Introduction. Classical fixation using a circular frame involves two rings per segment and in many units this remains the norm whether using ilizarov or hexapod type frames. We present the results of two ring circular frame at King's College Hospital. Materials & Methods. A prospective database has been maintained of all frames applied since 2007. Radiographs from frames applied prior to July 2022 were examined. Clinic letters were then used to identify complications. Included: two ring hexapod for fracture, malunion, nonunion, arthrodesis or deformity correction in the lower limb. Excluded: patients under 16 years old, diabetic feet, Charcot joints, soft tissue contractures, arthrodiastasis, correction of the mid/forefoot, plate fixation augmentation, fixation off a third ring. Results. 518 two ring hexapods were identified. Mean age was 46 (16–89). 55% were for fracture, 18% for malunion, 11% for nonunion. Mean frame time was 7 months (2–29 months). All clinic letters from 384 patients showed 203 patients (52%) had at least one pin site infection, 27 nonunions (7%), 16 frame revisions (4%), 25 bone grafting procedures (7%), 5 cases of septic arthritis (1%), 3 periprosthetic fractures (0.8%),), 12 malunions (3%), 4 Amputations (1%). Conclusions. These results demonstrate the efficacy of a two ring hexapod for patients requiring reconstruction of the lower limb

Introduction. The Oxford Unicompartmental Knee Replacement (OUKA) is the most popular unicompartmental knee replacement (UKR) in the New Zealand Joint Registry with the majority utilising cementless fixation. We report the 10-year radiological outcomes. Methods. This is a prospective observational study. All patients undergoing a cementless OUKA between May 2005 and April 2011 were enrolled. There were no exclusions due to age, gender, body mass index or reduced bone density. All knees underwent fluoroscopic screening achieving true anteroposterior (AP) and lateral images for radiographic assessment. AP assessment for the presence of radiolucent lines and coronal alignment of the tibial and femoral components used Inteliviewer radiographic software. The lateral view was assessed for lucencies as well as sagittal alignment. Results. 687 OUKAs were performed in 641 patients. Mean age at surgery was 66 years (39–90yrs), 382 in males and 194 right sided. 413 radiographs were available for analysis; 92 patients had died, 30 UKRs had been revised and 19 radiographs were too rotated to be analysed the remainder were lost to follow-up. Mean radiograph to surgery interval was 10.2 years (7.1–16.2yrs). RLLs were identified in zone 1 (3 knees), zone 2 (2 knees), zone 3 (3 knees), zone 5 (3 knees), zone 6 (2 knees) and zone 7 (42 knees). No RLL had progressed, and no case had any osteolysis or prosthesis subsidence. Alignment in the coronal plane: mean 2.90° varus (9.30° varus - 4.49° valgus) of the tibial component to the tibial anatomic axis and the femoral component in mean 4.57° varus (17.02° varus - 9.3° valgus). Sagittal plane posterior tibial slope was a mean 6.30° (0.44° -13.60° degrees) and mean femoral component flexion of 8.11° (23.70° flexion – 16.43° extension). Conclusion. The cementless OUKA demonstrates stable fixation with low revision rates at our centre supporting results earlier published by the design centre

Introduction. Non-union is an unfortunate outcome of the fracture healing process for some patients; with an estimated annual incidence of 17.4- 18.9 per 100,00. The management of these patients depicts a significant clinical challenge for surgeons and financial burden to health services. External ultrasound stimulation devices (Exogen. TM. ) have been highlighted as a novel non invasive therapy to achieve union in cases of delayed and non-union. The aim of the current study was to assess the rate of union in patients using Exogen. TM. therapy for delayed fracture union in a district general hospital. Materials & Methods. This is a single centre retrospective continuous cohort study. Patients were identified from a prospective database of all patients prescribed Exogen. TM. therapy between June 2013- September 2021 in a district general hospital. Patient data was collected retrospectively using electronic patient records. Fracture union was assessed both clinically and radiographically and recorded in patient records. Failure of treatment was defined as progression to operative treatment due to lack of progression with ultrasound therapy or established asymptomatic non-union. Patient were excluded from the study if Exogen. TM. therapy was prescribed within 6 weeks of injury. Results. 142 potential patient were identified from the database. 35 patients were excluded from the data set (17 patients due to insufficient data available, 9 lost to follow up, 4 died and 5 excluded due to early application of Exogen. TM. therapy). 58 Patients progressed to union with an average time to union of 41 weeks. 49 cases failed to progress to union, of which 7 cases had conversion to operative management prior to completion of single course of Exogen. TM. therapy and were excluded from all other data review. 12% of cases that failed to unite with ultrasound therapy required multiple operations to establish union. Conclusions. A union rate of 58% was reported by the current study, which is lower than previously published. This likely reflects the heterogenous nature of the patient population and fracture distribution included. However, this is potentially a more reflective union rate for the general population than previously published. There were no adverse events associated with the use of Exogen. TM. therapy in the current study. Therefore supporting its use as a first line management to promote union in delayed fracture union in the general population. Additionally, failure to achieve fracture union with utilisation of Exogen. TM. therapy was associated with risk for requirement of multiple surgeries to achieve union. This could serve as an indicator for surgeon to consider the requirement additional measures at the initial surgical procedure

