Patients with longstanding hip fusion are predisposed to symptomatic degenerative changes of the lumbar spine, ipsilateral knee and contralateral hip. 1. In such patients, conversion of hip arthrodesis to hip replacement can provide relief of such symptoms. 2 – 4. However, this is a technically demanding procedure associated with higher complication and failure rates than routine total hip replacement. The aim of this study was to determine the functional results and complications in patients undergoing hip fusion conversion to total hip replacement, performed or supervised by a single surgeon. Twenty-eight hip fusions were converted between 1996 and 2016. Mean follow up was 7 years (3 to 18 years). The reasons for arthrodesis were trauma 11, septic arthritis 10, and dysplasia 7. The mean age at conversion was 52.4 years (26 to 77). A trochanteric osteotomy was performed in all hips. Uncemented components were used. A constrained liner was used in 7 hips. Heterotopic ossification prophylaxis was not used in this series. HHS improved a mean of 27 points (37.4 pre-op to 64.3 post-op). A cane was used in 30% of patients before conversion and 80% after. Heterotopic ossification occurred in 12 (42.9%) hips. There was 2 peroneal nerve injuries, 1 dislocation, 1 GT non-union and 1 infection. There have been 5 revisions; 2 for aseptic loosening, 1 for infection, 1 for recurrent dislocation and 1 for leg length discrepancy. Conversion of hip fusion to hip replacement carries an increased risk of heterotopic ossification and neurological injury. We advise prophylaxis against heterotropic ossification. When there is concern about hip stability we suggest that the use of a constrained acetabular liner is considered. Despite the potential for complications, this procedure had a high success rate and was effective in restoring hip function

Introduction. Cephalomedullary nailing (CMN) is commonly used for unstable pertrochanteric fracture. CMN is relatively safe method although various complications can potentially occur needing revision surgery. Commonly used salvage procedures such as renailing, hemiarthroplasty, conservative treatment or total hip arthroplasty (THA) are viable alternatives. The aim was to investigate the rate of THA after CMN and evaluate the performance on conversion total hip arthroplasty (cTHA) after failure of CMN. Method. Collected data included patients from two orthopedic centers. Data consisted of all cTHAs after CMN between 2014-2020 and primary cementless THA operations between 2013-2023. Primary THA operations were treated as a control group where Oxford Hip Score (OHS) was the main compared variable. Result. From 2398 proximal femoral hip procedures 1667 CMN procedures were included. Altogether 46/1667 (2.8%) CMNs later received THA. Indications for THA after CMN failure were 13 (28.3%) cut-outs, nine (19.6%) cut-throughs, eight (17.4%) nail breakages, seven (15.2%) post traumatic arthrosis, seven (15.2%) nonunions, one (2.2%) malunion and one (2.2%) collum screw withdrawal. Mean (SD) time to complication after CMN operation is 5.9 (6.8) months. Mean (SD) time from nail procedure to THA was 10.4 (12.0) months. Total complication rate for cTHA after CMN was 17.4%. Reported complications were infection with seven (15.2%) cases and one (2.2%) nerve damage. Mean (SD) time to cTHA complication was 3.6 (6.1) months. One-sample T-test showed OHS to be significantly better (P<.001) for primary cementless THA compared to cTHA after one year. Conclusion. Altogether 2.8% of CMN were converted to THA. Nearly half (47.8%) of the cTHA procedures were due to CMN cut-out or cut-through. OHS was significantly better in primary cementless THA compared to cTHA. Prosthetic joint infection was the most frequent complication related to cTHA

