Introduction: Chronic hip arthroplasty infection is a difficult situation to solve. The use of uncemented stem is questionable, as no antibiotic loaded cement is used to fix the implant. Bone deficiencies are often enlarged by the chronic infection process and the multiple previous surgeries. We report our experience in two stage revisions with massive allograft and uncemented distal locked stem.

Material and method: We have retrospectively reviewed 15 patients operated on from chronic hip arthroplasty infection and secondary large femoral defects. Two stages revision with a temporarily antibiotic loaded cement spacer and 6-weeks second look reconstruction were performed with massive proximal femoral allograft and a long distally locked stem. The uncemented stem was cemented into the allograft and remained uncemented in the recipient distal femur. Outcome was assessed regarding infection control, allograft complication and function according to the Merle d’Aubigné score.

Results: Patients mean age was 62 years (SD 11). Patients were already operated from the same hip 5.9 +/− 2.3 times before the actual procedure. Isolated microorganisms were MRSE (7), staph Aureus (4), MRSA (1), VRE (1), enterococcus (2). Muscle flaps were performed in 2 cases and discuss for 2 more. Allograft length was 22 +/− 9 cm. Antibiotic treatment was maintained for 4.6 +/− 2.5 months (median 3 months). Mean follow-up was 29 months (SD 26; median 23). Clinical outcome based on Merle d’Aubigné score is 5.3 +/− 3 before treatment and 13.8 +/− 2.5 at the last visit. Complications were registered in 4 cases. Infection recurrence was observed in 3 cases (2,7,20 months) but the function was preserved in all cases. One of them needed a two stage procedure with a new allograft after 19 months due to acute staph Aureus infection. One allograft was broken after 80 months and need one stage revision.

Discussion: While the treatment of these cases was particularly demanding as bone deficiencies and microorganisms antibiotic resistance were high, functional result obtained was good. When infection recurrence was observed, function remains preserved. The use of uncemented distal locked stem with a cemented massive allograft did not lead to mechanical or hardware problem and allow us to restore the bone stock and the gluteus tendons insertion. The use of a modular stem was very helpful in solving these complex situations. Massive allografts can be used in case of infection as antibiotic delivery system.

Objective

Failures of internal fixation after intertrochanteric fractures pose great challenge to orthopaedic surgeons. Hip arthroplasty can be a remedy for such failures, however, the selection of femoral stem length is controversial. This study aims to report our experience of managing failed internal fixation after intertrochanteric fractures with standard femoral stem arthroplasty.

Aims. Current diagnostic tools are not always able to effectively identify periprosthetic joint infections (PJIs). Recent studies suggest that circulating microRNAs (miRNAs) undergo changes under pathological conditions such as infection. The aim of this study was to analyze miRNA expression in hip arthroplasty PJI patients. Methods. This was a prospective pilot study, including 24 patients divided into three groups, with eight patients each undergoing revision of their hip arthroplasty due to aseptic reasons, and low- and high-grade PJI, respectively. The number of intraoperative samples and the incidence of positive cultures were recorded for each patient. Additionally, venous blood samples and periarticular tissue samples were collected from each patient to determine miRNA expressions between the groups. MiRNA screening was performed by small RNA-sequencing using the miRNA next generation sequencing (NGS) discovery (miND) pipeline. Results. Overall, several miRNAs in plasma and tissue were identified to be progressively deregulated according to ongoing PJI. When comparing the plasma samples, patients with a high-grade infection showed significantly higher expression levels for hsa-miR-21-3p, hsa-miR-1290, and hsa-miR-4488, and lower expression levels for hsa-miR-130a-3p and hsa-miR-451a compared to the aseptic group. Furthermore, the high-grade group showed a significantly higher regulated expression level of hsa-miR-1260a and lower expression levels for hsa-miR-26a-5p, hsa-miR-26b-5p, hsa-miR-148b-5p, hsa-miR-301a-3p, hsa-miR-451a, and hsa-miR-454-3p compared to the low-grade group. No significant differences were found between the low-grade and aseptic groups. When comparing the tissue samples, the high-grade group showed significantly higher expression levels for 23 different miRNAs and lower expression levels for hsa-miR-2110 and hsa-miR-3200-3p compared to the aseptic group. No significant differences were found in miRNA expression between the high- and low-grade groups, as well as between the low-grade and aseptic groups. Conclusion. With this prospective pilot study, we were able to identify a circulating miRNA signature correlating with high-grade PJI compared to aseptic patients undergoing hip arthroplasty revision. Our data contribute to establishing miRNA signatures as potential novel diagnostic and prognostic biomarkers for PJI. Cite this article: Bone Jt Open 2024;5(6):479–488