Introduction & Aim. The use of All-Poly Tibia has been in practice since the early 1970's. Recently due to the reports on wear and osteolysis in other articulations, this component has generated significant interest. In the current study we aim to report early medium-term results of All-poly Tibial components in elderly (>70 years) patients. Method. Study of 455 cases done between 2005-2020. All the cases were performed by a single surgeon. All-Poly Tibial component implantations were performed using Standard mechanical jigs and the same posterior-stabilized implant was used for all cases. Results. 20 cases were lost to follow-up. 25 patients died due to natural causes. Mean age at index surgery was 74 years (70 - 91 years). Preop KSS average was 47 (31- 62). Post operative at the last follow up was 87 (71- 93). Of the 410 cases there were 8 revisions, 6 for deep sepsis and 2 for periprosthetic fractures. There were no revisions for aseptic loosening or osteolysis. All cases are performing well functionally and clinically. 18 cases had a non-progressive radiolucent line beneath the Tibial component. The combination of perfect alignment and soft tissue balance creates an environment for a successful TKR. The choice of the All-Poly Tibial component for functionally low demand age group patients reduces the chances of premature wear and osteolysis. In elderly patients the implant should outlive the patient. Here it is observed that at 5-7 years aseptic loosening and subsequent revision chances are low. The all-poly Tibial component is significantly cheaper as compared to its metal back counterpart. Conclusion. An excellent clinical result in our hands for this group of patients supports the continued use of this implant strongly

Aim. Aim of this study was to establish the first clinical results after implantation of ultrathin silver-polysiloxane-coated. 1. plates in the treatment of infected non-union of the femoral shaft. Method. As part of the REFECT study, a prospective, non-interventional analysis was conducted encompassing all patients who received internal stabilization with a silver-coated. 1. plate from 01/2023 to 09/2024 as part of the treatment for infected non-union of the femur. Standardized clinical follow-ups including PROMs (WOMAC-Index, LEF-S, EQ-5D, VAS) and X-rays were performed 3, 6, 12 (and 24) months postoperatively. For comparison, a retrospective analysis of 76 patients with infected femoral non-union, who had received a stabilization with an uncoated plate in the past 10 years, was performed. Results. The mean follow-up of the 8 included patients (mean bone defect: 3.6 cm) was 9 months (as of 04/24). Multiresistant bacteria were found in the intraoperative samples of 5 patients. The concentration of silver ions in blood serum reached a maximum of 0.014 mg/l in the laboratory controls. All patients showed a positive healing process with no sign of re-infection and no adverse procedure-associated events. Full weight bearing was achieved after an average of 4 months (n=6) with improved WOMAC-, LEF-S-, EQ-5D and VAS-score at 1-year FU. In the reference group (uncoated, mean FU: 3.5 years), there was a re-infection rate of 25 %, mostly in the first 2 years. Difficult-to-treat bacteria were detected in 22%, multiresistant Staph. epidermidis in 28% of cases. Conclusions. -. The silver-coated. 1. implants showed good biocompatibility with no evidence of procedure-associated complications. -. The use of silver-coated. 1. implants could reduce the risk of re-infection. -. Further clinical data with longer follow-up are needed to assess the long-term value of the procedure

Objectives. As per NICE guidance, one of the cornerstones of management of AKI is risk assessment. Aim of the audit is to identify the potential risk factors for postoperative AKI in hip fracture patients. Design and Methods. Using local NOF registration data, Patient details were selected using inclusion and exclusion criteria. Electronic records of patients were assessed retrospectively including blood results, radiological investigations, clinical documentation and drug chart. Inclusion Criteria: All patients > 50 years old with NOF fractures underwent operative management from January 2022 to June 2022 Exclusion Criteria: 1- Pathological fractures. 2- Non-operative management. 3- Died directly postoperative. Results. 250 patients underwent hip fracture surgery at our hospital in 6 months (January 2022-June 2022) (Cemented Procedures were 133 (53 %) while Fixation procedures were 117 (47%)). Female patients were 174 (70%), and male were 76 patients. Average age was 83.4 years and number of operations done over Weekend (Friday-Sunday) = 123 (49%). The incidence of Postoperative AKI was 56 (22.4%). Forty-five from fifty-six cases were stage 1 (80.4%) while 7 cases (12.5%) were stage 2. The studied risk factors for Postoperative AKI were: cemented procedures (61% of postoperative AKI incidence), female Gender (66%), time from admission to operation (>24 hours =33 %), day of operation (operations done Friday/Saturday/Sunday = 55%) and Postoperative antibiotics (71%). Conclusion. We need strategies to reduce incidence of postoperative AKI like: AKI alert on laboratory results, IV fluid prescription preoperative since arrival of patients to ED, avoid/stop nephrotoxic medications on admission, regular review of postoperative U&Es and fluid balance especially in high-risk patients, increase nursing staff and junior doctors on wards over weekends and we need to review our policy of giving postoperative IV antibiotics