In the past orthopaedic surgeons have kept their hands off from spontaneous or artificial fused hips, because those hips were painless, and the result of any further surgical procedure would be doubtful. In our days the need for conversion hip arthroplasty became a demand of patients having a better quality of life. In this paper we report on our results and the perioperative complications following conversion surgery. Between 1993 and 2002 thirty-one hips of twentyfive patients (18 males, 7 females) were converted from totally stiff hip to total hip arthroplasty in the two most frequented orthopaedic hospitals in Budapest, Hungary (Semmelweis University, Medical School, Dept. of Orthopaedics & Hospital of Hospitaller Brothers of St.John of God, Dept. of Orthopaedics). The mean age of the patients was 47.2 years (ranging from 14 to 75 years) at the time of surgery. The average follow up was 50.7 months (2–176). At our 25 patients the hips became stiff 15.7 years ago as an average (3–61). Spontaneous fusion occured in 14 cases due to Bechterews disease (spondylitis ankylopoetica). In 4 cases fused hips were converted following arthrodesis procedures. There was no significant difference between each groups, spontaneous ankylosis and surgical fusion were similar, they were evaluated as stiff hips on the same way. The indication for surgery was in most cases a painful lumbar spine or osteoarthritic knee joint on the ipsilateral side. The surrounding joints are obviously overloaded and overused because of the stiff hip joint, even though if the hip is painless. 27 cemented and 4 uncemented hip prostheses were implanted. The mean duration of conversion arthroplasties was 110 minutes, the perioperative blood loss was 1019 ml. Additional surgical procedures may be used, like intertrochanteric wedge resection, osteotomy of greater trochanter, muscle release from the iliac bone, tenotomy of the hip adductors or knee flexors. The Harris Hip Score increased significantly from 34.2 to 81.3 (p< 0.01). The leg length discrepancy decreased from 4.0 cm to 1.2 cm, the difference of thigh circumference changed from 4.3 cm to 2.7 cm, all results as an average. Trendelenburgs gait was detected at 25 hips pre-op, and at 5 hips at the time of follow up. Five cases were reoperated due to haematoma formation, there was one prosthesis disclocation and one early septic complication. Based upon the good clinical results at the follow up, we recommend to change the orthopaedic surgeons’ mind considering conversion arthroplasties. The surgical procedure can be performed securely, but it is technically challenging for each surgeon. The intraoperative use of fluoroscopy and preoperative planning are mandatory in conversion arthroplasty. Conversion arthroplasty is performed prior to severe degenerative changes in the surrounding joints

Patients with longstanding hip fusion are predisposed to symptomatic degenerative changes of the lumbar spine, ipsilateral knee and contralateral hip. In such patients, conversion of hip arthrodesis to hip replacement can provide relief of such symptoms. However, this is a technically demanding procedure associated with higher complication and failure rates than routine total hip replacement. The aim of this study was to determine the early functional results and complications in patients undergoing hip fusion conversion to total hip replacement, performed or supervised by a single surgeon, using a standardised approach and uncemented implants. We hypothesised that a satisfactory functional improvement can be achieved in following conversion of hip fusion to hip replacement. Eighteen hip fusions were converted to total hip replacements. A constrained acetabular liner was used in 3 hips. Mean follow up was 5 years (2 to 15 years). Two (11%) hips failed, requiring revision surgery and two patients (11%) had injury to the peroneal nerve. Heterotopic ossification developed in 7 (39%) hips, in one case resulting in joint ankylosis. No hips dislocated. Conversion of hip fusion to hip replacement carries an increased risk of heterotopic ossification and neurological injury. We advise prophylaxis against heterotopic ossification. When there is concern about hip stability we suggest that the use of a constrained acetabular liner is considered. Despite the potential for complications, this procedure had a high success rate and was effective in restoring hip function

Thru purpose of this study was to evaluate the clinical outcomes of a consecutive series of conversion total hip arthroplasty (cTHA) following previous hip fractures. A retrospective chart review of patients who underwent cTHAs from 2008–2017 at an urban academic teaching institution was performed. Eighty-eight patients were included in this study. The mean age at the cTHA was 66 years (range 27 to 89). 67% of the patients wre women. The mean BMI was 28 kg/m. 2. (range 17 to 41). The mean Charlson Comorbidity Index was 3 (range 0 to 9). The mean follow-up was 49 months (range 24 to 131). The mean duration from the hip fracture fixation to the cTHA was 51 months (range 10 to 144). The mean operating time was 188 minutes, (range 71 to 423) with a mean estimated blood loss of 780 ml (range 300 to 2500). Revision-type (long-stem) designs were used in 65% of the cases. The mean length of hospital stay was 8 days (range 2 to 61). The readmission rate was 37% within 90 days after the CTHAs. Of these, 57% were due to non-orthopaedic complications. There were 10 orthopaedic complications: 7 PJIs, all of which required I&D and 3 required staged revision. There were 2 dislocations treated with closed reduction and 1 case of intraoperative periprosthetic femur fracture during femoral component insertion. There was no revision for aseptic loosening within the follow-up period. The one-year mortality rate was 0%. cTHAs were associated with longer operating time, more blood loss, longer length of hospital stay, and higher readmission rates than the primary THAs in our institutional database. We believe utilizing a multi-disciplinary care protocol to optimize these patients is needed to reduce the high rate of readmissions, and the complications in this patient population

