Introduction. Frame HI is the #Days for device removal/cm. IM Nail HI is less relevant (31–45 D/cm). Albizzia HI was 33 D/cm (1991–2003). Patients felt fine approximately 1M after end of lengthening (EoL), resuming normal life and sports. This sometimes resulted in
Introduction. Approximately 2,000 Skeletal transcutaneous osseointegration (STOI) procedures have been performed worldwide as of 2020, more than half of which have been performed by the Osseointegration Group of Australia using a press-fit technique with either ILP or OPL implant designs. Despite the consistently demonstrated clinical benefits, concerns regarding potential complications following STOI have slowed its widespread adoption. As more patients are followed for a longer period of time, longitudinal studies have confirmed complication rates are very acceptable, similar to those of total ankle and total elbow replacements. One of the major risk category is implant removal. The primary goal of this study was to investigate the complications and technical issues associated with transtibial osseointegration implant removal due to any cause. The focus here will be on the press-fit ILP and OPL implants, including the indications for removal and patient outcomes following removal. Materials & Methods. A review of our osseointegration registry between November 2010 and March 2022 was performed. Inclusion criteria were patients who have undergone removal of a transtibial osseointegration implant due to any cause. Selected patients either had a follow-up of at least two years or had their index osseointegration surgery at least two years prior to when the study was performed. Patients who have had osseointegration at other anatomic levels, and patients who underwent simultaneous total knee replacement with transtibial osseointegration were excluded from the registry search. Results. There were a total of 148 transtibial osseointegration procedures performed during the study period, with 97 (65.5%) performed in males and 51 (34.5%) performed in females. The average age at first stage osseointegration procedure is 50.4 years (range 16.8–87.9, SD 14.1). In the study cohort of 22 cases requiring implant removals, 12 (54.5%) were male and 10 (45.5%) were female. The average age at first stage osseointegration procedure in this cohort is 51.3 (range 37.4–82.6, SD 10.7) and average BMI 30.3 (range 21.9–40.9, SD 5.8). Although men comprised the majority of removals, women had a greater relative risk (Fisher exact test p=0.032). The average duration from time of STOI to removal was 2.6 years (range 0.1–6.8, SD 1.9) within this 11.5 year follow-up period. The most frequent indication was infection (54.6%, n=12) followed equally by pain (13.6%, n=3), aseptic loosening (13.6%, n=3) and
Introduction. Osseointegration is a potential treatment option for transfemoral amputees experiencing socket related problems. Till this date, there is little data assessing the feasibility and advantages of osseointegration in individuals with transtibial amputations. Materials and Methods. We prospectively followed 91 patients undergoing transtibial osseointegration from 2014–2018 who either 1) reported pain or mobility dissatisfaction with socket prosthesis; 2) had an intact limb with incapacitating pain, complex deformity, or profound distal weakness or 3) were recent amputees preferring osseointegration. Adverse events were monitored including infection, periprosthetic
Traditional socket prosthesis (TSP) rehabilitation for amputees is associated with substantial dissatisfaction due to poor mobility and pain from soft tissue squeezing. Osseointegration (OI), eliminates skin compression and prosthesis fit issues, providing superior mobility and quality of life (QOL) for most amputees. The potential for OI to benefit patients with exceptionally poor mobility is understudied. To address this knowledge gap, this project investigated the mobility and QOL changes. A retrospective review was performed to identify transfemoral amputees who presented with wheelchair-bound mobility (K0) and had at least five years of post-osseointegration follow-up. Outcome measures included changes in mobility (K-level, daily prosthesis wear hours, Timed Up and Go (TUG), 6 minute walk test (6MWT)) and QOL (Questionnaire for persons with a Transfemoral Amputation (QTFA); Short Form Health Survey 36 (SF36). Adverse events recorded included debridement for infection,