Cementless fixation is an alternative to cemented unicompartmental knee replacement (UKR), with several advantages over cementation. This study reports on the 15-year survival and 10-year clinical outcomes of the cementless Oxford unicompartmental knee replacement (OUKR).

This prospective study describes the clinical outcomes and survival of first 693 consecutive cementless medial OUKRs implanted in New Zealand.

The sixteen-year survival was 89.2%, with forty-six knees being revised. The commonest reason for revision was progression of arthritis, which occurred in twenty-three knees, followed by primary dislocation of the bearing, which occurred in nine knees. There were two bearing dislocations secondary to trauma and a ruptured ACL, and two tibial plateau fractures. There were four revisions for polyethylene wear. There were four revisions for aseptic tibial loosening, and one revision for impingement secondary to overhang of the tibial component. There was only one revision for deep infection and one revision where the indication was not stated. The mean OKS improved from 23.3 (7.4 SD) to 40.59 (SD 6.8) at a mean follow-up of sixteen years.

In conclusion, the cementless OUKR is a safe and reproducible procedure with excellent sixteen-year survival and clinical outcomes.

Aim. Negative-pressure wound therapy (NPWT) is often propagated as treatment option for fracture-related infection (FRI). After surgical debridement and repeated NPWT dressing changes, the wounds are often closed by free flaps. Sometimes even healing by secondary intention seems an alternative. Recently, concerns have been raised on the long-term use of NPWT as it could be related to bacterial overgrowth and possible re-infection. The purpose of this study was to conduct a retrospective evaluation of the influence of long-term NPWT on tissue culture results and outcome in FRI patients. Method. Between January 1. st. , 2015 and December 31st, 2018, a total of 852 patients were treated with NPWT for different indications on the Department of Trauma Surgery. Inclusion criteria for this study were patients with a closed fracture, stabilized with osteosynthetic fixation and complicated with a confirmed FRI according to the FRI consensus definition. Patients were included when they received at least three NPWT dressing changes in the operating room. Exclusion criteria were patients younger than 18 years, or the absence of cultures results from dressing changes. Results. During the study period 23 patients met the inclusion criteria. According to the tripartite classification of Willenegger and Roth, one patient had an early, 14 a delayed and 8 patients a late onset FRI. Overall, 139 NPWT dressing applications were performed, with an average amount of six per patient. In 14 patients (61%) and 57 dressing changes (41%), at least 2 tissue cultures showed the same pathogen or at least one, in case of highly virulent organisms (e.g. S. aureus) during a single dressing exchange. Coagulase-negative staphylococci were present in 33% of the cases, followed by Enterococcus spp. (21%), S. aureus (16%), non-fermentative gram negative bacilli (14%) and Enterobacteriaceae (7%). Furthermore, 17 exchanges showed polymicrobial growth. Five patients had repeatedly significant growth of the same pathogen despite adequate antimicrobial therapy, within this group one patient was immunocompromised. Conclusions. In a large amount of patients (61%), a significant number of positive culture results could be acquired, even in the presence of adequate local and systemic antimicrobial therapy. The clinical relevance of these results remains unclear. This said, it seems important to limit the duration of NPWT as prolonged treatment could increase bacterial overgrowth and possible (re-)infection. Therefore, a rapid definitive soft tissue coverage should be encouraged. Future larger prospective clinical trials are required