Introduction. Total hip arthroplasty (THA) is the most common surgery performed for complications of bipolar arthroplasty. The present study evaluated the functional results and complications associated with this surgery. Patients and Methods. Forty eight hips (48 patients) who had conversion of bipolar arthroplasty to THA between 1998 June and 2013 June, and who were followed-up for more than one year were evaluated. Twenty one hips had conversion surgery to THA using a Fitmore cup with metal-on-metal articulation (28 mm head). Six hips had surgery using the SecurFit cup and three hips, using the Lima LTO cup with ceramic-on-ceramic articulation (28 mm or 32 mm head). Eighteen hips had surgery using a large head metal-on-metal bearing: –MMC (seven hips), ACCIS (six hips) and Magnum (five hips). The average time of follow-up duration was 3.9 years (range, 1.0–11.3). There were 22 men and 26 women between the ages of 28 and 80 years (average, 68.9 years) at the time of conversion surgery. Conversion arthroplasty was performed for acetabular erosion without femoral stem loosening in 19 hips, acetabular cartilage erosion with femoral stem loosening in 13 hips, periprosthetic fracture in 12 hips, and recurrent dislocation in four hips. Results were evaluated using Harris hip score (HHS) and Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) score. The radiographs were analyzed for evidence of acetabular and femoral osteolysis or loosening. The complications were evaluated. Results. The time interval between hemiarthroplasty and conversion total hip prosthesis was 6.7 years on average (range, 5 months to 12 years). Pain was the leading sign in all patients. Average HHS improved from 42 preoperatively (range, 34–67) to 86 (range, 65 – 97) postoperatively. The average total WOMAC score improved from 47 (range, 32–67) to 22 (range, 9–44) postoperatively. All the patients operated for groin pain reported significant improvement in their symptoms. Radiological evaluation showed good bony ingrowth and stability of all the femoral components. None of the acetabular component showed migration, loosening, wear, or osteolysis at last follow-up. Complications occurred in five hips. One dislocation and one recurrent dislocation were encountered in isolated acetabular revision hips; whereas one single dislocation, one recurrent dislocation, and one trochanteric nonunion occurred in the hips with revision of both components. All dislocations were occurred in hips with a femoral head size of 28 mm. Dislocations were managed by closed reduction, and none of the patients required revision for dislocation. Conclusions. Conversion THA after symptomatic bipolar arthroplasty can offer reliable pain relief and functional improvement. The perioperative complications approximate those of revision THAs

This study examines patient characteristics, indications for conversion, surgical and anaesthetic technique, peri-operative management and complications of surgery in this small and challenging group of patients. In the six years from 1994 to 1999, 33 conversion arthroplasties were performed for failed femoral hemiarthroplasty. The average age at conversion surgery was 75.5 years (range 65–90). The female to male ratio was 6:1. Primary hemiarthroplasties comprised 24 Austin-Moore, 6 Thompson & 3 Bipolar prostheses. The average interval from primary to conversion surgery was 50 months (6 months to 17 years). The average age at primary surgery was 71.2 years (62–88) – AMP:71.4 years, Thompson’s: 74.2 years, Bipolar: 63.5 years. All hemiarthroplasties were performed for fractured femoral necks. 62% of patients came from the Eastern Health Board area, while 38% were tertiary are referrals from other Health Boards. The average length of stay was 17.5 days (3–24). Indications for conversion included gross loosening/acetabular erosion in 9 cases, suspected infection in 4 cases and abscess/septicaemia in 1 case. All but 3 patients had significant pain (night pain etc.) and/or severely impaired mobility. We also looked at anaesthetic and analgesic practice, surgical technique and prostheses used. Post-operatively, mean total blood loss was 1430 ml (420–2280) with an average of 1.4 units of blood transfused (0–5). Intraoperative complications included acetabular & femoral perforation, periprosthetic fracture and cement reactions. Complications post-op (in hospital) included cardiac arrhythmia’s, cerebrovascular accidents, pulmonary embolus, myocardial infarct, respiratory & urinary tract infections, constipation, nausea & vomiting. The elderly nature of these patients and the physiological stress of what is major surgery allied with multiple co-morbidities make their care especially challenging. A conversion arthroplasty is a procedure with a significant risk of considerable morbidity. Primary total hip replacement or bipolar hemiarthroplasty are options which, therefore, should be seriously considered in the case of fractured femoral necks to minimise the need for further surgery in the future, with all its attendant risks