Extensive and severe bone loss of the femur may be a result of a failed total hip arthroplasty (THA) or total knee arthroplasty (TKA) with multiple revision surgeries which may be caused by factors such as infection, periprosthetic fracture or osteolysis. The aim of this study was to assess outcomes of using the “Push-Through Total Femoral Prosthesis” (PTTF) for revision of a total hip replacement with extreme bone loss. Fourteen patients who had extensive bone defects of the femur due to failed THR's and were treated with PTTF between 2012 and 2020 were included in this study. Primary functional outcomes were assessed using Harris Hip Score (HHS), Toronto Extremity Salvage Score (TESS) and Musculoskeletal Tumor Society (MSTS) scores. Range of motion, complications, and ambulatory status were also recorded to assess secondary outcomes. Two of 14 patients underwent surgery with PTTF for both knee and hip arthroplasty revision. The mean time between index surgery and PTTF was 15 years (3 to 32 yrs.). Acetabular components were revised in six of 14 patients. After a mean follow-up of 5.9 years, hip dislocations occurred in 3 patients. All dislocated hips were in patients with retained non-constrained acetabular bearings. Patient satisfaction was high (MSTS: 67%, HHS: 61.2%, TESS 64.6%) despite a high re-operation rate and minor postoperative problems. PTTF is a unique alternative that may be considered for a failed THA revision procedure in patients with an extreme femoral bone defect. Patients are able to ambulate pain free relatively well. Routine usage of constrained liners should be considered to avoid hip dislocation which was our main problem following the procedure

Purpose: To assess the extended trochanteric osteotomy approach, used for revision of hip replacement. Material – Methods: Between January 1998 and December 2002, sixteen (16) hip replacement revision procedures were performed on 16 patients, (10 male, 6 female), with extended trochanteric osteotomy approach. Average age was 67 years (52–79). Nine (9) procedures involved the femoral stem only, and seven (7) both components. Six (6) stems were fixed with cement and ten (10) without. In all cementless cases, fixation of the stem in the medullary canal was achieved for at least 4 cm below the osteotomy level. The length of the stem beyond the osteotomy was three times the width of the canal. The length of the osteotomy varied from 12 to 18 cm (av. 14 cm), and the length of the inserted components ranged from 210 – 280 mm (av.225 mm). Results: Union of the osteotomy was achieved in all cases from 4 – 9 months (av 5.5). There was no intra-operative or postoperative fracture. No dislocation or infection was recorded. Two prostheses presented sinkage of 1 and 1.5 cm respectively. So far no patient has been reoperated in the revised hip. Conclusions: The extended trochanteric osteotomy approach for hip replacement revision, offers excellent view of the femoral canal and facilitates the removal of the prosthesis, while the complications due to approach are minimal

The aim was to identify the acetabular center, fix the acetabular implant, and reconstruct the hip rotation center using the residual Harris fossa and acetabular notch as anatomical markers during revision hip arthroplasty. Osteolysis is commonly found in the acetabulum during hip arthroplasty revision. It causes extensive defects and malformation of the anatomical structure, making correct fixation of a hip prosthesis difficult. We studied the relations of the anatomical positions between the Harris fossa and acetabular notch and the acetabular center (Fig. 1). Vertical distance from the hip rotation center to the teardrop connection and horizontal distance from the hip rotation center to the teardrop were measured on preoperative and postoperative radiographs. Vertical distance increased from 14.22±3.39 mm preoperatively to 32.64±4.51 mm postoperatively (t=3.65, P<0.05) and the horizontal distance from 25.13±3.46 mm to 32.87±4.73 mm (t=2.72, P<0.05). Altogether, 28 patients underwent revision hip arthroplasty based on the Paprosky classification for bone loss. The anatomical hip center was identified using the residual Harris fossa and acetabular notch as anatomical markers during revision hip arthroplasty. Based on these relations, we were able to place the hip prosthesis correctly. After surgery, restoration of the anatomical hip center was accomplished based on data obtained from radiographs(Fig.2 and Fig.3)