Introduction. Angular deformities of the distal femur can be corrected by opening, closing and neutral wedge techniques. Opening wedge (OW) and closing wedge (CW) are popular and well described in the literature. CW and OW techniques lead to leg length difference whereas the advantage of neutral wedge (NW) technique has several unique advantages. NW technique maintains limb length, wedge taken from the closing side is utilised on the opening side and since the angular correction is only half of the measured wedge on either side, translation of distal fragment is minimum. Leg lengths are not altered with this technique hence a useful technique in large deformities. We found no reports of clinical outcomes using NW technique. We present a technique of performing external fixator assisted NW correction of large valgus and varus deformities of distal femur and dual plating and discuss the results. Materials & Methods. We have treated 20 (22 limbs – 2 patients requiring staged bilateral corrections) patients for distal femoral varus and valgus deformities with CWDFO between 2019 and 2022. Out of these 4 patients (5 limbs) requiring large corrections of distal femoral angular deformities were treated with Neutral Wedge (NW) technique. 3 patients (four limbs) had distal femoral valgus deformity and one distal femoral varus deformity. Indication for NW technique is an angular deformity (varus or valgus of distal femur) requiring > 12 mm opening/closing wedge correction. We approached the closing side first and marked out the half of the calculated wedge with K – wires in a uniplanar fashion. Then an external fixator with two Schanz screws is applied on the opposite side, inserting the distal screw parallel to the articular surface and the proximal screw 6–7 cm proximal to the first pin and at right angles to the femoral shaft mechanical axis. Then the measured wedge is removed and carefully saved. External fixator is now used to close the wedge and over correct, creating an appropriate opening wedge on the opposite side. A Tomofix (Depuoy Synthes) plate is applied on the closing side with two screws proximal to osteotomy and two distally (to be completed later). Next the osteotomy on the opposite side is exposed, the graft is inserted. mLDFA is measured under image intensifier to confirm satisfactory correction. Closing wedge side fixation is then completed followed by fixation of opposite side with a Tomofix or a locking plate. Results. 3 patients (4 limbs) had genu valgum due to constitutional causes and one was a case of distal femoral varus from a fracture. Preoperative mLDFA ranged from 70–75° and in one case of varus deformity it was 103°. We achieved satisfactory correction of mLDFA in (85–90°) in 4 limbs and one measured 91°. Femoral length was not altered. JLCA was not affected post correction. Patients were allowed to weight bear for transfers for the first six weeks and full weight bearing was allowed at six weeks with crutches until healing of osteotomy. All osteotomies healed at 16–18 weeks (average 16.8 weeks). Patients regained full range of movement. We routinely recommend removal of metal work to facilitate future knee replacement if one is needed. Follow up ranged from 4 months to 2 yrs. Irritation from metal work was noted in 2 patients and resolved after removing the plates at 9 months post-surgery. Conclusions. NWDFO is a good option for large corrections. We describe a technique that facilitates accurate correction of deformity in these complex cases. Osteotomy heals predictably with uniplanar osteotomy and dual plate fixation. Metal work might cause irritation like other osteotomy and plating techniques in this location

The Femoral Neck System (FNS) was introduced as an alternative device for the fixation of neck of femur fractures (NOFFs). The purported advantages include superior angular and rotatory stability compared to multiple cancellous screws, via a minimally invasive instrumentation that is simpler than conventional fixed angle devices. There were limited clinical studies regarding the utility of this device. We aimed to study the outcomes of NOFFs fixed with the FNS.

This was a single-institution, retrospective review of all undisplaced elderly (≥60 years old) undisplaced young, and displaced young NOFFs fixed with the FNS. Demographics, surgical parameters, radiographic parameters, and clinical outcomes including complications were reviewed.

Thirty-six subjects with a median age of 75 [44,89] years old, had NOFF fixation using the FNS. Thirty-one (86.1%) had undisplaced fractures. There were 6 (16.7%), 26 (72.2%), and 4 (11.1%) subjects with Pauwels types 1, 2, and 3 respectively. Thirty-two (88.9%) had posterior tilt of <20º. The mean duration of surgery was 71±18 minutes. Excluding 4 patients whom required revision surgery, 2 patients whom demised, and 10 patients whom defaulted reviews, the mean follow-up duration was 55±13 weeks. Four complications were recorded, namely implant cut out at the femoral head at week 8, breaking of the locking screw at the run-off region at week 22, avascular necrosis at week 25, and a refracture following near fall, causing the fracture to fail in varus at week 7 postoperation.

While reasonably fast to instrument, failures still occur and it is likely multifactorial. However, the rate of reoperation is lower than what has been reported for NOFFs fixed with the a fixed-angle device or 3 cancellous screws. In conclusion, the FNS is a reasonably safe instrument to use. Surgeons’ discretion is still needed in patient selection, keeping in mind the need for satisfactory radiological parameters.