Purpose of the study:. To determine the outcomes of cases converted from an external fixator to an internal fixation device in the management of limb reconstructions and deformity corrections. Method:. A retrospective review of 18 patients, that underwent a conversion procedure to internal fixation following long term external fixation use, was done. This comprised 24 limbs. Inclusion criteria: All cases of long term external fixator use converted to internal fixation over a 5 year period. Average external fixation time, pin site care, conversion timing, surgical device used as well as outcome were documented. Results:. The mean treatment time in an external fixator was 185 days (61–370). The reasons for conversion included patient dissatisfaction, pin tract sepsis and a refracture. The conversion procedures included 8 intramedullary nail fixations and 16 plate and screw fixations. An acute conversion was identified as an internal fixation that was done in the same sitting as external fixator removal. A delayed conversion was any internal stabilisation that was done thereafter. In total, the complication rate associated with conversion to internal fixation following long term external fixation was 25%, mainly due to persistent non-union or sepsis. In the 8 conversions to intramedullary nails, 7 were acute: 4 had good outcomes with sepsis free union being achieved. 3 had poorer outcomes with a non-union and 2 amputations being documented. The single delayed nailing achieved union. In the 16 conversions to plate fixation, 13 achieved union. 10 were acute conversions and 3 were delayed. The remaining 3 that developed complications included 2 acute conversions with septic non-unions and a single delayed conversion which resulted in sepsis. Conclusion:. Conversion of an external fixator to an internal fixator in a non-acute reconstructive setting has a 75% success rate. In the acute conversion group (19 cases), plate and screw fixation had a superior outcome. In the delayed conversion group (5 cases), intramedullary fixation was favoured

Introduction: ‘Revisability’ has been touted as one of the major advantages of resurfacing arthroplasty of the hip. However, this theoretical advantage has never been clearly demonstrated. The objective of the present study was to test the hypothesis that a failed, modern generation metal-on-metal resurfacing arthroplasty (MMRA) can be converted to a total hip (THA) as easily and with comparable results as a primary (THA). Methods: Twenty-two failed MMRA’s in 21 patients with an average age of 49.5 years (23 – 72 years) were converted to a THA. In 18 hips, the acetabular component was retained, and in 4 hips both components were revised. The control group of primary THA’s, implanted during the same time period by the same surgeon, consisted of 64 patients with an average age of 50.8 years (27 – 64 years). Results: There was no significant difference in operative time, blood loss and complication rates between the conversions and the controls. The average follow-up was 47 months (12 – 113 months) for the conversions and 57 months (24 – 105 months) for the controls. Clinical outcomes measures were comparable with average Harris Hip Scores of 92.7 and 90.3 for the MMRA conversions and primary THA’s, respectively. The UCLA activity scores were 6.6 and 6.4 in the conversion group and THA group, respectively. There have been no cases of aseptic loosening of the femoral or acetabular components in either group, and there have been no dislocations after MMRA conversion. Conclusion: Conversion of failed MMRA to a THA appears to be as safe and effective as a primary THA