Introduction. Osseointegration has emerged as a promising alternative to rehabilitating with a traditional socket mounted prosthesis. Advantages have been reported to include improved functional mobility, better osseoperception, improved comfort, reduced pain, better biomechanical alignment and better gait, which all lead to a less restricted lifestyle and significantly improved quality of life. A major concern of the Osseointegrated approach lies in the risk of infections occurring from the permanent transcutaneous opening often referred to as the stoma. Several systematic reviews have indicated that the occurrence of minor infections can be quite common, serious complications are reported to be rare. In addition to commonly anticipated complications including fractures, surgical debridements or revisions, we have identified several significant events in which a patient may require to be readmitted and go through additional surgery. The objective of this study is to examine the rate of occurrence and reports on the best management practices of serious complications across a multi-centre review of more than 1000 osseointegration surgeries. Materials & Methods. A detailed analysis has been performed on all osseointegration surgeries performed by the Osseointegration Group of Australia and it's affiliates between since 2010. The majority of surgeries took place in Australia, the United States, the Middle East as well as in Europe. All events leading to a re-admission and subsequent re-operation have been identified through hospital operation records and pooled together for meta-analysis. Events identified include: revision of
Introduction. Advantages of osseointegration have been reported to include improved functional mobility, better osseoperception, improved comfort, reduced pain, better biomechanical alignment and gait, which all lead to a less restricted lifestyle and significantly improved quality of life. A major concern of the Osseointegrated approach lies in the risk of infections occurring from the permanent transcutaneous opening often referred to as the stoma. Materials and Methods. Detailed analysis has been performed on all osseointegration surgeries performed by the Osseointegration Group of Australia and it's affiliates since 2010. All events leading to a re-admission and subsequent re-operation have been identified through hospital operation records and pooled together for meta-analysis. Events identified include: revision of
Recently, a special type of surface pitting found on metal implants was proposed to arise from “inflammatory cell-induced” corrosion (ICI, Figure 1) (1, 2). The actual mechanism of this was unknown, but similar features were suggested to be artefacts of electrocautery damage from revision surgery (3). Under lab conditions and without the influence of any cells, we aimed to reproduce the same surface pits and structures with electrocautery. Methods. A polished cobalt-chromium disk (40 mm diameter, 8 mm thick) was marked into 8 sections for various testing conditions (Figure 2a). A stainless steel Bovie tip with a unipolar electrocautery machine (SYSTEM 5000, ConMed, USA) was used at typical surgical coagulation conditions: (70 volt, 120 watts, 562 KHz frequency). We mimicked three types of surgical techniques with the electrocautery: “Dotting” was repeated, on and off, direct surface contact; “Dragging” was constant, direct surface contact; “Hovering” was pausing several millimeters above the surface. We also examined the interplay of these practices on diamond-tip-induced scratches and either dry or wet (normal saline) conditions. High magnification images (Keyence VHX-2000E) were taken after the disk was cleaned with laboratory soap, light mechanical scrubbing, and formalin soak. Results. Coagulation mode generated electrical sparks when dotting/dragging and electrical arcs when hovering. These left seared marks that persisted even after cleaning (Figure 2b). At higher magnification, the surface features were comparable in size and shape to those attributed to ICI (1, 2). Areas wet with saline (Figure 3a) showed an abundance of ringed pits with raised edges that closely resembled those observed in Figure 1. Furthermore we obtained images similar to the phenomenon of “cellular tracks” (Figure 3b) (1). Premade scratches did not influence the pit arrangement but scratches made by the Bovie tip produced the characteristic scratch-associated ICI features as observed on implant retrievals in the past (Figure 3c) (4). Discussion. In the absence of cells, pitting equivalent to proposed ICI features was successfully replicated using an electrocautery in coagulation mode. Previously (4), we found a high incidence but small surface area of these features on the majority of retrievals, predominantly located in a focal area of the superior aspect of the femoral ball next to the junction of the stem. There were fewer on the inferior aspect which is consistent with electocautery damage when dissecting the hip capsule. The effect of this damage on retained parts is unknown, but electrocautery damage around areas of