Aim. Excision of chronic osteomyelitis (cOM) creates a dead space which must be managed to avoid early recurrence of infection. Systemic antimicrobials cannot penetrate this space in high concentration so local therapy has become an attractive adjunct to surgery. This study presents the mid- long-term results of local therapy with gentamicin in a bioabsorbable ceramic carrier. Method. A prospective series of 100 patients with Cierny & Mader Types III and IV cOM, affecting 105 bones, were treated with a single stage procedure, including debridement, deep tissue sampling, local and systemic antimicrobials, stabilization and immediate skin closure. cOM was confirmed with strict diagnostic criteria. Patients were followed up for a mean of 6.05 years (range 4.2–8.4 years). Results. At final follow-up, 6 patients had evidence of recurrent infection (94% infection-free). 3 infections recurred in the first year, with 2 in the second year and one at 4.5 years after surgery. Recurrence was not dependent on host physiological class (1/20 Class A; 5% vs 5/80 Class B; 6.25%. p=0.833). Nor was it related to aetiology of the infection, microbial culture or the presence of an infected non-union before surgery (1/10 with non-union; 10% vs 5/90 without non-union; 5.6%. p=0.57). Organisms which demonstrated intermediate or high-grade resistance to gentamicin were more likely in polymicrobial infections (9/21; 42.8%) compared to single isolate osteomyelitis (7/79; 8.9%)(p<0.001). However, recurrence was not more frequent when a resistant organism was present (1/16; 6.25% for resistant cases vs 5/84; 5.95% in sensitive culture infection) (p=0.96). Conclusions. This study shows that the single stage protocol, including a high delivery local antibiotic ceramic, was effective over several years. The method can be applied to a wide range of patients, including those with significant comorbidities and infected non-union

Introduction. Sensoric soft tissue balancing in performing TKA is an upcoming topic to improve the results in TKA. A well balanced knee is working more proper together with the muscular stabilizing structures. Dynamic ligament balancing (DLB)R give us the opportunity to check the balance of the ligaments at the beginning and the end of the surgery before implanting the definitive prosthesis. It is a platform independent, single-use device, which can be combined with all common types of knee prosthesis. Materials and Methods. DLBR consists of a set of 10 different sizes of baseplates including a spring coil of 20N (A). Connected to a tablet all datas can be shown during surgery and stored for patient security. During the surgery the tibial cut is performed first, rectangular to the longitudinal axis respecting the right slope. A navigation system is recommended to ensure this request. Measurement before femoral cuts are performed and give an information about distance between tibial plate and femoral condyles, joint angle and calculated contact pressure. The femoral cuts can be performed with the original cutting block. After positioning the femoral trial, testing is repeated and should show a balanced situation over all the ROM. The overall period datas were stored and compared to the subjective feeling of the patients. Results. Performing the first 20 patients (DLB) a better balanced situation is visible in all knees respecting the including factors in comparison to the 20 patients of control group (CG). No extension of the surgical time was seen. All PROMs show good and excellent results. By example there was an improvement of the result of the OKS at the end of 10% by a much worse initial situation; so the overall progress was in the CG about 50%, in the DLB group 150%. The AKSS shows especially in the functional score a similar improvement (Fig. 1–4). Discussion. DLBR is a new concept using single-use devices and is platform independant. Further measurements and comparisons are necessary to value these first excellent results. By the moment the inclusion factors are settled narrow, but the future will show, where the borders of this method will be. Conclusion. Measuring the gap and ligament tension all over the ROM from 0 to 90° continuously gives the possibility to value the accuracy of the procedure together with marking points to compare it to the clinical postoperative result. Matching the procedure shows an increasing satisfaction of the patients due to a better balanced situation. Although there are limiting factors (no severe deformities, muscular deseases, ligament failure) it is a hopeful opportunity to increase the results in TKA in the future

Polyimide (MP-1, MMATech, Haifa, Israel), is a high performance aerospace thermoplastic used for its lubricity, stability, inertness and radiation resistance. A wear resistant thin robust bearing is needed for total hip arthroplasty (THR).

After independent laboratory testing, in 2006, the author used the material as a bearing in two Reflection (Smith and Nephew, USA) hip surgeries. The first, a revision for polyethylene wear, survives with no evidence of wear, noise, new osteolysis or complications related to the MP-1 bearing after 16 yrs. The second donated his asymptomatic MP-1 hip at 6.5yrs for post-mortem examination. There were no osteoclasts, cellular reaction bland in contrast to that of polyethylene.

In 2013 a clinical study with ethical committee approval was started using a Biolox Delta (Ceramtec, Germany) head against a polyimide liner in 97 patients. MMATech sold all liners, irradiated: steam 52:45. Sixteen were re-machined in New Zealand. Acetabular shells were Delta PF (LIMA, Italy). The liner locked by taper.

The cohort consisted of 46:51 M:F, and ages 43 to 85, mean 65. Ten received cemented stems. For contralateral surgery, a ceramic or polyethylene liner was used. Initial patients were lower demand, later, more active patients, mountain-biking and running.

All patients have on-going follow up, including MP-1 liner revision cases. There has been no measurable wear, or osteolysis around the acetabular components using weight-bearing radiographs. Squeaking within the first 6 weeks was noted in 39 number of cases and subtle increase in palpable friction, (passive rotation at 50 degrees flexion), but then disappeared. There were 6 revisions, four of which were related to cementless Stemsys implants (Evolutis, Italy) fixed distally with proximal linear lucencies in Gruen zones 1 and 7, and 2 and 6. No shells were revised and MP-1 liners were routinely changed to ceramic or polyethylene. The liners showed no head contact at the apex, with highly polished contact areas.