Recently, there has been a reluctance to perform hip arthrodesis. The number of patients requiring the conversion from hip arthrodesis to arthroplasty has also decreased. We present the functional results following conversion of hip arthrodesis to total hip arthroplasty at a specialist hip centre. 76 patients who underwent conversion of hip arthrodesis to total hip arthroplasty between 1963 and 2000 at the Centre for Hip Surgery, Wrightington Hospital, were included in this retrospective study. 9 patients died of unrelated causes and 7 patients were lost to follow up. The functional scoring was performed using the Merle d’Aubigné and Postel score. The mean age at the time of surgical hip arthrodesis was 16.7 years and at the time of conversion was 48.7 years. Back pain is the most common indication for the conversion. All the patients were pleased with the clinical outcome following conversion to Arthroplasty. 6 patients had postoperative complications. The mean Merle d’Aubigné and Postel score increased from 8.97 to 13.46 at the latest follow-up. The mean wear rate was 0.06 mm/year. Survival of hip arthroplasty was 92.78 % at 18 years. Conclusion: Our series demonstrates good outcome and patient satisfaction and high survival of the arthroplasty following the conversion from arthrodesis. Hip arthrodesis could be considered as a holding procedure in selected group of young patients with a later successful conversion to arthroplasty

Introduction: Arthodesis provides a durable, painless and stable hip. Conversion to arthroplasty was has been recommended to relieve the excessive stresses in the neighbouring joints. We present the long term results following conversion of hip athrodesis to total hip artho-plasty at specialist hip centre. Method and material: 67 patients underwent the conversion between 1963 and 2000 at the centre for hip surgery, wrightington hospital were included in the study. 45 patients are available for the evaluation. Merle d’ Aubigne and Postel as modified by Charnley was used for clinical scoring. The most recent radiograph in patients with surviving arthoplasty was analysed. Results: The mean age at the time of arthodesis was 16.8 years. The conversion to hip arthroplasty was performed after a mean period of 32.3 years (range 12 to 54 years). The mean folowup was 16.37years (range 2–28). The mean Merle d’ Aubigne and Postel score increased from 7.95 to 13.45 postoperatively. All the patients were delighted with the conversion. 7 patients had revision and 1 had pseudoarthrosis. Conclusion: Hip arthrodesis is a useful holding procedure for young persons with painful hip. This could be successfully converted to Hip arthroplasty after an interval of relatively high physical activity during young adult life

Purpose. The purpose of this study was to determine the functional outcome, imaging and complications of conversion of hip fusion to uncemented total hip replacement. Method. The study group comprised eighteen patients who had undergone conversion of unilateral hip fusion to total hip replacement between 1996 and 2007. There were five men and 13 women. The diagnosis prior to fusion was traumatic injury in eight patients, developmental dysplasia in three patients, and septic arthritis in seven patients. Four of the patient who had septic arthritis in childhood had spontaneous hips fusion while the other underwent surgical arthrodesis. The mean age at the time of conversion was 53 years (range, 21–77) and the mean time between fusion and conversion to hip replacement was 33 years (range, 11–60). Mean follow up was five years (range 2–15 years). Data was collected by retrospective review of a prospective database. Uncemented acetabular components were used in all cases and uncemented femoral components were used in all but two patients. In three patients with abductor and soft tissue deficiency an intraoperative decision was made to use a constrained acetabular liner. Results. The Harris hip score increased from a mean of 49 pre operatively to 75 at a mean of five years p<0.001. There was poor correlation between patient age, duration of hip fusion and hip scores at six months, 12 months and at final follow-up at a mean of five years. Heterotopic ossification developed in seven of the 18 (39%) patients. It was grade one in four patients, grade two in one patient, grade three in one patient and grade four in one patient. Four complications occurred in four of the 18 (22%) patients. Two patients (11%) had neurological injury in the common peroneal nerve distribution. In one patient heterotopic ossification resulted in joint ankylosis. This patient underwent reoperation to excise the heterotopic ossification 16 months after the initial hip replacement procedure. One patient developed a deep venous thrombosis. There were no hip dislocations. One acetabular component was loose and had migrated at 15 years follow up. Conclusion. Conversion of hip fusion to hip replacement carries an increased risk of heterotopic ossification and neurological injury. We advise prophylaxis against heterotopic ossification. When there is concern about hip stability we suggest that the use of a constrained acetabular liner is considered. Despite the potential for complications, this procedure had a high success rate and was effective in restoring hip function

