Results: We retrospectively identified all patients diagnosed with metastatic disease to bone between 1999 to 2003. 171 patients were diagnosed with bone metastases. Metastatic breast and renal cancer accounted for 47% of the lesions. 58 patients with bone metastasis to the appendicular skeleton had an endo-prosthetic reconstruction. There were 28 males and 30 females. 11 patients had lesions in the upper extremity and 47 patients had lesions in the lower extremity. Mean age at presentation was 62 years (24 to 88 years). 19 patients are still alive, 34 patients had died and 5 were lost to follow-up. Patients died of disease at a mean of 22 months (2 to 51 months) from surgery. Mean follow-up was 55 months (24 to 78 months). There were 5 wound infections, 1 aseptic loosening, 3 dislocations, 1 subluxation and 1 prosthesis rotated requiring open repositioning. Patients were followed up and evaluated using the Musculoskeletal Society Tumour Score (MSTS) and the Toronto Extremity Salvage Score. The mean MSTS score was 73% (57 to 90%) and TESS was 71% (84 to 95%).

Conclusions: We conclude that endoprosthetic replacement for the treatment of bone metastases in selected cases achieves the aims of restoring function, allowing early weight bearing and alleviating pain. The complication rate is low.

Background: Extra-compartmental limb soft tissue sarcomas are notoriously difficult to treat. These tumours can exhibit macro or microscopic spread beyond the confines of normal anatomical barriers and require radical resection, often necessitating excision of bone as well as soft tissue. This will inevitably affect the patient’s functional outcome. The primary operations for these aggressive sarcomas include wide local excision of soft tissue and adjacent involved bone, radical resection with endoprosthetic reconstruction and amputation.

Methods: 85 patients who underwent such an operation between 1995 to 2000 were reviewed and categorised according to whether they received wide local excision, endoprosthesis reconstruction or amputation. Patient demographics, sarcoma details, recurrence and survival rates were identified and compared between the three groups. Functional outcomes in the 45 patients still alive were assessed using TESS and MSTS scores.

Results: Mean age was 61 years (range 8 to 92). There were 51 males and 34 females. Anatomical distribution was as follows: arm 26, leg 47, pelvis 8 and other 4. The commonest histology subtypes were MFH, leiomyosarcoma and undifferentiated soft tissue sarcoma. 17 had wide local excision of bone and soft tissue, 32 underwent endoprosthesis reconstruction and 36 underwent primary amputation. Recurrence rates were highest in the endoprosthesis group at 19%. Five year survival was worst in the amputation group at 49%. Functional outcomes were highest in the wide local excision group, and similar in the other two surgical groups.

Conclusions: Unsurprisingly survival is poorest in the primary amputee group because of the highly aggressive nature of these sarcomas, despite having the most radical treatment. The similar functional outcomes shown between endoprosthesis reconstruction and primary amputation may be influential when considering cases in which this decision is unclear and function is the main issue at stake.