Introduction. The purpose of this study was to analyze trends in the surgical management of ON in recent years. Specifically, we evaluated the annual prevalences of: 1) joint preserving procedures (osteotomies and core decompression/grafts) and 2) joint non-preserving procedures (total hip arthroplasties [THAs], revision THAs, partial THAs) for the treatment of osteonecrosis of the femoral head (ONFH) between 2009 and 2016. Background. A total of 406,239 ONFH patients who were treated between 2009 and 2016 were identified from a nationwide database. Treatment procedures were extracted using ICD-9-CM and ICD-10-CM procedure codes. Annual rates of each of the above procedures were calculated and the trends in the procedure types were also evaluated. Chi-square tests were performed to compare the annual prevalence of each procedure. The mean annual prevalence over the 8-year study period was calculated for each procedure. Results. Throughout the study period, the number of joint preserving procedures steadily increased by 27%. In the earliest year studied, 2009, 41% (n=19,559) of the total procedures for ONFH were joint-preserving compared to 52% (n=13,715) in 2016. The rates of joint non-preserving procedures decreased (59 to 48%) over the same period (Figure 1). There was a decreasing annual prevalence of THAs (88 to 82%), revision THAs (2.0 to 1.4%), partial THAs (3.4 to 2.3%), osteotomies (4.2 to 3.2%), and core decompression (1.9 to 1.4%) throughout the study period (p<0.001). Throughout the 8-year period, THA was most commonly performed (mean annual prevalence 83%) whereas osteotomies (3.7%), partial THA (2.8%), core decompression/graft (1.9%), and revision THA (1.5%) were less commonly performed. Conclusion. In order to better understand trends in ONFH management, this study evaluated the annual prevalence of 5 commonly performed procedures. Although earlier data indicated decreasing rates of joint preserving procedure, this study found ONFH management has shifted more towards these procedures. For any tables or figures, please contact the authors directly

Aims

Orthopaedic surgeries are complex, frequently performed procedures associated with significant haemorrhage and perioperative blood transfusion. Given refinements in surgical techniques and changes to transfusion practices, we aim to describe contemporary transfusion practices in orthopaedic surgery in order to inform perioperative planning and blood banking requirements.

Aims

The aim of our study was to investigate the effect of asymmetric crosslinked polyethylene liner use on the risk of revision of cementless and hybrid total hip arthroplasties (THAs).

Purpose of the study: Locked implants have yielded favourable results for femoral bone reconstruction for revision total hip arthroplasty, but defective integration has also been reported due to insufficient bioactive coating. The purpose of this work was to evaluate a locked pivot with a two-third proximal hydroxyapatite coating. Material and methods: From 1996 to 2007, 158 femoral implants (Linea™) were implanted for hip arthroplasty revision. The 143 cases with more than one year follow-up were reviewed (14 deaths, 1 lost to follow-up); 83 revisions for aseptic loosening, 41 periprosthetic fractures, 19 revisions in an infected context. Patients were reviewed retrospectively by a non-operator observer. These were older patients (mean age 68 years, range 31–93) and 36 patients had complex situations requiring at least two prior prostheses; 25% had severe grade 3 or 4 (SOFCOT) bone lesions and 59% diaphyseal damage. Results: Clinical improvement was significant, the Postel Merle d’Aubigné score improved from 7.7 + 4.3 (0–17) to 15.6 + 2.2 (8–18) at mean 50 months (14–131) (p< 0.001). At last follow-up, 14 patients (10%) reported thigh pain and only seven pivots (5%) had not achieved Engh osteointegration (five with thigh pain two without). There were no fractures. There was on non-union of the femorotomy. According to the Hoffman index, femoral bone regeneration was significant at the metaphyseal and diaphyseal levels. Eighteen of the 19 infections cured, all periprosthetic fractures healed. The implant survival was 88.9% at 91 months (65–96.7%). There were five pivot replacements for non integration and/or thigh pain which resolved in all cases; there were no other pivot replacements. The quality of the metaphyseal and diaphyseal filling was predictive of the quality of the bone fixation of the pivot (p< 0.01). Discussion: Compared with older models of locked pivots, this implant reduced the rate of thigh pain while allowing constantly satisfactory bone reconstruction. The metaphyseal and diaphyseal filling index is the main factor predictive of clinical and radiological success by favouring osteointegration. Maximal filling, obtained with a full range of implant diameters and lengths, contributes to this good result