The purpose is to present our experiences with the conversion of external fixation to an intramedullary nail in the treatment of open fractures and fractures in polytraumatised patients. These are traumatological cases where primary use of an intramedullary nail is difficult or impossible. References in the world literature to the two-stage treatment of the fractures of the tibial shaft are more than 2O years old and are considered as unsuccessful. However, later papers presented conversion as an advantageous procedure. A higher stability of the fracture and better comfort of the patient are acquired by the use of conversion. From 1995 to 1999 in the Orthopedic Clinic Bulovka in Prague, Czech Republic, ten patients (8 male, 2 female) were treated by the method of conversion of external fixation to an intramedullary nail. The group of patients was composed of eight open fractures: one Gustillo-Anderson 1, two Gustillo-Anderson 2, three Gustillo-Anderson 3A, two Gustillo-Anderson 3B, one closed fracture Tscherne CIII, and one closed fracture Tscherne CII in a polytraumatised patient. Conversion was performed from 6 to 48 days after primary stabilisation by external fixation (mean 21.2 days). We currently use the UNI-fix clamp external fixator. Conversion by standard procedure is performed up to the 21st day to the 28th day after primary stabilisation. Injury of soft tissues and skin covering must be solved at the time of conversion. Analysis of the results in the ten cases was made from three months to 4.5 years. All of the cases were subjectively classified as excellent or very good. There were no deep infections. In three cases there was prolonged secretion from the screw holes of the external fixator. For one patient, bone grafting into a fracture bone defect was necessary after six months. ROM of the knee and ankle joint was without reduction of function. When the period of follow-up was more than one year, all patients had perfect healing of the fractures. This method gives very satisfactory therapeutic results with a minimum of complications, and covers the spectrum of the treatment of complicated fractures of the tibial shaft. However, the indications are very strict. If conversion is not able to be performed before the 21st to the 28th day after primary stabilisation, it is more advantageous to continue with treatment by external fixation because of the risk of deep infection. After the 28th day following primary stabilisation, conversion to an intramedullary nail is not indicated

Renewed interest in UKA necessitates further investigation into the ramifications of conversion to TKA due to either implant failure or progressive joint disease. The purpose of this study was to compare the depth of tibial resection at UKA and the resulting implications for conversion to TKA using two different UKA techniques and implant designs. A radiographic review of 42 UKA’s from a single surgeon was performed. Sixteen cases utilized a standard all-polyethylene tibial onlay UKA marketed as a minimally invasive resurfacing implant. The other 26 employed a novel robotically assisted technique and a tibial inlay implant design. Measurement techniques were developed to determine the depth of medial tibial plateau resection at initial UKA as well as potential tibial cuts and implant components required at conversion. Average depth of bony medial plateau resection was significantly greater in the standard technique onlay design group (8.5 ± 2.26 mm) compared to the robotically assisted inlay group (4.4 ± 0.93 mm) (p< .0001). At conversion to a standard TKA, the proposed tibial osteotomy would require medial augmentation/revision components in 75% of the onlay group as compared to 4% of the robotically assisted inlay group (p< .0001). Robotically assisted UKA using a tibial inlay design appears to be a truly resurfacing procedure with respect to the tibia, resulting in significantly less tibial bone resection at UKA as well as simpler conversion to TKA when compared to conventional onlay techniques

Purpose. The purpose of this study is to know the peri-operative morbidity, clinical and radiographical outcomes of conversion THA from failed transtrochanter rotational osteotomy (TRO). Patients and methods. From 2003 January to 2009 January, there were 18 hips(18 patients) who underwent conversion THA from TRO for osteonecrosis of the femoral head (ONFH) (Group I). The mean duration from TRO to conversion THA was 2.6 years. We made a matched control group of 18 primary THA for ONFH (Group II) and we evaluated perioperative morbidity and complications in each group. For the clinical evaluation, we checked Harris hip score (HHS) and WOMAC score. For the radiographical evaluation, we evaluated implant position, stability and osteolysis. Results. There was no significant differences in operation time, blood loss, hospital stay between two groups. In clinical results, there was no significant difference in postoperative HHS (p=0.986), but there was significant difference in postoperative WOMAC score. There was more significant postoperative internal rotation limitation in the Group II (p<0.001). In radiographical evaluation, there was no significant difference between two groups, except the preoperative leg length discrepancy (p=0.015). Conclusion. According to our study, there was no significant difference between conversion THA after TRO and primary THA in terms of perioperative morbidity and radiographical out come. But primary THA showed better postoperative internal rotation and better WOMAC score than conversion THA after previous TRO for ONFH