INTRODUCTION. Unlike current acetabular cups, this novel ceramic cup has a Ti/HA coating which removes the requirement for assembly into a metal shell which avoiding potential chipping/misalignment and reducing wall thickness [Figure 1]. This study examines the resistance of novel thin-walled, direct to bone fixation ceramic cups to critical impact loads. METHODS. Samples of the smallest (Ø46mm) and largest (Ø70mm) diameter ReCerf. TM. acetabular cups and corresponding femoral head implants were implanted into Sawbones foam blocks considered representative of pelvic cancellous bone. Two different positional configurations were tested and were considered worst case and the extremes of surgical compromise; P1 simulates the cup fully supported by the acetabulum with a high inclination angle (70°) and a vertical impaction axis (worst case loading near the cup rim) and. P2 simulates the cup implanted with a lower inclination (55°) but with the superior section unsupported by acetabulum bone [Figure 2]. For each size, three acetabular cups were tested in each position. The impact fixture was positioned within a drop weight rig above a bed of sand and ≈22mm of pork belly representative of soft tissues damping effect and the implant components aligned to achieve the defined impact point on the cup [Figure 2]. Lateral falls were tested on all available samples applying impact energy of 140J [1] and 3m/s impact velocity [2]. After the lateral fall test, each sample was tested under impact conditions equivalent to a frontal car crash considering a peak impact force of 5.7kN occurring 40ms from initial contact (able to produce acetabular fracture)[3]. RESULTS. None of the testing simulating a lateral fall produced fracture or any other damage to the ceramic acetabular cup. In 7 of the 12 tests, the impact force was sufficient to fracture the foam block representing the periprosthetic bone. The cups showed a good stability within the blocks, with a maximum recorded cup spinning angle relative to the acetabulum of 4.5˚. Subsequent testing simulating a car crash resulted in the fracture of two samples out of 12, one of the largest and one of the smallest ReCerf. TM. cups. In both instances, failure occurred very close to the inner edge. Of the remaining 10 samples no cup fractures were observed. All foam acetabulum blocks were severely damaged and 5 blocks fractured. The maximum recorded cup spinning angle following the car crash impact was 5.8˚. SIGNIFICANCE. Extreme testing scenarios presented here are not a regulatory requirement for manufacturers and have not previously been considered for ceramic acetabular components. Fracture is a possible failure mode of ceramics but this testing has proven that modern ceramics can withstand lateral falls and the large majority can withstand subsequent loading equivalent to head on car-crash; loading under which pelvic bone fracture and significant injury is far more likely to occur than
Introduction. Titanium and its alloys are attractive biomaterials attributable to their desirable corrosion, mechanical, biocompatibility and osseointegration properties. Ti6Al4V alloy in particular remains a prominent biomaterial used in Total Hip Arthroplasty (THA) today. This is partly due to biocompatibility and stress shielding issues with CoCrMo alloys, resulting in its increasing side-lining from the THA construct. For several decades now, research efforts have been dedicated to understanding wear, corrosion and surface degradation processes in implant materials. Only recently have researchers shown interest in understanding the subsurface implications of fretting and the role it plays on
Introduction:. The diagnosis of implant-associated infections is challenging, and the conventional culturing of periprosthetic tissue has been the gold standard for diagnosis of implant-associated infections. However, conventional diagnostic tests are inaccurate because the pathogenesis of implant-associated infection is related to microorganisms growing in biofilms. We compared culture of samples obtained by sonication of explanted implants to dislodge adherent bacteria from implants with conventional culture of periprosthetic tissue. The purpose of this study is to evaluate the results of sonication that is microbiological diagnostic method for implant-associated infections. Materials and Methods:. Between January 2013 and April 2013, a total of 19 consecutive patients underwent the removal of implants at our institution. There were 15 women and 4 men with a mean age of 71 years (32 to 90) at the time of the operation. Implants were removed because of aseptic loosening in 9 patients, infection in 6 patients, necrosis in 2 patients, dislocation in 1 patient and
Aim. Radiologic signs such as radiolucent lines around the
Purpose. Traditional total knee arthoplasty techniques have involved implantation of diaphyseal stems to aid in fixation expecially when using constrained polyethylene inserts. While the debate over cemented vs uncemented stems continues, the actual use of stems is considered routine. The authors' experience with cemented stemmed knee revisions in older patients with osteoporotic bone has been favorable. Our younger patients with press-fit stems from varying manufacturers have been plagued with a relatively high incidence of component loosening and stem tip pain in the tibia and occasionally thigh. We report the early results of the first 20 total knee revisions using press-fit metaphyseal filling sleeved stemless implants with constrained bearings. Methods. Twenty three patients with failed primary or revision total knees were assigned to receive stemless sleeved revision knee designs using the DePuy MBT/TC3 system. Reasons for revision included loosening,