There were no deep or superficial infections, but one traumatic anterior dislocation at 7 years associated with 5 mm subsidence of a non-collared stem.

The initial squeaking and increased friction was due to the engineering of the liner / shell composite as implanted, not allowing adequate clearance for fluid film lubrication and contributed to by shell distortion during impaction. The revised bearings were “equatorial” rather than polar, and with lack of wear or creep this never fully resolved. Where the clearance was better, function was normal. The “slow” utilization was due to my ongoing concern with clearances not being correct. The revision of 4 Stemsys stems, tribology issues may have contributed, but non “MP-1” / Stemsys combinations outside this study have shown the same response, thought to be due to de-bonding of the hydroxyapatite coating.

With correct engineering and clearances, a 3.6 mm thick MP-1 bearing, a surface Ra<0.5, steam sterilized, shows no appreciable wear, and with confidence, can be used as a high performance THR bearing.

Aim. Periprosthetic joint infection (PJI) is a complication of total joint arthroplasty that typically requires revision surgery for treatment. Systemic antibiotics are usually held prior to surgery to improve yield of intraoperative cultures. However, recent studies suggest that preoperative aspirations have a high concordance with intraoperative cultures, which may allow surgeons to initiate antibiotic treatment earlier. The purpose of the study was to investigate the effect of Pre-surgical systemic antibiotic therapy on the bacterial burden within the periprosthetic space and systemic immune reaction. Method. PJI was induced with MSSA (Xen36) S. aureus in the right knee of 16-week old, female, C57BL6 mice using a previously validated murine model. Mice were randomized to three groups (n=8, each): control; Vanc, receiving systemic vancomycin (110mg/kg, SQ, twice daily); or VancRif receiving vancomycin same as in Vanc group, plus rifampin (12mg/kg dose, IV, once daily). Following 2 weeks of treatment, mice were euthanized and periprosthetic bone, soft tissue and the implant were harvested. Bacterial burden, colony forming units (CFUs), was quantified in soft tissue, tibial bone, and on the implant. Specifically, tissues were homogenized and serially plated for CFUs, while the implant was sonicated and then plated for CFUs. The host immune response was analysed through weighing inguinal and iliac lymph nodes and through measuring serum amyloid A (SAA). Non-parametric pairwise group comparisons of the three outcome measures were performed using a Mann-Whitney U test. Results. VancRif, the combined treatment significantly reduced bacterial burden in the periprosthetic soft tissue, bone, and implant compared to control (p<0.001) and Vanc alone (p<0.001). While not significant, Vanc alone did reduce bacterial load as compared to control. The ipsilateral weight of the iliac lymph nodes was significantly reduced in Vanc and VancRif mice compared to controls (p<0.001), was well as in VancRif versus Vanc alone (p<0.001). Interestingly, SAA levels did not significantly differ among all groups. During tissue harvesting, minimal purulence was observed in antibiotic treatment groups, unlike controls. Conclusions. Treating active PJI with vancomycin alone decreases periprosthetic bacterial loads and reduces the local immunological response. This effect is significantly enhanced with the combined rifampin use. These findings could suggest that when culture positive PJI is diagnosed, pre-surgical treatment with antibiotics may decrease immunosuppression and soft tissue infiltration, leading to a better chance of infection cure with subsequent surgical debridement. Histological investigations and repeat experiments involving subsequent surgical treatment are underway. Acknowledgements. Funding comes from internal institutional grants

Abstract. Introduction. FHL transfer for management of chronic Achilles' tendon ruptures is done both open and endoscopically. But there are no published studies comparing open and endoscopic results. Our study aims to compare them and determine the suitability of these methods. Materials and methods. Fourteen patients were treated endoscopically while 26 with an open technique. Of the 26, fourteen had an open Achilles tendon repair and FHL transfer while 12 has only open FHL transfer. All the endoscopic patients had only an FHL transfer. We compared demographics, complications of the procedure, recovery times, return to work and strength after 1 year. We noted ATRS at 6 months and 1 year for all three groups. We also conducted an MRI scan of three patients each of the three groups to determine the state of Achilles tendon and FHL tendon after 1 year of surgery. Results. There were similar complication rates for both the only FHL groups but the open FHL + Achilles' repair had more complications both for wound complications and saphenous neuropraxia. The recovery time, return to work and ATRS at 6 months was better for the endoscopic group as compared to both open groups. The strength and ATRS at 1 year were similar for all three groups. Conclusion. Endoscopic FHL transfer is safe and provides earlier return to work and better 6 months patient satisfaction then the open method. It also has less post op complications than open FHL + Achilles tendon repair, while maintains the same strength after 1 year