Introduction: The conversion of the fused hip to a total hip replacement poses a challenging reconstructive problem. The technical pitfalls depend on the aetiology of the arthrodesis, the surgical technique used and the available bone stock. Indications include painful pseudo arthrosis, disabling back or ipsilateral knee pain and malposition of the arthrodesed hip. There are often difficulties restoring appropriate biomechanics and providing a functionally useful outcome. We present a short series where a custom CAD/CAM femoral prosthesis was used to accommodate the anatomical problems caused by previous spontaneous and operative arthrodesis. Patients and Method: 5 patients (4 female, 1 male) with primary diagnoses of septic arthritis, TB, trauma and DDH were reviewed. The average age at the time of conversion was 43.6 years (Range 20–62 years). The patients were reviewed with a mean follow up of 82 months (Range 24–110 months). All the patients were evaluated by an independent observer radiologically and clinically using Harris, WOMAC and Oxford hip scores. Results: The patients improved from preoperative HHS 55 (Range 39–73), Oxford 40 (Range 37–46) and WOMAC 80 (Range 65–92) to postoperative HHS 73 (Range 44–94), Oxford 26 (Range 17–42) and WOMAC 45 (Range 24–79). These results compare poorly to a large series of age and sex matched cases undergoing primary and revision hip arthroplasty. Nevertheless, 4 patients were extremely satisfied with the results of their operation. 1 patient showed no improvement in his scores although he reports that his spinal symptoms are better. His operation was complicated by non-union of the greater trochanter. Conclusion: Most series report poor results after the conversion of arthrodeses to total hip replacements. The commonest problems include instability, sepsis, fractures, limited mobility of the hip replacement and poor function. Careful planning is required to accommodate the atypical anatomy. The use of CAD/CAM femoral stems in the conversion of the arthrodesed hip has allowed preservation of valuable bone stock in anatomically abnormal femora whilst optimising biomechanics and improving function

Purpose. The purpose of the study was to determine the rate of conversion from RSA to THR in a number of Canadian centers performing resurfacings. Method. Retrospective review was undertaken in 12 Canadian Centers to determine the rate of revision and reason for conversion from RSA to THR. Averages and cross-tabulation with Chi-Squared analysis was performed. kaplan Meier survivorship was calculated. Results. A total of 2810 resurfacings were performed up to December 2008. 770 hips had a minimum of 5 year follow-up. The overall survivorship of this group was 97.8%. 80 patients underwent conversion to THR. Five resurfacing systems were used. The reason for failure is reported: 21 were for femoral neck fracture, 25 were for loosening, 9 were for deep infection, 3 foravn, 4 pseudotumors, 2 for impingement, 6 for groin pain and 10 for other reasons. The cumulative conversion rate is 2.8%. The survivorship was significantly different analyzed by gender. The 5 year female survivorship was 95.4% and for males was 97.7%. Surgeon experience proved to be a significant factor in conversion rates. Conclusion. The revision rate to date with this new technology suggests that with increasing experience hip resurfacing arthroplasty remains an acceptable option for the treatment of hip arthritis