Introduction. The development of new bearing surfaces for total joint replacement is constantly evolving. Oxidized zirconium (Oxinium) has been introduced for use in total hip arthroplasty (THA) and total knee arthroplasty (TKA). One of the most common causes of failure of THA is aseptic loosening secondary to polyethylene wear debris. The aetiology of wear is multifactorial and includes adhesive, abrasive, third-body and fatigue wear mechanisms. Oxidized zirconium is a relatively new material that features an oxidized ceramic surface chemically bonded to a hard metallic substrate. This material possesses the reduced polyethylene wear characteristics of a ceramic, without the increased risk of
Patients with severe knee instability remain a surgical challenge. Furthermore, in the presence of extensive bone loss, constrained condylar implants may be unsuitable. Hinged knee replacements have served an important role in the management of such complex knee pathologies. A combined prospective and retrospective study of 138 consecutive hinge knee arthroplasties (42 primary and 96 revisions) of 8 different models performed in our institution between 2004 and 2010 at a mean follow up of 4.2years. Outcomes were reviewed and knee scores preoperatively and postoperatively at 1, 2 and 5 years using the American knee scoring system. The mean preoperative American knee score of 31 improved to 87 postoperatively. Complication rate was 19%, 15% of which required re-revisions for: loosening (4%), Infection (4%), periprosthetic
Introduction. Patients with severe knee instability and extensive bone loss remain a surgical challenge. In such cases, regular knee implants and constrained condylar implants may not be suitable or have been attempted and failed. Hinged knee replacements have developed an important role in the management of such complex knee cases. They also have an increasingly important role in cases such as rheumatoid arthritis and other cases of severe joint destruction. We present a review of 138 consecutive hinge knee arthroplasties of 8 different Hinge models performed in our unit between 2004 and 2010. Method. Combined prospective and retrospective study of 138 (42 primary and 96 revisions) consecutive cases of Hinge knee replacements at a mean follow up of 4.2 years. Outcomes were recorded and scored using the American knee score preoperatively, 1, 2 and 5 years. Complications, re-revisions, implant failures and survivorship were also assessed. Results. Mean preoperative American knee score of 31 improved to 87 postoperatively. Implant survivorship was greater than 81% at 4 years, with most of the failures occuring in the salvage surgery cases. Complication rate was 19%; 15% of which required re-revisions for: loosening (4%), Infection (4%), periprosthetic
Aim. To study the efficacy of Hydroxyapatite (HAC) Ceramic Coated hip arthroplasty. Is it suitable for the younger patient?. Methods. This series of 2390 primary HAC hip arthroplasties has been studied for up to 21 years. (569 hips over 10 years including 98 hips over 15 years) Patients are assessed by Harris Hip Score and plain X-ray. The prosthesis consists of a fully coated stem and a fully coated acetabulum. A ceramic head articulates with an acetabular liner which is either plastic (UHMW polythene) or ceramic. No cement is used. HA coated implants are physiologically fixed to cancellous bone by a process of osseointegration. Other uncemented implants are pathologically fixed by fibrous scar tissue. These two methods of fixation should be considered separately and not combined as ‘uncemented’. Results. Aseptic loosening in this series is 0.63 %. The revision rate in this series for all reasons is only 3.5%. Harris Hip Score (HHS) demonstrates excellent medium to long term results in 97% of cases (i.e. up to 20 years). Poor HHS results (36 cases: 1.51%) are mostly related to medical or other joint problems. HA fixation will outlast some of the components and wear in polythene acetabular liners can be a problem after 15 years. A sub-group of 629 hips using alumina ceramic/ ceramic bearings is successful but five components fractured (out of 1258 individual components). Wear debris from ceramic materials appears to be benign. Zirconia Toughened Alumina (ZTA) has been introduced to replace alumina and should obviate problems of ceramic