Revision of massive femoral defects in revision hip arthroplasty is extremely difficult. This study assesses defects where bone loss extends to the isthmus of the femur. By using a medial allogeneic femoral graft in a wedge fashion, rotational and axial stability of the femoral implant is augmented, allowing bone ingrowth to occur. The technique is described which is simple, inexpensive and readily available in most institutions. A medial allogeneic femoral strut graft is assessed in hip arthroplasty revision to improve implant stability and thereby promote bony ingrowth into the implant. Thirty-three revision arthroplasties were preformed in twenty-nine patients (avg. age 63.7 yrs) using a fully-porous coated implant of eight or ten inch length. All patients had a Paprosky Type III or IV femoral defect. The implants, by definition were press-fit at or past the isthmus. To aid ingrowth and to decrease axial and rotational stresses, a medial femoral strut graft was wedged into the remaining medial host bone and under the collar of the implant. Cabling was utilized to prevent dislodgement of the graft from the implant and host. A radiographic and clinical comparison to a series of similar defects without grafting was performed for a minimum of thirty-five month follow-up. Twenty-eight of the thirty-three implants had radiographic evidence of ingrowth with migration of only two millimeters (average). Medial femoral strut grafting displayed much better potential for ingrowth and decreased potential for migration. Harris hip scores averaged eighty-one from a preoperative score of thirty-two. Cost of the grafts averaged $2100 cheaper compared to a bulk structural graft which would otherwise have been used in this situation. Medial femoral strut grafts augment initial implant stability to allow for implant in- growth. The advantages of the medial strut grafts are decreased cost, improved stability, and improved implant in- growth potential

Aims

Advances in surgical technique and implant design may influence the incidence and mechanism of failure resulting in revision total hip arthroplasty (rTHA). The purpose of the current study was to characterize aetiologies requiring rTHA, and to determine whether temporal changes existed in these aetiologies over a ten-year period.