Introduction. Reported advantages of unicompartmental knee replacement (UKR) over total knee replacement (TKR) include better kinematics and less postoperative pain. The reported longevity of UKRs, regardless of design, still does not compare as favourably as that of TKR. Resurfacing-type UKR differ to other UKR in that they result in minimal bone resection. Objectives. The aim of this study was to review our experience with conversion of a resurfacing UKR prosthesis to a TKR. We sought to determine the causes of failure and compare outcomes in terms of functional scores, range of motion and radiographic measures. We also determined the use of graft and prosthetic revision supplements as well as stemmed implants. Methods. We retrospectively reviewed the records of 55 patients (Group A), all consecutive, who underwent TKR for a failed UKR from 2003–2008. We chose a cohort of 55 patients (Group B) who had undergone a primary TKR from the same surgeon's database that most closely resembled the study cohort in terms of sex, age and BMI. Results. The most common mode of failure was base-plate subsidence and progression of disease to other compartments. 55% of patients did not have isolated disease at the time of the initial surgery. Interestingly, 42% who had revision due to progression of disease had mult-icompartmental disease at initial UKR but 19 of 24 patients (79%) who had multi-compartmental disease were revised for other reasons other than progression of disease. 3 (5%) of patients required either tibial and/or femoral augments and/or stems. Conclusions. Only 5% required complex revision surgery. Thus, a large proportion of conversions of resurfacing UKR to TKR require non-complex surgery with patients having no significant differences in their radiographic measures nor in their clinical measures to those of primary knee replacements

Converting unicompartmental knee arthroplasty (UKA) to total knee arthroplasty can be difficult, and specialised techniques are needed. Issues include bone loss, joint-line, sizing, and rotation. Determining the complexity of conversion preoperatively helps predict the need for augmentation, grafting, stems, or constraint. We examined insert thickness, augmentation, stem use, and effect of failure mode on complexity of UKA conversion. Fifty cases (1997–2007) were reviewed: 9 implants (18%) were modular fixed-bearing, 4 (8%) were metal-backed nonmodular fixed-bearing, 8 (16%) were resurfacing onlay, 10 (20%) were all-polyethylene step-cut, and 19 (38%) were mobile bearing designs; 5 knees (10%) failed due to infection, 5 (10%) due to wear and/or instability, 10 (20%) for pain or progression of arthritis, 8 (16%) for tibial fracture or severe subsidence, and 22 (44%) due to loosening of either one or both components. Complexity was evaluated using analysis of variance and chi-squared 2-by-k test (80% power; 95% confidence interval). Insert thickness was no different between implants (P=0.23) or failure modes (P=0.27). Stemmed component use was most frequent with nonmodular components (50%), all-polyethylene step-cut implants (44%), and modular fixed-bearing implants (33%; P=0.40). Stem use was highest in tibial fracture (86%; P=0.002). Augment use was highest among all-polyethylene step-cut implants (all-polyethylene, 56%; metal-backed, 50%; modular fixed-bearing, 33%; P=0.01). Augmentation use was highest in fracture (86%) and infection (67%), with a significant difference noted between failure modes (P=0.003). Failure of nonmodular all-polyethylene step-cut devices was more complex than resurfacing or mobile bearing. Failure mode was predictive of complexity. Reestablishing the joint-line, ligamentous balance, and durable fixation are critical to assuring a primary outcome

The primary aim was to assess survival of the opening wedge high tibial osteotomy (HTO) for medial compartment osteoarthritis. The secondary aim was to identify independent predictors of early (before 12 years) conversion to total knee arthroplasty (TKA). During the 18-year period (1994–2011) 111 opening wedge HTO were performed at the study centre. Mean patient age was 45 years (range 18–68) and the majority were male (84%). Mean follow-up was 12 (range 6–21) years. Failure was defined as conversion to TKA. Kaplan-Meier, Cox regression and receiver operating curve (ROC) analyses were performed. Forty (36%) HTO failed at a mean follow-up of 6.3 (range 1–15) years. The five-year survival rate was 84% (95% confidence interval (CI) 82.6–85.4), 10-year rate 65% (95% CI 63.5–66.5) and 15-year rate 55% (95% CI 53.3–56.7). Cox regression analysis identified older age (p<0.001) and female gender (hazard ratio (HR) 2.37, 95% CI 1.06–5.33, p=0.04) as independent predictors of failure. ROC analysis identified a threshold age of 47 years above which the risk of failure increased significantly (area under curve 0.72, 95% CI 0.62–0.81, p<0.001). Cox regression analysis, adjusting for covariates, identified a significantly greater (HR 2.49, 95% CI 1.26–4.91, p=0.01) risk of failure in patients aged 47 years old or more. The risk of early conversion to TKA after an opening wedge HTO is significantly increased in female patients and those older than 47 years old. These risk factors should be considered pre-operatively and discussed with patients when planning surgical intervention for isolated medial compartment osteoarthritis