Background. The Kotz Modular Femoral Tibial Replacement system has been one of the most widely utilised uncemented modular systems for bone and joint reconstruction after tumour resection. We have identified a significant incidence of mechanical failure and breakage of the prosthesis. The purpose of this investigation is to review the modes of implant failure and the outcomes after prosthetic revision for a broken Kotz prosthesis. Methods. Over 20 years there were 121 distal femoral, 55 proximal tibial, 47 proximal femoral and 12 total femoral replacements performed. Results. Out of 180 currently living patients there were 27
Distal femoral replacement is an operation long considered as salvage operation for neoplastic conditions. Outcomes of this procedure for difficult knee revisions with bone loss of distal femur have been sparsely reported. We present the early results of complex revision knee arthroplasty using distal femoral replacement implant, performed for severe osteolysis and bone loss. Retrospective review of clinic and radiological results of 25 consecutive patients operated at single centre between January 2010 and December 2014. All patients had single type of implant. All data was collected till the latest follow up. Re-revision for any reason was considered as primary end point. Mean age at surgery was 72.2 years (range 51 – 85 years). Average number of previous knee replacements was 2.28 (range 1 to 6). Most common indications were infection, aseptic loosening and peri-prosthetic fracture. Average follow up was 24.5 months (range: 3–63 months). 1 patient died 8 months post-op due to unrelated reasons. Re-revision rate was 2/25 (8%) during this period. One was re-revised for aseptic loosening and one was revised for peri-prosthetic fracture of femur. Two other peri-prosthetic fractures were managed by open reduction and internal fixation. All 3 peri-prosthetic fractures occurred with low energy trauma. It is noteworthy that there was no hinge or mechanical failures of the
EPRs are the treatment of choice following resection of tumours. These have been used for 39 years in our institution. There has been concern regarding the long term survival of endoprosthesis; this study investigates the fate of the reconstruction. Methods. Between 1966 and 1995, 3716 patients were seen with a suspected neoplasm and 776 patients underwent EPRs. Patients receiving growing endoprostheses were excluded from the study as they invariably require revision, leaving 667 replacements. Insufficient data was available in 6 cases, leaving 661 patients in the study group. Information was reviewed concerning the diagnosis, survival of implant and patient, subsequent surgery, complications and functional outcome. Kaplan-Meier survival analysis was used for implant survival with end points defined as revision for mechanical failure (aseptic loosening,
Intraoperative fractures during primary total hip arthroplasty (THA) can occur on either the acetabular or the femoral side. A range of risk factors including smaller incision surgery, uncemented components, prior surgery, female sex, osteoporosis, and inflammatory arthritis have been identified. Acetabular fractures are rare but when they do occur often are underrecognised. It is not uncommon for intraoperative acetabular fractures to be discovered only postoperatively. Intraoperative acetabular fractures are associated with cementless implants and a number of identified anatomic risk factors. Factors related to surgical technique, including excessive under-reaming, excessive medialization with aggressive reaming, and implant designs such as an elliptical cup design are associated with higher risk. Treatment of acetabular fractures is dependent on whether they are diagnosed intraoperatively or postoperatively. When discovered intraoperatively, supplemental fixation should be added in the form of additional screw fixation, placing a pelvic plate, or using an acetabular reconstruction cage and morselised allografts. Acetabular reamings, obtained during preparation of the acetabulum, can be used for local bone graft. The goal should be stability of both the fracture and acetabular cup. Postoperatively, weight bearing and mobilization protocols may require modification, with many surgeons choosing a period of toe-touch weight-bearing in such cases. Acetabular fractures found postoperatively require the surgeon to make a judgement on the relative stability of the implant and the fracture to determine if immediate revision surgery or protected weight-bearing alone is appropriate. On the femoral side intraoperative fractures can occur around the greater trochanter, the calcar, or in the diaphysis. Fractures of the greater trochanter are problematic because of their tendency to displace due to the attachment of the abductors and the strong force they apply. Tension band wiring techniques will work for many greater trochanteric fractures while a trochanteric plate may be occasionally called for. With either form of fixation strong consideration should be given to 6–8 weeks of protected weight bearing postoperatively. Short longitudinal cracks in the medial calcar region are not rare with uncemented