Background: During cemented hip arthroplasty revision removal of all the old cement mantle is a time staking process with multiple disadvantages. In some selected patients cementing revision stem into the old mantle is regarded as a highly attractive option. Contradictory evidence exists whether bond between two cement layers is strong enough, especially in the presence of interfering fluids. Aim: analysis of the shearing strength of the interface between two layers of polymethylmethacrylate cement in the presence of fluid. Methods: Cylindrical blocks of polymethylmethacrylate cement represented primary cement mantle. Its flat surface was machined to reproduce smooth old cement mantle surface comparable with that after removal of a highly polished stem (Ra=200nm). A second block was cast against the first and their junction represented the investigated interface. The influence of fluid was examined by injecting liquid onto the ‘primary’ surface prior to casting. Water or 2% water solution of carboxy-methyllcellulose (representing bone marrow viscosity of 400mPas) were used in two volumes: 0.02ml/cm2 (small) or 0.4ml/cm2 (large - surface submerged). 6 variants (control monoblock, dry surface, surface stained with small or large volume of water or highly viscous fluid) containing 7 repeats were exposed to a single shearing stress to failure at the speed of 1mm/min (Autograph AGS, Shimadzu, Japan). Results were analyzed using 1-way ANOVA with post-hoc analysis (equal N HSD) and power calculations. Results: Large volume of viscous fluid prevented bonding completely in two cases and significantly weakened the other samples showing mean failure stress of 5.53 MPa (95%CI:1.33–9.73 MPa). This was significantly lower compared with control monoblock (19.8–95% CI: 17.8–21.9 MPa), dry surface variant (16.9–95% CI: 15.9–18.0 MPa) and that stained with small amount of high viscosity fluid (16.01–95% CI: 15.12–17.0 MPa). Interestingly, presence of a large volume of low viscosity fluid (water) did not significantly reduce resistance to shear stress (17.05 – 95% CI:15.67–18.43 MPa). Similar relations were observed when strain at failure and toughness were analyzed. Conclusions: In all but large volume of viscous fluid variants, the failure occurred away from the interface between two cement layers. Large amount of viscous fluid weakened significantly this interface. If such a viscous fluid can be eliminated by copious water irrigation it is likely that strength of the cement-cement bond will be maintained. In the presence of low viscosity fluids (water, blood) careful use of gun technique is likely to allow for their escape as the cement is advanced within the femoral or the old mantle canal leading to a satisfactory bond. Our observations suggest that cement-in-cement technique seems to be biomechanically acceptable

Hap Paul was a unique individual. It is appropriate that this award should go a unique paper presented at this year’s ISTA. The name “Hap” comes from his initials Howard A. Paul. He was an outstanding veterinarian, but he was also much more than that. He had an insatiable curiosity combined with a quick mind and a surgeon’s practicality. His first love was research. After graduating from high school in Connecticut, he went to Notre Dame as a swimmer. He graduated with a degree in Microbiology and a strong desire to “cure cancer”. Acting on his dreams, as he always did, he decided to go to Paris to work with one of the pioneers of Interferon research. Never mind that he didn’t have a job and did not know a word of French. Of course he got the job and learned French playing rugby (hence his awful accent and colorful vocabulary). The funding ran out for the Interferon research, but he somehow got a shot at a spot in the veterinary school in Paris. He got married and finished his veterinary training. The veterinary thing worked out, but the marriage didn’t. He returned to the US after 9 years living in France, to attend the UC Davis School of Veterinary Science as a surgical resident in the small animal area. He met his wife, Dr. Wendy Shelton there… but that is another story. I met Hap when I was a new attending orthopaedic surgeon at UC Davis and looking to do some animal modeling of hip replacement revision techniques. He was an imposing figure: six feet four, big curly afro and wire glasses. He dressed like a Frenchman, wore big clogs and carried a purse. Needless to say I was intimidated initially. But, he had great joi de vive and lived up to his name… he was almost always happy. Hip replacement in dogs began in the 1970’s, but was nearly abandoned by the early 1980’s because of infections and “luxations” (dislocations). In order to develop an animal model we had to develop instruments and techniques that incorporated “third generation” cementing techniques. This we did, but Hap took these instruments and began using them clinically on working dogs. He developed quite a reputation for resurrecting hip replacements for dogs in the US and internationally. Hap and I went on to develop dog models for CT-based custom implants and later surgical robotics (eventually leading to the development of Robodoc). Despite our academic interests, both Hap and I went into private practice in the mid 1980’s… separately, of course (he as a veterinary orthpaedic surgeon and I specialized in hip and knee replacements for humans). Our research in surgical robotics took off when we landed a huge grant from IBM. But then the sky fell in when we learned that Hap had developed lymphoma. After surgery, radiation and chemotherapy, he was in remission, but temporarily couldn’t perform surgery due to a peripheral neuropathy attributed to Vincristine. So Hap went to the lab at UC Davis to work directly with the robotics team. He was a slave driver… but a pleasant one. Certainly the basic research behind Robodoc could not have been done without Hap getting lymphoma. Over 5 years (1986–91) we both had a ball working with some of the best minds in robotics and imaging research. We presented our research on CT-based customs and robotics at many international venues, and Hap made many friends… some are in the audience today. He was one of the founders of this organization (ISTA). Hap returned to veterinary practice when he could finally work with his hands again… but this was not for long. Soon our research lead to the founding of Integrated Surgical Services (ISS) in 1991, the makers of Robodoc. Hap agreed to leave his practice to lead the company and I stayed in clinical practice to develop and utilize the device on patients. In 1992, we shocked the world by being the first to use an active robot in human surgery. It looked like the dawning of a new age. (I still believe it is, but it has been a very slow dawn). For Hap, the joy was short-lived. He developed leukemia as a complication of his prior chemotherapy. He died while recovering from a bone marrow transplant on Feb. 10, 1993 at the young age of 44. During his short life he contributed tremendously to the benefit of others by his research and development work. But mostly he inspired others to excel in their endeavors. He was a wonderful guy. And we are all pleased to honor him with the presentation of the Hap Paul Award at each year’s meeting of ISTA