Background. Prospective study to compare patient reported outcome measures (PROM) for sacroiliac joint (SIJ) fusion using HA-coated screw (HACS) vs triangular titanium dowel (TTD). First study of its kind in English literature. Methods. 40 patients underwent percutaneous SIJ stabilisation using HACS and TTD was used in 70 patients. Patients were followed up closely and outcome scores were collected prospectively. PROMs were collected preoperatively and 12 months after surgery. Short Form (SF)-36, Oswestry Disability Index, EuroQol-5D-5L and Majeed Pelvic Scores were collected. Shapiro-wilk test was used to determine normality of data. Mann-whitney U test was used to compared non-parametric data and Independent sample T test for parametric data. Results. 33 patients in HACS group and 61 in TTD group completed follow-up. There was no significant difference in all preoperative PROMs in both groups hence the data was considered comparable. All postoperative PROMs were significantly higher in the TTD group. In the HACS group, 21 patients (63%) had lysis around the screw and a sub-group analysis showed that improvement in PROMs was significantly less in patients with lysis around the screw. 4 patients with lysis around the screw were offered revision due to ongoing pain. Revision was successful in only 1 patient. In TTD group only 5 patients (8.2 %) patients had radiological evidence of lysis. Relative risk of developing lysis was 6.7 times higher in HACS group. Conclusion. Percutaneous SIJ fixation procedure has been shown to have good clinical outcomes and TTD leads to significantly better patient reported outcomes compared to HACS. There is a 6.7 time higher risk of lysis with use of HACS and lysis is a risk factor for poor outcomes

Background. Anterior cruciate ligament (ACL) reconstruction with concomitant meniscal injury occurs frequently. Meniscal repair is associated with improved long-term outcomes compared to resection but is also associated with a higher reoperation rate. Knowledge of the risk factors for repair failure may be important in optimizing patient outcomes. Purpose. This study aimed to identify the patient and surgical risk factors for meniscal repair failure, defined as a subsequent meniscectomy, following concurrent primary ACL reconstruction. Methods. Data recorded by the New Zealand ACL Registry and the Accident Compensation Corporation, the New Zealand Government's sole funder of ACL reconstructions and any subsequent surgery, was reviewed. Meniscal repairs performed with concurrent primary ACL reconstruction was included. Root repairs were excluded. Univariate and multivariate survival analysis was performed to identify the patient and surgical risk factors for meniscal repair failure. Results. Between 2014 and 2020, a total of 3,024 meniscal repairs were performed during concurrent primary ACL reconstruction (medial repair = 1,814 and lateral repair = 1,210). The overall failure rate was 6.6% (n = 201) at a mean follow-up of 2.9 years, with a failure occurring in 7.8% of medial meniscal repairs (142 out of 1,814) and 4.9% of lateral meniscal repairs (59 out of 1,210). The risk of medial failure was higher in patients with a hamstring tendon autograft (adjusted HR = 2.20, p = 0.001), patients aged 21–30 years (adjusted HR = 1.60, p = 0.037) and in those with cartilage injury in the medial compartment (adjusted HR = 1.75, p = 0.002). The risk of lateral failure was higher in patients aged ≤ 20 years (adjusted HR = 2.79, p = 0.021) and when the procedure was performed by a surgeon with an annual ACL reconstruction case volume of less than 30 (adjusted HR = 1.84, p = 0.026). Conclusion. When performing meniscal repair during a primary ACL reconstruction, the use of a hamstring tendon autograft, younger age and the presence of concomitant cartilage injury in the medial compartment increases the risk of medial meniscal repair failure, whereas younger age and low surgeon volume increases the risk of lateral meniscal repair failure

The use of rotating hinge (RH) prostheses for severe primary as well as revision arthroplasty is widely established. Aim of this study was to investigate long term results of a new RH prosthesis (EnduRo®, B Braun, Germany), which uses carbon-fiber reinforced poly-ether-ether-ketone (CFR PEEK) as a new bearing material, first time used in knee arthroplasty.

Fifty-six consecutive patients, who received the EnduRo® RH prosthesis were included in this prospective study: 21 patients (37.5%) received the prosthesis as a primary total knee arthroplasty (TKA) and 35 patients (62.5%) underwent revision total knee arthroplasties (rTKA). Clinical and radiographic examinations were performed preoperatively as well as postoperatively after 3 and 12 months and annually thereafter. Min. Follow up was 7 and mean follow up 9,3 years. Clinical examination included Knee Society Score (KSS), Western Ontario and McMaster Osteoarthritis Index (WOMAC), Oxford Knee Score (OKS), and range of motion (ROM). Competing risk analysis was assessed for survival with respect to indication and failure mode.

KSS, WOMAC, OKS, and ROM significantly improved from the preoperative to the follow up investigations (p < 0.0001). There was no difference in clinical outcome between the primary and the revision group. The overall cumulative incidence for revision for any reason was 23.6% and the cumulative incidence for complications associated with failure of the prothesis was 5.6% at 7 years, respectively. Complications occurred more frequently in the revision group (p = 0.002).

The evaluated RH prosthesis provided reliable and durable results with a minimum follow-up of 7 years. Prosthesis survival was successful considering the complexity of cases. The use of this RH system in primary patients showed high survival rates. Long-term functional and clinical results proved to be satisfying in both revision and primary cases. No adverse events were associated with the new bearing material CFR-PEEK.

Hip resurfacing arthroplasty (HRA) is a bone conserving alternative to total hip arthroplasty. We present the early 1 and 2-year clinical and radiographical follow-up of a novel ceramic-on-ceramic (CoC) HRA in a multi-centric Australian cohort.

Patient undergoing HRA between September 2018 and April 2021 were prospectively included. Patient-reported outcome measures (PROMS) in the form of the Forgotten Joint Score (FJS), HOOS Jr, WOMAC, Oxford Hip Score (OHS) and UCLA Activity Score were collected preoperatively and at 1- and 2-years post-operation. Serial radiographs were assessed for migration, component alignment, evidence of osteolysis/loosening and heterotopic ossification formation.

209 patients were identified of which 106 reached 2-year follow-up. Of these, 187 completed PROMS at 1 year and 90 at 2 years. There was significant improvement in HOOS (p< 0.001) and OHS (p< 0.001) between the pre-operative, 1-year and 2-years outcomes. Patients also reported improved pain (p<0.001), function (p<0.001) and reduced stiffness (p<0.001) as measured by the WOMAC score. Patients had improved activity scores on the UCLA Active Score (p<0.001) with 53% reporting return to impact activity at 2 years. FJS at 1 and 2-years were not significantly different (p=0.38). There was no migration, osteolysis or loosening of any of the implants. The mean acetabular cup inclination angle was 41.3° and the femoral component shaft angle was 137°. No fractures were reported over the 2-year follow-up with only 1 patient reporting a sciatic nerve palsy.

There was early return to impact activities in more than half our patients at 2 years with no early clinical or radiological complications related to the implant. Longer term follow-up with increased patient numbers are required to restore surgeon confidence in HRA and expand the use of this novel product.

In conclusion, CoC resurfacing at 2-years post-operation demonstrate promising results with satisfactory outcomes in all recorded PROMS.

Background. Treatment of staphylococcal prosthetic joint infection (PJI) usually consists of surgical debridement and prolonged rifampicin combination therapy. Tailored antimicrobial treatment alternatives are needed due to frequent side effects and drug-drug interactions with rifampicin combination therapy. We aimed to assess the effectiveness of several alternative antibiotic strategies in patients with staphylococcal PJI. Methods. In this prospective, multicenter registry-based study, all consecutive patients with a staphylococcal PJI, treated with DAIR or one-stage revision surgery between January 1. st. , 2015 and November 3. rd. , 2020, were included. Patients were treated according to a predefined protocol for PJI. Antimicrobial treatment strategies differed between centers, which was accepted and used as pseudorandomization. Depending on the hospital patients were admitted to, they were treated with either a long-term rifampicin strategy (consisting of 12 weeks rifampicin combination therapy) ore one of several short-term rifampicin strategies, consisting of only five days of rifampicin combination treatment, started immediately postoperative, followed by clindamycin, flucloxacillin or vancomycin monotherapy. Patients were stratified in different groups, depending on the used antimicrobial strategy. Cox proportional hazards models were used to compare outcome between the groups. Results. Two hundred patients were included and, based on the antimicrobial treatment, stratified in one long-term rifampicin group (n=23) or one of the three short-term rifampicin groups: clindamycin (n=56), flucloxacillin (n=47), vancomycin (n=26), other (n=48). Outcome of PJI after DAIR or one-stage exchange was not statistically different between patients treated with long-term rifampicin combination therapy and patients treated with clindamycin or flucloxacillin monotherapy including only five days of rifampicin combination therapy. Moreover, treatment duration was four weeks shorter in the clindamycin-based and flucloxacillin-based groups. Adjusted hazard ratios for failure for patients treated with either flucloxacillin or clindamycin were almost equal to patients treated with long-term rifampicin combination therapy (aHR 1.21, 95%CI 0.34–4.40). Conclusions. A short-term rifampicin strategy with either clindamycin or flucloxacillin and only five days of rifampicin was found to be as effective as traditional long-term rifampicin combination therapy. A randomized controlled trial is needed to further address efficacy and safety of alternative treatment strategies for staphylococcal PJI