Orthopaedic treatment of upper and lower extremities has traditionally been attended by specialists in specific areas of expertise; arthroscopy, biologic reconstruction, total joint replacement. In many specialty centers of the US and worldwide, procedures performed by specialists do not consistently coincide with subspecialty training. This is particularly true for hip surgery, where a majority of total hip arthroplasty (THA) procedures are performed by Orthopaedists that undertake less that 50 fifty such procedures annually. With advances in knowledge and technique, surgical hip treatments have significantly progressed in recent decades. By all estimates, there is a need for specialized surgical treatment in this area, as the demand for hip replacement and revision is likely to far outpace that of population growth in the coming decades. Discreet categories of replacement versus preservation have become less clear, thus paving the way for an emerging specialty of exclusive hip surgery. The scope of such surgery encompasses an age span from the adolescent at skeletal maturity to elderly. Advances in hip arthroscopy have improved outcomes for young patients. Progressive data and knowledge have fueled biologic non-arthroplasty solutions in the hip such as osteotomy and surgical hip dislocation for femoral acetabular impingement. Development of limited replacement options such as resurfacing have also broadened the spectrum of treatments and added to the level of complexity in hip surgery. Total hip arthroplasty and revision numbers continue to climb annually. Combining preservation procedures with options for replacement and resurfacing, the hip specialty creates a continuum of medical care that may redefine the joint care paradigm

Objectives

Prosthetic joint infection (PJI) diagnosis is a major challenge in orthopaedics, and no reliable parameters have been established for accurate, preoperative predictions in the differential diagnosis of aseptic loosening or PJI. This study surveyed factors in synovial fluid (SF) for improving PJI diagnosis.

Aim: To review a single surgeon’s experience of EIG for femoral and acetabular revision arthroplasty. Method: A retrospective review of EIG revisions from Waikato Hospital from May, 1995 to November, 2000. The notes and x-rays of patients from this time were reviewed. All x-rays were reviewed by the senior author. Results: There were thirty-two revisions using the EIG system. The indication for revision in all cases was aseptic loosening of either or both of the acetabular or femoral components. There were 14 men and 12 women. Four patients had bilateral revisions. One required bilateral revisions to be repeated. The average age was 79 years and nine months (range: 53 to 90 years). The average time from initial hip replacement to revision was 10.4 years (range: 13 months to 24 years). Sixteen revisions had EIG to femur and acetabulum. Four acetabular cups and 10 femoral stems were revised with EIG alone or in combination with a replacement component.The average period of follow-up was 34 months. One acetabulum was revised for recurrent dislocation. Three other hips dislocated in the post-operative period. Two femoral stems (one patient) were revised again with EIG for subsidence. One is now stable, the other has been exchanged for a Solution stem because of repeated subsidence. The histological specimens taken from these showed the grafted bone was necrotic. One other stem subsided 2mm. There were two intraoperative femoral shaft fractures. Conclusions: EIG is one solution for complicated revision in the presence of proximal femoral bone stock loss. Subsidence requiring re-revision was been a problem with one patient